From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758489Ab3BSIHy (ORCPT ); Tue, 19 Feb 2013 03:07:54 -0500 Received: from ozlabs.org ([203.10.76.45]:48451 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758182Ab3BSICp (ORCPT ); Tue, 19 Feb 2013 03:02:45 -0500 From: Rusty Russell To: Paolo Bonzini Cc: Asias He , "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Rusty Russell Subject: [PATCH 01/16] scatterlist: introduce sg_unmark_end Date: Tue, 19 Feb 2013 18:26:19 +1030 Message-Id: <1361260594-601-2-git-send-email-rusty@rustcorp.com.au> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1361260594-601-1-git-send-email-rusty@rustcorp.com.au> References: <1361260594-601-1-git-send-email-rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paolo Bonzini 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 Signed-off-by: Rusty Russell --- 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 * -- 1.7.10.4