diff options
| author | Ilya Loginov <isloginov@gmail.com> | 2009-11-26 09:16:19 +0100 |
|---|---|---|
| committer | Gary King <gking@nvidia.com> | 2010-04-05 14:03:24 -0700 |
| commit | cedfa4f5754c5aa562d545865922626e2239f11b (patch) | |
| tree | b4a6e51490f076e6bfd02fd1e1be048b6922f621 /block | |
| parent | 3274abc33ec2c170acd6fd2732c271ad9dd0b17f (diff) | |
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 'block')
| -rw-r--r-- | block/blk-core.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index ae835b42b6a3..1c5999359bfb 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2359,6 +2359,25 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq, rq->rq_disk = bio->bi_bdev->bd_disk; } +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE +/** + * rq_flush_dcache_pages - Helper function to flush all pages in a request + * @rq: the request to be flushed + * + * Description: + * Flush all pages in @rq. + */ +void rq_flush_dcache_pages(struct request *rq) +{ + struct req_iterator iter; + struct bio_vec *bvec; + + rq_for_each_segment(bvec, rq, iter) + flush_dcache_page(bvec->bv_page); +} +EXPORT_SYMBOL_GPL(rq_flush_dcache_pages); +#endif + /** * blk_lld_busy - Check if underlying low-level drivers of a device are busy * @q : the queue of the device being checked |