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