1 /* 2 * AMD Cryptographic Coprocessor (CCP) crypto API support 3 * 4 * Copyright (C) 2013 Advanced Micro Devices, Inc. 5 * 6 * Author: Tom Lendacky <thomas.lendacky@amd.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/module.h> 14 #include <linux/moduleparam.h> 15 #include <linux/kernel.h> 16 #include <linux/list.h> 17 #include <linux/ccp.h> 18 #include <linux/scatterlist.h> 19 #include <crypto/internal/hash.h> 20 21 #include "ccp-crypto.h" 22 23 MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>"); 24 MODULE_LICENSE("GPL"); 25 MODULE_VERSION("1.0.0"); 26 MODULE_DESCRIPTION("AMD Cryptographic Coprocessor crypto API support"); 27 28 static unsigned int aes_disable; 29 module_param(aes_disable, uint, 0444); 30 MODULE_PARM_DESC(aes_disable, "Disable use of AES - any non-zero value"); 31 32 static unsigned int sha_disable; 33 module_param(sha_disable, uint, 0444); 34 MODULE_PARM_DESC(sha_disable, "Disable use of SHA - any non-zero value"); 35 36 37 /* List heads for the supported algorithms */ 38 static LIST_HEAD(hash_algs); 39 static LIST_HEAD(cipher_algs); 40 41 /* For any tfm, requests for that tfm must be returned on the order 42 * received. With multiple queues available, the CCP can process more 43 * than one cmd at a time. Therefore we must maintain a cmd list to insure 44 * the proper ordering of requests on a given tfm. 45 */ 46 struct ccp_crypto_queue { 47 struct list_head cmds; 48 struct list_head *backlog; 49 unsigned int cmd_count; 50 }; 51 #define CCP_CRYPTO_MAX_QLEN 100 52 53 static struct ccp_crypto_queue req_queue; 54 static spinlock_t req_queue_lock; 55 56 struct ccp_crypto_cmd { 57 struct list_head entry; 58 59 struct ccp_cmd *cmd; 60 61 /* Save the crypto_tfm and crypto_async_request addresses 62 * separately to avoid any reference to a possibly invalid 63 * crypto_async_request structure after invoking the request 64 * callback 65 */ 66 struct crypto_async_request *req; 67 struct crypto_tfm *tfm; 68 69 /* Used for held command processing to determine state */ 70 int ret; 71 }; 72 73 struct ccp_crypto_cpu { 74 struct work_struct work; 75 struct completion completion; 76 struct ccp_crypto_cmd *crypto_cmd; 77 int err; 78 }; 79 80 81 static inline bool ccp_crypto_success(int err) 82 { 83 if (err && (err != -EINPROGRESS) && (err != -EBUSY)) 84 return false; 85 86 return true; 87 } 88 89 static struct ccp_crypto_cmd *ccp_crypto_cmd_complete( 90 struct ccp_crypto_cmd *crypto_cmd, struct ccp_crypto_cmd **backlog) 91 { 92 struct ccp_crypto_cmd *held = NULL, *tmp; 93 unsigned long flags; 94 95 *backlog = NULL; 96 97 spin_lock_irqsave(&req_queue_lock, flags); 98 99 /* Held cmds will be after the current cmd in the queue so start 100 * searching for a cmd with a matching tfm for submission. 101 */ 102 tmp = crypto_cmd; 103 list_for_each_entry_continue(tmp, &req_queue.cmds, entry) { 104 if (crypto_cmd->tfm != tmp->tfm) 105 continue; 106 held = tmp; 107 break; 108 } 109 110 /* Process the backlog: 111 * Because cmds can be executed from any point in the cmd list 112 * special precautions have to be taken when handling the backlog. 113 */ 114 if (req_queue.backlog != &req_queue.cmds) { 115 /* Skip over this cmd if it is the next backlog cmd */ 116 if (req_queue.backlog == &crypto_cmd->entry) 117 req_queue.backlog = crypto_cmd->entry.next; 118 119 *backlog = container_of(req_queue.backlog, 120 struct ccp_crypto_cmd, entry); 121 req_queue.backlog = req_queue.backlog->next; 122 123 /* Skip over this cmd if it is now the next backlog cmd */ 124 if (req_queue.backlog == &crypto_cmd->entry) 125 req_queue.backlog = crypto_cmd->entry.next; 126 } 127 128 /* Remove the cmd entry from the list of cmds */ 129 req_queue.cmd_count--; 130 list_del(&crypto_cmd->entry); 131 132 spin_unlock_irqrestore(&req_queue_lock, flags); 133 134 return held; 135 } 136 137 static void ccp_crypto_complete(void *data, int err) 138 { 139 struct ccp_crypto_cmd *crypto_cmd = data; 140 struct ccp_crypto_cmd *held, *next, *backlog; 141 struct crypto_async_request *req = crypto_cmd->req; 142 struct ccp_ctx *ctx = crypto_tfm_ctx(req->tfm); 143 int ret; 144 145 if (err == -EINPROGRESS) { 146 /* Only propogate the -EINPROGRESS if necessary */ 147 if (crypto_cmd->ret == -EBUSY) { 148 crypto_cmd->ret = -EINPROGRESS; 149 req->complete(req, -EINPROGRESS); 150 } 151 152 return; 153 } 154 155 /* Operation has completed - update the queue before invoking 156 * the completion callbacks and retrieve the next cmd (cmd with 157 * a matching tfm) that can be submitted to the CCP. 158 */ 159 held = ccp_crypto_cmd_complete(crypto_cmd, &backlog); 160 if (backlog) { 161 backlog->ret = -EINPROGRESS; 162 backlog->req->complete(backlog->req, -EINPROGRESS); 163 } 164 165 /* Transition the state from -EBUSY to -EINPROGRESS first */ 166 if (crypto_cmd->ret == -EBUSY) 167 req->complete(req, -EINPROGRESS); 168 169 /* Completion callbacks */ 170 ret = err; 171 if (ctx->complete) 172 ret = ctx->complete(req, ret); 173 req->complete(req, ret); 174 175 /* Submit the next cmd */ 176 while (held) { 177 /* Since we have already queued the cmd, we must indicate that 178 * we can backlog so as not to "lose" this request. 179 */ 180 held->cmd->flags |= CCP_CMD_MAY_BACKLOG; 181 ret = ccp_enqueue_cmd(held->cmd); 182 if (ccp_crypto_success(ret)) 183 break; 184 185 /* Error occurred, report it and get the next entry */ 186 ctx = crypto_tfm_ctx(held->req->tfm); 187 if (ctx->complete) 188 ret = ctx->complete(held->req, ret); 189 held->req->complete(held->req, ret); 190 191 next = ccp_crypto_cmd_complete(held, &backlog); 192 if (backlog) { 193 backlog->ret = -EINPROGRESS; 194 backlog->req->complete(backlog->req, -EINPROGRESS); 195 } 196 197 kfree(held); 198 held = next; 199 } 200 201 kfree(crypto_cmd); 202 } 203 204 static int ccp_crypto_enqueue_cmd(struct ccp_crypto_cmd *crypto_cmd) 205 { 206 struct ccp_crypto_cmd *active = NULL, *tmp; 207 unsigned long flags; 208 bool free_cmd = true; 209 int ret; 210 211 spin_lock_irqsave(&req_queue_lock, flags); 212 213 /* Check if the cmd can/should be queued */ 214 if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) { 215 ret = -EBUSY; 216 if (!(crypto_cmd->cmd->flags & CCP_CMD_MAY_BACKLOG)) 217 goto e_lock; 218 } 219 220 /* Look for an entry with the same tfm. If there is a cmd 221 * with the same tfm in the list then the current cmd cannot 222 * be submitted to the CCP yet. 223 */ 224 list_for_each_entry(tmp, &req_queue.cmds, entry) { 225 if (crypto_cmd->tfm != tmp->tfm) 226 continue; 227 active = tmp; 228 break; 229 } 230 231 ret = -EINPROGRESS; 232 if (!active) { 233 ret = ccp_enqueue_cmd(crypto_cmd->cmd); 234 if (!ccp_crypto_success(ret)) 235 goto e_lock; /* Error, don't queue it */ 236 if ((ret == -EBUSY) && 237 !(crypto_cmd->cmd->flags & CCP_CMD_MAY_BACKLOG)) 238 goto e_lock; /* Not backlogging, don't queue it */ 239 } 240 241 if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) { 242 ret = -EBUSY; 243 if (req_queue.backlog == &req_queue.cmds) 244 req_queue.backlog = &crypto_cmd->entry; 245 } 246 crypto_cmd->ret = ret; 247 248 req_queue.cmd_count++; 249 list_add_tail(&crypto_cmd->entry, &req_queue.cmds); 250 251 free_cmd = false; 252 253 e_lock: 254 spin_unlock_irqrestore(&req_queue_lock, flags); 255 256 if (free_cmd) 257 kfree(crypto_cmd); 258 259 return ret; 260 } 261 262 /** 263 * ccp_crypto_enqueue_request - queue an crypto async request for processing 264 * by the CCP 265 * 266 * @req: crypto_async_request struct to be processed 267 * @cmd: ccp_cmd struct to be sent to the CCP 268 */ 269 int ccp_crypto_enqueue_request(struct crypto_async_request *req, 270 struct ccp_cmd *cmd) 271 { 272 struct ccp_crypto_cmd *crypto_cmd; 273 gfp_t gfp; 274 275 gfp = req->flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL : GFP_ATOMIC; 276 277 crypto_cmd = kzalloc(sizeof(*crypto_cmd), gfp); 278 if (!crypto_cmd) 279 return -ENOMEM; 280 281 /* The tfm pointer must be saved and not referenced from the 282 * crypto_async_request (req) pointer because it is used after 283 * completion callback for the request and the req pointer 284 * might not be valid anymore. 285 */ 286 crypto_cmd->cmd = cmd; 287 crypto_cmd->req = req; 288 crypto_cmd->tfm = req->tfm; 289 290 cmd->callback = ccp_crypto_complete; 291 cmd->data = crypto_cmd; 292 293 if (req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG) 294 cmd->flags |= CCP_CMD_MAY_BACKLOG; 295 else 296 cmd->flags &= ~CCP_CMD_MAY_BACKLOG; 297 298 return ccp_crypto_enqueue_cmd(crypto_cmd); 299 } 300 301 struct scatterlist *ccp_crypto_sg_table_add(struct sg_table *table, 302 struct scatterlist *sg_add) 303 { 304 struct scatterlist *sg, *sg_last = NULL; 305 306 for (sg = table->sgl; sg; sg = sg_next(sg)) 307 if (!sg_page(sg)) 308 break; 309 BUG_ON(!sg); 310 311 for (; sg && sg_add; sg = sg_next(sg), sg_add = sg_next(sg_add)) { 312 sg_set_page(sg, sg_page(sg_add), sg_add->length, 313 sg_add->offset); 314 sg_last = sg; 315 } 316 BUG_ON(sg_add); 317 318 return sg_last; 319 } 320 321 static int ccp_register_algs(void) 322 { 323 int ret; 324 325 if (!aes_disable) { 326 ret = ccp_register_aes_algs(&cipher_algs); 327 if (ret) 328 return ret; 329 330 ret = ccp_register_aes_cmac_algs(&hash_algs); 331 if (ret) 332 return ret; 333 334 ret = ccp_register_aes_xts_algs(&cipher_algs); 335 if (ret) 336 return ret; 337 } 338 339 if (!sha_disable) { 340 ret = ccp_register_sha_algs(&hash_algs); 341 if (ret) 342 return ret; 343 } 344 345 return 0; 346 } 347 348 static void ccp_unregister_algs(void) 349 { 350 struct ccp_crypto_ahash_alg *ahash_alg, *ahash_tmp; 351 struct ccp_crypto_ablkcipher_alg *ablk_alg, *ablk_tmp; 352 353 list_for_each_entry_safe(ahash_alg, ahash_tmp, &hash_algs, entry) { 354 crypto_unregister_ahash(&ahash_alg->alg); 355 list_del(&ahash_alg->entry); 356 kfree(ahash_alg); 357 } 358 359 list_for_each_entry_safe(ablk_alg, ablk_tmp, &cipher_algs, entry) { 360 crypto_unregister_alg(&ablk_alg->alg); 361 list_del(&ablk_alg->entry); 362 kfree(ablk_alg); 363 } 364 } 365 366 static int ccp_crypto_init(void) 367 { 368 int ret; 369 370 ret = ccp_present(); 371 if (ret) 372 return ret; 373 374 spin_lock_init(&req_queue_lock); 375 INIT_LIST_HEAD(&req_queue.cmds); 376 req_queue.backlog = &req_queue.cmds; 377 req_queue.cmd_count = 0; 378 379 ret = ccp_register_algs(); 380 if (ret) 381 ccp_unregister_algs(); 382 383 return ret; 384 } 385 386 static void ccp_crypto_exit(void) 387 { 388 ccp_unregister_algs(); 389 } 390 391 module_init(ccp_crypto_init); 392 module_exit(ccp_crypto_exit); 393