On 7/27/2015 3:03 AM, Catalin Marinas wrote:
On Sat, Jul 25, 2015 at 12:51:08AM +0100, Jonathan (Zhixiong) Zhang wrote:
From: "Jonathan (Zhixiong) Zhang" <zjzh...@codeaurora.org>

Table 8 of UEFI 2.5 section 2.3.6.1 defines mappings from EFI
memory types to MAIR attribute encodings for arm64.

If the physical address has memory attributes defined by EFI
memmap as EFI_MEMORY_[UC|WC|WT], return approprate page protection
type. Otherwise, return PAGE_KERNEL.

Change-Id: I7f836cae0fb3e74a34e27ac695c2637ffc4cddc6
Acked-by: Hanjun Guo <hanjun....@linaro.org>
Signed-off-by: Jonathan (Zhixiong) Zhang <zjzh...@codeaurora.org>

Same comment about the Change-Id.
Yes.

---
  arch/arm64/include/asm/acpi.h | 26 ++++++++++++++++++++++++++
  1 file changed, 26 insertions(+)

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 1ff9e6eb5e02..04720f819f0a 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -19,6 +19,11 @@
  #include <asm/psci.h>
  #include <asm/smp_plat.h>

+#ifdef CONFIG_ACPI_APEI
+#include <linux/efi.h>
+#include <asm/pgtable.h>
+#endif
+
  /* Macros for consistency checks of the GICC subtable of MADT */
  #define ACPI_MADT_GICC_LENGTH \
        (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
@@ -91,4 +95,26 @@ static inline const char *acpi_get_enable_method(int cpu)
  {
        return acpi_psci_present() ? "psci" : NULL;
  }
+
+#ifdef CONFIG_ACPI_APEI
+/*
+ * According to "Table 8 Map: EFI memory types to AArch64 memory types"
+ * of UEFI 2.5 section 2.3.6.1, each EFI memory type is mapped to
+ * corresponding MAIR attribute encoding.
+ */
+static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
+{
+       u64 attr;
+
+       attr = efi_mem_attributes(addr);
+       if (attr & EFI_MEMORY_UC)
+               return PROT_DEVICE_nGnRnE;
+       if (attr & EFI_MEMORY_WC)
+               return PROT_NORMAL_NC;
+       if (attr & EFI_MEMORY_WT)
+               return PROT_NORMAL_WT;

Just to match the strict mm types, please add __pgprot(PROT_*) here.

+       return PAGE_KERNEL;
Will do.

Otherwise:

Reviewed-by: Catalin Marinas <catalin.mari...@arm.com>
Thanks.

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