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Diffstat (limited to 'kernel/arch/powerpc/include/asm/checksum.h')
| -rw-r--r-- | kernel/arch/powerpc/include/asm/checksum.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/include/asm/checksum.h b/kernel/arch/powerpc/include/asm/checksum.h new file mode 100644 index 000000000..8251a3ba8 --- /dev/null +++ b/kernel/arch/powerpc/include/asm/checksum.h @@ -0,0 +1,132 @@ +#ifndef _ASM_POWERPC_CHECKSUM_H +#define _ASM_POWERPC_CHECKSUM_H +#ifdef __KERNEL__ + +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. ihl is the number + * of 32-bit words and is always >= 5. + */ +#ifdef CONFIG_GENERIC_CSUM +#include <asm-generic/checksum.h> +#else +extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented + */ +extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, + unsigned short len, + unsigned short proto, + __wsum sum); + +/* + * computes the checksum of a memory block at buff, length len, + * and adds in "sum" (32-bit) + * + * returns a 32-bit number suitable for feeding into itself + * or csum_tcpudp_magic + * + * this function must be called with even lengths, except + * for the last fragment, which may be odd + * + * it's best to have buff aligned on a 32-bit boundary + */ +extern __wsum csum_partial(const void *buff, int len, __wsum sum); + +/* + * Computes the checksum of a memory block at src, length len, + * and adds in "sum" (32-bit), while copying the block to dst. + * If an access exception occurs on src or dst, it stores -EFAULT + * to *src_err or *dst_err respectively (if that pointer is not + * NULL), and, for an error on src, zeroes the rest of dst. + * + * Like csum_partial, this must be called with even lengths, + * except for the last fragment. + */ +extern __wsum csum_partial_copy_generic(const void *src, void *dst, + int len, __wsum sum, + int *src_err, int *dst_err); + +#ifdef __powerpc64__ +#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER +extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, + int len, __wsum sum, int *err_ptr); +#define HAVE_CSUM_COPY_USER +extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, + int len, __wsum sum, int *err_ptr); +#else +/* + * the same as csum_partial, but copies from src to dst while it + * checksums. + */ +#define csum_partial_copy_from_user(src, dst, len, sum, errp) \ + csum_partial_copy_generic((__force const void *)(src), (dst), (len), (sum), (errp), NULL) +#endif + +#define csum_partial_copy_nocheck(src, dst, len, sum) \ + csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL) + + +/* + * turns a 32-bit partial checksum (e.g. from csum_partial) into a + * 1's complement 16-bit checksum. + */ +static inline __sum16 csum_fold(__wsum sum) +{ + unsigned int tmp; + + /* swap the two 16-bit halves of sum */ + __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); + /* if there is a carry from adding the two 16-bit halves, + it will carry from the lower half into the upper half, + giving us the correct sum in the upper half. */ + return (__force __sum16)(~((__force u32)sum + tmp) >> 16); +} + +/* + * this routine is used for miscellaneous IP-like checksums, mainly + * in icmp.c + */ +static inline __sum16 ip_compute_csum(const void *buff, int len) +{ + return csum_fold(csum_partial(buff, len, 0)); +} + +static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, + unsigned short len, + unsigned short proto, + __wsum sum) +{ +#ifdef __powerpc64__ + unsigned long s = (__force u32)sum; + + s += (__force u32)saddr; + s += (__force u32)daddr; + s += proto + len; + s += (s >> 32); + return (__force __wsum) s; +#else + __asm__("\n\ + addc %0,%0,%1 \n\ + adde %0,%0,%2 \n\ + adde %0,%0,%3 \n\ + addze %0,%0 \n\ + " + : "=r" (sum) + : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); + return sum; +#endif +} + +#endif +#endif /* __KERNEL__ */ +#endif |