[RFC, PATCHv1 11/28] x86/power: support p4d_t in hibernate code

From: Kirill A. Shutemov
Date: Thu Dec 08 2016 - 11:29:45 EST


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

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
arch/x86/power/hibernate_64.c | 35 ++++++++++++++++++++++-------------
1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index 9634557a5444..bf38f5df60b0 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -45,6 +45,7 @@ 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
@@ -71,8 +72,10 @@ 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_p4d(p4d + p4d_index(restore_jump_address),
+ __p4d(__pa(pud) | _KERNPG_TABLE));
set_pgd(pgd + pgd_index(restore_jump_address),
- __pgd(__pa(pud) | _KERNPG_TABLE));
+ __pgd(__pa(p4d) | _KERNPG_TABLE));

return 0;
}
@@ -120,7 +123,10 @@ 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)
@@ -130,22 +136,25 @@ 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;
}

--
2.10.2