summaryrefslogtreecommitdiffstats
path: root/drivers/crypto/ccp/ccp-dev.c
blob: c531d13d971f3f61f97c332972a741aa8fd289c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
// SPDX-License-Identifier: GPL-2.0-only
/*
 * AMD Cryptographic Coprocessor (CCP) driver
 *
 * Copyright (C) 2013,2019 Advanced Micro Devices, Inc.
 *
 * Author: Tom Lendacky <thomas.lendacky@amd.com>
 * Author: Gary R Hook <gary.hook@amd.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/spinlock_types.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/hw_random.h>
#include <linux/cpu.h>
#include <linux/atomic.h>
#ifdef CONFIG_X86
#include <asm/cpu_device_id.h>
#endif
#include <linux/ccp.h>

#include "ccp-dev.h"

#define MAX_CCPS 32

/* Limit CCP use to a specifed number of queues per device */
static unsigned int nqueues;
module_param(nqueues, uint, 0444);
MODULE_PARM_DESC(nqueues, "Number of queues per CCP (minimum 1; default: all available)");

/* Limit the maximum number of configured CCPs */
static atomic_t dev_count = ATOMIC_INIT(0);
static unsigned int max_devs = MAX_CCPS;
module_param(max_devs, uint, 0444);
MODULE_PARM_DESC(max_devs, "Maximum number of CCPs to enable (default: all; 0 disables all CCPs)");

struct ccp_tasklet_data {
	struct completion completion;
	struct ccp_cmd *cmd;
};

/* Human-readable error strings */
#define CCP_MAX_ERROR_CODE	64
static char *ccp_error_codes[] = {
	"",
	"ILLEGAL_ENGINE",
	"ILLEGAL_KEY_ID",
	"ILLEGAL_FUNCTION_TYPE",
	"ILLEGAL_FUNCTION_MODE",
	"ILLEGAL_FUNCTION_ENCRYPT",
	"ILLEGAL_FUNCTION_SIZE",
	"Zlib_MISSING_INIT_EOM",
	"ILLEGAL_FUNCTION_RSVD",
	"ILLEGAL_BUFFER_LENGTH",
	"VLSB_FAULT",
	"ILLEGAL_MEM_ADDR",
	"ILLEGAL_MEM_SEL",
	"ILLEGAL_CONTEXT_ID",
	"ILLEGAL_KEY_ADDR",
	"0xF Reserved",
	"Zlib_ILLEGAL_MULTI_QUEUE",
	"Zlib_ILLEGAL_JOBID_CHANGE",
	"CMD_TIMEOUT",
	"IDMA0_AXI_SLVERR",
	"IDMA0_AXI_DECERR",
	"0x15 Reserved",
	"IDMA1_AXI_SLAVE_FAULT",
	"IDMA1_AIXI_DECERR",
	"0x18 Reserved",
	"ZLIBVHB_AXI_SLVERR",
	"ZLIBVHB_AXI_DECERR",
	"0x1B Reserved",
	"ZLIB_UNEXPECTED_EOM",
	"ZLIB_EXTRA_DATA",
	"ZLIB_BTYPE",
	"ZLIB_UNDEFINED_SYMBOL",
	"ZLIB_UNDEFINED_DISTANCE_S",
	"ZLIB_CODE_LENGTH_SYMBOL",
	"ZLIB _VHB_ILLEGAL_FETCH",
	"ZLIB_UNCOMPRESSED_LEN",
	"ZLIB_LIMIT_REACHED",
	"ZLIB_CHECKSUM_MISMATCH0",
	"ODMA0_AXI_SLVERR",
	"ODMA0_AXI_DECERR",
	"0x28 Reserved",
	"ODMA1_AXI_SLVERR",
	"ODMA1_AXI_DECERR",
};

void ccp_log_error(struct ccp_device *d, unsigned int e)
{
	if (WARN_ON(e >= CCP_MAX_ERROR_CODE))
		return;

	if (e < ARRAY_SIZE(ccp_error_codes))
		dev_err(d->dev, "CCP error %d: %s\n", e, ccp_error_codes[e]);
	else
		dev_err(d->dev, "CCP error %d: Unknown Error\n", e);
}

/* List of CCPs, CCP count, read-write access lock, and access functions
 *
 * Lock structure: get ccp_unit_lock for reading whenever we need to
 * examine the CCP list. While holding it for reading we can acquire
 * the RR lock to update the round-robin next-CCP pointer. The unit lock
 * must be acquired before the RR lock.
 *
 * If the unit-lock is acquired for writing, we have total control over
 * the list, so there's no value in getting the RR lock.
 */
static DEFINE_RWLOCK(ccp_unit_lock);
static LIST_HEAD(ccp_units);

/* Round-robin counter */
static DEFINE_SPINLOCK(ccp_rr_lock);
static struct ccp_device *ccp_rr;

/**
 * ccp_add_device - add a CCP device to the list
 *
 * @ccp: ccp_device struct pointer
 *
 * Put this CCP on the unit list, which makes it available
 * for use.
 *
 * Returns zero if a CCP device is present, -ENODEV otherwise.
 */
void ccp_add_device(struct ccp_device *ccp)
{
	unsigned long flags;

	write_lock_irqsave(&ccp_unit_lock, flags);
	list_add_tail(&ccp->entry, &ccp_units);
	if (!ccp_rr)
		/* We already have the list lock (we're first) so this
		 * pointer can't change on us. Set its initial value.
		 */
		ccp_rr = ccp;
	write_unlock_irqrestore(&ccp_unit_lock, flags);
}

/**
 * ccp_del_device - remove a CCP device from the list
 *
 * @ccp: ccp_device struct pointer
 *
 * Remove this unit from the list of devices. If the next device
 * up for use is this one, adjust the pointer. If this is the last
 * device, NULL the pointer.
 */
void ccp_del_device(struct ccp_device *ccp)
{
	unsigned long flags;

	write_lock_irqsave(&ccp_unit_lock, flags);
	if (ccp_rr == ccp) {
		/* ccp_unit_lock is read/write; any read access
		 * will be suspended while we make changes to the
		 * list and RR pointer.
		 */
		if (list_is_last(&ccp_rr->entry, &ccp_units))
			ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
						  entry);
		else
			ccp_rr = list_next_entry(ccp_rr, entry);
	}
	list_del(&ccp->entry);
	if (list_empty(&ccp_units))
		ccp_rr = NULL;
	write_unlock_irqrestore(&ccp_unit_lock, flags);
}



int ccp_register_rng(struct ccp_device *ccp)
{
	int ret = 0;

	dev_dbg(ccp->dev, "Registering RNG...\n");
	/* Register an RNG */
	ccp->hwrng.name = ccp->rngname;
	ccp->hwrng.read = ccp_trng_read;
	ret = hwrng_register(&ccp->hwrng);
	if (ret)
		dev_err(ccp->dev, "error registering hwrng (%d)\n", ret);

	return ret;
}

void ccp_unregister_rng(struct ccp_device *ccp)
{
	if (ccp->hwrng.name)
		hwrng_unregister(&ccp->hwrng);
}

static struct ccp_device *ccp_get_device(void)
{
	unsigned long flags;
	struct ccp_device *dp = NULL;

	/* We round-robin through the unit list.
	 * The (ccp_rr) pointer refers to the next unit to use.
	 */
	read_lock_irqsave(&ccp_unit_lock, flags);
	if (!list_empty(&ccp_units)) {
		spin_lock(&ccp_rr_lock);
		dp = ccp_rr;
		if (list_is_last(&ccp_rr->entry, &ccp_units))
			ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
						  entry);
		else
			ccp_rr = list_next_entry(ccp_rr, entry);
		spin_unlock(&ccp_rr_lock);
	}
	read_unlock_irqrestore(&ccp_unit_lock, flags);

	return dp;
}

/**
 * ccp_present - check if a CCP device is present
 *
 * Returns zero if a CCP device is present, -ENODEV otherwise.
 */
int ccp_present(void)
{
	unsigned long flags;
	int ret;

	read_lock_irqsave(&ccp_unit_lock, flags);
	ret = list_empty(&ccp_units);
	read_unlock_irqrestore(&ccp_unit_lock, flags);

	return ret ? -ENODEV : 0;
}
EXPORT_SYMBOL_GPL(ccp_present);

/**
 * ccp_version - get the version of the CCP device
 *
 * Returns the version from the first unit on the list;
 * otherwise a zero if no CCP device is present
 */
unsigned int ccp_version(void)
{
	struct ccp_device *dp;
	unsigned long flags;
	int ret = 0;

	read_lock_irqsave(&ccp_unit_lock, flags);
	if (!list_empty(&ccp_units)) {
		dp = list_first_entry(&ccp_units, struct ccp_device, entry);
		ret = dp->vdata->version;
	}
	read_unlock_irqrestore(&ccp_unit_lock, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(ccp_version);

/**
 * ccp_enqueue_cmd - queue an operation for processing by the CCP
 *
 * @cmd: ccp_cmd struct to be processed
 *
 * Queue a cmd to be processed by the CCP. If queueing the cmd
 * would exceed the defined length of the cmd queue the cmd will
 * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
 * result in a return code of -EBUSY.
 *
 * The callback routine specified in the ccp_cmd struct will be
 * called to notify the caller of completion (if the cmd was not
 * backlogged) or advancement out of the backlog. If the cmd has
 * advanced out of the backlog the "err" value of the callback
 * will be -EINPROGRESS. Any other "err" value during callback is
 * the result of the operation.
 *
 * The cmd has been successfully queued if:
 *   the return code is -EINPROGRESS or
 *   the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
 */
int ccp_enqueue_cmd(struct ccp_cmd *cmd)
{
	struct ccp_device *ccp;
	unsigned long flags;
	unsigned int i;
	int ret;

	/* Some commands might need to be sent to a specific device */
	ccp = cmd->ccp ? cmd->ccp : ccp_get_device();

	if (!ccp)
		return -ENODEV;

	/* Caller must supply a callback routine */
	if (!cmd->callback)
		return -EINVAL;

	cmd->ccp = ccp;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	i = ccp->cmd_q_count;

	if (ccp->cmd_count >= MAX_CMD_QLEN) {
		if (cmd->flags & CCP_CMD_MAY_BACKLOG) {
			ret = -EBUSY;
			list_add_tail(&cmd->entry, &ccp->backlog);
		} else {
			ret = -ENOSPC;
		}
	} else {
		ret = -EINPROGRESS;
		ccp->cmd_count++;
		list_add_tail(&cmd->entry, &ccp->cmd);

		/* Find an idle queue */
		if (!ccp->suspending) {
			for (i = 0; i < ccp->cmd_q_count; i++) {
				if (ccp->cmd_q[i].active)
					continue;

				break;
			}
		}
	}

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	/* If we found an idle queue, wake it up */
	if (i < ccp->cmd_q_count)
		wake_up_process(ccp->cmd_q[i].kthread);

	return ret;
}
EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);

static void ccp_do_cmd_backlog(struct work_struct *work)
{
	struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
	struct ccp_device *ccp = cmd->ccp;
	unsigned long flags;
	unsigned int i;

	cmd->callback(cmd->data, -EINPROGRESS);

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	ccp->cmd_count++;
	list_add_tail(&cmd->entry, &ccp->cmd);

	/* Find an idle queue */
	for (i = 0; i < ccp->cmd_q_count; i++) {
		if (ccp->cmd_q[i].active)
			continue;

		break;
	}

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	/* If we found an idle queue, wake it up */
	if (i < ccp->cmd_q_count)
		wake_up_process(ccp->cmd_q[i].kthread);
}

static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
{
	struct ccp_device *ccp = cmd_q->ccp;
	struct ccp_cmd *cmd = NULL;
	struct ccp_cmd *backlog = NULL;
	unsigned long flags;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	cmd_q->active = 0;

	if (ccp->suspending) {
		cmd_q->suspended = 1;

		spin_unlock_irqrestore(&ccp->cmd_lock, flags);
		wake_up_interruptible(&ccp->suspend_queue);

		return NULL;
	}

	if (ccp->cmd_count) {
		cmd_q->active = 1;

		cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
		list_del(&cmd->entry);

		ccp->cmd_count--;
	}

	if (!list_empty(&ccp->backlog)) {
		backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
					   entry);
		list_del(&backlog->entry);
	}

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	if (backlog) {
		INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
		schedule_work(&backlog->work);
	}

	return cmd;
}

static void ccp_do_cmd_complete(unsigned long data)
{
	struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
	struct ccp_cmd *cmd = tdata->cmd;

	cmd->callback(cmd->data, cmd->ret);

	complete(&tdata->completion);
}

/**
 * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
 *
 * @data: thread-specific data
 */
int ccp_cmd_queue_thread(void *data)
{
	struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
	struct ccp_cmd *cmd;
	struct ccp_tasklet_data tdata;
	struct tasklet_struct tasklet;

	tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);

	set_current_state(TASK_INTERRUPTIBLE);
	while (!kthread_should_stop()) {
		schedule();

		set_current_state(TASK_INTERRUPTIBLE);

		cmd = ccp_dequeue_cmd(cmd_q);
		if (!cmd)
			continue;

		__set_current_state(TASK_RUNNING);

		/* Execute the command */
		cmd->ret = ccp_run_cmd(cmd_q, cmd);

		/* Schedule the completion callback */
		tdata.cmd = cmd;
		init_completion(&tdata.completion);
		tasklet_schedule(&tasklet);
		wait_for_completion(&tdata.completion);
	}

	__set_current_state(TASK_RUNNING);

	return 0;
}

/**
 * ccp_alloc_struct - allocate and initialize the ccp_device struct
 *
 * @sp: sp_device struct of the CCP
 */
struct ccp_device *ccp_alloc_struct(struct sp_device *sp)
{
	struct device *dev = sp->dev;
	struct ccp_device *ccp;

	ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL);
	if (!ccp)
		return NULL;
	ccp->dev = dev;
	ccp->sp = sp;
	ccp->axcache = sp->axcache;

	INIT_LIST_HEAD(&ccp->cmd);
	INIT_LIST_HEAD(&ccp->backlog);

	spin_lock_init(&ccp->cmd_lock);
	mutex_init(&ccp->req_mutex);
	mutex_init(&ccp->sb_mutex);
	ccp->sb_count = KSB_COUNT;
	ccp->sb_start = 0;

	/* Initialize the wait queues */
	init_waitqueue_head(&ccp->sb_queue);
	init_waitqueue_head(&ccp->suspend_queue);

	snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", sp->ord);
	snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", sp->ord);

	return ccp;
}

int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
	struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
	u32 trng_value;
	int len = min_t(int, sizeof(trng_value), max);

	/* Locking is provided by the caller so we can update device
	 * hwrng-related fields safely
	 */
	trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
	if (!trng_value) {
		/* Zero is returned if not data is available or if a
		 * bad-entropy error is present. Assume an error if
		 * we exceed TRNG_RETRIES reads of zero.
		 */
		if (ccp->hwrng_retries++ > TRNG_RETRIES)
			return -EIO;

		return 0;
	}

	/* Reset the counter and save the rng value */
	ccp->hwrng_retries = 0;
	memcpy(data, &trng_value, len);

	return len;
}

bool ccp_queues_suspended(struct ccp_device *ccp)
{
	unsigned int suspended = 0;
	unsigned long flags;
	unsigned int i;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	for (i = 0; i < ccp->cmd_q_count; i++)
		if (ccp->cmd_q[i].suspended)
			suspended++;

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	return ccp->cmd_q_count == suspended;
}

void ccp_dev_suspend(struct sp_device *sp)
{
	struct ccp_device *ccp = sp->ccp_data;
	unsigned long flags;
	unsigned int i;

	/* If there's no device there's nothing to do */
	if (!ccp)
		return;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	ccp->suspending = 1;

	/* Wake all the queue kthreads to prepare for suspend */
	for (i = 0; i < ccp->cmd_q_count; i++)
		wake_up_process(ccp->cmd_q[i].kthread);

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);

	/* Wait for all queue kthreads to say they're done */
	while (!ccp_queues_suspended(ccp))
		wait_event_interruptible(ccp->suspend_queue,
					 ccp_queues_suspended(ccp));
}

void ccp_dev_resume(struct sp_device *sp)
{
	struct ccp_device *ccp = sp->ccp_data;
	unsigned long flags;
	unsigned int i;

	/* If there's no device there's nothing to do */
	if (!ccp)
		return;

	spin_lock_irqsave(&ccp->cmd_lock, flags);

	ccp->suspending = 0;

	/* Wake up all the kthreads */
	for (i = 0; i < ccp->cmd_q_count; i++) {
		ccp->cmd_q[i].suspended = 0;
		wake_up_process(ccp->cmd_q[i].kthread);
	}

	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
}

int ccp_dev_init(struct sp_device *sp)
{
	struct device *dev = sp->dev;
	struct ccp_device *ccp;
	int ret;

	/*
	 * Check how many we have so far, and stop after reaching
	 * that number
	 */
	if (atomic_inc_return(&dev_count) > max_devs)
		return 0; /* don't fail the load */

	ret = -ENOMEM;
	ccp = ccp_alloc_struct(sp);
	if (!ccp)
		goto e_err;
	sp->ccp_data = ccp;

	if (!nqueues || (nqueues > MAX_HW_QUEUES))
		ccp->max_q_count = MAX_HW_QUEUES;
	else
		ccp->max_q_count = nqueues;

	ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
	if (!ccp->vdata || !ccp->vdata->version) {
		ret = -ENODEV;
		dev_err(dev, "missing driver data\n");
		goto e_err;
	}

	ccp->use_tasklet = sp->use_tasklet;

	ccp->io_regs = sp->io_map + ccp->vdata->offset;
	if (ccp->vdata->setup)
		ccp->vdata->setup(ccp);

	ret = ccp->vdata->perform->init(ccp);
	if (ret) {
		/* A positive number means that the device cannot be initialized,
		 * but no additional message is required.
		 */
		if (ret > 0)
			goto e_quiet;

		/* An unexpected problem occurred, and should be reported in the log */
		goto e_err;
	}

	dev_notice(dev, "ccp enabled\n");

	return 0;

e_err:
	dev_notice(dev, "ccp initialization failed\n");

e_quiet:
	sp->ccp_data = NULL;

	return ret;
}

void ccp_dev_destroy(struct sp_device *sp)
{
	struct ccp_device *ccp = sp->ccp_data;

	if (!ccp)
		return;

	ccp->vdata->perform->destroy(ccp);
}