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 <asm/uaccess.h>
42#include <asm/pgtable.h>
43#include "agp.h"
44
45struct agp_front_data agp_fe;
46
47struct 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
66static 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
99static struct
100agp_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
125static 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
140static 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
155static pgprot_t agp_convert_mmap_flags(int prot)
156{
157	unsigned long prot_bits;
158
159	prot_bits = calc_vm_prot_bits(prot) | VM_SHARED;
160	return vm_get_page_prot(prot_bits);
161}
162
163int 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 */
199static 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
215struct 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
230static 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
242static 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 */
270void agp_free_memory_wrap(struct agp_memory *memory)
271{
272	agp_remove_from_pool(memory);
273	agp_free_memory(memory);
274}
275
276struct 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
293static 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
308static 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
320static 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
335static 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
358static 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
372static 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
404static 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
425static 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
454static 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
473static 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
488struct 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
499static 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
513struct 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
526int 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
565static 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
630out_eperm:
631	mutex_unlock(&(agp_fe.agp_mutex));
632	return -EPERM;
633
634out_inval:
635	mutex_unlock(&(agp_fe.agp_mutex));
636	return -EINVAL;
637
638out_again:
639	mutex_unlock(&(agp_fe.agp_mutex));
640	return -EAGAIN;
641}
642
643static 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
674static 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
713static 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
737int 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
780int 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
787int 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
799static 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
867int agpioc_protect_wrap(struct agp_file_private *priv)
868{
869	DBG("");
870	/* This function is not currently implemented */
871	return -EINVAL;
872}
873
874static 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
901int 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
915static 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
932static 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
949static 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
1027ioctl_out:
1028	DBG("ioctl returns %d\n", ret_val);
1029	mutex_unlock(&(agp_fe.agp_mutex));
1030	return ret_val;
1031}
1032
1033static 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
1046static struct miscdevice agp_miscdev =
1047{
1048	.minor	= AGPGART_MINOR,
1049	.name	= "agpgart",
1050	.fops	= &agp_fops
1051};
1052
1053int 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
1065void agp_frontend_cleanup(void)
1066{
1067	misc_deregister(&agp_miscdev);
1068}
1069