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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);
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}