diff options
Diffstat (limited to 'drivers/crypto/vmx/aes_ctr.c')
| -rw-r--r-- | drivers/crypto/vmx/aes_ctr.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/crypto/vmx/aes_ctr.c b/drivers/crypto/vmx/aes_ctr.c new file mode 100644 index 000000000..9a3da8cd6 --- /dev/null +++ b/drivers/crypto/vmx/aes_ctr.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AES CTR routines supporting VMX instructions on the Power 8 + * + * Copyright (C) 2015 International Business Machines Inc. + * + * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com> + */ + +#include <asm/simd.h> +#include <asm/switch_to.h> +#include <crypto/aes.h> +#include <crypto/internal/simd.h> +#include <crypto/internal/skcipher.h> + +#include "aesp8-ppc.h" + +struct p8_aes_ctr_ctx { + struct crypto_skcipher *fallback; + struct aes_key enc_key; +}; + +static int p8_aes_ctr_init(struct crypto_skcipher *tfm) +{ + struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); + struct crypto_skcipher *fallback; + + fallback = crypto_alloc_skcipher("ctr(aes)", 0, + CRYPTO_ALG_NEED_FALLBACK | + CRYPTO_ALG_ASYNC); + if (IS_ERR(fallback)) { + pr_err("Failed to allocate ctr(aes) fallback: %ld\n", + PTR_ERR(fallback)); + return PTR_ERR(fallback); + } + + crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) + + crypto_skcipher_reqsize(fallback)); + ctx->fallback = fallback; + return 0; +} + +static void p8_aes_ctr_exit(struct crypto_skcipher *tfm) +{ + struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); + + crypto_free_skcipher(ctx->fallback); +} + +static int p8_aes_ctr_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen) +{ + struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); + int ret; + + preempt_disable(); + pagefault_disable(); + enable_kernel_vsx(); + ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key); + disable_kernel_vsx(); + pagefault_enable(); + preempt_enable(); + + ret |= crypto_skcipher_setkey(ctx->fallback, key, keylen); + + return ret ? -EINVAL : 0; +} + +static void p8_aes_ctr_final(const struct p8_aes_ctr_ctx *ctx, + struct skcipher_walk *walk) +{ + u8 *ctrblk = walk->iv; + u8 keystream[AES_BLOCK_SIZE]; + u8 *src = walk->src.virt.addr; + u8 *dst = walk->dst.virt.addr; + unsigned int nbytes = walk->nbytes; + + preempt_disable(); + pagefault_disable(); + enable_kernel_vsx(); + aes_p8_encrypt(ctrblk, keystream, &ctx->enc_key); + disable_kernel_vsx(); + pagefault_enable(); + preempt_enable(); + + crypto_xor_cpy(dst, keystream, src, nbytes); + crypto_inc(ctrblk, AES_BLOCK_SIZE); +} + +static int p8_aes_ctr_crypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + const struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int nbytes; + int ret; + + if (!crypto_simd_usable()) { + struct skcipher_request *subreq = skcipher_request_ctx(req); + + *subreq = *req; + skcipher_request_set_tfm(subreq, ctx->fallback); + return crypto_skcipher_encrypt(subreq); + } + + ret = skcipher_walk_virt(&walk, req, false); + while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) { + preempt_disable(); + pagefault_disable(); + enable_kernel_vsx(); + aes_p8_ctr32_encrypt_blocks(walk.src.virt.addr, + walk.dst.virt.addr, + nbytes / AES_BLOCK_SIZE, + &ctx->enc_key, walk.iv); + disable_kernel_vsx(); + pagefault_enable(); + preempt_enable(); + + do { + crypto_inc(walk.iv, AES_BLOCK_SIZE); + } while ((nbytes -= AES_BLOCK_SIZE) >= AES_BLOCK_SIZE); + + ret = skcipher_walk_done(&walk, nbytes); + } + if (nbytes) { + p8_aes_ctr_final(ctx, &walk); + ret = skcipher_walk_done(&walk, 0); + } + return ret; +} + +struct skcipher_alg p8_aes_ctr_alg = { + .base.cra_name = "ctr(aes)", + .base.cra_driver_name = "p8_aes_ctr", + .base.cra_module = THIS_MODULE, + .base.cra_priority = 2000, + .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct p8_aes_ctr_ctx), + .setkey = p8_aes_ctr_setkey, + .encrypt = p8_aes_ctr_crypt, + .decrypt = p8_aes_ctr_crypt, + .init = p8_aes_ctr_init, + .exit = p8_aes_ctr_exit, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .chunksize = AES_BLOCK_SIZE, +}; |