xref: /openbmc/linux/drivers/char/agp/frontend.c (revision dc6a81c3)
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 <asm/pgtable.h>
43 #include "agp.h"
44 
45 struct agp_front_data agp_fe;
46 
47 struct agp_memory *agp_find_mem_by_key(int key)
48 {
49 	struct agp_memory *curr;
50 
51 	if (agp_fe.current_controller == NULL)
52 		return NULL;
53 
54 	curr = agp_fe.current_controller->pool;
55 
56 	while (curr != NULL) {
57 		if (curr->key == key)
58 			break;
59 		curr = curr->next;
60 	}
61 
62 	DBG("key=%d -> mem=%p", key, curr);
63 	return curr;
64 }
65 
66 static void agp_remove_from_pool(struct agp_memory *temp)
67 {
68 	struct agp_memory *prev;
69 	struct agp_memory *next;
70 
71 	/* Check to see if this is even in the memory pool */
72 
73 	DBG("mem=%p", temp);
74 	if (agp_find_mem_by_key(temp->key) != NULL) {
75 		next = temp->next;
76 		prev = temp->prev;
77 
78 		if (prev != NULL) {
79 			prev->next = next;
80 			if (next != NULL)
81 				next->prev = prev;
82 
83 		} else {
84 			/* This is the first item on the list */
85 			if (next != NULL)
86 				next->prev = NULL;
87 
88 			agp_fe.current_controller->pool = next;
89 		}
90 	}
91 }
92 
93 /*
94  * Routines for managing each client's segment list -
95  * These routines handle adding and removing segments
96  * to each auth'ed client.
97  */
98 
99 static struct
100 agp_segment_priv *agp_find_seg_in_client(const struct agp_client *client,
101 						unsigned long offset,
102 					    int size, pgprot_t page_prot)
103 {
104 	struct agp_segment_priv *seg;
105 	int i;
106 	off_t pg_start;
107 	size_t pg_count;
108 
109 	pg_start = offset / 4096;
110 	pg_count = size / 4096;
111 	seg = *(client->segments);
112 
113 	for (i = 0; i < client->num_segments; i++) {
114 		if ((seg[i].pg_start == pg_start) &&
115 		    (seg[i].pg_count == pg_count) &&
116 		    (pgprot_val(seg[i].prot) == pgprot_val(page_prot))) {
117 			return seg + i;
118 		}
119 	}
120 
121 	return NULL;
122 }
123 
124 static void agp_remove_seg_from_client(struct agp_client *client)
125 {
126 	DBG("client=%p", client);
127 
128 	if (client->segments != NULL) {
129 		if (*(client->segments) != NULL) {
130 			DBG("Freeing %p from client %p", *(client->segments), client);
131 			kfree(*(client->segments));
132 		}
133 		DBG("Freeing %p from client %p", client->segments, client);
134 		kfree(client->segments);
135 		client->segments = NULL;
136 	}
137 }
138 
139 static void agp_add_seg_to_client(struct agp_client *client,
140 			       struct agp_segment_priv ** seg, int num_segments)
141 {
142 	struct agp_segment_priv **prev_seg;
143 
144 	prev_seg = client->segments;
145 
146 	if (prev_seg != NULL)
147 		agp_remove_seg_from_client(client);
148 
149 	DBG("Adding seg %p (%d segments) to client %p", seg, num_segments, client);
150 	client->num_segments = num_segments;
151 	client->segments = seg;
152 }
153 
154 static pgprot_t agp_convert_mmap_flags(int prot)
155 {
156 	unsigned long prot_bits;
157 
158 	prot_bits = calc_vm_prot_bits(prot, 0) | VM_SHARED;
159 	return vm_get_page_prot(prot_bits);
160 }
161 
162 int agp_create_segment(struct agp_client *client, struct agp_region *region)
163 {
164 	struct agp_segment_priv **ret_seg;
165 	struct agp_segment_priv *seg;
166 	struct agp_segment *user_seg;
167 	size_t i;
168 
169 	seg = kzalloc((sizeof(struct agp_segment_priv) * region->seg_count), GFP_KERNEL);
170 	if (seg == NULL) {
171 		kfree(region->seg_list);
172 		region->seg_list = NULL;
173 		return -ENOMEM;
174 	}
175 	user_seg = region->seg_list;
176 
177 	for (i = 0; i < region->seg_count; i++) {
178 		seg[i].pg_start = user_seg[i].pg_start;
179 		seg[i].pg_count = user_seg[i].pg_count;
180 		seg[i].prot = agp_convert_mmap_flags(user_seg[i].prot);
181 	}
182 	kfree(region->seg_list);
183 	region->seg_list = NULL;
184 
185 	ret_seg = kmalloc(sizeof(void *), GFP_KERNEL);
186 	if (ret_seg == NULL) {
187 		kfree(seg);
188 		return -ENOMEM;
189 	}
190 	*ret_seg = seg;
191 	agp_add_seg_to_client(client, ret_seg, region->seg_count);
192 	return 0;
193 }
194 
195 /* End - Routines for managing each client's segment list */
196 
197 /* This function must only be called when current_controller != NULL */
198 static void agp_insert_into_pool(struct agp_memory * temp)
199 {
200 	struct agp_memory *prev;
201 
202 	prev = agp_fe.current_controller->pool;
203 
204 	if (prev != NULL) {
205 		prev->prev = temp;
206 		temp->next = prev;
207 	}
208 	agp_fe.current_controller->pool = temp;
209 }
210 
211 
212 /* File private list routines */
213 
214 struct agp_file_private *agp_find_private(pid_t pid)
215 {
216 	struct agp_file_private *curr;
217 
218 	curr = agp_fe.file_priv_list;
219 
220 	while (curr != NULL) {
221 		if (curr->my_pid == pid)
222 			return curr;
223 		curr = curr->next;
224 	}
225 
226 	return NULL;
227 }
228 
229 static void agp_insert_file_private(struct agp_file_private * priv)
230 {
231 	struct agp_file_private *prev;
232 
233 	prev = agp_fe.file_priv_list;
234 
235 	if (prev != NULL)
236 		prev->prev = priv;
237 	priv->next = prev;
238 	agp_fe.file_priv_list = priv;
239 }
240 
241 static void agp_remove_file_private(struct agp_file_private * priv)
242 {
243 	struct agp_file_private *next;
244 	struct agp_file_private *prev;
245 
246 	next = priv->next;
247 	prev = priv->prev;
248 
249 	if (prev != NULL) {
250 		prev->next = next;
251 
252 		if (next != NULL)
253 			next->prev = prev;
254 
255 	} else {
256 		if (next != NULL)
257 			next->prev = NULL;
258 
259 		agp_fe.file_priv_list = next;
260 	}
261 }
262 
263 /* End - File flag list routines */
264 
265 /*
266  * Wrappers for agp_free_memory & agp_allocate_memory
267  * These make sure that internal lists are kept updated.
268  */
269 void agp_free_memory_wrap(struct agp_memory *memory)
270 {
271 	agp_remove_from_pool(memory);
272 	agp_free_memory(memory);
273 }
274 
275 struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
276 {
277 	struct agp_memory *memory;
278 
279 	memory = agp_allocate_memory(agp_bridge, pg_count, type);
280 	if (memory == NULL)
281 		return NULL;
282 
283 	agp_insert_into_pool(memory);
284 	return memory;
285 }
286 
287 /* Routines for managing the list of controllers -
288  * These routines manage the current controller, and the list of
289  * controllers
290  */
291 
292 static struct agp_controller *agp_find_controller_by_pid(pid_t id)
293 {
294 	struct agp_controller *controller;
295 
296 	controller = agp_fe.controllers;
297 
298 	while (controller != NULL) {
299 		if (controller->pid == id)
300 			return controller;
301 		controller = controller->next;
302 	}
303 
304 	return NULL;
305 }
306 
307 static struct agp_controller *agp_create_controller(pid_t id)
308 {
309 	struct agp_controller *controller;
310 
311 	controller = kzalloc(sizeof(struct agp_controller), GFP_KERNEL);
312 	if (controller == NULL)
313 		return NULL;
314 
315 	controller->pid = id;
316 	return controller;
317 }
318 
319 static int agp_insert_controller(struct agp_controller *controller)
320 {
321 	struct agp_controller *prev_controller;
322 
323 	prev_controller = agp_fe.controllers;
324 	controller->next = prev_controller;
325 
326 	if (prev_controller != NULL)
327 		prev_controller->prev = controller;
328 
329 	agp_fe.controllers = controller;
330 
331 	return 0;
332 }
333 
334 static void agp_remove_all_clients(struct agp_controller *controller)
335 {
336 	struct agp_client *client;
337 	struct agp_client *temp;
338 
339 	client = controller->clients;
340 
341 	while (client) {
342 		struct agp_file_private *priv;
343 
344 		temp = client;
345 		agp_remove_seg_from_client(temp);
346 		priv = agp_find_private(temp->pid);
347 
348 		if (priv != NULL) {
349 			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
350 			clear_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
351 		}
352 		client = client->next;
353 		kfree(temp);
354 	}
355 }
356 
357 static void agp_remove_all_memory(struct agp_controller *controller)
358 {
359 	struct agp_memory *memory;
360 	struct agp_memory *temp;
361 
362 	memory = controller->pool;
363 
364 	while (memory) {
365 		temp = memory;
366 		memory = memory->next;
367 		agp_free_memory_wrap(temp);
368 	}
369 }
370 
371 static int agp_remove_controller(struct agp_controller *controller)
372 {
373 	struct agp_controller *prev_controller;
374 	struct agp_controller *next_controller;
375 
376 	prev_controller = controller->prev;
377 	next_controller = controller->next;
378 
379 	if (prev_controller != NULL) {
380 		prev_controller->next = next_controller;
381 		if (next_controller != NULL)
382 			next_controller->prev = prev_controller;
383 
384 	} else {
385 		if (next_controller != NULL)
386 			next_controller->prev = NULL;
387 
388 		agp_fe.controllers = next_controller;
389 	}
390 
391 	agp_remove_all_memory(controller);
392 	agp_remove_all_clients(controller);
393 
394 	if (agp_fe.current_controller == controller) {
395 		agp_fe.current_controller = NULL;
396 		agp_fe.backend_acquired = false;
397 		agp_backend_release(agp_bridge);
398 	}
399 	kfree(controller);
400 	return 0;
401 }
402 
403 static void agp_controller_make_current(struct agp_controller *controller)
404 {
405 	struct agp_client *clients;
406 
407 	clients = controller->clients;
408 
409 	while (clients != NULL) {
410 		struct agp_file_private *priv;
411 
412 		priv = agp_find_private(clients->pid);
413 
414 		if (priv != NULL) {
415 			set_bit(AGP_FF_IS_VALID, &priv->access_flags);
416 			set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
417 		}
418 		clients = clients->next;
419 	}
420 
421 	agp_fe.current_controller = controller;
422 }
423 
424 static void agp_controller_release_current(struct agp_controller *controller,
425 				      struct agp_file_private *controller_priv)
426 {
427 	struct agp_client *clients;
428 
429 	clear_bit(AGP_FF_IS_VALID, &controller_priv->access_flags);
430 	clients = controller->clients;
431 
432 	while (clients != NULL) {
433 		struct agp_file_private *priv;
434 
435 		priv = agp_find_private(clients->pid);
436 
437 		if (priv != NULL)
438 			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
439 
440 		clients = clients->next;
441 	}
442 
443 	agp_fe.current_controller = NULL;
444 	agp_fe.used_by_controller = false;
445 	agp_backend_release(agp_bridge);
446 }
447 
448 /*
449  * Routines for managing client lists -
450  * These routines are for managing the list of auth'ed clients.
451  */
452 
453 static struct agp_client
454 *agp_find_client_in_controller(struct agp_controller *controller, pid_t id)
455 {
456 	struct agp_client *client;
457 
458 	if (controller == NULL)
459 		return NULL;
460 
461 	client = controller->clients;
462 
463 	while (client != NULL) {
464 		if (client->pid == id)
465 			return client;
466 		client = client->next;
467 	}
468 
469 	return NULL;
470 }
471 
472 static struct agp_controller *agp_find_controller_for_client(pid_t id)
473 {
474 	struct agp_controller *controller;
475 
476 	controller = agp_fe.controllers;
477 
478 	while (controller != NULL) {
479 		if ((agp_find_client_in_controller(controller, id)) != NULL)
480 			return controller;
481 		controller = controller->next;
482 	}
483 
484 	return NULL;
485 }
486 
487 struct agp_client *agp_find_client_by_pid(pid_t id)
488 {
489 	struct agp_client *temp;
490 
491 	if (agp_fe.current_controller == NULL)
492 		return NULL;
493 
494 	temp = agp_find_client_in_controller(agp_fe.current_controller, id);
495 	return temp;
496 }
497 
498 static void agp_insert_client(struct agp_client *client)
499 {
500 	struct agp_client *prev_client;
501 
502 	prev_client = agp_fe.current_controller->clients;
503 	client->next = prev_client;
504 
505 	if (prev_client != NULL)
506 		prev_client->prev = client;
507 
508 	agp_fe.current_controller->clients = client;
509 	agp_fe.current_controller->num_clients++;
510 }
511 
512 struct agp_client *agp_create_client(pid_t id)
513 {
514 	struct agp_client *new_client;
515 
516 	new_client = kzalloc(sizeof(struct agp_client), GFP_KERNEL);
517 	if (new_client == NULL)
518 		return NULL;
519 
520 	new_client->pid = id;
521 	agp_insert_client(new_client);
522 	return new_client;
523 }
524 
525 int agp_remove_client(pid_t id)
526 {
527 	struct agp_client *client;
528 	struct agp_client *prev_client;
529 	struct agp_client *next_client;
530 	struct agp_controller *controller;
531 
532 	controller = agp_find_controller_for_client(id);
533 	if (controller == NULL)
534 		return -EINVAL;
535 
536 	client = agp_find_client_in_controller(controller, id);
537 	if (client == NULL)
538 		return -EINVAL;
539 
540 	prev_client = client->prev;
541 	next_client = client->next;
542 
543 	if (prev_client != NULL) {
544 		prev_client->next = next_client;
545 		if (next_client != NULL)
546 			next_client->prev = prev_client;
547 
548 	} else {
549 		if (next_client != NULL)
550 			next_client->prev = NULL;
551 		controller->clients = next_client;
552 	}
553 
554 	controller->num_clients--;
555 	agp_remove_seg_from_client(client);
556 	kfree(client);
557 	return 0;
558 }
559 
560 /* End - Routines for managing client lists */
561 
562 /* File Operations */
563 
564 static int agp_mmap(struct file *file, struct vm_area_struct *vma)
565 {
566 	unsigned int size, current_size;
567 	unsigned long offset;
568 	struct agp_client *client;
569 	struct agp_file_private *priv = file->private_data;
570 	struct agp_kern_info kerninfo;
571 
572 	mutex_lock(&(agp_fe.agp_mutex));
573 
574 	if (agp_fe.backend_acquired != true)
575 		goto out_eperm;
576 
577 	if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
578 		goto out_eperm;
579 
580 	agp_copy_info(agp_bridge, &kerninfo);
581 	size = vma->vm_end - vma->vm_start;
582 	current_size = kerninfo.aper_size;
583 	current_size = current_size * 0x100000;
584 	offset = vma->vm_pgoff << PAGE_SHIFT;
585 	DBG("%lx:%lx", offset, offset+size);
586 
587 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
588 		if ((size + offset) > current_size)
589 			goto out_inval;
590 
591 		client = agp_find_client_by_pid(current->pid);
592 
593 		if (client == NULL)
594 			goto out_eperm;
595 
596 		if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
597 			goto out_inval;
598 
599 		DBG("client vm_ops=%p", kerninfo.vm_ops);
600 		if (kerninfo.vm_ops) {
601 			vma->vm_ops = kerninfo.vm_ops;
602 		} else if (io_remap_pfn_range(vma, vma->vm_start,
603 				(kerninfo.aper_base + offset) >> PAGE_SHIFT,
604 				size,
605 				pgprot_writecombine(vma->vm_page_prot))) {
606 			goto out_again;
607 		}
608 		mutex_unlock(&(agp_fe.agp_mutex));
609 		return 0;
610 	}
611 
612 	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
613 		if (size != current_size)
614 			goto out_inval;
615 
616 		DBG("controller vm_ops=%p", kerninfo.vm_ops);
617 		if (kerninfo.vm_ops) {
618 			vma->vm_ops = kerninfo.vm_ops;
619 		} else if (io_remap_pfn_range(vma, vma->vm_start,
620 				kerninfo.aper_base >> PAGE_SHIFT,
621 				size,
622 				pgprot_writecombine(vma->vm_page_prot))) {
623 			goto out_again;
624 		}
625 		mutex_unlock(&(agp_fe.agp_mutex));
626 		return 0;
627 	}
628 
629 out_eperm:
630 	mutex_unlock(&(agp_fe.agp_mutex));
631 	return -EPERM;
632 
633 out_inval:
634 	mutex_unlock(&(agp_fe.agp_mutex));
635 	return -EINVAL;
636 
637 out_again:
638 	mutex_unlock(&(agp_fe.agp_mutex));
639 	return -EAGAIN;
640 }
641 
642 static int agp_release(struct inode *inode, struct file *file)
643 {
644 	struct agp_file_private *priv = file->private_data;
645 
646 	mutex_lock(&(agp_fe.agp_mutex));
647 
648 	DBG("priv=%p", priv);
649 
650 	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
651 		struct agp_controller *controller;
652 
653 		controller = agp_find_controller_by_pid(priv->my_pid);
654 
655 		if (controller != NULL) {
656 			if (controller == agp_fe.current_controller)
657 				agp_controller_release_current(controller, priv);
658 			agp_remove_controller(controller);
659 			controller = NULL;
660 		}
661 	}
662 
663 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
664 		agp_remove_client(priv->my_pid);
665 
666 	agp_remove_file_private(priv);
667 	kfree(priv);
668 	file->private_data = NULL;
669 	mutex_unlock(&(agp_fe.agp_mutex));
670 	return 0;
671 }
672 
673 static int agp_open(struct inode *inode, struct file *file)
674 {
675 	int minor = iminor(inode);
676 	struct agp_file_private *priv;
677 	struct agp_client *client;
678 
679 	if (minor != AGPGART_MINOR)
680 		return -ENXIO;
681 
682 	mutex_lock(&(agp_fe.agp_mutex));
683 
684 	priv = kzalloc(sizeof(struct agp_file_private), GFP_KERNEL);
685 	if (priv == NULL) {
686 		mutex_unlock(&(agp_fe.agp_mutex));
687 		return -ENOMEM;
688 	}
689 
690 	set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
691 	priv->my_pid = current->pid;
692 
693 	if (capable(CAP_SYS_RAWIO))
694 		/* Root priv, can be controller */
695 		set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
696 
697 	client = agp_find_client_by_pid(current->pid);
698 
699 	if (client != NULL) {
700 		set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
701 		set_bit(AGP_FF_IS_VALID, &priv->access_flags);
702 	}
703 	file->private_data = (void *) priv;
704 	agp_insert_file_private(priv);
705 	DBG("private=%p, client=%p", priv, client);
706 
707 	mutex_unlock(&(agp_fe.agp_mutex));
708 
709 	return 0;
710 }
711 
712 static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
713 {
714 	struct agp_info userinfo;
715 	struct agp_kern_info kerninfo;
716 
717 	agp_copy_info(agp_bridge, &kerninfo);
718 
719 	memset(&userinfo, 0, sizeof(userinfo));
720 	userinfo.version.major = kerninfo.version.major;
721 	userinfo.version.minor = kerninfo.version.minor;
722 	userinfo.bridge_id = kerninfo.device->vendor |
723 	    (kerninfo.device->device << 16);
724 	userinfo.agp_mode = kerninfo.mode;
725 	userinfo.aper_base = kerninfo.aper_base;
726 	userinfo.aper_size = kerninfo.aper_size;
727 	userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
728 	userinfo.pg_used = kerninfo.current_memory;
729 
730 	if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
731 		return -EFAULT;
732 
733 	return 0;
734 }
735 
736 int agpioc_acquire_wrap(struct agp_file_private *priv)
737 {
738 	struct agp_controller *controller;
739 
740 	DBG("");
741 
742 	if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
743 		return -EPERM;
744 
745 	if (agp_fe.current_controller != NULL)
746 		return -EBUSY;
747 
748 	if (!agp_bridge)
749 		return -ENODEV;
750 
751         if (atomic_read(&agp_bridge->agp_in_use))
752                 return -EBUSY;
753 
754 	atomic_inc(&agp_bridge->agp_in_use);
755 
756 	agp_fe.backend_acquired = true;
757 
758 	controller = agp_find_controller_by_pid(priv->my_pid);
759 
760 	if (controller != NULL) {
761 		agp_controller_make_current(controller);
762 	} else {
763 		controller = agp_create_controller(priv->my_pid);
764 
765 		if (controller == NULL) {
766 			agp_fe.backend_acquired = false;
767 			agp_backend_release(agp_bridge);
768 			return -ENOMEM;
769 		}
770 		agp_insert_controller(controller);
771 		agp_controller_make_current(controller);
772 	}
773 
774 	set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
775 	set_bit(AGP_FF_IS_VALID, &priv->access_flags);
776 	return 0;
777 }
778 
779 int agpioc_release_wrap(struct agp_file_private *priv)
780 {
781 	DBG("");
782 	agp_controller_release_current(agp_fe.current_controller, priv);
783 	return 0;
784 }
785 
786 int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
787 {
788 	struct agp_setup mode;
789 
790 	DBG("");
791 	if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
792 		return -EFAULT;
793 
794 	agp_enable(agp_bridge, mode.agp_mode);
795 	return 0;
796 }
797 
798 static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
799 {
800 	struct agp_region reserve;
801 	struct agp_client *client;
802 	struct agp_file_private *client_priv;
803 
804 	DBG("");
805 	if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
806 		return -EFAULT;
807 
808 	if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
809 		return -EFAULT;
810 
811 	client = agp_find_client_by_pid(reserve.pid);
812 
813 	if (reserve.seg_count == 0) {
814 		/* remove a client */
815 		client_priv = agp_find_private(reserve.pid);
816 
817 		if (client_priv != NULL) {
818 			set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
819 			set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
820 		}
821 		if (client == NULL) {
822 			/* client is already removed */
823 			return 0;
824 		}
825 		return agp_remove_client(reserve.pid);
826 	} else {
827 		struct agp_segment *segment;
828 
829 		if (reserve.seg_count >= 16384)
830 			return -EINVAL;
831 
832 		segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
833 				  GFP_KERNEL);
834 
835 		if (segment == NULL)
836 			return -ENOMEM;
837 
838 		if (copy_from_user(segment, (void __user *) reserve.seg_list,
839 				   sizeof(struct agp_segment) * reserve.seg_count)) {
840 			kfree(segment);
841 			return -EFAULT;
842 		}
843 		reserve.seg_list = segment;
844 
845 		if (client == NULL) {
846 			/* Create the client and add the segment */
847 			client = agp_create_client(reserve.pid);
848 
849 			if (client == NULL) {
850 				kfree(segment);
851 				return -ENOMEM;
852 			}
853 			client_priv = agp_find_private(reserve.pid);
854 
855 			if (client_priv != NULL) {
856 				set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
857 				set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
858 			}
859 		}
860 		return agp_create_segment(client, &reserve);
861 	}
862 	/* Will never really happen */
863 	return -EINVAL;
864 }
865 
866 int agpioc_protect_wrap(struct agp_file_private *priv)
867 {
868 	DBG("");
869 	/* This function is not currently implemented */
870 	return -EINVAL;
871 }
872 
873 static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
874 {
875 	struct agp_memory *memory;
876 	struct agp_allocate alloc;
877 
878 	DBG("");
879 	if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
880 		return -EFAULT;
881 
882 	if (alloc.type >= AGP_USER_TYPES)
883 		return -EINVAL;
884 
885 	memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);
886 
887 	if (memory == NULL)
888 		return -ENOMEM;
889 
890 	alloc.key = memory->key;
891 	alloc.physical = memory->physical;
892 
893 	if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
894 		agp_free_memory_wrap(memory);
895 		return -EFAULT;
896 	}
897 	return 0;
898 }
899 
900 int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
901 {
902 	struct agp_memory *memory;
903 
904 	DBG("");
905 	memory = agp_find_mem_by_key(arg);
906 
907 	if (memory == NULL)
908 		return -EINVAL;
909 
910 	agp_free_memory_wrap(memory);
911 	return 0;
912 }
913 
914 static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
915 {
916 	struct agp_bind bind_info;
917 	struct agp_memory *memory;
918 
919 	DBG("");
920 	if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
921 		return -EFAULT;
922 
923 	memory = agp_find_mem_by_key(bind_info.key);
924 
925 	if (memory == NULL)
926 		return -EINVAL;
927 
928 	return agp_bind_memory(memory, bind_info.pg_start);
929 }
930 
931 static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
932 {
933 	struct agp_memory *memory;
934 	struct agp_unbind unbind;
935 
936 	DBG("");
937 	if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
938 		return -EFAULT;
939 
940 	memory = agp_find_mem_by_key(unbind.key);
941 
942 	if (memory == NULL)
943 		return -EINVAL;
944 
945 	return agp_unbind_memory(memory);
946 }
947 
948 static long agp_ioctl(struct file *file,
949 		     unsigned int cmd, unsigned long arg)
950 {
951 	struct agp_file_private *curr_priv = file->private_data;
952 	int ret_val = -ENOTTY;
953 
954 	DBG("priv=%p, cmd=%x", curr_priv, cmd);
955 	mutex_lock(&(agp_fe.agp_mutex));
956 
957 	if ((agp_fe.current_controller == NULL) &&
958 	    (cmd != AGPIOC_ACQUIRE)) {
959 		ret_val = -EINVAL;
960 		goto ioctl_out;
961 	}
962 	if ((agp_fe.backend_acquired != true) &&
963 	    (cmd != AGPIOC_ACQUIRE)) {
964 		ret_val = -EBUSY;
965 		goto ioctl_out;
966 	}
967 	if (cmd != AGPIOC_ACQUIRE) {
968 		if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
969 			ret_val = -EPERM;
970 			goto ioctl_out;
971 		}
972 		/* Use the original pid of the controller,
973 		 * in case it's threaded */
974 
975 		if (agp_fe.current_controller->pid != curr_priv->my_pid) {
976 			ret_val = -EBUSY;
977 			goto ioctl_out;
978 		}
979 	}
980 
981 	switch (cmd) {
982 	case AGPIOC_INFO:
983 		ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
984 		break;
985 
986 	case AGPIOC_ACQUIRE:
987 		ret_val = agpioc_acquire_wrap(curr_priv);
988 		break;
989 
990 	case AGPIOC_RELEASE:
991 		ret_val = agpioc_release_wrap(curr_priv);
992 		break;
993 
994 	case AGPIOC_SETUP:
995 		ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
996 		break;
997 
998 	case AGPIOC_RESERVE:
999 		ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
1000 		break;
1001 
1002 	case AGPIOC_PROTECT:
1003 		ret_val = agpioc_protect_wrap(curr_priv);
1004 		break;
1005 
1006 	case AGPIOC_ALLOCATE:
1007 		ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
1008 		break;
1009 
1010 	case AGPIOC_DEALLOCATE:
1011 		ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
1012 		break;
1013 
1014 	case AGPIOC_BIND:
1015 		ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
1016 		break;
1017 
1018 	case AGPIOC_UNBIND:
1019 		ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
1020 		break;
1021 
1022 	case AGPIOC_CHIPSET_FLUSH:
1023 		break;
1024 	}
1025 
1026 ioctl_out:
1027 	DBG("ioctl returns %d\n", ret_val);
1028 	mutex_unlock(&(agp_fe.agp_mutex));
1029 	return ret_val;
1030 }
1031 
1032 static const struct file_operations agp_fops =
1033 {
1034 	.owner		= THIS_MODULE,
1035 	.llseek		= no_llseek,
1036 	.unlocked_ioctl	= agp_ioctl,
1037 #ifdef CONFIG_COMPAT
1038 	.compat_ioctl	= compat_agp_ioctl,
1039 #endif
1040 	.mmap		= agp_mmap,
1041 	.open		= agp_open,
1042 	.release	= agp_release,
1043 };
1044 
1045 static struct miscdevice agp_miscdev =
1046 {
1047 	.minor	= AGPGART_MINOR,
1048 	.name	= "agpgart",
1049 	.fops	= &agp_fops
1050 };
1051 
1052 int agp_frontend_initialize(void)
1053 {
1054 	memset(&agp_fe, 0, sizeof(struct agp_front_data));
1055 	mutex_init(&(agp_fe.agp_mutex));
1056 
1057 	if (misc_register(&agp_miscdev)) {
1058 		printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
1059 		return -EIO;
1060 	}
1061 	return 0;
1062 }
1063 
1064 void agp_frontend_cleanup(void)
1065 {
1066 	misc_deregister(&agp_miscdev);
1067 }
1068