| Message ID | 20240215103205.2607016-8-ryan.roberts@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Transparent Contiguous PTEs for User Mappings | expand |
On Thu, Feb 15, 2024 at 10:31:54AM +0000, Ryan Roberts wrote: > There are a number of places in the arch code that read a pte by using > the READ_ONCE() macro. Refactor these call sites to instead use the > ptep_get() helper, which itself is a READ_ONCE(). Generated code should > be the same. > > This will benefit us when we shortly introduce the transparent contpte > support. In this case, ptep_get() will become more complex so we now > have all the code abstracted through it. > > Tested-by: John Hubbard <jhubbard@nvidia.com> > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Mark. > --- > arch/arm64/include/asm/pgtable.h | 12 +++++++++--- > arch/arm64/kernel/efi.c | 2 +- > arch/arm64/mm/fault.c | 4 ++-- > arch/arm64/mm/hugetlbpage.c | 6 +++--- > arch/arm64/mm/kasan_init.c | 2 +- > arch/arm64/mm/mmu.c | 12 ++++++------ > arch/arm64/mm/pageattr.c | 4 ++-- > arch/arm64/mm/trans_pgd.c | 2 +- > 8 files changed, 25 insertions(+), 19 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index b6d3e9e0a946..de034ca40bad 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -275,6 +275,12 @@ static inline void set_pte(pte_t *ptep, pte_t pte) > } > } > > +#define ptep_get ptep_get > +static inline pte_t ptep_get(pte_t *ptep) > +{ > + return READ_ONCE(*ptep); > +} > + > extern void __sync_icache_dcache(pte_t pteval); > bool pgattr_change_is_safe(u64 old, u64 new); > > @@ -302,7 +308,7 @@ static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, > if (!IS_ENABLED(CONFIG_DEBUG_VM)) > return; > > - old_pte = READ_ONCE(*ptep); > + old_pte = ptep_get(ptep); > > if (!pte_valid(old_pte) || !pte_valid(pte)) > return; > @@ -904,7 +910,7 @@ static inline int __ptep_test_and_clear_young(pte_t *ptep) > { > pte_t old_pte, pte; > > - pte = READ_ONCE(*ptep); > + pte = ptep_get(ptep); > do { > old_pte = pte; > pte = pte_mkold(pte); > @@ -986,7 +992,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres > { > pte_t old_pte, pte; > > - pte = READ_ONCE(*ptep); > + pte = ptep_get(ptep); > do { > old_pte = pte; > pte = pte_wrprotect(pte); > diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c > index 0228001347be..d0e08e93b246 100644 > --- a/arch/arm64/kernel/efi.c > +++ b/arch/arm64/kernel/efi.c > @@ -103,7 +103,7 @@ static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) > { > struct set_perm_data *spd = data; > const efi_memory_desc_t *md = spd->md; > - pte_t pte = READ_ONCE(*ptep); > + pte_t pte = ptep_get(ptep); > > if (md->attribute & EFI_MEMORY_RO) > pte = set_pte_bit(pte, __pgprot(PTE_RDONLY)); > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 55f6455a8284..a254761fa1bd 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -191,7 +191,7 @@ static void show_pte(unsigned long addr) > if (!ptep) > break; > > - pte = READ_ONCE(*ptep); > + pte = ptep_get(ptep); > pr_cont(", pte=%016llx", pte_val(pte)); > pte_unmap(ptep); > } while(0); > @@ -214,7 +214,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, > pte_t entry, int dirty) > { > pteval_t old_pteval, pteval; > - pte_t pte = READ_ONCE(*ptep); > + pte_t pte = ptep_get(ptep); > > if (pte_same(pte, entry)) > return 0; > diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c > index 6720ec8d50e7..2892f925ed66 100644 > --- a/arch/arm64/mm/hugetlbpage.c > +++ b/arch/arm64/mm/hugetlbpage.c > @@ -485,7 +485,7 @@ void huge_ptep_set_wrprotect(struct mm_struct *mm, > size_t pgsize; > pte_t pte; > > - if (!pte_cont(READ_ONCE(*ptep))) { > + if (!pte_cont(ptep_get(ptep))) { > ptep_set_wrprotect(mm, addr, ptep); > return; > } > @@ -510,7 +510,7 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, > size_t pgsize; > int ncontig; > > - if (!pte_cont(READ_ONCE(*ptep))) > + if (!pte_cont(ptep_get(ptep))) > return ptep_clear_flush(vma, addr, ptep); > > ncontig = find_num_contig(mm, addr, ptep, &pgsize); > @@ -543,7 +543,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr > * when the permission changes from executable to non-executable > * in cases where cpu is affected with errata #2645198. > */ > - if (pte_user_exec(READ_ONCE(*ptep))) > + if (pte_user_exec(ptep_get(ptep))) > return huge_ptep_clear_flush(vma, addr, ptep); > } > return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep); > diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c > index 4c7ad574b946..c2a9f4f6c7dd 100644 > --- a/arch/arm64/mm/kasan_init.c > +++ b/arch/arm64/mm/kasan_init.c > @@ -113,7 +113,7 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, > memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE); > next = addr + PAGE_SIZE; > set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL)); > - } while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))); > + } while (ptep++, addr = next, addr != end && pte_none(ptep_get(ptep))); > } > > static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr, > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 3a27d887f7dd..343629a17042 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -173,7 +173,7 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, > > ptep = pte_set_fixmap_offset(pmdp, addr); > do { > - pte_t old_pte = READ_ONCE(*ptep); > + pte_t old_pte = ptep_get(ptep); > > set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); > > @@ -182,7 +182,7 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, > * only allow updates to the permission attributes. > */ > BUG_ON(!pgattr_change_is_safe(pte_val(old_pte), > - READ_ONCE(pte_val(*ptep)))); > + pte_val(ptep_get(ptep)))); > > phys += PAGE_SIZE; > } while (ptep++, addr += PAGE_SIZE, addr != end); > @@ -852,7 +852,7 @@ static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr, > > do { > ptep = pte_offset_kernel(pmdp, addr); > - pte = READ_ONCE(*ptep); > + pte = ptep_get(ptep); > if (pte_none(pte)) > continue; > > @@ -985,7 +985,7 @@ static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, > > do { > ptep = pte_offset_kernel(pmdp, addr); > - pte = READ_ONCE(*ptep); > + pte = ptep_get(ptep); > > /* > * This is just a sanity check here which verifies that > @@ -1004,7 +1004,7 @@ static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, > */ > ptep = pte_offset_kernel(pmdp, 0UL); > for (i = 0; i < PTRS_PER_PTE; i++) { > - if (!pte_none(READ_ONCE(ptep[i]))) > + if (!pte_none(ptep_get(&ptep[i]))) > return; > } > > @@ -1473,7 +1473,7 @@ pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte > * when the permission changes from executable to non-executable > * in cases where cpu is affected with errata #2645198. > */ > - if (pte_user_exec(READ_ONCE(*ptep))) > + if (pte_user_exec(ptep_get(ptep))) > return ptep_clear_flush(vma, addr, ptep); > } > return ptep_get_and_clear(vma->vm_mm, addr, ptep); > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index 924843f1f661..73a5e8f82586 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -36,7 +36,7 @@ bool can_set_direct_map(void) > static int change_page_range(pte_t *ptep, unsigned long addr, void *data) > { > struct page_change_data *cdata = data; > - pte_t pte = READ_ONCE(*ptep); > + pte_t pte = ptep_get(ptep); > > pte = clear_pte_bit(pte, cdata->clear_mask); > pte = set_pte_bit(pte, cdata->set_mask); > @@ -245,5 +245,5 @@ bool kernel_page_present(struct page *page) > return true; > > ptep = pte_offset_kernel(pmdp, addr); > - return pte_valid(READ_ONCE(*ptep)); > + return pte_valid(ptep_get(ptep)); > } > diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c > index 7b14df3c6477..f71ab4704cce 100644 > --- a/arch/arm64/mm/trans_pgd.c > +++ b/arch/arm64/mm/trans_pgd.c > @@ -33,7 +33,7 @@ static void *trans_alloc(struct trans_pgd_info *info) > > static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr) > { > - pte_t pte = READ_ONCE(*src_ptep); > + pte_t pte = ptep_get(src_ptep); > > if (pte_valid(pte)) { > /* > -- > 2.25.1 >
On Thu, Feb 15, 2024 at 10:31:54AM +0000, Ryan Roberts wrote: > There are a number of places in the arch code that read a pte by using > the READ_ONCE() macro. Refactor these call sites to instead use the > ptep_get() helper, which itself is a READ_ONCE(). Generated code should > be the same. > > This will benefit us when we shortly introduce the transparent contpte > support. In this case, ptep_get() will become more complex so we now > have all the code abstracted through it. > > Tested-by: John Hubbard <jhubbard@nvidia.com> > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index b6d3e9e0a946..de034ca40bad 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -275,6 +275,12 @@ static inline void set_pte(pte_t *ptep, pte_t pte) } } +#define ptep_get ptep_get +static inline pte_t ptep_get(pte_t *ptep) +{ + return READ_ONCE(*ptep); +} + extern void __sync_icache_dcache(pte_t pteval); bool pgattr_change_is_safe(u64 old, u64 new); @@ -302,7 +308,7 @@ static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, if (!IS_ENABLED(CONFIG_DEBUG_VM)) return; - old_pte = READ_ONCE(*ptep); + old_pte = ptep_get(ptep); if (!pte_valid(old_pte) || !pte_valid(pte)) return; @@ -904,7 +910,7 @@ static inline int __ptep_test_and_clear_young(pte_t *ptep) { pte_t old_pte, pte; - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); do { old_pte = pte; pte = pte_mkold(pte); @@ -986,7 +992,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres { pte_t old_pte, pte; - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); do { old_pte = pte; pte = pte_wrprotect(pte); diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 0228001347be..d0e08e93b246 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -103,7 +103,7 @@ static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) { struct set_perm_data *spd = data; const efi_memory_desc_t *md = spd->md; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = ptep_get(ptep); if (md->attribute & EFI_MEMORY_RO) pte = set_pte_bit(pte, __pgprot(PTE_RDONLY)); diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 55f6455a8284..a254761fa1bd 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -191,7 +191,7 @@ static void show_pte(unsigned long addr) if (!ptep) break; - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); pr_cont(", pte=%016llx", pte_val(pte)); pte_unmap(ptep); } while(0); @@ -214,7 +214,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, pte_t entry, int dirty) { pteval_t old_pteval, pteval; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = ptep_get(ptep); if (pte_same(pte, entry)) return 0; diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 6720ec8d50e7..2892f925ed66 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -485,7 +485,7 @@ void huge_ptep_set_wrprotect(struct mm_struct *mm, size_t pgsize; pte_t pte; - if (!pte_cont(READ_ONCE(*ptep))) { + if (!pte_cont(ptep_get(ptep))) { ptep_set_wrprotect(mm, addr, ptep); return; } @@ -510,7 +510,7 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, size_t pgsize; int ncontig; - if (!pte_cont(READ_ONCE(*ptep))) + if (!pte_cont(ptep_get(ptep))) return ptep_clear_flush(vma, addr, ptep); ncontig = find_num_contig(mm, addr, ptep, &pgsize); @@ -543,7 +543,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr * when the permission changes from executable to non-executable * in cases where cpu is affected with errata #2645198. */ - if (pte_user_exec(READ_ONCE(*ptep))) + if (pte_user_exec(ptep_get(ptep))) return huge_ptep_clear_flush(vma, addr, ptep); } return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep); diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 4c7ad574b946..c2a9f4f6c7dd 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -113,7 +113,7 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE); next = addr + PAGE_SIZE; set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL)); - } while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))); + } while (ptep++, addr = next, addr != end && pte_none(ptep_get(ptep))); } static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr, diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 3a27d887f7dd..343629a17042 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -173,7 +173,7 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, ptep = pte_set_fixmap_offset(pmdp, addr); do { - pte_t old_pte = READ_ONCE(*ptep); + pte_t old_pte = ptep_get(ptep); set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); @@ -182,7 +182,7 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, * only allow updates to the permission attributes. */ BUG_ON(!pgattr_change_is_safe(pte_val(old_pte), - READ_ONCE(pte_val(*ptep)))); + pte_val(ptep_get(ptep)))); phys += PAGE_SIZE; } while (ptep++, addr += PAGE_SIZE, addr != end); @@ -852,7 +852,7 @@ static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr, do { ptep = pte_offset_kernel(pmdp, addr); - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); if (pte_none(pte)) continue; @@ -985,7 +985,7 @@ static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, do { ptep = pte_offset_kernel(pmdp, addr); - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); /* * This is just a sanity check here which verifies that @@ -1004,7 +1004,7 @@ static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr, */ ptep = pte_offset_kernel(pmdp, 0UL); for (i = 0; i < PTRS_PER_PTE; i++) { - if (!pte_none(READ_ONCE(ptep[i]))) + if (!pte_none(ptep_get(&ptep[i]))) return; } @@ -1473,7 +1473,7 @@ pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte * when the permission changes from executable to non-executable * in cases where cpu is affected with errata #2645198. */ - if (pte_user_exec(READ_ONCE(*ptep))) + if (pte_user_exec(ptep_get(ptep))) return ptep_clear_flush(vma, addr, ptep); } return ptep_get_and_clear(vma->vm_mm, addr, ptep); diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 924843f1f661..73a5e8f82586 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -36,7 +36,7 @@ bool can_set_direct_map(void) static int change_page_range(pte_t *ptep, unsigned long addr, void *data) { struct page_change_data *cdata = data; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = ptep_get(ptep); pte = clear_pte_bit(pte, cdata->clear_mask); pte = set_pte_bit(pte, cdata->set_mask); @@ -245,5 +245,5 @@ bool kernel_page_present(struct page *page) return true; ptep = pte_offset_kernel(pmdp, addr); - return pte_valid(READ_ONCE(*ptep)); + return pte_valid(ptep_get(ptep)); } diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c index 7b14df3c6477..f71ab4704cce 100644 --- a/arch/arm64/mm/trans_pgd.c +++ b/arch/arm64/mm/trans_pgd.c @@ -33,7 +33,7 @@ static void *trans_alloc(struct trans_pgd_info *info) static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr) { - pte_t pte = READ_ONCE(*src_ptep); + pte_t pte = ptep_get(src_ptep); if (pte_valid(pte)) { /*