diff options
Diffstat (limited to 'freebsd/sys/i386/i386/in_cksum.c')
| -rw-r--r-- | freebsd/sys/i386/i386/in_cksum.c | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/freebsd/sys/i386/i386/in_cksum.c b/freebsd/sys/i386/i386/in_cksum.c new file mode 100644 index 00000000..0f663989 --- /dev/null +++ b/freebsd/sys/i386/i386/in_cksum.c @@ -0,0 +1,493 @@ +#include <freebsd/machine/rtems-bsd-config.h> + +/*- + * 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 <freebsd/sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <freebsd/sys/param.h> +#include <freebsd/sys/systm.h> +#include <freebsd/sys/mbuf.h> + +#include <freebsd/netinet/in.h> +#include <freebsd/netinet/in_systm.h> +#include <freebsd/netinet/ip.h> + +#include <freebsd/machine/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 & (int) w) { + REDUCE; + if ((1 & (int) w) && (mlen > 0)) { + sum <<= 8; + su.c[0] = *(char *)w; + w = (u_short *)((char *)w + 1); + mlen--; + byte_swapped = 1; + } + if ((2 & (int) w) && (mlen >= 2)) { + sum += *w++; + mlen -= 2; + } + } + /* + * Advance to a 486 cache line boundary. + */ + if (4 & (int) 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 & (int) 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 |