2 * AMD Cryptographic Coprocessor (CCP) driver
4 * Copyright (C) 2013 Advanced Micro Devices, Inc.
6 * Author: Tom Lendacky <thomas.lendacky@amd.com>
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.
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>
28 MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
29 MODULE_LICENSE("GPL");
30 MODULE_VERSION("1.0.0");
31 MODULE_DESCRIPTION("AMD Cryptographic Coprocessor driver");
34 static struct ccp_device *ccp_dev;
35 static inline struct ccp_device *ccp_get_device(void)
40 static inline void ccp_add_device(struct ccp_device *ccp)
45 static inline void ccp_del_device(struct ccp_device *ccp)
51 * ccp_enqueue_cmd - queue an operation for processing by the CCP
53 * @cmd: ccp_cmd struct to be processed
55 * Queue a cmd to be processed by the CCP. If queueing the cmd
56 * would exceed the defined length of the cmd queue the cmd will
57 * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
58 * result in a return code of -EBUSY.
60 * The callback routine specified in the ccp_cmd struct will be
61 * called to notify the caller of completion (if the cmd was not
62 * backlogged) or advancement out of the backlog. If the cmd has
63 * advanced out of the backlog the "err" value of the callback
64 * will be -EINPROGRESS. Any other "err" value during callback is
65 * the result of the operation.
67 * The cmd has been successfully queued if:
68 * the return code is -EINPROGRESS or
69 * the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
71 int ccp_enqueue_cmd(struct ccp_cmd *cmd)
73 struct ccp_device *ccp = ccp_get_device();
81 /* Caller must supply a callback routine */
87 spin_lock_irqsave(&ccp->cmd_lock, flags);
91 if (ccp->cmd_count >= MAX_CMD_QLEN) {
93 if (cmd->flags & CCP_CMD_MAY_BACKLOG)
94 list_add_tail(&cmd->entry, &ccp->backlog);
98 list_add_tail(&cmd->entry, &ccp->cmd);
100 /* Find an idle queue */
101 if (!ccp->suspending) {
102 for (i = 0; i < ccp->cmd_q_count; i++) {
103 if (ccp->cmd_q[i].active)
111 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
113 /* If we found an idle queue, wake it up */
114 if (i < ccp->cmd_q_count)
115 wake_up_process(ccp->cmd_q[i].kthread);
119 EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
121 static void ccp_do_cmd_backlog(struct work_struct *work)
123 struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
124 struct ccp_device *ccp = cmd->ccp;
128 cmd->callback(cmd->data, -EINPROGRESS);
130 spin_lock_irqsave(&ccp->cmd_lock, flags);
133 list_add_tail(&cmd->entry, &ccp->cmd);
135 /* Find an idle queue */
136 for (i = 0; i < ccp->cmd_q_count; i++) {
137 if (ccp->cmd_q[i].active)
143 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
145 /* If we found an idle queue, wake it up */
146 if (i < ccp->cmd_q_count)
147 wake_up_process(ccp->cmd_q[i].kthread);
150 static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
152 struct ccp_device *ccp = cmd_q->ccp;
153 struct ccp_cmd *cmd = NULL;
154 struct ccp_cmd *backlog = NULL;
157 spin_lock_irqsave(&ccp->cmd_lock, flags);
161 if (ccp->suspending) {
162 cmd_q->suspended = 1;
164 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
165 wake_up_interruptible(&ccp->suspend_queue);
170 if (ccp->cmd_count) {
173 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
174 list_del(&cmd->entry);
179 if (!list_empty(&ccp->backlog)) {
180 backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
182 list_del(&backlog->entry);
185 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
188 INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
189 schedule_work(&backlog->work);
195 static void ccp_do_cmd_complete(struct work_struct *work)
197 struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
199 cmd->callback(cmd->data, cmd->ret);
202 static int ccp_cmd_queue_thread(void *data)
204 struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
207 set_current_state(TASK_INTERRUPTIBLE);
208 while (!kthread_should_stop()) {
211 set_current_state(TASK_INTERRUPTIBLE);
213 cmd = ccp_dequeue_cmd(cmd_q);
217 __set_current_state(TASK_RUNNING);
219 /* Execute the command */
220 cmd->ret = ccp_run_cmd(cmd_q, cmd);
222 /* Schedule the completion callback */
223 INIT_WORK(&cmd->work, ccp_do_cmd_complete);
224 schedule_work(&cmd->work);
227 __set_current_state(TASK_RUNNING);
232 static int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
234 struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
236 int len = min_t(int, sizeof(trng_value), max);
239 * Locking is provided by the caller so we can update device
240 * hwrng-related fields safely
242 trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
244 /* Zero is returned if not data is available or if a
245 * bad-entropy error is present. Assume an error if
246 * we exceed TRNG_RETRIES reads of zero.
248 if (ccp->hwrng_retries++ > TRNG_RETRIES)
254 /* Reset the counter and save the rng value */
255 ccp->hwrng_retries = 0;
256 memcpy(data, &trng_value, len);
262 * ccp_alloc_struct - allocate and initialize the ccp_device struct
264 * @dev: device struct of the CCP
266 struct ccp_device *ccp_alloc_struct(struct device *dev)
268 struct ccp_device *ccp;
270 ccp = kzalloc(sizeof(*ccp), GFP_KERNEL);
272 dev_err(dev, "unable to allocate device struct\n");
277 INIT_LIST_HEAD(&ccp->cmd);
278 INIT_LIST_HEAD(&ccp->backlog);
280 spin_lock_init(&ccp->cmd_lock);
281 mutex_init(&ccp->req_mutex);
282 mutex_init(&ccp->ksb_mutex);
283 ccp->ksb_count = KSB_COUNT;
290 * ccp_init - initialize the CCP device
292 * @ccp: ccp_device struct
294 int ccp_init(struct ccp_device *ccp)
296 struct device *dev = ccp->dev;
297 struct ccp_cmd_queue *cmd_q;
298 struct dma_pool *dma_pool;
299 char dma_pool_name[MAX_DMAPOOL_NAME_LEN];
300 unsigned int qmr, qim, i;
303 /* Find available queues */
305 qmr = ioread32(ccp->io_regs + Q_MASK_REG);
306 for (i = 0; i < MAX_HW_QUEUES; i++) {
307 if (!(qmr & (1 << i)))
310 /* Allocate a dma pool for this queue */
311 snprintf(dma_pool_name, sizeof(dma_pool_name), "ccp_q%d", i);
312 dma_pool = dma_pool_create(dma_pool_name, dev,
313 CCP_DMAPOOL_MAX_SIZE,
314 CCP_DMAPOOL_ALIGN, 0);
316 dev_err(dev, "unable to allocate dma pool\n");
321 cmd_q = &ccp->cmd_q[ccp->cmd_q_count];
326 cmd_q->dma_pool = dma_pool;
328 /* Reserve 2 KSB regions for the queue */
329 cmd_q->ksb_key = KSB_START + ccp->ksb_start++;
330 cmd_q->ksb_ctx = KSB_START + ccp->ksb_start++;
333 /* Preset some register values and masks that are queue
336 cmd_q->reg_status = ccp->io_regs + CMD_Q_STATUS_BASE +
337 (CMD_Q_STATUS_INCR * i);
338 cmd_q->reg_int_status = ccp->io_regs + CMD_Q_INT_STATUS_BASE +
339 (CMD_Q_STATUS_INCR * i);
340 cmd_q->int_ok = 1 << (i * 2);
341 cmd_q->int_err = 1 << ((i * 2) + 1);
343 cmd_q->free_slots = CMD_Q_DEPTH(ioread32(cmd_q->reg_status));
345 init_waitqueue_head(&cmd_q->int_queue);
347 /* Build queue interrupt mask (two interrupts per queue) */
348 qim |= cmd_q->int_ok | cmd_q->int_err;
350 dev_dbg(dev, "queue #%u available\n", i);
352 if (ccp->cmd_q_count == 0) {
353 dev_notice(dev, "no command queues available\n");
357 dev_notice(dev, "%u command queues available\n", ccp->cmd_q_count);
359 /* Disable and clear interrupts until ready */
360 iowrite32(0x00, ccp->io_regs + IRQ_MASK_REG);
361 for (i = 0; i < ccp->cmd_q_count; i++) {
362 cmd_q = &ccp->cmd_q[i];
364 ioread32(cmd_q->reg_int_status);
365 ioread32(cmd_q->reg_status);
367 iowrite32(qim, ccp->io_regs + IRQ_STATUS_REG);
370 ret = ccp->get_irq(ccp);
372 dev_err(dev, "unable to allocate an IRQ\n");
376 /* Initialize the queues used to wait for KSB space and suspend */
377 init_waitqueue_head(&ccp->ksb_queue);
378 init_waitqueue_head(&ccp->suspend_queue);
380 /* Create a kthread for each queue */
381 for (i = 0; i < ccp->cmd_q_count; i++) {
382 struct task_struct *kthread;
384 cmd_q = &ccp->cmd_q[i];
386 kthread = kthread_create(ccp_cmd_queue_thread, cmd_q,
387 "ccp-q%u", cmd_q->id);
388 if (IS_ERR(kthread)) {
389 dev_err(dev, "error creating queue thread (%ld)\n",
391 ret = PTR_ERR(kthread);
395 cmd_q->kthread = kthread;
396 wake_up_process(kthread);
399 /* Register the RNG */
400 ccp->hwrng.name = "ccp-rng";
401 ccp->hwrng.read = ccp_trng_read;
402 ret = hwrng_register(&ccp->hwrng);
404 dev_err(dev, "error registering hwrng (%d)\n", ret);
408 /* Make the device struct available before enabling interrupts */
411 /* Enable interrupts */
412 iowrite32(qim, ccp->io_regs + IRQ_MASK_REG);
417 for (i = 0; i < ccp->cmd_q_count; i++)
418 if (ccp->cmd_q[i].kthread)
419 kthread_stop(ccp->cmd_q[i].kthread);
424 for (i = 0; i < ccp->cmd_q_count; i++)
425 dma_pool_destroy(ccp->cmd_q[i].dma_pool);
431 * ccp_destroy - tear down the CCP device
433 * @ccp: ccp_device struct
435 void ccp_destroy(struct ccp_device *ccp)
437 struct ccp_cmd_queue *cmd_q;
441 /* Remove general access to the device struct */
444 /* Unregister the RNG */
445 hwrng_unregister(&ccp->hwrng);
447 /* Stop the queue kthreads */
448 for (i = 0; i < ccp->cmd_q_count; i++)
449 if (ccp->cmd_q[i].kthread)
450 kthread_stop(ccp->cmd_q[i].kthread);
452 /* Build queue interrupt mask (two interrupt masks per queue) */
454 for (i = 0; i < ccp->cmd_q_count; i++) {
455 cmd_q = &ccp->cmd_q[i];
456 qim |= cmd_q->int_ok | cmd_q->int_err;
459 /* Disable and clear interrupts */
460 iowrite32(0x00, ccp->io_regs + IRQ_MASK_REG);
461 for (i = 0; i < ccp->cmd_q_count; i++) {
462 cmd_q = &ccp->cmd_q[i];
464 ioread32(cmd_q->reg_int_status);
465 ioread32(cmd_q->reg_status);
467 iowrite32(qim, ccp->io_regs + IRQ_STATUS_REG);
471 for (i = 0; i < ccp->cmd_q_count; i++)
472 dma_pool_destroy(ccp->cmd_q[i].dma_pool);
474 /* Flush the cmd and backlog queue */
475 while (!list_empty(&ccp->cmd)) {
476 /* Invoke the callback directly with an error code */
477 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
478 list_del(&cmd->entry);
479 cmd->callback(cmd->data, -ENODEV);
481 while (!list_empty(&ccp->backlog)) {
482 /* Invoke the callback directly with an error code */
483 cmd = list_first_entry(&ccp->backlog, struct ccp_cmd, entry);
484 list_del(&cmd->entry);
485 cmd->callback(cmd->data, -ENODEV);
490 * ccp_irq_handler - handle interrupts generated by the CCP device
492 * @irq: the irq associated with the interrupt
493 * @data: the data value supplied when the irq was created
495 irqreturn_t ccp_irq_handler(int irq, void *data)
497 struct device *dev = data;
498 struct ccp_device *ccp = dev_get_drvdata(dev);
499 struct ccp_cmd_queue *cmd_q;
503 status = ioread32(ccp->io_regs + IRQ_STATUS_REG);
505 for (i = 0; i < ccp->cmd_q_count; i++) {
506 cmd_q = &ccp->cmd_q[i];
508 q_int = status & (cmd_q->int_ok | cmd_q->int_err);
510 cmd_q->int_status = status;
511 cmd_q->q_status = ioread32(cmd_q->reg_status);
512 cmd_q->q_int_status = ioread32(cmd_q->reg_int_status);
514 /* On error, only save the first error value */
515 if ((q_int & cmd_q->int_err) && !cmd_q->cmd_error)
516 cmd_q->cmd_error = CMD_Q_ERROR(cmd_q->q_status);
520 /* Acknowledge the interrupt and wake the kthread */
521 iowrite32(q_int, ccp->io_regs + IRQ_STATUS_REG);
522 wake_up_interruptible(&cmd_q->int_queue);
530 bool ccp_queues_suspended(struct ccp_device *ccp)
532 unsigned int suspended = 0;
536 spin_lock_irqsave(&ccp->cmd_lock, flags);
538 for (i = 0; i < ccp->cmd_q_count; i++)
539 if (ccp->cmd_q[i].suspended)
542 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
544 return ccp->cmd_q_count == suspended;
548 static const struct x86_cpu_id ccp_support[] = {
549 { X86_VENDOR_AMD, 22, },
552 static int __init ccp_mod_init(void)
554 struct cpuinfo_x86 *cpuinfo = &boot_cpu_data;
557 if (!x86_match_cpu(ccp_support))
560 switch (cpuinfo->x86) {
562 if ((cpuinfo->x86_model < 48) || (cpuinfo->x86_model > 63))
565 ret = ccp_pci_init();
569 /* Don't leave the driver loaded if init failed */
570 if (!ccp_get_device()) {
583 static void __exit ccp_mod_exit(void)
585 struct cpuinfo_x86 *cpuinfo = &boot_cpu_data;
587 switch (cpuinfo->x86) {
594 module_init(ccp_mod_init);
595 module_exit(ccp_mod_exit);