xref: /linux/drivers/firewire/core-cdev.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Char device for device raw access
4  *
5  * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
6  */
7 
8 #include <linux/bug.h>
9 #include <linux/compat.h>
10 #include <linux/delay.h>
11 #include <linux/device.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/err.h>
14 #include <linux/errno.h>
15 #include <linux/firewire.h>
16 #include <linux/firewire-cdev.h>
17 #include <linux/irqflags.h>
18 #include <linux/jiffies.h>
19 #include <linux/kernel.h>
20 #include <linux/kref.h>
21 #include <linux/mm.h>
22 #include <linux/module.h>
23 #include <linux/mutex.h>
24 #include <linux/poll.h>
25 #include <linux/sched.h> /* required for linux/wait.h */
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <linux/string.h>
29 #include <linux/time.h>
30 #include <linux/uaccess.h>
31 #include <linux/vmalloc.h>
32 #include <linux/wait.h>
33 #include <linux/workqueue.h>
34 
35 
36 #include "core.h"
37 #include <trace/events/firewire.h>
38 
39 #include "packet-header-definitions.h"
40 
41 /*
42  * ABI version history is documented in linux/firewire-cdev.h.
43  */
44 #define FW_CDEV_KERNEL_VERSION			5
45 #define FW_CDEV_VERSION_EVENT_REQUEST2		4
46 #define FW_CDEV_VERSION_ALLOCATE_REGION_END	4
47 #define FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW	5
48 #define FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP	6
49 
50 struct client {
51 	u32 version;
52 	struct fw_device *device;
53 
54 	spinlock_t lock;
55 	bool in_shutdown;
56 	struct xarray resource_xa;
57 	struct list_head event_list;
58 	wait_queue_head_t wait;
59 	wait_queue_head_t tx_flush_wait;
60 	u64 bus_reset_closure;
61 
62 	struct fw_iso_context *iso_context;
63 	u64 iso_closure;
64 	struct fw_iso_buffer buffer;
65 	unsigned long vm_start;
66 	bool buffer_is_mapped;
67 
68 	struct list_head phy_receiver_link;
69 	u64 phy_receiver_closure;
70 
71 	struct list_head link;
72 	struct kref kref;
73 };
74 
75 static inline void client_get(struct client *client)
76 {
77 	kref_get(&client->kref);
78 }
79 
80 static void client_release(struct kref *kref)
81 {
82 	struct client *client = container_of(kref, struct client, kref);
83 
84 	fw_device_put(client->device);
85 	kfree(client);
86 }
87 
88 static void client_put(struct client *client)
89 {
90 	kref_put(&client->kref, client_release);
91 }
92 
93 struct client_resource;
94 typedef void (*client_resource_release_fn_t)(struct client *,
95 					     struct client_resource *);
96 struct client_resource {
97 	client_resource_release_fn_t release;
98 	int handle;
99 };
100 
101 struct address_handler_resource {
102 	struct client_resource resource;
103 	struct fw_address_handler handler;
104 	__u64 closure;
105 	struct client *client;
106 };
107 
108 struct outbound_transaction_resource {
109 	struct client_resource resource;
110 	struct fw_transaction transaction;
111 };
112 
113 struct inbound_transaction_resource {
114 	struct client_resource resource;
115 	struct fw_card *card;
116 	struct fw_request *request;
117 	bool is_fcp;
118 	void *data;
119 	size_t length;
120 };
121 
122 struct descriptor_resource {
123 	struct client_resource resource;
124 	struct fw_descriptor descriptor;
125 	u32 data[];
126 };
127 
128 struct iso_resource {
129 	struct client_resource resource;
130 	struct client *client;
131 	/* Schedule work and access todo only with client->lock held. */
132 	struct delayed_work work;
133 	enum {ISO_RES_ALLOC, ISO_RES_REALLOC, ISO_RES_DEALLOC,
134 	      ISO_RES_ALLOC_ONCE, ISO_RES_DEALLOC_ONCE,} todo;
135 	int generation;
136 	u64 channels;
137 	s32 bandwidth;
138 	struct iso_resource_event *e_alloc, *e_dealloc;
139 };
140 
141 static struct address_handler_resource *to_address_handler_resource(struct client_resource *resource)
142 {
143 	return container_of(resource, struct address_handler_resource, resource);
144 }
145 
146 static struct inbound_transaction_resource *to_inbound_transaction_resource(struct client_resource *resource)
147 {
148 	return container_of(resource, struct inbound_transaction_resource, resource);
149 }
150 
151 static struct descriptor_resource *to_descriptor_resource(struct client_resource *resource)
152 {
153 	return container_of(resource, struct descriptor_resource, resource);
154 }
155 
156 static struct iso_resource *to_iso_resource(struct client_resource *resource)
157 {
158 	return container_of(resource, struct iso_resource, resource);
159 }
160 
161 static void release_iso_resource(struct client *, struct client_resource *);
162 
163 static int is_iso_resource(const struct client_resource *resource)
164 {
165 	return resource->release == release_iso_resource;
166 }
167 
168 static void release_transaction(struct client *client,
169 				struct client_resource *resource);
170 
171 static int is_outbound_transaction_resource(const struct client_resource *resource)
172 {
173 	return resource->release == release_transaction;
174 }
175 
176 static void schedule_iso_resource(struct iso_resource *r, unsigned long delay)
177 {
178 	client_get(r->client);
179 	if (!queue_delayed_work(fw_workqueue, &r->work, delay))
180 		client_put(r->client);
181 }
182 
183 /*
184  * dequeue_event() just kfree()'s the event, so the event has to be
185  * the first field in a struct XYZ_event.
186  */
187 struct event {
188 	struct { void *data; size_t size; } v[2];
189 	struct list_head link;
190 };
191 
192 struct bus_reset_event {
193 	struct event event;
194 	struct fw_cdev_event_bus_reset reset;
195 };
196 
197 struct outbound_transaction_event {
198 	struct event event;
199 	struct client *client;
200 	struct outbound_transaction_resource r;
201 	union {
202 		struct fw_cdev_event_response without_tstamp;
203 		struct fw_cdev_event_response2 with_tstamp;
204 	} rsp;
205 };
206 
207 struct inbound_transaction_event {
208 	struct event event;
209 	union {
210 		struct fw_cdev_event_request request;
211 		struct fw_cdev_event_request2 request2;
212 		struct fw_cdev_event_request3 with_tstamp;
213 	} req;
214 };
215 
216 struct iso_interrupt_event {
217 	struct event event;
218 	struct fw_cdev_event_iso_interrupt interrupt;
219 };
220 
221 struct iso_interrupt_mc_event {
222 	struct event event;
223 	struct fw_cdev_event_iso_interrupt_mc interrupt;
224 };
225 
226 struct iso_resource_event {
227 	struct event event;
228 	struct fw_cdev_event_iso_resource iso_resource;
229 };
230 
231 struct outbound_phy_packet_event {
232 	struct event event;
233 	struct client *client;
234 	struct fw_packet p;
235 	union {
236 		struct fw_cdev_event_phy_packet without_tstamp;
237 		struct fw_cdev_event_phy_packet2 with_tstamp;
238 	} phy_packet;
239 };
240 
241 struct inbound_phy_packet_event {
242 	struct event event;
243 	union {
244 		struct fw_cdev_event_phy_packet without_tstamp;
245 		struct fw_cdev_event_phy_packet2 with_tstamp;
246 	} phy_packet;
247 };
248 
249 #ifdef CONFIG_COMPAT
250 static void __user *u64_to_uptr(u64 value)
251 {
252 	if (in_compat_syscall())
253 		return compat_ptr(value);
254 	else
255 		return (void __user *)(unsigned long)value;
256 }
257 
258 static u64 uptr_to_u64(void __user *ptr)
259 {
260 	if (in_compat_syscall())
261 		return ptr_to_compat(ptr);
262 	else
263 		return (u64)(unsigned long)ptr;
264 }
265 #else
266 static inline void __user *u64_to_uptr(u64 value)
267 {
268 	return (void __user *)(unsigned long)value;
269 }
270 
271 static inline u64 uptr_to_u64(void __user *ptr)
272 {
273 	return (u64)(unsigned long)ptr;
274 }
275 #endif /* CONFIG_COMPAT */
276 
277 static int fw_device_op_open(struct inode *inode, struct file *file)
278 {
279 	struct fw_device *device;
280 	struct client *client;
281 
282 	device = fw_device_get_by_devt(inode->i_rdev);
283 	if (device == NULL)
284 		return -ENODEV;
285 
286 	if (fw_device_is_shutdown(device)) {
287 		fw_device_put(device);
288 		return -ENODEV;
289 	}
290 
291 	client = kzalloc(sizeof(*client), GFP_KERNEL);
292 	if (client == NULL) {
293 		fw_device_put(device);
294 		return -ENOMEM;
295 	}
296 
297 	client->device = device;
298 	spin_lock_init(&client->lock);
299 	xa_init_flags(&client->resource_xa, XA_FLAGS_ALLOC1 | XA_FLAGS_LOCK_BH);
300 	INIT_LIST_HEAD(&client->event_list);
301 	init_waitqueue_head(&client->wait);
302 	init_waitqueue_head(&client->tx_flush_wait);
303 	INIT_LIST_HEAD(&client->phy_receiver_link);
304 	INIT_LIST_HEAD(&client->link);
305 	kref_init(&client->kref);
306 
307 	file->private_data = client;
308 
309 	return nonseekable_open(inode, file);
310 }
311 
312 static void queue_event(struct client *client, struct event *event,
313 			void *data0, size_t size0, void *data1, size_t size1)
314 {
315 	event->v[0].data = data0;
316 	event->v[0].size = size0;
317 	event->v[1].data = data1;
318 	event->v[1].size = size1;
319 
320 	scoped_guard(spinlock_irqsave, &client->lock) {
321 		if (client->in_shutdown)
322 			kfree(event);
323 		else
324 			list_add_tail(&event->link, &client->event_list);
325 	}
326 
327 	wake_up_interruptible(&client->wait);
328 }
329 
330 static int dequeue_event(struct client *client,
331 			 char __user *buffer, size_t count)
332 {
333 	struct event *event;
334 	size_t size, total;
335 	int i, ret;
336 
337 	ret = wait_event_interruptible(client->wait,
338 			!list_empty(&client->event_list) ||
339 			fw_device_is_shutdown(client->device));
340 	if (ret < 0)
341 		return ret;
342 
343 	if (list_empty(&client->event_list) &&
344 		       fw_device_is_shutdown(client->device))
345 		return -ENODEV;
346 
347 	scoped_guard(spinlock_irq, &client->lock) {
348 		event = list_first_entry(&client->event_list, struct event, link);
349 		list_del(&event->link);
350 	}
351 
352 	total = 0;
353 	for (i = 0; i < ARRAY_SIZE(event->v) && total < count; i++) {
354 		size = min(event->v[i].size, count - total);
355 		if (copy_to_user(buffer + total, event->v[i].data, size)) {
356 			ret = -EFAULT;
357 			goto out;
358 		}
359 		total += size;
360 	}
361 	ret = total;
362 
363  out:
364 	kfree(event);
365 
366 	return ret;
367 }
368 
369 static ssize_t fw_device_op_read(struct file *file, char __user *buffer,
370 				 size_t count, loff_t *offset)
371 {
372 	struct client *client = file->private_data;
373 
374 	return dequeue_event(client, buffer, count);
375 }
376 
377 static void fill_bus_reset_event(struct fw_cdev_event_bus_reset *event,
378 				 struct client *client)
379 {
380 	struct fw_card *card = client->device->card;
381 
382 	guard(spinlock_irq)(&card->lock);
383 
384 	event->closure	     = client->bus_reset_closure;
385 	event->type          = FW_CDEV_EVENT_BUS_RESET;
386 	event->generation    = client->device->generation;
387 	event->node_id       = client->device->node_id;
388 	event->local_node_id = card->local_node->node_id;
389 	event->bm_node_id    = card->bm_node_id;
390 	event->irm_node_id   = card->irm_node->node_id;
391 	event->root_node_id  = card->root_node->node_id;
392 }
393 
394 static void for_each_client(struct fw_device *device,
395 			    void (*callback)(struct client *client))
396 {
397 	struct client *c;
398 
399 	guard(mutex)(&device->client_list_mutex);
400 
401 	list_for_each_entry(c, &device->client_list, link)
402 		callback(c);
403 }
404 
405 static void queue_bus_reset_event(struct client *client)
406 {
407 	struct bus_reset_event *e;
408 	struct client_resource *resource;
409 	unsigned long index;
410 
411 	e = kzalloc(sizeof(*e), GFP_KERNEL);
412 	if (e == NULL)
413 		return;
414 
415 	fill_bus_reset_event(&e->reset, client);
416 
417 	queue_event(client, &e->event,
418 		    &e->reset, sizeof(e->reset), NULL, 0);
419 
420 	guard(spinlock_irq)(&client->lock);
421 
422 	xa_for_each(&client->resource_xa, index, resource) {
423 		if (is_iso_resource(resource))
424 			schedule_iso_resource(to_iso_resource(resource), 0);
425 	}
426 }
427 
428 void fw_device_cdev_update(struct fw_device *device)
429 {
430 	for_each_client(device, queue_bus_reset_event);
431 }
432 
433 static void wake_up_client(struct client *client)
434 {
435 	wake_up_interruptible(&client->wait);
436 }
437 
438 void fw_device_cdev_remove(struct fw_device *device)
439 {
440 	for_each_client(device, wake_up_client);
441 }
442 
443 union ioctl_arg {
444 	struct fw_cdev_get_info			get_info;
445 	struct fw_cdev_send_request		send_request;
446 	struct fw_cdev_allocate			allocate;
447 	struct fw_cdev_deallocate		deallocate;
448 	struct fw_cdev_send_response		send_response;
449 	struct fw_cdev_initiate_bus_reset	initiate_bus_reset;
450 	struct fw_cdev_add_descriptor		add_descriptor;
451 	struct fw_cdev_remove_descriptor	remove_descriptor;
452 	struct fw_cdev_create_iso_context	create_iso_context;
453 	struct fw_cdev_queue_iso		queue_iso;
454 	struct fw_cdev_start_iso		start_iso;
455 	struct fw_cdev_stop_iso			stop_iso;
456 	struct fw_cdev_get_cycle_timer		get_cycle_timer;
457 	struct fw_cdev_allocate_iso_resource	allocate_iso_resource;
458 	struct fw_cdev_send_stream_packet	send_stream_packet;
459 	struct fw_cdev_get_cycle_timer2		get_cycle_timer2;
460 	struct fw_cdev_send_phy_packet		send_phy_packet;
461 	struct fw_cdev_receive_phy_packets	receive_phy_packets;
462 	struct fw_cdev_set_iso_channels		set_iso_channels;
463 	struct fw_cdev_flush_iso		flush_iso;
464 };
465 
466 static int ioctl_get_info(struct client *client, union ioctl_arg *arg)
467 {
468 	struct fw_cdev_get_info *a = &arg->get_info;
469 	struct fw_cdev_event_bus_reset bus_reset;
470 	unsigned long ret = 0;
471 
472 	client->version = a->version;
473 	a->version = FW_CDEV_KERNEL_VERSION;
474 	a->card = client->device->card->index;
475 
476 	scoped_guard(rwsem_read, &fw_device_rwsem) {
477 		if (a->rom != 0) {
478 			size_t want = a->rom_length;
479 			size_t have = client->device->config_rom_length * 4;
480 
481 			ret = copy_to_user(u64_to_uptr(a->rom), client->device->config_rom,
482 					   min(want, have));
483 			if (ret != 0)
484 				return -EFAULT;
485 		}
486 		a->rom_length = client->device->config_rom_length * 4;
487 	}
488 
489 	guard(mutex)(&client->device->client_list_mutex);
490 
491 	client->bus_reset_closure = a->bus_reset_closure;
492 	if (a->bus_reset != 0) {
493 		fill_bus_reset_event(&bus_reset, client);
494 		/* unaligned size of bus_reset is 36 bytes */
495 		ret = copy_to_user(u64_to_uptr(a->bus_reset), &bus_reset, 36);
496 	}
497 	if (ret == 0 && list_empty(&client->link))
498 		list_add_tail(&client->link, &client->device->client_list);
499 
500 	return ret ? -EFAULT : 0;
501 }
502 
503 static int add_client_resource(struct client *client, struct client_resource *resource,
504 			       gfp_t gfp_mask)
505 {
506 	int ret;
507 
508 	scoped_guard(spinlock_irqsave, &client->lock) {
509 		u32 index;
510 
511 		if (client->in_shutdown) {
512 			ret = -ECANCELED;
513 		} else {
514 			if (gfpflags_allow_blocking(gfp_mask)) {
515 				ret = xa_alloc(&client->resource_xa, &index, resource, xa_limit_32b,
516 					       GFP_NOWAIT);
517 			} else {
518 				ret = xa_alloc_bh(&client->resource_xa, &index, resource,
519 						  xa_limit_32b, GFP_NOWAIT);
520 			}
521 		}
522 		if (ret >= 0) {
523 			resource->handle = index;
524 			client_get(client);
525 			if (is_iso_resource(resource))
526 				schedule_iso_resource(to_iso_resource(resource), 0);
527 		}
528 	}
529 
530 	return ret < 0 ? ret : 0;
531 }
532 
533 static int release_client_resource(struct client *client, u32 handle,
534 				   client_resource_release_fn_t release,
535 				   struct client_resource **return_resource)
536 {
537 	unsigned long index = handle;
538 	struct client_resource *resource;
539 
540 	scoped_guard(spinlock_irq, &client->lock) {
541 		if (client->in_shutdown)
542 			return -EINVAL;
543 
544 		resource = xa_load(&client->resource_xa, index);
545 		if (!resource || resource->release != release)
546 			return -EINVAL;
547 
548 		xa_erase(&client->resource_xa, handle);
549 	}
550 
551 	if (return_resource)
552 		*return_resource = resource;
553 	else
554 		resource->release(client, resource);
555 
556 	client_put(client);
557 
558 	return 0;
559 }
560 
561 static void release_transaction(struct client *client,
562 				struct client_resource *resource)
563 {
564 }
565 
566 static void complete_transaction(struct fw_card *card, int rcode, u32 request_tstamp,
567 				 u32 response_tstamp, void *payload, size_t length, void *data)
568 {
569 	struct outbound_transaction_event *e = data;
570 	struct client *client = e->client;
571 	unsigned long index = e->r.resource.handle;
572 
573 	scoped_guard(spinlock_irqsave, &client->lock) {
574 		xa_erase(&client->resource_xa, index);
575 		if (client->in_shutdown)
576 			wake_up(&client->tx_flush_wait);
577 	}
578 
579 	switch (e->rsp.without_tstamp.type) {
580 	case FW_CDEV_EVENT_RESPONSE:
581 	{
582 		struct fw_cdev_event_response *rsp = &e->rsp.without_tstamp;
583 
584 		if (length < rsp->length)
585 			rsp->length = length;
586 		if (rcode == RCODE_COMPLETE)
587 			memcpy(rsp->data, payload, rsp->length);
588 
589 		rsp->rcode = rcode;
590 
591 		// In the case that sizeof(*rsp) doesn't align with the position of the
592 		// data, and the read is short, preserve an extra copy of the data
593 		// to stay compatible with a pre-2.6.27 bug.  Since the bug is harmless
594 		// for short reads and some apps depended on it, this is both safe
595 		// and prudent for compatibility.
596 		if (rsp->length <= sizeof(*rsp) - offsetof(typeof(*rsp), data))
597 			queue_event(client, &e->event, rsp, sizeof(*rsp), rsp->data, rsp->length);
598 		else
599 			queue_event(client, &e->event, rsp, sizeof(*rsp) + rsp->length, NULL, 0);
600 
601 		break;
602 	}
603 	case FW_CDEV_EVENT_RESPONSE2:
604 	{
605 		struct fw_cdev_event_response2 *rsp = &e->rsp.with_tstamp;
606 
607 		if (length < rsp->length)
608 			rsp->length = length;
609 		if (rcode == RCODE_COMPLETE)
610 			memcpy(rsp->data, payload, rsp->length);
611 
612 		rsp->rcode = rcode;
613 		rsp->request_tstamp = request_tstamp;
614 		rsp->response_tstamp = response_tstamp;
615 
616 		queue_event(client, &e->event, rsp, sizeof(*rsp) + rsp->length, NULL, 0);
617 
618 		break;
619 	}
620 	default:
621 		WARN_ON(1);
622 		break;
623 	}
624 
625 	// Drop the xarray's reference.
626 	client_put(client);
627 }
628 
629 static int init_request(struct client *client,
630 			struct fw_cdev_send_request *request,
631 			int destination_id, int speed)
632 {
633 	struct outbound_transaction_event *e;
634 	void *payload;
635 	int ret;
636 
637 	if (request->tcode != TCODE_STREAM_DATA &&
638 	    (request->length > 4096 || request->length > 512 << speed))
639 		return -EIO;
640 
641 	if (request->tcode == TCODE_WRITE_QUADLET_REQUEST &&
642 	    request->length < 4)
643 		return -EINVAL;
644 
645 	e = kmalloc(sizeof(*e) + request->length, GFP_KERNEL);
646 	if (e == NULL)
647 		return -ENOMEM;
648 	e->client = client;
649 
650 	if (client->version < FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP) {
651 		struct fw_cdev_event_response *rsp = &e->rsp.without_tstamp;
652 
653 		rsp->type = FW_CDEV_EVENT_RESPONSE;
654 		rsp->length = request->length;
655 		rsp->closure = request->closure;
656 		payload = rsp->data;
657 	} else {
658 		struct fw_cdev_event_response2 *rsp = &e->rsp.with_tstamp;
659 
660 		rsp->type = FW_CDEV_EVENT_RESPONSE2;
661 		rsp->length = request->length;
662 		rsp->closure = request->closure;
663 		payload = rsp->data;
664 	}
665 
666 	if (request->data && copy_from_user(payload, u64_to_uptr(request->data), request->length)) {
667 		ret = -EFAULT;
668 		goto failed;
669 	}
670 
671 	e->r.resource.release = release_transaction;
672 	ret = add_client_resource(client, &e->r.resource, GFP_KERNEL);
673 	if (ret < 0)
674 		goto failed;
675 
676 	fw_send_request_with_tstamp(client->device->card, &e->r.transaction, request->tcode,
677 				    destination_id, request->generation, speed, request->offset,
678 				    payload, request->length, complete_transaction, e);
679 	return 0;
680 
681  failed:
682 	kfree(e);
683 
684 	return ret;
685 }
686 
687 static int ioctl_send_request(struct client *client, union ioctl_arg *arg)
688 {
689 	switch (arg->send_request.tcode) {
690 	case TCODE_WRITE_QUADLET_REQUEST:
691 	case TCODE_WRITE_BLOCK_REQUEST:
692 	case TCODE_READ_QUADLET_REQUEST:
693 	case TCODE_READ_BLOCK_REQUEST:
694 	case TCODE_LOCK_MASK_SWAP:
695 	case TCODE_LOCK_COMPARE_SWAP:
696 	case TCODE_LOCK_FETCH_ADD:
697 	case TCODE_LOCK_LITTLE_ADD:
698 	case TCODE_LOCK_BOUNDED_ADD:
699 	case TCODE_LOCK_WRAP_ADD:
700 	case TCODE_LOCK_VENDOR_DEPENDENT:
701 		break;
702 	default:
703 		return -EINVAL;
704 	}
705 
706 	return init_request(client, &arg->send_request, client->device->node_id,
707 			    client->device->max_speed);
708 }
709 
710 static void release_request(struct client *client,
711 			    struct client_resource *resource)
712 {
713 	struct inbound_transaction_resource *r = to_inbound_transaction_resource(resource);
714 
715 	if (r->is_fcp)
716 		fw_request_put(r->request);
717 	else
718 		fw_send_response(r->card, r->request, RCODE_CONFLICT_ERROR);
719 
720 	fw_card_put(r->card);
721 	kfree(r);
722 }
723 
724 static void handle_request(struct fw_card *card, struct fw_request *request,
725 			   int tcode, int destination, int source,
726 			   int generation, unsigned long long offset,
727 			   void *payload, size_t length, void *callback_data)
728 {
729 	struct address_handler_resource *handler = callback_data;
730 	bool is_fcp = is_in_fcp_region(offset, length);
731 	struct inbound_transaction_resource *r;
732 	struct inbound_transaction_event *e;
733 	size_t event_size0;
734 	int ret;
735 
736 	/* card may be different from handler->client->device->card */
737 	fw_card_get(card);
738 
739 	// Extend the lifetime of data for request so that its payload is safely accessible in
740 	// the process context for the client.
741 	if (is_fcp)
742 		fw_request_get(request);
743 
744 	r = kmalloc(sizeof(*r), GFP_ATOMIC);
745 	e = kmalloc(sizeof(*e), GFP_ATOMIC);
746 	if (r == NULL || e == NULL)
747 		goto failed;
748 
749 	r->card    = card;
750 	r->request = request;
751 	r->is_fcp  = is_fcp;
752 	r->data    = payload;
753 	r->length  = length;
754 
755 	r->resource.release = release_request;
756 	ret = add_client_resource(handler->client, &r->resource, GFP_ATOMIC);
757 	if (ret < 0)
758 		goto failed;
759 
760 	if (handler->client->version < FW_CDEV_VERSION_EVENT_REQUEST2) {
761 		struct fw_cdev_event_request *req = &e->req.request;
762 
763 		if (tcode & 0x10)
764 			tcode = TCODE_LOCK_REQUEST;
765 
766 		req->type	= FW_CDEV_EVENT_REQUEST;
767 		req->tcode	= tcode;
768 		req->offset	= offset;
769 		req->length	= length;
770 		req->handle	= r->resource.handle;
771 		req->closure	= handler->closure;
772 		event_size0	= sizeof(*req);
773 	} else if (handler->client->version < FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP) {
774 		struct fw_cdev_event_request2 *req = &e->req.request2;
775 
776 		req->type	= FW_CDEV_EVENT_REQUEST2;
777 		req->tcode	= tcode;
778 		req->offset	= offset;
779 		req->source_node_id = source;
780 		req->destination_node_id = destination;
781 		req->card	= card->index;
782 		req->generation	= generation;
783 		req->length	= length;
784 		req->handle	= r->resource.handle;
785 		req->closure	= handler->closure;
786 		event_size0	= sizeof(*req);
787 	} else {
788 		struct fw_cdev_event_request3 *req = &e->req.with_tstamp;
789 
790 		req->type	= FW_CDEV_EVENT_REQUEST3;
791 		req->tcode	= tcode;
792 		req->offset	= offset;
793 		req->source_node_id = source;
794 		req->destination_node_id = destination;
795 		req->card	= card->index;
796 		req->generation	= generation;
797 		req->length	= length;
798 		req->handle	= r->resource.handle;
799 		req->closure	= handler->closure;
800 		req->tstamp	= fw_request_get_timestamp(request);
801 		event_size0	= sizeof(*req);
802 	}
803 
804 	queue_event(handler->client, &e->event,
805 		    &e->req, event_size0, r->data, length);
806 	return;
807 
808  failed:
809 	kfree(r);
810 	kfree(e);
811 
812 	if (!is_fcp)
813 		fw_send_response(card, request, RCODE_CONFLICT_ERROR);
814 	else
815 		fw_request_put(request);
816 
817 	fw_card_put(card);
818 }
819 
820 static void release_address_handler(struct client *client,
821 				    struct client_resource *resource)
822 {
823 	struct address_handler_resource *r = to_address_handler_resource(resource);
824 
825 	fw_core_remove_address_handler(&r->handler);
826 	kfree(r);
827 }
828 
829 static int ioctl_allocate(struct client *client, union ioctl_arg *arg)
830 {
831 	struct fw_cdev_allocate *a = &arg->allocate;
832 	struct address_handler_resource *r;
833 	struct fw_address_region region;
834 	int ret;
835 
836 	r = kmalloc(sizeof(*r), GFP_KERNEL);
837 	if (r == NULL)
838 		return -ENOMEM;
839 
840 	region.start = a->offset;
841 	if (client->version < FW_CDEV_VERSION_ALLOCATE_REGION_END)
842 		region.end = a->offset + a->length;
843 	else
844 		region.end = a->region_end;
845 
846 	r->handler.length           = a->length;
847 	r->handler.address_callback = handle_request;
848 	r->handler.callback_data    = r;
849 	r->closure   = a->closure;
850 	r->client    = client;
851 
852 	ret = fw_core_add_address_handler(&r->handler, &region);
853 	if (ret < 0) {
854 		kfree(r);
855 		return ret;
856 	}
857 	a->offset = r->handler.offset;
858 
859 	r->resource.release = release_address_handler;
860 	ret = add_client_resource(client, &r->resource, GFP_KERNEL);
861 	if (ret < 0) {
862 		release_address_handler(client, &r->resource);
863 		return ret;
864 	}
865 	a->handle = r->resource.handle;
866 
867 	return 0;
868 }
869 
870 static int ioctl_deallocate(struct client *client, union ioctl_arg *arg)
871 {
872 	return release_client_resource(client, arg->deallocate.handle,
873 				       release_address_handler, NULL);
874 }
875 
876 static int ioctl_send_response(struct client *client, union ioctl_arg *arg)
877 {
878 	struct fw_cdev_send_response *a = &arg->send_response;
879 	struct client_resource *resource;
880 	struct inbound_transaction_resource *r;
881 	int ret = 0;
882 
883 	if (release_client_resource(client, a->handle,
884 				    release_request, &resource) < 0)
885 		return -EINVAL;
886 
887 	r = to_inbound_transaction_resource(resource);
888 	if (r->is_fcp) {
889 		fw_request_put(r->request);
890 		goto out;
891 	}
892 
893 	if (a->length != fw_get_response_length(r->request)) {
894 		ret = -EINVAL;
895 		fw_request_put(r->request);
896 		goto out;
897 	}
898 	if (copy_from_user(r->data, u64_to_uptr(a->data), a->length)) {
899 		ret = -EFAULT;
900 		fw_request_put(r->request);
901 		goto out;
902 	}
903 	fw_send_response(r->card, r->request, a->rcode);
904  out:
905 	fw_card_put(r->card);
906 	kfree(r);
907 
908 	return ret;
909 }
910 
911 static int ioctl_initiate_bus_reset(struct client *client, union ioctl_arg *arg)
912 {
913 	fw_schedule_bus_reset(client->device->card, true,
914 			arg->initiate_bus_reset.type == FW_CDEV_SHORT_RESET);
915 	return 0;
916 }
917 
918 static void release_descriptor(struct client *client,
919 			       struct client_resource *resource)
920 {
921 	struct descriptor_resource *r = to_descriptor_resource(resource);
922 
923 	fw_core_remove_descriptor(&r->descriptor);
924 	kfree(r);
925 }
926 
927 static int ioctl_add_descriptor(struct client *client, union ioctl_arg *arg)
928 {
929 	struct fw_cdev_add_descriptor *a = &arg->add_descriptor;
930 	struct descriptor_resource *r;
931 	int ret;
932 
933 	/* Access policy: Allow this ioctl only on local nodes' device files. */
934 	if (!client->device->is_local)
935 		return -ENOSYS;
936 
937 	if (a->length > 256)
938 		return -EINVAL;
939 
940 	r = kmalloc(sizeof(*r) + a->length * 4, GFP_KERNEL);
941 	if (r == NULL)
942 		return -ENOMEM;
943 
944 	if (copy_from_user(r->data, u64_to_uptr(a->data), a->length * 4)) {
945 		ret = -EFAULT;
946 		goto failed;
947 	}
948 
949 	r->descriptor.length    = a->length;
950 	r->descriptor.immediate = a->immediate;
951 	r->descriptor.key       = a->key;
952 	r->descriptor.data      = r->data;
953 
954 	ret = fw_core_add_descriptor(&r->descriptor);
955 	if (ret < 0)
956 		goto failed;
957 
958 	r->resource.release = release_descriptor;
959 	ret = add_client_resource(client, &r->resource, GFP_KERNEL);
960 	if (ret < 0) {
961 		fw_core_remove_descriptor(&r->descriptor);
962 		goto failed;
963 	}
964 	a->handle = r->resource.handle;
965 
966 	return 0;
967  failed:
968 	kfree(r);
969 
970 	return ret;
971 }
972 
973 static int ioctl_remove_descriptor(struct client *client, union ioctl_arg *arg)
974 {
975 	return release_client_resource(client, arg->remove_descriptor.handle,
976 				       release_descriptor, NULL);
977 }
978 
979 static void iso_callback(struct fw_iso_context *context, u32 cycle,
980 			 size_t header_length, void *header, void *data)
981 {
982 	struct client *client = data;
983 	struct iso_interrupt_event *e;
984 
985 	e = kmalloc(sizeof(*e) + header_length, GFP_KERNEL);
986 	if (e == NULL)
987 		return;
988 
989 	e->interrupt.type      = FW_CDEV_EVENT_ISO_INTERRUPT;
990 	e->interrupt.closure   = client->iso_closure;
991 	e->interrupt.cycle     = cycle;
992 	e->interrupt.header_length = header_length;
993 	memcpy(e->interrupt.header, header, header_length);
994 	queue_event(client, &e->event, &e->interrupt,
995 		    sizeof(e->interrupt) + header_length, NULL, 0);
996 }
997 
998 static void iso_mc_callback(struct fw_iso_context *context,
999 			    dma_addr_t completed, void *data)
1000 {
1001 	struct client *client = data;
1002 	struct iso_interrupt_mc_event *e;
1003 
1004 	e = kmalloc(sizeof(*e), GFP_KERNEL);
1005 	if (e == NULL)
1006 		return;
1007 
1008 	e->interrupt.type      = FW_CDEV_EVENT_ISO_INTERRUPT_MULTICHANNEL;
1009 	e->interrupt.closure   = client->iso_closure;
1010 	e->interrupt.completed = fw_iso_buffer_lookup(&client->buffer,
1011 						      completed);
1012 	queue_event(client, &e->event, &e->interrupt,
1013 		    sizeof(e->interrupt), NULL, 0);
1014 }
1015 
1016 static enum dma_data_direction iso_dma_direction(struct fw_iso_context *context)
1017 {
1018 		if (context->type == FW_ISO_CONTEXT_TRANSMIT)
1019 			return DMA_TO_DEVICE;
1020 		else
1021 			return DMA_FROM_DEVICE;
1022 }
1023 
1024 static struct fw_iso_context *fw_iso_mc_context_create(struct fw_card *card,
1025 						fw_iso_mc_callback_t callback,
1026 						void *callback_data)
1027 {
1028 	struct fw_iso_context *ctx;
1029 
1030 	ctx = fw_iso_context_create(card, FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL,
1031 				    0, 0, 0, NULL, callback_data);
1032 	if (!IS_ERR(ctx))
1033 		ctx->callback.mc = callback;
1034 
1035 	return ctx;
1036 }
1037 
1038 static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
1039 {
1040 	struct fw_cdev_create_iso_context *a = &arg->create_iso_context;
1041 	struct fw_iso_context *context;
1042 	union fw_iso_callback cb;
1043 	int ret;
1044 
1045 	BUILD_BUG_ON(FW_CDEV_ISO_CONTEXT_TRANSMIT != FW_ISO_CONTEXT_TRANSMIT ||
1046 		     FW_CDEV_ISO_CONTEXT_RECEIVE  != FW_ISO_CONTEXT_RECEIVE  ||
1047 		     FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL !=
1048 					FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL);
1049 
1050 	switch (a->type) {
1051 	case FW_ISO_CONTEXT_TRANSMIT:
1052 		if (a->speed > SCODE_3200 || a->channel > 63)
1053 			return -EINVAL;
1054 
1055 		cb.sc = iso_callback;
1056 		break;
1057 
1058 	case FW_ISO_CONTEXT_RECEIVE:
1059 		if (a->header_size < 4 || (a->header_size & 3) ||
1060 		    a->channel > 63)
1061 			return -EINVAL;
1062 
1063 		cb.sc = iso_callback;
1064 		break;
1065 
1066 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
1067 		cb.mc = iso_mc_callback;
1068 		break;
1069 
1070 	default:
1071 		return -EINVAL;
1072 	}
1073 
1074 	if (a->type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL)
1075 		context = fw_iso_mc_context_create(client->device->card, cb.mc,
1076 						   client);
1077 	else
1078 		context = fw_iso_context_create(client->device->card, a->type,
1079 						a->channel, a->speed,
1080 						a->header_size, cb.sc, client);
1081 	if (IS_ERR(context))
1082 		return PTR_ERR(context);
1083 	if (client->version < FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW)
1084 		context->drop_overflow_headers = true;
1085 
1086 	// We only support one context at this time.
1087 	guard(spinlock_irq)(&client->lock);
1088 
1089 	if (client->iso_context != NULL) {
1090 		fw_iso_context_destroy(context);
1091 
1092 		return -EBUSY;
1093 	}
1094 	if (!client->buffer_is_mapped) {
1095 		ret = fw_iso_buffer_map_dma(&client->buffer,
1096 					    client->device->card,
1097 					    iso_dma_direction(context));
1098 		if (ret < 0) {
1099 			fw_iso_context_destroy(context);
1100 
1101 			return ret;
1102 		}
1103 		client->buffer_is_mapped = true;
1104 	}
1105 	client->iso_closure = a->closure;
1106 	client->iso_context = context;
1107 
1108 	a->handle = 0;
1109 
1110 	return 0;
1111 }
1112 
1113 static int ioctl_set_iso_channels(struct client *client, union ioctl_arg *arg)
1114 {
1115 	struct fw_cdev_set_iso_channels *a = &arg->set_iso_channels;
1116 	struct fw_iso_context *ctx = client->iso_context;
1117 
1118 	if (ctx == NULL || a->handle != 0)
1119 		return -EINVAL;
1120 
1121 	return fw_iso_context_set_channels(ctx, &a->channels);
1122 }
1123 
1124 /* Macros for decoding the iso packet control header. */
1125 #define GET_PAYLOAD_LENGTH(v)	((v) & 0xffff)
1126 #define GET_INTERRUPT(v)	(((v) >> 16) & 0x01)
1127 #define GET_SKIP(v)		(((v) >> 17) & 0x01)
1128 #define GET_TAG(v)		(((v) >> 18) & 0x03)
1129 #define GET_SY(v)		(((v) >> 20) & 0x0f)
1130 #define GET_HEADER_LENGTH(v)	(((v) >> 24) & 0xff)
1131 
1132 static int ioctl_queue_iso(struct client *client, union ioctl_arg *arg)
1133 {
1134 	struct fw_cdev_queue_iso *a = &arg->queue_iso;
1135 	struct fw_cdev_iso_packet __user *p, *end, *next;
1136 	struct fw_iso_context *ctx = client->iso_context;
1137 	unsigned long payload, buffer_end, transmit_header_bytes = 0;
1138 	u32 control;
1139 	int count;
1140 	struct {
1141 		struct fw_iso_packet packet;
1142 		u8 header[256];
1143 	} u;
1144 
1145 	if (ctx == NULL || a->handle != 0)
1146 		return -EINVAL;
1147 
1148 	/*
1149 	 * If the user passes a non-NULL data pointer, has mmap()'ed
1150 	 * the iso buffer, and the pointer points inside the buffer,
1151 	 * we setup the payload pointers accordingly.  Otherwise we
1152 	 * set them both to 0, which will still let packets with
1153 	 * payload_length == 0 through.  In other words, if no packets
1154 	 * use the indirect payload, the iso buffer need not be mapped
1155 	 * and the a->data pointer is ignored.
1156 	 */
1157 	payload = (unsigned long)a->data - client->vm_start;
1158 	buffer_end = client->buffer.page_count << PAGE_SHIFT;
1159 	if (a->data == 0 || client->buffer.pages == NULL ||
1160 	    payload >= buffer_end) {
1161 		payload = 0;
1162 		buffer_end = 0;
1163 	}
1164 
1165 	if (ctx->type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL && payload & 3)
1166 		return -EINVAL;
1167 
1168 	p = (struct fw_cdev_iso_packet __user *)u64_to_uptr(a->packets);
1169 
1170 	end = (void __user *)p + a->size;
1171 	count = 0;
1172 	while (p < end) {
1173 		if (get_user(control, &p->control))
1174 			return -EFAULT;
1175 		u.packet.payload_length = GET_PAYLOAD_LENGTH(control);
1176 		u.packet.interrupt = GET_INTERRUPT(control);
1177 		u.packet.skip = GET_SKIP(control);
1178 		u.packet.tag = GET_TAG(control);
1179 		u.packet.sy = GET_SY(control);
1180 		u.packet.header_length = GET_HEADER_LENGTH(control);
1181 
1182 		switch (ctx->type) {
1183 		case FW_ISO_CONTEXT_TRANSMIT:
1184 			if (u.packet.header_length & 3)
1185 				return -EINVAL;
1186 			transmit_header_bytes = u.packet.header_length;
1187 			break;
1188 
1189 		case FW_ISO_CONTEXT_RECEIVE:
1190 			if (u.packet.header_length == 0 ||
1191 			    u.packet.header_length % ctx->header_size != 0)
1192 				return -EINVAL;
1193 			break;
1194 
1195 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
1196 			if (u.packet.payload_length == 0 ||
1197 			    u.packet.payload_length & 3)
1198 				return -EINVAL;
1199 			break;
1200 		}
1201 
1202 		next = (struct fw_cdev_iso_packet __user *)
1203 			&p->header[transmit_header_bytes / 4];
1204 		if (next > end)
1205 			return -EINVAL;
1206 		if (copy_from_user
1207 		    (u.packet.header, p->header, transmit_header_bytes))
1208 			return -EFAULT;
1209 		if (u.packet.skip && ctx->type == FW_ISO_CONTEXT_TRANSMIT &&
1210 		    u.packet.header_length + u.packet.payload_length > 0)
1211 			return -EINVAL;
1212 		if (payload + u.packet.payload_length > buffer_end)
1213 			return -EINVAL;
1214 
1215 		if (fw_iso_context_queue(ctx, &u.packet,
1216 					 &client->buffer, payload))
1217 			break;
1218 
1219 		p = next;
1220 		payload += u.packet.payload_length;
1221 		count++;
1222 	}
1223 	fw_iso_context_queue_flush(ctx);
1224 
1225 	a->size    -= uptr_to_u64(p) - a->packets;
1226 	a->packets  = uptr_to_u64(p);
1227 	a->data     = client->vm_start + payload;
1228 
1229 	return count;
1230 }
1231 
1232 static int ioctl_start_iso(struct client *client, union ioctl_arg *arg)
1233 {
1234 	struct fw_cdev_start_iso *a = &arg->start_iso;
1235 
1236 	BUILD_BUG_ON(
1237 	    FW_CDEV_ISO_CONTEXT_MATCH_TAG0 != FW_ISO_CONTEXT_MATCH_TAG0 ||
1238 	    FW_CDEV_ISO_CONTEXT_MATCH_TAG1 != FW_ISO_CONTEXT_MATCH_TAG1 ||
1239 	    FW_CDEV_ISO_CONTEXT_MATCH_TAG2 != FW_ISO_CONTEXT_MATCH_TAG2 ||
1240 	    FW_CDEV_ISO_CONTEXT_MATCH_TAG3 != FW_ISO_CONTEXT_MATCH_TAG3 ||
1241 	    FW_CDEV_ISO_CONTEXT_MATCH_ALL_TAGS != FW_ISO_CONTEXT_MATCH_ALL_TAGS);
1242 
1243 	if (client->iso_context == NULL || a->handle != 0)
1244 		return -EINVAL;
1245 
1246 	if (client->iso_context->type == FW_ISO_CONTEXT_RECEIVE &&
1247 	    (a->tags == 0 || a->tags > 15 || a->sync > 15))
1248 		return -EINVAL;
1249 
1250 	return fw_iso_context_start(client->iso_context,
1251 				    a->cycle, a->sync, a->tags);
1252 }
1253 
1254 static int ioctl_stop_iso(struct client *client, union ioctl_arg *arg)
1255 {
1256 	struct fw_cdev_stop_iso *a = &arg->stop_iso;
1257 
1258 	if (client->iso_context == NULL || a->handle != 0)
1259 		return -EINVAL;
1260 
1261 	return fw_iso_context_stop(client->iso_context);
1262 }
1263 
1264 static int ioctl_flush_iso(struct client *client, union ioctl_arg *arg)
1265 {
1266 	struct fw_cdev_flush_iso *a = &arg->flush_iso;
1267 
1268 	if (client->iso_context == NULL || a->handle != 0)
1269 		return -EINVAL;
1270 
1271 	return fw_iso_context_flush_completions(client->iso_context);
1272 }
1273 
1274 static int ioctl_get_cycle_timer2(struct client *client, union ioctl_arg *arg)
1275 {
1276 	struct fw_cdev_get_cycle_timer2 *a = &arg->get_cycle_timer2;
1277 	struct fw_card *card = client->device->card;
1278 	struct timespec64 ts = {0, 0};
1279 	u32 cycle_time = 0;
1280 	int ret;
1281 
1282 	guard(irq)();
1283 
1284 	ret = fw_card_read_cycle_time(card, &cycle_time);
1285 	if (ret < 0)
1286 		return ret;
1287 
1288 	switch (a->clk_id) {
1289 	case CLOCK_REALTIME:      ktime_get_real_ts64(&ts);	break;
1290 	case CLOCK_MONOTONIC:     ktime_get_ts64(&ts);		break;
1291 	case CLOCK_MONOTONIC_RAW: ktime_get_raw_ts64(&ts);	break;
1292 	default:
1293 		return -EINVAL;
1294 	}
1295 
1296 	a->tv_sec      = ts.tv_sec;
1297 	a->tv_nsec     = ts.tv_nsec;
1298 	a->cycle_timer = cycle_time;
1299 
1300 	return 0;
1301 }
1302 
1303 static int ioctl_get_cycle_timer(struct client *client, union ioctl_arg *arg)
1304 {
1305 	struct fw_cdev_get_cycle_timer *a = &arg->get_cycle_timer;
1306 	struct fw_cdev_get_cycle_timer2 ct2;
1307 
1308 	ct2.clk_id = CLOCK_REALTIME;
1309 	ioctl_get_cycle_timer2(client, (union ioctl_arg *)&ct2);
1310 
1311 	a->local_time = ct2.tv_sec * USEC_PER_SEC + ct2.tv_nsec / NSEC_PER_USEC;
1312 	a->cycle_timer = ct2.cycle_timer;
1313 
1314 	return 0;
1315 }
1316 
1317 static void iso_resource_work(struct work_struct *work)
1318 {
1319 	struct iso_resource_event *e;
1320 	struct iso_resource *r =
1321 			container_of(work, struct iso_resource, work.work);
1322 	struct client *client = r->client;
1323 	unsigned long index = r->resource.handle;
1324 	int generation, channel, bandwidth, todo;
1325 	bool skip, free, success;
1326 
1327 	scoped_guard(spinlock_irq, &client->lock) {
1328 		generation = client->device->generation;
1329 		todo = r->todo;
1330 		// Allow 1000ms grace period for other reallocations.
1331 		if (todo == ISO_RES_ALLOC &&
1332 		    time_before64(get_jiffies_64(), client->device->card->reset_jiffies + HZ)) {
1333 			schedule_iso_resource(r, DIV_ROUND_UP(HZ, 3));
1334 			skip = true;
1335 		} else {
1336 			// We could be called twice within the same generation.
1337 			skip = todo == ISO_RES_REALLOC &&
1338 			       r->generation == generation;
1339 		}
1340 		free = todo == ISO_RES_DEALLOC ||
1341 		       todo == ISO_RES_ALLOC_ONCE ||
1342 		       todo == ISO_RES_DEALLOC_ONCE;
1343 		r->generation = generation;
1344 	}
1345 
1346 	if (skip)
1347 		goto out;
1348 
1349 	bandwidth = r->bandwidth;
1350 
1351 	fw_iso_resource_manage(client->device->card, generation,
1352 			r->channels, &channel, &bandwidth,
1353 			todo == ISO_RES_ALLOC ||
1354 			todo == ISO_RES_REALLOC ||
1355 			todo == ISO_RES_ALLOC_ONCE);
1356 	/*
1357 	 * Is this generation outdated already?  As long as this resource sticks
1358 	 * in the xarray, it will be scheduled again for a newer generation or at
1359 	 * shutdown.
1360 	 */
1361 	if (channel == -EAGAIN &&
1362 	    (todo == ISO_RES_ALLOC || todo == ISO_RES_REALLOC))
1363 		goto out;
1364 
1365 	success = channel >= 0 || bandwidth > 0;
1366 
1367 	scoped_guard(spinlock_irq, &client->lock) {
1368 		// Transit from allocation to reallocation, except if the client
1369 		// requested deallocation in the meantime.
1370 		if (r->todo == ISO_RES_ALLOC)
1371 			r->todo = ISO_RES_REALLOC;
1372 		// Allocation or reallocation failure?  Pull this resource out of the
1373 		// xarray and prepare for deletion, unless the client is shutting down.
1374 		if (r->todo == ISO_RES_REALLOC && !success &&
1375 		    !client->in_shutdown &&
1376 		    xa_erase(&client->resource_xa, index)) {
1377 			client_put(client);
1378 			free = true;
1379 		}
1380 	}
1381 
1382 	if (todo == ISO_RES_ALLOC && channel >= 0)
1383 		r->channels = 1ULL << channel;
1384 
1385 	if (todo == ISO_RES_REALLOC && success)
1386 		goto out;
1387 
1388 	if (todo == ISO_RES_ALLOC || todo == ISO_RES_ALLOC_ONCE) {
1389 		e = r->e_alloc;
1390 		r->e_alloc = NULL;
1391 	} else {
1392 		e = r->e_dealloc;
1393 		r->e_dealloc = NULL;
1394 	}
1395 	e->iso_resource.handle    = r->resource.handle;
1396 	e->iso_resource.channel   = channel;
1397 	e->iso_resource.bandwidth = bandwidth;
1398 
1399 	queue_event(client, &e->event,
1400 		    &e->iso_resource, sizeof(e->iso_resource), NULL, 0);
1401 
1402 	if (free) {
1403 		cancel_delayed_work(&r->work);
1404 		kfree(r->e_alloc);
1405 		kfree(r->e_dealloc);
1406 		kfree(r);
1407 	}
1408  out:
1409 	client_put(client);
1410 }
1411 
1412 static void release_iso_resource(struct client *client,
1413 				 struct client_resource *resource)
1414 {
1415 	struct iso_resource *r = to_iso_resource(resource);
1416 
1417 	guard(spinlock_irq)(&client->lock);
1418 
1419 	r->todo = ISO_RES_DEALLOC;
1420 	schedule_iso_resource(r, 0);
1421 }
1422 
1423 static int init_iso_resource(struct client *client,
1424 		struct fw_cdev_allocate_iso_resource *request, int todo)
1425 {
1426 	struct iso_resource_event *e1, *e2;
1427 	struct iso_resource *r;
1428 	int ret;
1429 
1430 	if ((request->channels == 0 && request->bandwidth == 0) ||
1431 	    request->bandwidth > BANDWIDTH_AVAILABLE_INITIAL)
1432 		return -EINVAL;
1433 
1434 	r  = kmalloc(sizeof(*r), GFP_KERNEL);
1435 	e1 = kmalloc(sizeof(*e1), GFP_KERNEL);
1436 	e2 = kmalloc(sizeof(*e2), GFP_KERNEL);
1437 	if (r == NULL || e1 == NULL || e2 == NULL) {
1438 		ret = -ENOMEM;
1439 		goto fail;
1440 	}
1441 
1442 	INIT_DELAYED_WORK(&r->work, iso_resource_work);
1443 	r->client	= client;
1444 	r->todo		= todo;
1445 	r->generation	= -1;
1446 	r->channels	= request->channels;
1447 	r->bandwidth	= request->bandwidth;
1448 	r->e_alloc	= e1;
1449 	r->e_dealloc	= e2;
1450 
1451 	e1->iso_resource.closure = request->closure;
1452 	e1->iso_resource.type    = FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED;
1453 	e2->iso_resource.closure = request->closure;
1454 	e2->iso_resource.type    = FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED;
1455 
1456 	if (todo == ISO_RES_ALLOC) {
1457 		r->resource.release = release_iso_resource;
1458 		ret = add_client_resource(client, &r->resource, GFP_KERNEL);
1459 		if (ret < 0)
1460 			goto fail;
1461 	} else {
1462 		r->resource.release = NULL;
1463 		r->resource.handle = -1;
1464 		schedule_iso_resource(r, 0);
1465 	}
1466 	request->handle = r->resource.handle;
1467 
1468 	return 0;
1469  fail:
1470 	kfree(r);
1471 	kfree(e1);
1472 	kfree(e2);
1473 
1474 	return ret;
1475 }
1476 
1477 static int ioctl_allocate_iso_resource(struct client *client,
1478 				       union ioctl_arg *arg)
1479 {
1480 	return init_iso_resource(client,
1481 			&arg->allocate_iso_resource, ISO_RES_ALLOC);
1482 }
1483 
1484 static int ioctl_deallocate_iso_resource(struct client *client,
1485 					 union ioctl_arg *arg)
1486 {
1487 	return release_client_resource(client,
1488 			arg->deallocate.handle, release_iso_resource, NULL);
1489 }
1490 
1491 static int ioctl_allocate_iso_resource_once(struct client *client,
1492 					    union ioctl_arg *arg)
1493 {
1494 	return init_iso_resource(client,
1495 			&arg->allocate_iso_resource, ISO_RES_ALLOC_ONCE);
1496 }
1497 
1498 static int ioctl_deallocate_iso_resource_once(struct client *client,
1499 					      union ioctl_arg *arg)
1500 {
1501 	return init_iso_resource(client,
1502 			&arg->allocate_iso_resource, ISO_RES_DEALLOC_ONCE);
1503 }
1504 
1505 /*
1506  * Returns a speed code:  Maximum speed to or from this device,
1507  * limited by the device's link speed, the local node's link speed,
1508  * and all PHY port speeds between the two links.
1509  */
1510 static int ioctl_get_speed(struct client *client, union ioctl_arg *arg)
1511 {
1512 	return client->device->max_speed;
1513 }
1514 
1515 static int ioctl_send_broadcast_request(struct client *client,
1516 					union ioctl_arg *arg)
1517 {
1518 	struct fw_cdev_send_request *a = &arg->send_request;
1519 
1520 	switch (a->tcode) {
1521 	case TCODE_WRITE_QUADLET_REQUEST:
1522 	case TCODE_WRITE_BLOCK_REQUEST:
1523 		break;
1524 	default:
1525 		return -EINVAL;
1526 	}
1527 
1528 	/* Security policy: Only allow accesses to Units Space. */
1529 	if (a->offset < CSR_REGISTER_BASE + CSR_CONFIG_ROM_END)
1530 		return -EACCES;
1531 
1532 	return init_request(client, a, LOCAL_BUS | 0x3f, SCODE_100);
1533 }
1534 
1535 static int ioctl_send_stream_packet(struct client *client, union ioctl_arg *arg)
1536 {
1537 	struct fw_cdev_send_stream_packet *a = &arg->send_stream_packet;
1538 	struct fw_cdev_send_request request;
1539 	int dest;
1540 
1541 	if (a->speed > client->device->card->link_speed ||
1542 	    a->length > 1024 << a->speed)
1543 		return -EIO;
1544 
1545 	if (a->tag > 3 || a->channel > 63 || a->sy > 15)
1546 		return -EINVAL;
1547 
1548 	dest = fw_stream_packet_destination_id(a->tag, a->channel, a->sy);
1549 	request.tcode		= TCODE_STREAM_DATA;
1550 	request.length		= a->length;
1551 	request.closure		= a->closure;
1552 	request.data		= a->data;
1553 	request.generation	= a->generation;
1554 
1555 	return init_request(client, &request, dest, a->speed);
1556 }
1557 
1558 static void outbound_phy_packet_callback(struct fw_packet *packet,
1559 					 struct fw_card *card, int status)
1560 {
1561 	struct outbound_phy_packet_event *e =
1562 		container_of(packet, struct outbound_phy_packet_event, p);
1563 	struct client *e_client = e->client;
1564 	u32 rcode;
1565 
1566 	trace_async_phy_outbound_complete((uintptr_t)packet, card->index, status, packet->generation,
1567 					  packet->timestamp);
1568 
1569 	switch (status) {
1570 	// expected:
1571 	case ACK_COMPLETE:
1572 		rcode = RCODE_COMPLETE;
1573 		break;
1574 	// should never happen with PHY packets:
1575 	case ACK_PENDING:
1576 		rcode = RCODE_COMPLETE;
1577 		break;
1578 	case ACK_BUSY_X:
1579 	case ACK_BUSY_A:
1580 	case ACK_BUSY_B:
1581 		rcode = RCODE_BUSY;
1582 		break;
1583 	case ACK_DATA_ERROR:
1584 		rcode = RCODE_DATA_ERROR;
1585 		break;
1586 	case ACK_TYPE_ERROR:
1587 		rcode = RCODE_TYPE_ERROR;
1588 		break;
1589 	// stale generation; cancelled; on certain controllers: no ack
1590 	default:
1591 		rcode = status;
1592 		break;
1593 	}
1594 
1595 	switch (e->phy_packet.without_tstamp.type) {
1596 	case FW_CDEV_EVENT_PHY_PACKET_SENT:
1597 	{
1598 		struct fw_cdev_event_phy_packet *pp = &e->phy_packet.without_tstamp;
1599 
1600 		pp->rcode = rcode;
1601 		pp->data[0] = packet->timestamp;
1602 		queue_event(e->client, &e->event, &e->phy_packet, sizeof(*pp) + pp->length,
1603 			    NULL, 0);
1604 		break;
1605 	}
1606 	case FW_CDEV_EVENT_PHY_PACKET_SENT2:
1607 	{
1608 		struct fw_cdev_event_phy_packet2 *pp = &e->phy_packet.with_tstamp;
1609 
1610 		pp->rcode = rcode;
1611 		pp->tstamp = packet->timestamp;
1612 		queue_event(e->client, &e->event, &e->phy_packet, sizeof(*pp) + pp->length,
1613 			    NULL, 0);
1614 		break;
1615 	}
1616 	default:
1617 		WARN_ON(1);
1618 		break;
1619 	}
1620 
1621 	client_put(e_client);
1622 }
1623 
1624 static int ioctl_send_phy_packet(struct client *client, union ioctl_arg *arg)
1625 {
1626 	struct fw_cdev_send_phy_packet *a = &arg->send_phy_packet;
1627 	struct fw_card *card = client->device->card;
1628 	struct outbound_phy_packet_event *e;
1629 
1630 	/* Access policy: Allow this ioctl only on local nodes' device files. */
1631 	if (!client->device->is_local)
1632 		return -ENOSYS;
1633 
1634 	e = kzalloc(sizeof(*e) + sizeof(a->data), GFP_KERNEL);
1635 	if (e == NULL)
1636 		return -ENOMEM;
1637 
1638 	client_get(client);
1639 	e->client		= client;
1640 	e->p.speed		= SCODE_100;
1641 	e->p.generation		= a->generation;
1642 	async_header_set_tcode(e->p.header, TCODE_LINK_INTERNAL);
1643 	e->p.header[1]		= a->data[0];
1644 	e->p.header[2]		= a->data[1];
1645 	e->p.header_length	= 12;
1646 	e->p.callback		= outbound_phy_packet_callback;
1647 
1648 	if (client->version < FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP) {
1649 		struct fw_cdev_event_phy_packet *pp = &e->phy_packet.without_tstamp;
1650 
1651 		pp->closure = a->closure;
1652 		pp->type = FW_CDEV_EVENT_PHY_PACKET_SENT;
1653 		if (is_ping_packet(a->data))
1654 			pp->length = 4;
1655 	} else {
1656 		struct fw_cdev_event_phy_packet2 *pp = &e->phy_packet.with_tstamp;
1657 
1658 		pp->closure = a->closure;
1659 		pp->type = FW_CDEV_EVENT_PHY_PACKET_SENT2;
1660 		// Keep the data field so that application can match the response event to the
1661 		// request.
1662 		pp->length = sizeof(a->data);
1663 		memcpy(pp->data, a->data, sizeof(a->data));
1664 	}
1665 
1666 	trace_async_phy_outbound_initiate((uintptr_t)&e->p, card->index, e->p.generation,
1667 					  e->p.header[1], e->p.header[2]);
1668 
1669 	card->driver->send_request(card, &e->p);
1670 
1671 	return 0;
1672 }
1673 
1674 static int ioctl_receive_phy_packets(struct client *client, union ioctl_arg *arg)
1675 {
1676 	struct fw_cdev_receive_phy_packets *a = &arg->receive_phy_packets;
1677 	struct fw_card *card = client->device->card;
1678 
1679 	/* Access policy: Allow this ioctl only on local nodes' device files. */
1680 	if (!client->device->is_local)
1681 		return -ENOSYS;
1682 
1683 	guard(spinlock_irq)(&card->lock);
1684 
1685 	list_move_tail(&client->phy_receiver_link, &card->phy_receiver_list);
1686 	client->phy_receiver_closure = a->closure;
1687 
1688 	return 0;
1689 }
1690 
1691 void fw_cdev_handle_phy_packet(struct fw_card *card, struct fw_packet *p)
1692 {
1693 	struct client *client;
1694 
1695 	guard(spinlock_irqsave)(&card->lock);
1696 
1697 	list_for_each_entry(client, &card->phy_receiver_list, phy_receiver_link) {
1698 		struct inbound_phy_packet_event *e = kmalloc(sizeof(*e) + 8, GFP_ATOMIC);
1699 		if (e == NULL)
1700 			break;
1701 
1702 		if (client->version < FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP) {
1703 			struct fw_cdev_event_phy_packet *pp = &e->phy_packet.without_tstamp;
1704 
1705 			pp->closure = client->phy_receiver_closure;
1706 			pp->type = FW_CDEV_EVENT_PHY_PACKET_RECEIVED;
1707 			pp->rcode = RCODE_COMPLETE;
1708 			pp->length = 8;
1709 			pp->data[0] = p->header[1];
1710 			pp->data[1] = p->header[2];
1711 			queue_event(client, &e->event, &e->phy_packet, sizeof(*pp) + 8, NULL, 0);
1712 		} else {
1713 			struct fw_cdev_event_phy_packet2 *pp = &e->phy_packet.with_tstamp;
1714 
1715 			pp = &e->phy_packet.with_tstamp;
1716 			pp->closure = client->phy_receiver_closure;
1717 			pp->type = FW_CDEV_EVENT_PHY_PACKET_RECEIVED2;
1718 			pp->rcode = RCODE_COMPLETE;
1719 			pp->length = 8;
1720 			pp->tstamp = p->timestamp;
1721 			pp->data[0] = p->header[1];
1722 			pp->data[1] = p->header[2];
1723 			queue_event(client, &e->event, &e->phy_packet, sizeof(*pp) + 8, NULL, 0);
1724 		}
1725 	}
1726 }
1727 
1728 static int (* const ioctl_handlers[])(struct client *, union ioctl_arg *) = {
1729 	[0x00] = ioctl_get_info,
1730 	[0x01] = ioctl_send_request,
1731 	[0x02] = ioctl_allocate,
1732 	[0x03] = ioctl_deallocate,
1733 	[0x04] = ioctl_send_response,
1734 	[0x05] = ioctl_initiate_bus_reset,
1735 	[0x06] = ioctl_add_descriptor,
1736 	[0x07] = ioctl_remove_descriptor,
1737 	[0x08] = ioctl_create_iso_context,
1738 	[0x09] = ioctl_queue_iso,
1739 	[0x0a] = ioctl_start_iso,
1740 	[0x0b] = ioctl_stop_iso,
1741 	[0x0c] = ioctl_get_cycle_timer,
1742 	[0x0d] = ioctl_allocate_iso_resource,
1743 	[0x0e] = ioctl_deallocate_iso_resource,
1744 	[0x0f] = ioctl_allocate_iso_resource_once,
1745 	[0x10] = ioctl_deallocate_iso_resource_once,
1746 	[0x11] = ioctl_get_speed,
1747 	[0x12] = ioctl_send_broadcast_request,
1748 	[0x13] = ioctl_send_stream_packet,
1749 	[0x14] = ioctl_get_cycle_timer2,
1750 	[0x15] = ioctl_send_phy_packet,
1751 	[0x16] = ioctl_receive_phy_packets,
1752 	[0x17] = ioctl_set_iso_channels,
1753 	[0x18] = ioctl_flush_iso,
1754 };
1755 
1756 static int dispatch_ioctl(struct client *client,
1757 			  unsigned int cmd, void __user *arg)
1758 {
1759 	union ioctl_arg buffer;
1760 	int ret;
1761 
1762 	if (fw_device_is_shutdown(client->device))
1763 		return -ENODEV;
1764 
1765 	if (_IOC_TYPE(cmd) != '#' ||
1766 	    _IOC_NR(cmd) >= ARRAY_SIZE(ioctl_handlers) ||
1767 	    _IOC_SIZE(cmd) > sizeof(buffer))
1768 		return -ENOTTY;
1769 
1770 	memset(&buffer, 0, sizeof(buffer));
1771 
1772 	if (_IOC_DIR(cmd) & _IOC_WRITE)
1773 		if (copy_from_user(&buffer, arg, _IOC_SIZE(cmd)))
1774 			return -EFAULT;
1775 
1776 	ret = ioctl_handlers[_IOC_NR(cmd)](client, &buffer);
1777 	if (ret < 0)
1778 		return ret;
1779 
1780 	if (_IOC_DIR(cmd) & _IOC_READ)
1781 		if (copy_to_user(arg, &buffer, _IOC_SIZE(cmd)))
1782 			return -EFAULT;
1783 
1784 	return ret;
1785 }
1786 
1787 static long fw_device_op_ioctl(struct file *file,
1788 			       unsigned int cmd, unsigned long arg)
1789 {
1790 	return dispatch_ioctl(file->private_data, cmd, (void __user *)arg);
1791 }
1792 
1793 static int fw_device_op_mmap(struct file *file, struct vm_area_struct *vma)
1794 {
1795 	struct client *client = file->private_data;
1796 	unsigned long size;
1797 	int page_count, ret;
1798 
1799 	if (fw_device_is_shutdown(client->device))
1800 		return -ENODEV;
1801 
1802 	/* FIXME: We could support multiple buffers, but we don't. */
1803 	if (client->buffer.pages != NULL)
1804 		return -EBUSY;
1805 
1806 	if (!(vma->vm_flags & VM_SHARED))
1807 		return -EINVAL;
1808 
1809 	if (vma->vm_start & ~PAGE_MASK)
1810 		return -EINVAL;
1811 
1812 	client->vm_start = vma->vm_start;
1813 	size = vma->vm_end - vma->vm_start;
1814 	page_count = size >> PAGE_SHIFT;
1815 	if (size & ~PAGE_MASK)
1816 		return -EINVAL;
1817 
1818 	ret = fw_iso_buffer_alloc(&client->buffer, page_count);
1819 	if (ret < 0)
1820 		return ret;
1821 
1822 	scoped_guard(spinlock_irq, &client->lock) {
1823 		if (client->iso_context) {
1824 			ret = fw_iso_buffer_map_dma(&client->buffer, client->device->card,
1825 						    iso_dma_direction(client->iso_context));
1826 			if (ret < 0)
1827 				goto fail;
1828 			client->buffer_is_mapped = true;
1829 		}
1830 	}
1831 
1832 	ret = vm_map_pages_zero(vma, client->buffer.pages,
1833 				client->buffer.page_count);
1834 	if (ret < 0)
1835 		goto fail;
1836 
1837 	return 0;
1838  fail:
1839 	fw_iso_buffer_destroy(&client->buffer, client->device->card);
1840 	return ret;
1841 }
1842 
1843 static bool has_outbound_transactions(struct client *client)
1844 {
1845 	struct client_resource *resource;
1846 	unsigned long index;
1847 
1848 	guard(spinlock_irq)(&client->lock);
1849 
1850 	xa_for_each(&client->resource_xa, index, resource) {
1851 		if (is_outbound_transaction_resource(resource))
1852 			return true;
1853 	}
1854 
1855 	return false;
1856 }
1857 
1858 static int fw_device_op_release(struct inode *inode, struct file *file)
1859 {
1860 	struct client *client = file->private_data;
1861 	struct event *event, *next_event;
1862 	struct client_resource *resource;
1863 	unsigned long index;
1864 
1865 	scoped_guard(spinlock_irq, &client->device->card->lock)
1866 		list_del(&client->phy_receiver_link);
1867 
1868 	scoped_guard(mutex, &client->device->client_list_mutex)
1869 		list_del(&client->link);
1870 
1871 	if (client->iso_context)
1872 		fw_iso_context_destroy(client->iso_context);
1873 
1874 	if (client->buffer.pages)
1875 		fw_iso_buffer_destroy(&client->buffer, client->device->card);
1876 
1877 	// Freeze client->resource_xa and client->event_list.
1878 	scoped_guard(spinlock_irq, &client->lock)
1879 		client->in_shutdown = true;
1880 
1881 	wait_event(client->tx_flush_wait, !has_outbound_transactions(client));
1882 
1883 	xa_for_each(&client->resource_xa, index, resource) {
1884 		resource->release(client, resource);
1885 		client_put(client);
1886 	}
1887 	xa_destroy(&client->resource_xa);
1888 
1889 	list_for_each_entry_safe(event, next_event, &client->event_list, link)
1890 		kfree(event);
1891 
1892 	client_put(client);
1893 
1894 	return 0;
1895 }
1896 
1897 static __poll_t fw_device_op_poll(struct file *file, poll_table * pt)
1898 {
1899 	struct client *client = file->private_data;
1900 	__poll_t mask = 0;
1901 
1902 	poll_wait(file, &client->wait, pt);
1903 
1904 	if (fw_device_is_shutdown(client->device))
1905 		mask |= EPOLLHUP | EPOLLERR;
1906 	if (!list_empty(&client->event_list))
1907 		mask |= EPOLLIN | EPOLLRDNORM;
1908 
1909 	return mask;
1910 }
1911 
1912 const struct file_operations fw_device_ops = {
1913 	.owner		= THIS_MODULE,
1914 	.open		= fw_device_op_open,
1915 	.read		= fw_device_op_read,
1916 	.unlocked_ioctl	= fw_device_op_ioctl,
1917 	.mmap		= fw_device_op_mmap,
1918 	.release	= fw_device_op_release,
1919 	.poll		= fw_device_op_poll,
1920 	.compat_ioctl	= compat_ptr_ioctl,
1921 };
1922