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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-15 23:15:24 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-15 23:20:41 (GMT) |
commit | 11520e5e7c1855fc3bf202bb3be35a39d9efa034 (patch) | |
tree | 734ea170f825000dceef3f724dff474b46fce11d /arch/x86/kernel/tboot.c | |
parent | 5bd665f28db2b04a8d6fe277342479906fc60b62 (diff) | |
download | linux-fsl-qoriq-11520e5e7c1855fc3bf202bb3be35a39d9efa034.tar.xz |
Revert "x86-64/efi: Use EFI to deal with platform wall clock (again)"
This reverts commit bd52276fa1d4 ("x86-64/efi: Use EFI to deal with
platform wall clock (again)"), and the two supporting commits:
da5a108d05b4: "x86/kernel: remove tboot 1:1 page table creation code"
185034e72d59: "x86, efi: 1:1 pagetable mapping for virtual EFI calls")
as they all depend semantically on commit 53b87cf088e2 ("x86, mm:
Include the entire kernel memory map in trampoline_pgd") that got
reverted earlier due to the problems it caused.
This was pointed out by Yinghai Lu, and verified by me on my Macbook Air
that uses EFI.
Pointed-out-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/tboot.c')
-rw-r--r-- | arch/x86/kernel/tboot.c | 78 |
1 files changed, 73 insertions, 5 deletions
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index d4f460f..f84fe00 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -103,13 +103,71 @@ void __init tboot_probe(void) pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); } +static pgd_t *tboot_pg_dir; +static struct mm_struct tboot_mm = { + .mm_rb = RB_ROOT, + .pgd = swapper_pg_dir, + .mm_users = ATOMIC_INIT(2), + .mm_count = ATOMIC_INIT(1), + .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem), + .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), + .mmlist = LIST_HEAD_INIT(init_mm.mmlist), +}; + static inline void switch_to_tboot_pt(void) { -#ifdef CONFIG_X86_32 - load_cr3(initial_page_table); -#else - write_cr3(real_mode_header->trampoline_pgd); -#endif + write_cr3(virt_to_phys(tboot_pg_dir)); +} + +static int map_tboot_page(unsigned long vaddr, unsigned long pfn, + pgprot_t prot) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + pgd = pgd_offset(&tboot_mm, vaddr); + pud = pud_alloc(&tboot_mm, pgd, vaddr); + if (!pud) + return -1; + pmd = pmd_alloc(&tboot_mm, pud, vaddr); + if (!pmd) + return -1; + pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr); + if (!pte) + return -1; + set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); + pte_unmap(pte); + return 0; +} + +static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, + unsigned long nr) +{ + /* Reuse the original kernel mapping */ + tboot_pg_dir = pgd_alloc(&tboot_mm); + if (!tboot_pg_dir) + return -1; + + for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { + if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) + return -1; + } + + return 0; +} + +static void tboot_create_trampoline(void) +{ + u32 map_base, map_size; + + /* Create identity map for tboot shutdown code. */ + map_base = PFN_DOWN(tboot->tboot_base); + map_size = PFN_UP(tboot->tboot_size); + if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) + panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", + map_base, map_size); } #ifdef CONFIG_ACPI_SLEEP @@ -167,6 +225,14 @@ void tboot_shutdown(u32 shutdown_type) if (!tboot_enabled()) return; + /* + * if we're being called before the 1:1 mapping is set up then just + * return and let the normal shutdown happen; this should only be + * due to very early panic() + */ + if (!tboot_pg_dir) + return; + /* if this is S3 then set regions to MAC */ if (shutdown_type == TB_SHUTDOWN_S3) if (tboot_setup_sleep()) @@ -277,6 +343,8 @@ static __init int tboot_late_init(void) if (!tboot_enabled()) return 0; + tboot_create_trampoline(); + atomic_set(&ap_wfs_count, 0); register_hotcpu_notifier(&tboot_cpu_notifier); |