xref: /openbmc/linux/drivers/char/agp/backend.c (revision 1da177e4)
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 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_phys(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 				phys_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 	if (bridge->key_list) {
210 		vfree(bridge->key_list);
211 		bridge->key_list = NULL;
212 	}
213 
214 	if (bridge->driver->agp_destroy_page &&
215 	    bridge->driver->needs_scratch_page)
216 		bridge->driver->agp_destroy_page(
217 				phys_to_virt(bridge->scratch_page_real));
218 }
219 
220 /* When we remove the global variable agp_bridge from all drivers
221  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
222  */
223 
224 struct agp_bridge_data *agp_alloc_bridge(void)
225 {
226 	struct agp_bridge_data *bridge = kmalloc(sizeof(*bridge), GFP_KERNEL);
227 
228 	if (!bridge)
229 		return NULL;
230 
231 	memset(bridge, 0, sizeof(*bridge));
232 	atomic_set(&bridge->agp_in_use, 0);
233 	atomic_set(&bridge->current_memory_agp, 0);
234 
235 	if (list_empty(&agp_bridges))
236 		agp_bridge = bridge;
237 
238 	return bridge;
239 }
240 EXPORT_SYMBOL(agp_alloc_bridge);
241 
242 
243 void agp_put_bridge(struct agp_bridge_data *bridge)
244 {
245         kfree(bridge);
246 
247         if (list_empty(&agp_bridges))
248                 agp_bridge = NULL;
249 }
250 EXPORT_SYMBOL(agp_put_bridge);
251 
252 
253 int agp_add_bridge(struct agp_bridge_data *bridge)
254 {
255 	int error;
256 
257 	if (agp_off)
258 		return -ENODEV;
259 
260 	if (!bridge->dev) {
261 		printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
262 		return -EINVAL;
263 	}
264 
265 	/* Grab reference on the chipset driver. */
266 	if (!try_module_get(bridge->driver->owner)) {
267 		printk (KERN_INFO PFX "Couldn't lock chipset driver.\n");
268 		return -EINVAL;
269 	}
270 
271 	error = agp_backend_initialize(bridge);
272 	if (error) {
273 		printk (KERN_INFO PFX "agp_backend_initialize() failed.\n");
274 		goto err_out;
275 	}
276 
277 	if (list_empty(&agp_bridges)) {
278 		error = agp_frontend_initialize();
279 		if (error) {
280 			printk (KERN_INFO PFX "agp_frontend_initialize() failed.\n");
281 			goto frontend_err;
282 		}
283 
284 		printk(KERN_INFO PFX "AGP aperture is %dM @ 0x%lx\n",
285 			bridge->driver->fetch_size(), bridge->gart_bus_addr);
286 
287 	}
288 
289 	list_add(&bridge->list, &agp_bridges);
290 	return 0;
291 
292 frontend_err:
293 	agp_backend_cleanup(bridge);
294 err_out:
295 	module_put(bridge->driver->owner);
296 	agp_put_bridge(bridge);
297 	return error;
298 }
299 EXPORT_SYMBOL_GPL(agp_add_bridge);
300 
301 
302 void agp_remove_bridge(struct agp_bridge_data *bridge)
303 {
304 	agp_backend_cleanup(bridge);
305 	list_del(&bridge->list);
306 	if (list_empty(&agp_bridges))
307 		agp_frontend_cleanup();
308 	module_put(bridge->driver->owner);
309 }
310 EXPORT_SYMBOL_GPL(agp_remove_bridge);
311 
312 int agp_off;
313 int agp_try_unsupported_boot;
314 EXPORT_SYMBOL(agp_off);
315 EXPORT_SYMBOL(agp_try_unsupported_boot);
316 
317 static int __init agp_init(void)
318 {
319 	if (!agp_off)
320 		printk(KERN_INFO "Linux agpgart interface v%d.%d (c) Dave Jones\n",
321 			AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
322 	return 0;
323 }
324 
325 void __exit agp_exit(void)
326 {
327 }
328 
329 #ifndef MODULE
330 static __init int agp_setup(char *s)
331 {
332 	if (!strcmp(s,"off"))
333 		agp_off = 1;
334 	if (!strcmp(s,"try_unsupported"))
335 		agp_try_unsupported_boot = 1;
336 	return 1;
337 }
338 __setup("agp=", agp_setup);
339 #endif
340 
341 MODULE_AUTHOR("Dave Jones <davej@codemonkey.org.uk>");
342 MODULE_DESCRIPTION("AGP GART driver");
343 MODULE_LICENSE("GPL and additional rights");
344 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
345 
346 module_init(agp_init);
347 module_exit(agp_exit);
348 
349