xref: /linux/drivers/crypto/ccp/psp-dev.c (revision 9a379e77033f02c4a071891afdf0f0a01eff8ccb)
1 /*
2  * AMD Platform Security Processor (PSP) interface
3  *
4  * Copyright (C) 2016-2017 Advanced Micro Devices, Inc.
5  *
6  * Author: Brijesh Singh <brijesh.singh@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/spinlock_types.h>
20 #include <linux/types.h>
21 #include <linux/mutex.h>
22 #include <linux/delay.h>
23 #include <linux/hw_random.h>
24 #include <linux/ccp.h>
25 
26 #include "sp-dev.h"
27 #include "psp-dev.h"
28 
29 #define DEVICE_NAME	"sev"
30 
31 static DEFINE_MUTEX(sev_cmd_mutex);
32 static struct sev_misc_dev *misc_dev;
33 static struct psp_device *psp_master;
34 
35 static struct psp_device *psp_alloc_struct(struct sp_device *sp)
36 {
37 	struct device *dev = sp->dev;
38 	struct psp_device *psp;
39 
40 	psp = devm_kzalloc(dev, sizeof(*psp), GFP_KERNEL);
41 	if (!psp)
42 		return NULL;
43 
44 	psp->dev = dev;
45 	psp->sp = sp;
46 
47 	snprintf(psp->name, sizeof(psp->name), "psp-%u", sp->ord);
48 
49 	return psp;
50 }
51 
52 static irqreturn_t psp_irq_handler(int irq, void *data)
53 {
54 	struct psp_device *psp = data;
55 	unsigned int status;
56 	int reg;
57 
58 	/* Read the interrupt status: */
59 	status = ioread32(psp->io_regs + PSP_P2CMSG_INTSTS);
60 
61 	/* Check if it is command completion: */
62 	if (!(status & BIT(PSP_CMD_COMPLETE_REG)))
63 		goto done;
64 
65 	/* Check if it is SEV command completion: */
66 	reg = ioread32(psp->io_regs + PSP_CMDRESP);
67 	if (reg & PSP_CMDRESP_RESP) {
68 		psp->sev_int_rcvd = 1;
69 		wake_up(&psp->sev_int_queue);
70 	}
71 
72 done:
73 	/* Clear the interrupt status by writing the same value we read. */
74 	iowrite32(status, psp->io_regs + PSP_P2CMSG_INTSTS);
75 
76 	return IRQ_HANDLED;
77 }
78 
79 static void sev_wait_cmd_ioc(struct psp_device *psp, unsigned int *reg)
80 {
81 	psp->sev_int_rcvd = 0;
82 
83 	wait_event(psp->sev_int_queue, psp->sev_int_rcvd);
84 	*reg = ioread32(psp->io_regs + PSP_CMDRESP);
85 }
86 
87 static int sev_cmd_buffer_len(int cmd)
88 {
89 	switch (cmd) {
90 	case SEV_CMD_INIT:			return sizeof(struct sev_data_init);
91 	case SEV_CMD_PLATFORM_STATUS:		return sizeof(struct sev_user_data_status);
92 	case SEV_CMD_PEK_CSR:			return sizeof(struct sev_data_pek_csr);
93 	case SEV_CMD_PEK_CERT_IMPORT:		return sizeof(struct sev_data_pek_cert_import);
94 	case SEV_CMD_PDH_CERT_EXPORT:		return sizeof(struct sev_data_pdh_cert_export);
95 	case SEV_CMD_LAUNCH_START:		return sizeof(struct sev_data_launch_start);
96 	case SEV_CMD_LAUNCH_UPDATE_DATA:	return sizeof(struct sev_data_launch_update_data);
97 	case SEV_CMD_LAUNCH_UPDATE_VMSA:	return sizeof(struct sev_data_launch_update_vmsa);
98 	case SEV_CMD_LAUNCH_FINISH:		return sizeof(struct sev_data_launch_finish);
99 	case SEV_CMD_LAUNCH_MEASURE:		return sizeof(struct sev_data_launch_measure);
100 	case SEV_CMD_ACTIVATE:			return sizeof(struct sev_data_activate);
101 	case SEV_CMD_DEACTIVATE:		return sizeof(struct sev_data_deactivate);
102 	case SEV_CMD_DECOMMISSION:		return sizeof(struct sev_data_decommission);
103 	case SEV_CMD_GUEST_STATUS:		return sizeof(struct sev_data_guest_status);
104 	case SEV_CMD_DBG_DECRYPT:		return sizeof(struct sev_data_dbg);
105 	case SEV_CMD_DBG_ENCRYPT:		return sizeof(struct sev_data_dbg);
106 	case SEV_CMD_SEND_START:		return sizeof(struct sev_data_send_start);
107 	case SEV_CMD_SEND_UPDATE_DATA:		return sizeof(struct sev_data_send_update_data);
108 	case SEV_CMD_SEND_UPDATE_VMSA:		return sizeof(struct sev_data_send_update_vmsa);
109 	case SEV_CMD_SEND_FINISH:		return sizeof(struct sev_data_send_finish);
110 	case SEV_CMD_RECEIVE_START:		return sizeof(struct sev_data_receive_start);
111 	case SEV_CMD_RECEIVE_FINISH:		return sizeof(struct sev_data_receive_finish);
112 	case SEV_CMD_RECEIVE_UPDATE_DATA:	return sizeof(struct sev_data_receive_update_data);
113 	case SEV_CMD_RECEIVE_UPDATE_VMSA:	return sizeof(struct sev_data_receive_update_vmsa);
114 	case SEV_CMD_LAUNCH_UPDATE_SECRET:	return sizeof(struct sev_data_launch_secret);
115 	default:				return 0;
116 	}
117 
118 	return 0;
119 }
120 
121 static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
122 {
123 	struct psp_device *psp = psp_master;
124 	unsigned int phys_lsb, phys_msb;
125 	unsigned int reg, ret = 0;
126 
127 	if (!psp)
128 		return -ENODEV;
129 
130 	/* Get the physical address of the command buffer */
131 	phys_lsb = data ? lower_32_bits(__psp_pa(data)) : 0;
132 	phys_msb = data ? upper_32_bits(__psp_pa(data)) : 0;
133 
134 	dev_dbg(psp->dev, "sev command id %#x buffer 0x%08x%08x\n",
135 		cmd, phys_msb, phys_lsb);
136 
137 	print_hex_dump_debug("(in):  ", DUMP_PREFIX_OFFSET, 16, 2, data,
138 			     sev_cmd_buffer_len(cmd), false);
139 
140 	iowrite32(phys_lsb, psp->io_regs + PSP_CMDBUFF_ADDR_LO);
141 	iowrite32(phys_msb, psp->io_regs + PSP_CMDBUFF_ADDR_HI);
142 
143 	reg = cmd;
144 	reg <<= PSP_CMDRESP_CMD_SHIFT;
145 	reg |= PSP_CMDRESP_IOC;
146 	iowrite32(reg, psp->io_regs + PSP_CMDRESP);
147 
148 	/* wait for command completion */
149 	sev_wait_cmd_ioc(psp, &reg);
150 
151 	if (psp_ret)
152 		*psp_ret = reg & PSP_CMDRESP_ERR_MASK;
153 
154 	if (reg & PSP_CMDRESP_ERR_MASK) {
155 		dev_dbg(psp->dev, "sev command %#x failed (%#010x)\n",
156 			cmd, reg & PSP_CMDRESP_ERR_MASK);
157 		ret = -EIO;
158 	}
159 
160 	print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data,
161 			     sev_cmd_buffer_len(cmd), false);
162 
163 	return ret;
164 }
165 
166 static int sev_do_cmd(int cmd, void *data, int *psp_ret)
167 {
168 	int rc;
169 
170 	mutex_lock(&sev_cmd_mutex);
171 	rc = __sev_do_cmd_locked(cmd, data, psp_ret);
172 	mutex_unlock(&sev_cmd_mutex);
173 
174 	return rc;
175 }
176 
177 static int __sev_platform_init_locked(int *error)
178 {
179 	struct psp_device *psp = psp_master;
180 	int rc = 0;
181 
182 	if (!psp)
183 		return -ENODEV;
184 
185 	if (psp->sev_state == SEV_STATE_INIT)
186 		return 0;
187 
188 	rc = __sev_do_cmd_locked(SEV_CMD_INIT, &psp->init_cmd_buf, error);
189 	if (rc)
190 		return rc;
191 
192 	psp->sev_state = SEV_STATE_INIT;
193 	dev_dbg(psp->dev, "SEV firmware initialized\n");
194 
195 	return rc;
196 }
197 
198 int sev_platform_init(int *error)
199 {
200 	int rc;
201 
202 	mutex_lock(&sev_cmd_mutex);
203 	rc = __sev_platform_init_locked(error);
204 	mutex_unlock(&sev_cmd_mutex);
205 
206 	return rc;
207 }
208 EXPORT_SYMBOL_GPL(sev_platform_init);
209 
210 static int __sev_platform_shutdown_locked(int *error)
211 {
212 	int ret;
213 
214 	ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, 0, error);
215 	if (ret)
216 		return ret;
217 
218 	psp_master->sev_state = SEV_STATE_UNINIT;
219 	dev_dbg(psp_master->dev, "SEV firmware shutdown\n");
220 
221 	return ret;
222 }
223 
224 static int sev_platform_shutdown(int *error)
225 {
226 	int rc;
227 
228 	mutex_lock(&sev_cmd_mutex);
229 	rc = __sev_platform_shutdown_locked(NULL);
230 	mutex_unlock(&sev_cmd_mutex);
231 
232 	return rc;
233 }
234 
235 static int sev_get_platform_state(int *state, int *error)
236 {
237 	int rc;
238 
239 	rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS,
240 				 &psp_master->status_cmd_buf, error);
241 	if (rc)
242 		return rc;
243 
244 	*state = psp_master->status_cmd_buf.state;
245 	return rc;
246 }
247 
248 static int sev_ioctl_do_reset(struct sev_issue_cmd *argp)
249 {
250 	int state, rc;
251 
252 	/*
253 	 * The SEV spec requires that FACTORY_RESET must be issued in
254 	 * UNINIT state. Before we go further lets check if any guest is
255 	 * active.
256 	 *
257 	 * If FW is in WORKING state then deny the request otherwise issue
258 	 * SHUTDOWN command do INIT -> UNINIT before issuing the FACTORY_RESET.
259 	 *
260 	 */
261 	rc = sev_get_platform_state(&state, &argp->error);
262 	if (rc)
263 		return rc;
264 
265 	if (state == SEV_STATE_WORKING)
266 		return -EBUSY;
267 
268 	if (state == SEV_STATE_INIT) {
269 		rc = __sev_platform_shutdown_locked(&argp->error);
270 		if (rc)
271 			return rc;
272 	}
273 
274 	return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, 0, &argp->error);
275 }
276 
277 static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
278 {
279 	struct sev_user_data_status *data = &psp_master->status_cmd_buf;
280 	int ret;
281 
282 	ret = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, data, &argp->error);
283 	if (ret)
284 		return ret;
285 
286 	if (copy_to_user((void __user *)argp->data, data, sizeof(*data)))
287 		ret = -EFAULT;
288 
289 	return ret;
290 }
291 
292 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp)
293 {
294 	int rc;
295 
296 	if (psp_master->sev_state == SEV_STATE_UNINIT) {
297 		rc = __sev_platform_init_locked(&argp->error);
298 		if (rc)
299 			return rc;
300 	}
301 
302 	return __sev_do_cmd_locked(cmd, 0, &argp->error);
303 }
304 
305 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp)
306 {
307 	struct sev_user_data_pek_csr input;
308 	struct sev_data_pek_csr *data;
309 	void *blob = NULL;
310 	int ret;
311 
312 	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
313 		return -EFAULT;
314 
315 	data = kzalloc(sizeof(*data), GFP_KERNEL);
316 	if (!data)
317 		return -ENOMEM;
318 
319 	/* userspace wants to query CSR length */
320 	if (!input.address || !input.length)
321 		goto cmd;
322 
323 	/* allocate a physically contiguous buffer to store the CSR blob */
324 	if (!access_ok(VERIFY_WRITE, input.address, input.length) ||
325 	    input.length > SEV_FW_BLOB_MAX_SIZE) {
326 		ret = -EFAULT;
327 		goto e_free;
328 	}
329 
330 	blob = kmalloc(input.length, GFP_KERNEL);
331 	if (!blob) {
332 		ret = -ENOMEM;
333 		goto e_free;
334 	}
335 
336 	data->address = __psp_pa(blob);
337 	data->len = input.length;
338 
339 cmd:
340 	if (psp_master->sev_state == SEV_STATE_UNINIT) {
341 		ret = __sev_platform_init_locked(&argp->error);
342 		if (ret)
343 			goto e_free_blob;
344 	}
345 
346 	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, data, &argp->error);
347 
348 	 /* If we query the CSR length, FW responded with expected data. */
349 	input.length = data->len;
350 
351 	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
352 		ret = -EFAULT;
353 		goto e_free_blob;
354 	}
355 
356 	if (blob) {
357 		if (copy_to_user((void __user *)input.address, blob, input.length))
358 			ret = -EFAULT;
359 	}
360 
361 e_free_blob:
362 	kfree(blob);
363 e_free:
364 	kfree(data);
365 	return ret;
366 }
367 
368 void *psp_copy_user_blob(u64 __user uaddr, u32 len)
369 {
370 	void *data;
371 
372 	if (!uaddr || !len)
373 		return ERR_PTR(-EINVAL);
374 
375 	/* verify that blob length does not exceed our limit */
376 	if (len > SEV_FW_BLOB_MAX_SIZE)
377 		return ERR_PTR(-EINVAL);
378 
379 	data = kmalloc(len, GFP_KERNEL);
380 	if (!data)
381 		return ERR_PTR(-ENOMEM);
382 
383 	if (copy_from_user(data, (void __user *)(uintptr_t)uaddr, len))
384 		goto e_free;
385 
386 	return data;
387 
388 e_free:
389 	kfree(data);
390 	return ERR_PTR(-EFAULT);
391 }
392 EXPORT_SYMBOL_GPL(psp_copy_user_blob);
393 
394 static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp)
395 {
396 	struct sev_user_data_pek_cert_import input;
397 	struct sev_data_pek_cert_import *data;
398 	void *pek_blob, *oca_blob;
399 	int ret;
400 
401 	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
402 		return -EFAULT;
403 
404 	data = kzalloc(sizeof(*data), GFP_KERNEL);
405 	if (!data)
406 		return -ENOMEM;
407 
408 	/* copy PEK certificate blobs from userspace */
409 	pek_blob = psp_copy_user_blob(input.pek_cert_address, input.pek_cert_len);
410 	if (IS_ERR(pek_blob)) {
411 		ret = PTR_ERR(pek_blob);
412 		goto e_free;
413 	}
414 
415 	data->pek_cert_address = __psp_pa(pek_blob);
416 	data->pek_cert_len = input.pek_cert_len;
417 
418 	/* copy PEK certificate blobs from userspace */
419 	oca_blob = psp_copy_user_blob(input.oca_cert_address, input.oca_cert_len);
420 	if (IS_ERR(oca_blob)) {
421 		ret = PTR_ERR(oca_blob);
422 		goto e_free_pek;
423 	}
424 
425 	data->oca_cert_address = __psp_pa(oca_blob);
426 	data->oca_cert_len = input.oca_cert_len;
427 
428 	/* If platform is not in INIT state then transition it to INIT */
429 	if (psp_master->sev_state != SEV_STATE_INIT) {
430 		ret = __sev_platform_init_locked(&argp->error);
431 		if (ret)
432 			goto e_free_oca;
433 	}
434 
435 	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, data, &argp->error);
436 
437 e_free_oca:
438 	kfree(oca_blob);
439 e_free_pek:
440 	kfree(pek_blob);
441 e_free:
442 	kfree(data);
443 	return ret;
444 }
445 
446 static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp)
447 {
448 	struct sev_user_data_pdh_cert_export input;
449 	void *pdh_blob = NULL, *cert_blob = NULL;
450 	struct sev_data_pdh_cert_export *data;
451 	int ret;
452 
453 	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
454 		return -EFAULT;
455 
456 	data = kzalloc(sizeof(*data), GFP_KERNEL);
457 	if (!data)
458 		return -ENOMEM;
459 
460 	/* Userspace wants to query the certificate length. */
461 	if (!input.pdh_cert_address ||
462 	    !input.pdh_cert_len ||
463 	    !input.cert_chain_address)
464 		goto cmd;
465 
466 	/* Allocate a physically contiguous buffer to store the PDH blob. */
467 	if ((input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) ||
468 	    !access_ok(VERIFY_WRITE, input.pdh_cert_address, input.pdh_cert_len)) {
469 		ret = -EFAULT;
470 		goto e_free;
471 	}
472 
473 	/* Allocate a physically contiguous buffer to store the cert chain blob. */
474 	if ((input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) ||
475 	    !access_ok(VERIFY_WRITE, input.cert_chain_address, input.cert_chain_len)) {
476 		ret = -EFAULT;
477 		goto e_free;
478 	}
479 
480 	pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL);
481 	if (!pdh_blob) {
482 		ret = -ENOMEM;
483 		goto e_free;
484 	}
485 
486 	data->pdh_cert_address = __psp_pa(pdh_blob);
487 	data->pdh_cert_len = input.pdh_cert_len;
488 
489 	cert_blob = kmalloc(input.cert_chain_len, GFP_KERNEL);
490 	if (!cert_blob) {
491 		ret = -ENOMEM;
492 		goto e_free_pdh;
493 	}
494 
495 	data->cert_chain_address = __psp_pa(cert_blob);
496 	data->cert_chain_len = input.cert_chain_len;
497 
498 cmd:
499 	/* If platform is not in INIT state then transition it to INIT. */
500 	if (psp_master->sev_state != SEV_STATE_INIT) {
501 		ret = __sev_platform_init_locked(&argp->error);
502 		if (ret)
503 			goto e_free_cert;
504 	}
505 
506 	ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, data, &argp->error);
507 
508 	/* If we query the length, FW responded with expected data. */
509 	input.cert_chain_len = data->cert_chain_len;
510 	input.pdh_cert_len = data->pdh_cert_len;
511 
512 	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
513 		ret = -EFAULT;
514 		goto e_free_cert;
515 	}
516 
517 	if (pdh_blob) {
518 		if (copy_to_user((void __user *)input.pdh_cert_address,
519 				 pdh_blob, input.pdh_cert_len)) {
520 			ret = -EFAULT;
521 			goto e_free_cert;
522 		}
523 	}
524 
525 	if (cert_blob) {
526 		if (copy_to_user((void __user *)input.cert_chain_address,
527 				 cert_blob, input.cert_chain_len))
528 			ret = -EFAULT;
529 	}
530 
531 e_free_cert:
532 	kfree(cert_blob);
533 e_free_pdh:
534 	kfree(pdh_blob);
535 e_free:
536 	kfree(data);
537 	return ret;
538 }
539 
540 static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
541 {
542 	void __user *argp = (void __user *)arg;
543 	struct sev_issue_cmd input;
544 	int ret = -EFAULT;
545 
546 	if (!psp_master)
547 		return -ENODEV;
548 
549 	if (ioctl != SEV_ISSUE_CMD)
550 		return -EINVAL;
551 
552 	if (copy_from_user(&input, argp, sizeof(struct sev_issue_cmd)))
553 		return -EFAULT;
554 
555 	if (input.cmd > SEV_MAX)
556 		return -EINVAL;
557 
558 	mutex_lock(&sev_cmd_mutex);
559 
560 	switch (input.cmd) {
561 
562 	case SEV_FACTORY_RESET:
563 		ret = sev_ioctl_do_reset(&input);
564 		break;
565 	case SEV_PLATFORM_STATUS:
566 		ret = sev_ioctl_do_platform_status(&input);
567 		break;
568 	case SEV_PEK_GEN:
569 		ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PEK_GEN, &input);
570 		break;
571 	case SEV_PDH_GEN:
572 		ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PDH_GEN, &input);
573 		break;
574 	case SEV_PEK_CSR:
575 		ret = sev_ioctl_do_pek_csr(&input);
576 		break;
577 	case SEV_PEK_CERT_IMPORT:
578 		ret = sev_ioctl_do_pek_import(&input);
579 		break;
580 	case SEV_PDH_CERT_EXPORT:
581 		ret = sev_ioctl_do_pdh_export(&input);
582 		break;
583 	default:
584 		ret = -EINVAL;
585 		goto out;
586 	}
587 
588 	if (copy_to_user(argp, &input, sizeof(struct sev_issue_cmd)))
589 		ret = -EFAULT;
590 out:
591 	mutex_unlock(&sev_cmd_mutex);
592 
593 	return ret;
594 }
595 
596 static const struct file_operations sev_fops = {
597 	.owner	= THIS_MODULE,
598 	.unlocked_ioctl = sev_ioctl,
599 };
600 
601 int sev_platform_status(struct sev_user_data_status *data, int *error)
602 {
603 	return sev_do_cmd(SEV_CMD_PLATFORM_STATUS, data, error);
604 }
605 EXPORT_SYMBOL_GPL(sev_platform_status);
606 
607 int sev_guest_deactivate(struct sev_data_deactivate *data, int *error)
608 {
609 	return sev_do_cmd(SEV_CMD_DEACTIVATE, data, error);
610 }
611 EXPORT_SYMBOL_GPL(sev_guest_deactivate);
612 
613 int sev_guest_activate(struct sev_data_activate *data, int *error)
614 {
615 	return sev_do_cmd(SEV_CMD_ACTIVATE, data, error);
616 }
617 EXPORT_SYMBOL_GPL(sev_guest_activate);
618 
619 int sev_guest_decommission(struct sev_data_decommission *data, int *error)
620 {
621 	return sev_do_cmd(SEV_CMD_DECOMMISSION, data, error);
622 }
623 EXPORT_SYMBOL_GPL(sev_guest_decommission);
624 
625 int sev_guest_df_flush(int *error)
626 {
627 	return sev_do_cmd(SEV_CMD_DF_FLUSH, 0, error);
628 }
629 EXPORT_SYMBOL_GPL(sev_guest_df_flush);
630 
631 static void sev_exit(struct kref *ref)
632 {
633 	struct sev_misc_dev *misc_dev = container_of(ref, struct sev_misc_dev, refcount);
634 
635 	misc_deregister(&misc_dev->misc);
636 }
637 
638 static int sev_misc_init(struct psp_device *psp)
639 {
640 	struct device *dev = psp->dev;
641 	int ret;
642 
643 	/*
644 	 * SEV feature support can be detected on multiple devices but the SEV
645 	 * FW commands must be issued on the master. During probe, we do not
646 	 * know the master hence we create /dev/sev on the first device probe.
647 	 * sev_do_cmd() finds the right master device to which to issue the
648 	 * command to the firmware.
649 	 */
650 	if (!misc_dev) {
651 		struct miscdevice *misc;
652 
653 		misc_dev = devm_kzalloc(dev, sizeof(*misc_dev), GFP_KERNEL);
654 		if (!misc_dev)
655 			return -ENOMEM;
656 
657 		misc = &misc_dev->misc;
658 		misc->minor = MISC_DYNAMIC_MINOR;
659 		misc->name = DEVICE_NAME;
660 		misc->fops = &sev_fops;
661 
662 		ret = misc_register(misc);
663 		if (ret)
664 			return ret;
665 
666 		kref_init(&misc_dev->refcount);
667 	} else {
668 		kref_get(&misc_dev->refcount);
669 	}
670 
671 	init_waitqueue_head(&psp->sev_int_queue);
672 	psp->sev_misc = misc_dev;
673 	dev_dbg(dev, "registered SEV device\n");
674 
675 	return 0;
676 }
677 
678 static int sev_init(struct psp_device *psp)
679 {
680 	/* Check if device supports SEV feature */
681 	if (!(ioread32(psp->io_regs + PSP_FEATURE_REG) & 1)) {
682 		dev_dbg(psp->dev, "device does not support SEV\n");
683 		return 1;
684 	}
685 
686 	return sev_misc_init(psp);
687 }
688 
689 int psp_dev_init(struct sp_device *sp)
690 {
691 	struct device *dev = sp->dev;
692 	struct psp_device *psp;
693 	int ret;
694 
695 	ret = -ENOMEM;
696 	psp = psp_alloc_struct(sp);
697 	if (!psp)
698 		goto e_err;
699 
700 	sp->psp_data = psp;
701 
702 	psp->vdata = (struct psp_vdata *)sp->dev_vdata->psp_vdata;
703 	if (!psp->vdata) {
704 		ret = -ENODEV;
705 		dev_err(dev, "missing driver data\n");
706 		goto e_err;
707 	}
708 
709 	psp->io_regs = sp->io_map + psp->vdata->offset;
710 
711 	/* Disable and clear interrupts until ready */
712 	iowrite32(0, psp->io_regs + PSP_P2CMSG_INTEN);
713 	iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTSTS);
714 
715 	/* Request an irq */
716 	ret = sp_request_psp_irq(psp->sp, psp_irq_handler, psp->name, psp);
717 	if (ret) {
718 		dev_err(dev, "psp: unable to allocate an IRQ\n");
719 		goto e_err;
720 	}
721 
722 	ret = sev_init(psp);
723 	if (ret)
724 		goto e_irq;
725 
726 	if (sp->set_psp_master_device)
727 		sp->set_psp_master_device(sp);
728 
729 	/* Enable interrupt */
730 	iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTEN);
731 
732 	return 0;
733 
734 e_irq:
735 	sp_free_psp_irq(psp->sp, psp);
736 e_err:
737 	sp->psp_data = NULL;
738 
739 	dev_notice(dev, "psp initialization failed\n");
740 
741 	return ret;
742 }
743 
744 void psp_dev_destroy(struct sp_device *sp)
745 {
746 	struct psp_device *psp = sp->psp_data;
747 
748 	if (psp->sev_misc)
749 		kref_put(&misc_dev->refcount, sev_exit);
750 
751 	sp_free_psp_irq(sp, psp);
752 }
753 
754 int sev_issue_cmd_external_user(struct file *filep, unsigned int cmd,
755 				void *data, int *error)
756 {
757 	if (!filep || filep->f_op != &sev_fops)
758 		return -EBADF;
759 
760 	return  sev_do_cmd(cmd, data, error);
761 }
762 EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
763 
764 void psp_pci_init(void)
765 {
766 	struct sev_user_data_status *status;
767 	struct sp_device *sp;
768 	int error, rc;
769 
770 	sp = sp_get_psp_master_device();
771 	if (!sp)
772 		return;
773 
774 	psp_master = sp->psp_data;
775 
776 	/* Initialize the platform */
777 	rc = sev_platform_init(&error);
778 	if (rc) {
779 		dev_err(sp->dev, "SEV: failed to INIT error %#x\n", error);
780 		goto err;
781 	}
782 
783 	/* Display SEV firmware version */
784 	status = &psp_master->status_cmd_buf;
785 	rc = sev_platform_status(status, &error);
786 	if (rc) {
787 		dev_err(sp->dev, "SEV: failed to get status error %#x\n", error);
788 		goto err;
789 	}
790 
791 	dev_info(sp->dev, "SEV API:%d.%d build:%d\n", status->api_major,
792 		 status->api_minor, status->build);
793 	return;
794 
795 err:
796 	psp_master = NULL;
797 }
798 
799 void psp_pci_exit(void)
800 {
801 	if (!psp_master)
802 		return;
803 
804 	sev_platform_shutdown(NULL);
805 }
806