revert "Hibernation: Use temporary page tables for kernel text mapping on x86_64"

Revert commit efa4d2fb047b25a6be67fe92178a2a78da6b3f6a ("Hibernation:
Use temporary page tables for kernel text mapping on x86_64") because it
causes my t61p to reboot right at the end of resume-from-disk.  For
reasons unknown at this time.

Cc: Pavel Machek <pavel@ucw.cz>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/x86/kernel/suspend_64.c b/arch/x86/kernel/suspend_64.c
index db284ef..2e5efaa 100644 (file)
--- a/arch/x86/kernel/suspend_64.c
+++ b/arch/x86/kernel/suspend_64.c
@@ -192,42 +192,25 @@ static int res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long en
        return 0;
 }
 
-static int res_kernel_text_pud_init(pud_t *pud, unsigned long start)
-{
-       pmd_t *pmd;
-       unsigned long paddr;
-
-       pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
-       if (!pmd)
-               return -ENOMEM;
-       set_pud(pud + pud_index(start), __pud(__pa(pmd) | _KERNPG_TABLE));
-       for (paddr = 0; paddr < KERNEL_TEXT_SIZE; pmd++, paddr += PMD_SIZE) {
-               unsigned long pe;
-
-               pe = __PAGE_KERNEL_LARGE_EXEC | _PAGE_GLOBAL | paddr;
-               pe &= __supported_pte_mask;
-               set_pmd(pmd, __pmd(pe));
-       }
-
-       return 0;
-}
-
 static int set_up_temporary_mappings(void)
 {
        unsigned long start, end, next;
-       pud_t *pud;
        int error;
 
        temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
        if (!temp_level4_pgt)
                return -ENOMEM;
 
+       /* It is safe to reuse the original kernel mapping */
+       set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
+               init_level4_pgt[pgd_index(__START_KERNEL_map)]);
+
        /* Set up the direct mapping from scratch */
        start = (unsigned long)pfn_to_kaddr(0);
        end = (unsigned long)pfn_to_kaddr(end_pfn);
 
        for (; start < end; start = next) {
-               pud = (pud_t *)get_safe_page(GFP_ATOMIC);
+               pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC);
                if (!pud)
                        return -ENOMEM;
                next = start + PGDIR_SIZE;
@@ -238,17 +221,7 @@ static int set_up_temporary_mappings(void)
                set_pgd(temp_level4_pgt + pgd_index(start),
                        mk_kernel_pgd(__pa(pud)));
        }
-
-       /* Set up the kernel text mapping from scratch */
-       pud = (pud_t *)get_safe_page(GFP_ATOMIC);
-       if (!pud)
-               return -ENOMEM;
-       error = res_kernel_text_pud_init(pud, __START_KERNEL_map);
-       if (!error)
-               set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
-                       __pgd(__pa(pud) | _PAGE_TABLE));
-
-       return error;
+       return 0;
 }
 
 int swsusp_arch_resume(void)