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