| Message ID | 20240322114136.61386-2-21cnbao@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | THP_SWAP support for ARM64 SoC with MTE | expand |
On 22/03/2024 11:41, Barry Song wrote: > From: Barry Song <v-songbaohua@oppo.com> > > Commit d0637c505f8a1 ("arm64: enable THP_SWAP for arm64") brings up > THP_SWAP on ARM64, but it doesn't enable THP_SWP on hardware with > MTE as the MTE code works with the assumption tags save/restore is > always handling a folio with only one page. > > The limitation should be removed as more and more ARM64 SoCs have > this feature. Co-existence of MTE and THP_SWAP becomes more and > more important. > > This patch makes MTE tags saving support large folios, then we don't > need to split large folios into base pages for swapping out on ARM64 > SoCs with MTE any more. > > arch_prepare_to_swap() should take folio rather than page as parameter > because we support THP swap-out as a whole. It saves tags for all > pages in a large folio. > > As now we are restoring tags based-on folio, in arch_swap_restore(), > we may increase some extra loops and early-exitings while refaulting > a large folio which is still in swapcache in do_swap_page(). In case > a large folio has nr pages, do_swap_page() will only set the PTE of > the particular page which is causing the page fault. > Thus do_swap_page() runs nr times, and each time, arch_swap_restore() > will loop nr times for those subpages in the folio. So right now the > algorithmic complexity becomes O(nr^2). > > Once we support mapping large folios in do_swap_page(), extra loops > and early-exitings will decrease while not being completely removed > as a large folio might get partially tagged in corner cases such as, > 1. a large folio in swapcache can be partially unmapped, thus, MTE > tags for the unmapped pages will be invalidated; > 2. users might use mprotect() to set MTEs on a part of a large folio. > > arch_thp_swp_supported() is dropped since ARM64 MTE was the only one > who needed it. > > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Ryan Roberts <ryan.roberts@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Kemeng Shi <shikemeng@huaweicloud.com> > Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> > Cc: Anshuman Khandual <anshuman.khandual@arm.com> > Cc: Peter Collingbourne <pcc@google.com> > Cc: Steven Price <steven.price@arm.com> > Cc: Yosry Ahmed <yosryahmed@google.com> > Cc: Peter Xu <peterx@redhat.com> > Cc: Lorenzo Stoakes <lstoakes@gmail.com> > Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> > Cc: Hugh Dickins <hughd@google.com> > CC: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> > Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> > Signed-off-by: Barry Song <v-songbaohua@oppo.com> > Reviewed-by: Steven Price <steven.price@arm.com> > Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> It would be really great if we can get this in for v6.10! > --- > arch/arm64/include/asm/pgtable.h | 19 ++------------ > arch/arm64/mm/mteswap.c | 45 ++++++++++++++++++++++++++++++++ > include/linux/huge_mm.h | 12 --------- > include/linux/pgtable.h | 2 +- > mm/internal.h | 14 ++++++++++ > mm/memory.c | 2 +- > mm/page_io.c | 2 +- > mm/shmem.c | 2 +- > mm/swap_slots.c | 2 +- > mm/swapfile.c | 2 +- > 10 files changed, 67 insertions(+), 35 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index afdd56d26ad7..259325e6b7e8 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -49,12 +49,6 @@ > __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 > @@ -1280,12 +1274,7 @@ 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; > -} > +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) > @@ -1301,11 +1290,7 @@ 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); > -} > +extern void arch_swap_restore(swp_entry_t entry, struct folio *folio); > > #endif /* CONFIG_ARM64_MTE */ > > diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c > index a31833e3ddc5..63e8d72f202a 100644 > --- a/arch/arm64/mm/mteswap.c > +++ b/arch/arm64/mm/mteswap.c > @@ -68,6 +68,13 @@ 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 +90,41 @@ void mte_invalidate_tags_area(int type) > } > xa_unlock(&mte_pages); > } > + > +int arch_prepare_to_swap(struct folio *folio) > +{ > + long i, nr; > + int err; > + > + if (!system_supports_mte()) > + return 0; > + > + 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 folio *folio) > +{ > + long i, nr; > + > + if (!system_supports_mte()) > + return; > + > + nr = folio_nr_pages(folio); > + > + for (i = 0; i < nr; i++) { > + mte_restore_tags(entry, folio_page(folio, i)); > + entry.val++; > + } > +} > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index de0c89105076..e04b93c43965 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -535,16 +535,4 @@ static inline int split_folio_to_order(struct folio *folio, int new_order) > #define split_folio_to_list(f, l) split_folio_to_list_to_order(f, l, 0) > #define split_folio(f) split_folio_to_order(f, 0) > > -/* > - * 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 85fc7554cd52..b10a7dd615bd 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -1052,7 +1052,7 @@ 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; > } > diff --git a/mm/internal.h b/mm/internal.h > index 7e486f2c502c..2551e93dd885 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -76,6 +76,20 @@ static inline int folio_nr_pages_mapped(struct folio *folio) > return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED; > } > > +/* > + * Retrieve the first entry of a folio based on a provided entry within the > + * folio. We cannot rely on folio->swap as there is no guarantee that it has > + * been initialized. Used for calling arch_swap_restore() > + */ > +static inline swp_entry_t folio_swap(swp_entry_t entry, struct folio *folio) > +{ > + swp_entry_t swap = { > + .val = ALIGN_DOWN(entry.val, folio_nr_pages(folio)), > + }; > + > + return swap; > +} > + > static inline void *folio_raw_mapping(struct folio *folio) > { > unsigned long mapping = (unsigned long)folio->mapping; > diff --git a/mm/memory.c b/mm/memory.c > index f2bc6dd15eb8..b7cab8be8632 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -4188,7 +4188,7 @@ 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(folio_swap(entry, folio), folio); > > /* > * 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 ae2b49055e43..a9a7c236aecc 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 0aad0d9a621b..44c1519ba881 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1913,7 +1913,7 @@ 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(folio_swap(swap, folio), folio); > > 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 90973ce7881d..53abeaf1371d 100644 > --- a/mm/swap_slots.c > +++ b/mm/swap_slots.c > @@ -310,7 +310,7 @@ 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 4919423cce76..5e6d2304a2a4 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -1806,7 +1806,7 @@ 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, folio); > + arch_swap_restore(folio_swap(entry, folio), folio); > > dec_mm_counter(vma->vm_mm, MM_SWAPENTS); > inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
On Sat, Mar 23, 2024 at 12:41:36AM +1300, Barry Song wrote: > From: Barry Song <v-songbaohua@oppo.com> > > Commit d0637c505f8a1 ("arm64: enable THP_SWAP for arm64") brings up > THP_SWAP on ARM64, but it doesn't enable THP_SWP on hardware with > MTE as the MTE code works with the assumption tags save/restore is > always handling a folio with only one page. > > The limitation should be removed as more and more ARM64 SoCs have > this feature. Co-existence of MTE and THP_SWAP becomes more and > more important. > > This patch makes MTE tags saving support large folios, then we don't > need to split large folios into base pages for swapping out on ARM64 > SoCs with MTE any more. > > arch_prepare_to_swap() should take folio rather than page as parameter > because we support THP swap-out as a whole. It saves tags for all > pages in a large folio. > > As now we are restoring tags based-on folio, in arch_swap_restore(), > we may increase some extra loops and early-exitings while refaulting > a large folio which is still in swapcache in do_swap_page(). In case > a large folio has nr pages, do_swap_page() will only set the PTE of > the particular page which is causing the page fault. > Thus do_swap_page() runs nr times, and each time, arch_swap_restore() > will loop nr times for those subpages in the folio. So right now the > algorithmic complexity becomes O(nr^2). > > Once we support mapping large folios in do_swap_page(), extra loops > and early-exitings will decrease while not being completely removed > as a large folio might get partially tagged in corner cases such as, > 1. a large folio in swapcache can be partially unmapped, thus, MTE > tags for the unmapped pages will be invalidated; > 2. users might use mprotect() to set MTEs on a part of a large folio. > > arch_thp_swp_supported() is dropped since ARM64 MTE was the only one > who needed it. > > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Ryan Roberts <ryan.roberts@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Kemeng Shi <shikemeng@huaweicloud.com> > Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> > Cc: Anshuman Khandual <anshuman.khandual@arm.com> > Cc: Peter Collingbourne <pcc@google.com> > Cc: Steven Price <steven.price@arm.com> > Cc: Yosry Ahmed <yosryahmed@google.com> > Cc: Peter Xu <peterx@redhat.com> > Cc: Lorenzo Stoakes <lstoakes@gmail.com> > Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> > Cc: Hugh Dickins <hughd@google.com> > CC: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> > Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> > Signed-off-by: Barry Song <v-songbaohua@oppo.com> > Reviewed-by: Steven Price <steven.price@arm.com> > Acked-by: Chris Li <chrisl@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
On Sat, Mar 23, 2024 at 12:41:36AM +1300, Barry Song wrote: > Commit d0637c505f8a1 ("arm64: enable THP_SWAP for arm64") brings up > THP_SWAP on ARM64, but it doesn't enable THP_SWP on hardware with > MTE as the MTE code works with the assumption tags save/restore is > always handling a folio with only one page. > > The limitation should be removed as more and more ARM64 SoCs have > this feature. Co-existence of MTE and THP_SWAP becomes more and > more important. > > This patch makes MTE tags saving support large folios, then we don't > need to split large folios into base pages for swapping out on ARM64 > SoCs with MTE any more. Can we go further than this patch and only support PG_mte_tagged and PG_mte_lock on folio->flags instead of page->flags? We're down to using page->flags for these two MTE bits, a whole lot of s390 junk, PG_hwpoison, PG_head, PG_anon_exclusive and Zone/Section/Node/KASAN/last_cpupid. Looking at some of the callers, the call in copy_highpage() would need to be lifted to its caller so that we only set the tags once per folio rather than try to set them per page of a folio ... might be a bit of churn, and I'd hate to try to do it myself without being able to test it.
On 27.03.24 15:53, Matthew Wilcox wrote: > On Sat, Mar 23, 2024 at 12:41:36AM +1300, Barry Song wrote: >> Commit d0637c505f8a1 ("arm64: enable THP_SWAP for arm64") brings up >> THP_SWAP on ARM64, but it doesn't enable THP_SWP on hardware with >> MTE as the MTE code works with the assumption tags save/restore is >> always handling a folio with only one page. >> >> The limitation should be removed as more and more ARM64 SoCs have >> this feature. Co-existence of MTE and THP_SWAP becomes more and >> more important. >> >> This patch makes MTE tags saving support large folios, then we don't >> need to split large folios into base pages for swapping out on ARM64 >> SoCs with MTE any more. > > Can we go further than this patch and only support PG_mte_tagged and > PG_mte_lock on folio->flags instead of page->flags? We're down to using I think we discussed that already and what I learned is that it "gets a bit complicated". But I'm hoping we can get that discussion started again. > page->flags for these two MTE bits, a whole lot of s390 junk, PG_hwpoison, > PG_head, PG_anon_exclusive and Zone/Section/Node/KASAN/last_cpupid. ... just like PG_anon_exclusive "gets a bit complicated". Well, I think I might have finally found a way to make it work, I'll only have to uglify fork() a bit.
On 27/03/2024 14:57, David Hildenbrand wrote: > On 27.03.24 15:53, Matthew Wilcox wrote: >> On Sat, Mar 23, 2024 at 12:41:36AM +1300, Barry Song wrote: >>> Commit d0637c505f8a1 ("arm64: enable THP_SWAP for arm64") brings up >>> THP_SWAP on ARM64, but it doesn't enable THP_SWP on hardware with >>> MTE as the MTE code works with the assumption tags save/restore is >>> always handling a folio with only one page. >>> >>> The limitation should be removed as more and more ARM64 SoCs have >>> this feature. Co-existence of MTE and THP_SWAP becomes more and >>> more important. >>> >>> This patch makes MTE tags saving support large folios, then we don't >>> need to split large folios into base pages for swapping out on ARM64 >>> SoCs with MTE any more. >> >> Can we go further than this patch and only support PG_mte_tagged and >> PG_mte_lock on folio->flags instead of page->flags? We're down to using > > I think we discussed that already and what I learned is that it "gets a bit > complicated". But I'm hoping we can get that discussion started again. The original conversation starts here: https://lore.kernel.org/linux-mm/fb34d312-1049-4932-8f2b-d7f33cfc297c@arm.com/ The issue is that you can have a large folio mapped to user space, and user space only wants to activate MTE for a portion of it. So at that point, you either have to deal with only part of it being tagged (as we do today with the per-page flag) or you have to split the folio. I haven't re-read the entire thread - so might be forgetting some important details. > >> page->flags for these two MTE bits, a whole lot of s390 junk, PG_hwpoison, >> PG_head, PG_anon_exclusive and Zone/Section/Node/KASAN/last_cpupid. > > ... just like PG_anon_exclusive "gets a bit complicated". Well, I think I might > have finally found a way to make it work, I'll only have to uglify fork() a bit. >
On 27/03/2024 15:13, Ryan Roberts wrote: > On 27/03/2024 14:57, David Hildenbrand wrote: >> On 27.03.24 15:53, Matthew Wilcox wrote: >>> On Sat, Mar 23, 2024 at 12:41:36AM +1300, Barry Song wrote: >>>> Commit d0637c505f8a1 ("arm64: enable THP_SWAP for arm64") brings up >>>> THP_SWAP on ARM64, but it doesn't enable THP_SWP on hardware with >>>> MTE as the MTE code works with the assumption tags save/restore is >>>> always handling a folio with only one page. >>>> >>>> The limitation should be removed as more and more ARM64 SoCs have >>>> this feature. Co-existence of MTE and THP_SWAP becomes more and >>>> more important. >>>> >>>> This patch makes MTE tags saving support large folios, then we don't >>>> need to split large folios into base pages for swapping out on ARM64 >>>> SoCs with MTE any more. >>> >>> Can we go further than this patch and only support PG_mte_tagged and >>> PG_mte_lock on folio->flags instead of page->flags? We're down to using Also, I wouldn't want to hold this patch up in order to do this extra work. I think the 2 things are orthogonal? (supporting THP swap with MTE vs not using tail page flags for MTE). Can we discuss and handle it separately? >> >> I think we discussed that already and what I learned is that it "gets a bit >> complicated". But I'm hoping we can get that discussion started again. > > The original conversation starts here: > https://lore.kernel.org/linux-mm/fb34d312-1049-4932-8f2b-d7f33cfc297c@arm.com/ > > The issue is that you can have a large folio mapped to user space, and user > space only wants to activate MTE for a portion of it. So at that point, you > either have to deal with only part of it being tagged (as we do today with the > per-page flag) or you have to split the folio. > > I haven't re-read the entire thread - so might be forgetting some important details. > >> >>> page->flags for these two MTE bits, a whole lot of s390 junk, PG_hwpoison, >>> PG_head, PG_anon_exclusive and Zone/Section/Node/KASAN/last_cpupid. >> >> ... just like PG_anon_exclusive "gets a bit complicated". Well, I think I might >> have finally found a way to make it work, I'll only have to uglify fork() a bit. >> >
On Wed, Mar 27, 2024 at 03:15:33PM +0000, Ryan Roberts wrote: > >>> Can we go further than this patch and only support PG_mte_tagged and > >>> PG_mte_lock on folio->flags instead of page->flags? We're down to using > > Also, I wouldn't want to hold this patch up in order to do this extra work. I > think the 2 things are orthogonal? (supporting THP swap with MTE vs not using > tail page flags for MTE). Can we discuss and handle it separately? Yes, I'm not trying to hold this patch hostage.
On Wed, Mar 27, 2024 at 03:13:18PM +0000, Ryan Roberts wrote: > On 27/03/2024 14:57, David Hildenbrand wrote: > > On 27.03.24 15:53, Matthew Wilcox wrote: > >> On Sat, Mar 23, 2024 at 12:41:36AM +1300, Barry Song wrote: > >>> Commit d0637c505f8a1 ("arm64: enable THP_SWAP for arm64") brings up > >>> THP_SWAP on ARM64, but it doesn't enable THP_SWP on hardware with > >>> MTE as the MTE code works with the assumption tags save/restore is > >>> always handling a folio with only one page. > >>> > >>> The limitation should be removed as more and more ARM64 SoCs have > >>> this feature. Co-existence of MTE and THP_SWAP becomes more and > >>> more important. > >>> > >>> This patch makes MTE tags saving support large folios, then we don't > >>> need to split large folios into base pages for swapping out on ARM64 > >>> SoCs with MTE any more. > >> > >> Can we go further than this patch and only support PG_mte_tagged and > >> PG_mte_lock on folio->flags instead of page->flags? We're down to using > > > > I think we discussed that already and what I learned is that it "gets a bit > > complicated". But I'm hoping we can get that discussion started again. > > The original conversation starts here: > https://lore.kernel.org/linux-mm/fb34d312-1049-4932-8f2b-d7f33cfc297c@arm.com/ > > The issue is that you can have a large folio mapped to user space, and user > space only wants to activate MTE for a portion of it. So at that point, you > either have to deal with only part of it being tagged (as we do today with the > per-page flag) or you have to split the folio. It needs splitting since the PROT_MTE property ends up in the pte as a memory attribute. So we can't have a THP mapping with PROT_MTE but only specific pages tagged. I had an attempt last year to only keep the PG_mte_tagged flag in the head page but I recall folio_copy() got in the way since it was calling copy_highpage() on individual pages and the arm64 code was not seeing the head PG_mte_tagged. I think it can be worked around but I got distracted and forgot about this.
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index afdd56d26ad7..259325e6b7e8 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -49,12 +49,6 @@ __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 @@ -1280,12 +1274,7 @@ 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; -} +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) @@ -1301,11 +1290,7 @@ 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); -} +extern void arch_swap_restore(swp_entry_t entry, struct folio *folio); #endif /* CONFIG_ARM64_MTE */ diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c index a31833e3ddc5..63e8d72f202a 100644 --- a/arch/arm64/mm/mteswap.c +++ b/arch/arm64/mm/mteswap.c @@ -68,6 +68,13 @@ 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 +90,41 @@ void mte_invalidate_tags_area(int type) } xa_unlock(&mte_pages); } + +int arch_prepare_to_swap(struct folio *folio) +{ + long i, nr; + int err; + + if (!system_supports_mte()) + return 0; + + 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 folio *folio) +{ + long i, nr; + + if (!system_supports_mte()) + return; + + nr = folio_nr_pages(folio); + + for (i = 0; i < nr; i++) { + mte_restore_tags(entry, folio_page(folio, i)); + entry.val++; + } +} diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index de0c89105076..e04b93c43965 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -535,16 +535,4 @@ static inline int split_folio_to_order(struct folio *folio, int new_order) #define split_folio_to_list(f, l) split_folio_to_list_to_order(f, l, 0) #define split_folio(f) split_folio_to_order(f, 0) -/* - * 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 85fc7554cd52..b10a7dd615bd 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1052,7 +1052,7 @@ 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; } diff --git a/mm/internal.h b/mm/internal.h index 7e486f2c502c..2551e93dd885 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -76,6 +76,20 @@ static inline int folio_nr_pages_mapped(struct folio *folio) return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED; } +/* + * Retrieve the first entry of a folio based on a provided entry within the + * folio. We cannot rely on folio->swap as there is no guarantee that it has + * been initialized. Used for calling arch_swap_restore() + */ +static inline swp_entry_t folio_swap(swp_entry_t entry, struct folio *folio) +{ + swp_entry_t swap = { + .val = ALIGN_DOWN(entry.val, folio_nr_pages(folio)), + }; + + return swap; +} + static inline void *folio_raw_mapping(struct folio *folio) { unsigned long mapping = (unsigned long)folio->mapping; diff --git a/mm/memory.c b/mm/memory.c index f2bc6dd15eb8..b7cab8be8632 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4188,7 +4188,7 @@ 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(folio_swap(entry, folio), folio); /* * 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 ae2b49055e43..a9a7c236aecc 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 0aad0d9a621b..44c1519ba881 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1913,7 +1913,7 @@ 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(folio_swap(swap, folio), folio); 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 90973ce7881d..53abeaf1371d 100644 --- a/mm/swap_slots.c +++ b/mm/swap_slots.c @@ -310,7 +310,7 @@ 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 4919423cce76..5e6d2304a2a4 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1806,7 +1806,7 @@ 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, folio); + arch_swap_restore(folio_swap(entry, folio), folio); dec_mm_counter(vma->vm_mm, MM_SWAPENTS); inc_mm_counter(vma->vm_mm, MM_ANONPAGES);