diff options
Diffstat (limited to 'arch/x86_64/lib/csum-partial_64.c')
| -rw-r--r-- | arch/x86_64/lib/csum-partial_64.c | 150 |
1 files changed, 0 insertions, 150 deletions
diff --git a/arch/x86_64/lib/csum-partial_64.c b/arch/x86_64/lib/csum-partial_64.c deleted file mode 100644 index bc503f50690..00000000000 --- a/arch/x86_64/lib/csum-partial_64.c +++ /dev/null @@ -1,150 +0,0 @@ -/* - * 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/module.h> -#include <asm/checksum.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 64-bit 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. - * - * Things tried and found to not make it faster: - * Manual Prefetching - * Unrolling to an 128 bytes inner loop. - * Using interleaving with more registers to break the carry chains. - */ -static unsigned do_csum(const unsigned char *buff, unsigned len) -{ - unsigned odd, count; - unsigned long result = 0; - - if (unlikely(len == 0)) - return result; - odd = 1 & (unsigned long) buff; - if (unlikely(odd)) { - result = *buff << 8; - len--; - buff++; - } - count = len >> 1; /* nr of 16-bit words.. */ - if (count) { - if (2 & (unsigned long) buff) { - result += *(unsigned short *)buff; - count--; - len -= 2; - buff += 2; - } - count >>= 1; /* nr of 32-bit words.. */ - if (count) { - unsigned long zero; - unsigned count64; - if (4 & (unsigned long) buff) { - result += *(unsigned int *) buff; - count--; - len -= 4; - buff += 4; - } - count >>= 1; /* nr of 64-bit words.. */ - - /* main loop using 64byte blocks */ - zero = 0; - count64 = count >> 3; - while (count64) { - 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 %[zero],%[res]" - : [res] "=r" (result) - : [src] "r" (buff), [zero] "r" (zero), - "[res]" (result)); - buff += 64; - count64--; - } - - /* last upto 7 8byte blocks */ - count %= 8; - while (count) { - asm("addq %1,%0\n\t" - "adcq %2,%0\n" - : "=r" (result) - : "m" (*(unsigned long *)buff), - "r" (zero), "0" (result)); - --count; - buff += 8; - } - result = add32_with_carry(result>>32, - result&0xffffffff); - - if (len & 4) { - result += *(unsigned int *) buff; - buff += 4; - } - } - if (len & 2) { - result += *(unsigned short *) buff; - buff += 2; - } - } - if (len & 1) - result += *buff; - result = add32_with_carry(result>>32, result & 0xffffffff); - if (unlikely(odd)) { - result = from32to16(result); - result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); - } - return result; -} - -/* - * 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 64-bit boundary - */ -__wsum csum_partial(const void *buff, int len, __wsum sum) -{ - return (__force __wsum)add32_with_carry(do_csum(buff, len), - (__force u32)sum); -} - -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); - |