agp: Add generic support for graphics dma remapping
[linux-2.6.git] / drivers / char / agp / backend.c
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
46 #define AGPGART_VERSION_MINOR 103
47 static const struct agp_version agp_current_version =
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
100 static const struct { int mem, agp; } maxes_table[] = {
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) {
144                 struct page *page = bridge->driver->agp_alloc_page(bridge);
145
146                 if (!page) {
147                         dev_err(&bridge->dev->dev,
148                                 "can't get memory for scratch page\n");
149                         return -ENOMEM;
150                 }
151
152                 bridge->scratch_page_real = phys_to_gart(page_to_phys(page));
153                 bridge->scratch_page = bridge->driver->mask_memory(bridge,
154                                            phys_to_gart(page_to_phys(page)), 0);
155
156                 if (bridge->driver->agp_map_page &&
157                     bridge->driver->agp_map_page(phys_to_virt(page_to_phys(page)),
158                                                 &bridge->scratch_page_dma)) {
159                         dev_err(&bridge->dev->dev,
160                                 "unable to dma-map scratch page\n");
161                         rc = -ENOMEM;
162                         goto err_out_nounmap;
163                 }
164         }
165
166         size_value = bridge->driver->fetch_size();
167         if (size_value == 0) {
168                 dev_err(&bridge->dev->dev, "can't determine aperture size\n");
169                 rc = -EINVAL;
170                 goto err_out;
171         }
172         if (bridge->driver->create_gatt_table(bridge)) {
173                 dev_err(&bridge->dev->dev,
174                         "can't get memory for graphics translation table\n");
175                 rc = -ENOMEM;
176                 goto err_out;
177         }
178         got_gatt = 1;
179
180         bridge->key_list = vmalloc(PAGE_SIZE * 4);
181         if (bridge->key_list == NULL) {
182                 dev_err(&bridge->dev->dev,
183                         "can't allocate memory for key lists\n");
184                 rc = -ENOMEM;
185                 goto err_out;
186         }
187         got_keylist = 1;
188
189         /* FIXME vmalloc'd memory not guaranteed contiguous */
190         memset(bridge->key_list, 0, PAGE_SIZE * 4);
191
192         if (bridge->driver->configure()) {
193                 dev_err(&bridge->dev->dev, "error configuring host chipset\n");
194                 rc = -EINVAL;
195                 goto err_out;
196         }
197         INIT_LIST_HEAD(&bridge->mapped_list);
198         spin_lock_init(&bridge->mapped_lock);
199
200         return 0;
201
202 err_out:
203         if (bridge->driver->needs_scratch_page &&
204             bridge->driver->agp_unmap_page) {
205                 void *va = gart_to_virt(bridge->scratch_page_real);
206
207                 bridge->driver->agp_unmap_page(va, bridge->scratch_page_dma);
208         }
209 err_out_nounmap:
210         if (bridge->driver->needs_scratch_page) {
211                 void *va = gart_to_virt(bridge->scratch_page_real);
212
213                 bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
214                 bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
215         }
216         if (got_gatt)
217                 bridge->driver->free_gatt_table(bridge);
218         if (got_keylist) {
219                 vfree(bridge->key_list);
220                 bridge->key_list = NULL;
221         }
222         return rc;
223 }
224
225 /* cannot be __exit b/c as it could be called from __init code */
226 static void agp_backend_cleanup(struct agp_bridge_data *bridge)
227 {
228         if (bridge->driver->cleanup)
229                 bridge->driver->cleanup();
230         if (bridge->driver->free_gatt_table)
231                 bridge->driver->free_gatt_table(bridge);
232
233         vfree(bridge->key_list);
234         bridge->key_list = NULL;
235
236         if (bridge->driver->agp_destroy_page &&
237             bridge->driver->needs_scratch_page) {
238                 void *va = gart_to_virt(bridge->scratch_page_real);
239
240                 if (bridge->driver->agp_unmap_page)
241                         bridge->driver->agp_unmap_page(va,
242                                                bridge->scratch_page_dma);
243
244                 bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
245                 bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
246         }
247 }
248
249 /* When we remove the global variable agp_bridge from all drivers
250  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
251  */
252
253 struct agp_bridge_data *agp_alloc_bridge(void)
254 {
255         struct agp_bridge_data *bridge;
256
257         bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
258         if (!bridge)
259                 return NULL;
260
261         atomic_set(&bridge->agp_in_use, 0);
262         atomic_set(&bridge->current_memory_agp, 0);
263
264         if (list_empty(&agp_bridges))
265                 agp_bridge = bridge;
266
267         return bridge;
268 }
269 EXPORT_SYMBOL(agp_alloc_bridge);
270
271
272 void agp_put_bridge(struct agp_bridge_data *bridge)
273 {
274         kfree(bridge);
275
276         if (list_empty(&agp_bridges))
277                 agp_bridge = NULL;
278 }
279 EXPORT_SYMBOL(agp_put_bridge);
280
281
282 int agp_add_bridge(struct agp_bridge_data *bridge)
283 {
284         int error;
285
286         if (agp_off)
287                 return -ENODEV;
288
289         if (!bridge->dev) {
290                 printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
291                 return -EINVAL;
292         }
293
294         /* Grab reference on the chipset driver. */
295         if (!try_module_get(bridge->driver->owner)) {
296                 dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
297                 return -EINVAL;
298         }
299
300         error = agp_backend_initialize(bridge);
301         if (error) {
302                 dev_info(&bridge->dev->dev,
303                          "agp_backend_initialize() failed\n");
304                 goto err_out;
305         }
306
307         if (list_empty(&agp_bridges)) {
308                 error = agp_frontend_initialize();
309                 if (error) {
310                         dev_info(&bridge->dev->dev,
311                                  "agp_frontend_initialize() failed\n");
312                         goto frontend_err;
313                 }
314
315                 dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
316                          bridge->driver->fetch_size(), bridge->gart_bus_addr);
317
318         }
319
320         list_add(&bridge->list, &agp_bridges);
321         return 0;
322
323 frontend_err:
324         agp_backend_cleanup(bridge);
325 err_out:
326         module_put(bridge->driver->owner);
327         agp_put_bridge(bridge);
328         return error;
329 }
330 EXPORT_SYMBOL_GPL(agp_add_bridge);
331
332
333 void agp_remove_bridge(struct agp_bridge_data *bridge)
334 {
335         agp_backend_cleanup(bridge);
336         list_del(&bridge->list);
337         if (list_empty(&agp_bridges))
338                 agp_frontend_cleanup();
339         module_put(bridge->driver->owner);
340 }
341 EXPORT_SYMBOL_GPL(agp_remove_bridge);
342
343 int agp_off;
344 int agp_try_unsupported_boot;
345 EXPORT_SYMBOL(agp_off);
346 EXPORT_SYMBOL(agp_try_unsupported_boot);
347
348 static int __init agp_init(void)
349 {
350         if (!agp_off)
351                 printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
352                         AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
353         return 0;
354 }
355
356 static void __exit agp_exit(void)
357 {
358 }
359
360 #ifndef MODULE
361 static __init int agp_setup(char *s)
362 {
363         if (!strcmp(s,"off"))
364                 agp_off = 1;
365         if (!strcmp(s,"try_unsupported"))
366                 agp_try_unsupported_boot = 1;
367         return 1;
368 }
369 __setup("agp=", agp_setup);
370 #endif
371
372 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
373 MODULE_DESCRIPTION("AGP GART driver");
374 MODULE_LICENSE("GPL and additional rights");
375 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
376
377 module_init(agp_init);
378 module_exit(agp_exit);
379