Loading...
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 <thomas.lendacky@amd.com>
8 * Author: Gary R Hook <gary.hook@amd.com>
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 */
34static unsigned int nqueues;
35module_param(nqueues, uint, 0444);
36MODULE_PARM_DESC(nqueues, "Number of queues per CCP (minimum 1; default: all available)");
37
38/* Limit the maximum number of configured CCPs */
39static atomic_t dev_count = ATOMIC_INIT(0);
40static unsigned int max_devs = MAX_CCPS;
41module_param(max_devs, uint, 0444);
42MODULE_PARM_DESC(max_devs, "Maximum number of CCPs to enable (default: all; 0 disables all CCPs)");
43
44struct 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
51static 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
97void 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 */
118static DEFINE_RWLOCK(ccp_unit_lock);
119static LIST_HEAD(ccp_units);
120
121/* Round-robin counter */
122static DEFINE_SPINLOCK(ccp_rr_lock);
123static 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 */
135void 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 */
158void 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
182int 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
197void ccp_unregister_rng(struct ccp_device *ccp)
198{
199 if (ccp->hwrng.name)
200 hwrng_unregister(&ccp->hwrng);
201}
202
203static 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 */
232int 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}
243EXPORT_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 */
251unsigned 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}
266EXPORT_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 */
289int 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}
343EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
344
345static 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
374static 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
419static 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 */
434int 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 * @sp: sp_device struct of the CCP
474 */
475struct 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
506int 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
534bool ccp_queues_suspended(struct ccp_device *ccp)
535{
536 unsigned int suspended = 0;
537 unsigned long flags;
538 unsigned int i;
539
540 spin_lock_irqsave(&ccp->cmd_lock, flags);
541
542 for (i = 0; i < ccp->cmd_q_count; i++)
543 if (ccp->cmd_q[i].suspended)
544 suspended++;
545
546 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
547
548 return ccp->cmd_q_count == suspended;
549}
550
551void ccp_dev_suspend(struct sp_device *sp)
552{
553 struct ccp_device *ccp = sp->ccp_data;
554 unsigned long flags;
555 unsigned int i;
556
557 /* If there's no device there's nothing to do */
558 if (!ccp)
559 return;
560
561 spin_lock_irqsave(&ccp->cmd_lock, flags);
562
563 ccp->suspending = 1;
564
565 /* Wake all the queue kthreads to prepare for suspend */
566 for (i = 0; i < ccp->cmd_q_count; i++)
567 wake_up_process(ccp->cmd_q[i].kthread);
568
569 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
570
571 /* Wait for all queue kthreads to say they're done */
572 while (!ccp_queues_suspended(ccp))
573 wait_event_interruptible(ccp->suspend_queue,
574 ccp_queues_suspended(ccp));
575}
576
577void ccp_dev_resume(struct sp_device *sp)
578{
579 struct ccp_device *ccp = sp->ccp_data;
580 unsigned long flags;
581 unsigned int i;
582
583 /* If there's no device there's nothing to do */
584 if (!ccp)
585 return;
586
587 spin_lock_irqsave(&ccp->cmd_lock, flags);
588
589 ccp->suspending = 0;
590
591 /* Wake up all the kthreads */
592 for (i = 0; i < ccp->cmd_q_count; i++) {
593 ccp->cmd_q[i].suspended = 0;
594 wake_up_process(ccp->cmd_q[i].kthread);
595 }
596
597 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
598}
599
600int ccp_dev_init(struct sp_device *sp)
601{
602 struct device *dev = sp->dev;
603 struct ccp_device *ccp;
604 int ret;
605
606 /*
607 * Check how many we have so far, and stop after reaching
608 * that number
609 */
610 if (atomic_inc_return(&dev_count) > max_devs)
611 return 0; /* don't fail the load */
612
613 ret = -ENOMEM;
614 ccp = ccp_alloc_struct(sp);
615 if (!ccp)
616 goto e_err;
617 sp->ccp_data = ccp;
618
619 if (!nqueues || (nqueues > MAX_HW_QUEUES))
620 ccp->max_q_count = MAX_HW_QUEUES;
621 else
622 ccp->max_q_count = nqueues;
623
624 ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
625 if (!ccp->vdata || !ccp->vdata->version) {
626 ret = -ENODEV;
627 dev_err(dev, "missing driver data\n");
628 goto e_err;
629 }
630
631 ccp->use_tasklet = sp->use_tasklet;
632
633 ccp->io_regs = sp->io_map + ccp->vdata->offset;
634 if (ccp->vdata->setup)
635 ccp->vdata->setup(ccp);
636
637 ret = ccp->vdata->perform->init(ccp);
638 if (ret) {
639 /* A positive number means that the device cannot be initialized,
640 * but no additional message is required.
641 */
642 if (ret > 0)
643 goto e_quiet;
644
645 /* An unexpected problem occurred, and should be reported in the log */
646 goto e_err;
647 }
648
649 dev_notice(dev, "ccp enabled\n");
650
651 return 0;
652
653e_err:
654 dev_notice(dev, "ccp initialization failed\n");
655
656e_quiet:
657 sp->ccp_data = NULL;
658
659 return ret;
660}
661
662void ccp_dev_destroy(struct sp_device *sp)
663{
664 struct ccp_device *ccp = sp->ccp_data;
665
666 if (!ccp)
667 return;
668
669 ccp->vdata->perform->destroy(ccp);
670}
1/*
2 * AMD Cryptographic Coprocessor (CCP) driver
3 *
4 * Copyright (C) 2013 Advanced Micro Devices, Inc.
5 *
6 * Author: Tom Lendacky <thomas.lendacky@amd.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/module.h>
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/mutex.h>
20#include <linux/delay.h>
21#include <linux/hw_random.h>
22#include <linux/cpu.h>
23#include <asm/cpu_device_id.h>
24#include <linux/ccp.h>
25
26#include "ccp-dev.h"
27
28MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
29MODULE_LICENSE("GPL");
30MODULE_VERSION("1.0.0");
31MODULE_DESCRIPTION("AMD Cryptographic Coprocessor driver");
32
33struct ccp_tasklet_data {
34 struct completion completion;
35 struct ccp_cmd *cmd;
36};
37
38
39static struct ccp_device *ccp_dev;
40static inline struct ccp_device *ccp_get_device(void)
41{
42 return ccp_dev;
43}
44
45static inline void ccp_add_device(struct ccp_device *ccp)
46{
47 ccp_dev = ccp;
48}
49
50static inline void ccp_del_device(struct ccp_device *ccp)
51{
52 ccp_dev = NULL;
53}
54
55/**
56 * ccp_enqueue_cmd - queue an operation for processing by the CCP
57 *
58 * @cmd: ccp_cmd struct to be processed
59 *
60 * Queue a cmd to be processed by the CCP. If queueing the cmd
61 * would exceed the defined length of the cmd queue the cmd will
62 * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
63 * result in a return code of -EBUSY.
64 *
65 * The callback routine specified in the ccp_cmd struct will be
66 * called to notify the caller of completion (if the cmd was not
67 * backlogged) or advancement out of the backlog. If the cmd has
68 * advanced out of the backlog the "err" value of the callback
69 * will be -EINPROGRESS. Any other "err" value during callback is
70 * the result of the operation.
71 *
72 * The cmd has been successfully queued if:
73 * the return code is -EINPROGRESS or
74 * the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
75 */
76int ccp_enqueue_cmd(struct ccp_cmd *cmd)
77{
78 struct ccp_device *ccp = ccp_get_device();
79 unsigned long flags;
80 unsigned int i;
81 int ret;
82
83 if (!ccp)
84 return -ENODEV;
85
86 /* Caller must supply a callback routine */
87 if (!cmd->callback)
88 return -EINVAL;
89
90 cmd->ccp = ccp;
91
92 spin_lock_irqsave(&ccp->cmd_lock, flags);
93
94 i = ccp->cmd_q_count;
95
96 if (ccp->cmd_count >= MAX_CMD_QLEN) {
97 ret = -EBUSY;
98 if (cmd->flags & CCP_CMD_MAY_BACKLOG)
99 list_add_tail(&cmd->entry, &ccp->backlog);
100 } else {
101 ret = -EINPROGRESS;
102 ccp->cmd_count++;
103 list_add_tail(&cmd->entry, &ccp->cmd);
104
105 /* Find an idle queue */
106 if (!ccp->suspending) {
107 for (i = 0; i < ccp->cmd_q_count; i++) {
108 if (ccp->cmd_q[i].active)
109 continue;
110
111 break;
112 }
113 }
114 }
115
116 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
117
118 /* If we found an idle queue, wake it up */
119 if (i < ccp->cmd_q_count)
120 wake_up_process(ccp->cmd_q[i].kthread);
121
122 return ret;
123}
124EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
125
126static void ccp_do_cmd_backlog(struct work_struct *work)
127{
128 struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
129 struct ccp_device *ccp = cmd->ccp;
130 unsigned long flags;
131 unsigned int i;
132
133 cmd->callback(cmd->data, -EINPROGRESS);
134
135 spin_lock_irqsave(&ccp->cmd_lock, flags);
136
137 ccp->cmd_count++;
138 list_add_tail(&cmd->entry, &ccp->cmd);
139
140 /* Find an idle queue */
141 for (i = 0; i < ccp->cmd_q_count; i++) {
142 if (ccp->cmd_q[i].active)
143 continue;
144
145 break;
146 }
147
148 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
149
150 /* If we found an idle queue, wake it up */
151 if (i < ccp->cmd_q_count)
152 wake_up_process(ccp->cmd_q[i].kthread);
153}
154
155static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
156{
157 struct ccp_device *ccp = cmd_q->ccp;
158 struct ccp_cmd *cmd = NULL;
159 struct ccp_cmd *backlog = NULL;
160 unsigned long flags;
161
162 spin_lock_irqsave(&ccp->cmd_lock, flags);
163
164 cmd_q->active = 0;
165
166 if (ccp->suspending) {
167 cmd_q->suspended = 1;
168
169 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
170 wake_up_interruptible(&ccp->suspend_queue);
171
172 return NULL;
173 }
174
175 if (ccp->cmd_count) {
176 cmd_q->active = 1;
177
178 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
179 list_del(&cmd->entry);
180
181 ccp->cmd_count--;
182 }
183
184 if (!list_empty(&ccp->backlog)) {
185 backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
186 entry);
187 list_del(&backlog->entry);
188 }
189
190 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
191
192 if (backlog) {
193 INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
194 schedule_work(&backlog->work);
195 }
196
197 return cmd;
198}
199
200static void ccp_do_cmd_complete(unsigned long data)
201{
202 struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
203 struct ccp_cmd *cmd = tdata->cmd;
204
205 cmd->callback(cmd->data, cmd->ret);
206 complete(&tdata->completion);
207}
208
209static int ccp_cmd_queue_thread(void *data)
210{
211 struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
212 struct ccp_cmd *cmd;
213 struct ccp_tasklet_data tdata;
214 struct tasklet_struct tasklet;
215
216 tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);
217
218 set_current_state(TASK_INTERRUPTIBLE);
219 while (!kthread_should_stop()) {
220 schedule();
221
222 set_current_state(TASK_INTERRUPTIBLE);
223
224 cmd = ccp_dequeue_cmd(cmd_q);
225 if (!cmd)
226 continue;
227
228 __set_current_state(TASK_RUNNING);
229
230 /* Execute the command */
231 cmd->ret = ccp_run_cmd(cmd_q, cmd);
232
233 /* Schedule the completion callback */
234 tdata.cmd = cmd;
235 init_completion(&tdata.completion);
236 tasklet_schedule(&tasklet);
237 wait_for_completion(&tdata.completion);
238 }
239
240 __set_current_state(TASK_RUNNING);
241
242 return 0;
243}
244
245static int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
246{
247 struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
248 u32 trng_value;
249 int len = min_t(int, sizeof(trng_value), max);
250
251 /*
252 * Locking is provided by the caller so we can update device
253 * hwrng-related fields safely
254 */
255 trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
256 if (!trng_value) {
257 /* Zero is returned if not data is available or if a
258 * bad-entropy error is present. Assume an error if
259 * we exceed TRNG_RETRIES reads of zero.
260 */
261 if (ccp->hwrng_retries++ > TRNG_RETRIES)
262 return -EIO;
263
264 return 0;
265 }
266
267 /* Reset the counter and save the rng value */
268 ccp->hwrng_retries = 0;
269 memcpy(data, &trng_value, len);
270
271 return len;
272}
273
274/**
275 * ccp_alloc_struct - allocate and initialize the ccp_device struct
276 *
277 * @dev: device struct of the CCP
278 */
279struct ccp_device *ccp_alloc_struct(struct device *dev)
280{
281 struct ccp_device *ccp;
282
283 ccp = kzalloc(sizeof(*ccp), GFP_KERNEL);
284 if (ccp == NULL) {
285 dev_err(dev, "unable to allocate device struct\n");
286 return NULL;
287 }
288 ccp->dev = dev;
289
290 INIT_LIST_HEAD(&ccp->cmd);
291 INIT_LIST_HEAD(&ccp->backlog);
292
293 spin_lock_init(&ccp->cmd_lock);
294 mutex_init(&ccp->req_mutex);
295 mutex_init(&ccp->ksb_mutex);
296 ccp->ksb_count = KSB_COUNT;
297 ccp->ksb_start = 0;
298
299 return ccp;
300}
301
302/**
303 * ccp_init - initialize the CCP device
304 *
305 * @ccp: ccp_device struct
306 */
307int ccp_init(struct ccp_device *ccp)
308{
309 struct device *dev = ccp->dev;
310 struct ccp_cmd_queue *cmd_q;
311 struct dma_pool *dma_pool;
312 char dma_pool_name[MAX_DMAPOOL_NAME_LEN];
313 unsigned int qmr, qim, i;
314 int ret;
315
316 /* Find available queues */
317 qim = 0;
318 qmr = ioread32(ccp->io_regs + Q_MASK_REG);
319 for (i = 0; i < MAX_HW_QUEUES; i++) {
320 if (!(qmr & (1 << i)))
321 continue;
322
323 /* Allocate a dma pool for this queue */
324 snprintf(dma_pool_name, sizeof(dma_pool_name), "ccp_q%d", i);
325 dma_pool = dma_pool_create(dma_pool_name, dev,
326 CCP_DMAPOOL_MAX_SIZE,
327 CCP_DMAPOOL_ALIGN, 0);
328 if (!dma_pool) {
329 dev_err(dev, "unable to allocate dma pool\n");
330 ret = -ENOMEM;
331 goto e_pool;
332 }
333
334 cmd_q = &ccp->cmd_q[ccp->cmd_q_count];
335 ccp->cmd_q_count++;
336
337 cmd_q->ccp = ccp;
338 cmd_q->id = i;
339 cmd_q->dma_pool = dma_pool;
340
341 /* Reserve 2 KSB regions for the queue */
342 cmd_q->ksb_key = KSB_START + ccp->ksb_start++;
343 cmd_q->ksb_ctx = KSB_START + ccp->ksb_start++;
344 ccp->ksb_count -= 2;
345
346 /* Preset some register values and masks that are queue
347 * number dependent
348 */
349 cmd_q->reg_status = ccp->io_regs + CMD_Q_STATUS_BASE +
350 (CMD_Q_STATUS_INCR * i);
351 cmd_q->reg_int_status = ccp->io_regs + CMD_Q_INT_STATUS_BASE +
352 (CMD_Q_STATUS_INCR * i);
353 cmd_q->int_ok = 1 << (i * 2);
354 cmd_q->int_err = 1 << ((i * 2) + 1);
355
356 cmd_q->free_slots = CMD_Q_DEPTH(ioread32(cmd_q->reg_status));
357
358 init_waitqueue_head(&cmd_q->int_queue);
359
360 /* Build queue interrupt mask (two interrupts per queue) */
361 qim |= cmd_q->int_ok | cmd_q->int_err;
362
363 dev_dbg(dev, "queue #%u available\n", i);
364 }
365 if (ccp->cmd_q_count == 0) {
366 dev_notice(dev, "no command queues available\n");
367 ret = -EIO;
368 goto e_pool;
369 }
370 dev_notice(dev, "%u command queues available\n", ccp->cmd_q_count);
371
372 /* Disable and clear interrupts until ready */
373 iowrite32(0x00, ccp->io_regs + IRQ_MASK_REG);
374 for (i = 0; i < ccp->cmd_q_count; i++) {
375 cmd_q = &ccp->cmd_q[i];
376
377 ioread32(cmd_q->reg_int_status);
378 ioread32(cmd_q->reg_status);
379 }
380 iowrite32(qim, ccp->io_regs + IRQ_STATUS_REG);
381
382 /* Request an irq */
383 ret = ccp->get_irq(ccp);
384 if (ret) {
385 dev_err(dev, "unable to allocate an IRQ\n");
386 goto e_pool;
387 }
388
389 /* Initialize the queues used to wait for KSB space and suspend */
390 init_waitqueue_head(&ccp->ksb_queue);
391 init_waitqueue_head(&ccp->suspend_queue);
392
393 /* Create a kthread for each queue */
394 for (i = 0; i < ccp->cmd_q_count; i++) {
395 struct task_struct *kthread;
396
397 cmd_q = &ccp->cmd_q[i];
398
399 kthread = kthread_create(ccp_cmd_queue_thread, cmd_q,
400 "ccp-q%u", cmd_q->id);
401 if (IS_ERR(kthread)) {
402 dev_err(dev, "error creating queue thread (%ld)\n",
403 PTR_ERR(kthread));
404 ret = PTR_ERR(kthread);
405 goto e_kthread;
406 }
407
408 cmd_q->kthread = kthread;
409 wake_up_process(kthread);
410 }
411
412 /* Register the RNG */
413 ccp->hwrng.name = "ccp-rng";
414 ccp->hwrng.read = ccp_trng_read;
415 ret = hwrng_register(&ccp->hwrng);
416 if (ret) {
417 dev_err(dev, "error registering hwrng (%d)\n", ret);
418 goto e_kthread;
419 }
420
421 /* Make the device struct available before enabling interrupts */
422 ccp_add_device(ccp);
423
424 /* Enable interrupts */
425 iowrite32(qim, ccp->io_regs + IRQ_MASK_REG);
426
427 return 0;
428
429e_kthread:
430 for (i = 0; i < ccp->cmd_q_count; i++)
431 if (ccp->cmd_q[i].kthread)
432 kthread_stop(ccp->cmd_q[i].kthread);
433
434 ccp->free_irq(ccp);
435
436e_pool:
437 for (i = 0; i < ccp->cmd_q_count; i++)
438 dma_pool_destroy(ccp->cmd_q[i].dma_pool);
439
440 return ret;
441}
442
443/**
444 * ccp_destroy - tear down the CCP device
445 *
446 * @ccp: ccp_device struct
447 */
448void ccp_destroy(struct ccp_device *ccp)
449{
450 struct ccp_cmd_queue *cmd_q;
451 struct ccp_cmd *cmd;
452 unsigned int qim, i;
453
454 /* Remove general access to the device struct */
455 ccp_del_device(ccp);
456
457 /* Unregister the RNG */
458 hwrng_unregister(&ccp->hwrng);
459
460 /* Stop the queue kthreads */
461 for (i = 0; i < ccp->cmd_q_count; i++)
462 if (ccp->cmd_q[i].kthread)
463 kthread_stop(ccp->cmd_q[i].kthread);
464
465 /* Build queue interrupt mask (two interrupt masks per queue) */
466 qim = 0;
467 for (i = 0; i < ccp->cmd_q_count; i++) {
468 cmd_q = &ccp->cmd_q[i];
469 qim |= cmd_q->int_ok | cmd_q->int_err;
470 }
471
472 /* Disable and clear interrupts */
473 iowrite32(0x00, ccp->io_regs + IRQ_MASK_REG);
474 for (i = 0; i < ccp->cmd_q_count; i++) {
475 cmd_q = &ccp->cmd_q[i];
476
477 ioread32(cmd_q->reg_int_status);
478 ioread32(cmd_q->reg_status);
479 }
480 iowrite32(qim, ccp->io_regs + IRQ_STATUS_REG);
481
482 ccp->free_irq(ccp);
483
484 for (i = 0; i < ccp->cmd_q_count; i++)
485 dma_pool_destroy(ccp->cmd_q[i].dma_pool);
486
487 /* Flush the cmd and backlog queue */
488 while (!list_empty(&ccp->cmd)) {
489 /* Invoke the callback directly with an error code */
490 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
491 list_del(&cmd->entry);
492 cmd->callback(cmd->data, -ENODEV);
493 }
494 while (!list_empty(&ccp->backlog)) {
495 /* Invoke the callback directly with an error code */
496 cmd = list_first_entry(&ccp->backlog, struct ccp_cmd, entry);
497 list_del(&cmd->entry);
498 cmd->callback(cmd->data, -ENODEV);
499 }
500}
501
502/**
503 * ccp_irq_handler - handle interrupts generated by the CCP device
504 *
505 * @irq: the irq associated with the interrupt
506 * @data: the data value supplied when the irq was created
507 */
508irqreturn_t ccp_irq_handler(int irq, void *data)
509{
510 struct device *dev = data;
511 struct ccp_device *ccp = dev_get_drvdata(dev);
512 struct ccp_cmd_queue *cmd_q;
513 u32 q_int, status;
514 unsigned int i;
515
516 status = ioread32(ccp->io_regs + IRQ_STATUS_REG);
517
518 for (i = 0; i < ccp->cmd_q_count; i++) {
519 cmd_q = &ccp->cmd_q[i];
520
521 q_int = status & (cmd_q->int_ok | cmd_q->int_err);
522 if (q_int) {
523 cmd_q->int_status = status;
524 cmd_q->q_status = ioread32(cmd_q->reg_status);
525 cmd_q->q_int_status = ioread32(cmd_q->reg_int_status);
526
527 /* On error, only save the first error value */
528 if ((q_int & cmd_q->int_err) && !cmd_q->cmd_error)
529 cmd_q->cmd_error = CMD_Q_ERROR(cmd_q->q_status);
530
531 cmd_q->int_rcvd = 1;
532
533 /* Acknowledge the interrupt and wake the kthread */
534 iowrite32(q_int, ccp->io_regs + IRQ_STATUS_REG);
535 wake_up_interruptible(&cmd_q->int_queue);
536 }
537 }
538
539 return IRQ_HANDLED;
540}
541
542#ifdef CONFIG_PM
543bool ccp_queues_suspended(struct ccp_device *ccp)
544{
545 unsigned int suspended = 0;
546 unsigned long flags;
547 unsigned int i;
548
549 spin_lock_irqsave(&ccp->cmd_lock, flags);
550
551 for (i = 0; i < ccp->cmd_q_count; i++)
552 if (ccp->cmd_q[i].suspended)
553 suspended++;
554
555 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
556
557 return ccp->cmd_q_count == suspended;
558}
559#endif
560
561static const struct x86_cpu_id ccp_support[] = {
562 { X86_VENDOR_AMD, 22, },
563};
564
565static int __init ccp_mod_init(void)
566{
567 struct cpuinfo_x86 *cpuinfo = &boot_cpu_data;
568 int ret;
569
570 if (!x86_match_cpu(ccp_support))
571 return -ENODEV;
572
573 switch (cpuinfo->x86) {
574 case 22:
575 if ((cpuinfo->x86_model < 48) || (cpuinfo->x86_model > 63))
576 return -ENODEV;
577
578 ret = ccp_pci_init();
579 if (ret)
580 return ret;
581
582 /* Don't leave the driver loaded if init failed */
583 if (!ccp_get_device()) {
584 ccp_pci_exit();
585 return -ENODEV;
586 }
587
588 return 0;
589
590 break;
591 }
592
593 return -ENODEV;
594}
595
596static void __exit ccp_mod_exit(void)
597{
598 struct cpuinfo_x86 *cpuinfo = &boot_cpu_data;
599
600 switch (cpuinfo->x86) {
601 case 22:
602 ccp_pci_exit();
603 break;
604 }
605}
606
607module_init(ccp_mod_init);
608module_exit(ccp_mod_exit);