[PATCH V3 0/4] map GHES memory region with EFI memory map

[PATCH V3 0/4] map GHES memory region with EFI memory map

[Jonathan (Zhixiong) Zhang]

From: "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org>

On a platform with APEI (ACPI Platform Error Interface) enabled, firmware
updates a memory region with hardware error record using nocache
attribute. When OS reads the region, since it maps the region with
cacahed attribute even though EFI memory map defines this region as
uncached, OS gets stale data and errorneously reports there is no new
HW error.

When ghes driver maps the memory region, it uses the cache attribute
according to EFI memory map, if EFI memory map feature is enabled
at runtime.

Since both arch/x86 and arch/ia64 implemented architecture agnostic EFI
memory map attribue lookup function efi_memattributes(), the code is
moved from arch/x86 into EFI subsystem and is declared as __weak; archs
other than ia64 should not override the default implementation. 

V3:
1. Rebased to v4.1-rc7.
2. Moved efi_mem_attributes() from arch/x86 to drivers/firmware/efi
   and declared it as __weak.
3. Introduced ARCH_APEI_PAGE_KERNEL_UC to allow arch specific page
   protection type for UC.
4. Removed efi_ioremap(). It can not be used for GHES memory region
   mapping purpose since ioremap can not be used in atomic context.

V2:
1. Rebased to v4.1-rc5.
2. Split removal of efi_mem_attributes() and creation of efi_ioremap()
into two patches.

Jonathan (Zhixiong) Zhang (4):
  x86: acpi: define uncached page flag
  arm64: acpi: define uncached page flag
  efi: x86: rearrange efi_mem_attributes()
  acpi, apei: use EFI memmap to map GHES memory

 arch/arm64/include/asm/acpi.h |  4 ++++
 arch/x86/include/asm/acpi.h   |  4 ++++
 arch/x86/platform/efi/efi.c   | 18 ------------------
 drivers/acpi/apei/ghes.c      |  9 ++++++++-
 drivers/firmware/efi/efi.c    | 18 ++++++++++++++++++
 5 files changed, 34 insertions(+), 19 deletions(-)

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH V3 3/4] efi: x86: rearrange efi_mem_attributes()

[Jonathan (Zhixiong) Zhang]

From: "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org>

x86 and ia64 implement efi_mem_attributes() differently. This
function needs to be available for other arch (such as arm64)
as well, such as for the purpose of ACPI/APEI.

ia64 efi does not setup memmap variable and does not set
EFI_MEMMAP flag, so it needs to have its unique implementation
of efi_mem_attributes().

Move efi_mem_attributes() implementation from x86 to efi, and
declare it with __weak. It is recommended that other archs
should not override the default implementation.

Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
---
 arch/x86/platform/efi/efi.c | 18 ------------------
 drivers/firmware/efi/efi.c  | 18 ++++++++++++++++++
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 02744df576d5..10bd5289c593 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -926,24 +926,6 @@ u32 efi_mem_type(unsigned long phys_addr)
 	return 0;
 }
 
-u64 efi_mem_attributes(unsigned long phys_addr)
-{
-	efi_memory_desc_t *md;
-	void *p;
-
-	if (!efi_enabled(EFI_MEMMAP))
-		return 0;
-
-	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
-		md = p;
-		if ((md->phys_addr <= phys_addr) &&
-		    (phys_addr < (md->phys_addr +
-				  (md->num_pages << EFI_PAGE_SHIFT))))
-			return md->attribute;
-	}
-	return 0;
-}
-
 static int __init arch_parse_efi_cmdline(char *str)
 {
 	if (parse_option_str(str, "old_map"))
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 3061bb8629dc..88531b0dee80 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -517,3 +517,21 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
 			 attr & EFI_MEMORY_UC      ? "UC"  : "");
 	return buf;
 }
+
+u64 __weak efi_mem_attributes(unsigned long phys_addr)
+{
+	efi_memory_desc_t *md;
+	void *p;
+
+	if (!efi_enabled(EFI_MEMMAP))
+		return 0;
+
+	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+		md = p;
+		if ((md->phys_addr <= phys_addr) &&
+		    (phys_addr < (md->phys_addr +
+		    (md->num_pages << EFI_PAGE_SHIFT))))
+			return md->attribute;
+	}
+	return 0;
+}
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project