xref: /openbmc/linux/drivers/misc/fastrpc.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2011-2018, The Linux Foundation. All rights reserved.
3 // Copyright (c) 2018, Linaro Limited
4 
5 #include <linux/completion.h>
6 #include <linux/device.h>
7 #include <linux/dma-buf.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/idr.h>
10 #include <linux/list.h>
11 #include <linux/miscdevice.h>
12 #include <linux/module.h>
13 #include <linux/of_address.h>
14 #include <linux/of.h>
15 #include <linux/sort.h>
16 #include <linux/of_platform.h>
17 #include <linux/rpmsg.h>
18 #include <linux/scatterlist.h>
19 #include <linux/slab.h>
20 #include <uapi/misc/fastrpc.h>
21 
22 #define ADSP_DOMAIN_ID (0)
23 #define MDSP_DOMAIN_ID (1)
24 #define SDSP_DOMAIN_ID (2)
25 #define CDSP_DOMAIN_ID (3)
26 #define FASTRPC_DEV_MAX		4 /* adsp, mdsp, slpi, cdsp*/
27 #define FASTRPC_MAX_SESSIONS	9 /*8 compute, 1 cpz*/
28 #define FASTRPC_ALIGN		128
29 #define FASTRPC_MAX_FDLIST	16
30 #define FASTRPC_MAX_CRCLIST	64
31 #define FASTRPC_PHYS(p)	((p) & 0xffffffff)
32 #define FASTRPC_CTX_MAX (256)
33 #define FASTRPC_INIT_HANDLE	1
34 #define FASTRPC_CTXID_MASK (0xFF0)
35 #define INIT_FILELEN_MAX (2 * 1024 * 1024)
36 #define FASTRPC_DEVICE_NAME	"fastrpc"
37 #define ADSP_MMAP_ADD_PAGES 0x1000
38 
39 /* Retrives number of input buffers from the scalars parameter */
40 #define REMOTE_SCALARS_INBUFS(sc)	(((sc) >> 16) & 0x0ff)
41 
42 /* Retrives number of output buffers from the scalars parameter */
43 #define REMOTE_SCALARS_OUTBUFS(sc)	(((sc) >> 8) & 0x0ff)
44 
45 /* Retrives number of input handles from the scalars parameter */
46 #define REMOTE_SCALARS_INHANDLES(sc)	(((sc) >> 4) & 0x0f)
47 
48 /* Retrives number of output handles from the scalars parameter */
49 #define REMOTE_SCALARS_OUTHANDLES(sc)	((sc) & 0x0f)
50 
51 #define REMOTE_SCALARS_LENGTH(sc)	(REMOTE_SCALARS_INBUFS(sc) +   \
52 					 REMOTE_SCALARS_OUTBUFS(sc) +  \
53 					 REMOTE_SCALARS_INHANDLES(sc)+ \
54 					 REMOTE_SCALARS_OUTHANDLES(sc))
55 #define FASTRPC_BUILD_SCALARS(attr, method, in, out, oin, oout)  \
56 				(((attr & 0x07) << 29) |		\
57 				((method & 0x1f) << 24) |	\
58 				((in & 0xff) << 16) |		\
59 				((out & 0xff) <<  8) |		\
60 				((oin & 0x0f) <<  4) |		\
61 				(oout & 0x0f))
62 
63 #define FASTRPC_SCALARS(method, in, out) \
64 		FASTRPC_BUILD_SCALARS(0, method, in, out, 0, 0)
65 
66 #define FASTRPC_CREATE_PROCESS_NARGS	6
67 /* Remote Method id table */
68 #define FASTRPC_RMID_INIT_ATTACH	0
69 #define FASTRPC_RMID_INIT_RELEASE	1
70 #define FASTRPC_RMID_INIT_MMAP		4
71 #define FASTRPC_RMID_INIT_MUNMAP	5
72 #define FASTRPC_RMID_INIT_CREATE	6
73 #define FASTRPC_RMID_INIT_CREATE_ATTR	7
74 #define FASTRPC_RMID_INIT_CREATE_STATIC	8
75 
76 #define miscdev_to_cctx(d) container_of(d, struct fastrpc_channel_ctx, miscdev)
77 
78 static const char *domains[FASTRPC_DEV_MAX] = { "adsp", "mdsp",
79 						"sdsp", "cdsp"};
80 struct fastrpc_phy_page {
81 	u64 addr;		/* physical address */
82 	u64 size;		/* size of contiguous region */
83 };
84 
85 struct fastrpc_invoke_buf {
86 	u32 num;		/* number of contiguous regions */
87 	u32 pgidx;		/* index to start of contiguous region */
88 };
89 
90 struct fastrpc_remote_arg {
91 	u64 pv;
92 	u64 len;
93 };
94 
95 struct fastrpc_mmap_rsp_msg {
96 	u64 vaddr;
97 };
98 
99 struct fastrpc_mmap_req_msg {
100 	s32 pgid;
101 	u32 flags;
102 	u64 vaddr;
103 	s32 num;
104 };
105 
106 struct fastrpc_munmap_req_msg {
107 	s32 pgid;
108 	u64 vaddr;
109 	u64 size;
110 };
111 
112 struct fastrpc_msg {
113 	int pid;		/* process group id */
114 	int tid;		/* thread id */
115 	u64 ctx;		/* invoke caller context */
116 	u32 handle;	/* handle to invoke */
117 	u32 sc;		/* scalars structure describing the data */
118 	u64 addr;		/* physical address */
119 	u64 size;		/* size of contiguous region */
120 };
121 
122 struct fastrpc_invoke_rsp {
123 	u64 ctx;		/* invoke caller context */
124 	int retval;		/* invoke return value */
125 };
126 
127 struct fastrpc_buf_overlap {
128 	u64 start;
129 	u64 end;
130 	int raix;
131 	u64 mstart;
132 	u64 mend;
133 	u64 offset;
134 };
135 
136 struct fastrpc_buf {
137 	struct fastrpc_user *fl;
138 	struct dma_buf *dmabuf;
139 	struct device *dev;
140 	void *virt;
141 	u64 phys;
142 	u64 size;
143 	/* Lock for dma buf attachments */
144 	struct mutex lock;
145 	struct list_head attachments;
146 	/* mmap support */
147 	struct list_head node; /* list of user requested mmaps */
148 	uintptr_t raddr;
149 };
150 
151 struct fastrpc_dma_buf_attachment {
152 	struct device *dev;
153 	struct sg_table sgt;
154 	struct list_head node;
155 };
156 
157 struct fastrpc_map {
158 	struct list_head node;
159 	struct fastrpc_user *fl;
160 	int fd;
161 	struct dma_buf *buf;
162 	struct sg_table *table;
163 	struct dma_buf_attachment *attach;
164 	u64 phys;
165 	u64 size;
166 	void *va;
167 	u64 len;
168 	struct kref refcount;
169 };
170 
171 struct fastrpc_invoke_ctx {
172 	int nscalars;
173 	int nbufs;
174 	int retval;
175 	int pid;
176 	int tgid;
177 	u32 sc;
178 	u32 *crc;
179 	u64 ctxid;
180 	u64 msg_sz;
181 	struct kref refcount;
182 	struct list_head node; /* list of ctxs */
183 	struct completion work;
184 	struct work_struct put_work;
185 	struct fastrpc_msg msg;
186 	struct fastrpc_user *fl;
187 	struct fastrpc_remote_arg *rpra;
188 	struct fastrpc_map **maps;
189 	struct fastrpc_buf *buf;
190 	struct fastrpc_invoke_args *args;
191 	struct fastrpc_buf_overlap *olaps;
192 	struct fastrpc_channel_ctx *cctx;
193 };
194 
195 struct fastrpc_session_ctx {
196 	struct device *dev;
197 	int sid;
198 	bool used;
199 	bool valid;
200 };
201 
202 struct fastrpc_channel_ctx {
203 	int domain_id;
204 	int sesscount;
205 	struct rpmsg_device *rpdev;
206 	struct fastrpc_session_ctx session[FASTRPC_MAX_SESSIONS];
207 	spinlock_t lock;
208 	struct idr ctx_idr;
209 	struct list_head users;
210 	struct miscdevice miscdev;
211 	struct kref refcount;
212 };
213 
214 struct fastrpc_user {
215 	struct list_head user;
216 	struct list_head maps;
217 	struct list_head pending;
218 	struct list_head mmaps;
219 
220 	struct fastrpc_channel_ctx *cctx;
221 	struct fastrpc_session_ctx *sctx;
222 	struct fastrpc_buf *init_mem;
223 
224 	int tgid;
225 	int pd;
226 	/* Lock for lists */
227 	spinlock_t lock;
228 	/* lock for allocations */
229 	struct mutex mutex;
230 };
231 
232 static void fastrpc_free_map(struct kref *ref)
233 {
234 	struct fastrpc_map *map;
235 
236 	map = container_of(ref, struct fastrpc_map, refcount);
237 
238 	if (map->table) {
239 		dma_buf_unmap_attachment(map->attach, map->table,
240 					 DMA_BIDIRECTIONAL);
241 		dma_buf_detach(map->buf, map->attach);
242 		dma_buf_put(map->buf);
243 	}
244 
245 	kfree(map);
246 }
247 
248 static void fastrpc_map_put(struct fastrpc_map *map)
249 {
250 	if (map)
251 		kref_put(&map->refcount, fastrpc_free_map);
252 }
253 
254 static void fastrpc_map_get(struct fastrpc_map *map)
255 {
256 	if (map)
257 		kref_get(&map->refcount);
258 }
259 
260 static int fastrpc_map_find(struct fastrpc_user *fl, int fd,
261 			    struct fastrpc_map **ppmap)
262 {
263 	struct fastrpc_map *map = NULL;
264 
265 	mutex_lock(&fl->mutex);
266 	list_for_each_entry(map, &fl->maps, node) {
267 		if (map->fd == fd) {
268 			fastrpc_map_get(map);
269 			*ppmap = map;
270 			mutex_unlock(&fl->mutex);
271 			return 0;
272 		}
273 	}
274 	mutex_unlock(&fl->mutex);
275 
276 	return -ENOENT;
277 }
278 
279 static void fastrpc_buf_free(struct fastrpc_buf *buf)
280 {
281 	dma_free_coherent(buf->dev, buf->size, buf->virt,
282 			  FASTRPC_PHYS(buf->phys));
283 	kfree(buf);
284 }
285 
286 static int fastrpc_buf_alloc(struct fastrpc_user *fl, struct device *dev,
287 			     u64 size, struct fastrpc_buf **obuf)
288 {
289 	struct fastrpc_buf *buf;
290 
291 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
292 	if (!buf)
293 		return -ENOMEM;
294 
295 	INIT_LIST_HEAD(&buf->attachments);
296 	INIT_LIST_HEAD(&buf->node);
297 	mutex_init(&buf->lock);
298 
299 	buf->fl = fl;
300 	buf->virt = NULL;
301 	buf->phys = 0;
302 	buf->size = size;
303 	buf->dev = dev;
304 	buf->raddr = 0;
305 
306 	buf->virt = dma_alloc_coherent(dev, buf->size, (dma_addr_t *)&buf->phys,
307 				       GFP_KERNEL);
308 	if (!buf->virt) {
309 		mutex_destroy(&buf->lock);
310 		kfree(buf);
311 		return -ENOMEM;
312 	}
313 
314 	if (fl->sctx && fl->sctx->sid)
315 		buf->phys += ((u64)fl->sctx->sid << 32);
316 
317 	*obuf = buf;
318 
319 	return 0;
320 }
321 
322 static void fastrpc_channel_ctx_free(struct kref *ref)
323 {
324 	struct fastrpc_channel_ctx *cctx;
325 
326 	cctx = container_of(ref, struct fastrpc_channel_ctx, refcount);
327 
328 	kfree(cctx);
329 }
330 
331 static void fastrpc_channel_ctx_get(struct fastrpc_channel_ctx *cctx)
332 {
333 	kref_get(&cctx->refcount);
334 }
335 
336 static void fastrpc_channel_ctx_put(struct fastrpc_channel_ctx *cctx)
337 {
338 	kref_put(&cctx->refcount, fastrpc_channel_ctx_free);
339 }
340 
341 static void fastrpc_context_free(struct kref *ref)
342 {
343 	struct fastrpc_invoke_ctx *ctx;
344 	struct fastrpc_channel_ctx *cctx;
345 	unsigned long flags;
346 	int i;
347 
348 	ctx = container_of(ref, struct fastrpc_invoke_ctx, refcount);
349 	cctx = ctx->cctx;
350 
351 	for (i = 0; i < ctx->nscalars; i++)
352 		fastrpc_map_put(ctx->maps[i]);
353 
354 	if (ctx->buf)
355 		fastrpc_buf_free(ctx->buf);
356 
357 	spin_lock_irqsave(&cctx->lock, flags);
358 	idr_remove(&cctx->ctx_idr, ctx->ctxid >> 4);
359 	spin_unlock_irqrestore(&cctx->lock, flags);
360 
361 	kfree(ctx->maps);
362 	kfree(ctx->olaps);
363 	kfree(ctx);
364 
365 	fastrpc_channel_ctx_put(cctx);
366 }
367 
368 static void fastrpc_context_get(struct fastrpc_invoke_ctx *ctx)
369 {
370 	kref_get(&ctx->refcount);
371 }
372 
373 static void fastrpc_context_put(struct fastrpc_invoke_ctx *ctx)
374 {
375 	kref_put(&ctx->refcount, fastrpc_context_free);
376 }
377 
378 static void fastrpc_context_put_wq(struct work_struct *work)
379 {
380 	struct fastrpc_invoke_ctx *ctx =
381 			container_of(work, struct fastrpc_invoke_ctx, put_work);
382 
383 	fastrpc_context_put(ctx);
384 }
385 
386 #define CMP(aa, bb) ((aa) == (bb) ? 0 : (aa) < (bb) ? -1 : 1)
387 static int olaps_cmp(const void *a, const void *b)
388 {
389 	struct fastrpc_buf_overlap *pa = (struct fastrpc_buf_overlap *)a;
390 	struct fastrpc_buf_overlap *pb = (struct fastrpc_buf_overlap *)b;
391 	/* sort with lowest starting buffer first */
392 	int st = CMP(pa->start, pb->start);
393 	/* sort with highest ending buffer first */
394 	int ed = CMP(pb->end, pa->end);
395 
396 	return st == 0 ? ed : st;
397 }
398 
399 static void fastrpc_get_buff_overlaps(struct fastrpc_invoke_ctx *ctx)
400 {
401 	u64 max_end = 0;
402 	int i;
403 
404 	for (i = 0; i < ctx->nbufs; ++i) {
405 		ctx->olaps[i].start = ctx->args[i].ptr;
406 		ctx->olaps[i].end = ctx->olaps[i].start + ctx->args[i].length;
407 		ctx->olaps[i].raix = i;
408 	}
409 
410 	sort(ctx->olaps, ctx->nbufs, sizeof(*ctx->olaps), olaps_cmp, NULL);
411 
412 	for (i = 0; i < ctx->nbufs; ++i) {
413 		/* Falling inside previous range */
414 		if (ctx->olaps[i].start < max_end) {
415 			ctx->olaps[i].mstart = max_end;
416 			ctx->olaps[i].mend = ctx->olaps[i].end;
417 			ctx->olaps[i].offset = max_end - ctx->olaps[i].start;
418 
419 			if (ctx->olaps[i].end > max_end) {
420 				max_end = ctx->olaps[i].end;
421 			} else {
422 				ctx->olaps[i].mend = 0;
423 				ctx->olaps[i].mstart = 0;
424 			}
425 
426 		} else  {
427 			ctx->olaps[i].mend = ctx->olaps[i].end;
428 			ctx->olaps[i].mstart = ctx->olaps[i].start;
429 			ctx->olaps[i].offset = 0;
430 			max_end = ctx->olaps[i].end;
431 		}
432 	}
433 }
434 
435 static struct fastrpc_invoke_ctx *fastrpc_context_alloc(
436 			struct fastrpc_user *user, u32 kernel, u32 sc,
437 			struct fastrpc_invoke_args *args)
438 {
439 	struct fastrpc_channel_ctx *cctx = user->cctx;
440 	struct fastrpc_invoke_ctx *ctx = NULL;
441 	unsigned long flags;
442 	int ret;
443 
444 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
445 	if (!ctx)
446 		return ERR_PTR(-ENOMEM);
447 
448 	INIT_LIST_HEAD(&ctx->node);
449 	ctx->fl = user;
450 	ctx->nscalars = REMOTE_SCALARS_LENGTH(sc);
451 	ctx->nbufs = REMOTE_SCALARS_INBUFS(sc) +
452 		     REMOTE_SCALARS_OUTBUFS(sc);
453 
454 	if (ctx->nscalars) {
455 		ctx->maps = kcalloc(ctx->nscalars,
456 				    sizeof(*ctx->maps), GFP_KERNEL);
457 		if (!ctx->maps) {
458 			kfree(ctx);
459 			return ERR_PTR(-ENOMEM);
460 		}
461 		ctx->olaps = kcalloc(ctx->nscalars,
462 				    sizeof(*ctx->olaps), GFP_KERNEL);
463 		if (!ctx->olaps) {
464 			kfree(ctx->maps);
465 			kfree(ctx);
466 			return ERR_PTR(-ENOMEM);
467 		}
468 		ctx->args = args;
469 		fastrpc_get_buff_overlaps(ctx);
470 	}
471 
472 	/* Released in fastrpc_context_put() */
473 	fastrpc_channel_ctx_get(cctx);
474 
475 	ctx->sc = sc;
476 	ctx->retval = -1;
477 	ctx->pid = current->pid;
478 	ctx->tgid = user->tgid;
479 	ctx->cctx = cctx;
480 	init_completion(&ctx->work);
481 	INIT_WORK(&ctx->put_work, fastrpc_context_put_wq);
482 
483 	spin_lock(&user->lock);
484 	list_add_tail(&ctx->node, &user->pending);
485 	spin_unlock(&user->lock);
486 
487 	spin_lock_irqsave(&cctx->lock, flags);
488 	ret = idr_alloc_cyclic(&cctx->ctx_idr, ctx, 1,
489 			       FASTRPC_CTX_MAX, GFP_ATOMIC);
490 	if (ret < 0) {
491 		spin_unlock_irqrestore(&cctx->lock, flags);
492 		goto err_idr;
493 	}
494 	ctx->ctxid = ret << 4;
495 	spin_unlock_irqrestore(&cctx->lock, flags);
496 
497 	kref_init(&ctx->refcount);
498 
499 	return ctx;
500 err_idr:
501 	spin_lock(&user->lock);
502 	list_del(&ctx->node);
503 	spin_unlock(&user->lock);
504 	fastrpc_channel_ctx_put(cctx);
505 	kfree(ctx->maps);
506 	kfree(ctx->olaps);
507 	kfree(ctx);
508 
509 	return ERR_PTR(ret);
510 }
511 
512 static struct sg_table *
513 fastrpc_map_dma_buf(struct dma_buf_attachment *attachment,
514 		    enum dma_data_direction dir)
515 {
516 	struct fastrpc_dma_buf_attachment *a = attachment->priv;
517 	struct sg_table *table;
518 
519 	table = &a->sgt;
520 
521 	if (!dma_map_sg(attachment->dev, table->sgl, table->nents, dir))
522 		return ERR_PTR(-ENOMEM);
523 
524 	return table;
525 }
526 
527 static void fastrpc_unmap_dma_buf(struct dma_buf_attachment *attach,
528 				  struct sg_table *table,
529 				  enum dma_data_direction dir)
530 {
531 	dma_unmap_sg(attach->dev, table->sgl, table->nents, dir);
532 }
533 
534 static void fastrpc_release(struct dma_buf *dmabuf)
535 {
536 	struct fastrpc_buf *buffer = dmabuf->priv;
537 
538 	fastrpc_buf_free(buffer);
539 }
540 
541 static int fastrpc_dma_buf_attach(struct dma_buf *dmabuf,
542 				  struct dma_buf_attachment *attachment)
543 {
544 	struct fastrpc_dma_buf_attachment *a;
545 	struct fastrpc_buf *buffer = dmabuf->priv;
546 	int ret;
547 
548 	a = kzalloc(sizeof(*a), GFP_KERNEL);
549 	if (!a)
550 		return -ENOMEM;
551 
552 	ret = dma_get_sgtable(buffer->dev, &a->sgt, buffer->virt,
553 			      FASTRPC_PHYS(buffer->phys), buffer->size);
554 	if (ret < 0) {
555 		dev_err(buffer->dev, "failed to get scatterlist from DMA API\n");
556 		kfree(a);
557 		return -EINVAL;
558 	}
559 
560 	a->dev = attachment->dev;
561 	INIT_LIST_HEAD(&a->node);
562 	attachment->priv = a;
563 
564 	mutex_lock(&buffer->lock);
565 	list_add(&a->node, &buffer->attachments);
566 	mutex_unlock(&buffer->lock);
567 
568 	return 0;
569 }
570 
571 static void fastrpc_dma_buf_detatch(struct dma_buf *dmabuf,
572 				    struct dma_buf_attachment *attachment)
573 {
574 	struct fastrpc_dma_buf_attachment *a = attachment->priv;
575 	struct fastrpc_buf *buffer = dmabuf->priv;
576 
577 	mutex_lock(&buffer->lock);
578 	list_del(&a->node);
579 	mutex_unlock(&buffer->lock);
580 	sg_free_table(&a->sgt);
581 	kfree(a);
582 }
583 
584 static void *fastrpc_vmap(struct dma_buf *dmabuf)
585 {
586 	struct fastrpc_buf *buf = dmabuf->priv;
587 
588 	return buf->virt;
589 }
590 
591 static int fastrpc_mmap(struct dma_buf *dmabuf,
592 			struct vm_area_struct *vma)
593 {
594 	struct fastrpc_buf *buf = dmabuf->priv;
595 	size_t size = vma->vm_end - vma->vm_start;
596 
597 	return dma_mmap_coherent(buf->dev, vma, buf->virt,
598 				 FASTRPC_PHYS(buf->phys), size);
599 }
600 
601 static const struct dma_buf_ops fastrpc_dma_buf_ops = {
602 	.attach = fastrpc_dma_buf_attach,
603 	.detach = fastrpc_dma_buf_detatch,
604 	.map_dma_buf = fastrpc_map_dma_buf,
605 	.unmap_dma_buf = fastrpc_unmap_dma_buf,
606 	.mmap = fastrpc_mmap,
607 	.vmap = fastrpc_vmap,
608 	.release = fastrpc_release,
609 };
610 
611 static int fastrpc_map_create(struct fastrpc_user *fl, int fd,
612 			      u64 len, struct fastrpc_map **ppmap)
613 {
614 	struct fastrpc_session_ctx *sess = fl->sctx;
615 	struct fastrpc_map *map = NULL;
616 	int err = 0;
617 
618 	if (!fastrpc_map_find(fl, fd, ppmap))
619 		return 0;
620 
621 	map = kzalloc(sizeof(*map), GFP_KERNEL);
622 	if (!map)
623 		return -ENOMEM;
624 
625 	INIT_LIST_HEAD(&map->node);
626 	map->fl = fl;
627 	map->fd = fd;
628 	map->buf = dma_buf_get(fd);
629 	if (IS_ERR(map->buf)) {
630 		err = PTR_ERR(map->buf);
631 		goto get_err;
632 	}
633 
634 	map->attach = dma_buf_attach(map->buf, sess->dev);
635 	if (IS_ERR(map->attach)) {
636 		dev_err(sess->dev, "Failed to attach dmabuf\n");
637 		err = PTR_ERR(map->attach);
638 		goto attach_err;
639 	}
640 
641 	map->table = dma_buf_map_attachment(map->attach, DMA_BIDIRECTIONAL);
642 	if (IS_ERR(map->table)) {
643 		err = PTR_ERR(map->table);
644 		goto map_err;
645 	}
646 
647 	map->phys = sg_dma_address(map->table->sgl);
648 	map->phys += ((u64)fl->sctx->sid << 32);
649 	map->size = len;
650 	map->va = sg_virt(map->table->sgl);
651 	map->len = len;
652 	kref_init(&map->refcount);
653 
654 	spin_lock(&fl->lock);
655 	list_add_tail(&map->node, &fl->maps);
656 	spin_unlock(&fl->lock);
657 	*ppmap = map;
658 
659 	return 0;
660 
661 map_err:
662 	dma_buf_detach(map->buf, map->attach);
663 attach_err:
664 	dma_buf_put(map->buf);
665 get_err:
666 	kfree(map);
667 
668 	return err;
669 }
670 
671 /*
672  * Fastrpc payload buffer with metadata looks like:
673  *
674  * >>>>>>  START of METADATA <<<<<<<<<
675  * +---------------------------------+
676  * |           Arguments             |
677  * | type:(struct fastrpc_remote_arg)|
678  * |             (0 - N)             |
679  * +---------------------------------+
680  * |         Invoke Buffer list      |
681  * | type:(struct fastrpc_invoke_buf)|
682  * |           (0 - N)               |
683  * +---------------------------------+
684  * |         Page info list          |
685  * | type:(struct fastrpc_phy_page)  |
686  * |             (0 - N)             |
687  * +---------------------------------+
688  * |         Optional info           |
689  * |(can be specific to SoC/Firmware)|
690  * +---------------------------------+
691  * >>>>>>>>  END of METADATA <<<<<<<<<
692  * +---------------------------------+
693  * |         Inline ARGS             |
694  * |            (0-N)                |
695  * +---------------------------------+
696  */
697 
698 static int fastrpc_get_meta_size(struct fastrpc_invoke_ctx *ctx)
699 {
700 	int size = 0;
701 
702 	size = (sizeof(struct fastrpc_remote_arg) +
703 		sizeof(struct fastrpc_invoke_buf) +
704 		sizeof(struct fastrpc_phy_page)) * ctx->nscalars +
705 		sizeof(u64) * FASTRPC_MAX_FDLIST +
706 		sizeof(u32) * FASTRPC_MAX_CRCLIST;
707 
708 	return size;
709 }
710 
711 static u64 fastrpc_get_payload_size(struct fastrpc_invoke_ctx *ctx, int metalen)
712 {
713 	u64 size = 0;
714 	int i;
715 
716 	size = ALIGN(metalen, FASTRPC_ALIGN);
717 	for (i = 0; i < ctx->nscalars; i++) {
718 		if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1) {
719 
720 			if (ctx->olaps[i].offset == 0)
721 				size = ALIGN(size, FASTRPC_ALIGN);
722 
723 			size += (ctx->olaps[i].mend - ctx->olaps[i].mstart);
724 		}
725 	}
726 
727 	return size;
728 }
729 
730 static int fastrpc_create_maps(struct fastrpc_invoke_ctx *ctx)
731 {
732 	struct device *dev = ctx->fl->sctx->dev;
733 	int i, err;
734 
735 	for (i = 0; i < ctx->nscalars; ++i) {
736 		/* Make sure reserved field is set to 0 */
737 		if (ctx->args[i].reserved)
738 			return -EINVAL;
739 
740 		if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1 ||
741 		    ctx->args[i].length == 0)
742 			continue;
743 
744 		err = fastrpc_map_create(ctx->fl, ctx->args[i].fd,
745 					 ctx->args[i].length, &ctx->maps[i]);
746 		if (err) {
747 			dev_err(dev, "Error Creating map %d\n", err);
748 			return -EINVAL;
749 		}
750 
751 	}
752 	return 0;
753 }
754 
755 static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
756 {
757 	struct device *dev = ctx->fl->sctx->dev;
758 	struct fastrpc_remote_arg *rpra;
759 	struct fastrpc_invoke_buf *list;
760 	struct fastrpc_phy_page *pages;
761 	int inbufs, i, oix, err = 0;
762 	u64 len, rlen, pkt_size;
763 	u64 pg_start, pg_end;
764 	uintptr_t args;
765 	int metalen;
766 
767 	inbufs = REMOTE_SCALARS_INBUFS(ctx->sc);
768 	metalen = fastrpc_get_meta_size(ctx);
769 	pkt_size = fastrpc_get_payload_size(ctx, metalen);
770 
771 	err = fastrpc_create_maps(ctx);
772 	if (err)
773 		return err;
774 
775 	ctx->msg_sz = pkt_size;
776 
777 	err = fastrpc_buf_alloc(ctx->fl, dev, pkt_size, &ctx->buf);
778 	if (err)
779 		return err;
780 
781 	rpra = ctx->buf->virt;
782 	list = ctx->buf->virt + ctx->nscalars * sizeof(*rpra);
783 	pages = ctx->buf->virt + ctx->nscalars * (sizeof(*list) +
784 		sizeof(*rpra));
785 	args = (uintptr_t)ctx->buf->virt + metalen;
786 	rlen = pkt_size - metalen;
787 	ctx->rpra = rpra;
788 
789 	for (oix = 0; oix < ctx->nbufs; ++oix) {
790 		int mlen;
791 
792 		i = ctx->olaps[oix].raix;
793 		len = ctx->args[i].length;
794 
795 		rpra[i].pv = 0;
796 		rpra[i].len = len;
797 		list[i].num = len ? 1 : 0;
798 		list[i].pgidx = i;
799 
800 		if (!len)
801 			continue;
802 
803 		if (ctx->maps[i]) {
804 			struct vm_area_struct *vma = NULL;
805 
806 			rpra[i].pv = (u64) ctx->args[i].ptr;
807 			pages[i].addr = ctx->maps[i]->phys;
808 
809 			vma = find_vma(current->mm, ctx->args[i].ptr);
810 			if (vma)
811 				pages[i].addr += ctx->args[i].ptr -
812 						 vma->vm_start;
813 
814 			pg_start = (ctx->args[i].ptr & PAGE_MASK) >> PAGE_SHIFT;
815 			pg_end = ((ctx->args[i].ptr + len - 1) & PAGE_MASK) >>
816 				  PAGE_SHIFT;
817 			pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE;
818 
819 		} else {
820 
821 			if (ctx->olaps[oix].offset == 0) {
822 				rlen -= ALIGN(args, FASTRPC_ALIGN) - args;
823 				args = ALIGN(args, FASTRPC_ALIGN);
824 			}
825 
826 			mlen = ctx->olaps[oix].mend - ctx->olaps[oix].mstart;
827 
828 			if (rlen < mlen)
829 				goto bail;
830 
831 			rpra[i].pv = args - ctx->olaps[oix].offset;
832 			pages[i].addr = ctx->buf->phys -
833 					ctx->olaps[oix].offset +
834 					(pkt_size - rlen);
835 			pages[i].addr = pages[i].addr &	PAGE_MASK;
836 
837 			pg_start = (args & PAGE_MASK) >> PAGE_SHIFT;
838 			pg_end = ((args + len - 1) & PAGE_MASK) >> PAGE_SHIFT;
839 			pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE;
840 			args = args + mlen;
841 			rlen -= mlen;
842 		}
843 
844 		if (i < inbufs && !ctx->maps[i]) {
845 			void *dst = (void *)(uintptr_t)rpra[i].pv;
846 			void *src = (void *)(uintptr_t)ctx->args[i].ptr;
847 
848 			if (!kernel) {
849 				if (copy_from_user(dst, (void __user *)src,
850 						   len)) {
851 					err = -EFAULT;
852 					goto bail;
853 				}
854 			} else {
855 				memcpy(dst, src, len);
856 			}
857 		}
858 	}
859 
860 	for (i = ctx->nbufs; i < ctx->nscalars; ++i) {
861 		rpra[i].pv = (u64) ctx->args[i].ptr;
862 		rpra[i].len = ctx->args[i].length;
863 		list[i].num = ctx->args[i].length ? 1 : 0;
864 		list[i].pgidx = i;
865 		pages[i].addr = ctx->maps[i]->phys;
866 		pages[i].size = ctx->maps[i]->size;
867 	}
868 
869 bail:
870 	if (err)
871 		dev_err(dev, "Error: get invoke args failed:%d\n", err);
872 
873 	return err;
874 }
875 
876 static int fastrpc_put_args(struct fastrpc_invoke_ctx *ctx,
877 			    u32 kernel)
878 {
879 	struct fastrpc_remote_arg *rpra = ctx->rpra;
880 	int i, inbufs;
881 
882 	inbufs = REMOTE_SCALARS_INBUFS(ctx->sc);
883 
884 	for (i = inbufs; i < ctx->nbufs; ++i) {
885 		void *src = (void *)(uintptr_t)rpra[i].pv;
886 		void *dst = (void *)(uintptr_t)ctx->args[i].ptr;
887 		u64 len = rpra[i].len;
888 
889 		if (!kernel) {
890 			if (copy_to_user((void __user *)dst, src, len))
891 				return -EFAULT;
892 		} else {
893 			memcpy(dst, src, len);
894 		}
895 	}
896 
897 	return 0;
898 }
899 
900 static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx,
901 			       struct fastrpc_invoke_ctx *ctx,
902 			       u32 kernel, uint32_t handle)
903 {
904 	struct fastrpc_channel_ctx *cctx;
905 	struct fastrpc_user *fl = ctx->fl;
906 	struct fastrpc_msg *msg = &ctx->msg;
907 
908 	cctx = fl->cctx;
909 	msg->pid = fl->tgid;
910 	msg->tid = current->pid;
911 
912 	if (kernel)
913 		msg->pid = 0;
914 
915 	msg->ctx = ctx->ctxid | fl->pd;
916 	msg->handle = handle;
917 	msg->sc = ctx->sc;
918 	msg->addr = ctx->buf ? ctx->buf->phys : 0;
919 	msg->size = roundup(ctx->msg_sz, PAGE_SIZE);
920 	fastrpc_context_get(ctx);
921 
922 	return rpmsg_send(cctx->rpdev->ept, (void *)msg, sizeof(*msg));
923 }
924 
925 static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
926 				   u32 handle, u32 sc,
927 				   struct fastrpc_invoke_args *args)
928 {
929 	struct fastrpc_invoke_ctx *ctx = NULL;
930 	int err = 0;
931 
932 	if (!fl->sctx)
933 		return -EINVAL;
934 
935 	if (!fl->cctx->rpdev)
936 		return -EPIPE;
937 
938 	ctx = fastrpc_context_alloc(fl, kernel, sc, args);
939 	if (IS_ERR(ctx))
940 		return PTR_ERR(ctx);
941 
942 	if (ctx->nscalars) {
943 		err = fastrpc_get_args(kernel, ctx);
944 		if (err)
945 			goto bail;
946 	}
947 
948 	/* make sure that all CPU memory writes are seen by DSP */
949 	dma_wmb();
950 	/* Send invoke buffer to remote dsp */
951 	err = fastrpc_invoke_send(fl->sctx, ctx, kernel, handle);
952 	if (err)
953 		goto bail;
954 
955 	if (kernel) {
956 		if (!wait_for_completion_timeout(&ctx->work, 10 * HZ))
957 			err = -ETIMEDOUT;
958 	} else {
959 		err = wait_for_completion_interruptible(&ctx->work);
960 	}
961 
962 	if (err)
963 		goto bail;
964 
965 	/* Check the response from remote dsp */
966 	err = ctx->retval;
967 	if (err)
968 		goto bail;
969 
970 	if (ctx->nscalars) {
971 		/* make sure that all memory writes by DSP are seen by CPU */
972 		dma_rmb();
973 		/* populate all the output buffers with results */
974 		err = fastrpc_put_args(ctx, kernel);
975 		if (err)
976 			goto bail;
977 	}
978 
979 bail:
980 	if (err != -ERESTARTSYS && err != -ETIMEDOUT) {
981 		/* We are done with this compute context */
982 		spin_lock(&fl->lock);
983 		list_del(&ctx->node);
984 		spin_unlock(&fl->lock);
985 		fastrpc_context_put(ctx);
986 	}
987 	if (err)
988 		dev_dbg(fl->sctx->dev, "Error: Invoke Failed %d\n", err);
989 
990 	return err;
991 }
992 
993 static int fastrpc_init_create_process(struct fastrpc_user *fl,
994 					char __user *argp)
995 {
996 	struct fastrpc_init_create init;
997 	struct fastrpc_invoke_args *args;
998 	struct fastrpc_phy_page pages[1];
999 	struct fastrpc_map *map = NULL;
1000 	struct fastrpc_buf *imem = NULL;
1001 	int memlen;
1002 	int err;
1003 	struct {
1004 		int pgid;
1005 		u32 namelen;
1006 		u32 filelen;
1007 		u32 pageslen;
1008 		u32 attrs;
1009 		u32 siglen;
1010 	} inbuf;
1011 	u32 sc;
1012 
1013 	args = kcalloc(FASTRPC_CREATE_PROCESS_NARGS, sizeof(*args), GFP_KERNEL);
1014 	if (!args)
1015 		return -ENOMEM;
1016 
1017 	if (copy_from_user(&init, argp, sizeof(init))) {
1018 		err = -EFAULT;
1019 		goto err;
1020 	}
1021 
1022 	if (init.filelen > INIT_FILELEN_MAX) {
1023 		err = -EINVAL;
1024 		goto err;
1025 	}
1026 
1027 	inbuf.pgid = fl->tgid;
1028 	inbuf.namelen = strlen(current->comm) + 1;
1029 	inbuf.filelen = init.filelen;
1030 	inbuf.pageslen = 1;
1031 	inbuf.attrs = init.attrs;
1032 	inbuf.siglen = init.siglen;
1033 	fl->pd = 1;
1034 
1035 	if (init.filelen && init.filefd) {
1036 		err = fastrpc_map_create(fl, init.filefd, init.filelen, &map);
1037 		if (err)
1038 			goto err;
1039 	}
1040 
1041 	memlen = ALIGN(max(INIT_FILELEN_MAX, (int)init.filelen * 4),
1042 		       1024 * 1024);
1043 	err = fastrpc_buf_alloc(fl, fl->sctx->dev, memlen,
1044 				&imem);
1045 	if (err)
1046 		goto err_alloc;
1047 
1048 	fl->init_mem = imem;
1049 	args[0].ptr = (u64)(uintptr_t)&inbuf;
1050 	args[0].length = sizeof(inbuf);
1051 	args[0].fd = -1;
1052 
1053 	args[1].ptr = (u64)(uintptr_t)current->comm;
1054 	args[1].length = inbuf.namelen;
1055 	args[1].fd = -1;
1056 
1057 	args[2].ptr = (u64) init.file;
1058 	args[2].length = inbuf.filelen;
1059 	args[2].fd = init.filefd;
1060 
1061 	pages[0].addr = imem->phys;
1062 	pages[0].size = imem->size;
1063 
1064 	args[3].ptr = (u64)(uintptr_t) pages;
1065 	args[3].length = 1 * sizeof(*pages);
1066 	args[3].fd = -1;
1067 
1068 	args[4].ptr = (u64)(uintptr_t)&inbuf.attrs;
1069 	args[4].length = sizeof(inbuf.attrs);
1070 	args[4].fd = -1;
1071 
1072 	args[5].ptr = (u64)(uintptr_t) &inbuf.siglen;
1073 	args[5].length = sizeof(inbuf.siglen);
1074 	args[5].fd = -1;
1075 
1076 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_CREATE, 4, 0);
1077 	if (init.attrs)
1078 		sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_CREATE_ATTR, 6, 0);
1079 
1080 	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
1081 				      sc, args);
1082 	if (err)
1083 		goto err_invoke;
1084 
1085 	kfree(args);
1086 
1087 	return 0;
1088 
1089 err_invoke:
1090 	fl->init_mem = NULL;
1091 	fastrpc_buf_free(imem);
1092 err_alloc:
1093 	if (map) {
1094 		spin_lock(&fl->lock);
1095 		list_del(&map->node);
1096 		spin_unlock(&fl->lock);
1097 		fastrpc_map_put(map);
1098 	}
1099 err:
1100 	kfree(args);
1101 
1102 	return err;
1103 }
1104 
1105 static struct fastrpc_session_ctx *fastrpc_session_alloc(
1106 					struct fastrpc_channel_ctx *cctx)
1107 {
1108 	struct fastrpc_session_ctx *session = NULL;
1109 	unsigned long flags;
1110 	int i;
1111 
1112 	spin_lock_irqsave(&cctx->lock, flags);
1113 	for (i = 0; i < cctx->sesscount; i++) {
1114 		if (!cctx->session[i].used && cctx->session[i].valid) {
1115 			cctx->session[i].used = true;
1116 			session = &cctx->session[i];
1117 			break;
1118 		}
1119 	}
1120 	spin_unlock_irqrestore(&cctx->lock, flags);
1121 
1122 	return session;
1123 }
1124 
1125 static void fastrpc_session_free(struct fastrpc_channel_ctx *cctx,
1126 				 struct fastrpc_session_ctx *session)
1127 {
1128 	unsigned long flags;
1129 
1130 	spin_lock_irqsave(&cctx->lock, flags);
1131 	session->used = false;
1132 	spin_unlock_irqrestore(&cctx->lock, flags);
1133 }
1134 
1135 static int fastrpc_release_current_dsp_process(struct fastrpc_user *fl)
1136 {
1137 	struct fastrpc_invoke_args args[1];
1138 	int tgid = 0;
1139 	u32 sc;
1140 
1141 	tgid = fl->tgid;
1142 	args[0].ptr = (u64)(uintptr_t) &tgid;
1143 	args[0].length = sizeof(tgid);
1144 	args[0].fd = -1;
1145 	args[0].reserved = 0;
1146 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_RELEASE, 1, 0);
1147 
1148 	return fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
1149 				       sc, &args[0]);
1150 }
1151 
1152 static int fastrpc_device_release(struct inode *inode, struct file *file)
1153 {
1154 	struct fastrpc_user *fl = (struct fastrpc_user *)file->private_data;
1155 	struct fastrpc_channel_ctx *cctx = fl->cctx;
1156 	struct fastrpc_invoke_ctx *ctx, *n;
1157 	struct fastrpc_map *map, *m;
1158 	struct fastrpc_buf *buf, *b;
1159 	unsigned long flags;
1160 
1161 	fastrpc_release_current_dsp_process(fl);
1162 
1163 	spin_lock_irqsave(&cctx->lock, flags);
1164 	list_del(&fl->user);
1165 	spin_unlock_irqrestore(&cctx->lock, flags);
1166 
1167 	if (fl->init_mem)
1168 		fastrpc_buf_free(fl->init_mem);
1169 
1170 	list_for_each_entry_safe(ctx, n, &fl->pending, node) {
1171 		list_del(&ctx->node);
1172 		fastrpc_context_put(ctx);
1173 	}
1174 
1175 	list_for_each_entry_safe(map, m, &fl->maps, node) {
1176 		list_del(&map->node);
1177 		fastrpc_map_put(map);
1178 	}
1179 
1180 	list_for_each_entry_safe(buf, b, &fl->mmaps, node) {
1181 		list_del(&buf->node);
1182 		fastrpc_buf_free(buf);
1183 	}
1184 
1185 	fastrpc_session_free(cctx, fl->sctx);
1186 	fastrpc_channel_ctx_put(cctx);
1187 
1188 	mutex_destroy(&fl->mutex);
1189 	kfree(fl);
1190 	file->private_data = NULL;
1191 
1192 	return 0;
1193 }
1194 
1195 static int fastrpc_device_open(struct inode *inode, struct file *filp)
1196 {
1197 	struct fastrpc_channel_ctx *cctx = miscdev_to_cctx(filp->private_data);
1198 	struct fastrpc_user *fl = NULL;
1199 	unsigned long flags;
1200 
1201 	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
1202 	if (!fl)
1203 		return -ENOMEM;
1204 
1205 	/* Released in fastrpc_device_release() */
1206 	fastrpc_channel_ctx_get(cctx);
1207 
1208 	filp->private_data = fl;
1209 	spin_lock_init(&fl->lock);
1210 	mutex_init(&fl->mutex);
1211 	INIT_LIST_HEAD(&fl->pending);
1212 	INIT_LIST_HEAD(&fl->maps);
1213 	INIT_LIST_HEAD(&fl->mmaps);
1214 	INIT_LIST_HEAD(&fl->user);
1215 	fl->tgid = current->tgid;
1216 	fl->cctx = cctx;
1217 
1218 	fl->sctx = fastrpc_session_alloc(cctx);
1219 	if (!fl->sctx) {
1220 		dev_err(&cctx->rpdev->dev, "No session available\n");
1221 		mutex_destroy(&fl->mutex);
1222 		kfree(fl);
1223 
1224 		return -EBUSY;
1225 	}
1226 
1227 	spin_lock_irqsave(&cctx->lock, flags);
1228 	list_add_tail(&fl->user, &cctx->users);
1229 	spin_unlock_irqrestore(&cctx->lock, flags);
1230 
1231 	return 0;
1232 }
1233 
1234 static int fastrpc_dmabuf_alloc(struct fastrpc_user *fl, char __user *argp)
1235 {
1236 	struct fastrpc_alloc_dma_buf bp;
1237 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
1238 	struct fastrpc_buf *buf = NULL;
1239 	int err;
1240 
1241 	if (copy_from_user(&bp, argp, sizeof(bp)))
1242 		return -EFAULT;
1243 
1244 	err = fastrpc_buf_alloc(fl, fl->sctx->dev, bp.size, &buf);
1245 	if (err)
1246 		return err;
1247 	exp_info.ops = &fastrpc_dma_buf_ops;
1248 	exp_info.size = bp.size;
1249 	exp_info.flags = O_RDWR;
1250 	exp_info.priv = buf;
1251 	buf->dmabuf = dma_buf_export(&exp_info);
1252 	if (IS_ERR(buf->dmabuf)) {
1253 		err = PTR_ERR(buf->dmabuf);
1254 		fastrpc_buf_free(buf);
1255 		return err;
1256 	}
1257 
1258 	bp.fd = dma_buf_fd(buf->dmabuf, O_ACCMODE);
1259 	if (bp.fd < 0) {
1260 		dma_buf_put(buf->dmabuf);
1261 		return -EINVAL;
1262 	}
1263 
1264 	if (copy_to_user(argp, &bp, sizeof(bp))) {
1265 		dma_buf_put(buf->dmabuf);
1266 		return -EFAULT;
1267 	}
1268 
1269 	return 0;
1270 }
1271 
1272 static int fastrpc_init_attach(struct fastrpc_user *fl)
1273 {
1274 	struct fastrpc_invoke_args args[1];
1275 	int tgid = fl->tgid;
1276 	u32 sc;
1277 
1278 	args[0].ptr = (u64)(uintptr_t) &tgid;
1279 	args[0].length = sizeof(tgid);
1280 	args[0].fd = -1;
1281 	args[0].reserved = 0;
1282 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_ATTACH, 1, 0);
1283 	fl->pd = 0;
1284 
1285 	return fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
1286 				       sc, &args[0]);
1287 }
1288 
1289 static int fastrpc_invoke(struct fastrpc_user *fl, char __user *argp)
1290 {
1291 	struct fastrpc_invoke_args *args = NULL;
1292 	struct fastrpc_invoke inv;
1293 	u32 nscalars;
1294 	int err;
1295 
1296 	if (copy_from_user(&inv, argp, sizeof(inv)))
1297 		return -EFAULT;
1298 
1299 	/* nscalars is truncated here to max supported value */
1300 	nscalars = REMOTE_SCALARS_LENGTH(inv.sc);
1301 	if (nscalars) {
1302 		args = kcalloc(nscalars, sizeof(*args), GFP_KERNEL);
1303 		if (!args)
1304 			return -ENOMEM;
1305 
1306 		if (copy_from_user(args, (void __user *)(uintptr_t)inv.args,
1307 				   nscalars * sizeof(*args))) {
1308 			kfree(args);
1309 			return -EFAULT;
1310 		}
1311 	}
1312 
1313 	err = fastrpc_internal_invoke(fl, false, inv.handle, inv.sc, args);
1314 	kfree(args);
1315 
1316 	return err;
1317 }
1318 
1319 static int fastrpc_req_munmap_impl(struct fastrpc_user *fl,
1320 				   struct fastrpc_req_munmap *req)
1321 {
1322 	struct fastrpc_invoke_args args[1] = { [0] = { 0 } };
1323 	struct fastrpc_buf *buf, *b;
1324 	struct fastrpc_munmap_req_msg req_msg;
1325 	struct device *dev = fl->sctx->dev;
1326 	int err;
1327 	u32 sc;
1328 
1329 	spin_lock(&fl->lock);
1330 	list_for_each_entry_safe(buf, b, &fl->mmaps, node) {
1331 		if ((buf->raddr == req->vaddrout) && (buf->size == req->size))
1332 			break;
1333 		buf = NULL;
1334 	}
1335 	spin_unlock(&fl->lock);
1336 
1337 	if (!buf) {
1338 		dev_err(dev, "mmap not in list\n");
1339 		return -EINVAL;
1340 	}
1341 
1342 	req_msg.pgid = fl->tgid;
1343 	req_msg.size = buf->size;
1344 	req_msg.vaddr = buf->raddr;
1345 
1346 	args[0].ptr = (u64) (uintptr_t) &req_msg;
1347 	args[0].length = sizeof(req_msg);
1348 
1349 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MUNMAP, 1, 0);
1350 	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
1351 				      &args[0]);
1352 	if (!err) {
1353 		dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr);
1354 		spin_lock(&fl->lock);
1355 		list_del(&buf->node);
1356 		spin_unlock(&fl->lock);
1357 		fastrpc_buf_free(buf);
1358 	} else {
1359 		dev_err(dev, "unmmap\tpt 0x%09lx ERROR\n", buf->raddr);
1360 	}
1361 
1362 	return err;
1363 }
1364 
1365 static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp)
1366 {
1367 	struct fastrpc_req_munmap req;
1368 
1369 	if (copy_from_user(&req, argp, sizeof(req)))
1370 		return -EFAULT;
1371 
1372 	return fastrpc_req_munmap_impl(fl, &req);
1373 }
1374 
1375 static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
1376 {
1377 	struct fastrpc_invoke_args args[3] = { [0 ... 2] = { 0 } };
1378 	struct fastrpc_buf *buf = NULL;
1379 	struct fastrpc_mmap_req_msg req_msg;
1380 	struct fastrpc_mmap_rsp_msg rsp_msg;
1381 	struct fastrpc_req_munmap req_unmap;
1382 	struct fastrpc_phy_page pages;
1383 	struct fastrpc_req_mmap req;
1384 	struct device *dev = fl->sctx->dev;
1385 	int err;
1386 	u32 sc;
1387 
1388 	if (copy_from_user(&req, argp, sizeof(req)))
1389 		return -EFAULT;
1390 
1391 	if (req.flags != ADSP_MMAP_ADD_PAGES) {
1392 		dev_err(dev, "flag not supported 0x%x\n", req.flags);
1393 		return -EINVAL;
1394 	}
1395 
1396 	if (req.vaddrin) {
1397 		dev_err(dev, "adding user allocated pages is not supported\n");
1398 		return -EINVAL;
1399 	}
1400 
1401 	err = fastrpc_buf_alloc(fl, fl->sctx->dev, req.size, &buf);
1402 	if (err) {
1403 		dev_err(dev, "failed to allocate buffer\n");
1404 		return err;
1405 	}
1406 
1407 	req_msg.pgid = fl->tgid;
1408 	req_msg.flags = req.flags;
1409 	req_msg.vaddr = req.vaddrin;
1410 	req_msg.num = sizeof(pages);
1411 
1412 	args[0].ptr = (u64) (uintptr_t) &req_msg;
1413 	args[0].length = sizeof(req_msg);
1414 
1415 	pages.addr = buf->phys;
1416 	pages.size = buf->size;
1417 
1418 	args[1].ptr = (u64) (uintptr_t) &pages;
1419 	args[1].length = sizeof(pages);
1420 
1421 	args[2].ptr = (u64) (uintptr_t) &rsp_msg;
1422 	args[2].length = sizeof(rsp_msg);
1423 
1424 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MMAP, 2, 1);
1425 	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
1426 				      &args[0]);
1427 	if (err) {
1428 		dev_err(dev, "mmap error (len 0x%08llx)\n", buf->size);
1429 		goto err_invoke;
1430 	}
1431 
1432 	/* update the buffer to be able to deallocate the memory on the DSP */
1433 	buf->raddr = (uintptr_t) rsp_msg.vaddr;
1434 
1435 	/* let the client know the address to use */
1436 	req.vaddrout = rsp_msg.vaddr;
1437 
1438 	spin_lock(&fl->lock);
1439 	list_add_tail(&buf->node, &fl->mmaps);
1440 	spin_unlock(&fl->lock);
1441 
1442 	if (copy_to_user((void __user *)argp, &req, sizeof(req))) {
1443 		/* unmap the memory and release the buffer */
1444 		req_unmap.vaddrout = buf->raddr;
1445 		req_unmap.size = buf->size;
1446 		fastrpc_req_munmap_impl(fl, &req_unmap);
1447 		return -EFAULT;
1448 	}
1449 
1450 	dev_dbg(dev, "mmap\t\tpt 0x%09lx OK [len 0x%08llx]\n",
1451 		buf->raddr, buf->size);
1452 
1453 	return 0;
1454 
1455 err_invoke:
1456 	fastrpc_buf_free(buf);
1457 
1458 	return err;
1459 }
1460 
1461 static long fastrpc_device_ioctl(struct file *file, unsigned int cmd,
1462 				 unsigned long arg)
1463 {
1464 	struct fastrpc_user *fl = (struct fastrpc_user *)file->private_data;
1465 	char __user *argp = (char __user *)arg;
1466 	int err;
1467 
1468 	switch (cmd) {
1469 	case FASTRPC_IOCTL_INVOKE:
1470 		err = fastrpc_invoke(fl, argp);
1471 		break;
1472 	case FASTRPC_IOCTL_INIT_ATTACH:
1473 		err = fastrpc_init_attach(fl);
1474 		break;
1475 	case FASTRPC_IOCTL_INIT_CREATE:
1476 		err = fastrpc_init_create_process(fl, argp);
1477 		break;
1478 	case FASTRPC_IOCTL_ALLOC_DMA_BUFF:
1479 		err = fastrpc_dmabuf_alloc(fl, argp);
1480 		break;
1481 	case FASTRPC_IOCTL_MMAP:
1482 		err = fastrpc_req_mmap(fl, argp);
1483 		break;
1484 	case FASTRPC_IOCTL_MUNMAP:
1485 		err = fastrpc_req_munmap(fl, argp);
1486 		break;
1487 	default:
1488 		err = -ENOTTY;
1489 		break;
1490 	}
1491 
1492 	return err;
1493 }
1494 
1495 static const struct file_operations fastrpc_fops = {
1496 	.open = fastrpc_device_open,
1497 	.release = fastrpc_device_release,
1498 	.unlocked_ioctl = fastrpc_device_ioctl,
1499 	.compat_ioctl = fastrpc_device_ioctl,
1500 };
1501 
1502 static int fastrpc_cb_probe(struct platform_device *pdev)
1503 {
1504 	struct fastrpc_channel_ctx *cctx;
1505 	struct fastrpc_session_ctx *sess;
1506 	struct device *dev = &pdev->dev;
1507 	int i, sessions = 0;
1508 	unsigned long flags;
1509 	int rc;
1510 
1511 	cctx = dev_get_drvdata(dev->parent);
1512 	if (!cctx)
1513 		return -EINVAL;
1514 
1515 	of_property_read_u32(dev->of_node, "qcom,nsessions", &sessions);
1516 
1517 	spin_lock_irqsave(&cctx->lock, flags);
1518 	sess = &cctx->session[cctx->sesscount];
1519 	sess->used = false;
1520 	sess->valid = true;
1521 	sess->dev = dev;
1522 	dev_set_drvdata(dev, sess);
1523 
1524 	if (of_property_read_u32(dev->of_node, "reg", &sess->sid))
1525 		dev_info(dev, "FastRPC Session ID not specified in DT\n");
1526 
1527 	if (sessions > 0) {
1528 		struct fastrpc_session_ctx *dup_sess;
1529 
1530 		for (i = 1; i < sessions; i++) {
1531 			if (cctx->sesscount++ >= FASTRPC_MAX_SESSIONS)
1532 				break;
1533 			dup_sess = &cctx->session[cctx->sesscount];
1534 			memcpy(dup_sess, sess, sizeof(*dup_sess));
1535 		}
1536 	}
1537 	cctx->sesscount++;
1538 	spin_unlock_irqrestore(&cctx->lock, flags);
1539 	rc = dma_set_mask(dev, DMA_BIT_MASK(32));
1540 	if (rc) {
1541 		dev_err(dev, "32-bit DMA enable failed\n");
1542 		return rc;
1543 	}
1544 
1545 	return 0;
1546 }
1547 
1548 static int fastrpc_cb_remove(struct platform_device *pdev)
1549 {
1550 	struct fastrpc_channel_ctx *cctx = dev_get_drvdata(pdev->dev.parent);
1551 	struct fastrpc_session_ctx *sess = dev_get_drvdata(&pdev->dev);
1552 	unsigned long flags;
1553 	int i;
1554 
1555 	spin_lock_irqsave(&cctx->lock, flags);
1556 	for (i = 1; i < FASTRPC_MAX_SESSIONS; i++) {
1557 		if (cctx->session[i].sid == sess->sid) {
1558 			cctx->session[i].valid = false;
1559 			cctx->sesscount--;
1560 		}
1561 	}
1562 	spin_unlock_irqrestore(&cctx->lock, flags);
1563 
1564 	return 0;
1565 }
1566 
1567 static const struct of_device_id fastrpc_match_table[] = {
1568 	{ .compatible = "qcom,fastrpc-compute-cb", },
1569 	{}
1570 };
1571 
1572 static struct platform_driver fastrpc_cb_driver = {
1573 	.probe = fastrpc_cb_probe,
1574 	.remove = fastrpc_cb_remove,
1575 	.driver = {
1576 		.name = "qcom,fastrpc-cb",
1577 		.of_match_table = fastrpc_match_table,
1578 		.suppress_bind_attrs = true,
1579 	},
1580 };
1581 
1582 static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
1583 {
1584 	struct device *rdev = &rpdev->dev;
1585 	struct fastrpc_channel_ctx *data;
1586 	int i, err, domain_id = -1;
1587 	const char *domain;
1588 
1589 	err = of_property_read_string(rdev->of_node, "label", &domain);
1590 	if (err) {
1591 		dev_info(rdev, "FastRPC Domain not specified in DT\n");
1592 		return err;
1593 	}
1594 
1595 	for (i = 0; i <= CDSP_DOMAIN_ID; i++) {
1596 		if (!strcmp(domains[i], domain)) {
1597 			domain_id = i;
1598 			break;
1599 		}
1600 	}
1601 
1602 	if (domain_id < 0) {
1603 		dev_info(rdev, "FastRPC Invalid Domain ID %d\n", domain_id);
1604 		return -EINVAL;
1605 	}
1606 
1607 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1608 	if (!data)
1609 		return -ENOMEM;
1610 
1611 	data->miscdev.minor = MISC_DYNAMIC_MINOR;
1612 	data->miscdev.name = devm_kasprintf(rdev, GFP_KERNEL, "fastrpc-%s",
1613 					    domains[domain_id]);
1614 	data->miscdev.fops = &fastrpc_fops;
1615 	err = misc_register(&data->miscdev);
1616 	if (err)
1617 		return err;
1618 
1619 	kref_init(&data->refcount);
1620 
1621 	dev_set_drvdata(&rpdev->dev, data);
1622 	dma_set_mask_and_coherent(rdev, DMA_BIT_MASK(32));
1623 	INIT_LIST_HEAD(&data->users);
1624 	spin_lock_init(&data->lock);
1625 	idr_init(&data->ctx_idr);
1626 	data->domain_id = domain_id;
1627 	data->rpdev = rpdev;
1628 
1629 	return of_platform_populate(rdev->of_node, NULL, NULL, rdev);
1630 }
1631 
1632 static void fastrpc_notify_users(struct fastrpc_user *user)
1633 {
1634 	struct fastrpc_invoke_ctx *ctx;
1635 
1636 	spin_lock(&user->lock);
1637 	list_for_each_entry(ctx, &user->pending, node)
1638 		complete(&ctx->work);
1639 	spin_unlock(&user->lock);
1640 }
1641 
1642 static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
1643 {
1644 	struct fastrpc_channel_ctx *cctx = dev_get_drvdata(&rpdev->dev);
1645 	struct fastrpc_user *user;
1646 	unsigned long flags;
1647 
1648 	spin_lock_irqsave(&cctx->lock, flags);
1649 	list_for_each_entry(user, &cctx->users, user)
1650 		fastrpc_notify_users(user);
1651 	spin_unlock_irqrestore(&cctx->lock, flags);
1652 
1653 	misc_deregister(&cctx->miscdev);
1654 	of_platform_depopulate(&rpdev->dev);
1655 
1656 	cctx->rpdev = NULL;
1657 	fastrpc_channel_ctx_put(cctx);
1658 }
1659 
1660 static int fastrpc_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
1661 				  int len, void *priv, u32 addr)
1662 {
1663 	struct fastrpc_channel_ctx *cctx = dev_get_drvdata(&rpdev->dev);
1664 	struct fastrpc_invoke_rsp *rsp = data;
1665 	struct fastrpc_invoke_ctx *ctx;
1666 	unsigned long flags;
1667 	unsigned long ctxid;
1668 
1669 	if (len < sizeof(*rsp))
1670 		return -EINVAL;
1671 
1672 	ctxid = ((rsp->ctx & FASTRPC_CTXID_MASK) >> 4);
1673 
1674 	spin_lock_irqsave(&cctx->lock, flags);
1675 	ctx = idr_find(&cctx->ctx_idr, ctxid);
1676 	spin_unlock_irqrestore(&cctx->lock, flags);
1677 
1678 	if (!ctx) {
1679 		dev_err(&rpdev->dev, "No context ID matches response\n");
1680 		return -ENOENT;
1681 	}
1682 
1683 	ctx->retval = rsp->retval;
1684 	complete(&ctx->work);
1685 
1686 	/*
1687 	 * The DMA buffer associated with the context cannot be freed in
1688 	 * interrupt context so schedule it through a worker thread to
1689 	 * avoid a kernel BUG.
1690 	 */
1691 	schedule_work(&ctx->put_work);
1692 
1693 	return 0;
1694 }
1695 
1696 static const struct of_device_id fastrpc_rpmsg_of_match[] = {
1697 	{ .compatible = "qcom,fastrpc" },
1698 	{ },
1699 };
1700 MODULE_DEVICE_TABLE(of, fastrpc_rpmsg_of_match);
1701 
1702 static struct rpmsg_driver fastrpc_driver = {
1703 	.probe = fastrpc_rpmsg_probe,
1704 	.remove = fastrpc_rpmsg_remove,
1705 	.callback = fastrpc_rpmsg_callback,
1706 	.drv = {
1707 		.name = "qcom,fastrpc",
1708 		.of_match_table = fastrpc_rpmsg_of_match,
1709 	},
1710 };
1711 
1712 static int fastrpc_init(void)
1713 {
1714 	int ret;
1715 
1716 	ret = platform_driver_register(&fastrpc_cb_driver);
1717 	if (ret < 0) {
1718 		pr_err("fastrpc: failed to register cb driver\n");
1719 		return ret;
1720 	}
1721 
1722 	ret = register_rpmsg_driver(&fastrpc_driver);
1723 	if (ret < 0) {
1724 		pr_err("fastrpc: failed to register rpmsg driver\n");
1725 		platform_driver_unregister(&fastrpc_cb_driver);
1726 		return ret;
1727 	}
1728 
1729 	return 0;
1730 }
1731 module_init(fastrpc_init);
1732 
1733 static void fastrpc_exit(void)
1734 {
1735 	platform_driver_unregister(&fastrpc_cb_driver);
1736 	unregister_rpmsg_driver(&fastrpc_driver);
1737 }
1738 module_exit(fastrpc_exit);
1739 
1740 MODULE_LICENSE("GPL v2");
1741