1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * sl3516-ce-cipher.c - hardware cryptographic offloader for Storlink SL3516 SoC 4 * 5 * Copyright (C) 2021 Corentin LABBE <clabbe@baylibre.com> 6 * 7 * This file adds support for AES cipher with 128,192,256 bits keysize in 8 * ECB mode. 9 */ 10 11 #include <linux/crypto.h> 12 #include <linux/dma-mapping.h> 13 #include <linux/delay.h> 14 #include <linux/io.h> 15 #include <linux/pm_runtime.h> 16 #include <crypto/scatterwalk.h> 17 #include <crypto/internal/skcipher.h> 18 #include "sl3516-ce.h" 19 20 /* sl3516_ce_need_fallback - check if a request can be handled by the CE */ 21 static bool sl3516_ce_need_fallback(struct skcipher_request *areq) 22 { 23 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq); 24 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm); 25 struct sl3516_ce_dev *ce = op->ce; 26 struct scatterlist *in_sg; 27 struct scatterlist *out_sg; 28 struct scatterlist *sg; 29 30 if (areq->cryptlen == 0 || areq->cryptlen % 16) { 31 ce->fallback_mod16++; 32 return true; 33 } 34 35 /* 36 * check if we have enough descriptors for TX 37 * Note: TX need one control desc for each SG 38 */ 39 if (sg_nents(areq->src) > MAXDESC / 2) { 40 ce->fallback_sg_count_tx++; 41 return true; 42 } 43 /* check if we have enough descriptors for RX */ 44 if (sg_nents(areq->dst) > MAXDESC) { 45 ce->fallback_sg_count_rx++; 46 return true; 47 } 48 49 sg = areq->src; 50 while (sg) { 51 if ((sg->length % 16) != 0) { 52 ce->fallback_mod16++; 53 return true; 54 } 55 if ((sg_dma_len(sg) % 16) != 0) { 56 ce->fallback_mod16++; 57 return true; 58 } 59 if (!IS_ALIGNED(sg->offset, 16)) { 60 ce->fallback_align16++; 61 return true; 62 } 63 sg = sg_next(sg); 64 } 65 sg = areq->dst; 66 while (sg) { 67 if ((sg->length % 16) != 0) { 68 ce->fallback_mod16++; 69 return true; 70 } 71 if ((sg_dma_len(sg) % 16) != 0) { 72 ce->fallback_mod16++; 73 return true; 74 } 75 if (!IS_ALIGNED(sg->offset, 16)) { 76 ce->fallback_align16++; 77 return true; 78 } 79 sg = sg_next(sg); 80 } 81 82 /* need same numbers of SG (with same length) for source and destination */ 83 in_sg = areq->src; 84 out_sg = areq->dst; 85 while (in_sg && out_sg) { 86 if (in_sg->length != out_sg->length) { 87 ce->fallback_not_same_len++; 88 return true; 89 } 90 in_sg = sg_next(in_sg); 91 out_sg = sg_next(out_sg); 92 } 93 if (in_sg || out_sg) 94 return true; 95 96 return false; 97 } 98 99 static int sl3516_ce_cipher_fallback(struct skcipher_request *areq) 100 { 101 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq); 102 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm); 103 struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq); 104 struct skcipher_alg *alg = crypto_skcipher_alg(tfm); 105 struct sl3516_ce_alg_template *algt; 106 int err; 107 108 algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher); 109 algt->stat_fb++; 110 111 skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm); 112 skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags, 113 areq->base.complete, areq->base.data); 114 skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst, 115 areq->cryptlen, areq->iv); 116 if (rctx->op_dir == CE_DECRYPTION) 117 err = crypto_skcipher_decrypt(&rctx->fallback_req); 118 else 119 err = crypto_skcipher_encrypt(&rctx->fallback_req); 120 return err; 121 } 122 123 static int sl3516_ce_cipher(struct skcipher_request *areq) 124 { 125 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq); 126 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm); 127 struct sl3516_ce_dev *ce = op->ce; 128 struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq); 129 struct skcipher_alg *alg = crypto_skcipher_alg(tfm); 130 struct sl3516_ce_alg_template *algt; 131 struct scatterlist *sg; 132 unsigned int todo, len; 133 struct pkt_control_ecb *ecb; 134 int nr_sgs = 0; 135 int nr_sgd = 0; 136 int err = 0; 137 int i; 138 139 algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher); 140 141 dev_dbg(ce->dev, "%s %s %u %x IV(%p %u) key=%u\n", __func__, 142 crypto_tfm_alg_name(areq->base.tfm), 143 areq->cryptlen, 144 rctx->op_dir, areq->iv, crypto_skcipher_ivsize(tfm), 145 op->keylen); 146 147 algt->stat_req++; 148 149 if (areq->src == areq->dst) { 150 nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src), 151 DMA_BIDIRECTIONAL); 152 if (nr_sgs <= 0 || nr_sgs > MAXDESC / 2) { 153 dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs); 154 err = -EINVAL; 155 goto theend; 156 } 157 nr_sgd = nr_sgs; 158 } else { 159 nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src), 160 DMA_TO_DEVICE); 161 if (nr_sgs <= 0 || nr_sgs > MAXDESC / 2) { 162 dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs); 163 err = -EINVAL; 164 goto theend; 165 } 166 nr_sgd = dma_map_sg(ce->dev, areq->dst, sg_nents(areq->dst), 167 DMA_FROM_DEVICE); 168 if (nr_sgd <= 0 || nr_sgd > MAXDESC) { 169 dev_err(ce->dev, "Invalid sg number %d\n", nr_sgd); 170 err = -EINVAL; 171 goto theend_sgs; 172 } 173 } 174 175 len = areq->cryptlen; 176 i = 0; 177 sg = areq->src; 178 while (i < nr_sgs && sg && len) { 179 if (sg_dma_len(sg) == 0) 180 goto sgs_next; 181 rctx->t_src[i].addr = sg_dma_address(sg); 182 todo = min(len, sg_dma_len(sg)); 183 rctx->t_src[i].len = todo; 184 dev_dbg(ce->dev, "%s total=%u SGS(%d %u off=%d) todo=%u\n", __func__, 185 areq->cryptlen, i, rctx->t_src[i].len, sg->offset, todo); 186 len -= todo; 187 i++; 188 sgs_next: 189 sg = sg_next(sg); 190 } 191 if (len > 0) { 192 dev_err(ce->dev, "remaining len %d/%u nr_sgs=%d\n", len, areq->cryptlen, nr_sgs); 193 err = -EINVAL; 194 goto theend_sgs; 195 } 196 197 len = areq->cryptlen; 198 i = 0; 199 sg = areq->dst; 200 while (i < nr_sgd && sg && len) { 201 if (sg_dma_len(sg) == 0) 202 goto sgd_next; 203 rctx->t_dst[i].addr = sg_dma_address(sg); 204 todo = min(len, sg_dma_len(sg)); 205 rctx->t_dst[i].len = todo; 206 dev_dbg(ce->dev, "%s total=%u SGD(%d %u off=%d) todo=%u\n", __func__, 207 areq->cryptlen, i, rctx->t_dst[i].len, sg->offset, todo); 208 len -= todo; 209 i++; 210 211 sgd_next: 212 sg = sg_next(sg); 213 } 214 if (len > 0) { 215 dev_err(ce->dev, "remaining len %d\n", len); 216 err = -EINVAL; 217 goto theend_sgs; 218 } 219 220 switch (algt->mode) { 221 case ECB_AES: 222 rctx->pctrllen = sizeof(struct pkt_control_ecb); 223 ecb = (struct pkt_control_ecb *)ce->pctrl; 224 225 rctx->tqflag = TQ0_TYPE_CTRL; 226 rctx->tqflag |= TQ1_CIPHER; 227 ecb->control.op_mode = rctx->op_dir; 228 ecb->control.cipher_algorithm = ECB_AES; 229 ecb->cipher.header_len = 0; 230 ecb->cipher.algorithm_len = areq->cryptlen; 231 cpu_to_be32_array((__be32 *)ecb->key, (u32 *)op->key, op->keylen / 4); 232 rctx->h = &ecb->cipher; 233 234 rctx->tqflag |= TQ4_KEY0; 235 rctx->tqflag |= TQ5_KEY4; 236 rctx->tqflag |= TQ6_KEY6; 237 ecb->control.aesnk = op->keylen / 4; 238 break; 239 } 240 241 rctx->nr_sgs = nr_sgs; 242 rctx->nr_sgd = nr_sgd; 243 err = sl3516_ce_run_task(ce, rctx, crypto_tfm_alg_name(areq->base.tfm)); 244 245 theend_sgs: 246 if (areq->src == areq->dst) { 247 dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src), 248 DMA_BIDIRECTIONAL); 249 } else { 250 dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src), 251 DMA_TO_DEVICE); 252 dma_unmap_sg(ce->dev, areq->dst, sg_nents(areq->dst), 253 DMA_FROM_DEVICE); 254 } 255 256 theend: 257 258 return err; 259 } 260 261 static int sl3516_ce_handle_cipher_request(struct crypto_engine *engine, void *areq) 262 { 263 int err; 264 struct skcipher_request *breq = container_of(areq, struct skcipher_request, base); 265 266 err = sl3516_ce_cipher(breq); 267 local_bh_disable(); 268 crypto_finalize_skcipher_request(engine, breq, err); 269 local_bh_enable(); 270 271 return 0; 272 } 273 274 int sl3516_ce_skdecrypt(struct skcipher_request *areq) 275 { 276 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq); 277 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm); 278 struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq); 279 struct crypto_engine *engine; 280 281 memset(rctx, 0, sizeof(struct sl3516_ce_cipher_req_ctx)); 282 rctx->op_dir = CE_DECRYPTION; 283 284 if (sl3516_ce_need_fallback(areq)) 285 return sl3516_ce_cipher_fallback(areq); 286 287 engine = op->ce->engine; 288 289 return crypto_transfer_skcipher_request_to_engine(engine, areq); 290 } 291 292 int sl3516_ce_skencrypt(struct skcipher_request *areq) 293 { 294 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq); 295 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm); 296 struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq); 297 struct crypto_engine *engine; 298 299 memset(rctx, 0, sizeof(struct sl3516_ce_cipher_req_ctx)); 300 rctx->op_dir = CE_ENCRYPTION; 301 302 if (sl3516_ce_need_fallback(areq)) 303 return sl3516_ce_cipher_fallback(areq); 304 305 engine = op->ce->engine; 306 307 return crypto_transfer_skcipher_request_to_engine(engine, areq); 308 } 309 310 int sl3516_ce_cipher_init(struct crypto_tfm *tfm) 311 { 312 struct sl3516_ce_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm); 313 struct sl3516_ce_alg_template *algt; 314 const char *name = crypto_tfm_alg_name(tfm); 315 struct crypto_skcipher *sktfm = __crypto_skcipher_cast(tfm); 316 struct skcipher_alg *alg = crypto_skcipher_alg(sktfm); 317 int err; 318 319 memset(op, 0, sizeof(struct sl3516_ce_cipher_tfm_ctx)); 320 321 algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher); 322 op->ce = algt->ce; 323 324 op->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); 325 if (IS_ERR(op->fallback_tfm)) { 326 dev_err(op->ce->dev, "ERROR: Cannot allocate fallback for %s %ld\n", 327 name, PTR_ERR(op->fallback_tfm)); 328 return PTR_ERR(op->fallback_tfm); 329 } 330 331 sktfm->reqsize = sizeof(struct sl3516_ce_cipher_req_ctx) + 332 crypto_skcipher_reqsize(op->fallback_tfm); 333 334 dev_info(op->ce->dev, "Fallback for %s is %s\n", 335 crypto_tfm_alg_driver_name(&sktfm->base), 336 crypto_tfm_alg_driver_name(crypto_skcipher_tfm(op->fallback_tfm))); 337 338 op->enginectx.op.do_one_request = sl3516_ce_handle_cipher_request; 339 op->enginectx.op.prepare_request = NULL; 340 op->enginectx.op.unprepare_request = NULL; 341 342 err = pm_runtime_get_sync(op->ce->dev); 343 if (err < 0) 344 goto error_pm; 345 346 return 0; 347 error_pm: 348 pm_runtime_put_noidle(op->ce->dev); 349 crypto_free_skcipher(op->fallback_tfm); 350 return err; 351 } 352 353 void sl3516_ce_cipher_exit(struct crypto_tfm *tfm) 354 { 355 struct sl3516_ce_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm); 356 357 kfree_sensitive(op->key); 358 crypto_free_skcipher(op->fallback_tfm); 359 pm_runtime_put_sync_suspend(op->ce->dev); 360 } 361 362 int sl3516_ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *key, 363 unsigned int keylen) 364 { 365 struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm); 366 struct sl3516_ce_dev *ce = op->ce; 367 368 switch (keylen) { 369 case 128 / 8: 370 break; 371 case 192 / 8: 372 break; 373 case 256 / 8: 374 break; 375 default: 376 dev_dbg(ce->dev, "ERROR: Invalid keylen %u\n", keylen); 377 return -EINVAL; 378 } 379 kfree_sensitive(op->key); 380 op->keylen = keylen; 381 op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA); 382 if (!op->key) 383 return -ENOMEM; 384 385 crypto_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK); 386 crypto_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK); 387 388 return crypto_skcipher_setkey(op->fallback_tfm, key, keylen); 389 } 390