xref: /kernel/linux/linux-5.10/drivers/soc/qcom/apr.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2011-2017, The Linux Foundation. All rights reserved.
3// Copyright (c) 2018, Linaro Limited
4
5#include <linux/kernel.h>
6#include <linux/module.h>
7#include <linux/device.h>
8#include <linux/spinlock.h>
9#include <linux/idr.h>
10#include <linux/slab.h>
11#include <linux/workqueue.h>
12#include <linux/of_device.h>
13#include <linux/soc/qcom/apr.h>
14#include <linux/soc/qcom/pdr.h>
15#include <linux/rpmsg.h>
16#include <linux/of.h>
17
18enum {
19	PR_TYPE_APR = 0,
20};
21
22struct packet_router {
23	struct rpmsg_endpoint *ch;
24	struct device *dev;
25	spinlock_t svcs_lock;
26	spinlock_t rx_lock;
27	struct idr svcs_idr;
28	int dest_domain_id;
29	int type;
30	struct pdr_handle *pdr;
31	struct workqueue_struct *rxwq;
32	struct work_struct rx_work;
33	struct list_head rx_list;
34};
35
36struct apr_rx_buf {
37	struct list_head node;
38	int len;
39	uint8_t buf[];
40};
41
42/**
43 * apr_send_pkt() - Send a apr message from apr device
44 *
45 * @adev: Pointer to previously registered apr device.
46 * @pkt: Pointer to apr packet to send
47 *
48 * Return: Will be an negative on packet size on success.
49 */
50int apr_send_pkt(struct apr_device *adev, struct apr_pkt *pkt)
51{
52	struct packet_router *apr = dev_get_drvdata(adev->dev.parent);
53	struct apr_hdr *hdr;
54	unsigned long flags;
55	int ret;
56
57	spin_lock_irqsave(&adev->svc.lock, flags);
58
59	hdr = &pkt->hdr;
60	hdr->src_domain = APR_DOMAIN_APPS;
61	hdr->src_svc = adev->svc.id;
62	hdr->dest_domain = adev->domain_id;
63	hdr->dest_svc = adev->svc.id;
64
65	ret = rpmsg_trysend(apr->ch, pkt, hdr->pkt_size);
66	spin_unlock_irqrestore(&adev->svc.lock, flags);
67
68	return ret ? ret : hdr->pkt_size;
69}
70EXPORT_SYMBOL_GPL(apr_send_pkt);
71
72static void apr_dev_release(struct device *dev)
73{
74	struct apr_device *adev = to_apr_device(dev);
75
76	kfree(adev);
77}
78
79static int apr_callback(struct rpmsg_device *rpdev, void *buf,
80				  int len, void *priv, u32 addr)
81{
82	struct packet_router *apr = dev_get_drvdata(&rpdev->dev);
83	struct apr_rx_buf *abuf;
84	unsigned long flags;
85
86	if (len <= APR_HDR_SIZE) {
87		dev_err(apr->dev, "APR: Improper apr pkt received:%p %d\n",
88			buf, len);
89		return -EINVAL;
90	}
91
92	abuf = kzalloc(sizeof(*abuf) + len, GFP_ATOMIC);
93	if (!abuf)
94		return -ENOMEM;
95
96	abuf->len = len;
97	memcpy(abuf->buf, buf, len);
98
99	spin_lock_irqsave(&apr->rx_lock, flags);
100	list_add_tail(&abuf->node, &apr->rx_list);
101	spin_unlock_irqrestore(&apr->rx_lock, flags);
102
103	queue_work(apr->rxwq, &apr->rx_work);
104
105	return 0;
106}
107
108static int apr_do_rx_callback(struct packet_router *apr, struct apr_rx_buf *abuf)
109{
110	uint16_t hdr_size, msg_type, ver, svc_id;
111	struct pkt_router_svc *svc;
112	struct apr_device *adev;
113	struct apr_driver *adrv = NULL;
114	struct apr_resp_pkt resp;
115	struct apr_hdr *hdr;
116	unsigned long flags;
117	void *buf = abuf->buf;
118	int len = abuf->len;
119
120	hdr = buf;
121	ver = APR_HDR_FIELD_VER(hdr->hdr_field);
122	if (ver > APR_PKT_VER + 1)
123		return -EINVAL;
124
125	hdr_size = APR_HDR_FIELD_SIZE_BYTES(hdr->hdr_field);
126	if (hdr_size < APR_HDR_SIZE) {
127		dev_err(apr->dev, "APR: Wrong hdr size:%d\n", hdr_size);
128		return -EINVAL;
129	}
130
131	if (hdr->pkt_size < APR_HDR_SIZE || hdr->pkt_size != len) {
132		dev_err(apr->dev, "APR: Wrong packet size\n");
133		return -EINVAL;
134	}
135
136	msg_type = APR_HDR_FIELD_MT(hdr->hdr_field);
137	if (msg_type >= APR_MSG_TYPE_MAX) {
138		dev_err(apr->dev, "APR: Wrong message type: %d\n", msg_type);
139		return -EINVAL;
140	}
141
142	if (hdr->src_domain >= APR_DOMAIN_MAX ||
143			hdr->dest_domain >= APR_DOMAIN_MAX ||
144			hdr->src_svc >= APR_SVC_MAX ||
145			hdr->dest_svc >= APR_SVC_MAX) {
146		dev_err(apr->dev, "APR: Wrong APR header\n");
147		return -EINVAL;
148	}
149
150	svc_id = hdr->dest_svc;
151	spin_lock_irqsave(&apr->svcs_lock, flags);
152	svc = idr_find(&apr->svcs_idr, svc_id);
153	if (svc && svc->dev->driver) {
154		adev = svc_to_apr_device(svc);
155		adrv = to_apr_driver(adev->dev.driver);
156	}
157	spin_unlock_irqrestore(&apr->svcs_lock, flags);
158
159	if (!adrv || !adev) {
160		dev_err(apr->dev, "APR: service is not registered (%d)\n",
161			svc_id);
162		return -EINVAL;
163	}
164
165	resp.hdr = *hdr;
166	resp.payload_size = hdr->pkt_size - hdr_size;
167
168	/*
169	 * NOTE: hdr_size is not same as APR_HDR_SIZE as remote can include
170	 * optional headers in to apr_hdr which should be ignored
171	 */
172	if (resp.payload_size > 0)
173		resp.payload = buf + hdr_size;
174
175	adrv->callback(adev, &resp);
176
177	return 0;
178}
179
180static void apr_rxwq(struct work_struct *work)
181{
182	struct packet_router *apr = container_of(work, struct packet_router, rx_work);
183	struct apr_rx_buf *abuf, *b;
184	unsigned long flags;
185
186	if (!list_empty(&apr->rx_list)) {
187		list_for_each_entry_safe(abuf, b, &apr->rx_list, node) {
188			switch (apr->type) {
189			case PR_TYPE_APR:
190				apr_do_rx_callback(apr, abuf);
191				break;
192			default:
193				break;
194			}
195			spin_lock_irqsave(&apr->rx_lock, flags);
196			list_del(&abuf->node);
197			spin_unlock_irqrestore(&apr->rx_lock, flags);
198			kfree(abuf);
199		}
200	}
201}
202
203static int apr_device_match(struct device *dev, struct device_driver *drv)
204{
205	struct apr_device *adev = to_apr_device(dev);
206	struct apr_driver *adrv = to_apr_driver(drv);
207	const struct apr_device_id *id = adrv->id_table;
208
209	/* Attempt an OF style match first */
210	if (of_driver_match_device(dev, drv))
211		return 1;
212
213	if (!id)
214		return 0;
215
216	while (id->domain_id != 0 || id->svc_id != 0) {
217		if (id->domain_id == adev->domain_id &&
218		    id->svc_id == adev->svc.id)
219			return 1;
220		id++;
221	}
222
223	return 0;
224}
225
226static int apr_device_probe(struct device *dev)
227{
228	struct apr_device *adev = to_apr_device(dev);
229	struct apr_driver *adrv = to_apr_driver(dev->driver);
230
231	return adrv->probe(adev);
232}
233
234static int apr_device_remove(struct device *dev)
235{
236	struct apr_device *adev = to_apr_device(dev);
237	struct apr_driver *adrv;
238	struct packet_router *apr = dev_get_drvdata(adev->dev.parent);
239
240	if (dev->driver) {
241		adrv = to_apr_driver(dev->driver);
242		if (adrv->remove)
243			adrv->remove(adev);
244		spin_lock(&apr->svcs_lock);
245		idr_remove(&apr->svcs_idr, adev->svc.id);
246		spin_unlock(&apr->svcs_lock);
247	}
248
249	return 0;
250}
251
252static int apr_uevent(struct device *dev, struct kobj_uevent_env *env)
253{
254	struct apr_device *adev = to_apr_device(dev);
255	int ret;
256
257	ret = of_device_uevent_modalias(dev, env);
258	if (ret != -ENODEV)
259		return ret;
260
261	return add_uevent_var(env, "MODALIAS=apr:%s", adev->name);
262}
263
264struct bus_type aprbus = {
265	.name		= "aprbus",
266	.match		= apr_device_match,
267	.probe		= apr_device_probe,
268	.uevent		= apr_uevent,
269	.remove		= apr_device_remove,
270};
271EXPORT_SYMBOL_GPL(aprbus);
272
273static int apr_add_device(struct device *dev, struct device_node *np,
274			  u32 svc_id, u32 domain_id)
275{
276	struct packet_router *apr = dev_get_drvdata(dev);
277	struct apr_device *adev = NULL;
278	struct pkt_router_svc *svc;
279	int ret;
280
281	adev = kzalloc(sizeof(*adev), GFP_KERNEL);
282	if (!adev)
283		return -ENOMEM;
284
285	adev->svc_id = svc_id;
286	svc = &adev->svc;
287
288	svc->id = svc_id;
289	svc->pr = apr;
290	svc->priv = adev;
291	svc->dev = dev;
292	spin_lock_init(&svc->lock);
293
294	adev->domain_id = domain_id;
295
296	if (np)
297		snprintf(adev->name, APR_NAME_SIZE, "%pOFn", np);
298
299	switch (apr->type) {
300	case PR_TYPE_APR:
301		dev_set_name(&adev->dev, "aprsvc:%s:%x:%x", adev->name,
302			     domain_id, svc_id);
303		break;
304	default:
305		break;
306	}
307
308	adev->dev.bus = &aprbus;
309	adev->dev.parent = dev;
310	adev->dev.of_node = np;
311	adev->dev.release = apr_dev_release;
312	adev->dev.driver = NULL;
313
314	spin_lock(&apr->svcs_lock);
315	ret = idr_alloc(&apr->svcs_idr, svc, svc_id, svc_id + 1, GFP_ATOMIC);
316	spin_unlock(&apr->svcs_lock);
317	if (ret < 0) {
318		dev_err(dev, "idr_alloc failed: %d\n", ret);
319		goto out;
320	}
321
322	/* Protection domain is optional, it does not exist on older platforms */
323	ret = of_property_read_string_index(np, "qcom,protection-domain",
324					    1, &adev->service_path);
325	if (ret < 0 && ret != -EINVAL) {
326		dev_err(dev, "Failed to read second value of qcom,protection-domain\n");
327		goto out;
328	}
329
330	dev_info(dev, "Adding APR dev: %s\n", dev_name(&adev->dev));
331
332	ret = device_register(&adev->dev);
333	if (ret) {
334		dev_err(dev, "device_register failed: %d\n", ret);
335		put_device(&adev->dev);
336	}
337
338out:
339	return ret;
340}
341
342static int of_apr_add_pd_lookups(struct device *dev)
343{
344	const char *service_name, *service_path;
345	struct packet_router *apr = dev_get_drvdata(dev);
346	struct device_node *node;
347	struct pdr_service *pds;
348	int ret;
349
350	for_each_child_of_node(dev->of_node, node) {
351		ret = of_property_read_string_index(node, "qcom,protection-domain",
352						    0, &service_name);
353		if (ret < 0)
354			continue;
355
356		ret = of_property_read_string_index(node, "qcom,protection-domain",
357						    1, &service_path);
358		if (ret < 0) {
359			dev_err(dev, "pdr service path missing: %d\n", ret);
360			of_node_put(node);
361			return ret;
362		}
363
364		pds = pdr_add_lookup(apr->pdr, service_name, service_path);
365		if (IS_ERR(pds) && PTR_ERR(pds) != -EALREADY) {
366			dev_err(dev, "pdr add lookup failed: %ld\n", PTR_ERR(pds));
367			of_node_put(node);
368			return PTR_ERR(pds);
369		}
370	}
371
372	return 0;
373}
374
375static void of_register_apr_devices(struct device *dev, const char *svc_path)
376{
377	struct packet_router *apr = dev_get_drvdata(dev);
378	struct device_node *node;
379	const char *service_path;
380	int ret;
381
382	for_each_child_of_node(dev->of_node, node) {
383		u32 svc_id;
384		u32 domain_id;
385
386		/*
387		 * This function is called with svc_path NULL during
388		 * apr_probe(), in which case we register any apr devices
389		 * without a qcom,protection-domain specified.
390		 *
391		 * Then as the protection domains becomes available
392		 * (if applicable) this function is again called, but with
393		 * svc_path representing the service becoming available. In
394		 * this case we register any apr devices with a matching
395		 * qcom,protection-domain.
396		 */
397
398		ret = of_property_read_string_index(node, "qcom,protection-domain",
399						    1, &service_path);
400		if (svc_path) {
401			/* skip APR services that are PD independent */
402			if (ret)
403				continue;
404
405			/* skip APR services whose PD paths don't match */
406			if (strcmp(service_path, svc_path))
407				continue;
408		} else {
409			/* skip APR services whose PD lookups are registered */
410			if (ret == 0)
411				continue;
412		}
413
414		if (of_property_read_u32(node, "reg", &svc_id))
415			continue;
416
417		domain_id = apr->dest_domain_id;
418
419		if (apr_add_device(dev, node, svc_id, domain_id))
420			dev_err(dev, "Failed to add apr %d svc\n", svc_id);
421	}
422}
423
424static int apr_remove_device(struct device *dev, void *svc_path)
425{
426	struct apr_device *adev = to_apr_device(dev);
427
428	if (svc_path && adev->service_path) {
429		if (!strcmp(adev->service_path, (char *)svc_path))
430			device_unregister(&adev->dev);
431	} else {
432		device_unregister(&adev->dev);
433	}
434
435	return 0;
436}
437
438static void apr_pd_status(int state, char *svc_path, void *priv)
439{
440	struct packet_router *apr = (struct packet_router *)priv;
441
442	switch (state) {
443	case SERVREG_SERVICE_STATE_UP:
444		of_register_apr_devices(apr->dev, svc_path);
445		break;
446	case SERVREG_SERVICE_STATE_DOWN:
447		device_for_each_child(apr->dev, svc_path, apr_remove_device);
448		break;
449	}
450}
451
452static int apr_probe(struct rpmsg_device *rpdev)
453{
454	struct device *dev = &rpdev->dev;
455	struct packet_router *apr;
456	int ret;
457
458	apr = devm_kzalloc(dev, sizeof(*apr), GFP_KERNEL);
459	if (!apr)
460		return -ENOMEM;
461
462	ret = of_property_read_u32(dev->of_node, "qcom,domain", &apr->dest_domain_id);
463	if (ret) /* try deprecated apr-domain property */
464		ret = of_property_read_u32(dev->of_node, "qcom,apr-domain",
465					   &apr->dest_domain_id);
466	apr->type = PR_TYPE_APR;
467	if (ret) {
468		dev_err(dev, "Domain ID not specified in DT\n");
469		return ret;
470	}
471
472	dev_set_drvdata(dev, apr);
473	apr->ch = rpdev->ept;
474	apr->dev = dev;
475	apr->rxwq = create_singlethread_workqueue("qcom_apr_rx");
476	if (!apr->rxwq) {
477		dev_err(apr->dev, "Failed to start Rx WQ\n");
478		return -ENOMEM;
479	}
480	INIT_WORK(&apr->rx_work, apr_rxwq);
481
482	apr->pdr = pdr_handle_alloc(apr_pd_status, apr);
483	if (IS_ERR(apr->pdr)) {
484		dev_err(dev, "Failed to init PDR handle\n");
485		ret = PTR_ERR(apr->pdr);
486		goto destroy_wq;
487	}
488
489	INIT_LIST_HEAD(&apr->rx_list);
490	spin_lock_init(&apr->rx_lock);
491	spin_lock_init(&apr->svcs_lock);
492	idr_init(&apr->svcs_idr);
493
494	ret = of_apr_add_pd_lookups(dev);
495	if (ret)
496		goto handle_release;
497
498	of_register_apr_devices(dev, NULL);
499
500	return 0;
501
502handle_release:
503	pdr_handle_release(apr->pdr);
504destroy_wq:
505	destroy_workqueue(apr->rxwq);
506	return ret;
507}
508
509static void apr_remove(struct rpmsg_device *rpdev)
510{
511	struct packet_router *apr = dev_get_drvdata(&rpdev->dev);
512
513	pdr_handle_release(apr->pdr);
514	device_for_each_child(&rpdev->dev, NULL, apr_remove_device);
515	flush_workqueue(apr->rxwq);
516	destroy_workqueue(apr->rxwq);
517}
518
519/*
520 * __apr_driver_register() - Client driver registration with aprbus
521 *
522 * @drv:Client driver to be associated with client-device.
523 * @owner: owning module/driver
524 *
525 * This API will register the client driver with the aprbus
526 * It is called from the driver's module-init function.
527 */
528int __apr_driver_register(struct apr_driver *drv, struct module *owner)
529{
530	drv->driver.bus = &aprbus;
531	drv->driver.owner = owner;
532
533	return driver_register(&drv->driver);
534}
535EXPORT_SYMBOL_GPL(__apr_driver_register);
536
537/*
538 * apr_driver_unregister() - Undo effect of apr_driver_register
539 *
540 * @drv: Client driver to be unregistered
541 */
542void apr_driver_unregister(struct apr_driver *drv)
543{
544	driver_unregister(&drv->driver);
545}
546EXPORT_SYMBOL_GPL(apr_driver_unregister);
547
548static const struct of_device_id pkt_router_of_match[] = {
549	{ .compatible = "qcom,apr"},
550	{ .compatible = "qcom,apr-v2"},
551	{}
552};
553MODULE_DEVICE_TABLE(of, pkt_router_of_match);
554
555static struct rpmsg_driver packet_router_driver = {
556	.probe = apr_probe,
557	.remove = apr_remove,
558	.callback = apr_callback,
559	.drv = {
560		.name = "qcom,apr",
561		.of_match_table = pkt_router_of_match,
562	},
563};
564
565static int __init apr_init(void)
566{
567	int ret;
568
569	ret = bus_register(&aprbus);
570	if (!ret)
571		ret = register_rpmsg_driver(&packet_router_driver);
572	else
573		bus_unregister(&aprbus);
574
575	return ret;
576}
577
578static void __exit apr_exit(void)
579{
580	bus_unregister(&aprbus);
581	unregister_rpmsg_driver(&packet_router_driver);
582}
583
584subsys_initcall(apr_init);
585module_exit(apr_exit);
586
587MODULE_LICENSE("GPL v2");
588MODULE_DESCRIPTION("Qualcomm APR Bus");
589