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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/lib/csum-partial_64.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/lib/csum-partial_64.c')
-rw-r--r-- | arch/x86/lib/csum-partial_64.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/x86/lib/csum-partial_64.c b/arch/x86/lib/csum-partial_64.c new file mode 100644 index 000000000..50734a230 --- /dev/null +++ b/arch/x86/lib/csum-partial_64.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * arch/x86_64/lib/csum-partial.c + * + * This file contains network checksum routines that are better done + * in an architecture-specific manner due to speed. + */ + +#include <linux/compiler.h> +#include <linux/export.h> +#include <asm/checksum.h> +#include <asm/word-at-a-time.h> + +static inline unsigned short from32to16(unsigned a) +{ + unsigned short b = a >> 16; + asm("addw %w2,%w0\n\t" + "adcw $0,%w0\n" + : "=r" (b) + : "0" (b), "r" (a)); + return b; +} + +/* + * Do a checksum on an arbitrary memory area. + * Returns a 32bit checksum. + * + * This isn't as time critical as it used to be because many NICs + * do hardware checksumming these days. + * + * Still, with CHECKSUM_COMPLETE this is called to compute + * checksums on IPv6 headers (40 bytes) and other small parts. + * it's best to have buff aligned on a 64-bit boundary + */ +__wsum csum_partial(const void *buff, int len, __wsum sum) +{ + u64 temp64 = (__force u64)sum; + unsigned odd, result; + + odd = 1 & (unsigned long) buff; + if (unlikely(odd)) { + if (unlikely(len == 0)) + return sum; + temp64 = ror32((__force u32)sum, 8); + temp64 += (*(unsigned char *)buff << 8); + len--; + buff++; + } + + while (unlikely(len >= 64)) { + asm("addq 0*8(%[src]),%[res]\n\t" + "adcq 1*8(%[src]),%[res]\n\t" + "adcq 2*8(%[src]),%[res]\n\t" + "adcq 3*8(%[src]),%[res]\n\t" + "adcq 4*8(%[src]),%[res]\n\t" + "adcq 5*8(%[src]),%[res]\n\t" + "adcq 6*8(%[src]),%[res]\n\t" + "adcq 7*8(%[src]),%[res]\n\t" + "adcq $0,%[res]" + : [res] "+r" (temp64) + : [src] "r" (buff) + : "memory"); + buff += 64; + len -= 64; + } + + if (len & 32) { + asm("addq 0*8(%[src]),%[res]\n\t" + "adcq 1*8(%[src]),%[res]\n\t" + "adcq 2*8(%[src]),%[res]\n\t" + "adcq 3*8(%[src]),%[res]\n\t" + "adcq $0,%[res]" + : [res] "+r" (temp64) + : [src] "r" (buff) + : "memory"); + buff += 32; + } + if (len & 16) { + asm("addq 0*8(%[src]),%[res]\n\t" + "adcq 1*8(%[src]),%[res]\n\t" + "adcq $0,%[res]" + : [res] "+r" (temp64) + : [src] "r" (buff) + : "memory"); + buff += 16; + } + if (len & 8) { + asm("addq 0*8(%[src]),%[res]\n\t" + "adcq $0,%[res]" + : [res] "+r" (temp64) + : [src] "r" (buff) + : "memory"); + buff += 8; + } + if (len & 7) { + unsigned int shift = (8 - (len & 7)) * 8; + unsigned long trail; + + trail = (load_unaligned_zeropad(buff) << shift) >> shift; + + asm("addq %[trail],%[res]\n\t" + "adcq $0,%[res]" + : [res] "+r" (temp64) + : [trail] "r" (trail)); + } + result = add32_with_carry(temp64 >> 32, temp64 & 0xffffffff); + if (unlikely(odd)) { + result = from32to16(result); + result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); + } + return (__force __wsum)result; +} +EXPORT_SYMBOL(csum_partial); + +/* + * this routine is used for miscellaneous IP-like checksums, mainly + * in icmp.c + */ +__sum16 ip_compute_csum(const void *buff, int len) +{ + return csum_fold(csum_partial(buff,len,0)); +} +EXPORT_SYMBOL(ip_compute_csum); |