[PATCH v4 0/5] ACPI: ARM64: support for ACPI_TABLE_UPGRADE

[PATCH v4 0/5] ACPI: ARM64: support for ACPI_TABLE_UPGRADE

[Aleksey Makarov]

Hi Rafael,

You said you are ok with the ACPI part of the patches [4].
The patchset has received ACK from Will [5].  Can you consider pulling it please?

Thank you
Aleksey Makarov

This patchset adds support for ACPI_TABLE_UPGRADE for ARM64

These patches help with:

1). During development of a platform, it is much easier to debug
problems with tables if you can test replacement ones without having to
respin the firmware. In the server world, you usually don't have the
firmware source code, so to get it respun could be days-weeks even if
you are working with the authors closely. We have practically used this
feature on a number of platforms already and it will continue.

2). They empower (advanced) users and developers to work around problems
that they find on platforms. Sure, we want firmware to always be fixed
and working well, but it is better if folks have the tools.

It's also required for parity with x86 functionality on servers as Redhat
use that method in their tooling.

The patchset refactors the code introduced by the patches by Lv Zheng [1],
fixes access to the destination of new ACPI tables as suggested
by Mark Rutland [2] and enables the feature for ARM64

It was first sent by Jon Masters [3] to linaro-acpi in December 2015

Tested on QEMU (arm64 and x86) and ThunderX
Should be applied to next-20160620

v4:
- rebase to next-20160620
- add Acked-by: Will Deacon <will.deacon@arm.com>
- add Acked-by: Lv Zheng <lv.zheng@intel.com> for [2/5]

v3:
https://lkml.kernel.org/g/20160602174910.30428-1-aleksey.makarov@linaro.org -- only [5/5]
- change PFN_PHYS(max_pfn) to MEMBLOCK_ALLOC_ACCESSIBLE. (Catalin Marinas)

v2:
https://lkml.kernel.org/g/1463674518-22477-1-git-send-email-aleksey.makarov@linaro.org
- add Acked-by: Lv Zheng <lv.zheng@intel.com>
- replace the original patch "ACPI: table upgrade: move early_initrd_acpi_init()
  to header file" with the patch "ACPI: table upgrade: refactor function
  definitions".  This new patch is just the original one rewritten following the
  suggestion by Lv Zheng to use initrd_start, inird_end directly in
  acpi_table_initrd_init().  It simplifies things noticeably.
- add Jon's explanations to the cover of the patchset and my explanations
  to "ACPI: ARM64: support for ACPI_TABLE_UPGRADE"
- introduce ARCH_HAS_ACPI_TABLE_UPGRADE in a separate patch (Mark Rutland)
- move arch-specific definition to an arch-specific header in a separate patch
  (Mark Rutland)

v1:
https://lkml.kernel.org/g/1463486765-31827-1-git-send-email-aleksey.makarov@linaro.org

[1]: https://lkml.kernel.org/g/cover.1460340514.git.lv.zheng@intel.com
[2]: https://lists.linaro.org/pipermail/linaro-acpi/2015-December/006101.html
[3]: https://lists.linaro.org/pipermail/linaro-acpi/2015-December/006099.html
[4]: https://lkml.kernel.org/g/CAJZ5v0is7c833aQkRm-D+TwLM+eUYeKEAdLOOdrEdT-hrC_M1A@mail.gmail.com
[5]: https://lkml.kernel.org/g/20160614164116.GF16531@arm.com

Aleksey Makarov (4):
  ACPI: table upgrade: use cacheable map for tables
  ACPI: table upgrade: refactor function definitions
  ACPI: table upgrade: move arch-specific symbol to asm/acpi.h
  ACPI: table upgrade: introduce ARCH_HAS_ACPI_TABLE_UPGRADE

Jon Masters (1):
  ACPI: ARM64: support for ACPI_TABLE_UPGRADE

 arch/arm64/Kconfig            |  1 +
 arch/arm64/include/asm/acpi.h |  2 ++
 arch/arm64/kernel/setup.c     |  6 ++++--
 arch/x86/Kconfig              |  1 +
 arch/x86/include/asm/acpi.h   |  2 ++
 arch/x86/kernel/setup.c       |  9 +--------
 drivers/acpi/Kconfig          |  5 ++++-
 drivers/acpi/tables.c         | 23 +++++++++--------------
 include/linux/acpi.h          |  8 ++++++--
 9 files changed, 30 insertions(+), 27 deletions(-)

-- 
2.8.3

[PATCH v4 1/5] ACPI: table upgrade: use cacheable map for tables

[Aleksey Makarov]

The new memory allocated in acpi_table_initrd_init() is used to
copy the upgraded tables to it.  So it should be mapped with
early_memunmap() instead of early_ioremap().

This is critical for ARM.

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Acked-by: Lv Zheng <lv.zheng@intel.com>
---
 drivers/acpi/tables.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index a372f9e..f829e6a 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -578,10 +578,10 @@ static void __init acpi_table_initrd_init(void *data, size_t size)
 			clen = size;
 			if (clen > MAP_CHUNK_SIZE - slop)
 				clen = MAP_CHUNK_SIZE - slop;
-			dest_p = early_ioremap(dest_addr & PAGE_MASK,
-						 clen + slop);
+			dest_p = early_memremap(dest_addr & PAGE_MASK,
+						clen + slop);
 			memcpy(dest_p + slop, src_p, clen);
-			early_iounmap(dest_p, clen + slop);
+			early_memunmap(dest_p, clen + slop);
 			src_p += clen;
 			dest_addr += clen;
 			size -= clen;
-- 
2.8.3

[PATCH v4 2/5] ACPI: table upgrade: refactor function definitions

[Aleksey Makarov]

Refer initrd_start, initrd_end directly from drivers/acpi/tables.c.
This allows to use the table upgrade feature in architectures
other than x86.  Also this simplifies header files.

The patch renames acpi_table_initrd_init() to acpi_table_upgrade()
(what reflects the purpose of the function) and removes the unneeded
wraps early_acpi_table_init() and early_initrd_acpi_init().

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Acked-by: Lv Zheng <lv.zheng@intel.com>
---
 arch/x86/kernel/setup.c |  9 +--------
 drivers/acpi/tables.c   | 14 ++++----------
 include/linux/acpi.h    |  8 ++++++--
 3 files changed, 11 insertions(+), 20 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index eb2f3b5..09d2f5b 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -399,10 +399,6 @@ static void __init reserve_initrd(void)
 	memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
 }
 
-static void __init early_initrd_acpi_init(void)
-{
-	early_acpi_table_init((void *)initrd_start, initrd_end - initrd_start);
-}
 #else
 static void __init early_reserve_initrd(void)
 {
@@ -410,9 +406,6 @@ static void __init early_reserve_initrd(void)
 static void __init reserve_initrd(void)
 {
 }
-static void __init early_initrd_acpi_init(void)
-{
-}
 #endif /* CONFIG_BLK_DEV_INITRD */
 
 static void __init parse_setup_data(void)
@@ -1146,7 +1139,7 @@ void __init setup_arch(char **cmdline_p)
 
 	reserve_initrd();
 
-	early_initrd_acpi_init();
+	acpi_table_upgrade();
 
 	vsmp_init();
 
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index f829e6a..b05df13 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -34,6 +34,7 @@
 #include <linux/bootmem.h>
 #include <linux/earlycpio.h>
 #include <linux/memblock.h>
+#include <linux/initrd.h>
 #include "internal.h"
 
 #ifdef CONFIG_ACPI_CUSTOM_DSDT
@@ -481,8 +482,10 @@ static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
 
 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
 
-static void __init acpi_table_initrd_init(void *data, size_t size)
+void __init acpi_table_upgrade(void)
 {
+	void *data = (void *)initrd_start;
+	size_t size = initrd_end - initrd_start;
 	int sig, no, table_nr = 0, total_offset = 0;
 	long offset = 0;
 	struct acpi_table_header *table;
@@ -696,10 +699,6 @@ next_table:
 	}
 }
 #else
-static void __init acpi_table_initrd_init(void *data, size_t size)
-{
-}
-
 static acpi_status
 acpi_table_initrd_override(struct acpi_table_header *existing_table,
 			   acpi_physical_address *address,
@@ -742,11 +741,6 @@ acpi_os_table_override(struct acpi_table_header *existing_table,
 	return AE_OK;
 }
 
-void __init early_acpi_table_init(void *data, size_t size)
-{
-	acpi_table_initrd_init(data, size);
-}
-
 /*
  * acpi_table_init()
  *
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 9cab064..fb9d568 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -208,7 +208,6 @@ void acpi_boot_table_init (void);
 int acpi_mps_check (void);
 int acpi_numa_init (void);
 
-void early_acpi_table_init(void *data, size_t size);
 int acpi_table_init (void);
 int acpi_table_parse(char *id, acpi_tbl_table_handler handler);
 int __init acpi_parse_entries(char *id, unsigned long table_size,
@@ -592,7 +591,6 @@ static inline const char *acpi_dev_name(struct acpi_device *adev)
 	return NULL;
 }
 
-static inline void early_acpi_table_init(void *data, size_t size) { }
 static inline void acpi_early_init(void) { }
 static inline void acpi_subsystem_init(void) { }
 
@@ -1009,4 +1007,10 @@ static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
 #define acpi_probe_device_table(t)	({ int __r = 0; __r;})
 #endif
 
+#ifdef CONFIG_ACPI_TABLE_UPGRADE
+void acpi_table_upgrade(void);
+#else
+static inline void acpi_table_upgrade(void) { }
+#endif
+
 #endif	/*_LINUX_ACPI_H*/
-- 
2.8.3

[PATCH v4 3/5] ACPI: table upgrade: move arch-specific symbol to asm/acpi.h

[Aleksey Makarov]

The constant that defines max phys address where the new upgraded
ACPI table should be allocated is arch-specific.  Move it to
<asm/acpi.h>

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
---
 arch/x86/include/asm/acpi.h | 2 ++
 drivers/acpi/tables.c       | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index 65f1e95..5391b0a 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -169,4 +169,6 @@ static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
 }
 #endif
 
+#define ACPI_TABLE_UPGRADE_MAX_PHYS (max_low_pfn_mapped << PAGE_SHIFT)
+
 #endif /* _ASM_X86_ACPI_H */
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index b05df13..9f0ad6e 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -35,6 +35,7 @@
 #include <linux/earlycpio.h>
 #include <linux/memblock.h>
 #include <linux/initrd.h>
+#include <linux/acpi.h>
 #include "internal.h"
 
 #ifdef CONFIG_ACPI_CUSTOM_DSDT
@@ -543,7 +544,7 @@ void __init acpi_table_upgrade(void)
 		return;
 
 	acpi_tables_addr =
-		memblock_find_in_range(0, max_low_pfn_mapped << PAGE_SHIFT,
+		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
 				       all_tables_size, PAGE_SIZE);
 	if (!acpi_tables_addr) {
 		WARN_ON(1);
-- 
2.8.3

[PATCH v4 4/5] ACPI: table upgrade: introduce ARCH_HAS_ACPI_TABLE_UPGRADE

[Aleksey Makarov]

We want to use the table upgrade feature in ARM64.
Introduce a new configuration option that allows that.

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
---
 arch/x86/Kconfig     | 1 +
 drivers/acpi/Kconfig | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 39f8277..bb73293 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -22,6 +22,7 @@ config X86
 	select ANON_INODES
 	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_DISCARD_MEMBLOCK
+	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index f98c328..1cde30b 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -314,9 +314,12 @@ config ACPI_CUSTOM_DSDT
 	bool
 	default ACPI_CUSTOM_DSDT_FILE != ""
 
+config ARCH_HAS_ACPI_TABLE_UPGRADE
+	def_bool n
+
 config ACPI_TABLE_UPGRADE
 	bool "Allow upgrading ACPI tables via initrd"
-	depends on BLK_DEV_INITRD && X86
+	depends on BLK_DEV_INITRD && ARCH_HAS_ACPI_TABLE_UPGRADE
 	default y
 	help
 	  This option provides functionality to upgrade arbitrary ACPI tables
-- 
2.8.3

[PATCH v4 5/5] ACPI: ARM64: support for ACPI_TABLE_UPGRADE

[Aleksey Makarov]

From: Jon Masters <jcm@redhat.com>

This patch adds support for ACPI_TABLE_UPGRADE for ARM64

To access initrd image we need to move initialization
of linear mapping a bit earlier.

The implementation of the feature acpi_table_upgrade()
(drivers/acpi/tables.c) works with initrd data represented as an array
in virtual memory.  It uses some library utility to find the redefined
tables in that array and iterates over it to copy the data to new
allocated memory.  So to access the initrd data via fixmap
we need to rewrite it considerably.

In x86 arch, kernel memory is already mapped by the time when
acpi_table_upgrade() and acpi_boot_table_init() are called so I
think that we can just move this mapping one function earlier too.

Signed-off-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/Kconfig            | 1 +
 arch/arm64/include/asm/acpi.h | 2 ++
 arch/arm64/kernel/setup.c     | 6 ++++--
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a377a1f..0cf7b43 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -5,6 +5,7 @@ config ARM64
 	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
 	select ACPI_MCFG if ACPI
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
+	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 4b13ecd..5420cb0 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -121,4 +121,6 @@ static inline int arm64_acpi_numa_init(void) { return -ENOSYS; }
 static inline int acpi_numa_get_nid(unsigned int cpu, u64 hwid) { return NUMA_NO_NODE; }
 #endif /* CONFIG_ACPI_NUMA */
 
+#define ACPI_TABLE_UPGRADE_MAX_PHYS MEMBLOCK_ALLOC_ACCESSIBLE
+
 #endif /*_ASM_ACPI_H*/
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index feab2ee..4bce811 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -261,11 +261,13 @@ void __init setup_arch(char **cmdline_p)
 	efi_init();
 	arm64_memblock_init();
 
+	paging_init();
+
+	acpi_table_upgrade();
+
 	/* Parse the ACPI tables for possible boot-time configuration */
 	acpi_boot_table_init();
 
-	paging_init();
-
 	if (acpi_disabled)
 		unflatten_device_tree();
 
-- 
2.8.3

Re: [PATCH v4 0/5] ACPI: ARM64: support for ACPI_TABLE_UPGRADE

[Rafael J. Wysocki]

On Mon, Jun 20, 2016 at 12:56 PM, Aleksey Makarov
<aleksey.makarov@linaro.org> wrote:
> Hi Rafael,
>
> You said you are ok with the ACPI part of the patches [4].
> The patchset has received ACK from Will [5].  Can you consider pulling it please?

I've queued this up for v4.8, but can you please base your patches on
the Linus' tree next time?

Thanks,
Rafael