diff options
Diffstat (limited to 'drivers/crypto/vmx/ghash.c')
| -rw-r--r-- | drivers/crypto/vmx/ghash.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/drivers/crypto/vmx/ghash.c b/drivers/crypto/vmx/ghash.c new file mode 100644 index 000000000000..d0ffe277af5c --- /dev/null +++ b/drivers/crypto/vmx/ghash.c @@ -0,0 +1,214 @@ +/** + * GHASH routines supporting VMX instructions on the Power 8 + * + * Copyright (C) 2015 International Business Machines Inc. + * + * 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; version 2 only. + * + * 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 for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com> + */ + +#include <linux/types.h> +#include <linux/err.h> +#include <linux/crypto.h> +#include <linux/delay.h> +#include <linux/hardirq.h> +#include <asm/switch_to.h> +#include <crypto/aes.h> +#include <crypto/scatterwalk.h> +#include <crypto/internal/hash.h> +#include <crypto/b128ops.h> + +#define IN_INTERRUPT in_interrupt() + +#define GHASH_BLOCK_SIZE (16) +#define GHASH_DIGEST_SIZE (16) +#define GHASH_KEY_LEN (16) + +void gcm_init_p8(u128 htable[16], const u64 Xi[2]); +void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]); +void gcm_ghash_p8(u64 Xi[2], const u128 htable[16], + const u8 *in,size_t len); + +struct p8_ghash_ctx { + u128 htable[16]; + struct crypto_shash *fallback; +}; + +struct p8_ghash_desc_ctx { + u64 shash[2]; + u8 buffer[GHASH_DIGEST_SIZE]; + int bytes; + struct shash_desc fallback_desc; +}; + +static int p8_ghash_init_tfm(struct crypto_tfm *tfm) +{ + const char *alg; + struct crypto_shash *fallback; + struct crypto_shash *shash_tfm = __crypto_shash_cast(tfm); + struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm); + + if (!(alg = crypto_tfm_alg_name(tfm))) { + printk(KERN_ERR "Failed to get algorithm name.\n"); + return -ENOENT; + } + + fallback = crypto_alloc_shash(alg, 0 ,CRYPTO_ALG_NEED_FALLBACK); + if (IS_ERR(fallback)) { + printk(KERN_ERR "Failed to allocate transformation for '%s': %ld\n", + alg, PTR_ERR(fallback)); + return PTR_ERR(fallback); + } + printk(KERN_INFO "Using '%s' as fallback implementation.\n", + crypto_tfm_alg_driver_name(crypto_shash_tfm(fallback))); + + crypto_shash_set_flags(fallback, + crypto_shash_get_flags((struct crypto_shash *) tfm)); + ctx->fallback = fallback; + + shash_tfm->descsize = sizeof(struct p8_ghash_desc_ctx) + + crypto_shash_descsize(fallback); + + return 0; +} + +static void p8_ghash_exit_tfm(struct crypto_tfm *tfm) +{ + struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm); + + if (ctx->fallback) { + crypto_free_shash(ctx->fallback); + ctx->fallback = NULL; + } +} + +static int p8_ghash_init(struct shash_desc *desc) +{ + struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm)); + struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc); + + dctx->bytes = 0; + memset(dctx->shash, 0, GHASH_DIGEST_SIZE); + dctx->fallback_desc.tfm = ctx->fallback; + dctx->fallback_desc.flags = desc->flags; + return crypto_shash_init(&dctx->fallback_desc); +} + +static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key, + unsigned int keylen) +{ + struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm)); + + if (keylen != GHASH_KEY_LEN) + return -EINVAL; + + pagefault_disable(); + enable_kernel_altivec(); + enable_kernel_fp(); + gcm_init_p8(ctx->htable, (const u64 *) key); + pagefault_enable(); + return crypto_shash_setkey(ctx->fallback, key, keylen); +} + +static int p8_ghash_update(struct shash_desc *desc, + const u8 *src, unsigned int srclen) +{ + unsigned int len; + struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm)); + struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc); + + if (IN_INTERRUPT) { + return crypto_shash_update(&dctx->fallback_desc, src, srclen); + } else { + if (dctx->bytes) { + if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) { + memcpy(dctx->buffer + dctx->bytes, src, srclen); + dctx->bytes += srclen; + return 0; + } + memcpy(dctx->buffer + dctx->bytes, src, + GHASH_DIGEST_SIZE - dctx->bytes); + pagefault_disable(); + enable_kernel_altivec(); + enable_kernel_fp(); + gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer, + GHASH_DIGEST_SIZE); + pagefault_enable(); + src += GHASH_DIGEST_SIZE - dctx->bytes; + srclen -= GHASH_DIGEST_SIZE - dctx->bytes; + dctx->bytes = 0; + } + len = srclen & ~(GHASH_DIGEST_SIZE - 1); + if (len) { + pagefault_disable(); + enable_kernel_altivec(); + enable_kernel_fp(); + gcm_ghash_p8(dctx->shash, ctx->htable, src, len); + pagefault_enable(); + src += len; + srclen -= len; + } + if (srclen) { + memcpy(dctx->buffer, src, srclen); + dctx->bytes = srclen; + } + return 0; + } +} + +static int p8_ghash_final(struct shash_desc *desc, u8 *out) +{ + int i; + struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm)); + struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc); + + if (IN_INTERRUPT) { + return crypto_shash_final(&dctx->fallback_desc, out); + } else { + if (dctx->bytes) { + for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++) + dctx->buffer[i] = 0; + pagefault_disable(); + enable_kernel_altivec(); + enable_kernel_fp(); + gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer, + GHASH_DIGEST_SIZE); + pagefault_enable(); + dctx->bytes = 0; + } + memcpy(out, dctx->shash, GHASH_DIGEST_SIZE); + return 0; + } +} + +struct shash_alg p8_ghash_alg = { + .digestsize = GHASH_DIGEST_SIZE, + .init = p8_ghash_init, + .update = p8_ghash_update, + .final = p8_ghash_final, + .setkey = p8_ghash_setkey, + .descsize = sizeof(struct p8_ghash_desc_ctx), + .base = { + .cra_name = "ghash", + .cra_driver_name = "p8_ghash", + .cra_priority = 1000, + .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_NEED_FALLBACK, + .cra_blocksize = GHASH_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct p8_ghash_ctx), + .cra_module = THIS_MODULE, + .cra_init = p8_ghash_init_tfm, + .cra_exit = p8_ghash_exit_tfm, + }, +}; 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