1 /*
2  * Remote Processor Framework
3  *
4  * Copyright (C) 2011 Texas Instruments, Inc.
5  * Copyright (C) 2011 Google, Inc.
6  *
7  * Ohad Ben-Cohen <ohad@wizery.com>
8  * Brian Swetland <swetland@google.com>
9  * Mark Grosen <mgrosen@ti.com>
10  * Fernando Guzman Lugo <fernando.lugo@ti.com>
11  * Suman Anna <s-anna@ti.com>
12  * Robert Tivy <rtivy@ti.com>
13  * Armando Uribe De Leon <x0095078@ti.com>
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License
17  * version 2 as published by the Free Software Foundation.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  */
24 
25 #define pr_fmt(fmt)    "%s: " fmt, __func__
26 
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/device.h>
30 #include <linux/slab.h>
31 #include <linux/mutex.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/firmware.h>
34 #include <linux/string.h>
35 #include <linux/debugfs.h>
36 #include <linux/remoteproc.h>
37 #include <linux/iommu.h>
38 #include <linux/idr.h>
39 #include <linux/elf.h>
40 #include <linux/crc32.h>
41 #include <linux/virtio_ids.h>
42 #include <linux/virtio_ring.h>
43 #include <asm/byteorder.h>
44 
45 #include "remoteproc_internal.h"
46 
47 static DEFINE_MUTEX(rproc_list_mutex);
48 static LIST_HEAD(rproc_list);
49 
50 typedef int (*rproc_handle_resources_t)(struct rproc *rproc,
51 				struct resource_table *table, int len);
52 typedef int (*rproc_handle_resource_t)(struct rproc *rproc,
53 				 void *, int offset, int avail);
54 
55 /* Unique indices for remoteproc devices */
56 static DEFINE_IDA(rproc_dev_index);
57 
58 static const char * const rproc_crash_names[] = {
59 	[RPROC_MMUFAULT]	= "mmufault",
60 	[RPROC_WATCHDOG]	= "watchdog",
61 	[RPROC_FATAL_ERROR]	= "fatal error",
62 };
63 
64 /* translate rproc_crash_type to string */
65 static const char *rproc_crash_to_string(enum rproc_crash_type type)
66 {
67 	if (type < ARRAY_SIZE(rproc_crash_names))
68 		return rproc_crash_names[type];
69 	return "unknown";
70 }
71 
72 /*
73  * This is the IOMMU fault handler we register with the IOMMU API
74  * (when relevant; not all remote processors access memory through
75  * an IOMMU).
76  *
77  * IOMMU core will invoke this handler whenever the remote processor
78  * will try to access an unmapped device address.
79  */
80 static int rproc_iommu_fault(struct iommu_domain *domain, struct device *dev,
81 			     unsigned long iova, int flags, void *token)
82 {
83 	struct rproc *rproc = token;
84 
85 	dev_err(dev, "iommu fault: da 0x%lx flags 0x%x\n", iova, flags);
86 
87 	rproc_report_crash(rproc, RPROC_MMUFAULT);
88 
89 	/*
90 	 * Let the iommu core know we're not really handling this fault;
91 	 * we just used it as a recovery trigger.
92 	 */
93 	return -ENOSYS;
94 }
95 
96 static int rproc_enable_iommu(struct rproc *rproc)
97 {
98 	struct iommu_domain *domain;
99 	struct device *dev = rproc->dev.parent;
100 	int ret;
101 
102 	if (!rproc->has_iommu) {
103 		dev_dbg(dev, "iommu not present\n");
104 		return 0;
105 	}
106 
107 	domain = iommu_domain_alloc(dev->bus);
108 	if (!domain) {
109 		dev_err(dev, "can't alloc iommu domain\n");
110 		return -ENOMEM;
111 	}
112 
113 	iommu_set_fault_handler(domain, rproc_iommu_fault, rproc);
114 
115 	ret = iommu_attach_device(domain, dev);
116 	if (ret) {
117 		dev_err(dev, "can't attach iommu device: %d\n", ret);
118 		goto free_domain;
119 	}
120 
121 	rproc->domain = domain;
122 
123 	return 0;
124 
125 free_domain:
126 	iommu_domain_free(domain);
127 	return ret;
128 }
129 
130 static void rproc_disable_iommu(struct rproc *rproc)
131 {
132 	struct iommu_domain *domain = rproc->domain;
133 	struct device *dev = rproc->dev.parent;
134 
135 	if (!domain)
136 		return;
137 
138 	iommu_detach_device(domain, dev);
139 	iommu_domain_free(domain);
140 }
141 
142 /**
143  * rproc_da_to_va() - lookup the kernel virtual address for a remoteproc address
144  * @rproc: handle of a remote processor
145  * @da: remoteproc device address to translate
146  * @len: length of the memory region @da is pointing to
147  *
148  * Some remote processors will ask us to allocate them physically contiguous
149  * memory regions (which we call "carveouts"), and map them to specific
150  * device addresses (which are hardcoded in the firmware). They may also have
151  * dedicated memory regions internal to the processors, and use them either
152  * exclusively or alongside carveouts.
153  *
154  * They may then ask us to copy objects into specific device addresses (e.g.
155  * code/data sections) or expose us certain symbols in other device address
156  * (e.g. their trace buffer).
157  *
158  * This function is a helper function with which we can go over the allocated
159  * carveouts and translate specific device addresses to kernel virtual addresses
160  * so we can access the referenced memory. This function also allows to perform
161  * translations on the internal remoteproc memory regions through a platform
162  * implementation specific da_to_va ops, if present.
163  *
164  * The function returns a valid kernel address on success or NULL on failure.
165  *
166  * Note: phys_to_virt(iommu_iova_to_phys(rproc->domain, da)) will work too,
167  * but only on kernel direct mapped RAM memory. Instead, we're just using
168  * here the output of the DMA API for the carveouts, which should be more
169  * correct.
170  */
171 void *rproc_da_to_va(struct rproc *rproc, u64 da, int len)
172 {
173 	struct rproc_mem_entry *carveout;
174 	void *ptr = NULL;
175 
176 	if (rproc->ops->da_to_va) {
177 		ptr = rproc->ops->da_to_va(rproc, da, len);
178 		if (ptr)
179 			goto out;
180 	}
181 
182 	list_for_each_entry(carveout, &rproc->carveouts, node) {
183 		int offset = da - carveout->da;
184 
185 		/* try next carveout if da is too small */
186 		if (offset < 0)
187 			continue;
188 
189 		/* try next carveout if da is too large */
190 		if (offset + len > carveout->len)
191 			continue;
192 
193 		ptr = carveout->va + offset;
194 
195 		break;
196 	}
197 
198 out:
199 	return ptr;
200 }
201 EXPORT_SYMBOL(rproc_da_to_va);
202 
203 int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
204 {
205 	struct rproc *rproc = rvdev->rproc;
206 	struct device *dev = &rproc->dev;
207 	struct rproc_vring *rvring = &rvdev->vring[i];
208 	struct fw_rsc_vdev *rsc;
209 	dma_addr_t dma;
210 	void *va;
211 	int ret, size, notifyid;
212 
213 	/* actual size of vring (in bytes) */
214 	size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
215 
216 	/*
217 	 * Allocate non-cacheable memory for the vring. In the future
218 	 * this call will also configure the IOMMU for us
219 	 */
220 	va = dma_alloc_coherent(dev->parent, size, &dma, GFP_KERNEL);
221 	if (!va) {
222 		dev_err(dev->parent, "dma_alloc_coherent failed\n");
223 		return -EINVAL;
224 	}
225 
226 	/*
227 	 * Assign an rproc-wide unique index for this vring
228 	 * TODO: assign a notifyid for rvdev updates as well
229 	 * TODO: support predefined notifyids (via resource table)
230 	 */
231 	ret = idr_alloc(&rproc->notifyids, rvring, 0, 0, GFP_KERNEL);
232 	if (ret < 0) {
233 		dev_err(dev, "idr_alloc failed: %d\n", ret);
234 		dma_free_coherent(dev->parent, size, va, dma);
235 		return ret;
236 	}
237 	notifyid = ret;
238 
239 	/* Potentially bump max_notifyid */
240 	if (notifyid > rproc->max_notifyid)
241 		rproc->max_notifyid = notifyid;
242 
243 	dev_dbg(dev, "vring%d: va %p dma %pad size 0x%x idr %d\n",
244 		i, va, &dma, size, notifyid);
245 
246 	rvring->va = va;
247 	rvring->dma = dma;
248 	rvring->notifyid = notifyid;
249 
250 	/*
251 	 * Let the rproc know the notifyid and da of this vring.
252 	 * Not all platforms use dma_alloc_coherent to automatically
253 	 * set up the iommu. In this case the device address (da) will
254 	 * hold the physical address and not the device address.
255 	 */
256 	rsc = (void *)rproc->table_ptr + rvdev->rsc_offset;
257 	rsc->vring[i].da = dma;
258 	rsc->vring[i].notifyid = notifyid;
259 	return 0;
260 }
261 
262 static int
263 rproc_parse_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i)
264 {
265 	struct rproc *rproc = rvdev->rproc;
266 	struct device *dev = &rproc->dev;
267 	struct fw_rsc_vdev_vring *vring = &rsc->vring[i];
268 	struct rproc_vring *rvring = &rvdev->vring[i];
269 
270 	dev_dbg(dev, "vdev rsc: vring%d: da 0x%x, qsz %d, align %d\n",
271 		i, vring->da, vring->num, vring->align);
272 
273 	/* verify queue size and vring alignment are sane */
274 	if (!vring->num || !vring->align) {
275 		dev_err(dev, "invalid qsz (%d) or alignment (%d)\n",
276 			vring->num, vring->align);
277 		return -EINVAL;
278 	}
279 
280 	rvring->len = vring->num;
281 	rvring->align = vring->align;
282 	rvring->rvdev = rvdev;
283 
284 	return 0;
285 }
286 
287 void rproc_free_vring(struct rproc_vring *rvring)
288 {
289 	int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
290 	struct rproc *rproc = rvring->rvdev->rproc;
291 	int idx = rvring->rvdev->vring - rvring;
292 	struct fw_rsc_vdev *rsc;
293 
294 	dma_free_coherent(rproc->dev.parent, size, rvring->va, rvring->dma);
295 	idr_remove(&rproc->notifyids, rvring->notifyid);
296 
297 	/* reset resource entry info */
298 	rsc = (void *)rproc->table_ptr + rvring->rvdev->rsc_offset;
299 	rsc->vring[idx].da = 0;
300 	rsc->vring[idx].notifyid = -1;
301 }
302 
303 static int rproc_vdev_do_probe(struct rproc_subdev *subdev)
304 {
305 	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
306 
307 	return rproc_add_virtio_dev(rvdev, rvdev->id);
308 }
309 
310 static void rproc_vdev_do_remove(struct rproc_subdev *subdev)
311 {
312 	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
313 
314 	rproc_remove_virtio_dev(rvdev);
315 }
316 
317 /**
318  * rproc_handle_vdev() - handle a vdev fw resource
319  * @rproc: the remote processor
320  * @rsc: the vring resource descriptor
321  * @avail: size of available data (for sanity checking the image)
322  *
323  * This resource entry requests the host to statically register a virtio
324  * device (vdev), and setup everything needed to support it. It contains
325  * everything needed to make it possible: the virtio device id, virtio
326  * device features, vrings information, virtio config space, etc...
327  *
328  * Before registering the vdev, the vrings are allocated from non-cacheable
329  * physically contiguous memory. Currently we only support two vrings per
330  * remote processor (temporary limitation). We might also want to consider
331  * doing the vring allocation only later when ->find_vqs() is invoked, and
332  * then release them upon ->del_vqs().
333  *
334  * Note: @da is currently not really handled correctly: we dynamically
335  * allocate it using the DMA API, ignoring requested hard coded addresses,
336  * and we don't take care of any required IOMMU programming. This is all
337  * going to be taken care of when the generic iommu-based DMA API will be
338  * merged. Meanwhile, statically-addressed iommu-based firmware images should
339  * use RSC_DEVMEM resource entries to map their required @da to the physical
340  * address of their base CMA region (ouch, hacky!).
341  *
342  * Returns 0 on success, or an appropriate error code otherwise
343  */
344 static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
345 			     int offset, int avail)
346 {
347 	struct device *dev = &rproc->dev;
348 	struct rproc_vdev *rvdev;
349 	int i, ret;
350 
351 	/* make sure resource isn't truncated */
352 	if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
353 			+ rsc->config_len > avail) {
354 		dev_err(dev, "vdev rsc is truncated\n");
355 		return -EINVAL;
356 	}
357 
358 	/* make sure reserved bytes are zeroes */
359 	if (rsc->reserved[0] || rsc->reserved[1]) {
360 		dev_err(dev, "vdev rsc has non zero reserved bytes\n");
361 		return -EINVAL;
362 	}
363 
364 	dev_dbg(dev, "vdev rsc: id %d, dfeatures 0x%x, cfg len %d, %d vrings\n",
365 		rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings);
366 
367 	/* we currently support only two vrings per rvdev */
368 	if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) {
369 		dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings);
370 		return -EINVAL;
371 	}
372 
373 	rvdev = kzalloc(sizeof(*rvdev), GFP_KERNEL);
374 	if (!rvdev)
375 		return -ENOMEM;
376 
377 	kref_init(&rvdev->refcount);
378 
379 	rvdev->id = rsc->id;
380 	rvdev->rproc = rproc;
381 
382 	/* parse the vrings */
383 	for (i = 0; i < rsc->num_of_vrings; i++) {
384 		ret = rproc_parse_vring(rvdev, rsc, i);
385 		if (ret)
386 			goto free_rvdev;
387 	}
388 
389 	/* remember the resource offset*/
390 	rvdev->rsc_offset = offset;
391 
392 	/* allocate the vring resources */
393 	for (i = 0; i < rsc->num_of_vrings; i++) {
394 		ret = rproc_alloc_vring(rvdev, i);
395 		if (ret)
396 			goto unwind_vring_allocations;
397 	}
398 
399 	list_add_tail(&rvdev->node, &rproc->rvdevs);
400 
401 	rproc_add_subdev(rproc, &rvdev->subdev,
402 			 rproc_vdev_do_probe, rproc_vdev_do_remove);
403 
404 	return 0;
405 
406 unwind_vring_allocations:
407 	for (i--; i >= 0; i--)
408 		rproc_free_vring(&rvdev->vring[i]);
409 free_rvdev:
410 	kfree(rvdev);
411 	return ret;
412 }
413 
414 void rproc_vdev_release(struct kref *ref)
415 {
416 	struct rproc_vdev *rvdev = container_of(ref, struct rproc_vdev, refcount);
417 	struct rproc_vring *rvring;
418 	struct rproc *rproc = rvdev->rproc;
419 	int id;
420 
421 	for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
422 		rvring = &rvdev->vring[id];
423 		if (!rvring->va)
424 			continue;
425 
426 		rproc_free_vring(rvring);
427 	}
428 
429 	rproc_remove_subdev(rproc, &rvdev->subdev);
430 	list_del(&rvdev->node);
431 	kfree(rvdev);
432 }
433 
434 /**
435  * rproc_handle_trace() - handle a shared trace buffer resource
436  * @rproc: the remote processor
437  * @rsc: the trace resource descriptor
438  * @avail: size of available data (for sanity checking the image)
439  *
440  * In case the remote processor dumps trace logs into memory,
441  * export it via debugfs.
442  *
443  * Currently, the 'da' member of @rsc should contain the device address
444  * where the remote processor is dumping the traces. Later we could also
445  * support dynamically allocating this address using the generic
446  * DMA API (but currently there isn't a use case for that).
447  *
448  * Returns 0 on success, or an appropriate error code otherwise
449  */
450 static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc,
451 			      int offset, int avail)
452 {
453 	struct rproc_mem_entry *trace;
454 	struct device *dev = &rproc->dev;
455 	void *ptr;
456 	char name[15];
457 
458 	if (sizeof(*rsc) > avail) {
459 		dev_err(dev, "trace rsc is truncated\n");
460 		return -EINVAL;
461 	}
462 
463 	/* make sure reserved bytes are zeroes */
464 	if (rsc->reserved) {
465 		dev_err(dev, "trace rsc has non zero reserved bytes\n");
466 		return -EINVAL;
467 	}
468 
469 	/* what's the kernel address of this resource ? */
470 	ptr = rproc_da_to_va(rproc, rsc->da, rsc->len);
471 	if (!ptr) {
472 		dev_err(dev, "erroneous trace resource entry\n");
473 		return -EINVAL;
474 	}
475 
476 	trace = kzalloc(sizeof(*trace), GFP_KERNEL);
477 	if (!trace)
478 		return -ENOMEM;
479 
480 	/* set the trace buffer dma properties */
481 	trace->len = rsc->len;
482 	trace->va = ptr;
483 
484 	/* make sure snprintf always null terminates, even if truncating */
485 	snprintf(name, sizeof(name), "trace%d", rproc->num_traces);
486 
487 	/* create the debugfs entry */
488 	trace->priv = rproc_create_trace_file(name, rproc, trace);
489 	if (!trace->priv) {
490 		trace->va = NULL;
491 		kfree(trace);
492 		return -EINVAL;
493 	}
494 
495 	list_add_tail(&trace->node, &rproc->traces);
496 
497 	rproc->num_traces++;
498 
499 	dev_dbg(dev, "%s added: va %p, da 0x%x, len 0x%x\n",
500 		name, ptr, rsc->da, rsc->len);
501 
502 	return 0;
503 }
504 
505 /**
506  * rproc_handle_devmem() - handle devmem resource entry
507  * @rproc: remote processor handle
508  * @rsc: the devmem resource entry
509  * @avail: size of available data (for sanity checking the image)
510  *
511  * Remote processors commonly need to access certain on-chip peripherals.
512  *
513  * Some of these remote processors access memory via an iommu device,
514  * and might require us to configure their iommu before they can access
515  * the on-chip peripherals they need.
516  *
517  * This resource entry is a request to map such a peripheral device.
518  *
519  * These devmem entries will contain the physical address of the device in
520  * the 'pa' member. If a specific device address is expected, then 'da' will
521  * contain it (currently this is the only use case supported). 'len' will
522  * contain the size of the physical region we need to map.
523  *
524  * Currently we just "trust" those devmem entries to contain valid physical
525  * addresses, but this is going to change: we want the implementations to
526  * tell us ranges of physical addresses the firmware is allowed to request,
527  * and not allow firmwares to request access to physical addresses that
528  * are outside those ranges.
529  */
530 static int rproc_handle_devmem(struct rproc *rproc, struct fw_rsc_devmem *rsc,
531 			       int offset, int avail)
532 {
533 	struct rproc_mem_entry *mapping;
534 	struct device *dev = &rproc->dev;
535 	int ret;
536 
537 	/* no point in handling this resource without a valid iommu domain */
538 	if (!rproc->domain)
539 		return -EINVAL;
540 
541 	if (sizeof(*rsc) > avail) {
542 		dev_err(dev, "devmem rsc is truncated\n");
543 		return -EINVAL;
544 	}
545 
546 	/* make sure reserved bytes are zeroes */
547 	if (rsc->reserved) {
548 		dev_err(dev, "devmem rsc has non zero reserved bytes\n");
549 		return -EINVAL;
550 	}
551 
552 	mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
553 	if (!mapping)
554 		return -ENOMEM;
555 
556 	ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len, rsc->flags);
557 	if (ret) {
558 		dev_err(dev, "failed to map devmem: %d\n", ret);
559 		goto out;
560 	}
561 
562 	/*
563 	 * We'll need this info later when we'll want to unmap everything
564 	 * (e.g. on shutdown).
565 	 *
566 	 * We can't trust the remote processor not to change the resource
567 	 * table, so we must maintain this info independently.
568 	 */
569 	mapping->da = rsc->da;
570 	mapping->len = rsc->len;
571 	list_add_tail(&mapping->node, &rproc->mappings);
572 
573 	dev_dbg(dev, "mapped devmem pa 0x%x, da 0x%x, len 0x%x\n",
574 		rsc->pa, rsc->da, rsc->len);
575 
576 	return 0;
577 
578 out:
579 	kfree(mapping);
580 	return ret;
581 }
582 
583 /**
584  * rproc_handle_carveout() - handle phys contig memory allocation requests
585  * @rproc: rproc handle
586  * @rsc: the resource entry
587  * @avail: size of available data (for image validation)
588  *
589  * This function will handle firmware requests for allocation of physically
590  * contiguous memory regions.
591  *
592  * These request entries should come first in the firmware's resource table,
593  * as other firmware entries might request placing other data objects inside
594  * these memory regions (e.g. data/code segments, trace resource entries, ...).
595  *
596  * Allocating memory this way helps utilizing the reserved physical memory
597  * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries
598  * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB
599  * pressure is important; it may have a substantial impact on performance.
600  */
601 static int rproc_handle_carveout(struct rproc *rproc,
602 				 struct fw_rsc_carveout *rsc,
603 				 int offset, int avail)
604 {
605 	struct rproc_mem_entry *carveout, *mapping;
606 	struct device *dev = &rproc->dev;
607 	dma_addr_t dma;
608 	void *va;
609 	int ret;
610 
611 	if (sizeof(*rsc) > avail) {
612 		dev_err(dev, "carveout rsc is truncated\n");
613 		return -EINVAL;
614 	}
615 
616 	/* make sure reserved bytes are zeroes */
617 	if (rsc->reserved) {
618 		dev_err(dev, "carveout rsc has non zero reserved bytes\n");
619 		return -EINVAL;
620 	}
621 
622 	dev_dbg(dev, "carveout rsc: name: %s, da 0x%x, pa 0x%x, len 0x%x, flags 0x%x\n",
623 		rsc->name, rsc->da, rsc->pa, rsc->len, rsc->flags);
624 
625 	carveout = kzalloc(sizeof(*carveout), GFP_KERNEL);
626 	if (!carveout)
627 		return -ENOMEM;
628 
629 	va = dma_alloc_coherent(dev->parent, rsc->len, &dma, GFP_KERNEL);
630 	if (!va) {
631 		dev_err(dev->parent,
632 			"failed to allocate dma memory: len 0x%x\n", rsc->len);
633 		ret = -ENOMEM;
634 		goto free_carv;
635 	}
636 
637 	dev_dbg(dev, "carveout va %p, dma %pad, len 0x%x\n",
638 		va, &dma, rsc->len);
639 
640 	/*
641 	 * Ok, this is non-standard.
642 	 *
643 	 * Sometimes we can't rely on the generic iommu-based DMA API
644 	 * to dynamically allocate the device address and then set the IOMMU
645 	 * tables accordingly, because some remote processors might
646 	 * _require_ us to use hard coded device addresses that their
647 	 * firmware was compiled with.
648 	 *
649 	 * In this case, we must use the IOMMU API directly and map
650 	 * the memory to the device address as expected by the remote
651 	 * processor.
652 	 *
653 	 * Obviously such remote processor devices should not be configured
654 	 * to use the iommu-based DMA API: we expect 'dma' to contain the
655 	 * physical address in this case.
656 	 */
657 	if (rproc->domain) {
658 		mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
659 		if (!mapping) {
660 			ret = -ENOMEM;
661 			goto dma_free;
662 		}
663 
664 		ret = iommu_map(rproc->domain, rsc->da, dma, rsc->len,
665 				rsc->flags);
666 		if (ret) {
667 			dev_err(dev, "iommu_map failed: %d\n", ret);
668 			goto free_mapping;
669 		}
670 
671 		/*
672 		 * We'll need this info later when we'll want to unmap
673 		 * everything (e.g. on shutdown).
674 		 *
675 		 * We can't trust the remote processor not to change the
676 		 * resource table, so we must maintain this info independently.
677 		 */
678 		mapping->da = rsc->da;
679 		mapping->len = rsc->len;
680 		list_add_tail(&mapping->node, &rproc->mappings);
681 
682 		dev_dbg(dev, "carveout mapped 0x%x to %pad\n",
683 			rsc->da, &dma);
684 	}
685 
686 	/*
687 	 * Some remote processors might need to know the pa
688 	 * even though they are behind an IOMMU. E.g., OMAP4's
689 	 * remote M3 processor needs this so it can control
690 	 * on-chip hardware accelerators that are not behind
691 	 * the IOMMU, and therefor must know the pa.
692 	 *
693 	 * Generally we don't want to expose physical addresses
694 	 * if we don't have to (remote processors are generally
695 	 * _not_ trusted), so we might want to do this only for
696 	 * remote processor that _must_ have this (e.g. OMAP4's
697 	 * dual M3 subsystem).
698 	 *
699 	 * Non-IOMMU processors might also want to have this info.
700 	 * In this case, the device address and the physical address
701 	 * are the same.
702 	 */
703 	rsc->pa = dma;
704 
705 	carveout->va = va;
706 	carveout->len = rsc->len;
707 	carveout->dma = dma;
708 	carveout->da = rsc->da;
709 
710 	list_add_tail(&carveout->node, &rproc->carveouts);
711 
712 	return 0;
713 
714 free_mapping:
715 	kfree(mapping);
716 dma_free:
717 	dma_free_coherent(dev->parent, rsc->len, va, dma);
718 free_carv:
719 	kfree(carveout);
720 	return ret;
721 }
722 
723 /*
724  * A lookup table for resource handlers. The indices are defined in
725  * enum fw_resource_type.
726  */
727 static rproc_handle_resource_t rproc_loading_handlers[RSC_LAST] = {
728 	[RSC_CARVEOUT] = (rproc_handle_resource_t)rproc_handle_carveout,
729 	[RSC_DEVMEM] = (rproc_handle_resource_t)rproc_handle_devmem,
730 	[RSC_TRACE] = (rproc_handle_resource_t)rproc_handle_trace,
731 	[RSC_VDEV] = (rproc_handle_resource_t)rproc_handle_vdev,
732 };
733 
734 /* handle firmware resource entries before booting the remote processor */
735 static int rproc_handle_resources(struct rproc *rproc, int len,
736 				  rproc_handle_resource_t handlers[RSC_LAST])
737 {
738 	struct device *dev = &rproc->dev;
739 	rproc_handle_resource_t handler;
740 	int ret = 0, i;
741 
742 	for (i = 0; i < rproc->table_ptr->num; i++) {
743 		int offset = rproc->table_ptr->offset[i];
744 		struct fw_rsc_hdr *hdr = (void *)rproc->table_ptr + offset;
745 		int avail = len - offset - sizeof(*hdr);
746 		void *rsc = (void *)hdr + sizeof(*hdr);
747 
748 		/* make sure table isn't truncated */
749 		if (avail < 0) {
750 			dev_err(dev, "rsc table is truncated\n");
751 			return -EINVAL;
752 		}
753 
754 		dev_dbg(dev, "rsc: type %d\n", hdr->type);
755 
756 		if (hdr->type >= RSC_LAST) {
757 			dev_warn(dev, "unsupported resource %d\n", hdr->type);
758 			continue;
759 		}
760 
761 		handler = handlers[hdr->type];
762 		if (!handler)
763 			continue;
764 
765 		ret = handler(rproc, rsc, offset + sizeof(*hdr), avail);
766 		if (ret)
767 			break;
768 	}
769 
770 	return ret;
771 }
772 
773 static int rproc_probe_subdevices(struct rproc *rproc)
774 {
775 	struct rproc_subdev *subdev;
776 	int ret;
777 
778 	list_for_each_entry(subdev, &rproc->subdevs, node) {
779 		ret = subdev->probe(subdev);
780 		if (ret)
781 			goto unroll_registration;
782 	}
783 
784 	return 0;
785 
786 unroll_registration:
787 	list_for_each_entry_continue_reverse(subdev, &rproc->subdevs, node)
788 		subdev->remove(subdev);
789 
790 	return ret;
791 }
792 
793 static void rproc_remove_subdevices(struct rproc *rproc)
794 {
795 	struct rproc_subdev *subdev;
796 
797 	list_for_each_entry_reverse(subdev, &rproc->subdevs, node)
798 		subdev->remove(subdev);
799 }
800 
801 /**
802  * rproc_resource_cleanup() - clean up and free all acquired resources
803  * @rproc: rproc handle
804  *
805  * This function will free all resources acquired for @rproc, and it
806  * is called whenever @rproc either shuts down or fails to boot.
807  */
808 static void rproc_resource_cleanup(struct rproc *rproc)
809 {
810 	struct rproc_mem_entry *entry, *tmp;
811 	struct rproc_vdev *rvdev, *rvtmp;
812 	struct device *dev = &rproc->dev;
813 
814 	/* clean up debugfs trace entries */
815 	list_for_each_entry_safe(entry, tmp, &rproc->traces, node) {
816 		rproc_remove_trace_file(entry->priv);
817 		rproc->num_traces--;
818 		list_del(&entry->node);
819 		kfree(entry);
820 	}
821 
822 	/* clean up iommu mapping entries */
823 	list_for_each_entry_safe(entry, tmp, &rproc->mappings, node) {
824 		size_t unmapped;
825 
826 		unmapped = iommu_unmap(rproc->domain, entry->da, entry->len);
827 		if (unmapped != entry->len) {
828 			/* nothing much to do besides complaining */
829 			dev_err(dev, "failed to unmap %u/%zu\n", entry->len,
830 				unmapped);
831 		}
832 
833 		list_del(&entry->node);
834 		kfree(entry);
835 	}
836 
837 	/* clean up carveout allocations */
838 	list_for_each_entry_safe(entry, tmp, &rproc->carveouts, node) {
839 		dma_free_coherent(dev->parent, entry->len, entry->va,
840 				  entry->dma);
841 		list_del(&entry->node);
842 		kfree(entry);
843 	}
844 
845 	/* clean up remote vdev entries */
846 	list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
847 		kref_put(&rvdev->refcount, rproc_vdev_release);
848 }
849 
850 static int rproc_start(struct rproc *rproc, const struct firmware *fw)
851 {
852 	struct resource_table *table, *loaded_table;
853 	struct device *dev = &rproc->dev;
854 	int ret, tablesz;
855 
856 	/* look for the resource table */
857 	table = rproc_find_rsc_table(rproc, fw, &tablesz);
858 	if (!table) {
859 		dev_err(dev, "Resource table look up failed\n");
860 		return -EINVAL;
861 	}
862 
863 	/* load the ELF segments to memory */
864 	ret = rproc_load_segments(rproc, fw);
865 	if (ret) {
866 		dev_err(dev, "Failed to load program segments: %d\n", ret);
867 		return ret;
868 	}
869 
870 	/*
871 	 * The starting device has been given the rproc->cached_table as the
872 	 * resource table. The address of the vring along with the other
873 	 * allocated resources (carveouts etc) is stored in cached_table.
874 	 * In order to pass this information to the remote device we must copy
875 	 * this information to device memory. We also update the table_ptr so
876 	 * that any subsequent changes will be applied to the loaded version.
877 	 */
878 	loaded_table = rproc_find_loaded_rsc_table(rproc, fw);
879 	if (loaded_table) {
880 		memcpy(loaded_table, rproc->cached_table, tablesz);
881 		rproc->table_ptr = loaded_table;
882 	}
883 
884 	/* power up the remote processor */
885 	ret = rproc->ops->start(rproc);
886 	if (ret) {
887 		dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret);
888 		return ret;
889 	}
890 
891 	/* probe any subdevices for the remote processor */
892 	ret = rproc_probe_subdevices(rproc);
893 	if (ret) {
894 		dev_err(dev, "failed to probe subdevices for %s: %d\n",
895 			rproc->name, ret);
896 		rproc->ops->stop(rproc);
897 		return ret;
898 	}
899 
900 	rproc->state = RPROC_RUNNING;
901 
902 	dev_info(dev, "remote processor %s is now up\n", rproc->name);
903 
904 	return 0;
905 }
906 
907 /*
908  * take a firmware and boot a remote processor with it.
909  */
910 static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
911 {
912 	struct device *dev = &rproc->dev;
913 	const char *name = rproc->firmware;
914 	struct resource_table *table;
915 	int ret, tablesz;
916 
917 	ret = rproc_fw_sanity_check(rproc, fw);
918 	if (ret)
919 		return ret;
920 
921 	dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
922 
923 	/*
924 	 * if enabling an IOMMU isn't relevant for this rproc, this is
925 	 * just a nop
926 	 */
927 	ret = rproc_enable_iommu(rproc);
928 	if (ret) {
929 		dev_err(dev, "can't enable iommu: %d\n", ret);
930 		return ret;
931 	}
932 
933 	rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
934 	ret = -EINVAL;
935 
936 	/* look for the resource table */
937 	table = rproc_find_rsc_table(rproc, fw, &tablesz);
938 	if (!table) {
939 		dev_err(dev, "Failed to find resource table\n");
940 		goto clean_up;
941 	}
942 
943 	/*
944 	 * Create a copy of the resource table. When a virtio device starts
945 	 * and calls vring_new_virtqueue() the address of the allocated vring
946 	 * will be stored in the cached_table. Before the device is started,
947 	 * cached_table will be copied into device memory.
948 	 */
949 	rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
950 	if (!rproc->cached_table)
951 		goto clean_up;
952 
953 	rproc->table_ptr = rproc->cached_table;
954 
955 	/* reset max_notifyid */
956 	rproc->max_notifyid = -1;
957 
958 	/* handle fw resources which are required to boot rproc */
959 	ret = rproc_handle_resources(rproc, tablesz, rproc_loading_handlers);
960 	if (ret) {
961 		dev_err(dev, "Failed to process resources: %d\n", ret);
962 		goto clean_up_resources;
963 	}
964 
965 	ret = rproc_start(rproc, fw);
966 	if (ret)
967 		goto clean_up_resources;
968 
969 	return 0;
970 
971 clean_up_resources:
972 	rproc_resource_cleanup(rproc);
973 clean_up:
974 	kfree(rproc->cached_table);
975 	rproc->cached_table = NULL;
976 	rproc->table_ptr = NULL;
977 
978 	rproc_disable_iommu(rproc);
979 	return ret;
980 }
981 
982 /*
983  * take a firmware and boot it up.
984  *
985  * Note: this function is called asynchronously upon registration of the
986  * remote processor (so we must wait until it completes before we try
987  * to unregister the device. one other option is just to use kref here,
988  * that might be cleaner).
989  */
990 static void rproc_auto_boot_callback(const struct firmware *fw, void *context)
991 {
992 	struct rproc *rproc = context;
993 
994 	rproc_boot(rproc);
995 
996 	release_firmware(fw);
997 }
998 
999 static int rproc_trigger_auto_boot(struct rproc *rproc)
1000 {
1001 	int ret;
1002 
1003 	/*
1004 	 * We're initiating an asynchronous firmware loading, so we can
1005 	 * be built-in kernel code, without hanging the boot process.
1006 	 */
1007 	ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG,
1008 				      rproc->firmware, &rproc->dev, GFP_KERNEL,
1009 				      rproc, rproc_auto_boot_callback);
1010 	if (ret < 0)
1011 		dev_err(&rproc->dev, "request_firmware_nowait err: %d\n", ret);
1012 
1013 	return ret;
1014 }
1015 
1016 static int rproc_stop(struct rproc *rproc)
1017 {
1018 	struct device *dev = &rproc->dev;
1019 	int ret;
1020 
1021 	/* remove any subdevices for the remote processor */
1022 	rproc_remove_subdevices(rproc);
1023 
1024 	/* power off the remote processor */
1025 	ret = rproc->ops->stop(rproc);
1026 	if (ret) {
1027 		dev_err(dev, "can't stop rproc: %d\n", ret);
1028 		return ret;
1029 	}
1030 
1031 	/* if in crash state, unlock crash handler */
1032 	if (rproc->state == RPROC_CRASHED)
1033 		complete_all(&rproc->crash_comp);
1034 
1035 	rproc->state = RPROC_OFFLINE;
1036 
1037 	dev_info(dev, "stopped remote processor %s\n", rproc->name);
1038 
1039 	return 0;
1040 }
1041 
1042 /**
1043  * rproc_trigger_recovery() - recover a remoteproc
1044  * @rproc: the remote processor
1045  *
1046  * The recovery is done by resetting all the virtio devices, that way all the
1047  * rpmsg drivers will be reseted along with the remote processor making the
1048  * remoteproc functional again.
1049  *
1050  * This function can sleep, so it cannot be called from atomic context.
1051  */
1052 int rproc_trigger_recovery(struct rproc *rproc)
1053 {
1054 	const struct firmware *firmware_p;
1055 	struct device *dev = &rproc->dev;
1056 	int ret;
1057 
1058 	dev_err(dev, "recovering %s\n", rproc->name);
1059 
1060 	init_completion(&rproc->crash_comp);
1061 
1062 	ret = mutex_lock_interruptible(&rproc->lock);
1063 	if (ret)
1064 		return ret;
1065 
1066 	ret = rproc_stop(rproc);
1067 	if (ret)
1068 		goto unlock_mutex;
1069 
1070 	/* wait until there is no more rproc users */
1071 	wait_for_completion(&rproc->crash_comp);
1072 
1073 	/* load firmware */
1074 	ret = request_firmware(&firmware_p, rproc->firmware, dev);
1075 	if (ret < 0) {
1076 		dev_err(dev, "request_firmware failed: %d\n", ret);
1077 		goto unlock_mutex;
1078 	}
1079 
1080 	/* boot the remote processor up again */
1081 	ret = rproc_start(rproc, firmware_p);
1082 
1083 	release_firmware(firmware_p);
1084 
1085 unlock_mutex:
1086 	mutex_unlock(&rproc->lock);
1087 	return ret;
1088 }
1089 
1090 /**
1091  * rproc_crash_handler_work() - handle a crash
1092  *
1093  * This function needs to handle everything related to a crash, like cpu
1094  * registers and stack dump, information to help to debug the fatal error, etc.
1095  */
1096 static void rproc_crash_handler_work(struct work_struct *work)
1097 {
1098 	struct rproc *rproc = container_of(work, struct rproc, crash_handler);
1099 	struct device *dev = &rproc->dev;
1100 
1101 	dev_dbg(dev, "enter %s\n", __func__);
1102 
1103 	mutex_lock(&rproc->lock);
1104 
1105 	if (rproc->state == RPROC_CRASHED || rproc->state == RPROC_OFFLINE) {
1106 		/* handle only the first crash detected */
1107 		mutex_unlock(&rproc->lock);
1108 		return;
1109 	}
1110 
1111 	rproc->state = RPROC_CRASHED;
1112 	dev_err(dev, "handling crash #%u in %s\n", ++rproc->crash_cnt,
1113 		rproc->name);
1114 
1115 	mutex_unlock(&rproc->lock);
1116 
1117 	if (!rproc->recovery_disabled)
1118 		rproc_trigger_recovery(rproc);
1119 }
1120 
1121 /**
1122  * rproc_boot() - boot a remote processor
1123  * @rproc: handle of a remote processor
1124  *
1125  * Boot a remote processor (i.e. load its firmware, power it on, ...).
1126  *
1127  * If the remote processor is already powered on, this function immediately
1128  * returns (successfully).
1129  *
1130  * Returns 0 on success, and an appropriate error value otherwise.
1131  */
1132 int rproc_boot(struct rproc *rproc)
1133 {
1134 	const struct firmware *firmware_p;
1135 	struct device *dev;
1136 	int ret;
1137 
1138 	if (!rproc) {
1139 		pr_err("invalid rproc handle\n");
1140 		return -EINVAL;
1141 	}
1142 
1143 	dev = &rproc->dev;
1144 
1145 	ret = mutex_lock_interruptible(&rproc->lock);
1146 	if (ret) {
1147 		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
1148 		return ret;
1149 	}
1150 
1151 	if (rproc->state == RPROC_DELETED) {
1152 		ret = -ENODEV;
1153 		dev_err(dev, "can't boot deleted rproc %s\n", rproc->name);
1154 		goto unlock_mutex;
1155 	}
1156 
1157 	/* skip the boot process if rproc is already powered up */
1158 	if (atomic_inc_return(&rproc->power) > 1) {
1159 		ret = 0;
1160 		goto unlock_mutex;
1161 	}
1162 
1163 	dev_info(dev, "powering up %s\n", rproc->name);
1164 
1165 	/* load firmware */
1166 	ret = request_firmware(&firmware_p, rproc->firmware, dev);
1167 	if (ret < 0) {
1168 		dev_err(dev, "request_firmware failed: %d\n", ret);
1169 		goto downref_rproc;
1170 	}
1171 
1172 	ret = rproc_fw_boot(rproc, firmware_p);
1173 
1174 	release_firmware(firmware_p);
1175 
1176 downref_rproc:
1177 	if (ret)
1178 		atomic_dec(&rproc->power);
1179 unlock_mutex:
1180 	mutex_unlock(&rproc->lock);
1181 	return ret;
1182 }
1183 EXPORT_SYMBOL(rproc_boot);
1184 
1185 /**
1186  * rproc_shutdown() - power off the remote processor
1187  * @rproc: the remote processor
1188  *
1189  * Power off a remote processor (previously booted with rproc_boot()).
1190  *
1191  * In case @rproc is still being used by an additional user(s), then
1192  * this function will just decrement the power refcount and exit,
1193  * without really powering off the device.
1194  *
1195  * Every call to rproc_boot() must (eventually) be accompanied by a call
1196  * to rproc_shutdown(). Calling rproc_shutdown() redundantly is a bug.
1197  *
1198  * Notes:
1199  * - we're not decrementing the rproc's refcount, only the power refcount.
1200  *   which means that the @rproc handle stays valid even after rproc_shutdown()
1201  *   returns, and users can still use it with a subsequent rproc_boot(), if
1202  *   needed.
1203  */
1204 void rproc_shutdown(struct rproc *rproc)
1205 {
1206 	struct device *dev = &rproc->dev;
1207 	int ret;
1208 
1209 	ret = mutex_lock_interruptible(&rproc->lock);
1210 	if (ret) {
1211 		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
1212 		return;
1213 	}
1214 
1215 	/* if the remote proc is still needed, bail out */
1216 	if (!atomic_dec_and_test(&rproc->power))
1217 		goto out;
1218 
1219 	ret = rproc_stop(rproc);
1220 	if (ret) {
1221 		atomic_inc(&rproc->power);
1222 		goto out;
1223 	}
1224 
1225 	/* clean up all acquired resources */
1226 	rproc_resource_cleanup(rproc);
1227 
1228 	rproc_disable_iommu(rproc);
1229 
1230 	/* Free the copy of the resource table */
1231 	kfree(rproc->cached_table);
1232 	rproc->cached_table = NULL;
1233 	rproc->table_ptr = NULL;
1234 out:
1235 	mutex_unlock(&rproc->lock);
1236 }
1237 EXPORT_SYMBOL(rproc_shutdown);
1238 
1239 /**
1240  * rproc_get_by_phandle() - find a remote processor by phandle
1241  * @phandle: phandle to the rproc
1242  *
1243  * Finds an rproc handle using the remote processor's phandle, and then
1244  * return a handle to the rproc.
1245  *
1246  * This function increments the remote processor's refcount, so always
1247  * use rproc_put() to decrement it back once rproc isn't needed anymore.
1248  *
1249  * Returns the rproc handle on success, and NULL on failure.
1250  */
1251 #ifdef CONFIG_OF
1252 struct rproc *rproc_get_by_phandle(phandle phandle)
1253 {
1254 	struct rproc *rproc = NULL, *r;
1255 	struct device_node *np;
1256 
1257 	np = of_find_node_by_phandle(phandle);
1258 	if (!np)
1259 		return NULL;
1260 
1261 	mutex_lock(&rproc_list_mutex);
1262 	list_for_each_entry(r, &rproc_list, node) {
1263 		if (r->dev.parent && r->dev.parent->of_node == np) {
1264 			/* prevent underlying implementation from being removed */
1265 			if (!try_module_get(r->dev.parent->driver->owner)) {
1266 				dev_err(&r->dev, "can't get owner\n");
1267 				break;
1268 			}
1269 
1270 			rproc = r;
1271 			get_device(&rproc->dev);
1272 			break;
1273 		}
1274 	}
1275 	mutex_unlock(&rproc_list_mutex);
1276 
1277 	of_node_put(np);
1278 
1279 	return rproc;
1280 }
1281 #else
1282 struct rproc *rproc_get_by_phandle(phandle phandle)
1283 {
1284 	return NULL;
1285 }
1286 #endif
1287 EXPORT_SYMBOL(rproc_get_by_phandle);
1288 
1289 /**
1290  * rproc_add() - register a remote processor
1291  * @rproc: the remote processor handle to register
1292  *
1293  * Registers @rproc with the remoteproc framework, after it has been
1294  * allocated with rproc_alloc().
1295  *
1296  * This is called by the platform-specific rproc implementation, whenever
1297  * a new remote processor device is probed.
1298  *
1299  * Returns 0 on success and an appropriate error code otherwise.
1300  *
1301  * Note: this function initiates an asynchronous firmware loading
1302  * context, which will look for virtio devices supported by the rproc's
1303  * firmware.
1304  *
1305  * If found, those virtio devices will be created and added, so as a result
1306  * of registering this remote processor, additional virtio drivers might be
1307  * probed.
1308  */
1309 int rproc_add(struct rproc *rproc)
1310 {
1311 	struct device *dev = &rproc->dev;
1312 	int ret;
1313 
1314 	ret = device_add(dev);
1315 	if (ret < 0)
1316 		return ret;
1317 
1318 	dev_info(dev, "%s is available\n", rproc->name);
1319 
1320 	/* create debugfs entries */
1321 	rproc_create_debug_dir(rproc);
1322 
1323 	/* if rproc is marked always-on, request it to boot */
1324 	if (rproc->auto_boot) {
1325 		ret = rproc_trigger_auto_boot(rproc);
1326 		if (ret < 0)
1327 			return ret;
1328 	}
1329 
1330 	/* expose to rproc_get_by_phandle users */
1331 	mutex_lock(&rproc_list_mutex);
1332 	list_add(&rproc->node, &rproc_list);
1333 	mutex_unlock(&rproc_list_mutex);
1334 
1335 	return 0;
1336 }
1337 EXPORT_SYMBOL(rproc_add);
1338 
1339 /**
1340  * rproc_type_release() - release a remote processor instance
1341  * @dev: the rproc's device
1342  *
1343  * This function should _never_ be called directly.
1344  *
1345  * It will be called by the driver core when no one holds a valid pointer
1346  * to @dev anymore.
1347  */
1348 static void rproc_type_release(struct device *dev)
1349 {
1350 	struct rproc *rproc = container_of(dev, struct rproc, dev);
1351 
1352 	dev_info(&rproc->dev, "releasing %s\n", rproc->name);
1353 
1354 	idr_destroy(&rproc->notifyids);
1355 
1356 	if (rproc->index >= 0)
1357 		ida_simple_remove(&rproc_dev_index, rproc->index);
1358 
1359 	kfree(rproc->firmware);
1360 	kfree(rproc);
1361 }
1362 
1363 static const struct device_type rproc_type = {
1364 	.name		= "remoteproc",
1365 	.release	= rproc_type_release,
1366 };
1367 
1368 /**
1369  * rproc_alloc() - allocate a remote processor handle
1370  * @dev: the underlying device
1371  * @name: name of this remote processor
1372  * @ops: platform-specific handlers (mainly start/stop)
1373  * @firmware: name of firmware file to load, can be NULL
1374  * @len: length of private data needed by the rproc driver (in bytes)
1375  *
1376  * Allocates a new remote processor handle, but does not register
1377  * it yet. if @firmware is NULL, a default name is used.
1378  *
1379  * This function should be used by rproc implementations during initialization
1380  * of the remote processor.
1381  *
1382  * After creating an rproc handle using this function, and when ready,
1383  * implementations should then call rproc_add() to complete
1384  * the registration of the remote processor.
1385  *
1386  * On success the new rproc is returned, and on failure, NULL.
1387  *
1388  * Note: _never_ directly deallocate @rproc, even if it was not registered
1389  * yet. Instead, when you need to unroll rproc_alloc(), use rproc_free().
1390  */
1391 struct rproc *rproc_alloc(struct device *dev, const char *name,
1392 			  const struct rproc_ops *ops,
1393 			  const char *firmware, int len)
1394 {
1395 	struct rproc *rproc;
1396 	char *p, *template = "rproc-%s-fw";
1397 	int name_len;
1398 
1399 	if (!dev || !name || !ops)
1400 		return NULL;
1401 
1402 	if (!firmware) {
1403 		/*
1404 		 * If the caller didn't pass in a firmware name then
1405 		 * construct a default name.
1406 		 */
1407 		name_len = strlen(name) + strlen(template) - 2 + 1;
1408 		p = kmalloc(name_len, GFP_KERNEL);
1409 		if (!p)
1410 			return NULL;
1411 		snprintf(p, name_len, template, name);
1412 	} else {
1413 		p = kstrdup(firmware, GFP_KERNEL);
1414 		if (!p)
1415 			return NULL;
1416 	}
1417 
1418 	rproc = kzalloc(sizeof(struct rproc) + len, GFP_KERNEL);
1419 	if (!rproc) {
1420 		kfree(p);
1421 		return NULL;
1422 	}
1423 
1424 	rproc->firmware = p;
1425 	rproc->name = name;
1426 	rproc->ops = ops;
1427 	rproc->priv = &rproc[1];
1428 	rproc->auto_boot = true;
1429 
1430 	device_initialize(&rproc->dev);
1431 	rproc->dev.parent = dev;
1432 	rproc->dev.type = &rproc_type;
1433 	rproc->dev.class = &rproc_class;
1434 	rproc->dev.driver_data = rproc;
1435 
1436 	/* Assign a unique device index and name */
1437 	rproc->index = ida_simple_get(&rproc_dev_index, 0, 0, GFP_KERNEL);
1438 	if (rproc->index < 0) {
1439 		dev_err(dev, "ida_simple_get failed: %d\n", rproc->index);
1440 		put_device(&rproc->dev);
1441 		return NULL;
1442 	}
1443 
1444 	dev_set_name(&rproc->dev, "remoteproc%d", rproc->index);
1445 
1446 	atomic_set(&rproc->power, 0);
1447 
1448 	/* Set ELF as the default fw_ops handler */
1449 	rproc->fw_ops = &rproc_elf_fw_ops;
1450 
1451 	mutex_init(&rproc->lock);
1452 
1453 	idr_init(&rproc->notifyids);
1454 
1455 	INIT_LIST_HEAD(&rproc->carveouts);
1456 	INIT_LIST_HEAD(&rproc->mappings);
1457 	INIT_LIST_HEAD(&rproc->traces);
1458 	INIT_LIST_HEAD(&rproc->rvdevs);
1459 	INIT_LIST_HEAD(&rproc->subdevs);
1460 
1461 	INIT_WORK(&rproc->crash_handler, rproc_crash_handler_work);
1462 	init_completion(&rproc->crash_comp);
1463 
1464 	rproc->state = RPROC_OFFLINE;
1465 
1466 	return rproc;
1467 }
1468 EXPORT_SYMBOL(rproc_alloc);
1469 
1470 /**
1471  * rproc_free() - unroll rproc_alloc()
1472  * @rproc: the remote processor handle
1473  *
1474  * This function decrements the rproc dev refcount.
1475  *
1476  * If no one holds any reference to rproc anymore, then its refcount would
1477  * now drop to zero, and it would be freed.
1478  */
1479 void rproc_free(struct rproc *rproc)
1480 {
1481 	put_device(&rproc->dev);
1482 }
1483 EXPORT_SYMBOL(rproc_free);
1484 
1485 /**
1486  * rproc_put() - release rproc reference
1487  * @rproc: the remote processor handle
1488  *
1489  * This function decrements the rproc dev refcount.
1490  *
1491  * If no one holds any reference to rproc anymore, then its refcount would
1492  * now drop to zero, and it would be freed.
1493  */
1494 void rproc_put(struct rproc *rproc)
1495 {
1496 	module_put(rproc->dev.parent->driver->owner);
1497 	put_device(&rproc->dev);
1498 }
1499 EXPORT_SYMBOL(rproc_put);
1500 
1501 /**
1502  * rproc_del() - unregister a remote processor
1503  * @rproc: rproc handle to unregister
1504  *
1505  * This function should be called when the platform specific rproc
1506  * implementation decides to remove the rproc device. it should
1507  * _only_ be called if a previous invocation of rproc_add()
1508  * has completed successfully.
1509  *
1510  * After rproc_del() returns, @rproc isn't freed yet, because
1511  * of the outstanding reference created by rproc_alloc. To decrement that
1512  * one last refcount, one still needs to call rproc_free().
1513  *
1514  * Returns 0 on success and -EINVAL if @rproc isn't valid.
1515  */
1516 int rproc_del(struct rproc *rproc)
1517 {
1518 	if (!rproc)
1519 		return -EINVAL;
1520 
1521 	/* if rproc is marked always-on, rproc_add() booted it */
1522 	/* TODO: make sure this works with rproc->power > 1 */
1523 	if (rproc->auto_boot)
1524 		rproc_shutdown(rproc);
1525 
1526 	mutex_lock(&rproc->lock);
1527 	rproc->state = RPROC_DELETED;
1528 	mutex_unlock(&rproc->lock);
1529 
1530 	rproc_delete_debug_dir(rproc);
1531 
1532 	/* the rproc is downref'ed as soon as it's removed from the klist */
1533 	mutex_lock(&rproc_list_mutex);
1534 	list_del(&rproc->node);
1535 	mutex_unlock(&rproc_list_mutex);
1536 
1537 	device_del(&rproc->dev);
1538 
1539 	return 0;
1540 }
1541 EXPORT_SYMBOL(rproc_del);
1542 
1543 /**
1544  * rproc_add_subdev() - add a subdevice to a remoteproc
1545  * @rproc: rproc handle to add the subdevice to
1546  * @subdev: subdev handle to register
1547  * @probe: function to call when the rproc boots
1548  * @remove: function to call when the rproc shuts down
1549  */
1550 void rproc_add_subdev(struct rproc *rproc,
1551 		      struct rproc_subdev *subdev,
1552 		      int (*probe)(struct rproc_subdev *subdev),
1553 		      void (*remove)(struct rproc_subdev *subdev))
1554 {
1555 	subdev->probe = probe;
1556 	subdev->remove = remove;
1557 
1558 	list_add_tail(&subdev->node, &rproc->subdevs);
1559 }
1560 EXPORT_SYMBOL(rproc_add_subdev);
1561 
1562 /**
1563  * rproc_remove_subdev() - remove a subdevice from a remoteproc
1564  * @rproc: rproc handle to remove the subdevice from
1565  * @subdev: subdev handle, previously registered with rproc_add_subdev()
1566  */
1567 void rproc_remove_subdev(struct rproc *rproc, struct rproc_subdev *subdev)
1568 {
1569 	list_del(&subdev->node);
1570 }
1571 EXPORT_SYMBOL(rproc_remove_subdev);
1572 
1573 /**
1574  * rproc_get_by_child() - acquire rproc handle of @dev's ancestor
1575  * @dev:	child device to find ancestor of
1576  *
1577  * Returns the ancestor rproc instance, or NULL if not found.
1578  */
1579 struct rproc *rproc_get_by_child(struct device *dev)
1580 {
1581 	for (dev = dev->parent; dev; dev = dev->parent) {
1582 		if (dev->type == &rproc_type)
1583 			return dev->driver_data;
1584 	}
1585 
1586 	return NULL;
1587 }
1588 EXPORT_SYMBOL(rproc_get_by_child);
1589 
1590 /**
1591  * rproc_report_crash() - rproc crash reporter function
1592  * @rproc: remote processor
1593  * @type: crash type
1594  *
1595  * This function must be called every time a crash is detected by the low-level
1596  * drivers implementing a specific remoteproc. This should not be called from a
1597  * non-remoteproc driver.
1598  *
1599  * This function can be called from atomic/interrupt context.
1600  */
1601 void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type)
1602 {
1603 	if (!rproc) {
1604 		pr_err("NULL rproc pointer\n");
1605 		return;
1606 	}
1607 
1608 	dev_err(&rproc->dev, "crash detected in %s: type %s\n",
1609 		rproc->name, rproc_crash_to_string(type));
1610 
1611 	/* create a new task to handle the error */
1612 	schedule_work(&rproc->crash_handler);
1613 }
1614 EXPORT_SYMBOL(rproc_report_crash);
1615 
1616 static int __init remoteproc_init(void)
1617 {
1618 	rproc_init_sysfs();
1619 	rproc_init_debugfs();
1620 
1621 	return 0;
1622 }
1623 module_init(remoteproc_init);
1624 
1625 static void __exit remoteproc_exit(void)
1626 {
1627 	ida_destroy(&rproc_dev_index);
1628 
1629 	rproc_exit_debugfs();
1630 	rproc_exit_sysfs();
1631 }
1632 module_exit(remoteproc_exit);
1633 
1634 MODULE_LICENSE("GPL v2");
1635 MODULE_DESCRIPTION("Generic Remote Processor Framework");
1636