Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757125AbXJ0RCv (ORCPT ); Sat, 27 Oct 2007 13:02:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755186AbXJ0RCo (ORCPT ); Sat, 27 Oct 2007 13:02:44 -0400 Received: from ug-out-1314.google.com ([66.249.92.169]:19686 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753724AbXJ0RCn (ORCPT ); Sat, 27 Oct 2007 13:02:43 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:date:from:to:cc:subject:message-id:mime-version:content-type:content-disposition:user-agent; b=OPcb3YAskfJwp3x5fJKxpuHPE1901A+/+lBrQFJ/A06MHS95ZOvrb/s94efF8i9eC6Ms20ik9VgmR4EVKCwV0YucYcBo+QsJpNNTkwZRN0xUbRwyRKlqJm5p1lmxIBbyVb7wpqDqV9Lp7sRBj3fZ5NIcXYmGNKIni0eNnDVk7gQ= Date: Sat, 27 Oct 2007 21:02:28 +0400 From: Cyrill Gorcunov To: LKML Cc: Andrew Morton Subject: [PATCH] SG: set names for numeric constants Message-ID: <20071027170228.GA7257@cvg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3059 Lines: 96 This patch defines names for numeric constants that used in scatter list for more convenient code reading. Signed-off-by: Cyrill Gorcunov --- I'm not sure if it really needed but who knows ;) Any comments are welcome. include/linux/scatterlist.h | 21 ++++++++++++--------- 1 files changed, 12 insertions(+), 9 deletions(-) diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 4571231..fcc05a5 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -25,6 +25,9 @@ */ #define SG_MAGIC 0x87654321 +#define SG_CHAIN 0x1 +#define SG_LAST 0x2 +#define SG_MASK 0x3 /** * sg_assign_page - Assign a given page to an SG entry @@ -38,13 +41,13 @@ **/ static inline void sg_assign_page(struct scatterlist *sg, struct page *page) { - unsigned long page_link = sg->page_link & 0x3; + unsigned long page_link = sg->page_link & SG_MASK; /* * In order for the low bit stealing approach to work, pages * must be aligned at a 32-bit boundary as a minimum. */ - BUG_ON((unsigned long) page & 0x03); + BUG_ON((unsigned long) page & SG_MASK); #ifdef CONFIG_DEBUG_SG BUG_ON(sg->sg_magic != SG_MAGIC); #endif @@ -73,7 +76,7 @@ static inline void sg_set_page(struct scatterlist *sg, struct page *page, sg->length = len; } -#define sg_page(sg) ((struct page *) ((sg)->page_link & ~0x3)) +#define sg_page(sg) ((struct page *) ((sg)->page_link & ~SG_MASK)) /** * sg_set_buf - Set sg entry to point at given data @@ -93,10 +96,10 @@ static inline void sg_set_buf(struct scatterlist *sg, const void *buf, * a valid sg entry, or whether it points to the start of a new scatterlist. * Those low bits are there for everyone! (thanks mason :-) */ -#define sg_is_chain(sg) ((sg)->page_link & 0x01) -#define sg_is_last(sg) ((sg)->page_link & 0x02) +#define sg_is_chain(sg) ((sg)->page_link & SG_CHAIN) +#define sg_is_last(sg) ((sg)->page_link & SG_LAST) #define sg_chain_ptr(sg) \ - ((struct scatterlist *) ((sg)->page_link & ~0x03)) + ((struct scatterlist *) ((sg)->page_link & ~SG_MASK)) /** * sg_next - return the next scatterlist entry in a list @@ -179,7 +182,7 @@ static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents, #ifndef ARCH_HAS_SG_CHAIN BUG(); #endif - prv[prv_nents - 1].page_link = (unsigned long) sgl | 0x01; + prv[prv_nents - 1].page_link = (unsigned long) sgl | SG_CHAIN; } /** @@ -193,12 +196,12 @@ static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents, **/ static inline void sg_mark_end(struct scatterlist *sgl, unsigned int nents) { - sgl[nents - 1].page_link = 0x02; + sgl[nents - 1].page_link = SG_LAST; } static inline void __sg_mark_end(struct scatterlist *sg) { - sg->page_link |= 0x02; + sg->page_link |= SG_LAST; } /** - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/