diff options
Diffstat (limited to 'arch/arm/crypto/crc32-ce-glue.c')
| -rw-r--r-- | arch/arm/crypto/crc32-ce-glue.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/arch/arm/crypto/crc32-ce-glue.c b/arch/arm/crypto/crc32-ce-glue.c new file mode 100644 index 000000000..cd9e93b46 --- /dev/null +++ b/arch/arm/crypto/crc32-ce-glue.c @@ -0,0 +1,250 @@ +/* + * Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions + * + * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> + * + * 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[], u32 len, u32 init_crc); +asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], u32 len); + +asmlinkage u32 crc32c_pmull_le(const u8 buf[], u32 len, u32 init_crc); +asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], u32 len); + +static u32 (*fallback_crc32)(u32 init_crc, const u8 buf[], u32 len); +static u32 (*fallback_crc32c)(u32 init_crc, const u8 buf[], u32 len); + +static int crc32_cra_init(struct crypto_tfm *tfm) +{ + u32 *key = crypto_tfm_ctx(tfm); + + *key = 0; + return 0; +} + +static int crc32c_cra_init(struct crypto_tfm *tfm) +{ + u32 *key = crypto_tfm_ctx(tfm); + + *key = ~0; + return 0; +} + +static int crc32_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_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_final(struct shash_desc *desc, u8 *out) +{ + u32 *crc = shash_desc_ctx(desc); + + put_unaligned_le32(*crc, out); + return 0; +} + +static int crc32c_final(struct shash_desc *desc, u8 *out) +{ + u32 *crc = shash_desc_ctx(desc); + + put_unaligned_le32(~*crc, out); + 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 (may_use_simd()) { + if ((u32)data % SCALE_F) { + l = min_t(u32, length, SCALE_F - ((u32)data % SCALE_F)); + + *crc = fallback_crc32(*crc, data, l); + + data += l; + length -= l; + } + + if (length >= PMULL_MIN_LEN) { + 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 (may_use_simd()) { + if ((u32)data % SCALE_F) { + l = min_t(u32, length, SCALE_F - ((u32)data % SCALE_F)); + + *crc = fallback_crc32c(*crc, data, l); + + data += l; + length -= l; + } + + if (length >= PMULL_MIN_LEN) { + 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 struct shash_alg crc32_pmull_algs[] = { { + .setkey = crc32_setkey, + .init = crc32_init, + .update = crc32_update, + .final = crc32_final, + .descsize = sizeof(u32), + .digestsize = sizeof(u32), + + .base.cra_ctxsize = sizeof(u32), + .base.cra_init = crc32_cra_init, + .base.cra_name = "crc32", + .base.cra_driver_name = "crc32-arm-ce", + .base.cra_priority = 200, + .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY, + .base.cra_blocksize = 1, + .base.cra_module = THIS_MODULE, +}, { + .setkey = crc32_setkey, + .init = crc32_init, + .update = crc32c_update, + .final = crc32c_final, + .descsize = sizeof(u32), + .digestsize = sizeof(u32), + + .base.cra_ctxsize = sizeof(u32), + .base.cra_init = crc32c_cra_init, + .base.cra_name = "crc32c", + .base.cra_driver_name = "crc32c-arm-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 (elf_hwcap2 & HWCAP2_PMULL) { + crc32_pmull_algs[0].update = crc32_pmull_update; + crc32_pmull_algs[1].update = crc32c_pmull_update; + + if (elf_hwcap2 & HWCAP2_CRC32) { + fallback_crc32 = crc32_armv8_le; + fallback_crc32c = crc32c_armv8_le; + } else { + fallback_crc32 = crc32_le; + fallback_crc32c = __crc32c_le; + } + } else if (!(elf_hwcap2 & HWCAP2_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 __maybe_unused 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@linaro.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS_CRYPTO("crc32"); +MODULE_ALIAS_CRYPTO("crc32c"); |