[PATCH V3 4/4] acpi, apei: use EFI memmap to map GHES memory

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: "Jonathan (Zhixiong) Zhang" <zjzhang@xxxxxxxxxxxxxx>

With ACPI APEI firmware first handling, generic hardware error
record is updated by firmware in GHES memory region. When firmware
updated GHES memory region with uncached access attribute, Linux
reads stale data from cache.

GHES memory region should be mapped with cache attributes
according to EFI memory map when applicable. On such system, if
firmware updates RAM directly without going through cache,
EFI memory map has GHES memory region defined as uncached;
If firmware updates cache, EFI memory map has GHES memory region
defined as cached.

On EFI system, if GHES memory region has EFI_MEMORY_UC attribute
defined, map the page with arch defined UC page protection type.

Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@xxxxxxxxxxxxxx>
---
 drivers/acpi/apei/ghes.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index e82d0976a5d0..5cfd951ebf67 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -48,6 +48,7 @@
 #include <linux/pci.h>
 #include <linux/aer.h>
 #include <linux/nmi.h>
+#include <linux/efi.h>
 
 #include <acpi/ghes.h>
 #include <acpi/apei.h>
@@ -164,8 +165,14 @@ static void __iomem *ghes_ioremap_pfn_irq(u64 pfn)
 	unsigned long vaddr;
 
 	vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr);
-	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
+
+	if (efi_mem_attributes(pfn << PAGE_SHIFT) & EFI_MEMORY_UC) {
+		ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
+				   pfn << PAGE_SHIFT, ARCH_APEI_PAGE_KERNEL_UC);
+	} else {
+		ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
 			   pfn << PAGE_SHIFT, PAGE_KERNEL);
+	}
 
 	return (void __iomem *)vaddr;
 }
-- 
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-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux IBM ACPI]     [Linux Power Management]     [Linux Kernel]     [Linux Laptop]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux