From: "Jonathan (Zhixiong) Zhang" <[email protected]> If it is a EFI system, if EFI memmap is enabled and if a memory region has attribute of EFI_MEMORY_UC, map it as uncached.
On x86, EFI memmap is unmapped in efi_free_boot_services(), before kernel finishes booting. So when efi_remap() is called during runtime on x86, it maps the region as cached. Signed-off-by: Jonathan (Zhixiong) Zhang <[email protected]> --- drivers/firmware/efi/efi.c | 9 +++++++++ include/linux/efi.h | 1 + 2 files changed, 10 insertions(+) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 86da85368778..5b42bb6d1fde 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -535,3 +535,12 @@ u64 efi_mem_attributes(unsigned long phys_addr) } return 0; } + +void __iomem *efi_remap(phys_addr_t phys_addr, size_t size) +{ + if (efi_enabled(EFI_MEMMAP) && + (efi_mem_attributes(phys_addr) & EFI_MEMORY_UC)) + return ioremap(phys_addr, size); + else + return ioremap_cache(phys_addr, size); +} diff --git a/include/linux/efi.h b/include/linux/efi.h index af5be0368dec..0a0aa25d44d7 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -888,6 +888,7 @@ extern void efi_get_time(struct timespec *now); extern void efi_reserve_boot_services(void); extern int efi_get_fdt_params(struct efi_fdt_params *params, int verbose); extern struct efi_memory_map memmap; +extern void __iomem *efi_remap(phys_addr_t phys_addr, size_t size); extern int efi_reboot_quirk_mode; extern bool efi_poweroff_required(void); -- 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
