[PATCH 4/4] crypto: arm64/crc32 - remove PMULL based CRC32 driver

From: Ard Biesheuvel
Date: Mon Aug 27 2018 - 07:03:11 EST


Now that the scalar fallbacks have been moved out of this driver into
the core crc32()/crc32c() routines, we are left with a CRC32 crypto API
driver for arm64 that is based only on 64x64 polynomial multiplication,
which is an optional instruction in the ARMv8 architecture, and is less
and less likely to be available on cores that do not also implement the
CRC32 instructions, given that those are mandatory in the architecture
as of ARMv8.1.

Since the scalar instructions do not require the special handling that
SIMD instructions do, and since they turn out to be considerably faster
on some cores (Cortex-A53) as well, there is really no point in keeping
this code around so let's just remove it.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm64/configs/defconfig | 1 -
arch/arm64/crypto/Kconfig | 5 -
arch/arm64/crypto/Makefile | 3 -
arch/arm64/crypto/crc32-ce-core.S | 287 --------------------
arch/arm64/crypto/crc32-ce-glue.c | 244 -----------------
5 files changed, 540 deletions(-)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index f67e8d5e93ad..323da306e9f4 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -703,7 +703,6 @@ CONFIG_CRYPTO_SHA3_ARM64=m
CONFIG_CRYPTO_SM3_ARM64_CE=m
CONFIG_CRYPTO_GHASH_ARM64_CE=y
CONFIG_CRYPTO_CRCT10DIF_ARM64_CE=m
-CONFIG_CRYPTO_CRC32_ARM64_CE=m
CONFIG_CRYPTO_AES_ARM64_CE_CCM=y
CONFIG_CRYPTO_AES_ARM64_CE_BLK=y
CONFIG_CRYPTO_CHACHA20_NEON=m
diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index e3fdb0fd6f70..63dc00423ca0 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -66,11 +66,6 @@ config CRYPTO_CRCT10DIF_ARM64_CE
depends on KERNEL_MODE_NEON && CRC_T10DIF
select CRYPTO_HASH

-config CRYPTO_CRC32_ARM64_CE
- tristate "CRC32 and CRC32C digest algorithms using ARMv8 extensions"
- depends on CRC32
- select CRYPTO_HASH
-
config CRYPTO_AES_ARM64
tristate "AES core cipher using scalar instructions"
select CRYPTO_AES
diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile
index bcafd016618e..776357a3be35 100644
--- a/arch/arm64/crypto/Makefile
+++ b/arch/arm64/crypto/Makefile
@@ -32,9 +32,6 @@ ghash-ce-y := ghash-ce-glue.o ghash-ce-core.o
obj-$(CONFIG_CRYPTO_CRCT10DIF_ARM64_CE) += crct10dif-ce.o
crct10dif-ce-y := crct10dif-ce-core.o crct10dif-ce-glue.o

-obj-$(CONFIG_CRYPTO_CRC32_ARM64_CE) += crc32-ce.o
-crc32-ce-y:= crc32-ce-core.o crc32-ce-glue.o
-
obj-$(CONFIG_CRYPTO_AES_ARM64_CE) += aes-ce-cipher.o
aes-ce-cipher-y := aes-ce-core.o aes-ce-glue.o

diff --git a/arch/arm64/crypto/crc32-ce-core.S b/arch/arm64/crypto/crc32-ce-core.S
deleted file mode 100644
index 8061bf0f9c66..000000000000
--- a/arch/arm64/crypto/crc32-ce-core.S
+++ /dev/null
@@ -1,287 +0,0 @@
-/*
- * Accelerated CRC32(C) using arm64 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>
-
- .section ".rodata", "a"
- .align 6
- .cpu generic+crypto+crc
-
-.Lcrc32_constants:
- /*
- * [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
- */
- .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
- */
- .octa 0x00000000ccaa009e00000001751997d0
-
- /*
- * [(x64 mod P(x) << 32)]' << 1 = 0x163cd6124
- * #define CONSTANT_R5 0x163cd6124LL
- */
- .quad 0x0000000163cd6124
- .quad 0x00000000FFFFFFFF
-
- /*
- * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL
- *
- * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))`
- * = 0x1F7011641LL
- * #define CONSTANT_RU 0x1F7011641LL
- */
- .octa 0x00000001F701164100000001DB710641
-
-.Lcrc32c_constants:
- .octa 0x000000009e4addf800000000740eef02
- .octa 0x000000014cd00bd600000000f20c0dfe
- .quad 0x00000000dd45aab8
- .quad 0x00000000FFFFFFFF
- .octa 0x00000000dea713f10000000105ec76f0
-
- vCONSTANT .req v0
- dCONSTANT .req d0
- qCONSTANT .req q0
-
- BUF .req x19
- LEN .req x20
- CRC .req x21
- CONST .req x22
-
- vzr .req v9
-
- /**
- * 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)
- */
- .text
-ENTRY(crc32_pmull_le)
- adr_l x3, .Lcrc32_constants
- b 0f
-
-ENTRY(crc32c_pmull_le)
- adr_l x3, .Lcrc32c_constants
-
-0: frame_push 4, 64
-
- mov BUF, x0
- mov LEN, x1
- mov CRC, x2
- mov CONST, x3
-
- bic LEN, LEN, #15
- ld1 {v1.16b-v4.16b}, [BUF], #0x40
- movi vzr.16b, #0
- fmov dCONSTANT, CRC
- eor v1.16b, v1.16b, vCONSTANT.16b
- sub LEN, LEN, #0x40
- cmp LEN, #0x40
- b.lt less_64
-
- ldr qCONSTANT, [CONST]
-
-loop_64: /* 64 bytes Full cache line folding */
- sub LEN, LEN, #0x40
-
- pmull2 v5.1q, v1.2d, vCONSTANT.2d
- pmull2 v6.1q, v2.2d, vCONSTANT.2d
- pmull2 v7.1q, v3.2d, vCONSTANT.2d
- pmull2 v8.1q, v4.2d, vCONSTANT.2d
-
- pmull v1.1q, v1.1d, vCONSTANT.1d
- pmull v2.1q, v2.1d, vCONSTANT.1d
- pmull v3.1q, v3.1d, vCONSTANT.1d
- pmull v4.1q, v4.1d, vCONSTANT.1d
-
- eor v1.16b, v1.16b, v5.16b
- ld1 {v5.16b}, [BUF], #0x10
- eor v2.16b, v2.16b, v6.16b
- ld1 {v6.16b}, [BUF], #0x10
- eor v3.16b, v3.16b, v7.16b
- ld1 {v7.16b}, [BUF], #0x10
- eor v4.16b, v4.16b, v8.16b
- ld1 {v8.16b}, [BUF], #0x10
-
- eor v1.16b, v1.16b, v5.16b
- eor v2.16b, v2.16b, v6.16b
- eor v3.16b, v3.16b, v7.16b
- eor v4.16b, v4.16b, v8.16b
-
- cmp LEN, #0x40
- b.lt less_64
-
- if_will_cond_yield_neon
- stp q1, q2, [sp, #.Lframe_local_offset]
- stp q3, q4, [sp, #.Lframe_local_offset + 32]
- do_cond_yield_neon
- ldp q1, q2, [sp, #.Lframe_local_offset]
- ldp q3, q4, [sp, #.Lframe_local_offset + 32]
- ldr qCONSTANT, [CONST]
- movi vzr.16b, #0
- endif_yield_neon
- b loop_64
-
-less_64: /* Folding cache line into 128bit */
- ldr qCONSTANT, [CONST, #16]
-
- pmull2 v5.1q, v1.2d, vCONSTANT.2d
- pmull v1.1q, v1.1d, vCONSTANT.1d
- eor v1.16b, v1.16b, v5.16b
- eor v1.16b, v1.16b, v2.16b
-
- pmull2 v5.1q, v1.2d, vCONSTANT.2d
- pmull v1.1q, v1.1d, vCONSTANT.1d
- eor v1.16b, v1.16b, v5.16b
- eor v1.16b, v1.16b, v3.16b
-
- pmull2 v5.1q, v1.2d, vCONSTANT.2d
- pmull v1.1q, v1.1d, vCONSTANT.1d
- eor v1.16b, v1.16b, v5.16b
- eor v1.16b, v1.16b, v4.16b
-
- cbz LEN, fold_64
-
-loop_16: /* Folding rest buffer into 128bit */
- subs LEN, LEN, #0x10
-
- ld1 {v2.16b}, [BUF], #0x10
- pmull2 v5.1q, v1.2d, vCONSTANT.2d
- pmull v1.1q, v1.1d, vCONSTANT.1d
- eor v1.16b, v1.16b, v5.16b
- eor v1.16b, v1.16b, v2.16b
-
- b.ne loop_16
-
-fold_64:
- /* perform the last 64 bit fold, also adds 32 zeroes
- * to the input stream */
- ext v2.16b, v1.16b, v1.16b, #8
- pmull2 v2.1q, v2.2d, vCONSTANT.2d
- ext v1.16b, v1.16b, vzr.16b, #8
- eor v1.16b, v1.16b, v2.16b
-
- /* final 32-bit fold */
- ldr dCONSTANT, [CONST, #32]
- ldr d3, [CONST, #40]
-
- ext v2.16b, v1.16b, vzr.16b, #4
- and v1.16b, v1.16b, v3.16b
- pmull v1.1q, v1.1d, vCONSTANT.1d
- eor v1.16b, v1.16b, v2.16b
-
- /* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */
- ldr qCONSTANT, [CONST, #48]
-
- and v2.16b, v1.16b, v3.16b
- ext v2.16b, vzr.16b, v2.16b, #8
- pmull2 v2.1q, v2.2d, vCONSTANT.2d
- and v2.16b, v2.16b, v3.16b
- pmull v2.1q, v2.1d, vCONSTANT.1d
- eor v1.16b, v1.16b, v2.16b
- mov w0, v1.s[1]
-
- frame_pop
- ret
-ENDPROC(crc32_pmull_le)
-ENDPROC(crc32c_pmull_le)
-
- .macro __crc32, c
-0: subs x2, x2, #16
- b.mi 8f
- ldp x3, x4, [x1], #16
-CPU_BE( rev x3, x3 )
-CPU_BE( rev x4, x4 )
- crc32\c\()x w0, w0, x3
- crc32\c\()x w0, w0, x4
- b.ne 0b
- ret
-
-8: tbz x2, #3, 4f
- ldr x3, [x1], #8
-CPU_BE( rev x3, x3 )
- crc32\c\()x w0, w0, x3
-4: tbz x2, #2, 2f
- ldr w3, [x1], #4
-CPU_BE( rev w3, w3 )
- crc32\c\()w w0, w0, w3
-2: tbz x2, #1, 1f
- ldrh w3, [x1], #2
-CPU_BE( rev16 w3, w3 )
- crc32\c\()h w0, w0, w3
-1: tbz x2, #0, 0f
- ldrb w3, [x1]
- crc32\c\()b w0, w0, w3
-0: ret
- .endm
-
- .align 5
-ENTRY(crc32_armv8_le)
- __crc32
-ENDPROC(crc32_armv8_le)
-
- .align 5
-ENTRY(crc32c_armv8_le)
- __crc32 c
-ENDPROC(crc32c_armv8_le)
diff --git a/arch/arm64/crypto/crc32-ce-glue.c b/arch/arm64/crypto/crc32-ce-glue.c
deleted file mode 100644
index 34b4e3d46aab..000000000000
--- a/arch/arm64/crypto/crc32-ce-glue.c
+++ /dev/null
@@ -1,244 +0,0 @@
-/*
- * Accelerated CRC32(C) using arm64 NEON and Crypto Extensions instructions
- *
- * Copyright (C) 2016 - 2017 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/cpufeature.h>
-#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[], u64 len, u32 init_crc);
-asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], size_t len);
-
-asmlinkage u32 crc32c_pmull_le(const u8 buf[], u64 len, u32 init_crc);
-asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], size_t len);
-
-static u32 (*fallback_crc32)(u32 init_crc, const u8 buf[], size_t len);
-static u32 (*fallback_crc32c)(u32 init_crc, const u8 buf[], size_t len);
-
-static int crc32_pmull_cra_init(struct crypto_tfm *tfm)
-{
- u32 *key = crypto_tfm_ctx(tfm);
-
- *key = 0;
- return 0;
-}
-
-static int crc32c_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_update(struct shash_desc *desc, const u8 *data,
- unsigned int length)
-{
- u32 *crc = shash_desc_ctx(desc);
-
- *crc = crc32_armv8_le(*crc, data, length);
- return 0;
-}
-
-static int crc32c_update(struct shash_desc *desc, const u8 *data,
- unsigned int length)
-{
- u32 *crc = shash_desc_ctx(desc);
-
- *crc = crc32c_armv8_le(*crc, data, length);
- return 0;
-}
-
-static int crc32_pmull_update(struct shash_desc *desc, const u8 *data,
- unsigned int length)
-{
- u32 *crc = shash_desc_ctx(desc);
- unsigned int l;
-
- if ((u64)data % SCALE_F) {
- l = min_t(u32, length, SCALE_F - ((u64)data % SCALE_F));
-
- *crc = fallback_crc32(*crc, data, l);
-
- data += l;
- length -= l;
- }
-
- if (length >= PMULL_MIN_LEN && may_use_simd()) {
- l = round_down(length, SCALE_F);
-
- kernel_neon_begin();
- *crc = crc32_pmull_le(data, l, *crc);
- kernel_neon_end();
-
- data += l;
- length -= l;
- }
-
- if (length > 0)
- *crc = fallback_crc32(*crc, data, length);
-
- return 0;
-}
-
-static int crc32c_pmull_update(struct shash_desc *desc, const u8 *data,
- unsigned int length)
-{
- u32 *crc = shash_desc_ctx(desc);
- unsigned int l;
-
- if ((u64)data % SCALE_F) {
- l = min_t(u32, length, SCALE_F - ((u64)data % SCALE_F));
-
- *crc = fallback_crc32c(*crc, data, l);
-
- data += l;
- length -= l;
- }
-
- if (length >= PMULL_MIN_LEN && may_use_simd()) {
- l = round_down(length, SCALE_F);
-
- kernel_neon_begin();
- *crc = crc32c_pmull_le(data, l, *crc);
- kernel_neon_end();
-
- data += l;
- length -= l;
- }
-
- if (length > 0) {
- *crc = fallback_crc32c(*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 int crc32c_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_algs[] = { {
- .setkey = crc32_pmull_setkey,
- .init = crc32_pmull_init,
- .update = crc32_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-arm64-ce",
- .base.cra_priority = 200,
- .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
- .base.cra_blocksize = 1,
- .base.cra_module = THIS_MODULE,
-}, {
- .setkey = crc32_pmull_setkey,
- .init = crc32_pmull_init,
- .update = crc32c_update,
- .final = crc32c_pmull_final,
- .descsize = sizeof(u32),
- .digestsize = sizeof(u32),
-
- .base.cra_ctxsize = sizeof(u32),
- .base.cra_init = crc32c_pmull_cra_init,
- .base.cra_name = "crc32c",
- .base.cra_driver_name = "crc32c-arm64-ce",
- .base.cra_priority = 200,
- .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
- .base.cra_blocksize = 1,
- .base.cra_module = THIS_MODULE,
-} };
-
-static int __init crc32_pmull_mod_init(void)
-{
- if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_PMULL)) {
- crc32_pmull_algs[0].update = crc32_pmull_update;
- crc32_pmull_algs[1].update = crc32c_pmull_update;
-
- if (elf_hwcap & HWCAP_CRC32) {
- fallback_crc32 = crc32_armv8_le;
- fallback_crc32c = crc32c_armv8_le;
- } else {
- fallback_crc32 = crc32_le;
- fallback_crc32c = __crc32c_le;
- }
- } else if (!(elf_hwcap & HWCAP_CRC32)) {
- return -ENODEV;
- }
- return crypto_register_shashes(crc32_pmull_algs,
- ARRAY_SIZE(crc32_pmull_algs));
-}
-
-static void __exit crc32_pmull_mod_exit(void)
-{
- crypto_unregister_shashes(crc32_pmull_algs,
- ARRAY_SIZE(crc32_pmull_algs));
-}
-
-static const struct cpu_feature crc32_cpu_feature[] = {
- { cpu_feature(CRC32) }, { cpu_feature(PMULL) }, { }
-};
-MODULE_DEVICE_TABLE(cpu, crc32_cpu_feature);
-
-module_init(crc32_pmull_mod_init);
-module_exit(crc32_pmull_mod_exit);
-
-MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>");
-MODULE_LICENSE("GPL v2");
--
2.18.0