diff options
Diffstat (limited to 'arch/s390/include/asm/checksum.h')
| -rw-r--r-- | arch/s390/include/asm/checksum.h | 46 |
1 files changed, 10 insertions, 36 deletions
diff --git a/arch/s390/include/asm/checksum.h b/arch/s390/include/asm/checksum.h index d5a8e7c1477..74036485635 100644 --- a/arch/s390/include/asm/checksum.h +++ b/arch/s390/include/asm/checksum.h @@ -1,18 +1,16 @@ -#ifndef _S390_CHECKSUM_H -#define _S390_CHECKSUM_H - /* - * include/asm-s390/checksum.h * S390 fast network checksum routines - * see also arch/S390/lib/checksum.c * * S390 version - * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Copyright IBM Corp. 1999 * Author(s): Ulrich Hild (first version) * Martin Schwidefsky (heavily optimized CKSM version) * D.J. Barrow (third attempt) */ +#ifndef _S390_CHECKSUM_H +#define _S390_CHECKSUM_H + #include <asm/uaccess.h> /* @@ -46,22 +44,15 @@ csum_partial(const void *buff, int len, __wsum sum) * here even more important to align src and dst on a 32-bit (or even * better 64-bit) boundary * - * Copy from userspace and compute checksum. If we catch an exception - * then zero the rest of the buffer. + * Copy from userspace and compute checksum. */ static inline __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr) { - int missing; - - missing = copy_from_user(dst, src, len); - if (missing) { - memset(dst + len - missing, 0, missing); + if (unlikely(copy_from_user(dst, src, len))) *err_ptr = -EFAULT; - } - return csum_partial(dst, len, sum); } @@ -78,28 +69,11 @@ csum_partial_copy_nocheck (const void *src, void *dst, int len, __wsum sum) */ static inline __sum16 csum_fold(__wsum sum) { -#ifndef __s390x__ - register_pair rp; + u32 csum = (__force u32) sum; - asm volatile( - " slr %N1,%N1\n" /* %0 = H L */ - " lr %1,%0\n" /* %0 = H L, %1 = H L 0 0 */ - " srdl %1,16\n" /* %0 = H L, %1 = 0 H L 0 */ - " alr %1,%N1\n" /* %0 = H L, %1 = L H L 0 */ - " alr %0,%1\n" /* %0 = H+L+C L+H */ - " srl %0,16\n" /* %0 = H+L+C */ - : "+&d" (sum), "=d" (rp) : : "cc"); -#else /* __s390x__ */ - asm volatile( - " sr 3,3\n" /* %0 = H*65536 + L */ - " lr 2,%0\n" /* %0 = H L, 2/3 = H L / 0 0 */ - " srdl 2,16\n" /* %0 = H L, 2/3 = 0 H / L 0 */ - " alr 2,3\n" /* %0 = H L, 2/3 = L H / L 0 */ - " alr %0,2\n" /* %0 = H+L+C L+H */ - " srl %0,16\n" /* %0 = H+L+C */ - : "+&d" (sum) : : "cc", "2", "3"); -#endif /* __s390x__ */ - return (__force __sum16) ~sum; + csum += (csum >> 16) + (csum << 16); + csum >>= 16; + return (__force __sum16) ~csum; } /* |