Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1203330 > unrolled thread

[PATCH V11 0/5] map GHES memory region according to EFI memory map

Back to article view | Back to linux.kernel

Contents

  [PATCH V11 0/5] map GHES memory region according to EFI memory map "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org> - 2015-08-08 19:20 +0200
    [PATCH V11 2/5] x86: acpi: implement arch_apei_get_mem_attributes() "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org> - 2015-08-08 19:30 +0200
    [PATCH V11 1/5] efi: x86: rearrange efi_mem_attributes() "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org> - 2015-08-08 19:30 +0200
    [PATCH V11 3/5] arm64: mm: add PROT_DEVICE_nGnRnE and PROT_NORMAL_WT "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org> - 2015-08-08 19:30 +0200

#1203330 — [PATCH V11 0/5] map GHES memory region according to EFI memory map

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.

V11:
1. Changed how we deal with superimposed memory region attributes as
   provided in UEFI memory map, on arm64.
V10:
1. Fixed compilation issue on x86.
V9:
1. Rebased to arm64-upstream-14543 of arm64/master.
2. Match strict MM type in arch_apei_get_mem_attribute().
V8:
1. For x86, always return PAGE_KERNEL for arch_apei_get_mem_attribute().
   The rational is explained in comment.
2. Rebased to arm64-upstream-14201 of arm64/master,
   next-20150724 of linux-next/master.
V7:
1. Added PROT_DEVICE_nGnRnE and PROT_NORMAL_WT to support all
   possible UEFI memory types for arm64.
V6:
1. Implemented arch_apei_get_mem_attributes() for arm64 as inline
   function.
2. Rebased to efi-next-14364 of efi/next, pm+acpi-4.2-rc3 of
   linux-pm/master, arm64-upstream-13521 of arm64/master,
   next-20150720 of linux-next/master.
V5:
1. Rebased to next-20150713 of linux-next/master, efi-next-14359 of
   efi/next, pm+acpi-4.2-rc2 of linux-pm/master,
   arm64-fixes-1215 of arm64/master.
2. Added comment for efi_mem_attributes(), explained why it is marked
   as __weak at the function definition site.
V4:
1. Introduced arch_apei_get_mem_attributes() to allow arch specific
   implementation of getting pgprot_t appropriate for a physical
   address.
2. Implemented arch_apei_get_mem_attributes() for x86 and for arm64.
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 (5):
  efi: x86: rearrange efi_mem_attributes()
  x86: acpi: implement arch_apei_get_mem_attributes()
  arm64: mm: add PROT_DEVICE_nGnRnE and PROT_NORMAL_WT
  arm64: apei: implement arch_apei_get_mem_attributes()
  acpi, apei: use appropriate pgprot_t to map GHES memory

 arch/arm64/include/asm/acpi.h    | 30 ++++++++++++++++++++++++++++++
 arch/arm64/include/asm/memory.h  |  1 +
 arch/arm64/include/asm/pgtable.h |  2 ++
 arch/arm64/mm/proc.S             |  4 +++-
 arch/x86/include/asm/acpi.h      | 24 ++++++++++++++++++++++++
 arch/x86/platform/efi/efi.c      | 18 ------------------
 drivers/acpi/apei/ghes.c         |  6 ++++--
 drivers/firmware/efi/efi.c       | 31 +++++++++++++++++++++++++++++++
 8 files changed, 95 insertions(+), 21 deletions(-)

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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]

#1203332 — [PATCH V11 2/5] x86: acpi: implement arch_apei_get_mem_attributes()

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

... to allow arch specific implementation of getting page
protection type associated with a physical address.

On x86, we currently have no way to lookup the EFI memory map
attributes for a region in a consistent way because the
memmap is discarded after efi_free_boot_services(). So if
you call efi_mem_attributes() during boot and at runtime,
you could theoretically see different attributes.

Since we are yet to see any x86 platforms that require
anything other than PAGE_KERNEL (some arm64 platforms
require the equivalent of PAGE_KERNEL_NOCACHE), return that
until we know differently.

Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
---
 arch/x86/include/asm/acpi.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index 3a45668f6dc3..ffe22c6b17bd 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -32,6 +32,10 @@
 #include <asm/mpspec.h>
 #include <asm/realmode.h>
 
+#ifdef CONFIG_ACPI_APEI
+#include <asm/pgtable_types.h>
+#endif
+
 #ifdef CONFIG_ACPI
 extern int acpi_lapic;
 extern int acpi_ioapic;
@@ -147,4 +151,24 @@ extern int x86_acpi_numa_init(void);
 
 #define acpi_unlazy_tlb(x)	leave_mm(x)
 
+#ifdef CONFIG_ACPI_APEI
+static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
+{
+	/*
+	 * We currently have no way to lookup the EFI memory map
+	 * attributes for a region in a consistent way because the
+	 * memmap is discarded after efi_free_boot_services(). So if
+	 * you call efi_mem_attributes() during boot and at runtime,
+	 * you could theoretically see different attributes.
+	 *
+	 * Since we are yet to see any x86 platforms that require
+	 * anything other than PAGE_KERNEL (some arm64 platforms
+	 * require the equivalent of PAGE_KERNEL_NOCACHE), return that
+	 * until we know differently.
+	 */
+
+	 return PAGE_KERNEL;
+}
+#endif
+
 #endif /* _ASM_X86_ACPI_H */
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1203333 — [PATCH V11 1/5] efi: x86: rearrange efi_mem_attributes()

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.

Reviewed-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
---
 arch/x86/platform/efi/efi.c | 18 ------------------
 drivers/firmware/efi/efi.c  | 31 +++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index dbc8627a5cdf..88b3ebaeb72f 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -917,24 +917,6 @@ 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..bf4190a4f3f5 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -517,3 +517,34 @@ char * __init efi_md_typeattr_format(char *buf, size_t size,
 			 attr & EFI_MEMORY_UC      ? "UC"  : "");
 	return buf;
 }
+
+/*
+ * efi_mem_attributes - lookup memmap attributes for physical address
+ * @phys_addr: the physical address to lookup
+ *
+ * Search in the EFI memory map for the region covering
+ * @phys_addr. Returns the EFI memory attributes if the region
+ * was found in the memory map, 0 otherwise.
+ *
+ * Despite being marked __weak, most architectures should *not*
+ * override this function. It is __weak solely for the benefit
+ * of ia64 which has a funky EFI memory map that doesn't work
+ * the same way as other architectures.
+ */
+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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1203335 — [PATCH V11 3/5] arm64: mm: add PROT_DEVICE_nGnRnE and PROT_NORMAL_WT

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

UEFI spec 2.5 section 2.3.6.1 defines that EFI_MEMORY_[UC|WC|WT|WB] are
possible EFI memory types for AArch64. Each of those EFI memory types
is mapped to a corresponding AArch64 memory type. So we need to define
PROT_DEVICE_nGnRnE and PROT_NORMWL_WT additionaly.

MT_NORMAL_WT is defined, and its encoding is added to MAIR_EL1 when
initializing cpu.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
---
 arch/arm64/include/asm/memory.h  | 1 +
 arch/arm64/include/asm/pgtable.h | 2 ++
 arch/arm64/mm/proc.S             | 4 +++-
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index f800d45ea226..4112b3d7468e 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -100,6 +100,7 @@
 #define MT_DEVICE_GRE		2
 #define MT_NORMAL_NC		3
 #define MT_NORMAL		4
+#define MT_NORMAL_WT		5
 
 /*
  * Memory types for Stage-2 translation
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 800ec0e87ed9..5c108ad13558 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -61,8 +61,10 @@ extern void __pgd_error(const char *file, int line, unsigned long val);
 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF)
 #endif
 
+#define PROT_DEVICE_nGnRnE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRnE))
 #define PROT_DEVICE_nGnRE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
 #define PROT_NORMAL_NC		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_NC))
+#define PROT_NORMAL_WT		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_WT))
 #define PROT_NORMAL		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL))
 
 #define PROT_SECT_DEVICE_nGnRE	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 4fe4b7d1d65f..2ddb82ff38c2 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -233,12 +233,14 @@ ENTRY(__cpu_setup)
 	 *   DEVICE_GRE		010	00001100
 	 *   NORMAL_NC		011	01000100
 	 *   NORMAL		100	11111111
+	 *   NORMAL_WT		101	10111011
 	 */
 	ldr	x5, =MAIR(0x00, MT_DEVICE_nGnRnE) | \
 		     MAIR(0x04, MT_DEVICE_nGnRE) | \
 		     MAIR(0x0c, MT_DEVICE_GRE) | \
 		     MAIR(0x44, MT_NORMAL_NC) | \
-		     MAIR(0xff, MT_NORMAL)
+		     MAIR(0xff, MT_NORMAL) | \
+		     MAIR(0xbb, MT_NORMAL_WT)
 	msr	mair_el1, x5
 	/*
 	 * Prepare SCTLR
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web