drivers/crypto/ccp/ccp-crypto-main.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AMD Cryptographic Coprocessor (CCP) crypto API support
   4  *
   5  * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
   6  *
   7  * Author: Tom Lendacky <thomas.lendacky@amd.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/moduleparam.h>
  12 #include <linux/kernel.h>
  13 #include <linux/list.h>
  14 #include <linux/ccp.h>
  15 #include <linux/scatterlist.h>
  16 #include <crypto/internal/hash.h>
  17 #include <crypto/internal/akcipher.h>
  18
  19 #include "ccp-crypto.h"
  20
  21 MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
  22 MODULE_LICENSE("GPL");
  23 MODULE_VERSION("1.0.0");
  24 MODULE_DESCRIPTION("AMD Cryptographic Coprocessor crypto API support");
  25
  26 static unsigned int aes_disable;
  27 module_param(aes_disable, uint, 0444);
  28 MODULE_PARM_DESC(aes_disable, "Disable use of AES - any non-zero value");
  29
  30 static unsigned int sha_disable;
  31 module_param(sha_disable, uint, 0444);
  32 MODULE_PARM_DESC(sha_disable, "Disable use of SHA - any non-zero value");
  33
  34 static unsigned int des3_disable;
  35 module_param(des3_disable, uint, 0444);
  36 MODULE_PARM_DESC(des3_disable, "Disable use of 3DES - any non-zero value");
  37
  38 static unsigned int rsa_disable;
  39 module_param(rsa_disable, uint, 0444);
  40 MODULE_PARM_DESC(rsa_disable, "Disable use of RSA - any non-zero value");
  41
  42 /* List heads for the supported algorithms */
  43 static LIST_HEAD(hash_algs);
  44 static LIST_HEAD(skcipher_algs);
  45 static LIST_HEAD(aead_algs);
  46 static LIST_HEAD(akcipher_algs);
  47
  48 /* For any tfm, requests for that tfm must be returned on the order
  49  * received.  With multiple queues available, the CCP can process more
  50  * than one cmd at a time.  Therefore we must maintain a cmd list to insure
  51  * the proper ordering of requests on a given tfm.
  52  */
  53 struct ccp_crypto_queue {
  54         struct list_head cmds;
  55         struct list_head *backlog;
  56         unsigned int cmd_count;
  57 };
  58
  59 #define CCP_CRYPTO_MAX_QLEN     100
  60
  61 static struct ccp_crypto_queue req_queue;
  62 static spinlock_t req_queue_lock;
  63
  64 struct ccp_crypto_cmd {
  65         struct list_head entry;
  66
  67         struct ccp_cmd *cmd;
  68
  69         /* Save the crypto_tfm and crypto_async_request addresses
  70          * separately to avoid any reference to a possibly invalid
  71          * crypto_async_request structure after invoking the request
  72          * callback
  73          */
  74         struct crypto_async_request *req;
  75         struct crypto_tfm *tfm;
  76
  77         /* Used for held command processing to determine state */
  78         int ret;
  79 };
  80
  81 struct ccp_crypto_cpu {
  82         struct work_struct work;
  83         struct completion completion;
  84         struct ccp_crypto_cmd *crypto_cmd;
  85         int err;
  86 };
  87
  88 static inline bool ccp_crypto_success(int err)
  89 {
  90         if (err && (err != -EINPROGRESS) && (err != -EBUSY))
  91                 return false;
  92
  93         return true;
  94 }
  95
  96 static struct ccp_crypto_cmd *ccp_crypto_cmd_complete(
  97         struct ccp_crypto_cmd *crypto_cmd, struct ccp_crypto_cmd **backlog)
  98 {
  99         struct ccp_crypto_cmd *held = NULL, *tmp;
 100         unsigned long flags;
 101
 102         *backlog = NULL;
 103
 104         spin_lock_irqsave(&req_queue_lock, flags);
 105
 106         /* Held cmds will be after the current cmd in the queue so start
 107          * searching for a cmd with a matching tfm for submission.
 108          */
 109         tmp = crypto_cmd;
 110         list_for_each_entry_continue(tmp, &req_queue.cmds, entry) {
 111                 if (crypto_cmd->tfm != tmp->tfm)
 112                         continue;
 113                 held = tmp;
 114                 break;
 115         }
 116
 117         /* Process the backlog:
 118          *   Because cmds can be executed from any point in the cmd list
 119          *   special precautions have to be taken when handling the backlog.
 120          */
 121         if (req_queue.backlog != &req_queue.cmds) {
 122                 /* Skip over this cmd if it is the next backlog cmd */
 123                 if (req_queue.backlog == &crypto_cmd->entry)
 124                         req_queue.backlog = crypto_cmd->entry.next;
 125
 126                 *backlog = container_of(req_queue.backlog,
 127                                         struct ccp_crypto_cmd, entry);
 128                 req_queue.backlog = req_queue.backlog->next;
 129
 130                 /* Skip over this cmd if it is now the next backlog cmd */
 131                 if (req_queue.backlog == &crypto_cmd->entry)
 132                         req_queue.backlog = crypto_cmd->entry.next;
 133         }
 134
 135         /* Remove the cmd entry from the list of cmds */
 136         req_queue.cmd_count--;
 137         list_del(&crypto_cmd->entry);
 138
 139         spin_unlock_irqrestore(&req_queue_lock, flags);
 140
 141         return held;
 142 }
 143
 144 static void ccp_crypto_complete(void *data, int err)
 145 {
 146         struct ccp_crypto_cmd *crypto_cmd = data;
 147         struct ccp_crypto_cmd *held, *next, *backlog;
 148         struct crypto_async_request *req = crypto_cmd->req;
 149         struct ccp_ctx *ctx = crypto_tfm_ctx(req->tfm);
 150         int ret;
 151
 152         if (err == -EINPROGRESS) {
 153                 /* Only propagate the -EINPROGRESS if necessary */
 154                 if (crypto_cmd->ret == -EBUSY) {
 155                         crypto_cmd->ret = -EINPROGRESS;
 156                         req->complete(req, -EINPROGRESS);
 157                 }
 158
 159                 return;
 160         }
 161
 162         /* Operation has completed - update the queue before invoking
 163          * the completion callbacks and retrieve the next cmd (cmd with
 164          * a matching tfm) that can be submitted to the CCP.
 165          */
 166         held = ccp_crypto_cmd_complete(crypto_cmd, &backlog);
 167         if (backlog) {
 168                 backlog->ret = -EINPROGRESS;
 169                 backlog->req->complete(backlog->req, -EINPROGRESS);
 170         }
 171
 172         /* Transition the state from -EBUSY to -EINPROGRESS first */
 173         if (crypto_cmd->ret == -EBUSY)
 174                 req->complete(req, -EINPROGRESS);
 175
 176         /* Completion callbacks */
 177         ret = err;
 178         if (ctx->complete)
 179                 ret = ctx->complete(req, ret);
 180         req->complete(req, ret);
 181
 182         /* Submit the next cmd */
 183         while (held) {
 184                 /* Since we have already queued the cmd, we must indicate that
 185                  * we can backlog so as not to "lose" this request.
 186                  */
 187                 held->cmd->flags |= CCP_CMD_MAY_BACKLOG;
 188                 ret = ccp_enqueue_cmd(held->cmd);
 189                 if (ccp_crypto_success(ret))
 190                         break;
 191
 192                 /* Error occurred, report it and get the next entry */
 193                 ctx = crypto_tfm_ctx(held->req->tfm);
 194                 if (ctx->complete)
 195                         ret = ctx->complete(held->req, ret);
 196                 held->req->complete(held->req, ret);
 197
 198                 next = ccp_crypto_cmd_complete(held, &backlog);
 199                 if (backlog) {
 200                         backlog->ret = -EINPROGRESS;
 201                         backlog->req->complete(backlog->req, -EINPROGRESS);
 202                 }
 203
 204                 kfree(held);
 205                 held = next;
 206         }
 207
 208         kfree(crypto_cmd);
 209 }
 210
 211 static int ccp_crypto_enqueue_cmd(struct ccp_crypto_cmd *crypto_cmd)
 212 {
 213         struct ccp_crypto_cmd *active = NULL, *tmp;
 214         unsigned long flags;
 215         bool free_cmd = true;
 216         int ret;
 217
 218         spin_lock_irqsave(&req_queue_lock, flags);
 219
 220         /* Check if the cmd can/should be queued */
 221         if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) {
 222                 if (!(crypto_cmd->cmd->flags & CCP_CMD_MAY_BACKLOG)) {
 223                         ret = -ENOSPC;
 224                         goto e_lock;
 225                 }
 226         }
 227
 228         /* Look for an entry with the same tfm.  If there is a cmd
 229          * with the same tfm in the list then the current cmd cannot
 230          * be submitted to the CCP yet.
 231          */
 232         list_for_each_entry(tmp, &req_queue.cmds, entry) {
 233                 if (crypto_cmd->tfm != tmp->tfm)
 234                         continue;
 235                 active = tmp;
 236                 break;
 237         }
 238
 239         ret = -EINPROGRESS;
 240         if (!active) {
 241                 ret = ccp_enqueue_cmd(crypto_cmd->cmd);
 242                 if (!ccp_crypto_success(ret))
 243                         goto e_lock;    /* Error, don't queue it */
 244         }
 245
 246         if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) {
 247                 ret = -EBUSY;
 248                 if (req_queue.backlog == &req_queue.cmds)
 249                         req_queue.backlog = &crypto_cmd->entry;
 250         }
 251         crypto_cmd->ret = ret;
 252
 253         req_queue.cmd_count++;
 254         list_add_tail(&crypto_cmd->entry, &req_queue.cmds);
 255
 256         free_cmd = false;
 257
 258 e_lock:
 259         spin_unlock_irqrestore(&req_queue_lock, flags);
 260
 261         if (free_cmd)
 262                 kfree(crypto_cmd);
 263
 264         return ret;
 265 }
 266
 267 /**
 268  * ccp_crypto_enqueue_request - queue an crypto async request for processing
 269  *                              by the CCP
 270  *
 271  * @req: crypto_async_request struct to be processed
 272  * @cmd: ccp_cmd struct to be sent to the CCP
 273  */
 274 int ccp_crypto_enqueue_request(struct crypto_async_request *req,
 275                                struct ccp_cmd *cmd)
 276 {
 277         struct ccp_crypto_cmd *crypto_cmd;
 278         gfp_t gfp;
 279
 280         gfp = req->flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
 281
 282         crypto_cmd = kzalloc(sizeof(*crypto_cmd), gfp);
 283         if (!crypto_cmd)
 284                 return -ENOMEM;
 285
 286         /* The tfm pointer must be saved and not referenced from the
 287          * crypto_async_request (req) pointer because it is used after
 288          * completion callback for the request and the req pointer
 289          * might not be valid anymore.
 290          */
 291         crypto_cmd->cmd = cmd;
 292         crypto_cmd->req = req;
 293         crypto_cmd->tfm = req->tfm;
 294
 295         cmd->callback = ccp_crypto_complete;
 296         cmd->data = crypto_cmd;
 297
 298         if (req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)
 299                 cmd->flags |= CCP_CMD_MAY_BACKLOG;
 300         else
 301                 cmd->flags &= ~CCP_CMD_MAY_BACKLOG;
 302
 303         return ccp_crypto_enqueue_cmd(crypto_cmd);
 304 }
 305
 306 struct scatterlist *ccp_crypto_sg_table_add(struct sg_table *table,
 307                                             struct scatterlist *sg_add)
 308 {
 309         struct scatterlist *sg, *sg_last = NULL;
 310
 311         for (sg = table->sgl; sg; sg = sg_next(sg))
 312                 if (!sg_page(sg))
 313                         break;
 314         if (WARN_ON(!sg))
 315                 return NULL;
 316
 317         for (; sg && sg_add; sg = sg_next(sg), sg_add = sg_next(sg_add)) {
 318                 sg_set_page(sg, sg_page(sg_add), sg_add->length,
 319                             sg_add->offset);
 320                 sg_last = sg;
 321         }
 322         if (WARN_ON(sg_add))
 323                 return NULL;
 324
 325         return sg_last;
 326 }
 327
 328 static int ccp_register_algs(void)
 329 {
 330         int ret;
 331
 332         if (!aes_disable) {
 333                 ret = ccp_register_aes_algs(&skcipher_algs);
 334                 if (ret)
 335                         return ret;
 336
 337                 ret = ccp_register_aes_cmac_algs(&hash_algs);
 338                 if (ret)
 339                         return ret;
 340
 341                 ret = ccp_register_aes_xts_algs(&skcipher_algs);
 342                 if (ret)
 343                         return ret;
 344
 345                 ret = ccp_register_aes_aeads(&aead_algs);
 346                 if (ret)
 347                         return ret;
 348         }
 349
 350         if (!des3_disable) {
 351                 ret = ccp_register_des3_algs(&skcipher_algs);
 352                 if (ret)
 353                         return ret;
 354         }
 355
 356         if (!sha_disable) {
 357                 ret = ccp_register_sha_algs(&hash_algs);
 358                 if (ret)
 359                         return ret;
 360         }
 361
 362         if (!rsa_disable) {
 363                 ret = ccp_register_rsa_algs(&akcipher_algs);
 364                 if (ret)
 365                         return ret;
 366         }
 367
 368         return 0;
 369 }
 370
 371 static void ccp_unregister_algs(void)
 372 {
 373         struct ccp_crypto_ahash_alg *ahash_alg, *ahash_tmp;
 374         struct ccp_crypto_skcipher_alg *ablk_alg, *ablk_tmp;
 375         struct ccp_crypto_aead *aead_alg, *aead_tmp;
 376         struct ccp_crypto_akcipher_alg *akc_alg, *akc_tmp;
 377
 378         list_for_each_entry_safe(ahash_alg, ahash_tmp, &hash_algs, entry) {
 379                 crypto_unregister_ahash(&ahash_alg->alg);
 380                 list_del(&ahash_alg->entry);
 381                 kfree(ahash_alg);
 382         }
 383
 384         list_for_each_entry_safe(ablk_alg, ablk_tmp, &skcipher_algs, entry) {
 385                 crypto_unregister_skcipher(&ablk_alg->alg);
 386                 list_del(&ablk_alg->entry);
 387                 kfree(ablk_alg);
 388         }
 389
 390         list_for_each_entry_safe(aead_alg, aead_tmp, &aead_algs, entry) {
 391                 crypto_unregister_aead(&aead_alg->alg);
 392                 list_del(&aead_alg->entry);
 393                 kfree(aead_alg);
 394         }
 395
 396         list_for_each_entry_safe(akc_alg, akc_tmp, &akcipher_algs, entry) {
 397                 crypto_unregister_akcipher(&akc_alg->alg);
 398                 list_del(&akc_alg->entry);
 399                 kfree(akc_alg);
 400         }
 401 }
 402
 403 static int ccp_crypto_init(void)
 404 {
 405         int ret;
 406
 407         ret = ccp_present();
 408         if (ret) {
 409                 pr_err("Cannot load: there are no available CCPs\n");
 410                 return ret;
 411         }
 412
 413         spin_lock_init(&req_queue_lock);
 414         INIT_LIST_HEAD(&req_queue.cmds);
 415         req_queue.backlog = &req_queue.cmds;
 416         req_queue.cmd_count = 0;
 417
 418         ret = ccp_register_algs();
 419         if (ret)
 420                 ccp_unregister_algs();
 421
 422         return ret;
 423 }
 424
 425 static void ccp_crypto_exit(void)
 426 {
 427         ccp_unregister_algs();
 428 }
 429
 430 module_init(ccp_crypto_init);
 431 module_exit(ccp_crypto_exit);