x86/power: Add 5-level paging support

set_up_temporary_text_mapping() and relocate_restore_code() require
adjustments to handle additional page table level.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170313143309.16020-7-kirill.shutemov@linux.intel.com
[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index ded2e82..2a9f993 100644 (file)
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -49,6 +49,7 @@ static int set_up_temporary_text_mapping(pgd_t *pgd)
 {
        pmd_t *pmd;
        pud_t *pud;
+       p4d_t *p4d;
 
        /*
         * The new mapping only has to cover the page containing the image
@@ -63,6 +64,13 @@ static int set_up_temporary_text_mapping(pgd_t *pgd)
         * the virtual address space after switching over to the original page
         * tables used by the image kernel.
         */
+
+       if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+               p4d = (p4d_t *)get_safe_page(GFP_ATOMIC);
+               if (!p4d)
+                       return -ENOMEM;
+       }
+
        pud = (pud_t *)get_safe_page(GFP_ATOMIC);
        if (!pud)
                return -ENOMEM;
@@ -75,8 +83,13 @@ static int set_up_temporary_text_mapping(pgd_t *pgd)
                __pmd((jump_address_phys & PMD_MASK) | __PAGE_KERNEL_LARGE_EXEC));
        set_pud(pud + pud_index(restore_jump_address),
                __pud(__pa(pmd) | _KERNPG_TABLE));
-       set_pgd(pgd + pgd_index(restore_jump_address),
-               __pgd(__pa(pud) | _KERNPG_TABLE));
+       if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+               set_p4d(p4d + p4d_index(restore_jump_address), __p4d(__pa(pud) | _KERNPG_TABLE));
+               set_pgd(pgd + pgd_index(restore_jump_address), __pgd(__pa(p4d) | _KERNPG_TABLE));
+       } else {
+               /* No p4d for 4-level paging: point the pgd to the pud page table */
+               set_pgd(pgd + pgd_index(restore_jump_address), __pgd(__pa(pud) | _KERNPG_TABLE));
+       }
 
        return 0;
 }
@@ -124,7 +137,10 @@ static int set_up_temporary_mappings(void)
 static int relocate_restore_code(void)
 {
        pgd_t *pgd;
+       p4d_t *p4d;
        pud_t *pud;
+       pmd_t *pmd;
+       pte_t *pte;
 
        relocated_restore_code = get_safe_page(GFP_ATOMIC);
        if (!relocated_restore_code)
@@ -134,22 +150,25 @@ static int relocate_restore_code(void)
 
        /* Make the page containing the relocated code executable */
        pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
-       pud = pud_offset(pgd, relocated_restore_code);
+       p4d = p4d_offset(pgd, relocated_restore_code);
+       if (p4d_large(*p4d)) {
+               set_p4d(p4d, __p4d(p4d_val(*p4d) & ~_PAGE_NX));
+               goto out;
+       }
+       pud = pud_offset(p4d, relocated_restore_code);
        if (pud_large(*pud)) {
                set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX));
-       } else {
-               pmd_t *pmd = pmd_offset(pud, relocated_restore_code);
-
-               if (pmd_large(*pmd)) {
-                       set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX));
-               } else {
-                       pte_t *pte = pte_offset_kernel(pmd, relocated_restore_code);
-
-                       set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX));
-               }
+               goto out;
+       }
+       pmd = pmd_offset(pud, relocated_restore_code);
+       if (pmd_large(*pmd)) {
+               set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX));
+               goto out;
        }
+       pte = pte_offset_kernel(pmd, relocated_restore_code);
+       set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX));
+out:
        __flush_tlb_all();
-
        return 0;
 }