On Fri, 14 Aug, at 03:37:30PM, Jonathan (Zhixiong) Zhang wrote: > From: "Jonathan (Zhixiong) Zhang" <zjzhang@xxxxxxxxxxxxxx> > > With ACPI APEI firmware first handling, generic hardware error > record is updated by firmware in GHES memory region. On an arm64 > platform, firmware updates GHES memory region with uncached > access attribute, and then Linux reads stale data from cache. > > With current code, GHES memory region is mapped with PAGE_KERNEL > based on the assumption that cache coherency of GHES memory region > is maintained by firmware on all platforms. This assumption is > not true for above mentioned arm64 platform. > > Instead GHES memory region should be mapped with page protection type > according to what is returned from arch_apei_get_mem_attribute(). > > Acked-by: Borislav Petkov <bp@xxxxxxx> > Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@xxxxxxxxxxxxxx> > --- > drivers/acpi/apei/ghes.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index 23981ac1c6c2..f742335bd8bb 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -160,8 +160,10 @@ 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, > - pfn << PAGE_SHIFT, PAGE_KERNEL); > + ioremap_page_range(vaddr, > + vaddr + PAGE_SIZE, > + pfn << PAGE_SHIFT, > + arch_apei_get_mem_attribute(pfn << PAGE_SHIFT)); > > return (void __iomem *)vaddr; > } Y'know, this would be more readable if written as, unsigned long vaddr, paddr; pgprot_t prot; vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr); paddr = pfn << PAGE_SHIFT; prot = arch_apei_get_mem_attribute(paddr); ioremap_page_range(vaddr, vaddr + PAGE_SIZE, paddr, prot); But either way, Reviewed-by: Matt Fleming <matt.fleming@xxxxxxxxx> -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
