diff options
Diffstat (limited to 'include/asm-generic/pgtable.h')
| -rw-r--r-- | include/asm-generic/pgtable.h | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 359fb935ded6..a9cac82e9a7a 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -375,7 +375,6 @@ static inline int pte_unused(pte_t pte) #endif #ifndef __HAVE_ARCH_PMD_SAME -#ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b) { return pmd_val(pmd_a) == pmd_val(pmd_b); @@ -385,21 +384,60 @@ static inline int pud_same(pud_t pud_a, pud_t pud_b) { return pud_val(pud_a) == pud_val(pud_b); } -#else /* CONFIG_TRANSPARENT_HUGEPAGE */ -static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b) +#endif + +#ifndef __HAVE_ARCH_P4D_SAME +static inline int p4d_same(p4d_t p4d_a, p4d_t p4d_b) { - BUILD_BUG(); - return 0; + return p4d_val(p4d_a) == p4d_val(p4d_b); } +#endif -static inline int pud_same(pud_t pud_a, pud_t pud_b) +#ifndef __HAVE_ARCH_PGD_SAME +static inline int pgd_same(pgd_t pgd_a, pgd_t pgd_b) { - BUILD_BUG(); - return 0; + return pgd_val(pgd_a) == pgd_val(pgd_b); } -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif +/* + * Use set_p*_safe(), and elide TLB flushing, when confident that *no* + * TLB flush will be required as a result of the "set". For example, use + * in scenarios where it is known ahead of time that the routine is + * setting non-present entries, or re-setting an existing entry to the + * same value. Otherwise, use the typical "set" helpers and flush the + * TLB. + */ +#define set_pte_safe(ptep, pte) \ +({ \ + WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \ + set_pte(ptep, pte); \ +}) + +#define set_pmd_safe(pmdp, pmd) \ +({ \ + WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \ + set_pmd(pmdp, pmd); \ +}) + +#define set_pud_safe(pudp, pud) \ +({ \ + WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \ + set_pud(pudp, pud); \ +}) + +#define set_p4d_safe(p4dp, p4d) \ +({ \ + WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \ + set_p4d(p4dp, p4d); \ +}) + +#define set_pgd_safe(pgdp, pgd) \ +({ \ + WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \ + set_pgd(pgdp, pgd); \ +}) + #ifndef __HAVE_ARCH_DO_SWAP_PAGE /* * Some architectures support metadata associated with a page. When a |