From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: [PATCH 5/9] scatterlist: introduce sg_unmark_end Date: Tue, 12 Feb 2013 13:23:31 +0100 Message-ID: <1360671815-2135-6-git-send-email-pbonzini@redhat.com> References: <1360671815-2135-1-git-send-email-pbonzini@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1360671815-2135-1-git-send-email-pbonzini@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, mst@redhat.com, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org This is useful in places that recycle the same scatterlist multiple times, and do not want to incur the cost of sg_init_table every time in hot paths. Acked-by: Jens Axboe Signed-off-by: Paolo Bonzini --- block/blk-integrity.c | 2 +- block/blk-merge.c | 2 +- include/linux/scatterlist.h | 16 ++++++++++++++++ 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/block/blk-integrity.c b/block/blk-integrity.c index da2a818..0f5004f 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -110,7 +110,7 @@ new_segment: if (!sg) sg = sglist; else { - sg->page_link &= ~0x02; + sg_unmark_end(sg); sg = sg_next(sg); } diff --git a/block/blk-merge.c b/block/blk-merge.c index 936a110..5f24482 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -143,7 +143,7 @@ new_segment: * termination bit to avoid doing a full * sg_init_table() in drivers for each command. */ - (*sg)->page_link &= ~0x02; + sg_unmark_end(*sg); *sg = sg_next(*sg); } diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 4bd6c06..9b83784 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -172,6 +172,22 @@ static inline void sg_mark_end(struct scatterlist *sg) } /** + * sg_unmark_end - Undo setting the end of the scatterlist + * @sg: SG entryScatterlist + * + * Description: + * Removes the termination marker from the given entry of the scatterlist. + * + **/ +static inline void sg_unmark_end(struct scatterlist *sg) +{ +#ifdef CONFIG_DEBUG_SG + BUG_ON(sg->sg_magic != SG_MAGIC); +#endif + sg->page_link &= ~0x02; +} + +/** * sg_phys - Return physical address of an sg entry * @sg: SG entry * -- 1.7.1