diff options
author | Peter Zijlstra <peterz@infradead.org> | 2020-11-26 19:02:29 +0300 |
---|---|---|
committer | Dave Hansen <dave.hansen@linux.intel.com> | 2022-12-15 21:37:27 +0300 |
commit | fbfdec9989e69e0b17aa3bf32fcb22d04cc33301 (patch) | |
tree | c4f9d34fff5fca3e6875c22b97932187f03a4844 /arch/x86/include/asm/pgtable-3level.h | |
parent | 93b3037a1482758349f3b0431406bcc457ca1cbc (diff) | |
download | linux-fbfdec9989e69e0b17aa3bf32fcb22d04cc33301.tar.xz |
x86/mm/pae: Make pmd_t similar to pte_t
Instead of mucking about with at least 2 different ways of fudging
it, do the same thing we do for pte_t.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221022114424.580310787%40infradead.org
Diffstat (limited to 'arch/x86/include/asm/pgtable-3level.h')
-rw-r--r-- | arch/x86/include/asm/pgtable-3level.h | 42 |
1 files changed, 14 insertions, 28 deletions
diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h index 28421a887209..28556d22feb8 100644 --- a/arch/x86/include/asm/pgtable-3level.h +++ b/arch/x86/include/asm/pgtable-3level.h @@ -87,7 +87,7 @@ static inline pmd_t pmd_read_atomic(pmd_t *pmdp) ret |= ((pmdval_t)*(tmp + 1)) << 32; } - return (pmd_t) { ret }; + return (pmd_t) { .pmd = ret }; } static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte) @@ -121,12 +121,11 @@ static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr, ptep->pte_high = 0; } -static inline void native_pmd_clear(pmd_t *pmd) +static inline void native_pmd_clear(pmd_t *pmdp) { - u32 *tmp = (u32 *)pmd; - *tmp = 0; + pmdp->pmd_low = 0; smp_wmb(); - *(tmp + 1) = 0; + pmdp->pmd_high = 0; } static inline void native_pud_clear(pud_t *pudp) @@ -162,25 +161,17 @@ static inline pte_t native_ptep_get_and_clear(pte_t *ptep) #define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp) #endif -union split_pmd { - struct { - u32 pmd_low; - u32 pmd_high; - }; - pmd_t pmd; -}; - #ifdef CONFIG_SMP static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp) { - union split_pmd res, *orig = (union split_pmd *)pmdp; + pmd_t res; /* xchg acts as a barrier before setting of the high bits */ - res.pmd_low = xchg(&orig->pmd_low, 0); - res.pmd_high = orig->pmd_high; - orig->pmd_high = 0; + res.pmd_low = xchg(&pmdp->pmd_low, 0); + res.pmd_high = READ_ONCE(pmdp->pmd_high); + WRITE_ONCE(pmdp->pmd_high, 0); - return res.pmd; + return res; } #else #define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp) @@ -199,17 +190,12 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, * anybody. */ if (!(pmd_val(pmd) & _PAGE_PRESENT)) { - union split_pmd old, new, *ptr; - - ptr = (union split_pmd *)pmdp; - - new.pmd = pmd; - /* xchg acts as a barrier before setting of the high bits */ - old.pmd_low = xchg(&ptr->pmd_low, new.pmd_low); - old.pmd_high = ptr->pmd_high; - ptr->pmd_high = new.pmd_high; - return old.pmd; + old.pmd_low = xchg(&pmdp->pmd_low, pmd.pmd_low); + old.pmd_high = READ_ONCE(pmdp->pmd_high); + WRITE_ONCE(pmdp->pmd_high, pmd.pmd_high); + + return old; } do { |