svn commit: r313006 - in head: sys/conf sys/libkern sys/libkern/x86 sys/sys tests/sys/kern
Conrad E. Meyer
cem at FreeBSD.org
Tue Jan 31 03:26:34 UTC 2017
Author: cem
Date: Tue Jan 31 03:26:32 2017
New Revision: 313006
URL: https://svnweb.freebsd.org/changeset/base/313006
Log:
calculate_crc32c: Add SSE4.2 implementation on x86
Derived from an implementation by Mark Adler.
The fast loop performs three simultaneous CRCs over subsets of the data
before composing them. This takes advantage of certain properties of
the CRC32 implementation in Intel hardware. (The CRC instruction takes 1
cycle but has 2-3 cycles of latency.)
The CRC32 instruction does not manipulate FPU state.
i386 does not have the crc32q instruction, so avoid it there. Otherwise
the implementation is identical to amd64.
Add basic userland tests to verify correctness on a variety of inputs.
PR: 216467
Reported by: Ben RUBSON <ben.rubson at gmail.com>
Reviewed by: kib@, markj@ (earlier version)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D9342
Added:
head/sys/libkern/x86/
head/sys/libkern/x86/crc32_sse42.c (contents, props changed)
head/tests/sys/kern/libkern_crc32.c (contents, props changed)
Modified:
head/sys/conf/files.amd64
head/sys/conf/files.i386
head/sys/libkern/crc32.c
head/sys/sys/libkern.h
head/tests/sys/kern/Makefile
Modified: head/sys/conf/files.amd64
==============================================================================
--- head/sys/conf/files.amd64 Tue Jan 31 01:55:29 2017 (r313005)
+++ head/sys/conf/files.amd64 Tue Jan 31 03:26:32 2017 (r313006)
@@ -593,6 +593,11 @@ compat/ndis/subr_pe.c optional ndisapi
compat/ndis/subr_usbd.c optional ndisapi pci
compat/ndis/winx64_wrap.S optional ndisapi pci
#
+crc32_sse42.o standard \
+ dependency "$S/libkern/x86/crc32_sse42.c" \
+ compile-with "${CC} -c ${CFLAGS:N-nostdinc} ${WERROR} ${PROF} -msse4 ${.IMPSRC}" \
+ no-implicit-rule \
+ clean "crc32_sse42.o"
libkern/memmove.c standard
libkern/memset.c standard
#
Modified: head/sys/conf/files.i386
==============================================================================
--- head/sys/conf/files.i386 Tue Jan 31 01:55:29 2017 (r313005)
+++ head/sys/conf/files.i386 Tue Jan 31 03:26:32 2017 (r313006)
@@ -554,6 +554,11 @@ kern/kern_clocksource.c standard
kern/imgact_aout.c optional compat_aout
kern/imgact_gzip.c optional gzip
kern/subr_sfbuf.c standard
+crc32_sse42.o standard \
+ dependency "$S/libkern/x86/crc32_sse42.c" \
+ compile-with "${CC} -c ${CFLAGS:N-nostdinc} ${WERROR} ${PROF} -msse4 ${.IMPSRC}" \
+ no-implicit-rule \
+ clean "crc32_sse42.o"
libkern/divdi3.c standard
libkern/ffsll.c standard
libkern/flsll.c standard
Modified: head/sys/libkern/crc32.c
==============================================================================
--- head/sys/libkern/crc32.c Tue Jan 31 01:55:29 2017 (r313005)
+++ head/sys/libkern/crc32.c Tue Jan 31 03:26:32 2017 (r313006)
@@ -46,8 +46,14 @@
__FBSDID("$FreeBSD$");
#include <sys/param.h>
+#include <sys/libkern.h>
#include <sys/systm.h>
+#if defined(__amd64__) || defined(__i386__)
+#include <machine/md_var.h>
+#include <machine/specialreg.h>
+#endif
+
const uint32_t crc32_tab[] = {
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
@@ -749,6 +755,11 @@ calculate_crc32c(uint32_t crc32c,
const unsigned char *buffer,
unsigned int length)
{
+#if defined(__amd64__) || defined(__i386__)
+ if ((cpu_feature2 & CPUID2_SSE42) != 0) {
+ return (sse42_crc32c(crc32c, buffer, length));
+ } else
+#endif
if (length < 4) {
return (singletable_crc32c(crc32c, buffer, length));
} else {
Added: head/sys/libkern/x86/crc32_sse42.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/libkern/x86/crc32_sse42.c Tue Jan 31 03:26:32 2017 (r313006)
@@ -0,0 +1,288 @@
+/*
+ * Derived from crc32c.c version 1.1 by Mark Adler.
+ *
+ * Copyright (C) 2013 Mark Adler
+ *
+ * This software is provided 'as-is', without any express or implied warranty.
+ * In no event will the author be held liable for any damages arising from the
+ * use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ * claim that you wrote the original software. If you use this software
+ * in a product, an acknowledgment in the product documentation would be
+ * appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ * misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ *
+ * Mark Adler
+ * madler at alumni.caltech.edu
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * This file is compiled in userspace in order to run ATF unit tests.
+ */
+#ifdef USERSPACE_TESTING
+#include <stdint.h>
+#else
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/libkern.h>
+#include <sys/systm.h>
+#endif
+
+#include <nmmintrin.h>
+
+/* CRC-32C (iSCSI) polynomial in reversed bit order. */
+#define POLY 0x82f63b78
+
+/*
+ * Block sizes for three-way parallel crc computation. LONG and SHORT must
+ * both be powers of two.
+ */
+#define LONG 8192
+#define SHORT 256
+
+/* Tables for hardware crc that shift a crc by LONG and SHORT zeros. */
+static uint32_t crc32c_long[4][256];
+static uint32_t crc32c_short[4][256];
+
+/*
+ * Multiply a matrix times a vector over the Galois field of two elements,
+ * GF(2). Each element is a bit in an unsigned integer. mat must have at
+ * least as many entries as the power of two for most significant one bit in
+ * vec.
+ */
+static inline uint32_t
+gf2_matrix_times(uint32_t *mat, uint32_t vec)
+{
+ uint32_t sum;
+
+ sum = 0;
+ while (vec) {
+ if (vec & 1)
+ sum ^= *mat;
+ vec >>= 1;
+ mat++;
+ }
+ return (sum);
+}
+
+/*
+ * Multiply a matrix by itself over GF(2). Both mat and square must have 32
+ * rows.
+ */
+static inline void
+gf2_matrix_square(uint32_t *square, uint32_t *mat)
+{
+ int n;
+
+ for (n = 0; n < 32; n++)
+ square[n] = gf2_matrix_times(mat, mat[n]);
+}
+
+/*
+ * Construct an operator to apply len zeros to a crc. len must be a power of
+ * two. If len is not a power of two, then the result is the same as for the
+ * largest power of two less than len. The result for len == 0 is the same as
+ * for len == 1. A version of this routine could be easily written for any
+ * len, but that is not needed for this application.
+ */
+static void
+crc32c_zeros_op(uint32_t *even, size_t len)
+{
+ uint32_t odd[32]; /* odd-power-of-two zeros operator */
+ uint32_t row;
+ int n;
+
+ /* put operator for one zero bit in odd */
+ odd[0] = POLY; /* CRC-32C polynomial */
+ row = 1;
+ for (n = 1; n < 32; n++) {
+ odd[n] = row;
+ row <<= 1;
+ }
+
+ /* put operator for two zero bits in even */
+ gf2_matrix_square(even, odd);
+
+ /* put operator for four zero bits in odd */
+ gf2_matrix_square(odd, even);
+
+ /*
+ * first square will put the operator for one zero byte (eight zero
+ * bits), in even -- next square puts operator for two zero bytes in
+ * odd, and so on, until len has been rotated down to zero
+ */
+ do {
+ gf2_matrix_square(even, odd);
+ len >>= 1;
+ if (len == 0)
+ return;
+ gf2_matrix_square(odd, even);
+ len >>= 1;
+ } while (len);
+
+ /* answer ended up in odd -- copy to even */
+ for (n = 0; n < 32; n++)
+ even[n] = odd[n];
+}
+
+/*
+ * Take a length and build four lookup tables for applying the zeros operator
+ * for that length, byte-by-byte on the operand.
+ */
+static void
+crc32c_zeros(uint32_t zeros[][256], size_t len)
+{
+ uint32_t op[32];
+ uint32_t n;
+
+ crc32c_zeros_op(op, len);
+ for (n = 0; n < 256; n++) {
+ zeros[0][n] = gf2_matrix_times(op, n);
+ zeros[1][n] = gf2_matrix_times(op, n << 8);
+ zeros[2][n] = gf2_matrix_times(op, n << 16);
+ zeros[3][n] = gf2_matrix_times(op, n << 24);
+ }
+}
+
+/* Apply the zeros operator table to crc. */
+static inline uint32_t
+crc32c_shift(uint32_t zeros[][256], uint32_t crc)
+{
+
+ return (zeros[0][crc & 0xff] ^ zeros[1][(crc >> 8) & 0xff] ^
+ zeros[2][(crc >> 16) & 0xff] ^ zeros[3][crc >> 24]);
+}
+
+/* Initialize tables for shifting crcs. */
+static void
+#ifdef USERSPACE_TESTING
+__attribute__((__constructor__))
+#endif
+crc32c_init_hw(void)
+{
+ crc32c_zeros(crc32c_long, LONG);
+ crc32c_zeros(crc32c_short, SHORT);
+}
+#ifdef _KERNEL
+SYSINIT(crc32c_sse42, SI_SUB_LOCK, SI_ORDER_ANY, crc32c_init_hw, NULL);
+#endif
+
+/* Compute CRC-32C using the Intel hardware instruction. */
+#ifdef USERSPACE_TESTING
+uint32_t sse42_crc32c(uint32_t, const unsigned char *, unsigned);
+#endif
+uint32_t
+sse42_crc32c(uint32_t crc, const unsigned char *buf, unsigned len)
+{
+#ifdef __amd64__
+ const size_t align = 8;
+#else
+ const size_t align = 4;
+#endif
+ const unsigned char *next, *end;
+ uint64_t crc0, crc1, crc2; /* need to be 64 bits for crc32q */
+
+ next = buf;
+ crc0 = crc;
+
+ /* Compute the crc to bring the data pointer to an aligned boundary. */
+ while (len && ((uintptr_t)next & (align - 1)) != 0) {
+ crc0 = _mm_crc32_u8(crc0, *next);
+ next++;
+ len--;
+ }
+
+ /*
+ * Compute the crc on sets of LONG*3 bytes, executing three independent
+ * crc instructions, each on LONG bytes -- this is optimized for the
+ * Nehalem, Westmere, Sandy Bridge, and Ivy Bridge architectures, which
+ * have a throughput of one crc per cycle, but a latency of three
+ * cycles.
+ */
+ while (len >= LONG * 3) {
+ crc1 = 0;
+ crc2 = 0;
+ end = next + LONG;
+ do {
+#ifdef __amd64__
+ crc0 = _mm_crc32_u64(crc0, *(const uint64_t *)next);
+ crc1 = _mm_crc32_u64(crc1,
+ *(const uint64_t *)(next + LONG));
+ crc2 = _mm_crc32_u64(crc2,
+ *(const uint64_t *)(next + (LONG * 2)));
+#else
+ crc0 = _mm_crc32_u32(crc0, *(const uint32_t *)next);
+ crc1 = _mm_crc32_u32(crc1,
+ *(const uint32_t *)(next + LONG));
+ crc2 = _mm_crc32_u32(crc2,
+ *(const uint32_t *)(next + (LONG * 2)));
+#endif
+ next += align;
+ } while (next < end);
+ crc0 = crc32c_shift(crc32c_long, crc0) ^ crc1;
+ crc0 = crc32c_shift(crc32c_long, crc0) ^ crc2;
+ next += LONG * 2;
+ len -= LONG * 3;
+ }
+
+ /*
+ * Do the same thing, but now on SHORT*3 blocks for the remaining data
+ * less than a LONG*3 block
+ */
+ while (len >= SHORT * 3) {
+ crc1 = 0;
+ crc2 = 0;
+ end = next + SHORT;
+ do {
+#ifdef __amd64__
+ crc0 = _mm_crc32_u64(crc0, *(const uint64_t *)next);
+ crc1 = _mm_crc32_u64(crc1,
+ *(const uint64_t *)(next + SHORT));
+ crc2 = _mm_crc32_u64(crc2,
+ *(const uint64_t *)(next + (SHORT * 2)));
+#else
+ crc0 = _mm_crc32_u32(crc0, *(const uint32_t *)next);
+ crc1 = _mm_crc32_u32(crc1,
+ *(const uint32_t *)(next + SHORT));
+ crc2 = _mm_crc32_u32(crc2,
+ *(const uint32_t *)(next + (SHORT * 2)));
+#endif
+ next += align;
+ } while (next < end);
+ crc0 = crc32c_shift(crc32c_short, crc0) ^ crc1;
+ crc0 = crc32c_shift(crc32c_short, crc0) ^ crc2;
+ next += SHORT * 2;
+ len -= SHORT * 3;
+ }
+
+ /* Compute the crc on the remaining bytes at native word size. */
+ end = next + (len - (len & (align - 1)));
+ while (next < end) {
+#ifdef __amd64__
+ crc0 = _mm_crc32_u64(crc0, *(const uint64_t *)next);
+#else
+ crc0 = _mm_crc32_u32(crc0, *(const uint32_t *)next);
+#endif
+ next += align;
+ }
+ len &= (align - 1);
+
+ /* Compute the crc for any trailing bytes. */
+ while (len) {
+ crc0 = _mm_crc32_u8(crc0, *next);
+ next++;
+ len--;
+ }
+
+ return ((uint32_t)crc0);
+}
Modified: head/sys/sys/libkern.h
==============================================================================
--- head/sys/sys/libkern.h Tue Jan 31 01:55:29 2017 (r313005)
+++ head/sys/sys/libkern.h Tue Jan 31 03:26:32 2017 (r313006)
@@ -205,6 +205,11 @@ crc32(const void *buf, size_t size)
uint32_t
calculate_crc32c(uint32_t crc32c, const unsigned char *buffer,
unsigned int length);
+#ifdef _KERNEL
+#if defined(__amd64__) || defined(__i386__)
+uint32_t sse42_crc32c(uint32_t, const unsigned char *, unsigned);
+#endif
+#endif
LIBKERN_INLINE void *memset(void *, int, size_t);
Modified: head/tests/sys/kern/Makefile
==============================================================================
--- head/tests/sys/kern/Makefile Tue Jan 31 01:55:29 2017 (r313005)
+++ head/tests/sys/kern/Makefile Tue Jan 31 03:26:32 2017 (r313006)
@@ -29,13 +29,19 @@ NETBSD_ATF_TESTS_C+= mqueue_test
CFLAGS.mqueue_test+= -I${SRCTOP}/tests
LIBADD.mqueue_test+= rt
+.if ${MACHINE_ARCH} == "amd64" || ${MACHINE_ARCH} == "i386"
+ATF_TESTS_C+= libkern_crc32
+CFLAGS.libkern_crc32+= -msse4 -DUSERSPACE_TESTING
+LDADD.libkern_crc32+= ${SRCTOP}/sys/libkern/x86/crc32_sse42.c
+.endif
+
# subr_unit.c contains functions whose prototypes lie in headers that cannot be
# included in userland. But as far as subr_unit_test goes, they're effectively
# static. So it's ok to disable -Wmissing-prototypes for this program.
CFLAGS.subr_unit.c+= -Wno-missing-prototypes
SRCS.subr_unit_test+= subr_unit.c
-WARNS?= 5
+WARNS?= 3
TESTS_SUBDIRS+= acct
TESTS_SUBDIRS+= execve
Added: head/tests/sys/kern/libkern_crc32.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/tests/sys/kern/libkern_crc32.c Tue Jan 31 03:26:32 2017 (r313006)
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2017 Conrad Meyer <cem at FreeBSD.org>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/param.h>
+
+#include <stdint.h>
+
+#include <atf-c.h>
+
+extern uint32_t sse42_crc32c(uint32_t, const unsigned char *, unsigned);
+
+ATF_TC_WITHOUT_HEAD(crc32c_basic_correctness);
+ATF_TC_BODY(crc32c_basic_correctness, tc)
+{
+ const uint64_t inputs[] = {
+ 0xf408c634b3a9142,
+ 0x80539e8c7c352e2b,
+ 0x62e9121db6e4d649,
+ 0x899345850ed0a286,
+ 0x2302df11b4a43b15,
+ 0xe943de7b3d35d70,
+ 0xdf1ff2bf41abf56b,
+ 0x9bc138abae315de2,
+ 0x31cc82e56234f0ff,
+ 0xce63c0cd6988e847,
+ 0x3e42f6b78ee352fa,
+ 0xfa4085436078cfa6,
+ 0x53349558bf670a4b,
+ 0x2714e10e7d722c61,
+ 0xc0d3261addfc6908,
+ 0xd1567c3181d3a1bf,
+ };
+ const uint32_t results[] = {
+ 0x2ce33ede,
+ 0xc49cc573,
+ 0xb8683c96,
+ 0x6918660d,
+ 0xa904e522,
+ 0x52dbc42c,
+ 0x98863c22,
+ 0x894d5d2c,
+ 0xb003745d,
+ 0xfc496dbd,
+ 0x97d2fbb5,
+ 0x3c062ef1,
+ 0xcc2eff18,
+ 0x6a9b09f6,
+ 0x420242c1,
+ 0xfd562dc3,
+ };
+ size_t i;
+ uint32_t act;
+
+ ATF_REQUIRE(nitems(inputs) == nitems(results));
+
+ for (i = 0; i < nitems(inputs); i++) {
+ act = sse42_crc32c(~0, (const void *)&inputs[i],
+ sizeof(inputs[0]));
+ ATF_REQUIRE_MSG(act == results[i],
+ "crc32c(0x%jx) = 0x%08x, got 0x%08x", (uintmax_t)inputs[i],
+ results[i], act);
+ }
+}
+
+ATF_TC_WITHOUT_HEAD(crc32c_alignment);
+ATF_TC_BODY(crc32c_alignment, tc)
+{
+ const uint64_t input = 0xf408c634b3a9142;
+ const uint32_t result = 0x2ce33ede;
+ unsigned char buf[15];
+ size_t i;
+ uint32_t act;
+
+
+ for (i = 1; i < 8; i++) {
+ memcpy(&buf[i], &input, sizeof(input));
+
+ act = sse42_crc32c(~0, (const void *)&buf[i], sizeof(input));
+ ATF_REQUIRE_MSG(act == result,
+ "crc32c(0x%jx) = 0x%08x, got 0x%08x", (uintmax_t)input,
+ result, act);
+ }
+}
+
+ATF_TC_WITHOUT_HEAD(crc32c_trailing_bytes);
+ATF_TC_BODY(crc32c_trailing_bytes, tc)
+{
+ const unsigned char input[] = {
+ 0x87, 0x54, 0x74, 0xd2, 0xb, 0x9b, 0xdd, 0xf6, 0x68, 0x37,
+ 0xd4, 0x4, 0x5e, 0xa9, 0xb3
+ };
+ const uint32_t result = 0xec638d62;
+ uint32_t act;
+
+ act = sse42_crc32c(~0, input, sizeof(input));
+ ATF_REQUIRE_MSG(act == result, "expected 0x%08x, got 0x%08x", result,
+ act);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+
+ ATF_TP_ADD_TC(tp, crc32c_basic_correctness);
+ ATF_TP_ADD_TC(tp, crc32c_alignment);
+ ATF_TP_ADD_TC(tp, crc32c_trailing_bytes);
+ return (atf_no_error());
+}
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