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* [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges
@ 2020-07-12 16:26 Dan Williams
  2020-07-12 16:26 ` [PATCH v2 01/22] x86/numa: Cleanup configuration dependent command-line options Dan Williams
                   ` (22 more replies)
  0 siblings, 23 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: David Hildenbrand, Ard Biesheuvel, Mike Rapoport,
	Borislav Petkov, David Airlie, Will Deacon, Catalin Marinas,
	Ard Biesheuvel, joao.m.martins, Tom Lendacky, Rafael J. Wysocki,
	Jonathan Cameron, x86, H. Peter Anvin, Thomas Gleixner,
	Greg Kroah-Hartman, Pavel Tatashin, Andrew Morton,
	Peter Zijlstra, Ben Skeggs, Benjamin Herrenschmidt,
	Jason Gunthorpe, Jia He, Ingo Molnar, Dave Hansen,
	Paul Mackerras, Brice Goglin

Changes since v1 [1]:

- Combine this series with "Manual definition of Soft Reserved memory
  devices" [2] as the pre-requisites are required to test the device-dax
  facility, the device-dax changes are part of the justification for the
  numa-info reworks.

- Provide a generic version of numa data retrieval based on memblock for
  arm64 rather than adding a new / empty phys_to_target_node() stub
  alongside memory_add_physaddr_to_nid(). (Will)

- Fix several corner case allocation bugs and pass the unit test written
  by Joao.

- Lift the restriction that a 'seed' device must be activated before a
  new seed can be created. This minor sanity check was to prevent userspace
  spamming devices, but it gets in the way of some of allocation
  scenarios like allocating a memory-range that is guaranteed to never be
  evicted due to memory-side-cache conflicts. (Iqbal)

- Add debug prints for space allocation decisions (Joao)

- Rebased on v5.8-rc2 which included resolving conflicts in the kmem
  driver and memremap_pages().

[1]: http://lore.kernel.org/r/158500767138.2088294.17131646259803932461.stgit@dwillia2-desk3.amr.corp.intel.com
[2]: http://lore.kernel.org/r/158489354353.1457606.8327903161927980740.stgit@dwillia2-desk3.amr.corp.intel.com/

---

The device-dax facility allows an address range to be directly mapped
through a chardev, or optionally hotplugged to the core kernel page
allocator as System-RAM. It is the mechanism for converting persistent
memory (pmem) to be used as another volatile memory pool i.e. the
current Memory Tiering hot topic on linux-mm.

In the case of pmem the nvdimm-namespace-label mechanism can sub-divide
it, but that labeling mechanism is not available / applicable to
soft-reserved ("EFI specific purpose") memory [3]. This series provides
a sysfs-mechanism for the daxctl utility to enable provisioning of
volatile-soft-reserved memory ranges.

The motivations for this facility are:

1/ Allow performance differentiated memory ranges to be split between
   kernel-managed and directly-accessed use cases.

2/ Allow physical memory to be provisioned along performance relevant
   address boundaries. For example, divide a memory-side cache [4] along
   cache-color boundaries.

3/ Parcel out soft-reserved memory to VMs using device-dax as a security
   / permissions boundary [5]. Specifically I have seen people (ab)using
   memmap=nn!ss (mark System-RAM as Persistent Memory) just to get the
   device-dax interface on custom address ranges. A follow-on for the VM
   use case is to teach device-dax to dynamically allocate 'struct page' at
   runtime to reduce the duplication of 'struct page' space in both the
   guest and the host kernel for the same physical pages.

Given the intersections of arm64, x86, and core memremap_pages() changes
I'd like to explore taking this through the libnvdimm tree, but that is
step 2. Any concerns with the proposed infrastructure changes
(memblock-numainfo and multi-range-memremap-pages)?

[3]: http://lore.kernel.org/r/157309097008.1579826.12818463304589384434.stgit@dwillia2-desk3.amr.corp.intel.com
[4]: http://lore.kernel.org/r/154899811738.3165233.12325692939590944259.stgit@dwillia2-desk3.amr.corp.intel.com
[5]: http://lore.kernel.org/r/20200110190313.17144-1-joao.m.martins@oracle.com

---

Dan Williams (22):
      x86/numa: Cleanup configuration dependent command-line options
      x86/numa: Add 'nohmat' option
      efi/fake_mem: Arrange for a resource entry per efi_fake_mem instance
      ACPI: HMAT: Refactor hmat_register_target_device to hmem_register_device
      resource: Report parent to walk_iomem_res_desc() callback
      x86: Move NUMA_KEEP_MEMINFO and related definition to x86-internals
      numa: Introduce a generic memory_add_physaddr_to_nid()
      memblock: Introduce a generic phys_addr_to_target_node()
      arm64: Convert to generic memblock for numa-info
      ACPI: HMAT: Attach a device for each soft-reserved range
      device-dax: Drop the dax_region.pfn_flags attribute
      device-dax: Move instance creation parameters to 'struct dev_dax_data'
      device-dax: Make pgmap optional for instance creation
      device-dax: Kill dax_kmem_res
      device-dax: Add an allocation interface for device-dax instances
      device-dax: Introduce 'seed' devices
      drivers/base: Make device_find_child_by_name() compatible with sysfs inputs
      device-dax: Add resize support
      mm/memremap_pages: Convert to 'struct range'
      mm/memremap_pages: Support multiple ranges per invocation
      device-dax: Add dis-contiguous resource support
      device-dax: Introduce 'mapping' devices

 arch/arm64/Kconfig                     |    1 
 arch/arm64/mm/numa.c                   |   10 
 arch/powerpc/kvm/book3s_hv_uvmem.c     |   14 
 arch/x86/Kconfig                       |    7 
 arch/x86/include/asm/numa.h            |    8 
 arch/x86/kernel/e820.c                 |   16 +
 arch/x86/mm/numa.c                     |   12 
 arch/x86/mm/numa_emulation.c           |    3 
 arch/x86/mm/numa_internal.h            |    7 
 arch/x86/xen/enlighten_pv.c            |    2 
 drivers/acpi/numa/hmat.c               |   76 ---
 drivers/acpi/numa/srat.c               |    9 
 drivers/base/core.c                    |    2 
 drivers/dax/Kconfig                    |    6 
 drivers/dax/Makefile                   |    3 
 drivers/dax/bus.c                      |  902 ++++++++++++++++++++++++++++++--
 drivers/dax/bus.h                      |   28 +
 drivers/dax/dax-private.h              |   39 +
 drivers/dax/device.c                   |   97 ++-
 drivers/dax/hmem/Makefile              |    6 
 drivers/dax/hmem/device.c              |  100 ++++
 drivers/dax/hmem/hmem.c                |   20 -
 drivers/dax/kmem.c                     |  199 ++++---
 drivers/dax/pmem/compat.c              |    2 
 drivers/dax/pmem/core.c                |   22 +
 drivers/firmware/efi/x86_fake_mem.c    |   12 
 drivers/gpu/drm/nouveau/nouveau_dmem.c |    4 
 drivers/nvdimm/badrange.c              |   26 -
 drivers/nvdimm/claim.c                 |   13 
 drivers/nvdimm/nd.h                    |    3 
 drivers/nvdimm/pfn_devs.c              |   13 
 drivers/nvdimm/pmem.c                  |   27 +
 drivers/nvdimm/region.c                |   21 -
 drivers/pci/p2pdma.c                   |   12 
 include/acpi/acpi_numa.h               |   14 
 include/linux/dax.h                    |    8 
 include/linux/memblock.h               |    4 
 include/linux/memremap.h               |   11 
 include/linux/mm.h                     |   13 
 include/linux/numa.h                   |    9 
 include/linux/range.h                  |    6 
 kernel/resource.c                      |   11 
 mm/Kconfig                             |    7 
 mm/memblock.c                          |   22 +
 mm/memremap.c                          |  300 ++++++-----
 mm/page_alloc.c                        |   82 +++
 tools/testing/nvdimm/dax-dev.c         |   22 +
 tools/testing/nvdimm/test/iomap.c      |    2 
 48 files changed, 1705 insertions(+), 528 deletions(-)
 create mode 100644 drivers/dax/hmem/Makefile
 create mode 100644 drivers/dax/hmem/device.c
 rename drivers/dax/{hmem.c => hmem/hmem.c} (74%)

base-commit: 48778464bb7d346b47157d21ffde2af6b2d39110
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* [PATCH v2 01/22] x86/numa: Cleanup configuration dependent command-line options
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-12 16:26 ` [PATCH v2 02/22] x86/numa: Add 'nohmat' option Dan Williams
                   ` (21 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Rafael J. Wysocki, peterz, dave.hansen, ard.biesheuvel, linux-mm,
	linux-kernel, linux-acpi, hch, joao.m.martins

In preparation for adding a new numa= option clean up the existing ones
to avoid ifdefs in numa_setup(), and provide feedback when the option is
numa=fake= option is invalid due to kernel config. The same does not
need to be done for numa=noacpi, since the capability is already hard
disabled at compile-time.

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/x86/include/asm/numa.h  |    8 +++++++-
 arch/x86/mm/numa.c           |    8 ++------
 arch/x86/mm/numa_emulation.c |    3 ++-
 arch/x86/xen/enlighten_pv.c  |    2 +-
 drivers/acpi/numa/srat.c     |    9 +++++++--
 include/acpi/acpi_numa.h     |    6 +++++-
 6 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h
index bbfde3d2662f..0aecc0b629e0 100644
--- a/arch/x86/include/asm/numa.h
+++ b/arch/x86/include/asm/numa.h
@@ -3,6 +3,7 @@
 #define _ASM_X86_NUMA_H
 
 #include <linux/nodemask.h>
+#include <linux/errno.h>
 
 #include <asm/topology.h>
 #include <asm/apicdef.h>
@@ -77,7 +78,12 @@ void debug_cpumask_set_cpu(int cpu, int node, bool enable);
 #ifdef CONFIG_NUMA_EMU
 #define FAKE_NODE_MIN_SIZE	((u64)32 << 20)
 #define FAKE_NODE_MIN_HASH_MASK	(~(FAKE_NODE_MIN_SIZE - 1UL))
-void numa_emu_cmdline(char *);
+int numa_emu_cmdline(char *str);
+#else /* CONFIG_NUMA_EMU */
+static inline int numa_emu_cmdline(char *str)
+{
+	return -EINVAL;
+}
 #endif /* CONFIG_NUMA_EMU */
 
 #endif	/* _ASM_X86_NUMA_H */
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 8ee952038c80..ee24646dc44e 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -37,14 +37,10 @@ static __init int numa_setup(char *opt)
 		return -EINVAL;
 	if (!strncmp(opt, "off", 3))
 		numa_off = 1;
-#ifdef CONFIG_NUMA_EMU
 	if (!strncmp(opt, "fake=", 5))
-		numa_emu_cmdline(opt + 5);
-#endif
-#ifdef CONFIG_ACPI_NUMA
+		return numa_emu_cmdline(opt + 5);
 	if (!strncmp(opt, "noacpi", 6))
-		acpi_numa = -1;
-#endif
+		disable_srat();
 	return 0;
 }
 early_param("numa", numa_setup);
diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c
index c5174b4e318b..847c23196e57 100644
--- a/arch/x86/mm/numa_emulation.c
+++ b/arch/x86/mm/numa_emulation.c
@@ -13,9 +13,10 @@
 static int emu_nid_to_phys[MAX_NUMNODES];
 static char *emu_cmdline __initdata;
 
-void __init numa_emu_cmdline(char *str)
+int __init numa_emu_cmdline(char *str)
 {
 	emu_cmdline = str;
+	return 0;
 }
 
 static int __init emu_find_memblk_by_nid(int nid, const struct numa_meminfo *mi)
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index acc49fa6a097..39321b49b65d 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1318,7 +1318,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
 	 * any NUMA information the kernel tries to get from ACPI will
 	 * be meaningless.  Prevent it from trying.
 	 */
-	acpi_numa = -1;
+	disable_srat();
 #endif
 	WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_pv, xen_cpu_dead_pv));
 
diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 5be5a977da1b..09a5e54d8575 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -27,7 +27,12 @@ static int node_to_pxm_map[MAX_NUMNODES]
 			= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
 
 unsigned char acpi_srat_revision __initdata;
-int acpi_numa __initdata;
+static int acpi_numa __initdata;
+
+void __init disable_srat(void)
+{
+	acpi_numa = -1;
+}
 
 int pxm_to_node(int pxm)
 {
@@ -163,7 +168,7 @@ static int __init slit_valid(struct acpi_table_slit *slit)
 void __init bad_srat(void)
 {
 	pr_err("SRAT: SRAT not used.\n");
-	acpi_numa = -1;
+	disable_srat();
 }
 
 int __init srat_disabled(void)
diff --git a/include/acpi/acpi_numa.h b/include/acpi/acpi_numa.h
index fdebcfc6c8df..8784183b2204 100644
--- a/include/acpi/acpi_numa.h
+++ b/include/acpi/acpi_numa.h
@@ -17,10 +17,14 @@ extern int pxm_to_node(int);
 extern int node_to_pxm(int);
 extern int acpi_map_pxm_to_node(int);
 extern unsigned char acpi_srat_revision;
-extern int acpi_numa __initdata;
+extern void disable_srat(void);
 
 extern void bad_srat(void);
 extern int srat_disabled(void);
 
+#else				/* CONFIG_ACPI_NUMA */
+static inline void disable_srat(void)
+{
+}
 #endif				/* CONFIG_ACPI_NUMA */
 #endif				/* __ACP_NUMA_H */
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* [PATCH v2 02/22] x86/numa: Add 'nohmat' option
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
  2020-07-12 16:26 ` [PATCH v2 01/22] x86/numa: Cleanup configuration dependent command-line options Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-12 16:58   ` Randy Dunlap
  2020-07-12 16:26 ` [PATCH v2 03/22] efi/fake_mem: Arrange for a resource entry per efi_fake_mem instance Dan Williams
                   ` (20 subsequent siblings)
  22 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: x86, Rafael J. Wysocki, Dave Hansen, Andy Lutomirski,
	Peter Zijlstra, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

Disable parsing of the HMAT for debug, to workaround broken platform
instances, or cases where it is otherwise not wanted.

Cc: x86@kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/x86/mm/numa.c       |    2 ++
 drivers/acpi/numa/hmat.c |    8 +++++++-
 include/acpi/acpi_numa.h |    8 ++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index ee24646dc44e..44fdf06d497e 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -41,6 +41,8 @@ static __init int numa_setup(char *opt)
 		return numa_emu_cmdline(opt + 5);
 	if (!strncmp(opt, "noacpi", 6))
 		disable_srat();
+	if (!strncmp(opt, "nohmat", 6))
+		disable_hmat();
 	return 0;
 }
 early_param("numa", numa_setup);
diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
index 2c32cfb72370..a12e36a12618 100644
--- a/drivers/acpi/numa/hmat.c
+++ b/drivers/acpi/numa/hmat.c
@@ -26,6 +26,12 @@
 #include <linux/sysfs.h>
 
 static u8 hmat_revision;
+static int hmat_disable __initdata;
+
+void __init disable_hmat(void)
+{
+	hmat_disable = 1;
+}
 
 static LIST_HEAD(targets);
 static LIST_HEAD(initiators);
@@ -814,7 +820,7 @@ static __init int hmat_init(void)
 	enum acpi_hmat_type i;
 	acpi_status status;
 
-	if (srat_disabled())
+	if (srat_disabled() || hmat_disable)
 		return 0;
 
 	status = acpi_get_table(ACPI_SIG_SRAT, 0, &tbl);
diff --git a/include/acpi/acpi_numa.h b/include/acpi/acpi_numa.h
index 8784183b2204..0e9302285f14 100644
--- a/include/acpi/acpi_numa.h
+++ b/include/acpi/acpi_numa.h
@@ -27,4 +27,12 @@ static inline void disable_srat(void)
 {
 }
 #endif				/* CONFIG_ACPI_NUMA */
+
+#ifdef CONFIG_ACPI_HMAT
+extern void disable_hmat(void);
+#else				/* CONFIG_ACPI_HMAT */
+static inline void disable_hmat(void)
+{
+}
+#endif				/* CONFIG_ACPI_HMAT */
 #endif				/* __ACP_NUMA_H */
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* [PATCH v2 03/22] efi/fake_mem: Arrange for a resource entry per efi_fake_mem instance
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
  2020-07-12 16:26 ` [PATCH v2 01/22] x86/numa: Cleanup configuration dependent command-line options Dan Williams
  2020-07-12 16:26 ` [PATCH v2 02/22] x86/numa: Add 'nohmat' option Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-12 16:26 ` [PATCH v2 04/22] ACPI: HMAT: Refactor hmat_register_target_device to hmem_register_device Dan Williams
                   ` (19 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin,
	x86, Ard Biesheuvel, peterz, dave.hansen, ard.biesheuvel,
	linux-mm, linux-kernel, linux-acpi, hch, joao.m.martins

In preparation for attaching a platform device per iomem resource teach
the efi_fake_mem code to create an e820 entry per instance. Similar to
E820_TYPE_PRAM, bypass merging resource when the e820 map is sanitized.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/x86/kernel/e820.c              |   16 +++++++++++++++-
 drivers/firmware/efi/x86_fake_mem.c |   12 +++++++++---
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 983cd53ed4c9..22aad412f965 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -305,6 +305,20 @@ static int __init cpcompare(const void *a, const void *b)
 	return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
 }
 
+static bool e820_nomerge(enum e820_type type)
+{
+	/*
+	 * These types may indicate distinct platform ranges aligned to
+	 * numa node, protection domain, performance domain, or other
+	 * boundaries. Do not merge them.
+	 */
+	if (type == E820_TYPE_PRAM)
+		return true;
+	if (type == E820_TYPE_SOFT_RESERVED)
+		return true;
+	return false;
+}
+
 int __init e820__update_table(struct e820_table *table)
 {
 	struct e820_entry *entries = table->entries;
@@ -380,7 +394,7 @@ int __init e820__update_table(struct e820_table *table)
 		}
 
 		/* Continue building up new map based on this information: */
-		if (current_type != last_type || current_type == E820_TYPE_PRAM) {
+		if (current_type != last_type || e820_nomerge(current_type)) {
 			if (last_type != 0)	 {
 				new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
 				/* Move forward only if the new size was non-zero: */
diff --git a/drivers/firmware/efi/x86_fake_mem.c b/drivers/firmware/efi/x86_fake_mem.c
index e5d6d5a1b240..0bafcc1bb0f6 100644
--- a/drivers/firmware/efi/x86_fake_mem.c
+++ b/drivers/firmware/efi/x86_fake_mem.c
@@ -38,7 +38,7 @@ void __init efi_fake_memmap_early(void)
 		m_start = mem->range.start;
 		m_end = mem->range.end;
 		for_each_efi_memory_desc(md) {
-			u64 start, end;
+			u64 start, end, size;
 
 			if (md->type != EFI_CONVENTIONAL_MEMORY)
 				continue;
@@ -58,11 +58,17 @@ void __init efi_fake_memmap_early(void)
 			 */
 			start = max(start, m_start);
 			end = min(end, m_end);
+			size = end - start + 1;
 
 			if (end <= start)
 				continue;
-			e820__range_update(start, end - start + 1, E820_TYPE_RAM,
-					E820_TYPE_SOFT_RESERVED);
+
+			/*
+			 * Ensure each efi_fake_mem instance results in
+			 * a unique e820 resource
+			 */
+			e820__range_remove(start, size, E820_TYPE_RAM, 1);
+			e820__range_add(start, size, E820_TYPE_SOFT_RESERVED);
 			e820__update_table(e820_table);
 		}
 	}
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* [PATCH v2 04/22] ACPI: HMAT: Refactor hmat_register_target_device to hmem_register_device
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (2 preceding siblings ...)
  2020-07-12 16:26 ` [PATCH v2 03/22] efi/fake_mem: Arrange for a resource entry per efi_fake_mem instance Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-12 16:26 ` [PATCH v2 05/22] resource: Report parent to walk_iomem_res_desc() callback Dan Williams
                   ` (18 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Rafael J. Wysocki, peterz, dave.hansen, ard.biesheuvel, linux-mm,
	linux-kernel, linux-acpi, hch, joao.m.martins

In preparation for exposing "Soft Reserved" memory ranges without an
HMAT, move the hmem device registration to its own compilation unit and
make the implementation generic.

The generic implementation drops usage acpi_map_pxm_to_online_node()
that was translating ACPI proximity domain values and instead relies on
numa_map_to_online_node() to determine the numa node for the device.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: https://lore.kernel.org/r/158318761484.2216124.2049322072599482736.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/acpi/numa/hmat.c  |   68 ++++-----------------------------------------
 drivers/dax/Kconfig       |    4 +++
 drivers/dax/Makefile      |    3 +-
 drivers/dax/hmem/Makefile |    5 +++
 drivers/dax/hmem/device.c |   65 +++++++++++++++++++++++++++++++++++++++++++
 drivers/dax/hmem/hmem.c   |    2 +
 include/linux/dax.h       |    8 +++++
 7 files changed, 90 insertions(+), 65 deletions(-)
 create mode 100644 drivers/dax/hmem/Makefile
 create mode 100644 drivers/dax/hmem/device.c
 rename drivers/dax/{hmem.c => hmem/hmem.c} (98%)

diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
index a12e36a12618..134bcb40b2af 100644
--- a/drivers/acpi/numa/hmat.c
+++ b/drivers/acpi/numa/hmat.c
@@ -24,6 +24,7 @@
 #include <linux/mutex.h>
 #include <linux/node.h>
 #include <linux/sysfs.h>
+#include <linux/dax.h>
 
 static u8 hmat_revision;
 static int hmat_disable __initdata;
@@ -640,66 +641,6 @@ static void hmat_register_target_perf(struct memory_target *target)
 	node_set_perf_attrs(mem_nid, &target->hmem_attrs, 0);
 }
 
-static void hmat_register_target_device(struct memory_target *target,
-		struct resource *r)
-{
-	/* define a clean / non-busy resource for the platform device */
-	struct resource res = {
-		.start = r->start,
-		.end = r->end,
-		.flags = IORESOURCE_MEM,
-	};
-	struct platform_device *pdev;
-	struct memregion_info info;
-	int rc, id;
-
-	rc = region_intersects(res.start, resource_size(&res), IORESOURCE_MEM,
-			IORES_DESC_SOFT_RESERVED);
-	if (rc != REGION_INTERSECTS)
-		return;
-
-	id = memregion_alloc(GFP_KERNEL);
-	if (id < 0) {
-		pr_err("memregion allocation failure for %pr\n", &res);
-		return;
-	}
-
-	pdev = platform_device_alloc("hmem", id);
-	if (!pdev) {
-		pr_err("hmem device allocation failure for %pr\n", &res);
-		goto out_pdev;
-	}
-
-	pdev->dev.numa_node = acpi_map_pxm_to_online_node(target->memory_pxm);
-	info = (struct memregion_info) {
-		.target_node = acpi_map_pxm_to_node(target->memory_pxm),
-	};
-	rc = platform_device_add_data(pdev, &info, sizeof(info));
-	if (rc < 0) {
-		pr_err("hmem memregion_info allocation failure for %pr\n", &res);
-		goto out_pdev;
-	}
-
-	rc = platform_device_add_resources(pdev, &res, 1);
-	if (rc < 0) {
-		pr_err("hmem resource allocation failure for %pr\n", &res);
-		goto out_resource;
-	}
-
-	rc = platform_device_add(pdev);
-	if (rc < 0) {
-		dev_err(&pdev->dev, "device add failed for %pr\n", &res);
-		goto out_resource;
-	}
-
-	return;
-
-out_resource:
-	put_device(&pdev->dev);
-out_pdev:
-	memregion_free(id);
-}
-
 static void hmat_register_target_devices(struct memory_target *target)
 {
 	struct resource *res;
@@ -711,8 +652,11 @@ static void hmat_register_target_devices(struct memory_target *target)
 	if (!IS_ENABLED(CONFIG_DEV_DAX_HMEM))
 		return;
 
-	for (res = target->memregions.child; res; res = res->sibling)
-		hmat_register_target_device(target, res);
+	for (res = target->memregions.child; res; res = res->sibling) {
+		int target_nid = acpi_map_pxm_to_node(target->memory_pxm);
+
+		hmem_register_device(target_nid, res);
+	}
 }
 
 static void hmat_register_target(struct memory_target *target)
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index 3b6c06f07326..a229f45d34aa 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -48,6 +48,10 @@ config DEV_DAX_HMEM
 
 	  Say M if unsure.
 
+config DEV_DAX_HMEM_DEVICES
+	depends on DEV_DAX_HMEM
+	def_bool y
+
 config DEV_DAX_KMEM
 	tristate "KMEM DAX: volatile-use of persistent memory"
 	default DEV_DAX
diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile
index 80065b38b3c4..9d4ba672d305 100644
--- a/drivers/dax/Makefile
+++ b/drivers/dax/Makefile
@@ -2,11 +2,10 @@
 obj-$(CONFIG_DAX) += dax.o
 obj-$(CONFIG_DEV_DAX) += device_dax.o
 obj-$(CONFIG_DEV_DAX_KMEM) += kmem.o
-obj-$(CONFIG_DEV_DAX_HMEM) += dax_hmem.o
 
 dax-y := super.o
 dax-y += bus.o
 device_dax-y := device.o
-dax_hmem-y := hmem.o
 
 obj-y += pmem/
+obj-y += hmem/
diff --git a/drivers/dax/hmem/Makefile b/drivers/dax/hmem/Makefile
new file mode 100644
index 000000000000..a9d353d0c9ed
--- /dev/null
+++ b/drivers/dax/hmem/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_DEV_DAX_HMEM) += dax_hmem.o
+obj-$(CONFIG_DEV_DAX_HMEM_DEVICES) += device.o
+
+dax_hmem-y := hmem.o
diff --git a/drivers/dax/hmem/device.c b/drivers/dax/hmem/device.c
new file mode 100644
index 000000000000..b9dd6b27745c
--- /dev/null
+++ b/drivers/dax/hmem/device.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/platform_device.h>
+#include <linux/memregion.h>
+#include <linux/module.h>
+#include <linux/dax.h>
+#include <linux/mm.h>
+
+void hmem_register_device(int target_nid, struct resource *r)
+{
+	/* define a clean / non-busy resource for the platform device */
+	struct resource res = {
+		.start = r->start,
+		.end = r->end,
+		.flags = IORESOURCE_MEM,
+	};
+	struct platform_device *pdev;
+	struct memregion_info info;
+	int rc, id;
+
+	rc = region_intersects(res.start, resource_size(&res), IORESOURCE_MEM,
+			IORES_DESC_SOFT_RESERVED);
+	if (rc != REGION_INTERSECTS)
+		return;
+
+	id = memregion_alloc(GFP_KERNEL);
+	if (id < 0) {
+		pr_err("memregion allocation failure for %pr\n", &res);
+		return;
+	}
+
+	pdev = platform_device_alloc("hmem", id);
+	if (!pdev) {
+		pr_err("hmem device allocation failure for %pr\n", &res);
+		goto out_pdev;
+	}
+
+	pdev->dev.numa_node = numa_map_to_online_node(target_nid);
+	info = (struct memregion_info) {
+		.target_node = target_nid,
+	};
+	rc = platform_device_add_data(pdev, &info, sizeof(info));
+	if (rc < 0) {
+		pr_err("hmem memregion_info allocation failure for %pr\n", &res);
+		goto out_pdev;
+	}
+
+	rc = platform_device_add_resources(pdev, &res, 1);
+	if (rc < 0) {
+		pr_err("hmem resource allocation failure for %pr\n", &res);
+		goto out_resource;
+	}
+
+	rc = platform_device_add(pdev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "device add failed for %pr\n", &res);
+		goto out_resource;
+	}
+
+	return;
+
+out_resource:
+	put_device(&pdev->dev);
+out_pdev:
+	memregion_free(id);
+}
diff --git a/drivers/dax/hmem.c b/drivers/dax/hmem/hmem.c
similarity index 98%
rename from drivers/dax/hmem.c
rename to drivers/dax/hmem/hmem.c
index fe7214daf62e..29ceb5795297 100644
--- a/drivers/dax/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -3,7 +3,7 @@
 #include <linux/memregion.h>
 #include <linux/module.h>
 #include <linux/pfn_t.h>
-#include "bus.h"
+#include "../bus.h"
 
 static int dax_hmem_probe(struct platform_device *pdev)
 {
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 6904d4e0b2e0..5d2c3d9aeb5e 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -221,4 +221,12 @@ static inline bool dax_mapping(struct address_space *mapping)
 	return mapping->host && IS_DAX(mapping->host);
 }
 
+#ifdef CONFIG_DEV_DAX_HMEM_DEVICES
+void hmem_register_device(int target_nid, struct resource *r);
+#else
+static inline void hmem_register_device(int target_nid, struct resource *r)
+{
+}
+#endif
+
 #endif
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 05/22] resource: Report parent to walk_iomem_res_desc() callback
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (3 preceding siblings ...)
  2020-07-12 16:26 ` [PATCH v2 04/22] ACPI: HMAT: Refactor hmat_register_target_device to hmem_register_device Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-12 16:26 ` [PATCH v2 06/22] x86: Move NUMA_KEEP_MEMINFO and related definition to x86-internals Dan Williams
                   ` (17 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Jason Gunthorpe, Dave Hansen, Tom Lendacky, peterz,
	ard.biesheuvel, linux-mm, linux-kernel, linux-acpi, hch,
	joao.m.martins

In support of detecting whether a resource might have been been claimed,
report the parent to the walk_iomem_res_desc() callback. For example,
the ACPI HMAT parser publishes "hmem" platform devices per target range.
However, if the HMAT is disabled / missing a fallback driver can attach
devices to the raw memory ranges as a fallback if it sees unclaimed /
orphan "Soft Reserved" resources in the resource tree.

Otherwise, find_next_iomem_res() returns a resource with garbage data
from the stack allocation in __walk_iomem_res_desc() for the res->parent
field.

There are currently no users that expect ->child and ->sibling to be
valid, and the resource_lock would be needed to traverse them. Use a
compound literal to implicitly zero initialize the fields that are not
being returned in addition to setting ->parent.

Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 kernel/resource.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/kernel/resource.c b/kernel/resource.c
index 841737bbda9e..f1175ce93a1d 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -382,10 +382,13 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 
 	if (p) {
 		/* copy data */
-		res->start = max(start, p->start);
-		res->end = min(end, p->end);
-		res->flags = p->flags;
-		res->desc = p->desc;
+		*res = (struct resource) {
+			.start = max(start, p->start),
+			.end = min(end, p->end),
+			.flags = p->flags,
+			.desc = p->desc,
+			.parent = p->parent,
+		};
 	}
 
 	read_unlock(&resource_lock);
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 06/22] x86: Move NUMA_KEEP_MEMINFO and related definition to x86-internals
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (4 preceding siblings ...)
  2020-07-12 16:26 ` [PATCH v2 05/22] resource: Report parent to walk_iomem_res_desc() callback Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-12 16:26 ` [PATCH v2 07/22] numa: Introduce a generic memory_add_physaddr_to_nid() Dan Williams
                   ` (16 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Peter Zijlstra,
	Andrew Morton, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

x86 is the lone architecture that uses numa_meminfo. Move and rename
NUMA_KEEP_MEMINFO from the core mm/Kconfig to X86_NUMA_KEEP_MEMINFO in
arch/x86/mm/Kconfig. This is in preparation for defining a generic
memblock based implementation of memory_add_physaddr_to_nid() and
phys_to_target_node().

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/x86/Kconfig            |    7 ++++++-
 arch/x86/mm/numa.c          |    2 +-
 arch/x86/mm/numa_internal.h |    7 +++++++
 include/linux/numa.h        |    7 -------
 mm/Kconfig                  |    5 -----
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6a0cc524882d..fc9264ea4041 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1560,6 +1560,11 @@ config NUMA
 
 	  Otherwise, you should say N.
 
+# Keep NUMA mapping infrastructure post-init.
+config X86_NUMA_KEEP_MEMINFO
+	def_bool MEMORY_HOTPLUG
+	depends on NUMA
+
 config AMD_NUMA
 	def_bool y
 	prompt "Old style AMD Opteron NUMA detection"
@@ -1640,7 +1645,7 @@ config X86_PMEM_LEGACY
 	depends on PHYS_ADDR_T_64BIT
 	depends on BLK_DEV
 	select X86_PMEM_LEGACY_DEVICE
-	select NUMA_KEEP_MEMINFO if NUMA
+	select X86_NUMA_KEEP_MEMINFO if NUMA
 	select LIBNVDIMM
 	help
 	  Treat memory marked using the non-standard e820 type of 12 as used
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 44fdf06d497e..311d22cf8ac2 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -893,7 +893,7 @@ EXPORT_SYMBOL(cpumask_of_node);
 
 #endif	/* !CONFIG_DEBUG_PER_CPU_MAPS */
 
-#ifdef CONFIG_NUMA_KEEP_MEMINFO
+#ifdef CONFIG_X86_NUMA_KEEP_MEMINFO
 static int meminfo_to_nid(struct numa_meminfo *mi, u64 start)
 {
 	int i;
diff --git a/arch/x86/mm/numa_internal.h b/arch/x86/mm/numa_internal.h
index 86860f279662..7b843414335f 100644
--- a/arch/x86/mm/numa_internal.h
+++ b/arch/x86/mm/numa_internal.h
@@ -11,6 +11,13 @@ struct numa_memblk {
 	int			nid;
 };
 
+/* optionally keep NUMA memory info available post init */
+#ifdef CONFIG_X86_NUMA_KEEP_MEMINFO
+#define __initdata_or_meminfo
+#else
+#define __initdata_or_meminfo __initdata
+#endif
+
 struct numa_meminfo {
 	int			nr_blks;
 	struct numa_memblk	blk[NR_NODE_MEMBLKS];
diff --git a/include/linux/numa.h b/include/linux/numa.h
index a42df804679e..5d25c5de1322 100644
--- a/include/linux/numa.h
+++ b/include/linux/numa.h
@@ -13,13 +13,6 @@
 
 #define	NUMA_NO_NODE	(-1)
 
-/* optionally keep NUMA memory info available post init */
-#ifdef CONFIG_NUMA_KEEP_MEMINFO
-#define __initdata_or_meminfo
-#else
-#define __initdata_or_meminfo __initdata
-#endif
-
 #ifdef CONFIG_NUMA
 /* Generic implementation available */
 int numa_map_to_online_node(int node);
diff --git a/mm/Kconfig b/mm/Kconfig
index f2104cc0d35c..0051f735ad98 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -139,10 +139,6 @@ config HAVE_FAST_GUP
 config ARCH_KEEP_MEMBLOCK
 	bool
 
-# Keep arch NUMA mapping infrastructure post-init.
-config NUMA_KEEP_MEMINFO
-	bool
-
 config MEMORY_ISOLATION
 	bool
 
@@ -159,7 +155,6 @@ config MEMORY_HOTPLUG
 	depends on SPARSEMEM || X86_64_ACPI_NUMA
 	depends on ARCH_ENABLE_MEMORY_HOTPLUG
 	depends on 64BIT || BROKEN
-	select NUMA_KEEP_MEMINFO if NUMA
 
 config MEMORY_HOTPLUG_SPARSE
 	def_bool y
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 07/22] numa: Introduce a generic memory_add_physaddr_to_nid()
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (5 preceding siblings ...)
  2020-07-12 16:26 ` [PATCH v2 06/22] x86: Move NUMA_KEEP_MEMINFO and related definition to x86-internals Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-13  6:58   ` Mike Rapoport
  2020-07-12 16:26 ` [PATCH v2 08/22] memblock: Introduce a generic phys_addr_to_target_node() Dan Williams
                   ` (15 subsequent siblings)
  22 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Mike Rapoport, Jia He, Will Deacon, David Hildenbrand,
	Andrew Morton, peterz, dave.hansen, ard.biesheuvel, linux-mm,
	linux-kernel, linux-acpi, hch, joao.m.martins

For architectures that opt into storing their numa data in memblock
(only ARM64 currently), add a memblock generic way to interrogate that
data for memory_add_physaddr_to_nid(). This requires ARCH_KEEP_MEMBLOCK
to keep memblock text and data around after boot.

Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jia He <justin.he@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 include/linux/mm.h |   11 +++++++++++
 mm/Kconfig         |    6 ++++++
 mm/page_alloc.c    |   23 ++++++++++++++++++++++-
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index dc7b87310c10..1e76ee5da20b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2425,6 +2425,17 @@ unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
 						unsigned long end_pfn);
 extern unsigned long absent_pages_in_range(unsigned long start_pfn,
 						unsigned long end_pfn);
+
+/*
+ * Allow archs to opt-in to keeping get_pfn_range_for_nid() available
+ * after boot.
+ */
+#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
+#define __init_or_memblock
+#else
+#define __init_or_memblock __init
+#endif
+
 extern void get_pfn_range_for_nid(unsigned int nid,
 			unsigned long *start_pfn, unsigned long *end_pfn);
 extern unsigned long find_min_pfn_with_active_regions(void);
diff --git a/mm/Kconfig b/mm/Kconfig
index 0051f735ad98..178ed76cae1b 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -139,6 +139,12 @@ config HAVE_FAST_GUP
 config ARCH_KEEP_MEMBLOCK
 	bool
 
+# If the arch populates numa data into memblock, it can use memblock
+# apis to interrogate that data at runtime.
+config MEMBLOCK_NUMA_INFO
+	bool
+	depends on ARCH_KEEP_MEMBLOCK
+
 config MEMORY_ISOLATION
 	bool
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 48eb0f1410d4..df8bd169dbb4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6351,7 +6351,7 @@ void __init sparse_memory_present_with_active_regions(int nid)
  * with no available memory, a warning is printed and the start and end
  * PFNs will be 0.
  */
-void __init get_pfn_range_for_nid(unsigned int nid,
+void __init_or_memblock get_pfn_range_for_nid(unsigned int nid,
 			unsigned long *start_pfn, unsigned long *end_pfn)
 {
 	unsigned long this_start_pfn, this_end_pfn;
@@ -6369,6 +6369,27 @@ void __init get_pfn_range_for_nid(unsigned int nid,
 		*start_pfn = 0;
 }
 
+/*
+ * Generic implementation of memory_add_physaddr_to_nid() depends on
+ * architecture using memblock data for numa information.
+ */
+#ifdef CONFIG_MEMBLOCK_NUMA_INFO
+int __init_or_memblock memory_add_physaddr_to_nid(u64 addr)
+{
+	unsigned long start_pfn, end_pfn, pfn = PHYS_PFN(addr);
+	int nid;
+
+	for_each_online_node(nid) {
+		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+		if (pfn >= start_pfn && pfn <= end_pfn)
+			return nid;
+	}
+	/* Default to node0 as not all callers are prepared for this to fail */
+	return 0;
+}
+EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
+#endif /* CONFIG_MEMBLOCK_NUMA_INFO */
+
 /*
  * This finds a zone that can be used for ZONE_MOVABLE pages. The
  * assumption is made that zones within a node are ordered in monotonic
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* [PATCH v2 08/22] memblock: Introduce a generic phys_addr_to_target_node()
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (6 preceding siblings ...)
  2020-07-12 16:26 ` [PATCH v2 07/22] numa: Introduce a generic memory_add_physaddr_to_nid() Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-13  7:03   ` Mike Rapoport
  2020-07-12 16:26 ` [PATCH v2 09/22] arm64: Convert to generic memblock for numa-info Dan Williams
                   ` (14 subsequent siblings)
  22 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Mike Rapoport, Jia He, Will Deacon, David Hildenbrand,
	Andrew Morton, peterz, dave.hansen, ard.biesheuvel, linux-mm,
	linux-kernel, linux-acpi, hch, joao.m.martins

Similar to how generic memory_add_physaddr_to_nid() interrogates
memblock data for numa information, introduce
get_reserved_pfn_range_from_nid() to enable the same operation for
reserved memory ranges. Example memory ranges that are reserved, but
still have associated numa-info are persistent memory or Soft Reserved
(EFI_MEMORY_SP) memory.

Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jia He <justin.he@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 include/linux/memblock.h |    4 +++
 include/linux/mm.h       |    2 +
 include/linux/numa.h     |    2 +
 mm/memblock.c            |   22 ++++++++++++++--
 mm/page_alloc.c          |   63 +++++++++++++++++++++++++++++++++++++++++++++-
 5 files changed, 87 insertions(+), 6 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 017fae833d4a..0655e8376c72 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -234,6 +234,10 @@ void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
 	for (i = -1, __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid); \
 	     i >= 0; __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid))
 
+#define for_each_reserved_pfn_range(i, nid, p_start, p_end, p_nid)		\
+	for (i = -1, __next_reserved_pfn_range(&i, nid, p_start, p_end, p_nid); \
+	     i >= 0; __next_reserved_pfn_range(&i, nid, p_start, p_end, p_nid))
+
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 void __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
 				  unsigned long *out_spfn,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1e76ee5da20b..82dac9f42c46 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2438,6 +2438,8 @@ extern unsigned long absent_pages_in_range(unsigned long start_pfn,
 
 extern void get_pfn_range_for_nid(unsigned int nid,
 			unsigned long *start_pfn, unsigned long *end_pfn);
+extern void get_reserved_pfn_range_for_nid(unsigned int nid,
+			unsigned long *start_pfn, unsigned long *end_pfn);
 extern unsigned long find_min_pfn_with_active_regions(void);
 extern void sparse_memory_present_with_active_regions(int nid);
 
diff --git a/include/linux/numa.h b/include/linux/numa.h
index 5d25c5de1322..52b2430bc759 100644
--- a/include/linux/numa.h
+++ b/include/linux/numa.h
@@ -19,7 +19,7 @@ int numa_map_to_online_node(int node);
 
 /*
  * Optional architecture specific implementation, users need a "depends
- * on $ARCH"
+ * on $ARCH" or depends on CONFIG_MEMBLOCK_NUMA_INFO
  */
 int phys_to_target_node(phys_addr_t addr);
 #else
diff --git a/mm/memblock.c b/mm/memblock.c
index 39aceafc57f6..43c3abab705e 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1200,11 +1200,11 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
 /*
  * Common iterator interface used to define for_each_mem_pfn_range().
  */
-void __init_memblock __next_mem_pfn_range(int *idx, int nid,
+static void __init_memblock __next_memblock_pfn_range(int *idx, int nid,
 				unsigned long *out_start_pfn,
-				unsigned long *out_end_pfn, int *out_nid)
+				unsigned long *out_end_pfn, int *out_nid,
+				struct memblock_type *type)
 {
-	struct memblock_type *type = &memblock.memory;
 	struct memblock_region *r;
 	int r_nid;
 
@@ -1230,6 +1230,22 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid,
 		*out_nid = r_nid;
 }
 
+void __init_memblock __next_mem_pfn_range(int *idx, int nid,
+				unsigned long *out_start_pfn,
+				unsigned long *out_end_pfn, int *out_nid)
+{
+	__next_memblock_pfn_range(idx, nid, out_start_pfn, out_end_pfn, out_nid,
+				  &memblock.memory);
+}
+
+void __init_memblock __next_reserved_pfn_range(int *idx, int nid,
+				unsigned long *out_start_pfn,
+				unsigned long *out_end_pfn, int *out_nid)
+{
+	__next_memblock_pfn_range(idx, nid, out_start_pfn, out_end_pfn, out_nid,
+				  &memblock.reserved);
+}
+
 /**
  * memblock_set_node - set node ID on memblock regions
  * @base: base of area to set node ID for
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index df8bd169dbb4..94ad77c0c338 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6369,12 +6369,39 @@ void __init_or_memblock get_pfn_range_for_nid(unsigned int nid,
 		*start_pfn = 0;
 }
 
+/**
+ * get_reserved_pfn_range_for_nid - Return the start and end page frames for a node
+ * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
+ * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
+ * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
+ *
+ * Mostly identical to get_pfn_range_for_nid() except it operates on
+ * reserved ranges rather than online memory.
+ */
+void __init_or_memblock get_reserved_pfn_range_for_nid(unsigned int nid,
+			unsigned long *start_pfn, unsigned long *end_pfn)
+{
+	unsigned long this_start_pfn, this_end_pfn;
+	int i;
+
+	*start_pfn = -1UL;
+	*end_pfn = 0;
+
+	for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
+		*start_pfn = min(*start_pfn, this_start_pfn);
+		*end_pfn = max(*end_pfn, this_end_pfn);
+	}
+
+	if (*start_pfn == -1UL)
+		*start_pfn = 0;
+}
+
 /*
  * Generic implementation of memory_add_physaddr_to_nid() depends on
  * architecture using memblock data for numa information.
  */
 #ifdef CONFIG_MEMBLOCK_NUMA_INFO
-int __init_or_memblock memory_add_physaddr_to_nid(u64 addr)
+static int __init_or_memblock __memory_add_physaddr_to_nid(u64 addr)
 {
 	unsigned long start_pfn, end_pfn, pfn = PHYS_PFN(addr);
 	int nid;
@@ -6384,10 +6411,42 @@ int __init_or_memblock memory_add_physaddr_to_nid(u64 addr)
 		if (pfn >= start_pfn && pfn <= end_pfn)
 			return nid;
 	}
+	return NUMA_NO_NODE;
+}
+
+int __init_or_memblock memory_add_physaddr_to_nid(u64 addr)
+{
+	int nid = __memory_add_physaddr_to_nid(addr);
+
 	/* Default to node0 as not all callers are prepared for this to fail */
-	return 0;
+	if (nid == NUMA_NO_NODE)
+		return 0;
+	return nid;
 }
 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
+
+int __init_or_memblock phys_to_target_node(u64 addr)
+{
+	unsigned long start_pfn, end_pfn, pfn = PHYS_PFN(addr);
+	int nid = __memory_add_physaddr_to_nid(addr);
+
+	if (nid != NUMA_NO_NODE)
+		return nid;
+
+	/*
+	 * Search reserved memory ranges since the memory address does
+	 * not appear to be online
+	 */
+	for_each_possible_node(nid) {
+		if (node_online(nid))
+			continue;
+		get_reserved_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+		if (pfn >= start_pfn && pfn <= end_pfn)
+			return nid;
+	}
+	return NUMA_NO_NODE;
+}
+EXPORT_SYMBOL_GPL(phys_to_target_node);
 #endif /* CONFIG_MEMBLOCK_NUMA_INFO */
 
 /*
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 09/22] arm64: Convert to generic memblock for numa-info
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (7 preceding siblings ...)
  2020-07-12 16:26 ` [PATCH v2 08/22] memblock: Introduce a generic phys_addr_to_target_node() Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-12 16:26 ` [PATCH v2 10/22] ACPI: HMAT: Attach a device for each soft-reserved range Dan Williams
                   ` (13 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Mike Rapoport, Jia He, Will Deacon, David Hildenbrand,
	Catalin Marinas, Andrew Morton, peterz, dave.hansen,
	ard.biesheuvel, linux-mm, linux-kernel, linux-acpi, hch,
	joao.m.martins

Drop the existing memory_add_physaddr_to_nid() stub and add support for
phys_to_target_node() by selecting the generic CONFIG_MEMBLOCK_NUMAINFO
mechanism for querying firmware numa data at runtime.

Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jia He <justin.he@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/arm64/Kconfig   |    1 +
 arch/arm64/mm/numa.c |   10 ----------
 2 files changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a4a094bedcb2..cfef26ce8c0c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -65,6 +65,7 @@ config ARM64
 	select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
 	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
 	select ARCH_KEEP_MEMBLOCK
+	select MEMBLOCK_NUMA_INFO
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select ARCH_USE_GNU_PROPERTY
 	select ARCH_USE_QUEUED_RWLOCKS
diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
index aafcee3e3f7e..73f8b49d485c 100644
--- a/arch/arm64/mm/numa.c
+++ b/arch/arm64/mm/numa.c
@@ -461,13 +461,3 @@ void __init arm64_numa_init(void)
 
 	numa_init(dummy_numa_init);
 }
-
-/*
- * We hope that we will be hotplugging memory on nodes we already know about,
- * such that acpi_get_node() succeeds and we never fall back to this...
- */
-int memory_add_physaddr_to_nid(u64 addr)
-{
-	pr_warn("Unknown node for memory at 0x%llx, assuming node 0\n", addr);
-	return 0;
-}
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 10/22] ACPI: HMAT: Attach a device for each soft-reserved range
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (8 preceding siblings ...)
  2020-07-12 16:26 ` [PATCH v2 09/22] arm64: Convert to generic memblock for numa-info Dan Williams
@ 2020-07-12 16:26 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 11/22] device-dax: Drop the dax_region.pfn_flags attribute Dan Williams
                   ` (12 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:26 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Jonathan Cameron, Brice Goglin, Ard Biesheuvel,
	Rafael J. Wysocki, Catalin Marinas, Will Deacon, joao.m.martins,
	peterz, dave.hansen, linux-mm, linux-kernel, linux-acpi, hch

The hmem enabling in commit 'cf8741ac57ed ("ACPI: NUMA: HMAT: Register
"soft reserved" memory as an "hmem" device")' only registered ranges to
the hmem driver for each soft-reservation that also appeared in the
HMAT. While this is meant to encourage platform firmware to "do the
right thing" and publish an HMAT, the corollary is that platforms that
fail to publish an accurate HMAT will strand memory from Linux usage.
Additionally, the "efi_fake_mem" kernel command line option enabling
will strand memory by default without an HMAT.

Arrange for "soft reserved" memory that goes unclaimed by HMAT entries
to be published as raw resource ranges for the hmem driver to consume.

Include a module parameter to disable either this fallback behavior, or
the hmat enabling from creating hmem devices. The module parameter
requires the hmem device enabling to have unique name in the module
namespace: "device_hmem".

The driver depends on the architecture providing phys_to_target_node()
which is only x86 via numa_meminfo() and arm64 via a generic memblock
implementation.

Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/Kconfig       |    2 ++
 drivers/dax/hmem/Makefile |    3 ++-
 drivers/dax/hmem/device.c |   35 +++++++++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index a229f45d34aa..557483ed2e9c 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -50,6 +50,8 @@ config DEV_DAX_HMEM
 
 config DEV_DAX_HMEM_DEVICES
 	depends on DEV_DAX_HMEM
+	# requires phys_to_target_node() support
+	depends on X86_NUMA_KEEP_MEMINFO || MEMBLOCK_NUMA_INFO
 	def_bool y
 
 config DEV_DAX_KMEM
diff --git a/drivers/dax/hmem/Makefile b/drivers/dax/hmem/Makefile
index a9d353d0c9ed..57377b4c3d47 100644
--- a/drivers/dax/hmem/Makefile
+++ b/drivers/dax/hmem/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_DEV_DAX_HMEM) += dax_hmem.o
-obj-$(CONFIG_DEV_DAX_HMEM_DEVICES) += device.o
+obj-$(CONFIG_DEV_DAX_HMEM_DEVICES) += device_hmem.o
 
+device_hmem-y := device.o
 dax_hmem-y := hmem.o
diff --git a/drivers/dax/hmem/device.c b/drivers/dax/hmem/device.c
index b9dd6b27745c..cb6401c9e9a4 100644
--- a/drivers/dax/hmem/device.c
+++ b/drivers/dax/hmem/device.c
@@ -5,6 +5,9 @@
 #include <linux/dax.h>
 #include <linux/mm.h>
 
+static bool nohmem;
+module_param_named(disable, nohmem, bool, 0444);
+
 void hmem_register_device(int target_nid, struct resource *r)
 {
 	/* define a clean / non-busy resource for the platform device */
@@ -17,6 +20,9 @@ void hmem_register_device(int target_nid, struct resource *r)
 	struct memregion_info info;
 	int rc, id;
 
+	if (nohmem)
+		return;
+
 	rc = region_intersects(res.start, resource_size(&res), IORESOURCE_MEM,
 			IORES_DESC_SOFT_RESERVED);
 	if (rc != REGION_INTERSECTS)
@@ -63,3 +69,32 @@ void hmem_register_device(int target_nid, struct resource *r)
 out_pdev:
 	memregion_free(id);
 }
+
+static __init int hmem_register_one(struct resource *res, void *data)
+{
+	/*
+	 * If the resource is not a top-level resource it was already
+	 * assigned to a device by the HMAT parsing.
+	 */
+	if (res->parent != &iomem_resource) {
+		pr_info("HMEM: skip %pr, already claimed\n", res);
+		return 0;
+	}
+
+	hmem_register_device(phys_to_target_node(res->start), res);
+
+	return 0;
+}
+
+static __init int hmem_init(void)
+{
+	walk_iomem_res_desc(IORES_DESC_SOFT_RESERVED,
+			IORESOURCE_MEM, 0, -1, NULL, hmem_register_one);
+	return 0;
+}
+
+/*
+ * As this is a fallback for address ranges unclaimed by the ACPI HMAT
+ * parsing it must be at an initcall level greater than hmat_init().
+ */
+late_initcall(hmem_init);
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 11/22] device-dax: Drop the dax_region.pfn_flags attribute
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (9 preceding siblings ...)
  2020-07-12 16:26 ` [PATCH v2 10/22] ACPI: HMAT: Attach a device for each soft-reserved range Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 12/22] device-dax: Move instance creation parameters to 'struct dev_dax_data' Dan Williams
                   ` (11 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: peterz, dave.hansen, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

All callers specify the same flags to alloc_dax_region(), so there is no
need to allow for anything other than PFN_DEV|PFN_MAP, or carry a
->pfn_flags around on the region. Device-dax instances are always page
backed.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c         |    4 +---
 drivers/dax/bus.h         |    3 +--
 drivers/dax/dax-private.h |    2 --
 drivers/dax/device.c      |   26 +++-----------------------
 drivers/dax/hmem/hmem.c   |    2 +-
 drivers/dax/pmem/core.c   |    3 +--
 6 files changed, 7 insertions(+), 33 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index df238c8b6ef2..f06ffa66cd78 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -226,8 +226,7 @@ static void dax_region_unregister(void *region)
 }
 
 struct dax_region *alloc_dax_region(struct device *parent, int region_id,
-		struct resource *res, int target_node, unsigned int align,
-		unsigned long long pfn_flags)
+		struct resource *res, int target_node, unsigned int align)
 {
 	struct dax_region *dax_region;
 
@@ -251,7 +250,6 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 
 	dev_set_drvdata(parent, dax_region);
 	memcpy(&dax_region->res, res, sizeof(*res));
-	dax_region->pfn_flags = pfn_flags;
 	kref_init(&dax_region->kref);
 	dax_region->id = region_id;
 	dax_region->align = align;
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index 9e4eba67e8b9..55577e9791da 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -10,8 +10,7 @@ struct dax_device;
 struct dax_region;
 void dax_region_put(struct dax_region *dax_region);
 struct dax_region *alloc_dax_region(struct device *parent, int region_id,
-		struct resource *res, int target_node, unsigned int align,
-		unsigned long long flags);
+		struct resource *res, int target_node, unsigned int align);
 
 enum dev_dax_subsys {
 	DEV_DAX_BUS,
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 16850d5388ab..8a4c40ccd2ef 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -23,7 +23,6 @@ void dax_bus_exit(void);
  * @dev: parent device backing this region
  * @align: allocation and mapping alignment for child dax devices
  * @res: physical address range of the region
- * @pfn_flags: identify whether the pfns are paged back or not
  */
 struct dax_region {
 	int id;
@@ -32,7 +31,6 @@ struct dax_region {
 	struct device *dev;
 	unsigned int align;
 	struct resource res;
-	unsigned long long pfn_flags;
 };
 
 /**
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 4c0af2eb7e19..bffef1b21144 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -41,14 +41,6 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 		return -EINVAL;
 	}
 
-	if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV
-			&& (vma->vm_flags & VM_DONTCOPY) == 0) {
-		dev_info_ratelimited(dev,
-				"%s: %s: fail, dax range requires MADV_DONTFORK\n",
-				current->comm, func);
-		return -EINVAL;
-	}
-
 	if (!vma_is_dax(vma)) {
 		dev_info_ratelimited(dev,
 				"%s: %s: fail, vma is not DAX capable\n",
@@ -102,7 +94,7 @@ static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 	}
 
-	*pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+	*pfn = phys_to_pfn_t(phys, PFN_DEV|PFN_MAP);
 
 	return vmf_insert_mixed(vmf->vma, vmf->address, *pfn);
 }
@@ -127,12 +119,6 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 	}
 
-	/* dax pmd mappings require pfn_t_devmap() */
-	if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
-		dev_dbg(dev, "region lacks devmap flags\n");
-		return VM_FAULT_SIGBUS;
-	}
-
 	if (fault_size < dax_region->align)
 		return VM_FAULT_SIGBUS;
 	else if (fault_size > dax_region->align)
@@ -150,7 +136,7 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 	}
 
-	*pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+	*pfn = phys_to_pfn_t(phys, PFN_DEV|PFN_MAP);
 
 	return vmf_insert_pfn_pmd(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);
 }
@@ -177,12 +163,6 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 	}
 
-	/* dax pud mappings require pfn_t_devmap() */
-	if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
-		dev_dbg(dev, "region lacks devmap flags\n");
-		return VM_FAULT_SIGBUS;
-	}
-
 	if (fault_size < dax_region->align)
 		return VM_FAULT_SIGBUS;
 	else if (fault_size > dax_region->align)
@@ -200,7 +180,7 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 	}
 
-	*pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+	*pfn = phys_to_pfn_t(phys, PFN_DEV|PFN_MAP);
 
 	return vmf_insert_pfn_pud(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);
 }
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index 29ceb5795297..506893861253 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -22,7 +22,7 @@ static int dax_hmem_probe(struct platform_device *pdev)
 	memcpy(&pgmap.res, res, sizeof(*res));
 
 	dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node,
-			PMD_SIZE, PFN_DEV|PFN_MAP);
+			PMD_SIZE);
 	if (!dax_region)
 		return -ENOMEM;
 
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
index 2bedf8414fff..ea52bb77a294 100644
--- a/drivers/dax/pmem/core.c
+++ b/drivers/dax/pmem/core.c
@@ -53,8 +53,7 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 	memcpy(&res, &pgmap.res, sizeof(res));
 	res.start += offset;
 	dax_region = alloc_dax_region(dev, region_id, &res,
-			nd_region->target_node, le32_to_cpu(pfn_sb->align),
-			PFN_DEV|PFN_MAP);
+			nd_region->target_node, le32_to_cpu(pfn_sb->align));
 	if (!dax_region)
 		return ERR_PTR(-ENOMEM);
 
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 12/22] device-dax: Move instance creation parameters to 'struct dev_dax_data'
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (10 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 11/22] device-dax: Drop the dax_region.pfn_flags attribute Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 13/22] device-dax: Make pgmap optional for instance creation Dan Williams
                   ` (10 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: peterz, dave.hansen, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

In preparation for adding more parameters to instance creation, move
existing parameters to a new struct.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c       |   14 +++++++-------
 drivers/dax/bus.h       |   16 ++++++++--------
 drivers/dax/hmem/hmem.c |    8 +++++++-
 drivers/dax/pmem/core.c |    9 ++++++++-
 4 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index f06ffa66cd78..dffa4655e128 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -395,9 +395,9 @@ static void unregister_dev_dax(void *dev)
 	put_device(dev);
 }
 
-struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id,
-		struct dev_pagemap *pgmap, enum dev_dax_subsys subsys)
+struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 {
+	struct dax_region *dax_region = data->dax_region;
 	struct device *parent = dax_region->dev;
 	struct dax_device *dax_dev;
 	struct dev_dax *dev_dax;
@@ -405,14 +405,14 @@ struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id,
 	struct device *dev;
 	int rc = -ENOMEM;
 
-	if (id < 0)
+	if (data->id < 0)
 		return ERR_PTR(-EINVAL);
 
 	dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL);
 	if (!dev_dax)
 		return ERR_PTR(-ENOMEM);
 
-	memcpy(&dev_dax->pgmap, pgmap, sizeof(*pgmap));
+	memcpy(&dev_dax->pgmap, data->pgmap, sizeof(struct dev_pagemap));
 
 	/*
 	 * No 'host' or dax_operations since there is no access to this
@@ -438,13 +438,13 @@ struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id,
 
 	inode = dax_inode(dax_dev);
 	dev->devt = inode->i_rdev;
-	if (subsys == DEV_DAX_BUS)
+	if (data->subsys == DEV_DAX_BUS)
 		dev->bus = &dax_bus_type;
 	else
 		dev->class = dax_class;
 	dev->parent = parent;
 	dev->type = &dev_dax_type;
-	dev_set_name(dev, "dax%d.%d", dax_region->id, id);
+	dev_set_name(dev, "dax%d.%d", dax_region->id, data->id);
 
 	rc = device_add(dev);
 	if (rc) {
@@ -464,7 +464,7 @@ struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id,
 
 	return ERR_PTR(rc);
 }
-EXPORT_SYMBOL_GPL(__devm_create_dev_dax);
+EXPORT_SYMBOL_GPL(devm_create_dev_dax);
 
 static int match_always_count;
 
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index 55577e9791da..299c2e7fac09 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -13,18 +13,18 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 		struct resource *res, int target_node, unsigned int align);
 
 enum dev_dax_subsys {
-	DEV_DAX_BUS,
+	DEV_DAX_BUS = 0, /* zeroed dev_dax_data picks this by default */
 	DEV_DAX_CLASS,
 };
 
-struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id,
-		struct dev_pagemap *pgmap, enum dev_dax_subsys subsys);
+struct dev_dax_data {
+	struct dax_region *dax_region;
+	struct dev_pagemap *pgmap;
+	enum dev_dax_subsys subsys;
+	int id;
+};
 
-static inline struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
-		int id, struct dev_pagemap *pgmap)
-{
-	return __devm_create_dev_dax(dax_region, id, pgmap, DEV_DAX_BUS);
-}
+struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data);
 
 /* to be deleted when DEV_DAX_CLASS is removed */
 struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys);
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index 506893861253..b84fe17178d8 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -11,6 +11,7 @@ static int dax_hmem_probe(struct platform_device *pdev)
 	struct dev_pagemap pgmap = { };
 	struct dax_region *dax_region;
 	struct memregion_info *mri;
+	struct dev_dax_data data;
 	struct dev_dax *dev_dax;
 	struct resource *res;
 
@@ -26,7 +27,12 @@ static int dax_hmem_probe(struct platform_device *pdev)
 	if (!dax_region)
 		return -ENOMEM;
 
-	dev_dax = devm_create_dev_dax(dax_region, 0, &pgmap);
+	data = (struct dev_dax_data) {
+		.dax_region = dax_region,
+		.id = 0,
+		.pgmap = &pgmap,
+	};
+	dev_dax = devm_create_dev_dax(&data);
 	if (IS_ERR(dev_dax))
 		return PTR_ERR(dev_dax);
 
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
index ea52bb77a294..08ee5947a49c 100644
--- a/drivers/dax/pmem/core.c
+++ b/drivers/dax/pmem/core.c
@@ -14,6 +14,7 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 	resource_size_t offset;
 	struct nd_pfn_sb *pfn_sb;
 	struct dev_dax *dev_dax;
+	struct dev_dax_data data;
 	struct nd_namespace_io *nsio;
 	struct dax_region *dax_region;
 	struct dev_pagemap pgmap = { };
@@ -57,7 +58,13 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 	if (!dax_region)
 		return ERR_PTR(-ENOMEM);
 
-	dev_dax = __devm_create_dev_dax(dax_region, id, &pgmap, subsys);
+	data = (struct dev_dax_data) {
+		.dax_region = dax_region,
+		.id = id,
+		.pgmap = &pgmap,
+		.subsys = subsys,
+	};
+	dev_dax = devm_create_dev_dax(&data);
 
 	/* child dev_dax instances now own the lifetime of the dax_region */
 	dax_region_put(dax_region);
_______________________________________________
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To unsubscribe send an email to linux-nvdimm-leave@lists.01.org

^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 13/22] device-dax: Make pgmap optional for instance creation
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (11 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 12/22] device-dax: Move instance creation parameters to 'struct dev_dax_data' Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 14/22] device-dax: Kill dax_kmem_res Dan Williams
                   ` (9 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: peterz, dave.hansen, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

The passed in dev_pagemap is only required in the pmem case as the
libnvdimm core may have reserved a vmem_altmap for dev_memremap_pages()
to place the memmap in pmem directly. In the hmem case there is no
agent reserving an altmap so it can all be handled by a core internal
default.

Pass the resource range via a new @range property of 'struct
dev_dax_data'.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c              |   29 +++++++++++++++--------------
 drivers/dax/bus.h              |    2 ++
 drivers/dax/dax-private.h      |    9 ++++++++-
 drivers/dax/device.c           |   28 +++++++++++++++++++---------
 drivers/dax/hmem/hmem.c        |    8 ++++----
 drivers/dax/kmem.c             |   12 ++++++------
 drivers/dax/pmem/core.c        |    4 ++++
 tools/testing/nvdimm/dax-dev.c |    8 ++++----
 8 files changed, 62 insertions(+), 38 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index dffa4655e128..96bd64ba95a5 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -271,7 +271,7 @@ static ssize_t size_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
-	unsigned long long size = resource_size(&dev_dax->region->res);
+	unsigned long long size = range_len(&dev_dax->range);
 
 	return sprintf(buf, "%llu\n", size);
 }
@@ -293,19 +293,12 @@ static ssize_t target_node_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(target_node);
 
-static unsigned long long dev_dax_resource(struct dev_dax *dev_dax)
-{
-	struct dax_region *dax_region = dev_dax->region;
-
-	return dax_region->res.start;
-}
-
 static ssize_t resource_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
 
-	return sprintf(buf, "%#llx\n", dev_dax_resource(dev_dax));
+	return sprintf(buf, "%#llx\n", dev_dax->range.start);
 }
 static DEVICE_ATTR(resource, 0400, resource_show, NULL);
 
@@ -376,6 +369,7 @@ static void dev_dax_release(struct device *dev)
 
 	dax_region_put(dax_region);
 	put_dax(dax_dev);
+	kfree(dev_dax->pgmap);
 	kfree(dev_dax);
 }
 
@@ -412,7 +406,12 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	if (!dev_dax)
 		return ERR_PTR(-ENOMEM);
 
-	memcpy(&dev_dax->pgmap, data->pgmap, sizeof(struct dev_pagemap));
+	if (data->pgmap) {
+		dev_dax->pgmap = kmemdup(data->pgmap,
+				sizeof(struct dev_pagemap), GFP_KERNEL);
+		if (!dev_dax->pgmap)
+			goto err_pgmap;
+	}
 
 	/*
 	 * No 'host' or dax_operations since there is no access to this
@@ -421,18 +420,19 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC);
 	if (IS_ERR(dax_dev)) {
 		rc = PTR_ERR(dax_dev);
-		goto err;
+		goto err_alloc_dax;
 	}
 
 	/* a device_dax instance is dead while the driver is not attached */
 	kill_dax(dax_dev);
 
-	/* from here on we're committed to teardown via dax_dev_release() */
+	/* from here on we're committed to teardown via dev_dax_release() */
 	dev = &dev_dax->dev;
 	device_initialize(dev);
 
 	dev_dax->dax_dev = dax_dev;
 	dev_dax->region = dax_region;
+	dev_dax->range = data->range;
 	dev_dax->target_node = dax_region->target_node;
 	kref_get(&dax_region->kref);
 
@@ -458,8 +458,9 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 		return ERR_PTR(rc);
 
 	return dev_dax;
-
- err:
+err_alloc_dax:
+	kfree(dev_dax->pgmap);
+err_pgmap:
 	kfree(dev_dax);
 
 	return ERR_PTR(rc);
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index 299c2e7fac09..4aeb36da83a4 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -3,6 +3,7 @@
 #ifndef __DAX_BUS_H__
 #define __DAX_BUS_H__
 #include <linux/device.h>
+#include <linux/range.h>
 
 struct dev_dax;
 struct resource;
@@ -21,6 +22,7 @@ struct dev_dax_data {
 	struct dax_region *dax_region;
 	struct dev_pagemap *pgmap;
 	enum dev_dax_subsys subsys;
+	struct range range;
 	int id;
 };
 
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 8a4c40ccd2ef..6779f683671d 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -41,6 +41,7 @@ struct dax_region {
  * @target_node: effective numa node if dev_dax memory range is onlined
  * @dev - device core
  * @pgmap - pgmap for memmap setup / lifetime (driver owned)
+ * @range: resource range for the instance
  * @dax_mem_res: physical address range of hotadded DAX memory
  * @dax_mem_name: name for hotadded DAX memory via add_memory_driver_managed()
  */
@@ -49,10 +50,16 @@ struct dev_dax {
 	struct dax_device *dax_dev;
 	int target_node;
 	struct device dev;
-	struct dev_pagemap pgmap;
+	struct dev_pagemap *pgmap;
+	struct range range;
 	struct resource *dax_kmem_res;
 };
 
+static inline u64 range_len(struct range *range)
+{
+	return range->end - range->start + 1;
+}
+
 static inline struct dev_dax *to_dev_dax(struct device *dev)
 {
 	return container_of(dev, struct dev_dax, dev);
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index bffef1b21144..a86b2c9788c5 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -55,12 +55,12 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 		unsigned long size)
 {
-	struct resource *res = &dev_dax->region->res;
+	struct range *range = &dev_dax->range;
 	phys_addr_t phys;
 
-	phys = pgoff * PAGE_SIZE + res->start;
-	if (phys >= res->start && phys <= res->end) {
-		if (phys + size - 1 <= res->end)
+	phys = pgoff * PAGE_SIZE + range->start;
+	if (phys >= range->start && phys <= range->end) {
+		if (phys + size - 1 <= range->end)
 			return phys;
 	}
 
@@ -396,21 +396,31 @@ int dev_dax_probe(struct device *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
 	struct dax_device *dax_dev = dev_dax->dax_dev;
-	struct resource *res = &dev_dax->region->res;
+	struct range *range = &dev_dax->range;
+	struct dev_pagemap *pgmap;
 	struct inode *inode;
 	struct cdev *cdev;
 	void *addr;
 	int rc;
 
 	/* 1:1 map region resource range to device-dax instance range */
-	if (!devm_request_mem_region(dev, res->start, resource_size(res),
+	if (!devm_request_mem_region(dev, range->start, range_len(range),
 				dev_name(dev))) {
-		dev_warn(dev, "could not reserve region %pR\n", res);
+		dev_warn(dev, "could not reserve range: %#llx - %#llx\n",
+				range->start, range->end);
 		return -EBUSY;
 	}
 
-	dev_dax->pgmap.type = MEMORY_DEVICE_DEVDAX;
-	addr = devm_memremap_pages(dev, &dev_dax->pgmap);
+	pgmap = dev_dax->pgmap;
+	if (!pgmap) {
+		pgmap = devm_kzalloc(dev, sizeof(*pgmap), GFP_KERNEL);
+		if (!pgmap)
+			return -ENOMEM;
+		pgmap->res.start = range->start;
+		pgmap->res.end = range->end;
+	}
+	pgmap->type = MEMORY_DEVICE_DEVDAX;
+	addr = devm_memremap_pages(dev, pgmap);
 	if (IS_ERR(addr))
 		return PTR_ERR(addr);
 
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index b84fe17178d8..af82d6ba820a 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -8,7 +8,6 @@
 static int dax_hmem_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct dev_pagemap pgmap = { };
 	struct dax_region *dax_region;
 	struct memregion_info *mri;
 	struct dev_dax_data data;
@@ -20,8 +19,6 @@ static int dax_hmem_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	mri = dev->platform_data;
-	memcpy(&pgmap.res, res, sizeof(*res));
-
 	dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node,
 			PMD_SIZE);
 	if (!dax_region)
@@ -30,7 +27,10 @@ static int dax_hmem_probe(struct platform_device *pdev)
 	data = (struct dev_dax_data) {
 		.dax_region = dax_region,
 		.id = 0,
-		.pgmap = &pgmap,
+		.range = {
+			.start = res->start,
+			.end = res->end,
+		},
 	};
 	dev_dax = devm_create_dev_dax(&data);
 	if (IS_ERR(dev_dax))
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 275aa5f87399..5bb133df147d 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -22,7 +22,7 @@ static bool any_hotremove_failed;
 int dev_dax_kmem_probe(struct device *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
-	struct resource *res = &dev_dax->region->res;
+	struct range *range = &dev_dax->range;
 	resource_size_t kmem_start;
 	resource_size_t kmem_size;
 	resource_size_t kmem_end;
@@ -39,17 +39,17 @@ int dev_dax_kmem_probe(struct device *dev)
 	 */
 	numa_node = dev_dax->target_node;
 	if (numa_node < 0) {
-		dev_warn(dev, "rejecting DAX region %pR with invalid node: %d\n",
-			 res, numa_node);
+		dev_warn(dev, "rejecting DAX region with invalid node: %d\n",
+				numa_node);
 		return -EINVAL;
 	}
 
 	/* Hotplug starting at the beginning of the next block: */
-	kmem_start = ALIGN(res->start, memory_block_size_bytes());
+	kmem_start = ALIGN(range->start, memory_block_size_bytes());
 
-	kmem_size = resource_size(res);
+	kmem_size = range_len(range);
 	/* Adjust the size down to compensate for moving up kmem_start: */
-	kmem_size -= kmem_start - res->start;
+	kmem_size -= kmem_start - range->start;
 	/* Align the size down to cover only complete blocks: */
 	kmem_size &= ~(memory_block_size_bytes() - 1);
 	kmem_end = kmem_start + kmem_size;
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
index 08ee5947a49c..4fa81d3d2f65 100644
--- a/drivers/dax/pmem/core.c
+++ b/drivers/dax/pmem/core.c
@@ -63,6 +63,10 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 		.id = id,
 		.pgmap = &pgmap,
 		.subsys = subsys,
+		.range = {
+			.start = res.start,
+			.end = res.end,
+		},
 	};
 	dev_dax = devm_create_dev_dax(&data);
 
diff --git a/tools/testing/nvdimm/dax-dev.c b/tools/testing/nvdimm/dax-dev.c
index 7e5d979e73cb..38d8e55c4a0d 100644
--- a/tools/testing/nvdimm/dax-dev.c
+++ b/tools/testing/nvdimm/dax-dev.c
@@ -9,12 +9,12 @@
 phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 		unsigned long size)
 {
-	struct resource *res = &dev_dax->region->res;
+	struct range *range = &dev_dax->range;
 	phys_addr_t addr;
 
-	addr = pgoff * PAGE_SIZE + res->start;
-	if (addr >= res->start && addr <= res->end) {
-		if (addr + size - 1 <= res->end) {
+	addr = pgoff * PAGE_SIZE + range->start;
+	if (addr >= range->start && addr <= range->end) {
+		if (addr + size - 1 <= range->end) {
 			if (get_nfit_res(addr)) {
 				struct page *page;
 
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 14/22] device-dax: Kill dax_kmem_res
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (12 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 13/22] device-dax: Make pgmap optional for instance creation Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 15/22] device-dax: Add an allocation interface for device-dax instances Dan Williams
                   ` (8 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: David Hildenbrand, Dave Hansen, Pavel Tatashin, peterz,
	ard.biesheuvel, linux-mm, linux-kernel, linux-acpi, hch,
	joao.m.martins

Several related issues around this unneeded attribute:

- The dax_kmem_res property allows the kmem driver to stash the adjusted
  resource range that was used for the hotplug operation, but that can be
  recalculated from the original base range.

- kmem is using an open coded release_resource() + kfree() when an
  idiomatic release_mem_region() is sufficient.

- The driver managed resource need only manage the busy flag. Other flags
  are of no concern to the kmem driver. In fact if kmem inherits some
  memory range that add_memory_driver_managed() rejects that is a
  memory-hotplug-core policy that the driver is in no position to
  override.

- The implementation trusts that failed remove_memory() results in the
  entire resource range remaining pinned busy. The driver need not make
  that layering violation assumption and just maintain the busy state in
  its local resource.

- The "Hot-remove not yet implemented." comment is stale since hotremove
  support is now included.

Cc: David Hildenbrand <david@redhat.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/dax-private.h |    3 -
 drivers/dax/kmem.c        |  123 +++++++++++++++++++++------------------------
 2 files changed, 58 insertions(+), 68 deletions(-)

diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 6779f683671d..12a2dbc43b40 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -42,8 +42,6 @@ struct dax_region {
  * @dev - device core
  * @pgmap - pgmap for memmap setup / lifetime (driver owned)
  * @range: resource range for the instance
- * @dax_mem_res: physical address range of hotadded DAX memory
- * @dax_mem_name: name for hotadded DAX memory via add_memory_driver_managed()
  */
 struct dev_dax {
 	struct dax_region *region;
@@ -52,7 +50,6 @@ struct dev_dax {
 	struct device dev;
 	struct dev_pagemap *pgmap;
 	struct range range;
-	struct resource *dax_kmem_res;
 };
 
 static inline u64 range_len(struct range *range)
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 5bb133df147d..77e25361fbeb 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -19,16 +19,24 @@ static const char *kmem_name;
 /* Set if any memory will remain added when the driver will be unloaded. */
 static bool any_hotremove_failed;
 
+static struct range dax_kmem_range(struct dev_dax *dev_dax)
+{
+	struct range range;
+
+	/* memory-block align the hotplug range */
+	range.start = ALIGN(dev_dax->range.start, memory_block_size_bytes());
+	range.end = ALIGN_DOWN(dev_dax->range.end + 1,
+			memory_block_size_bytes()) - 1;
+	return range;
+}
+
 int dev_dax_kmem_probe(struct device *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
-	struct range *range = &dev_dax->range;
-	resource_size_t kmem_start;
-	resource_size_t kmem_size;
-	resource_size_t kmem_end;
-	struct resource *new_res;
-	const char *new_res_name;
-	int numa_node;
+	struct range range = dax_kmem_range(dev_dax);
+	int numa_node = dev_dax->target_node;
+	struct resource *res;
+	char *res_name;
 	int rc;
 
 	/*
@@ -37,109 +45,94 @@ int dev_dax_kmem_probe(struct device *dev)
 	 * could be mixed in a node with faster memory, causing
 	 * unavoidable performance issues.
 	 */
-	numa_node = dev_dax->target_node;
 	if (numa_node < 0) {
 		dev_warn(dev, "rejecting DAX region with invalid node: %d\n",
 				numa_node);
 		return -EINVAL;
 	}
 
-	/* Hotplug starting at the beginning of the next block: */
-	kmem_start = ALIGN(range->start, memory_block_size_bytes());
-
-	kmem_size = range_len(range);
-	/* Adjust the size down to compensate for moving up kmem_start: */
-	kmem_size -= kmem_start - range->start;
-	/* Align the size down to cover only complete blocks: */
-	kmem_size &= ~(memory_block_size_bytes() - 1);
-	kmem_end = kmem_start + kmem_size;
-
-	new_res_name = kstrdup(dev_name(dev), GFP_KERNEL);
-	if (!new_res_name)
+	res_name = kstrdup(dev_name(dev), GFP_KERNEL);
+	if (!res_name)
 		return -ENOMEM;
 
-	/* Region is permanently reserved if hotremove fails. */
-	new_res = request_mem_region(kmem_start, kmem_size, new_res_name);
-	if (!new_res) {
-		dev_warn(dev, "could not reserve region [%pa-%pa]\n",
-			 &kmem_start, &kmem_end);
-		kfree(new_res_name);
+	res = request_mem_region(range.start, range_len(&range), res_name);
+	if (!res) {
+		dev_warn(dev, "could not reserve region [%#llx-%#llx]\n",
+				range.start, range.end);
+		kfree(res_name);
 		return -EBUSY;
 	}
 
 	/*
-	 * Set flags appropriate for System RAM.  Leave ..._BUSY clear
-	 * so that add_memory() can add a child resource.  Do not
-	 * inherit flags from the parent since it may set new flags
-	 * unknown to us that will break add_memory() below.
+	 * Temporarily clear busy to allow add_memory_driver_managed()
+	 * to claim it.
 	 */
-	new_res->flags = IORESOURCE_SYSTEM_RAM;
+	res->flags &= ~IORESOURCE_BUSY;
 
 	/*
 	 * Ensure that future kexec'd kernels will not treat this as RAM
 	 * automatically.
 	 */
-	rc = add_memory_driver_managed(numa_node, new_res->start,
-				       resource_size(new_res), kmem_name);
+	rc = add_memory_driver_managed(numa_node, res->start,
+				       resource_size(res), kmem_name);
+
+	res->flags |= IORESOURCE_BUSY;
 	if (rc) {
-		release_resource(new_res);
-		kfree(new_res);
-		kfree(new_res_name);
+		release_mem_region(range.start, range_len(&range));
+		kfree(res_name);
 		return rc;
 	}
-	dev_dax->dax_kmem_res = new_res;
+
+	dev_set_drvdata(dev, res_name);
 
 	return 0;
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-static int dev_dax_kmem_remove(struct device *dev)
+static void dax_kmem_release(struct dev_dax *dev_dax)
 {
-	struct dev_dax *dev_dax = to_dev_dax(dev);
-	struct resource *res = dev_dax->dax_kmem_res;
-	resource_size_t kmem_start = res->start;
-	resource_size_t kmem_size = resource_size(res);
-	const char *res_name = res->name;
 	int rc;
+	struct device *dev = &dev_dax->dev;
+	const char *res_name = dev_get_drvdata(dev);
+	struct range range = dax_kmem_range(dev_dax);
 
 	/*
 	 * We have one shot for removing memory, if some memory blocks were not
 	 * offline prior to calling this function remove_memory() will fail, and
 	 * there is no way to hotremove this memory until reboot because device
-	 * unbind will succeed even if we return failure.
+	 * unbind will proceed regardless of the remove_memory result.
 	 */
-	rc = remove_memory(dev_dax->target_node, kmem_start, kmem_size);
-	if (rc) {
-		any_hotremove_failed = true;
-		dev_err(dev,
-			"DAX region %pR cannot be hotremoved until the next reboot\n",
-			res);
-		return rc;
+	rc = remove_memory(dev_dax->target_node, range.start, range_len(&range));
+	if (rc == 0) {
+		release_mem_region(range.start, range_len(&range));
+		dev_set_drvdata(dev, NULL);
+		kfree(res_name);
+		return;
 	}
 
-	/* Release and free dax resources */
-	release_resource(res);
-	kfree(res);
-	kfree(res_name);
-	dev_dax->dax_kmem_res = NULL;
-
-	return 0;
+	any_hotremove_failed = true;
+	dev_err(dev, "%#llx-%#llx cannot be hotremoved until the next reboot\n",
+			range.start, range.end);
 }
 #else
-static int dev_dax_kmem_remove(struct device *dev)
+static void dax_kmem_release(struct dev_dax *dev_dax)
 {
 	/*
-	 * Without hotremove purposely leak the request_mem_region() for the
-	 * device-dax range and return '0' to ->remove() attempts. The removal
-	 * of the device from the driver always succeeds, but the region is
-	 * permanently pinned as reserved by the unreleased
-	 * request_mem_region().
+	 * Without hotremove purposely leak the request_mem_region() for
+	 * the device-dax range attempts. The removal of the device from
+	 * the driver always succeeds, but the region is permanently
+	 * pinned as reserved by the unreleased request_mem_region().
 	 */
 	any_hotremove_failed = true;
-	return 0;
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
+static int dev_dax_kmem_remove(struct device *dev)
+{
+	dax_kmem_release(to_dev_dax(dev));
+	return 0;
+}
+
 static struct dax_device_driver device_dax_kmem_driver = {
 	.drv = {
 		.probe = dev_dax_kmem_probe,
_______________________________________________
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 15/22] device-dax: Add an allocation interface for device-dax instances
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (13 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 14/22] device-dax: Kill dax_kmem_res Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 16/22] device-dax: Introduce 'seed' devices Dan Williams
                   ` (7 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: peterz, dave.hansen, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

In preparation for a facility that enables dax regions to be
sub-divided, introduce infrastructure to track and allocate region
capacity.

The new dax_region/available_size attribute is only enabled for volatile
hmem devices, not pmem devices that are defined by nvdimm namespace
boundaries. This is per Jeff's feedback the last time dynamic device-dax
capacity allocation support was discussed.

Link: https://lore.kernel.org/linux-nvdimm/x49shpp3zn8.fsf@segfault.boston.devel.redhat.com
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c         |  120 +++++++++++++++++++++++++++++++++++++++++----
 drivers/dax/bus.h         |    7 ++-
 drivers/dax/dax-private.h |    2 -
 drivers/dax/hmem/hmem.c   |    7 +--
 drivers/dax/pmem/core.c   |    8 +--
 5 files changed, 121 insertions(+), 23 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 96bd64ba95a5..0a48ce378686 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -130,6 +130,11 @@ ATTRIBUTE_GROUPS(dax_drv);
 
 static int dax_bus_match(struct device *dev, struct device_driver *drv);
 
+static bool is_static(struct dax_region *dax_region)
+{
+	return (dax_region->res.flags & IORESOURCE_DAX_STATIC) != 0;
+}
+
 static struct bus_type dax_bus_type = {
 	.name = "dax",
 	.uevent = dax_bus_uevent,
@@ -185,7 +190,48 @@ static ssize_t align_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(align);
 
+#define for_each_dax_region_resource(dax_region, res) \
+	for (res = (dax_region)->res.child; res; res = res->sibling)
+
+static unsigned long long dax_region_avail_size(struct dax_region *dax_region)
+{
+	resource_size_t size = resource_size(&dax_region->res);
+	struct resource *res;
+
+	device_lock_assert(dax_region->dev);
+
+	for_each_dax_region_resource(dax_region, res)
+		size -= resource_size(res);
+	return size;
+}
+
+static ssize_t available_size_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dax_region *dax_region = dev_get_drvdata(dev);
+	unsigned long long size;
+
+	device_lock(dev);
+	size = dax_region_avail_size(dax_region);
+	device_unlock(dev);
+
+	return sprintf(buf, "%llu\n", size);
+}
+static DEVICE_ATTR_RO(available_size);
+
+static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a,
+		int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct dax_region *dax_region = dev_get_drvdata(dev);
+
+	if (is_static(dax_region) && a == &dev_attr_available_size.attr)
+		return 0;
+	return a->mode;
+}
+
 static struct attribute *dax_region_attributes[] = {
+	&dev_attr_available_size.attr,
 	&dev_attr_region_size.attr,
 	&dev_attr_align.attr,
 	&dev_attr_id.attr,
@@ -195,6 +241,7 @@ static struct attribute *dax_region_attributes[] = {
 static const struct attribute_group dax_region_attribute_group = {
 	.name = "dax_region",
 	.attrs = dax_region_attributes,
+	.is_visible = dax_region_visible,
 };
 
 static const struct attribute_group *dax_region_attribute_groups[] = {
@@ -226,7 +273,8 @@ static void dax_region_unregister(void *region)
 }
 
 struct dax_region *alloc_dax_region(struct device *parent, int region_id,
-		struct resource *res, int target_node, unsigned int align)
+		struct resource *res, int target_node, unsigned int align,
+		unsigned long flags)
 {
 	struct dax_region *dax_region;
 
@@ -249,12 +297,17 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 		return NULL;
 
 	dev_set_drvdata(parent, dax_region);
-	memcpy(&dax_region->res, res, sizeof(*res));
 	kref_init(&dax_region->kref);
 	dax_region->id = region_id;
 	dax_region->align = align;
 	dax_region->dev = parent;
 	dax_region->target_node = target_node;
+	dax_region->res = (struct resource) {
+		.start = res->start,
+		.end = res->end,
+		.flags = IORESOURCE_MEM | flags,
+	};
+
 	if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) {
 		kfree(dax_region);
 		return NULL;
@@ -267,6 +320,32 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 }
 EXPORT_SYMBOL_GPL(alloc_dax_region);
 
+static int alloc_dev_dax_range(struct dev_dax *dev_dax, resource_size_t size)
+{
+	struct dax_region *dax_region = dev_dax->region;
+	struct resource *res = &dax_region->res;
+	struct device *dev = &dev_dax->dev;
+	struct resource *alloc;
+
+	device_lock_assert(dax_region->dev);
+
+	/* TODO: handle multiple allocations per region */
+	if (res->child)
+		return -ENOMEM;
+
+	alloc = __request_region(res, res->start, size, dev_name(dev), 0);
+
+	if (!alloc)
+		return -ENOMEM;
+
+	dev_dax->range = (struct range) {
+		.start = alloc->start,
+		.end = alloc->end,
+	};
+
+	return 0;
+}
+
 static ssize_t size_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
@@ -361,6 +440,15 @@ void kill_dev_dax(struct dev_dax *dev_dax)
 }
 EXPORT_SYMBOL_GPL(kill_dev_dax);
 
+static void free_dev_dax_range(struct dev_dax *dev_dax)
+{
+	struct dax_region *dax_region = dev_dax->region;
+	struct range *range = &dev_dax->range;
+
+	device_lock_assert(dax_region->dev);
+	__release_region(&dax_region->res, range->start, range_len(range));
+}
+
 static void dev_dax_release(struct device *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
@@ -385,6 +473,7 @@ static void unregister_dev_dax(void *dev)
 	dev_dbg(dev, "%s\n", __func__);
 
 	kill_dev_dax(dev_dax);
+	free_dev_dax_range(dev_dax);
 	device_del(dev);
 	put_device(dev);
 }
@@ -397,7 +486,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	struct dev_dax *dev_dax;
 	struct inode *inode;
 	struct device *dev;
-	int rc = -ENOMEM;
+	int rc;
 
 	if (data->id < 0)
 		return ERR_PTR(-EINVAL);
@@ -406,11 +495,25 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	if (!dev_dax)
 		return ERR_PTR(-ENOMEM);
 
+	dev_dax->region = dax_region;
+	dev = &dev_dax->dev;
+	device_initialize(dev);
+	dev_set_name(dev, "dax%d.%d", dax_region->id, data->id);
+
+	rc = alloc_dev_dax_range(dev_dax, data->size);
+	if (rc)
+		goto err_range;
+
 	if (data->pgmap) {
+		dev_WARN_ONCE(parent, !is_static(dax_region),
+			"custom dev_pagemap requires a static dax_region\n");
+
 		dev_dax->pgmap = kmemdup(data->pgmap,
 				sizeof(struct dev_pagemap), GFP_KERNEL);
-		if (!dev_dax->pgmap)
+		if (!dev_dax->pgmap) {
+			rc = -ENOMEM;
 			goto err_pgmap;
+		}
 	}
 
 	/*
@@ -427,12 +530,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	kill_dax(dax_dev);
 
 	/* from here on we're committed to teardown via dev_dax_release() */
-	dev = &dev_dax->dev;
-	device_initialize(dev);
-
 	dev_dax->dax_dev = dax_dev;
-	dev_dax->region = dax_region;
-	dev_dax->range = data->range;
 	dev_dax->target_node = dax_region->target_node;
 	kref_get(&dax_region->kref);
 
@@ -444,7 +542,6 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 		dev->class = dax_class;
 	dev->parent = parent;
 	dev->type = &dev_dax_type;
-	dev_set_name(dev, "dax%d.%d", dax_region->id, data->id);
 
 	rc = device_add(dev);
 	if (rc) {
@@ -458,9 +555,12 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 		return ERR_PTR(rc);
 
 	return dev_dax;
+
 err_alloc_dax:
 	kfree(dev_dax->pgmap);
 err_pgmap:
+	free_dev_dax_range(dev_dax);
+err_range:
 	kfree(dev_dax);
 
 	return ERR_PTR(rc);
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index 4aeb36da83a4..44592a8cac0f 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -10,8 +10,11 @@ struct resource;
 struct dax_device;
 struct dax_region;
 void dax_region_put(struct dax_region *dax_region);
+
+#define IORESOURCE_DAX_STATIC (1UL << 0)
 struct dax_region *alloc_dax_region(struct device *parent, int region_id,
-		struct resource *res, int target_node, unsigned int align);
+		struct resource *res, int target_node, unsigned int align,
+		unsigned long flags);
 
 enum dev_dax_subsys {
 	DEV_DAX_BUS = 0, /* zeroed dev_dax_data picks this by default */
@@ -22,7 +25,7 @@ struct dev_dax_data {
 	struct dax_region *dax_region;
 	struct dev_pagemap *pgmap;
 	enum dev_dax_subsys subsys;
-	struct range range;
+	resource_size_t size;
 	int id;
 };
 
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 12a2dbc43b40..99b1273bb232 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -22,7 +22,7 @@ void dax_bus_exit(void);
  * @kref: to pin while other agents have a need to do lookups
  * @dev: parent device backing this region
  * @align: allocation and mapping alignment for child dax devices
- * @res: physical address range of the region
+ * @res: resource tree to track instance allocations
  */
 struct dax_region {
 	int id;
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index af82d6ba820a..e7b64539e23e 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -20,17 +20,14 @@ static int dax_hmem_probe(struct platform_device *pdev)
 
 	mri = dev->platform_data;
 	dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node,
-			PMD_SIZE);
+			PMD_SIZE, 0);
 	if (!dax_region)
 		return -ENOMEM;
 
 	data = (struct dev_dax_data) {
 		.dax_region = dax_region,
 		.id = 0,
-		.range = {
-			.start = res->start,
-			.end = res->end,
-		},
+		.size = resource_size(res),
 	};
 	dev_dax = devm_create_dev_dax(&data);
 	if (IS_ERR(dev_dax))
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
index 4fa81d3d2f65..4fe700884338 100644
--- a/drivers/dax/pmem/core.c
+++ b/drivers/dax/pmem/core.c
@@ -54,7 +54,8 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 	memcpy(&res, &pgmap.res, sizeof(res));
 	res.start += offset;
 	dax_region = alloc_dax_region(dev, region_id, &res,
-			nd_region->target_node, le32_to_cpu(pfn_sb->align));
+			nd_region->target_node, le32_to_cpu(pfn_sb->align),
+			IORESOURCE_DAX_STATIC);
 	if (!dax_region)
 		return ERR_PTR(-ENOMEM);
 
@@ -63,10 +64,7 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 		.id = id,
 		.pgmap = &pgmap,
 		.subsys = subsys,
-		.range = {
-			.start = res.start,
-			.end = res.end,
-		},
+		.size = resource_size(&res),
 	};
 	dev_dax = devm_create_dev_dax(&data);
 
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 16/22] device-dax: Introduce 'seed' devices
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (14 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 15/22] device-dax: Add an allocation interface for device-dax instances Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs Dan Williams
                   ` (6 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: peterz, dave.hansen, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

Add a seed device concept for dynamic dax regions to be able to split
the region amongst multiple sub-instances. The seed device, similar to
libnvdimm seed devices, is a device that starts with zero capacity
allocated and unbound to a driver. In contrast to libnvdimm seed devices
explicit 'create' and 'delete' interfaces are added to the region to
trigger seeds to be created and unused devices to be reclaimed. The
explicit create and delete replaces implicit create as a side effect of
probe and implicit delete when writing 0 to the size that libnvdimm
implements.

Delete can be performed on any 0-sized and idle device.  This avoids the
gymnastics of needing to move device_unregister() to its own async
context.  Specifically, it avoids the deadlock of deleting a device via
one of its own attributes. It is also less surprising to userspace which
never sees an extra device it did not request.

For now just add the device creation, teardown, and ->probe()
prevention. A later patch will arrange for the 'dax/size' attribute to
be writable to allocate capacity from the region.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c         |  317 ++++++++++++++++++++++++++++++++++++++++-----
 drivers/dax/bus.h         |    4 -
 drivers/dax/dax-private.h |    9 +
 drivers/dax/device.c      |   12 +-
 drivers/dax/hmem/hmem.c   |    2 
 drivers/dax/kmem.c        |   14 +-
 drivers/dax/pmem/compat.c |    2 
 7 files changed, 304 insertions(+), 56 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 0a48ce378686..dce9413a4394 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -135,10 +135,46 @@ static bool is_static(struct dax_region *dax_region)
 	return (dax_region->res.flags & IORESOURCE_DAX_STATIC) != 0;
 }
 
+static int dax_bus_probe(struct device *dev)
+{
+	struct dax_device_driver *dax_drv = to_dax_drv(dev->driver);
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+	struct dax_region *dax_region = dev_dax->region;
+	struct range *range = &dev_dax->range;
+	int rc;
+
+	if (range_len(range) == 0 || dev_dax->id < 0)
+		return -ENXIO;
+
+	rc = dax_drv->probe(dev_dax);
+
+	if (rc || is_static(dax_region))
+		return rc;
+
+	/*
+	 * Track new seed creation only after successful probe of the
+	 * previous seed.
+	 */
+	if (dax_region->seed == dev)
+		dax_region->seed = NULL;
+
+	return 0;
+}
+
+static int dax_bus_remove(struct device *dev)
+{
+	struct dax_device_driver *dax_drv = to_dax_drv(dev->driver);
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+
+	return dax_drv->remove(dev_dax);
+}
+
 static struct bus_type dax_bus_type = {
 	.name = "dax",
 	.uevent = dax_bus_uevent,
 	.match = dax_bus_match,
+	.probe = dax_bus_probe,
+	.remove = dax_bus_remove,
 	.drv_groups = dax_drv_groups,
 };
 
@@ -219,14 +255,216 @@ static ssize_t available_size_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(available_size);
 
+static ssize_t seed_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dax_region *dax_region = dev_get_drvdata(dev);
+	struct device *seed;
+	ssize_t rc;
+
+	if (is_static(dax_region))
+		return -EINVAL;
+
+	device_lock(dev);
+	seed = dax_region->seed;
+	rc = sprintf(buf, "%s\n", seed ? dev_name(seed) : "");
+	device_unlock(dev);
+
+	return rc;
+}
+static DEVICE_ATTR_RO(seed);
+
+static ssize_t create_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dax_region *dax_region = dev_get_drvdata(dev);
+	struct device *youngest;
+	ssize_t rc;
+
+	if (is_static(dax_region))
+		return -EINVAL;
+
+	device_lock(dev);
+	youngest = dax_region->youngest;
+	rc = sprintf(buf, "%s\n", youngest ? dev_name(youngest) : "");
+	device_unlock(dev);
+
+	return rc;
+}
+
+static ssize_t create_store(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t len)
+{
+	struct dax_region *dax_region = dev_get_drvdata(dev);
+	unsigned long long avail;
+	ssize_t rc;
+	int val;
+
+	if (is_static(dax_region))
+		return -EINVAL;
+
+	rc = kstrtoint(buf, 0, &val);
+	if (rc)
+		return rc;
+	if (val != 1)
+		return -EINVAL;
+
+	device_lock(dev);
+	avail = dax_region_avail_size(dax_region);
+	if (avail == 0)
+		rc = -ENOSPC;
+	else {
+		struct dev_dax_data data = {
+			.dax_region = dax_region,
+			.size = 0,
+			.id = -1,
+		};
+		struct dev_dax *dev_dax = devm_create_dev_dax(&data);
+
+		if (IS_ERR(dev_dax))
+			rc = PTR_ERR(dev_dax);
+		else {
+			/*
+			 * In support of crafting multiple new devices
+			 * simultaneously multiple seeds can be created,
+			 * but only the first one that has not been
+			 * successfully bound is tracked as the region
+			 * seed.
+			 */
+			if (!dax_region->seed)
+				dax_region->seed = &dev_dax->dev;
+			dax_region->youngest = &dev_dax->dev;
+			rc = len;
+		}
+	}
+	device_unlock(dev);
+
+	return rc;
+}
+static DEVICE_ATTR_RW(create);
+
+void kill_dev_dax(struct dev_dax *dev_dax)
+{
+	struct dax_device *dax_dev = dev_dax->dax_dev;
+	struct inode *inode = dax_inode(dax_dev);
+
+	kill_dax(dax_dev);
+	unmap_mapping_range(inode->i_mapping, 0, 0, 1);
+}
+EXPORT_SYMBOL_GPL(kill_dev_dax);
+
+static void free_dev_dax_range(struct dev_dax *dev_dax)
+{
+	struct dax_region *dax_region = dev_dax->region;
+	struct range *range = &dev_dax->range;
+
+	device_lock_assert(dax_region->dev);
+	if (range_len(range))
+		__release_region(&dax_region->res, range->start,
+				range_len(range));
+}
+
+static void unregister_dev_dax(void *dev)
+{
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+
+	dev_dbg(dev, "%s\n", __func__);
+
+	kill_dev_dax(dev_dax);
+	free_dev_dax_range(dev_dax);
+	device_del(dev);
+	put_device(dev);
+}
+
+/* a return value >= 0 indicates this invocation invalidated the id */
+static int __free_dev_dax_id(struct dev_dax *dev_dax)
+{
+	struct dax_region *dax_region = dev_dax->region;
+	struct device *dev = &dev_dax->dev;
+	int rc = dev_dax->id;
+
+	device_lock_assert(dev);
+
+	if (is_static(dax_region) || dev_dax->id < 0)
+		return -1;
+	ida_free(&dax_region->ida, dev_dax->id);
+	dev_dax->id = -1;
+	return rc;
+}
+
+static int free_dev_dax_id(struct dev_dax *dev_dax)
+{
+	struct device *dev = &dev_dax->dev;
+	int rc;
+
+	device_lock(dev);
+	rc = __free_dev_dax_id(dev_dax);
+	device_unlock(dev);
+	return rc;
+}
+
+static ssize_t delete_store(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t len)
+{
+	struct dax_region *dax_region = dev_get_drvdata(dev);
+	struct dev_dax *dev_dax;
+	struct device *victim;
+	bool do_del = false;
+	int rc;
+
+	if (is_static(dax_region))
+		return -EINVAL;
+
+	victim = device_find_child_by_name(dax_region->dev, buf);
+	if (!victim)
+		return -ENXIO;
+
+	device_lock(dev);
+	device_lock(victim);
+	dev_dax = to_dev_dax(victim);
+	if (victim->driver || range_len(&dev_dax->range))
+		rc = -EBUSY;
+	else {
+		/*
+		 * Invalidate the device so it does not become active
+		 * again, but always preserve device-id-0 so that
+		 * /sys/bus/dax/ is guaranteed to be populated while any
+		 * dax_region is registered.
+		 */
+		if (dev_dax->id > 0) {
+			do_del = __free_dev_dax_id(dev_dax) >= 0;
+			rc = len;
+			if (dax_region->seed == victim)
+				dax_region->seed = NULL;
+			if (dax_region->youngest == victim)
+				dax_region->youngest = NULL;
+		} else
+			rc = -EBUSY;
+	}
+	device_unlock(victim);
+
+	/* won the race to invalidate the device, clean it up */
+	if (do_del)
+		devm_release_action(dev, unregister_dev_dax, victim);
+	device_unlock(dev);
+	put_device(victim);
+
+	return rc;
+}
+static DEVICE_ATTR_WO(delete);
+
 static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a,
 		int n)
 {
 	struct device *dev = container_of(kobj, struct device, kobj);
 	struct dax_region *dax_region = dev_get_drvdata(dev);
 
-	if (is_static(dax_region) && a == &dev_attr_available_size.attr)
-		return 0;
+	if (is_static(dax_region))
+		if (a == &dev_attr_available_size.attr
+				|| a == &dev_attr_create.attr
+				|| a == &dev_attr_seed.attr
+				|| a == &dev_attr_delete.attr)
+			return 0;
 	return a->mode;
 }
 
@@ -234,6 +472,9 @@ static struct attribute *dax_region_attributes[] = {
 	&dev_attr_available_size.attr,
 	&dev_attr_region_size.attr,
 	&dev_attr_align.attr,
+	&dev_attr_create.attr,
+	&dev_attr_seed.attr,
+	&dev_attr_delete.attr,
 	&dev_attr_id.attr,
 	NULL,
 };
@@ -302,6 +543,7 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 	dax_region->align = align;
 	dax_region->dev = parent;
 	dax_region->target_node = target_node;
+	ida_init(&dax_region->ida);
 	dax_region->res = (struct resource) {
 		.start = res->start,
 		.end = res->end,
@@ -329,6 +571,15 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, resource_size_t size)
 
 	device_lock_assert(dax_region->dev);
 
+	/* handle the seed alloc special case */
+	if (!size) {
+		dev_dax->range = (struct range) {
+			.start = res->start,
+			.end = res->start - 1,
+		};
+		return 0;
+	}
+
 	/* TODO: handle multiple allocations per region */
 	if (res->child)
 		return -ENOMEM;
@@ -430,33 +681,15 @@ static const struct attribute_group *dax_attribute_groups[] = {
 	NULL,
 };
 
-void kill_dev_dax(struct dev_dax *dev_dax)
-{
-	struct dax_device *dax_dev = dev_dax->dax_dev;
-	struct inode *inode = dax_inode(dax_dev);
-
-	kill_dax(dax_dev);
-	unmap_mapping_range(inode->i_mapping, 0, 0, 1);
-}
-EXPORT_SYMBOL_GPL(kill_dev_dax);
-
-static void free_dev_dax_range(struct dev_dax *dev_dax)
-{
-	struct dax_region *dax_region = dev_dax->region;
-	struct range *range = &dev_dax->range;
-
-	device_lock_assert(dax_region->dev);
-	__release_region(&dax_region->res, range->start, range_len(range));
-}
-
 static void dev_dax_release(struct device *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
 	struct dax_region *dax_region = dev_dax->region;
 	struct dax_device *dax_dev = dev_dax->dax_dev;
 
-	dax_region_put(dax_region);
 	put_dax(dax_dev);
+	free_dev_dax_id(dev_dax);
+	dax_region_put(dax_region);
 	kfree(dev_dax->pgmap);
 	kfree(dev_dax);
 }
@@ -466,18 +699,6 @@ static const struct device_type dev_dax_type = {
 	.groups = dax_attribute_groups,
 };
 
-static void unregister_dev_dax(void *dev)
-{
-	struct dev_dax *dev_dax = to_dev_dax(dev);
-
-	dev_dbg(dev, "%s\n", __func__);
-
-	kill_dev_dax(dev_dax);
-	free_dev_dax_range(dev_dax);
-	device_del(dev);
-	put_device(dev);
-}
-
 struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 {
 	struct dax_region *dax_region = data->dax_region;
@@ -488,17 +709,35 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	struct device *dev;
 	int rc;
 
-	if (data->id < 0)
-		return ERR_PTR(-EINVAL);
-
 	dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL);
 	if (!dev_dax)
 		return ERR_PTR(-ENOMEM);
 
+	if (is_static(dax_region)) {
+		if (dev_WARN_ONCE(parent, data->id < 0,
+				"dynamic id specified to static region\n")) {
+			rc = -EINVAL;
+			goto err_id;
+		}
+
+		dev_dax->id = data->id;
+	} else {
+		if (dev_WARN_ONCE(parent, data->id >= 0,
+				"static id specified to dynamic region\n")) {
+			rc = -EINVAL;
+			goto err_id;
+		}
+
+		rc = ida_alloc(&dax_region->ida, GFP_KERNEL);
+		if (rc < 0)
+			goto err_id;
+		dev_dax->id = rc;
+	}
+
 	dev_dax->region = dax_region;
 	dev = &dev_dax->dev;
 	device_initialize(dev);
-	dev_set_name(dev, "dax%d.%d", dax_region->id, data->id);
+	dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
 
 	rc = alloc_dev_dax_range(dev_dax, data->size);
 	if (rc)
@@ -561,6 +800,8 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 err_pgmap:
 	free_dev_dax_range(dev_dax);
 err_range:
+	free_dev_dax_id(dev_dax);
+err_id:
 	kfree(dev_dax);
 
 	return ERR_PTR(rc);
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index 44592a8cac0f..da27ea70a19a 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -38,6 +38,8 @@ struct dax_device_driver {
 	struct device_driver drv;
 	struct list_head ids;
 	int match_always;
+	int (*probe)(struct dev_dax *dev);
+	int (*remove)(struct dev_dax *dev);
 };
 
 int __dax_driver_register(struct dax_device_driver *dax_drv,
@@ -48,7 +50,7 @@ void dax_driver_unregister(struct dax_device_driver *dax_drv);
 void kill_dev_dax(struct dev_dax *dev_dax);
 
 #if IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT)
-int dev_dax_probe(struct device *dev);
+int dev_dax_probe(struct dev_dax *dev_dax);
 #endif
 
 /*
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 99b1273bb232..b81a1494d82b 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -7,6 +7,7 @@
 
 #include <linux/device.h>
 #include <linux/cdev.h>
+#include <linux/idr.h>
 
 /* private routines between core files */
 struct dax_device;
@@ -22,7 +23,10 @@ void dax_bus_exit(void);
  * @kref: to pin while other agents have a need to do lookups
  * @dev: parent device backing this region
  * @align: allocation and mapping alignment for child dax devices
+ * @ida: instance id allocator
  * @res: resource tree to track instance allocations
+ * @seed: allow userspace to find the first unbound seed device
+ * @youngest: allow userspace to find the most recently created device
  */
 struct dax_region {
 	int id;
@@ -30,7 +34,10 @@ struct dax_region {
 	struct kref kref;
 	struct device *dev;
 	unsigned int align;
+	struct ida ida;
 	struct resource res;
+	struct device *seed;
+	struct device *youngest;
 };
 
 /**
@@ -39,6 +46,7 @@ struct dax_region {
  * @region - parent region
  * @dax_dev - core dax functionality
  * @target_node: effective numa node if dev_dax memory range is onlined
+ * @id: ida allocated id
  * @dev - device core
  * @pgmap - pgmap for memmap setup / lifetime (driver owned)
  * @range: resource range for the instance
@@ -47,6 +55,7 @@ struct dev_dax {
 	struct dax_region *region;
 	struct dax_device *dax_dev;
 	int target_node;
+	int id;
 	struct device dev;
 	struct dev_pagemap *pgmap;
 	struct range range;
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index a86b2c9788c5..5496331f6eb6 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -392,11 +392,11 @@ static void dev_dax_kill(void *dev_dax)
 	kill_dev_dax(dev_dax);
 }
 
-int dev_dax_probe(struct device *dev)
+int dev_dax_probe(struct dev_dax *dev_dax)
 {
-	struct dev_dax *dev_dax = to_dev_dax(dev);
 	struct dax_device *dax_dev = dev_dax->dax_dev;
 	struct range *range = &dev_dax->range;
+	struct device *dev = &dev_dax->dev;
 	struct dev_pagemap *pgmap;
 	struct inode *inode;
 	struct cdev *cdev;
@@ -446,17 +446,15 @@ int dev_dax_probe(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_dax_probe);
 
-static int dev_dax_remove(struct device *dev)
+static int dev_dax_remove(struct dev_dax *dev_dax)
 {
 	/* all probe actions are unwound by devm */
 	return 0;
 }
 
 static struct dax_device_driver device_dax_driver = {
-	.drv = {
-		.probe = dev_dax_probe,
-		.remove = dev_dax_remove,
-	},
+	.probe = dev_dax_probe,
+	.remove = dev_dax_remove,
 	.match_always = 1,
 };
 
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index e7b64539e23e..aa260009dfc7 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -26,7 +26,7 @@ static int dax_hmem_probe(struct platform_device *pdev)
 
 	data = (struct dev_dax_data) {
 		.dax_region = dax_region,
-		.id = 0,
+		.id = -1,
 		.size = resource_size(res),
 	};
 	dev_dax = devm_create_dev_dax(&data);
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 77e25361fbeb..b1be8a53b26a 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -30,11 +30,11 @@ static struct range dax_kmem_range(struct dev_dax *dev_dax)
 	return range;
 }
 
-int dev_dax_kmem_probe(struct device *dev)
+int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 {
-	struct dev_dax *dev_dax = to_dev_dax(dev);
 	struct range range = dax_kmem_range(dev_dax);
 	int numa_node = dev_dax->target_node;
+	struct device *dev = &dev_dax->dev;
 	struct resource *res;
 	char *res_name;
 	int rc;
@@ -127,17 +127,15 @@ static void dax_kmem_release(struct dev_dax *dev_dax)
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
-static int dev_dax_kmem_remove(struct device *dev)
+static int dev_dax_kmem_remove(struct dev_dax *dev_dax)
 {
-	dax_kmem_release(to_dev_dax(dev));
+	dax_kmem_release(dev_dax);
 	return 0;
 }
 
 static struct dax_device_driver device_dax_kmem_driver = {
-	.drv = {
-		.probe = dev_dax_kmem_probe,
-		.remove = dev_dax_kmem_remove,
-	},
+	.probe = dev_dax_kmem_probe,
+	.remove = dev_dax_kmem_remove,
 };
 
 static int __init dax_kmem_init(void)
diff --git a/drivers/dax/pmem/compat.c b/drivers/dax/pmem/compat.c
index d7b15e6f30c5..863c114fd88c 100644
--- a/drivers/dax/pmem/compat.c
+++ b/drivers/dax/pmem/compat.c
@@ -22,7 +22,7 @@ static int dax_pmem_compat_probe(struct device *dev)
 		return -ENOMEM;
 
 	device_lock(&dev_dax->dev);
-	rc = dev_dax_probe(&dev_dax->dev);
+	rc = dev_dax_probe(dev_dax);
 	device_unlock(&dev_dax->dev);
 
 	devres_close_group(&dev_dax->dev, dev_dax);
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (15 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 16/22] device-dax: Introduce 'seed' devices Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 17:09   ` Greg Kroah-Hartman
  2020-07-12 16:27 ` [PATCH v2 18/22] device-dax: Add resize support Dan Williams
                   ` (5 subsequent siblings)
  22 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Greg Kroah-Hartman, Rafael J. Wysocki, peterz, dave.hansen,
	ard.biesheuvel, linux-mm, linux-kernel, linux-acpi, hch,
	joao.m.martins

Use sysfs_streq() in device_find_child_by_name() to allow it to use a
sysfs input string that might contain a trailing newline.

The other "device by name" interfaces,
{bus,driver,class}_find_device_by_name(), already account for sysfs
strings.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/base/core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 67d39a90b45c..5d31b962c898 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3078,7 +3078,7 @@ struct device *device_find_child_by_name(struct device *parent,
 
 	klist_iter_init(&parent->p->klist_children, &i);
 	while ((child = next_device(&i)))
-		if (!strcmp(dev_name(child), name) && get_device(child))
+		if (sysfs_streq(dev_name(child), name) && get_device(child))
 			break;
 	klist_iter_exit(&i);
 	return child;
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 18/22] device-dax: Add resize support
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (16 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 19/22] mm/memremap_pages: Convert to 'struct range' Dan Williams
                   ` (4 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: peterz, dave.hansen, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

Make the device-dax 'size' attribute writable to allow capacity to be
split between multiple instances in a region. The intended consumers of
this capability are users that want to split a scarce memory resource
between device-dax and System-RAM access, or users that want to have
multiple security domains for a large region.

By default the hmem instance provider allocates an entire region to the
first instance. The process of creating a new instance (assuming a
region-id of 0) is find the region and trigger the 'create' attribute
which yields an empty instance to configure. For example:

    cd /sys/bus/dax/devices
    echo dax0.0 > dax0.0/driver/unbind
    echo $new_size > dax0.0/size
    echo 1 > $(readlink -f dax0.0)../dax_region/create
    seed=$(cat $(readlink -f dax0.0)../dax_region/seed)
    echo $new_size > $seed/size
    echo dax0.0 > ../drivers/{device_dax,kmem}/bind
    echo dax0.1 > ../drivers/{device_dax,kmem}/bind

Instances can be destroyed by:

    echo $device > $(readlink -f $device)../dax_region/delete

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c |  161 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 152 insertions(+), 9 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index dce9413a4394..85ff6ee3a5c5 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -6,6 +6,7 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/dax.h>
+#include <linux/io.h>
 #include "dax-private.h"
 #include "bus.h"
 
@@ -562,7 +563,8 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 }
 EXPORT_SYMBOL_GPL(alloc_dax_region);
 
-static int alloc_dev_dax_range(struct dev_dax *dev_dax, resource_size_t size)
+static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
+		resource_size_t size)
 {
 	struct dax_region *dax_region = dev_dax->region;
 	struct resource *res = &dax_region->res;
@@ -580,12 +582,7 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, resource_size_t size)
 		return 0;
 	}
 
-	/* TODO: handle multiple allocations per region */
-	if (res->child)
-		return -ENOMEM;
-
-	alloc = __request_region(res, res->start, size, dev_name(dev), 0);
-
+	alloc = __request_region(res, start, size, dev_name(dev), 0);
 	if (!alloc)
 		return -ENOMEM;
 
@@ -597,6 +594,29 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, resource_size_t size)
 	return 0;
 }
 
+static int adjust_dev_dax_range(struct dev_dax *dev_dax, struct resource *res, resource_size_t size)
+{
+	struct dax_region *dax_region = dev_dax->region;
+	struct range *range = &dev_dax->range;
+	int rc = 0;
+
+	device_lock_assert(dax_region->dev);
+
+	if (size)
+		rc = adjust_resource(res, range->start, size);
+	else
+		__release_region(&dax_region->res, range->start, range_len(range));
+	if (rc)
+		return rc;
+
+	dev_dax->range = (struct range) {
+		.start = range->start,
+		.end = range->start + size - 1,
+	};
+
+	return 0;
+}
+
 static ssize_t size_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
@@ -605,7 +625,127 @@ static ssize_t size_show(struct device *dev,
 
 	return sprintf(buf, "%llu\n", size);
 }
-static DEVICE_ATTR_RO(size);
+
+static bool alloc_is_aligned(struct dax_region *dax_region,
+		resource_size_t size)
+{
+	/*
+	 * The minimum mapping granularity for a device instance is a
+	 * single subsection, unless the arch says otherwise.
+	 */
+	return IS_ALIGNED(size, max_t(unsigned long, dax_region->align,
+				memremap_compat_align()));
+}
+
+static int dev_dax_shrink(struct dev_dax *dev_dax, resource_size_t size)
+{
+	struct dax_region *dax_region = dev_dax->region;
+	struct range *range = &dev_dax->range;
+	struct resource *res, *adjust = NULL;
+	struct device *dev = &dev_dax->dev;
+
+	for_each_dax_region_resource(dax_region, res)
+		if (strcmp(res->name, dev_name(dev)) == 0
+				&& res->start == range->start) {
+			adjust = res;
+			break;
+		}
+
+	if (dev_WARN_ONCE(dev, !adjust, "failed to find matching resource\n"))
+		return -ENXIO;
+	return __adjust_dev_dax_range(dev_dax, adjust, size);
+}
+
+static ssize_t dev_dax_resize(struct dax_region *dax_region,
+		struct dev_dax *dev_dax, resource_size_t size)
+{
+	resource_size_t avail = dax_region_avail_size(dax_region), to_alloc;
+	resource_size_t dev_size = range_len(&dev_dax->range);
+	struct resource *region_res = &dax_region->res;
+	struct device *dev = &dev_dax->dev;
+	const char *name = dev_name(dev);
+	struct resource *res, *first;
+
+	if (dev->driver)
+		return -EBUSY;
+	if (size == dev_size)
+		return 0;
+	if (size > dev_size && size - dev_size > avail)
+		return -ENOSPC;
+	if (size < dev_size)
+		return dev_dax_shrink(dev_dax, size);
+
+	to_alloc = size - dev_size;
+	if (dev_WARN_ONCE(dev, !alloc_is_aligned(dax_region, to_alloc),
+			"resize of %pa misaligned\n", &to_alloc))
+		return -ENXIO;
+
+	/*
+	 * Expand the device into the unused portion of the region. This
+	 * may involve adjusting the end of an existing resource, or
+	 * allocating a new resource.
+	 */
+	first = region_res->child;
+	if (!first)
+		return alloc_dev_dax_range(dev_dax, dax_region->res.start, to_alloc);
+	for (res = first; to_alloc && res; res = res->sibling) {
+		struct resource *next = res->sibling;
+		resource_size_t free;
+
+		/* space at the beginning of the region */
+		free = 0;
+		if (res == first && res->start > dax_region->res.start)
+			free = res->start - dax_region->res.start;
+		if (free >= to_alloc && dev_size == 0)
+			return alloc_dev_dax_range(dev_dax, dax_region->res.start, to_alloc);
+
+		free = 0;
+		/* space between allocations */
+		if (next && next->start > res->end + 1)
+			free = next->start - res->end + 1;
+
+		/* space at the end of the region */
+		if (free < to_alloc && !next && res->end < region_res->end)
+			free = region_res->end - res->end;
+
+		if (free >= to_alloc && strcmp(name, res->name) == 0)
+			return adjust_dev_dax_range(dev_dax, res, resource_size(res) + to_alloc);
+		else if (free >= to_alloc && dev_size == 0)
+			return alloc_dev_dax_range(dev_dax, res->end + 1, to_alloc);
+	}
+	return -ENOSPC;
+}
+
+static ssize_t size_store(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t len)
+{
+	ssize_t rc;
+	unsigned long long val;
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+	struct dax_region *dax_region = dev_dax->region;
+
+	rc = kstrtoull(buf, 0, &val);
+	if (rc)
+		return rc;
+
+	if (!alloc_is_aligned(dax_region, val)) {
+		dev_dbg(dev, "%s: size: %lld misaligned\n", __func__, val);
+		return -EINVAL;
+	}
+
+	device_lock(dax_region->dev);
+	if (!dax_region->dev->driver) {
+		device_unlock(dax_region->dev);
+		return -ENXIO;
+	}
+	device_lock(dev);
+	rc = dev_dax_resize(dax_region, dev_dax, val);
+	device_unlock(dev);
+	device_unlock(dax_region->dev);
+
+	return rc == 0 ? len : rc;
+}
+static DEVICE_ATTR_RW(size);
 
 static int dev_dax_target_node(struct dev_dax *dev_dax)
 {
@@ -654,11 +794,14 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n)
 {
 	struct device *dev = container_of(kobj, struct device, kobj);
 	struct dev_dax *dev_dax = to_dev_dax(dev);
+	struct dax_region *dax_region = dev_dax->region;
 
 	if (a == &dev_attr_target_node.attr && dev_dax_target_node(dev_dax) < 0)
 		return 0;
 	if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA))
 		return 0;
+	if (a == &dev_attr_size.attr && is_static(dax_region))
+		return 0444;
 	return a->mode;
 }
 
@@ -739,7 +882,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	device_initialize(dev);
 	dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
 
-	rc = alloc_dev_dax_range(dev_dax, data->size);
+	rc = alloc_dev_dax_range(dev_dax, dax_region->res.start, data->size);
 	if (rc)
 		goto err_range;
 
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 19/22] mm/memremap_pages: Convert to 'struct range'
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (17 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 18/22] device-dax: Add resize support Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-13 16:36   ` Ralph Campbell
  2020-07-12 16:27 ` [PATCH v2 20/22] mm/memremap_pages: Support multiple ranges per invocation Dan Williams
                   ` (3 subsequent siblings)
  22 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Paul Mackerras, Michael Ellerman, Benjamin Herrenschmidt,
	Ben Skeggs, David Airlie, Daniel Vetter, Jason Gunthorpe, peterz,
	dave.hansen, ard.biesheuvel, linux-mm, linux-kernel, linux-acpi,
	hch, joao.m.martins

The 'struct resource' in 'struct dev_pagemap' is only used for holding
resource span information. The other fields, 'name', 'flags', 'desc',
'parent', 'sibling', and 'child' are all unused wasted space.

This is in preparation for introducing a multi-range extension of
devm_memremap_pages().

The bulk of this change is unwinding all the places internal to
libnvdimm that used 'struct resource' unnecessarily.

P2PDMA had a minor usage of the flags field, but only to report failures
with "%pR". That is replaced with an open coded print of the range.

Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/powerpc/kvm/book3s_hv_uvmem.c     |   13 +++--
 drivers/dax/bus.c                      |   10 ++--
 drivers/dax/bus.h                      |    2 -
 drivers/dax/dax-private.h              |    5 --
 drivers/dax/device.c                   |    3 -
 drivers/dax/hmem/hmem.c                |    5 ++
 drivers/dax/pmem/core.c                |   12 ++---
 drivers/gpu/drm/nouveau/nouveau_dmem.c |    3 +
 drivers/nvdimm/badrange.c              |   26 +++++------
 drivers/nvdimm/claim.c                 |   13 +++--
 drivers/nvdimm/nd.h                    |    3 +
 drivers/nvdimm/pfn_devs.c              |   12 ++---
 drivers/nvdimm/pmem.c                  |   26 ++++++-----
 drivers/nvdimm/region.c                |   21 +++++----
 drivers/pci/p2pdma.c                   |   11 ++---
 include/linux/memremap.h               |    5 +-
 include/linux/range.h                  |    6 ++
 mm/memremap.c                          |   77 ++++++++++++++++----------------
 tools/testing/nvdimm/test/iomap.c      |    2 -
 19 files changed, 135 insertions(+), 120 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 09d8119024db..a3032cc9a4da 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -343,9 +343,9 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm)
 	struct kvmppc_uvmem_page_pvt *pvt;
 	unsigned long pfn_last, pfn_first;
 
-	pfn_first = kvmppc_uvmem_pgmap.res.start >> PAGE_SHIFT;
+	pfn_first = kvmppc_uvmem_pgmap.range.start >> PAGE_SHIFT;
 	pfn_last = pfn_first +
-		   (resource_size(&kvmppc_uvmem_pgmap.res) >> PAGE_SHIFT);
+		   (range_len(&kvmppc_uvmem_pgmap.range) >> PAGE_SHIFT);
 
 	spin_lock(&kvmppc_uvmem_bitmap_lock);
 	bit = find_first_zero_bit(kvmppc_uvmem_bitmap,
@@ -661,7 +661,7 @@ static vm_fault_t kvmppc_uvmem_migrate_to_ram(struct vm_fault *vmf)
 static void kvmppc_uvmem_page_free(struct page *page)
 {
 	unsigned long pfn = page_to_pfn(page) -
-			(kvmppc_uvmem_pgmap.res.start >> PAGE_SHIFT);
+			(kvmppc_uvmem_pgmap.range.start >> PAGE_SHIFT);
 	struct kvmppc_uvmem_page_pvt *pvt;
 
 	spin_lock(&kvmppc_uvmem_bitmap_lock);
@@ -806,7 +806,8 @@ int kvmppc_uvmem_init(void)
 	}
 
 	kvmppc_uvmem_pgmap.type = MEMORY_DEVICE_PRIVATE;
-	kvmppc_uvmem_pgmap.res = *res;
+	kvmppc_uvmem_pgmap.range.start = res->start;
+	kvmppc_uvmem_pgmap.range.end = res->end;
 	kvmppc_uvmem_pgmap.ops = &kvmppc_uvmem_ops;
 	/* just one global instance: */
 	kvmppc_uvmem_pgmap.owner = &kvmppc_uvmem_pgmap;
@@ -841,7 +842,7 @@ void kvmppc_uvmem_free(void)
 		return;
 
 	memunmap_pages(&kvmppc_uvmem_pgmap);
-	release_mem_region(kvmppc_uvmem_pgmap.res.start,
-			   resource_size(&kvmppc_uvmem_pgmap.res));
+	release_mem_region(kvmppc_uvmem_pgmap.range.start,
+			   range_len(&kvmppc_uvmem_pgmap.range));
 	kfree(kvmppc_uvmem_bitmap);
 }
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 85ff6ee3a5c5..aca7914287f5 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -515,7 +515,7 @@ static void dax_region_unregister(void *region)
 }
 
 struct dax_region *alloc_dax_region(struct device *parent, int region_id,
-		struct resource *res, int target_node, unsigned int align,
+		struct range *range, int target_node, unsigned int align,
 		unsigned long flags)
 {
 	struct dax_region *dax_region;
@@ -530,8 +530,8 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 		return NULL;
 	}
 
-	if (!IS_ALIGNED(res->start, align)
-			|| !IS_ALIGNED(resource_size(res), align))
+	if (!IS_ALIGNED(range->start, align)
+			|| !IS_ALIGNED(range_len(range), align))
 		return NULL;
 
 	dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL);
@@ -546,8 +546,8 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 	dax_region->target_node = target_node;
 	ida_init(&dax_region->ida);
 	dax_region->res = (struct resource) {
-		.start = res->start,
-		.end = res->end,
+		.start = range->start,
+		.end = range->end,
 		.flags = IORESOURCE_MEM | flags,
 	};
 
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index da27ea70a19a..72b92f95509f 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -13,7 +13,7 @@ void dax_region_put(struct dax_region *dax_region);
 
 #define IORESOURCE_DAX_STATIC (1UL << 0)
 struct dax_region *alloc_dax_region(struct device *parent, int region_id,
-		struct resource *res, int target_node, unsigned int align,
+		struct range *range, int target_node, unsigned int align,
 		unsigned long flags);
 
 enum dev_dax_subsys {
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index b81a1494d82b..0cbb2ec81ca7 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -61,11 +61,6 @@ struct dev_dax {
 	struct range range;
 };
 
-static inline u64 range_len(struct range *range)
-{
-	return range->end - range->start + 1;
-}
-
 static inline struct dev_dax *to_dev_dax(struct device *dev)
 {
 	return container_of(dev, struct dev_dax, dev);
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 5496331f6eb6..fffc54ce0911 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -416,8 +416,7 @@ int dev_dax_probe(struct dev_dax *dev_dax)
 		pgmap = devm_kzalloc(dev, sizeof(*pgmap), GFP_KERNEL);
 		if (!pgmap)
 			return -ENOMEM;
-		pgmap->res.start = range->start;
-		pgmap->res.end = range->end;
+		pgmap->range = *range;
 	}
 	pgmap->type = MEMORY_DEVICE_DEVDAX;
 	addr = devm_memremap_pages(dev, pgmap);
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index aa260009dfc7..1a3347bb6143 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -13,13 +13,16 @@ static int dax_hmem_probe(struct platform_device *pdev)
 	struct dev_dax_data data;
 	struct dev_dax *dev_dax;
 	struct resource *res;
+	struct range range;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENOMEM;
 
 	mri = dev->platform_data;
-	dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node,
+	range.start = res->start;
+	range.end = res->end;
+	dax_region = alloc_dax_region(dev, pdev->id, &range, mri->target_node,
 			PMD_SIZE, 0);
 	if (!dax_region)
 		return -ENOMEM;
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
index 4fe700884338..62b26bfceab1 100644
--- a/drivers/dax/pmem/core.c
+++ b/drivers/dax/pmem/core.c
@@ -9,7 +9,7 @@
 
 struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 {
-	struct resource res;
+	struct range range;
 	int rc, id, region_id;
 	resource_size_t offset;
 	struct nd_pfn_sb *pfn_sb;
@@ -50,10 +50,10 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 	if (rc != 2)
 		return ERR_PTR(-EINVAL);
 
-	/* adjust the dax_region resource to the start of data */
-	memcpy(&res, &pgmap.res, sizeof(res));
-	res.start += offset;
-	dax_region = alloc_dax_region(dev, region_id, &res,
+	/* adjust the dax_region range to the start of data */
+	range = pgmap.range;
+	range.start += offset,
+	dax_region = alloc_dax_region(dev, region_id, &range,
 			nd_region->target_node, le32_to_cpu(pfn_sb->align),
 			IORESOURCE_DAX_STATIC);
 	if (!dax_region)
@@ -64,7 +64,7 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
 		.id = id,
 		.pgmap = &pgmap,
 		.subsys = subsys,
-		.size = resource_size(&res),
+		.size = range_len(&range),
 	};
 	dev_dax = devm_create_dev_dax(&data);
 
diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index e5c230d9ae24..395a5b7cb76d 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -239,7 +239,8 @@ nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage)
 
 	chunk->drm = drm;
 	chunk->pagemap.type = MEMORY_DEVICE_PRIVATE;
-	chunk->pagemap.res = *res;
+	chunk->pagemap.range.start = res->start;
+	chunk->pagemap.range.end = res->end;
 	chunk->pagemap.ops = &nouveau_dmem_pagemap_ops;
 	chunk->pagemap.owner = drm->dev;
 
diff --git a/drivers/nvdimm/badrange.c b/drivers/nvdimm/badrange.c
index b9eeefa27e3a..aaf6e215a8c6 100644
--- a/drivers/nvdimm/badrange.c
+++ b/drivers/nvdimm/badrange.c
@@ -211,7 +211,7 @@ static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
 }
 
 static void badblocks_populate(struct badrange *badrange,
-		struct badblocks *bb, const struct resource *res)
+		struct badblocks *bb, const struct range *range)
 {
 	struct badrange_entry *bre;
 
@@ -222,34 +222,34 @@ static void badblocks_populate(struct badrange *badrange,
 		u64 bre_end = bre->start + bre->length - 1;
 
 		/* Discard intervals with no intersection */
-		if (bre_end < res->start)
+		if (bre_end < range->start)
 			continue;
-		if (bre->start >  res->end)
+		if (bre->start > range->end)
 			continue;
 		/* Deal with any overlap after start of the namespace */
-		if (bre->start >= res->start) {
+		if (bre->start >= range->start) {
 			u64 start = bre->start;
 			u64 len;
 
-			if (bre_end <= res->end)
+			if (bre_end <= range->end)
 				len = bre->length;
 			else
-				len = res->start + resource_size(res)
+				len = range->start + range_len(range)
 					- bre->start;
-			__add_badblock_range(bb, start - res->start, len);
+			__add_badblock_range(bb, start - range->start, len);
 			continue;
 		}
 		/*
 		 * Deal with overlap for badrange starting before
 		 * the namespace.
 		 */
-		if (bre->start < res->start) {
+		if (bre->start < range->start) {
 			u64 len;
 
-			if (bre_end < res->end)
-				len = bre->start + bre->length - res->start;
+			if (bre_end < range->end)
+				len = bre->start + bre->length - range->start;
 			else
-				len = resource_size(res);
+				len = range_len(range);
 			__add_badblock_range(bb, 0, len);
 		}
 	}
@@ -267,7 +267,7 @@ static void badblocks_populate(struct badrange *badrange,
  * and add badblocks entries for all matching sub-ranges
  */
 void nvdimm_badblocks_populate(struct nd_region *nd_region,
-		struct badblocks *bb, const struct resource *res)
+		struct badblocks *bb, const struct range *range)
 {
 	struct nvdimm_bus *nvdimm_bus;
 
@@ -279,7 +279,7 @@ void nvdimm_badblocks_populate(struct nd_region *nd_region,
 	nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 
 	nvdimm_bus_lock(&nvdimm_bus->dev);
-	badblocks_populate(&nvdimm_bus->badrange, bb, res);
+	badblocks_populate(&nvdimm_bus->badrange, bb, range);
 	nvdimm_bus_unlock(&nvdimm_bus->dev);
 }
 EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 45964acba944..290267e1ff9f 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -303,13 +303,16 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
 int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
 		resource_size_t size)
 {
-	struct resource *res = &nsio->res;
 	struct nd_namespace_common *ndns = &nsio->common;
+	struct range range = {
+		.start = nsio->res.start,
+		.end = nsio->res.end,
+	};
 
 	nsio->size = size;
-	if (!devm_request_mem_region(dev, res->start, size,
+	if (!devm_request_mem_region(dev, range.start, size,
 				dev_name(&ndns->dev))) {
-		dev_warn(dev, "could not reserve region %pR\n", res);
+		dev_warn(dev, "could not reserve region %pR\n", &nsio->res);
 		return -EBUSY;
 	}
 
@@ -317,9 +320,9 @@ int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
 	if (devm_init_badblocks(dev, &nsio->bb))
 		return -ENOMEM;
 	nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
-			&nsio->res);
+			&range);
 
-	nsio->addr = devm_memremap(dev, res->start, size, ARCH_MEMREMAP_PMEM);
+	nsio->addr = devm_memremap(dev, range.start, size, ARCH_MEMREMAP_PMEM);
 
 	return PTR_ERR_OR_ZERO(nsio->addr);
 }
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 85c1ae813ea3..bac90afa4604 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -377,8 +377,9 @@ int nvdimm_namespace_detach_btt(struct nd_btt *nd_btt);
 const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
 		char *name);
 unsigned int pmem_sector_size(struct nd_namespace_common *ndns);
+struct range;
 void nvdimm_badblocks_populate(struct nd_region *nd_region,
-		struct badblocks *bb, const struct resource *res);
+		struct badblocks *bb, const struct range *range);
 int devm_namespace_enable(struct device *dev, struct nd_namespace_common *ndns,
 		resource_size_t size);
 void devm_namespace_disable(struct device *dev,
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 34db557dbad1..7ad9ea107810 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -672,7 +672,7 @@ static unsigned long init_altmap_reserve(resource_size_t base)
 
 static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
 {
-	struct resource *res = &pgmap->res;
+	struct range *range = &pgmap->range;
 	struct vmem_altmap *altmap = &pgmap->altmap;
 	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 	u64 offset = le64_to_cpu(pfn_sb->dataoff);
@@ -689,16 +689,16 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
 		.end_pfn = PHYS_PFN(end),
 	};
 
-	memcpy(res, &nsio->res, sizeof(*res));
-	res->start += start_pad;
-	res->end -= end_trunc;
-
+	*range = (struct range) {
+		.start = nsio->res.start + start_pad,
+		.end = nsio->res.end - end_trunc,
+	};
 	if (nd_pfn->mode == PFN_MODE_RAM) {
 		if (offset < reserve)
 			return -EINVAL;
 		nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
 	} else if (nd_pfn->mode == PFN_MODE_PMEM) {
-		nd_pfn->npfns = PHYS_PFN((resource_size(res) - offset));
+		nd_pfn->npfns = PHYS_PFN((range_len(range) - offset));
 		if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
 			dev_info(&nd_pfn->dev,
 					"number of pfns truncated from %lld to %ld\n",
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index d25e66fd942d..08efe0cc9903 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -377,7 +377,7 @@ static int pmem_attach_disk(struct device *dev,
 	struct nd_region *nd_region = to_nd_region(dev->parent);
 	int nid = dev_to_node(dev), fua;
 	struct resource *res = &nsio->res;
-	struct resource bb_res;
+	struct range bb_range;
 	struct nd_pfn *nd_pfn = NULL;
 	struct dax_device *dax_dev;
 	struct nd_pfn_sb *pfn_sb;
@@ -436,24 +436,26 @@ static int pmem_attach_disk(struct device *dev,
 		pfn_sb = nd_pfn->pfn_sb;
 		pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
 		pmem->pfn_pad = resource_size(res) -
-			resource_size(&pmem->pgmap.res);
+			range_len(&pmem->pgmap.range);
 		pmem->pfn_flags |= PFN_MAP;
-		memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
-		bb_res.start += pmem->data_offset;
+		bb_range = pmem->pgmap.range;
+		bb_range.start += pmem->data_offset;
 	} else if (pmem_should_map_pages(dev)) {
-		memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
+		pmem->pgmap.range.start = res->start;
+		pmem->pgmap.range.end = res->end;
 		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
 		pmem->pgmap.ops = &fsdax_pagemap_ops;
 		addr = devm_memremap_pages(dev, &pmem->pgmap);
 		pmem->pfn_flags |= PFN_MAP;
-		memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
+		bb_range = pmem->pgmap.range;
 	} else {
 		if (devm_add_action_or_reset(dev, pmem_release_queue,
 					&pmem->pgmap))
 			return -ENOMEM;
 		addr = devm_memremap(dev, pmem->phys_addr,
 				pmem->size, ARCH_MEMREMAP_PMEM);
-		memcpy(&bb_res, &nsio->res, sizeof(bb_res));
+		bb_range.start =  res->start;
+		bb_range.end = res->end;
 	}
 
 	if (IS_ERR(addr))
@@ -483,7 +485,7 @@ static int pmem_attach_disk(struct device *dev,
 			/ 512);
 	if (devm_init_badblocks(dev, &pmem->bb))
 		return -ENOMEM;
-	nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
+	nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range);
 	disk->bb = &pmem->bb;
 
 	if (is_nvdimm_sync(nd_region))
@@ -594,8 +596,8 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
 	resource_size_t offset = 0, end_trunc = 0;
 	struct nd_namespace_common *ndns;
 	struct nd_namespace_io *nsio;
-	struct resource res;
 	struct badblocks *bb;
+	struct range range;
 	struct kernfs_node *bb_state;
 
 	if (event != NVDIMM_REVALIDATE_POISON)
@@ -631,9 +633,9 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
 		nsio = to_nd_namespace_io(&ndns->dev);
 	}
 
-	res.start = nsio->res.start + offset;
-	res.end = nsio->res.end - end_trunc;
-	nvdimm_badblocks_populate(nd_region, bb, &res);
+	range.start = nsio->res.start + offset;
+	range.end = nsio->res.end - end_trunc;
+	nvdimm_badblocks_populate(nd_region, bb, &range);
 	if (bb_state)
 		sysfs_notify_dirent(bb_state);
 }
diff --git a/drivers/nvdimm/region.c b/drivers/nvdimm/region.c
index 0f6978e72e7c..bfce87ed72ab 100644
--- a/drivers/nvdimm/region.c
+++ b/drivers/nvdimm/region.c
@@ -35,7 +35,10 @@ static int nd_region_probe(struct device *dev)
 		return rc;
 
 	if (is_memory(&nd_region->dev)) {
-		struct resource ndr_res;
+		struct range range = {
+			.start = nd_region->ndr_start,
+			.end = nd_region->ndr_start + nd_region->ndr_size - 1,
+		};
 
 		if (devm_init_badblocks(dev, &nd_region->bb))
 			return -ENODEV;
@@ -44,9 +47,7 @@ static int nd_region_probe(struct device *dev)
 		if (!nd_region->bb_state)
 			dev_warn(&nd_region->dev,
 					"'badblocks' notification disabled\n");
-		ndr_res.start = nd_region->ndr_start;
-		ndr_res.end = nd_region->ndr_start + nd_region->ndr_size - 1;
-		nvdimm_badblocks_populate(nd_region, &nd_region->bb, &ndr_res);
+		nvdimm_badblocks_populate(nd_region, &nd_region->bb, &range);
 	}
 
 	rc = nd_region_register_namespaces(nd_region, &err);
@@ -121,14 +122,16 @@ static void nd_region_notify(struct device *dev, enum nvdimm_event event)
 {
 	if (event == NVDIMM_REVALIDATE_POISON) {
 		struct nd_region *nd_region = to_nd_region(dev);
-		struct resource res;
 
 		if (is_memory(&nd_region->dev)) {
-			res.start = nd_region->ndr_start;
-			res.end = nd_region->ndr_start +
-				nd_region->ndr_size - 1;
+			struct range range = {
+				.start = nd_region->ndr_start,
+				.end = nd_region->ndr_start +
+					nd_region->ndr_size - 1,
+			};
+
 			nvdimm_badblocks_populate(nd_region,
-					&nd_region->bb, &res);
+					&nd_region->bb, &range);
 			if (nd_region->bb_state)
 				sysfs_notify_dirent(nd_region->bb_state);
 		}
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index e8e444eeb1cd..5ed28a8c7264 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -185,9 +185,8 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
 		return -ENOMEM;
 
 	pgmap = &p2p_pgmap->pgmap;
-	pgmap->res.start = pci_resource_start(pdev, bar) + offset;
-	pgmap->res.end = pgmap->res.start + size - 1;
-	pgmap->res.flags = pci_resource_flags(pdev, bar);
+	pgmap->range.start = pci_resource_start(pdev, bar) + offset;
+	pgmap->range.end = pgmap->range.start + size - 1;
 	pgmap->type = MEMORY_DEVICE_PCI_P2PDMA;
 
 	p2p_pgmap->provider = pdev;
@@ -202,13 +201,13 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
 
 	error = gen_pool_add_owner(pdev->p2pdma->pool, (unsigned long)addr,
 			pci_bus_address(pdev, bar) + offset,
-			resource_size(&pgmap->res), dev_to_node(&pdev->dev),
+			range_len(&pgmap->range), dev_to_node(&pdev->dev),
 			pgmap->ref);
 	if (error)
 		goto pages_free;
 
-	pci_info(pdev, "added peer-to-peer DMA memory %pR\n",
-		 &pgmap->res);
+	pci_info(pdev, "added peer-to-peer DMA memory %#llx-%#llx\n",
+		 pgmap->range.start, pgmap->range.end);
 
 	return 0;
 
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 5f5b2df06e61..d5d5e37db916 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_MEMREMAP_H_
 #define _LINUX_MEMREMAP_H_
+#include <linux/range.h>
 #include <linux/ioport.h>
 #include <linux/percpu-refcount.h>
 
@@ -94,7 +95,7 @@ struct dev_pagemap_ops {
 /**
  * struct dev_pagemap - metadata for ZONE_DEVICE mappings
  * @altmap: pre-allocated/reserved memory for vmemmap allocations
- * @res: physical address range covered by @ref
+ * @range: physical address range covered by @ref
  * @ref: reference count that pins the devm_memremap_pages() mapping
  * @internal_ref: internal reference if @ref is not provided by the caller
  * @done: completion for @internal_ref
@@ -107,7 +108,7 @@ struct dev_pagemap_ops {
  */
 struct dev_pagemap {
 	struct vmem_altmap altmap;
-	struct resource res;
+	struct range range;
 	struct percpu_ref *ref;
 	struct percpu_ref internal_ref;
 	struct completion done;
diff --git a/include/linux/range.h b/include/linux/range.h
index d1fbeb664012..274681cc3154 100644
--- a/include/linux/range.h
+++ b/include/linux/range.h
@@ -1,12 +1,18 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_RANGE_H
 #define _LINUX_RANGE_H
+#include <linux/types.h>
 
 struct range {
 	u64   start;
 	u64   end;
 };
 
+static inline u64 range_len(const struct range *range)
+{
+	return range->end - range->start + 1;
+}
+
 int add_range(struct range *range, int az, int nr_range,
 		u64 start, u64 end);
 
diff --git a/mm/memremap.c b/mm/memremap.c
index 03e38b7a38f1..91a79a958f66 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -70,24 +70,24 @@ static void devmap_managed_enable_put(void)
 }
 #endif /* CONFIG_DEV_PAGEMAP_OPS */
 
-static void pgmap_array_delete(struct resource *res)
+static void pgmap_array_delete(struct range *range)
 {
-	xa_store_range(&pgmap_array, PHYS_PFN(res->start), PHYS_PFN(res->end),
+	xa_store_range(&pgmap_array, PHYS_PFN(range->start), PHYS_PFN(range->end),
 			NULL, GFP_KERNEL);
 	synchronize_rcu();
 }
 
 static unsigned long pfn_first(struct dev_pagemap *pgmap)
 {
-	return PHYS_PFN(pgmap->res.start) +
+	return PHYS_PFN(pgmap->range.start) +
 		vmem_altmap_offset(pgmap_altmap(pgmap));
 }
 
 static unsigned long pfn_end(struct dev_pagemap *pgmap)
 {
-	const struct resource *res = &pgmap->res;
+	const struct range *range = &pgmap->range;
 
-	return (res->start + resource_size(res)) >> PAGE_SHIFT;
+	return (range->start + range_len(range)) >> PAGE_SHIFT;
 }
 
 static unsigned long pfn_next(unsigned long pfn)
@@ -126,7 +126,7 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap)
 
 void memunmap_pages(struct dev_pagemap *pgmap)
 {
-	struct resource *res = &pgmap->res;
+	struct range *range = &pgmap->range;
 	struct page *first_page;
 	unsigned long pfn;
 	int nid;
@@ -143,20 +143,20 @@ void memunmap_pages(struct dev_pagemap *pgmap)
 	nid = page_to_nid(first_page);
 
 	mem_hotplug_begin();
-	remove_pfn_range_from_zone(page_zone(first_page), PHYS_PFN(res->start),
-				   PHYS_PFN(resource_size(res)));
+	remove_pfn_range_from_zone(page_zone(first_page), PHYS_PFN(range->start),
+				   PHYS_PFN(range_len(range)));
 	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
-		__remove_pages(PHYS_PFN(res->start),
-			       PHYS_PFN(resource_size(res)), NULL);
+		__remove_pages(PHYS_PFN(range->start),
+			       PHYS_PFN(range_len(range)), NULL);
 	} else {
-		arch_remove_memory(nid, res->start, resource_size(res),
+		arch_remove_memory(nid, range->start, range_len(range),
 				pgmap_altmap(pgmap));
-		kasan_remove_zero_shadow(__va(res->start), resource_size(res));
+		kasan_remove_zero_shadow(__va(range->start), range_len(range));
 	}
 	mem_hotplug_done();
 
-	untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
-	pgmap_array_delete(res);
+	untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
+	pgmap_array_delete(range);
 	WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
 	devmap_managed_enable_put();
 }
@@ -182,7 +182,7 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref)
  */
 void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 {
-	struct resource *res = &pgmap->res;
+	struct range *range = &pgmap->range;
 	struct dev_pagemap *conflict_pgmap;
 	struct mhp_params params = {
 		/*
@@ -251,7 +251,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 			return ERR_PTR(error);
 	}
 
-	conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->start), NULL);
+	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->start), NULL);
 	if (conflict_pgmap) {
 		WARN(1, "Conflicting mapping in same section\n");
 		put_dev_pagemap(conflict_pgmap);
@@ -259,7 +259,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 		goto err_array;
 	}
 
-	conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->end), NULL);
+	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->end), NULL);
 	if (conflict_pgmap) {
 		WARN(1, "Conflicting mapping in same section\n");
 		put_dev_pagemap(conflict_pgmap);
@@ -267,26 +267,27 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 		goto err_array;
 	}
 
-	is_ram = region_intersects(res->start, resource_size(res),
+	is_ram = region_intersects(range->start, range_len(range),
 		IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
 
 	if (is_ram != REGION_DISJOINT) {
-		WARN_ONCE(1, "%s attempted on %s region %pr\n", __func__,
-				is_ram == REGION_MIXED ? "mixed" : "ram", res);
+		WARN_ONCE(1, "attempted on %s region %#llx-%#llx\n",
+				is_ram == REGION_MIXED ? "mixed" : "ram",
+				range->start, range->end);
 		error = -ENXIO;
 		goto err_array;
 	}
 
-	error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(res->start),
-				PHYS_PFN(res->end), pgmap, GFP_KERNEL));
+	error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(range->start),
+				PHYS_PFN(range->end), pgmap, GFP_KERNEL));
 	if (error)
 		goto err_array;
 
 	if (nid < 0)
 		nid = numa_mem_id();
 
-	error = track_pfn_remap(NULL, &params.pgprot, PHYS_PFN(res->start),
-				0, resource_size(res));
+	error = track_pfn_remap(NULL, &params.pgprot, PHYS_PFN(range->start), 0,
+			range_len(range));
 	if (error)
 		goto err_pfn_remap;
 
@@ -304,16 +305,16 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 	 * arch_add_memory().
 	 */
 	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
-		error = add_pages(nid, PHYS_PFN(res->start),
-				PHYS_PFN(resource_size(res)), &params);
+		error = add_pages(nid, PHYS_PFN(range->start),
+				PHYS_PFN(range_len(range)), &params);
 	} else {
-		error = kasan_add_zero_shadow(__va(res->start), resource_size(res));
+		error = kasan_add_zero_shadow(__va(range->start), range_len(range));
 		if (error) {
 			mem_hotplug_done();
 			goto err_kasan;
 		}
 
-		error = arch_add_memory(nid, res->start, resource_size(res),
+		error = arch_add_memory(nid, range->start, range_len(range),
 					&params);
 	}
 
@@ -321,8 +322,8 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 		struct zone *zone;
 
 		zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
-		move_pfn_range_to_zone(zone, PHYS_PFN(res->start),
-				PHYS_PFN(resource_size(res)), params.altmap);
+		move_pfn_range_to_zone(zone, PHYS_PFN(range->start),
+				PHYS_PFN(range_len(range)), params.altmap);
 	}
 
 	mem_hotplug_done();
@@ -334,17 +335,17 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 	 * to allow us to do the work while not holding the hotplug lock.
 	 */
 	memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
-				PHYS_PFN(res->start),
-				PHYS_PFN(resource_size(res)), pgmap);
+				PHYS_PFN(range->start),
+				PHYS_PFN(range_len(range)), pgmap);
 	percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap));
-	return __va(res->start);
+	return __va(range->start);
 
  err_add_memory:
-	kasan_remove_zero_shadow(__va(res->start), resource_size(res));
+	kasan_remove_zero_shadow(__va(range->start), range_len(range));
  err_kasan:
-	untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
+	untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
  err_pfn_remap:
-	pgmap_array_delete(res);
+	pgmap_array_delete(range);
  err_array:
 	dev_pagemap_kill(pgmap);
 	dev_pagemap_cleanup(pgmap);
@@ -369,7 +370,7 @@ EXPORT_SYMBOL_GPL(memremap_pages);
  *    'live' on entry and will be killed and reaped at
  *    devm_memremap_pages_release() time, or if this routine fails.
  *
- * 4/ res is expected to be a host memory range that could feasibly be
+ * 4/ range is expected to be a host memory range that could feasibly be
  *    treated as a "System RAM" range, i.e. not a device mmio range, but
  *    this is not enforced.
  */
@@ -426,7 +427,7 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
 	 * In the cached case we're already holding a live reference.
 	 */
 	if (pgmap) {
-		if (phys >= pgmap->res.start && phys <= pgmap->res.end)
+		if (phys >= pgmap->range.start && phys <= pgmap->range.end)
 			return pgmap;
 		put_dev_pagemap(pgmap);
 	}
diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c
index 03e40b3b0106..c62d372d426f 100644
--- a/tools/testing/nvdimm/test/iomap.c
+++ b/tools/testing/nvdimm/test/iomap.c
@@ -126,7 +126,7 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref)
 void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 {
 	int error;
-	resource_size_t offset = pgmap->res.start;
+	resource_size_t offset = pgmap->range.start;
 	struct nfit_test_resource *nfit_res = get_nfit_res(offset);
 
 	if (!nfit_res)
_______________________________________________
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 20/22] mm/memremap_pages: Support multiple ranges per invocation
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (18 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 19/22] mm/memremap_pages: Convert to 'struct range' Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:27 ` [PATCH v2 21/22] device-dax: Add dis-contiguous resource support Dan Williams
                   ` (2 subsequent siblings)
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: Paul Mackerras, Michael Ellerman, Benjamin Herrenschmidt,
	Ben Skeggs, David Airlie, Daniel Vetter, Jason Gunthorpe, peterz,
	dave.hansen, ard.biesheuvel, linux-mm, linux-kernel, linux-acpi,
	hch, joao.m.martins

In support of device-dax growing the ability to front physically
dis-contiguous ranges of memory, update devm_memremap_pages() to track
multiple ranges with a single reference counter and devm instance.

Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/powerpc/kvm/book3s_hv_uvmem.c     |    1 
 drivers/dax/device.c                   |    1 
 drivers/gpu/drm/nouveau/nouveau_dmem.c |    1 
 drivers/nvdimm/pfn_devs.c              |    1 
 drivers/nvdimm/pmem.c                  |    1 
 drivers/pci/p2pdma.c                   |    1 
 include/linux/memremap.h               |   10 +
 mm/memremap.c                          |  259 +++++++++++++++++++-------------
 8 files changed, 165 insertions(+), 110 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index a3032cc9a4da..f5108c20d926 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -808,6 +808,7 @@ int kvmppc_uvmem_init(void)
 	kvmppc_uvmem_pgmap.type = MEMORY_DEVICE_PRIVATE;
 	kvmppc_uvmem_pgmap.range.start = res->start;
 	kvmppc_uvmem_pgmap.range.end = res->end;
+	kvmppc_uvmem_pgmap.nr_range = 1;
 	kvmppc_uvmem_pgmap.ops = &kvmppc_uvmem_ops;
 	/* just one global instance: */
 	kvmppc_uvmem_pgmap.owner = &kvmppc_uvmem_pgmap;
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index fffc54ce0911..f3755df4ae29 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -417,6 +417,7 @@ int dev_dax_probe(struct dev_dax *dev_dax)
 		if (!pgmap)
 			return -ENOMEM;
 		pgmap->range = *range;
+		pgmap->nr_range = 1;
 	}
 	pgmap->type = MEMORY_DEVICE_DEVDAX;
 	addr = devm_memremap_pages(dev, pgmap);
diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 395a5b7cb76d..ab0788dd8a97 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -241,6 +241,7 @@ nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage)
 	chunk->pagemap.type = MEMORY_DEVICE_PRIVATE;
 	chunk->pagemap.range.start = res->start;
 	chunk->pagemap.range.end = res->end;
+	chunk->pagemap.nr_range = 1;
 	chunk->pagemap.ops = &nouveau_dmem_pagemap_ops;
 	chunk->pagemap.owner = drm->dev;
 
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 7ad9ea107810..88a1aabe0657 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -693,6 +693,7 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
 		.start = nsio->res.start + start_pad,
 		.end = nsio->res.end - end_trunc,
 	};
+	pgmap->nr_range = 1;
 	if (nd_pfn->mode == PFN_MODE_RAM) {
 		if (offset < reserve)
 			return -EINVAL;
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 08efe0cc9903..705d6df43d72 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -443,6 +443,7 @@ static int pmem_attach_disk(struct device *dev,
 	} else if (pmem_should_map_pages(dev)) {
 		pmem->pgmap.range.start = res->start;
 		pmem->pgmap.range.end = res->end;
+		pmem->pgmap.nr_range = 1;
 		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
 		pmem->pgmap.ops = &fsdax_pagemap_ops;
 		addr = devm_memremap_pages(dev, &pmem->pgmap);
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 5ed28a8c7264..4ed77f0bd9e3 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -187,6 +187,7 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
 	pgmap = &p2p_pgmap->pgmap;
 	pgmap->range.start = pci_resource_start(pdev, bar) + offset;
 	pgmap->range.end = pgmap->range.start + size - 1;
+	pgmap->nr_range = 1;
 	pgmap->type = MEMORY_DEVICE_PCI_P2PDMA;
 
 	p2p_pgmap->provider = pdev;
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index d5d5e37db916..e63f3aff8f7d 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -95,7 +95,6 @@ struct dev_pagemap_ops {
 /**
  * struct dev_pagemap - metadata for ZONE_DEVICE mappings
  * @altmap: pre-allocated/reserved memory for vmemmap allocations
- * @range: physical address range covered by @ref
  * @ref: reference count that pins the devm_memremap_pages() mapping
  * @internal_ref: internal reference if @ref is not provided by the caller
  * @done: completion for @internal_ref
@@ -105,10 +104,12 @@ struct dev_pagemap_ops {
  * @owner: an opaque pointer identifying the entity that manages this
  *	instance.  Used by various helpers to make sure that no
  *	foreign ZONE_DEVICE memory is accessed.
+ * @nr_range: number of ranges to be mapped
+ * @range: range to be mapped when nr_range == 1
+ * @ranges: array of ranges to be mapped when nr_range > 1
  */
 struct dev_pagemap {
 	struct vmem_altmap altmap;
-	struct range range;
 	struct percpu_ref *ref;
 	struct percpu_ref internal_ref;
 	struct completion done;
@@ -116,6 +117,11 @@ struct dev_pagemap {
 	unsigned int flags;
 	const struct dev_pagemap_ops *ops;
 	void *owner;
+	int nr_range;
+	union {
+		struct range range;
+		struct range ranges[0];
+	};
 };
 
 static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap)
diff --git a/mm/memremap.c b/mm/memremap.c
index 91a79a958f66..a84b1d6f2ca5 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -77,15 +77,19 @@ static void pgmap_array_delete(struct range *range)
 	synchronize_rcu();
 }
 
-static unsigned long pfn_first(struct dev_pagemap *pgmap)
+static unsigned long pfn_first(struct dev_pagemap *pgmap, int range_id)
 {
-	return PHYS_PFN(pgmap->range.start) +
-		vmem_altmap_offset(pgmap_altmap(pgmap));
+	struct range *range = &pgmap->ranges[range_id];
+	unsigned long pfn = PHYS_PFN(range->start);
+
+	if (range_id)
+		return pfn;
+	return pfn + vmem_altmap_offset(pgmap_altmap(pgmap));
 }
 
-static unsigned long pfn_end(struct dev_pagemap *pgmap)
+static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id)
 {
-	const struct range *range = &pgmap->range;
+	const struct range *range = &pgmap->ranges[range_id];
 
 	return (range->start + range_len(range)) >> PAGE_SHIFT;
 }
@@ -97,8 +101,9 @@ static unsigned long pfn_next(unsigned long pfn)
 	return pfn + 1;
 }
 
-#define for_each_device_pfn(pfn, map) \
-	for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn))
+#define for_each_device_pfn(pfn, map, i) \
+	for (pfn = pfn_first(map, i); pfn < pfn_end(map, i); \
+	     pfn = pfn_next(pfn))
 
 static void dev_pagemap_kill(struct dev_pagemap *pgmap)
 {
@@ -124,20 +129,14 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap)
 		pgmap->ref = NULL;
 }
 
-void memunmap_pages(struct dev_pagemap *pgmap)
+static void pageunmap_range(struct dev_pagemap *pgmap, int range_id)
 {
-	struct range *range = &pgmap->range;
+	struct range *range = &pgmap->ranges[range_id];
 	struct page *first_page;
-	unsigned long pfn;
 	int nid;
 
-	dev_pagemap_kill(pgmap);
-	for_each_device_pfn(pfn, pgmap)
-		put_page(pfn_to_page(pfn));
-	dev_pagemap_cleanup(pgmap);
-
 	/* make sure to access a memmap that was actually initialized */
-	first_page = pfn_to_page(pfn_first(pgmap));
+	first_page = pfn_to_page(pfn_first(pgmap, range_id));
 
 	/* pages are dead and unused, undo the arch mapping */
 	nid = page_to_nid(first_page);
@@ -157,6 +156,22 @@ void memunmap_pages(struct dev_pagemap *pgmap)
 
 	untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
 	pgmap_array_delete(range);
+}
+
+void memunmap_pages(struct dev_pagemap *pgmap)
+{
+	unsigned long pfn;
+	int i;
+
+	dev_pagemap_kill(pgmap);
+	for (i = 0; i < pgmap->nr_range; i++)
+		for_each_device_pfn(pfn, pgmap, i)
+			put_page(pfn_to_page(pfn));
+	dev_pagemap_cleanup(pgmap);
+
+	for (i = 0; i < pgmap->nr_range; i++)
+		pageunmap_range(pgmap, i);
+
 	WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
 	devmap_managed_enable_put();
 }
@@ -175,96 +190,29 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref)
 	complete(&pgmap->done);
 }
 
-/*
- * Not device managed version of dev_memremap_pages, undone by
- * memunmap_pages().  Please use dev_memremap_pages if you have a struct
- * device available.
- */
-void *memremap_pages(struct dev_pagemap *pgmap, int nid)
+static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
+		int range_id, int nid)
 {
-	struct range *range = &pgmap->range;
+	struct range *range = &pgmap->ranges[range_id];
 	struct dev_pagemap *conflict_pgmap;
-	struct mhp_params params = {
-		/*
-		 * We do not want any optional features only our own memmap
-		 */
-		.altmap = pgmap_altmap(pgmap),
-		.pgprot = PAGE_KERNEL,
-	};
 	int error, is_ram;
-	bool need_devmap_managed = true;
 
-	switch (pgmap->type) {
-	case MEMORY_DEVICE_PRIVATE:
-		if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) {
-			WARN(1, "Device private memory not supported\n");
-			return ERR_PTR(-EINVAL);
-		}
-		if (!pgmap->ops || !pgmap->ops->migrate_to_ram) {
-			WARN(1, "Missing migrate_to_ram method\n");
-			return ERR_PTR(-EINVAL);
-		}
-		if (!pgmap->owner) {
-			WARN(1, "Missing owner\n");
-			return ERR_PTR(-EINVAL);
-		}
-		break;
-	case MEMORY_DEVICE_FS_DAX:
-		if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
-		    IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
-			WARN(1, "File system DAX not supported\n");
-			return ERR_PTR(-EINVAL);
-		}
-		break;
-	case MEMORY_DEVICE_DEVDAX:
-		need_devmap_managed = false;
-		break;
-	case MEMORY_DEVICE_PCI_P2PDMA:
-		params.pgprot = pgprot_noncached(params.pgprot);
-		need_devmap_managed = false;
-		break;
-	default:
-		WARN(1, "Invalid pgmap type %d\n", pgmap->type);
-		break;
-	}
-
-	if (!pgmap->ref) {
-		if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup))
-			return ERR_PTR(-EINVAL);
-
-		init_completion(&pgmap->done);
-		error = percpu_ref_init(&pgmap->internal_ref,
-				dev_pagemap_percpu_release, 0, GFP_KERNEL);
-		if (error)
-			return ERR_PTR(error);
-		pgmap->ref = &pgmap->internal_ref;
-	} else {
-		if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) {
-			WARN(1, "Missing reference count teardown definition\n");
-			return ERR_PTR(-EINVAL);
-		}
-	}
-
-	if (need_devmap_managed) {
-		error = devmap_managed_enable_get(pgmap);
-		if (error)
-			return ERR_PTR(error);
-	}
+	if (WARN_ONCE(pgmap_altmap(pgmap) && range_id > 0,
+				"altmap not supported for multiple ranges\n"))
+		return -EINVAL;
 
 	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->start), NULL);
 	if (conflict_pgmap) {
 		WARN(1, "Conflicting mapping in same section\n");
 		put_dev_pagemap(conflict_pgmap);
-		error = -ENOMEM;
-		goto err_array;
+		return -ENOMEM;
 	}
 
 	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->end), NULL);
 	if (conflict_pgmap) {
 		WARN(1, "Conflicting mapping in same section\n");
 		put_dev_pagemap(conflict_pgmap);
-		error = -ENOMEM;
-		goto err_array;
+		return -ENOMEM;
 	}
 
 	is_ram = region_intersects(range->start, range_len(range),
@@ -274,19 +222,18 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 		WARN_ONCE(1, "attempted on %s region %#llx-%#llx\n",
 				is_ram == REGION_MIXED ? "mixed" : "ram",
 				range->start, range->end);
-		error = -ENXIO;
-		goto err_array;
+		return -ENXIO;
 	}
 
 	error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(range->start),
 				PHYS_PFN(range->end), pgmap, GFP_KERNEL));
 	if (error)
-		goto err_array;
+		return error;
 
 	if (nid < 0)
 		nid = numa_mem_id();
 
-	error = track_pfn_remap(NULL, &params.pgprot, PHYS_PFN(range->start), 0,
+	error = track_pfn_remap(NULL, &params->pgprot, PHYS_PFN(range->start), 0,
 			range_len(range));
 	if (error)
 		goto err_pfn_remap;
@@ -306,7 +253,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 	 */
 	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
 		error = add_pages(nid, PHYS_PFN(range->start),
-				PHYS_PFN(range_len(range)), &params);
+				PHYS_PFN(range_len(range)), params);
 	} else {
 		error = kasan_add_zero_shadow(__va(range->start), range_len(range));
 		if (error) {
@@ -315,7 +262,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 		}
 
 		error = arch_add_memory(nid, range->start, range_len(range),
-					&params);
+					params);
 	}
 
 	if (!error) {
@@ -323,7 +270,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 
 		zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
 		move_pfn_range_to_zone(zone, PHYS_PFN(range->start),
-				PHYS_PFN(range_len(range)), params.altmap);
+				PHYS_PFN(range_len(range)), params->altmap);
 	}
 
 	mem_hotplug_done();
@@ -337,20 +284,116 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 	memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
 				PHYS_PFN(range->start),
 				PHYS_PFN(range_len(range)), pgmap);
-	percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap));
-	return __va(range->start);
+	percpu_ref_get_many(pgmap->ref, pfn_end(pgmap, range_id)
+			- pfn_first(pgmap, range_id));
+	return 0;
 
- err_add_memory:
+err_add_memory:
 	kasan_remove_zero_shadow(__va(range->start), range_len(range));
- err_kasan:
+err_kasan:
 	untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
- err_pfn_remap:
+err_pfn_remap:
 	pgmap_array_delete(range);
- err_array:
-	dev_pagemap_kill(pgmap);
-	dev_pagemap_cleanup(pgmap);
-	devmap_managed_enable_put();
-	return ERR_PTR(error);
+	return error;
+}
+
+
+/*
+ * Not device managed version of dev_memremap_pages, undone by
+ * memunmap_pages().  Please use dev_memremap_pages if you have a struct
+ * device available.
+ */
+void *memremap_pages(struct dev_pagemap *pgmap, int nid)
+{
+	struct mhp_params params = {
+		.altmap = pgmap_altmap(pgmap),
+		.pgprot = PAGE_KERNEL,
+	};
+	const int nr_range = pgmap->nr_range;
+	bool need_devmap_managed = true;
+	int error, i;
+
+	if (WARN_ONCE(!nr_range, "nr_range must be specified\n"))
+		return ERR_PTR(-EINVAL);
+
+	switch (pgmap->type) {
+	case MEMORY_DEVICE_PRIVATE:
+		if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) {
+			WARN(1, "Device private memory not supported\n");
+			return ERR_PTR(-EINVAL);
+		}
+		if (!pgmap->ops || !pgmap->ops->migrate_to_ram) {
+			WARN(1, "Missing migrate_to_ram method\n");
+			return ERR_PTR(-EINVAL);
+		}
+		if (!pgmap->owner) {
+			WARN(1, "Missing owner\n");
+			return ERR_PTR(-EINVAL);
+		}
+		break;
+	case MEMORY_DEVICE_FS_DAX:
+		if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
+		    IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
+			WARN(1, "File system DAX not supported\n");
+			return ERR_PTR(-EINVAL);
+		}
+		break;
+	case MEMORY_DEVICE_DEVDAX:
+		need_devmap_managed = false;
+		break;
+	case MEMORY_DEVICE_PCI_P2PDMA:
+		params.pgprot = pgprot_noncached(params.pgprot);
+		need_devmap_managed = false;
+		break;
+	default:
+		WARN(1, "Invalid pgmap type %d\n", pgmap->type);
+		break;
+	}
+
+	if (!pgmap->ref) {
+		if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup))
+			return ERR_PTR(-EINVAL);
+
+		init_completion(&pgmap->done);
+		error = percpu_ref_init(&pgmap->internal_ref,
+				dev_pagemap_percpu_release, 0, GFP_KERNEL);
+		if (error)
+			return ERR_PTR(error);
+		pgmap->ref = &pgmap->internal_ref;
+	} else {
+		if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) {
+			WARN(1, "Missing reference count teardown definition\n");
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	if (need_devmap_managed) {
+		error = devmap_managed_enable_get(pgmap);
+		if (error)
+			return ERR_PTR(error);
+	}
+
+	/*
+	 * Clear the pgmap nr_range as it will be incremented for each
+	 * successfully processed range. This communicates how many
+	 * regions to unwind in the abort case.
+	 */
+	pgmap->nr_range = 0;
+	error = 0;
+	for (i = 0; i < nr_range; i++) {
+		error = pagemap_range(pgmap, &params, i, nid);
+		if (error)
+			break;
+		pgmap->nr_range++;
+	}
+
+	if (i < nr_range) {
+		memunmap_pages(pgmap);
+		pgmap->nr_range = nr_range;
+		return ERR_PTR(error);
+	}
+
+	return __va(pgmap->ranges[0].start);
 }
 EXPORT_SYMBOL_GPL(memremap_pages);
 
_______________________________________________
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 21/22] device-dax: Add dis-contiguous resource support
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (19 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 20/22] mm/memremap_pages: Support multiple ranges per invocation Dan Williams
@ 2020-07-12 16:27 ` Dan Williams
  2020-07-12 16:28 ` [PATCH v2 22/22] device-dax: Introduce 'mapping' devices Dan Williams
  2020-07-16 17:29 ` [PATCH v1 0/4] device-dax: Further improvements to subdivision Joao Martins
  22 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:27 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: joao.m.martins, peterz, dave.hansen, ard.biesheuvel, linux-mm,
	linux-kernel, linux-acpi, hch

Break the requirement that device-dax instances are physically
contiguous. With this constraint removed it allows fragmented available
capacity to be fully allocated.

This capability is useful to mitigate the "noisy neighbor" problem with
memory-side-cache management for virtual machines, or any other scenario
where a platform address boundary also designates a performance
boundary. For example a direct mapped memory side cache might rotate
cache colors at 1GB boundaries.  With dis-contiguous allocations a
device-dax instance could be configured to contain only 1 cache color.

It also satisfies Joao's use case (see link) for partitioning memory for
exclusive guest access. It allows for a future potential mode where the
host kernel need not allocate 'struct page' capacity up-front.

Link: https://lore.kernel.org/lkml/20200110190313.17144-1-joao.m.martins@oracle.com/
Reported-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c              |  230 +++++++++++++++++++++++++++++++---------
 drivers/dax/dax-private.h      |    9 +-
 drivers/dax/device.c           |   55 ++++++----
 drivers/dax/kmem.c             |  132 +++++++++++++++--------
 tools/testing/nvdimm/dax-dev.c |   20 ++-
 5 files changed, 319 insertions(+), 127 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index aca7914287f5..f342e36c69a1 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -136,15 +136,27 @@ static bool is_static(struct dax_region *dax_region)
 	return (dax_region->res.flags & IORESOURCE_DAX_STATIC) != 0;
 }
 
+static u64 dev_dax_size(struct dev_dax *dev_dax)
+{
+	u64 size = 0;
+	int i;
+
+	device_lock_assert(&dev_dax->dev);
+
+	for (i = 0; i < dev_dax->nr_range; i++)
+		size += range_len(&dev_dax->ranges[i].range);
+
+	return size;
+}
+
 static int dax_bus_probe(struct device *dev)
 {
 	struct dax_device_driver *dax_drv = to_dax_drv(dev->driver);
 	struct dev_dax *dev_dax = to_dev_dax(dev);
 	struct dax_region *dax_region = dev_dax->region;
-	struct range *range = &dev_dax->range;
 	int rc;
 
-	if (range_len(range) == 0 || dev_dax->id < 0)
+	if (dev_dax_size(dev_dax) == 0 || dev_dax->id < 0)
 		return -ENXIO;
 
 	rc = dax_drv->probe(dev_dax);
@@ -354,15 +366,19 @@ void kill_dev_dax(struct dev_dax *dev_dax)
 }
 EXPORT_SYMBOL_GPL(kill_dev_dax);
 
-static void free_dev_dax_range(struct dev_dax *dev_dax)
+static void free_dev_dax_ranges(struct dev_dax *dev_dax)
 {
 	struct dax_region *dax_region = dev_dax->region;
-	struct range *range = &dev_dax->range;
+	int i;
 
 	device_lock_assert(dax_region->dev);
-	if (range_len(range))
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		struct range *range = &dev_dax->ranges[i].range;
+
 		__release_region(&dax_region->res, range->start,
 				range_len(range));
+	}
+	dev_dax->nr_range = 0;
 }
 
 static void unregister_dev_dax(void *dev)
@@ -372,7 +388,7 @@ static void unregister_dev_dax(void *dev)
 	dev_dbg(dev, "%s\n", __func__);
 
 	kill_dev_dax(dev_dax);
-	free_dev_dax_range(dev_dax);
+	free_dev_dax_ranges(dev_dax);
 	device_del(dev);
 	put_device(dev);
 }
@@ -423,7 +439,7 @@ static ssize_t delete_store(struct device *dev, struct device_attribute *attr,
 	device_lock(dev);
 	device_lock(victim);
 	dev_dax = to_dev_dax(victim);
-	if (victim->driver || range_len(&dev_dax->range))
+	if (victim->driver || dev_dax_size(dev_dax))
 		rc = -EBUSY;
 	else {
 		/*
@@ -569,51 +585,83 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
 	struct dax_region *dax_region = dev_dax->region;
 	struct resource *res = &dax_region->res;
 	struct device *dev = &dev_dax->dev;
+	struct dev_dax_range *ranges;
+	unsigned long pgoff = 0;
 	struct resource *alloc;
+	int i;
 
 	device_lock_assert(dax_region->dev);
 
 	/* handle the seed alloc special case */
 	if (!size) {
-		dev_dax->range = (struct range) {
-			.start = res->start,
-			.end = res->start - 1,
-		};
+		if (dev_WARN_ONCE(dev, dev_dax->nr_range,
+					"0-size allocation must be first\n"))
+			return -EBUSY;
+		/* nr_range == 0 is elsewhere special cased as 0-size device */
 		return 0;
 	}
 
+	ranges = krealloc(dev_dax->ranges, sizeof(*ranges)
+			* (dev_dax->nr_range + 1), GFP_KERNEL);
+	if (!ranges)
+		return -ENOMEM;
+
 	alloc = __request_region(res, start, size, dev_name(dev), 0);
-	if (!alloc)
+	if (!alloc && !dev_dax->nr_range) {
+		/*
+		 * If we adjusted an existing @ranges leave it alone,
+		 * but if this was an empty set of ranges nothing else
+		 * will release @ranges, so do it now.
+		 */
+		kfree(ranges);
 		return -ENOMEM;
+	}
 
-	dev_dax->range = (struct range) {
-		.start = alloc->start,
-		.end = alloc->end,
+	for (i = 0; i < dev_dax->nr_range; i++)
+		pgoff += PHYS_PFN(range_len(&ranges[i].range));
+	dev_dax->ranges = ranges;
+	ranges[dev_dax->nr_range++] = (struct dev_dax_range) {
+		.pgoff = pgoff,
+		.range = {
+			.start = alloc->start,
+			.end = alloc->end,
+		},
 	};
 
+	dev_dbg(dev, "alloc range[%d]: %pa:%pa\n", dev_dax->nr_range - 1,
+			&alloc->start, &alloc->end);
+
 	return 0;
 }
 
 static int adjust_dev_dax_range(struct dev_dax *dev_dax, struct resource *res, resource_size_t size)
 {
+	int last_range = dev_dax->nr_range - 1;
+	struct dev_dax_range *dax_range = &dev_dax->ranges[last_range];
 	struct dax_region *dax_region = dev_dax->region;
-	struct range *range = &dev_dax->range;
-	int rc = 0;
+	bool is_shrink = resource_size(res) > size;
+	struct range *range = &dax_range->range;
+	struct device *dev = &dev_dax->dev;
+	int rc;
 
 	device_lock_assert(dax_region->dev);
 
-	if (size)
-		rc = adjust_resource(res, range->start, size);
-	else
-		__release_region(&dax_region->res, range->start, range_len(range));
+	if (dev_WARN_ONCE(dev, !size, "deletion is handled by dev_dax_shrink\n"))
+		return -EINVAL;
+
+	rc = adjust_resource(res, range->start, size);
 	if (rc)
 		return rc;
 
-	dev_dax->range = (struct range) {
+	*range = (struct range) {
 		.start = range->start,
 		.end = range->start + size - 1,
 	};
 
+	dev_dbg(dev, "%s range[%d]: %#llx:%#llx\n", is_shrink ? "shrink" : "extend",
+			last_range, (unsigned long long) range->start,
+			(unsigned long long) range->end);
+
 	return 0;
 }
 
@@ -621,7 +669,11 @@ static ssize_t size_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
-	unsigned long long size = range_len(&dev_dax->range);
+	unsigned long long size;
+
+	device_lock(dev);
+	size = dev_dax_size(dev_dax);
+	device_unlock(dev);
 
 	return sprintf(buf, "%llu\n", size);
 }
@@ -639,32 +691,82 @@ static bool alloc_is_aligned(struct dax_region *dax_region,
 
 static int dev_dax_shrink(struct dev_dax *dev_dax, resource_size_t size)
 {
+	resource_size_t to_shrink = dev_dax_size(dev_dax) - size;
 	struct dax_region *dax_region = dev_dax->region;
-	struct range *range = &dev_dax->range;
-	struct resource *res, *adjust = NULL;
 	struct device *dev = &dev_dax->dev;
-
-	for_each_dax_region_resource(dax_region, res)
-		if (strcmp(res->name, dev_name(dev)) == 0
-				&& res->start == range->start) {
-			adjust = res;
-			break;
+	int i;
+
+	for (i = dev_dax->nr_range - 1; i >= 0; i--) {
+		struct range *range = &dev_dax->ranges[i].range;
+		struct resource *adjust = NULL, *res;
+		resource_size_t shrink;
+
+		shrink = min(to_shrink, range_len(range));
+		if (shrink >= range_len(range)) {
+			__release_region(&dax_region->res, range->start,
+					range_len(range));
+			dev_dax->nr_range--;
+			dev_dbg(dev, "delete range[%d]: %#llx:%#llx\n", i,
+					(unsigned long long) range->start,
+					(unsigned long long) range->end);
+			to_shrink -= shrink;
+			if (!to_shrink)
+				break;
+			continue;
 		}
 
-	if (dev_WARN_ONCE(dev, !adjust, "failed to find matching resource\n"))
-		return -ENXIO;
-	return __adjust_dev_dax_range(dev_dax, adjust, size);
+		for_each_dax_region_resource(dax_region, res)
+			if (strcmp(res->name, dev_name(dev)) == 0
+					&& res->start == range->start) {
+				adjust = res;
+				break;
+			}
+
+		if (dev_WARN_ONCE(dev, !adjust || i != dev_dax->nr_range - 1,
+					"failed to find matching resource\n"))
+			return -ENXIO;
+		return adjust_dev_dax_range(dev_dax, adjust, range_len(range)
+				- shrink);
+	}
+	return 0;
+}
+
+/*
+ * Only allow adjustments that preserve the relative pgoff of existing
+ * allocations. I.e. the dev_dax->ranges array is ordered by increasing pgoff.
+ */
+static bool adjust_ok(struct dev_dax *dev_dax, struct resource *res)
+{
+	struct dev_dax_range *last;
+	int i;
+
+	if (dev_dax->nr_range == 0)
+		return false;
+	if (strcmp(res->name, dev_name(&dev_dax->dev)) != 0)
+		return false;
+	last = &dev_dax->ranges[dev_dax->nr_range - 1];
+	if (last->range.start != res->start || last->range.end != res->end)
+		return false;
+	for (i = 0; i < dev_dax->nr_range - 1; i++) {
+		struct dev_dax_range *dax_range = &dev_dax->ranges[i];
+
+		if (dax_range->pgoff > last->pgoff)
+			return false;
+	}
+
+	return true;
 }
 
 static ssize_t dev_dax_resize(struct dax_region *dax_region,
 		struct dev_dax *dev_dax, resource_size_t size)
 {
 	resource_size_t avail = dax_region_avail_size(dax_region), to_alloc;
-	resource_size_t dev_size = range_len(&dev_dax->range);
+	resource_size_t dev_size = dev_dax_size(dev_dax);
 	struct resource *region_res = &dax_region->res;
 	struct device *dev = &dev_dax->dev;
-	const char *name = dev_name(dev);
 	struct resource *res, *first;
+	resource_size_t alloc = 0;
+	int rc;
 
 	if (dev->driver)
 		return -EBUSY;
@@ -685,35 +787,47 @@ static ssize_t dev_dax_resize(struct dax_region *dax_region,
 	 * may involve adjusting the end of an existing resource, or
 	 * allocating a new resource.
 	 */
+retry:
 	first = region_res->child;
 	if (!first)
 		return alloc_dev_dax_range(dev_dax, dax_region->res.start, to_alloc);
-	for (res = first; to_alloc && res; res = res->sibling) {
+
+	rc = -ENOSPC;
+	for (res = first; res; res = res->sibling) {
 		struct resource *next = res->sibling;
-		resource_size_t free;
 
 		/* space at the beginning of the region */
-		free = 0;
-		if (res == first && res->start > dax_region->res.start)
-			free = res->start - dax_region->res.start;
-		if (free >= to_alloc && dev_size == 0)
-			return alloc_dev_dax_range(dev_dax, dax_region->res.start, to_alloc);
+		if (res == first && res->start > dax_region->res.start) {
+			alloc = min(res->start - dax_region->res.start, to_alloc);
+			rc = alloc_dev_dax_range(dev_dax, dax_region->res.start, alloc);
+			break;
+		}
 
-		free = 0;
+		alloc = 0;
 		/* space between allocations */
 		if (next && next->start > res->end + 1)
-			free = next->start - res->end + 1;
+			alloc = min(next->start - (res->end + 1), to_alloc);
 
 		/* space at the end of the region */
-		if (free < to_alloc && !next && res->end < region_res->end)
-			free = region_res->end - res->end;
+		if (!alloc && !next && res->end < region_res->end)
+			alloc = min(region_res->end - res->end, to_alloc);
 
-		if (free >= to_alloc && strcmp(name, res->name) == 0)
-			return adjust_dev_dax_range(dev_dax, res, resource_size(res) + to_alloc);
-		else if (free >= to_alloc && dev_size == 0)
-			return alloc_dev_dax_range(dev_dax, res->end + 1, to_alloc);
+		if (!alloc)
+			continue;
+
+		if (adjust_ok(dev_dax, res)) {
+			rc = adjust_dev_dax_range(dev_dax, res, resource_size(res) + alloc);
+			break;
+		}
+		rc = alloc_dev_dax_range(dev_dax, res->end + 1, alloc);
+		break;
 	}
-	return -ENOSPC;
+	if (rc)
+		return rc;
+	to_alloc -= alloc;
+	if (to_alloc)
+		goto retry;
+	return 0;
 }
 
 static ssize_t size_store(struct device *dev, struct device_attribute *attr,
@@ -767,8 +881,15 @@ static ssize_t resource_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
+	struct dax_region *dax_region = dev_dax->region;
+	unsigned long long start;
+
+	if (dev_dax->nr_range < 1)
+		start = dax_region->res.start;
+	else
+		start = dev_dax->ranges[0].range.start;
 
-	return sprintf(buf, "%#llx\n", dev_dax->range.start);
+	return sprintf(buf, "%#llx\n", start);
 }
 static DEVICE_ATTR(resource, 0400, resource_show, NULL);
 
@@ -833,6 +954,7 @@ static void dev_dax_release(struct device *dev)
 	put_dax(dax_dev);
 	free_dev_dax_id(dev_dax);
 	dax_region_put(dax_region);
+	kfree(dev_dax->ranges);
 	kfree(dev_dax->pgmap);
 	kfree(dev_dax);
 }
@@ -941,7 +1063,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 err_alloc_dax:
 	kfree(dev_dax->pgmap);
 err_pgmap:
-	free_dev_dax_range(dev_dax);
+	free_dev_dax_ranges(dev_dax);
 err_range:
 	free_dev_dax_id(dev_dax);
 err_id:
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 0cbb2ec81ca7..f863287107fd 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -49,7 +49,8 @@ struct dax_region {
  * @id: ida allocated id
  * @dev - device core
  * @pgmap - pgmap for memmap setup / lifetime (driver owned)
- * @range: resource range for the instance
+ * @nr_range: size of @ranges
+ * @ranges: resource-span + pgoff tuples for the instance
  */
 struct dev_dax {
 	struct dax_region *region;
@@ -58,7 +59,11 @@ struct dev_dax {
 	int id;
 	struct device dev;
 	struct dev_pagemap *pgmap;
-	struct range range;
+	int nr_range;
+	struct dev_dax_range {
+		unsigned long pgoff;
+		struct range range;
+	} *ranges;
 };
 
 static inline struct dev_dax *to_dev_dax(struct device *dev)
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index f3755df4ae29..2bfc5c83e3b0 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -55,15 +55,22 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 		unsigned long size)
 {
-	struct range *range = &dev_dax->range;
-	phys_addr_t phys;
-
-	phys = pgoff * PAGE_SIZE + range->start;
-	if (phys >= range->start && phys <= range->end) {
+	int i;
+
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		struct dev_dax_range *dax_range = &dev_dax->ranges[i];
+		struct range *range = &dax_range->range;
+		unsigned long long pgoff_end;
+		phys_addr_t phys;
+
+		pgoff_end = dax_range->pgoff + PHYS_PFN(range_len(range)) - 1;
+		if (pgoff < dax_range->pgoff || pgoff > pgoff_end)
+			continue;
+		phys = PFN_PHYS(pgoff - dax_range->pgoff) + range->start;
 		if (phys + size - 1 <= range->end)
 			return phys;
+		break;
 	}
-
 	return -1;
 }
 
@@ -395,30 +402,40 @@ static void dev_dax_kill(void *dev_dax)
 int dev_dax_probe(struct dev_dax *dev_dax)
 {
 	struct dax_device *dax_dev = dev_dax->dax_dev;
-	struct range *range = &dev_dax->range;
 	struct device *dev = &dev_dax->dev;
 	struct dev_pagemap *pgmap;
 	struct inode *inode;
 	struct cdev *cdev;
 	void *addr;
-	int rc;
-
-	/* 1:1 map region resource range to device-dax instance range */
-	if (!devm_request_mem_region(dev, range->start, range_len(range),
-				dev_name(dev))) {
-		dev_warn(dev, "could not reserve range: %#llx - %#llx\n",
-				range->start, range->end);
-		return -EBUSY;
-	}
+	int rc, i;
 
 	pgmap = dev_dax->pgmap;
+	if (dev_WARN_ONCE(dev, pgmap && dev_dax->nr_range > 1,
+			"static pgmap / multi-range device conflict\n"))
+		return -EINVAL;
+
 	if (!pgmap) {
-		pgmap = devm_kzalloc(dev, sizeof(*pgmap), GFP_KERNEL);
+		pgmap = devm_kzalloc(dev, sizeof(*pgmap) + sizeof(struct range)
+				* (dev_dax->nr_range - 1), GFP_KERNEL);
 		if (!pgmap)
 			return -ENOMEM;
-		pgmap->range = *range;
-		pgmap->nr_range = 1;
+		pgmap->nr_range = dev_dax->nr_range;
+	}
+
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		struct range *range = &dev_dax->ranges[i].range;
+
+		if (!devm_request_mem_region(dev, range->start,
+					range_len(range), dev_name(dev))) {
+			dev_warn(dev, "mapping%d: %#llx-%#llx could not reserve range\n",
+					i, range->start, range->end);
+			return -EBUSY;
+		}
+		/* don't update the range for static pgmap */
+		if (!dev_dax->pgmap)
+			pgmap->ranges[i] = *range;
 	}
+
 	pgmap->type = MEMORY_DEVICE_DEVDAX;
 	addr = devm_memremap_pages(dev, pgmap);
 	if (IS_ERR(addr))
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index b1be8a53b26a..7dcb2902e9b1 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -19,25 +19,28 @@ static const char *kmem_name;
 /* Set if any memory will remain added when the driver will be unloaded. */
 static bool any_hotremove_failed;
 
-static struct range dax_kmem_range(struct dev_dax *dev_dax)
+static int dax_kmem_range(struct dev_dax *dev_dax, int i, struct range *r)
 {
-	struct range range;
+	struct dev_dax_range *dax_range = &dev_dax->ranges[i];
+	struct range *range = &dax_range->range;
 
 	/* memory-block align the hotplug range */
-	range.start = ALIGN(dev_dax->range.start, memory_block_size_bytes());
-	range.end = ALIGN_DOWN(dev_dax->range.end + 1,
-			memory_block_size_bytes()) - 1;
-	return range;
+	r->start = ALIGN(range->start, memory_block_size_bytes());
+	r->end = ALIGN_DOWN(range->end + 1, memory_block_size_bytes()) - 1;
+	if (r->start >= r->end) {
+		r->start = range->start;
+		r->end = range->end;
+		return -ENOSPC;
+	}
+	return 0;
 }
 
 int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 {
-	struct range range = dax_kmem_range(dev_dax);
 	int numa_node = dev_dax->target_node;
 	struct device *dev = &dev_dax->dev;
-	struct resource *res;
+	int i, mapped = 0;
 	char *res_name;
-	int rc;
 
 	/*
 	 * Ensure good NUMA information for the persistent memory.
@@ -55,32 +58,56 @@ int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 	if (!res_name)
 		return -ENOMEM;
 
-	res = request_mem_region(range.start, range_len(&range), res_name);
-	if (!res) {
-		dev_warn(dev, "could not reserve region [%#llx-%#llx]\n",
-				range.start, range.end);
-		kfree(res_name);
-		return -EBUSY;
-	}
-
-	/*
-	 * Temporarily clear busy to allow add_memory_driver_managed()
-	 * to claim it.
-	 */
-	res->flags &= ~IORESOURCE_BUSY;
-
-	/*
-	 * Ensure that future kexec'd kernels will not treat this as RAM
-	 * automatically.
-	 */
-	rc = add_memory_driver_managed(numa_node, res->start,
-				       resource_size(res), kmem_name);
-
-	res->flags |= IORESOURCE_BUSY;
-	if (rc) {
-		release_mem_region(range.start, range_len(&range));
-		kfree(res_name);
-		return rc;
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		struct resource *res;
+		struct range range;
+		int rc;
+
+		rc = dax_kmem_range(dev_dax, i, &range);
+		if (rc) {
+			dev_info(dev, "mapping%d: %#llx-%#llx too small after alignment\n",
+					i, range.start, range.end);
+			continue;
+		}
+
+		res = request_mem_region(range.start, range_len(&range), res_name);
+		if (!res) {
+			dev_warn(dev, "mapping%d: %#llx-%#llx could not reserve region\n",
+					i, range.start, range.end);
+			/*
+			 * Once some memory has been onlined we can't
+			 * assume that it can be un-onlined safely.
+			 */
+			if (mapped)
+				continue;
+			kfree(res_name);
+			return -EBUSY;
+		}
+
+		/*
+		 * Temporarily clear busy to allow
+		 * add_memory_driver_managed() to claim it.
+		 */
+		res->flags &= ~IORESOURCE_BUSY;
+
+		/*
+		 * Ensure that future kexec'd kernels will not treat
+		 * this as RAM automatically.
+		 */
+		rc = add_memory_driver_managed(numa_node, range.start,
+				range_len(&range), kmem_name);
+
+		res->flags |= IORESOURCE_BUSY;
+		if (rc) {
+			dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n",
+					i, range.start, range.end);
+			release_mem_region(range.start, range_len(&range));
+			if (mapped)
+				continue;
+			kfree(res_name);
+			return rc;
+		}
+		mapped++;
 	}
 
 	dev_set_drvdata(dev, res_name);
@@ -91,10 +118,9 @@ int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 #ifdef CONFIG_MEMORY_HOTREMOVE
 static void dax_kmem_release(struct dev_dax *dev_dax)
 {
-	int rc;
+	int i, success = 0;
 	struct device *dev = &dev_dax->dev;
 	const char *res_name = dev_get_drvdata(dev);
-	struct range range = dax_kmem_range(dev_dax);
 
 	/*
 	 * We have one shot for removing memory, if some memory blocks were not
@@ -102,17 +128,31 @@ static void dax_kmem_release(struct dev_dax *dev_dax)
 	 * there is no way to hotremove this memory until reboot because device
 	 * unbind will proceed regardless of the remove_memory result.
 	 */
-	rc = remove_memory(dev_dax->target_node, range.start, range_len(&range));
-	if (rc == 0) {
-		release_mem_region(range.start, range_len(&range));
-		dev_set_drvdata(dev, NULL);
-		kfree(res_name);
-		return;
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		struct range range;
+		int rc;
+
+		rc = dax_kmem_range(dev_dax, i, &range);
+		if (rc)
+			continue;
+
+		rc = remove_memory(dev_dax->target_node, range.start,
+				range_len(&range));
+		if (rc == 0) {
+			release_mem_region(range.start, range_len(&range));
+			success++;
+			continue;
+		}
+		any_hotremove_failed = true;
+		dev_err(dev,
+			"mapping%d: %#llx-%#llx cannot be hotremoved until the next reboot\n",
+				i, range.start, range.end);
 	}
 
-	any_hotremove_failed = true;
-	dev_err(dev, "%#llx-%#llx cannot be hotremoved until the next reboot\n",
-			range.start, range.end);
+	if (success >= dev_dax->nr_range) {
+		kfree(res_name);
+		dev_set_drvdata(dev, NULL);
+	}
 }
 #else
 static void dax_kmem_release(struct dev_dax *dev_dax)
diff --git a/tools/testing/nvdimm/dax-dev.c b/tools/testing/nvdimm/dax-dev.c
index 38d8e55c4a0d..fb342a8c98d3 100644
--- a/tools/testing/nvdimm/dax-dev.c
+++ b/tools/testing/nvdimm/dax-dev.c
@@ -9,11 +9,18 @@
 phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 		unsigned long size)
 {
-	struct range *range = &dev_dax->range;
-	phys_addr_t addr;
+	int i;
 
-	addr = pgoff * PAGE_SIZE + range->start;
-	if (addr >= range->start && addr <= range->end) {
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		struct dev_dax_range *dax_range = &dev_dax->ranges[i];
+		struct range *range = &dax_range->range;
+		unsigned long long pgoff_end;
+		phys_addr_t addr;
+
+		pgoff_end = dax_range->pgoff + PHYS_PFN(range_len(range)) - 1;
+		if (pgoff < dax_range->pgoff || pgoff > pgoff_end)
+			continue;
+		addr = PFN_PHYS(pgoff - dax_range->pgoff) + range->start;
 		if (addr + size - 1 <= range->end) {
 			if (get_nfit_res(addr)) {
 				struct page *page;
@@ -23,9 +30,10 @@ phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 
 				page = vmalloc_to_page((void *)addr);
 				return PFN_PHYS(page_to_pfn(page));
-			} else
-				return addr;
+			}
+			return addr;
 		}
+		break;
 	}
 	return -1;
 }
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v2 22/22] device-dax: Introduce 'mapping' devices
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (20 preceding siblings ...)
  2020-07-12 16:27 ` [PATCH v2 21/22] device-dax: Add dis-contiguous resource support Dan Williams
@ 2020-07-12 16:28 ` Dan Williams
  2020-07-16 13:18   ` Joao Martins
  2020-07-16 17:29 ` [PATCH v1 0/4] device-dax: Further improvements to subdivision Joao Martins
  22 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-12 16:28 UTC (permalink / raw)
  To: linux-nvdimm
  Cc: peterz, dave.hansen, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

In support of interrogating the physical address layout of a device with
dis-contiguous ranges, introduce a sysfs directory with 'start', 'end',
and 'page_offset' attributes. The alternative is trying to parse
/proc/iomem, and that file will not reflect the extent layout until the
device is enabled.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c         |  191 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/dax/dax-private.h |   14 +++
 2 files changed, 203 insertions(+), 2 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index f342e36c69a1..8b6c4ddc5f42 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -579,6 +579,167 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 }
 EXPORT_SYMBOL_GPL(alloc_dax_region);
 
+static void dax_mapping_release(struct device *dev)
+{
+	struct dax_mapping *mapping = to_dax_mapping(dev);
+	struct dev_dax *dev_dax = to_dev_dax(dev->parent);
+
+	ida_free(&dev_dax->ida, mapping->id);
+	kfree(mapping);
+}
+
+static void unregister_dax_mapping(void *data)
+{
+	struct device *dev = data;
+	struct dax_mapping *mapping = to_dax_mapping(dev);
+	struct dev_dax *dev_dax = to_dev_dax(dev->parent);
+	struct dax_region *dax_region = dev_dax->region;
+
+	dev_dbg(dev, "%s\n", __func__);
+
+	device_lock_assert(dax_region->dev);
+
+	dev_dax->ranges[mapping->range_id].mapping = NULL;
+	mapping->range_id = -1;
+
+	device_del(dev);
+	put_device(dev);
+}
+
+static struct dev_dax_range *get_dax_range(struct device *dev)
+{
+	struct dax_mapping *mapping = to_dax_mapping(dev);
+	struct dev_dax *dev_dax = to_dev_dax(dev->parent);
+	struct dax_region *dax_region = dev_dax->region;
+
+	device_lock(dax_region->dev);
+	if (mapping->range_id < 1) {
+		device_unlock(dax_region->dev);
+		return NULL;
+	}
+
+	return &dev_dax->ranges[mapping->range_id];
+}
+
+static void put_dax_range(struct dev_dax_range *dax_range)
+{
+	struct dax_mapping *mapping = dax_range->mapping;
+	struct dev_dax *dev_dax = to_dev_dax(mapping->dev.parent);
+	struct dax_region *dax_region = dev_dax->region;
+
+	device_unlock(dax_region->dev);
+}
+
+static ssize_t start_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dev_dax_range *dax_range;
+	ssize_t rc;
+
+	dax_range = get_dax_range(dev);
+	if (!dax_range)
+		return -ENXIO;
+	rc = sprintf(buf, "%#llx\n", dax_range->range.start);
+	put_dax_range(dax_range);
+
+	return rc;
+}
+static DEVICE_ATTR(start, 0400, start_show, NULL);
+
+static ssize_t end_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dev_dax_range *dax_range;
+	ssize_t rc;
+
+	dax_range = get_dax_range(dev);
+	if (!dax_range)
+		return -ENXIO;
+	rc = sprintf(buf, "%#llx\n", dax_range->range.end);
+	put_dax_range(dax_range);
+
+	return rc;
+}
+static DEVICE_ATTR(end, 0400, end_show, NULL);
+
+static ssize_t pgoff_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dev_dax_range *dax_range;
+	ssize_t rc;
+
+	dax_range = get_dax_range(dev);
+	if (!dax_range)
+		return -ENXIO;
+	rc = sprintf(buf, "%#lx\n", dax_range->pgoff);
+	put_dax_range(dax_range);
+
+	return rc;
+}
+static DEVICE_ATTR(page_offset, 0400, pgoff_show, NULL);
+
+static struct attribute *dax_mapping_attributes[] = {
+	&dev_attr_start.attr,
+	&dev_attr_end.attr,
+	&dev_attr_page_offset.attr,
+	NULL,
+};
+
+static const struct attribute_group dax_mapping_attribute_group = {
+	.attrs = dax_mapping_attributes,
+};
+
+static const struct attribute_group *dax_mapping_attribute_groups[] = {
+	&dax_mapping_attribute_group,
+	NULL,
+};
+
+static struct device_type dax_mapping_type = {
+	.release = dax_mapping_release,
+	.groups = dax_mapping_attribute_groups,
+};
+
+static int devm_register_dax_mapping(struct dev_dax *dev_dax, int range_id)
+{
+	struct dax_region *dax_region = dev_dax->region;
+	struct dax_mapping *mapping;
+	struct device *dev;
+	int rc;
+
+	device_lock_assert(dax_region->dev);
+
+	if (dev_WARN_ONCE(&dev_dax->dev, !dax_region->dev->driver,
+				"region disabled\n"))
+		return -ENXIO;
+
+	mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
+	if (!mapping)
+		return -ENOMEM;
+	mapping->range_id = range_id;
+	mapping->id = ida_alloc(&dev_dax->ida, GFP_KERNEL);
+	if (mapping->id < 0) {
+		kfree(mapping);
+		return -ENOMEM;
+	}
+	dev_dax->ranges[range_id].mapping = mapping;
+	dev = &mapping->dev;
+	device_initialize(dev);
+	dev->parent = &dev_dax->dev;
+	dev->type = &dax_mapping_type;
+	dev_set_name(dev, "mapping%d", mapping->id);
+	rc = device_add(dev);
+	if (rc) {
+		put_device(dev);
+		return rc;
+	}
+
+	rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_mapping,
+			dev);
+	if (rc)
+		return rc;
+	return 0;
+}
+
 static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
 		resource_size_t size)
 {
@@ -588,7 +749,7 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
 	struct dev_dax_range *ranges;
 	unsigned long pgoff = 0;
 	struct resource *alloc;
-	int i;
+	int i, rc;
 
 	device_lock_assert(dax_region->dev);
 
@@ -630,6 +791,22 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
 
 	dev_dbg(dev, "alloc range[%d]: %pa:%pa\n", dev_dax->nr_range - 1,
 			&alloc->start, &alloc->end);
+	/*
+	 * A dev_dax instance must be registered before mapping device
+	 * children can be added. Defer to devm_create_dev_dax() to add
+	 * the initial mapping device.
+	 */
+	if (!device_is_registered(&dev_dax->dev))
+		return 0;
+
+	rc = devm_register_dax_mapping(dev_dax, dev_dax->nr_range - 1);
+	if (rc) {
+		dev_dbg(dev, "delete range[%d]: %pa:%pa\n", dev_dax->nr_range - 1,
+				&alloc->start, &alloc->end);
+		dev_dax->nr_range--;
+		__release_region(res, alloc->start, resource_size(alloc));
+		return rc;
+	}
 
 	return 0;
 }
@@ -698,11 +875,14 @@ static int dev_dax_shrink(struct dev_dax *dev_dax, resource_size_t size)
 
 	for (i = dev_dax->nr_range - 1; i >= 0; i--) {
 		struct range *range = &dev_dax->ranges[i].range;
+		struct dax_mapping *mapping = dev_dax->ranges[i].mapping;
 		struct resource *adjust = NULL, *res;
 		resource_size_t shrink;
 
 		shrink = min(to_shrink, range_len(range));
 		if (shrink >= range_len(range)) {
+			devm_release_action(dax_region->dev,
+					unregister_dax_mapping, &mapping->dev);
 			__release_region(&dax_region->res, range->start,
 					range_len(range));
 			dev_dax->nr_range--;
@@ -1033,9 +1213,9 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	/* a device_dax instance is dead while the driver is not attached */
 	kill_dax(dax_dev);
 
-	/* from here on we're committed to teardown via dev_dax_release() */
 	dev_dax->dax_dev = dax_dev;
 	dev_dax->target_node = dax_region->target_node;
+	ida_init(&dev_dax->ida);
 	kref_get(&dax_region->kref);
 
 	inode = dax_inode(dax_dev);
@@ -1058,6 +1238,13 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	if (rc)
 		return ERR_PTR(rc);
 
+	/* register mapping device for the initial allocation range */
+	if (dev_dax->nr_range && range_len(&dev_dax->ranges[0].range)) {
+		rc = devm_register_dax_mapping(dev_dax, 0);
+		if (rc)
+			return ERR_PTR(rc);
+	}
+
 	return dev_dax;
 
 err_alloc_dax:
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index f863287107fd..13780f62b95e 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -40,6 +40,12 @@ struct dax_region {
 	struct device *youngest;
 };
 
+struct dax_mapping {
+	struct device dev;
+	int range_id;
+	int id;
+};
+
 /**
  * struct dev_dax - instance data for a subdivision of a dax region, and
  * data while the device is activated in the driver.
@@ -47,6 +53,7 @@ struct dax_region {
  * @dax_dev - core dax functionality
  * @target_node: effective numa node if dev_dax memory range is onlined
  * @id: ida allocated id
+ * @ida: mapping id allocator
  * @dev - device core
  * @pgmap - pgmap for memmap setup / lifetime (driver owned)
  * @nr_range: size of @ranges
@@ -57,12 +64,14 @@ struct dev_dax {
 	struct dax_device *dax_dev;
 	int target_node;
 	int id;
+	struct ida ida;
 	struct device dev;
 	struct dev_pagemap *pgmap;
 	int nr_range;
 	struct dev_dax_range {
 		unsigned long pgoff;
 		struct range range;
+		struct dax_mapping *mapping;
 	} *ranges;
 };
 
@@ -70,4 +79,9 @@ static inline struct dev_dax *to_dev_dax(struct device *dev)
 {
 	return container_of(dev, struct dev_dax, dev);
 }
+
+static inline struct dax_mapping *to_dax_mapping(struct device *dev)
+{
+	return container_of(dev, struct dax_mapping, dev);
+}
 #endif
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 02/22] x86/numa: Add 'nohmat' option
  2020-07-12 16:26 ` [PATCH v2 02/22] x86/numa: Add 'nohmat' option Dan Williams
@ 2020-07-12 16:58   ` Randy Dunlap
  0 siblings, 0 replies; 46+ messages in thread
From: Randy Dunlap @ 2020-07-12 16:58 UTC (permalink / raw)
  To: Dan Williams, linux-nvdimm
  Cc: x86, Rafael J. Wysocki, Dave Hansen, Andy Lutomirski,
	Peter Zijlstra, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, ard.biesheuvel, linux-mm, linux-kernel,
	linux-acpi, hch, joao.m.martins

On 7/12/20 9:26 AM, Dan Williams wrote:
> Disable parsing of the HMAT for debug, to workaround broken platform
> instances, or cases where it is otherwise not wanted.
> 
> Cc: x86@kernel.org
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  arch/x86/mm/numa.c       |    2 ++
>  drivers/acpi/numa/hmat.c |    8 +++++++-
>  include/acpi/acpi_numa.h |    8 ++++++++
>  3 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index ee24646dc44e..44fdf06d497e 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -41,6 +41,8 @@ static __init int numa_setup(char *opt)
>  		return numa_emu_cmdline(opt + 5);
>  	if (!strncmp(opt, "noacpi", 6))
>  		disable_srat();
> +	if (!strncmp(opt, "nohmat", 6))
> +		disable_hmat();
>  	return 0;
>  }
>  early_param("numa", numa_setup);

Please add that to
Documentation/x86/x86_64/boot-options.rst.

thanks.
-- 
~Randy
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* Re: [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs
  2020-07-12 16:27 ` [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs Dan Williams
@ 2020-07-12 17:09   ` Greg Kroah-Hartman
  2020-07-13 15:39     ` Dan Williams
  0 siblings, 1 reply; 46+ messages in thread
From: Greg Kroah-Hartman @ 2020-07-12 17:09 UTC (permalink / raw)
  To: Dan Williams
  Cc: linux-nvdimm, Rafael J. Wysocki, peterz, dave.hansen,
	ard.biesheuvel, linux-mm, linux-kernel, linux-acpi, hch,
	joao.m.martins

On Sun, Jul 12, 2020 at 09:27:37AM -0700, Dan Williams wrote:
> Use sysfs_streq() in device_find_child_by_name() to allow it to use a
> sysfs input string that might contain a trailing newline.
> 
> The other "device by name" interfaces,
> {bus,driver,class}_find_device_by_name(), already account for sysfs
> strings.
> 
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/base/core.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 67d39a90b45c..5d31b962c898 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -3078,7 +3078,7 @@ struct device *device_find_child_by_name(struct device *parent,
>  
>  	klist_iter_init(&parent->p->klist_children, &i);
>  	while ((child = next_device(&i)))
> -		if (!strcmp(dev_name(child), name) && get_device(child))
> +		if (sysfs_streq(dev_name(child), name) && get_device(child))

Who wants to call this function with a name passed from userspace?

Not objecting to it, just curious...

thanks,

greg k-h
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* Re: [PATCH v2 07/22] numa: Introduce a generic memory_add_physaddr_to_nid()
  2020-07-12 16:26 ` [PATCH v2 07/22] numa: Introduce a generic memory_add_physaddr_to_nid() Dan Williams
@ 2020-07-13  6:58   ` Mike Rapoport
  2020-07-13 15:42     ` Dan Williams
  0 siblings, 1 reply; 46+ messages in thread
From: Mike Rapoport @ 2020-07-13  6:58 UTC (permalink / raw)
  To: Dan Williams
  Cc: linux-nvdimm, Jia He, Will Deacon, David Hildenbrand,
	Andrew Morton, peterz, dave.hansen, ard.biesheuvel, linux-mm,
	linux-kernel, linux-acpi, hch, joao.m.martins

Hi Dan,

On Sun, Jul 12, 2020 at 09:26:43AM -0700, Dan Williams wrote:
> For architectures that opt into storing their numa data in memblock
> (only ARM64 currently), add a memblock generic way to interrogate that
> data for memory_add_physaddr_to_nid(). This requires ARCH_KEEP_MEMBLOCK
> to keep memblock text and data around after boot.

I afraid we are too far from using memblock as a generic placeholder for
numa data. Although all architectures now have the numa info in
memblock, only arm64 uses memblock as the primary source of that data.

I'd rather prefer Jia's solution [1] to have a weak default for
memory_add_physaddr_to_nid() and let architectures override it.

[1] https://lore.kernel.org/lkml/20200710031619.18762-2-justin.he@arm.com

> Cc: Mike Rapoport <rppt@linux.ibm.com>
> Cc: Jia He <justin.he@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  include/linux/mm.h |   11 +++++++++++
>  mm/Kconfig         |    6 ++++++
>  mm/page_alloc.c    |   23 ++++++++++++++++++++++-
>  3 files changed, 39 insertions(+), 1 deletion(-)
> 

-- 
Sincerely yours,
Mike.
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* Re: [PATCH v2 08/22] memblock: Introduce a generic phys_addr_to_target_node()
  2020-07-12 16:26 ` [PATCH v2 08/22] memblock: Introduce a generic phys_addr_to_target_node() Dan Williams
@ 2020-07-13  7:03   ` Mike Rapoport
  2020-07-13 15:48     ` Dan Williams
  0 siblings, 1 reply; 46+ messages in thread
From: Mike Rapoport @ 2020-07-13  7:03 UTC (permalink / raw)
  To: Dan Williams
  Cc: linux-nvdimm, Jia He, Will Deacon, David Hildenbrand,
	Andrew Morton, peterz, dave.hansen, ard.biesheuvel, linux-mm,
	linux-kernel, linux-acpi, hch, joao.m.martins

Hi Dan,

On Sun, Jul 12, 2020 at 09:26:48AM -0700, Dan Williams wrote:
> Similar to how generic memory_add_physaddr_to_nid() interrogates
> memblock data for numa information, introduce
> get_reserved_pfn_range_from_nid() to enable the same operation for
> reserved memory ranges. Example memory ranges that are reserved, but
> still have associated numa-info are persistent memory or Soft Reserved
> (EFI_MEMORY_SP) memory.

Here again, I would prefer to add a weak default for
phys_to_target_node() because the "generic" implementation is not really
generic.

The fallback to reserved ranges is x86 specfic because on x86 most of the
reserved areas is not in memblock.memory. AFAIK, no other architecture
does this.

And x86 anyway has implementation of phys_to_target_node().

> Cc: Mike Rapoport <rppt@linux.ibm.com>
> Cc: Jia He <justin.he@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  include/linux/memblock.h |    4 +++
>  include/linux/mm.h       |    2 +
>  include/linux/numa.h     |    2 +
>  mm/memblock.c            |   22 ++++++++++++++--
>  mm/page_alloc.c          |   63 +++++++++++++++++++++++++++++++++++++++++++++-
>  5 files changed, 87 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 017fae833d4a..0655e8376c72 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -234,6 +234,10 @@ void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
>  	for (i = -1, __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid); \
>  	     i >= 0; __next_mem_pfn_range(&i, nid, p_start, p_end, p_nid))
>  
> +#define for_each_reserved_pfn_range(i, nid, p_start, p_end, p_nid)		\
> +	for (i = -1, __next_reserved_pfn_range(&i, nid, p_start, p_end, p_nid); \
> +	     i >= 0; __next_reserved_pfn_range(&i, nid, p_start, p_end, p_nid))
> +
>  #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
>  void __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
>  				  unsigned long *out_spfn,
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 1e76ee5da20b..82dac9f42c46 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2438,6 +2438,8 @@ extern unsigned long absent_pages_in_range(unsigned long start_pfn,
>  
>  extern void get_pfn_range_for_nid(unsigned int nid,
>  			unsigned long *start_pfn, unsigned long *end_pfn);
> +extern void get_reserved_pfn_range_for_nid(unsigned int nid,
> +			unsigned long *start_pfn, unsigned long *end_pfn);
>  extern unsigned long find_min_pfn_with_active_regions(void);
>  extern void sparse_memory_present_with_active_regions(int nid);
>  
> diff --git a/include/linux/numa.h b/include/linux/numa.h
> index 5d25c5de1322..52b2430bc759 100644
> --- a/include/linux/numa.h
> +++ b/include/linux/numa.h
> @@ -19,7 +19,7 @@ int numa_map_to_online_node(int node);
>  
>  /*
>   * Optional architecture specific implementation, users need a "depends
> - * on $ARCH"
> + * on $ARCH" or depends on CONFIG_MEMBLOCK_NUMA_INFO
>   */
>  int phys_to_target_node(phys_addr_t addr);
>  #else
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 39aceafc57f6..43c3abab705e 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -1200,11 +1200,11 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
>  /*
>   * Common iterator interface used to define for_each_mem_pfn_range().
>   */
> -void __init_memblock __next_mem_pfn_range(int *idx, int nid,
> +static void __init_memblock __next_memblock_pfn_range(int *idx, int nid,
>  				unsigned long *out_start_pfn,
> -				unsigned long *out_end_pfn, int *out_nid)
> +				unsigned long *out_end_pfn, int *out_nid,
> +				struct memblock_type *type)
>  {
> -	struct memblock_type *type = &memblock.memory;
>  	struct memblock_region *r;
>  	int r_nid;
>  
> @@ -1230,6 +1230,22 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid,
>  		*out_nid = r_nid;
>  }
>  
> +void __init_memblock __next_mem_pfn_range(int *idx, int nid,
> +				unsigned long *out_start_pfn,
> +				unsigned long *out_end_pfn, int *out_nid)
> +{
> +	__next_memblock_pfn_range(idx, nid, out_start_pfn, out_end_pfn, out_nid,
> +				  &memblock.memory);
> +}
> +
> +void __init_memblock __next_reserved_pfn_range(int *idx, int nid,
> +				unsigned long *out_start_pfn,
> +				unsigned long *out_end_pfn, int *out_nid)
> +{
> +	__next_memblock_pfn_range(idx, nid, out_start_pfn, out_end_pfn, out_nid,
> +				  &memblock.reserved);
> +}
> +
>  /**
>   * memblock_set_node - set node ID on memblock regions
>   * @base: base of area to set node ID for
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index df8bd169dbb4..94ad77c0c338 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -6369,12 +6369,39 @@ void __init_or_memblock get_pfn_range_for_nid(unsigned int nid,
>  		*start_pfn = 0;
>  }
>  
> +/**
> + * get_reserved_pfn_range_for_nid - Return the start and end page frames for a node
> + * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
> + * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
> + * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
> + *
> + * Mostly identical to get_pfn_range_for_nid() except it operates on
> + * reserved ranges rather than online memory.
> + */
> +void __init_or_memblock get_reserved_pfn_range_for_nid(unsigned int nid,
> +			unsigned long *start_pfn, unsigned long *end_pfn)
> +{
> +	unsigned long this_start_pfn, this_end_pfn;
> +	int i;
> +
> +	*start_pfn = -1UL;
> +	*end_pfn = 0;
> +
> +	for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
> +		*start_pfn = min(*start_pfn, this_start_pfn);
> +		*end_pfn = max(*end_pfn, this_end_pfn);
> +	}
> +
> +	if (*start_pfn == -1UL)
> +		*start_pfn = 0;
> +}
> +
>  /*
>   * Generic implementation of memory_add_physaddr_to_nid() depends on
>   * architecture using memblock data for numa information.
>   */
>  #ifdef CONFIG_MEMBLOCK_NUMA_INFO
> -int __init_or_memblock memory_add_physaddr_to_nid(u64 addr)
> +static int __init_or_memblock __memory_add_physaddr_to_nid(u64 addr)
>  {
>  	unsigned long start_pfn, end_pfn, pfn = PHYS_PFN(addr);
>  	int nid;
> @@ -6384,10 +6411,42 @@ int __init_or_memblock memory_add_physaddr_to_nid(u64 addr)
>  		if (pfn >= start_pfn && pfn <= end_pfn)
>  			return nid;
>  	}
> +	return NUMA_NO_NODE;
> +}
> +
> +int __init_or_memblock memory_add_physaddr_to_nid(u64 addr)
> +{
> +	int nid = __memory_add_physaddr_to_nid(addr);
> +
>  	/* Default to node0 as not all callers are prepared for this to fail */
> -	return 0;
> +	if (nid == NUMA_NO_NODE)
> +		return 0;
> +	return nid;
>  }
>  EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
> +
> +int __init_or_memblock phys_to_target_node(u64 addr)
> +{
> +	unsigned long start_pfn, end_pfn, pfn = PHYS_PFN(addr);
> +	int nid = __memory_add_physaddr_to_nid(addr);
> +
> +	if (nid != NUMA_NO_NODE)
> +		return nid;
> +
> +	/*
> +	 * Search reserved memory ranges since the memory address does
> +	 * not appear to be online
> +	 */
> +	for_each_possible_node(nid) {
> +		if (node_online(nid))
> +			continue;
> +		get_reserved_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
> +		if (pfn >= start_pfn && pfn <= end_pfn)
> +			return nid;
> +	}
> +	return NUMA_NO_NODE;
> +}
> +EXPORT_SYMBOL_GPL(phys_to_target_node);
>  #endif /* CONFIG_MEMBLOCK_NUMA_INFO */
>  
>  /*
> 

-- 
Sincerely yours,
Mike.
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs
  2020-07-12 17:09   ` Greg Kroah-Hartman
@ 2020-07-13 15:39     ` Dan Williams
  2020-07-13 15:52       ` Greg Kroah-Hartman
  0 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-13 15:39 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: linux-nvdimm, Rafael J. Wysocki, Peter Zijlstra, Dave Hansen,
	Ard Biesheuvel, Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig, Joao Martins

On Sun, Jul 12, 2020 at 10:09 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Sun, Jul 12, 2020 at 09:27:37AM -0700, Dan Williams wrote:
> > Use sysfs_streq() in device_find_child_by_name() to allow it to use a
> > sysfs input string that might contain a trailing newline.
> >
> > The other "device by name" interfaces,
> > {bus,driver,class}_find_device_by_name(), already account for sysfs
> > strings.
> >
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> > ---
> >  drivers/base/core.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > index 67d39a90b45c..5d31b962c898 100644
> > --- a/drivers/base/core.c
> > +++ b/drivers/base/core.c
> > @@ -3078,7 +3078,7 @@ struct device *device_find_child_by_name(struct device *parent,
> >
> >       klist_iter_init(&parent->p->klist_children, &i);
> >       while ((child = next_device(&i)))
> > -             if (!strcmp(dev_name(child), name) && get_device(child))
> > +             if (sysfs_streq(dev_name(child), name) && get_device(child))
>
> Who wants to call this function with a name passed from userspace?
>
> Not objecting to it, just curious...
>

The series that incorporates this patch adds a partitioning mechanism
to "device-dax region" devices with an:
    "echo 1 > regionX/create" to create a new partition / sub-instance
of a region, and...
    "echo $devname > regionX/delete" to delete. Where $devname is
searched in the child devices of regionX to trigger device_del().

This arrangement avoids one of the design mistakes of libnvdimm which
uses a sysfs attribute of the device to delete itself. Parent-device
triggered deletion rather than self-deletion avoids those locking
entanglements.
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 07/22] numa: Introduce a generic memory_add_physaddr_to_nid()
  2020-07-13  6:58   ` Mike Rapoport
@ 2020-07-13 15:42     ` Dan Williams
  0 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-13 15:42 UTC (permalink / raw)
  To: Mike Rapoport
  Cc: linux-nvdimm, Jia He, Will Deacon, David Hildenbrand,
	Andrew Morton, Peter Zijlstra, Dave Hansen, Ard Biesheuvel,
	Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig, Joao Martins

On Sun, Jul 12, 2020 at 11:58 PM Mike Rapoport <rppt@linux.ibm.com> wrote:
>
> Hi Dan,
>
> On Sun, Jul 12, 2020 at 09:26:43AM -0700, Dan Williams wrote:
> > For architectures that opt into storing their numa data in memblock
> > (only ARM64 currently), add a memblock generic way to interrogate that
> > data for memory_add_physaddr_to_nid(). This requires ARCH_KEEP_MEMBLOCK
> > to keep memblock text and data around after boot.
>
> I afraid we are too far from using memblock as a generic placeholder for
> numa data. Although all architectures now have the numa info in
> memblock, only arm64 uses memblock as the primary source of that data.
>
> I'd rather prefer Jia's solution [1] to have a weak default for
> memory_add_physaddr_to_nid() and let architectures override it.

I'm ok with that as long as we do the same for phys_to_target_node().

Will had the concern about adding a generic numa-info facility the
last I tried this. I just don't see a practical way to get there in
the near term.
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 08/22] memblock: Introduce a generic phys_addr_to_target_node()
  2020-07-13  7:03   ` Mike Rapoport
@ 2020-07-13 15:48     ` Dan Williams
  2020-07-14  1:36       ` Justin He
  0 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-13 15:48 UTC (permalink / raw)
  To: Mike Rapoport
  Cc: linux-nvdimm, Jia He, Will Deacon, David Hildenbrand,
	Andrew Morton, Peter Zijlstra, Dave Hansen, Ard Biesheuvel,
	Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig, Joao Martins

On Mon, Jul 13, 2020 at 12:04 AM Mike Rapoport <rppt@linux.ibm.com> wrote:
>
> Hi Dan,
>
> On Sun, Jul 12, 2020 at 09:26:48AM -0700, Dan Williams wrote:
> > Similar to how generic memory_add_physaddr_to_nid() interrogates
> > memblock data for numa information, introduce
> > get_reserved_pfn_range_from_nid() to enable the same operation for
> > reserved memory ranges. Example memory ranges that are reserved, but
> > still have associated numa-info are persistent memory or Soft Reserved
> > (EFI_MEMORY_SP) memory.
>
> Here again, I would prefer to add a weak default for
> phys_to_target_node() because the "generic" implementation is not really
> generic.
>
> The fallback to reserved ranges is x86 specfic because on x86 most of the
> reserved areas is not in memblock.memory. AFAIK, no other architecture
> does this.

True, I was pre-fetching ARM using the new EFI "Special Purpose"
memory attribute. However, until that becomes something that platforms
deploy in practice I'm ok with not solving that problem for now.

> And x86 anyway has implementation of phys_to_target_node().

Sure, let's go with the default stub for non-x86.

Justin, do you think it would make sense to fold your dax_kmem
enabling for arm64 series into my enabling of dax_hmem for all
memory-hotplug archs?
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs
  2020-07-13 15:39     ` Dan Williams
@ 2020-07-13 15:52       ` Greg Kroah-Hartman
  2020-07-13 16:09         ` Dan Williams
  0 siblings, 1 reply; 46+ messages in thread
From: Greg Kroah-Hartman @ 2020-07-13 15:52 UTC (permalink / raw)
  To: Dan Williams
  Cc: linux-nvdimm, Rafael J. Wysocki, Peter Zijlstra, Dave Hansen,
	Ard Biesheuvel, Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig, Joao Martins

On Mon, Jul 13, 2020 at 08:39:43AM -0700, Dan Williams wrote:
> On Sun, Jul 12, 2020 at 10:09 AM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Sun, Jul 12, 2020 at 09:27:37AM -0700, Dan Williams wrote:
> > > Use sysfs_streq() in device_find_child_by_name() to allow it to use a
> > > sysfs input string that might contain a trailing newline.
> > >
> > > The other "device by name" interfaces,
> > > {bus,driver,class}_find_device_by_name(), already account for sysfs
> > > strings.
> > >
> > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> > > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> > > ---
> > >  drivers/base/core.c |    2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > > index 67d39a90b45c..5d31b962c898 100644
> > > --- a/drivers/base/core.c
> > > +++ b/drivers/base/core.c
> > > @@ -3078,7 +3078,7 @@ struct device *device_find_child_by_name(struct device *parent,
> > >
> > >       klist_iter_init(&parent->p->klist_children, &i);
> > >       while ((child = next_device(&i)))
> > > -             if (!strcmp(dev_name(child), name) && get_device(child))
> > > +             if (sysfs_streq(dev_name(child), name) && get_device(child))
> >
> > Who wants to call this function with a name passed from userspace?
> >
> > Not objecting to it, just curious...
> >
> 
> The series that incorporates this patch adds a partitioning mechanism
> to "device-dax region" devices with an:
>     "echo 1 > regionX/create" to create a new partition / sub-instance
> of a region, and...
>     "echo $devname > regionX/delete" to delete. Where $devname is
> searched in the child devices of regionX to trigger device_del().

Shouldn't that be done in configfs, not sysfs?

> This arrangement avoids one of the design mistakes of libnvdimm which
> uses a sysfs attribute of the device to delete itself. Parent-device
> triggered deletion rather than self-deletion avoids those locking
> entanglements.

Ugh, yeah, getting rid of that would be great, it's a mess.  I think
scsi still does that :(

thanks,

greg k-h
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs
  2020-07-13 15:52       ` Greg Kroah-Hartman
@ 2020-07-13 16:09         ` Dan Williams
  2020-07-13 16:12           ` Greg Kroah-Hartman
  0 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-13 16:09 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: linux-nvdimm, Rafael J. Wysocki, Peter Zijlstra, Dave Hansen,
	Ard Biesheuvel, Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig, Joao Martins

On Mon, Jul 13, 2020 at 8:52 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Mon, Jul 13, 2020 at 08:39:43AM -0700, Dan Williams wrote:
> > On Sun, Jul 12, 2020 at 10:09 AM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Sun, Jul 12, 2020 at 09:27:37AM -0700, Dan Williams wrote:
> > > > Use sysfs_streq() in device_find_child_by_name() to allow it to use a
> > > > sysfs input string that might contain a trailing newline.
> > > >
> > > > The other "device by name" interfaces,
> > > > {bus,driver,class}_find_device_by_name(), already account for sysfs
> > > > strings.
> > > >
> > > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > > Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> > > > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> > > > ---
> > > >  drivers/base/core.c |    2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > > > index 67d39a90b45c..5d31b962c898 100644
> > > > --- a/drivers/base/core.c
> > > > +++ b/drivers/base/core.c
> > > > @@ -3078,7 +3078,7 @@ struct device *device_find_child_by_name(struct device *parent,
> > > >
> > > >       klist_iter_init(&parent->p->klist_children, &i);
> > > >       while ((child = next_device(&i)))
> > > > -             if (!strcmp(dev_name(child), name) && get_device(child))
> > > > +             if (sysfs_streq(dev_name(child), name) && get_device(child))
> > >
> > > Who wants to call this function with a name passed from userspace?
> > >
> > > Not objecting to it, just curious...
> > >
> >
> > The series that incorporates this patch adds a partitioning mechanism
> > to "device-dax region" devices with an:
> >     "echo 1 > regionX/create" to create a new partition / sub-instance
> > of a region, and...
> >     "echo $devname > regionX/delete" to delete. Where $devname is
> > searched in the child devices of regionX to trigger device_del().
>
> Shouldn't that be done in configfs, not sysfs?

I see configfs as an awkward fit for this situation. configfs wants to
software define kernel objects whereas this facility wants to augment
existing kernel enumerated device objects. The region device is
created by firmware policy and is optionally partitioned, configfs
objects don't exist at all until created. So for this I see sysfs +
'scheme to trigger child device creation' as just enough mechanism
that does not warrant full blown configfs.

I believe it was debates like this [1] that have led me to the camp of
sysfs being capable of some device creation dynamism and leave
configfs for purely software constructed objects.

[1]: https://lore.kernel.org/lkml/17377.42813.479466.690408@cse.unsw.edu.au/

> > This arrangement avoids one of the design mistakes of libnvdimm which
> > uses a sysfs attribute of the device to delete itself. Parent-device
> > triggered deletion rather than self-deletion avoids those locking
> > entanglements.
>
> Ugh, yeah, getting rid of that would be great, it's a mess.  I think
> scsi still does that :(

Yeah, both nvdimm and scsi both end up need to delay device deletion
to its own thread, and it has led to bugs in the nvdimm case.
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs
  2020-07-13 16:09         ` Dan Williams
@ 2020-07-13 16:12           ` Greg Kroah-Hartman
  2020-07-13 16:36             ` Dan Williams
  0 siblings, 1 reply; 46+ messages in thread
From: Greg Kroah-Hartman @ 2020-07-13 16:12 UTC (permalink / raw)
  To: Dan Williams
  Cc: linux-nvdimm, Rafael J. Wysocki, Peter Zijlstra, Dave Hansen,
	Ard Biesheuvel, Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig, Joao Martins

On Mon, Jul 13, 2020 at 09:09:18AM -0700, Dan Williams wrote:
> On Mon, Jul 13, 2020 at 8:52 AM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Mon, Jul 13, 2020 at 08:39:43AM -0700, Dan Williams wrote:
> > > On Sun, Jul 12, 2020 at 10:09 AM Greg Kroah-Hartman
> > > <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > On Sun, Jul 12, 2020 at 09:27:37AM -0700, Dan Williams wrote:
> > > > > Use sysfs_streq() in device_find_child_by_name() to allow it to use a
> > > > > sysfs input string that might contain a trailing newline.
> > > > >
> > > > > The other "device by name" interfaces,
> > > > > {bus,driver,class}_find_device_by_name(), already account for sysfs
> > > > > strings.
> > > > >
> > > > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > > > Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> > > > > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> > > > > ---
> > > > >  drivers/base/core.c |    2 +-
> > > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > > > > index 67d39a90b45c..5d31b962c898 100644
> > > > > --- a/drivers/base/core.c
> > > > > +++ b/drivers/base/core.c
> > > > > @@ -3078,7 +3078,7 @@ struct device *device_find_child_by_name(struct device *parent,
> > > > >
> > > > >       klist_iter_init(&parent->p->klist_children, &i);
> > > > >       while ((child = next_device(&i)))
> > > > > -             if (!strcmp(dev_name(child), name) && get_device(child))
> > > > > +             if (sysfs_streq(dev_name(child), name) && get_device(child))
> > > >
> > > > Who wants to call this function with a name passed from userspace?
> > > >
> > > > Not objecting to it, just curious...
> > > >
> > >
> > > The series that incorporates this patch adds a partitioning mechanism
> > > to "device-dax region" devices with an:
> > >     "echo 1 > regionX/create" to create a new partition / sub-instance
> > > of a region, and...
> > >     "echo $devname > regionX/delete" to delete. Where $devname is
> > > searched in the child devices of regionX to trigger device_del().
> >
> > Shouldn't that be done in configfs, not sysfs?
> 
> I see configfs as an awkward fit for this situation. configfs wants to
> software define kernel objects whereas this facility wants to augment
> existing kernel enumerated device objects. The region device is
> created by firmware policy and is optionally partitioned, configfs
> objects don't exist at all until created. So for this I see sysfs +
> 'scheme to trigger child device creation' as just enough mechanism
> that does not warrant full blown configfs.
> 
> I believe it was debates like this [1] that have led me to the camp of
> sysfs being capable of some device creation dynamism and leave
> configfs for purely software constructed objects.
> 
> [1]: https://lore.kernel.org/lkml/17377.42813.479466.690408@cse.unsw.edu.au/

"some" :)

And that was from 2006, ugh, how did you find that...

Ok, that's fine, no objection from me for this patch:

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs
  2020-07-13 16:12           ` Greg Kroah-Hartman
@ 2020-07-13 16:36             ` Dan Williams
  0 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-13 16:36 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: linux-nvdimm, Rafael J. Wysocki, Peter Zijlstra, Dave Hansen,
	Ard Biesheuvel, Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig, Joao Martins

On Mon, Jul 13, 2020 at 9:13 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Mon, Jul 13, 2020 at 09:09:18AM -0700, Dan Williams wrote:
> > On Mon, Jul 13, 2020 at 8:52 AM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Mon, Jul 13, 2020 at 08:39:43AM -0700, Dan Williams wrote:
> > > > On Sun, Jul 12, 2020 at 10:09 AM Greg Kroah-Hartman
> > > > <gregkh@linuxfoundation.org> wrote:
> > > > >
> > > > > On Sun, Jul 12, 2020 at 09:27:37AM -0700, Dan Williams wrote:
> > > > > > Use sysfs_streq() in device_find_child_by_name() to allow it to use a
> > > > > > sysfs input string that might contain a trailing newline.
> > > > > >
> > > > > > The other "device by name" interfaces,
> > > > > > {bus,driver,class}_find_device_by_name(), already account for sysfs
> > > > > > strings.
> > > > > >
> > > > > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > > > > Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> > > > > > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> > > > > > ---
> > > > > >  drivers/base/core.c |    2 +-
> > > > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > >
> > > > > > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > > > > > index 67d39a90b45c..5d31b962c898 100644
> > > > > > --- a/drivers/base/core.c
> > > > > > +++ b/drivers/base/core.c
> > > > > > @@ -3078,7 +3078,7 @@ struct device *device_find_child_by_name(struct device *parent,
> > > > > >
> > > > > >       klist_iter_init(&parent->p->klist_children, &i);
> > > > > >       while ((child = next_device(&i)))
> > > > > > -             if (!strcmp(dev_name(child), name) && get_device(child))
> > > > > > +             if (sysfs_streq(dev_name(child), name) && get_device(child))
> > > > >
> > > > > Who wants to call this function with a name passed from userspace?
> > > > >
> > > > > Not objecting to it, just curious...
> > > > >
> > > >
> > > > The series that incorporates this patch adds a partitioning mechanism
> > > > to "device-dax region" devices with an:
> > > >     "echo 1 > regionX/create" to create a new partition / sub-instance
> > > > of a region, and...
> > > >     "echo $devname > regionX/delete" to delete. Where $devname is
> > > > searched in the child devices of regionX to trigger device_del().
> > >
> > > Shouldn't that be done in configfs, not sysfs?
> >
> > I see configfs as an awkward fit for this situation. configfs wants to
> > software define kernel objects whereas this facility wants to augment
> > existing kernel enumerated device objects. The region device is
> > created by firmware policy and is optionally partitioned, configfs
> > objects don't exist at all until created. So for this I see sysfs +
> > 'scheme to trigger child device creation' as just enough mechanism
> > that does not warrant full blown configfs.
> >
> > I believe it was debates like this [1] that have led me to the camp of
> > sysfs being capable of some device creation dynamism and leave
> > configfs for purely software constructed objects.
> >
> > [1]: https://lore.kernel.org/lkml/17377.42813.479466.690408@cse.unsw.edu.au/
>
> "some" :)

Yes, lowercase and quoted: "some" :).

> And that was from 2006, ugh, how did you find that...

Oh, public-inbox is a wonderful thing. "I kinda sort of remember Neil
laying out a configfs vs sysfs argument", /me searches for "f:neil
configfs" and voila.

> Ok, that's fine, no objection from me for this patch:
>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Thanks, Greg.
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 19/22] mm/memremap_pages: Convert to 'struct range'
  2020-07-12 16:27 ` [PATCH v2 19/22] mm/memremap_pages: Convert to 'struct range' Dan Williams
@ 2020-07-13 16:36   ` Ralph Campbell
  2020-07-13 16:54     ` Dan Williams
  0 siblings, 1 reply; 46+ messages in thread
From: Ralph Campbell @ 2020-07-13 16:36 UTC (permalink / raw)
  To: Dan Williams, linux-nvdimm
  Cc: Paul Mackerras, Michael Ellerman, Benjamin Herrenschmidt,
	Ben Skeggs, David Airlie, Daniel Vetter, Jason Gunthorpe, peterz,
	dave.hansen, ard.biesheuvel, linux-mm, linux-kernel, linux-acpi,
	hch, joao.m.martins


On 7/12/20 9:27 AM, Dan Williams wrote:
> The 'struct resource' in 'struct dev_pagemap' is only used for holding
> resource span information. The other fields, 'name', 'flags', 'desc',
> 'parent', 'sibling', and 'child' are all unused wasted space.
> 
> This is in preparation for introducing a multi-range extension of
> devm_memremap_pages().
> 
> The bulk of this change is unwinding all the places internal to
> libnvdimm that used 'struct resource' unnecessarily.
> 
> P2PDMA had a minor usage of the flags field, but only to report failures
> with "%pR". That is replaced with an open coded print of the range.
> 
> Cc: Paul Mackerras <paulus@ozlabs.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Ben Skeggs <bskeggs@redhat.com>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Jason Gunthorpe <jgg@mellanox.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>   arch/powerpc/kvm/book3s_hv_uvmem.c     |   13 +++--
>   drivers/dax/bus.c                      |   10 ++--
>   drivers/dax/bus.h                      |    2 -
>   drivers/dax/dax-private.h              |    5 --
>   drivers/dax/device.c                   |    3 -
>   drivers/dax/hmem/hmem.c                |    5 ++
>   drivers/dax/pmem/core.c                |   12 ++---
>   drivers/gpu/drm/nouveau/nouveau_dmem.c |    3 +
>   drivers/nvdimm/badrange.c              |   26 +++++------
>   drivers/nvdimm/claim.c                 |   13 +++--
>   drivers/nvdimm/nd.h                    |    3 +
>   drivers/nvdimm/pfn_devs.c              |   12 ++---
>   drivers/nvdimm/pmem.c                  |   26 ++++++-----
>   drivers/nvdimm/region.c                |   21 +++++----
>   drivers/pci/p2pdma.c                   |   11 ++---
>   include/linux/memremap.h               |    5 +-
>   include/linux/range.h                  |    6 ++
>   mm/memremap.c                          |   77 ++++++++++++++++----------------
>   tools/testing/nvdimm/test/iomap.c      |    2 -
>   19 files changed, 135 insertions(+), 120 deletions(-)

I think you are missing a call to memremap_pages() in lib/test_hmm.c
and a call to release_mem_region() that need to be converted too.
Try setting CONFIG_TEST_HMM=m.

Also, what about the call to release_mem_region() in
drivers/gpu/drm/nouveau/nouveau_dmem.c? Doesn't that need a small change too?
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 19/22] mm/memremap_pages: Convert to 'struct range'
  2020-07-13 16:36   ` Ralph Campbell
@ 2020-07-13 16:54     ` Dan Williams
  0 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-13 16:54 UTC (permalink / raw)
  To: Ralph Campbell
  Cc: linux-nvdimm, Paul Mackerras, Michael Ellerman,
	Benjamin Herrenschmidt, Ben Skeggs, David Airlie, Daniel Vetter,
	Jason Gunthorpe, Peter Zijlstra, Dave Hansen, Ard Biesheuvel,
	Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig, Joao Martins

On Mon, Jul 13, 2020 at 9:36 AM Ralph Campbell <rcampbell@nvidia.com> wrote:
>
>
> On 7/12/20 9:27 AM, Dan Williams wrote:
> > The 'struct resource' in 'struct dev_pagemap' is only used for holding
> > resource span information. The other fields, 'name', 'flags', 'desc',
> > 'parent', 'sibling', and 'child' are all unused wasted space.
> >
> > This is in preparation for introducing a multi-range extension of
> > devm_memremap_pages().
> >
> > The bulk of this change is unwinding all the places internal to
> > libnvdimm that used 'struct resource' unnecessarily.
> >
> > P2PDMA had a minor usage of the flags field, but only to report failures
> > with "%pR". That is replaced with an open coded print of the range.
> >
> > Cc: Paul Mackerras <paulus@ozlabs.org>
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Dan Williams <dan.j.williams@intel.com>
> > Cc: Vishal Verma <vishal.l.verma@intel.com>
> > Cc: Dave Jiang <dave.jiang@intel.com>
> > Cc: Ben Skeggs <bskeggs@redhat.com>
> > Cc: David Airlie <airlied@linux.ie>
> > Cc: Daniel Vetter <daniel@ffwll.ch>
> > Cc: Ira Weiny <ira.weiny@intel.com>
> > Cc: Jason Gunthorpe <jgg@mellanox.com>
> > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> > ---
> >   arch/powerpc/kvm/book3s_hv_uvmem.c     |   13 +++--
> >   drivers/dax/bus.c                      |   10 ++--
> >   drivers/dax/bus.h                      |    2 -
> >   drivers/dax/dax-private.h              |    5 --
> >   drivers/dax/device.c                   |    3 -
> >   drivers/dax/hmem/hmem.c                |    5 ++
> >   drivers/dax/pmem/core.c                |   12 ++---
> >   drivers/gpu/drm/nouveau/nouveau_dmem.c |    3 +
> >   drivers/nvdimm/badrange.c              |   26 +++++------
> >   drivers/nvdimm/claim.c                 |   13 +++--
> >   drivers/nvdimm/nd.h                    |    3 +
> >   drivers/nvdimm/pfn_devs.c              |   12 ++---
> >   drivers/nvdimm/pmem.c                  |   26 ++++++-----
> >   drivers/nvdimm/region.c                |   21 +++++----
> >   drivers/pci/p2pdma.c                   |   11 ++---
> >   include/linux/memremap.h               |    5 +-
> >   include/linux/range.h                  |    6 ++
> >   mm/memremap.c                          |   77 ++++++++++++++++----------------
> >   tools/testing/nvdimm/test/iomap.c      |    2 -
> >   19 files changed, 135 insertions(+), 120 deletions(-)
>
> I think you are missing a call to memremap_pages() in lib/test_hmm.c
> and a call to release_mem_region() that need to be converted too.
> Try setting CONFIG_TEST_HMM=m.

Thanks Ralph, looks like I overlooked these changes since the rebase.

> Also, what about the call to release_mem_region() in
> drivers/gpu/drm/nouveau/nouveau_dmem.c? Doesn't that need a small change too?

I'll double check my config, that one should have been flagged at build time.
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* RE: [PATCH v2 08/22] memblock: Introduce a generic phys_addr_to_target_node()
  2020-07-13 15:48     ` Dan Williams
@ 2020-07-14  1:36       ` Justin He
  0 siblings, 0 replies; 46+ messages in thread
From: Justin He @ 2020-07-14  1:36 UTC (permalink / raw)
  To: Dan Williams, Mike Rapoport
  Cc: linux-nvdimm, Will Deacon, David Hildenbrand, Andrew Morton,
	Peter Zijlstra, Dave Hansen, Ard Biesheuvel, Linux MM,
	Linux Kernel Mailing List, Linux ACPI, Christoph Hellwig,
	Joao Martins

Hi Dan

> -----Original Message-----
> From: Dan Williams <dan.j.williams@intel.com>
> Sent: Monday, July 13, 2020 11:48 PM
> To: Mike Rapoport <rppt@linux.ibm.com>
> Cc: linux-nvdimm <linux-nvdimm@lists.01.org>; Justin He
> <Justin.He@arm.com>; Will Deacon <will@kernel.org>; David Hildenbrand
> <david@redhat.com>; Andrew Morton <akpm@linux-foundation.org>; Peter
> Zijlstra <peterz@infradead.org>; Vishal L Verma <vishal.l.verma@intel.com>;
> Dave Hansen <dave.hansen@linux.intel.com>; Ard Biesheuvel
> <ard.biesheuvel@linaro.org>; Linux MM <linux-mm@kvack.org>; Linux Kernel
> Mailing List <linux-kernel@vger.kernel.org>; Linux ACPI <linux-
> acpi@vger.kernel.org>; Christoph Hellwig <hch@lst.de>; Joao Martins
> <joao.m.martins@oracle.com>
> Subject: Re: [PATCH v2 08/22] memblock: Introduce a generic
> phys_addr_to_target_node()
>
> On Mon, Jul 13, 2020 at 12:04 AM Mike Rapoport <rppt@linux.ibm.com> wrote:
> >
> > Hi Dan,
> >
> > On Sun, Jul 12, 2020 at 09:26:48AM -0700, Dan Williams wrote:
> > > Similar to how generic memory_add_physaddr_to_nid() interrogates
> > > memblock data for numa information, introduce
> > > get_reserved_pfn_range_from_nid() to enable the same operation for
> > > reserved memory ranges. Example memory ranges that are reserved, but
> > > still have associated numa-info are persistent memory or Soft Reserved
> > > (EFI_MEMORY_SP) memory.
> >
> > Here again, I would prefer to add a weak default for
> > phys_to_target_node() because the "generic" implementation is not really
> > generic.
> >
> > The fallback to reserved ranges is x86 specfic because on x86 most of
> the
> > reserved areas is not in memblock.memory. AFAIK, no other architecture
> > does this.
>
> True, I was pre-fetching ARM using the new EFI "Special Purpose"
> memory attribute. However, until that becomes something that platforms
> deploy in practice I'm ok with not solving that problem for now.
>
> > And x86 anyway has implementation of phys_to_target_node().
>
> Sure, let's go with the default stub for non-x86.
>
> Justin, do you think it would make sense to fold your dax_kmem
> enabling for arm64 series into my enabling of dax_hmem for all
> memory-hotplug archs?

It is ok with me, thanks for the folding 😊

--
Cheers,
Justin (Jia He)



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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 22/22] device-dax: Introduce 'mapping' devices
  2020-07-12 16:28 ` [PATCH v2 22/22] device-dax: Introduce 'mapping' devices Dan Williams
@ 2020-07-16 13:18   ` Joao Martins
  2020-07-16 16:00     ` Dan Williams
  0 siblings, 1 reply; 46+ messages in thread
From: Joao Martins @ 2020-07-16 13:18 UTC (permalink / raw)
  To: Dan Williams
  Cc: linux-nvdimm, peterz, dave.hansen, ard.biesheuvel, linux-mm,
	linux-kernel, linux-acpi, hch

On 7/12/20 5:28 PM, Dan Williams wrote:
> In support of interrogating the physical address layout of a device with
> dis-contiguous ranges, introduce a sysfs directory with 'start', 'end',
> and 'page_offset' attributes. The alternative is trying to parse
> /proc/iomem, and that file will not reflect the extent layout until the
> device is enabled.
> 
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/dax/bus.c         |  191 +++++++++++++++++++++++++++++++++++++++++++++
>  drivers/dax/dax-private.h |   14 +++
>  2 files changed, 203 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> index f342e36c69a1..8b6c4ddc5f42 100644
> --- a/drivers/dax/bus.c
> +++ b/drivers/dax/bus.c
> @@ -579,6 +579,167 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
>  }
>  EXPORT_SYMBOL_GPL(alloc_dax_region);
>  
> +static void dax_mapping_release(struct device *dev)
> +{
> +	struct dax_mapping *mapping = to_dax_mapping(dev);
> +	struct dev_dax *dev_dax = to_dev_dax(dev->parent);
> +
> +	ida_free(&dev_dax->ida, mapping->id);
> +	kfree(mapping);
> +}
> +
> +static void unregister_dax_mapping(void *data)
> +{
> +	struct device *dev = data;
> +	struct dax_mapping *mapping = to_dax_mapping(dev);
> +	struct dev_dax *dev_dax = to_dev_dax(dev->parent);
> +	struct dax_region *dax_region = dev_dax->region;
> +
> +	dev_dbg(dev, "%s\n", __func__);
> +
> +	device_lock_assert(dax_region->dev);
> +
> +	dev_dax->ranges[mapping->range_id].mapping = NULL;
> +	mapping->range_id = -1;
> +
> +	device_del(dev);
> +	put_device(dev);
> +}
> +
> +static struct dev_dax_range *get_dax_range(struct device *dev)
> +{
> +	struct dax_mapping *mapping = to_dax_mapping(dev);
> +	struct dev_dax *dev_dax = to_dev_dax(dev->parent);
> +	struct dax_region *dax_region = dev_dax->region;
> +
> +	device_lock(dax_region->dev);
> +	if (mapping->range_id < 1) {
            ^^^^^^^^^^^^^^^^^^^^^ it's 'mapping->range_id < 0'

Otherwise 'mapping0' sysfs entries won't work.
Disabled ranges use id -1.

	Joao
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* Re: [PATCH v2 22/22] device-dax: Introduce 'mapping' devices
  2020-07-16 13:18   ` Joao Martins
@ 2020-07-16 16:00     ` Dan Williams
  2020-07-16 19:04       ` Joao Martins
  0 siblings, 1 reply; 46+ messages in thread
From: Dan Williams @ 2020-07-16 16:00 UTC (permalink / raw)
  To: Joao Martins
  Cc: linux-nvdimm, Peter Zijlstra, Dave Hansen, Ard Biesheuvel,
	Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig

On Thu, Jul 16, 2020 at 6:19 AM Joao Martins <joao.m.martins@oracle.com> wrote:
>
> On 7/12/20 5:28 PM, Dan Williams wrote:
> > In support of interrogating the physical address layout of a device with
> > dis-contiguous ranges, introduce a sysfs directory with 'start', 'end',
> > and 'page_offset' attributes. The alternative is trying to parse
> > /proc/iomem, and that file will not reflect the extent layout until the
> > device is enabled.
> >
> > Cc: Vishal Verma <vishal.l.verma@intel.com>
> > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> > ---
> >  drivers/dax/bus.c         |  191 +++++++++++++++++++++++++++++++++++++++++++++
> >  drivers/dax/dax-private.h |   14 +++
> >  2 files changed, 203 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> > index f342e36c69a1..8b6c4ddc5f42 100644
> > --- a/drivers/dax/bus.c
> > +++ b/drivers/dax/bus.c
> > @@ -579,6 +579,167 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
> >  }
> >  EXPORT_SYMBOL_GPL(alloc_dax_region);
> >
> > +static void dax_mapping_release(struct device *dev)
> > +{
> > +     struct dax_mapping *mapping = to_dax_mapping(dev);
> > +     struct dev_dax *dev_dax = to_dev_dax(dev->parent);
> > +
> > +     ida_free(&dev_dax->ida, mapping->id);
> > +     kfree(mapping);
> > +}
> > +
> > +static void unregister_dax_mapping(void *data)
> > +{
> > +     struct device *dev = data;
> > +     struct dax_mapping *mapping = to_dax_mapping(dev);
> > +     struct dev_dax *dev_dax = to_dev_dax(dev->parent);
> > +     struct dax_region *dax_region = dev_dax->region;
> > +
> > +     dev_dbg(dev, "%s\n", __func__);
> > +
> > +     device_lock_assert(dax_region->dev);
> > +
> > +     dev_dax->ranges[mapping->range_id].mapping = NULL;
> > +     mapping->range_id = -1;
> > +
> > +     device_del(dev);
> > +     put_device(dev);
> > +}
> > +
> > +static struct dev_dax_range *get_dax_range(struct device *dev)
> > +{
> > +     struct dax_mapping *mapping = to_dax_mapping(dev);
> > +     struct dev_dax *dev_dax = to_dev_dax(dev->parent);
> > +     struct dax_region *dax_region = dev_dax->region;
> > +
> > +     device_lock(dax_region->dev);
> > +     if (mapping->range_id < 1) {
>             ^^^^^^^^^^^^^^^^^^^^^ it's 'mapping->range_id < 0'
>
> Otherwise 'mapping0' sysfs entries won't work.
> Disabled ranges use id -1.

Whoops, yes. Needs a unit test.
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v1 0/4] device-dax: Further improvements to subdivision
  2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
                   ` (21 preceding siblings ...)
  2020-07-12 16:28 ` [PATCH v2 22/22] device-dax: Introduce 'mapping' devices Dan Williams
@ 2020-07-16 17:29 ` Joao Martins
  2020-07-16 17:29   ` [PATCH v1 1/4] device-dax: Make align a per-device property Joao Martins
                     ` (3 more replies)
  22 siblings, 4 replies; 46+ messages in thread
From: Joao Martins @ 2020-07-16 17:29 UTC (permalink / raw)
  To: Dan Williams; +Cc: linux-nvdimm, linux-kernel, linux-mm, Jason Zeng

Hey,

Here's a small set of improvements that I was hoping you would consider as part
of your Soft-Reserved series[0]; should you think they make sense. It does the
following:

  Patch 1-2: Add an align sysfs attribute, as opposed to being limited to 2M.
  This brings parity to static dax regions, which support 1G.

  Patch 3. Add a module parameter to hmem, to initialize the region as idle
  with full available_size for child devices. When the region is gonna be
  partiotined by default and assigned to guests, doesn't help to
  initialize the region. Also if the majority of the region starts
  non-idle and it's a region which memmap is bigger than System-Ram,
  then there not be enough space for the device to be probed successfully.

  Patch 4: Add an sysfs attribute for range allocation. It is a single entry
  where you pass a range <start>-<end> and where the ordering plus range
  length designate the page_offset. It is meant for recreate the same
  mappings after kexec (retaining the GPA->HPA association), but could
  also allow application to implement their own allocation strategy.

I will submit a separate daxctl counterpart shortly, to help visualize its use.

[0] https://lore.kernel.org/linux-mm/159457116473.754248.7879464730875147365.stgit@dwillia2-desk3.amr.corp.intel.com

	Joao

Joao Martins (4):
  device-dax: Make align a per-device property
  device-dax: Add an 'align' attribute
  dax/hmem: Introduce dax_hmem.region_idle parameter
  device-dax: Add a range mapping allocation attribute

 drivers/dax/bus.c         | 166 +++++++++++++++++++++++++++++++++++---
 drivers/dax/dax-private.h |   1 +
 drivers/dax/device.c      |  35 ++++----
 drivers/dax/hmem/hmem.c   |   5 +-
 4 files changed, 177 insertions(+), 30 deletions(-)

-- 
2.17.1
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v1 1/4] device-dax: Make align a per-device property
  2020-07-16 17:29 ` [PATCH v1 0/4] device-dax: Further improvements to subdivision Joao Martins
@ 2020-07-16 17:29   ` Joao Martins
  2020-07-16 17:29   ` [PATCH v1 2/4] device-dax: Add an 'align' attribute Joao Martins
                     ` (2 subsequent siblings)
  3 siblings, 0 replies; 46+ messages in thread
From: Joao Martins @ 2020-07-16 17:29 UTC (permalink / raw)
  To: Dan Williams; +Cc: linux-nvdimm, linux-kernel, linux-mm

Introduce @align to struct dev_dax.

When creating a new device, we still initialize to the default
dax_region @align. Child devices belonging to a region may wish
to keep a different alignment property instead of a global
region-defined one.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 drivers/dax/bus.c         |  1 +
 drivers/dax/dax-private.h |  1 +
 drivers/dax/device.c      | 35 +++++++++++++++--------------------
 3 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 8b6c4ddc5f42..2578651c596e 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1215,6 +1215,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 
 	dev_dax->dax_dev = dax_dev;
 	dev_dax->target_node = dax_region->target_node;
+	dev_dax->align = dax_region->align;
 	ida_init(&dev_dax->ida);
 	kref_get(&dax_region->kref);
 
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 13780f62b95e..96ef5a8ae0ba 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -62,6 +62,7 @@ struct dax_mapping {
 struct dev_dax {
 	struct dax_region *region;
 	struct dax_device *dax_dev;
+	unsigned int align;
 	int target_node;
 	int id;
 	struct ida ida;
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 2bfc5c83e3b0..346c7bb8cf06 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -17,7 +17,6 @@
 static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 		const char *func)
 {
-	struct dax_region *dax_region = dev_dax->region;
 	struct device *dev = &dev_dax->dev;
 	unsigned long mask;
 
@@ -32,7 +31,7 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 		return -EINVAL;
 	}
 
-	mask = dax_region->align - 1;
+	mask = dev_dax->align - 1;
 	if (vma->vm_start & mask || vma->vm_end & mask) {
 		dev_info_ratelimited(dev,
 				"%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n",
@@ -86,13 +85,13 @@ static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 
 	dax_region = dev_dax->region;
-	if (dax_region->align > PAGE_SIZE) {
+	if (dev_dax->align > PAGE_SIZE) {
 		dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
-			dax_region->align, fault_size);
+			dev_dax->align, fault_size);
 		return VM_FAULT_SIGBUS;
 	}
 
-	if (fault_size != dax_region->align)
+	if (fault_size != dev_dax->align)
 		return VM_FAULT_SIGBUS;
 
 	phys = dax_pgoff_to_phys(dev_dax, vmf->pgoff, PAGE_SIZE);
@@ -120,15 +119,15 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 
 	dax_region = dev_dax->region;
-	if (dax_region->align > PMD_SIZE) {
+	if (dev_dax->align > PMD_SIZE) {
 		dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
-			dax_region->align, fault_size);
+			dev_dax->align, fault_size);
 		return VM_FAULT_SIGBUS;
 	}
 
-	if (fault_size < dax_region->align)
+	if (fault_size < dev_dax->align)
 		return VM_FAULT_SIGBUS;
-	else if (fault_size > dax_region->align)
+	else if (fault_size > dev_dax->align)
 		return VM_FAULT_FALLBACK;
 
 	/* if we are outside of the VMA */
@@ -164,15 +163,15 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 
 	dax_region = dev_dax->region;
-	if (dax_region->align > PUD_SIZE) {
+	if (dev_dax->align > PUD_SIZE) {
 		dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
-			dax_region->align, fault_size);
+			dev_dax->align, fault_size);
 		return VM_FAULT_SIGBUS;
 	}
 
-	if (fault_size < dax_region->align)
+	if (fault_size < dev_dax->align)
 		return VM_FAULT_SIGBUS;
-	else if (fault_size > dax_region->align)
+	else if (fault_size > dev_dax->align)
 		return VM_FAULT_FALLBACK;
 
 	/* if we are outside of the VMA */
@@ -267,9 +266,8 @@ static int dev_dax_split(struct vm_area_struct *vma, unsigned long addr)
 {
 	struct file *filp = vma->vm_file;
 	struct dev_dax *dev_dax = filp->private_data;
-	struct dax_region *dax_region = dev_dax->region;
 
-	if (!IS_ALIGNED(addr, dax_region->align))
+	if (!IS_ALIGNED(addr, dev_dax->align))
 		return -EINVAL;
 	return 0;
 }
@@ -278,9 +276,8 @@ static unsigned long dev_dax_pagesize(struct vm_area_struct *vma)
 {
 	struct file *filp = vma->vm_file;
 	struct dev_dax *dev_dax = filp->private_data;
-	struct dax_region *dax_region = dev_dax->region;
 
-	return dax_region->align;
+	return dev_dax->align;
 }
 
 static const struct vm_operations_struct dax_vm_ops = {
@@ -319,13 +316,11 @@ static unsigned long dax_get_unmapped_area(struct file *filp,
 {
 	unsigned long off, off_end, off_align, len_align, addr_align, align;
 	struct dev_dax *dev_dax = filp ? filp->private_data : NULL;
-	struct dax_region *dax_region;
 
 	if (!dev_dax || addr)
 		goto out;
 
-	dax_region = dev_dax->region;
-	align = dax_region->align;
+	align = dev_dax->align;
 	off = pgoff << PAGE_SHIFT;
 	off_end = off + len;
 	off_align = round_up(off, align);
-- 
2.17.1
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* [PATCH v1 2/4] device-dax: Add an 'align' attribute
  2020-07-16 17:29 ` [PATCH v1 0/4] device-dax: Further improvements to subdivision Joao Martins
  2020-07-16 17:29   ` [PATCH v1 1/4] device-dax: Make align a per-device property Joao Martins
@ 2020-07-16 17:29   ` Joao Martins
  2020-07-31 14:52     ` Dan Williams
  2020-07-16 17:29   ` [PATCH v1 3/4] dax/hmem: Introduce dax_hmem.region_idle parameter Joao Martins
  2020-07-16 17:29   ` [PATCH v1 4/4] device-dax: Add a range mapping allocation attribute Joao Martins
  3 siblings, 1 reply; 46+ messages in thread
From: Joao Martins @ 2020-07-16 17:29 UTC (permalink / raw)
  To: Dan Williams; +Cc: linux-nvdimm, linux-kernel, linux-mm

Introduce a device align attribute. While doing so,
rename the region align attribute to be more explicitly
named as so, but keep it named as @align to retain the API
for tools like daxctl.

Changes on align may not always be valid, when say certain
mappings were created with 2M and then we switch to 1G. So, we
validate all ranges against the new value being attempted,
post resizing.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 drivers/dax/bus.c | 101 +++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 92 insertions(+), 9 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 2578651c596e..eb384dd6a376 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -230,14 +230,15 @@ static ssize_t region_size_show(struct device *dev,
 static struct device_attribute dev_attr_region_size = __ATTR(size, 0444,
 		region_size_show, NULL);
 
-static ssize_t align_show(struct device *dev,
+static ssize_t region_align_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct dax_region *dax_region = dev_get_drvdata(dev);
 
 	return sprintf(buf, "%u\n", dax_region->align);
 }
-static DEVICE_ATTR_RO(align);
+static struct device_attribute dev_attr_region_align =
+		__ATTR(align, 0400, region_align_show, NULL);
 
 #define for_each_dax_region_resource(dax_region, res) \
 	for (res = (dax_region)->res.child; res; res = res->sibling)
@@ -488,7 +489,7 @@ static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a,
 static struct attribute *dax_region_attributes[] = {
 	&dev_attr_available_size.attr,
 	&dev_attr_region_size.attr,
-	&dev_attr_align.attr,
+	&dev_attr_region_align.attr,
 	&dev_attr_create.attr,
 	&dev_attr_seed.attr,
 	&dev_attr_delete.attr,
@@ -855,14 +856,13 @@ static ssize_t size_show(struct device *dev,
 	return sprintf(buf, "%llu\n", size);
 }
 
-static bool alloc_is_aligned(struct dax_region *dax_region,
-		resource_size_t size)
+static bool alloc_is_aligned(resource_size_t size, unsigned long align)
 {
 	/*
 	 * The minimum mapping granularity for a device instance is a
 	 * single subsection, unless the arch says otherwise.
 	 */
-	return IS_ALIGNED(size, max_t(unsigned long, dax_region->align,
+	return IS_ALIGNED(size, max_t(unsigned long, align,
 				memremap_compat_align()));
 }
 
@@ -958,7 +958,7 @@ static ssize_t dev_dax_resize(struct dax_region *dax_region,
 		return dev_dax_shrink(dev_dax, size);
 
 	to_alloc = size - dev_size;
-	if (dev_WARN_ONCE(dev, !alloc_is_aligned(dax_region, to_alloc),
+	if (dev_WARN_ONCE(dev, !alloc_is_aligned(to_alloc, dev_dax->align),
 			"resize of %pa misaligned\n", &to_alloc))
 		return -ENXIO;
 
@@ -1022,7 +1022,7 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 	if (rc)
 		return rc;
 
-	if (!alloc_is_aligned(dax_region, val)) {
+	if (!alloc_is_aligned(val, dev_dax->align)) {
 		dev_dbg(dev, "%s: size: %lld misaligned\n", __func__, val);
 		return -EINVAL;
 	}
@@ -1041,6 +1041,87 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RW(size);
 
+static ssize_t align_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+
+	return sprintf(buf, "%d\n", dev_dax->align);
+}
+
+static ssize_t dev_dax_set_align(struct dev_dax *dev_dax,
+				 unsigned long long align)
+{
+	resource_size_t dev_size = dev_dax_size(dev_dax);
+	struct device *dev = &dev_dax->dev;
+	ssize_t rc, i;
+
+	if (dev->driver)
+		return -EBUSY;
+
+	rc = -EINVAL;
+	if (dev_size > 0 && !alloc_is_aligned(dev_size, align)) {
+		dev_dbg(dev, "%s: align %llx invalid for size %llu\n",
+			__func__, align, dev_size);
+		return rc;
+	}
+
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		size_t len = range_len(&dev_dax->ranges[i].range);
+
+		if (!alloc_is_aligned(len, align)) {
+			dev_dbg(dev, "%s: align %llx invalid for range %ld\n",
+				__func__, align, i);
+			return rc;
+		}
+	}
+
+	switch (align) {
+	case PUD_SIZE:
+		if (!IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
+			break;
+		fallthrough;
+	case PMD_SIZE:
+		if (!has_transparent_hugepage())
+			break;
+		fallthrough;
+	case PAGE_SIZE:
+		rc = 0;
+		break;
+	}
+
+	if (!rc)
+		dev_dax->align = align;
+
+	return rc;
+}
+
+static ssize_t align_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+	struct dax_region *dax_region = dev_dax->region;
+	unsigned long long val;
+	ssize_t rc;
+
+	rc = kstrtoull(buf, 0, &val);
+	if (rc)
+		return -ENXIO;
+
+	device_lock(dax_region->dev);
+	if (!dax_region->dev->driver) {
+		device_unlock(dax_region->dev);
+		return -ENXIO;
+	}
+
+	device_lock(dev);
+	rc = dev_dax_set_align(dev_dax, val);
+	device_unlock(dev);
+	device_unlock(dax_region->dev);
+	return rc == 0 ? len : rc;
+}
+static DEVICE_ATTR_RW(align);
+
 static int dev_dax_target_node(struct dev_dax *dev_dax)
 {
 	struct dax_region *dax_region = dev_dax->region;
@@ -1101,7 +1182,8 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n)
 		return 0;
 	if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA))
 		return 0;
-	if (a == &dev_attr_size.attr && is_static(dax_region))
+	if ((a == &dev_attr_align.attr ||
+	     a == &dev_attr_size.attr) && is_static(dax_region))
 		return 0444;
 	return a->mode;
 }
@@ -1110,6 +1192,7 @@ static struct attribute *dev_dax_attributes[] = {
 	&dev_attr_modalias.attr,
 	&dev_attr_size.attr,
 	&dev_attr_target_node.attr,
+	&dev_attr_align.attr,
 	&dev_attr_resource.attr,
 	&dev_attr_numa_node.attr,
 	NULL,
-- 
2.17.1
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^ permalink raw reply	[flat|nested] 46+ messages in thread

* [PATCH v1 3/4] dax/hmem: Introduce dax_hmem.region_idle parameter
  2020-07-16 17:29 ` [PATCH v1 0/4] device-dax: Further improvements to subdivision Joao Martins
  2020-07-16 17:29   ` [PATCH v1 1/4] device-dax: Make align a per-device property Joao Martins
  2020-07-16 17:29   ` [PATCH v1 2/4] device-dax: Add an 'align' attribute Joao Martins
@ 2020-07-16 17:29   ` Joao Martins
  2020-07-16 17:29   ` [PATCH v1 4/4] device-dax: Add a range mapping allocation attribute Joao Martins
  3 siblings, 0 replies; 46+ messages in thread
From: Joao Martins @ 2020-07-16 17:29 UTC (permalink / raw)
  To: Dan Williams; +Cc: linux-nvdimm, linux-kernel, linux-mm

Introduce a new module parameter for dax_hmem which
initializes all region devices as free, rather than allocating
a pagemap for the region by default.

All hmem devices created with dax_hmem.region_idle=1 will have full
available size for creating dynamic dax devices.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 drivers/dax/hmem/hmem.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index 1a3347bb6143..1bf040dbc834 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -5,6 +5,9 @@
 #include <linux/pfn_t.h>
 #include "../bus.h"
 
+static bool region_idle;
+module_param_named(region_idle, region_idle, bool, 0644);
+
 static int dax_hmem_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -30,7 +33,7 @@ static int dax_hmem_probe(struct platform_device *pdev)
 	data = (struct dev_dax_data) {
 		.dax_region = dax_region,
 		.id = -1,
-		.size = resource_size(res),
+		.size = region_idle ? 0 : resource_size(res),
 	};
 	dev_dax = devm_create_dev_dax(&data);
 	if (IS_ERR(dev_dax))
-- 
2.17.1
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* [PATCH v1 4/4] device-dax: Add a range mapping allocation attribute
  2020-07-16 17:29 ` [PATCH v1 0/4] device-dax: Further improvements to subdivision Joao Martins
                     ` (2 preceding siblings ...)
  2020-07-16 17:29   ` [PATCH v1 3/4] dax/hmem: Introduce dax_hmem.region_idle parameter Joao Martins
@ 2020-07-16 17:29   ` Joao Martins
  3 siblings, 0 replies; 46+ messages in thread
From: Joao Martins @ 2020-07-16 17:29 UTC (permalink / raw)
  To: Dan Williams; +Cc: linux-nvdimm, linux-kernel, linux-mm, Jason Zeng

Add a sysfs attribute which denotes a range from the dax region
to be allocated. It's an write only @mapping sysfs attribute in
the format of '<start>-<end>' to allocate a range. @start and
@end use hexadecimal values and the @pgoff is implicitly ordered
wrt to previous writes to @mapping sysfs e.g. a write of a range
of length 1G the pgoff is 0..1G(-4K), a second write will use
@pgoff for 1G+4K..<size>.

This range mapping interface is useful for:

 1) Application which want to implement its own allocation logic,
 and thus pick the desired ranges from dax_region.

 2) For use cases like VMM fast restart[0] where after kexec we
 want to the same gpa<->phys mappings (as originally created
 before kexec).

[0] https://static.sched.com/hosted_files/kvmforum2019/66/VMM-fast-restart_kvmforum2019.pdf

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 drivers/dax/bus.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index eb384dd6a376..83cc55d7517d 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1041,6 +1041,67 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RW(size);
 
+static ssize_t range_parse(const char *opt, size_t len, struct range *range)
+{
+	unsigned long long addr = 0;
+	char *start, *end, *str;
+	ssize_t rc = EINVAL;
+
+	str = kstrdup(opt, GFP_KERNEL);
+	if (!str)
+		return rc;
+
+	end = str;
+	start = strsep(&end, "-");
+	if (!start || !end)
+		goto err;
+
+	rc = kstrtoull(start, 16, &addr);
+	if (rc)
+		goto err;
+	range->start = addr;
+
+	rc = kstrtoull(end, 16, &addr);
+	if (rc)
+		goto err;
+	range->end = addr;
+
+err:
+	kfree(str);
+	return rc;
+}
+
+static ssize_t mapping_store(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t len)
+{
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+	struct dax_region *dax_region = dev_dax->region;
+	size_t to_alloc;
+	struct range r;
+	ssize_t rc;
+
+	rc = range_parse(buf, len, &r);
+	if (rc)
+		return rc;
+
+	rc = -ENXIO;
+	device_lock(dax_region->dev);
+	if (!dax_region->dev->driver) {
+		device_unlock(dax_region->dev);
+		return rc;
+	}
+	device_lock(dev);
+
+	to_alloc = range_len(&r);
+	if (alloc_is_aligned(to_alloc, dev_dax->align))
+		rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc);
+	device_unlock(dev);
+	device_unlock(dax_region->dev);
+
+	return rc == 0 ? len : rc;
+}
+static DEVICE_ATTR_WO(mapping);
+
 static ssize_t align_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
@@ -1182,6 +1243,8 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n)
 		return 0;
 	if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA))
 		return 0;
+	if (a == &dev_attr_mapping.attr && is_static(dax_region))
+		return 0;
 	if ((a == &dev_attr_align.attr ||
 	     a == &dev_attr_size.attr) && is_static(dax_region))
 		return 0444;
@@ -1191,6 +1254,7 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n)
 static struct attribute *dev_dax_attributes[] = {
 	&dev_attr_modalias.attr,
 	&dev_attr_size.attr,
+	&dev_attr_mapping.attr,
 	&dev_attr_target_node.attr,
 	&dev_attr_align.attr,
 	&dev_attr_resource.attr,
-- 
2.17.1
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* Re: [PATCH v2 22/22] device-dax: Introduce 'mapping' devices
  2020-07-16 16:00     ` Dan Williams
@ 2020-07-16 19:04       ` Joao Martins
  0 siblings, 0 replies; 46+ messages in thread
From: Joao Martins @ 2020-07-16 19:04 UTC (permalink / raw)
  To: Dan Williams
  Cc: linux-nvdimm, Peter Zijlstra, Dave Hansen, Ard Biesheuvel,
	Linux MM, Linux Kernel Mailing List, Linux ACPI,
	Christoph Hellwig

On 7/16/20 5:00 PM, Dan Williams wrote:
> On Thu, Jul 16, 2020 at 6:19 AM Joao Martins <joao.m.martins@oracle.com> wrote:
>> On 7/12/20 5:28 PM, Dan Williams wrote:
>>> In support of interrogating the physical address layout of a device with
>>> dis-contiguous ranges, introduce a sysfs directory with 'start', 'end',
>>> and 'page_offset' attributes. The alternative is trying to parse
>>> /proc/iomem, and that file will not reflect the extent layout until the
>>> device is enabled.
>>>
>>> Cc: Vishal Verma <vishal.l.verma@intel.com>
>>> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
>>> ---
>>>  drivers/dax/bus.c         |  191 +++++++++++++++++++++++++++++++++++++++++++++
>>>  drivers/dax/dax-private.h |   14 +++
>>>  2 files changed, 203 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
>>> index f342e36c69a1..8b6c4ddc5f42 100644
>>> --- a/drivers/dax/bus.c
>>> +++ b/drivers/dax/bus.c
>>> @@ -579,6 +579,167 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
>>>  }
>>>  EXPORT_SYMBOL_GPL(alloc_dax_region);
>>>
>>> +static void dax_mapping_release(struct device *dev)
>>> +{
>>> +     struct dax_mapping *mapping = to_dax_mapping(dev);
>>> +     struct dev_dax *dev_dax = to_dev_dax(dev->parent);
>>> +
>>> +     ida_free(&dev_dax->ida, mapping->id);
>>> +     kfree(mapping);
>>> +}
>>> +
>>> +static void unregister_dax_mapping(void *data)
>>> +{
>>> +     struct device *dev = data;
>>> +     struct dax_mapping *mapping = to_dax_mapping(dev);
>>> +     struct dev_dax *dev_dax = to_dev_dax(dev->parent);
>>> +     struct dax_region *dax_region = dev_dax->region;
>>> +
>>> +     dev_dbg(dev, "%s\n", __func__);
>>> +
>>> +     device_lock_assert(dax_region->dev);
>>> +
>>> +     dev_dax->ranges[mapping->range_id].mapping = NULL;
>>> +     mapping->range_id = -1;
>>> +
>>> +     device_del(dev);
>>> +     put_device(dev);
>>> +}
>>> +
>>> +static struct dev_dax_range *get_dax_range(struct device *dev)
>>> +{
>>> +     struct dax_mapping *mapping = to_dax_mapping(dev);
>>> +     struct dev_dax *dev_dax = to_dev_dax(dev->parent);
>>> +     struct dax_region *dax_region = dev_dax->region;
>>> +
>>> +     device_lock(dax_region->dev);
>>> +     if (mapping->range_id < 1) {
>>             ^^^^^^^^^^^^^^^^^^^^^ it's 'mapping->range_id < 0'
>>
>> Otherwise 'mapping0' sysfs entries won't work.
>> Disabled ranges use id -1.
> 
> Whoops, yes. Needs a unit test.
> 
If it helps, this particular patch for daxctl:

https://lore.kernel.org/linux-nvdimm/20200716184707.23018-7-joao.m.martins@oracle.com/

May help in the immediate term: if it's broken no mappings are listed.

But yeah, a unit test in 'test/daxctl-create.sh' should be added.

	Joao
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* Re: [PATCH v1 2/4] device-dax: Add an 'align' attribute
  2020-07-16 17:29   ` [PATCH v1 2/4] device-dax: Add an 'align' attribute Joao Martins
@ 2020-07-31 14:52     ` Dan Williams
  0 siblings, 0 replies; 46+ messages in thread
From: Dan Williams @ 2020-07-31 14:52 UTC (permalink / raw)
  To: Joao Martins; +Cc: linux-nvdimm, Linux Kernel Mailing List, Linux MM

On Thu, Jul 16, 2020 at 10:31 AM Joao Martins <joao.m.martins@oracle.com> wrote:
>
> Introduce a device align attribute. While doing so,
> rename the region align attribute to be more explicitly
> named as so, but keep it named as @align to retain the API
> for tools like daxctl.
>
> Changes on align may not always be valid, when say certain
> mappings were created with 2M and then we switch to 1G. So, we
> validate all ranges against the new value being attempted,
> post resizing.
>
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> ---
>  drivers/dax/bus.c | 101 +++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 92 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> index 2578651c596e..eb384dd6a376 100644
> --- a/drivers/dax/bus.c
> +++ b/drivers/dax/bus.c
> @@ -230,14 +230,15 @@ static ssize_t region_size_show(struct device *dev,
>  static struct device_attribute dev_attr_region_size = __ATTR(size, 0444,
>                 region_size_show, NULL);
>
> -static ssize_t align_show(struct device *dev,
> +static ssize_t region_align_show(struct device *dev,
>                 struct device_attribute *attr, char *buf)
>  {
>         struct dax_region *dax_region = dev_get_drvdata(dev);
>
>         return sprintf(buf, "%u\n", dax_region->align);
>  }
> -static DEVICE_ATTR_RO(align);
> +static struct device_attribute dev_attr_region_align =
> +               __ATTR(align, 0400, region_align_show, NULL);
>
>  #define for_each_dax_region_resource(dax_region, res) \
>         for (res = (dax_region)->res.child; res; res = res->sibling)
> @@ -488,7 +489,7 @@ static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a,
>  static struct attribute *dax_region_attributes[] = {
>         &dev_attr_available_size.attr,
>         &dev_attr_region_size.attr,
> -       &dev_attr_align.attr,
> +       &dev_attr_region_align.attr,
>         &dev_attr_create.attr,
>         &dev_attr_seed.attr,
>         &dev_attr_delete.attr,
> @@ -855,14 +856,13 @@ static ssize_t size_show(struct device *dev,
>         return sprintf(buf, "%llu\n", size);
>  }
>
> -static bool alloc_is_aligned(struct dax_region *dax_region,
> -               resource_size_t size)
> +static bool alloc_is_aligned(resource_size_t size, unsigned long align)

For type safety, let's make this take @dev_dax as a parameter. For the
dev_dax_set_align() case I think it is ok to provisionally adjust
dev_dax->align under the lock before entry and revert to the old
alignment on failure.

I can fix that up locally on applying.
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end of thread, back to index

Thread overview: 46+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-12 16:26 [PATCH v2 00/22] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
2020-07-12 16:26 ` [PATCH v2 01/22] x86/numa: Cleanup configuration dependent command-line options Dan Williams
2020-07-12 16:26 ` [PATCH v2 02/22] x86/numa: Add 'nohmat' option Dan Williams
2020-07-12 16:58   ` Randy Dunlap
2020-07-12 16:26 ` [PATCH v2 03/22] efi/fake_mem: Arrange for a resource entry per efi_fake_mem instance Dan Williams
2020-07-12 16:26 ` [PATCH v2 04/22] ACPI: HMAT: Refactor hmat_register_target_device to hmem_register_device Dan Williams
2020-07-12 16:26 ` [PATCH v2 05/22] resource: Report parent to walk_iomem_res_desc() callback Dan Williams
2020-07-12 16:26 ` [PATCH v2 06/22] x86: Move NUMA_KEEP_MEMINFO and related definition to x86-internals Dan Williams
2020-07-12 16:26 ` [PATCH v2 07/22] numa: Introduce a generic memory_add_physaddr_to_nid() Dan Williams
2020-07-13  6:58   ` Mike Rapoport
2020-07-13 15:42     ` Dan Williams
2020-07-12 16:26 ` [PATCH v2 08/22] memblock: Introduce a generic phys_addr_to_target_node() Dan Williams
2020-07-13  7:03   ` Mike Rapoport
2020-07-13 15:48     ` Dan Williams
2020-07-14  1:36       ` Justin He
2020-07-12 16:26 ` [PATCH v2 09/22] arm64: Convert to generic memblock for numa-info Dan Williams
2020-07-12 16:26 ` [PATCH v2 10/22] ACPI: HMAT: Attach a device for each soft-reserved range Dan Williams
2020-07-12 16:27 ` [PATCH v2 11/22] device-dax: Drop the dax_region.pfn_flags attribute Dan Williams
2020-07-12 16:27 ` [PATCH v2 12/22] device-dax: Move instance creation parameters to 'struct dev_dax_data' Dan Williams
2020-07-12 16:27 ` [PATCH v2 13/22] device-dax: Make pgmap optional for instance creation Dan Williams
2020-07-12 16:27 ` [PATCH v2 14/22] device-dax: Kill dax_kmem_res Dan Williams
2020-07-12 16:27 ` [PATCH v2 15/22] device-dax: Add an allocation interface for device-dax instances Dan Williams
2020-07-12 16:27 ` [PATCH v2 16/22] device-dax: Introduce 'seed' devices Dan Williams
2020-07-12 16:27 ` [PATCH v2 17/22] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs Dan Williams
2020-07-12 17:09   ` Greg Kroah-Hartman
2020-07-13 15:39     ` Dan Williams
2020-07-13 15:52       ` Greg Kroah-Hartman
2020-07-13 16:09         ` Dan Williams
2020-07-13 16:12           ` Greg Kroah-Hartman
2020-07-13 16:36             ` Dan Williams
2020-07-12 16:27 ` [PATCH v2 18/22] device-dax: Add resize support Dan Williams
2020-07-12 16:27 ` [PATCH v2 19/22] mm/memremap_pages: Convert to 'struct range' Dan Williams
2020-07-13 16:36   ` Ralph Campbell
2020-07-13 16:54     ` Dan Williams
2020-07-12 16:27 ` [PATCH v2 20/22] mm/memremap_pages: Support multiple ranges per invocation Dan Williams
2020-07-12 16:27 ` [PATCH v2 21/22] device-dax: Add dis-contiguous resource support Dan Williams
2020-07-12 16:28 ` [PATCH v2 22/22] device-dax: Introduce 'mapping' devices Dan Williams
2020-07-16 13:18   ` Joao Martins
2020-07-16 16:00     ` Dan Williams
2020-07-16 19:04       ` Joao Martins
2020-07-16 17:29 ` [PATCH v1 0/4] device-dax: Further improvements to subdivision Joao Martins
2020-07-16 17:29   ` [PATCH v1 1/4] device-dax: Make align a per-device property Joao Martins
2020-07-16 17:29   ` [PATCH v1 2/4] device-dax: Add an 'align' attribute Joao Martins
2020-07-31 14:52     ` Dan Williams
2020-07-16 17:29   ` [PATCH v1 3/4] dax/hmem: Introduce dax_hmem.region_idle parameter Joao Martins
2020-07-16 17:29   ` [PATCH v1 4/4] device-dax: Add a range mapping allocation attribute Joao Martins

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