drivers/crypto/ccp/ccp-dev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AMD Cryptographic Coprocessor (CCP) driver
   4  *
   5  * Copyright (C) 2013,2019 Advanced Micro Devices, Inc.
   6  *
   7  * Author: Tom Lendacky <[email protected]>
   8  * Author: Gary R Hook <[email protected]>
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/kthread.h>
  14 #include <linux/sched.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/spinlock_types.h>
  18 #include <linux/types.h>
  19 #include <linux/mutex.h>
  20 #include <linux/delay.h>
  21 #include <linux/hw_random.h>
  22 #include <linux/cpu.h>
  23 #include <linux/atomic.h>
  24 #ifdef CONFIG_X86
  25 #include <asm/cpu_device_id.h>
  26 #endif
  27 #include <linux/ccp.h>
  28
  29 #include "ccp-dev.h"
  30
  31 #define MAX_CCPS 32
  32
  33 /* Limit CCP use to a specifed number of queues per device */
  34 static unsigned int nqueues = 0;
  35 module_param(nqueues, uint, 0444);
  36 MODULE_PARM_DESC(nqueues, "Number of queues per CCP (minimum 1; default: all available)");
  37
  38 /* Limit the maximum number of configured CCPs */
  39 static atomic_t dev_count = ATOMIC_INIT(0);
  40 static unsigned int max_devs = MAX_CCPS;
  41 module_param(max_devs, uint, 0444);
  42 MODULE_PARM_DESC(max_devs, "Maximum number of CCPs to enable (default: all; 0 disables all CCPs)");
  43
  44 struct ccp_tasklet_data {
  45         struct completion completion;
  46         struct ccp_cmd *cmd;
  47 };
  48
  49 /* Human-readable error strings */
  50 #define CCP_MAX_ERROR_CODE      64
  51 static char *ccp_error_codes[] = {
  52         "",
  53         "ILLEGAL_ENGINE",
  54         "ILLEGAL_KEY_ID",
  55         "ILLEGAL_FUNCTION_TYPE",
  56         "ILLEGAL_FUNCTION_MODE",
  57         "ILLEGAL_FUNCTION_ENCRYPT",
  58         "ILLEGAL_FUNCTION_SIZE",
  59         "Zlib_MISSING_INIT_EOM",
  60         "ILLEGAL_FUNCTION_RSVD",
  61         "ILLEGAL_BUFFER_LENGTH",
  62         "VLSB_FAULT",
  63         "ILLEGAL_MEM_ADDR",
  64         "ILLEGAL_MEM_SEL",
  65         "ILLEGAL_CONTEXT_ID",
  66         "ILLEGAL_KEY_ADDR",
  67         "0xF Reserved",
  68         "Zlib_ILLEGAL_MULTI_QUEUE",
  69         "Zlib_ILLEGAL_JOBID_CHANGE",
  70         "CMD_TIMEOUT",
  71         "IDMA0_AXI_SLVERR",
  72         "IDMA0_AXI_DECERR",
  73         "0x15 Reserved",
  74         "IDMA1_AXI_SLAVE_FAULT",
  75         "IDMA1_AIXI_DECERR",
  76         "0x18 Reserved",
  77         "ZLIBVHB_AXI_SLVERR",
  78         "ZLIBVHB_AXI_DECERR",
  79         "0x1B Reserved",
  80         "ZLIB_UNEXPECTED_EOM",
  81         "ZLIB_EXTRA_DATA",
  82         "ZLIB_BTYPE",
  83         "ZLIB_UNDEFINED_SYMBOL",
  84         "ZLIB_UNDEFINED_DISTANCE_S",
  85         "ZLIB_CODE_LENGTH_SYMBOL",
  86         "ZLIB _VHB_ILLEGAL_FETCH",
  87         "ZLIB_UNCOMPRESSED_LEN",
  88         "ZLIB_LIMIT_REACHED",
  89         "ZLIB_CHECKSUM_MISMATCH0",
  90         "ODMA0_AXI_SLVERR",
  91         "ODMA0_AXI_DECERR",
  92         "0x28 Reserved",
  93         "ODMA1_AXI_SLVERR",
  94         "ODMA1_AXI_DECERR",
  95 };
  96
  97 void ccp_log_error(struct ccp_device *d, unsigned int e)
  98 {
  99         if (WARN_ON(e >= CCP_MAX_ERROR_CODE))
 100                 return;
 101
 102         if (e < ARRAY_SIZE(ccp_error_codes))
 103                 dev_err(d->dev, "CCP error %d: %s\n", e, ccp_error_codes[e]);
 104         else
 105                 dev_err(d->dev, "CCP error %d: Unknown Error\n", e);
 106 }
 107
 108 /* List of CCPs, CCP count, read-write access lock, and access functions
 109  *
 110  * Lock structure: get ccp_unit_lock for reading whenever we need to
 111  * examine the CCP list. While holding it for reading we can acquire
 112  * the RR lock to update the round-robin next-CCP pointer. The unit lock
 113  * must be acquired before the RR lock.
 114  *
 115  * If the unit-lock is acquired for writing, we have total control over
 116  * the list, so there's no value in getting the RR lock.
 117  */
 118 static DEFINE_RWLOCK(ccp_unit_lock);
 119 static LIST_HEAD(ccp_units);
 120
 121 /* Round-robin counter */
 122 static DEFINE_SPINLOCK(ccp_rr_lock);
 123 static struct ccp_device *ccp_rr;
 124
 125 /**
 126  * ccp_add_device - add a CCP device to the list
 127  *
 128  * @ccp: ccp_device struct pointer
 129  *
 130  * Put this CCP on the unit list, which makes it available
 131  * for use.
 132  *
 133  * Returns zero if a CCP device is present, -ENODEV otherwise.
 134  */
 135 void ccp_add_device(struct ccp_device *ccp)
 136 {
 137         unsigned long flags;
 138
 139         write_lock_irqsave(&ccp_unit_lock, flags);
 140         list_add_tail(&ccp->entry, &ccp_units);
 141         if (!ccp_rr)
 142                 /* We already have the list lock (we're first) so this
 143                  * pointer can't change on us. Set its initial value.
 144                  */
 145                 ccp_rr = ccp;
 146         write_unlock_irqrestore(&ccp_unit_lock, flags);
 147 }
 148
 149 /**
 150  * ccp_del_device - remove a CCP device from the list
 151  *
 152  * @ccp: ccp_device struct pointer
 153  *
 154  * Remove this unit from the list of devices. If the next device
 155  * up for use is this one, adjust the pointer. If this is the last
 156  * device, NULL the pointer.
 157  */
 158 void ccp_del_device(struct ccp_device *ccp)
 159 {
 160         unsigned long flags;
 161
 162         write_lock_irqsave(&ccp_unit_lock, flags);
 163         if (ccp_rr == ccp) {
 164                 /* ccp_unit_lock is read/write; any read access
 165                  * will be suspended while we make changes to the
 166                  * list and RR pointer.
 167                  */
 168                 if (list_is_last(&ccp_rr->entry, &ccp_units))
 169                         ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
 170                                                   entry);
 171                 else
 172                         ccp_rr = list_next_entry(ccp_rr, entry);
 173         }
 174         list_del(&ccp->entry);
 175         if (list_empty(&ccp_units))
 176                 ccp_rr = NULL;
 177         write_unlock_irqrestore(&ccp_unit_lock, flags);
 178 }
 179
 180
 181
 182 int ccp_register_rng(struct ccp_device *ccp)
 183 {
 184         int ret = 0;
 185
 186         dev_dbg(ccp->dev, "Registering RNG...\n");
 187         /* Register an RNG */
 188         ccp->hwrng.name = ccp->rngname;
 189         ccp->hwrng.read = ccp_trng_read;
 190         ret = hwrng_register(&ccp->hwrng);
 191         if (ret)
 192                 dev_err(ccp->dev, "error registering hwrng (%d)\n", ret);
 193
 194         return ret;
 195 }
 196
 197 void ccp_unregister_rng(struct ccp_device *ccp)
 198 {
 199         if (ccp->hwrng.name)
 200                 hwrng_unregister(&ccp->hwrng);
 201 }
 202
 203 static struct ccp_device *ccp_get_device(void)
 204 {
 205         unsigned long flags;
 206         struct ccp_device *dp = NULL;
 207
 208         /* We round-robin through the unit list.
 209          * The (ccp_rr) pointer refers to the next unit to use.
 210          */
 211         read_lock_irqsave(&ccp_unit_lock, flags);
 212         if (!list_empty(&ccp_units)) {
 213                 spin_lock(&ccp_rr_lock);
 214                 dp = ccp_rr;
 215                 if (list_is_last(&ccp_rr->entry, &ccp_units))
 216                         ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
 217                                                   entry);
 218                 else
 219                         ccp_rr = list_next_entry(ccp_rr, entry);
 220                 spin_unlock(&ccp_rr_lock);
 221         }
 222         read_unlock_irqrestore(&ccp_unit_lock, flags);
 223
 224         return dp;
 225 }
 226
 227 /**
 228  * ccp_present - check if a CCP device is present
 229  *
 230  * Returns zero if a CCP device is present, -ENODEV otherwise.
 231  */
 232 int ccp_present(void)
 233 {
 234         unsigned long flags;
 235         int ret;
 236
 237         read_lock_irqsave(&ccp_unit_lock, flags);
 238         ret = list_empty(&ccp_units);
 239         read_unlock_irqrestore(&ccp_unit_lock, flags);
 240
 241         return ret ? -ENODEV : 0;
 242 }
 243 EXPORT_SYMBOL_GPL(ccp_present);
 244
 245 /**
 246  * ccp_version - get the version of the CCP device
 247  *
 248  * Returns the version from the first unit on the list;
 249  * otherwise a zero if no CCP device is present
 250  */
 251 unsigned int ccp_version(void)
 252 {
 253         struct ccp_device *dp;
 254         unsigned long flags;
 255         int ret = 0;
 256
 257         read_lock_irqsave(&ccp_unit_lock, flags);
 258         if (!list_empty(&ccp_units)) {
 259                 dp = list_first_entry(&ccp_units, struct ccp_device, entry);
 260                 ret = dp->vdata->version;
 261         }
 262         read_unlock_irqrestore(&ccp_unit_lock, flags);
 263
 264         return ret;
 265 }
 266 EXPORT_SYMBOL_GPL(ccp_version);
 267
 268 /**
 269  * ccp_enqueue_cmd - queue an operation for processing by the CCP
 270  *
 271  * @cmd: ccp_cmd struct to be processed
 272  *
 273  * Queue a cmd to be processed by the CCP. If queueing the cmd
 274  * would exceed the defined length of the cmd queue the cmd will
 275  * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
 276  * result in a return code of -EBUSY.
 277  *
 278  * The callback routine specified in the ccp_cmd struct will be
 279  * called to notify the caller of completion (if the cmd was not
 280  * backlogged) or advancement out of the backlog. If the cmd has
 281  * advanced out of the backlog the "err" value of the callback
 282  * will be -EINPROGRESS. Any other "err" value during callback is
 283  * the result of the operation.
 284  *
 285  * The cmd has been successfully queued if:
 286  *   the return code is -EINPROGRESS or
 287  *   the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
 288  */
 289 int ccp_enqueue_cmd(struct ccp_cmd *cmd)
 290 {
 291         struct ccp_device *ccp;
 292         unsigned long flags;
 293         unsigned int i;
 294         int ret;
 295
 296         /* Some commands might need to be sent to a specific device */
 297         ccp = cmd->ccp ? cmd->ccp : ccp_get_device();
 298
 299         if (!ccp)
 300                 return -ENODEV;
 301
 302         /* Caller must supply a callback routine */
 303         if (!cmd->callback)
 304                 return -EINVAL;
 305
 306         cmd->ccp = ccp;
 307
 308         spin_lock_irqsave(&ccp->cmd_lock, flags);
 309
 310         i = ccp->cmd_q_count;
 311
 312         if (ccp->cmd_count >= MAX_CMD_QLEN) {
 313                 if (cmd->flags & CCP_CMD_MAY_BACKLOG) {
 314                         ret = -EBUSY;
 315                         list_add_tail(&cmd->entry, &ccp->backlog);
 316                 } else {
 317                         ret = -ENOSPC;
 318                 }
 319         } else {
 320                 ret = -EINPROGRESS;
 321                 ccp->cmd_count++;
 322                 list_add_tail(&cmd->entry, &ccp->cmd);
 323
 324                 /* Find an idle queue */
 325                 if (!ccp->suspending) {
 326                         for (i = 0; i < ccp->cmd_q_count; i++) {
 327                                 if (ccp->cmd_q[i].active)
 328                                         continue;
 329
 330                                 break;
 331                         }
 332                 }
 333         }
 334
 335         spin_unlock_irqrestore(&ccp->cmd_lock, flags);
 336
 337         /* If we found an idle queue, wake it up */
 338         if (i < ccp->cmd_q_count)
 339                 wake_up_process(ccp->cmd_q[i].kthread);
 340
 341         return ret;
 342 }
 343 EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
 344
 345 static void ccp_do_cmd_backlog(struct work_struct *work)
 346 {
 347         struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
 348         struct ccp_device *ccp = cmd->ccp;
 349         unsigned long flags;
 350         unsigned int i;
 351
 352         cmd->callback(cmd->data, -EINPROGRESS);
 353
 354         spin_lock_irqsave(&ccp->cmd_lock, flags);
 355
 356         ccp->cmd_count++;
 357         list_add_tail(&cmd->entry, &ccp->cmd);
 358
 359         /* Find an idle queue */
 360         for (i = 0; i < ccp->cmd_q_count; i++) {
 361                 if (ccp->cmd_q[i].active)
 362                         continue;
 363
 364                 break;
 365         }
 366
 367         spin_unlock_irqrestore(&ccp->cmd_lock, flags);
 368
 369         /* If we found an idle queue, wake it up */
 370         if (i < ccp->cmd_q_count)
 371                 wake_up_process(ccp->cmd_q[i].kthread);
 372 }
 373
 374 static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
 375 {
 376         struct ccp_device *ccp = cmd_q->ccp;
 377         struct ccp_cmd *cmd = NULL;
 378         struct ccp_cmd *backlog = NULL;
 379         unsigned long flags;
 380
 381         spin_lock_irqsave(&ccp->cmd_lock, flags);
 382
 383         cmd_q->active = 0;
 384
 385         if (ccp->suspending) {
 386                 cmd_q->suspended = 1;
 387
 388                 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
 389                 wake_up_interruptible(&ccp->suspend_queue);
 390
 391                 return NULL;
 392         }
 393
 394         if (ccp->cmd_count) {
 395                 cmd_q->active = 1;
 396
 397                 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
 398                 list_del(&cmd->entry);
 399
 400                 ccp->cmd_count--;
 401         }
 402
 403         if (!list_empty(&ccp->backlog)) {
 404                 backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
 405                                            entry);
 406                 list_del(&backlog->entry);
 407         }
 408
 409         spin_unlock_irqrestore(&ccp->cmd_lock, flags);
 410
 411         if (backlog) {
 412                 INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
 413                 schedule_work(&backlog->work);
 414         }
 415
 416         return cmd;
 417 }
 418
 419 static void ccp_do_cmd_complete(unsigned long data)
 420 {
 421         struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
 422         struct ccp_cmd *cmd = tdata->cmd;
 423
 424         cmd->callback(cmd->data, cmd->ret);
 425
 426         complete(&tdata->completion);
 427 }
 428
 429 /**
 430  * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
 431  *
 432  * @data: thread-specific data
 433  */
 434 int ccp_cmd_queue_thread(void *data)
 435 {
 436         struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
 437         struct ccp_cmd *cmd;
 438         struct ccp_tasklet_data tdata;
 439         struct tasklet_struct tasklet;
 440
 441         tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);
 442
 443         set_current_state(TASK_INTERRUPTIBLE);
 444         while (!kthread_should_stop()) {
 445                 schedule();
 446
 447                 set_current_state(TASK_INTERRUPTIBLE);
 448
 449                 cmd = ccp_dequeue_cmd(cmd_q);
 450                 if (!cmd)
 451                         continue;
 452
 453                 __set_current_state(TASK_RUNNING);
 454
 455                 /* Execute the command */
 456                 cmd->ret = ccp_run_cmd(cmd_q, cmd);
 457
 458                 /* Schedule the completion callback */
 459                 tdata.cmd = cmd;
 460                 init_completion(&tdata.completion);
 461                 tasklet_schedule(&tasklet);
 462                 wait_for_completion(&tdata.completion);
 463         }
 464
 465         __set_current_state(TASK_RUNNING);
 466
 467         return 0;
 468 }
 469
 470 /**
 471  * ccp_alloc_struct - allocate and initialize the ccp_device struct
 472  *
 473  * @dev: device struct of the CCP
 474  */
 475 struct ccp_device *ccp_alloc_struct(struct sp_device *sp)
 476 {
 477         struct device *dev = sp->dev;
 478         struct ccp_device *ccp;
 479
 480         ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL);
 481         if (!ccp)
 482                 return NULL;
 483         ccp->dev = dev;
 484         ccp->sp = sp;
 485         ccp->axcache = sp->axcache;
 486
 487         INIT_LIST_HEAD(&ccp->cmd);
 488         INIT_LIST_HEAD(&ccp->backlog);
 489
 490         spin_lock_init(&ccp->cmd_lock);
 491         mutex_init(&ccp->req_mutex);
 492         mutex_init(&ccp->sb_mutex);
 493         ccp->sb_count = KSB_COUNT;
 494         ccp->sb_start = 0;
 495
 496         /* Initialize the wait queues */
 497         init_waitqueue_head(&ccp->sb_queue);
 498         init_waitqueue_head(&ccp->suspend_queue);
 499
 500         snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", sp->ord);
 501         snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", sp->ord);
 502
 503         return ccp;
 504 }
 505
 506 int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 507 {
 508         struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
 509         u32 trng_value;
 510         int len = min_t(int, sizeof(trng_value), max);
 511
 512         /* Locking is provided by the caller so we can update device
 513          * hwrng-related fields safely
 514          */
 515         trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
 516         if (!trng_value) {
 517                 /* Zero is returned if not data is available or if a
 518                  * bad-entropy error is present. Assume an error if
 519                  * we exceed TRNG_RETRIES reads of zero.
 520                  */
 521                 if (ccp->hwrng_retries++ > TRNG_RETRIES)
 522                         return -EIO;
 523
 524                 return 0;
 525         }
 526
 527         /* Reset the counter and save the rng value */
 528         ccp->hwrng_retries = 0;
 529         memcpy(data, &trng_value, len);
 530
 531         return len;
 532 }
 533
 534 #ifdef CONFIG_PM
 535 bool ccp_queues_suspended(struct ccp_device *ccp)
 536 {
 537         unsigned int suspended = 0;
 538         unsigned long flags;
 539         unsigned int i;
 540
 541         spin_lock_irqsave(&ccp->cmd_lock, flags);
 542
 543         for (i = 0; i < ccp->cmd_q_count; i++)
 544                 if (ccp->cmd_q[i].suspended)
 545                         suspended++;
 546
 547         spin_unlock_irqrestore(&ccp->cmd_lock, flags);
 548
 549         return ccp->cmd_q_count == suspended;
 550 }
 551
 552 int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
 553 {
 554         struct ccp_device *ccp = sp->ccp_data;
 555         unsigned long flags;
 556         unsigned int i;
 557
 558         /* If there's no device there's nothing to do */
 559         if (!ccp)
 560                 return 0;
 561
 562         spin_lock_irqsave(&ccp->cmd_lock, flags);
 563
 564         ccp->suspending = 1;
 565
 566         /* Wake all the queue kthreads to prepare for suspend */
 567         for (i = 0; i < ccp->cmd_q_count; i++)
 568                 wake_up_process(ccp->cmd_q[i].kthread);
 569
 570         spin_unlock_irqrestore(&ccp->cmd_lock, flags);
 571
 572         /* Wait for all queue kthreads to say they're done */
 573         while (!ccp_queues_suspended(ccp))
 574                 wait_event_interruptible(ccp->suspend_queue,
 575                                          ccp_queues_suspended(ccp));
 576
 577         return 0;
 578 }
 579
 580 int ccp_dev_resume(struct sp_device *sp)
 581 {
 582         struct ccp_device *ccp = sp->ccp_data;
 583         unsigned long flags;
 584         unsigned int i;
 585
 586         /* If there's no device there's nothing to do */
 587         if (!ccp)
 588                 return 0;
 589
 590         spin_lock_irqsave(&ccp->cmd_lock, flags);
 591
 592         ccp->suspending = 0;
 593
 594         /* Wake up all the kthreads */
 595         for (i = 0; i < ccp->cmd_q_count; i++) {
 596                 ccp->cmd_q[i].suspended = 0;
 597                 wake_up_process(ccp->cmd_q[i].kthread);
 598         }
 599
 600         spin_unlock_irqrestore(&ccp->cmd_lock, flags);
 601
 602         return 0;
 603 }
 604 #endif
 605
 606 int ccp_dev_init(struct sp_device *sp)
 607 {
 608         struct device *dev = sp->dev;
 609         struct ccp_device *ccp;
 610         int ret;
 611
 612         /*
 613          * Check how many we have so far, and stop after reaching
 614          * that number
 615          */
 616         if (atomic_inc_return(&dev_count) > max_devs)
 617                 return 0; /* don't fail the load */
 618
 619         ret = -ENOMEM;
 620         ccp = ccp_alloc_struct(sp);
 621         if (!ccp)
 622                 goto e_err;
 623         sp->ccp_data = ccp;
 624
 625         if (!nqueues || (nqueues > MAX_HW_QUEUES))
 626                 ccp->max_q_count = MAX_HW_QUEUES;
 627         else
 628                 ccp->max_q_count = nqueues;
 629
 630         ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
 631         if (!ccp->vdata || !ccp->vdata->version) {
 632                 ret = -ENODEV;
 633                 dev_err(dev, "missing driver data\n");
 634                 goto e_err;
 635         }
 636
 637         ccp->use_tasklet = sp->use_tasklet;
 638
 639         ccp->io_regs = sp->io_map + ccp->vdata->offset;
 640         if (ccp->vdata->setup)
 641                 ccp->vdata->setup(ccp);
 642
 643         ret = ccp->vdata->perform->init(ccp);
 644         if (ret) {
 645                 /* A positive number means that the device cannot be initialized,
 646                  * but no additional message is required.
 647                  */
 648                 if (ret > 0)
 649                         goto e_quiet;
 650
 651                 /* An unexpected problem occurred, and should be reported in the log */
 652                 goto e_err;
 653         }
 654
 655         dev_notice(dev, "ccp enabled\n");
 656
 657         return 0;
 658
 659 e_err:
 660         dev_notice(dev, "ccp initialization failed\n");
 661
 662 e_quiet:
 663         sp->ccp_data = NULL;
 664
 665         return ret;
 666 }
 667
 668 void ccp_dev_destroy(struct sp_device *sp)
 669 {
 670         struct ccp_device *ccp = sp->ccp_data;
 671
 672         if (!ccp)
 673                 return;
 674
 675         ccp->vdata->perform->destroy(ccp);
 676 }