From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754018AbYIEQ5o (ORCPT ); Fri, 5 Sep 2008 12:57:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751719AbYIEQ5f (ORCPT ); Fri, 5 Sep 2008 12:57:35 -0400 Received: from mga14.intel.com ([143.182.124.37]:55272 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751634AbYIEQ5e (ORCPT ); Fri, 5 Sep 2008 12:57:34 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.32,340,1217833200"; d="scan'208";a="42253833" From: Chris Leech Subject: [PATCH 1/3] 24-bit types: typedef and macros for accessing 3-byte arrays as integers To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, devel@open-fcoe.org Date: Fri, 05 Sep 2008 09:57:32 -0700 Message-ID: <20080905165732.16689.50256.stgit@localhost.localdomain> User-Agent: StGIT/0.14.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Both iSCSI and Fibre Channel make use of 24-bit big-endian values in frame headers. This patch defines __be24 and __le24 typedefs for a structure wrapped around a 3-byte array, and macros to convert back and forth to a 32-bit integer. The undefs in iscsi_proto.h are because of the different calling convention for the existing hton24 macro in the iSCSI code. iSCSI will be converted in a subsequent patch. Signed-off-by: Chris Leech --- include/linux/byteorder.h | 56 ++++++++++++++++++++++++++++++++++++ include/linux/byteorder/generic.h | 57 +++++++++++++++++++++++++++++++++++++ include/linux/types.h | 2 + include/scsi/iscsi_proto.h | 2 + 4 files changed, 117 insertions(+), 0 deletions(-) diff --git a/include/linux/byteorder.h b/include/linux/byteorder.h index 29f002d..e41c17b 100644 --- a/include/linux/byteorder.h +++ b/include/linux/byteorder.h @@ -62,6 +62,54 @@ # define __cpu_to_le64(x) ((__force __le64)__swab64(x)) #endif +/** + * __le24_to_cpu - read a 3-byte array as a 24-bit little-endian integer + * @x: __le24, a structure wrapper around a 3-byte array + * + * Evaluates to a __u32 integer type + */ +#define __le24_to_cpu(x) \ +({ \ + __le24 _x = (x); \ + (__u32) ((_x.b[2] << 16) | (_x.b[1] << 8) | (_x.b[0])); \ +}) + +/** + * __cpu_to_le24 - store a value in a 3-byte array in little-endian format + * @x: __u32, there is no checking to ensure only the lower 24 bits are set + * + * Evaluates to an __le24 compound literal + */ +#define __cpu_to_le24(x) \ +({ \ + __u32 _x = (x); \ + (__le24) { .b = { _x & 0xff, (_x >> 8) & 0xff, (_x >> 16) & 0xff } }; \ +}) + +/** + * __be24_to_cpu - read a 3-byte array as a 24-bit big-endian integer + * @x: __be24, a structure wrapper around a 3-byte array + * + * Evaluates to a __u32 integer type + */ +#define __be24_to_cpu(x) \ +({ \ + __be24 _x = (x); \ + (__u32) ((_x.b[0] << 16) | (_x.b[1] << 8) | (_x.b[2])); \ +}) + +/** + * __cpu_to_be24 - store a value in a 3-byte array in big-endian format + * @x: __u32, there is no checking to ensure only the lower 24 bits are set + * + * Evaluates to an __be24 compound literal + */ +#define __cpu_to_be24(x) \ +({ \ + __u32 _x = (x); \ + (__be24) { .b = { (_x >> 16) & 0xff, (_x >> 8) & 0xff, _x & 0xff } }; \ +}) + /* * These helpers could be phased out over time as the base version * handles constant folding. @@ -280,15 +328,19 @@ static inline __be64 __cpu_to_be64p(const __u64 *p) #ifdef __KERNEL__ # define le16_to_cpu __le16_to_cpu +# define le24_to_cpu __le24_to_cpu # define le32_to_cpu __le32_to_cpu # define le64_to_cpu __le64_to_cpu # define be16_to_cpu __be16_to_cpu +# define be24_to_cpu __be24_to_cpu # define be32_to_cpu __be32_to_cpu # define be64_to_cpu __be64_to_cpu # define cpu_to_le16 __cpu_to_le16 +# define cpu_to_le24 __cpu_to_le24 # define cpu_to_le32 __cpu_to_le32 # define cpu_to_le64 __cpu_to_le64 # define cpu_to_be16 __cpu_to_be16 +# define cpu_to_be24 __cpu_to_be24 # define cpu_to_be32 __cpu_to_be32 # define cpu_to_be64 __cpu_to_be64 @@ -332,11 +384,15 @@ static inline __be64 __cpu_to_be64p(const __u64 *p) # define ___htons(x) __cpu_to_be16(x) # define ___ntohl(x) __be32_to_cpu(x) # define ___ntohs(x) __be16_to_cpu(x) +# define ___hton24(x) __cpu_to_be24(x) +# define ___ntoh24(x) __be24_to_cpu(x) # define htonl(x) ___htonl(x) # define ntohl(x) ___ntohl(x) # define htons(x) ___htons(x) # define ntohs(x) ___ntohs(x) +# define hton24(x) ___hton24(x) +# define ntoh24(x) ___ntoh24(x) static inline void le16_add_cpu(__le16 *var, u16 val) { diff --git a/include/linux/byteorder/generic.h b/include/linux/byteorder/generic.h index 0846e6b..a57fbc3 100644 --- a/include/linux/byteorder/generic.h +++ b/include/linux/byteorder/generic.h @@ -119,6 +119,59 @@ #define cpu_to_be16s __cpu_to_be16s #define be16_to_cpus __be16_to_cpus +/** + * __le24_to_cpu - read a 3-byte array as a 24-bit little-endian integer + * @x: __le24, a structure wrapper around a 3-byte array + * + * Evaluates to a __u32 integer type + */ +#define __le24_to_cpu(x) \ +({ \ + __le24 _x = (x); \ + (__u32) ((_x.b[2] << 16) | (_x.b[1] << 8) | (_x.b[0])); \ +}) + +/** + * __cpu_to_le24 - store a value in a 3-byte array in little-endian format + * @x: __u32, there is no checking to ensure only the lower 24 bits are set + * + * Evaluates to an __le24 compound literal + */ +#define __cpu_to_le24(x) \ +({ \ + __u32 _x = (x); \ + (__le24) { .b = { _x & 0xff, (_x >> 8) & 0xff, (_x >> 16) & 0xff } }; \ +}) + +/** + * __be24_to_cpu - read a 3-byte array as a 24-bit big-endian integer + * @x: __be24, a structure wrapper around a 3-byte array + * + * Evaluates to a __u32 integer type + */ +#define __be24_to_cpu(x) \ +({ \ + __be24 _x = (x); \ + (__u32) ((_x.b[0] << 16) | (_x.b[1] << 8) | (_x.b[2])); \ +}) + +/** + * __cpu_to_be24 - store a value in a 3-byte array in big-endian format + * @x: __u32, there is no checking to ensure only the lower 24 bits are set + * + * Evaluates to an __be24 compound literal + */ +#define __cpu_to_be24(x) \ +({ \ + __u32 _x = (x); \ + (__be24) { .b = { (_x >> 16) & 0xff, (_x >> 8) & 0xff, _x & 0xff } }; \ +}) + +#define le24_to_cpu __le24_to_cpu +#define cpu_to_le24 __cpu_to_le24 +#define be24_to_cpu __be24_to_cpu +#define cpu_to_be24 __cpu_to_be24 + /* * They have to be macros in order to do the constant folding * correctly - if the argument passed into a inline function @@ -134,11 +187,15 @@ #define ___htons(x) __cpu_to_be16(x) #define ___ntohl(x) __be32_to_cpu(x) #define ___ntohs(x) __be16_to_cpu(x) +#define ___hton24(x) __cpu_to_be24(x) +#define ___ntoh24(x) __be24_to_cpu(x) #define htonl(x) ___htonl(x) #define ntohl(x) ___ntohl(x) #define htons(x) ___htons(x) #define ntohs(x) ___ntohs(x) +#define hton24(x) ___hton24(x) +#define ntoh24(x) ___ntoh24(x) static inline void le16_add_cpu(__le16 *var, u16 val) { diff --git a/include/linux/types.h b/include/linux/types.h index d4a9ce6..85fcff7 100644 --- a/include/linux/types.h +++ b/include/linux/types.h @@ -188,6 +188,8 @@ typedef __u64 __bitwise __be64; typedef __u16 __bitwise __sum16; typedef __u32 __bitwise __wsum; +typedef struct { __u8 b[3]; } __be24, __le24; + #ifdef __KERNEL__ typedef unsigned __bitwise__ gfp_t; diff --git a/include/scsi/iscsi_proto.h b/include/scsi/iscsi_proto.h index f2a2c11..429c5ff 100644 --- a/include/scsi/iscsi_proto.h +++ b/include/scsi/iscsi_proto.h @@ -35,6 +35,8 @@ /* * useful common(control and data pathes) macro */ +#undef ntoh24 +#undef hton24 #define ntoh24(p) (((p)[0] << 16) | ((p)[1] << 8) | ((p)[2])) #define hton24(p, v) { \ p[0] = (((v) >> 16) & 0xFF); \