diff options
Diffstat (limited to 'arch/x86/crypto/crc32c-intel.c')
| -rw-r--r-- | arch/x86/crypto/crc32c-intel.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/arch/x86/crypto/crc32c-intel.c b/arch/x86/crypto/crc32c-intel.c new file mode 100644 index 0000000..070afc5 --- /dev/null +++ b/arch/x86/crypto/crc32c-intel.c @@ -0,0 +1,197 @@ +/* + * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal. + * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE) + * CRC32 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 2A: Instruction Set Reference, A-M + * + * Copyright (c) 2008 Austin Zhang <austin_zhang@linux.intel.com> + * Copyright (c) 2008 Kent Liu <kent.liu@intel.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ +#include <linux/init.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <crypto/internal/hash.h> + +#include <asm/cpufeature.h> + +#define CHKSUM_BLOCK_SIZE 1 +#define CHKSUM_DIGEST_SIZE 4 + +#define SCALE_F sizeof(unsigned long) + +#ifdef CONFIG_X86_64 +#define REX_PRE "0x48, " +#else +#define REX_PRE +#endif + +static u32 crc32c_intel_le_hw_byte(u32 crc, unsigned char const *data, size_t length) +{ + while (length--) { + __asm__ __volatile__( + ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1" + :"=S"(crc) + :"0"(crc), "c"(*data) + ); + data++; + } + + return crc; +} + +static u32 __pure crc32c_intel_le_hw(u32 crc, unsigned char const *p, size_t len) +{ + unsigned int iquotient = len / SCALE_F; + unsigned int iremainder = len % SCALE_F; + unsigned long *ptmp = (unsigned long *)p; + + while (iquotient--) { + __asm__ __volatile__( + ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;" + :"=S"(crc) + :"0"(crc), "c"(*ptmp) + ); + ptmp++; + } + + if (iremainder) + crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp, + iremainder); + + return crc; +} + +/* + * Setting the seed allows arbitrary accumulators and flexible XOR policy + * If your algorithm starts with ~0, then XOR with ~0 before you set + * the seed. + */ +static int crc32c_intel_setkey(struct crypto_ahash *hash, const u8 *key, + unsigned int keylen) +{ + u32 *mctx = crypto_ahash_ctx(hash); + + if (keylen != sizeof(u32)) { + crypto_ahash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN); + return -EINVAL; + } + *mctx = le32_to_cpup((__le32 *)key); + return 0; +} + +static int crc32c_intel_init(struct ahash_request *req) +{ + u32 *mctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req)); + u32 *crcp = ahash_request_ctx(req); + + *crcp = *mctx; + + return 0; +} + +static int crc32c_intel_update(struct ahash_request *req) +{ + struct crypto_hash_walk walk; + u32 *crcp = ahash_request_ctx(req); + u32 crc = *crcp; + int nbytes; + + for (nbytes = crypto_hash_walk_first(req, &walk); nbytes; + nbytes = crypto_hash_walk_done(&walk, 0)) + crc = crc32c_intel_le_hw(crc, walk.data, nbytes); + + *crcp = crc; + return 0; +} + +static int crc32c_intel_final(struct ahash_request *req) +{ + u32 *crcp = ahash_request_ctx(req); + + *(__le32 *)req->result = ~cpu_to_le32p(crcp); + return 0; +} + +static int crc32c_intel_digest(struct ahash_request *req) +{ + struct crypto_hash_walk walk; + u32 *mctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req)); + u32 crc = *mctx; + int nbytes; + + for (nbytes = crypto_hash_walk_first(req, &walk); nbytes; + nbytes = crypto_hash_walk_done(&walk, 0)) + crc = crc32c_intel_le_hw(crc, walk.data, nbytes); + + *(__le32 *)req->result = ~cpu_to_le32(crc); + return 0; +} + +static int crc32c_intel_cra_init(struct crypto_tfm *tfm) +{ + u32 *key = crypto_tfm_ctx(tfm); + + *key = ~0; + + tfm->crt_ahash.reqsize = sizeof(u32); + + return 0; +} + +static struct crypto_alg alg = { + .cra_name = "crc32c", + .cra_driver_name = "crc32c-intel", + .cra_priority = 200, + .cra_flags = CRYPTO_ALG_TYPE_AHASH, + .cra_blocksize = CHKSUM_BLOCK_SIZE, + .cra_alignmask = 3, + .cra_ctxsize = sizeof(u32), + .cra_module = THIS_MODULE, + .cra_list = LIST_HEAD_INIT(alg.cra_list), + .cra_init = crc32c_intel_cra_init, + .cra_type = &crypto_ahash_type, + .cra_u = { + .ahash = { + .digestsize = CHKSUM_DIGEST_SIZE, + .setkey = crc32c_intel_setkey, + .init = crc32c_intel_init, + .update = crc32c_intel_update, + .final = crc32c_intel_final, + .digest = crc32c_intel_digest, + } + } +}; + + +static int __init crc32c_intel_mod_init(void) +{ + if (cpu_has_xmm4_2) + return crypto_register_alg(&alg); + else + return -ENODEV; +} + +static void __exit crc32c_intel_mod_fini(void) +{ + crypto_unregister_alg(&alg); +} + +module_init(crc32c_intel_mod_init); +module_exit(crc32c_intel_mod_fini); + +MODULE_AUTHOR("Austin Zhang <austin.zhang@intel.com>, Kent Liu <kent.liu@intel.com>"); +MODULE_DESCRIPTION("CRC32c (Castagnoli) optimization using Intel Hardware."); +MODULE_LICENSE("GPL"); + +MODULE_ALIAS("crc32c"); +MODULE_ALIAS("crc32c-intel"); + |