b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /** |
| 3 | * AES CTR routines supporting VMX instructions on the Power 8 |
| 4 | * |
| 5 | * Copyright (C) 2015 International Business Machines Inc. |
| 6 | * |
| 7 | * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com> |
| 8 | */ |
| 9 | |
| 10 | #include <asm/simd.h> |
| 11 | #include <asm/switch_to.h> |
| 12 | #include <crypto/aes.h> |
| 13 | #include <crypto/internal/simd.h> |
| 14 | #include <crypto/internal/skcipher.h> |
| 15 | |
| 16 | #include "aesp8-ppc.h" |
| 17 | |
| 18 | struct p8_aes_ctr_ctx { |
| 19 | struct crypto_skcipher *fallback; |
| 20 | struct aes_key enc_key; |
| 21 | }; |
| 22 | |
| 23 | static int p8_aes_ctr_init(struct crypto_skcipher *tfm) |
| 24 | { |
| 25 | struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); |
| 26 | struct crypto_skcipher *fallback; |
| 27 | |
| 28 | fallback = crypto_alloc_skcipher("ctr(aes)", 0, |
| 29 | CRYPTO_ALG_NEED_FALLBACK | |
| 30 | CRYPTO_ALG_ASYNC); |
| 31 | if (IS_ERR(fallback)) { |
| 32 | pr_err("Failed to allocate ctr(aes) fallback: %ld\n", |
| 33 | PTR_ERR(fallback)); |
| 34 | return PTR_ERR(fallback); |
| 35 | } |
| 36 | |
| 37 | crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) + |
| 38 | crypto_skcipher_reqsize(fallback)); |
| 39 | ctx->fallback = fallback; |
| 40 | return 0; |
| 41 | } |
| 42 | |
| 43 | static void p8_aes_ctr_exit(struct crypto_skcipher *tfm) |
| 44 | { |
| 45 | struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); |
| 46 | |
| 47 | crypto_free_skcipher(ctx->fallback); |
| 48 | } |
| 49 | |
| 50 | static int p8_aes_ctr_setkey(struct crypto_skcipher *tfm, const u8 *key, |
| 51 | unsigned int keylen) |
| 52 | { |
| 53 | struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); |
| 54 | int ret; |
| 55 | |
| 56 | preempt_disable(); |
| 57 | pagefault_disable(); |
| 58 | enable_kernel_vsx(); |
| 59 | ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key); |
| 60 | disable_kernel_vsx(); |
| 61 | pagefault_enable(); |
| 62 | preempt_enable(); |
| 63 | |
| 64 | ret |= crypto_skcipher_setkey(ctx->fallback, key, keylen); |
| 65 | |
| 66 | return ret ? -EINVAL : 0; |
| 67 | } |
| 68 | |
| 69 | static void p8_aes_ctr_final(const struct p8_aes_ctr_ctx *ctx, |
| 70 | struct skcipher_walk *walk) |
| 71 | { |
| 72 | u8 *ctrblk = walk->iv; |
| 73 | u8 keystream[AES_BLOCK_SIZE]; |
| 74 | u8 *src = walk->src.virt.addr; |
| 75 | u8 *dst = walk->dst.virt.addr; |
| 76 | unsigned int nbytes = walk->nbytes; |
| 77 | |
| 78 | preempt_disable(); |
| 79 | pagefault_disable(); |
| 80 | enable_kernel_vsx(); |
| 81 | aes_p8_encrypt(ctrblk, keystream, &ctx->enc_key); |
| 82 | disable_kernel_vsx(); |
| 83 | pagefault_enable(); |
| 84 | preempt_enable(); |
| 85 | |
| 86 | crypto_xor_cpy(dst, keystream, src, nbytes); |
| 87 | crypto_inc(ctrblk, AES_BLOCK_SIZE); |
| 88 | } |
| 89 | |
| 90 | static int p8_aes_ctr_crypt(struct skcipher_request *req) |
| 91 | { |
| 92 | struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); |
| 93 | const struct p8_aes_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); |
| 94 | struct skcipher_walk walk; |
| 95 | unsigned int nbytes; |
| 96 | int ret; |
| 97 | |
| 98 | if (!crypto_simd_usable()) { |
| 99 | struct skcipher_request *subreq = skcipher_request_ctx(req); |
| 100 | |
| 101 | *subreq = *req; |
| 102 | skcipher_request_set_tfm(subreq, ctx->fallback); |
| 103 | return crypto_skcipher_encrypt(subreq); |
| 104 | } |
| 105 | |
| 106 | ret = skcipher_walk_virt(&walk, req, false); |
| 107 | while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) { |
| 108 | preempt_disable(); |
| 109 | pagefault_disable(); |
| 110 | enable_kernel_vsx(); |
| 111 | aes_p8_ctr32_encrypt_blocks(walk.src.virt.addr, |
| 112 | walk.dst.virt.addr, |
| 113 | nbytes / AES_BLOCK_SIZE, |
| 114 | &ctx->enc_key, walk.iv); |
| 115 | disable_kernel_vsx(); |
| 116 | pagefault_enable(); |
| 117 | preempt_enable(); |
| 118 | |
| 119 | do { |
| 120 | crypto_inc(walk.iv, AES_BLOCK_SIZE); |
| 121 | } while ((nbytes -= AES_BLOCK_SIZE) >= AES_BLOCK_SIZE); |
| 122 | |
| 123 | ret = skcipher_walk_done(&walk, nbytes); |
| 124 | } |
| 125 | if (nbytes) { |
| 126 | p8_aes_ctr_final(ctx, &walk); |
| 127 | ret = skcipher_walk_done(&walk, 0); |
| 128 | } |
| 129 | return ret; |
| 130 | } |
| 131 | |
| 132 | struct skcipher_alg p8_aes_ctr_alg = { |
| 133 | .base.cra_name = "ctr(aes)", |
| 134 | .base.cra_driver_name = "p8_aes_ctr", |
| 135 | .base.cra_module = THIS_MODULE, |
| 136 | .base.cra_priority = 2000, |
| 137 | .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, |
| 138 | .base.cra_blocksize = 1, |
| 139 | .base.cra_ctxsize = sizeof(struct p8_aes_ctr_ctx), |
| 140 | .setkey = p8_aes_ctr_setkey, |
| 141 | .encrypt = p8_aes_ctr_crypt, |
| 142 | .decrypt = p8_aes_ctr_crypt, |
| 143 | .init = p8_aes_ctr_init, |
| 144 | .exit = p8_aes_ctr_exit, |
| 145 | .min_keysize = AES_MIN_KEY_SIZE, |
| 146 | .max_keysize = AES_MAX_KEY_SIZE, |
| 147 | .ivsize = AES_BLOCK_SIZE, |
| 148 | .chunksize = AES_BLOCK_SIZE, |
| 149 | }; |