2 * AMD Cryptographic Coprocessor (CCP) driver
4 * Copyright (C) 2013,2016 Advanced Micro Devices, Inc.
6 * Author: Tom Lendacky <thomas.lendacky@amd.com>
7 * Author: Gary R Hook <gary.hook@amd.com>
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.
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>
27 #include <asm/cpu_device_id.h>
29 #include <linux/ccp.h>
33 MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
34 MODULE_LICENSE("GPL");
35 MODULE_VERSION("1.0.0");
36 MODULE_DESCRIPTION("AMD Cryptographic Coprocessor driver");
38 struct ccp_tasklet_data
{
39 struct completion completion
;
43 /* Human-readable error strings */
44 static char *ccp_error_codes
[] = {
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",
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",
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",
91 void ccp_log_error(struct ccp_device
*d
, int e
)
93 dev_err(d
->dev
, "CCP error: %s (0x%x)\n", ccp_error_codes
[e
], e
);
96 /* List of CCPs, CCP count, read-write access lock, and access functions
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.
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.
106 static DEFINE_RWLOCK(ccp_unit_lock
);
107 static LIST_HEAD(ccp_units
);
109 /* Round-robin counter */
110 static DEFINE_SPINLOCK(ccp_rr_lock
);
111 static struct ccp_device
*ccp_rr
;
113 /* Ever-increasing value to produce unique unit numbers */
114 static atomic_t ccp_unit_ordinal
;
115 static unsigned int ccp_increment_unit_ordinal(void)
117 return atomic_inc_return(&ccp_unit_ordinal
);
121 * ccp_add_device - add a CCP device to the list
123 * @ccp: ccp_device struct pointer
125 * Put this CCP on the unit list, which makes it available
128 * Returns zero if a CCP device is present, -ENODEV otherwise.
130 void ccp_add_device(struct ccp_device
*ccp
)
134 write_lock_irqsave(&ccp_unit_lock
, flags
);
135 list_add_tail(&ccp
->entry
, &ccp_units
);
137 /* We already have the list lock (we're first) so this
138 * pointer can't change on us. Set its initial value.
141 write_unlock_irqrestore(&ccp_unit_lock
, flags
);
145 * ccp_del_device - remove a CCP device from the list
147 * @ccp: ccp_device struct pointer
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.
153 void ccp_del_device(struct ccp_device
*ccp
)
157 write_lock_irqsave(&ccp_unit_lock
, flags
);
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.
163 if (list_is_last(&ccp_rr
->entry
, &ccp_units
))
164 ccp_rr
= list_first_entry(&ccp_units
, struct ccp_device
,
167 ccp_rr
= list_next_entry(ccp_rr
, entry
);
169 list_del(&ccp
->entry
);
170 if (list_empty(&ccp_units
))
172 write_unlock_irqrestore(&ccp_unit_lock
, flags
);
177 int ccp_register_rng(struct ccp_device
*ccp
)
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
);
187 dev_err(ccp
->dev
, "error registering hwrng (%d)\n", ret
);
192 void ccp_unregister_rng(struct ccp_device
*ccp
)
195 hwrng_unregister(&ccp
->hwrng
);
198 static struct ccp_device
*ccp_get_device(void)
201 struct ccp_device
*dp
= NULL
;
203 /* We round-robin through the unit list.
204 * The (ccp_rr) pointer refers to the next unit to use.
206 read_lock_irqsave(&ccp_unit_lock
, flags
);
207 if (!list_empty(&ccp_units
)) {
208 spin_lock(&ccp_rr_lock
);
210 if (list_is_last(&ccp_rr
->entry
, &ccp_units
))
211 ccp_rr
= list_first_entry(&ccp_units
, struct ccp_device
,
214 ccp_rr
= list_next_entry(ccp_rr
, entry
);
215 spin_unlock(&ccp_rr_lock
);
217 read_unlock_irqrestore(&ccp_unit_lock
, flags
);
223 * ccp_present - check if a CCP device is present
225 * Returns zero if a CCP device is present, -ENODEV otherwise.
227 int ccp_present(void)
232 read_lock_irqsave(&ccp_unit_lock
, flags
);
233 ret
= list_empty(&ccp_units
);
234 read_unlock_irqrestore(&ccp_unit_lock
, flags
);
236 return ret
? -ENODEV
: 0;
238 EXPORT_SYMBOL_GPL(ccp_present
);
241 * ccp_version - get the version of the CCP device
243 * Returns the version from the first unit on the list;
244 * otherwise a zero if no CCP device is present
246 unsigned int ccp_version(void)
248 struct ccp_device
*dp
;
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
;
257 read_unlock_irqrestore(&ccp_unit_lock
, flags
);
261 EXPORT_SYMBOL_GPL(ccp_version
);
264 * ccp_enqueue_cmd - queue an operation for processing by the CCP
266 * @cmd: ccp_cmd struct to be processed
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.
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.
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
284 int ccp_enqueue_cmd(struct ccp_cmd
*cmd
)
286 struct ccp_device
*ccp
= ccp_get_device();
294 /* Caller must supply a callback routine */
300 spin_lock_irqsave(&ccp
->cmd_lock
, flags
);
302 i
= ccp
->cmd_q_count
;
304 if (ccp
->cmd_count
>= MAX_CMD_QLEN
) {
306 if (cmd
->flags
& CCP_CMD_MAY_BACKLOG
)
307 list_add_tail(&cmd
->entry
, &ccp
->backlog
);
311 list_add_tail(&cmd
->entry
, &ccp
->cmd
);
313 /* Find an idle queue */
314 if (!ccp
->suspending
) {
315 for (i
= 0; i
< ccp
->cmd_q_count
; i
++) {
316 if (ccp
->cmd_q
[i
].active
)
324 spin_unlock_irqrestore(&ccp
->cmd_lock
, flags
);
326 /* If we found an idle queue, wake it up */
327 if (i
< ccp
->cmd_q_count
)
328 wake_up_process(ccp
->cmd_q
[i
].kthread
);
332 EXPORT_SYMBOL_GPL(ccp_enqueue_cmd
);
334 static void ccp_do_cmd_backlog(struct work_struct
*work
)
336 struct ccp_cmd
*cmd
= container_of(work
, struct ccp_cmd
, work
);
337 struct ccp_device
*ccp
= cmd
->ccp
;
341 cmd
->callback(cmd
->data
, -EINPROGRESS
);
343 spin_lock_irqsave(&ccp
->cmd_lock
, flags
);
346 list_add_tail(&cmd
->entry
, &ccp
->cmd
);
348 /* Find an idle queue */
349 for (i
= 0; i
< ccp
->cmd_q_count
; i
++) {
350 if (ccp
->cmd_q
[i
].active
)
356 spin_unlock_irqrestore(&ccp
->cmd_lock
, flags
);
358 /* If we found an idle queue, wake it up */
359 if (i
< ccp
->cmd_q_count
)
360 wake_up_process(ccp
->cmd_q
[i
].kthread
);
363 static struct ccp_cmd
*ccp_dequeue_cmd(struct ccp_cmd_queue
*cmd_q
)
365 struct ccp_device
*ccp
= cmd_q
->ccp
;
366 struct ccp_cmd
*cmd
= NULL
;
367 struct ccp_cmd
*backlog
= NULL
;
370 spin_lock_irqsave(&ccp
->cmd_lock
, flags
);
374 if (ccp
->suspending
) {
375 cmd_q
->suspended
= 1;
377 spin_unlock_irqrestore(&ccp
->cmd_lock
, flags
);
378 wake_up_interruptible(&ccp
->suspend_queue
);
383 if (ccp
->cmd_count
) {
386 cmd
= list_first_entry(&ccp
->cmd
, struct ccp_cmd
, entry
);
387 list_del(&cmd
->entry
);
392 if (!list_empty(&ccp
->backlog
)) {
393 backlog
= list_first_entry(&ccp
->backlog
, struct ccp_cmd
,
395 list_del(&backlog
->entry
);
398 spin_unlock_irqrestore(&ccp
->cmd_lock
, flags
);
401 INIT_WORK(&backlog
->work
, ccp_do_cmd_backlog
);
402 schedule_work(&backlog
->work
);
408 static void ccp_do_cmd_complete(unsigned long data
)
410 struct ccp_tasklet_data
*tdata
= (struct ccp_tasklet_data
*)data
;
411 struct ccp_cmd
*cmd
= tdata
->cmd
;
413 cmd
->callback(cmd
->data
, cmd
->ret
);
414 complete(&tdata
->completion
);
418 * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
420 * @data: thread-specific data
422 int ccp_cmd_queue_thread(void *data
)
424 struct ccp_cmd_queue
*cmd_q
= (struct ccp_cmd_queue
*)data
;
426 struct ccp_tasklet_data tdata
;
427 struct tasklet_struct tasklet
;
429 tasklet_init(&tasklet
, ccp_do_cmd_complete
, (unsigned long)&tdata
);
431 set_current_state(TASK_INTERRUPTIBLE
);
432 while (!kthread_should_stop()) {
435 set_current_state(TASK_INTERRUPTIBLE
);
437 cmd
= ccp_dequeue_cmd(cmd_q
);
441 __set_current_state(TASK_RUNNING
);
443 /* Execute the command */
444 cmd
->ret
= ccp_run_cmd(cmd_q
, cmd
);
446 /* Schedule the completion callback */
448 init_completion(&tdata
.completion
);
449 tasklet_schedule(&tasklet
);
450 wait_for_completion(&tdata
.completion
);
453 __set_current_state(TASK_RUNNING
);
459 * ccp_alloc_struct - allocate and initialize the ccp_device struct
461 * @dev: device struct of the CCP
463 struct ccp_device
*ccp_alloc_struct(struct device
*dev
)
465 struct ccp_device
*ccp
;
467 ccp
= devm_kzalloc(dev
, sizeof(*ccp
), GFP_KERNEL
);
472 INIT_LIST_HEAD(&ccp
->cmd
);
473 INIT_LIST_HEAD(&ccp
->backlog
);
475 spin_lock_init(&ccp
->cmd_lock
);
476 mutex_init(&ccp
->req_mutex
);
477 mutex_init(&ccp
->sb_mutex
);
478 ccp
->sb_count
= KSB_COUNT
;
481 /* Initialize the wait queues */
482 init_waitqueue_head(&ccp
->sb_queue
);
483 init_waitqueue_head(&ccp
->suspend_queue
);
485 ccp
->ord
= ccp_increment_unit_ordinal();
486 snprintf(ccp
->name
, MAX_CCP_NAME_LEN
, "ccp-%u", ccp
->ord
);
487 snprintf(ccp
->rngname
, MAX_CCP_NAME_LEN
, "ccp-%u-rng", ccp
->ord
);
492 int ccp_trng_read(struct hwrng
*rng
, void *data
, size_t max
, bool wait
)
494 struct ccp_device
*ccp
= container_of(rng
, struct ccp_device
, hwrng
);
496 int len
= min_t(int, sizeof(trng_value
), max
);
498 /* Locking is provided by the caller so we can update device
499 * hwrng-related fields safely
501 trng_value
= ioread32(ccp
->io_regs
+ TRNG_OUT_REG
);
503 /* Zero is returned if not data is available or if a
504 * bad-entropy error is present. Assume an error if
505 * we exceed TRNG_RETRIES reads of zero.
507 if (ccp
->hwrng_retries
++ > TRNG_RETRIES
)
513 /* Reset the counter and save the rng value */
514 ccp
->hwrng_retries
= 0;
515 memcpy(data
, &trng_value
, len
);
521 bool ccp_queues_suspended(struct ccp_device
*ccp
)
523 unsigned int suspended
= 0;
527 spin_lock_irqsave(&ccp
->cmd_lock
, flags
);
529 for (i
= 0; i
< ccp
->cmd_q_count
; i
++)
530 if (ccp
->cmd_q
[i
].suspended
)
533 spin_unlock_irqrestore(&ccp
->cmd_lock
, flags
);
535 return ccp
->cmd_q_count
== suspended
;
539 static int __init
ccp_mod_init(void)
544 ret
= ccp_pci_init();
548 /* Don't leave the driver loaded if init failed */
549 if (ccp_present() != 0) {
560 ret
= ccp_platform_init();
564 /* Don't leave the driver loaded if init failed */
565 if (ccp_present() != 0) {
576 static void __exit
ccp_mod_exit(void)
587 module_init(ccp_mod_init
);
588 module_exit(ccp_mod_exit
);