| /*- |
| * Copyright (c) 1990 The Regents of the University of California. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * |
| * from tahoe: in_cksum.c 1.2 86/01/05 |
| * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91 |
| */ |
| |
| #include <sys/bsd_cdefs.h> |
| //__FBSDID("$FreeBSD$"); |
| |
| #include <sys/bsd_param.h> |
| #include <sys/bsd_systm.h> |
| #include <sys/bsd_mbuf.h> |
| |
| #include <netinet/bsd_in.h> |
| #include <netinet/bsd_in_systm.h> |
| #include <netinet/bsd_ip.h> |
| |
| #include <machine/bsd_in_cksum.h> |
| |
| /* |
| * Checksum routine for Internet Protocol family headers. |
| * |
| * This routine is very heavily used in the network |
| * code and should be modified for each CPU to be as fast as possible. |
| * |
| * This implementation is 386 version. |
| */ |
| |
| #undef ADDCARRY |
| #define ADDCARRY(x) if ((x) > 0xffff) (x) -= 0xffff |
| /* |
| * icc needs to be special cased here, as the asm code below results |
| * in broken code if compiled with icc. |
| */ |
| #if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER) |
| /* non gcc parts stolen from sys/alpha/alpha/in_cksum.c */ |
| #define REDUCE32 \ |
| { \ |
| q_util.q = sum; \ |
| sum = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ |
| } |
| #define REDUCE16 \ |
| { \ |
| q_util.q = sum; \ |
| l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ |
| sum = l_util.s[0] + l_util.s[1]; \ |
| ADDCARRY(sum); \ |
| } |
| #endif |
| #define REDUCE {sum = (sum & 0xffff) + (sum >> 16); ADDCARRY(sum);} |
| |
| #if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER) |
| static const u_int32_t in_masks[] = { |
| /*0 bytes*/ /*1 byte*/ /*2 bytes*/ /*3 bytes*/ |
| 0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF, /* offset 0 */ |
| 0x00000000, 0x0000FF00, 0x00FFFF00, 0xFFFFFF00, /* offset 1 */ |
| 0x00000000, 0x00FF0000, 0xFFFF0000, 0xFFFF0000, /* offset 2 */ |
| 0x00000000, 0xFF000000, 0xFF000000, 0xFF000000, /* offset 3 */ |
| }; |
| |
| union l_util { |
| u_int16_t s[2]; |
| u_int32_t l; |
| }; |
| union q_util { |
| u_int16_t s[4]; |
| u_int32_t l[2]; |
| u_int64_t q; |
| }; |
| |
| static u_int64_t |
| in_cksumdata(const u_int32_t *lw, int len) |
| { |
| u_int64_t sum = 0; |
| u_int64_t prefilled; |
| int offset; |
| union q_util q_util; |
| |
| if ((3 & (long) lw) == 0 && len == 20) { |
| sum = (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3] + lw[4]; |
| REDUCE32; |
| return sum; |
| } |
| |
| if ((offset = 3 & (long) lw) != 0) { |
| const u_int32_t *masks = in_masks + (offset << 2); |
| lw = (u_int32_t *) (((long) lw) - offset); |
| sum = *lw++ & masks[len >= 3 ? 3 : len]; |
| len -= 4 - offset; |
| if (len <= 0) { |
| REDUCE32; |
| return sum; |
| } |
| } |
| #if 0 |
| /* |
| * Force to cache line boundary. |
| */ |
| offset = 32 - (0x1f & (long) lw); |
| if (offset < 32 && len > offset) { |
| len -= offset; |
| if (4 & offset) { |
| sum += (u_int64_t) lw[0]; |
| lw += 1; |
| } |
| if (8 & offset) { |
| sum += (u_int64_t) lw[0] + lw[1]; |
| lw += 2; |
| } |
| if (16 & offset) { |
| sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3]; |
| lw += 4; |
| } |
| } |
| #endif |
| /* |
| * access prefilling to start load of next cache line. |
| * then add current cache line |
| * save result of prefilling for loop iteration. |
| */ |
| prefilled = lw[0]; |
| while ((len -= 32) >= 4) { |
| u_int64_t prefilling = lw[8]; |
| sum += prefilled + lw[1] + lw[2] + lw[3] |
| + lw[4] + lw[5] + lw[6] + lw[7]; |
| lw += 8; |
| prefilled = prefilling; |
| } |
| if (len >= 0) { |
| sum += prefilled + lw[1] + lw[2] + lw[3] |
| + lw[4] + lw[5] + lw[6] + lw[7]; |
| lw += 8; |
| } else { |
| len += 32; |
| } |
| while ((len -= 16) >= 0) { |
| sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3]; |
| lw += 4; |
| } |
| len += 16; |
| while ((len -= 4) >= 0) { |
| sum += (u_int64_t) *lw++; |
| } |
| len += 4; |
| if (len > 0) |
| sum += (u_int64_t) (in_masks[len] & *lw); |
| REDUCE32; |
| return sum; |
| } |
| |
| u_short |
| in_addword(u_short a, u_short b) |
| { |
| u_int64_t sum = a + b; |
| |
| ADDCARRY(sum); |
| return (sum); |
| } |
| |
| u_short |
| in_pseudo(u_int32_t a, u_int32_t b, u_int32_t c) |
| { |
| u_int64_t sum; |
| union q_util q_util; |
| union l_util l_util; |
| |
| sum = (u_int64_t) a + b + c; |
| REDUCE16; |
| return (sum); |
| } |
| |
| u_short |
| in_cksum_skip(struct mbuf *m, int len, int skip) |
| { |
| u_int64_t sum = 0; |
| int mlen = 0; |
| int clen = 0; |
| caddr_t addr; |
| union q_util q_util; |
| union l_util l_util; |
| |
| len -= skip; |
| for (; skip && m; m = m->m_next) { |
| if (m->m_len > skip) { |
| mlen = m->m_len - skip; |
| addr = mtod(m, caddr_t) + skip; |
| goto skip_start; |
| } else { |
| skip -= m->m_len; |
| } |
| } |
| |
| for (; m && len; m = m->m_next) { |
| if (m->m_len == 0) |
| continue; |
| mlen = m->m_len; |
| addr = mtod(m, caddr_t); |
| skip_start: |
| if (len < mlen) |
| mlen = len; |
| if ((clen ^ (long) addr) & 1) |
| sum += in_cksumdata((const u_int32_t *)addr, mlen) << 8; |
| else |
| sum += in_cksumdata((const u_int32_t *)addr, mlen); |
| |
| clen += mlen; |
| len -= mlen; |
| } |
| REDUCE16; |
| return (~sum & 0xffff); |
| } |
| |
| u_int in_cksum_hdr(const struct ip *ip) |
| { |
| u_int64_t sum = in_cksumdata((const u_int32_t *)ip, sizeof(struct ip)); |
| union q_util q_util; |
| union l_util l_util; |
| |
| REDUCE16; |
| return (~sum & 0xffff); |
| } |
| #else |
| |
| /* |
| * These asm statements require __volatile because they pass information |
| * via the condition codes. GCC does not currently provide a way to specify |
| * the condition codes as an input or output operand. |
| * |
| * The LOAD macro below is effectively a prefetch into cache. GCC will |
| * load the value into a register but will not use it. Since modern CPUs |
| * reorder operations, this will generally take place in parallel with |
| * other calculations. |
| */ |
| u_short |
| in_cksum_skip(m, len, skip) |
| struct mbuf *m; |
| int len; |
| int skip; |
| { |
| register u_short *w; |
| register unsigned sum = 0; |
| register int mlen = 0; |
| int byte_swapped = 0; |
| union { char c[2]; u_short s; } su; |
| |
| len -= skip; |
| for (; skip && m; m = m->m_next) { |
| if (m->m_len > skip) { |
| mlen = m->m_len - skip; |
| w = (u_short *)(mtod(m, u_char *) + skip); |
| goto skip_start; |
| } else { |
| skip -= m->m_len; |
| } |
| } |
| |
| for (;m && len; m = m->m_next) { |
| if (m->m_len == 0) |
| continue; |
| w = mtod(m, u_short *); |
| if (mlen == -1) { |
| /* |
| * The first byte of this mbuf is the continuation |
| * of a word spanning between this mbuf and the |
| * last mbuf. |
| */ |
| |
| /* su.c[0] is already saved when scanning previous |
| * mbuf. sum was REDUCEd when we found mlen == -1 |
| */ |
| su.c[1] = *(u_char *)w; |
| sum += su.s; |
| w = (u_short *)((char *)w + 1); |
| mlen = m->m_len - 1; |
| len--; |
| } else |
| mlen = m->m_len; |
| skip_start: |
| if (len < mlen) |
| mlen = len; |
| len -= mlen; |
| /* |
| * Force to long boundary so we do longword aligned |
| * memory operations |
| */ |
| if (3 & (long) w) { |
| REDUCE; |
| if ((1 & (long) w) && (mlen > 0)) { |
| sum <<= 8; |
| su.c[0] = *(char *)w; |
| w = (u_short *)((char *)w + 1); |
| mlen--; |
| byte_swapped = 1; |
| } |
| if ((2 & (long) w) && (mlen >= 2)) { |
| sum += *w++; |
| mlen -= 2; |
| } |
| } |
| /* |
| * Advance to a 486 cache line boundary. |
| */ |
| if (4 & (long) w && mlen >= 4) { |
| __asm __volatile ( |
| "addl %1, %0\n" |
| "adcl $0, %0" |
| : "+r" (sum) |
| : "g" (((const u_int32_t *)w)[0]) |
| ); |
| w += 2; |
| mlen -= 4; |
| } |
| if (8 & (long) w && mlen >= 8) { |
| __asm __volatile ( |
| "addl %1, %0\n" |
| "adcl %2, %0\n" |
| "adcl $0, %0" |
| : "+r" (sum) |
| : "g" (((const u_int32_t *)w)[0]), |
| "g" (((const u_int32_t *)w)[1]) |
| ); |
| w += 4; |
| mlen -= 8; |
| } |
| /* |
| * Do as much of the checksum as possible 32 bits at at time. |
| * In fact, this loop is unrolled to make overhead from |
| * branches &c small. |
| */ |
| mlen -= 1; |
| while ((mlen -= 32) >= 0) { |
| /* |
| * Add with carry 16 words and fold in the last |
| * carry by adding a 0 with carry. |
| * |
| * The early ADD(16) and the LOAD(32) are to load |
| * the next 2 cache lines in advance on 486's. The |
| * 486 has a penalty of 2 clock cycles for loading |
| * a cache line, plus whatever time the external |
| * memory takes to load the first word(s) addressed. |
| * These penalties are unavoidable. Subsequent |
| * accesses to a cache line being loaded (and to |
| * other external memory?) are delayed until the |
| * whole load finishes. These penalties are mostly |
| * avoided by not accessing external memory for |
| * 8 cycles after the ADD(16) and 12 cycles after |
| * the LOAD(32). The loop terminates when mlen |
| * is initially 33 (not 32) to guaranteed that |
| * the LOAD(32) is within bounds. |
| */ |
| __asm __volatile ( |
| "addl %1, %0\n" |
| "adcl %2, %0\n" |
| "adcl %3, %0\n" |
| "adcl %4, %0\n" |
| "adcl %5, %0\n" |
| "mov %6, %%eax\n" |
| "adcl %7, %0\n" |
| "adcl %8, %0\n" |
| "adcl %9, %0\n" |
| "adcl $0, %0" |
| : "+r" (sum) |
| : "g" (((const u_int32_t *)w)[4]), |
| "g" (((const u_int32_t *)w)[0]), |
| "g" (((const u_int32_t *)w)[1]), |
| "g" (((const u_int32_t *)w)[2]), |
| "g" (((const u_int32_t *)w)[3]), |
| "g" (((const u_int32_t *)w)[8]), |
| "g" (((const u_int32_t *)w)[5]), |
| "g" (((const u_int32_t *)w)[6]), |
| "g" (((const u_int32_t *)w)[7]) |
| : "eax" |
| ); |
| w += 16; |
| } |
| mlen += 32 + 1; |
| if (mlen >= 32) { |
| __asm __volatile ( |
| "addl %1, %0\n" |
| "adcl %2, %0\n" |
| "adcl %3, %0\n" |
| "adcl %4, %0\n" |
| "adcl %5, %0\n" |
| "adcl %6, %0\n" |
| "adcl %7, %0\n" |
| "adcl %8, %0\n" |
| "adcl $0, %0" |
| : "+r" (sum) |
| : "g" (((const u_int32_t *)w)[4]), |
| "g" (((const u_int32_t *)w)[0]), |
| "g" (((const u_int32_t *)w)[1]), |
| "g" (((const u_int32_t *)w)[2]), |
| "g" (((const u_int32_t *)w)[3]), |
| "g" (((const u_int32_t *)w)[5]), |
| "g" (((const u_int32_t *)w)[6]), |
| "g" (((const u_int32_t *)w)[7]) |
| ); |
| w += 16; |
| mlen -= 32; |
| } |
| if (mlen >= 16) { |
| __asm __volatile ( |
| "addl %1, %0\n" |
| "adcl %2, %0\n" |
| "adcl %3, %0\n" |
| "adcl %4, %0\n" |
| "adcl $0, %0" |
| : "+r" (sum) |
| : "g" (((const u_int32_t *)w)[0]), |
| "g" (((const u_int32_t *)w)[1]), |
| "g" (((const u_int32_t *)w)[2]), |
| "g" (((const u_int32_t *)w)[3]) |
| ); |
| w += 8; |
| mlen -= 16; |
| } |
| if (mlen >= 8) { |
| __asm __volatile ( |
| "addl %1, %0\n" |
| "adcl %2, %0\n" |
| "adcl $0, %0" |
| : "+r" (sum) |
| : "g" (((const u_int32_t *)w)[0]), |
| "g" (((const u_int32_t *)w)[1]) |
| ); |
| w += 4; |
| mlen -= 8; |
| } |
| if (mlen == 0 && byte_swapped == 0) |
| continue; /* worth 1% maybe ?? */ |
| REDUCE; |
| while ((mlen -= 2) >= 0) { |
| sum += *w++; |
| } |
| if (byte_swapped) { |
| sum <<= 8; |
| byte_swapped = 0; |
| if (mlen == -1) { |
| su.c[1] = *(char *)w; |
| sum += su.s; |
| mlen = 0; |
| } else |
| mlen = -1; |
| } else if (mlen == -1) |
| /* |
| * This mbuf has odd number of bytes. |
| * There could be a word split betwen |
| * this mbuf and the next mbuf. |
| * Save the last byte (to prepend to next mbuf). |
| */ |
| su.c[0] = *(char *)w; |
| } |
| |
| if (len) |
| printf("%s: out of data by %d\n", __func__, len); |
| if (mlen == -1) { |
| /* The last mbuf has odd # of bytes. Follow the |
| standard (the odd byte is shifted left by 8 bits) */ |
| su.c[1] = 0; |
| sum += su.s; |
| } |
| REDUCE; |
| return (~sum & 0xffff); |
| } |
| #endif |
