[net-next-2.6.git] / drivers / char / agp / backend.c

/*
 * AGPGART driver backend routines.
 * Copyright (C) 2004 Silicon Graphics, Inc.
 * Copyright (C) 2002-2003 Dave Jones.
 * Copyright (C) 1999 Jeff Hartmann.
 * Copyright (C) 1999 Precision Insight, Inc.
 * Copyright (C) 1999 Xi Graphics, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * JEFF HARTMANN, DAVE JONES, OR ANY OTHER CONTRIBUTORS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * TODO:
 * - Allocate more than order 0 pages to avoid too much linear map splitting.
 */
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/miscdevice.h>
#include <linux/pm.h>
#include <linux/agp_backend.h>
#include <linux/agpgart.h>
#include <linux/vmalloc.h>
#include <asm/io.h>
#include "agp.h"

/* Due to XFree86 brain-damage, we can't go to 1.0 until they
 * fix some real stupidity. It's only by chance we can bump
 * past 0.99 at all due to some boolean logic error. */
#define AGPGART_VERSION_MAJOR 0
#define AGPGART_VERSION_MINOR 103
static const struct agp_version agp_current_version =
{
	.major = AGPGART_VERSION_MAJOR,
	.minor = AGPGART_VERSION_MINOR,
};

struct agp_bridge_data *(*agp_find_bridge)(struct pci_dev *) =
	&agp_generic_find_bridge;

struct agp_bridge_data *agp_bridge;
LIST_HEAD(agp_bridges);
EXPORT_SYMBOL(agp_bridge);
EXPORT_SYMBOL(agp_bridges);
EXPORT_SYMBOL(agp_find_bridge);

/**
 *	agp_backend_acquire  -  attempt to acquire an agp backend.
 *
 */
struct agp_bridge_data *agp_backend_acquire(struct pci_dev *pdev)
{
	struct agp_bridge_data *bridge;

	bridge = agp_find_bridge(pdev);

	if (!bridge)
		return NULL;

	if (atomic_read(&bridge->agp_in_use))
		return NULL;
	atomic_inc(&bridge->agp_in_use);
	return bridge;
}
EXPORT_SYMBOL(agp_backend_acquire);


/**
 *	agp_backend_release  -  release the lock on the agp backend.
 *
 *	The caller must insure that the graphics aperture translation table
 *	is read for use by another entity.
 *
 *	(Ensure that all memory it bound is unbound.)
 */
void agp_backend_release(struct agp_bridge_data *bridge)
{

	if (bridge)
		atomic_dec(&bridge->agp_in_use);
}
EXPORT_SYMBOL(agp_backend_release);


static const struct { int mem, agp; } maxes_table[] = {
	{0, 0},
	{32, 4},
	{64, 28},
	{128, 96},
	{256, 204},
	{512, 440},
	{1024, 942},
	{2048, 1920},
	{4096, 3932}
};

static int agp_find_max(void)
{
	long memory, index, result;

#if PAGE_SHIFT < 20
	memory = num_physpages >> (20 - PAGE_SHIFT);
#else
	memory = num_physpages << (PAGE_SHIFT - 20);
#endif
	index = 1;

	while ((memory > maxes_table[index].mem) && (index < 8))
		index++;

	result = maxes_table[index - 1].agp +
	   ( (memory - maxes_table[index - 1].mem)  *
	     (maxes_table[index].agp - maxes_table[index - 1].agp)) /
	   (maxes_table[index].mem - maxes_table[index - 1].mem);

	result = result << (20 - PAGE_SHIFT);
	return result;
}


static int agp_backend_initialize(struct agp_bridge_data *bridge)
{
	int size_value, rc, got_gatt=0, got_keylist=0;

	bridge->max_memory_agp = agp_find_max();
	bridge->version = &agp_current_version;

	if (bridge->driver->needs_scratch_page) {
		struct page *page = bridge->driver->agp_alloc_page(bridge);

		if (!page) {
			dev_err(&bridge->dev->dev,
				"can't get memory for scratch page\n");
			return -ENOMEM;
		}

		bridge->scratch_page_real = phys_to_gart(page_to_phys(page));
		if (bridge->driver->agp_map_page) {
			if (bridge->driver->agp_map_page(phys_to_virt(page_to_phys(page)),
							 &bridge->scratch_page_dma)) {
				dev_err(&bridge->dev->dev,
					"unable to dma-map scratch page\n");
				rc = -ENOMEM;
				goto err_out_nounmap;
			}
		} else {
			bridge->scratch_page_dma = phys_to_gart(page_to_phys(page));
		}

		bridge->scratch_page = bridge->driver->mask_memory(bridge,
						   bridge->scratch_page_dma, 0);
	}

	size_value = bridge->driver->fetch_size();
	if (size_value == 0) {
		dev_err(&bridge->dev->dev, "can't determine aperture size\n");
		rc = -EINVAL;
		goto err_out;
	}
	if (bridge->driver->create_gatt_table(bridge)) {
		dev_err(&bridge->dev->dev,
			"can't get memory for graphics translation table\n");
		rc = -ENOMEM;
		goto err_out;
	}
	got_gatt = 1;

	bridge->key_list = vmalloc(PAGE_SIZE * 4);
	if (bridge->key_list == NULL) {
		dev_err(&bridge->dev->dev,
			"can't allocate memory for key lists\n");
		rc = -ENOMEM;
		goto err_out;
	}
	got_keylist = 1;

	/* FIXME vmalloc'd memory not guaranteed contiguous */
	memset(bridge->key_list, 0, PAGE_SIZE * 4);

	if (bridge->driver->configure()) {
		dev_err(&bridge->dev->dev, "error configuring host chipset\n");
		rc = -EINVAL;
		goto err_out;
	}
	INIT_LIST_HEAD(&bridge->mapped_list);
	spin_lock_init(&bridge->mapped_lock);

	return 0;

err_out:
	if (bridge->driver->needs_scratch_page &&
	    bridge->driver->agp_unmap_page) {
		void *va = gart_to_virt(bridge->scratch_page_real);

		bridge->driver->agp_unmap_page(va, bridge->scratch_page_dma);
	}
err_out_nounmap:
	if (bridge->driver->needs_scratch_page) {
		void *va = gart_to_virt(bridge->scratch_page_real);

		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
	}
	if (got_gatt)
		bridge->driver->free_gatt_table(bridge);
	if (got_keylist) {
		vfree(bridge->key_list);
		bridge->key_list = NULL;
	}
	return rc;
}

/* cannot be __exit b/c as it could be called from __init code */
static void agp_backend_cleanup(struct agp_bridge_data *bridge)
{
	if (bridge->driver->cleanup)
		bridge->driver->cleanup();
	if (bridge->driver->free_gatt_table)
		bridge->driver->free_gatt_table(bridge);

	vfree(bridge->key_list);
	bridge->key_list = NULL;

	if (bridge->driver->agp_destroy_page &&
	    bridge->driver->needs_scratch_page) {
		void *va = gart_to_virt(bridge->scratch_page_real);

		if (bridge->driver->agp_unmap_page)
			bridge->driver->agp_unmap_page(va,
					       bridge->scratch_page_dma);

		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
	}
}

/* When we remove the global variable agp_bridge from all drivers
 * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
 */

struct agp_bridge_data *agp_alloc_bridge(void)
{
	struct agp_bridge_data *bridge;

	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
	if (!bridge)
		return NULL;

	atomic_set(&bridge->agp_in_use, 0);
	atomic_set(&bridge->current_memory_agp, 0);

	if (list_empty(&agp_bridges))
		agp_bridge = bridge;

	return bridge;
}
EXPORT_SYMBOL(agp_alloc_bridge);


void agp_put_bridge(struct agp_bridge_data *bridge)
{
        kfree(bridge);

        if (list_empty(&agp_bridges))
                agp_bridge = NULL;
}
EXPORT_SYMBOL(agp_put_bridge);


int agp_add_bridge(struct agp_bridge_data *bridge)
{
	int error;

	if (agp_off)
		return -ENODEV;

	if (!bridge->dev) {
		printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
		return -EINVAL;
	}

	/* Grab reference on the chipset driver. */
	if (!try_module_get(bridge->driver->owner)) {
		dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
		return -EINVAL;
	}

	error = agp_backend_initialize(bridge);
	if (error) {
		dev_info(&bridge->dev->dev,
			 "agp_backend_initialize() failed\n");
		goto err_out;
	}

	if (list_empty(&agp_bridges)) {
		error = agp_frontend_initialize();
		if (error) {
			dev_info(&bridge->dev->dev,
				 "agp_frontend_initialize() failed\n");
			goto frontend_err;
		}

		dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
			 bridge->driver->fetch_size(), bridge->gart_bus_addr);

	}

	list_add(&bridge->list, &agp_bridges);
	return 0;

frontend_err:
	agp_backend_cleanup(bridge);
err_out:
	module_put(bridge->driver->owner);
	agp_put_bridge(bridge);
	return error;
}
EXPORT_SYMBOL_GPL(agp_add_bridge);


void agp_remove_bridge(struct agp_bridge_data *bridge)
{
	agp_backend_cleanup(bridge);
	list_del(&bridge->list);
	if (list_empty(&agp_bridges))
		agp_frontend_cleanup();
	module_put(bridge->driver->owner);
}
EXPORT_SYMBOL_GPL(agp_remove_bridge);

int agp_off;
int agp_try_unsupported_boot;
EXPORT_SYMBOL(agp_off);
EXPORT_SYMBOL(agp_try_unsupported_boot);

static int __init agp_init(void)
{
	if (!agp_off)
		printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
			AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
	return 0;
}

static void __exit agp_exit(void)
{
}

#ifndef MODULE
static __init int agp_setup(char *s)
{
	if (!strcmp(s,"off"))
		agp_off = 1;
	if (!strcmp(s,"try_unsupported"))
		agp_try_unsupported_boot = 1;
	return 1;
}
__setup("agp=", agp_setup);
#endif

MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
MODULE_DESCRIPTION("AGP GART driver");
MODULE_LICENSE("GPL and additional rights");
MODULE_ALIAS_MISCDEV(AGPGART_MINOR);

module_init(agp_init);
module_exit(agp_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* AGPGART driver backend routines.
	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, DAVE JONES, 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	* TODO:
	28	* - Allocate more than order 0 pages to avoid too much linear map splitting.
	29	*/
	30	#include <linux/module.h>
	31	#include <linux/pci.h>
	32	#include <linux/init.h>
	33	#include <linux/pagemap.h>
	34	#include <linux/miscdevice.h>
	35	#include <linux/pm.h>
	36	#include <linux/agp_backend.h>
	37	#include <linux/agpgart.h>
	38	#include <linux/vmalloc.h>
	39	#include <asm/io.h>
	40	#include "agp.h"
	41
	42	/* Due to XFree86 brain-damage, we can't go to 1.0 until they
	43	* fix some real stupidity. It's only by chance we can bump
	44	* past 0.99 at all due to some boolean logic error. */
	45	#define AGPGART_VERSION_MAJOR 0
a13af4b4	46	#define AGPGART_VERSION_MINOR 103
e7745d4e	47	static const struct agp_version agp_current_version =
1da177e4 LT	48	{
	49	.major = AGPGART_VERSION_MAJOR,
	50	.minor = AGPGART_VERSION_MINOR,
	51	};
	52
	53	struct agp_bridge_data (agp_find_bridge)(struct pci_dev *) =
	54	&agp_generic_find_bridge;
	55
	56	struct agp_bridge_data *agp_bridge;
	57	LIST_HEAD(agp_bridges);
	58	EXPORT_SYMBOL(agp_bridge);
	59	EXPORT_SYMBOL(agp_bridges);
	60	EXPORT_SYMBOL(agp_find_bridge);
	61
	62	/**
	63	* agp_backend_acquire - attempt to acquire an agp backend.
	64	*
	65	*/
	66	struct agp_bridge_data agp_backend_acquire(struct pci_dev pdev)
	67	{
	68	struct agp_bridge_data *bridge;
	69
	70	bridge = agp_find_bridge(pdev);
	71
	72	if (!bridge)
	73	return NULL;
	74
	75	if (atomic_read(&bridge->agp_in_use))
	76	return NULL;
	77	atomic_inc(&bridge->agp_in_use);
	78	return bridge;
	79	}
	80	EXPORT_SYMBOL(agp_backend_acquire);
	81
	82
	83	/**
	84	* agp_backend_release - release the lock on the agp backend.
	85	*
	86	* The caller must insure that the graphics aperture translation table
	87	* is read for use by another entity.
	88	*
	89	* (Ensure that all memory it bound is unbound.)
	90	*/
	91	void agp_backend_release(struct agp_bridge_data *bridge)
	92	{
	93
	94	if (bridge)
	95	atomic_dec(&bridge->agp_in_use);
	96	}
	97	EXPORT_SYMBOL(agp_backend_release);
	98
	99
5e9ad06a	100	static const struct { int mem, agp; } maxes_table[] = {
1da177e4 LT	101	{0, 0},
	102	{32, 4},
	103	{64, 28},
	104	{128, 96},
	105	{256, 204},
	106	{512, 440},
	107	{1024, 942},
	108	{2048, 1920},
	109	{4096, 3932}
	110	};
	111
	112	static int agp_find_max(void)
	113	{
	114	long memory, index, result;
	115
	116	#if PAGE_SHIFT < 20
	117	memory = num_physpages >> (20 - PAGE_SHIFT);
	118	#else
	119	memory = num_physpages << (PAGE_SHIFT - 20);
	120	#endif
	121	index = 1;
	122
	123	while ((memory > maxes_table[index].mem) && (index < 8))
	124	index++;
	125
	126	result = maxes_table[index - 1].agp +
	127	( (memory - maxes_table[index - 1].mem) *
	128	(maxes_table[index].agp - maxes_table[index - 1].agp)) /
	129	(maxes_table[index].mem - maxes_table[index - 1].mem);
	130
	131	result = result << (20 - PAGE_SHIFT);
	132	return result;
	133	}
	134
	135
	136	static int agp_backend_initialize(struct agp_bridge_data *bridge)
	137	{
	138	int size_value, rc, got_gatt=0, got_keylist=0;
	139
	140	bridge->max_memory_agp = agp_find_max();
	141	bridge->version = &agp_current_version;
	142
	143	if (bridge->driver->needs_scratch_page) {
07613ba2	144	struct page *page = bridge->driver->agp_alloc_page(bridge);
1da177e4	145
07613ba2	146	if (!page) {
e3cf6951 BH	147	dev_err(&bridge->dev->dev,
e3cf6951 BH	148	"can't get memory for scratch page\n");
1da177e4 LT	149	return -ENOMEM;
	150	}
	151
07613ba2	152	bridge->scratch_page_real = phys_to_gart(page_to_phys(page));
56ec4c1e DW	153	if (bridge->driver->agp_map_page) {
	154	if (bridge->driver->agp_map_page(phys_to_virt(page_to_phys(page)),
	155	&bridge->scratch_page_dma)) {
	156	dev_err(&bridge->dev->dev,
	157	"unable to dma-map scratch page\n");
	158	rc = -ENOMEM;
	159	goto err_out_nounmap;
	160	}
	161	} else {
	162	bridge->scratch_page_dma = phys_to_gart(page_to_phys(page));
ff663cf8	163	}
56ec4c1e DW	164
	165	bridge->scratch_page = bridge->driver->mask_memory(bridge,
	166	bridge->scratch_page_dma, 0);
1da177e4 LT	167	}
	168
	169	size_value = bridge->driver->fetch_size();
	170	if (size_value == 0) {
e3cf6951	171	dev_err(&bridge->dev->dev, "can't determine aperture size\n");
1da177e4 LT	172	rc = -EINVAL;
	173	goto err_out;
	174	}
	175	if (bridge->driver->create_gatt_table(bridge)) {
e3cf6951 BH	176	dev_err(&bridge->dev->dev,
e3cf6951 BH	177	"can't get memory for graphics translation table\n");
1da177e4 LT	178	rc = -ENOMEM;
	179	goto err_out;
	180	}
	181	got_gatt = 1;
	182
	183	bridge->key_list = vmalloc(PAGE_SIZE * 4);
	184	if (bridge->key_list == NULL) {
e3cf6951 BH	185	dev_err(&bridge->dev->dev,
e3cf6951 BH	186	"can't allocate memory for key lists\n");
1da177e4 LT	187	rc = -ENOMEM;
	188	goto err_out;
	189	}
	190	got_keylist = 1;
	191
	192	/* FIXME vmalloc'd memory not guaranteed contiguous */
	193	memset(bridge->key_list, 0, PAGE_SIZE * 4);
	194
	195	if (bridge->driver->configure()) {
e3cf6951	196	dev_err(&bridge->dev->dev, "error configuring host chipset\n");
1da177e4 LT	197	rc = -EINVAL;
	198	goto err_out;
	199	}
a8c84df9 KP	200	INIT_LIST_HEAD(&bridge->mapped_list);
a8c84df9 KP	201	spin_lock_init(&bridge->mapped_lock);
1da177e4 LT	202
	203	return 0;
	204
	205	err_out:
ff663cf8 ZW	206	if (bridge->driver->needs_scratch_page &&
	207	bridge->driver->agp_unmap_page) {
	208	void *va = gart_to_virt(bridge->scratch_page_real);
	209
	210	bridge->driver->agp_unmap_page(va, bridge->scratch_page_dma);
	211	}
	212	err_out_nounmap:
88d51967	213	if (bridge->driver->needs_scratch_page) {
da503fa6 JB	214	void *va = gart_to_virt(bridge->scratch_page_real);
	215
	216	bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
	217	bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
88d51967	218	}
1da177e4 LT	219	if (got_gatt)
	220	bridge->driver->free_gatt_table(bridge);
	221	if (got_keylist) {
	222	vfree(bridge->key_list);
	223	bridge->key_list = NULL;
	224	}
	225	return rc;
	226	}
	227
	228	/* cannot be __exit b/c as it could be called from __init code */
	229	static void agp_backend_cleanup(struct agp_bridge_data *bridge)
	230	{
	231	if (bridge->driver->cleanup)
	232	bridge->driver->cleanup();
	233	if (bridge->driver->free_gatt_table)
	234	bridge->driver->free_gatt_table(bridge);
f9101210 JJ	235
	236	vfree(bridge->key_list);
	237	bridge->key_list = NULL;
1da177e4 LT	238
1da177e4 LT	239	if (bridge->driver->agp_destroy_page &&
88d51967	240	bridge->driver->needs_scratch_page) {
da503fa6 JB	241	void *va = gart_to_virt(bridge->scratch_page_real);
da503fa6 JB	242
ff663cf8 ZW	243	if (bridge->driver->agp_unmap_page)
	244	bridge->driver->agp_unmap_page(va,
	245	bridge->scratch_page_dma);
	246
da503fa6 JB	247	bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
da503fa6 JB	248	bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
88d51967	249	}
1da177e4 LT	250	}
	251
	252	/* When we remove the global variable agp_bridge from all drivers
	253	* then agp_alloc_bridge and agp_generic_find_bridge need to be updated
	254	*/
	255
	256	struct agp_bridge_data *agp_alloc_bridge(void)
	257	{
0ea27d9f	258	struct agp_bridge_data *bridge;
6a92a4e0	259
0ea27d9f	260	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
1da177e4 LT	261	if (!bridge)
	262	return NULL;
	263
1da177e4 LT	264	atomic_set(&bridge->agp_in_use, 0);
	265	atomic_set(&bridge->current_memory_agp, 0);
	266
	267	if (list_empty(&agp_bridges))
	268	agp_bridge = bridge;
	269
	270	return bridge;
	271	}
	272	EXPORT_SYMBOL(agp_alloc_bridge);
	273
	274
	275	void agp_put_bridge(struct agp_bridge_data *bridge)
	276	{
	277	kfree(bridge);
	278
	279	if (list_empty(&agp_bridges))
	280	agp_bridge = NULL;
	281	}
	282	EXPORT_SYMBOL(agp_put_bridge);
	283
	284
	285	int agp_add_bridge(struct agp_bridge_data *bridge)
	286	{
	287	int error;
	288
	289	if (agp_off)
	290	return -ENODEV;
	291
	292	if (!bridge->dev) {
	293	printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
	294	return -EINVAL;
	295	}
	296
	297	/* Grab reference on the chipset driver. */
	298	if (!try_module_get(bridge->driver->owner)) {
e3cf6951	299	dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
1da177e4 LT	300	return -EINVAL;
	301	}
	302
	303	error = agp_backend_initialize(bridge);
	304	if (error) {
e3cf6951 BH	305	dev_info(&bridge->dev->dev,
e3cf6951 BH	306	"agp_backend_initialize() failed\n");
1da177e4 LT	307	goto err_out;
	308	}
	309
	310	if (list_empty(&agp_bridges)) {
	311	error = agp_frontend_initialize();
	312	if (error) {
e3cf6951 BH	313	dev_info(&bridge->dev->dev,
e3cf6951 BH	314	"agp_frontend_initialize() failed\n");
1da177e4 LT	315	goto frontend_err;
	316	}
	317
e3cf6951 BH	318	dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
e3cf6951 BH	319	bridge->driver->fetch_size(), bridge->gart_bus_addr);
1da177e4 LT	320
	321	}
	322
	323	list_add(&bridge->list, &agp_bridges);
	324	return 0;
	325
	326	frontend_err:
	327	agp_backend_cleanup(bridge);
	328	err_out:
	329	module_put(bridge->driver->owner);
	330	agp_put_bridge(bridge);
	331	return error;
	332	}
	333	EXPORT_SYMBOL_GPL(agp_add_bridge);
	334
	335
	336	void agp_remove_bridge(struct agp_bridge_data *bridge)
	337	{
	338	agp_backend_cleanup(bridge);
	339	list_del(&bridge->list);
	340	if (list_empty(&agp_bridges))
	341	agp_frontend_cleanup();
	342	module_put(bridge->driver->owner);
	343	}
	344	EXPORT_SYMBOL_GPL(agp_remove_bridge);
	345
	346	int agp_off;
	347	int agp_try_unsupported_boot;
	348	EXPORT_SYMBOL(agp_off);
	349	EXPORT_SYMBOL(agp_try_unsupported_boot);
	350
	351	static int __init agp_init(void)
	352	{
	353	if (!agp_off)
70e8992e	354	printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
1da177e4 LT	355	AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
	356	return 0;
	357	}
	358
408b664a	359	static void __exit agp_exit(void)
1da177e4 LT	360	{
	361	}
	362
	363	#ifndef MODULE
	364	static __init int agp_setup(char *s)
	365	{
	366	if (!strcmp(s,"off"))
	367	agp_off = 1;
	368	if (!strcmp(s,"try_unsupported"))
	369	agp_try_unsupported_boot = 1;
	370	return 1;
	371	}
	372	__setup("agp=", agp_setup);
	373	#endif
	374
f4432c5c	375	MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
1da177e4 LT	376	MODULE_DESCRIPTION("AGP GART driver");
	377	MODULE_LICENSE("GPL and additional rights");
	378	MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
	379
	380	module_init(agp_init);
	381	module_exit(agp_exit);
	382