1 // SPDX-License-Identifier: GPL-2.0-only 2 /** 3 * AES CBC 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 <linux/types.h> 11 #include <linux/err.h> 12 #include <linux/crypto.h> 13 #include <linux/delay.h> 14 #include <asm/simd.h> 15 #include <asm/switch_to.h> 16 #include <crypto/aes.h> 17 #include <crypto/internal/simd.h> 18 #include <crypto/scatterwalk.h> 19 #include <crypto/skcipher.h> 20 21 #include "aesp8-ppc.h" 22 23 struct p8_aes_cbc_ctx { 24 struct crypto_sync_skcipher *fallback; 25 struct aes_key enc_key; 26 struct aes_key dec_key; 27 }; 28 29 static int p8_aes_cbc_init(struct crypto_tfm *tfm) 30 { 31 const char *alg = crypto_tfm_alg_name(tfm); 32 struct crypto_sync_skcipher *fallback; 33 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm); 34 35 fallback = crypto_alloc_sync_skcipher(alg, 0, 36 CRYPTO_ALG_NEED_FALLBACK); 37 38 if (IS_ERR(fallback)) { 39 printk(KERN_ERR 40 "Failed to allocate transformation for '%s': %ld\n", 41 alg, PTR_ERR(fallback)); 42 return PTR_ERR(fallback); 43 } 44 45 crypto_sync_skcipher_set_flags( 46 fallback, 47 crypto_skcipher_get_flags((struct crypto_skcipher *)tfm)); 48 ctx->fallback = fallback; 49 50 return 0; 51 } 52 53 static void p8_aes_cbc_exit(struct crypto_tfm *tfm) 54 { 55 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm); 56 57 if (ctx->fallback) { 58 crypto_free_sync_skcipher(ctx->fallback); 59 ctx->fallback = NULL; 60 } 61 } 62 63 static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key, 64 unsigned int keylen) 65 { 66 int ret; 67 struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm); 68 69 preempt_disable(); 70 pagefault_disable(); 71 enable_kernel_vsx(); 72 ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key); 73 ret |= aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key); 74 disable_kernel_vsx(); 75 pagefault_enable(); 76 preempt_enable(); 77 78 ret |= crypto_sync_skcipher_setkey(ctx->fallback, key, keylen); 79 80 return ret ? -EINVAL : 0; 81 } 82 83 static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc, 84 struct scatterlist *dst, 85 struct scatterlist *src, unsigned int nbytes) 86 { 87 int ret; 88 struct blkcipher_walk walk; 89 struct p8_aes_cbc_ctx *ctx = 90 crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm)); 91 92 if (!crypto_simd_usable()) { 93 SYNC_SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback); 94 skcipher_request_set_sync_tfm(req, ctx->fallback); 95 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 96 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 97 ret = crypto_skcipher_encrypt(req); 98 skcipher_request_zero(req); 99 } else { 100 blkcipher_walk_init(&walk, dst, src, nbytes); 101 ret = blkcipher_walk_virt(desc, &walk); 102 while ((nbytes = walk.nbytes)) { 103 preempt_disable(); 104 pagefault_disable(); 105 enable_kernel_vsx(); 106 aes_p8_cbc_encrypt(walk.src.virt.addr, 107 walk.dst.virt.addr, 108 nbytes & AES_BLOCK_MASK, 109 &ctx->enc_key, walk.iv, 1); 110 disable_kernel_vsx(); 111 pagefault_enable(); 112 preempt_enable(); 113 114 nbytes &= AES_BLOCK_SIZE - 1; 115 ret = blkcipher_walk_done(desc, &walk, nbytes); 116 } 117 } 118 119 return ret; 120 } 121 122 static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc, 123 struct scatterlist *dst, 124 struct scatterlist *src, unsigned int nbytes) 125 { 126 int ret; 127 struct blkcipher_walk walk; 128 struct p8_aes_cbc_ctx *ctx = 129 crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm)); 130 131 if (!crypto_simd_usable()) { 132 SYNC_SKCIPHER_REQUEST_ON_STACK(req, ctx->fallback); 133 skcipher_request_set_sync_tfm(req, ctx->fallback); 134 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 135 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 136 ret = crypto_skcipher_decrypt(req); 137 skcipher_request_zero(req); 138 } else { 139 blkcipher_walk_init(&walk, dst, src, nbytes); 140 ret = blkcipher_walk_virt(desc, &walk); 141 while ((nbytes = walk.nbytes)) { 142 preempt_disable(); 143 pagefault_disable(); 144 enable_kernel_vsx(); 145 aes_p8_cbc_encrypt(walk.src.virt.addr, 146 walk.dst.virt.addr, 147 nbytes & AES_BLOCK_MASK, 148 &ctx->dec_key, walk.iv, 0); 149 disable_kernel_vsx(); 150 pagefault_enable(); 151 preempt_enable(); 152 153 nbytes &= AES_BLOCK_SIZE - 1; 154 ret = blkcipher_walk_done(desc, &walk, nbytes); 155 } 156 } 157 158 return ret; 159 } 160 161 162 struct crypto_alg p8_aes_cbc_alg = { 163 .cra_name = "cbc(aes)", 164 .cra_driver_name = "p8_aes_cbc", 165 .cra_module = THIS_MODULE, 166 .cra_priority = 2000, 167 .cra_type = &crypto_blkcipher_type, 168 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK, 169 .cra_alignmask = 0, 170 .cra_blocksize = AES_BLOCK_SIZE, 171 .cra_ctxsize = sizeof(struct p8_aes_cbc_ctx), 172 .cra_init = p8_aes_cbc_init, 173 .cra_exit = p8_aes_cbc_exit, 174 .cra_blkcipher = { 175 .ivsize = AES_BLOCK_SIZE, 176 .min_keysize = AES_MIN_KEY_SIZE, 177 .max_keysize = AES_MAX_KEY_SIZE, 178 .setkey = p8_aes_cbc_setkey, 179 .encrypt = p8_aes_cbc_encrypt, 180 .decrypt = p8_aes_cbc_decrypt, 181 }, 182 }; 183