This patch makes MTE tags saving and restoring support large folios, then we don't need to split them into base pages for swapping out on ARM64 SoCs with MTE. arch_prepare_to_swap() should take folio rather than page as parameter because we support THP swap-out as a whole. Meanwhile, arch_swap_restore() should use page parameter rather than folio as swap-in always works at the granularity of base pages right now. arch_thp_swp_supported() is dropped since ARM64 MTE was the only one who needed it. Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx> --- rfc v3: * move arch_swap_restore() to take page rather than folio according to the discussion with Ryan and Steven; * fix some other issues commented by Ryan rfc v2: https://lore.kernel.org/lkml/20231104093423.170054-1-v-songbaohua@xxxxxxxx/ rfc v1: https://lore.kernel.org/lkml/20231102223643.7733-1-v-songbaohua@xxxxxxxx/ arch/arm64/include/asm/pgtable.h | 21 ++++---------------- arch/arm64/mm/mteswap.c | 34 ++++++++++++++++++++++++++++++++ include/linux/huge_mm.h | 12 ----------- include/linux/pgtable.h | 4 ++-- mm/memory.c | 2 +- mm/page_io.c | 2 +- mm/shmem.c | 2 +- mm/swap_slots.c | 2 +- mm/swapfile.c | 2 +- 9 files changed, 45 insertions(+), 36 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index b19a8aee684c..c3eef11c1a9e 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -45,12 +45,6 @@ __flush_tlb_range(vma, addr, end, PUD_SIZE, false, 1) #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -static inline bool arch_thp_swp_supported(void) -{ - return !system_supports_mte(); -} -#define arch_thp_swp_supported arch_thp_swp_supported - /* * Outside of a few very special situations (e.g. hibernation), we always * use broadcast TLB invalidation instructions, therefore a spurious page @@ -1036,12 +1030,8 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, #ifdef CONFIG_ARM64_MTE #define __HAVE_ARCH_PREPARE_TO_SWAP -static inline int arch_prepare_to_swap(struct page *page) -{ - if (system_supports_mte()) - return mte_save_tags(page); - return 0; -} +#define arch_prepare_to_swap arch_prepare_to_swap +extern int arch_prepare_to_swap(struct folio *folio); #define __HAVE_ARCH_SWAP_INVALIDATE static inline void arch_swap_invalidate_page(int type, pgoff_t offset) @@ -1057,11 +1047,8 @@ static inline void arch_swap_invalidate_area(int type) } #define __HAVE_ARCH_SWAP_RESTORE -static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio) -{ - if (system_supports_mte()) - mte_restore_tags(entry, &folio->page); -} +#define arch_swap_restore arch_swap_restore +extern void arch_swap_restore(swp_entry_t entry, struct page *page); #endif /* CONFIG_ARM64_MTE */ diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c index a31833e3ddc5..75c2836e8240 100644 --- a/arch/arm64/mm/mteswap.c +++ b/arch/arm64/mm/mteswap.c @@ -68,6 +68,12 @@ void mte_invalidate_tags(int type, pgoff_t offset) mte_free_tag_storage(tags); } +static inline void __mte_invalidate_tags(struct page *page) +{ + swp_entry_t entry = page_swap_entry(page); + mte_invalidate_tags(swp_type(entry), swp_offset(entry)); +} + void mte_invalidate_tags_area(int type) { swp_entry_t entry = swp_entry(type, 0); @@ -83,3 +89,31 @@ void mte_invalidate_tags_area(int type) } xa_unlock(&mte_pages); } + +int arch_prepare_to_swap(struct folio *folio) +{ + int err; + long i; + + if (system_supports_mte()) { + long nr = folio_nr_pages(folio); + + for (i = 0; i < nr; i++) { + err = mte_save_tags(folio_page(folio, i)); + if (err) + goto out; + } + } + return 0; + +out: + while (i--) + __mte_invalidate_tags(folio_page(folio, i)); + return err; +} + +void arch_swap_restore(swp_entry_t entry, struct page *page) +{ + if (system_supports_mte()) + mte_restore_tags(entry, page); +} diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index fa0350b0812a..f83fb8d5241e 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -400,16 +400,4 @@ static inline int split_folio(struct folio *folio) return split_folio_to_list(folio, NULL); } -/* - * archs that select ARCH_WANTS_THP_SWAP but don't support THP_SWP due to - * limitations in the implementation like arm64 MTE can override this to - * false - */ -#ifndef arch_thp_swp_supported -static inline bool arch_thp_swp_supported(void) -{ - return true; -} -#endif - #endif /* _LINUX_HUGE_MM_H */ diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index af7639c3b0a3..87e3140a55ca 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -897,7 +897,7 @@ static inline int arch_unmap_one(struct mm_struct *mm, * prototypes must be defined in the arch-specific asm/pgtable.h file. */ #ifndef __HAVE_ARCH_PREPARE_TO_SWAP -static inline int arch_prepare_to_swap(struct page *page) +static inline int arch_prepare_to_swap(struct folio *folio) { return 0; } @@ -914,7 +914,7 @@ static inline void arch_swap_invalidate_area(int type) #endif #ifndef __HAVE_ARCH_SWAP_RESTORE -static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio) +static inline void arch_swap_restore(swp_entry_t entry, struct page *page) { } #endif diff --git a/mm/memory.c b/mm/memory.c index 1f18ed4a5497..fad238dd38e7 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4022,7 +4022,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) * when reading from swap. This metadata may be indexed by swap entry * so this must be called before swap_free(). */ - arch_swap_restore(entry, folio); + arch_swap_restore(entry, page); /* * Remove the swap entry and conditionally try to free up the swapcache. diff --git a/mm/page_io.c b/mm/page_io.c index cb559ae324c6..0fd832474c1d 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -189,7 +189,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc) * Arch code may have to preserve more data than just the page * contents, e.g. memory tags. */ - ret = arch_prepare_to_swap(&folio->page); + ret = arch_prepare_to_swap(folio); if (ret) { folio_mark_dirty(folio); folio_unlock(folio); diff --git a/mm/shmem.c b/mm/shmem.c index 91e2620148b2..7d32e50da121 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1892,7 +1892,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, * Some architectures may have to restore extra metadata to the * folio after reading from swap. */ - arch_swap_restore(swap, folio); + arch_swap_restore(swap, &folio->page); if (shmem_should_replace_folio(folio, gfp)) { error = shmem_replace_folio(&folio, gfp, info, index); diff --git a/mm/swap_slots.c b/mm/swap_slots.c index 0bec1f705f8e..2325adbb1f19 100644 --- a/mm/swap_slots.c +++ b/mm/swap_slots.c @@ -307,7 +307,7 @@ swp_entry_t folio_alloc_swap(struct folio *folio) entry.val = 0; if (folio_test_large(folio)) { - if (IS_ENABLED(CONFIG_THP_SWAP) && arch_thp_swp_supported()) + if (IS_ENABLED(CONFIG_THP_SWAP)) get_swap_pages(1, &entry, folio_nr_pages(folio)); goto out; } diff --git a/mm/swapfile.c b/mm/swapfile.c index 4bc70f459164..6450e0279e35 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1784,7 +1784,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, * when reading from swap. This metadata may be indexed by swap entry * so this must be called before swap_free(). */ - arch_swap_restore(entry, page_folio(page)); + arch_swap_restore(entry, page); /* See do_swap_page() */ BUG_ON(!PageAnon(page) && PageMappedToDisk(page)); -- 2.34.1
