diff options
Diffstat (limited to 'drivers/crypto/vmx/aes_xts.c')
| -rw-r--r-- | drivers/crypto/vmx/aes_xts.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c new file mode 100644 index 0000000000..dabbccb415 --- /dev/null +++ b/drivers/crypto/vmx/aes_xts.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AES XTS routines supporting VMX In-core instructions on Power 8 + * + * Copyright (C) 2015 International Business Machines Inc. + * + * Author: Leonidas S. Barbosa <leosilva@linux.vnet.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 <crypto/xts.h> + +#include "aesp8-ppc.h" + +struct p8_aes_xts_ctx { + struct crypto_skcipher *fallback; + struct aes_key enc_key; + struct aes_key dec_key; + struct aes_key tweak_key; +}; + +static int p8_aes_xts_init(struct crypto_skcipher *tfm) +{ + struct p8_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm); + struct crypto_skcipher *fallback; + + fallback = crypto_alloc_skcipher("xts(aes)", 0, + CRYPTO_ALG_NEED_FALLBACK | + CRYPTO_ALG_ASYNC); + if (IS_ERR(fallback)) { + pr_err("Failed to allocate xts(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_xts_exit(struct crypto_skcipher *tfm) +{ + struct p8_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm); + + crypto_free_skcipher(ctx->fallback); +} + +static int p8_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen) +{ + struct p8_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm); + int ret; + + ret = xts_verify_key(tfm, key, keylen); + if (ret) + return ret; + + preempt_disable(); + pagefault_disable(); + enable_kernel_vsx(); + ret = aes_p8_set_encrypt_key(key + keylen/2, (keylen/2) * 8, &ctx->tweak_key); + ret |= aes_p8_set_encrypt_key(key, (keylen/2) * 8, &ctx->enc_key); + ret |= aes_p8_set_decrypt_key(key, (keylen/2) * 8, &ctx->dec_key); + disable_kernel_vsx(); + pagefault_enable(); + preempt_enable(); + + ret |= crypto_skcipher_setkey(ctx->fallback, key, keylen); + + return ret ? -EINVAL : 0; +} + +static int p8_aes_xts_crypt(struct skcipher_request *req, int enc) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + const struct p8_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int nbytes; + u8 tweak[AES_BLOCK_SIZE]; + int ret; + + if (req->cryptlen < AES_BLOCK_SIZE) + return -EINVAL; + + if (!crypto_simd_usable() || (req->cryptlen % XTS_BLOCK_SIZE) != 0) { + struct skcipher_request *subreq = skcipher_request_ctx(req); + + *subreq = *req; + skcipher_request_set_tfm(subreq, ctx->fallback); + return enc ? crypto_skcipher_encrypt(subreq) : + crypto_skcipher_decrypt(subreq); + } + + ret = skcipher_walk_virt(&walk, req, false); + if (ret) + return ret; + + preempt_disable(); + pagefault_disable(); + enable_kernel_vsx(); + + aes_p8_encrypt(walk.iv, tweak, &ctx->tweak_key); + + disable_kernel_vsx(); + pagefault_enable(); + preempt_enable(); + + while ((nbytes = walk.nbytes) != 0) { + preempt_disable(); + pagefault_disable(); + enable_kernel_vsx(); + if (enc) + aes_p8_xts_encrypt(walk.src.virt.addr, + walk.dst.virt.addr, + round_down(nbytes, AES_BLOCK_SIZE), + &ctx->enc_key, NULL, tweak); + else + aes_p8_xts_decrypt(walk.src.virt.addr, + walk.dst.virt.addr, + round_down(nbytes, AES_BLOCK_SIZE), + &ctx->dec_key, NULL, tweak); + disable_kernel_vsx(); + pagefault_enable(); + preempt_enable(); + + ret = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE); + } + return ret; +} + +static int p8_aes_xts_encrypt(struct skcipher_request *req) +{ + return p8_aes_xts_crypt(req, 1); +} + +static int p8_aes_xts_decrypt(struct skcipher_request *req) +{ + return p8_aes_xts_crypt(req, 0); +} + +struct skcipher_alg p8_aes_xts_alg = { + .base.cra_name = "xts(aes)", + .base.cra_driver_name = "p8_aes_xts", + .base.cra_module = THIS_MODULE, + .base.cra_priority = 2000, + .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, + .base.cra_blocksize = AES_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct p8_aes_xts_ctx), + .setkey = p8_aes_xts_setkey, + .encrypt = p8_aes_xts_encrypt, + .decrypt = p8_aes_xts_decrypt, + .init = p8_aes_xts_init, + .exit = p8_aes_xts_exit, + .min_keysize = 2 * AES_MIN_KEY_SIZE, + .max_keysize = 2 * AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, +}; |