Commit-ID: b61a76f8850d2979550abc42d7e09154ebb8d785 Gitweb: http://git.kernel.org/tip/b61a76f8850d2979550abc42d7e09154ebb8d785 Author: Matt Fleming <m...@codeblueprint.co.uk> AuthorDate: Fri, 27 Nov 2015 21:09:32 +0000 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sun, 29 Nov 2015 09:15:42 +0100
x86/efi: Map RAM into the identity page table for mixed mode We are relying on the pre-existing mappings in 'trampoline_pgd' when accessing function arguments in the EFI mixed mode thunking code. Instead let's map memory explicitly so that things will continue to work when we move to a separate page table in the future. Signed-off-by: Matt Fleming <m...@codeblueprint.co.uk> Reviewed-by: Borislav Petkov <b...@suse.de> Acked-by: Borislav Petkov <b...@suse.de> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Ard Biesheuvel <ard.biesheu...@linaro.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prak...@intel.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Toshi Kani <toshi.k...@hp.com> Cc: linux-...@vger.kernel.org Link: http://lkml.kernel.org/r/1448658575-17029-4-git-send-email-m...@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/platform/efi/efi_64.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 5aa186d..102976d 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -144,6 +144,7 @@ void efi_sync_low_kernel_mappings(void) int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { unsigned long pfn, text; + efi_memory_desc_t *md; struct page *page; unsigned npages; pgd_t *pgd; @@ -177,6 +178,25 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) if (!IS_ENABLED(CONFIG_EFI_MIXED)) return 0; + /* + * Map all of RAM so that we can access arguments in the 1:1 + * mapping when making EFI runtime calls. + */ + for_each_efi_memory_desc(&memmap, md) { + if (md->type != EFI_CONVENTIONAL_MEMORY && + md->type != EFI_LOADER_DATA && + md->type != EFI_LOADER_CODE) + continue; + + pfn = md->phys_addr >> PAGE_SHIFT; + npages = md->num_pages; + + if (kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, npages, 0)) { + pr_err("Failed to map 1:1 memory\n"); + return 1; + } + } + page = alloc_page(GFP_KERNEL|__GFP_DMA32); if (!page) panic("Unable to allocate EFI runtime stack < 4GB\n"); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
