diff options
Diffstat (limited to 'arch/x86/crypto/crc32-pclmul_glue.c')
| -rw-r--r-- | arch/x86/crypto/crc32-pclmul_glue.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/arch/x86/crypto/crc32-pclmul_glue.c b/arch/x86/crypto/crc32-pclmul_glue.c new file mode 100644 index 000000000..c8d9cdacb --- /dev/null +++ b/arch/x86/crypto/crc32-pclmul_glue.c @@ -0,0 +1,202 @@ +/* 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 + * + * Wrappers for kernel crypto shash api to pclmulqdq crc32 imlementation. + */ +#include <linux/init.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/crc32.h> +#include <crypto/internal/hash.h> + +#include <asm/cpufeatures.h> +#include <asm/cpu_device_id.h> +#include <asm/fpu/api.h> + +#define CHKSUM_BLOCK_SIZE 1 +#define CHKSUM_DIGEST_SIZE 4 + +#define PCLMUL_MIN_LEN 64L /* minimum size of buffer + * for crc32_pclmul_le_16 */ +#define SCALE_F 16L /* size of xmm register */ +#define SCALE_F_MASK (SCALE_F - 1) + +u32 crc32_pclmul_le_16(unsigned char const *buffer, size_t len, u32 crc32); + +static u32 __attribute__((pure)) + crc32_pclmul_le(u32 crc, unsigned char const *p, size_t len) +{ + unsigned int iquotient; + unsigned int iremainder; + unsigned int prealign; + + if (len < PCLMUL_MIN_LEN + SCALE_F_MASK || !irq_fpu_usable()) + return crc32_le(crc, p, len); + + if ((long)p & SCALE_F_MASK) { + /* align p to 16 byte */ + prealign = SCALE_F - ((long)p & SCALE_F_MASK); + + crc = crc32_le(crc, p, prealign); + len -= prealign; + p = (unsigned char *)(((unsigned long)p + SCALE_F_MASK) & + ~SCALE_F_MASK); + } + iquotient = len & (~SCALE_F_MASK); + iremainder = len & SCALE_F_MASK; + + kernel_fpu_begin(); + crc = crc32_pclmul_le_16(p, iquotient, crc); + kernel_fpu_end(); + + if (iremainder) + crc = crc32_le(crc, p + iquotient, iremainder); + + return crc; +} + +static int crc32_pclmul_cra_init(struct crypto_tfm *tfm) +{ + u32 *key = crypto_tfm_ctx(tfm); + + *key = 0; + + return 0; +} + +static int crc32_pclmul_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_pclmul_init(struct shash_desc *desc) +{ + u32 *mctx = crypto_shash_ctx(desc->tfm); + u32 *crcp = shash_desc_ctx(desc); + + *crcp = *mctx; + + return 0; +} + +static int crc32_pclmul_update(struct shash_desc *desc, const u8 *data, + unsigned int len) +{ + u32 *crcp = shash_desc_ctx(desc); + + *crcp = crc32_pclmul_le(*crcp, data, len); + return 0; +} + +/* No final XOR 0xFFFFFFFF, like crc32_le */ +static int __crc32_pclmul_finup(u32 *crcp, const u8 *data, unsigned int len, + u8 *out) +{ + *(__le32 *)out = cpu_to_le32(crc32_pclmul_le(*crcp, data, len)); + return 0; +} + +static int crc32_pclmul_finup(struct shash_desc *desc, const u8 *data, + unsigned int len, u8 *out) +{ + return __crc32_pclmul_finup(shash_desc_ctx(desc), data, len, out); +} + +static int crc32_pclmul_final(struct shash_desc *desc, u8 *out) +{ + u32 *crcp = shash_desc_ctx(desc); + + *(__le32 *)out = cpu_to_le32p(crcp); + return 0; +} + +static int crc32_pclmul_digest(struct shash_desc *desc, const u8 *data, + unsigned int len, u8 *out) +{ + return __crc32_pclmul_finup(crypto_shash_ctx(desc->tfm), data, len, + out); +} + +static struct shash_alg alg = { + .setkey = crc32_pclmul_setkey, + .init = crc32_pclmul_init, + .update = crc32_pclmul_update, + .final = crc32_pclmul_final, + .finup = crc32_pclmul_finup, + .digest = crc32_pclmul_digest, + .descsize = sizeof(u32), + .digestsize = CHKSUM_DIGEST_SIZE, + .base = { + .cra_name = "crc32", + .cra_driver_name = "crc32-pclmul", + .cra_priority = 200, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, + .cra_blocksize = CHKSUM_BLOCK_SIZE, + .cra_ctxsize = sizeof(u32), + .cra_module = THIS_MODULE, + .cra_init = crc32_pclmul_cra_init, + } +}; + +static const struct x86_cpu_id crc32pclmul_cpu_id[] = { + X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), + {} +}; +MODULE_DEVICE_TABLE(x86cpu, crc32pclmul_cpu_id); + + +static int __init crc32_pclmul_mod_init(void) +{ + + if (!x86_match_cpu(crc32pclmul_cpu_id)) { + pr_info("PCLMULQDQ-NI instructions are not detected.\n"); + return -ENODEV; + } + return crypto_register_shash(&alg); +} + +static void __exit crc32_pclmul_mod_fini(void) +{ + crypto_unregister_shash(&alg); +} + +module_init(crc32_pclmul_mod_init); +module_exit(crc32_pclmul_mod_fini); + +MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>"); +MODULE_LICENSE("GPL"); + +MODULE_ALIAS_CRYPTO("crc32"); +MODULE_ALIAS_CRYPTO("crc32-pclmul"); |