diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 71 | ||||
| -rw-r--r-- | arch/arm64/mm/fault.c | 24 |
2 files changed, 44 insertions, 51 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 6eae342ced6b..9127688ae775 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -39,6 +39,7 @@ #ifndef __ASSEMBLY__ +#include <asm/cmpxchg.h> #include <asm/fixmap.h> #include <linux/mmdebug.h> @@ -173,6 +174,11 @@ static inline pte_t pte_clear_rdonly(pte_t pte) return clear_pte_bit(pte, __pgprot(PTE_RDONLY)); } +static inline pte_t pte_set_rdonly(pte_t pte) +{ + return set_pte_bit(pte, __pgprot(PTE_RDONLY)); +} + static inline pte_t pte_mkpresent(pte_t pte) { return set_pte_bit(pte, __pgprot(PTE_VALID)); @@ -593,20 +599,17 @@ static inline int pmdp_set_access_flags(struct vm_area_struct *vma, #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG static inline int __ptep_test_and_clear_young(pte_t *ptep) { - pteval_t pteval; - unsigned int tmp, res; + pte_t old_pte, pte; - asm volatile("// __ptep_test_and_clear_young\n" - " prfm pstl1strm, %2\n" - "1: ldxr %0, %2\n" - " ubfx %w3, %w0, %5, #1 // extract PTE_AF (young)\n" - " and %0, %0, %4 // clear PTE_AF\n" - " stxr %w1, %0, %2\n" - " cbnz %w1, 1b\n" - : "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)), "=&r" (res) - : "L" (~PTE_AF), "I" (ilog2(PTE_AF))); + pte = READ_ONCE(*ptep); + do { + old_pte = pte; + pte = pte_mkold(pte); + pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), + pte_val(old_pte), pte_val(pte)); + } while (pte_val(pte) != pte_val(old_pte)); - return res; + return pte_young(pte); } static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, @@ -630,17 +633,7 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long address, pte_t *ptep) { - pteval_t old_pteval; - unsigned int tmp; - - asm volatile("// ptep_get_and_clear\n" - " prfm pstl1strm, %2\n" - "1: ldxr %0, %2\n" - " stxr %w1, xzr, %2\n" - " cbnz %w1, 1b\n" - : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))); - - return __pte(old_pteval); + return __pte(xchg_relaxed(&pte_val(*ptep), 0)); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -659,21 +652,23 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, #define __HAVE_ARCH_PTEP_SET_WRPROTECT static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep) { - pteval_t pteval; - unsigned long tmp; - - asm volatile("// ptep_set_wrprotect\n" - " prfm pstl1strm, %2\n" - "1: ldxr %0, %2\n" - " tst %0, %4 // check for hw dirty (!PTE_RDONLY)\n" - " csel %1, %3, xzr, eq // set PTE_DIRTY|PTE_RDONLY if dirty\n" - " orr %0, %0, %1 // if !dirty, PTE_RDONLY is already set\n" - " and %0, %0, %5 // clear PTE_WRITE/PTE_DBM\n" - " stxr %w1, %0, %2\n" - " cbnz %w1, 1b\n" - : "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)) - : "r" (PTE_DIRTY|PTE_RDONLY), "L" (PTE_RDONLY), "L" (~PTE_WRITE) - : "cc"); + pte_t old_pte, pte; + + pte = READ_ONCE(*ptep); + do { + old_pte = pte; + /* + * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY + * clear), set the PTE_DIRTY and PTE_RDONLY bits. + */ + if (pte_hw_dirty(pte)) { + pte = pte_mkdirty(pte); + pte = pte_set_rdonly(pte); + } + pte = pte_wrprotect(pte); + pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), + pte_val(old_pte), pte_val(pte)); + } while (pte_val(pte) != pte_val(old_pte)); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 52ee273afeec..430eaf82da49 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -34,6 +34,7 @@ #include <linux/hugetlb.h> #include <asm/bug.h> +#include <asm/cmpxchg.h> #include <asm/cpufeature.h> #include <asm/exception.h> #include <asm/debug-monitors.h> @@ -197,8 +198,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address, pte_t *ptep, pte_t entry, int dirty) { - pteval_t old_pteval; - unsigned int tmp; + pteval_t old_pteval, pteval; if (pte_same(*ptep, entry)) return 0; @@ -208,7 +208,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, /* set PTE_RDONLY if actual read-only or clean PTE */ if (!pte_write(entry) || !pte_sw_dirty(entry)) - pte_val(entry) |= PTE_RDONLY; + entry = pte_set_rdonly(entry); /* * Setting the flags must be done atomically to avoid racing with the @@ -217,16 +217,14 @@ int ptep_set_access_flags(struct vm_area_struct *vma, * (calculated as: a & b == ~(~a | ~b)). */ pte_val(entry) ^= PTE_RDONLY; - asm volatile("// ptep_set_access_flags\n" - " prfm pstl1strm, %2\n" - "1: ldxr %0, %2\n" - " eor %0, %0, %3 // negate PTE_RDONLY in *ptep\n" - " orr %0, %0, %4 // set flags\n" - " eor %0, %0, %3 // negate final PTE_RDONLY\n" - " stxr %w1, %0, %2\n" - " cbnz %w1, 1b\n" - : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)) - : "L" (PTE_RDONLY), "r" (pte_val(entry))); + pteval = READ_ONCE(pte_val(*ptep)); + do { + old_pteval = pteval; + pteval ^= PTE_RDONLY; + pteval |= pte_val(entry); + pteval ^= PTE_RDONLY; + pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval); + } while (pteval != old_pteval); flush_tlb_fix_spurious_fault(vma, address); return 1; |