diff options
Diffstat (limited to 'arch/powerpc/include/asm/checksum.h')
| -rw-r--r-- | arch/powerpc/include/asm/checksum.h | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h new file mode 100644 index 000000000..82f099ba2 --- /dev/null +++ b/arch/powerpc/include/asm/checksum.h @@ -0,0 +1,214 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _ASM_POWERPC_CHECKSUM_H +#define _ASM_POWERPC_CHECKSUM_H +#ifdef __KERNEL__ + +/* + */ + +#include <linux/bitops.h> +#include <linux/in6.h> +/* + * 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); + +#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER +extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, + int len); +#define HAVE_CSUM_COPY_USER +extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, + int len); + +#define _HAVE_ARCH_CSUM_AND_COPY +#define csum_partial_copy_nocheck(src, dst, len) \ + csum_partial_copy_generic((src), (dst), (len)) + + +/* + * 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); +} + +static inline u32 from64to32(u64 x) +{ + return (x + ror64(x, 32)) >> 32; +} + +static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, + __u8 proto, __wsum sum) +{ +#ifdef __powerpc64__ + u64 s = (__force u32)sum; + + s += (__force u32)saddr; + s += (__force u32)daddr; +#ifdef __BIG_ENDIAN__ + s += proto + len; +#else + s += (proto + len) << 8; +#endif + return (__force __wsum) from64to32(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 +} + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented + */ +static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, + __u8 proto, __wsum sum) +{ + return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); +} + +#define HAVE_ARCH_CSUM_ADD +static inline __wsum csum_add(__wsum csum, __wsum addend) +{ +#ifdef __powerpc64__ + u64 res = (__force u64)csum; +#endif + if (__builtin_constant_p(csum) && csum == 0) + return addend; + if (__builtin_constant_p(addend) && addend == 0) + return csum; + +#ifdef __powerpc64__ + res += (__force u64)addend; + return (__force __wsum)((u32)res + (res >> 32)); +#else + asm("addc %0,%0,%1;" + "addze %0,%0;" + : "+r" (csum) : "r" (addend) : "xer"); + return csum; +#endif +} + +/* + * 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. + */ +static inline __wsum ip_fast_csum_nofold(const void *iph, unsigned int ihl) +{ + const u32 *ptr = (const u32 *)iph + 1; +#ifdef __powerpc64__ + unsigned int i; + u64 s = *(const u32 *)iph; + + for (i = 0; i < ihl - 1; i++, ptr++) + s += *ptr; + return (__force __wsum)from64to32(s); +#else + __wsum sum, tmp; + + asm("mtctr %3;" + "addc %0,%4,%5;" + "1: lwzu %1, 4(%2);" + "adde %0,%0,%1;" + "bdnz 1b;" + "addze %0,%0;" + : "=r" (sum), "=r" (tmp), "+b" (ptr) + : "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr) + : "ctr", "xer", "memory"); + + return sum; +#endif +} + +static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) +{ + return csum_fold(ip_fast_csum_nofold(iph, ihl)); +} + +/* + * 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 + */ +__wsum __csum_partial(const void *buff, int len, __wsum sum); + +static inline __wsum csum_partial(const void *buff, int len, __wsum sum) +{ + if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) { + if (len == 2) + sum = csum_add(sum, (__force __wsum)*(const u16 *)buff); + if (len >= 4) + sum = csum_add(sum, (__force __wsum)*(const u32 *)buff); + if (len == 6) + sum = csum_add(sum, (__force __wsum) + *(const u16 *)(buff + 4)); + if (len >= 8) + sum = csum_add(sum, (__force __wsum) + *(const u32 *)(buff + 4)); + if (len == 10) + sum = csum_add(sum, (__force __wsum) + *(const u16 *)(buff + 8)); + if (len >= 12) + sum = csum_add(sum, (__force __wsum) + *(const u32 *)(buff + 8)); + if (len == 14) + sum = csum_add(sum, (__force __wsum) + *(const u16 *)(buff + 12)); + if (len >= 16) + sum = csum_add(sum, (__force __wsum) + *(const u32 *)(buff + 12)); + } else if (__builtin_constant_p(len) && (len & 3) == 0) { + sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2)); + } else { + sum = __csum_partial(buff, len, sum); + } + return sum; +} + +/* + * 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)); +} + +#define _HAVE_ARCH_IPV6_CSUM +__sum16 csum_ipv6_magic(const struct in6_addr *saddr, + const struct in6_addr *daddr, + __u32 len, __u8 proto, __wsum sum); + +#endif /* __KERNEL__ */ +#endif |