xref: /openbmc/linux/drivers/char/agp/backend.c (revision 4800cd83)
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 = vmalloc(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 	memset(bridge->key_list, 0, PAGE_SIZE * 4);
185 
186 	if (bridge->driver->configure()) {
187 		dev_err(&bridge->dev->dev, "error configuring host chipset\n");
188 		rc = -EINVAL;
189 		goto err_out;
190 	}
191 	INIT_LIST_HEAD(&bridge->mapped_list);
192 	spin_lock_init(&bridge->mapped_lock);
193 
194 	return 0;
195 
196 err_out:
197 	if (bridge->driver->needs_scratch_page) {
198 		void *va = page_address(bridge->scratch_page_page);
199 
200 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
201 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
202 	}
203 	if (got_gatt)
204 		bridge->driver->free_gatt_table(bridge);
205 	if (got_keylist) {
206 		vfree(bridge->key_list);
207 		bridge->key_list = NULL;
208 	}
209 	return rc;
210 }
211 
212 /* cannot be __exit b/c as it could be called from __init code */
213 static void agp_backend_cleanup(struct agp_bridge_data *bridge)
214 {
215 	if (bridge->driver->cleanup)
216 		bridge->driver->cleanup();
217 	if (bridge->driver->free_gatt_table)
218 		bridge->driver->free_gatt_table(bridge);
219 
220 	vfree(bridge->key_list);
221 	bridge->key_list = NULL;
222 
223 	if (bridge->driver->agp_destroy_page &&
224 	    bridge->driver->needs_scratch_page) {
225 		void *va = page_address(bridge->scratch_page_page);
226 
227 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
228 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
229 	}
230 }
231 
232 /* When we remove the global variable agp_bridge from all drivers
233  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
234  */
235 
236 struct agp_bridge_data *agp_alloc_bridge(void)
237 {
238 	struct agp_bridge_data *bridge;
239 
240 	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
241 	if (!bridge)
242 		return NULL;
243 
244 	atomic_set(&bridge->agp_in_use, 0);
245 	atomic_set(&bridge->current_memory_agp, 0);
246 
247 	if (list_empty(&agp_bridges))
248 		agp_bridge = bridge;
249 
250 	return bridge;
251 }
252 EXPORT_SYMBOL(agp_alloc_bridge);
253 
254 
255 void agp_put_bridge(struct agp_bridge_data *bridge)
256 {
257         kfree(bridge);
258 
259         if (list_empty(&agp_bridges))
260                 agp_bridge = NULL;
261 }
262 EXPORT_SYMBOL(agp_put_bridge);
263 
264 
265 int agp_add_bridge(struct agp_bridge_data *bridge)
266 {
267 	int error;
268 
269 	if (agp_off) {
270 		error = -ENODEV;
271 		goto err_put_bridge;
272 	}
273 
274 	if (!bridge->dev) {
275 		printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
276 		error = -EINVAL;
277 		goto err_put_bridge;
278 	}
279 
280 	/* Grab reference on the chipset driver. */
281 	if (!try_module_get(bridge->driver->owner)) {
282 		dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
283 		error = -EINVAL;
284 		goto err_put_bridge;
285 	}
286 
287 	error = agp_backend_initialize(bridge);
288 	if (error) {
289 		dev_info(&bridge->dev->dev,
290 			 "agp_backend_initialize() failed\n");
291 		goto err_out;
292 	}
293 
294 	if (list_empty(&agp_bridges)) {
295 		error = agp_frontend_initialize();
296 		if (error) {
297 			dev_info(&bridge->dev->dev,
298 				 "agp_frontend_initialize() failed\n");
299 			goto frontend_err;
300 		}
301 
302 		dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
303 			 bridge->driver->fetch_size(), bridge->gart_bus_addr);
304 
305 	}
306 
307 	list_add(&bridge->list, &agp_bridges);
308 	return 0;
309 
310 frontend_err:
311 	agp_backend_cleanup(bridge);
312 err_out:
313 	module_put(bridge->driver->owner);
314 err_put_bridge:
315 	agp_put_bridge(bridge);
316 	return error;
317 }
318 EXPORT_SYMBOL_GPL(agp_add_bridge);
319 
320 
321 void agp_remove_bridge(struct agp_bridge_data *bridge)
322 {
323 	agp_backend_cleanup(bridge);
324 	list_del(&bridge->list);
325 	if (list_empty(&agp_bridges))
326 		agp_frontend_cleanup();
327 	module_put(bridge->driver->owner);
328 }
329 EXPORT_SYMBOL_GPL(agp_remove_bridge);
330 
331 int agp_off;
332 int agp_try_unsupported_boot;
333 EXPORT_SYMBOL(agp_off);
334 EXPORT_SYMBOL(agp_try_unsupported_boot);
335 
336 static int __init agp_init(void)
337 {
338 	if (!agp_off)
339 		printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
340 			AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
341 	return 0;
342 }
343 
344 static void __exit agp_exit(void)
345 {
346 }
347 
348 #ifndef MODULE
349 static __init int agp_setup(char *s)
350 {
351 	if (!strcmp(s,"off"))
352 		agp_off = 1;
353 	if (!strcmp(s,"try_unsupported"))
354 		agp_try_unsupported_boot = 1;
355 	return 1;
356 }
357 __setup("agp=", agp_setup);
358 #endif
359 
360 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
361 MODULE_DESCRIPTION("AGP GART driver");
362 MODULE_LICENSE("GPL and additional rights");
363 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
364 
365 module_init(agp_init);
366 module_exit(agp_exit);
367 
368