diff options
| -rw-r--r-- | arch/x86/mm/pgtable.c | 38 |
1 files changed, 14 insertions, 24 deletions
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index cb03f5a2b..4a105f283 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -705,47 +705,37 @@ int pmd_clear_huge(pmd_t *pmd) } #ifdef CONFIG_X86_64 -/** - * pud_free_pmd_page - Clear PUD entry and free PMD page - * @pud: Pointer to a PUD - * @addr: Virtual address associated with PUD - * - * Context: The PUD range has been unmapped and TLB purged. - * Return: 1 if clearing the entry succeeded. 0 otherwise. - * - * NOTE: Callers must allow a single page allocation. +/* + * Given a PUD poitner, detach and free the pointed-to + * PMD page and any PTE page children. The entire range + * under the PUD must not have any valid translations + * and the TLB must have already been flushed. */ int pud_free_pmd_page(pud_t *pud, unsigned long addr) { - pmd_t *pmd, *pmd_sv; struct ptdesc *pt; + pmd_t *pmd; int i; pmd = pud_pgtable(*pud); - pmd_sv = (pmd_t *)__get_free_page(GFP_KERNEL); - if (!pmd_sv) - return 0; - - for (i = 0; i < PTRS_PER_PMD; i++) { - pmd_sv[i] = pmd[i]; - if (!pmd_none(pmd[i])) - pmd_clear(&pmd[i]); - } + /* Detach the PMD page: */ pud_clear(pud); - /* INVLPG to clear all paging-structure caches */ + /* + * PMD and all its descendents are unreachable + * via normal page walks. Make them unreachable + * in cached mid-level walks too: + */ flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1); for (i = 0; i < PTRS_PER_PMD; i++) { - if (!pmd_none(pmd_sv[i])) { - pt = page_ptdesc(pmd_page(pmd_sv[i])); + if (!pmd_none(pmd[i])) { + pt = page_ptdesc(pmd_page(pmd[i])); pagetable_dtor_free(pt); } } - free_page((unsigned long)pmd_sv); - pmd_free(&init_mm, pmd); return 1; |