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");
33 struct ccp_tasklet_data {
34 struct completion completion;
39 static struct ccp_device *ccp_dev;
40 static inline struct ccp_device *ccp_get_device(void)
45 static inline void ccp_add_device(struct ccp_device *ccp)
50 static inline void ccp_del_device(struct ccp_device *ccp)
56 * ccp_enqueue_cmd - queue an operation for processing by the CCP
58 * @cmd: ccp_cmd struct to be processed
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.
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.
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
76 int ccp_enqueue_cmd(struct ccp_cmd *cmd)
78 struct ccp_device *ccp = ccp_get_device();
86 /* Caller must supply a callback routine */
92 spin_lock_irqsave(&ccp->cmd_lock, flags);
96 if (ccp->cmd_count >= MAX_CMD_QLEN) {
98 if (cmd->flags & CCP_CMD_MAY_BACKLOG)
99 list_add_tail(&cmd->entry, &ccp->backlog);
103 list_add_tail(&cmd->entry, &ccp->cmd);
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)
116 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
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);
124 EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
126 static void ccp_do_cmd_backlog(struct work_struct *work)
128 struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
129 struct ccp_device *ccp = cmd->ccp;
133 cmd->callback(cmd->data, -EINPROGRESS);
135 spin_lock_irqsave(&ccp->cmd_lock, flags);
138 list_add_tail(&cmd->entry, &ccp->cmd);
140 /* Find an idle queue */
141 for (i = 0; i < ccp->cmd_q_count; i++) {
142 if (ccp->cmd_q[i].active)
148 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
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);
155 static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
157 struct ccp_device *ccp = cmd_q->ccp;
158 struct ccp_cmd *cmd = NULL;
159 struct ccp_cmd *backlog = NULL;
162 spin_lock_irqsave(&ccp->cmd_lock, flags);
166 if (ccp->suspending) {
167 cmd_q->suspended = 1;
169 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
170 wake_up_interruptible(&ccp->suspend_queue);
175 if (ccp->cmd_count) {
178 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
179 list_del(&cmd->entry);
184 if (!list_empty(&ccp->backlog)) {
185 backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
187 list_del(&backlog->entry);
190 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
193 INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
194 schedule_work(&backlog->work);
200 static void ccp_do_cmd_complete(unsigned long data)
202 struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
203 struct ccp_cmd *cmd = tdata->cmd;
205 cmd->callback(cmd->data, cmd->ret);
206 complete(&tdata->completion);
209 static int ccp_cmd_queue_thread(void *data)
211 struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
213 struct ccp_tasklet_data tdata;
214 struct tasklet_struct tasklet;
216 tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);
218 set_current_state(TASK_INTERRUPTIBLE);
219 while (!kthread_should_stop()) {
222 set_current_state(TASK_INTERRUPTIBLE);
224 cmd = ccp_dequeue_cmd(cmd_q);
228 __set_current_state(TASK_RUNNING);
230 /* Execute the command */
231 cmd->ret = ccp_run_cmd(cmd_q, cmd);
233 /* Schedule the completion callback */
235 init_completion(&tdata.completion);
236 tasklet_schedule(&tasklet);
237 wait_for_completion(&tdata.completion);
240 __set_current_state(TASK_RUNNING);
245 static int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
247 struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
249 int len = min_t(int, sizeof(trng_value), max);
252 * Locking is provided by the caller so we can update device
253 * hwrng-related fields safely
255 trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
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.
261 if (ccp->hwrng_retries++ > TRNG_RETRIES)
267 /* Reset the counter and save the rng value */
268 ccp->hwrng_retries = 0;
269 memcpy(data, &trng_value, len);
275 * ccp_alloc_struct - allocate and initialize the ccp_device struct
277 * @dev: device struct of the CCP
279 struct ccp_device *ccp_alloc_struct(struct device *dev)
281 struct ccp_device *ccp;
283 ccp = kzalloc(sizeof(*ccp), GFP_KERNEL);
285 dev_err(dev, "unable to allocate device struct\n");
290 INIT_LIST_HEAD(&ccp->cmd);
291 INIT_LIST_HEAD(&ccp->backlog);
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;
303 * ccp_init - initialize the CCP device
305 * @ccp: ccp_device struct
307 int ccp_init(struct ccp_device *ccp)
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;
316 /* Find available queues */
318 qmr = ioread32(ccp->io_regs + Q_MASK_REG);
319 for (i = 0; i < MAX_HW_QUEUES; i++) {
320 if (!(qmr & (1 << i)))
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);
329 dev_err(dev, "unable to allocate dma pool\n");
334 cmd_q = &ccp->cmd_q[ccp->cmd_q_count];
339 cmd_q->dma_pool = dma_pool;
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++;
346 /* Preset some register values and masks that are queue
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);
356 cmd_q->free_slots = CMD_Q_DEPTH(ioread32(cmd_q->reg_status));
358 init_waitqueue_head(&cmd_q->int_queue);
360 /* Build queue interrupt mask (two interrupts per queue) */
361 qim |= cmd_q->int_ok | cmd_q->int_err;
363 dev_dbg(dev, "queue #%u available\n", i);
365 if (ccp->cmd_q_count == 0) {
366 dev_notice(dev, "no command queues available\n");
370 dev_notice(dev, "%u command queues available\n", ccp->cmd_q_count);
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];
377 ioread32(cmd_q->reg_int_status);
378 ioread32(cmd_q->reg_status);
380 iowrite32(qim, ccp->io_regs + IRQ_STATUS_REG);
383 ret = ccp->get_irq(ccp);
385 dev_err(dev, "unable to allocate an IRQ\n");
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);
393 /* Create a kthread for each queue */
394 for (i = 0; i < ccp->cmd_q_count; i++) {
395 struct task_struct *kthread;
397 cmd_q = &ccp->cmd_q[i];
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",
404 ret = PTR_ERR(kthread);
408 cmd_q->kthread = kthread;
409 wake_up_process(kthread);
412 /* Register the RNG */
413 ccp->hwrng.name = "ccp-rng";
414 ccp->hwrng.read = ccp_trng_read;
415 ret = hwrng_register(&ccp->hwrng);
417 dev_err(dev, "error registering hwrng (%d)\n", ret);
421 /* Make the device struct available before enabling interrupts */
424 /* Enable interrupts */
425 iowrite32(qim, ccp->io_regs + IRQ_MASK_REG);
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);
437 for (i = 0; i < ccp->cmd_q_count; i++)
438 dma_pool_destroy(ccp->cmd_q[i].dma_pool);
444 * ccp_destroy - tear down the CCP device
446 * @ccp: ccp_device struct
448 void ccp_destroy(struct ccp_device *ccp)
450 struct ccp_cmd_queue *cmd_q;
454 /* Remove general access to the device struct */
457 /* Unregister the RNG */
458 hwrng_unregister(&ccp->hwrng);
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);
465 /* Build queue interrupt mask (two interrupt masks per queue) */
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;
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];
477 ioread32(cmd_q->reg_int_status);
478 ioread32(cmd_q->reg_status);
480 iowrite32(qim, ccp->io_regs + IRQ_STATUS_REG);
484 for (i = 0; i < ccp->cmd_q_count; i++)
485 dma_pool_destroy(ccp->cmd_q[i].dma_pool);
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);
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);
503 * ccp_irq_handler - handle interrupts generated by the CCP device
505 * @irq: the irq associated with the interrupt
506 * @data: the data value supplied when the irq was created
508 irqreturn_t ccp_irq_handler(int irq, void *data)
510 struct device *dev = data;
511 struct ccp_device *ccp = dev_get_drvdata(dev);
512 struct ccp_cmd_queue *cmd_q;
516 status = ioread32(ccp->io_regs + IRQ_STATUS_REG);
518 for (i = 0; i < ccp->cmd_q_count; i++) {
519 cmd_q = &ccp->cmd_q[i];
521 q_int = status & (cmd_q->int_ok | cmd_q->int_err);
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);
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);
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);
543 bool ccp_queues_suspended(struct ccp_device *ccp)
545 unsigned int suspended = 0;
549 spin_lock_irqsave(&ccp->cmd_lock, flags);
551 for (i = 0; i < ccp->cmd_q_count; i++)
552 if (ccp->cmd_q[i].suspended)
555 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
557 return ccp->cmd_q_count == suspended;
561 static const struct x86_cpu_id ccp_support[] = {
562 { X86_VENDOR_AMD, 22, },
565 static int __init ccp_mod_init(void)
567 struct cpuinfo_x86 *cpuinfo = &boot_cpu_data;
570 if (!x86_match_cpu(ccp_support))
573 switch (cpuinfo->x86) {
575 if ((cpuinfo->x86_model < 48) || (cpuinfo->x86_model > 63))
578 ret = ccp_pci_init();
582 /* Don't leave the driver loaded if init failed */
583 if (!ccp_get_device()) {
596 static void __exit ccp_mod_exit(void)
598 struct cpuinfo_x86 *cpuinfo = &boot_cpu_data;
600 switch (cpuinfo->x86) {
607 module_init(ccp_mod_init);
608 module_exit(ccp_mod_exit);