aboutsummaryrefslogtreecommitdiff
path: root/block/blk-core.c
diff options
context:
space:
mode:
authorIlya Loginov <isloginov@gmail.com>2009-11-26 09:16:19 +0100
committerJens Axboe <jens.axboe@oracle.com>2009-11-26 09:16:19 +0100
commit2d4dc890b5c8fabd818a8586607e6843c4375e62 (patch)
tree9976ed7b0eed0056f8289aeb6a2b0abf8c940454 /block/blk-core.c
parent3586e917f2c7df769d173c4ec99554cb40a911e5 (diff)
downloadlinux-2.6.34-ux500-2d4dc890b5c8fabd818a8586607e6843c4375e62.tar.gz
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/blk-core.c')
-rw-r--r--block/blk-core.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 71da5111120..718897e6d37 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2358,6 +2358,25 @@ 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