lkml.org 
[lkml]   [2015]   [Jul]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH V7 4/5] arm64: apei: implement arch_apei_get_mem_attributes()
Date
From: "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org>

If the physical address has memory attributes defined by EFI
memmap as EFI_MEMORY_UC, the page protection type is
PROT_DEVICE_nGnRE. Otherwise, the page protection type is
PAGE_KERNEL.

Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
---
This patch applies cleanly to efi-next-14364 of efi/next and
arm64-upstream-13521 of arm64/master, but needed slight change
to apply to next-20150720 of linux-next/master and
pm+acpi-4.2-rc3 of linux-pm/master. The later two branches
has newer arch/arm64/include/asm/acpi.h with following patch:
b6cfb277378e ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro
---
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..41c7623d5b84 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
+
/* Basic configuration for ACPI */
#ifdef CONFIG_ACPI
/* ACPI table mapping after acpi_gbl_permanent_mmap is set */
@@ -84,4 +89,25 @@ 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)
+{
+ pgprot_t prot;
+
+ prot = efi_mem_attributes(addr);
+ if (prot & EFI_MEMORY_UC)
+ return PROT_DEVICE_nGnRnE;
+ if (prot & EFI_MEMORY_WC)
+ return PROT_NORMAL_NC;
+ if (prot & EFI_MEMORY_WT)
+ return PROT_NORMAL_WT;
+ return PAGE_KERNEL;
+}
+#endif
+
#endif /*_ASM_ACPI_H*/
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


\
 
 \ /
  Last update: 2015-07-22 00:21    [W:0.139 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site