diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/xtensa/include/asm/Kbuild | 2 | ||||
| -rw-r--r-- | arch/xtensa/include/asm/byteorder.h | 72 | ||||
| -rw-r--r-- | arch/xtensa/include/asm/swab.h | 70 |
3 files changed, 75 insertions, 69 deletions
diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild index c68e168..58c02a4 100644 --- a/arch/xtensa/include/asm/Kbuild +++ b/arch/xtensa/include/asm/Kbuild @@ -1 +1,3 @@ include include/asm-generic/Kbuild.asm + +unifdef-y += swab.h diff --git a/arch/xtensa/include/asm/byteorder.h b/arch/xtensa/include/asm/byteorder.h index 07d10ad..329b945 100644 --- a/arch/xtensa/include/asm/byteorder.h +++ b/arch/xtensa/include/asm/byteorder.h @@ -1,80 +1,14 @@ -/* - * include/asm-xtensa/byteorder.h - * - * This file is subject to the terms and conditions of the GNU General Public - * License. See the file "COPYING" in the main directory of this archive - * for more details. - * - * Copyright (C) 2001 - 2005 Tensilica Inc. - */ - #ifndef _XTENSA_BYTEORDER_H #define _XTENSA_BYTEORDER_H -#include <asm/types.h> -#include <linux/compiler.h> +#include <asm/swab.h> #ifdef __XTENSA_EL__ -# define __LITTLE_ENDIAN +#include <linux/byteorder/little_endian.h> #elif defined(__XTENSA_EB__) -# define __BIG_ENDIAN +#include <linux/byteorder/big_endian.h> #else # error processor byte order undefined! #endif -#define __SWAB_64_THRU_32__ - -static inline __attribute_const__ __u32 __arch_swab32(__u32 x) -{ - __u32 res; - /* instruction sequence from Xtensa ISA release 2/2000 */ - __asm__("ssai 8 \n\t" - "srli %0, %1, 16 \n\t" - "src %0, %0, %1 \n\t" - "src %0, %0, %0 \n\t" - "src %0, %1, %0 \n" - : "=&a" (res) - : "a" (x) - ); - return res; -} -#define __arch_swab32 __arch_swab32 - -static inline __attribute_const__ __u16 __arch_swab16(__u16 x) -{ - /* Given that 'short' values are signed (i.e., can be negative), - * we cannot assume that the upper 16-bits of the register are - * zero. We are careful to mask values after shifting. - */ - - /* There exists an anomaly between xt-gcc and xt-xcc. xt-gcc - * inserts an extui instruction after putting this function inline - * to ensure that it uses only the least-significant 16 bits of - * the result. xt-xcc doesn't use an extui, but assumes the - * __asm__ macro follows convention that the upper 16 bits of an - * 'unsigned short' result are still zero. This macro doesn't - * follow convention; indeed, it leaves garbage in the upport 16 - * bits of the register. - - * Declaring the temporary variables 'res' and 'tmp' to be 32-bit - * types while the return type of the function is a 16-bit type - * forces both compilers to insert exactly one extui instruction - * (or equivalent) to mask off the upper 16 bits. */ - - __u32 res; - __u32 tmp; - - __asm__("extui %1, %2, 8, 8\n\t" - "slli %0, %2, 8 \n\t" - "or %0, %0, %1 \n" - : "=&a" (res), "=&a" (tmp) - : "a" (x) - ); - - return res; -} -#define __arch_swab16 __arch_swab16 - -#include <linux/byteorder.h> - #endif /* _XTENSA_BYTEORDER_H */ diff --git a/arch/xtensa/include/asm/swab.h b/arch/xtensa/include/asm/swab.h new file mode 100644 index 0000000..f50b697 --- /dev/null +++ b/arch/xtensa/include/asm/swab.h @@ -0,0 +1,70 @@ +/* + * include/asm-xtensa/swab.h + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + */ + +#ifndef _XTENSA_SWAB_H +#define _XTENSA_SWAB_H + +#include <asm/types.h> +#include <linux/compiler.h> + +#define __SWAB_64_THRU_32__ + +static inline __attribute_const__ __u32 __arch_swab32(__u32 x) +{ + __u32 res; + /* instruction sequence from Xtensa ISA release 2/2000 */ + __asm__("ssai 8 \n\t" + "srli %0, %1, 16 \n\t" + "src %0, %0, %1 \n\t" + "src %0, %0, %0 \n\t" + "src %0, %1, %0 \n" + : "=&a" (res) + : "a" (x) + ); + return res; +} +#define __arch_swab32 __arch_swab32 + +static inline __attribute_const__ __u16 __arch_swab16(__u16 x) +{ + /* Given that 'short' values are signed (i.e., can be negative), + * we cannot assume that the upper 16-bits of the register are + * zero. We are careful to mask values after shifting. + */ + + /* There exists an anomaly between xt-gcc and xt-xcc. xt-gcc + * inserts an extui instruction after putting this function inline + * to ensure that it uses only the least-significant 16 bits of + * the result. xt-xcc doesn't use an extui, but assumes the + * __asm__ macro follows convention that the upper 16 bits of an + * 'unsigned short' result are still zero. This macro doesn't + * follow convention; indeed, it leaves garbage in the upport 16 + * bits of the register. + + * Declaring the temporary variables 'res' and 'tmp' to be 32-bit + * types while the return type of the function is a 16-bit type + * forces both compilers to insert exactly one extui instruction + * (or equivalent) to mask off the upper 16 bits. */ + + __u32 res; + __u32 tmp; + + __asm__("extui %1, %2, 8, 8\n\t" + "slli %0, %2, 8 \n\t" + "or %0, %0, %1 \n" + : "=&a" (res), "=&a" (tmp) + : "a" (x) + ); + + return res; +} +#define __arch_swab16 __arch_swab16 + +#endif /* _XTENSA_SWAB_H */ |
