From da5a108d05b4f350be33e62d2db125673823e7ff Mon Sep 17 00:00:00 2001 From: Xiaoyan Zhang Date: Fri, 7 Sep 2012 19:29:04 +0100 Subject: [PATCH] x86/kernel: remove tboot 1:1 page table creation code For TXT boot, while Linux kernel trys to shutdown/S3/S4/reboot, it need to jump back to tboot code and do TXT teardown work. Previously kernel zapped all mem page identity mapping (va=pa) after booting, so tboot code mem address was mapped again with identity mapping. Now kernel didn't zap the identity mapping page table, so tboot related code can remove the remapping code before trapping back now. Signed-off-by: Xiaoyan Zhang Acked-by: Gang Wei Signed-off-by: Matt Fleming --- arch/x86/kernel/tboot.c | 78 +++-------------------------------------- 1 file changed, 5 insertions(+), 73 deletions(-) diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index f84fe00fad48..d4f460f962ee 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -103,71 +103,13 @@ 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) { - 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_X86_32 + load_cr3(initial_page_table); +#else + write_cr3(real_mode_header->trampoline_pgd); +#endif } #ifdef CONFIG_ACPI_SLEEP @@ -225,14 +167,6 @@ 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()) @@ -343,8 +277,6 @@ 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); -- 2.30.2