diff options
| -rw-r--r-- | Documentation/cachetlb.txt | 24 | ||||
| -rw-r--r-- | arch/arm/include/asm/cacheflush.h | 10 | ||||
| -rw-r--r-- | arch/parisc/include/asm/cacheflush.h | 12 | ||||
| -rw-r--r-- | arch/sh/include/asm/cacheflush.h | 8 | ||||
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 30 | ||||
| -rw-r--r-- | include/linux/highmem.h | 6 |
6 files changed, 89 insertions, 1 deletions
diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt index da42ab414c4..b231414bb8b 100644 --- a/Documentation/cachetlb.txt +++ b/Documentation/cachetlb.txt @@ -377,3 +377,27 @@ maps this page at its virtual address. All the functionality of flush_icache_page can be implemented in flush_dcache_page and update_mmu_cache. In 2.7 the hope is to remove this interface completely. + +The final category of APIs is for I/O to deliberately aliased address +ranges inside the kernel. Such aliases are set up by use of the +vmap/vmalloc API. Since kernel I/O goes via physical pages, the I/O +subsystem assumes that the user mapping and kernel offset mapping are +the only aliases. This isn't true for vmap aliases, so anything in +the kernel trying to do I/O to vmap areas must manually manage +coherency. It must do this by flushing the vmap range before doing +I/O and invalidating it after the I/O returns. + + void flush_kernel_vmap_range(void *vaddr, int size) + flushes the kernel cache for a given virtual address range in + the vmap area. This is to make sure that any data the kernel + modified in the vmap range is made visible to the physical + page. The design is to make this area safe to perform I/O on. + Note that this API does *not* also flush the offset map alias + of the area. + + void invalidate_kernel_vmap_range(void *vaddr, int size) invalidates + the cache for a given virtual address range in the vmap area + which prevents the processor from making the cache stale by + speculatively reading data while the I/O was occurring to the + physical pages. This is only necessary for data reads into the + vmap area. diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h index 8113bb5fb66..5fe4a2ad7fa 100644 --- a/arch/arm/include/asm/cacheflush.h +++ b/arch/arm/include/asm/cacheflush.h @@ -447,6 +447,16 @@ static inline void __flush_icache_all(void) : "r" (0)); #endif } +static inline void flush_kernel_vmap_range(void *addr, int size) +{ + if ((cache_is_vivt() || cache_is_vipt_aliasing())) + __cpuc_flush_dcache_area(addr, (size_t)size); +} +static inline void invalidate_kernel_vmap_range(void *addr, int size) +{ + if ((cache_is_vivt() || cache_is_vipt_aliasing())) + __cpuc_flush_dcache_area(addr, (size_t)size); +} #define ARCH_HAS_FLUSH_ANON_PAGE static inline void flush_anon_page(struct vm_area_struct *vma, diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h index 7a73b615c23..477277739da 100644 --- a/arch/parisc/include/asm/cacheflush.h +++ b/arch/parisc/include/asm/cacheflush.h @@ -38,6 +38,18 @@ void flush_cache_mm(struct mm_struct *mm); #define flush_kernel_dcache_range(start,size) \ flush_kernel_dcache_range_asm((start), (start)+(size)); +/* vmap range flushes and invalidates. Architecturally, we don't need + * the invalidate, because the CPU should refuse to speculate once an + * area has been flushed, so invalidate is left empty */ +static inline void flush_kernel_vmap_range(void *vaddr, int size) +{ + unsigned long start = (unsigned long)vaddr; + + flush_kernel_dcache_range_asm(start, start + size); +} +static inline void invalidate_kernel_vmap_range(void *vaddr, int size) +{ +} #define flush_cache_vmap(start, end) flush_cache_all() #define flush_cache_vunmap(start, end) flush_cache_all() diff --git a/arch/sh/include/asm/cacheflush.h b/arch/sh/include/asm/cacheflush.h index dda96eb3e7c..da3ebec921a 100644 --- a/arch/sh/include/asm/cacheflush.h +++ b/arch/sh/include/asm/cacheflush.h @@ -63,6 +63,14 @@ 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); } +static inline void flush_kernel_vmap_range(void *addr, int size) +{ + __flush_wback_region(addr, size); +} +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) diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index 77b8be81c76..6f3ebb634b8 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -76,6 +76,27 @@ struct workqueue_struct *xfsconvertd_workqueue; #define xfs_buf_deallocate(bp) \ kmem_zone_free(xfs_buf_zone, (bp)); +static inline int +xfs_buf_is_vmapped( + struct xfs_buf *bp) +{ + /* + * Return true if the buffer is vmapped. + * + * The XBF_MAPPED flag is set if the buffer should be mapped, but the + * code is clever enough to know it doesn't have to map a single page, + * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1. + */ + return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1; +} + +static inline int +xfs_buf_vmap_len( + struct xfs_buf *bp) +{ + return (bp->b_page_count * PAGE_SIZE) - bp->b_offset; +} + /* * Page Region interfaces. * @@ -314,7 +335,7 @@ xfs_buf_free( if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) { uint i; - if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1)) + if (xfs_buf_is_vmapped(bp)) free_address(bp->b_addr - bp->b_offset); for (i = 0; i < bp->b_page_count; i++) { @@ -1107,6 +1128,9 @@ xfs_buf_bio_end_io( xfs_buf_ioerror(bp, -error); + if (!error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) + invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); + do { struct page *page = bvec->bv_page; @@ -1216,6 +1240,10 @@ next_chunk: submit_io: if (likely(bio->bi_size)) { + if (xfs_buf_is_vmapped(bp)) { + flush_kernel_vmap_range(bp->b_addr, + xfs_buf_vmap_len(bp)); + } submit_bio(rw, bio); if (size) goto next_chunk; diff --git a/include/linux/highmem.h b/include/linux/highmem.h index ab2cc20e21a..74152c08ad0 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -17,6 +17,12 @@ static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page static inline void flush_kernel_dcache_page(struct page *page) { } +static inline void flush_kernel_vmap_range(void *vaddr, int size) +{ +} +static inline void invalidate_kernel_vmap_range(void *vaddr, int size) +{ +} #endif #include <asm/kmap_types.h> |