Messages in this thread Patch in this message | | | From | Will Deacon <> | Subject | [RFC PATCH 03/11] arm64: pgtable: Implement p[mu]d_valid() and check in set_p[mu]d() | Date | Fri, 24 Aug 2018 16:52:38 +0100 |
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Now that our walk-cache invalidation routines imply a DSB before the invalidation, we no longer need one when we are clearing an entry during unmap.
Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/include/asm/pgtable.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 1bdeca8918a6..2ab2031b778c 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -360,6 +360,7 @@ static inline int pmd_protnone(pmd_t pmd) #define pmd_present(pmd) pte_present(pmd_pte(pmd)) #define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd)) #define pmd_young(pmd) pte_young(pmd_pte(pmd)) +#define pmd_valid(pmd) pte_valid(pmd_pte(pmd)) #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) #define pmd_mkold(pmd) pte_pmd(pte_mkold(pmd_pte(pmd))) #define pmd_mkwrite(pmd) pte_pmd(pte_mkwrite(pmd_pte(pmd))) @@ -431,7 +432,9 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, static inline void set_pmd(pmd_t *pmdp, pmd_t pmd) { WRITE_ONCE(*pmdp, pmd); - dsb(ishst); + + if (pmd_valid(pmd)) + dsb(ishst); } static inline void pmd_clear(pmd_t *pmdp) @@ -477,11 +480,14 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd) #define pud_none(pud) (!pud_val(pud)) #define pud_bad(pud) (!(pud_val(pud) & PUD_TABLE_BIT)) #define pud_present(pud) pte_present(pud_pte(pud)) +#define pud_valid(pud) pte_valid(pud_pte(pud)) static inline void set_pud(pud_t *pudp, pud_t pud) { WRITE_ONCE(*pudp, pud); - dsb(ishst); + + if (pud_valid(pud)) + dsb(ishst); } static inline void pud_clear(pud_t *pudp) -- 2.1.4
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