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