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1/*
2 * AMD Cryptographic Coprocessor (CCP) driver
3 *
4 * Copyright (C) 2013,2016 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/module.h>
15#include <linux/kernel.h>
16#include <linux/kthread.h>
17#include <linux/sched.h>
18#include <linux/interrupt.h>
19#include <linux/spinlock.h>
20#include <linux/spinlock_types.h>
21#include <linux/types.h>
22#include <linux/mutex.h>
23#include <linux/delay.h>
24#include <linux/hw_random.h>
25#include <linux/cpu.h>
26#ifdef CONFIG_X86
27#include <asm/cpu_device_id.h>
28#endif
29#include <linux/ccp.h>
30
31#include "ccp-dev.h"
32
33MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
34MODULE_LICENSE("GPL");
35MODULE_VERSION("1.0.0");
36MODULE_DESCRIPTION("AMD Cryptographic Coprocessor driver");
37
38struct ccp_tasklet_data {
39 struct completion completion;
40 struct ccp_cmd *cmd;
41};
42
43/* Human-readable error strings */
44static char *ccp_error_codes[] = {
45 "",
46 "ERR 01: ILLEGAL_ENGINE",
47 "ERR 02: ILLEGAL_KEY_ID",
48 "ERR 03: ILLEGAL_FUNCTION_TYPE",
49 "ERR 04: ILLEGAL_FUNCTION_MODE",
50 "ERR 05: ILLEGAL_FUNCTION_ENCRYPT",
51 "ERR 06: ILLEGAL_FUNCTION_SIZE",
52 "ERR 07: Zlib_MISSING_INIT_EOM",
53 "ERR 08: ILLEGAL_FUNCTION_RSVD",
54 "ERR 09: ILLEGAL_BUFFER_LENGTH",
55 "ERR 10: VLSB_FAULT",
56 "ERR 11: ILLEGAL_MEM_ADDR",
57 "ERR 12: ILLEGAL_MEM_SEL",
58 "ERR 13: ILLEGAL_CONTEXT_ID",
59 "ERR 14: ILLEGAL_KEY_ADDR",
60 "ERR 15: 0xF Reserved",
61 "ERR 16: Zlib_ILLEGAL_MULTI_QUEUE",
62 "ERR 17: Zlib_ILLEGAL_JOBID_CHANGE",
63 "ERR 18: CMD_TIMEOUT",
64 "ERR 19: IDMA0_AXI_SLVERR",
65 "ERR 20: IDMA0_AXI_DECERR",
66 "ERR 21: 0x15 Reserved",
67 "ERR 22: IDMA1_AXI_SLAVE_FAULT",
68 "ERR 23: IDMA1_AIXI_DECERR",
69 "ERR 24: 0x18 Reserved",
70 "ERR 25: ZLIBVHB_AXI_SLVERR",
71 "ERR 26: ZLIBVHB_AXI_DECERR",
72 "ERR 27: 0x1B Reserved",
73 "ERR 27: ZLIB_UNEXPECTED_EOM",
74 "ERR 27: ZLIB_EXTRA_DATA",
75 "ERR 30: ZLIB_BTYPE",
76 "ERR 31: ZLIB_UNDEFINED_SYMBOL",
77 "ERR 32: ZLIB_UNDEFINED_DISTANCE_S",
78 "ERR 33: ZLIB_CODE_LENGTH_SYMBOL",
79 "ERR 34: ZLIB _VHB_ILLEGAL_FETCH",
80 "ERR 35: ZLIB_UNCOMPRESSED_LEN",
81 "ERR 36: ZLIB_LIMIT_REACHED",
82 "ERR 37: ZLIB_CHECKSUM_MISMATCH0",
83 "ERR 38: ODMA0_AXI_SLVERR",
84 "ERR 39: ODMA0_AXI_DECERR",
85 "ERR 40: 0x28 Reserved",
86 "ERR 41: ODMA1_AXI_SLVERR",
87 "ERR 42: ODMA1_AXI_DECERR",
88 "ERR 43: LSB_PARITY_ERR",
89};
90
91void ccp_log_error(struct ccp_device *d, int e)
92{
93 dev_err(d->dev, "CCP error: %s (0x%x)\n", ccp_error_codes[e], e);
94}
95
96/* List of CCPs, CCP count, read-write access lock, and access functions
97 *
98 * Lock structure: get ccp_unit_lock for reading whenever we need to
99 * examine the CCP list. While holding it for reading we can acquire
100 * the RR lock to update the round-robin next-CCP pointer. The unit lock
101 * must be acquired before the RR lock.
102 *
103 * If the unit-lock is acquired for writing, we have total control over
104 * the list, so there's no value in getting the RR lock.
105 */
106static DEFINE_RWLOCK(ccp_unit_lock);
107static LIST_HEAD(ccp_units);
108
109/* Round-robin counter */
110static DEFINE_SPINLOCK(ccp_rr_lock);
111static struct ccp_device *ccp_rr;
112
113/* Ever-increasing value to produce unique unit numbers */
114static atomic_t ccp_unit_ordinal;
115static unsigned int ccp_increment_unit_ordinal(void)
116{
117 return atomic_inc_return(&ccp_unit_ordinal);
118}
119
120/**
121 * ccp_add_device - add a CCP device to the list
122 *
123 * @ccp: ccp_device struct pointer
124 *
125 * Put this CCP on the unit list, which makes it available
126 * for use.
127 *
128 * Returns zero if a CCP device is present, -ENODEV otherwise.
129 */
130void ccp_add_device(struct ccp_device *ccp)
131{
132 unsigned long flags;
133
134 write_lock_irqsave(&ccp_unit_lock, flags);
135 list_add_tail(&ccp->entry, &ccp_units);
136 if (!ccp_rr)
137 /* We already have the list lock (we're first) so this
138 * pointer can't change on us. Set its initial value.
139 */
140 ccp_rr = ccp;
141 write_unlock_irqrestore(&ccp_unit_lock, flags);
142}
143
144/**
145 * ccp_del_device - remove a CCP device from the list
146 *
147 * @ccp: ccp_device struct pointer
148 *
149 * Remove this unit from the list of devices. If the next device
150 * up for use is this one, adjust the pointer. If this is the last
151 * device, NULL the pointer.
152 */
153void ccp_del_device(struct ccp_device *ccp)
154{
155 unsigned long flags;
156
157 write_lock_irqsave(&ccp_unit_lock, flags);
158 if (ccp_rr == ccp) {
159 /* ccp_unit_lock is read/write; any read access
160 * will be suspended while we make changes to the
161 * list and RR pointer.
162 */
163 if (list_is_last(&ccp_rr->entry, &ccp_units))
164 ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
165 entry);
166 else
167 ccp_rr = list_next_entry(ccp_rr, entry);
168 }
169 list_del(&ccp->entry);
170 if (list_empty(&ccp_units))
171 ccp_rr = NULL;
172 write_unlock_irqrestore(&ccp_unit_lock, flags);
173}
174
175
176
177int ccp_register_rng(struct ccp_device *ccp)
178{
179 int ret = 0;
180
181 dev_dbg(ccp->dev, "Registering RNG...\n");
182 /* Register an RNG */
183 ccp->hwrng.name = ccp->rngname;
184 ccp->hwrng.read = ccp_trng_read;
185 ret = hwrng_register(&ccp->hwrng);
186 if (ret)
187 dev_err(ccp->dev, "error registering hwrng (%d)\n", ret);
188
189 return ret;
190}
191
192void ccp_unregister_rng(struct ccp_device *ccp)
193{
194 if (ccp->hwrng.name)
195 hwrng_unregister(&ccp->hwrng);
196}
197
198static struct ccp_device *ccp_get_device(void)
199{
200 unsigned long flags;
201 struct ccp_device *dp = NULL;
202
203 /* We round-robin through the unit list.
204 * The (ccp_rr) pointer refers to the next unit to use.
205 */
206 read_lock_irqsave(&ccp_unit_lock, flags);
207 if (!list_empty(&ccp_units)) {
208 spin_lock(&ccp_rr_lock);
209 dp = ccp_rr;
210 if (list_is_last(&ccp_rr->entry, &ccp_units))
211 ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
212 entry);
213 else
214 ccp_rr = list_next_entry(ccp_rr, entry);
215 spin_unlock(&ccp_rr_lock);
216 }
217 read_unlock_irqrestore(&ccp_unit_lock, flags);
218
219 return dp;
220}
221
222/**
223 * ccp_present - check if a CCP device is present
224 *
225 * Returns zero if a CCP device is present, -ENODEV otherwise.
226 */
227int ccp_present(void)
228{
229 unsigned long flags;
230 int ret;
231
232 read_lock_irqsave(&ccp_unit_lock, flags);
233 ret = list_empty(&ccp_units);
234 read_unlock_irqrestore(&ccp_unit_lock, flags);
235
236 return ret ? -ENODEV : 0;
237}
238EXPORT_SYMBOL_GPL(ccp_present);
239
240/**
241 * ccp_version - get the version of the CCP device
242 *
243 * Returns the version from the first unit on the list;
244 * otherwise a zero if no CCP device is present
245 */
246unsigned int ccp_version(void)
247{
248 struct ccp_device *dp;
249 unsigned long flags;
250 int ret = 0;
251
252 read_lock_irqsave(&ccp_unit_lock, flags);
253 if (!list_empty(&ccp_units)) {
254 dp = list_first_entry(&ccp_units, struct ccp_device, entry);
255 ret = dp->vdata->version;
256 }
257 read_unlock_irqrestore(&ccp_unit_lock, flags);
258
259 return ret;
260}
261EXPORT_SYMBOL_GPL(ccp_version);
262
263/**
264 * ccp_enqueue_cmd - queue an operation for processing by the CCP
265 *
266 * @cmd: ccp_cmd struct to be processed
267 *
268 * Queue a cmd to be processed by the CCP. If queueing the cmd
269 * would exceed the defined length of the cmd queue the cmd will
270 * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
271 * result in a return code of -EBUSY.
272 *
273 * The callback routine specified in the ccp_cmd struct will be
274 * called to notify the caller of completion (if the cmd was not
275 * backlogged) or advancement out of the backlog. If the cmd has
276 * advanced out of the backlog the "err" value of the callback
277 * will be -EINPROGRESS. Any other "err" value during callback is
278 * the result of the operation.
279 *
280 * The cmd has been successfully queued if:
281 * the return code is -EINPROGRESS or
282 * the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
283 */
284int ccp_enqueue_cmd(struct ccp_cmd *cmd)
285{
286 struct ccp_device *ccp;
287 unsigned long flags;
288 unsigned int i;
289 int ret;
290
291 /* Some commands might need to be sent to a specific device */
292 ccp = cmd->ccp ? cmd->ccp : ccp_get_device();
293
294 if (!ccp)
295 return -ENODEV;
296
297 /* Caller must supply a callback routine */
298 if (!cmd->callback)
299 return -EINVAL;
300
301 cmd->ccp = ccp;
302
303 spin_lock_irqsave(&ccp->cmd_lock, flags);
304
305 i = ccp->cmd_q_count;
306
307 if (ccp->cmd_count >= MAX_CMD_QLEN) {
308 ret = -EBUSY;
309 if (cmd->flags & CCP_CMD_MAY_BACKLOG)
310 list_add_tail(&cmd->entry, &ccp->backlog);
311 } else {
312 ret = -EINPROGRESS;
313 ccp->cmd_count++;
314 list_add_tail(&cmd->entry, &ccp->cmd);
315
316 /* Find an idle queue */
317 if (!ccp->suspending) {
318 for (i = 0; i < ccp->cmd_q_count; i++) {
319 if (ccp->cmd_q[i].active)
320 continue;
321
322 break;
323 }
324 }
325 }
326
327 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
328
329 /* If we found an idle queue, wake it up */
330 if (i < ccp->cmd_q_count)
331 wake_up_process(ccp->cmd_q[i].kthread);
332
333 return ret;
334}
335EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
336
337static void ccp_do_cmd_backlog(struct work_struct *work)
338{
339 struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
340 struct ccp_device *ccp = cmd->ccp;
341 unsigned long flags;
342 unsigned int i;
343
344 cmd->callback(cmd->data, -EINPROGRESS);
345
346 spin_lock_irqsave(&ccp->cmd_lock, flags);
347
348 ccp->cmd_count++;
349 list_add_tail(&cmd->entry, &ccp->cmd);
350
351 /* Find an idle queue */
352 for (i = 0; i < ccp->cmd_q_count; i++) {
353 if (ccp->cmd_q[i].active)
354 continue;
355
356 break;
357 }
358
359 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
360
361 /* If we found an idle queue, wake it up */
362 if (i < ccp->cmd_q_count)
363 wake_up_process(ccp->cmd_q[i].kthread);
364}
365
366static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
367{
368 struct ccp_device *ccp = cmd_q->ccp;
369 struct ccp_cmd *cmd = NULL;
370 struct ccp_cmd *backlog = NULL;
371 unsigned long flags;
372
373 spin_lock_irqsave(&ccp->cmd_lock, flags);
374
375 cmd_q->active = 0;
376
377 if (ccp->suspending) {
378 cmd_q->suspended = 1;
379
380 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
381 wake_up_interruptible(&ccp->suspend_queue);
382
383 return NULL;
384 }
385
386 if (ccp->cmd_count) {
387 cmd_q->active = 1;
388
389 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
390 list_del(&cmd->entry);
391
392 ccp->cmd_count--;
393 }
394
395 if (!list_empty(&ccp->backlog)) {
396 backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
397 entry);
398 list_del(&backlog->entry);
399 }
400
401 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
402
403 if (backlog) {
404 INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
405 schedule_work(&backlog->work);
406 }
407
408 return cmd;
409}
410
411static void ccp_do_cmd_complete(unsigned long data)
412{
413 struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
414 struct ccp_cmd *cmd = tdata->cmd;
415
416 cmd->callback(cmd->data, cmd->ret);
417 complete(&tdata->completion);
418}
419
420/**
421 * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
422 *
423 * @data: thread-specific data
424 */
425int ccp_cmd_queue_thread(void *data)
426{
427 struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
428 struct ccp_cmd *cmd;
429 struct ccp_tasklet_data tdata;
430 struct tasklet_struct tasklet;
431
432 tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);
433
434 set_current_state(TASK_INTERRUPTIBLE);
435 while (!kthread_should_stop()) {
436 schedule();
437
438 set_current_state(TASK_INTERRUPTIBLE);
439
440 cmd = ccp_dequeue_cmd(cmd_q);
441 if (!cmd)
442 continue;
443
444 __set_current_state(TASK_RUNNING);
445
446 /* Execute the command */
447 cmd->ret = ccp_run_cmd(cmd_q, cmd);
448
449 /* Schedule the completion callback */
450 tdata.cmd = cmd;
451 init_completion(&tdata.completion);
452 tasklet_schedule(&tasklet);
453 wait_for_completion(&tdata.completion);
454 }
455
456 __set_current_state(TASK_RUNNING);
457
458 return 0;
459}
460
461/**
462 * ccp_alloc_struct - allocate and initialize the ccp_device struct
463 *
464 * @dev: device struct of the CCP
465 */
466struct ccp_device *ccp_alloc_struct(struct device *dev)
467{
468 struct ccp_device *ccp;
469
470 ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL);
471 if (!ccp)
472 return NULL;
473 ccp->dev = dev;
474
475 INIT_LIST_HEAD(&ccp->cmd);
476 INIT_LIST_HEAD(&ccp->backlog);
477
478 spin_lock_init(&ccp->cmd_lock);
479 mutex_init(&ccp->req_mutex);
480 mutex_init(&ccp->sb_mutex);
481 ccp->sb_count = KSB_COUNT;
482 ccp->sb_start = 0;
483
484 /* Initialize the wait queues */
485 init_waitqueue_head(&ccp->sb_queue);
486 init_waitqueue_head(&ccp->suspend_queue);
487
488 ccp->ord = ccp_increment_unit_ordinal();
489 snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", ccp->ord);
490 snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", ccp->ord);
491
492 return ccp;
493}
494
495int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
496{
497 struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
498 u32 trng_value;
499 int len = min_t(int, sizeof(trng_value), max);
500
501 /* Locking is provided by the caller so we can update device
502 * hwrng-related fields safely
503 */
504 trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
505 if (!trng_value) {
506 /* Zero is returned if not data is available or if a
507 * bad-entropy error is present. Assume an error if
508 * we exceed TRNG_RETRIES reads of zero.
509 */
510 if (ccp->hwrng_retries++ > TRNG_RETRIES)
511 return -EIO;
512
513 return 0;
514 }
515
516 /* Reset the counter and save the rng value */
517 ccp->hwrng_retries = 0;
518 memcpy(data, &trng_value, len);
519
520 return len;
521}
522
523#ifdef CONFIG_PM
524bool ccp_queues_suspended(struct ccp_device *ccp)
525{
526 unsigned int suspended = 0;
527 unsigned long flags;
528 unsigned int i;
529
530 spin_lock_irqsave(&ccp->cmd_lock, flags);
531
532 for (i = 0; i < ccp->cmd_q_count; i++)
533 if (ccp->cmd_q[i].suspended)
534 suspended++;
535
536 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
537
538 return ccp->cmd_q_count == suspended;
539}
540#endif
541
542static int __init ccp_mod_init(void)
543{
544#ifdef CONFIG_X86
545 int ret;
546
547 ret = ccp_pci_init();
548 if (ret)
549 return ret;
550
551 /* Don't leave the driver loaded if init failed */
552 if (ccp_present() != 0) {
553 ccp_pci_exit();
554 return -ENODEV;
555 }
556
557 return 0;
558#endif
559
560#ifdef CONFIG_ARM64
561 int ret;
562
563 ret = ccp_platform_init();
564 if (ret)
565 return ret;
566
567 /* Don't leave the driver loaded if init failed */
568 if (ccp_present() != 0) {
569 ccp_platform_exit();
570 return -ENODEV;
571 }
572
573 return 0;
574#endif
575
576 return -ENODEV;
577}
578
579static void __exit ccp_mod_exit(void)
580{
581#ifdef CONFIG_X86
582 ccp_pci_exit();
583#endif
584
585#ifdef CONFIG_ARM64
586 ccp_platform_exit();
587#endif
588}
589
590module_init(ccp_mod_init);
591module_exit(ccp_mod_exit);