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| author |   Ilya Loginov <isloginov@gmail.com> | 2009-11-26 09:16:19 +0100 |
|---|---|---|
| committer |   Jens Axboe <jens.axboe@oracle.com> | 2009-11-26 09:16:19 +0100 |
| commit | 2d4dc890b5c8fabd818a8586607e6843c4375e62 (patch) | |
| tree | 9976ed7b0eed0056f8289aeb6a2b0abf8c940454 /include | |
| parent | cfq: Make use of service count to estimate the rb_key offset (diff) | |
| download | linux-dev-2d4dc890b5c8fabd818a8586607e6843c4375e62.tar.xz linux-dev-2d4dc890b5c8fabd818a8586607e6843c4375e62.zip | |
block: add helpers to run flush_dcache_page() against a bio and a request's pages
Mtdblock driver doesn't call flush_dcache_page for pages in request. So,
this causes problems on architectures where the icache doesn't fill from
the dcache or with dcache aliases. The patch fixes this.
The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid
pointless empty cache-thrashing loops on architectures for which
flush_dcache_page() is a no-op. Every architecture was provided with this
flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is
equal 1 or do nothing otherwise.
See "fix mtd_blkdevs problem with caches on some architectures" discussion
on LKML for more information.
Signed-off-by: Ilya Loginov <isloginov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Peter Horton <phorton@bitbox.co.uk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/cacheflush.h | 1 | ||||
| -rw-r--r-- | include/linux/bio.h | 12 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 11 |
3 files changed, 24 insertions, 0 deletions
diff --git a/include/asm-generic/cacheflush.h b/include/asm-generic/cacheflush.h index ba4ec39a1131..57b5c3c82e86 100644 --- a/include/asm-generic/cacheflush.h +++ b/include/asm-generic/cacheflush.h @@ -13,6 +13,7 @@ #define flush_cache_dup_mm(mm) do { } while (0) #define flush_cache_range(vma, start, end) do { } while (0) #define flush_cache_page(vma, vmaddr, pfn) do { } while (0) +#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0 #define flush_dcache_page(page) do { } while (0) #define flush_dcache_mmap_lock(mapping) do { } while (0) #define flush_dcache_mmap_unlock(mapping) do { } while (0) diff --git a/include/linux/bio.h b/include/linux/bio.h index 474792b825d0..7fc5606e6ea5 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -391,6 +391,18 @@ extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int, gfp_t, int); extern void bio_set_pages_dirty(struct bio *bio); extern void bio_check_pages_dirty(struct bio *bio); + +#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE +# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" +#endif +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE +extern void bio_flush_dcache_pages(struct bio *bi); +#else +static inline void bio_flush_dcache_pages(struct bio *bi) +{ +} +#endif + extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *, unsigned long, unsigned int, int, gfp_t); extern struct bio *bio_copy_user_iov(struct request_queue *, diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1cc02972fbe2..e727f6c44c44 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -752,6 +752,17 @@ struct req_iterator { #define rq_iter_last(rq, _iter) \ (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) +#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE +# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform" +#endif +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE +extern void rq_flush_dcache_pages(struct request *rq); +#else +static inline void rq_flush_dcache_pages(struct request *rq) +{ +} +#endif + extern int blk_register_queue(struct gendisk *disk); extern void blk_unregister_queue(struct gendisk *disk); extern void register_disk(struct gendisk *dev); |