1/*
2 * AMD Cryptographic Coprocessor (CCP) driver
3 *
4 * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
5 *
6 * Author: Tom Lendacky <thomas.lendacky@amd.com>
7 * Author: Gary R Hook <gary.hook@amd.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/kernel.h>
15#include <linux/kthread.h>
16#include <linux/sched.h>
17#include <linux/interrupt.h>
18#include <linux/spinlock.h>
19#include <linux/spinlock_types.h>
20#include <linux/types.h>
21#include <linux/mutex.h>
22#include <linux/delay.h>
23#include <linux/hw_random.h>
24#include <linux/cpu.h>
25#ifdef CONFIG_X86
26#include <asm/cpu_device_id.h>
27#endif
28#include <linux/ccp.h>
29
30#include "ccp-dev.h"
31
32struct ccp_tasklet_data {
33 struct completion completion;
34 struct ccp_cmd *cmd;
35};
36
37/* Human-readable error strings */
38static char *ccp_error_codes[] = {
39 "",
40 "ERR 01: ILLEGAL_ENGINE",
41 "ERR 02: ILLEGAL_KEY_ID",
42 "ERR 03: ILLEGAL_FUNCTION_TYPE",
43 "ERR 04: ILLEGAL_FUNCTION_MODE",
44 "ERR 05: ILLEGAL_FUNCTION_ENCRYPT",
45 "ERR 06: ILLEGAL_FUNCTION_SIZE",
46 "ERR 07: Zlib_MISSING_INIT_EOM",
47 "ERR 08: ILLEGAL_FUNCTION_RSVD",
48 "ERR 09: ILLEGAL_BUFFER_LENGTH",
49 "ERR 10: VLSB_FAULT",
50 "ERR 11: ILLEGAL_MEM_ADDR",
51 "ERR 12: ILLEGAL_MEM_SEL",
52 "ERR 13: ILLEGAL_CONTEXT_ID",
53 "ERR 14: ILLEGAL_KEY_ADDR",
54 "ERR 15: 0xF Reserved",
55 "ERR 16: Zlib_ILLEGAL_MULTI_QUEUE",
56 "ERR 17: Zlib_ILLEGAL_JOBID_CHANGE",
57 "ERR 18: CMD_TIMEOUT",
58 "ERR 19: IDMA0_AXI_SLVERR",
59 "ERR 20: IDMA0_AXI_DECERR",
60 "ERR 21: 0x15 Reserved",
61 "ERR 22: IDMA1_AXI_SLAVE_FAULT",
62 "ERR 23: IDMA1_AIXI_DECERR",
63 "ERR 24: 0x18 Reserved",
64 "ERR 25: ZLIBVHB_AXI_SLVERR",
65 "ERR 26: ZLIBVHB_AXI_DECERR",
66 "ERR 27: 0x1B Reserved",
67 "ERR 27: ZLIB_UNEXPECTED_EOM",
68 "ERR 27: ZLIB_EXTRA_DATA",
69 "ERR 30: ZLIB_BTYPE",
70 "ERR 31: ZLIB_UNDEFINED_SYMBOL",
71 "ERR 32: ZLIB_UNDEFINED_DISTANCE_S",
72 "ERR 33: ZLIB_CODE_LENGTH_SYMBOL",
73 "ERR 34: ZLIB _VHB_ILLEGAL_FETCH",
74 "ERR 35: ZLIB_UNCOMPRESSED_LEN",
75 "ERR 36: ZLIB_LIMIT_REACHED",
76 "ERR 37: ZLIB_CHECKSUM_MISMATCH0",
77 "ERR 38: ODMA0_AXI_SLVERR",
78 "ERR 39: ODMA0_AXI_DECERR",
79 "ERR 40: 0x28 Reserved",
80 "ERR 41: ODMA1_AXI_SLVERR",
81 "ERR 42: ODMA1_AXI_DECERR",
82 "ERR 43: LSB_PARITY_ERR",
83};
84
85void ccp_log_error(struct ccp_device *d, int e)
86{
87 dev_err(d->dev, "CCP error: %s (0x%x)\n", ccp_error_codes[e], e);
88}
89
90/* List of CCPs, CCP count, read-write access lock, and access functions
91 *
92 * Lock structure: get ccp_unit_lock for reading whenever we need to
93 * examine the CCP list. While holding it for reading we can acquire
94 * the RR lock to update the round-robin next-CCP pointer. The unit lock
95 * must be acquired before the RR lock.
96 *
97 * If the unit-lock is acquired for writing, we have total control over
98 * the list, so there's no value in getting the RR lock.
99 */
100static DEFINE_RWLOCK(ccp_unit_lock);
101static LIST_HEAD(ccp_units);
102
103/* Round-robin counter */
104static DEFINE_SPINLOCK(ccp_rr_lock);
105static struct ccp_device *ccp_rr;
106
107/**
108 * ccp_add_device - add a CCP device to the list
109 *
110 * @ccp: ccp_device struct pointer
111 *
112 * Put this CCP on the unit list, which makes it available
113 * for use.
114 *
115 * Returns zero if a CCP device is present, -ENODEV otherwise.
116 */
117void ccp_add_device(struct ccp_device *ccp)
118{
119 unsigned long flags;
120
121 write_lock_irqsave(&ccp_unit_lock, flags);
122 list_add_tail(&ccp->entry, &ccp_units);
123 if (!ccp_rr)
124 /* We already have the list lock (we're first) so this
125 * pointer can't change on us. Set its initial value.
126 */
127 ccp_rr = ccp;
128 write_unlock_irqrestore(&ccp_unit_lock, flags);
129}
130
131/**
132 * ccp_del_device - remove a CCP device from the list
133 *
134 * @ccp: ccp_device struct pointer
135 *
136 * Remove this unit from the list of devices. If the next device
137 * up for use is this one, adjust the pointer. If this is the last
138 * device, NULL the pointer.
139 */
140void ccp_del_device(struct ccp_device *ccp)
141{
142 unsigned long flags;
143
144 write_lock_irqsave(&ccp_unit_lock, flags);
145 if (ccp_rr == ccp) {
146 /* ccp_unit_lock is read/write; any read access
147 * will be suspended while we make changes to the
148 * list and RR pointer.
149 */
150 if (list_is_last(&ccp_rr->entry, &ccp_units))
151 ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
152 entry);
153 else
154 ccp_rr = list_next_entry(ccp_rr, entry);
155 }
156 list_del(&ccp->entry);
157 if (list_empty(&ccp_units))
158 ccp_rr = NULL;
159 write_unlock_irqrestore(&ccp_unit_lock, flags);
160}
161
162
163
164int ccp_register_rng(struct ccp_device *ccp)
165{
166 int ret = 0;
167
168 dev_dbg(ccp->dev, "Registering RNG...\n");
169 /* Register an RNG */
170 ccp->hwrng.name = ccp->rngname;
171 ccp->hwrng.read = ccp_trng_read;
172 ret = hwrng_register(&ccp->hwrng);
173 if (ret)
174 dev_err(ccp->dev, "error registering hwrng (%d)\n", ret);
175
176 return ret;
177}
178
179void ccp_unregister_rng(struct ccp_device *ccp)
180{
181 if (ccp->hwrng.name)
182 hwrng_unregister(&ccp->hwrng);
183}
184
185static struct ccp_device *ccp_get_device(void)
186{
187 unsigned long flags;
188 struct ccp_device *dp = NULL;
189
190 /* We round-robin through the unit list.
191 * The (ccp_rr) pointer refers to the next unit to use.
192 */
193 read_lock_irqsave(&ccp_unit_lock, flags);
194 if (!list_empty(&ccp_units)) {
195 spin_lock(&ccp_rr_lock);
196 dp = ccp_rr;
197 if (list_is_last(&ccp_rr->entry, &ccp_units))
198 ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
199 entry);
200 else
201 ccp_rr = list_next_entry(ccp_rr, entry);
202 spin_unlock(&ccp_rr_lock);
203 }
204 read_unlock_irqrestore(&ccp_unit_lock, flags);
205
206 return dp;
207}
208
209/**
210 * ccp_present - check if a CCP device is present
211 *
212 * Returns zero if a CCP device is present, -ENODEV otherwise.
213 */
214int ccp_present(void)
215{
216 unsigned long flags;
217 int ret;
218
219 read_lock_irqsave(&ccp_unit_lock, flags);
220 ret = list_empty(&ccp_units);
221 read_unlock_irqrestore(&ccp_unit_lock, flags);
222
223 return ret ? -ENODEV : 0;
224}
225EXPORT_SYMBOL_GPL(ccp_present);
226
227/**
228 * ccp_version - get the version of the CCP device
229 *
230 * Returns the version from the first unit on the list;
231 * otherwise a zero if no CCP device is present
232 */
233unsigned int ccp_version(void)
234{
235 struct ccp_device *dp;
236 unsigned long flags;
237 int ret = 0;
238
239 read_lock_irqsave(&ccp_unit_lock, flags);
240 if (!list_empty(&ccp_units)) {
241 dp = list_first_entry(&ccp_units, struct ccp_device, entry);
242 ret = dp->vdata->version;
243 }
244 read_unlock_irqrestore(&ccp_unit_lock, flags);
245
246 return ret;
247}
248EXPORT_SYMBOL_GPL(ccp_version);
249
250/**
251 * ccp_enqueue_cmd - queue an operation for processing by the CCP
252 *
253 * @cmd: ccp_cmd struct to be processed
254 *
255 * Queue a cmd to be processed by the CCP. If queueing the cmd
256 * would exceed the defined length of the cmd queue the cmd will
257 * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
258 * result in a return code of -EBUSY.
259 *
260 * The callback routine specified in the ccp_cmd struct will be
261 * called to notify the caller of completion (if the cmd was not
262 * backlogged) or advancement out of the backlog. If the cmd has
263 * advanced out of the backlog the "err" value of the callback
264 * will be -EINPROGRESS. Any other "err" value during callback is
265 * the result of the operation.
266 *
267 * The cmd has been successfully queued if:
268 * the return code is -EINPROGRESS or
269 * the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
270 */
271int ccp_enqueue_cmd(struct ccp_cmd *cmd)
272{
273 struct ccp_device *ccp;
274 unsigned long flags;
275 unsigned int i;
276 int ret;
277
278 /* Some commands might need to be sent to a specific device */
279 ccp = cmd->ccp ? cmd->ccp : ccp_get_device();
280
281 if (!ccp)
282 return -ENODEV;
283
284 /* Caller must supply a callback routine */
285 if (!cmd->callback)
286 return -EINVAL;
287
288 cmd->ccp = ccp;
289
290 spin_lock_irqsave(&ccp->cmd_lock, flags);
291
292 i = ccp->cmd_q_count;
293
294 if (ccp->cmd_count >= MAX_CMD_QLEN) {
295 if (cmd->flags & CCP_CMD_MAY_BACKLOG) {
296 ret = -EBUSY;
297 list_add_tail(&cmd->entry, &ccp->backlog);
298 } else {
299 ret = -ENOSPC;
300 }
301 } else {
302 ret = -EINPROGRESS;
303 ccp->cmd_count++;
304 list_add_tail(&cmd->entry, &ccp->cmd);
305
306 /* Find an idle queue */
307 if (!ccp->suspending) {
308 for (i = 0; i < ccp->cmd_q_count; i++) {
309 if (ccp->cmd_q[i].active)
310 continue;
311
312 break;
313 }
314 }
315 }
316
317 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
318
319 /* If we found an idle queue, wake it up */
320 if (i < ccp->cmd_q_count)
321 wake_up_process(ccp->cmd_q[i].kthread);
322
323 return ret;
324}
325EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
326
327static void ccp_do_cmd_backlog(struct work_struct *work)
328{
329 struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
330 struct ccp_device *ccp = cmd->ccp;
331 unsigned long flags;
332 unsigned int i;
333
334 cmd->callback(cmd->data, -EINPROGRESS);
335
336 spin_lock_irqsave(&ccp->cmd_lock, flags);
337
338 ccp->cmd_count++;
339 list_add_tail(&cmd->entry, &ccp->cmd);
340
341 /* Find an idle queue */
342 for (i = 0; i < ccp->cmd_q_count; i++) {
343 if (ccp->cmd_q[i].active)
344 continue;
345
346 break;
347 }
348
349 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
350
351 /* If we found an idle queue, wake it up */
352 if (i < ccp->cmd_q_count)
353 wake_up_process(ccp->cmd_q[i].kthread);
354}
355
356static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
357{
358 struct ccp_device *ccp = cmd_q->ccp;
359 struct ccp_cmd *cmd = NULL;
360 struct ccp_cmd *backlog = NULL;
361 unsigned long flags;
362
363 spin_lock_irqsave(&ccp->cmd_lock, flags);
364
365 cmd_q->active = 0;
366
367 if (ccp->suspending) {
368 cmd_q->suspended = 1;
369
370 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
371 wake_up_interruptible(&ccp->suspend_queue);
372
373 return NULL;
374 }
375
376 if (ccp->cmd_count) {
377 cmd_q->active = 1;
378
379 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
380 list_del(&cmd->entry);
381
382 ccp->cmd_count--;
383 }
384
385 if (!list_empty(&ccp->backlog)) {
386 backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
387 entry);
388 list_del(&backlog->entry);
389 }
390
391 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
392
393 if (backlog) {
394 INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
395 schedule_work(&backlog->work);
396 }
397
398 return cmd;
399}
400
401static void ccp_do_cmd_complete(unsigned long data)
402{
403 struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
404 struct ccp_cmd *cmd = tdata->cmd;
405
406 cmd->callback(cmd->data, cmd->ret);
407
408 complete(&tdata->completion);
409}
410
411/**
412 * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
413 *
414 * @data: thread-specific data
415 */
416int ccp_cmd_queue_thread(void *data)
417{
418 struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
419 struct ccp_cmd *cmd;
420 struct ccp_tasklet_data tdata;
421 struct tasklet_struct tasklet;
422
423 tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);
424
425 set_current_state(TASK_INTERRUPTIBLE);
426 while (!kthread_should_stop()) {
427 schedule();
428
429 set_current_state(TASK_INTERRUPTIBLE);
430
431 cmd = ccp_dequeue_cmd(cmd_q);
432 if (!cmd)
433 continue;
434
435 __set_current_state(TASK_RUNNING);
436
437 /* Execute the command */
438 cmd->ret = ccp_run_cmd(cmd_q, cmd);
439
440 /* Schedule the completion callback */
441 tdata.cmd = cmd;
442 init_completion(&tdata.completion);
443 tasklet_schedule(&tasklet);
444 wait_for_completion(&tdata.completion);
445 }
446
447 __set_current_state(TASK_RUNNING);
448
449 return 0;
450}
451
452/**
453 * ccp_alloc_struct - allocate and initialize the ccp_device struct
454 *
455 * @dev: device struct of the CCP
456 */
457struct ccp_device *ccp_alloc_struct(struct sp_device *sp)
458{
459 struct device *dev = sp->dev;
460 struct ccp_device *ccp;
461
462 ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL);
463 if (!ccp)
464 return NULL;
465 ccp->dev = dev;
466 ccp->sp = sp;
467 ccp->axcache = sp->axcache;
468
469 INIT_LIST_HEAD(&ccp->cmd);
470 INIT_LIST_HEAD(&ccp->backlog);
471
472 spin_lock_init(&ccp->cmd_lock);
473 mutex_init(&ccp->req_mutex);
474 mutex_init(&ccp->sb_mutex);
475 ccp->sb_count = KSB_COUNT;
476 ccp->sb_start = 0;
477
478 /* Initialize the wait queues */
479 init_waitqueue_head(&ccp->sb_queue);
480 init_waitqueue_head(&ccp->suspend_queue);
481
482 snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", sp->ord);
483 snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", sp->ord);
484
485 return ccp;
486}
487
488int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
489{
490 struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
491 u32 trng_value;
492 int len = min_t(int, sizeof(trng_value), max);
493
494 /* Locking is provided by the caller so we can update device
495 * hwrng-related fields safely
496 */
497 trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
498 if (!trng_value) {
499 /* Zero is returned if not data is available or if a
500 * bad-entropy error is present. Assume an error if
501 * we exceed TRNG_RETRIES reads of zero.
502 */
503 if (ccp->hwrng_retries++ > TRNG_RETRIES)
504 return -EIO;
505
506 return 0;
507 }
508
509 /* Reset the counter and save the rng value */
510 ccp->hwrng_retries = 0;
511 memcpy(data, &trng_value, len);
512
513 return len;
514}
515
516#ifdef CONFIG_PM
517bool ccp_queues_suspended(struct ccp_device *ccp)
518{
519 unsigned int suspended = 0;
520 unsigned long flags;
521 unsigned int i;
522
523 spin_lock_irqsave(&ccp->cmd_lock, flags);
524
525 for (i = 0; i < ccp->cmd_q_count; i++)
526 if (ccp->cmd_q[i].suspended)
527 suspended++;
528
529 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
530
531 return ccp->cmd_q_count == suspended;
532}
533
534int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
535{
536 struct ccp_device *ccp = sp->ccp_data;
537 unsigned long flags;
538 unsigned int i;
539
540 spin_lock_irqsave(&ccp->cmd_lock, flags);
541
542 ccp->suspending = 1;
543
544 /* Wake all the queue kthreads to prepare for suspend */
545 for (i = 0; i < ccp->cmd_q_count; i++)
546 wake_up_process(ccp->cmd_q[i].kthread);
547
548 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
549
550 /* Wait for all queue kthreads to say they're done */
551 while (!ccp_queues_suspended(ccp))
552 wait_event_interruptible(ccp->suspend_queue,
553 ccp_queues_suspended(ccp));
554
555 return 0;
556}
557
558int ccp_dev_resume(struct sp_device *sp)
559{
560 struct ccp_device *ccp = sp->ccp_data;
561 unsigned long flags;
562 unsigned int i;
563
564 spin_lock_irqsave(&ccp->cmd_lock, flags);
565
566 ccp->suspending = 0;
567
568 /* Wake up all the kthreads */
569 for (i = 0; i < ccp->cmd_q_count; i++) {
570 ccp->cmd_q[i].suspended = 0;
571 wake_up_process(ccp->cmd_q[i].kthread);
572 }
573
574 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
575
576 return 0;
577}
578#endif
579
580int ccp_dev_init(struct sp_device *sp)
581{
582 struct device *dev = sp->dev;
583 struct ccp_device *ccp;
584 int ret;
585
586 ret = -ENOMEM;
587 ccp = ccp_alloc_struct(sp);
588 if (!ccp)
589 goto e_err;
590 sp->ccp_data = ccp;
591
592 ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
593 if (!ccp->vdata || !ccp->vdata->version) {
594 ret = -ENODEV;
595 dev_err(dev, "missing driver data\n");
596 goto e_err;
597 }
598
599 ccp->use_tasklet = sp->use_tasklet;
600
601 ccp->io_regs = sp->io_map + ccp->vdata->offset;
602 if (ccp->vdata->setup)
603 ccp->vdata->setup(ccp);
604
605 ret = ccp->vdata->perform->init(ccp);
606 if (ret)
607 goto e_err;
608
609 dev_notice(dev, "ccp enabled\n");
610
611 return 0;
612
613e_err:
614 sp->ccp_data = NULL;
615
616 dev_notice(dev, "ccp initialization failed\n");
617
618 return ret;
619}
620
621void ccp_dev_destroy(struct sp_device *sp)
622{
623 struct ccp_device *ccp = sp->ccp_data;
624
625 if (!ccp)
626 return;
627
628 ccp->vdata->perform->destroy(ccp);
629}
630