xref: /openbmc/linux/drivers/char/agp/frontend.c (revision 842ed298)
1 /*
2  * AGPGART driver frontend
3  * Copyright (C) 2004 Silicon Graphics, Inc.
4  * Copyright (C) 2002-2003 Dave Jones
5  * Copyright (C) 1999 Jeff Hartmann
6  * Copyright (C) 1999 Precision Insight, Inc.
7  * Copyright (C) 1999 Xi Graphics, Inc.
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a
10  * copy of this software and associated documentation files (the "Software"),
11  * to deal in the Software without restriction, including without limitation
12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13  * and/or sell copies of the Software, and to permit persons to whom the
14  * Software is furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included
17  * in all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
22  * JEFF HARTMANN, OR ANY OTHER CONTRIBUTORS BE LIABLE FOR ANY CLAIM,
23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
25  * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26  *
27  */
28 
29 #include <linux/types.h>
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/mman.h>
33 #include <linux/pci.h>
34 #include <linux/miscdevice.h>
35 #include <linux/agp_backend.h>
36 #include <linux/agpgart.h>
37 #include <linux/slab.h>
38 #include <linux/mm.h>
39 #include <linux/fs.h>
40 #include <linux/sched.h>
41 #include <linux/uaccess.h>
42 #include "agp.h"
43 
44 struct agp_front_data agp_fe;
45 
46 struct agp_memory *agp_find_mem_by_key(int key)
47 {
48 	struct agp_memory *curr;
49 
50 	if (agp_fe.current_controller == NULL)
51 		return NULL;
52 
53 	curr = agp_fe.current_controller->pool;
54 
55 	while (curr != NULL) {
56 		if (curr->key == key)
57 			break;
58 		curr = curr->next;
59 	}
60 
61 	DBG("key=%d -> mem=%p", key, curr);
62 	return curr;
63 }
64 
65 static void agp_remove_from_pool(struct agp_memory *temp)
66 {
67 	struct agp_memory *prev;
68 	struct agp_memory *next;
69 
70 	/* Check to see if this is even in the memory pool */
71 
72 	DBG("mem=%p", temp);
73 	if (agp_find_mem_by_key(temp->key) != NULL) {
74 		next = temp->next;
75 		prev = temp->prev;
76 
77 		if (prev != NULL) {
78 			prev->next = next;
79 			if (next != NULL)
80 				next->prev = prev;
81 
82 		} else {
83 			/* This is the first item on the list */
84 			if (next != NULL)
85 				next->prev = NULL;
86 
87 			agp_fe.current_controller->pool = next;
88 		}
89 	}
90 }
91 
92 /*
93  * Routines for managing each client's segment list -
94  * These routines handle adding and removing segments
95  * to each auth'ed client.
96  */
97 
98 static struct
99 agp_segment_priv *agp_find_seg_in_client(const struct agp_client *client,
100 						unsigned long offset,
101 					    int size, pgprot_t page_prot)
102 {
103 	struct agp_segment_priv *seg;
104 	int i;
105 	off_t pg_start;
106 	size_t pg_count;
107 
108 	pg_start = offset / 4096;
109 	pg_count = size / 4096;
110 	seg = *(client->segments);
111 
112 	for (i = 0; i < client->num_segments; i++) {
113 		if ((seg[i].pg_start == pg_start) &&
114 		    (seg[i].pg_count == pg_count) &&
115 		    (pgprot_val(seg[i].prot) == pgprot_val(page_prot))) {
116 			return seg + i;
117 		}
118 	}
119 
120 	return NULL;
121 }
122 
123 static void agp_remove_seg_from_client(struct agp_client *client)
124 {
125 	DBG("client=%p", client);
126 
127 	if (client->segments != NULL) {
128 		if (*(client->segments) != NULL) {
129 			DBG("Freeing %p from client %p", *(client->segments), client);
130 			kfree(*(client->segments));
131 		}
132 		DBG("Freeing %p from client %p", client->segments, client);
133 		kfree(client->segments);
134 		client->segments = NULL;
135 	}
136 }
137 
138 static void agp_add_seg_to_client(struct agp_client *client,
139 			       struct agp_segment_priv ** seg, int num_segments)
140 {
141 	struct agp_segment_priv **prev_seg;
142 
143 	prev_seg = client->segments;
144 
145 	if (prev_seg != NULL)
146 		agp_remove_seg_from_client(client);
147 
148 	DBG("Adding seg %p (%d segments) to client %p", seg, num_segments, client);
149 	client->num_segments = num_segments;
150 	client->segments = seg;
151 }
152 
153 static pgprot_t agp_convert_mmap_flags(int prot)
154 {
155 	unsigned long prot_bits;
156 
157 	prot_bits = calc_vm_prot_bits(prot, 0) | VM_SHARED;
158 	return vm_get_page_prot(prot_bits);
159 }
160 
161 int agp_create_segment(struct agp_client *client, struct agp_region *region)
162 {
163 	struct agp_segment_priv **ret_seg;
164 	struct agp_segment_priv *seg;
165 	struct agp_segment *user_seg;
166 	size_t i;
167 
168 	seg = kzalloc((sizeof(struct agp_segment_priv) * region->seg_count), GFP_KERNEL);
169 	if (seg == NULL) {
170 		kfree(region->seg_list);
171 		region->seg_list = NULL;
172 		return -ENOMEM;
173 	}
174 	user_seg = region->seg_list;
175 
176 	for (i = 0; i < region->seg_count; i++) {
177 		seg[i].pg_start = user_seg[i].pg_start;
178 		seg[i].pg_count = user_seg[i].pg_count;
179 		seg[i].prot = agp_convert_mmap_flags(user_seg[i].prot);
180 	}
181 	kfree(region->seg_list);
182 	region->seg_list = NULL;
183 
184 	ret_seg = kmalloc(sizeof(void *), GFP_KERNEL);
185 	if (ret_seg == NULL) {
186 		kfree(seg);
187 		return -ENOMEM;
188 	}
189 	*ret_seg = seg;
190 	agp_add_seg_to_client(client, ret_seg, region->seg_count);
191 	return 0;
192 }
193 
194 /* End - Routines for managing each client's segment list */
195 
196 /* This function must only be called when current_controller != NULL */
197 static void agp_insert_into_pool(struct agp_memory * temp)
198 {
199 	struct agp_memory *prev;
200 
201 	prev = agp_fe.current_controller->pool;
202 
203 	if (prev != NULL) {
204 		prev->prev = temp;
205 		temp->next = prev;
206 	}
207 	agp_fe.current_controller->pool = temp;
208 }
209 
210 
211 /* File private list routines */
212 
213 struct agp_file_private *agp_find_private(pid_t pid)
214 {
215 	struct agp_file_private *curr;
216 
217 	curr = agp_fe.file_priv_list;
218 
219 	while (curr != NULL) {
220 		if (curr->my_pid == pid)
221 			return curr;
222 		curr = curr->next;
223 	}
224 
225 	return NULL;
226 }
227 
228 static void agp_insert_file_private(struct agp_file_private * priv)
229 {
230 	struct agp_file_private *prev;
231 
232 	prev = agp_fe.file_priv_list;
233 
234 	if (prev != NULL)
235 		prev->prev = priv;
236 	priv->next = prev;
237 	agp_fe.file_priv_list = priv;
238 }
239 
240 static void agp_remove_file_private(struct agp_file_private * priv)
241 {
242 	struct agp_file_private *next;
243 	struct agp_file_private *prev;
244 
245 	next = priv->next;
246 	prev = priv->prev;
247 
248 	if (prev != NULL) {
249 		prev->next = next;
250 
251 		if (next != NULL)
252 			next->prev = prev;
253 
254 	} else {
255 		if (next != NULL)
256 			next->prev = NULL;
257 
258 		agp_fe.file_priv_list = next;
259 	}
260 }
261 
262 /* End - File flag list routines */
263 
264 /*
265  * Wrappers for agp_free_memory & agp_allocate_memory
266  * These make sure that internal lists are kept updated.
267  */
268 void agp_free_memory_wrap(struct agp_memory *memory)
269 {
270 	agp_remove_from_pool(memory);
271 	agp_free_memory(memory);
272 }
273 
274 struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
275 {
276 	struct agp_memory *memory;
277 
278 	memory = agp_allocate_memory(agp_bridge, pg_count, type);
279 	if (memory == NULL)
280 		return NULL;
281 
282 	agp_insert_into_pool(memory);
283 	return memory;
284 }
285 
286 /* Routines for managing the list of controllers -
287  * These routines manage the current controller, and the list of
288  * controllers
289  */
290 
291 static struct agp_controller *agp_find_controller_by_pid(pid_t id)
292 {
293 	struct agp_controller *controller;
294 
295 	controller = agp_fe.controllers;
296 
297 	while (controller != NULL) {
298 		if (controller->pid == id)
299 			return controller;
300 		controller = controller->next;
301 	}
302 
303 	return NULL;
304 }
305 
306 static struct agp_controller *agp_create_controller(pid_t id)
307 {
308 	struct agp_controller *controller;
309 
310 	controller = kzalloc(sizeof(struct agp_controller), GFP_KERNEL);
311 	if (controller == NULL)
312 		return NULL;
313 
314 	controller->pid = id;
315 	return controller;
316 }
317 
318 static int agp_insert_controller(struct agp_controller *controller)
319 {
320 	struct agp_controller *prev_controller;
321 
322 	prev_controller = agp_fe.controllers;
323 	controller->next = prev_controller;
324 
325 	if (prev_controller != NULL)
326 		prev_controller->prev = controller;
327 
328 	agp_fe.controllers = controller;
329 
330 	return 0;
331 }
332 
333 static void agp_remove_all_clients(struct agp_controller *controller)
334 {
335 	struct agp_client *client;
336 	struct agp_client *temp;
337 
338 	client = controller->clients;
339 
340 	while (client) {
341 		struct agp_file_private *priv;
342 
343 		temp = client;
344 		agp_remove_seg_from_client(temp);
345 		priv = agp_find_private(temp->pid);
346 
347 		if (priv != NULL) {
348 			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
349 			clear_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
350 		}
351 		client = client->next;
352 		kfree(temp);
353 	}
354 }
355 
356 static void agp_remove_all_memory(struct agp_controller *controller)
357 {
358 	struct agp_memory *memory;
359 	struct agp_memory *temp;
360 
361 	memory = controller->pool;
362 
363 	while (memory) {
364 		temp = memory;
365 		memory = memory->next;
366 		agp_free_memory_wrap(temp);
367 	}
368 }
369 
370 static int agp_remove_controller(struct agp_controller *controller)
371 {
372 	struct agp_controller *prev_controller;
373 	struct agp_controller *next_controller;
374 
375 	prev_controller = controller->prev;
376 	next_controller = controller->next;
377 
378 	if (prev_controller != NULL) {
379 		prev_controller->next = next_controller;
380 		if (next_controller != NULL)
381 			next_controller->prev = prev_controller;
382 
383 	} else {
384 		if (next_controller != NULL)
385 			next_controller->prev = NULL;
386 
387 		agp_fe.controllers = next_controller;
388 	}
389 
390 	agp_remove_all_memory(controller);
391 	agp_remove_all_clients(controller);
392 
393 	if (agp_fe.current_controller == controller) {
394 		agp_fe.current_controller = NULL;
395 		agp_fe.backend_acquired = false;
396 		agp_backend_release(agp_bridge);
397 	}
398 	kfree(controller);
399 	return 0;
400 }
401 
402 static void agp_controller_make_current(struct agp_controller *controller)
403 {
404 	struct agp_client *clients;
405 
406 	clients = controller->clients;
407 
408 	while (clients != NULL) {
409 		struct agp_file_private *priv;
410 
411 		priv = agp_find_private(clients->pid);
412 
413 		if (priv != NULL) {
414 			set_bit(AGP_FF_IS_VALID, &priv->access_flags);
415 			set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
416 		}
417 		clients = clients->next;
418 	}
419 
420 	agp_fe.current_controller = controller;
421 }
422 
423 static void agp_controller_release_current(struct agp_controller *controller,
424 				      struct agp_file_private *controller_priv)
425 {
426 	struct agp_client *clients;
427 
428 	clear_bit(AGP_FF_IS_VALID, &controller_priv->access_flags);
429 	clients = controller->clients;
430 
431 	while (clients != NULL) {
432 		struct agp_file_private *priv;
433 
434 		priv = agp_find_private(clients->pid);
435 
436 		if (priv != NULL)
437 			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
438 
439 		clients = clients->next;
440 	}
441 
442 	agp_fe.current_controller = NULL;
443 	agp_fe.used_by_controller = false;
444 	agp_backend_release(agp_bridge);
445 }
446 
447 /*
448  * Routines for managing client lists -
449  * These routines are for managing the list of auth'ed clients.
450  */
451 
452 static struct agp_client
453 *agp_find_client_in_controller(struct agp_controller *controller, pid_t id)
454 {
455 	struct agp_client *client;
456 
457 	if (controller == NULL)
458 		return NULL;
459 
460 	client = controller->clients;
461 
462 	while (client != NULL) {
463 		if (client->pid == id)
464 			return client;
465 		client = client->next;
466 	}
467 
468 	return NULL;
469 }
470 
471 static struct agp_controller *agp_find_controller_for_client(pid_t id)
472 {
473 	struct agp_controller *controller;
474 
475 	controller = agp_fe.controllers;
476 
477 	while (controller != NULL) {
478 		if ((agp_find_client_in_controller(controller, id)) != NULL)
479 			return controller;
480 		controller = controller->next;
481 	}
482 
483 	return NULL;
484 }
485 
486 struct agp_client *agp_find_client_by_pid(pid_t id)
487 {
488 	struct agp_client *temp;
489 
490 	if (agp_fe.current_controller == NULL)
491 		return NULL;
492 
493 	temp = agp_find_client_in_controller(agp_fe.current_controller, id);
494 	return temp;
495 }
496 
497 static void agp_insert_client(struct agp_client *client)
498 {
499 	struct agp_client *prev_client;
500 
501 	prev_client = agp_fe.current_controller->clients;
502 	client->next = prev_client;
503 
504 	if (prev_client != NULL)
505 		prev_client->prev = client;
506 
507 	agp_fe.current_controller->clients = client;
508 	agp_fe.current_controller->num_clients++;
509 }
510 
511 struct agp_client *agp_create_client(pid_t id)
512 {
513 	struct agp_client *new_client;
514 
515 	new_client = kzalloc(sizeof(struct agp_client), GFP_KERNEL);
516 	if (new_client == NULL)
517 		return NULL;
518 
519 	new_client->pid = id;
520 	agp_insert_client(new_client);
521 	return new_client;
522 }
523 
524 int agp_remove_client(pid_t id)
525 {
526 	struct agp_client *client;
527 	struct agp_client *prev_client;
528 	struct agp_client *next_client;
529 	struct agp_controller *controller;
530 
531 	controller = agp_find_controller_for_client(id);
532 	if (controller == NULL)
533 		return -EINVAL;
534 
535 	client = agp_find_client_in_controller(controller, id);
536 	if (client == NULL)
537 		return -EINVAL;
538 
539 	prev_client = client->prev;
540 	next_client = client->next;
541 
542 	if (prev_client != NULL) {
543 		prev_client->next = next_client;
544 		if (next_client != NULL)
545 			next_client->prev = prev_client;
546 
547 	} else {
548 		if (next_client != NULL)
549 			next_client->prev = NULL;
550 		controller->clients = next_client;
551 	}
552 
553 	controller->num_clients--;
554 	agp_remove_seg_from_client(client);
555 	kfree(client);
556 	return 0;
557 }
558 
559 /* End - Routines for managing client lists */
560 
561 /* File Operations */
562 
563 static int agp_mmap(struct file *file, struct vm_area_struct *vma)
564 {
565 	unsigned int size, current_size;
566 	unsigned long offset;
567 	struct agp_client *client;
568 	struct agp_file_private *priv = file->private_data;
569 	struct agp_kern_info kerninfo;
570 
571 	mutex_lock(&(agp_fe.agp_mutex));
572 
573 	if (agp_fe.backend_acquired != true)
574 		goto out_eperm;
575 
576 	if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
577 		goto out_eperm;
578 
579 	agp_copy_info(agp_bridge, &kerninfo);
580 	size = vma->vm_end - vma->vm_start;
581 	current_size = kerninfo.aper_size;
582 	current_size = current_size * 0x100000;
583 	offset = vma->vm_pgoff << PAGE_SHIFT;
584 	DBG("%lx:%lx", offset, offset+size);
585 
586 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
587 		if ((size + offset) > current_size)
588 			goto out_inval;
589 
590 		client = agp_find_client_by_pid(current->pid);
591 
592 		if (client == NULL)
593 			goto out_eperm;
594 
595 		if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
596 			goto out_inval;
597 
598 		DBG("client vm_ops=%p", kerninfo.vm_ops);
599 		if (kerninfo.vm_ops) {
600 			vma->vm_ops = kerninfo.vm_ops;
601 		} else if (io_remap_pfn_range(vma, vma->vm_start,
602 				(kerninfo.aper_base + offset) >> PAGE_SHIFT,
603 				size,
604 				pgprot_writecombine(vma->vm_page_prot))) {
605 			goto out_again;
606 		}
607 		mutex_unlock(&(agp_fe.agp_mutex));
608 		return 0;
609 	}
610 
611 	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
612 		if (size != current_size)
613 			goto out_inval;
614 
615 		DBG("controller vm_ops=%p", kerninfo.vm_ops);
616 		if (kerninfo.vm_ops) {
617 			vma->vm_ops = kerninfo.vm_ops;
618 		} else if (io_remap_pfn_range(vma, vma->vm_start,
619 				kerninfo.aper_base >> PAGE_SHIFT,
620 				size,
621 				pgprot_writecombine(vma->vm_page_prot))) {
622 			goto out_again;
623 		}
624 		mutex_unlock(&(agp_fe.agp_mutex));
625 		return 0;
626 	}
627 
628 out_eperm:
629 	mutex_unlock(&(agp_fe.agp_mutex));
630 	return -EPERM;
631 
632 out_inval:
633 	mutex_unlock(&(agp_fe.agp_mutex));
634 	return -EINVAL;
635 
636 out_again:
637 	mutex_unlock(&(agp_fe.agp_mutex));
638 	return -EAGAIN;
639 }
640 
641 static int agp_release(struct inode *inode, struct file *file)
642 {
643 	struct agp_file_private *priv = file->private_data;
644 
645 	mutex_lock(&(agp_fe.agp_mutex));
646 
647 	DBG("priv=%p", priv);
648 
649 	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
650 		struct agp_controller *controller;
651 
652 		controller = agp_find_controller_by_pid(priv->my_pid);
653 
654 		if (controller != NULL) {
655 			if (controller == agp_fe.current_controller)
656 				agp_controller_release_current(controller, priv);
657 			agp_remove_controller(controller);
658 			controller = NULL;
659 		}
660 	}
661 
662 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
663 		agp_remove_client(priv->my_pid);
664 
665 	agp_remove_file_private(priv);
666 	kfree(priv);
667 	file->private_data = NULL;
668 	mutex_unlock(&(agp_fe.agp_mutex));
669 	return 0;
670 }
671 
672 static int agp_open(struct inode *inode, struct file *file)
673 {
674 	int minor = iminor(inode);
675 	struct agp_file_private *priv;
676 	struct agp_client *client;
677 
678 	if (minor != AGPGART_MINOR)
679 		return -ENXIO;
680 
681 	mutex_lock(&(agp_fe.agp_mutex));
682 
683 	priv = kzalloc(sizeof(struct agp_file_private), GFP_KERNEL);
684 	if (priv == NULL) {
685 		mutex_unlock(&(agp_fe.agp_mutex));
686 		return -ENOMEM;
687 	}
688 
689 	set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
690 	priv->my_pid = current->pid;
691 
692 	if (capable(CAP_SYS_RAWIO))
693 		/* Root priv, can be controller */
694 		set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
695 
696 	client = agp_find_client_by_pid(current->pid);
697 
698 	if (client != NULL) {
699 		set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
700 		set_bit(AGP_FF_IS_VALID, &priv->access_flags);
701 	}
702 	file->private_data = (void *) priv;
703 	agp_insert_file_private(priv);
704 	DBG("private=%p, client=%p", priv, client);
705 
706 	mutex_unlock(&(agp_fe.agp_mutex));
707 
708 	return 0;
709 }
710 
711 static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
712 {
713 	struct agp_info userinfo;
714 	struct agp_kern_info kerninfo;
715 
716 	agp_copy_info(agp_bridge, &kerninfo);
717 
718 	memset(&userinfo, 0, sizeof(userinfo));
719 	userinfo.version.major = kerninfo.version.major;
720 	userinfo.version.minor = kerninfo.version.minor;
721 	userinfo.bridge_id = kerninfo.device->vendor |
722 	    (kerninfo.device->device << 16);
723 	userinfo.agp_mode = kerninfo.mode;
724 	userinfo.aper_base = kerninfo.aper_base;
725 	userinfo.aper_size = kerninfo.aper_size;
726 	userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
727 	userinfo.pg_used = kerninfo.current_memory;
728 
729 	if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
730 		return -EFAULT;
731 
732 	return 0;
733 }
734 
735 int agpioc_acquire_wrap(struct agp_file_private *priv)
736 {
737 	struct agp_controller *controller;
738 
739 	DBG("");
740 
741 	if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
742 		return -EPERM;
743 
744 	if (agp_fe.current_controller != NULL)
745 		return -EBUSY;
746 
747 	if (!agp_bridge)
748 		return -ENODEV;
749 
750         if (atomic_read(&agp_bridge->agp_in_use))
751                 return -EBUSY;
752 
753 	atomic_inc(&agp_bridge->agp_in_use);
754 
755 	agp_fe.backend_acquired = true;
756 
757 	controller = agp_find_controller_by_pid(priv->my_pid);
758 
759 	if (controller != NULL) {
760 		agp_controller_make_current(controller);
761 	} else {
762 		controller = agp_create_controller(priv->my_pid);
763 
764 		if (controller == NULL) {
765 			agp_fe.backend_acquired = false;
766 			agp_backend_release(agp_bridge);
767 			return -ENOMEM;
768 		}
769 		agp_insert_controller(controller);
770 		agp_controller_make_current(controller);
771 	}
772 
773 	set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
774 	set_bit(AGP_FF_IS_VALID, &priv->access_flags);
775 	return 0;
776 }
777 
778 int agpioc_release_wrap(struct agp_file_private *priv)
779 {
780 	DBG("");
781 	agp_controller_release_current(agp_fe.current_controller, priv);
782 	return 0;
783 }
784 
785 int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
786 {
787 	struct agp_setup mode;
788 
789 	DBG("");
790 	if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
791 		return -EFAULT;
792 
793 	agp_enable(agp_bridge, mode.agp_mode);
794 	return 0;
795 }
796 
797 static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
798 {
799 	struct agp_region reserve;
800 	struct agp_client *client;
801 	struct agp_file_private *client_priv;
802 
803 	DBG("");
804 	if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
805 		return -EFAULT;
806 
807 	if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
808 		return -EFAULT;
809 
810 	client = agp_find_client_by_pid(reserve.pid);
811 
812 	if (reserve.seg_count == 0) {
813 		/* remove a client */
814 		client_priv = agp_find_private(reserve.pid);
815 
816 		if (client_priv != NULL) {
817 			set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
818 			set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
819 		}
820 		if (client == NULL) {
821 			/* client is already removed */
822 			return 0;
823 		}
824 		return agp_remove_client(reserve.pid);
825 	} else {
826 		struct agp_segment *segment;
827 
828 		if (reserve.seg_count >= 16384)
829 			return -EINVAL;
830 
831 		segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
832 				  GFP_KERNEL);
833 
834 		if (segment == NULL)
835 			return -ENOMEM;
836 
837 		if (copy_from_user(segment, (void __user *) reserve.seg_list,
838 				   sizeof(struct agp_segment) * reserve.seg_count)) {
839 			kfree(segment);
840 			return -EFAULT;
841 		}
842 		reserve.seg_list = segment;
843 
844 		if (client == NULL) {
845 			/* Create the client and add the segment */
846 			client = agp_create_client(reserve.pid);
847 
848 			if (client == NULL) {
849 				kfree(segment);
850 				return -ENOMEM;
851 			}
852 			client_priv = agp_find_private(reserve.pid);
853 
854 			if (client_priv != NULL) {
855 				set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
856 				set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
857 			}
858 		}
859 		return agp_create_segment(client, &reserve);
860 	}
861 	/* Will never really happen */
862 	return -EINVAL;
863 }
864 
865 int agpioc_protect_wrap(struct agp_file_private *priv)
866 {
867 	DBG("");
868 	/* This function is not currently implemented */
869 	return -EINVAL;
870 }
871 
872 static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
873 {
874 	struct agp_memory *memory;
875 	struct agp_allocate alloc;
876 
877 	DBG("");
878 	if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
879 		return -EFAULT;
880 
881 	if (alloc.type >= AGP_USER_TYPES)
882 		return -EINVAL;
883 
884 	memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);
885 
886 	if (memory == NULL)
887 		return -ENOMEM;
888 
889 	alloc.key = memory->key;
890 	alloc.physical = memory->physical;
891 
892 	if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
893 		agp_free_memory_wrap(memory);
894 		return -EFAULT;
895 	}
896 	return 0;
897 }
898 
899 int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
900 {
901 	struct agp_memory *memory;
902 
903 	DBG("");
904 	memory = agp_find_mem_by_key(arg);
905 
906 	if (memory == NULL)
907 		return -EINVAL;
908 
909 	agp_free_memory_wrap(memory);
910 	return 0;
911 }
912 
913 static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
914 {
915 	struct agp_bind bind_info;
916 	struct agp_memory *memory;
917 
918 	DBG("");
919 	if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
920 		return -EFAULT;
921 
922 	memory = agp_find_mem_by_key(bind_info.key);
923 
924 	if (memory == NULL)
925 		return -EINVAL;
926 
927 	return agp_bind_memory(memory, bind_info.pg_start);
928 }
929 
930 static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
931 {
932 	struct agp_memory *memory;
933 	struct agp_unbind unbind;
934 
935 	DBG("");
936 	if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
937 		return -EFAULT;
938 
939 	memory = agp_find_mem_by_key(unbind.key);
940 
941 	if (memory == NULL)
942 		return -EINVAL;
943 
944 	return agp_unbind_memory(memory);
945 }
946 
947 static long agp_ioctl(struct file *file,
948 		     unsigned int cmd, unsigned long arg)
949 {
950 	struct agp_file_private *curr_priv = file->private_data;
951 	int ret_val = -ENOTTY;
952 
953 	DBG("priv=%p, cmd=%x", curr_priv, cmd);
954 	mutex_lock(&(agp_fe.agp_mutex));
955 
956 	if ((agp_fe.current_controller == NULL) &&
957 	    (cmd != AGPIOC_ACQUIRE)) {
958 		ret_val = -EINVAL;
959 		goto ioctl_out;
960 	}
961 	if ((agp_fe.backend_acquired != true) &&
962 	    (cmd != AGPIOC_ACQUIRE)) {
963 		ret_val = -EBUSY;
964 		goto ioctl_out;
965 	}
966 	if (cmd != AGPIOC_ACQUIRE) {
967 		if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
968 			ret_val = -EPERM;
969 			goto ioctl_out;
970 		}
971 		/* Use the original pid of the controller,
972 		 * in case it's threaded */
973 
974 		if (agp_fe.current_controller->pid != curr_priv->my_pid) {
975 			ret_val = -EBUSY;
976 			goto ioctl_out;
977 		}
978 	}
979 
980 	switch (cmd) {
981 	case AGPIOC_INFO:
982 		ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
983 		break;
984 
985 	case AGPIOC_ACQUIRE:
986 		ret_val = agpioc_acquire_wrap(curr_priv);
987 		break;
988 
989 	case AGPIOC_RELEASE:
990 		ret_val = agpioc_release_wrap(curr_priv);
991 		break;
992 
993 	case AGPIOC_SETUP:
994 		ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
995 		break;
996 
997 	case AGPIOC_RESERVE:
998 		ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
999 		break;
1000 
1001 	case AGPIOC_PROTECT:
1002 		ret_val = agpioc_protect_wrap(curr_priv);
1003 		break;
1004 
1005 	case AGPIOC_ALLOCATE:
1006 		ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
1007 		break;
1008 
1009 	case AGPIOC_DEALLOCATE:
1010 		ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
1011 		break;
1012 
1013 	case AGPIOC_BIND:
1014 		ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
1015 		break;
1016 
1017 	case AGPIOC_UNBIND:
1018 		ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
1019 		break;
1020 
1021 	case AGPIOC_CHIPSET_FLUSH:
1022 		break;
1023 	}
1024 
1025 ioctl_out:
1026 	DBG("ioctl returns %d\n", ret_val);
1027 	mutex_unlock(&(agp_fe.agp_mutex));
1028 	return ret_val;
1029 }
1030 
1031 static const struct file_operations agp_fops =
1032 {
1033 	.owner		= THIS_MODULE,
1034 	.llseek		= no_llseek,
1035 	.unlocked_ioctl	= agp_ioctl,
1036 #ifdef CONFIG_COMPAT
1037 	.compat_ioctl	= compat_agp_ioctl,
1038 #endif
1039 	.mmap		= agp_mmap,
1040 	.open		= agp_open,
1041 	.release	= agp_release,
1042 };
1043 
1044 static struct miscdevice agp_miscdev =
1045 {
1046 	.minor	= AGPGART_MINOR,
1047 	.name	= "agpgart",
1048 	.fops	= &agp_fops
1049 };
1050 
1051 int agp_frontend_initialize(void)
1052 {
1053 	memset(&agp_fe, 0, sizeof(struct agp_front_data));
1054 	mutex_init(&(agp_fe.agp_mutex));
1055 
1056 	if (misc_register(&agp_miscdev)) {
1057 		printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
1058 		return -EIO;
1059 	}
1060 	return 0;
1061 }
1062 
1063 void agp_frontend_cleanup(void)
1064 {
1065 	misc_deregister(&agp_miscdev);
1066 }
1067