[PATCH v2 0/2] PCI: Sparc 64-bit resource fixups

[PATCH v2 0/2] PCI: Sparc 64-bit resource fixups

[Bjorn Helgaas]

These are from an old series from Yinghai [1] that fix some issues on
sparc64.  The v1 posting is at [2].

[1] https://lkml.kernel.org/r/20170421050500.13957-1-yinghai@kernel.org
[2] https://lkml.kernel.org/r/20180215151118.196756.99622.stgit@bhelgaas-glaptop.roam.corp.google.com

Changes from v1:
- In v1, I reserved the "Video ROM" and "System ROM" regions from system
  memory, not from the PCI bus address space.  In v2, I removed those
  reservations completely because they seem to be copied from x86 and are
  not applicable on sparc.

---

Bjorn Helgaas (1):
      sparc/PCI: Stop reserving System ROM and Video ROM in PCI space

Yinghai Lu (1):
      sparc/PCI: Support arbitrary host bridge address offset


 arch/sparc/kernel/pci.c        |    6 ++--
 arch/sparc/kernel/pci_common.c |   54 +++++++++++++++++++---------------------
 arch/sparc/kernel/pci_impl.h   |    4 +++
 3 files changed, 33 insertions(+), 31 deletions(-)

[PATCH v2 1/2] sparc/PCI: Support arbitrary host bridge address offset

[Bjorn Helgaas]

From: Yinghai Lu <yinghai@kernel.org>

Add support for arbitrary bus address offset.  Previously we ignored the
child (PCI) address in the "ranges" property and assumed it was always
zero.  That means every host bridge window mapped to PCI bus address zero,
e.g.,

  pci_bus 0000:00: root bus resource [mem 0x2000000000000-0x200007fffffff] (bus address [0x00000000-0x7fffffff])

But some systems have host bridge windows with non-zero child addresses, so
parse the child address and compute the offset between the parent (CPU) and
child (PCI) addresses.  This allows windows like these:

  /pci@305: PCI MEM [mem 0x2000000100000-0x200007effffff] offset 2000000000000
  pci_sun4v f02ae7f8: PCI host bridge to bus 0000:00
  pci_bus 0000:00: root bus resource [mem 0x2000000100000-0x200007effffff] (bus address [0x00100000-0x7effffff])

[bhelgaas: changelog]
Tested-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: sparclinux@vger.kernel.org
---
 arch/sparc/kernel/pci.c        |    6 +++---
 arch/sparc/kernel/pci_common.c |   34 ++++++++++++++++++++++++++--------
 arch/sparc/kernel/pci_impl.h   |    4 ++++
 3 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index 220d0f36560a..41b20edb427d 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -664,12 +664,12 @@ struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
 	printk("PCI: Scanning PBM %s\n", node->full_name);
 
 	pci_add_resource_offset(&resources, &pbm->io_space,
-				pbm->io_space.start);
+				pbm->io_offset);
 	pci_add_resource_offset(&resources, &pbm->mem_space,
-				pbm->mem_space.start);
+				pbm->mem_offset);
 	if (pbm->mem64_space.flags)
 		pci_add_resource_offset(&resources, &pbm->mem64_space,
-					pbm->mem_space.start);
+					pbm->mem64_offset);
 	pbm->busn.start = pbm->pci_first_busno;
 	pbm->busn.end	= pbm->pci_last_busno;
 	pbm->busn.flags	= IORESOURCE_BUS;
diff --git a/arch/sparc/kernel/pci_common.c b/arch/sparc/kernel/pci_common.c
index 1e10fb26fa88..14fa74f90fdb 100644
--- a/arch/sparc/kernel/pci_common.c
+++ b/arch/sparc/kernel/pci_common.c
@@ -397,6 +397,8 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
 	int i, saw_mem, saw_io;
 	int num_pbm_ranges;
 
+	/* Corresponding generic code in of_pci_get_host_bridge_resources() */
+
 	saw_mem = saw_io = 0;
 	pbm_ranges = of_get_property(pbm->op->dev.of_node, "ranges", &i);
 	if (!pbm_ranges) {
@@ -411,13 +413,16 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
 
 	for (i = 0; i < num_pbm_ranges; i++) {
 		const struct linux_prom_pci_ranges *pr = &pbm_ranges[i];
-		unsigned long a, size;
+		unsigned long a, size, region_a;
 		u32 parent_phys_hi, parent_phys_lo;
+		u32 child_phys_mid, child_phys_lo;
 		u32 size_hi, size_lo;
 		int type;
 
 		parent_phys_hi = pr->parent_phys_hi;
 		parent_phys_lo = pr->parent_phys_lo;
+		child_phys_mid = pr->child_phys_mid;
+		child_phys_lo = pr->child_phys_lo;
 		if (tlb_type == hypervisor)
 			parent_phys_hi &= 0x0fffffff;
 
@@ -427,6 +432,8 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
 		type = (pr->child_phys_hi >> 24) & 0x3;
 		a = (((unsigned long)parent_phys_hi << 32UL) |
 		     ((unsigned long)parent_phys_lo  <<  0UL));
+		region_a = (((unsigned long)child_phys_mid << 32UL) |
+		     ((unsigned long)child_phys_lo  <<  0UL));
 		size = (((unsigned long)size_hi << 32UL) |
 			((unsigned long)size_lo  <<  0UL));
 
@@ -441,6 +448,7 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
 			pbm->io_space.start = a;
 			pbm->io_space.end = a + size - 1UL;
 			pbm->io_space.flags = IORESOURCE_IO;
+			pbm->io_offset = a - region_a;
 			saw_io = 1;
 			break;
 
@@ -449,6 +457,7 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
 			pbm->mem_space.start = a;
 			pbm->mem_space.end = a + size - 1UL;
 			pbm->mem_space.flags = IORESOURCE_MEM;
+			pbm->mem_offset = a - region_a;
 			saw_mem = 1;
 			break;
 
@@ -457,6 +466,7 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
 			pbm->mem64_space.start = a;
 			pbm->mem64_space.end = a + size - 1UL;
 			pbm->mem64_space.flags = IORESOURCE_MEM;
+			pbm->mem64_offset = a - region_a;
 			saw_mem = 1;
 			break;
 
@@ -472,14 +482,22 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
 		prom_halt();
 	}
 
-	printk("%s: PCI IO[%llx] MEM[%llx]",
-	       pbm->name,
-	       pbm->io_space.start,
-	       pbm->mem_space.start);
+	if (pbm->io_space.flags)
+		printk("%s: PCI IO %pR offset %llx\n",
+		       pbm->name, &pbm->io_space, pbm->io_offset);
+	if (pbm->mem_space.flags)
+		printk("%s: PCI MEM %pR offset %llx\n",
+		       pbm->name, &pbm->mem_space, pbm->mem_offset);
+	if (pbm->mem64_space.flags && pbm->mem_space.flags) {
+		if (pbm->mem64_space.start <= pbm->mem_space.end)
+			pbm->mem64_space.start = pbm->mem_space.end + 1;
+		if (pbm->mem64_space.start > pbm->mem64_space.end)
+			pbm->mem64_space.flags = 0;
+	}
+
 	if (pbm->mem64_space.flags)
-		printk(" MEM64[%llx]",
-		       pbm->mem64_space.start);
-	printk("\n");
+		printk("%s: PCI MEM64 %pR offset %llx\n",
+		       pbm->name, &pbm->mem64_space, pbm->mem64_offset);
 
 	pbm->io_space.name = pbm->mem_space.name = pbm->name;
 	pbm->mem64_space.name = pbm->name;
diff --git a/arch/sparc/kernel/pci_impl.h b/arch/sparc/kernel/pci_impl.h
index ac172961d276..4e3d15189fa9 100644
--- a/arch/sparc/kernel/pci_impl.h
+++ b/arch/sparc/kernel/pci_impl.h
@@ -100,6 +100,10 @@ struct pci_pbm_info {
 	struct resource			mem_space;
 	struct resource			mem64_space;
 	struct resource			busn;
+	/* offset */
+	resource_size_t			io_offset;
+	resource_size_t			mem_offset;
+	resource_size_t			mem64_offset;
 
 	/* Base of PCI Config space, can be per-PBM or shared. */
 	unsigned long			config_space;

[PATCH v2 2/2] sparc/PCI: Stop reserving System ROM and Video ROM in PCI space

[Bjorn Helgaas]

From: Bjorn Helgaas <bhelgaas@google.com>

Previously, pci_register_legacy_regions() reserved PCI address space under
every PCI host bridge for the System ROM and the Video ROM, but these
regions are not part of PCI address space.

Previously, pci_register_legacy_regions() reserved the following areas of
PCI address space under every PCI host bridge:

  [bus 0xa0000-0xbffff]    Video RAM area (VGA frame buffer)
  [bus 0xc0000-0xc7fff]    Video ROM
  [bus 0xf0000-0xfffff]    System ROM

It does need to reserve the [bus 0xa0000-0xbffff] region (at least if
there's a possibility of a VGA device below the bridge) because VGA devices
can respond to that even if they don't describe it with a BAR.

But the Video ROM and System ROM areas don't seem necessary because they
are not areas that legacy PCI devices respond to.

They appear to be copied from x86, where they describe areas of system
memory that depend on BIOS conventions.  On x86, BIOS copies the option ROM
of the primary VGA device to RAM at 0xc0000, and the 0xf0000-0xfffff region
is reserved for the motherboard BIOS.  Neither of these things applies to
sparc.

Stop reserving the System ROM and Video ROM regions in PCI space.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 arch/sparc/kernel/pci_common.c |   20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/arch/sparc/kernel/pci_common.c b/arch/sparc/kernel/pci_common.c
index 14fa74f90fdb..38d46bcc8634 100644
--- a/arch/sparc/kernel/pci_common.c
+++ b/arch/sparc/kernel/pci_common.c
@@ -344,26 +344,6 @@ static void pci_register_legacy_regions(struct resource *io_res,
 	p->end = p->start + 0x1ffffUL;
 	p->flags = IORESOURCE_BUSY;
 	request_resource(mem_res, p);
-
-	p = kzalloc(sizeof(*p), GFP_KERNEL);
-	if (!p)
-		return;
-
-	p->name = "System ROM";
-	p->start = mem_res->start + 0xf0000UL;
-	p->end = p->start + 0xffffUL;
-	p->flags = IORESOURCE_BUSY;
-	request_resource(mem_res, p);
-
-	p = kzalloc(sizeof(*p), GFP_KERNEL);
-	if (!p)
-		return;
-
-	p->name = "Video ROM";
-	p->start = mem_res->start + 0xc0000UL;
-	p->end = p->start + 0x7fffUL;
-	p->flags = IORESOURCE_BUSY;
-	request_resource(mem_res, p);
 }
 
 static void pci_register_iommu_region(struct pci_pbm_info *pbm)

Re: [PATCH v2 0/2] PCI: Sparc 64-bit resource fixups

[David Miller]

From: Bjorn Helgaas <helgaas@kernel.org>
Date: Tue, 20 Mar 2018 15:14:01 -0500

> These are from an old series from Yinghai [1] that fix some issues on
> sparc64.  The v1 posting is at [2].
> 
> [1] https://lkml.kernel.org/r/20170421050500.13957-1-yinghai@kernel.org
> [2] https://lkml.kernel.org/r/20180215151118.196756.99622.stgit@bhelgaas-glaptop.roam.corp.google.com
> 
> Changes from v1:
> - In v1, I reserved the "Video ROM" and "System ROM" regions from system
>   memory, not from the PCI bus address space.  In v2, I removed those
>   reservations completely because they seem to be copied from x86 and are
>   not applicable on sparc.

For the series:

Acked-by: David S. Miller <davem@davemloft.net>