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| author |  Christophe Leroy <christophe.leroy@csgroup.eu>
| 2023-09-25 20:31:27 +0200 |
|---|---|---|
| committer |  Michael Ellerman <mpe@ellerman.id.au>
| 2023-10-19 17:12:45 +1100 |
| commit | 7c929ad0b3167e980a3963e03403a761138a4350 (patch) | |
| tree | ca215f5b8b95afb6e1289a15d3e6608d4ced6b63 | |
| parent | powerpc/nohash: Refactor pte_update() (diff) | |
| download | linux-7c929ad0b3167e980a3963e03403a761138a4350.tar.gz linux-7c929ad0b3167e980a3963e03403a761138a4350.tar.bz2 linux-7c929ad0b3167e980a3963e03403a761138a4350.zip | |
powerpc/nohash: Refactor checking of no-change in pte_update()
On nohash/64, a few callers of pte_update() check if there is
really a change in order to avoid an unnecessary write.
Refactor that inside pte_update().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/076563e611c2b51036686a8d378bfd5ef1726341.1695659959.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/include/asm/nohash/64/pgtable.h | 9 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/nohash/pgtable.h | 3 |
2 files changed, 3 insertions, 9 deletions
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h index b149a39f2685..cba08a62c52c 100644 --- a/arch/powerpc/include/asm/nohash/64/pgtable.h +++ b/arch/powerpc/include/asm/nohash/64/pgtable.h @@ -181,8 +181,6 @@ static inline int __ptep_test_and_clear_young(struct mm_struct *mm, { unsigned long old; - if (!pte_young(*ptep)) - return 0; old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0); return (old & _PAGE_ACCESSED) != 0; } @@ -198,10 +196,6 @@ static inline int __ptep_test_and_clear_young(struct mm_struct *mm, static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { - - if ((pte_val(*ptep) & _PAGE_RW) == 0) - return; - pte_update(mm, addr, ptep, _PAGE_RW, 0, 0); } @@ -209,9 +203,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, static inline void huge_ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { - if ((pte_val(*ptep) & _PAGE_RW) == 0) - return; - pte_update(mm, addr, ptep, _PAGE_RW, 0, 1); } diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h index bd5c3a4baabd..8adaacbbdd1d 100644 --- a/arch/powerpc/include/asm/nohash/pgtable.h +++ b/arch/powerpc/include/asm/nohash/pgtable.h @@ -47,6 +47,9 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p pte_basic_t old = pte_val(*p); pte_basic_t new = (old & ~(pte_basic_t)clr) | set; + if (new == old) + return old; + *p = __pte(new); if (IS_ENABLED(CONFIG_44x) && (old & _PAGE_USER) && (old & _PAGE_EXEC)) |