/* * Copyright 2002, 2003 Andi Kleen, SuSE Labs. * Subject to the GNU Public License v.2 * * Wrappers of assembly checksum functions for x86-64. */ #include <asm/checksum.h> #include <linux/module.h> /** * csum_partial_copy_from_user - Copy and checksum from user space. * @src: source address (user space) * @dst: destination address * @len: number of bytes to be copied. * @isum: initial sum that is added into the result (32bit unfolded) * @errp: set to -EFAULT for an bad source address. * * Returns an 32bit unfolded checksum of the buffer. * src and dst are best aligned to 64bits. */ __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum isum, int *errp) { might_sleep(); *errp = 0; if (!likely(access_ok(VERIFY_READ, src, len))) goto out_err; /* * Why 6, not 7? To handle odd addresses aligned we * would need to do considerable complications to fix the * checksum which is defined as an 16bit accumulator. The * fix alignment code is primarily for performance * compatibility with 32bit and that will handle odd * addresses slowly too. */ if (unlikely((unsigned long)src & 6)) { while (((unsigned long)src & 6) && len >= 2) { __u16 val16; *errp = __get_user(val16, (const __u16 __user *)src); if (*errp) return isum; *(__u16 *)dst = val16; isum = (__force __wsum)add32_with_carry( (__force unsigned)isum, val16); src += 2; dst += 2; len -= 2; } } isum = csum_partial_copy_generic((__force const void *)src, dst, len, isum, errp, NULL); if (unlikely(*errp)) goto out_err; return isum; out_err: *errp = -EFAULT; memset(dst, 0, len); return isum; } EXPORT_SYMBOL(csum_partial_copy_from_user); /** * csum_partial_copy_to_user - Copy and checksum to user space. * @src: source address * @dst: destination address (user space) * @len: number of bytes to be copied. * @isum: initial sum that is added into the result (32bit unfolded) * @errp: set to -EFAULT for an bad destination address. * * Returns an 32bit unfolded checksum of the buffer. * src and dst are best aligned to 64bits. */ __wsum csum_partial_copy_to_user(const void *src, void __user *dst, int len, __wsum isum, int *errp) { might_sleep(); if (unlikely(!access_ok(VERIFY_WRITE, dst, len))) { *errp = -EFAULT; return 0; } if (unlikely((unsigned long)dst & 6)) { while (((unsigned long)dst & 6) && len >= 2) { __u16 val16 = *(__u16 *)src; isum = (__force __wsum)add32_with_carry( (__force unsigned)isum, val16); *errp = __put_user(val16, (__u16 __user *)dst); if (*errp) return isum; src += 2; dst += 2; len -= 2; } } *errp = 0; return csum_partial_copy_generic(src, (void __force *)dst, len, isum, NULL, errp); } EXPORT_SYMBOL(csum_partial_copy_to_user); /** * csum_partial_copy_nocheck - Copy and checksum. * @src: source address * @dst: destination address * @len: number of bytes to be copied. * @isum: initial sum that is added into the result (32bit unfolded) * * Returns an 32bit unfolded checksum of the buffer. */ __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum) { return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); } EXPORT_SYMBOL(csum_partial_copy_nocheck); __sum16 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len, unsigned short proto, __wsum sum) { __u64 rest, sum64; rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) + (__force __u64)sum; asm(" addq (%[saddr]),%[sum]\n" " adcq 8(%[saddr]),%[sum]\n" " adcq (%[daddr]),%[sum]\n" " adcq 8(%[daddr]),%[sum]\n" " adcq $0,%[sum]\n" : [sum] "=r" (sum64) : "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr)); return csum_fold( (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32)); } EXPORT_SYMBOL(csum_ipv6_magic);