starfive-tech/linux.git/include/linux/highmem.h, branch VF2_v2.8.0

mm: remove flush_kernel_dcache_page

2021-09-03T16:58:13+00:00

flush_kernel_dcache_page is a rather confusing interface that implements a subset of flush_dcache_page by not being able to properly handle page cache mapped pages. The only callers left are in the exec code as all other previous callers were incorrect as they could have dealt with page cache pages. Replace the calls to flush_kernel_dcache_page with calls to flush_dcache_page, which for all architectures does either exactly the same thing, can contains one or more of the following: 1) an optimization to defer the cache flush for page cache pages not mapped into userspace 2) additional flushing for mapped page cache pages if cache aliases are possible Link: https://lkml.kernel.org/r/20210712060928.4161649-7-hch@lst.de Signed-off-by: Christoph Hellwig Acked-by: Linus Torvalds Reviewed-by: Ira Weiny Cc: Alex Shi Cc: Geoff Levand Cc: Greentime Hu Cc: Guo Ren Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: Nick Hu Cc: Paul Cercueil Cc: Rich Felker Cc: Russell King Cc: Thomas Bogendoerfer Cc: Ulf Hansson Cc: Vincent Chen Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: use kmap_local_page in memzero_page

2021-07-24T00:43:28+00:00

The commit message introducing the global memzero_page explicitly mentions switching to kmap_local_page in the commit log but doesn't actually do that. Link: https://lkml.kernel.org/r/20210713055231.137602-3-hch@lst.de Fixes: 28961998f858 ("iov_iter: lift memzero_page() to highmem.h") Signed-off-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Reviewed-by: Ira Weiny Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: call flush_dcache_page() in memcpy_to_page() and memzero_page()

2021-07-24T00:43:28+00:00

memcpy_to_page and memzero_page can write to arbitrary pages, which could be in the page cache or in high memory, so call flush_kernel_dcache_pages to flush the dcache. This is a problem when using these helpers on dcache challeneged architectures. Right now there are just a few users, chances are no one used the PC floppy driver, the aha1542 driver for an ISA SCSI HBA, and a few advanced and optional btrfs and ext4 features on those platforms yet since the conversion. Link: https://lkml.kernel.org/r/20210713055231.137602-2-hch@lst.de Fixes: bb90d4bc7b6a ("mm/highmem: Lift memcpy_[to|from]_page to core") Fixes: 28961998f858 ("iov_iter: lift memzero_page() to highmem.h") Signed-off-by: Christoph Hellwig Reviewed-by: Ira Weiny Cc: Chaitanya Kulkarni Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arm64: mte: handle tags zeroing at page allocation time

2021-06-04T18:32:21+00:00

Currently, on an anonymous page fault, the kernel allocates a zeroed page and maps it in user space. If the mapping is tagged (PROT_MTE), set_pte_at() additionally clears the tags. It is, however, more efficient to clear the tags at the same time as zeroing the data on allocation. To avoid clearing the tags on any page (which may not be mapped as tagged), only do this if the vma flags contain VM_MTE. This requires introducing a new GFP flag that is used to determine whether to clear the tags. The DC GZVA instruction with a 0 top byte (and 0 tag) requires top-byte-ignore. Set the TCR_EL1.{TBI1,TBID1} bits irrespective of whether KASAN_HW is enabled. Signed-off-by: Peter Collingbourne Co-developed-by: Catalin Marinas Signed-off-by: Catalin Marinas Link: https://linux-review.googlesource.com/id/Id46dc94e30fe11474f7e54f5d65e7658dbdddb26 Reviewed-by: Catalin Marinas Reviewed-by: Andrey Konovalov Link: https://lore.kernel.org/r/20210602235230.3928842-4-pcc@google.com Signed-off-by: Will Deacon

mm: arch: remove indirection level in alloc_zeroed_user_highpage_movable()

2021-06-04T18:32:21+00:00

In an upcoming change we would like to add a flag to GFP_HIGHUSER_MOVABLE so that it would no longer be an OR of GFP_HIGHUSER and __GFP_MOVABLE. This poses a problem for alloc_zeroed_user_highpage_movable() which passes __GFP_MOVABLE into an arch-specific __alloc_zeroed_user_highpage() hook which ORs in GFP_HIGHUSER. Since __alloc_zeroed_user_highpage() is only ever called from alloc_zeroed_user_highpage_movable(), we can remove one level of indirection here. Remove __alloc_zeroed_user_highpage(), make alloc_zeroed_user_highpage_movable() the hook, and use GFP_HIGHUSER_MOVABLE in the hook implementations so that they will pick up the new flag that we are going to add. Signed-off-by: Peter Collingbourne Link: https://linux-review.googlesource.com/id/Ic6361c657b2cdcd896adbe0cf7cb5a7fbb1ed7bf Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20210602235230.3928842-2-pcc@google.com Signed-off-by: Will Deacon

iov_iter: lift memzero_page() to highmem.h

2021-05-05T18:27:27+00:00

Patch series "btrfs: Convert kmap/memset/kunmap to memzero_user()". Lifting memzero_user(), convert it to kmap_local_page() and then use it in btrfs. This patch (of 3): memzero_page() can replace the kmap/memset/kunmap pattern in other places in the code. While zero_user() has the same interface it is not the same call and its use should be limited and some of those calls may be better converted from zero_user() to memzero_page().[1] But that is not addressed in this series. Lift memzero_page() to highmem. [1] https://lore.kernel.org/lkml/CAHk-=wijdojzo56FzYqE5TOYw2Vws7ik3LEMGj9SPQaJJ+Z73Q@mail.gmail.com/ Link: https://lkml.kernel.org/r/20210309212137.2610186-1-ira.weiny@intel.com Link: https://lkml.kernel.org/r/20210309212137.2610186-2-ira.weiny@intel.com Signed-off-by: Ira Weiny Cc: Alexander Viro Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: Chaitanya Kulkarni Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/highmem: Add VM_BUG_ON() to mem*_page() calls

2021-02-11T18:56:15+00:00

Add VM_BUG_ON bounds checks to ensure the newly lifted and created page memory operations do not result in corrupted data in neighbor pages.[1][2] [1] https://lore.kernel.org/lkml/20201210053502.GS1563847@iweiny-DESK2.sc.intel.com/ [2] https://lore.kernel.org/lkml/20210209110931.00f00e47d9a0529fcee2ff01@linux-foundation.org/ Suggested-by: Matthew Wilcox Suggested-by: Andrew Morton Reviewed-by: Christoph Hellwig Signed-off-by: Ira Weiny Signed-off-by: David Sterba

mm/highmem: Introduce memcpy_page(), memmove_page(), and memset_page()

2021-02-11T18:55:37+00:00

3 more common kmap patterns are kmap/memcpy/kunmap, kmap/memmove/kunmap. and kmap/memset/kunmap. Add helper functions for those patterns which use kmap_local_page(). Cc: Andrew Morton Cc: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Ira Weiny Signed-off-by: David Sterba

mm/highmem: Convert memcpy_[to|from]_page() to kmap_local_page()

2021-02-11T18:55:16+00:00

kmap_local_page() is more efficient and is well suited for these calls. Convert the kmap() to kmap_local_page() Cc: Andrew Morton Cc: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Ira Weiny Signed-off-by: David Sterba

mm/highmem: Lift memcpy_[to|from]_page to core

2021-02-11T18:54:43+00:00

Working through a conversion to a call kmap_local_page() instead of kmap() revealed many places where the pattern kmap/memcpy/kunmap occurred. Eric Biggers, Matthew Wilcox, Christoph Hellwig, Dan Williams, and Al Viro all suggested putting this code into helper functions. Al Viro further pointed out that these functions already existed in the iov_iter code.[1] Various locations for the lifted functions were considered. Headers like mm.h or string.h seem ok but don't really portray the functionality well. pagemap.h made some sense but is for page cache functionality.[2] Another alternative would be to create a new header for the promoted memcpy functions, but it masks the fact that these are designed to copy to/from pages using the kernel direct mappings and complicates matters with a new header. Placing these functions in 'highmem.h' is suboptimal especially with the changes being proposed in the functionality of kmap. From a caller perspective including/using 'highmem.h' implies that the functions defined in that header are only required when highmem is in use which is increasingly not the case with modern processors. However, highmem.h is where all the current functions like this reside (zero_user(), clear_highpage(), clear_user_highpage(), copy_user_highpage(), and copy_highpage()). So it makes the most sense even though it is distasteful for some.[3] Lift memcpy_to_page() and memcpy_from_page() to pagemap.h. [1] https://lore.kernel.org/lkml/20201013200149.GI3576660@ZenIV.linux.org.uk/ https://lore.kernel.org/lkml/20201013112544.GA5249@infradead.org/ [2] https://lore.kernel.org/lkml/20201208122316.GH7338@casper.infradead.org/ [3] https://lore.kernel.org/lkml/20201013200149.GI3576660@ZenIV.linux.org.uk/#t https://lore.kernel.org/lkml/20201208163814.GN1563847@iweiny-DESK2.sc.intel.com/ Cc: Boris Pismenny Cc: Or Gerlitz Cc: Dave Hansen Suggested-by: Matthew Wilcox Suggested-by: Christoph Hellwig Suggested-by: Dan Williams Suggested-by: Al Viro Suggested-by: Eric Biggers Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Ira Weiny Signed-off-by: David Sterba