From d2f7cbe7b26a74dbbbf8f325b2a6fd01bc34032c Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Thu, 31 Oct 2013 17:25:08 +0100 Subject: x86/efi: Runtime services virtual mapping We map the EFI regions needed for runtime services non-contiguously, with preserved alignment on virtual addresses starting from -4G down for a total max space of 64G. This way, we provide for stable runtime services addresses across kernels so that a kexec'd kernel can still use them. Thus, they're mapped in a separate pagetable so that we don't pollute the kernel namespace. Add an efi= kernel command line parameter for passing miscellaneous options and chicken bits from the command line. While at it, add a chicken bit called "efi=old_map" which can be used as a fallback to the old runtime services mapping method in case there's some b0rkage with a particular EFI implementation (haha, it is hard to hold up the sarcasm here...). Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt. Signed-off-by: Borislav Petkov Signed-off-by: Matt Fleming --- arch/x86/platform/efi/efi_32.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'arch/x86/platform/efi/efi_32.c') diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c index 40e446941dd7..e94557cf5487 100644 --- a/arch/x86/platform/efi/efi_32.c +++ b/arch/x86/platform/efi/efi_32.c @@ -37,9 +37,16 @@ * claim EFI runtime service handler exclusively and to duplicate a memory in * low memory space say 0 - 3G. */ - static unsigned long efi_rt_eflags; +void efi_sync_low_kernel_mappings(void) {} +void efi_setup_page_tables(void) {} + +void __init efi_map_region(efi_memory_desc_t *md) +{ + old_map_region(md); +} + void efi_call_phys_prelog(void) { struct desc_ptr gdt_descr; -- cgit v1.2.3