diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 07789647bf33..d83f5e7ddbdf 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -396,6 +396,7 @@ static inline void update_page_count(int level, unsigned long pages) { } extern pte_t *lookup_address(unsigned long address, unsigned int *level); extern pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, unsigned int *level); +extern pmd_t *lookup_pmd_address(unsigned long address); extern phys_addr_t slow_virt_to_phys(void *__address); extern int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, unsigned numpages, unsigned long page_flags); diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 36de293caf25..129810887e83 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -383,6 +383,26 @@ static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address, return lookup_address(address, level); } +/* + * Lookup the PMD entry for a virtual address. Return a pointer to the entry + * or NULL if not present. + */ +pmd_t *lookup_pmd_address(unsigned long address) +{ + pgd_t *pgd; + pud_t *pud; + + pgd = pgd_offset_k(address); + if (pgd_none(*pgd)) + return NULL; + + pud = pud_offset(pgd, address); + if (pud_none(*pud) || pud_large(*pud) || !pud_present(*pud)) + return NULL; + + return pmd_offset(pud, address); +} + /* * This is necessary because __pa() does not work on some * kinds of memory, like vmalloc() or the alloc_remap()