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-rw-r--r--arch/arm64/include/asm/pgtable.h71
1 files changed, 33 insertions, 38 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