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authorLinus Torvalds <torvalds@linux-foundation.org>2025-03-26 04:33:04 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2025-03-26 04:33:04 +0300
commitee6740fd34eb53c5c76be01201c15310f461b69f (patch)
tree09a51108245a2e8f644d1956a9e5b9f974bc23b8 /arch/x86/lib
parenta86c6d0b2ad12f6ce6560f735f4799cf1f631ab2 (diff)
parentacf9f8da5e19fc1cbf26f2ecb749369e13e7cd85 (diff)
downloadlinux-ee6740fd34eb53c5c76be01201c15310f461b69f.tar.xz
Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux
Pull CRC updates from Eric Biggers: "Another set of improvements to the kernel's CRC (cyclic redundancy check) code: - Rework the CRC64 library functions to be directly optimized, like what I did last cycle for the CRC32 and CRC-T10DIF library functions - Rewrite the x86 PCLMULQDQ-optimized CRC code, and add VPCLMULQDQ support and acceleration for crc64_be and crc64_nvme - Rewrite the riscv Zbc-optimized CRC code, and add acceleration for crc_t10dif, crc64_be, and crc64_nvme - Remove crc_t10dif and crc64_rocksoft from the crypto API, since they are no longer needed there - Rename crc64_rocksoft to crc64_nvme, as the old name was incorrect - Add kunit test cases for crc64_nvme and crc7 - Eliminate redundant functions for calculating the Castagnoli CRC32, settling on just crc32c() - Remove unnecessary prompts from some of the CRC kconfig options - Further optimize the x86 crc32c code" * tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (36 commits) x86/crc: drop the avx10_256 functions and rename avx10_512 to avx512 lib/crc: remove unnecessary prompt for CONFIG_CRC64 lib/crc: remove unnecessary prompt for CONFIG_LIBCRC32C lib/crc: remove unnecessary prompt for CONFIG_CRC8 lib/crc: remove unnecessary prompt for CONFIG_CRC7 lib/crc: remove unnecessary prompt for CONFIG_CRC4 lib/crc7: unexport crc7_be_syndrome_table lib/crc_kunit.c: update comment in crc_benchmark() lib/crc_kunit.c: add test and benchmark for crc7_be() x86/crc32: optimize tail handling for crc32c short inputs riscv/crc64: add Zbc optimized CRC64 functions riscv/crc-t10dif: add Zbc optimized CRC-T10DIF function riscv/crc32: reimplement the CRC32 functions using new template riscv/crc: add "template" for Zbc optimized CRC functions x86/crc: add ANNOTATE_NOENDBR to suppress objtool warnings x86/crc32: improve crc32c_arch() code generation with clang x86/crc64: implement crc64_be and crc64_nvme using new template x86/crc-t10dif: implement crc_t10dif using new template x86/crc32: implement crc32_le using new template x86/crc: add "template" for [V]PCLMULQDQ based CRC functions ...
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/Makefile5
-rw-r--r--arch/x86/lib/crc-pclmul-consts.h195
-rw-r--r--arch/x86/lib/crc-pclmul-template.S582
-rw-r--r--arch/x86/lib/crc-pclmul-template.h76
-rw-r--r--arch/x86/lib/crc-t10dif-glue.c29
-rw-r--r--arch/x86/lib/crc16-msb-pclmul.S6
-rw-r--r--arch/x86/lib/crc32-glue.c57
-rw-r--r--arch/x86/lib/crc32-pclmul.S219
-rw-r--r--arch/x86/lib/crc64-glue.c50
-rw-r--r--arch/x86/lib/crc64-pclmul.S7
-rw-r--r--arch/x86/lib/crct10dif-pcl-asm_64.S332
11 files changed, 955 insertions, 603 deletions
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 64ccecedc9f8..1c50352eb49f 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -42,8 +42,11 @@ obj-$(CONFIG_CRC32_ARCH) += crc32-x86.o
crc32-x86-y := crc32-glue.o crc32-pclmul.o
crc32-x86-$(CONFIG_64BIT) += crc32c-3way.o
+obj-$(CONFIG_CRC64_ARCH) += crc64-x86.o
+crc64-x86-y := crc64-glue.o crc64-pclmul.o
+
obj-$(CONFIG_CRC_T10DIF_ARCH) += crc-t10dif-x86.o
-crc-t10dif-x86-y := crc-t10dif-glue.o crct10dif-pcl-asm_64.o
+crc-t10dif-x86-y := crc-t10dif-glue.o crc16-msb-pclmul.o
obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o
obj-y += iomem.o
diff --git a/arch/x86/lib/crc-pclmul-consts.h b/arch/x86/lib/crc-pclmul-consts.h
new file mode 100644
index 000000000000..fcc63c064333
--- /dev/null
+++ b/arch/x86/lib/crc-pclmul-consts.h
@@ -0,0 +1,195 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * CRC constants generated by:
+ *
+ * ./scripts/gen-crc-consts.py x86_pclmul crc16_msb_0x8bb7,crc32_lsb_0xedb88320,crc64_msb_0x42f0e1eba9ea3693,crc64_lsb_0x9a6c9329ac4bc9b5
+ *
+ * Do not edit manually.
+ */
+
+/*
+ * CRC folding constants generated for most-significant-bit-first CRC-16 using
+ * G(x) = x^16 + x^15 + x^11 + x^9 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + x^0
+ */
+static const struct {
+ u8 bswap_mask[16];
+ u64 fold_across_2048_bits_consts[2];
+ u64 fold_across_1024_bits_consts[2];
+ u64 fold_across_512_bits_consts[2];
+ u64 fold_across_256_bits_consts[2];
+ u64 fold_across_128_bits_consts[2];
+ u8 shuf_table[48];
+ u64 barrett_reduction_consts[2];
+} crc16_msb_0x8bb7_consts ____cacheline_aligned __maybe_unused = {
+ .bswap_mask = {15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0},
+ .fold_across_2048_bits_consts = {
+ 0xdccf000000000000, /* LO64_TERMS: (x^2000 mod G) * x^48 */
+ 0x4b0b000000000000, /* HI64_TERMS: (x^2064 mod G) * x^48 */
+ },
+ .fold_across_1024_bits_consts = {
+ 0x9d9d000000000000, /* LO64_TERMS: (x^976 mod G) * x^48 */
+ 0x7cf5000000000000, /* HI64_TERMS: (x^1040 mod G) * x^48 */
+ },
+ .fold_across_512_bits_consts = {
+ 0x044c000000000000, /* LO64_TERMS: (x^464 mod G) * x^48 */
+ 0xe658000000000000, /* HI64_TERMS: (x^528 mod G) * x^48 */
+ },
+ .fold_across_256_bits_consts = {
+ 0x6ee3000000000000, /* LO64_TERMS: (x^208 mod G) * x^48 */
+ 0xe7b5000000000000, /* HI64_TERMS: (x^272 mod G) * x^48 */
+ },
+ .fold_across_128_bits_consts = {
+ 0x2d56000000000000, /* LO64_TERMS: (x^80 mod G) * x^48 */
+ 0x06df000000000000, /* HI64_TERMS: (x^144 mod G) * x^48 */
+ },
+ .shuf_table = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ },
+ .barrett_reduction_consts = {
+ 0x8bb7000000000000, /* LO64_TERMS: (G - x^16) * x^48 */
+ 0xf65a57f81d33a48a, /* HI64_TERMS: (floor(x^79 / G) * x) - x^64 */
+ },
+};
+
+/*
+ * CRC folding constants generated for least-significant-bit-first CRC-32 using
+ * G(x) = x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 +
+ * x^5 + x^4 + x^2 + x^1 + x^0
+ */
+static const struct {
+ u64 fold_across_2048_bits_consts[2];
+ u64 fold_across_1024_bits_consts[2];
+ u64 fold_across_512_bits_consts[2];
+ u64 fold_across_256_bits_consts[2];
+ u64 fold_across_128_bits_consts[2];
+ u8 shuf_table[48];
+ u64 barrett_reduction_consts[2];
+} crc32_lsb_0xedb88320_consts ____cacheline_aligned __maybe_unused = {
+ .fold_across_2048_bits_consts = {
+ 0x00000000ce3371cb, /* HI64_TERMS: (x^2079 mod G) * x^32 */
+ 0x00000000e95c1271, /* LO64_TERMS: (x^2015 mod G) * x^32 */
+ },
+ .fold_across_1024_bits_consts = {
+ 0x0000000033fff533, /* HI64_TERMS: (x^1055 mod G) * x^32 */
+ 0x00000000910eeec1, /* LO64_TERMS: (x^991 mod G) * x^32 */
+ },
+ .fold_across_512_bits_consts = {
+ 0x000000008f352d95, /* HI64_TERMS: (x^543 mod G) * x^32 */
+ 0x000000001d9513d7, /* LO64_TERMS: (x^479 mod G) * x^32 */
+ },
+ .fold_across_256_bits_consts = {
+ 0x00000000f1da05aa, /* HI64_TERMS: (x^287 mod G) * x^32 */
+ 0x0000000081256527, /* LO64_TERMS: (x^223 mod G) * x^32 */
+ },
+ .fold_across_128_bits_consts = {
+ 0x00000000ae689191, /* HI64_TERMS: (x^159 mod G) * x^32 */
+ 0x00000000ccaa009e, /* LO64_TERMS: (x^95 mod G) * x^32 */
+ },
+ .shuf_table = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ },
+ .barrett_reduction_consts = {
+ 0xb4e5b025f7011641, /* HI64_TERMS: floor(x^95 / G) */
+ 0x00000001db710640, /* LO64_TERMS: (G - x^32) * x^31 */
+ },
+};
+
+/*
+ * CRC folding constants generated for most-significant-bit-first CRC-64 using
+ * G(x) = x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
+ * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
+ * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
+ * x^7 + x^4 + x^1 + x^0
+ */
+static const struct {
+ u8 bswap_mask[16];
+ u64 fold_across_2048_bits_consts[2];
+ u64 fold_across_1024_bits_consts[2];
+ u64 fold_across_512_bits_consts[2];
+ u64 fold_across_256_bits_consts[2];
+ u64 fold_across_128_bits_consts[2];
+ u8 shuf_table[48];
+ u64 barrett_reduction_consts[2];
+} crc64_msb_0x42f0e1eba9ea3693_consts ____cacheline_aligned __maybe_unused = {
+ .bswap_mask = {15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0},
+ .fold_across_2048_bits_consts = {
+ 0x7f52691a60ddc70d, /* LO64_TERMS: (x^2048 mod G) * x^0 */
+ 0x7036b0389f6a0c82, /* HI64_TERMS: (x^2112 mod G) * x^0 */
+ },
+ .fold_across_1024_bits_consts = {
+ 0x05cf79dea9ac37d6, /* LO64_TERMS: (x^1024 mod G) * x^0 */
+ 0x001067e571d7d5c2, /* HI64_TERMS: (x^1088 mod G) * x^0 */
+ },
+ .fold_across_512_bits_consts = {
+ 0x5f6843ca540df020, /* LO64_TERMS: (x^512 mod G) * x^0 */
+ 0xddf4b6981205b83f, /* HI64_TERMS: (x^576 mod G) * x^0 */
+ },
+ .fold_across_256_bits_consts = {
+ 0x571bee0a227ef92b, /* LO64_TERMS: (x^256 mod G) * x^0 */
+ 0x44bef2a201b5200c, /* HI64_TERMS: (x^320 mod G) * x^0 */
+ },
+ .fold_across_128_bits_consts = {
+ 0x05f5c3c7eb52fab6, /* LO64_TERMS: (x^128 mod G) * x^0 */
+ 0x4eb938a7d257740e, /* HI64_TERMS: (x^192 mod G) * x^0 */
+ },
+ .shuf_table = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ },
+ .barrett_reduction_consts = {
+ 0x42f0e1eba9ea3693, /* LO64_TERMS: (G - x^64) * x^0 */
+ 0x578d29d06cc4f872, /* HI64_TERMS: (floor(x^127 / G) * x) - x^64 */
+ },
+};
+
+/*
+ * CRC folding constants generated for least-significant-bit-first CRC-64 using
+ * G(x) = x^64 + x^63 + x^61 + x^59 + x^58 + x^56 + x^55 + x^52 + x^49 + x^48 +
+ * x^47 + x^46 + x^44 + x^41 + x^37 + x^36 + x^34 + x^32 + x^31 + x^28 +
+ * x^26 + x^23 + x^22 + x^19 + x^16 + x^13 + x^12 + x^10 + x^9 + x^6 +
+ * x^4 + x^3 + x^0
+ */
+static const struct {
+ u64 fold_across_2048_bits_consts[2];
+ u64 fold_across_1024_bits_consts[2];
+ u64 fold_across_512_bits_consts[2];
+ u64 fold_across_256_bits_consts[2];
+ u64 fold_across_128_bits_consts[2];
+ u8 shuf_table[48];
+ u64 barrett_reduction_consts[2];
+} crc64_lsb_0x9a6c9329ac4bc9b5_consts ____cacheline_aligned __maybe_unused = {
+ .fold_across_2048_bits_consts = {
+ 0x37ccd3e14069cabc, /* HI64_TERMS: (x^2111 mod G) * x^0 */
+ 0xa043808c0f782663, /* LO64_TERMS: (x^2047 mod G) * x^0 */
+ },
+ .fold_across_1024_bits_consts = {
+ 0xa1ca681e733f9c40, /* HI64_TERMS: (x^1087 mod G) * x^0 */
+ 0x5f852fb61e8d92dc, /* LO64_TERMS: (x^1023 mod G) * x^0 */
+ },
+ .fold_across_512_bits_consts = {
+ 0x0c32cdb31e18a84a, /* HI64_TERMS: (x^575 mod G) * x^0 */
+ 0x62242240ace5045a, /* LO64_TERMS: (x^511 mod G) * x^0 */
+ },
+ .fold_across_256_bits_consts = {
+ 0xb0bc2e589204f500, /* HI64_TERMS: (x^319 mod G) * x^0 */
+ 0xe1e0bb9d45d7a44c, /* LO64_TERMS: (x^255 mod G) * x^0 */
+ },
+ .fold_across_128_bits_consts = {
+ 0xeadc41fd2ba3d420, /* HI64_TERMS: (x^191 mod G) * x^0 */
+ 0x21e9761e252621ac, /* LO64_TERMS: (x^127 mod G) * x^0 */
+ },
+ .shuf_table = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ },
+ .barrett_reduction_consts = {
+ 0x27ecfa329aef9f77, /* HI64_TERMS: floor(x^127 / G) */
+ 0x34d926535897936a, /* LO64_TERMS: (G - x^64 - x^0) / x */
+ },
+};
diff --git a/arch/x86/lib/crc-pclmul-template.S b/arch/x86/lib/crc-pclmul-template.S
new file mode 100644
index 000000000000..ae0b6144c503
--- /dev/null
+++ b/arch/x86/lib/crc-pclmul-template.S
@@ -0,0 +1,582 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+//
+// Template to generate [V]PCLMULQDQ-based CRC functions for x86
+//
+// Copyright 2025 Google LLC
+//
+// Author: Eric Biggers <ebiggers@google.com>
+
+#include <linux/linkage.h>
+#include <linux/objtool.h>
+
+// Offsets within the generated constants table
+.set OFFSETOF_BSWAP_MASK, -5*16 // msb-first CRCs only
+.set OFFSETOF_FOLD_ACROSS_2048_BITS_CONSTS, -4*16 // must precede next
+.set OFFSETOF_FOLD_ACROSS_1024_BITS_CONSTS, -3*16 // must precede next
+.set OFFSETOF_FOLD_ACROSS_512_BITS_CONSTS, -2*16 // must precede next
+.set OFFSETOF_FOLD_ACROSS_256_BITS_CONSTS, -1*16 // must precede next
+.set OFFSETOF_FOLD_ACROSS_128_BITS_CONSTS, 0*16 // must be 0
+.set OFFSETOF_SHUF_TABLE, 1*16
+.set OFFSETOF_BARRETT_REDUCTION_CONSTS, 4*16
+
+// Emit a VEX (or EVEX) coded instruction if allowed, or emulate it using the
+// corresponding non-VEX instruction plus any needed moves. The supported
+// instruction formats are:
+//
+// - Two-arg [src, dst], where the non-VEX format is the same.
+// - Three-arg [src1, src2, dst] where the non-VEX format is
+// [src1, src2_and_dst]. If src2 != dst, then src1 must != dst too.
+//
+// \insn gives the instruction without a "v" prefix and including any immediate
+// argument if needed to make the instruction follow one of the above formats.
+// If \unaligned_mem_tmp is given, then the emitted non-VEX code moves \arg1 to
+// it first; this is needed when \arg1 is an unaligned mem operand.
+.macro _cond_vex insn:req, arg1:req, arg2:req, arg3, unaligned_mem_tmp
+.if AVX_LEVEL == 0
+ // VEX not allowed. Emulate it.
+ .ifnb \arg3 // Three-arg [src1, src2, dst]
+ .ifc "\arg2", "\arg3" // src2 == dst?
+ .ifnb \unaligned_mem_tmp
+ movdqu \arg1, \unaligned_mem_tmp
+ \insn \unaligned_mem_tmp, \arg3
+ .else
+ \insn \arg1, \arg3
+ .endif
+ .else // src2 != dst
+ .ifc "\arg1", "\arg3"
+ .error "Can't have src1 == dst when src2 != dst"
+ .endif
+ .ifnb \unaligned_mem_tmp
+ movdqu \arg1, \unaligned_mem_tmp
+ movdqa \arg2, \arg3
+ \insn \unaligned_mem_tmp, \arg3
+ .else
+ movdqa \arg2, \arg3
+ \insn \arg1, \arg3
+ .endif
+ .endif
+ .else // Two-arg [src, dst]
+ .ifnb \unaligned_mem_tmp
+ movdqu \arg1, \unaligned_mem_tmp
+ \insn \unaligned_mem_tmp, \arg2
+ .else
+ \insn \arg1, \arg2
+ .endif
+ .endif
+.else
+ // VEX is allowed. Emit the desired instruction directly.
+ .ifnb \arg3
+ v\insn \arg1, \arg2, \arg3
+ .else
+ v\insn \arg1, \arg2
+ .endif
+.endif
+.endm
+
+// Broadcast an aligned 128-bit mem operand to all 128-bit lanes of a vector
+// register of length VL.
+.macro _vbroadcast src, dst
+.if VL == 16
+ _cond_vex movdqa, \src, \dst
+.elseif VL == 32
+ vbroadcasti128 \src, \dst
+.else
+ vbroadcasti32x4 \src, \dst
+.endif
+.endm
+
+// Load \vl bytes from the unaligned mem operand \src into \dst, and if the CRC
+// is msb-first use \bswap_mask to reflect the bytes within each 128-bit lane.
+.macro _load_data vl, src, bswap_mask, dst
+.if \vl < 64
+ _cond_vex movdqu, "\src", \dst
+.else
+ vmovdqu8 \src, \dst
+.endif
+.if !LSB_CRC
+ _cond_vex pshufb, \bswap_mask, \dst, \dst
+.endif
+.endm
+
+.macro _prepare_v0 vl, v0, v1, bswap_mask
+.if LSB_CRC
+ .if \vl < 64
+ _cond_vex pxor, (BUF), \v0, \v0, unaligned_mem_tmp=\v1
+ .else
+ vpxorq (BUF), \v0, \v0
+ .endif
+.else
+ _load_data \vl, (BUF), \bswap_mask, \v1
+ .if \vl < 64
+ _cond_vex pxor, \v1, \v0, \v0
+ .else
+ vpxorq \v1, \v0, \v0
+ .endif
+.endif
+.endm
+
+// The x^0..x^63 terms, i.e. poly128 mod x^64, i.e. the physically low qword for
+// msb-first order or the physically high qword for lsb-first order
+#define LO64_TERMS 0
+
+// The x^64..x^127 terms, i.e. floor(poly128 / x^64), i.e. the physically high
+// qword for msb-first order or the physically low qword for lsb-first order
+#define HI64_TERMS 1
+
+// Multiply the given \src1_terms of each 128-bit lane of \src1 by the given
+// \src2_terms of each 128-bit lane of \src2, and write the result(s) to \dst.
+.macro _pclmulqdq src1, src1_terms, src2, src2_terms, dst
+ _cond_vex "pclmulqdq $((\src1_terms ^ LSB_CRC) << 4) ^ (\src2_terms ^ LSB_CRC),", \
+ \src1, \src2, \dst
+.endm
+
+// Fold \acc into \data and store the result back into \acc. \data can be an
+// unaligned mem operand if using VEX is allowed and the CRC is lsb-first so no
+// byte-reflection is needed; otherwise it must be a vector register. \consts
+// is a vector register containing the needed fold constants, and \tmp is a
+// temporary vector register. All arguments must be the same length.
+.macro _fold_vec acc, data, consts, tmp
+ _pclmulqdq \consts, HI64_TERMS, \acc, HI64_TERMS, \tmp
+ _pclmulqdq \consts, LO64_TERMS, \acc, LO64_TERMS, \acc
+.if AVX_LEVEL <= 2
+ _cond_vex pxor, \data, \tmp, \tmp
+ _cond_vex pxor, \tmp, \acc, \acc
+.else
+ vpternlogq $0x96, \data, \tmp, \acc
+.endif
+.endm
+
+// Fold \acc into \data and store the result back into \acc. \data is an
+// unaligned mem operand, \consts is a vector register containing the needed
+// fold constants, \bswap_mask is a vector register containing the
+// byte-reflection table if the CRC is msb-first, and \tmp1 and \tmp2 are
+// temporary vector registers. All arguments must have length \vl.
+.macro _fold_vec_mem vl, acc, data, consts, bswap_mask, tmp1, tmp2
+.if AVX_LEVEL == 0 || !LSB_CRC
+ _load_data \vl, \data, \bswap_mask, \tmp1
+ _fold_vec \acc, \tmp1, \consts, \tmp2
+.else
+ _fold_vec \acc, \data, \consts, \tmp1
+.endif
+.endm
+
+// Load the constants for folding across 2**i vectors of length VL at a time
+// into all 128-bit lanes of the vector register CONSTS.
+.macro _load_vec_folding_consts i
+ _vbroadcast OFFSETOF_FOLD_ACROSS_128_BITS_CONSTS+(4-LOG2_VL-\i)*16(CONSTS_PTR), \
+ CONSTS
+.endm
+
+// Given vector registers \v0 and \v1 of length \vl, fold \v0 into \v1 and store
+// the result back into \v0. If the remaining length mod \vl is nonzero, also
+// fold \vl data bytes from BUF. For both operations the fold distance is \vl.
+// \consts must be a register of length \vl containing the fold constants.
+.macro _fold_vec_final vl, v0, v1, consts, bswap_mask, tmp1, tmp2
+ _fold_vec \v0, \v1, \consts, \tmp1
+ test $\vl, LEN8
+ jz .Lfold_vec_final_done\@
+ _fold_vec_mem \vl, \v0, (BUF), \consts, \bswap_mask, \tmp1, \tmp2
+ add $\vl, BUF
+.Lfold_vec_final_done\@:
+.endm
+
+// This macro generates the body of a CRC function with the following prototype:
+//
+// crc_t crc_func(crc_t crc, const u8 *buf, size_t len, const void *consts);
+//
+// |crc| is the initial CRC, and crc_t is a data type wide enough to hold it.
+// |buf| is the data to checksum. |len| is the data length in bytes, which must
+// be at least 16. |consts| is a pointer to the fold_across_128_bits_consts
+// field of the constants struct that was generated for the chosen CRC variant.
+//
+// Moving onto the macro parameters, \n is the number of bits in the CRC, e.g.
+// 32 for a CRC-32. Currently the supported values are 8, 16, 32, and 64. If
+// the file is compiled in i386 mode, then the maximum supported value is 32.
+//
+// \lsb_crc is 1 if the CRC processes the least significant bit of each byte
+// first, i.e. maps bit0 to x^7, bit1 to x^6, ..., bit7 to x^0. \lsb_crc is 0
+// if the CRC processes the most significant bit of each byte first, i.e. maps
+// bit0 to x^0, bit1 to x^1, bit7 to x^7.
+//
+// \vl is the maximum length of vector register to use in bytes: 16, 32, or 64.
+//
+// \avx_level is the level of AVX support to use: 0 for SSE only, 2 for AVX2, or
+// 512 for AVX512.
+//
+// If \vl == 16 && \avx_level == 0, the generated code requires:
+// PCLMULQDQ && SSE4.1. (Note: all known CPUs with PCLMULQDQ also have SSE4.1.)
+//
+// If \vl == 32 && \avx_level == 2, the generated code requires:
+// VPCLMULQDQ && AVX2.
+//
+// If \vl == 64 && \avx_level == 512, the generated code requires:
+// VPCLMULQDQ && AVX512BW && AVX512VL.
+//
+// Other \vl and \avx_level combinations are either not supported or not useful.
+.macro _crc_pclmul n, lsb_crc, vl, avx_level
+ .set LSB_CRC, \lsb_crc
+ .set VL, \vl
+ .set AVX_LEVEL, \avx_level
+
+ // Define aliases for the xmm, ymm, or zmm registers according to VL.
+.irp i, 0,1,2,3,4,5,6,7
+ .if VL == 16
+ .set V\i, %xmm\i
+ .set LOG2_VL, 4
+ .elseif VL == 32
+ .set V\i, %ymm\i
+ .set LOG2_VL, 5
+ .elseif VL == 64
+ .set V\i, %zmm\i
+ .set LOG2_VL, 6
+ .else
+ .error "Unsupported vector length"
+ .endif
+.endr
+ // Define aliases for the function parameters.
+ // Note: when crc_t is shorter than u32, zero-extension to 32 bits is
+ // guaranteed by the ABI. Zero-extension to 64 bits is *not* guaranteed
+ // when crc_t is shorter than u64.
+#ifdef __x86_64__
+.if \n <= 32
+ .set CRC, %edi
+.else
+ .set CRC, %rdi
+.endif
+ .set BUF, %rsi
+ .set LEN, %rdx
+ .set LEN32, %edx
+ .set LEN8, %dl
+ .set CONSTS_PTR, %rcx
+#else
+ // 32-bit support, assuming -mregparm=3 and not including support for
+ // CRC-64 (which would use both eax and edx to pass the crc parameter).
+ .set CRC, %eax
+ .set BUF, %edx
+ .set LEN, %ecx
+ .set LEN32, %ecx
+ .set LEN8, %cl
+ .set CONSTS_PTR, %ebx // Passed on stack
+#endif
+
+ // Define aliases for some local variables. V0-V5 are used without
+ // aliases (for accumulators, data, temporary values, etc). Staying
+ // within the first 8 vector registers keeps the code 32-bit SSE
+ // compatible and reduces the size of 64-bit SSE code slightly.
+ .set BSWAP_MASK, V6
+ .set BSWAP_MASK_YMM, %ymm6
+ .set BSWAP_MASK_XMM, %xmm6
+ .set CONSTS, V7
+ .set CONSTS_YMM, %ymm7
+ .set CONSTS_XMM, %xmm7
+
+ // Use ANNOTATE_NOENDBR to suppress an objtool warning, since the
+ // functions generated by this macro are called only by static_call.
+ ANNOTATE_NOENDBR
+
+#ifdef __i386__
+ push CONSTS_PTR
+ mov 8(%esp), CONSTS_PTR
+#endif
+
+ // Create a 128-bit vector that contains the initial CRC in the end
+ // representing the high-order polynomial coefficients, and the rest 0.
+ // If the CRC is msb-first, also load the byte-reflection table.
+.if \n <= 32
+ _cond_vex movd, CRC, %xmm0
+.else
+ _cond_vex movq, CRC, %xmm0
+.endif
+.if !LSB_CRC
+ _cond_vex pslldq, $(128-\n)/8, %xmm0, %xmm0
+ _vbroadcast OFFSETOF_BSWAP_MASK(CONSTS_PTR), BSWAP_MASK
+.endif
+
+ // Load the first vector of data and XOR the initial CRC into the
+ // appropriate end of the first 128-bit lane of data. If LEN < VL, then
+ // use a short vector and jump ahead to the final reduction. (LEN >= 16
+ // is guaranteed here but not necessarily LEN >= VL.)
+.if VL >= 32
+ cmp $VL, LEN
+ jae .Lat_least_1vec\@
+ .if VL == 64
+ cmp $32, LEN32
+ jb .Lless_than_32bytes\@
+ _prepare_v0 32, %ymm0, %ymm1, BSWAP_MASK_YMM
+ add $32, BUF
+ jmp .Lreduce_256bits_to_128bits\@
+.Lless_than_32bytes\@:
+ .endif
+ _prepare_v0 16, %xmm0, %xmm1, BSWAP_MASK_XMM
+ add $16, BUF
+ vmovdqa OFFSETOF_FOLD_ACROSS_128_BITS_CONSTS(CONSTS_PTR), CONSTS_XMM
+ jmp .Lcheck_for_partial_block\@
+.Lat_least_1vec\@:
+.endif
+ _prepare_v0 VL, V0, V1, BSWAP_MASK
+
+ // Handle VL <= LEN < 4*VL.
+ cmp $4*VL-1, LEN
+ ja .Lat_least_4vecs\@
+ add $VL, BUF
+ // If VL <= LEN < 2*VL, then jump ahead to the reduction from 1 vector.
+ // If VL==16 then load fold_across_128_bits_consts first, as the final
+ // reduction depends on it and it won't be loaded anywhere else.
+ cmp $2*VL-1, LEN32
+.if VL == 16
+ _cond_vex movdqa, OFFSETOF_FOLD_ACROSS_128_BITS_CONSTS(CONSTS_PTR), CONSTS_XMM
+.endif
+ jbe .Lreduce_1vec_to_128bits\@
+ // Otherwise 2*VL <= LEN < 4*VL. Load one more vector and jump ahead to
+ // the reduction from 2 vectors.
+ _load_data VL, (BUF), BSWAP_MASK, V1
+ add $VL, BUF
+ jmp .Lreduce_2vecs_to_1\@
+
+.Lat_least_4vecs\@:
+ // Load 3 more vectors of data.
+ _load_data VL, 1*VL(BUF), BSWAP_MASK, V1
+ _load_data VL, 2*VL(BUF), BSWAP_MASK, V2
+ _load_data VL, 3*VL(BUF), BSWAP_MASK, V3
+ sub $-4*VL, BUF // Shorter than 'add 4*VL' when VL=32
+ add $-4*VL, LEN // Shorter than 'sub 4*VL' when VL=32
+
+ // Main loop: while LEN >= 4*VL, fold the 4 vectors V0-V3 into the next
+ // 4 vectors of data and write the result back to V0-V3.
+ cmp $4*VL-1, LEN // Shorter than 'cmp 4*VL' when VL=32
+ jbe .Lreduce_4vecs_to_2\@
+ _load_vec_folding_consts 2
+.Lfold_4vecs_loop\@:
+ _fold_vec_mem VL, V0, 0*VL(BUF), CONSTS, BSWAP_MASK, V4, V5
+ _fold_vec_mem VL, V1, 1*VL(BUF), CONSTS, BSWAP_MASK, V4, V5
+ _fold_vec_mem VL, V2, 2*VL(BUF), CONSTS, BSWAP_MASK, V4, V5
+ _fold_vec_mem VL, V3, 3*VL(BUF), CONSTS, BSWAP_MASK, V4, V5
+ sub $-4*VL, BUF
+ add $-4*VL, LEN
+ cmp $4*VL-1, LEN
+ ja .Lfold_4vecs_loop\@
+
+ // Fold V0,V1 into V2,V3 and write the result back to V0,V1. Then fold
+ // two more vectors of data from BUF, if at least that much remains.
+.Lreduce_4vecs_to_2\@:
+ _load_vec_folding_consts 1
+ _fold_vec V0, V2, CONSTS, V4
+ _fold_vec V1, V3, CONSTS, V4
+ test $2*VL, LEN8
+ jz .Lreduce_2vecs_to_1\@
+ _fold_vec_mem VL, V0, 0*VL(BUF), CONSTS, BSWAP_MASK, V4, V5
+ _fold_vec_mem VL, V1, 1*VL(BUF), CONSTS, BSWAP_MASK, V4, V5
+ sub $-2*VL, BUF
+
+ // Fold V0 into V1 and write the result back to V0. Then fold one more
+ // vector of data from BUF, if at least that much remains.
+.Lreduce_2vecs_to_1\@:
+ _load_vec_folding_consts 0
+ _fold_vec_final VL, V0, V1, CONSTS, BSWAP_MASK, V4, V5
+
+.Lreduce_1vec_to_128bits\@:
+.if VL == 64
+ // Reduce 512-bit %zmm0 to 256-bit %ymm0. Then fold 256 more bits of
+ // data from BUF, if at least that much remains.
+ vbroadcasti128 OFFSETOF_FOLD_ACROSS_256_BITS_CONSTS(CONSTS_PTR), CONSTS_YMM
+ vextracti64x4 $1, %zmm0, %ymm1
+ _fold_vec_final 32, %ymm0, %ymm1, CONSTS_YMM, BSWAP_MASK_YMM, %ymm4, %ymm5
+.Lreduce_256bits_to_128bits\@:
+.endif
+.if VL >= 32
+ // Reduce 256-bit %ymm0 to 128-bit %xmm0. Then fold 128 more bits of
+ // data from BUF, if at least that much remains.
+ vmovdqa OFFSETOF_FOLD_ACROSS_128_BITS_CONSTS(CONSTS_PTR), CONSTS_XMM
+ vextracti128 $1, %ymm0, %xmm1
+ _fold_vec_final 16, %xmm0, %xmm1, CONSTS_XMM, BSWAP_MASK_XMM, %xmm4, %xmm5
+.Lcheck_for_partial_block\@:
+.endif
+ and $15, LEN32
+ jz .Lreduce_128bits_to_crc\@
+
+ // 1 <= LEN <= 15 data bytes remain in BUF. The polynomial is now
+ // A*(x^(8*LEN)) + B, where A is the 128-bit polynomial stored in %xmm0
+ // and B is the polynomial of the remaining LEN data bytes. To reduce
+ // this to 128 bits without needing fold constants for each possible
+ // LEN, rearrange this expression into C1*(x^128) + C2, where
+ // C1 = floor(A / x^(128 - 8*LEN)) and C2 = A*x^(8*LEN) + B mod x^128.
+ // Then fold C1 into C2, which is just another fold across 128 bits.
+
+.if !LSB_CRC || AVX_LEVEL == 0
+ // Load the last 16 data bytes. Note that originally LEN was >= 16.
+ _load_data 16, "-16(BUF,LEN)", BSWAP_MASK_XMM, %xmm2
+.endif // Else will use vpblendvb mem operand later.
+.if !LSB_CRC
+ neg LEN // Needed for indexing shuf_table
+.endif
+
+ // tmp = A*x^(8*LEN) mod x^128
+ // lsb: pshufb by [LEN, LEN+1, ..., 15, -1, -1, ..., -1]
+ // i.e. right-shift by LEN bytes.
+ // msb: pshufb by [-1, -1, ..., -1, 0, 1, ..., 15-LEN]
+ // i.e. left-shift by LEN bytes.
+ _cond_vex movdqu, "OFFSETOF_SHUF_TABLE+16(CONSTS_PTR,LEN)", %xmm3
+ _cond_vex pshufb, %xmm3, %xmm0, %xmm1
+
+ // C1 = floor(A / x^(128 - 8*LEN))
+ // lsb: pshufb by [-1, -1, ..., -1, 0, 1, ..., LEN-1]
+ // i.e. left-shift by 16-LEN bytes.
+ // msb: pshufb by [16-LEN, 16-LEN+1, ..., 15, -1, -1, ..., -1]
+ // i.e. right-shift by 16-LEN bytes.
+ _cond_vex pshufb, "OFFSETOF_SHUF_TABLE+32*!LSB_CRC(CONSTS_PTR,LEN)", \
+ %xmm0, %xmm0, unaligned_mem_tmp=%xmm4
+
+ // C2 = tmp + B. This is just a blend of tmp with the last 16 data
+ // bytes (reflected if msb-first). The blend mask is the shuffle table
+ // that was used to create tmp. 0 selects tmp, and 1 last16databytes.
+.if AVX_LEVEL == 0
+ movdqa %xmm0, %xmm4
+ movdqa %xmm3, %xmm0
+ pblendvb %xmm2, %xmm1 // uses %xmm0 as implicit operand
+ movdqa %xmm4, %xmm0
+.elseif LSB_CRC
+ vpblendvb %xmm3, -16(BUF,LEN), %xmm1, %xmm1
+.else
+ vpblendvb %xmm3, %xmm2, %xmm1, %xmm1
+.endif
+
+ // Fold C1 into C2 and store the 128-bit result in %xmm0.
+ _fold_vec %xmm0, %xmm1, CONSTS_XMM, %xmm4
+
+.Lreduce_128bits_to_crc\@:
+ // Compute the CRC as %xmm0 * x^n mod G. Here %xmm0 means the 128-bit
+ // polynomial stored in %xmm0 (using either lsb-first or msb-first bit
+ // order according to LSB_CRC), and G is the CRC's generator polynomial.
+
+ // First, multiply %xmm0 by x^n and reduce the result to 64+n bits:
+ //
+ // t0 := (x^(64+n) mod G) * floor(%xmm0 / x^64) +
+ // x^n * (%xmm0 mod x^64)
+ //
+ // Store t0 * x^(64-n) in %xmm0. I.e., actually do:
+ //
+ // %xmm0 := ((x^(64+n) mod G) * x^(64-n)) * floor(%xmm0 / x^64) +
+ // x^64 * (%xmm0 mod x^64)
+ //
+ // The extra unreduced factor of x^(64-n) makes floor(t0 / x^n) aligned
+ // to the HI64_TERMS of %xmm0 so that the next pclmulqdq can easily
+ // select it. The 64-bit constant (x^(64+n) mod G) * x^(64-n) in the
+ // msb-first case, or (x^(63+n) mod G) * x^(64-n) in the lsb-first case
+ // (considering the extra factor of x that gets implicitly introduced by
+ // each pclmulqdq when using lsb-first order), is identical to the
+ // constant that was used earlier for folding the LO64_TERMS across 128
+ // bits. Thus it's already available in LO64_TERMS of CONSTS_XMM.
+ _pclmulqdq CONSTS_XMM, LO64_TERMS, %xmm0, HI64_TERMS, %xmm1
+.if LSB_CRC
+ _cond_vex psrldq, $8, %xmm0, %xmm0 // x^64 * (%xmm0 mod x^64)
+.else
+ _cond_vex pslldq, $8, %xmm0, %xmm0 // x^64 * (%xmm0 mod x^64)
+.endif
+ _cond_vex pxor, %xmm1, %xmm0, %xmm0
+ // The HI64_TERMS of %xmm0 now contain floor(t0 / x^n).
+ // The LO64_TERMS of %xmm0 now contain (t0 mod x^n) * x^(64-n).
+
+ // First step of Barrett reduction: Compute floor(t0 / G). This is the
+ // polynomial by which G needs to be multiplied to cancel out the x^n
+ // and higher terms of t0, i.e. to reduce t0 mod G. First do:
+ //
+ // t1 := floor(x^(63+n) / G) * x * floor(t0 / x^n)
+ //
+ // Then the desired value floor(t0 / G) is floor(t1 / x^64). The 63 in
+ // x^(63+n) is the maximum degree of floor(t0 / x^n) and thus the lowest
+ // value that makes enough precision be carried through the calculation.
+ //
+ // The '* x' makes it so the result is floor(t1 / x^64) rather than
+ // floor(t1 / x^63), making it qword-aligned in HI64_TERMS so that it
+ // can be extracted much more easily in the next step. In the lsb-first
+ // case the '* x' happens implicitly. In the msb-first case it must be
+ // done explicitly; floor(x^(63+n) / G) * x is a 65-bit constant, so the
+ // constant passed to pclmulqdq is (floor(x^(63+n) / G) * x) - x^64, and
+ // the multiplication by the x^64 term is handled using a pxor. The
+ // pxor causes the low 64 terms of t1 to be wrong, but they are unused.
+ _cond_vex movdqa, OFFSETOF_BARRETT_REDUCTION_CONSTS(CONSTS_PTR), CONSTS_XMM
+ _pclmulqdq CONSTS_XMM, HI64_TERMS, %xmm0, HI64_TERMS, %xmm1
+.if !LSB_CRC
+ _cond_vex pxor, %xmm0, %xmm1, %xmm1 // += x^64 * floor(t0 / x^n)
+.endif
+ // The HI64_TERMS of %xmm1 now contain floor(t1 / x^64) = floor(t0 / G).
+
+ // Second step of Barrett reduction: Cancel out the x^n and higher terms
+ // of t0 by subtracting the needed multiple of G. This gives the CRC:
+ //
+ // crc := t0 - (G * floor(t0 / G))
+ //
+ // But %xmm0 contains t0 * x^(64-n), so it's more convenient to do:
+ //
+ // crc := ((t0 * x^(64-n)) - ((G * x^(64-n)) * floor(t0 / G))) / x^(64-n)
+ //
+ // Furthermore, since the resulting CRC is n-bit, if mod x^n is
+ // explicitly applied to it then the x^n term of G makes no difference
+ // in the result and can be omitted. This helps keep the constant
+ // multiplier in 64 bits in most cases. This gives the following:
+ //
+ // %xmm0 := %xmm0 - (((G - x^n) * x^(64-n)) * floor(t0 / G))
+ // crc := (%xmm0 / x^(64-n)) mod x^n
+ //
+ // In the lsb-first case, each pclmulqdq implicitly introduces
+ // an extra factor of x, so in that case the constant that needs to be
+ // passed to pclmulqdq is actually '(G - x^n) * x^(63-n)' when n <= 63.
+ // For lsb-first CRCs where n=64, the extra factor of x cannot be as
+ // easily avoided. In that case, instead pass '(G - x^n - x^0) / x' to
+ // pclmulqdq and handle the x^0 term (i.e. 1) separately. (All CRC
+ // polynomials have nonzero x^n and x^0 terms.) It works out as: the
+ // CRC has be XORed with the physically low qword of %xmm1, representing
+ // floor(t0 / G). The most efficient way to do that is to move it to
+ // the physically high qword and use a ternlog to combine the two XORs.
+.if LSB_CRC && \n == 64
+ _cond_vex punpcklqdq, %xmm1, %xmm2, %xmm2
+ _pclmulqdq CONSTS_XMM, LO64_TERMS, %xmm1, HI64_TERMS, %xmm1
+ .if AVX_LEVEL <= 2
+ _cond_vex pxor, %xmm2, %xmm0, %xmm0
+ _cond_vex pxor, %xmm1, %xmm0, %xmm0
+ .else
+ vpternlogq $0x96, %xmm2, %xmm1, %xmm0
+ .endif
+ _cond_vex "pextrq $1,", %xmm0, %rax // (%xmm0 / x^0) mod x^64
+.else
+ _pclmulqdq CONSTS_XMM, LO64_TERMS, %xmm1, HI64_TERMS, %xmm1
+ _cond_vex pxor, %xmm1, %xmm0, %xmm0
+ .if \n == 8
+ _cond_vex "pextrb $7 + LSB_CRC,", %xmm0, %eax // (%xmm0 / x^56) mod x^8
+ .elseif \n == 16
+ _cond_vex "pextrw $3 + LSB_CRC,", %xmm0, %eax // (%xmm0 / x^48) mod x^16
+ .elseif \n == 32
+ _cond_vex "pextrd $1 + LSB_CRC,", %xmm0, %eax // (%xmm0 / x^32) mod x^32
+ .else // \n == 64 && !LSB_CRC
+ _cond_vex movq, %xmm0, %rax // (%xmm0 / x^0) mod x^64
+ .endif
+.endif
+
+.if VL > 16
+ vzeroupper // Needed when ymm or zmm registers may have been used.
+.endif
+#ifdef __i386__
+ pop CONSTS_PTR
+#endif
+ RET
+.endm
+
+#ifdef CONFIG_AS_VPCLMULQDQ
+#define DEFINE_CRC_PCLMUL_FUNCS(prefix, bits, lsb) \
+SYM_FUNC_START(prefix##_pclmul_sse); \
+ _crc_pclmul n=bits, lsb_crc=lsb, vl=16, avx_level=0; \
+SYM_FUNC_END(prefix##_pclmul_sse); \
+ \
+SYM_FUNC_START(prefix##_vpclmul_avx2); \
+ _crc_pclmul n=bits, lsb_crc=lsb, vl=32, avx_level=2; \
+SYM_FUNC_END(prefix##_vpclmul_avx2); \
+ \
+SYM_FUNC_START(prefix##_vpclmul_avx512); \
+ _crc_pclmul n=bits, lsb_crc=lsb, vl=64, avx_level=512; \
+SYM_FUNC_END(prefix##_vpclmul_avx512);
+#else
+#define DEFINE_CRC_PCLMUL_FUNCS(prefix, bits, lsb) \
+SYM_FUNC_START(prefix##_pclmul_sse); \
+ _crc_pclmul n=bits, lsb_crc=lsb, vl=16, avx_level=0; \
+SYM_FUNC_END(prefix##_pclmul_sse);
+#endif // !CONFIG_AS_VPCLMULQDQ
diff --git a/arch/x86/lib/crc-pclmul-template.h b/arch/x86/lib/crc-pclmul-template.h
new file mode 100644
index 000000000000..c5b3bfe11d8d
--- /dev/null
+++ b/arch/x86/lib/crc-pclmul-template.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Macros for accessing the [V]PCLMULQDQ-based CRC functions that are
+ * instantiated by crc-pclmul-template.S
+ *
+ * Copyright 2025 Google LLC
+ *
+ * Author: Eric Biggers <ebiggers@google.com>
+ */
+#ifndef _CRC_PCLMUL_TEMPLATE_H
+#define _CRC_PCLMUL_TEMPLATE_H
+
+#include <asm/cpufeatures.h>
+#include <asm/simd.h>
+#include <crypto/internal/simd.h>
+#include <linux/static_call.h>
+#include "crc-pclmul-consts.h"
+
+#define DECLARE_CRC_PCLMUL_FUNCS(prefix, crc_t) \
+crc_t prefix##_pclmul_sse(crc_t crc, const u8 *p, size_t len, \
+ const void *consts_ptr); \
+crc_t prefix##_vpclmul_avx2(crc_t crc, const u8 *p, size_t len, \
+ const void *consts_ptr); \
+crc_t prefix##_vpclmul_avx512(crc_t crc, const u8 *p, size_t len, \
+ const void *consts_ptr); \
+DEFINE_STATIC_CALL(prefix##_pclmul, prefix##_pclmul_sse)
+
+#define INIT_CRC_PCLMUL(prefix) \
+do { \
+ if (IS_ENABLED(CONFIG_AS_VPCLMULQDQ) && \
+ boot_cpu_has(X86_FEATURE_VPCLMULQDQ) && \
+ boot_cpu_has(X86_FEATURE_AVX2) && \
+ cpu_has_xfeatures(XFEATURE_MASK_YMM, NULL)) { \
+ if (boot_cpu_has(X86_FEATURE_AVX512BW) && \
+ boot_cpu_has(X86_FEATURE_AVX512VL) && \
+ !boot_cpu_has(X86_FEATURE_PREFER_YMM) && \
+ cpu_has_xfeatures(XFEATURE_MASK_AVX512, NULL)) { \
+ static_call_update(prefix##_pclmul, \
+ prefix##_vpclmul_avx512); \
+ } else { \
+ static_call_update(prefix##_pclmul, \
+ prefix##_vpclmul_avx2); \
+ } \
+ } \
+} while (0)
+
+/*
+ * Call a [V]PCLMULQDQ optimized CRC function if the data length is at least 16
+ * bytes, the CPU has PCLMULQDQ support, and the current context may use SIMD.
+ *
+ * 16 bytes is the minimum length supported by the [V]PCLMULQDQ functions.
+ * There is overhead associated with kernel_fpu_begin() and kernel_fpu_end(),
+ * varying by CPU and factors such as which parts of the "FPU" state userspace
+ * has touched, which could result in a larger cutoff being better. Indeed, a
+ * larger cutoff is usually better for a *single* message. However, the
+ * overhead of the FPU section gets amortized if multiple FPU sections get
+ * executed before returning to userspace, since the XSAVE and XRSTOR occur only
+ * once. Considering that and the fact that the [V]PCLMULQDQ code is lighter on
+ * the dcache than the table-based code is, a 16-byte cutoff seems to work well.
+ */
+#define CRC_PCLMUL(crc, p, len, prefix, consts, have_pclmulqdq) \
+do { \
+ if ((len) >= 16 && static_branch_likely(&(have_pclmulqdq)) && \
+ crypto_simd_usable()) { \
+ const void *consts_ptr; \
+ \
+ consts_ptr = (consts).fold_across_128_bits_consts; \
+ kernel_fpu_begin(); \
+ crc = static_call(prefix##_pclmul)((crc), (p), (len), \
+ consts_ptr); \
+ kernel_fpu_end(); \
+ return crc; \
+ } \
+} while (0)
+
+#endif /* _CRC_PCLMUL_TEMPLATE_H */
diff --git a/arch/x86/lib/crc-t10dif-glue.c b/arch/x86/lib/crc-t10dif-glue.c
index 13f07ddc9122..f89c335cde3c 100644
--- a/arch/x86/lib/crc-t10dif-glue.c
+++ b/arch/x86/lib/crc-t10dif-glue.c
@@ -1,37 +1,32 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
- * CRC-T10DIF using PCLMULQDQ instructions
+ * CRC-T10DIF using [V]PCLMULQDQ instructions
*
* Copyright 2024 Google LLC
*/
-#include <asm/cpufeatures.h>
-#include <asm/simd.h>
-#include <crypto/internal/simd.h>
#include <linux/crc-t10dif.h>
#include <linux/module.h>
+#include "crc-pclmul-template.h"
static DEFINE_STATIC_KEY_FALSE(have_pclmulqdq);
-asmlinkage u16 crc_t10dif_pcl(u16 init_crc, const u8 *buf, size_t len);
+DECLARE_CRC_PCLMUL_FUNCS(crc16_msb, u16);
u16 crc_t10dif_arch(u16 crc, const u8 *p, size_t len)
{
- if (len >= 16 &&
- static_key_enabled(&have_pclmulqdq) && crypto_simd_usable()) {
- kernel_fpu_begin();
- crc = crc_t10dif_pcl(crc, p, len);
- kernel_fpu_end();
- return crc;
- }
+ CRC_PCLMUL(crc, p, len, crc16_msb, crc16_msb_0x8bb7_consts,
+ have_pclmulqdq);
return crc_t10dif_generic(crc, p, len);
}
EXPORT_SYMBOL(crc_t10dif_arch);
static int __init crc_t10dif_x86_init(void)
{
- if (boot_cpu_has(X86_FEATURE_PCLMULQDQ))
+ if (boot_cpu_has(X86_FEATURE_PCLMULQDQ)) {
static_branch_enable(&have_pclmulqdq);
+ INIT_CRC_PCLMUL(crc16_msb);
+ }
return 0;
}
arch_initcall(crc_t10dif_x86_init);
@@ -41,11 +36,5 @@ static void __exit crc_t10dif_x86_exit(void)
}
module_exit(crc_t10dif_x86_exit);
-bool crc_t10dif_is_optimized(void)
-{
- return static_key_enabled(&have_pclmulqdq);
-}
-EXPORT_SYMBOL(crc_t10dif_is_optimized);
-
-MODULE_DESCRIPTION("CRC-T10DIF using PCLMULQDQ instructions");
+MODULE_DESCRIPTION("CRC-T10DIF using [V]PCLMULQDQ instructions");
MODULE_LICENSE("GPL");
diff --git a/arch/x86/lib/crc16-msb-pclmul.S b/arch/x86/lib/crc16-msb-pclmul.S
new file mode 100644
index 000000000000..e9fe248093a8
--- /dev/null
+++ b/arch/x86/lib/crc16-msb-pclmul.S
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+// Copyright 2025 Google LLC
+
+#include "crc-pclmul-template.S"
+
+DEFINE_CRC_PCLMUL_FUNCS(crc16_msb, /* bits= */ 16, /* lsb= */ 0)
diff --git a/arch/x86/lib/crc32-glue.c b/arch/x86/lib/crc32-glue.c
index 2dd18a886ded..e3f93b17ac3f 100644
--- a/arch/x86/lib/crc32-glue.c
+++ b/arch/x86/lib/crc32-glue.c
@@ -7,43 +7,20 @@
* Copyright 2024 Google LLC
*/
-#include <asm/cpufeatures.h>
-#include <asm/simd.h>
-#include <crypto/internal/simd.h>
#include <linux/crc32.h>
-#include <linux/linkage.h>
#include <linux/module.h>
-
-/* minimum size of buffer for crc32_pclmul_le_16 */
-#define CRC32_PCLMUL_MIN_LEN 64
+#include "crc-pclmul-template.h"
static DEFINE_STATIC_KEY_FALSE(have_crc32);
static DEFINE_STATIC_KEY_FALSE(have_pclmulqdq);
-u32 crc32_pclmul_le_16(u32 crc, const u8 *buffer, size_t len);
+DECLARE_CRC_PCLMUL_FUNCS(crc32_lsb, u32);
u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
{
- if (len >= CRC32_PCLMUL_MIN_LEN + 15 &&
- static_branch_likely(&have_pclmulqdq) && crypto_simd_usable()) {
- size_t n = -(uintptr_t)p & 15;
-
- /* align p to 16-byte boundary */
- if (n) {
- crc = crc32_le_base(crc, p, n);
- p += n;
- len -= n;
- }
- n = round_down(len, 16);
- kernel_fpu_begin();
- crc = crc32_pclmul_le_16(crc, p, n);
- kernel_fpu_end();
- p += n;
- len -= n;
- }
- if (len)
- crc = crc32_le_base(crc, p, len);
- return crc;
+ CRC_PCLMUL(crc, p, len, crc32_lsb, crc32_lsb_0xedb88320_consts,
+ have_pclmulqdq);
+ return crc32_le_base(crc, p, len);
}
EXPORT_SYMBOL(crc32_le_arch);
@@ -61,12 +38,12 @@ EXPORT_SYMBOL(crc32_le_arch);
asmlinkage u32 crc32c_x86_3way(u32 crc, const u8 *buffer, size_t len);
-u32 crc32c_le_arch(u32 crc, const u8 *p, size_t len)
+u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
{
size_t num_longs;
if (!static_branch_likely(&have_crc32))
- return crc32c_le_base(crc, p, len);
+ return crc32c_base(crc, p, len);
if (IS_ENABLED(CONFIG_X86_64) && len >= CRC32C_PCLMUL_BREAKEVEN &&
static_branch_likely(&have_pclmulqdq) && crypto_simd_usable()) {
@@ -78,14 +55,22 @@ u32 crc32c_le_arch(u32 crc, const u8 *p, size_t len)
for (num_longs = len / sizeof(unsigned long);
num_longs != 0; num_longs--, p += sizeof(unsigned long))
- asm(CRC32_INST : "+r" (crc) : "rm" (*(unsigned long *)p));
+ asm(CRC32_INST : "+r" (crc) : ASM_INPUT_RM (*(unsigned long *)p));
- for (len %= sizeof(unsigned long); len; len--, p++)
- asm("crc32b %1, %0" : "+r" (crc) : "rm" (*p));
+ if (sizeof(unsigned long) > 4 && (len & 4)) {
+ asm("crc32l %1, %0" : "+r" (crc) : ASM_INPUT_RM (*(u32 *)p));
+ p += 4;
+ }
+ if (len & 2) {
+ asm("crc32w %1, %0" : "+r" (crc) : ASM_INPUT_RM (*(u16 *)p));
+ p += 2;
+ }
+ if (len & 1)
+ asm("crc32b %1, %0" : "+r" (crc) : ASM_INPUT_RM (*p));
return crc;
}
-EXPORT_SYMBOL(crc32c_le_arch);
+EXPORT_SYMBOL(crc32c_arch);
u32 crc32_be_arch(u32 crc, const u8 *p, size_t len)
{
@@ -97,8 +82,10 @@ static int __init crc32_x86_init(void)
{
if (boot_cpu_has(X86_FEATURE_XMM4_2))
static_branch_enable(&have_crc32);
- if (boot_cpu_has(X86_FEATURE_PCLMULQDQ))
+ if (boot_cpu_has(X86_FEATURE_PCLMULQDQ)) {
static_branch_enable(&have_pclmulqdq);
+ INIT_CRC_PCLMUL(crc32_lsb);
+ }
return 0;
}
arch_initcall(crc32_x86_init);
diff --git a/arch/x86/lib/crc32-pclmul.S b/arch/x86/lib/crc32-pclmul.S
index f9637789cac1..f20f40fb0172 100644
--- a/arch/x86/lib/crc32-pclmul.S
+++ b/arch/x86/lib/crc32-pclmul.S
@@ -1,217 +1,6 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright 2012 Xyratex Technology Limited
- *
- * Using hardware provided PCLMULQDQ instruction to accelerate the CRC32
- * calculation.
- * CRC32 polynomial:0x04c11db7(BE)/0xEDB88320(LE)
- * PCLMULQDQ is a new instruction in Intel SSE4.2, the reference can be found
- * at:
- * http://www.intel.com/products/processor/manuals/
- * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
- * Volume 2B: Instruction Set Reference, N-Z
- *
- * Authors: Gregory Prestas <Gregory_Prestas@us.xyratex.com>
- * Alexander Boyko <Alexander_Boyko@xyratex.com>
- */
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+// Copyright 2025 Google LLC
-#include <linux/linkage.h>
+#include "crc-pclmul-template.S"
-
-.section .rodata
-.align 16
-/*
- * [x4*128+32 mod P(x) << 32)]' << 1 = 0x154442bd4
- * #define CONSTANT_R1 0x154442bd4LL
- *
- * [(x4*128-32 mod P(x) << 32)]' << 1 = 0x1c6e41596
- * #define CONSTANT_R2 0x1c6e41596LL
- */
-.Lconstant_R2R1:
- .octa 0x00000001c6e415960000000154442bd4
-/*
- * [(x128+32 mod P(x) << 32)]' << 1 = 0x1751997d0
- * #define CONSTANT_R3 0x1751997d0LL
- *
- * [(x128-32 mod P(x) << 32)]' << 1 = 0x0ccaa009e
- * #define CONSTANT_R4 0x0ccaa009eLL
- */
-.Lconstant_R4R3:
- .octa 0x00000000ccaa009e00000001751997d0
-/*
- * [(x64 mod P(x) << 32)]' << 1 = 0x163cd6124
- * #define CONSTANT_R5 0x163cd6124LL
- */
-.Lconstant_R5:
- .octa 0x00000000000000000000000163cd6124
-.Lconstant_mask32:
- .octa 0x000000000000000000000000FFFFFFFF
-/*
- * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL
- *
- * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))` = 0x1F7011641LL
- * #define CONSTANT_RU 0x1F7011641LL
- */
-.Lconstant_RUpoly:
- .octa 0x00000001F701164100000001DB710641
-
-#define CONSTANT %xmm0
-
-#ifdef __x86_64__
-#define CRC %edi
-#define BUF %rsi
-#define LEN %rdx
-#else
-#define CRC %eax
-#define BUF %edx
-#define LEN %ecx
-#endif
-
-
-
-.text
-/**
- * Calculate crc32
- * CRC - initial crc32
- * BUF - buffer (16 bytes aligned)
- * LEN - sizeof buffer (16 bytes aligned), LEN should be greater than 63
- * return %eax crc32
- * u32 crc32_pclmul_le_16(u32 crc, const u8 *buffer, size_t len);
- */
-
-SYM_FUNC_START(crc32_pclmul_le_16) /* buffer and buffer size are 16 bytes aligned */
- movdqa (BUF), %xmm1
- movdqa 0x10(BUF), %xmm2
- movdqa 0x20(BUF), %xmm3
- movdqa 0x30(BUF), %xmm4
- movd CRC, CONSTANT
- pxor CONSTANT, %xmm1
- sub $0x40, LEN
- add $0x40, BUF
- cmp $0x40, LEN
- jb .Lless_64
-
-#ifdef __x86_64__
- movdqa .Lconstant_R2R1(%rip), CONSTANT
-#else
- movdqa .Lconstant_R2R1, CONSTANT
-#endif
-
-.Lloop_64:/* 64 bytes Full cache line folding */
- prefetchnta 0x40(BUF)
- movdqa %xmm1, %xmm5
- movdqa %xmm2, %xmm6
- movdqa %xmm3, %xmm7
-#ifdef __x86_64__
- movdqa %xmm4, %xmm8
-#endif
- pclmulqdq $0x00, CONSTANT, %xmm1
- pclmulqdq $0x00, CONSTANT, %xmm2
- pclmulqdq $0x00, CONSTANT, %xmm3
-#ifdef __x86_64__
- pclmulqdq $0x00, CONSTANT, %xmm4
-#endif
- pclmulqdq $0x11, CONSTANT, %xmm5
- pclmulqdq $0x11, CONSTANT, %xmm6
- pclmulqdq $0x11, CONSTANT, %xmm7
-#ifdef __x86_64__
- pclmulqdq $0x11, CONSTANT, %xmm8
-#endif
- pxor %xmm5, %xmm1
- pxor %xmm6, %xmm2
- pxor %xmm7, %xmm3
-#ifdef __x86_64__
- pxor %xmm8, %xmm4
-#else
- /* xmm8 unsupported for x32 */
- movdqa %xmm4, %xmm5
- pclmulqdq $0x00, CONSTANT, %xmm4
- pclmulqdq $0x11, CONSTANT, %xmm5
- pxor %xmm5, %xmm4
-#endif
-
- pxor (BUF), %xmm1
- pxor 0x10(BUF), %xmm2
- pxor 0x20(BUF), %xmm3
- pxor 0x30(BUF), %xmm4
-
- sub $0x40, LEN
- add $0x40, BUF
- cmp $0x40, LEN
- jge .Lloop_64
-.Lless_64:/* Folding cache line into 128bit */
-#ifdef __x86_64__
- movdqa .Lconstant_R4R3(%rip), CONSTANT
-#else
- movdqa .Lconstant_R4R3, CONSTANT
-#endif
- prefetchnta (BUF)
-
- movdqa %xmm1, %xmm5
- pclmulqdq $0x00, CONSTANT, %xmm1
- pclmulqdq $0x11, CONSTANT, %xmm5
- pxor %xmm5, %xmm1
- pxor %xmm2, %xmm1
-
- movdqa %xmm1, %xmm5
- pclmulqdq $0x00, CONSTANT, %xmm1
- pclmulqdq $0x11, CONSTANT, %xmm5
- pxor %xmm5, %xmm1
- pxor %xmm3, %xmm1
-
- movdqa %xmm1, %xmm5
- pclmulqdq $0x00, CONSTANT, %xmm1
- pclmulqdq $0x11, CONSTANT, %xmm5
- pxor %xmm5, %xmm1
- pxor %xmm4, %xmm1
-
- cmp $0x10, LEN
- jb .Lfold_64
-.Lloop_16:/* Folding rest buffer into 128bit */
- movdqa %xmm1, %xmm5
- pclmulqdq $0x00, CONSTANT, %xmm1
- pclmulqdq $0x11, CONSTANT, %xmm5
- pxor %xmm5, %xmm1
- pxor (BUF), %xmm1
- sub $0x10, LEN
- add $0x10, BUF
- cmp $0x10, LEN
- jge .Lloop_16
-
-.Lfold_64:
- /* perform the last 64 bit fold, also adds 32 zeroes
- * to the input stream */
- pclmulqdq $0x01, %xmm1, CONSTANT /* R4 * xmm1.low */
- psrldq $0x08, %xmm1
- pxor CONSTANT, %xmm1
-
- /* final 32-bit fold */
- movdqa %xmm1, %xmm2
-#ifdef __x86_64__
- movdqa .Lconstant_R5(%rip), CONSTANT
- movdqa .Lconstant_mask32(%rip), %xmm3
-#else
- movdqa .Lconstant_R5, CONSTANT
- movdqa .Lconstant_mask32, %xmm3
-#endif
- psrldq $0x04, %xmm2
- pand %xmm3, %xmm1
- pclmulqdq $0x00, CONSTANT, %xmm1
- pxor %xmm2, %xmm1
-
- /* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */
-#ifdef __x86_64__
- movdqa .Lconstant_RUpoly(%rip), CONSTANT
-#else
- movdqa .Lconstant_RUpoly, CONSTANT
-#endif
- movdqa %xmm1, %xmm2
- pand %xmm3, %xmm1
- pclmulqdq $0x10, CONSTANT, %xmm1
- pand %xmm3, %xmm1
- pclmulqdq $0x00, CONSTANT, %xmm1
- pxor %xmm2, %xmm1
- pextrd $0x01, %xmm1, %eax
-
- RET
-SYM_FUNC_END(crc32_pclmul_le_16)
+DEFINE_CRC_PCLMUL_FUNCS(crc32_lsb, /* bits= */ 32, /* lsb= */ 1)
diff --git a/arch/x86/lib/crc64-glue.c b/arch/x86/lib/crc64-glue.c
new file mode 100644
index 000000000000..b0e1b719ecbf
--- /dev/null
+++ b/arch/x86/lib/crc64-glue.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * CRC64 using [V]PCLMULQDQ instructions
+ *
+ * Copyright 2025 Google LLC
+ */
+
+#include <linux/crc64.h>
+#include <linux/module.h>
+#include "crc-pclmul-template.h"
+
+static DEFINE_STATIC_KEY_FALSE(have_pclmulqdq);
+
+DECLARE_CRC_PCLMUL_FUNCS(crc64_msb, u64);
+DECLARE_CRC_PCLMUL_FUNCS(crc64_lsb, u64);
+
+u64 crc64_be_arch(u64 crc, const u8 *p, size_t len)
+{
+ CRC_PCLMUL(crc, p, len, crc64_msb, crc64_msb_0x42f0e1eba9ea3693_consts,
+ have_pclmulqdq);
+ return crc64_be_generic(crc, p, len);
+}
+EXPORT_SYMBOL_GPL(crc64_be_arch);
+
+u64 crc64_nvme_arch(u64 crc, const u8 *p, size_t len)
+{
+ CRC_PCLMUL(crc, p, len, crc64_lsb, crc64_lsb_0x9a6c9329ac4bc9b5_consts,
+ have_pclmulqdq);
+ return crc64_nvme_generic(crc, p, len);
+}
+EXPORT_SYMBOL_GPL(crc64_nvme_arch);
+
+static int __init crc64_x86_init(void)
+{
+ if (boot_cpu_has(X86_FEATURE_PCLMULQDQ)) {
+ static_branch_enable(&have_pclmulqdq);
+ INIT_CRC_PCLMUL(crc64_msb);
+ INIT_CRC_PCLMUL(crc64_lsb);
+ }
+ return 0;
+}
+arch_initcall(crc64_x86_init);
+
+static void __exit crc64_x86_exit(void)
+{
+}
+module_exit(crc64_x86_exit);
+
+MODULE_DESCRIPTION("CRC64 using [V]PCLMULQDQ instructions");
+MODULE_LICENSE("GPL");
diff --git a/arch/x86/lib/crc64-pclmul.S b/arch/x86/lib/crc64-pclmul.S
new file mode 100644
index 000000000000..4173051b5197
--- /dev/null
+++ b/arch/x86/lib/crc64-pclmul.S
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+// Copyright 2025 Google LLC
+
+#include "crc-pclmul-template.S"
+
+DEFINE_CRC_PCLMUL_FUNCS(crc64_msb, /* bits= */ 64, /* lsb= */ 0)
+DEFINE_CRC_PCLMUL_FUNCS(crc64_lsb, /* bits= */ 64, /* lsb= */ 1)
diff --git a/arch/x86/lib/crct10dif-pcl-asm_64.S b/arch/x86/lib/crct10dif-pcl-asm_64.S
deleted file mode 100644
index 5286db5b8165..000000000000
--- a/arch/x86/lib/crct10dif-pcl-asm_64.S
+++ /dev/null
@@ -1,332 +0,0 @@
-########################################################################
-# Implement fast CRC-T10DIF computation with SSE and PCLMULQDQ instructions
-#
-# Copyright (c) 2013, Intel Corporation
-#
-# Authors:
-# Erdinc Ozturk <erdinc.ozturk@intel.com>
-# Vinodh Gopal <vinodh.gopal@intel.com>
-# James Guilford <james.guilford@intel.com>
-# Tim Chen <tim.c.chen@linux.intel.com>
-#
-# This software is available to you under a choice of one of two
-# licenses. You may choose to be licensed under the terms of the GNU
-# General Public License (GPL) Version 2, available from the file
-# COPYING in the main directory of this source tree, or the
-# OpenIB.org BSD license below:
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-# * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-#
-# * 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.
-#
-# * Neither the name of the Intel Corporation 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 INTEL CORPORATION ""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 INTEL CORPORATION 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.
-#
-# Reference paper titled "Fast CRC Computation for Generic
-# Polynomials Using PCLMULQDQ Instruction"
-# URL: http://www.intel.com/content/dam/www/public/us/en/documents
-# /white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
-#
-
-#include <linux/linkage.h>
-
-.text
-
-#define init_crc %edi
-#define buf %rsi
-#define len %rdx
-
-#define FOLD_CONSTS %xmm10
-#define BSWAP_MASK %xmm11
-
-# Fold reg1, reg2 into the next 32 data bytes, storing the result back into
-# reg1, reg2.
-.macro fold_32_bytes offset, reg1, reg2
- movdqu \offset(buf), %xmm9
- movdqu \offset+16(buf), %xmm12
- pshufb BSWAP_MASK, %xmm9
- pshufb BSWAP_MASK, %xmm12
- movdqa \reg1, %xmm8
- movdqa \reg2, %xmm13
- pclmulqdq $0x00, FOLD_CONSTS, \reg1
- pclmulqdq $0x11, FOLD_CONSTS, %xmm8
- pclmulqdq $0x00, FOLD_CONSTS, \reg2
- pclmulqdq $0x11, FOLD_CONSTS, %xmm13
- pxor %xmm9 , \reg1
- xorps %xmm8 , \reg1
- pxor %xmm12, \reg2
- xorps %xmm13, \reg2
-.endm
-
-# Fold src_reg into dst_reg.
-.macro fold_16_bytes src_reg, dst_reg
- movdqa \src_reg, %xmm8
- pclmulqdq $0x11, FOLD_CONSTS, \src_reg
- pclmulqdq $0x00, FOLD_CONSTS, %xmm8
- pxor %xmm8, \dst_reg
- xorps \src_reg, \dst_reg
-.endm
-
-#
-# u16 crc_t10dif_pcl(u16 init_crc, const *u8 buf, size_t len);
-#
-# Assumes len >= 16.
-#
-SYM_FUNC_START(crc_t10dif_pcl)
-
- movdqa .Lbswap_mask(%rip), BSWAP_MASK
-
- # For sizes less than 256 bytes, we can't fold 128 bytes at a time.
- cmp $256, len
- jl .Lless_than_256_bytes
-
- # Load the first 128 data bytes. Byte swapping is necessary to make the
- # bit order match the polynomial coefficient order.
- movdqu 16*0(buf), %xmm0
- movdqu 16*1(buf), %xmm1
- movdqu 16*2(buf), %xmm2
- movdqu 16*3(buf), %xmm3
- movdqu 16*4(buf), %xmm4
- movdqu 16*5(buf), %xmm5
- movdqu 16*6(buf), %xmm6
- movdqu 16*7(buf), %xmm7
- add $128, buf
- pshufb BSWAP_MASK, %xmm0
- pshufb BSWAP_MASK, %xmm1
- pshufb BSWAP_MASK, %xmm2
- pshufb BSWAP_MASK, %xmm3
- pshufb BSWAP_MASK, %xmm4
- pshufb BSWAP_MASK, %xmm5
- pshufb BSWAP_MASK, %xmm6
- pshufb BSWAP_MASK, %xmm7
-
- # XOR the first 16 data *bits* with the initial CRC value.
- pxor %xmm8, %xmm8
- pinsrw $7, init_crc, %xmm8
- pxor %xmm8, %xmm0
-
- movdqa .Lfold_across_128_bytes_consts(%rip), FOLD_CONSTS
-
- # Subtract 128 for the 128 data bytes just consumed. Subtract another
- # 128 to simplify the termination condition of the following loop.
- sub $256, len
-
- # While >= 128 data bytes remain (not counting xmm0-7), fold the 128
- # bytes xmm0-7 into them, storing the result back into xmm0-7.
-.Lfold_128_bytes_loop:
- fold_32_bytes 0, %xmm0, %xmm1
- fold_32_bytes 32, %xmm2, %xmm3
- fold_32_bytes 64, %xmm4, %xmm5
- fold_32_bytes 96, %xmm6, %xmm7
- add $128, buf
- sub $128, len
- jge .Lfold_128_bytes_loop
-
- # Now fold the 112 bytes in xmm0-xmm6 into the 16 bytes in xmm7.
-
- # Fold across 64 bytes.
- movdqa .Lfold_across_64_bytes_consts(%rip), FOLD_CONSTS
- fold_16_bytes %xmm0, %xmm4
- fold_16_bytes %xmm1, %xmm5
- fold_16_bytes %xmm2, %xmm6
- fold_16_bytes %xmm3, %xmm7
- # Fold across 32 bytes.
- movdqa .Lfold_across_32_bytes_consts(%rip), FOLD_CONSTS
- fold_16_bytes %xmm4, %xmm6
- fold_16_bytes %xmm5, %xmm7
- # Fold across 16 bytes.
- movdqa .Lfold_across_16_bytes_consts(%rip), FOLD_CONSTS
- fold_16_bytes %xmm6, %xmm7
-
- # Add 128 to get the correct number of data bytes remaining in 0...127
- # (not counting xmm7), following the previous extra subtraction by 128.
- # Then subtract 16 to simplify the termination condition of the
- # following loop.
- add $128-16, len
-
- # While >= 16 data bytes remain (not counting xmm7), fold the 16 bytes
- # xmm7 into them, storing the result back into xmm7.
- jl .Lfold_16_bytes_loop_done
-.Lfold_16_bytes_loop:
- movdqa %xmm7, %xmm8
- pclmulqdq $0x11, FOLD_CONSTS, %xmm7
- pclmulqdq $0x00, FOLD_CONSTS, %xmm8
- pxor %xmm8, %xmm7
- movdqu (buf), %xmm0
- pshufb BSWAP_MASK, %xmm0
- pxor %xmm0 , %xmm7
- add $16, buf
- sub $16, len
- jge .Lfold_16_bytes_loop
-
-.Lfold_16_bytes_loop_done:
- # Add 16 to get the correct number of data bytes remaining in 0...15
- # (not counting xmm7), following the previous extra subtraction by 16.
- add $16, len
- je .Lreduce_final_16_bytes
-
-.Lhandle_partial_segment:
- # Reduce the last '16 + len' bytes where 1 <= len <= 15 and the first 16
- # bytes are in xmm7 and the rest are the remaining data in 'buf'. To do
- # this without needing a fold constant for each possible 'len', redivide
- # the bytes into a first chunk of 'len' bytes and a second chunk of 16
- # bytes, then fold the first chunk into the second.
-
- movdqa %xmm7, %xmm2
-
- # xmm1 = last 16 original data bytes
- movdqu -16(buf, len), %xmm1
- pshufb BSWAP_MASK, %xmm1
-
- # xmm2 = high order part of second chunk: xmm7 left-shifted by 'len' bytes.
- lea .Lbyteshift_table+16(%rip), %rax
- sub len, %rax
- movdqu (%rax), %xmm0
- pshufb %xmm0, %xmm2
-
- # xmm7 = first chunk: xmm7 right-shifted by '16-len' bytes.
- pxor .Lmask1(%rip), %xmm0
- pshufb %xmm0, %xmm7
-
- # xmm1 = second chunk: 'len' bytes from xmm1 (low-order bytes),
- # then '16-len' bytes from xmm2 (high-order bytes).
- pblendvb %xmm2, %xmm1 #xmm0 is implicit
-
- # Fold the first chunk into the second chunk, storing the result in xmm7.
- movdqa %xmm7, %xmm8
- pclmulqdq $0x11, FOLD_CONSTS, %xmm7
- pclmulqdq $0x00, FOLD_CONSTS, %xmm8
- pxor %xmm8, %xmm7
- pxor %xmm1, %xmm7
-
-.Lreduce_final_16_bytes:
- # Reduce the 128-bit value M(x), stored in xmm7, to the final 16-bit CRC
-
- # Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'.
- movdqa .Lfinal_fold_consts(%rip), FOLD_CONSTS
-
- # Fold the high 64 bits into the low 64 bits, while also multiplying by
- # x^64. This produces a 128-bit value congruent to x^64 * M(x) and
- # whose low 48 bits are 0.
- movdqa %xmm7, %xmm0
- pclmulqdq $0x11, FOLD_CONSTS, %xmm7 # high bits * x^48 * (x^80 mod G(x))
- pslldq $8, %xmm0
- pxor %xmm0, %xmm7 # + low bits * x^64
-
- # Fold the high 32 bits into the low 96 bits. This produces a 96-bit
- # value congruent to x^64 * M(x) and whose low 48 bits are 0.
- movdqa %xmm7, %xmm0
- pand .Lmask2(%rip), %xmm0 # zero high 32 bits
- psrldq $12, %xmm7 # extract high 32 bits
- pclmulqdq $0x00, FOLD_CONSTS, %xmm7 # high 32 bits * x^48 * (x^48 mod G(x))
- pxor %xmm0, %xmm7 # + low bits
-
- # Load G(x) and floor(x^48 / G(x)).
- movdqa .Lbarrett_reduction_consts(%rip), FOLD_CONSTS
-
- # Use Barrett reduction to compute the final CRC value.
- movdqa %xmm7, %xmm0
- pclmulqdq $0x11, FOLD_CONSTS, %xmm7 # high 32 bits * floor(x^48 / G(x))
- psrlq $32, %xmm7 # /= x^32
- pclmulqdq $0x00, FOLD_CONSTS, %xmm7 # *= G(x)
- psrlq $48, %xmm0
- pxor %xmm7, %xmm0 # + low 16 nonzero bits
- # Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of xmm0.
-
- pextrw $0, %xmm0, %eax
- RET
-
-.align 16
-.Lless_than_256_bytes:
- # Checksumming a buffer of length 16...255 bytes
-
- # Load the first 16 data bytes.
- movdqu (buf), %xmm7
- pshufb BSWAP_MASK, %xmm7
- add $16, buf
-
- # XOR the first 16 data *bits* with the initial CRC value.
- pxor %xmm0, %xmm0
- pinsrw $7, init_crc, %xmm0
- pxor %xmm0, %xmm7
-
- movdqa .Lfold_across_16_bytes_consts(%rip), FOLD_CONSTS
- cmp $16, len
- je .Lreduce_final_16_bytes # len == 16
- sub $32, len
- jge .Lfold_16_bytes_loop # 32 <= len <= 255
- add $16, len
- jmp .Lhandle_partial_segment # 17 <= len <= 31
-SYM_FUNC_END(crc_t10dif_pcl)
-
-.section .rodata, "a", @progbits
-.align 16
-
-# Fold constants precomputed from the polynomial 0x18bb7
-# G(x) = x^16 + x^15 + x^11 + x^9 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + x^0
-.Lfold_across_128_bytes_consts:
- .quad 0x0000000000006123 # x^(8*128) mod G(x)
- .quad 0x0000000000002295 # x^(8*128+64) mod G(x)
-.Lfold_across_64_bytes_consts:
- .quad 0x0000000000001069 # x^(4*128) mod G(x)
- .quad 0x000000000000dd31 # x^(4*128+64) mod G(x)
-.Lfold_across_32_bytes_consts:
- .quad 0x000000000000857d # x^(2*128) mod G(x)
- .quad 0x0000000000007acc # x^(2*128+64) mod G(x)
-.Lfold_across_16_bytes_consts:
- .quad 0x000000000000a010 # x^(1*128) mod G(x)
- .quad 0x0000000000001faa # x^(1*128+64) mod G(x)
-.Lfinal_fold_consts:
- .quad 0x1368000000000000 # x^48 * (x^48 mod G(x))
- .quad 0x2d56000000000000 # x^48 * (x^80 mod G(x))
-.Lbarrett_reduction_consts:
- .quad 0x0000000000018bb7 # G(x)
- .quad 0x00000001f65a57f8 # floor(x^48 / G(x))
-
-.section .rodata.cst16.mask1, "aM", @progbits, 16
-.align 16
-.Lmask1:
- .octa 0x80808080808080808080808080808080
-
-.section .rodata.cst16.mask2, "aM", @progbits, 16
-.align 16
-.Lmask2:
- .octa 0x00000000FFFFFFFFFFFFFFFFFFFFFFFF
-
-.section .rodata.cst16.bswap_mask, "aM", @progbits, 16
-.align 16
-.Lbswap_mask:
- .octa 0x000102030405060708090A0B0C0D0E0F
-
-.section .rodata.cst32.byteshift_table, "aM", @progbits, 32
-.align 16
-# For 1 <= len <= 15, the 16-byte vector beginning at &byteshift_table[16 - len]
-# is the index vector to shift left by 'len' bytes, and is also {0x80, ...,
-# 0x80} XOR the index vector to shift right by '16 - len' bytes.
-.Lbyteshift_table:
- .byte 0x0, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87
- .byte 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f
- .byte 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7
- .byte 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe , 0x0