xref: /openbmc/linux/drivers/char/agp/frontend.c (revision 4800cd83) 
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/init.h>
35 #include <linux/miscdevice.h>
36 #include <linux/agp_backend.h>
37 #include <linux/agpgart.h>
38 #include <linux/slab.h>
39 #include <linux/mm.h>
40 #include <linux/fs.h>
41 #include <linux/sched.h>
42 #include <asm/uaccess.h>
43 #include <asm/pgtable.h>
44 #include "agp.h"
45 
46 struct agp_front_data agp_fe;
47 
48 struct agp_memory *agp_find_mem_by_key(int key)
49 {
50 	struct agp_memory *curr;
51 
52 	if (agp_fe.current_controller == NULL)
53 		return NULL;
54 
55 	curr = agp_fe.current_controller->pool;
56 
57 	while (curr != NULL) {
58 		if (curr->key == key)
59 			break;
60 		curr = curr->next;
61 	}
62 
63 	DBG("key=%d -> mem=%p", key, curr);
64 	return curr;
65 }
66 
67 static void agp_remove_from_pool(struct agp_memory *temp)
68 {
69 	struct agp_memory *prev;
70 	struct agp_memory *next;
71 
72 	/* Check to see if this is even in the memory pool */
73 
74 	DBG("mem=%p", temp);
75 	if (agp_find_mem_by_key(temp->key) != NULL) {
76 		next = temp->next;
77 		prev = temp->prev;
78 
79 		if (prev != NULL) {
80 			prev->next = next;
81 			if (next != NULL)
82 				next->prev = prev;
83 
84 		} else {
85 			/* This is the first item on the list */
86 			if (next != NULL)
87 				next->prev = NULL;
88 
89 			agp_fe.current_controller->pool = next;
90 		}
91 	}
92 }
93 
94 /*
95  * Routines for managing each client's segment list -
96  * These routines handle adding and removing segments
97  * to each auth'ed client.
98  */
99 
100 static struct
101 agp_segment_priv *agp_find_seg_in_client(const struct agp_client *client,
102 						unsigned long offset,
103 					    int size, pgprot_t page_prot)
104 {
105 	struct agp_segment_priv *seg;
106 	int num_segments, i;
107 	off_t pg_start;
108 	size_t pg_count;
109 
110 	pg_start = offset / 4096;
111 	pg_count = size / 4096;
112 	seg = *(client->segments);
113 	num_segments = client->num_segments;
114 
115 	for (i = 0; i < client->num_segments; i++) {
116 		if ((seg[i].pg_start == pg_start) &&
117 		    (seg[i].pg_count == pg_count) &&
118 		    (pgprot_val(seg[i].prot) == pgprot_val(page_prot))) {
119 			return seg + i;
120 		}
121 	}
122 
123 	return NULL;
124 }
125 
126 static void agp_remove_seg_from_client(struct agp_client *client)
127 {
128 	DBG("client=%p", client);
129 
130 	if (client->segments != NULL) {
131 		if (*(client->segments) != NULL) {
132 			DBG("Freeing %p from client %p", *(client->segments), client);
133 			kfree(*(client->segments));
134 		}
135 		DBG("Freeing %p from client %p", client->segments, client);
136 		kfree(client->segments);
137 		client->segments = NULL;
138 	}
139 }
140 
141 static void agp_add_seg_to_client(struct agp_client *client,
142 			       struct agp_segment_priv ** seg, int num_segments)
143 {
144 	struct agp_segment_priv **prev_seg;
145 
146 	prev_seg = client->segments;
147 
148 	if (prev_seg != NULL)
149 		agp_remove_seg_from_client(client);
150 
151 	DBG("Adding seg %p (%d segments) to client %p", seg, num_segments, client);
152 	client->num_segments = num_segments;
153 	client->segments = seg;
154 }
155 
156 static pgprot_t agp_convert_mmap_flags(int prot)
157 {
158 	unsigned long prot_bits;
159 
160 	prot_bits = calc_vm_prot_bits(prot) | VM_SHARED;
161 	return vm_get_page_prot(prot_bits);
162 }
163 
164 int agp_create_segment(struct agp_client *client, struct agp_region *region)
165 {
166 	struct agp_segment_priv **ret_seg;
167 	struct agp_segment_priv *seg;
168 	struct agp_segment *user_seg;
169 	size_t i;
170 
171 	seg = kzalloc((sizeof(struct agp_segment_priv) * region->seg_count), GFP_KERNEL);
172 	if (seg == NULL) {
173 		kfree(region->seg_list);
174 		region->seg_list = NULL;
175 		return -ENOMEM;
176 	}
177 	user_seg = region->seg_list;
178 
179 	for (i = 0; i < region->seg_count; i++) {
180 		seg[i].pg_start = user_seg[i].pg_start;
181 		seg[i].pg_count = user_seg[i].pg_count;
182 		seg[i].prot = agp_convert_mmap_flags(user_seg[i].prot);
183 	}
184 	kfree(region->seg_list);
185 	region->seg_list = NULL;
186 
187 	ret_seg = kmalloc(sizeof(void *), GFP_KERNEL);
188 	if (ret_seg == NULL) {
189 		kfree(seg);
190 		return -ENOMEM;
191 	}
192 	*ret_seg = seg;
193 	agp_add_seg_to_client(client, ret_seg, region->seg_count);
194 	return 0;
195 }
196 
197 /* End - Routines for managing each client's segment list */
198 
199 /* This function must only be called when current_controller != NULL */
200 static void agp_insert_into_pool(struct agp_memory * temp)
201 {
202 	struct agp_memory *prev;
203 
204 	prev = agp_fe.current_controller->pool;
205 
206 	if (prev != NULL) {
207 		prev->prev = temp;
208 		temp->next = prev;
209 	}
210 	agp_fe.current_controller->pool = temp;
211 }
212 
213 
214 /* File private list routines */
215 
216 struct agp_file_private *agp_find_private(pid_t pid)
217 {
218 	struct agp_file_private *curr;
219 
220 	curr = agp_fe.file_priv_list;
221 
222 	while (curr != NULL) {
223 		if (curr->my_pid == pid)
224 			return curr;
225 		curr = curr->next;
226 	}
227 
228 	return NULL;
229 }
230 
231 static void agp_insert_file_private(struct agp_file_private * priv)
232 {
233 	struct agp_file_private *prev;
234 
235 	prev = agp_fe.file_priv_list;
236 
237 	if (prev != NULL)
238 		prev->prev = priv;
239 	priv->next = prev;
240 	agp_fe.file_priv_list = priv;
241 }
242 
243 static void agp_remove_file_private(struct agp_file_private * priv)
244 {
245 	struct agp_file_private *next;
246 	struct agp_file_private *prev;
247 
248 	next = priv->next;
249 	prev = priv->prev;
250 
251 	if (prev != NULL) {
252 		prev->next = next;
253 
254 		if (next != NULL)
255 			next->prev = prev;
256 
257 	} else {
258 		if (next != NULL)
259 			next->prev = NULL;
260 
261 		agp_fe.file_priv_list = next;
262 	}
263 }
264 
265 /* End - File flag list routines */
266 
267 /*
268  * Wrappers for agp_free_memory & agp_allocate_memory
269  * These make sure that internal lists are kept updated.
270  */
271 void agp_free_memory_wrap(struct agp_memory *memory)
272 {
273 	agp_remove_from_pool(memory);
274 	agp_free_memory(memory);
275 }
276 
277 struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
278 {
279 	struct agp_memory *memory;
280 
281 	memory = agp_allocate_memory(agp_bridge, pg_count, type);
282 	if (memory == NULL)
283 		return NULL;
284 
285 	agp_insert_into_pool(memory);
286 	return memory;
287 }
288 
289 /* Routines for managing the list of controllers -
290  * These routines manage the current controller, and the list of
291  * controllers
292  */
293 
294 static struct agp_controller *agp_find_controller_by_pid(pid_t id)
295 {
296 	struct agp_controller *controller;
297 
298 	controller = agp_fe.controllers;
299 
300 	while (controller != NULL) {
301 		if (controller->pid == id)
302 			return controller;
303 		controller = controller->next;
304 	}
305 
306 	return NULL;
307 }
308 
309 static struct agp_controller *agp_create_controller(pid_t id)
310 {
311 	struct agp_controller *controller;
312 
313 	controller = kzalloc(sizeof(struct agp_controller), GFP_KERNEL);
314 	if (controller == NULL)
315 		return NULL;
316 
317 	controller->pid = id;
318 	return controller;
319 }
320 
321 static int agp_insert_controller(struct agp_controller *controller)
322 {
323 	struct agp_controller *prev_controller;
324 
325 	prev_controller = agp_fe.controllers;
326 	controller->next = prev_controller;
327 
328 	if (prev_controller != NULL)
329 		prev_controller->prev = controller;
330 
331 	agp_fe.controllers = controller;
332 
333 	return 0;
334 }
335 
336 static void agp_remove_all_clients(struct agp_controller *controller)
337 {
338 	struct agp_client *client;
339 	struct agp_client *temp;
340 
341 	client = controller->clients;
342 
343 	while (client) {
344 		struct agp_file_private *priv;
345 
346 		temp = client;
347 		agp_remove_seg_from_client(temp);
348 		priv = agp_find_private(temp->pid);
349 
350 		if (priv != NULL) {
351 			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
352 			clear_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
353 		}
354 		client = client->next;
355 		kfree(temp);
356 	}
357 }
358 
359 static void agp_remove_all_memory(struct agp_controller *controller)
360 {
361 	struct agp_memory *memory;
362 	struct agp_memory *temp;
363 
364 	memory = controller->pool;
365 
366 	while (memory) {
367 		temp = memory;
368 		memory = memory->next;
369 		agp_free_memory_wrap(temp);
370 	}
371 }
372 
373 static int agp_remove_controller(struct agp_controller *controller)
374 {
375 	struct agp_controller *prev_controller;
376 	struct agp_controller *next_controller;
377 
378 	prev_controller = controller->prev;
379 	next_controller = controller->next;
380 
381 	if (prev_controller != NULL) {
382 		prev_controller->next = next_controller;
383 		if (next_controller != NULL)
384 			next_controller->prev = prev_controller;
385 
386 	} else {
387 		if (next_controller != NULL)
388 			next_controller->prev = NULL;
389 
390 		agp_fe.controllers = next_controller;
391 	}
392 
393 	agp_remove_all_memory(controller);
394 	agp_remove_all_clients(controller);
395 
396 	if (agp_fe.current_controller == controller) {
397 		agp_fe.current_controller = NULL;
398 		agp_fe.backend_acquired = false;
399 		agp_backend_release(agp_bridge);
400 	}
401 	kfree(controller);
402 	return 0;
403 }
404 
405 static void agp_controller_make_current(struct agp_controller *controller)
406 {
407 	struct agp_client *clients;
408 
409 	clients = controller->clients;
410 
411 	while (clients != NULL) {
412 		struct agp_file_private *priv;
413 
414 		priv = agp_find_private(clients->pid);
415 
416 		if (priv != NULL) {
417 			set_bit(AGP_FF_IS_VALID, &priv->access_flags);
418 			set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
419 		}
420 		clients = clients->next;
421 	}
422 
423 	agp_fe.current_controller = controller;
424 }
425 
426 static void agp_controller_release_current(struct agp_controller *controller,
427 				      struct agp_file_private *controller_priv)
428 {
429 	struct agp_client *clients;
430 
431 	clear_bit(AGP_FF_IS_VALID, &controller_priv->access_flags);
432 	clients = controller->clients;
433 
434 	while (clients != NULL) {
435 		struct agp_file_private *priv;
436 
437 		priv = agp_find_private(clients->pid);
438 
439 		if (priv != NULL)
440 			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
441 
442 		clients = clients->next;
443 	}
444 
445 	agp_fe.current_controller = NULL;
446 	agp_fe.used_by_controller = false;
447 	agp_backend_release(agp_bridge);
448 }
449 
450 /*
451  * Routines for managing client lists -
452  * These routines are for managing the list of auth'ed clients.
453  */
454 
455 static struct agp_client
456 *agp_find_client_in_controller(struct agp_controller *controller, pid_t id)
457 {
458 	struct agp_client *client;
459 
460 	if (controller == NULL)
461 		return NULL;
462 
463 	client = controller->clients;
464 
465 	while (client != NULL) {
466 		if (client->pid == id)
467 			return client;
468 		client = client->next;
469 	}
470 
471 	return NULL;
472 }
473 
474 static struct agp_controller *agp_find_controller_for_client(pid_t id)
475 {
476 	struct agp_controller *controller;
477 
478 	controller = agp_fe.controllers;
479 
480 	while (controller != NULL) {
481 		if ((agp_find_client_in_controller(controller, id)) != NULL)
482 			return controller;
483 		controller = controller->next;
484 	}
485 
486 	return NULL;
487 }
488 
489 struct agp_client *agp_find_client_by_pid(pid_t id)
490 {
491 	struct agp_client *temp;
492 
493 	if (agp_fe.current_controller == NULL)
494 		return NULL;
495 
496 	temp = agp_find_client_in_controller(agp_fe.current_controller, id);
497 	return temp;
498 }
499 
500 static void agp_insert_client(struct agp_client *client)
501 {
502 	struct agp_client *prev_client;
503 
504 	prev_client = agp_fe.current_controller->clients;
505 	client->next = prev_client;
506 
507 	if (prev_client != NULL)
508 		prev_client->prev = client;
509 
510 	agp_fe.current_controller->clients = client;
511 	agp_fe.current_controller->num_clients++;
512 }
513 
514 struct agp_client *agp_create_client(pid_t id)
515 {
516 	struct agp_client *new_client;
517 
518 	new_client = kzalloc(sizeof(struct agp_client), GFP_KERNEL);
519 	if (new_client == NULL)
520 		return NULL;
521 
522 	new_client->pid = id;
523 	agp_insert_client(new_client);
524 	return new_client;
525 }
526 
527 int agp_remove_client(pid_t id)
528 {
529 	struct agp_client *client;
530 	struct agp_client *prev_client;
531 	struct agp_client *next_client;
532 	struct agp_controller *controller;
533 
534 	controller = agp_find_controller_for_client(id);
535 	if (controller == NULL)
536 		return -EINVAL;
537 
538 	client = agp_find_client_in_controller(controller, id);
539 	if (client == NULL)
540 		return -EINVAL;
541 
542 	prev_client = client->prev;
543 	next_client = client->next;
544 
545 	if (prev_client != NULL) {
546 		prev_client->next = next_client;
547 		if (next_client != NULL)
548 			next_client->prev = prev_client;
549 
550 	} else {
551 		if (next_client != NULL)
552 			next_client->prev = NULL;
553 		controller->clients = next_client;
554 	}
555 
556 	controller->num_clients--;
557 	agp_remove_seg_from_client(client);
558 	kfree(client);
559 	return 0;
560 }
561 
562 /* End - Routines for managing client lists */
563 
564 /* File Operations */
565 
566 static int agp_mmap(struct file *file, struct vm_area_struct *vma)
567 {
568 	unsigned int size, current_size;
569 	unsigned long offset;
570 	struct agp_client *client;
571 	struct agp_file_private *priv = file->private_data;
572 	struct agp_kern_info kerninfo;
573 
574 	mutex_lock(&(agp_fe.agp_mutex));
575 
576 	if (agp_fe.backend_acquired != true)
577 		goto out_eperm;
578 
579 	if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
580 		goto out_eperm;
581 
582 	agp_copy_info(agp_bridge, &kerninfo);
583 	size = vma->vm_end - vma->vm_start;
584 	current_size = kerninfo.aper_size;
585 	current_size = current_size * 0x100000;
586 	offset = vma->vm_pgoff << PAGE_SHIFT;
587 	DBG("%lx:%lx", offset, offset+size);
588 
589 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
590 		if ((size + offset) > current_size)
591 			goto out_inval;
592 
593 		client = agp_find_client_by_pid(current->pid);
594 
595 		if (client == NULL)
596 			goto out_eperm;
597 
598 		if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
599 			goto out_inval;
600 
601 		DBG("client vm_ops=%p", kerninfo.vm_ops);
602 		if (kerninfo.vm_ops) {
603 			vma->vm_ops = kerninfo.vm_ops;
604 		} else if (io_remap_pfn_range(vma, vma->vm_start,
605 				(kerninfo.aper_base + offset) >> PAGE_SHIFT,
606 					    size, vma->vm_page_prot)) {
607 			goto out_again;
608 		}
609 		mutex_unlock(&(agp_fe.agp_mutex));
610 		return 0;
611 	}
612 
613 	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
614 		if (size != current_size)
615 			goto out_inval;
616 
617 		DBG("controller vm_ops=%p", kerninfo.vm_ops);
618 		if (kerninfo.vm_ops) {
619 			vma->vm_ops = kerninfo.vm_ops;
620 		} else if (io_remap_pfn_range(vma, vma->vm_start,
621 					    kerninfo.aper_base >> PAGE_SHIFT,
622 					    size, 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 
713 static ssize_t agp_read(struct file *file, char __user *buf,
714 			size_t count, loff_t * ppos)
715 {
716 	return -EINVAL;
717 }
718 
719 static ssize_t agp_write(struct file *file, const char __user *buf,
720 			 size_t count, loff_t * ppos)
721 {
722 	return -EINVAL;
723 }
724 
725 static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
726 {
727 	struct agp_info userinfo;
728 	struct agp_kern_info kerninfo;
729 
730 	agp_copy_info(agp_bridge, &kerninfo);
731 
732 	userinfo.version.major = kerninfo.version.major;
733 	userinfo.version.minor = kerninfo.version.minor;
734 	userinfo.bridge_id = kerninfo.device->vendor |
735 	    (kerninfo.device->device << 16);
736 	userinfo.agp_mode = kerninfo.mode;
737 	userinfo.aper_base = kerninfo.aper_base;
738 	userinfo.aper_size = kerninfo.aper_size;
739 	userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
740 	userinfo.pg_used = kerninfo.current_memory;
741 
742 	if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
743 		return -EFAULT;
744 
745 	return 0;
746 }
747 
748 int agpioc_acquire_wrap(struct agp_file_private *priv)
749 {
750 	struct agp_controller *controller;
751 
752 	DBG("");
753 
754 	if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
755 		return -EPERM;
756 
757 	if (agp_fe.current_controller != NULL)
758 		return -EBUSY;
759 
760 	if (!agp_bridge)
761 		return -ENODEV;
762 
763         if (atomic_read(&agp_bridge->agp_in_use))
764                 return -EBUSY;
765 
766 	atomic_inc(&agp_bridge->agp_in_use);
767 
768 	agp_fe.backend_acquired = true;
769 
770 	controller = agp_find_controller_by_pid(priv->my_pid);
771 
772 	if (controller != NULL) {
773 		agp_controller_make_current(controller);
774 	} else {
775 		controller = agp_create_controller(priv->my_pid);
776 
777 		if (controller == NULL) {
778 			agp_fe.backend_acquired = false;
779 			agp_backend_release(agp_bridge);
780 			return -ENOMEM;
781 		}
782 		agp_insert_controller(controller);
783 		agp_controller_make_current(controller);
784 	}
785 
786 	set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
787 	set_bit(AGP_FF_IS_VALID, &priv->access_flags);
788 	return 0;
789 }
790 
791 int agpioc_release_wrap(struct agp_file_private *priv)
792 {
793 	DBG("");
794 	agp_controller_release_current(agp_fe.current_controller, priv);
795 	return 0;
796 }
797 
798 int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
799 {
800 	struct agp_setup mode;
801 
802 	DBG("");
803 	if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
804 		return -EFAULT;
805 
806 	agp_enable(agp_bridge, mode.agp_mode);
807 	return 0;
808 }
809 
810 static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
811 {
812 	struct agp_region reserve;
813 	struct agp_client *client;
814 	struct agp_file_private *client_priv;
815 
816 	DBG("");
817 	if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
818 		return -EFAULT;
819 
820 	if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
821 		return -EFAULT;
822 
823 	client = agp_find_client_by_pid(reserve.pid);
824 
825 	if (reserve.seg_count == 0) {
826 		/* remove a client */
827 		client_priv = agp_find_private(reserve.pid);
828 
829 		if (client_priv != NULL) {
830 			set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
831 			set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
832 		}
833 		if (client == NULL) {
834 			/* client is already removed */
835 			return 0;
836 		}
837 		return agp_remove_client(reserve.pid);
838 	} else {
839 		struct agp_segment *segment;
840 
841 		if (reserve.seg_count >= 16384)
842 			return -EINVAL;
843 
844 		segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
845 				  GFP_KERNEL);
846 
847 		if (segment == NULL)
848 			return -ENOMEM;
849 
850 		if (copy_from_user(segment, (void __user *) reserve.seg_list,
851 				   sizeof(struct agp_segment) * reserve.seg_count)) {
852 			kfree(segment);
853 			return -EFAULT;
854 		}
855 		reserve.seg_list = segment;
856 
857 		if (client == NULL) {
858 			/* Create the client and add the segment */
859 			client = agp_create_client(reserve.pid);
860 
861 			if (client == NULL) {
862 				kfree(segment);
863 				return -ENOMEM;
864 			}
865 			client_priv = agp_find_private(reserve.pid);
866 
867 			if (client_priv != NULL) {
868 				set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
869 				set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
870 			}
871 		}
872 		return agp_create_segment(client, &reserve);
873 	}
874 	/* Will never really happen */
875 	return -EINVAL;
876 }
877 
878 int agpioc_protect_wrap(struct agp_file_private *priv)
879 {
880 	DBG("");
881 	/* This function is not currently implemented */
882 	return -EINVAL;
883 }
884 
885 static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
886 {
887 	struct agp_memory *memory;
888 	struct agp_allocate alloc;
889 
890 	DBG("");
891 	if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
892 		return -EFAULT;
893 
894 	if (alloc.type >= AGP_USER_TYPES)
895 		return -EINVAL;
896 
897 	memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);
898 
899 	if (memory == NULL)
900 		return -ENOMEM;
901 
902 	alloc.key = memory->key;
903 	alloc.physical = memory->physical;
904 
905 	if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
906 		agp_free_memory_wrap(memory);
907 		return -EFAULT;
908 	}
909 	return 0;
910 }
911 
912 int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
913 {
914 	struct agp_memory *memory;
915 
916 	DBG("");
917 	memory = agp_find_mem_by_key(arg);
918 
919 	if (memory == NULL)
920 		return -EINVAL;
921 
922 	agp_free_memory_wrap(memory);
923 	return 0;
924 }
925 
926 static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
927 {
928 	struct agp_bind bind_info;
929 	struct agp_memory *memory;
930 
931 	DBG("");
932 	if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
933 		return -EFAULT;
934 
935 	memory = agp_find_mem_by_key(bind_info.key);
936 
937 	if (memory == NULL)
938 		return -EINVAL;
939 
940 	return agp_bind_memory(memory, bind_info.pg_start);
941 }
942 
943 static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
944 {
945 	struct agp_memory *memory;
946 	struct agp_unbind unbind;
947 
948 	DBG("");
949 	if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
950 		return -EFAULT;
951 
952 	memory = agp_find_mem_by_key(unbind.key);
953 
954 	if (memory == NULL)
955 		return -EINVAL;
956 
957 	return agp_unbind_memory(memory);
958 }
959 
960 static long agp_ioctl(struct file *file,
961 		     unsigned int cmd, unsigned long arg)
962 {
963 	struct agp_file_private *curr_priv = file->private_data;
964 	int ret_val = -ENOTTY;
965 
966 	DBG("priv=%p, cmd=%x", curr_priv, cmd);
967 	mutex_lock(&(agp_fe.agp_mutex));
968 
969 	if ((agp_fe.current_controller == NULL) &&
970 	    (cmd != AGPIOC_ACQUIRE)) {
971 		ret_val = -EINVAL;
972 		goto ioctl_out;
973 	}
974 	if ((agp_fe.backend_acquired != true) &&
975 	    (cmd != AGPIOC_ACQUIRE)) {
976 		ret_val = -EBUSY;
977 		goto ioctl_out;
978 	}
979 	if (cmd != AGPIOC_ACQUIRE) {
980 		if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
981 			ret_val = -EPERM;
982 			goto ioctl_out;
983 		}
984 		/* Use the original pid of the controller,
985 		 * in case it's threaded */
986 
987 		if (agp_fe.current_controller->pid != curr_priv->my_pid) {
988 			ret_val = -EBUSY;
989 			goto ioctl_out;
990 		}
991 	}
992 
993 	switch (cmd) {
994 	case AGPIOC_INFO:
995 		ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
996 		break;
997 
998 	case AGPIOC_ACQUIRE:
999 		ret_val = agpioc_acquire_wrap(curr_priv);
1000 		break;
1001 
1002 	case AGPIOC_RELEASE:
1003 		ret_val = agpioc_release_wrap(curr_priv);
1004 		break;
1005 
1006 	case AGPIOC_SETUP:
1007 		ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
1008 		break;
1009 
1010 	case AGPIOC_RESERVE:
1011 		ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
1012 		break;
1013 
1014 	case AGPIOC_PROTECT:
1015 		ret_val = agpioc_protect_wrap(curr_priv);
1016 		break;
1017 
1018 	case AGPIOC_ALLOCATE:
1019 		ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
1020 		break;
1021 
1022 	case AGPIOC_DEALLOCATE:
1023 		ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
1024 		break;
1025 
1026 	case AGPIOC_BIND:
1027 		ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
1028 		break;
1029 
1030 	case AGPIOC_UNBIND:
1031 		ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
1032 		break;
1033 
1034 	case AGPIOC_CHIPSET_FLUSH:
1035 		break;
1036 	}
1037 
1038 ioctl_out:
1039 	DBG("ioctl returns %d\n", ret_val);
1040 	mutex_unlock(&(agp_fe.agp_mutex));
1041 	return ret_val;
1042 }
1043 
1044 static const struct file_operations agp_fops =
1045 {
1046 	.owner		= THIS_MODULE,
1047 	.llseek		= no_llseek,
1048 	.read		= agp_read,
1049 	.write		= agp_write,
1050 	.unlocked_ioctl	= agp_ioctl,
1051 #ifdef CONFIG_COMPAT
1052 	.compat_ioctl	= compat_agp_ioctl,
1053 #endif
1054 	.mmap		= agp_mmap,
1055 	.open		= agp_open,
1056 	.release	= agp_release,
1057 };
1058 
1059 static struct miscdevice agp_miscdev =
1060 {
1061 	.minor	= AGPGART_MINOR,
1062 	.name	= "agpgart",
1063 	.fops	= &agp_fops
1064 };
1065 
1066 int agp_frontend_initialize(void)
1067 {
1068 	memset(&agp_fe, 0, sizeof(struct agp_front_data));
1069 	mutex_init(&(agp_fe.agp_mutex));
1070 
1071 	if (misc_register(&agp_miscdev)) {
1072 		printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
1073 		return -EIO;
1074 	}
1075 	return 0;
1076 }
1077 
1078 void agp_frontend_cleanup(void)
1079 {
1080 	misc_deregister(&agp_miscdev);
1081 }
1082