1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 /*
3  * Copyright (c) 2014 Raspberry Pi (Trading) Ltd. All rights reserved.
4  * Copyright (c) 2010-2012 Broadcom. All rights reserved.
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/sched/signal.h>
10 #include <linux/types.h>
11 #include <linux/errno.h>
12 #include <linux/cdev.h>
13 #include <linux/fs.h>
14 #include <linux/device.h>
15 #include <linux/mm.h>
16 #include <linux/highmem.h>
17 #include <linux/pagemap.h>
18 #include <linux/bug.h>
19 #include <linux/completion.h>
20 #include <linux/list.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/compat.h>
24 #include <linux/dma-mapping.h>
25 #include <linux/rcupdate.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/interrupt.h>
29 #include <linux/io.h>
30 #include <linux/uaccess.h>
31 #include <soc/bcm2835/raspberrypi-firmware.h>
32 
33 #include "vchiq_core.h"
34 #include "vchiq_ioctl.h"
35 #include "vchiq_arm.h"
36 #include "vchiq_debugfs.h"
37 #include "vchiq_connected.h"
38 #include "vchiq_pagelist.h"
39 
40 #define DEVICE_NAME "vchiq"
41 
42 #define TOTAL_SLOTS (VCHIQ_SLOT_ZERO_SLOTS + 2 * 32)
43 
44 #define MAX_FRAGMENTS (VCHIQ_NUM_CURRENT_BULKS * 2)
45 
46 #define VCHIQ_PLATFORM_FRAGMENTS_OFFSET_IDX 0
47 #define VCHIQ_PLATFORM_FRAGMENTS_COUNT_IDX  1
48 
49 #define BELL0	0x00
50 #define BELL2	0x08
51 
52 #define ARM_DS_ACTIVE	BIT(2)
53 
54 /* Override the default prefix, which would be vchiq_arm (from the filename) */
55 #undef MODULE_PARAM_PREFIX
56 #define MODULE_PARAM_PREFIX DEVICE_NAME "."
57 
58 #define KEEPALIVE_VER 1
59 #define KEEPALIVE_VER_MIN KEEPALIVE_VER
60 
61 /* Run time control of log level, based on KERN_XXX level. */
62 int vchiq_arm_log_level = VCHIQ_LOG_DEFAULT;
63 int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
64 
65 DEFINE_SPINLOCK(msg_queue_spinlock);
66 struct vchiq_state g_state;
67 
68 static struct platform_device *bcm2835_camera;
69 static struct platform_device *bcm2835_audio;
70 
71 struct vchiq_drvdata {
72 	const unsigned int cache_line_size;
73 	struct rpi_firmware *fw;
74 };
75 
76 static struct vchiq_drvdata bcm2835_drvdata = {
77 	.cache_line_size = 32,
78 };
79 
80 static struct vchiq_drvdata bcm2836_drvdata = {
81 	.cache_line_size = 64,
82 };
83 
84 struct vchiq_arm_state {
85 	/* Keepalive-related data */
86 	struct task_struct *ka_thread;
87 	struct completion ka_evt;
88 	atomic_t ka_use_count;
89 	atomic_t ka_use_ack_count;
90 	atomic_t ka_release_count;
91 
92 	rwlock_t susp_res_lock;
93 
94 	struct vchiq_state *state;
95 
96 	/*
97 	 * Global use count for videocore.
98 	 * This is equal to the sum of the use counts for all services.  When
99 	 * this hits zero the videocore suspend procedure will be initiated.
100 	 */
101 	int videocore_use_count;
102 
103 	/*
104 	 * Use count to track requests from videocore peer.
105 	 * This use count is not associated with a service, so needs to be
106 	 * tracked separately with the state.
107 	 */
108 	int peer_use_count;
109 
110 	/*
111 	 * Flag to indicate that the first vchiq connect has made it through.
112 	 * This means that both sides should be fully ready, and we should
113 	 * be able to suspend after this point.
114 	 */
115 	int first_connect;
116 };
117 
118 struct vchiq_2835_state {
119 	int inited;
120 	struct vchiq_arm_state arm_state;
121 };
122 
123 struct vchiq_pagelist_info {
124 	struct pagelist *pagelist;
125 	size_t pagelist_buffer_size;
126 	dma_addr_t dma_addr;
127 	enum dma_data_direction dma_dir;
128 	unsigned int num_pages;
129 	unsigned int pages_need_release;
130 	struct page **pages;
131 	struct scatterlist *scatterlist;
132 	unsigned int scatterlist_mapped;
133 };
134 
135 static void __iomem *g_regs;
136 /* This value is the size of the L2 cache lines as understood by the
137  * VPU firmware, which determines the required alignment of the
138  * offsets/sizes in pagelists.
139  *
140  * Modern VPU firmware looks for a DT "cache-line-size" property in
141  * the VCHIQ node and will overwrite it with the actual L2 cache size,
142  * which the kernel must then respect.  That property was rejected
143  * upstream, so we have to use the VPU firmware's compatibility value
144  * of 32.
145  */
146 static unsigned int g_cache_line_size = 32;
147 static unsigned int g_fragments_size;
148 static char *g_fragments_base;
149 static char *g_free_fragments;
150 static struct semaphore g_free_fragments_sema;
151 
152 static DEFINE_SEMAPHORE(g_free_fragments_mutex, 1);
153 
154 static int
155 vchiq_blocking_bulk_transfer(struct vchiq_instance *instance, unsigned int handle, void *data,
156 			     unsigned int size, enum vchiq_bulk_dir dir);
157 
158 static irqreturn_t
vchiq_doorbell_irq(int irq,void * dev_id)159 vchiq_doorbell_irq(int irq, void *dev_id)
160 {
161 	struct vchiq_state *state = dev_id;
162 	irqreturn_t ret = IRQ_NONE;
163 	unsigned int status;
164 
165 	/* Read (and clear) the doorbell */
166 	status = readl(g_regs + BELL0);
167 
168 	if (status & ARM_DS_ACTIVE) {  /* Was the doorbell rung? */
169 		remote_event_pollall(state);
170 		ret = IRQ_HANDLED;
171 	}
172 
173 	return ret;
174 }
175 
176 static void
cleanup_pagelistinfo(struct vchiq_instance * instance,struct vchiq_pagelist_info * pagelistinfo)177 cleanup_pagelistinfo(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagelistinfo)
178 {
179 	if (pagelistinfo->scatterlist_mapped) {
180 		dma_unmap_sg(instance->state->dev, pagelistinfo->scatterlist,
181 			     pagelistinfo->num_pages, pagelistinfo->dma_dir);
182 	}
183 
184 	if (pagelistinfo->pages_need_release)
185 		unpin_user_pages(pagelistinfo->pages, pagelistinfo->num_pages);
186 
187 	dma_free_coherent(instance->state->dev, pagelistinfo->pagelist_buffer_size,
188 			  pagelistinfo->pagelist, pagelistinfo->dma_addr);
189 }
190 
191 static inline bool
is_adjacent_block(u32 * addrs,u32 addr,unsigned int k)192 is_adjacent_block(u32 *addrs, u32 addr, unsigned int k)
193 {
194 	u32 tmp;
195 
196 	if (!k)
197 		return false;
198 
199 	tmp = (addrs[k - 1] & PAGE_MASK) +
200 	      (((addrs[k - 1] & ~PAGE_MASK) + 1) << PAGE_SHIFT);
201 
202 	return tmp == (addr & PAGE_MASK);
203 }
204 
205 /* There is a potential problem with partial cache lines (pages?)
206  * at the ends of the block when reading. If the CPU accessed anything in
207  * the same line (page?) then it may have pulled old data into the cache,
208  * obscuring the new data underneath. We can solve this by transferring the
209  * partial cache lines separately, and allowing the ARM to copy into the
210  * cached area.
211  */
212 
213 static struct vchiq_pagelist_info *
create_pagelist(struct vchiq_instance * instance,char * buf,char __user * ubuf,size_t count,unsigned short type)214 create_pagelist(struct vchiq_instance *instance, char *buf, char __user *ubuf,
215 		size_t count, unsigned short type)
216 {
217 	struct pagelist *pagelist;
218 	struct vchiq_pagelist_info *pagelistinfo;
219 	struct page **pages;
220 	u32 *addrs;
221 	unsigned int num_pages, offset, i, k;
222 	int actual_pages;
223 	size_t pagelist_size;
224 	struct scatterlist *scatterlist, *sg;
225 	int dma_buffers;
226 	dma_addr_t dma_addr;
227 
228 	if (count >= INT_MAX - PAGE_SIZE)
229 		return NULL;
230 
231 	if (buf)
232 		offset = (uintptr_t)buf & (PAGE_SIZE - 1);
233 	else
234 		offset = (uintptr_t)ubuf & (PAGE_SIZE - 1);
235 	num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
236 
237 	if ((size_t)num_pages > (SIZE_MAX - sizeof(struct pagelist) -
238 			 sizeof(struct vchiq_pagelist_info)) /
239 			(sizeof(u32) + sizeof(pages[0]) +
240 			 sizeof(struct scatterlist)))
241 		return NULL;
242 
243 	pagelist_size = sizeof(struct pagelist) +
244 			(num_pages * sizeof(u32)) +
245 			(num_pages * sizeof(pages[0]) +
246 			(num_pages * sizeof(struct scatterlist))) +
247 			sizeof(struct vchiq_pagelist_info);
248 
249 	/* Allocate enough storage to hold the page pointers and the page
250 	 * list
251 	 */
252 	pagelist = dma_alloc_coherent(instance->state->dev, pagelist_size, &dma_addr,
253 				      GFP_KERNEL);
254 
255 	vchiq_log_trace(vchiq_arm_log_level, "%s - %pK", __func__, pagelist);
256 
257 	if (!pagelist)
258 		return NULL;
259 
260 	addrs		= pagelist->addrs;
261 	pages		= (struct page **)(addrs + num_pages);
262 	scatterlist	= (struct scatterlist *)(pages + num_pages);
263 	pagelistinfo	= (struct vchiq_pagelist_info *)
264 			  (scatterlist + num_pages);
265 
266 	pagelist->length = count;
267 	pagelist->type = type;
268 	pagelist->offset = offset;
269 
270 	/* Populate the fields of the pagelistinfo structure */
271 	pagelistinfo->pagelist = pagelist;
272 	pagelistinfo->pagelist_buffer_size = pagelist_size;
273 	pagelistinfo->dma_addr = dma_addr;
274 	pagelistinfo->dma_dir =  (type == PAGELIST_WRITE) ?
275 				  DMA_TO_DEVICE : DMA_FROM_DEVICE;
276 	pagelistinfo->num_pages = num_pages;
277 	pagelistinfo->pages_need_release = 0;
278 	pagelistinfo->pages = pages;
279 	pagelistinfo->scatterlist = scatterlist;
280 	pagelistinfo->scatterlist_mapped = 0;
281 
282 	if (buf) {
283 		unsigned long length = count;
284 		unsigned int off = offset;
285 
286 		for (actual_pages = 0; actual_pages < num_pages;
287 		     actual_pages++) {
288 			struct page *pg =
289 				vmalloc_to_page((buf +
290 						 (actual_pages * PAGE_SIZE)));
291 			size_t bytes = PAGE_SIZE - off;
292 
293 			if (!pg) {
294 				cleanup_pagelistinfo(instance, pagelistinfo);
295 				return NULL;
296 			}
297 
298 			if (bytes > length)
299 				bytes = length;
300 			pages[actual_pages] = pg;
301 			length -= bytes;
302 			off = 0;
303 		}
304 		/* do not try and release vmalloc pages */
305 	} else {
306 		actual_pages = pin_user_pages_fast((unsigned long)ubuf & PAGE_MASK, num_pages,
307 						   type == PAGELIST_READ, pages);
308 
309 		if (actual_pages != num_pages) {
310 			vchiq_log_info(vchiq_arm_log_level,
311 				       "%s - only %d/%d pages locked",
312 				       __func__, actual_pages, num_pages);
313 
314 			/* This is probably due to the process being killed */
315 			if (actual_pages > 0)
316 				unpin_user_pages(pages, actual_pages);
317 			cleanup_pagelistinfo(instance, pagelistinfo);
318 			return NULL;
319 		}
320 		 /* release user pages */
321 		pagelistinfo->pages_need_release = 1;
322 	}
323 
324 	/*
325 	 * Initialize the scatterlist so that the magic cookie
326 	 *  is filled if debugging is enabled
327 	 */
328 	sg_init_table(scatterlist, num_pages);
329 	/* Now set the pages for each scatterlist */
330 	for (i = 0; i < num_pages; i++)	{
331 		unsigned int len = PAGE_SIZE - offset;
332 
333 		if (len > count)
334 			len = count;
335 		sg_set_page(scatterlist + i, pages[i], len, offset);
336 		offset = 0;
337 		count -= len;
338 	}
339 
340 	dma_buffers = dma_map_sg(instance->state->dev,
341 				 scatterlist,
342 				 num_pages,
343 				 pagelistinfo->dma_dir);
344 
345 	if (dma_buffers == 0) {
346 		cleanup_pagelistinfo(instance, pagelistinfo);
347 		return NULL;
348 	}
349 
350 	pagelistinfo->scatterlist_mapped = 1;
351 
352 	/* Combine adjacent blocks for performance */
353 	k = 0;
354 	for_each_sg(scatterlist, sg, dma_buffers, i) {
355 		u32 len = sg_dma_len(sg);
356 		u32 addr = sg_dma_address(sg);
357 
358 		/* Note: addrs is the address + page_count - 1
359 		 * The firmware expects blocks after the first to be page-
360 		 * aligned and a multiple of the page size
361 		 */
362 		WARN_ON(len == 0);
363 		WARN_ON(i && (i != (dma_buffers - 1)) && (len & ~PAGE_MASK));
364 		WARN_ON(i && (addr & ~PAGE_MASK));
365 		if (is_adjacent_block(addrs, addr, k))
366 			addrs[k - 1] += ((len + PAGE_SIZE - 1) >> PAGE_SHIFT);
367 		else
368 			addrs[k++] = (addr & PAGE_MASK) |
369 				(((len + PAGE_SIZE - 1) >> PAGE_SHIFT) - 1);
370 	}
371 
372 	/* Partial cache lines (fragments) require special measures */
373 	if ((type == PAGELIST_READ) &&
374 	    ((pagelist->offset & (g_cache_line_size - 1)) ||
375 	    ((pagelist->offset + pagelist->length) &
376 	    (g_cache_line_size - 1)))) {
377 		char *fragments;
378 
379 		if (down_interruptible(&g_free_fragments_sema)) {
380 			cleanup_pagelistinfo(instance, pagelistinfo);
381 			return NULL;
382 		}
383 
384 		WARN_ON(!g_free_fragments);
385 
386 		down(&g_free_fragments_mutex);
387 		fragments = g_free_fragments;
388 		WARN_ON(!fragments);
389 		g_free_fragments = *(char **)g_free_fragments;
390 		up(&g_free_fragments_mutex);
391 		pagelist->type = PAGELIST_READ_WITH_FRAGMENTS +
392 			(fragments - g_fragments_base) / g_fragments_size;
393 	}
394 
395 	return pagelistinfo;
396 }
397 
398 static void
free_pagelist(struct vchiq_instance * instance,struct vchiq_pagelist_info * pagelistinfo,int actual)399 free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagelistinfo,
400 	      int actual)
401 {
402 	struct pagelist *pagelist = pagelistinfo->pagelist;
403 	struct page **pages = pagelistinfo->pages;
404 	unsigned int num_pages = pagelistinfo->num_pages;
405 
406 	vchiq_log_trace(vchiq_arm_log_level, "%s - %pK, %d",
407 			__func__, pagelistinfo->pagelist, actual);
408 
409 	/*
410 	 * NOTE: dma_unmap_sg must be called before the
411 	 * cpu can touch any of the data/pages.
412 	 */
413 	dma_unmap_sg(instance->state->dev, pagelistinfo->scatterlist,
414 		     pagelistinfo->num_pages, pagelistinfo->dma_dir);
415 	pagelistinfo->scatterlist_mapped = 0;
416 
417 	/* Deal with any partial cache lines (fragments) */
418 	if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS && g_fragments_base) {
419 		char *fragments = g_fragments_base +
420 			(pagelist->type - PAGELIST_READ_WITH_FRAGMENTS) *
421 			g_fragments_size;
422 		int head_bytes, tail_bytes;
423 
424 		head_bytes = (g_cache_line_size - pagelist->offset) &
425 			(g_cache_line_size - 1);
426 		tail_bytes = (pagelist->offset + actual) &
427 			(g_cache_line_size - 1);
428 
429 		if ((actual >= 0) && (head_bytes != 0)) {
430 			if (head_bytes > actual)
431 				head_bytes = actual;
432 
433 			memcpy_to_page(pages[0],
434 				pagelist->offset,
435 				fragments,
436 				head_bytes);
437 		}
438 		if ((actual >= 0) && (head_bytes < actual) &&
439 		    (tail_bytes != 0))
440 			memcpy_to_page(pages[num_pages - 1],
441 				(pagelist->offset + actual) &
442 				(PAGE_SIZE - 1) & ~(g_cache_line_size - 1),
443 				fragments + g_cache_line_size,
444 				tail_bytes);
445 
446 		down(&g_free_fragments_mutex);
447 		*(char **)fragments = g_free_fragments;
448 		g_free_fragments = fragments;
449 		up(&g_free_fragments_mutex);
450 		up(&g_free_fragments_sema);
451 	}
452 
453 	/* Need to mark all the pages dirty. */
454 	if (pagelist->type != PAGELIST_WRITE &&
455 	    pagelistinfo->pages_need_release) {
456 		unsigned int i;
457 
458 		for (i = 0; i < num_pages; i++)
459 			set_page_dirty(pages[i]);
460 	}
461 
462 	cleanup_pagelistinfo(instance, pagelistinfo);
463 }
464 
vchiq_platform_init(struct platform_device * pdev,struct vchiq_state * state)465 static int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state *state)
466 {
467 	struct device *dev = &pdev->dev;
468 	struct vchiq_drvdata *drvdata = platform_get_drvdata(pdev);
469 	struct rpi_firmware *fw = drvdata->fw;
470 	struct vchiq_slot_zero *vchiq_slot_zero;
471 	void *slot_mem;
472 	dma_addr_t slot_phys;
473 	u32 channelbase;
474 	int slot_mem_size, frag_mem_size;
475 	int err, irq, i;
476 
477 	/*
478 	 * VCHI messages between the CPU and firmware use
479 	 * 32-bit bus addresses.
480 	 */
481 	err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
482 
483 	if (err < 0)
484 		return err;
485 
486 	g_cache_line_size = drvdata->cache_line_size;
487 	g_fragments_size = 2 * g_cache_line_size;
488 
489 	/* Allocate space for the channels in coherent memory */
490 	slot_mem_size = PAGE_ALIGN(TOTAL_SLOTS * VCHIQ_SLOT_SIZE);
491 	frag_mem_size = PAGE_ALIGN(g_fragments_size * MAX_FRAGMENTS);
492 
493 	slot_mem = dmam_alloc_coherent(dev, slot_mem_size + frag_mem_size,
494 				       &slot_phys, GFP_KERNEL);
495 	if (!slot_mem) {
496 		dev_err(dev, "could not allocate DMA memory\n");
497 		return -ENOMEM;
498 	}
499 
500 	WARN_ON(((unsigned long)slot_mem & (PAGE_SIZE - 1)) != 0);
501 
502 	vchiq_slot_zero = vchiq_init_slots(slot_mem, slot_mem_size);
503 	if (!vchiq_slot_zero)
504 		return -ENOMEM;
505 
506 	vchiq_slot_zero->platform_data[VCHIQ_PLATFORM_FRAGMENTS_OFFSET_IDX] =
507 		(int)slot_phys + slot_mem_size;
508 	vchiq_slot_zero->platform_data[VCHIQ_PLATFORM_FRAGMENTS_COUNT_IDX] =
509 		MAX_FRAGMENTS;
510 
511 	g_fragments_base = (char *)slot_mem + slot_mem_size;
512 
513 	g_free_fragments = g_fragments_base;
514 	for (i = 0; i < (MAX_FRAGMENTS - 1); i++) {
515 		*(char **)&g_fragments_base[i * g_fragments_size] =
516 			&g_fragments_base[(i + 1) * g_fragments_size];
517 	}
518 	*(char **)&g_fragments_base[i * g_fragments_size] = NULL;
519 	sema_init(&g_free_fragments_sema, MAX_FRAGMENTS);
520 
521 	err = vchiq_init_state(state, vchiq_slot_zero, dev);
522 	if (err)
523 		return err;
524 
525 	g_regs = devm_platform_ioremap_resource(pdev, 0);
526 	if (IS_ERR(g_regs))
527 		return PTR_ERR(g_regs);
528 
529 	irq = platform_get_irq(pdev, 0);
530 	if (irq <= 0)
531 		return irq;
532 
533 	err = devm_request_irq(dev, irq, vchiq_doorbell_irq, IRQF_IRQPOLL,
534 			       "VCHIQ doorbell", state);
535 	if (err) {
536 		dev_err(dev, "failed to register irq=%d\n", irq);
537 		return err;
538 	}
539 
540 	/* Send the base address of the slots to VideoCore */
541 	channelbase = slot_phys;
542 	err = rpi_firmware_property(fw, RPI_FIRMWARE_VCHIQ_INIT,
543 				    &channelbase, sizeof(channelbase));
544 	if (err) {
545 		dev_err(dev, "failed to send firmware property: %d\n", err);
546 		return err;
547 	}
548 
549 	if (channelbase) {
550 		dev_err(dev, "failed to set channelbase (response: %x)\n",
551 			channelbase);
552 		return -ENXIO;
553 	}
554 
555 	vchiq_log_info(vchiq_arm_log_level, "vchiq_init - done (slots %pK, phys %pad)",
556 		       vchiq_slot_zero, &slot_phys);
557 
558 	vchiq_call_connected_callbacks();
559 
560 	return 0;
561 }
562 
563 static void
vchiq_arm_init_state(struct vchiq_state * state,struct vchiq_arm_state * arm_state)564 vchiq_arm_init_state(struct vchiq_state *state,
565 		     struct vchiq_arm_state *arm_state)
566 {
567 	if (arm_state) {
568 		rwlock_init(&arm_state->susp_res_lock);
569 
570 		init_completion(&arm_state->ka_evt);
571 		atomic_set(&arm_state->ka_use_count, 0);
572 		atomic_set(&arm_state->ka_use_ack_count, 0);
573 		atomic_set(&arm_state->ka_release_count, 0);
574 
575 		arm_state->state = state;
576 		arm_state->first_connect = 0;
577 	}
578 }
579 
580 int
vchiq_platform_init_state(struct vchiq_state * state)581 vchiq_platform_init_state(struct vchiq_state *state)
582 {
583 	struct vchiq_2835_state *platform_state;
584 
585 	state->platform_state = kzalloc(sizeof(*platform_state), GFP_KERNEL);
586 	if (!state->platform_state)
587 		return -ENOMEM;
588 
589 	platform_state = (struct vchiq_2835_state *)state->platform_state;
590 
591 	platform_state->inited = 1;
592 	vchiq_arm_init_state(state, &platform_state->arm_state);
593 
594 	return 0;
595 }
596 
vchiq_platform_get_arm_state(struct vchiq_state * state)597 static struct vchiq_arm_state *vchiq_platform_get_arm_state(struct vchiq_state *state)
598 {
599 	struct vchiq_2835_state *platform_state;
600 
601 	platform_state   = (struct vchiq_2835_state *)state->platform_state;
602 
603 	WARN_ON_ONCE(!platform_state->inited);
604 
605 	return &platform_state->arm_state;
606 }
607 
608 void
remote_event_signal(struct remote_event * event)609 remote_event_signal(struct remote_event *event)
610 {
611 	/*
612 	 * Ensure that all writes to shared data structures have completed
613 	 * before signalling the peer.
614 	 */
615 	wmb();
616 
617 	event->fired = 1;
618 
619 	dsb(sy);         /* data barrier operation */
620 
621 	if (event->armed)
622 		writel(0, g_regs + BELL2); /* trigger vc interrupt */
623 }
624 
625 int
vchiq_prepare_bulk_data(struct vchiq_instance * instance,struct vchiq_bulk * bulk,void * offset,void __user * uoffset,int size,int dir)626 vchiq_prepare_bulk_data(struct vchiq_instance *instance, struct vchiq_bulk *bulk, void *offset,
627 			void __user *uoffset, int size, int dir)
628 {
629 	struct vchiq_pagelist_info *pagelistinfo;
630 
631 	pagelistinfo = create_pagelist(instance, offset, uoffset, size,
632 				       (dir == VCHIQ_BULK_RECEIVE)
633 				       ? PAGELIST_READ
634 				       : PAGELIST_WRITE);
635 
636 	if (!pagelistinfo)
637 		return -ENOMEM;
638 
639 	bulk->data = pagelistinfo->dma_addr;
640 
641 	/*
642 	 * Store the pagelistinfo address in remote_data,
643 	 * which isn't used by the slave.
644 	 */
645 	bulk->remote_data = pagelistinfo;
646 
647 	return 0;
648 }
649 
650 void
vchiq_complete_bulk(struct vchiq_instance * instance,struct vchiq_bulk * bulk)651 vchiq_complete_bulk(struct vchiq_instance *instance, struct vchiq_bulk *bulk)
652 {
653 	if (bulk && bulk->remote_data && bulk->actual)
654 		free_pagelist(instance, (struct vchiq_pagelist_info *)bulk->remote_data,
655 			      bulk->actual);
656 }
657 
vchiq_dump_platform_state(void * dump_context)658 int vchiq_dump_platform_state(void *dump_context)
659 {
660 	char buf[80];
661 	int len;
662 
663 	len = snprintf(buf, sizeof(buf), "  Platform: 2835 (VC master)");
664 	return vchiq_dump(dump_context, buf, len + 1);
665 }
666 
667 #define VCHIQ_INIT_RETRIES 10
vchiq_initialise(struct vchiq_instance ** instance_out)668 int vchiq_initialise(struct vchiq_instance **instance_out)
669 {
670 	struct vchiq_state *state;
671 	struct vchiq_instance *instance = NULL;
672 	int i, ret;
673 
674 	/*
675 	 * VideoCore may not be ready due to boot up timing.
676 	 * It may never be ready if kernel and firmware are mismatched,so don't
677 	 * block forever.
678 	 */
679 	for (i = 0; i < VCHIQ_INIT_RETRIES; i++) {
680 		state = vchiq_get_state();
681 		if (state)
682 			break;
683 		usleep_range(500, 600);
684 	}
685 	if (i == VCHIQ_INIT_RETRIES) {
686 		vchiq_log_error(vchiq_core_log_level, "%s: videocore not initialized\n", __func__);
687 		ret = -ENOTCONN;
688 		goto failed;
689 	} else if (i > 0) {
690 		vchiq_log_warning(vchiq_core_log_level,
691 				  "%s: videocore initialized after %d retries\n", __func__, i);
692 	}
693 
694 	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
695 	if (!instance) {
696 		vchiq_log_error(vchiq_core_log_level,
697 				"%s: error allocating vchiq instance\n", __func__);
698 		ret = -ENOMEM;
699 		goto failed;
700 	}
701 
702 	instance->connected = 0;
703 	instance->state = state;
704 	mutex_init(&instance->bulk_waiter_list_mutex);
705 	INIT_LIST_HEAD(&instance->bulk_waiter_list);
706 
707 	*instance_out = instance;
708 
709 	ret = 0;
710 
711 failed:
712 	vchiq_log_trace(vchiq_core_log_level, "%s(%p): returning %d", __func__, instance, ret);
713 
714 	return ret;
715 }
716 EXPORT_SYMBOL(vchiq_initialise);
717 
free_bulk_waiter(struct vchiq_instance * instance)718 void free_bulk_waiter(struct vchiq_instance *instance)
719 {
720 	struct bulk_waiter_node *waiter, *next;
721 
722 	list_for_each_entry_safe(waiter, next,
723 				 &instance->bulk_waiter_list, list) {
724 		list_del(&waiter->list);
725 		vchiq_log_info(vchiq_arm_log_level, "bulk_waiter - cleaned up %pK for pid %d",
726 			       waiter, waiter->pid);
727 		kfree(waiter);
728 	}
729 }
730 
vchiq_shutdown(struct vchiq_instance * instance)731 int vchiq_shutdown(struct vchiq_instance *instance)
732 {
733 	int status = 0;
734 	struct vchiq_state *state = instance->state;
735 
736 	if (mutex_lock_killable(&state->mutex))
737 		return -EAGAIN;
738 
739 	/* Remove all services */
740 	vchiq_shutdown_internal(state, instance);
741 
742 	mutex_unlock(&state->mutex);
743 
744 	vchiq_log_trace(vchiq_core_log_level, "%s(%p): returning %d", __func__, instance, status);
745 
746 	free_bulk_waiter(instance);
747 	kfree(instance);
748 
749 	return status;
750 }
751 EXPORT_SYMBOL(vchiq_shutdown);
752 
vchiq_is_connected(struct vchiq_instance * instance)753 static int vchiq_is_connected(struct vchiq_instance *instance)
754 {
755 	return instance->connected;
756 }
757 
vchiq_connect(struct vchiq_instance * instance)758 int vchiq_connect(struct vchiq_instance *instance)
759 {
760 	int status;
761 	struct vchiq_state *state = instance->state;
762 
763 	if (mutex_lock_killable(&state->mutex)) {
764 		vchiq_log_trace(vchiq_core_log_level, "%s: call to mutex_lock failed", __func__);
765 		status = -EAGAIN;
766 		goto failed;
767 	}
768 	status = vchiq_connect_internal(state, instance);
769 
770 	if (!status)
771 		instance->connected = 1;
772 
773 	mutex_unlock(&state->mutex);
774 
775 failed:
776 	vchiq_log_trace(vchiq_core_log_level, "%s(%p): returning %d", __func__, instance, status);
777 
778 	return status;
779 }
780 EXPORT_SYMBOL(vchiq_connect);
781 
782 static int
vchiq_add_service(struct vchiq_instance * instance,const struct vchiq_service_params_kernel * params,unsigned int * phandle)783 vchiq_add_service(struct vchiq_instance *instance,
784 		  const struct vchiq_service_params_kernel *params,
785 		  unsigned int *phandle)
786 {
787 	int status;
788 	struct vchiq_state *state = instance->state;
789 	struct vchiq_service *service = NULL;
790 	int srvstate;
791 
792 	*phandle = VCHIQ_SERVICE_HANDLE_INVALID;
793 
794 	srvstate = vchiq_is_connected(instance)
795 		? VCHIQ_SRVSTATE_LISTENING
796 		: VCHIQ_SRVSTATE_HIDDEN;
797 
798 	service = vchiq_add_service_internal(state, params, srvstate, instance, NULL);
799 
800 	if (service) {
801 		*phandle = service->handle;
802 		status = 0;
803 	} else {
804 		status = -EINVAL;
805 	}
806 
807 	vchiq_log_trace(vchiq_core_log_level, "%s(%p): returning %d", __func__, instance, status);
808 
809 	return status;
810 }
811 
812 int
vchiq_open_service(struct vchiq_instance * instance,const struct vchiq_service_params_kernel * params,unsigned int * phandle)813 vchiq_open_service(struct vchiq_instance *instance,
814 		   const struct vchiq_service_params_kernel *params,
815 		   unsigned int *phandle)
816 {
817 	int status = -EINVAL;
818 	struct vchiq_state   *state = instance->state;
819 	struct vchiq_service *service = NULL;
820 
821 	*phandle = VCHIQ_SERVICE_HANDLE_INVALID;
822 
823 	if (!vchiq_is_connected(instance))
824 		goto failed;
825 
826 	service = vchiq_add_service_internal(state, params, VCHIQ_SRVSTATE_OPENING, instance, NULL);
827 
828 	if (service) {
829 		*phandle = service->handle;
830 		status = vchiq_open_service_internal(service, current->pid);
831 		if (status) {
832 			vchiq_remove_service(instance, service->handle);
833 			*phandle = VCHIQ_SERVICE_HANDLE_INVALID;
834 		}
835 	}
836 
837 failed:
838 	vchiq_log_trace(vchiq_core_log_level, "%s(%p): returning %d", __func__, instance, status);
839 
840 	return status;
841 }
842 EXPORT_SYMBOL(vchiq_open_service);
843 
844 int
vchiq_bulk_transmit(struct vchiq_instance * instance,unsigned int handle,const void * data,unsigned int size,void * userdata,enum vchiq_bulk_mode mode)845 vchiq_bulk_transmit(struct vchiq_instance *instance, unsigned int handle, const void *data,
846 		    unsigned int size, void *userdata, enum vchiq_bulk_mode mode)
847 {
848 	int status;
849 
850 	while (1) {
851 		switch (mode) {
852 		case VCHIQ_BULK_MODE_NOCALLBACK:
853 		case VCHIQ_BULK_MODE_CALLBACK:
854 			status = vchiq_bulk_transfer(instance, handle,
855 						     (void *)data, NULL,
856 						     size, userdata, mode,
857 						     VCHIQ_BULK_TRANSMIT);
858 			break;
859 		case VCHIQ_BULK_MODE_BLOCKING:
860 			status = vchiq_blocking_bulk_transfer(instance, handle, (void *)data, size,
861 							      VCHIQ_BULK_TRANSMIT);
862 			break;
863 		default:
864 			return -EINVAL;
865 		}
866 
867 		/*
868 		 * vchiq_*_bulk_transfer() may return -EAGAIN, so we need
869 		 * to implement a retry mechanism since this function is
870 		 * supposed to block until queued
871 		 */
872 		if (status != -EAGAIN)
873 			break;
874 
875 		msleep(1);
876 	}
877 
878 	return status;
879 }
880 EXPORT_SYMBOL(vchiq_bulk_transmit);
881 
vchiq_bulk_receive(struct vchiq_instance * instance,unsigned int handle,void * data,unsigned int size,void * userdata,enum vchiq_bulk_mode mode)882 int vchiq_bulk_receive(struct vchiq_instance *instance, unsigned int handle,
883 		       void *data, unsigned int size, void *userdata,
884 		       enum vchiq_bulk_mode mode)
885 {
886 	int status;
887 
888 	while (1) {
889 		switch (mode) {
890 		case VCHIQ_BULK_MODE_NOCALLBACK:
891 		case VCHIQ_BULK_MODE_CALLBACK:
892 			status = vchiq_bulk_transfer(instance, handle, data, NULL,
893 						     size, userdata,
894 						     mode, VCHIQ_BULK_RECEIVE);
895 			break;
896 		case VCHIQ_BULK_MODE_BLOCKING:
897 			status = vchiq_blocking_bulk_transfer(instance, handle, (void *)data, size,
898 							      VCHIQ_BULK_RECEIVE);
899 			break;
900 		default:
901 			return -EINVAL;
902 		}
903 
904 		/*
905 		 * vchiq_*_bulk_transfer() may return -EAGAIN, so we need
906 		 * to implement a retry mechanism since this function is
907 		 * supposed to block until queued
908 		 */
909 		if (status != -EAGAIN)
910 			break;
911 
912 		msleep(1);
913 	}
914 
915 	return status;
916 }
917 EXPORT_SYMBOL(vchiq_bulk_receive);
918 
919 static int
vchiq_blocking_bulk_transfer(struct vchiq_instance * instance,unsigned int handle,void * data,unsigned int size,enum vchiq_bulk_dir dir)920 vchiq_blocking_bulk_transfer(struct vchiq_instance *instance, unsigned int handle, void *data,
921 			     unsigned int size, enum vchiq_bulk_dir dir)
922 {
923 	struct vchiq_service *service;
924 	int status;
925 	struct bulk_waiter_node *waiter = NULL, *iter;
926 
927 	service = find_service_by_handle(instance, handle);
928 	if (!service)
929 		return -EINVAL;
930 
931 	vchiq_service_put(service);
932 
933 	mutex_lock(&instance->bulk_waiter_list_mutex);
934 	list_for_each_entry(iter, &instance->bulk_waiter_list, list) {
935 		if (iter->pid == current->pid) {
936 			list_del(&iter->list);
937 			waiter = iter;
938 			break;
939 		}
940 	}
941 	mutex_unlock(&instance->bulk_waiter_list_mutex);
942 
943 	if (waiter) {
944 		struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk;
945 
946 		if (bulk) {
947 			/* This thread has an outstanding bulk transfer. */
948 			/* FIXME: why compare a dma address to a pointer? */
949 			if ((bulk->data != (dma_addr_t)(uintptr_t)data) || (bulk->size != size)) {
950 				/*
951 				 * This is not a retry of the previous one.
952 				 * Cancel the signal when the transfer completes.
953 				 */
954 				spin_lock(&bulk_waiter_spinlock);
955 				bulk->userdata = NULL;
956 				spin_unlock(&bulk_waiter_spinlock);
957 			}
958 		}
959 	} else {
960 		waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
961 		if (!waiter) {
962 			vchiq_log_error(vchiq_core_log_level, "%s - out of memory", __func__);
963 			return -ENOMEM;
964 		}
965 	}
966 
967 	status = vchiq_bulk_transfer(instance, handle, data, NULL, size,
968 				     &waiter->bulk_waiter,
969 				     VCHIQ_BULK_MODE_BLOCKING, dir);
970 	if ((status != -EAGAIN) || fatal_signal_pending(current) || !waiter->bulk_waiter.bulk) {
971 		struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk;
972 
973 		if (bulk) {
974 			/* Cancel the signal when the transfer completes. */
975 			spin_lock(&bulk_waiter_spinlock);
976 			bulk->userdata = NULL;
977 			spin_unlock(&bulk_waiter_spinlock);
978 		}
979 		kfree(waiter);
980 	} else {
981 		waiter->pid = current->pid;
982 		mutex_lock(&instance->bulk_waiter_list_mutex);
983 		list_add(&waiter->list, &instance->bulk_waiter_list);
984 		mutex_unlock(&instance->bulk_waiter_list_mutex);
985 		vchiq_log_info(vchiq_arm_log_level, "saved bulk_waiter %pK for pid %d", waiter,
986 			       current->pid);
987 	}
988 
989 	return status;
990 }
991 
992 static int
add_completion(struct vchiq_instance * instance,enum vchiq_reason reason,struct vchiq_header * header,struct user_service * user_service,void * bulk_userdata)993 add_completion(struct vchiq_instance *instance, enum vchiq_reason reason,
994 	       struct vchiq_header *header, struct user_service *user_service,
995 	       void *bulk_userdata)
996 {
997 	struct vchiq_completion_data_kernel *completion;
998 	int insert;
999 
1000 	DEBUG_INITIALISE(g_state.local);
1001 
1002 	insert = instance->completion_insert;
1003 	while ((insert - instance->completion_remove) >= MAX_COMPLETIONS) {
1004 		/* Out of space - wait for the client */
1005 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1006 		vchiq_log_trace(vchiq_arm_log_level, "%s - completion queue full", __func__);
1007 		DEBUG_COUNT(COMPLETION_QUEUE_FULL_COUNT);
1008 		if (wait_for_completion_interruptible(&instance->remove_event)) {
1009 			vchiq_log_info(vchiq_arm_log_level, "service_callback interrupted");
1010 			return -EAGAIN;
1011 		} else if (instance->closing) {
1012 			vchiq_log_info(vchiq_arm_log_level, "service_callback closing");
1013 			return 0;
1014 		}
1015 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1016 	}
1017 
1018 	completion = &instance->completions[insert & (MAX_COMPLETIONS - 1)];
1019 
1020 	completion->header = header;
1021 	completion->reason = reason;
1022 	/* N.B. service_userdata is updated while processing AWAIT_COMPLETION */
1023 	completion->service_userdata = user_service->service;
1024 	completion->bulk_userdata = bulk_userdata;
1025 
1026 	if (reason == VCHIQ_SERVICE_CLOSED) {
1027 		/*
1028 		 * Take an extra reference, to be held until
1029 		 * this CLOSED notification is delivered.
1030 		 */
1031 		vchiq_service_get(user_service->service);
1032 		if (instance->use_close_delivered)
1033 			user_service->close_pending = 1;
1034 	}
1035 
1036 	/*
1037 	 * A write barrier is needed here to ensure that the entire completion
1038 	 * record is written out before the insert point.
1039 	 */
1040 	wmb();
1041 
1042 	if (reason == VCHIQ_MESSAGE_AVAILABLE)
1043 		user_service->message_available_pos = insert;
1044 
1045 	insert++;
1046 	instance->completion_insert = insert;
1047 
1048 	complete(&instance->insert_event);
1049 
1050 	return 0;
1051 }
1052 
1053 int
service_callback(struct vchiq_instance * instance,enum vchiq_reason reason,struct vchiq_header * header,unsigned int handle,void * bulk_userdata)1054 service_callback(struct vchiq_instance *instance, enum vchiq_reason reason,
1055 		 struct vchiq_header *header, unsigned int handle, void *bulk_userdata)
1056 {
1057 	/*
1058 	 * How do we ensure the callback goes to the right client?
1059 	 * The service_user data points to a user_service record
1060 	 * containing the original callback and the user state structure, which
1061 	 * contains a circular buffer for completion records.
1062 	 */
1063 	struct user_service *user_service;
1064 	struct vchiq_service *service;
1065 	bool skip_completion = false;
1066 
1067 	DEBUG_INITIALISE(g_state.local);
1068 
1069 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1070 
1071 	rcu_read_lock();
1072 	service = handle_to_service(instance, handle);
1073 	if (WARN_ON(!service)) {
1074 		rcu_read_unlock();
1075 		return 0;
1076 	}
1077 
1078 	user_service = (struct user_service *)service->base.userdata;
1079 
1080 	if (!instance || instance->closing) {
1081 		rcu_read_unlock();
1082 		return 0;
1083 	}
1084 
1085 	/*
1086 	 * As hopping around different synchronization mechanism,
1087 	 * taking an extra reference results in simpler implementation.
1088 	 */
1089 	vchiq_service_get(service);
1090 	rcu_read_unlock();
1091 
1092 	vchiq_log_trace(vchiq_arm_log_level,
1093 			"%s - service %lx(%d,%p), reason %d, header %lx, instance %lx, bulk_userdata %lx",
1094 			__func__, (unsigned long)user_service, service->localport,
1095 			user_service->userdata, reason, (unsigned long)header,
1096 			(unsigned long)instance, (unsigned long)bulk_userdata);
1097 
1098 	if (header && user_service->is_vchi) {
1099 		spin_lock(&msg_queue_spinlock);
1100 		while (user_service->msg_insert ==
1101 			(user_service->msg_remove + MSG_QUEUE_SIZE)) {
1102 			spin_unlock(&msg_queue_spinlock);
1103 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1104 			DEBUG_COUNT(MSG_QUEUE_FULL_COUNT);
1105 			vchiq_log_trace(vchiq_arm_log_level, "%s - msg queue full", __func__);
1106 			/*
1107 			 * If there is no MESSAGE_AVAILABLE in the completion
1108 			 * queue, add one
1109 			 */
1110 			if ((user_service->message_available_pos -
1111 				instance->completion_remove) < 0) {
1112 				int status;
1113 
1114 				vchiq_log_info(vchiq_arm_log_level,
1115 					       "Inserting extra MESSAGE_AVAILABLE");
1116 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1117 				status = add_completion(instance, reason, NULL, user_service,
1118 							bulk_userdata);
1119 				if (status) {
1120 					DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1121 					vchiq_service_put(service);
1122 					return status;
1123 				}
1124 			}
1125 
1126 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1127 			if (wait_for_completion_interruptible(&user_service->remove_event)) {
1128 				vchiq_log_info(vchiq_arm_log_level, "%s interrupted", __func__);
1129 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1130 				vchiq_service_put(service);
1131 				return -EAGAIN;
1132 			} else if (instance->closing) {
1133 				vchiq_log_info(vchiq_arm_log_level, "%s closing", __func__);
1134 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1135 				vchiq_service_put(service);
1136 				return -EINVAL;
1137 			}
1138 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1139 			spin_lock(&msg_queue_spinlock);
1140 		}
1141 
1142 		user_service->msg_queue[user_service->msg_insert &
1143 			(MSG_QUEUE_SIZE - 1)] = header;
1144 		user_service->msg_insert++;
1145 
1146 		/*
1147 		 * If there is a thread waiting in DEQUEUE_MESSAGE, or if
1148 		 * there is a MESSAGE_AVAILABLE in the completion queue then
1149 		 * bypass the completion queue.
1150 		 */
1151 		if (((user_service->message_available_pos -
1152 			instance->completion_remove) >= 0) ||
1153 			user_service->dequeue_pending) {
1154 			user_service->dequeue_pending = 0;
1155 			skip_completion = true;
1156 		}
1157 
1158 		spin_unlock(&msg_queue_spinlock);
1159 		complete(&user_service->insert_event);
1160 
1161 		header = NULL;
1162 	}
1163 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
1164 	vchiq_service_put(service);
1165 
1166 	if (skip_completion)
1167 		return 0;
1168 
1169 	return add_completion(instance, reason, header, user_service,
1170 		bulk_userdata);
1171 }
1172 
vchiq_dump(void * dump_context,const char * str,int len)1173 int vchiq_dump(void *dump_context, const char *str, int len)
1174 {
1175 	struct dump_context *context = (struct dump_context *)dump_context;
1176 	int copy_bytes;
1177 
1178 	if (context->actual >= context->space)
1179 		return 0;
1180 
1181 	if (context->offset > 0) {
1182 		int skip_bytes = min_t(int, len, context->offset);
1183 
1184 		str += skip_bytes;
1185 		len -= skip_bytes;
1186 		context->offset -= skip_bytes;
1187 		if (context->offset > 0)
1188 			return 0;
1189 	}
1190 	copy_bytes = min_t(int, len, context->space - context->actual);
1191 	if (copy_bytes == 0)
1192 		return 0;
1193 	if (copy_to_user(context->buf + context->actual, str,
1194 			 copy_bytes))
1195 		return -EFAULT;
1196 	context->actual += copy_bytes;
1197 	len -= copy_bytes;
1198 
1199 	/*
1200 	 * If the terminating NUL is included in the length, then it
1201 	 * marks the end of a line and should be replaced with a
1202 	 * carriage return.
1203 	 */
1204 	if ((len == 0) && (str[copy_bytes - 1] == '\0')) {
1205 		char cr = '\n';
1206 
1207 		if (copy_to_user(context->buf + context->actual - 1,
1208 				 &cr, 1))
1209 			return -EFAULT;
1210 	}
1211 	return 0;
1212 }
1213 
vchiq_dump_platform_instances(void * dump_context)1214 int vchiq_dump_platform_instances(void *dump_context)
1215 {
1216 	struct vchiq_state *state = vchiq_get_state();
1217 	char buf[80];
1218 	int len;
1219 	int i;
1220 
1221 	if (!state)
1222 		return -ENOTCONN;
1223 
1224 	/*
1225 	 * There is no list of instances, so instead scan all services,
1226 	 * marking those that have been dumped.
1227 	 */
1228 
1229 	rcu_read_lock();
1230 	for (i = 0; i < state->unused_service; i++) {
1231 		struct vchiq_service *service;
1232 		struct vchiq_instance *instance;
1233 
1234 		service = rcu_dereference(state->services[i]);
1235 		if (!service || service->base.callback != service_callback)
1236 			continue;
1237 
1238 		instance = service->instance;
1239 		if (instance)
1240 			instance->mark = 0;
1241 	}
1242 	rcu_read_unlock();
1243 
1244 	for (i = 0; i < state->unused_service; i++) {
1245 		struct vchiq_service *service;
1246 		struct vchiq_instance *instance;
1247 		int err;
1248 
1249 		rcu_read_lock();
1250 		service = rcu_dereference(state->services[i]);
1251 		if (!service || service->base.callback != service_callback) {
1252 			rcu_read_unlock();
1253 			continue;
1254 		}
1255 
1256 		instance = service->instance;
1257 		if (!instance || instance->mark) {
1258 			rcu_read_unlock();
1259 			continue;
1260 		}
1261 		rcu_read_unlock();
1262 
1263 		len = snprintf(buf, sizeof(buf),
1264 			       "Instance %pK: pid %d,%s completions %d/%d",
1265 			       instance, instance->pid,
1266 			       instance->connected ? " connected, " :
1267 			       "",
1268 			       instance->completion_insert -
1269 			       instance->completion_remove,
1270 			       MAX_COMPLETIONS);
1271 		err = vchiq_dump(dump_context, buf, len + 1);
1272 		if (err)
1273 			return err;
1274 		instance->mark = 1;
1275 	}
1276 	return 0;
1277 }
1278 
vchiq_dump_platform_service_state(void * dump_context,struct vchiq_service * service)1279 int vchiq_dump_platform_service_state(void *dump_context,
1280 				      struct vchiq_service *service)
1281 {
1282 	struct user_service *user_service =
1283 			(struct user_service *)service->base.userdata;
1284 	char buf[80];
1285 	int len;
1286 
1287 	len = scnprintf(buf, sizeof(buf), "  instance %pK", service->instance);
1288 
1289 	if ((service->base.callback == service_callback) && user_service->is_vchi) {
1290 		len += scnprintf(buf + len, sizeof(buf) - len, ", %d/%d messages",
1291 				 user_service->msg_insert - user_service->msg_remove,
1292 				 MSG_QUEUE_SIZE);
1293 
1294 		if (user_service->dequeue_pending)
1295 			len += scnprintf(buf + len, sizeof(buf) - len,
1296 				" (dequeue pending)");
1297 	}
1298 
1299 	return vchiq_dump(dump_context, buf, len + 1);
1300 }
1301 
1302 struct vchiq_state *
vchiq_get_state(void)1303 vchiq_get_state(void)
1304 {
1305 	if (!g_state.remote) {
1306 		pr_err("%s: g_state.remote == NULL\n", __func__);
1307 		return NULL;
1308 	}
1309 
1310 	if (g_state.remote->initialised != 1) {
1311 		pr_notice("%s: g_state.remote->initialised != 1 (%d)\n",
1312 			  __func__, g_state.remote->initialised);
1313 		return NULL;
1314 	}
1315 
1316 	return &g_state;
1317 }
1318 
1319 /*
1320  * Autosuspend related functionality
1321  */
1322 
1323 static int
vchiq_keepalive_vchiq_callback(struct vchiq_instance * instance,enum vchiq_reason reason,struct vchiq_header * header,unsigned int service_user,void * bulk_user)1324 vchiq_keepalive_vchiq_callback(struct vchiq_instance *instance,
1325 			       enum vchiq_reason reason,
1326 			       struct vchiq_header *header,
1327 			       unsigned int service_user, void *bulk_user)
1328 {
1329 	vchiq_log_error(vchiq_susp_log_level, "%s callback reason %d", __func__, reason);
1330 	return 0;
1331 }
1332 
1333 static int
vchiq_keepalive_thread_func(void * v)1334 vchiq_keepalive_thread_func(void *v)
1335 {
1336 	struct vchiq_state *state = (struct vchiq_state *)v;
1337 	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
1338 
1339 	int status;
1340 	struct vchiq_instance *instance;
1341 	unsigned int ka_handle;
1342 	int ret;
1343 
1344 	struct vchiq_service_params_kernel params = {
1345 		.fourcc      = VCHIQ_MAKE_FOURCC('K', 'E', 'E', 'P'),
1346 		.callback    = vchiq_keepalive_vchiq_callback,
1347 		.version     = KEEPALIVE_VER,
1348 		.version_min = KEEPALIVE_VER_MIN
1349 	};
1350 
1351 	ret = vchiq_initialise(&instance);
1352 	if (ret) {
1353 		vchiq_log_error(vchiq_susp_log_level, "%s vchiq_initialise failed %d", __func__,
1354 				ret);
1355 		goto exit;
1356 	}
1357 
1358 	status = vchiq_connect(instance);
1359 	if (status) {
1360 		vchiq_log_error(vchiq_susp_log_level, "%s vchiq_connect failed %d", __func__,
1361 				status);
1362 		goto shutdown;
1363 	}
1364 
1365 	status = vchiq_add_service(instance, &params, &ka_handle);
1366 	if (status) {
1367 		vchiq_log_error(vchiq_susp_log_level, "%s vchiq_open_service failed %d", __func__,
1368 				status);
1369 		goto shutdown;
1370 	}
1371 
1372 	while (1) {
1373 		long rc = 0, uc = 0;
1374 
1375 		if (wait_for_completion_interruptible(&arm_state->ka_evt)) {
1376 			vchiq_log_error(vchiq_susp_log_level, "%s interrupted", __func__);
1377 			flush_signals(current);
1378 			continue;
1379 		}
1380 
1381 		/*
1382 		 * read and clear counters.  Do release_count then use_count to
1383 		 * prevent getting more releases than uses
1384 		 */
1385 		rc = atomic_xchg(&arm_state->ka_release_count, 0);
1386 		uc = atomic_xchg(&arm_state->ka_use_count, 0);
1387 
1388 		/*
1389 		 * Call use/release service the requisite number of times.
1390 		 * Process use before release so use counts don't go negative
1391 		 */
1392 		while (uc--) {
1393 			atomic_inc(&arm_state->ka_use_ack_count);
1394 			status = vchiq_use_service(instance, ka_handle);
1395 			if (status) {
1396 				vchiq_log_error(vchiq_susp_log_level,
1397 						"%s vchiq_use_service error %d", __func__, status);
1398 			}
1399 		}
1400 		while (rc--) {
1401 			status = vchiq_release_service(instance, ka_handle);
1402 			if (status) {
1403 				vchiq_log_error(vchiq_susp_log_level,
1404 						"%s vchiq_release_service error %d", __func__,
1405 						status);
1406 			}
1407 		}
1408 	}
1409 
1410 shutdown:
1411 	vchiq_shutdown(instance);
1412 exit:
1413 	return 0;
1414 }
1415 
1416 int
vchiq_use_internal(struct vchiq_state * state,struct vchiq_service * service,enum USE_TYPE_E use_type)1417 vchiq_use_internal(struct vchiq_state *state, struct vchiq_service *service,
1418 		   enum USE_TYPE_E use_type)
1419 {
1420 	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
1421 	int ret = 0;
1422 	char entity[16];
1423 	int *entity_uc;
1424 	int local_uc;
1425 
1426 	if (!arm_state) {
1427 		ret = -EINVAL;
1428 		goto out;
1429 	}
1430 
1431 	if (use_type == USE_TYPE_VCHIQ) {
1432 		sprintf(entity, "VCHIQ:   ");
1433 		entity_uc = &arm_state->peer_use_count;
1434 	} else if (service) {
1435 		sprintf(entity, "%c%c%c%c:%03d",
1436 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
1437 			service->client_id);
1438 		entity_uc = &service->service_use_count;
1439 	} else {
1440 		vchiq_log_error(vchiq_susp_log_level, "%s null service ptr", __func__);
1441 		ret = -EINVAL;
1442 		goto out;
1443 	}
1444 
1445 	write_lock_bh(&arm_state->susp_res_lock);
1446 	local_uc = ++arm_state->videocore_use_count;
1447 	++(*entity_uc);
1448 
1449 	vchiq_log_trace(vchiq_susp_log_level, "%s %s count %d, state count %d", __func__, entity,
1450 			*entity_uc, local_uc);
1451 
1452 	write_unlock_bh(&arm_state->susp_res_lock);
1453 
1454 	if (!ret) {
1455 		int status = 0;
1456 		long ack_cnt = atomic_xchg(&arm_state->ka_use_ack_count, 0);
1457 
1458 		while (ack_cnt && !status) {
1459 			/* Send the use notify to videocore */
1460 			status = vchiq_send_remote_use_active(state);
1461 			if (!status)
1462 				ack_cnt--;
1463 			else
1464 				atomic_add(ack_cnt, &arm_state->ka_use_ack_count);
1465 		}
1466 	}
1467 
1468 out:
1469 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
1470 	return ret;
1471 }
1472 
1473 int
vchiq_release_internal(struct vchiq_state * state,struct vchiq_service * service)1474 vchiq_release_internal(struct vchiq_state *state, struct vchiq_service *service)
1475 {
1476 	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
1477 	int ret = 0;
1478 	char entity[16];
1479 	int *entity_uc;
1480 
1481 	if (!arm_state) {
1482 		ret = -EINVAL;
1483 		goto out;
1484 	}
1485 
1486 	if (service) {
1487 		sprintf(entity, "%c%c%c%c:%03d",
1488 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
1489 			service->client_id);
1490 		entity_uc = &service->service_use_count;
1491 	} else {
1492 		sprintf(entity, "PEER:   ");
1493 		entity_uc = &arm_state->peer_use_count;
1494 	}
1495 
1496 	write_lock_bh(&arm_state->susp_res_lock);
1497 	if (!arm_state->videocore_use_count || !(*entity_uc)) {
1498 		/* Don't use BUG_ON - don't allow user thread to crash kernel */
1499 		WARN_ON(!arm_state->videocore_use_count);
1500 		WARN_ON(!(*entity_uc));
1501 		ret = -EINVAL;
1502 		goto unlock;
1503 	}
1504 	--arm_state->videocore_use_count;
1505 	--(*entity_uc);
1506 
1507 	vchiq_log_trace(vchiq_susp_log_level, "%s %s count %d, state count %d", __func__, entity,
1508 			*entity_uc, arm_state->videocore_use_count);
1509 
1510 unlock:
1511 	write_unlock_bh(&arm_state->susp_res_lock);
1512 
1513 out:
1514 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
1515 	return ret;
1516 }
1517 
1518 void
vchiq_on_remote_use(struct vchiq_state * state)1519 vchiq_on_remote_use(struct vchiq_state *state)
1520 {
1521 	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
1522 
1523 	atomic_inc(&arm_state->ka_use_count);
1524 	complete(&arm_state->ka_evt);
1525 }
1526 
1527 void
vchiq_on_remote_release(struct vchiq_state * state)1528 vchiq_on_remote_release(struct vchiq_state *state)
1529 {
1530 	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
1531 
1532 	atomic_inc(&arm_state->ka_release_count);
1533 	complete(&arm_state->ka_evt);
1534 }
1535 
1536 int
vchiq_use_service_internal(struct vchiq_service * service)1537 vchiq_use_service_internal(struct vchiq_service *service)
1538 {
1539 	return vchiq_use_internal(service->state, service, USE_TYPE_SERVICE);
1540 }
1541 
1542 int
vchiq_release_service_internal(struct vchiq_service * service)1543 vchiq_release_service_internal(struct vchiq_service *service)
1544 {
1545 	return vchiq_release_internal(service->state, service);
1546 }
1547 
1548 struct vchiq_debugfs_node *
vchiq_instance_get_debugfs_node(struct vchiq_instance * instance)1549 vchiq_instance_get_debugfs_node(struct vchiq_instance *instance)
1550 {
1551 	return &instance->debugfs_node;
1552 }
1553 
1554 int
vchiq_instance_get_use_count(struct vchiq_instance * instance)1555 vchiq_instance_get_use_count(struct vchiq_instance *instance)
1556 {
1557 	struct vchiq_service *service;
1558 	int use_count = 0, i;
1559 
1560 	i = 0;
1561 	rcu_read_lock();
1562 	while ((service = __next_service_by_instance(instance->state,
1563 						     instance, &i)))
1564 		use_count += service->service_use_count;
1565 	rcu_read_unlock();
1566 	return use_count;
1567 }
1568 
1569 int
vchiq_instance_get_pid(struct vchiq_instance * instance)1570 vchiq_instance_get_pid(struct vchiq_instance *instance)
1571 {
1572 	return instance->pid;
1573 }
1574 
1575 int
vchiq_instance_get_trace(struct vchiq_instance * instance)1576 vchiq_instance_get_trace(struct vchiq_instance *instance)
1577 {
1578 	return instance->trace;
1579 }
1580 
1581 void
vchiq_instance_set_trace(struct vchiq_instance * instance,int trace)1582 vchiq_instance_set_trace(struct vchiq_instance *instance, int trace)
1583 {
1584 	struct vchiq_service *service;
1585 	int i;
1586 
1587 	i = 0;
1588 	rcu_read_lock();
1589 	while ((service = __next_service_by_instance(instance->state,
1590 						     instance, &i)))
1591 		service->trace = trace;
1592 	rcu_read_unlock();
1593 	instance->trace = (trace != 0);
1594 }
1595 
1596 int
vchiq_use_service(struct vchiq_instance * instance,unsigned int handle)1597 vchiq_use_service(struct vchiq_instance *instance, unsigned int handle)
1598 {
1599 	int ret = -EINVAL;
1600 	struct vchiq_service *service = find_service_by_handle(instance, handle);
1601 
1602 	if (service) {
1603 		ret = vchiq_use_internal(service->state, service, USE_TYPE_SERVICE);
1604 		vchiq_service_put(service);
1605 	}
1606 	return ret;
1607 }
1608 EXPORT_SYMBOL(vchiq_use_service);
1609 
1610 int
vchiq_release_service(struct vchiq_instance * instance,unsigned int handle)1611 vchiq_release_service(struct vchiq_instance *instance, unsigned int handle)
1612 {
1613 	int ret = -EINVAL;
1614 	struct vchiq_service *service = find_service_by_handle(instance, handle);
1615 
1616 	if (service) {
1617 		ret = vchiq_release_internal(service->state, service);
1618 		vchiq_service_put(service);
1619 	}
1620 	return ret;
1621 }
1622 EXPORT_SYMBOL(vchiq_release_service);
1623 
1624 struct service_data_struct {
1625 	int fourcc;
1626 	int clientid;
1627 	int use_count;
1628 };
1629 
1630 void
vchiq_dump_service_use_state(struct vchiq_state * state)1631 vchiq_dump_service_use_state(struct vchiq_state *state)
1632 {
1633 	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
1634 	struct service_data_struct *service_data;
1635 	int i, found = 0;
1636 	/*
1637 	 * If there's more than 64 services, only dump ones with
1638 	 * non-zero counts
1639 	 */
1640 	int only_nonzero = 0;
1641 	static const char *nz = "<-- preventing suspend";
1642 
1643 	int peer_count;
1644 	int vc_use_count;
1645 	int active_services;
1646 
1647 	if (!arm_state)
1648 		return;
1649 
1650 	service_data = kmalloc_array(MAX_SERVICES, sizeof(*service_data),
1651 				     GFP_KERNEL);
1652 	if (!service_data)
1653 		return;
1654 
1655 	read_lock_bh(&arm_state->susp_res_lock);
1656 	peer_count = arm_state->peer_use_count;
1657 	vc_use_count = arm_state->videocore_use_count;
1658 	active_services = state->unused_service;
1659 	if (active_services > MAX_SERVICES)
1660 		only_nonzero = 1;
1661 
1662 	rcu_read_lock();
1663 	for (i = 0; i < active_services; i++) {
1664 		struct vchiq_service *service_ptr =
1665 			rcu_dereference(state->services[i]);
1666 
1667 		if (!service_ptr)
1668 			continue;
1669 
1670 		if (only_nonzero && !service_ptr->service_use_count)
1671 			continue;
1672 
1673 		if (service_ptr->srvstate == VCHIQ_SRVSTATE_FREE)
1674 			continue;
1675 
1676 		service_data[found].fourcc = service_ptr->base.fourcc;
1677 		service_data[found].clientid = service_ptr->client_id;
1678 		service_data[found].use_count = service_ptr->service_use_count;
1679 		found++;
1680 		if (found >= MAX_SERVICES)
1681 			break;
1682 	}
1683 	rcu_read_unlock();
1684 
1685 	read_unlock_bh(&arm_state->susp_res_lock);
1686 
1687 	if (only_nonzero)
1688 		vchiq_log_warning(vchiq_susp_log_level, "Too many active services (%d). Only dumping up to first %d services with non-zero use-count",
1689 				  active_services, found);
1690 
1691 	for (i = 0; i < found; i++) {
1692 		vchiq_log_warning(vchiq_susp_log_level, "----- %c%c%c%c:%d service count %d %s",
1693 				  VCHIQ_FOURCC_AS_4CHARS(service_data[i].fourcc),
1694 				  service_data[i].clientid, service_data[i].use_count,
1695 				  service_data[i].use_count ? nz : "");
1696 	}
1697 	vchiq_log_warning(vchiq_susp_log_level, "----- VCHIQ use count %d", peer_count);
1698 	vchiq_log_warning(vchiq_susp_log_level, "--- Overall vchiq instance use count %d",
1699 			  vc_use_count);
1700 
1701 	kfree(service_data);
1702 }
1703 
1704 int
vchiq_check_service(struct vchiq_service * service)1705 vchiq_check_service(struct vchiq_service *service)
1706 {
1707 	struct vchiq_arm_state *arm_state;
1708 	int ret = -EINVAL;
1709 
1710 	if (!service || !service->state)
1711 		goto out;
1712 
1713 	arm_state = vchiq_platform_get_arm_state(service->state);
1714 
1715 	read_lock_bh(&arm_state->susp_res_lock);
1716 	if (service->service_use_count)
1717 		ret = 0;
1718 	read_unlock_bh(&arm_state->susp_res_lock);
1719 
1720 	if (ret) {
1721 		vchiq_log_error(vchiq_susp_log_level,
1722 				"%s ERROR - %c%c%c%c:%d service count %d, state count %d", __func__,
1723 				VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc), service->client_id,
1724 				service->service_use_count, arm_state->videocore_use_count);
1725 		vchiq_dump_service_use_state(service->state);
1726 	}
1727 out:
1728 	return ret;
1729 }
1730 
vchiq_platform_conn_state_changed(struct vchiq_state * state,enum vchiq_connstate oldstate,enum vchiq_connstate newstate)1731 void vchiq_platform_conn_state_changed(struct vchiq_state *state,
1732 				       enum vchiq_connstate oldstate,
1733 				       enum vchiq_connstate newstate)
1734 {
1735 	struct vchiq_arm_state *arm_state = vchiq_platform_get_arm_state(state);
1736 	char threadname[16];
1737 
1738 	vchiq_log_info(vchiq_susp_log_level, "%d: %s->%s", state->id,
1739 		       get_conn_state_name(oldstate), get_conn_state_name(newstate));
1740 	if (state->conn_state != VCHIQ_CONNSTATE_CONNECTED)
1741 		return;
1742 
1743 	write_lock_bh(&arm_state->susp_res_lock);
1744 	if (arm_state->first_connect) {
1745 		write_unlock_bh(&arm_state->susp_res_lock);
1746 		return;
1747 	}
1748 
1749 	arm_state->first_connect = 1;
1750 	write_unlock_bh(&arm_state->susp_res_lock);
1751 	snprintf(threadname, sizeof(threadname), "vchiq-keep/%d",
1752 		 state->id);
1753 	arm_state->ka_thread = kthread_create(&vchiq_keepalive_thread_func,
1754 					      (void *)state,
1755 					      threadname);
1756 	if (IS_ERR(arm_state->ka_thread)) {
1757 		vchiq_log_error(vchiq_susp_log_level,
1758 				"vchiq: FATAL: couldn't create thread %s",
1759 				threadname);
1760 	} else {
1761 		wake_up_process(arm_state->ka_thread);
1762 	}
1763 }
1764 
1765 static const struct of_device_id vchiq_of_match[] = {
1766 	{ .compatible = "brcm,bcm2835-vchiq", .data = &bcm2835_drvdata },
1767 	{ .compatible = "brcm,bcm2836-vchiq", .data = &bcm2836_drvdata },
1768 	{},
1769 };
1770 MODULE_DEVICE_TABLE(of, vchiq_of_match);
1771 
1772 static struct platform_device *
vchiq_register_child(struct platform_device * pdev,const char * name)1773 vchiq_register_child(struct platform_device *pdev, const char *name)
1774 {
1775 	struct platform_device_info pdevinfo;
1776 	struct platform_device *child;
1777 
1778 	memset(&pdevinfo, 0, sizeof(pdevinfo));
1779 
1780 	pdevinfo.parent = &pdev->dev;
1781 	pdevinfo.name = name;
1782 	pdevinfo.id = PLATFORM_DEVID_NONE;
1783 	pdevinfo.dma_mask = DMA_BIT_MASK(32);
1784 
1785 	child = platform_device_register_full(&pdevinfo);
1786 	if (IS_ERR(child)) {
1787 		dev_warn(&pdev->dev, "%s not registered\n", name);
1788 		child = NULL;
1789 	}
1790 
1791 	return child;
1792 }
1793 
vchiq_probe(struct platform_device * pdev)1794 static int vchiq_probe(struct platform_device *pdev)
1795 {
1796 	struct device_node *fw_node;
1797 	const struct of_device_id *of_id;
1798 	struct vchiq_drvdata *drvdata;
1799 	int err;
1800 
1801 	of_id = of_match_node(vchiq_of_match, pdev->dev.of_node);
1802 	drvdata = (struct vchiq_drvdata *)of_id->data;
1803 	if (!drvdata)
1804 		return -EINVAL;
1805 
1806 	fw_node = of_find_compatible_node(NULL, NULL,
1807 					  "raspberrypi,bcm2835-firmware");
1808 	if (!fw_node) {
1809 		dev_err(&pdev->dev, "Missing firmware node\n");
1810 		return -ENOENT;
1811 	}
1812 
1813 	drvdata->fw = devm_rpi_firmware_get(&pdev->dev, fw_node);
1814 	of_node_put(fw_node);
1815 	if (!drvdata->fw)
1816 		return -EPROBE_DEFER;
1817 
1818 	platform_set_drvdata(pdev, drvdata);
1819 
1820 	err = vchiq_platform_init(pdev, &g_state);
1821 	if (err)
1822 		goto failed_platform_init;
1823 
1824 	vchiq_debugfs_init();
1825 
1826 	vchiq_log_info(vchiq_arm_log_level,
1827 		       "vchiq: platform initialised - version %d (min %d)",
1828 		       VCHIQ_VERSION, VCHIQ_VERSION_MIN);
1829 
1830 	/*
1831 	 * Simply exit on error since the function handles cleanup in
1832 	 * cases of failure.
1833 	 */
1834 	err = vchiq_register_chrdev(&pdev->dev);
1835 	if (err) {
1836 		vchiq_log_warning(vchiq_arm_log_level,
1837 				  "Failed to initialize vchiq cdev");
1838 		goto error_exit;
1839 	}
1840 
1841 	bcm2835_camera = vchiq_register_child(pdev, "bcm2835-camera");
1842 	bcm2835_audio = vchiq_register_child(pdev, "bcm2835_audio");
1843 
1844 	return 0;
1845 
1846 failed_platform_init:
1847 	vchiq_log_warning(vchiq_arm_log_level, "could not initialize vchiq platform");
1848 error_exit:
1849 	return err;
1850 }
1851 
vchiq_remove(struct platform_device * pdev)1852 static void vchiq_remove(struct platform_device *pdev)
1853 {
1854 	platform_device_unregister(bcm2835_audio);
1855 	platform_device_unregister(bcm2835_camera);
1856 	vchiq_debugfs_deinit();
1857 	vchiq_deregister_chrdev();
1858 }
1859 
1860 static struct platform_driver vchiq_driver = {
1861 	.driver = {
1862 		.name = "bcm2835_vchiq",
1863 		.of_match_table = vchiq_of_match,
1864 	},
1865 	.probe = vchiq_probe,
1866 	.remove_new = vchiq_remove,
1867 };
1868 
vchiq_driver_init(void)1869 static int __init vchiq_driver_init(void)
1870 {
1871 	int ret;
1872 
1873 	ret = platform_driver_register(&vchiq_driver);
1874 	if (ret)
1875 		pr_err("Failed to register vchiq driver\n");
1876 
1877 	return ret;
1878 }
1879 module_init(vchiq_driver_init);
1880 
vchiq_driver_exit(void)1881 static void __exit vchiq_driver_exit(void)
1882 {
1883 	platform_driver_unregister(&vchiq_driver);
1884 }
1885 module_exit(vchiq_driver_exit);
1886 
1887 MODULE_LICENSE("Dual BSD/GPL");
1888 MODULE_DESCRIPTION("Videocore VCHIQ driver");
1889 MODULE_AUTHOR("Broadcom Corporation");
1890