diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/x86_64/lib/csum-wrappers.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/x86_64/lib/csum-wrappers.c')
-rw-r--r-- | arch/x86_64/lib/csum-wrappers.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/arch/x86_64/lib/csum-wrappers.c b/arch/x86_64/lib/csum-wrappers.c new file mode 100644 index 00000000000..94323f20816 --- /dev/null +++ b/arch/x86_64/lib/csum-wrappers.c @@ -0,0 +1,129 @@ +/* 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. + */ +unsigned int +csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst, + int len, unsigned int isum, int *errp) +{ + might_sleep(); + *errp = 0; + if (likely(access_ok(VERIFY_READ,src, len))) { + /* 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, (__u16 __user *)src); + if (*errp) + return isum; + *(__u16 *)dst = val16; + isum = add32_with_carry(isum, val16); + src += 2; + dst += 2; + len -= 2; + } + } + isum = csum_partial_copy_generic((__force void *)src,dst,len,isum,errp,NULL); + if (likely(*errp == 0)) + return isum; + } + *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. + */ +unsigned int +csum_partial_copy_to_user(unsigned const char *src, unsigned char __user *dst, + int len, unsigned int 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 = add32_with_carry(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. + */ +unsigned int +csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, int len, unsigned int sum) +{ + return csum_partial_copy_generic(src,dst,len,sum,NULL,NULL); +} + +unsigned short csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, + __u32 len, unsigned short proto, unsigned int sum) +{ + __u64 rest, sum64; + + rest = (__u64)htonl(len) + (__u64)htons(proto) + (__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(add32_with_carry(sum64 & 0xffffffff, sum64>>32)); +} + +EXPORT_SYMBOL(csum_ipv6_magic); |