Acked-by: Gang Wei <gang....@intel.com>
> From: Xiaoyan Zhang <xiaoyan.zh...@intel.com>
>
> 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 <xiaoyan.zh...@intel.com>
> ---
> arch/x86/kernel/tboot.c | 78
+++--------------------------------------------
> 1 files changed, 5 insertions(+), 73 deletions(-)
>
> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
> index f84fe00..d4f460f 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);
>
> --
> 1.7.7.6
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