xref: /openbmc/linux/drivers/char/agp/backend.c (revision e3b9f1e8)
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
48 static const struct agp_version agp_current_version =
49 {
50 	.major = AGPGART_VERSION_MAJOR,
51 	.minor = AGPGART_VERSION_MINOR,
52 };
53 
54 struct agp_bridge_data *(*agp_find_bridge)(struct pci_dev *) =
55 	&agp_generic_find_bridge;
56 
57 struct agp_bridge_data *agp_bridge;
58 LIST_HEAD(agp_bridges);
59 EXPORT_SYMBOL(agp_bridge);
60 EXPORT_SYMBOL(agp_bridges);
61 EXPORT_SYMBOL(agp_find_bridge);
62 
63 /**
64  *	agp_backend_acquire  -  attempt to acquire an agp backend.
65  *
66  */
67 struct 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 }
81 EXPORT_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  */
92 void agp_backend_release(struct agp_bridge_data *bridge)
93 {
94 
95 	if (bridge)
96 		atomic_dec(&bridge->agp_in_use);
97 }
98 EXPORT_SYMBOL(agp_backend_release);
99 
100 
101 static 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 
113 static 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 
137 static 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 
195 err_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 */
212 static 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 
235 struct 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 }
251 EXPORT_SYMBOL(agp_alloc_bridge);
252 
253 
254 void agp_put_bridge(struct agp_bridge_data *bridge)
255 {
256         kfree(bridge);
257 
258         if (list_empty(&agp_bridges))
259                 agp_bridge = NULL;
260 }
261 EXPORT_SYMBOL(agp_put_bridge);
262 
263 
264 int 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 
309 frontend_err:
310 	agp_backend_cleanup(bridge);
311 err_out:
312 	module_put(bridge->driver->owner);
313 err_put_bridge:
314 	agp_put_bridge(bridge);
315 	return error;
316 }
317 EXPORT_SYMBOL_GPL(agp_add_bridge);
318 
319 
320 void 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 }
328 EXPORT_SYMBOL_GPL(agp_remove_bridge);
329 
330 int agp_off;
331 int agp_try_unsupported_boot;
332 EXPORT_SYMBOL(agp_off);
333 EXPORT_SYMBOL(agp_try_unsupported_boot);
334 
335 static 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 
343 static void __exit agp_exit(void)
344 {
345 }
346 
347 #ifndef MODULE
348 static __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 
359 MODULE_AUTHOR("Dave Jones, Jeff Hartmann");
360 MODULE_DESCRIPTION("AGP GART driver");
361 MODULE_LICENSE("GPL and additional rights");
362 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
363 
364 module_init(agp_init);
365 module_exit(agp_exit);
366 
367