Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / 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 101
47 static 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 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(
192                                 gart_to_virt(bridge->scratch_page_real));
193         if (got_gatt)
194                 bridge->driver->free_gatt_table(bridge);
195         if (got_keylist) {
196                 vfree(bridge->key_list);
197                 bridge->key_list = NULL;
198         }
199         return rc;
200 }
201
202 /* cannot be __exit b/c as it could be called from __init code */
203 static void agp_backend_cleanup(struct agp_bridge_data *bridge)
204 {
205         if (bridge->driver->cleanup)
206                 bridge->driver->cleanup();
207         if (bridge->driver->free_gatt_table)
208                 bridge->driver->free_gatt_table(bridge);
209
210         vfree(bridge->key_list);
211         bridge->key_list = NULL;
212
213         if (bridge->driver->agp_destroy_page &&
214             bridge->driver->needs_scratch_page)
215                 bridge->driver->agp_destroy_page(
216                                 gart_to_virt(bridge->scratch_page_real));
217 }
218
219 /* When we remove the global variable agp_bridge from all drivers
220  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
221  */
222
223 struct agp_bridge_data *agp_alloc_bridge(void)
224 {
225         struct agp_bridge_data *bridge = kmalloc(sizeof(*bridge), GFP_KERNEL);
226
227         if (!bridge)
228                 return NULL;
229
230         memset(bridge, 0, sizeof(*bridge));
231         atomic_set(&bridge->agp_in_use, 0);
232         atomic_set(&bridge->current_memory_agp, 0);
233
234         if (list_empty(&agp_bridges))
235                 agp_bridge = bridge;
236
237         return bridge;
238 }
239 EXPORT_SYMBOL(agp_alloc_bridge);
240
241
242 void agp_put_bridge(struct agp_bridge_data *bridge)
243 {
244         kfree(bridge);
245
246         if (list_empty(&agp_bridges))
247                 agp_bridge = NULL;
248 }
249 EXPORT_SYMBOL(agp_put_bridge);
250
251
252 int agp_add_bridge(struct agp_bridge_data *bridge)
253 {
254         int error;
255
256         if (agp_off)
257                 return -ENODEV;
258
259         if (!bridge->dev) {
260                 printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
261                 return -EINVAL;
262         }
263
264         /* Grab reference on the chipset driver. */
265         if (!try_module_get(bridge->driver->owner)) {
266                 printk (KERN_INFO PFX "Couldn't lock chipset driver.\n");
267                 return -EINVAL;
268         }
269
270         error = agp_backend_initialize(bridge);
271         if (error) {
272                 printk (KERN_INFO PFX "agp_backend_initialize() failed.\n");
273                 goto err_out;
274         }
275
276         if (list_empty(&agp_bridges)) {
277                 error = agp_frontend_initialize();
278                 if (error) {
279                         printk (KERN_INFO PFX "agp_frontend_initialize() failed.\n");
280                         goto frontend_err;
281                 }
282
283                 printk(KERN_INFO PFX "AGP aperture is %dM @ 0x%lx\n",
284                         bridge->driver->fetch_size(), bridge->gart_bus_addr);
285
286         }
287
288         list_add(&bridge->list, &agp_bridges);
289         return 0;
290
291 frontend_err:
292         agp_backend_cleanup(bridge);
293 err_out:
294         module_put(bridge->driver->owner);
295         agp_put_bridge(bridge);
296         return error;
297 }
298 EXPORT_SYMBOL_GPL(agp_add_bridge);
299
300
301 void agp_remove_bridge(struct agp_bridge_data *bridge)
302 {
303         agp_backend_cleanup(bridge);
304         list_del(&bridge->list);
305         if (list_empty(&agp_bridges))
306                 agp_frontend_cleanup();
307         module_put(bridge->driver->owner);
308 }
309 EXPORT_SYMBOL_GPL(agp_remove_bridge);
310
311 int agp_off;
312 int agp_try_unsupported_boot;
313 EXPORT_SYMBOL(agp_off);
314 EXPORT_SYMBOL(agp_try_unsupported_boot);
315
316 static int __init agp_init(void)
317 {
318         if (!agp_off)
319                 printk(KERN_INFO "Linux agpgart interface v%d.%d (c) Dave Jones\n",
320                         AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
321         return 0;
322 }
323
324 static void __exit agp_exit(void)
325 {
326 }
327
328 #ifndef MODULE
329 static __init int agp_setup(char *s)
330 {
331         if (!strcmp(s,"off"))
332                 agp_off = 1;
333         if (!strcmp(s,"try_unsupported"))
334                 agp_try_unsupported_boot = 1;
335         return 1;
336 }
337 __setup("agp=", agp_setup);
338 #endif
339
340 MODULE_AUTHOR("Dave Jones <davej@codemonkey.org.uk>");
341 MODULE_DESCRIPTION("AGP GART driver");
342 MODULE_LICENSE("GPL and additional rights");
343 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
344
345 module_init(agp_init);
346 module_exit(agp_exit);
347