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Revert "x86-64/efi: Use EFI to deal with platform wall clock (again)"

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This reverts commit bd52276fa1 ("x86-64/efi: Use EFI to deal with
platform wall clock (again)"), and the two supporting commits:

  da5a108d05: "x86/kernel: remove tboot 1:1 page table creation code"

  185034e72d: "x86, efi: 1:1 pagetable mapping for virtual EFI calls")

as they all depend semantically on commit 53b87cf088 ("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>
This commit is contained in:
Linus Torvalds
2012-12-15 15:15:24 -08:00
parent 5bd665f28d
commit 11520e5e7c
7 changed files with 116 additions and 55 deletions
Download Patch File Download Diff File Expand all files Collapse all files

78
arch/x86/kernel/tboot.c
View File

@@ -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);