^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * arch/x86_64/lib/csum-partial.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * This file contains network checksum routines that are better done
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * in an architecture-specific manner due to speed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/compiler.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <asm/checksum.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) static inline unsigned short from32to16(unsigned a)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) unsigned short b = a >> 16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) asm("addw %w2,%w0\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) "adcw $0,%w0\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) : "=r" (b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) : "0" (b), "r" (a));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) return b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * Do a 64-bit checksum on an arbitrary memory area.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * Returns a 32bit checksum.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * This isn't as time critical as it used to be because many NICs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * do hardware checksumming these days.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * Things tried and found to not make it faster:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * Manual Prefetching
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * Unrolling to an 128 bytes inner loop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * Using interleaving with more registers to break the carry chains.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) static unsigned do_csum(const unsigned char *buff, unsigned len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) unsigned odd, count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) unsigned long result = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) if (unlikely(len == 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) return result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) odd = 1 & (unsigned long) buff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) if (unlikely(odd)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) result = *buff << 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) len--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) buff++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) count = len >> 1; /* nr of 16-bit words.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) if (count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) if (2 & (unsigned long) buff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) result += *(unsigned short *)buff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) count--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) len -= 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) buff += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) count >>= 1; /* nr of 32-bit words.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) if (count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) unsigned long zero;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) unsigned count64;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) if (4 & (unsigned long) buff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) result += *(unsigned int *) buff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) count--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) len -= 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) buff += 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) count >>= 1; /* nr of 64-bit words.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) /* main loop using 64byte blocks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) zero = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) count64 = count >> 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) while (count64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) asm("addq 0*8(%[src]),%[res]\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) "adcq 1*8(%[src]),%[res]\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) "adcq 2*8(%[src]),%[res]\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) "adcq 3*8(%[src]),%[res]\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) "adcq 4*8(%[src]),%[res]\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) "adcq 5*8(%[src]),%[res]\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) "adcq 6*8(%[src]),%[res]\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) "adcq 7*8(%[src]),%[res]\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) "adcq %[zero],%[res]"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) : [res] "=r" (result)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) : [src] "r" (buff), [zero] "r" (zero),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) "[res]" (result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) buff += 64;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) count64--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) /* last up to 7 8byte blocks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) count %= 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) while (count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) asm("addq %1,%0\n\t"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) "adcq %2,%0\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) : "=r" (result)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) : "m" (*(unsigned long *)buff),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) "r" (zero), "0" (result));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) --count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) buff += 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) result = add32_with_carry(result>>32,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) result&0xffffffff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (len & 4) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) result += *(unsigned int *) buff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) buff += 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (len & 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) result += *(unsigned short *) buff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) buff += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) if (len & 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) result += *buff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) result = add32_with_carry(result>>32, result & 0xffffffff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) if (unlikely(odd)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) result = from32to16(result);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) return result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * computes the checksum of a memory block at buff, length len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) * and adds in "sum" (32-bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * returns a 32-bit number suitable for feeding into itself
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * or csum_tcpudp_magic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * this function must be called with even lengths, except
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * for the last fragment, which may be odd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) * it's best to have buff aligned on a 64-bit boundary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) __wsum csum_partial(const void *buff, int len, __wsum sum)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) return (__force __wsum)add32_with_carry(do_csum(buff, len),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) (__force u32)sum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) EXPORT_SYMBOL(csum_partial);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) * this routine is used for miscellaneous IP-like checksums, mainly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) * in icmp.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) __sum16 ip_compute_csum(const void *buff, int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) return csum_fold(csum_partial(buff,len,0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) EXPORT_SYMBOL(ip_compute_csum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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