1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Data Object Exchange
4 *	PCIe r6.0, sec 6.30 DOE
5 *
6 * Copyright (C) 2021 Huawei
7 *	Jonathan Cameron <Jonathan.Cameron@huawei.com>
8 *
9 * Copyright (C) 2022 Intel Corporation
10 *	Ira Weiny <ira.weiny@intel.com>
11 */
12
13#define dev_fmt(fmt) "DOE: " fmt
14
15#include <linux/bitfield.h>
16#include <linux/delay.h>
17#include <linux/jiffies.h>
18#include <linux/mutex.h>
19#include <linux/pci.h>
20#include <linux/pci-doe.h>
21#include <linux/workqueue.h>
22
23#include "pci.h"
24
25#define PCI_DOE_PROTOCOL_DISCOVERY 0
26
27/* Timeout of 1 second from 6.30.2 Operation, PCI Spec r6.0 */
28#define PCI_DOE_TIMEOUT HZ
29#define PCI_DOE_POLL_INTERVAL	(PCI_DOE_TIMEOUT / 128)
30
31#define PCI_DOE_FLAG_CANCEL	0
32#define PCI_DOE_FLAG_DEAD	1
33
34/* Max data object length is 2^18 dwords */
35#define PCI_DOE_MAX_LENGTH	(1 << 18)
36
37/**
38 * struct pci_doe_mb - State for a single DOE mailbox
39 *
40 * This state is used to manage a single DOE mailbox capability.  All fields
41 * should be considered opaque to the consumers and the structure passed into
42 * the helpers below after being created by pci_doe_create_mb().
43 *
44 * @pdev: PCI device this mailbox belongs to
45 * @cap_offset: Capability offset
46 * @prots: Array of protocols supported (encoded as long values)
47 * @wq: Wait queue for work item
48 * @work_queue: Queue of pci_doe_work items
49 * @flags: Bit array of PCI_DOE_FLAG_* flags
50 */
51struct pci_doe_mb {
52	struct pci_dev *pdev;
53	u16 cap_offset;
54	struct xarray prots;
55
56	wait_queue_head_t wq;
57	struct workqueue_struct *work_queue;
58	unsigned long flags;
59};
60
61struct pci_doe_protocol {
62	u16 vid;
63	u8 type;
64};
65
66/**
67 * struct pci_doe_task - represents a single query/response
68 *
69 * @prot: DOE Protocol
70 * @request_pl: The request payload
71 * @request_pl_sz: Size of the request payload (bytes)
72 * @response_pl: The response payload
73 * @response_pl_sz: Size of the response payload (bytes)
74 * @rv: Return value.  Length of received response or error (bytes)
75 * @complete: Called when task is complete
76 * @private: Private data for the consumer
77 * @work: Used internally by the mailbox
78 * @doe_mb: Used internally by the mailbox
79 */
80struct pci_doe_task {
81	struct pci_doe_protocol prot;
82	const __le32 *request_pl;
83	size_t request_pl_sz;
84	__le32 *response_pl;
85	size_t response_pl_sz;
86	int rv;
87	void (*complete)(struct pci_doe_task *task);
88	void *private;
89
90	/* initialized by pci_doe_submit_task() */
91	struct work_struct work;
92	struct pci_doe_mb *doe_mb;
93};
94
95static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout)
96{
97	if (wait_event_timeout(doe_mb->wq,
98			       test_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags),
99			       timeout))
100		return -EIO;
101	return 0;
102}
103
104static void pci_doe_write_ctrl(struct pci_doe_mb *doe_mb, u32 val)
105{
106	struct pci_dev *pdev = doe_mb->pdev;
107	int offset = doe_mb->cap_offset;
108
109	pci_write_config_dword(pdev, offset + PCI_DOE_CTRL, val);
110}
111
112static int pci_doe_abort(struct pci_doe_mb *doe_mb)
113{
114	struct pci_dev *pdev = doe_mb->pdev;
115	int offset = doe_mb->cap_offset;
116	unsigned long timeout_jiffies;
117
118	pci_dbg(pdev, "[%x] Issuing Abort\n", offset);
119
120	timeout_jiffies = jiffies + PCI_DOE_TIMEOUT;
121	pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_ABORT);
122
123	do {
124		int rc;
125		u32 val;
126
127		rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL);
128		if (rc)
129			return rc;
130		pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
131
132		/* Abort success! */
133		if (!FIELD_GET(PCI_DOE_STATUS_ERROR, val) &&
134		    !FIELD_GET(PCI_DOE_STATUS_BUSY, val))
135			return 0;
136
137	} while (!time_after(jiffies, timeout_jiffies));
138
139	/* Abort has timed out and the MB is dead */
140	pci_err(pdev, "[%x] ABORT timed out\n", offset);
141	return -EIO;
142}
143
144static int pci_doe_send_req(struct pci_doe_mb *doe_mb,
145			    struct pci_doe_task *task)
146{
147	struct pci_dev *pdev = doe_mb->pdev;
148	int offset = doe_mb->cap_offset;
149	size_t length, remainder;
150	u32 val;
151	int i;
152
153	/*
154	 * Check the DOE busy bit is not set. If it is set, this could indicate
155	 * someone other than Linux (e.g. firmware) is using the mailbox. Note
156	 * it is expected that firmware and OS will negotiate access rights via
157	 * an, as yet to be defined, method.
158	 */
159	pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
160	if (FIELD_GET(PCI_DOE_STATUS_BUSY, val))
161		return -EBUSY;
162
163	if (FIELD_GET(PCI_DOE_STATUS_ERROR, val))
164		return -EIO;
165
166	/* Length is 2 DW of header + length of payload in DW */
167	length = 2 + DIV_ROUND_UP(task->request_pl_sz, sizeof(__le32));
168	if (length > PCI_DOE_MAX_LENGTH)
169		return -EIO;
170	if (length == PCI_DOE_MAX_LENGTH)
171		length = 0;
172
173	/* Write DOE Header */
174	val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, task->prot.vid) |
175		FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, task->prot.type);
176	pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val);
177	pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
178			       FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH,
179					  length));
180
181	/* Write payload */
182	for (i = 0; i < task->request_pl_sz / sizeof(__le32); i++)
183		pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
184				       le32_to_cpu(task->request_pl[i]));
185
186	/* Write last payload dword */
187	remainder = task->request_pl_sz % sizeof(__le32);
188	if (remainder) {
189		val = 0;
190		memcpy(&val, &task->request_pl[i], remainder);
191		le32_to_cpus(&val);
192		pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val);
193	}
194
195	pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_GO);
196
197	return 0;
198}
199
200static bool pci_doe_data_obj_ready(struct pci_doe_mb *doe_mb)
201{
202	struct pci_dev *pdev = doe_mb->pdev;
203	int offset = doe_mb->cap_offset;
204	u32 val;
205
206	pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
207	if (FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val))
208		return true;
209	return false;
210}
211
212static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *task)
213{
214	size_t length, payload_length, remainder, received;
215	struct pci_dev *pdev = doe_mb->pdev;
216	int offset = doe_mb->cap_offset;
217	int i = 0;
218	u32 val;
219
220	/* Read the first dword to get the protocol */
221	pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
222	if ((FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val) != task->prot.vid) ||
223	    (FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val) != task->prot.type)) {
224		dev_err_ratelimited(&pdev->dev, "[%x] expected [VID, Protocol] = [%04x, %02x], got [%04x, %02x]\n",
225				    doe_mb->cap_offset, task->prot.vid, task->prot.type,
226				    FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val),
227				    FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val));
228		return -EIO;
229	}
230
231	pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
232	/* Read the second dword to get the length */
233	pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
234	pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
235
236	length = FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, val);
237	/* A value of 0x0 indicates max data object length */
238	if (!length)
239		length = PCI_DOE_MAX_LENGTH;
240	if (length < 2)
241		return -EIO;
242
243	/* First 2 dwords have already been read */
244	length -= 2;
245	received = task->response_pl_sz;
246	payload_length = DIV_ROUND_UP(task->response_pl_sz, sizeof(__le32));
247	remainder = task->response_pl_sz % sizeof(__le32);
248
249	/* remainder signifies number of data bytes in last payload dword */
250	if (!remainder)
251		remainder = sizeof(__le32);
252
253	if (length < payload_length) {
254		received = length * sizeof(__le32);
255		payload_length = length;
256		remainder = sizeof(__le32);
257	}
258
259	if (payload_length) {
260		/* Read all payload dwords except the last */
261		for (; i < payload_length - 1; i++) {
262			pci_read_config_dword(pdev, offset + PCI_DOE_READ,
263					      &val);
264			task->response_pl[i] = cpu_to_le32(val);
265			pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
266		}
267
268		/* Read last payload dword */
269		pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
270		cpu_to_le32s(&val);
271		memcpy(&task->response_pl[i], &val, remainder);
272		/* Prior to the last ack, ensure Data Object Ready */
273		if (!pci_doe_data_obj_ready(doe_mb))
274			return -EIO;
275		pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
276		i++;
277	}
278
279	/* Flush excess length */
280	for (; i < length; i++) {
281		pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
282		pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
283	}
284
285	/* Final error check to pick up on any since Data Object Ready */
286	pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
287	if (FIELD_GET(PCI_DOE_STATUS_ERROR, val))
288		return -EIO;
289
290	return received;
291}
292
293static void signal_task_complete(struct pci_doe_task *task, int rv)
294{
295	task->rv = rv;
296	destroy_work_on_stack(&task->work);
297	task->complete(task);
298}
299
300static void signal_task_abort(struct pci_doe_task *task, int rv)
301{
302	struct pci_doe_mb *doe_mb = task->doe_mb;
303	struct pci_dev *pdev = doe_mb->pdev;
304
305	if (pci_doe_abort(doe_mb)) {
306		/*
307		 * If the device can't process an abort; set the mailbox dead
308		 *	- no more submissions
309		 */
310		pci_err(pdev, "[%x] Abort failed marking mailbox dead\n",
311			doe_mb->cap_offset);
312		set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags);
313	}
314	signal_task_complete(task, rv);
315}
316
317static void doe_statemachine_work(struct work_struct *work)
318{
319	struct pci_doe_task *task = container_of(work, struct pci_doe_task,
320						 work);
321	struct pci_doe_mb *doe_mb = task->doe_mb;
322	struct pci_dev *pdev = doe_mb->pdev;
323	int offset = doe_mb->cap_offset;
324	unsigned long timeout_jiffies;
325	u32 val;
326	int rc;
327
328	if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags)) {
329		signal_task_complete(task, -EIO);
330		return;
331	}
332
333	/* Send request */
334	rc = pci_doe_send_req(doe_mb, task);
335	if (rc) {
336		/*
337		 * The specification does not provide any guidance on how to
338		 * resolve conflicting requests from other entities.
339		 * Furthermore, it is likely that busy will not be detected
340		 * most of the time.  Flag any detection of status busy with an
341		 * error.
342		 */
343		if (rc == -EBUSY)
344			dev_err_ratelimited(&pdev->dev, "[%x] busy detected; another entity is sending conflicting requests\n",
345					    offset);
346		signal_task_abort(task, rc);
347		return;
348	}
349
350	timeout_jiffies = jiffies + PCI_DOE_TIMEOUT;
351	/* Poll for response */
352retry_resp:
353	pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
354	if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) {
355		signal_task_abort(task, -EIO);
356		return;
357	}
358
359	if (!FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val)) {
360		if (time_after(jiffies, timeout_jiffies)) {
361			signal_task_abort(task, -EIO);
362			return;
363		}
364		rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL);
365		if (rc) {
366			signal_task_abort(task, rc);
367			return;
368		}
369		goto retry_resp;
370	}
371
372	rc  = pci_doe_recv_resp(doe_mb, task);
373	if (rc < 0) {
374		signal_task_abort(task, rc);
375		return;
376	}
377
378	signal_task_complete(task, rc);
379}
380
381static void pci_doe_task_complete(struct pci_doe_task *task)
382{
383	complete(task->private);
384}
385
386static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 *index, u16 *vid,
387			     u8 *protocol)
388{
389	u32 request_pl = FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX,
390				    *index);
391	__le32 request_pl_le = cpu_to_le32(request_pl);
392	__le32 response_pl_le;
393	u32 response_pl;
394	int rc;
395
396	rc = pci_doe(doe_mb, PCI_VENDOR_ID_PCI_SIG, PCI_DOE_PROTOCOL_DISCOVERY,
397		     &request_pl_le, sizeof(request_pl_le),
398		     &response_pl_le, sizeof(response_pl_le));
399	if (rc < 0)
400		return rc;
401
402	if (rc != sizeof(response_pl_le))
403		return -EIO;
404
405	response_pl = le32_to_cpu(response_pl_le);
406	*vid = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID, response_pl);
407	*protocol = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL,
408			      response_pl);
409	*index = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX,
410			   response_pl);
411
412	return 0;
413}
414
415static void *pci_doe_xa_prot_entry(u16 vid, u8 prot)
416{
417	return xa_mk_value((vid << 8) | prot);
418}
419
420static int pci_doe_cache_protocols(struct pci_doe_mb *doe_mb)
421{
422	u8 index = 0;
423	u8 xa_idx = 0;
424
425	do {
426		int rc;
427		u16 vid;
428		u8 prot;
429
430		rc = pci_doe_discovery(doe_mb, &index, &vid, &prot);
431		if (rc)
432			return rc;
433
434		pci_dbg(doe_mb->pdev,
435			"[%x] Found protocol %d vid: %x prot: %x\n",
436			doe_mb->cap_offset, xa_idx, vid, prot);
437
438		rc = xa_insert(&doe_mb->prots, xa_idx++,
439			       pci_doe_xa_prot_entry(vid, prot), GFP_KERNEL);
440		if (rc)
441			return rc;
442	} while (index);
443
444	return 0;
445}
446
447static void pci_doe_cancel_tasks(struct pci_doe_mb *doe_mb)
448{
449	/* Stop all pending work items from starting */
450	set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags);
451
452	/* Cancel an in progress work item, if necessary */
453	set_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags);
454	wake_up(&doe_mb->wq);
455}
456
457/**
458 * pci_doe_create_mb() - Create a DOE mailbox object
459 *
460 * @pdev: PCI device to create the DOE mailbox for
461 * @cap_offset: Offset of the DOE mailbox
462 *
463 * Create a single mailbox object to manage the mailbox protocol at the
464 * cap_offset specified.
465 *
466 * RETURNS: created mailbox object on success
467 *	    ERR_PTR(-errno) on failure
468 */
469static struct pci_doe_mb *pci_doe_create_mb(struct pci_dev *pdev,
470					    u16 cap_offset)
471{
472	struct pci_doe_mb *doe_mb;
473	int rc;
474
475	doe_mb = kzalloc(sizeof(*doe_mb), GFP_KERNEL);
476	if (!doe_mb)
477		return ERR_PTR(-ENOMEM);
478
479	doe_mb->pdev = pdev;
480	doe_mb->cap_offset = cap_offset;
481	init_waitqueue_head(&doe_mb->wq);
482	xa_init(&doe_mb->prots);
483
484	doe_mb->work_queue = alloc_ordered_workqueue("%s %s DOE [%x]", 0,
485						dev_bus_name(&pdev->dev),
486						pci_name(pdev),
487						doe_mb->cap_offset);
488	if (!doe_mb->work_queue) {
489		pci_err(pdev, "[%x] failed to allocate work queue\n",
490			doe_mb->cap_offset);
491		rc = -ENOMEM;
492		goto err_free;
493	}
494
495	/* Reset the mailbox by issuing an abort */
496	rc = pci_doe_abort(doe_mb);
497	if (rc) {
498		pci_err(pdev, "[%x] failed to reset mailbox with abort command : %d\n",
499			doe_mb->cap_offset, rc);
500		goto err_destroy_wq;
501	}
502
503	/*
504	 * The state machine and the mailbox should be in sync now;
505	 * Use the mailbox to query protocols.
506	 */
507	rc = pci_doe_cache_protocols(doe_mb);
508	if (rc) {
509		pci_err(pdev, "[%x] failed to cache protocols : %d\n",
510			doe_mb->cap_offset, rc);
511		goto err_cancel;
512	}
513
514	return doe_mb;
515
516err_cancel:
517	pci_doe_cancel_tasks(doe_mb);
518	xa_destroy(&doe_mb->prots);
519err_destroy_wq:
520	destroy_workqueue(doe_mb->work_queue);
521err_free:
522	kfree(doe_mb);
523	return ERR_PTR(rc);
524}
525
526/**
527 * pci_doe_destroy_mb() - Destroy a DOE mailbox object
528 *
529 * @doe_mb: DOE mailbox
530 *
531 * Destroy all internal data structures created for the DOE mailbox.
532 */
533static void pci_doe_destroy_mb(struct pci_doe_mb *doe_mb)
534{
535	pci_doe_cancel_tasks(doe_mb);
536	xa_destroy(&doe_mb->prots);
537	destroy_workqueue(doe_mb->work_queue);
538	kfree(doe_mb);
539}
540
541/**
542 * pci_doe_supports_prot() - Return if the DOE instance supports the given
543 *			     protocol
544 * @doe_mb: DOE mailbox capability to query
545 * @vid: Protocol Vendor ID
546 * @type: Protocol type
547 *
548 * RETURNS: True if the DOE mailbox supports the protocol specified
549 */
550static bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type)
551{
552	unsigned long index;
553	void *entry;
554
555	/* The discovery protocol must always be supported */
556	if (vid == PCI_VENDOR_ID_PCI_SIG && type == PCI_DOE_PROTOCOL_DISCOVERY)
557		return true;
558
559	xa_for_each(&doe_mb->prots, index, entry)
560		if (entry == pci_doe_xa_prot_entry(vid, type))
561			return true;
562
563	return false;
564}
565
566/**
567 * pci_doe_submit_task() - Submit a task to be processed by the state machine
568 *
569 * @doe_mb: DOE mailbox capability to submit to
570 * @task: task to be queued
571 *
572 * Submit a DOE task (request/response) to the DOE mailbox to be processed.
573 * Returns upon queueing the task object.  If the queue is full this function
574 * will sleep until there is room in the queue.
575 *
576 * task->complete will be called when the state machine is done processing this
577 * task.
578 *
579 * @task must be allocated on the stack.
580 *
581 * Excess data will be discarded.
582 *
583 * RETURNS: 0 when task has been successfully queued, -ERRNO on error
584 */
585static int pci_doe_submit_task(struct pci_doe_mb *doe_mb,
586			       struct pci_doe_task *task)
587{
588	if (!pci_doe_supports_prot(doe_mb, task->prot.vid, task->prot.type))
589		return -EINVAL;
590
591	if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags))
592		return -EIO;
593
594	task->doe_mb = doe_mb;
595	INIT_WORK_ONSTACK(&task->work, doe_statemachine_work);
596	queue_work(doe_mb->work_queue, &task->work);
597	return 0;
598}
599
600/**
601 * pci_doe() - Perform Data Object Exchange
602 *
603 * @doe_mb: DOE Mailbox
604 * @vendor: Vendor ID
605 * @type: Data Object Type
606 * @request: Request payload
607 * @request_sz: Size of request payload (bytes)
608 * @response: Response payload
609 * @response_sz: Size of response payload (bytes)
610 *
611 * Submit @request to @doe_mb and store the @response.
612 * The DOE exchange is performed synchronously and may therefore sleep.
613 *
614 * Payloads are treated as opaque byte streams which are transmitted verbatim,
615 * without byte-swapping.  If payloads contain little-endian register values,
616 * the caller is responsible for conversion with cpu_to_le32() / le32_to_cpu().
617 *
618 * For convenience, arbitrary payload sizes are allowed even though PCIe r6.0
619 * sec 6.30.1 specifies the Data Object Header 2 "Length" in dwords.  The last
620 * (partial) dword is copied with byte granularity and padded with zeroes if
621 * necessary.  Callers are thus relieved of using dword-sized bounce buffers.
622 *
623 * RETURNS: Length of received response or negative errno.
624 * Received data in excess of @response_sz is discarded.
625 * The length may be smaller than @response_sz and the caller
626 * is responsible for checking that.
627 */
628int pci_doe(struct pci_doe_mb *doe_mb, u16 vendor, u8 type,
629	    const void *request, size_t request_sz,
630	    void *response, size_t response_sz)
631{
632	DECLARE_COMPLETION_ONSTACK(c);
633	struct pci_doe_task task = {
634		.prot.vid = vendor,
635		.prot.type = type,
636		.request_pl = request,
637		.request_pl_sz = request_sz,
638		.response_pl = response,
639		.response_pl_sz = response_sz,
640		.complete = pci_doe_task_complete,
641		.private = &c,
642	};
643	int rc;
644
645	rc = pci_doe_submit_task(doe_mb, &task);
646	if (rc)
647		return rc;
648
649	wait_for_completion(&c);
650
651	return task.rv;
652}
653EXPORT_SYMBOL_GPL(pci_doe);
654
655/**
656 * pci_find_doe_mailbox() - Find Data Object Exchange mailbox
657 *
658 * @pdev: PCI device
659 * @vendor: Vendor ID
660 * @type: Data Object Type
661 *
662 * Find first DOE mailbox of a PCI device which supports the given protocol.
663 *
664 * RETURNS: Pointer to the DOE mailbox or NULL if none was found.
665 */
666struct pci_doe_mb *pci_find_doe_mailbox(struct pci_dev *pdev, u16 vendor,
667					u8 type)
668{
669	struct pci_doe_mb *doe_mb;
670	unsigned long index;
671
672	xa_for_each(&pdev->doe_mbs, index, doe_mb)
673		if (pci_doe_supports_prot(doe_mb, vendor, type))
674			return doe_mb;
675
676	return NULL;
677}
678EXPORT_SYMBOL_GPL(pci_find_doe_mailbox);
679
680void pci_doe_init(struct pci_dev *pdev)
681{
682	struct pci_doe_mb *doe_mb;
683	u16 offset = 0;
684	int rc;
685
686	xa_init(&pdev->doe_mbs);
687
688	while ((offset = pci_find_next_ext_capability(pdev, offset,
689						      PCI_EXT_CAP_ID_DOE))) {
690		doe_mb = pci_doe_create_mb(pdev, offset);
691		if (IS_ERR(doe_mb)) {
692			pci_err(pdev, "[%x] failed to create mailbox: %ld\n",
693				offset, PTR_ERR(doe_mb));
694			continue;
695		}
696
697		rc = xa_insert(&pdev->doe_mbs, offset, doe_mb, GFP_KERNEL);
698		if (rc) {
699			pci_err(pdev, "[%x] failed to insert mailbox: %d\n",
700				offset, rc);
701			pci_doe_destroy_mb(doe_mb);
702		}
703	}
704}
705
706void pci_doe_destroy(struct pci_dev *pdev)
707{
708	struct pci_doe_mb *doe_mb;
709	unsigned long index;
710
711	xa_for_each(&pdev->doe_mbs, index, doe_mb)
712		pci_doe_destroy_mb(doe_mb);
713
714	xa_destroy(&pdev->doe_mbs);
715}
716
717void pci_doe_disconnected(struct pci_dev *pdev)
718{
719	struct pci_doe_mb *doe_mb;
720	unsigned long index;
721
722	xa_for_each(&pdev->doe_mbs, index, doe_mb)
723		pci_doe_cancel_tasks(doe_mb);
724}
725