Some EFI BIOS stores BGRT data in the wrong place and some EFI based BIOS also requires mapping of boot code/data when doing efi_enter_virtual_mode. Current code in efi_enter_virtual_mode maps both EFI_RUNTIME_MEMORY and BIOS boot code/data. This patch gives the option to switch off that behavior - if your BIOS has neither BGRT - nor bugs that require mapping of EFI boot code/data Removes the following warning when booting Linux with an EFI BIOS that is bug free on IA32 ------------[ cut here ]------------ WARNING: at arch/x86/mm/ioremap.c:102 __ioremap_caller+0x3d3/0x440() Modules linked in: Pid: 0, comm: swapper Not tainted 3.9.0-rc7+ #95 Call Trace: [<c102b6af>] warn_slowpath_common+0x5f/0x80 [<c1023fb3>] ? __ioremap_caller+0x3d3/0x440 [<c1023fb3>] ? __ioremap_caller+0x3d3/0x440 [<c102b6ed>] warn_slowpath_null+0x1d/0x20 [<c1023fb3>] __ioremap_caller+0x3d3/0x440 [<c106007b>] ? get_usage_chars+0xfb/0x110 [<c102d937>] ? vprintk_emit+0x147/0x480 [<c1418593>] ? efi_enter_virtual_mode+0x1e4/0x3de [<c102406a>] ioremap_cache+0x1a/0x20 [<c1418593>] ? efi_enter_virtual_mode+0x1e4/0x3de [<c1418593>] efi_enter_virtual_mode+0x1e4/0x3de [<c1407984>] start_kernel+0x286/0x2f4 [<c1407535>] ? repair_env_string+0x51/0x51 [<c1407362>] i386_start_kernel+0x12c/0x12f ---[ end trace 4eaa2a86a8e2da22 ]--- Mapping only memory EFI_RUNTIME_MEMORY is is consistent with the code in arch/ia64/kernel/efi.c:efi_enter_virtual_mode(); Signed-off-by: Bryan O'Donoghue <bryan.odonoghue.lkml@xxxxxxxxxxxxxxxxx> --- Documentation/kernel-parameters.txt | 4 ++++ arch/x86/platform/efi/efi.c | 14 +++++++++++--- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4609e81..faaa5cb 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1856,6 +1856,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noefi [X86] Disable EFI runtime services support. + noefi_virt_mapboot + [X86] Do not map EFI boot code/data when calling + efi_enter_virtual_mode(). + noexec [IA-64] noexec [X86] diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 5f2ecaf..64f98cd 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -88,6 +88,14 @@ static int __init setup_noefi(char *arg) } early_param("noefi", setup_noefi); +static bool __initdata virt_mapboot = true; +static int __init setup_noefi_virt_mapboot(char *arg) +{ + virt_mapboot = false; + return 0; +} +early_param("noefi_virt_mapboot", setup_noefi_virt_mapboot); + int add_efi_memmap; EXPORT_SYMBOL(add_efi_memmap); @@ -884,9 +892,9 @@ void __init efi_enter_virtual_mode(void) for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { md = p; - if (!(md->attribute & EFI_MEMORY_RUNTIME) && - md->type != EFI_BOOT_SERVICES_CODE && - md->type != EFI_BOOT_SERVICES_DATA) + if (!((md->attribute & EFI_MEMORY_RUNTIME) || (virt_mapboot && + (md->type == EFI_BOOT_SERVICES_CODE || + md->type == EFI_BOOT_SERVICES_DATA)))) continue; size = md->num_pages << EFI_PAGE_SHIFT; -- 1.7.10.4 -- 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