This is a combination of the the Intel algorithm implemented using SSE
and PCLMULQDQ instructions from arch/x86/crypto/crc32-pclmul_asm.S, and
the new CRC32 extensions introduced for both 32-bit and 64-bit ARM in
version 8 of the architecture.
The PMULL/NEON algorithm is faster, but operates on blocks of at least
64 bytes, and on multiples of 16 bytes only. For the remaining input,
or for all input on systems that lack the PMULL 64x64->128 instructions,
the CRC32 instructions will be used.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm/crypto/Kconfig | 5 +
arch/arm/crypto/Makefile | 2 +
arch/arm/crypto/crc32-ce-core.S | 257 ++++++++++++++++++++
arch/arm/crypto/crc32-ce-glue.c | 129 ++++++++++
4 files changed, 393 insertions(+)
diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
index fce801fa52a1..be5cb5a7d3fa 100644
--- a/arch/arm/crypto/Kconfig
+++ b/arch/arm/crypto/Kconfig
@@ -125,4 +125,9 @@ config CRYPTO_CRCT10DIF_ARM_CE
depends on KERNEL_MODE_NEON && CRC_T10DIF
select CRYPTO_HASH
+config CRYPTO_CRC32_ARM_CE
+ tristate "CRC32 digest algorithm using CRC and/or PMULL instructions"
+ depends on KERNEL_MODE_NEON && CRC32
+ select CRYPTO_HASH
+
endif
diff --git a/arch/arm/crypto/Makefile b/arch/arm/crypto/Makefile
index fc77265014b7..b578a1820ab1 100644
--- a/arch/arm/crypto/Makefile
+++ b/arch/arm/crypto/Makefile
@@ -14,6 +14,7 @@ ce-obj-$(CONFIG_CRYPTO_SHA1_ARM_CE) += sha1-arm-ce.o
ce-obj-$(CONFIG_CRYPTO_SHA2_ARM_CE) += sha2-arm-ce.o
ce-obj-$(CONFIG_CRYPTO_GHASH_ARM_CE) += ghash-arm-ce.o
ce-obj-$(CONFIG_CRYPTO_CRCT10DIF_ARM_CE) += crct10dif-arm-ce.o
+ce-obj-$(CONFIG_CRYPTO_CRC32_ARM_CE) += crc32-arm-ce.o
ifneq ($(ce-obj-y)$(ce-obj-m),)
ifeq ($(call as-instr,.fpu crypto-neon-fp-armv8,y,n),y)
@@ -38,6 +39,7 @@ sha2-arm-ce-y := sha2-ce-core.o sha2-ce-glue.o
aes-arm-ce-y := aes-ce-core.o aes-ce-glue.o
ghash-arm-ce-y := ghash-ce-core.o ghash-ce-glue.o
crct10dif-arm-ce-y := crct10dif-ce-core.o crct10dif-ce-glue.o
+crc32-arm-ce-y:= crc32-ce-core.o crc32-ce-glue.o
quiet_cmd_perl = PERL $@
cmd_perl = $(PERL) $(<) > $(@)
diff --git a/arch/arm/crypto/crc32-ce-core.S b/arch/arm/crypto/crc32-ce-core.S
new file mode 100644
index 000000000000..ef671f040672
--- /dev/null
+++ b/arch/arm/crypto/crc32-ce-core.S
@@ -0,0 +1,257 @@
+/*
+ * Accelerated CRC32 using ARM CRC, NEON and Crypto Extensions instructions
+ *
+ * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/* GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see http://www.gnu.org/licenses
+ *
+ * Please visit http://www.xyratex.com/contact if you need additional
+ * information or have any questions.
+ *
+ * GPL HEADER END
+ */
+
+/*
+ * 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@xxxxxxxxxxxxxx>
+ * Alexander Boyko <Alexander_Boyko@xxxxxxxxxxx>
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+ .text
+ .align 4
+ .arch armv8-a
+ .arch_extension crc
+ .fpu crypto-neon-fp-armv8
+
+ /*
+ * [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:
+ .quad 0x0000000154442bd4
+ .quad 0x00000001c6e41596
+
+ /*
+ * [(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:
+ .quad 0x00000001751997d0
+ .quad 0x00000000ccaa009e
+
+ /*
+ * [(x64 mod P(x) << 32)]' << 1 = 0x163cd6124
+ * #define CONSTANT_R5 0x163cd6124LL
+ */
+.Lconstant_R5:
+ .quad 0x0000000163cd6124
+
+.Lconstant_mask32:
+ .quad 0x00000000FFFFFFFF
+
+ /*
+ * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL
+ *
+ * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))`
+ * = 0x1F7011641LL
+ * #define CONSTANT_RU 0x1F7011641LL
+ */
+.Lconstant_RUpoly:
+ .quad 0x00000001DB710641
+ .quad 0x00000001F7011641
+
+ dCONSTANTl .req d0
+ dCONSTANTh .req d1
+ qCONSTANT .req q0
+
+ BUF .req r0
+ LEN .req r1
+ CRC .req r2
+
+ qzr .req q9
+
+ /**
+ * Calculate crc32
+ * BUF - buffer
+ * LEN - sizeof buffer (multiple of 16 bytes), LEN should be > 63
+ * CRC - initial crc32
+ * return %eax crc32
+ * uint crc32_pmull_le(unsigned char const *buffer,
+ * size_t len, uint crc32)
+ */
+ENTRY(crc32_pmull_le)
+ bic LEN, LEN, #15
+ vld1.8 {q1-q2}, [BUF]!
+ vld1.8 {q3-q4}, [BUF]!
+ vmov.i8 qzr, #0
+ vmov.i8 qCONSTANT, #0
+ vmov dCONSTANTl[0], CRC
+ veor.8 d2, d2, dCONSTANTl
+ sub LEN, LEN, #0x40
+ cmp LEN, #0x40
+ blt less_64
+
+ vldr dCONSTANTl, .Lconstant_R2R1
+ vldr dCONSTANTh, .Lconstant_R2R1 + 8
+
+loop_64: /* 64 bytes Full cache line folding */
+ sub LEN, LEN, #0x40
+
+ vmull.p64 q5, d3, dCONSTANTh
+ vmull.p64 q6, d5, dCONSTANTh
+ vmull.p64 q7, d7, dCONSTANTh
+ vmull.p64 q8, d9, dCONSTANTh
+
+ vmull.p64 q1, d2, dCONSTANTl
+ vmull.p64 q2, d4, dCONSTANTl
+ vmull.p64 q3, d6, dCONSTANTl
+ vmull.p64 q4, d8, dCONSTANTl
+
+ veor.8 q1, q1, q5
+ vld1.8 {q5}, [BUF]!
+ veor.8 q2, q2, q6
+ vld1.8 {q6}, [BUF]!
+ veor.8 q3, q3, q7
+ vld1.8 {q7}, [BUF]!
+ veor.8 q4, q4, q8
+ vld1.8 {q8}, [BUF]!
+
+ veor.8 q1, q1, q5
+ veor.8 q2, q2, q6
+ veor.8 q3, q3, q7
+ veor.8 q4, q4, q8
+
+ cmp LEN, #0x40
+ bge loop_64
+
+less_64: /* Folding cache line into 128bit */
+ vldr dCONSTANTl, .Lconstant_R4R3
+ vldr dCONSTANTh, .Lconstant_R4R3 + 8
+
+ vmull.p64 q5, d3, dCONSTANTh
+ vmull.p64 q1, d2, dCONSTANTl
+ veor.8 q1, q1, q5
+ veor.8 q1, q1, q2
+
+ vmull.p64 q5, d3, dCONSTANTh
+ vmull.p64 q1, d2, dCONSTANTl
+ veor.8 q1, q1, q5
+ veor.8 q1, q1, q3
+
+ vmull.p64 q5, d3, dCONSTANTh
+ vmull.p64 q1, d2, dCONSTANTl
+ veor.8 q1, q1, q5
+ veor.8 q1, q1, q4
+
+ teq LEN, #0
+ beq fold_64
+
+loop_16: /* Folding rest buffer into 128bit */
+ subs LEN, LEN, #0x10
+
+ vld1.8 {q2}, [BUF]!
+ vmull.p64 q5, d3, dCONSTANTh
+ vmull.p64 q1, d2, dCONSTANTl
+ veor.8 q1, q1, q5
+ veor.8 q1, q1, q2
+
+ bne loop_16
+
+fold_64:
+ /* perform the last 64 bit fold, also adds 32 zeroes
+ * to the input stream */
+ vmull.p64 q2, d2, dCONSTANTh
+ vext.8 q1, q1, qzr, #8
+ veor.8 q1, q1, q2
+
+ /* final 32-bit fold */
+ vldr dCONSTANTl, .Lconstant_R5
+ vldr d6, .Lconstant_mask32
+ vmov.i8 d7, #0
+
+ vext.8 q2, q1, qzr, #4
+ vand.8 d2, d2, d6
+ vmull.p64 q1, d2, dCONSTANTl
+ veor.8 q1, q1, q2
+
+ /* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */
+ vldr dCONSTANTl, .Lconstant_RUpoly
+ vldr dCONSTANTh, .Lconstant_RUpoly + 8
+
+ vand.8 q2, q1, q3
+ vext.8 q2, qzr, q2, #8
+ vmull.p64 q2, d5, dCONSTANTh
+ vand.8 q2, q2, q3
+ vmull.p64 q2, d4, dCONSTANTl
+ veor.8 q1, q1, q2
+ vmov r0, s5
+
+ bx lr
+ENDPROC(crc32_pmull_le)
+
+ENTRY(crc32_armv8_le)
+ mov ip, r2
+0: subs ip, ip, #8
+ bmi 4f
+ ldrd r2, r3, [r1], #8
+ARM_BE8(rev r2, r2 )
+ARM_BE8(rev r3, r3 )
+ crc32w r0, r0, r2
+ crc32w r0, r0, r3
+ b 0b
+
+4: tst ip, #4
+ beq 2f
+ ldr r3, [r1], #4
+ARM_BE8(rev r3, r3 )
+ crc32w r0, r0, r3
+2: tst ip, #2
+ beq 1f
+ ldrh r3, [r1], #2
+ARM_BE8(rev16 r3, r3 )
+ crc32h r0, r0, r3
+1: tst ip, #1
+ bxeq lr
+ ldrb r3, [r1]
+ crc32b r0, r0, r3
+ bx lr
+ENDPROC(crc32_armv8_le)
diff --git a/arch/arm/crypto/crc32-ce-glue.c b/arch/arm/crypto/crc32-ce-glue.c
new file mode 100644
index 000000000000..61916b6b40e9
--- /dev/null
+++ b/arch/arm/crypto/crc32-ce-glue.c
@@ -0,0 +1,129 @@
+/*
+ * Accelerated CRC32 using ARM CRC, NEON and Crypto Extensions instructions
+ *
+ * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/crc32.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <crypto/internal/hash.h>
+
+#include <asm/hwcap.h>
+#include <asm/neon.h>
+#include <asm/simd.h>
+#include <asm/unaligned.h>
+
+#define PMULL_MIN_LEN 64L /* minimum size of buffer
+ * for crc32_pmull_le_16 */
+#define SCALE_F 16L /* size of NEON register */
+
+asmlinkage u32 crc32_pmull_le(const u8 buf[], u32 len, u32 init_crc);
+asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], u32 len);
+
+static int crc32_pmull_cra_init(struct crypto_tfm *tfm)
+{
+ u32 *key = crypto_tfm_ctx(tfm);
+
+ *key = 0;
+ return 0;
+}
+
+static int crc32_pmull_setkey(struct crypto_shash *hash, const u8 *key,
+ unsigned int keylen)
+{
+ u32 *mctx = crypto_shash_ctx(hash);
+
+ if (keylen != sizeof(u32)) {
+ crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
+ return -EINVAL;
+ }
+ *mctx = le32_to_cpup((__le32 *)key);
+ return 0;
+}
+
+static int crc32_pmull_init(struct shash_desc *desc)
+{
+ u32 *mctx = crypto_shash_ctx(desc->tfm);
+ u32 *crc = shash_desc_ctx(desc);
+
+ *crc = *mctx;
+ return 0;
+}
+
+static int crc32_pmull_update(struct shash_desc *desc, const u8 *data,
+ unsigned int length)
+{
+ u32 *crc = shash_desc_ctx(desc);
+
+ if (length >= PMULL_MIN_LEN && may_use_simd() &&
+ (elf_hwcap2 & HWCAP2_PMULL)) {
+ kernel_neon_begin();
+ *crc = crc32_pmull_le(data, round_down(length, SCALE_F), *crc);
+ kernel_neon_end();
+
+ data += round_down(length, SCALE_F);
+ length %= SCALE_F;
+ }
+
+ if (length > 0) {
+ if (elf_hwcap2 & HWCAP2_CRC32)
+ *crc = crc32_armv8_le(*crc, data, length);
+ else
+ *crc = crc32_le(*crc, data, length);
+ }
+
+ return 0;
+}
+
+static int crc32_pmull_final(struct shash_desc *desc, u8 *out)
+{
+ u32 *crc = shash_desc_ctx(desc);
+
+ put_unaligned_le32(*crc, out);
+ return 0;
+}
+
+static struct shash_alg crc32_pmull_alg = {
+ .setkey = crc32_pmull_setkey,
+ .init = crc32_pmull_init,
+ .update = crc32_pmull_update,
+ .final = crc32_pmull_final,
+ .descsize = sizeof(u32),
+ .digestsize = sizeof(u32),
+
+ .base.cra_ctxsize = sizeof(u32),
+ .base.cra_init = crc32_pmull_cra_init,
+ .base.cra_name = "crc32",
+ .base.cra_driver_name = "crc32-arm-ce",
+ .base.cra_priority = 200,
+ .base.cra_blocksize = 1,
+ .base.cra_module = THIS_MODULE,
+};
+
+static int __init crc32_pmull_mod_init(void)
+{
+ if (!(elf_hwcap2 & (HWCAP2_PMULL|HWCAP2_CRC32)))
+ return -ENODEV;
+
+ return crypto_register_shash(&crc32_pmull_alg);
+}
+
+static void __exit crc32_pmull_mod_exit(void)
+{
+ crypto_unregister_shash(&crc32_pmull_alg);
+}
+
+module_init(crc32_pmull_mod_init);
+module_exit(crc32_pmull_mod_exit);
+
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CRYPTO("crc32");
--
2.7.4
--
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