diff options
| -rw-r--r-- | Documentation/core-api/cachetlb.rst | 86 | ||||
| -rw-r--r-- | Documentation/translations/zh_CN/core-api/cachetlb.rst | 9 | ||||
| -rw-r--r-- | arch/arm/include/asm/cacheflush.h | 4 | ||||
| -rw-r--r-- | arch/arm/mm/flush.c | 33 | ||||
| -rw-r--r-- | arch/arm/mm/nommu.c | 6 | ||||
| -rw-r--r-- | arch/csky/abiv1/cacheflush.c | 11 | ||||
| -rw-r--r-- | arch/csky/abiv1/inc/abi/cacheflush.h | 4 | ||||
| -rw-r--r-- | arch/mips/include/asm/cacheflush.h | 8 | ||||
| -rw-r--r-- | arch/nds32/include/asm/cacheflush.h | 3 | ||||
| -rw-r--r-- | arch/nds32/mm/cacheflush.c | 9 | ||||
| -rw-r--r-- | arch/parisc/include/asm/cacheflush.h | 8 | ||||
| -rw-r--r-- | arch/parisc/kernel/cache.c | 3 | ||||
| -rw-r--r-- | arch/sh/include/asm/cacheflush.h | 8 | ||||
| -rw-r--r-- | block/blk-map.c | 2 | ||||
| -rw-r--r-- | fs/exec.c | 6 | ||||
| -rw-r--r-- | include/linux/highmem.h | 5 | ||||
| -rw-r--r-- | tools/testing/scatterlist/linux/mm.h | 1 |
17 files changed, 51 insertions, 155 deletions
diff --git a/Documentation/core-api/cachetlb.rst b/Documentation/core-api/cachetlb.rst index fe4290e26729..8aed9103e48a 100644 --- a/Documentation/core-api/cachetlb.rst +++ b/Documentation/core-api/cachetlb.rst @@ -271,10 +271,15 @@ maps this page at its virtual address. ``void flush_dcache_page(struct page *page)`` - Any time the kernel writes to a page cache page, _OR_ - the kernel is about to read from a page cache page and - user space shared/writable mappings of this page potentially - exist, this routine is called. + This routines must be called when: + + a) the kernel did write to a page that is in the page cache page + and / or in high memory + b) the kernel is about to read from a page cache page and user space + shared/writable mappings of this page potentially exist. Note + that {get,pin}_user_pages{_fast} already call flush_dcache_page + on any page found in the user address space and thus driver + code rarely needs to take this into account. .. note:: @@ -284,38 +289,34 @@ maps this page at its virtual address. handling vfs symlinks in the page cache need not call this interface at all. - The phrase "kernel writes to a page cache page" means, - specifically, that the kernel executes store instructions - that dirty data in that page at the page->virtual mapping - of that page. It is important to flush here to handle - D-cache aliasing, to make sure these kernel stores are - visible to user space mappings of that page. - - The corollary case is just as important, if there are users - which have shared+writable mappings of this file, we must make - sure that kernel reads of these pages will see the most recent - stores done by the user. - - If D-cache aliasing is not an issue, this routine may - simply be defined as a nop on that architecture. - - There is a bit set aside in page->flags (PG_arch_1) as - "architecture private". The kernel guarantees that, - for pagecache pages, it will clear this bit when such - a page first enters the pagecache. - - This allows these interfaces to be implemented much more - efficiently. It allows one to "defer" (perhaps indefinitely) - the actual flush if there are currently no user processes - mapping this page. See sparc64's flush_dcache_page and - update_mmu_cache implementations for an example of how to go - about doing this. - - The idea is, first at flush_dcache_page() time, if - page->mapping->i_mmap is an empty tree, just mark the architecture - private page flag bit. Later, in update_mmu_cache(), a check is - made of this flag bit, and if set the flush is done and the flag - bit is cleared. + The phrase "kernel writes to a page cache page" means, specifically, + that the kernel executes store instructions that dirty data in that + page at the page->virtual mapping of that page. It is important to + flush here to handle D-cache aliasing, to make sure these kernel stores + are visible to user space mappings of that page. + + The corollary case is just as important, if there are users which have + shared+writable mappings of this file, we must make sure that kernel + reads of these pages will see the most recent stores done by the user. + + If D-cache aliasing is not an issue, this routine may simply be defined + as a nop on that architecture. + + There is a bit set aside in page->flags (PG_arch_1) as "architecture + private". The kernel guarantees that, for pagecache pages, it will + clear this bit when such a page first enters the pagecache. + + This allows these interfaces to be implemented much more efficiently. + It allows one to "defer" (perhaps indefinitely) the actual flush if + there are currently no user processes mapping this page. See sparc64's + flush_dcache_page and update_mmu_cache implementations for an example + of how to go about doing this. + + The idea is, first at flush_dcache_page() time, if page_file_mapping() + returns a mapping, and mapping_mapped on that mapping returns %false, + just mark the architecture private page flag bit. Later, in + update_mmu_cache(), a check is made of this flag bit, and if set the + flush is done and the flag bit is cleared. .. important:: @@ -351,19 +352,6 @@ maps this page at its virtual address. architectures). For incoherent architectures, it should flush the cache of the page at vmaddr. - ``void flush_kernel_dcache_page(struct page *page)`` - - When the kernel needs to modify a user page is has obtained - with kmap, it calls this function after all modifications are - complete (but before kunmapping it) to bring the underlying - page up to date. It is assumed here that the user has no - incoherent cached copies (i.e. the original page was obtained - from a mechanism like get_user_pages()). The default - implementation is a nop and should remain so on all coherent - architectures. On incoherent architectures, this should flush - the kernel cache for page (using page_address(page)). - - ``void flush_icache_range(unsigned long start, unsigned long end)`` When the kernel stores into addresses that it will execute diff --git a/Documentation/translations/zh_CN/core-api/cachetlb.rst b/Documentation/translations/zh_CN/core-api/cachetlb.rst index 8376485a534d..55827b8a7c53 100644 --- a/Documentation/translations/zh_CN/core-api/cachetlb.rst +++ b/Documentation/translations/zh_CN/core-api/cachetlb.rst @@ -298,15 +298,6 @@ HyperSparc cpu就是这样一个具有这种属性的cpu。 用。默认的实现是nop（对于所有相干的架构应该保持这样）。对于不一致性 的架构，它应该刷新vmaddr处的页面缓存。 - ``void flush_kernel_dcache_page(struct page *page)`` - - 当内核需要修改一个用kmap获得的用户页时，它会在所有修改完成后（但在 - kunmapping之前）调用这个函数，以使底层页面达到最新状态。这里假定用 - 户没有不一致性的缓存副本（即原始页面是从类似get_user_pages()的机制 - 中获得的）。默认的实现是一个nop，在所有相干的架构上都应该如此。在不 - 一致性的架构上，这应该刷新内核缓存中的页面（使用page_address(page)）。 - - ``void flush_icache_range(unsigned long start, unsigned long end)`` 当内核存储到它将执行的地址中时（例如在加载模块时），这个函数被调用。 diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h index 2e24e765e6d3..5e56288e343b 100644 --- a/arch/arm/include/asm/cacheflush.h +++ b/arch/arm/include/asm/cacheflush.h @@ -291,6 +291,7 @@ extern void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1 extern void flush_dcache_page(struct page *); +#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1 static inline void flush_kernel_vmap_range(void *addr, int size) { if ((cache_is_vivt() || cache_is_vipt_aliasing())) @@ -312,9 +313,6 @@ static inline void flush_anon_page(struct vm_area_struct *vma, __flush_anon_page(vma, page, vmaddr); } -#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE -extern void flush_kernel_dcache_page(struct page *); - #define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages) #define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages) diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index 6d89db7895d1..7ff9feea13a6 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -346,39 +346,6 @@ void flush_dcache_page(struct page *page) EXPORT_SYMBOL(flush_dcache_page); /* - * Ensure cache coherency for the kernel mapping of this page. We can - * assume that the page is pinned via kmap. - * - * If the page only exists in the page cache and there are no user - * space mappings, this is a no-op since the page was already marked - * dirty at creation. Otherwise, we need to flush the dirty kernel - * cache lines directly. - */ -void flush_kernel_dcache_page(struct page *page) -{ - if (cache_is_vivt() || cache_is_vipt_aliasing()) { - struct address_space *mapping; - - mapping = page_mapping_file(page); - - if (!mapping || mapping_mapped(mapping)) { - void *addr; - - addr = page_address(page); - /* - * kmap_atomic() doesn't set the page virtual - * address for highmem pages, and - * kunmap_atomic() takes care of cache - * flushing already. - */ - if (!IS_ENABLED(CONFIG_HIGHMEM) || addr) - __cpuc_flush_dcache_area(addr, PAGE_SIZE); - } - } -} -EXPORT_SYMBOL(flush_kernel_dcache_page); - -/* * Flush an anonymous page so that users of get_user_pages() * can safely access the data. The expected sequence is: * diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c index 8b3d7191e2b8..2658f52903da 100644 --- a/arch/arm/mm/nommu.c +++ b/arch/arm/mm/nommu.c @@ -166,12 +166,6 @@ void flush_dcache_page(struct page *page) } EXPORT_SYMBOL(flush_dcache_page); -void flush_kernel_dcache_page(struct page *page) -{ - __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE); -} -EXPORT_SYMBOL(flush_kernel_dcache_page); - void copy_to_user_page(struct vm_area_struct *vma, struct page *page, unsigned long uaddr, void *dst, const void *src, unsigned long len) diff --git a/arch/csky/abiv1/cacheflush.c b/arch/csky/abiv1/cacheflush.c index 07ff17ea33de..fb91b069dc69 100644 --- a/arch/csky/abiv1/cacheflush.c +++ b/arch/csky/abiv1/cacheflush.c @@ -56,17 +56,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, } } -void flush_kernel_dcache_page(struct page *page) -{ - struct address_space *mapping; - - mapping = page_mapping_file(page); - - if (!mapping || mapping_mapped(mapping)) - dcache_wbinv_all(); -} -EXPORT_SYMBOL(flush_kernel_dcache_page); - void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { diff --git a/arch/csky/abiv1/inc/abi/cacheflush.h b/arch/csky/abiv1/inc/abi/cacheflush.h index 6cab7afae962..ed62e2066ba7 100644 --- a/arch/csky/abiv1/inc/abi/cacheflush.h +++ b/arch/csky/abiv1/inc/abi/cacheflush.h @@ -14,12 +14,10 @@ extern void flush_dcache_page(struct page *); #define flush_cache_page(vma, page, pfn) cache_wbinv_all() #define flush_cache_dup_mm(mm) cache_wbinv_all() -#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE -extern void flush_kernel_dcache_page(struct page *); - #define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages) #define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages) +#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1 static inline void flush_kernel_vmap_range(void *addr, int size) { dcache_wbinv_all(); diff --git a/arch/mips/include/asm/cacheflush.h b/arch/mips/include/asm/cacheflush.h index d687b40b9fbb..b3dc9c589442 100644 --- a/arch/mips/include/asm/cacheflush.h +++ b/arch/mips/include/asm/cacheflush.h @@ -125,13 +125,7 @@ static inline void kunmap_noncoherent(void) kunmap_coherent(); } -#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE -static inline void flush_kernel_dcache_page(struct page *page) -{ - BUG_ON(cpu_has_dc_aliases && PageHighMem(page)); - flush_dcache_page(page); -} - +#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1 /* * For now flush_kernel_vmap_range and invalidate_kernel_vmap_range both do a * cache writeback and invalidate operation. diff --git a/arch/nds32/include/asm/cacheflush.h b/arch/nds32/include/asm/cacheflush.h index 7d6824f7c0e8..c2a222ebfa2a 100644 --- a/arch/nds32/include/asm/cacheflush.h +++ b/arch/nds32/include/asm/cacheflush.h @@ -36,8 +36,7 @@ void copy_from_user_page(struct vm_area_struct *vma, struct page *page, void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vaddr); -#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE -void flush_kernel_dcache_page(struct page *page); +#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1 void flush_kernel_vmap_range(void *addr, int size); void invalidate_kernel_vmap_range(void *addr, int size); #define flush_dcache_mmap_lock(mapping) xa_lock_irq(&(mapping)->i_pages) diff --git a/arch/nds32/mm/cacheflush.c b/arch/nds32/mm/cacheflush.c index ad5344ef5d33..07aac65d1cab 100644 --- a/arch/nds32/mm/cacheflush.c +++ b/arch/nds32/mm/cacheflush.c @@ -318,15 +318,6 @@ void flush_anon_page(struct vm_area_struct *vma, local_irq_restore(flags); } -void flush_kernel_dcache_page(struct page *page) -{ - unsigned long flags; - local_irq_save(flags); - cpu_dcache_wbinval_page((unsigned long)page_address(page)); - local_irq_restore(flags); -} -EXPORT_SYMBOL(flush_kernel_dcache_page); - void flush_kernel_vmap_range(void *addr, int size) { unsigned long flags; diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h index 99663fc1f997..eef0096db5f8 100644 --- a/arch/parisc/include/asm/cacheflush.h +++ b/arch/parisc/include/asm/cacheflush.h @@ -36,16 +36,12 @@ void flush_cache_all_local(void); void flush_cache_all(void); void flush_cache_mm(struct mm_struct *mm); -#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE void flush_kernel_dcache_page_addr(void *addr); -static inline void flush_kernel_dcache_page(struct page *page) -{ - flush_kernel_dcache_page_addr(page_address(page)); -} #define flush_kernel_dcache_range(start,size) \ flush_kernel_dcache_range_asm((start), (start)+(size)); +#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1 void flush_kernel_vmap_range(void *vaddr, int size); void invalidate_kernel_vmap_range(void *vaddr, int size); @@ -59,7 +55,7 @@ extern void flush_dcache_page(struct page *page); #define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages) #define flush_icache_page(vma,page) do { \ - flush_kernel_dcache_page(page); \ + flush_kernel_dcache_page_addr(page_address(page)); \ flush_kernel_icache_page(page_address(page)); \ } while (0) diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index 86a1a63563fd..39e02227e231 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -334,7 +334,7 @@ void flush_dcache_page(struct page *page) return; } - flush_kernel_dcache_page(page); + flush_kernel_dcache_page_addr(page_address(page)); if (!mapping) return; @@ -375,7 +375,6 @@ EXPORT_SYMBOL(flush_dcache_page); /* Defined in arch/parisc/kernel/pacache.S */ EXPORT_SYMBOL(flush_kernel_dcache_range_asm); -EXPORT_SYMBOL(flush_kernel_dcache_page_asm); EXPORT_SYMBOL(flush_data_cache_local); EXPORT_SYMBOL(flush_kernel_icache_range_asm); diff --git a/arch/sh/include/asm/cacheflush.h b/arch/sh/include/asm/cacheflush.h index 4486a865ff62..372afa82fee6 100644 --- a/arch/sh/include/asm/cacheflush.h +++ b/arch/sh/include/asm/cacheflush.h @@ -63,6 +63,8 @@ static inline void flush_anon_page(struct vm_area_struct *vma, if (boot_cpu_data.dcache.n_aliases && PageAnon(page)) __flush_anon_page(page, vmaddr); } + +#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1 static inline void flush_kernel_vmap_range(void *addr, int size) { __flush_wback_region(addr, size); @@ -72,12 +74,6 @@ static inline void invalidate_kernel_vmap_range(void *addr, int size) __flush_invalidate_region(addr, size); } -#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE -static inline void flush_kernel_dcache_page(struct page *page) -{ - flush_dcache_page(page); -} - extern void copy_to_user_page(struct vm_area_struct *vma, struct page *page, unsigned long vaddr, void *dst, const void *src, unsigned long len); diff --git a/block/blk-map.c b/block/blk-map.c index 3743158ddaeb..4639bc6b5c62 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -309,7 +309,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, static void bio_invalidate_vmalloc_pages(struct bio *bio) { -#ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE +#ifdef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE if (bio->bi_private && !op_is_write(bio_op(bio))) { unsigned long i, len = 0; diff --git a/fs/exec.c b/fs/exec.c index 38f63451b928..41a888d4edde 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -574,7 +574,7 @@ static int copy_strings(int argc, struct user_arg_ptr argv, } if (kmapped_page) { - flush_kernel_dcache_page(kmapped_page); + flush_dcache_page(kmapped_page); kunmap(kmapped_page); put_arg_page(kmapped_page); } @@ -592,7 +592,7 @@ static int copy_strings(int argc, struct user_arg_ptr argv, ret = 0; out: if (kmapped_page) { - flush_kernel_dcache_page(kmapped_page); + flush_dcache_page(kmapped_page); kunmap(kmapped_page); put_arg_page(kmapped_page); } @@ -634,7 +634,7 @@ int copy_string_kernel(const char *arg, struct linux_binprm *bprm) kaddr = kmap_atomic(page); flush_arg_page(bprm, pos & PAGE_MASK, page); memcpy(kaddr + offset_in_page(pos), arg, bytes_to_copy); - flush_kernel_dcache_page(page); + flush_dcache_page(page); kunmap_atomic(kaddr); put_arg_page(page); } diff --git a/include/linux/highmem.h b/include/linux/highmem.h index d9a606a9fc64..b4c49f9cc379 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -130,10 +130,7 @@ static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page } #endif -#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE -static inline void flush_kernel_dcache_page(struct page *page) -{ -} +#ifndef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE static inline void flush_kernel_vmap_range(void *vaddr, int size) { } diff --git a/tools/testing/scatterlist/linux/mm.h b/tools/testing/scatterlist/linux/mm.h index f9a12005fcea..16ec895bbe5f 100644 --- a/tools/testing/scatterlist/linux/mm.h +++ b/tools/testing/scatterlist/linux/mm.h @@ -127,7 +127,6 @@ kmalloc_array(unsigned int n, unsigned int size, unsigned int flags) #define kmemleak_free(a) #define PageSlab(p) (0) -#define flush_kernel_dcache_page(p) #define MAX_ERRNO 4095 |