xref: /openbmc/linux/drivers/char/agp/frontend.c (revision aac5987a) 
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 num_segments, 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 	num_segments = client->num_segments;
113 
114 	for (i = 0; i < client->num_segments; i++) {
115 		if ((seg[i].pg_start == pg_start) &&
116 		    (seg[i].pg_count == pg_count) &&
117 		    (pgprot_val(seg[i].prot) == pgprot_val(page_prot))) {
118 			return seg + i;
119 		}
120 	}
121 
122 	return NULL;
123 }
124 
125 static void agp_remove_seg_from_client(struct agp_client *client)
126 {
127 	DBG("client=%p", client);
128 
129 	if (client->segments != NULL) {
130 		if (*(client->segments) != NULL) {
131 			DBG("Freeing %p from client %p", *(client->segments), client);
132 			kfree(*(client->segments));
133 		}
134 		DBG("Freeing %p from client %p", client->segments, client);
135 		kfree(client->segments);
136 		client->segments = NULL;
137 	}
138 }
139 
140 static void agp_add_seg_to_client(struct agp_client *client,
141 			       struct agp_segment_priv ** seg, int num_segments)
142 {
143 	struct agp_segment_priv **prev_seg;
144 
145 	prev_seg = client->segments;
146 
147 	if (prev_seg != NULL)
148 		agp_remove_seg_from_client(client);
149 
150 	DBG("Adding seg %p (%d segments) to client %p", seg, num_segments, client);
151 	client->num_segments = num_segments;
152 	client->segments = seg;
153 }
154 
155 static pgprot_t agp_convert_mmap_flags(int prot)
156 {
157 	unsigned long prot_bits;
158 
159 	prot_bits = calc_vm_prot_bits(prot, 0) | VM_SHARED;
160 	return vm_get_page_prot(prot_bits);
161 }
162 
163 int agp_create_segment(struct agp_client *client, struct agp_region *region)
164 {
165 	struct agp_segment_priv **ret_seg;
166 	struct agp_segment_priv *seg;
167 	struct agp_segment *user_seg;
168 	size_t i;
169 
170 	seg = kzalloc((sizeof(struct agp_segment_priv) * region->seg_count), GFP_KERNEL);
171 	if (seg == NULL) {
172 		kfree(region->seg_list);
173 		region->seg_list = NULL;
174 		return -ENOMEM;
175 	}
176 	user_seg = region->seg_list;
177 
178 	for (i = 0; i < region->seg_count; i++) {
179 		seg[i].pg_start = user_seg[i].pg_start;
180 		seg[i].pg_count = user_seg[i].pg_count;
181 		seg[i].prot = agp_convert_mmap_flags(user_seg[i].prot);
182 	}
183 	kfree(region->seg_list);
184 	region->seg_list = NULL;
185 
186 	ret_seg = kmalloc(sizeof(void *), GFP_KERNEL);
187 	if (ret_seg == NULL) {
188 		kfree(seg);
189 		return -ENOMEM;
190 	}
191 	*ret_seg = seg;
192 	agp_add_seg_to_client(client, ret_seg, region->seg_count);
193 	return 0;
194 }
195 
196 /* End - Routines for managing each client's segment list */
197 
198 /* This function must only be called when current_controller != NULL */
199 static void agp_insert_into_pool(struct agp_memory * temp)
200 {
201 	struct agp_memory *prev;
202 
203 	prev = agp_fe.current_controller->pool;
204 
205 	if (prev != NULL) {
206 		prev->prev = temp;
207 		temp->next = prev;
208 	}
209 	agp_fe.current_controller->pool = temp;
210 }
211 
212 
213 /* File private list routines */
214 
215 struct agp_file_private *agp_find_private(pid_t pid)
216 {
217 	struct agp_file_private *curr;
218 
219 	curr = agp_fe.file_priv_list;
220 
221 	while (curr != NULL) {
222 		if (curr->my_pid == pid)
223 			return curr;
224 		curr = curr->next;
225 	}
226 
227 	return NULL;
228 }
229 
230 static void agp_insert_file_private(struct agp_file_private * priv)
231 {
232 	struct agp_file_private *prev;
233 
234 	prev = agp_fe.file_priv_list;
235 
236 	if (prev != NULL)
237 		prev->prev = priv;
238 	priv->next = prev;
239 	agp_fe.file_priv_list = priv;
240 }
241 
242 static void agp_remove_file_private(struct agp_file_private * priv)
243 {
244 	struct agp_file_private *next;
245 	struct agp_file_private *prev;
246 
247 	next = priv->next;
248 	prev = priv->prev;
249 
250 	if (prev != NULL) {
251 		prev->next = next;
252 
253 		if (next != NULL)
254 			next->prev = prev;
255 
256 	} else {
257 		if (next != NULL)
258 			next->prev = NULL;
259 
260 		agp_fe.file_priv_list = next;
261 	}
262 }
263 
264 /* End - File flag list routines */
265 
266 /*
267  * Wrappers for agp_free_memory & agp_allocate_memory
268  * These make sure that internal lists are kept updated.
269  */
270 void agp_free_memory_wrap(struct agp_memory *memory)
271 {
272 	agp_remove_from_pool(memory);
273 	agp_free_memory(memory);
274 }
275 
276 struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type)
277 {
278 	struct agp_memory *memory;
279 
280 	memory = agp_allocate_memory(agp_bridge, pg_count, type);
281 	if (memory == NULL)
282 		return NULL;
283 
284 	agp_insert_into_pool(memory);
285 	return memory;
286 }
287 
288 /* Routines for managing the list of controllers -
289  * These routines manage the current controller, and the list of
290  * controllers
291  */
292 
293 static struct agp_controller *agp_find_controller_by_pid(pid_t id)
294 {
295 	struct agp_controller *controller;
296 
297 	controller = agp_fe.controllers;
298 
299 	while (controller != NULL) {
300 		if (controller->pid == id)
301 			return controller;
302 		controller = controller->next;
303 	}
304 
305 	return NULL;
306 }
307 
308 static struct agp_controller *agp_create_controller(pid_t id)
309 {
310 	struct agp_controller *controller;
311 
312 	controller = kzalloc(sizeof(struct agp_controller), GFP_KERNEL);
313 	if (controller == NULL)
314 		return NULL;
315 
316 	controller->pid = id;
317 	return controller;
318 }
319 
320 static int agp_insert_controller(struct agp_controller *controller)
321 {
322 	struct agp_controller *prev_controller;
323 
324 	prev_controller = agp_fe.controllers;
325 	controller->next = prev_controller;
326 
327 	if (prev_controller != NULL)
328 		prev_controller->prev = controller;
329 
330 	agp_fe.controllers = controller;
331 
332 	return 0;
333 }
334 
335 static void agp_remove_all_clients(struct agp_controller *controller)
336 {
337 	struct agp_client *client;
338 	struct agp_client *temp;
339 
340 	client = controller->clients;
341 
342 	while (client) {
343 		struct agp_file_private *priv;
344 
345 		temp = client;
346 		agp_remove_seg_from_client(temp);
347 		priv = agp_find_private(temp->pid);
348 
349 		if (priv != NULL) {
350 			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
351 			clear_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
352 		}
353 		client = client->next;
354 		kfree(temp);
355 	}
356 }
357 
358 static void agp_remove_all_memory(struct agp_controller *controller)
359 {
360 	struct agp_memory *memory;
361 	struct agp_memory *temp;
362 
363 	memory = controller->pool;
364 
365 	while (memory) {
366 		temp = memory;
367 		memory = memory->next;
368 		agp_free_memory_wrap(temp);
369 	}
370 }
371 
372 static int agp_remove_controller(struct agp_controller *controller)
373 {
374 	struct agp_controller *prev_controller;
375 	struct agp_controller *next_controller;
376 
377 	prev_controller = controller->prev;
378 	next_controller = controller->next;
379 
380 	if (prev_controller != NULL) {
381 		prev_controller->next = next_controller;
382 		if (next_controller != NULL)
383 			next_controller->prev = prev_controller;
384 
385 	} else {
386 		if (next_controller != NULL)
387 			next_controller->prev = NULL;
388 
389 		agp_fe.controllers = next_controller;
390 	}
391 
392 	agp_remove_all_memory(controller);
393 	agp_remove_all_clients(controller);
394 
395 	if (agp_fe.current_controller == controller) {
396 		agp_fe.current_controller = NULL;
397 		agp_fe.backend_acquired = false;
398 		agp_backend_release(agp_bridge);
399 	}
400 	kfree(controller);
401 	return 0;
402 }
403 
404 static void agp_controller_make_current(struct agp_controller *controller)
405 {
406 	struct agp_client *clients;
407 
408 	clients = controller->clients;
409 
410 	while (clients != NULL) {
411 		struct agp_file_private *priv;
412 
413 		priv = agp_find_private(clients->pid);
414 
415 		if (priv != NULL) {
416 			set_bit(AGP_FF_IS_VALID, &priv->access_flags);
417 			set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
418 		}
419 		clients = clients->next;
420 	}
421 
422 	agp_fe.current_controller = controller;
423 }
424 
425 static void agp_controller_release_current(struct agp_controller *controller,
426 				      struct agp_file_private *controller_priv)
427 {
428 	struct agp_client *clients;
429 
430 	clear_bit(AGP_FF_IS_VALID, &controller_priv->access_flags);
431 	clients = controller->clients;
432 
433 	while (clients != NULL) {
434 		struct agp_file_private *priv;
435 
436 		priv = agp_find_private(clients->pid);
437 
438 		if (priv != NULL)
439 			clear_bit(AGP_FF_IS_VALID, &priv->access_flags);
440 
441 		clients = clients->next;
442 	}
443 
444 	agp_fe.current_controller = NULL;
445 	agp_fe.used_by_controller = false;
446 	agp_backend_release(agp_bridge);
447 }
448 
449 /*
450  * Routines for managing client lists -
451  * These routines are for managing the list of auth'ed clients.
452  */
453 
454 static struct agp_client
455 *agp_find_client_in_controller(struct agp_controller *controller, pid_t id)
456 {
457 	struct agp_client *client;
458 
459 	if (controller == NULL)
460 		return NULL;
461 
462 	client = controller->clients;
463 
464 	while (client != NULL) {
465 		if (client->pid == id)
466 			return client;
467 		client = client->next;
468 	}
469 
470 	return NULL;
471 }
472 
473 static struct agp_controller *agp_find_controller_for_client(pid_t id)
474 {
475 	struct agp_controller *controller;
476 
477 	controller = agp_fe.controllers;
478 
479 	while (controller != NULL) {
480 		if ((agp_find_client_in_controller(controller, id)) != NULL)
481 			return controller;
482 		controller = controller->next;
483 	}
484 
485 	return NULL;
486 }
487 
488 struct agp_client *agp_find_client_by_pid(pid_t id)
489 {
490 	struct agp_client *temp;
491 
492 	if (agp_fe.current_controller == NULL)
493 		return NULL;
494 
495 	temp = agp_find_client_in_controller(agp_fe.current_controller, id);
496 	return temp;
497 }
498 
499 static void agp_insert_client(struct agp_client *client)
500 {
501 	struct agp_client *prev_client;
502 
503 	prev_client = agp_fe.current_controller->clients;
504 	client->next = prev_client;
505 
506 	if (prev_client != NULL)
507 		prev_client->prev = client;
508 
509 	agp_fe.current_controller->clients = client;
510 	agp_fe.current_controller->num_clients++;
511 }
512 
513 struct agp_client *agp_create_client(pid_t id)
514 {
515 	struct agp_client *new_client;
516 
517 	new_client = kzalloc(sizeof(struct agp_client), GFP_KERNEL);
518 	if (new_client == NULL)
519 		return NULL;
520 
521 	new_client->pid = id;
522 	agp_insert_client(new_client);
523 	return new_client;
524 }
525 
526 int agp_remove_client(pid_t id)
527 {
528 	struct agp_client *client;
529 	struct agp_client *prev_client;
530 	struct agp_client *next_client;
531 	struct agp_controller *controller;
532 
533 	controller = agp_find_controller_for_client(id);
534 	if (controller == NULL)
535 		return -EINVAL;
536 
537 	client = agp_find_client_in_controller(controller, id);
538 	if (client == NULL)
539 		return -EINVAL;
540 
541 	prev_client = client->prev;
542 	next_client = client->next;
543 
544 	if (prev_client != NULL) {
545 		prev_client->next = next_client;
546 		if (next_client != NULL)
547 			next_client->prev = prev_client;
548 
549 	} else {
550 		if (next_client != NULL)
551 			next_client->prev = NULL;
552 		controller->clients = next_client;
553 	}
554 
555 	controller->num_clients--;
556 	agp_remove_seg_from_client(client);
557 	kfree(client);
558 	return 0;
559 }
560 
561 /* End - Routines for managing client lists */
562 
563 /* File Operations */
564 
565 static int agp_mmap(struct file *file, struct vm_area_struct *vma)
566 {
567 	unsigned int size, current_size;
568 	unsigned long offset;
569 	struct agp_client *client;
570 	struct agp_file_private *priv = file->private_data;
571 	struct agp_kern_info kerninfo;
572 
573 	mutex_lock(&(agp_fe.agp_mutex));
574 
575 	if (agp_fe.backend_acquired != true)
576 		goto out_eperm;
577 
578 	if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags)))
579 		goto out_eperm;
580 
581 	agp_copy_info(agp_bridge, &kerninfo);
582 	size = vma->vm_end - vma->vm_start;
583 	current_size = kerninfo.aper_size;
584 	current_size = current_size * 0x100000;
585 	offset = vma->vm_pgoff << PAGE_SHIFT;
586 	DBG("%lx:%lx", offset, offset+size);
587 
588 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
589 		if ((size + offset) > current_size)
590 			goto out_inval;
591 
592 		client = agp_find_client_by_pid(current->pid);
593 
594 		if (client == NULL)
595 			goto out_eperm;
596 
597 		if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
598 			goto out_inval;
599 
600 		DBG("client vm_ops=%p", kerninfo.vm_ops);
601 		if (kerninfo.vm_ops) {
602 			vma->vm_ops = kerninfo.vm_ops;
603 		} else if (io_remap_pfn_range(vma, vma->vm_start,
604 				(kerninfo.aper_base + offset) >> PAGE_SHIFT,
605 				size,
606 				pgprot_writecombine(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,
623 				pgprot_writecombine(vma->vm_page_prot))) {
624 			goto out_again;
625 		}
626 		mutex_unlock(&(agp_fe.agp_mutex));
627 		return 0;
628 	}
629 
630 out_eperm:
631 	mutex_unlock(&(agp_fe.agp_mutex));
632 	return -EPERM;
633 
634 out_inval:
635 	mutex_unlock(&(agp_fe.agp_mutex));
636 	return -EINVAL;
637 
638 out_again:
639 	mutex_unlock(&(agp_fe.agp_mutex));
640 	return -EAGAIN;
641 }
642 
643 static int agp_release(struct inode *inode, struct file *file)
644 {
645 	struct agp_file_private *priv = file->private_data;
646 
647 	mutex_lock(&(agp_fe.agp_mutex));
648 
649 	DBG("priv=%p", priv);
650 
651 	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
652 		struct agp_controller *controller;
653 
654 		controller = agp_find_controller_by_pid(priv->my_pid);
655 
656 		if (controller != NULL) {
657 			if (controller == agp_fe.current_controller)
658 				agp_controller_release_current(controller, priv);
659 			agp_remove_controller(controller);
660 			controller = NULL;
661 		}
662 	}
663 
664 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
665 		agp_remove_client(priv->my_pid);
666 
667 	agp_remove_file_private(priv);
668 	kfree(priv);
669 	file->private_data = NULL;
670 	mutex_unlock(&(agp_fe.agp_mutex));
671 	return 0;
672 }
673 
674 static int agp_open(struct inode *inode, struct file *file)
675 {
676 	int minor = iminor(inode);
677 	struct agp_file_private *priv;
678 	struct agp_client *client;
679 
680 	if (minor != AGPGART_MINOR)
681 		return -ENXIO;
682 
683 	mutex_lock(&(agp_fe.agp_mutex));
684 
685 	priv = kzalloc(sizeof(struct agp_file_private), GFP_KERNEL);
686 	if (priv == NULL) {
687 		mutex_unlock(&(agp_fe.agp_mutex));
688 		return -ENOMEM;
689 	}
690 
691 	set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
692 	priv->my_pid = current->pid;
693 
694 	if (capable(CAP_SYS_RAWIO))
695 		/* Root priv, can be controller */
696 		set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
697 
698 	client = agp_find_client_by_pid(current->pid);
699 
700 	if (client != NULL) {
701 		set_bit(AGP_FF_IS_CLIENT, &priv->access_flags);
702 		set_bit(AGP_FF_IS_VALID, &priv->access_flags);
703 	}
704 	file->private_data = (void *) priv;
705 	agp_insert_file_private(priv);
706 	DBG("private=%p, client=%p", priv, client);
707 
708 	mutex_unlock(&(agp_fe.agp_mutex));
709 
710 	return 0;
711 }
712 
713 static int agpioc_info_wrap(struct agp_file_private *priv, void __user *arg)
714 {
715 	struct agp_info userinfo;
716 	struct agp_kern_info kerninfo;
717 
718 	agp_copy_info(agp_bridge, &kerninfo);
719 
720 	memset(&userinfo, 0, sizeof(userinfo));
721 	userinfo.version.major = kerninfo.version.major;
722 	userinfo.version.minor = kerninfo.version.minor;
723 	userinfo.bridge_id = kerninfo.device->vendor |
724 	    (kerninfo.device->device << 16);
725 	userinfo.agp_mode = kerninfo.mode;
726 	userinfo.aper_base = kerninfo.aper_base;
727 	userinfo.aper_size = kerninfo.aper_size;
728 	userinfo.pg_total = userinfo.pg_system = kerninfo.max_memory;
729 	userinfo.pg_used = kerninfo.current_memory;
730 
731 	if (copy_to_user(arg, &userinfo, sizeof(struct agp_info)))
732 		return -EFAULT;
733 
734 	return 0;
735 }
736 
737 int agpioc_acquire_wrap(struct agp_file_private *priv)
738 {
739 	struct agp_controller *controller;
740 
741 	DBG("");
742 
743 	if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
744 		return -EPERM;
745 
746 	if (agp_fe.current_controller != NULL)
747 		return -EBUSY;
748 
749 	if (!agp_bridge)
750 		return -ENODEV;
751 
752         if (atomic_read(&agp_bridge->agp_in_use))
753                 return -EBUSY;
754 
755 	atomic_inc(&agp_bridge->agp_in_use);
756 
757 	agp_fe.backend_acquired = true;
758 
759 	controller = agp_find_controller_by_pid(priv->my_pid);
760 
761 	if (controller != NULL) {
762 		agp_controller_make_current(controller);
763 	} else {
764 		controller = agp_create_controller(priv->my_pid);
765 
766 		if (controller == NULL) {
767 			agp_fe.backend_acquired = false;
768 			agp_backend_release(agp_bridge);
769 			return -ENOMEM;
770 		}
771 		agp_insert_controller(controller);
772 		agp_controller_make_current(controller);
773 	}
774 
775 	set_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags);
776 	set_bit(AGP_FF_IS_VALID, &priv->access_flags);
777 	return 0;
778 }
779 
780 int agpioc_release_wrap(struct agp_file_private *priv)
781 {
782 	DBG("");
783 	agp_controller_release_current(agp_fe.current_controller, priv);
784 	return 0;
785 }
786 
787 int agpioc_setup_wrap(struct agp_file_private *priv, void __user *arg)
788 {
789 	struct agp_setup mode;
790 
791 	DBG("");
792 	if (copy_from_user(&mode, arg, sizeof(struct agp_setup)))
793 		return -EFAULT;
794 
795 	agp_enable(agp_bridge, mode.agp_mode);
796 	return 0;
797 }
798 
799 static int agpioc_reserve_wrap(struct agp_file_private *priv, void __user *arg)
800 {
801 	struct agp_region reserve;
802 	struct agp_client *client;
803 	struct agp_file_private *client_priv;
804 
805 	DBG("");
806 	if (copy_from_user(&reserve, arg, sizeof(struct agp_region)))
807 		return -EFAULT;
808 
809 	if ((unsigned) reserve.seg_count >= ~0U/sizeof(struct agp_segment))
810 		return -EFAULT;
811 
812 	client = agp_find_client_by_pid(reserve.pid);
813 
814 	if (reserve.seg_count == 0) {
815 		/* remove a client */
816 		client_priv = agp_find_private(reserve.pid);
817 
818 		if (client_priv != NULL) {
819 			set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
820 			set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
821 		}
822 		if (client == NULL) {
823 			/* client is already removed */
824 			return 0;
825 		}
826 		return agp_remove_client(reserve.pid);
827 	} else {
828 		struct agp_segment *segment;
829 
830 		if (reserve.seg_count >= 16384)
831 			return -EINVAL;
832 
833 		segment = kmalloc((sizeof(struct agp_segment) * reserve.seg_count),
834 				  GFP_KERNEL);
835 
836 		if (segment == NULL)
837 			return -ENOMEM;
838 
839 		if (copy_from_user(segment, (void __user *) reserve.seg_list,
840 				   sizeof(struct agp_segment) * reserve.seg_count)) {
841 			kfree(segment);
842 			return -EFAULT;
843 		}
844 		reserve.seg_list = segment;
845 
846 		if (client == NULL) {
847 			/* Create the client and add the segment */
848 			client = agp_create_client(reserve.pid);
849 
850 			if (client == NULL) {
851 				kfree(segment);
852 				return -ENOMEM;
853 			}
854 			client_priv = agp_find_private(reserve.pid);
855 
856 			if (client_priv != NULL) {
857 				set_bit(AGP_FF_IS_CLIENT, &client_priv->access_flags);
858 				set_bit(AGP_FF_IS_VALID, &client_priv->access_flags);
859 			}
860 		}
861 		return agp_create_segment(client, &reserve);
862 	}
863 	/* Will never really happen */
864 	return -EINVAL;
865 }
866 
867 int agpioc_protect_wrap(struct agp_file_private *priv)
868 {
869 	DBG("");
870 	/* This function is not currently implemented */
871 	return -EINVAL;
872 }
873 
874 static int agpioc_allocate_wrap(struct agp_file_private *priv, void __user *arg)
875 {
876 	struct agp_memory *memory;
877 	struct agp_allocate alloc;
878 
879 	DBG("");
880 	if (copy_from_user(&alloc, arg, sizeof(struct agp_allocate)))
881 		return -EFAULT;
882 
883 	if (alloc.type >= AGP_USER_TYPES)
884 		return -EINVAL;
885 
886 	memory = agp_allocate_memory_wrap(alloc.pg_count, alloc.type);
887 
888 	if (memory == NULL)
889 		return -ENOMEM;
890 
891 	alloc.key = memory->key;
892 	alloc.physical = memory->physical;
893 
894 	if (copy_to_user(arg, &alloc, sizeof(struct agp_allocate))) {
895 		agp_free_memory_wrap(memory);
896 		return -EFAULT;
897 	}
898 	return 0;
899 }
900 
901 int agpioc_deallocate_wrap(struct agp_file_private *priv, int arg)
902 {
903 	struct agp_memory *memory;
904 
905 	DBG("");
906 	memory = agp_find_mem_by_key(arg);
907 
908 	if (memory == NULL)
909 		return -EINVAL;
910 
911 	agp_free_memory_wrap(memory);
912 	return 0;
913 }
914 
915 static int agpioc_bind_wrap(struct agp_file_private *priv, void __user *arg)
916 {
917 	struct agp_bind bind_info;
918 	struct agp_memory *memory;
919 
920 	DBG("");
921 	if (copy_from_user(&bind_info, arg, sizeof(struct agp_bind)))
922 		return -EFAULT;
923 
924 	memory = agp_find_mem_by_key(bind_info.key);
925 
926 	if (memory == NULL)
927 		return -EINVAL;
928 
929 	return agp_bind_memory(memory, bind_info.pg_start);
930 }
931 
932 static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
933 {
934 	struct agp_memory *memory;
935 	struct agp_unbind unbind;
936 
937 	DBG("");
938 	if (copy_from_user(&unbind, arg, sizeof(struct agp_unbind)))
939 		return -EFAULT;
940 
941 	memory = agp_find_mem_by_key(unbind.key);
942 
943 	if (memory == NULL)
944 		return -EINVAL;
945 
946 	return agp_unbind_memory(memory);
947 }
948 
949 static long agp_ioctl(struct file *file,
950 		     unsigned int cmd, unsigned long arg)
951 {
952 	struct agp_file_private *curr_priv = file->private_data;
953 	int ret_val = -ENOTTY;
954 
955 	DBG("priv=%p, cmd=%x", curr_priv, cmd);
956 	mutex_lock(&(agp_fe.agp_mutex));
957 
958 	if ((agp_fe.current_controller == NULL) &&
959 	    (cmd != AGPIOC_ACQUIRE)) {
960 		ret_val = -EINVAL;
961 		goto ioctl_out;
962 	}
963 	if ((agp_fe.backend_acquired != true) &&
964 	    (cmd != AGPIOC_ACQUIRE)) {
965 		ret_val = -EBUSY;
966 		goto ioctl_out;
967 	}
968 	if (cmd != AGPIOC_ACQUIRE) {
969 		if (!(test_bit(AGP_FF_IS_CONTROLLER, &curr_priv->access_flags))) {
970 			ret_val = -EPERM;
971 			goto ioctl_out;
972 		}
973 		/* Use the original pid of the controller,
974 		 * in case it's threaded */
975 
976 		if (agp_fe.current_controller->pid != curr_priv->my_pid) {
977 			ret_val = -EBUSY;
978 			goto ioctl_out;
979 		}
980 	}
981 
982 	switch (cmd) {
983 	case AGPIOC_INFO:
984 		ret_val = agpioc_info_wrap(curr_priv, (void __user *) arg);
985 		break;
986 
987 	case AGPIOC_ACQUIRE:
988 		ret_val = agpioc_acquire_wrap(curr_priv);
989 		break;
990 
991 	case AGPIOC_RELEASE:
992 		ret_val = agpioc_release_wrap(curr_priv);
993 		break;
994 
995 	case AGPIOC_SETUP:
996 		ret_val = agpioc_setup_wrap(curr_priv, (void __user *) arg);
997 		break;
998 
999 	case AGPIOC_RESERVE:
1000 		ret_val = agpioc_reserve_wrap(curr_priv, (void __user *) arg);
1001 		break;
1002 
1003 	case AGPIOC_PROTECT:
1004 		ret_val = agpioc_protect_wrap(curr_priv);
1005 		break;
1006 
1007 	case AGPIOC_ALLOCATE:
1008 		ret_val = agpioc_allocate_wrap(curr_priv, (void __user *) arg);
1009 		break;
1010 
1011 	case AGPIOC_DEALLOCATE:
1012 		ret_val = agpioc_deallocate_wrap(curr_priv, (int) arg);
1013 		break;
1014 
1015 	case AGPIOC_BIND:
1016 		ret_val = agpioc_bind_wrap(curr_priv, (void __user *) arg);
1017 		break;
1018 
1019 	case AGPIOC_UNBIND:
1020 		ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
1021 		break;
1022 
1023 	case AGPIOC_CHIPSET_FLUSH:
1024 		break;
1025 	}
1026 
1027 ioctl_out:
1028 	DBG("ioctl returns %d\n", ret_val);
1029 	mutex_unlock(&(agp_fe.agp_mutex));
1030 	return ret_val;
1031 }
1032 
1033 static const struct file_operations agp_fops =
1034 {
1035 	.owner		= THIS_MODULE,
1036 	.llseek		= no_llseek,
1037 	.unlocked_ioctl	= agp_ioctl,
1038 #ifdef CONFIG_COMPAT
1039 	.compat_ioctl	= compat_agp_ioctl,
1040 #endif
1041 	.mmap		= agp_mmap,
1042 	.open		= agp_open,
1043 	.release	= agp_release,
1044 };
1045 
1046 static struct miscdevice agp_miscdev =
1047 {
1048 	.minor	= AGPGART_MINOR,
1049 	.name	= "agpgart",
1050 	.fops	= &agp_fops
1051 };
1052 
1053 int agp_frontend_initialize(void)
1054 {
1055 	memset(&agp_fe, 0, sizeof(struct agp_front_data));
1056 	mutex_init(&(agp_fe.agp_mutex));
1057 
1058 	if (misc_register(&agp_miscdev)) {
1059 		printk(KERN_ERR PFX "unable to get minor: %d\n", AGPGART_MINOR);
1060 		return -EIO;
1061 	}
1062 	return 0;
1063 }
1064 
1065 void agp_frontend_cleanup(void)
1066 {
1067 	misc_deregister(&agp_miscdev);
1068 }
1069