1 // SPDX-License-Identifier: GPL-2.0-only
3 * AMD Cryptographic Coprocessor (CCP) driver
5 * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
7 * Author: Tom Lendacky <thomas.lendacky@amd.com>
8 * Author: Gary R Hook <gary.hook@amd.com>
11 #include <linux/kernel.h>
12 #include <linux/kthread.h>
13 #include <linux/sched.h>
14 #include <linux/interrupt.h>
15 #include <linux/spinlock.h>
16 #include <linux/spinlock_types.h>
17 #include <linux/types.h>
18 #include <linux/mutex.h>
19 #include <linux/delay.h>
20 #include <linux/hw_random.h>
21 #include <linux/cpu.h>
23 #include <asm/cpu_device_id.h>
25 #include <linux/ccp.h>
29 struct ccp_tasklet_data {
30 struct completion completion;
34 /* Human-readable error strings */
35 #define CCP_MAX_ERROR_CODE 64
36 static char *ccp_error_codes[] = {
40 "ILLEGAL_FUNCTION_TYPE",
41 "ILLEGAL_FUNCTION_MODE",
42 "ILLEGAL_FUNCTION_ENCRYPT",
43 "ILLEGAL_FUNCTION_SIZE",
44 "Zlib_MISSING_INIT_EOM",
45 "ILLEGAL_FUNCTION_RSVD",
46 "ILLEGAL_BUFFER_LENGTH",
53 "Zlib_ILLEGAL_MULTI_QUEUE",
54 "Zlib_ILLEGAL_JOBID_CHANGE",
59 "IDMA1_AXI_SLAVE_FAULT",
65 "ZLIB_UNEXPECTED_EOM",
68 "ZLIB_UNDEFINED_SYMBOL",
69 "ZLIB_UNDEFINED_DISTANCE_S",
70 "ZLIB_CODE_LENGTH_SYMBOL",
71 "ZLIB _VHB_ILLEGAL_FETCH",
72 "ZLIB_UNCOMPRESSED_LEN",
74 "ZLIB_CHECKSUM_MISMATCH0",
82 void ccp_log_error(struct ccp_device *d, unsigned int e)
84 if (WARN_ON(e >= CCP_MAX_ERROR_CODE))
87 if (e < ARRAY_SIZE(ccp_error_codes))
88 dev_err(d->dev, "CCP error %d: %s\n", e, ccp_error_codes[e]);
90 dev_err(d->dev, "CCP error %d: Unknown Error\n", e);
93 /* List of CCPs, CCP count, read-write access lock, and access functions
95 * Lock structure: get ccp_unit_lock for reading whenever we need to
96 * examine the CCP list. While holding it for reading we can acquire
97 * the RR lock to update the round-robin next-CCP pointer. The unit lock
98 * must be acquired before the RR lock.
100 * If the unit-lock is acquired for writing, we have total control over
101 * the list, so there's no value in getting the RR lock.
103 static DEFINE_RWLOCK(ccp_unit_lock);
104 static LIST_HEAD(ccp_units);
106 /* Round-robin counter */
107 static DEFINE_SPINLOCK(ccp_rr_lock);
108 static struct ccp_device *ccp_rr;
111 * ccp_add_device - add a CCP device to the list
113 * @ccp: ccp_device struct pointer
115 * Put this CCP on the unit list, which makes it available
118 * Returns zero if a CCP device is present, -ENODEV otherwise.
120 void ccp_add_device(struct ccp_device *ccp)
124 write_lock_irqsave(&ccp_unit_lock, flags);
125 list_add_tail(&ccp->entry, &ccp_units);
127 /* We already have the list lock (we're first) so this
128 * pointer can't change on us. Set its initial value.
131 write_unlock_irqrestore(&ccp_unit_lock, flags);
135 * ccp_del_device - remove a CCP device from the list
137 * @ccp: ccp_device struct pointer
139 * Remove this unit from the list of devices. If the next device
140 * up for use is this one, adjust the pointer. If this is the last
141 * device, NULL the pointer.
143 void ccp_del_device(struct ccp_device *ccp)
147 write_lock_irqsave(&ccp_unit_lock, flags);
149 /* ccp_unit_lock is read/write; any read access
150 * will be suspended while we make changes to the
151 * list and RR pointer.
153 if (list_is_last(&ccp_rr->entry, &ccp_units))
154 ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
157 ccp_rr = list_next_entry(ccp_rr, entry);
159 list_del(&ccp->entry);
160 if (list_empty(&ccp_units))
162 write_unlock_irqrestore(&ccp_unit_lock, flags);
167 int ccp_register_rng(struct ccp_device *ccp)
171 dev_dbg(ccp->dev, "Registering RNG...\n");
172 /* Register an RNG */
173 ccp->hwrng.name = ccp->rngname;
174 ccp->hwrng.read = ccp_trng_read;
175 ret = hwrng_register(&ccp->hwrng);
177 dev_err(ccp->dev, "error registering hwrng (%d)\n", ret);
182 void ccp_unregister_rng(struct ccp_device *ccp)
185 hwrng_unregister(&ccp->hwrng);
188 static struct ccp_device *ccp_get_device(void)
191 struct ccp_device *dp = NULL;
193 /* We round-robin through the unit list.
194 * The (ccp_rr) pointer refers to the next unit to use.
196 read_lock_irqsave(&ccp_unit_lock, flags);
197 if (!list_empty(&ccp_units)) {
198 spin_lock(&ccp_rr_lock);
200 if (list_is_last(&ccp_rr->entry, &ccp_units))
201 ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
204 ccp_rr = list_next_entry(ccp_rr, entry);
205 spin_unlock(&ccp_rr_lock);
207 read_unlock_irqrestore(&ccp_unit_lock, flags);
213 * ccp_present - check if a CCP device is present
215 * Returns zero if a CCP device is present, -ENODEV otherwise.
217 int ccp_present(void)
222 read_lock_irqsave(&ccp_unit_lock, flags);
223 ret = list_empty(&ccp_units);
224 read_unlock_irqrestore(&ccp_unit_lock, flags);
226 return ret ? -ENODEV : 0;
228 EXPORT_SYMBOL_GPL(ccp_present);
231 * ccp_version - get the version of the CCP device
233 * Returns the version from the first unit on the list;
234 * otherwise a zero if no CCP device is present
236 unsigned int ccp_version(void)
238 struct ccp_device *dp;
242 read_lock_irqsave(&ccp_unit_lock, flags);
243 if (!list_empty(&ccp_units)) {
244 dp = list_first_entry(&ccp_units, struct ccp_device, entry);
245 ret = dp->vdata->version;
247 read_unlock_irqrestore(&ccp_unit_lock, flags);
251 EXPORT_SYMBOL_GPL(ccp_version);
254 * ccp_enqueue_cmd - queue an operation for processing by the CCP
256 * @cmd: ccp_cmd struct to be processed
258 * Queue a cmd to be processed by the CCP. If queueing the cmd
259 * would exceed the defined length of the cmd queue the cmd will
260 * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
261 * result in a return code of -EBUSY.
263 * The callback routine specified in the ccp_cmd struct will be
264 * called to notify the caller of completion (if the cmd was not
265 * backlogged) or advancement out of the backlog. If the cmd has
266 * advanced out of the backlog the "err" value of the callback
267 * will be -EINPROGRESS. Any other "err" value during callback is
268 * the result of the operation.
270 * The cmd has been successfully queued if:
271 * the return code is -EINPROGRESS or
272 * the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
274 int ccp_enqueue_cmd(struct ccp_cmd *cmd)
276 struct ccp_device *ccp;
281 /* Some commands might need to be sent to a specific device */
282 ccp = cmd->ccp ? cmd->ccp : ccp_get_device();
287 /* Caller must supply a callback routine */
293 spin_lock_irqsave(&ccp->cmd_lock, flags);
295 i = ccp->cmd_q_count;
297 if (ccp->cmd_count >= MAX_CMD_QLEN) {
298 if (cmd->flags & CCP_CMD_MAY_BACKLOG) {
300 list_add_tail(&cmd->entry, &ccp->backlog);
307 list_add_tail(&cmd->entry, &ccp->cmd);
309 /* Find an idle queue */
310 if (!ccp->suspending) {
311 for (i = 0; i < ccp->cmd_q_count; i++) {
312 if (ccp->cmd_q[i].active)
320 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
322 /* If we found an idle queue, wake it up */
323 if (i < ccp->cmd_q_count)
324 wake_up_process(ccp->cmd_q[i].kthread);
328 EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
330 static void ccp_do_cmd_backlog(struct work_struct *work)
332 struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
333 struct ccp_device *ccp = cmd->ccp;
337 cmd->callback(cmd->data, -EINPROGRESS);
339 spin_lock_irqsave(&ccp->cmd_lock, flags);
342 list_add_tail(&cmd->entry, &ccp->cmd);
344 /* Find an idle queue */
345 for (i = 0; i < ccp->cmd_q_count; i++) {
346 if (ccp->cmd_q[i].active)
352 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
354 /* If we found an idle queue, wake it up */
355 if (i < ccp->cmd_q_count)
356 wake_up_process(ccp->cmd_q[i].kthread);
359 static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
361 struct ccp_device *ccp = cmd_q->ccp;
362 struct ccp_cmd *cmd = NULL;
363 struct ccp_cmd *backlog = NULL;
366 spin_lock_irqsave(&ccp->cmd_lock, flags);
370 if (ccp->suspending) {
371 cmd_q->suspended = 1;
373 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
374 wake_up_interruptible(&ccp->suspend_queue);
379 if (ccp->cmd_count) {
382 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
383 list_del(&cmd->entry);
388 if (!list_empty(&ccp->backlog)) {
389 backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
391 list_del(&backlog->entry);
394 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
397 INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
398 schedule_work(&backlog->work);
404 static void ccp_do_cmd_complete(unsigned long data)
406 struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
407 struct ccp_cmd *cmd = tdata->cmd;
409 cmd->callback(cmd->data, cmd->ret);
411 complete(&tdata->completion);
415 * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
417 * @data: thread-specific data
419 int ccp_cmd_queue_thread(void *data)
421 struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
423 struct ccp_tasklet_data tdata;
424 struct tasklet_struct tasklet;
426 tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);
428 set_current_state(TASK_INTERRUPTIBLE);
429 while (!kthread_should_stop()) {
432 set_current_state(TASK_INTERRUPTIBLE);
434 cmd = ccp_dequeue_cmd(cmd_q);
438 __set_current_state(TASK_RUNNING);
440 /* Execute the command */
441 cmd->ret = ccp_run_cmd(cmd_q, cmd);
443 /* Schedule the completion callback */
445 init_completion(&tdata.completion);
446 tasklet_schedule(&tasklet);
447 wait_for_completion(&tdata.completion);
450 __set_current_state(TASK_RUNNING);
456 * ccp_alloc_struct - allocate and initialize the ccp_device struct
458 * @dev: device struct of the CCP
460 struct ccp_device *ccp_alloc_struct(struct sp_device *sp)
462 struct device *dev = sp->dev;
463 struct ccp_device *ccp;
465 ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL);
470 ccp->axcache = sp->axcache;
472 INIT_LIST_HEAD(&ccp->cmd);
473 INIT_LIST_HEAD(&ccp->backlog);
475 spin_lock_init(&ccp->cmd_lock);
476 mutex_init(&ccp->req_mutex);
477 mutex_init(&ccp->sb_mutex);
478 ccp->sb_count = KSB_COUNT;
481 /* Initialize the wait queues */
482 init_waitqueue_head(&ccp->sb_queue);
483 init_waitqueue_head(&ccp->suspend_queue);
485 snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", sp->ord);
486 snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", sp->ord);
491 int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
493 struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
495 int len = min_t(int, sizeof(trng_value), max);
497 /* Locking is provided by the caller so we can update device
498 * hwrng-related fields safely
500 trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
502 /* Zero is returned if not data is available or if a
503 * bad-entropy error is present. Assume an error if
504 * we exceed TRNG_RETRIES reads of zero.
506 if (ccp->hwrng_retries++ > TRNG_RETRIES)
512 /* Reset the counter and save the rng value */
513 ccp->hwrng_retries = 0;
514 memcpy(data, &trng_value, len);
520 bool ccp_queues_suspended(struct ccp_device *ccp)
522 unsigned int suspended = 0;
526 spin_lock_irqsave(&ccp->cmd_lock, flags);
528 for (i = 0; i < ccp->cmd_q_count; i++)
529 if (ccp->cmd_q[i].suspended)
532 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
534 return ccp->cmd_q_count == suspended;
537 int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
539 struct ccp_device *ccp = sp->ccp_data;
543 spin_lock_irqsave(&ccp->cmd_lock, flags);
547 /* Wake all the queue kthreads to prepare for suspend */
548 for (i = 0; i < ccp->cmd_q_count; i++)
549 wake_up_process(ccp->cmd_q[i].kthread);
551 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
553 /* Wait for all queue kthreads to say they're done */
554 while (!ccp_queues_suspended(ccp))
555 wait_event_interruptible(ccp->suspend_queue,
556 ccp_queues_suspended(ccp));
561 int ccp_dev_resume(struct sp_device *sp)
563 struct ccp_device *ccp = sp->ccp_data;
567 spin_lock_irqsave(&ccp->cmd_lock, flags);
571 /* Wake up all the kthreads */
572 for (i = 0; i < ccp->cmd_q_count; i++) {
573 ccp->cmd_q[i].suspended = 0;
574 wake_up_process(ccp->cmd_q[i].kthread);
577 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
583 int ccp_dev_init(struct sp_device *sp)
585 struct device *dev = sp->dev;
586 struct ccp_device *ccp;
590 ccp = ccp_alloc_struct(sp);
595 ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
596 if (!ccp->vdata || !ccp->vdata->version) {
598 dev_err(dev, "missing driver data\n");
602 ccp->use_tasklet = sp->use_tasklet;
604 ccp->io_regs = sp->io_map + ccp->vdata->offset;
605 if (ccp->vdata->setup)
606 ccp->vdata->setup(ccp);
608 ret = ccp->vdata->perform->init(ccp);
612 dev_notice(dev, "ccp enabled\n");
619 dev_notice(dev, "ccp initialization failed\n");
624 void ccp_dev_destroy(struct sp_device *sp)
626 struct ccp_device *ccp = sp->ccp_data;
631 ccp->vdata->perform->destroy(ccp);