xref: /openbmc/linux/drivers/char/agp/backend.c (revision e8e0929d)
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 = totalram_pages >> (20 - PAGE_SHIFT);
118 #else
119 	memory = totalram_pages << (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_page = page;
153 		if (bridge->driver->agp_map_page) {
154 			if (bridge->driver->agp_map_page(page,
155 							 &bridge->scratch_page_dma)) {
156 				dev_err(&bridge->dev->dev,
157 					"unable to dma-map scratch page\n");
158 				rc = -ENOMEM;
159 				goto err_out_nounmap;
160 			}
161 		} else {
162 			bridge->scratch_page_dma = page_to_phys(page);
163 		}
164 
165 		bridge->scratch_page = bridge->driver->mask_memory(bridge,
166 						   bridge->scratch_page_dma, 0);
167 	}
168 
169 	size_value = bridge->driver->fetch_size();
170 	if (size_value == 0) {
171 		dev_err(&bridge->dev->dev, "can't determine aperture size\n");
172 		rc = -EINVAL;
173 		goto err_out;
174 	}
175 	if (bridge->driver->create_gatt_table(bridge)) {
176 		dev_err(&bridge->dev->dev,
177 			"can't get memory for graphics translation table\n");
178 		rc = -ENOMEM;
179 		goto err_out;
180 	}
181 	got_gatt = 1;
182 
183 	bridge->key_list = vmalloc(PAGE_SIZE * 4);
184 	if (bridge->key_list == NULL) {
185 		dev_err(&bridge->dev->dev,
186 			"can't allocate memory for key lists\n");
187 		rc = -ENOMEM;
188 		goto err_out;
189 	}
190 	got_keylist = 1;
191 
192 	/* FIXME vmalloc'd memory not guaranteed contiguous */
193 	memset(bridge->key_list, 0, PAGE_SIZE * 4);
194 
195 	if (bridge->driver->configure()) {
196 		dev_err(&bridge->dev->dev, "error configuring host chipset\n");
197 		rc = -EINVAL;
198 		goto err_out;
199 	}
200 	INIT_LIST_HEAD(&bridge->mapped_list);
201 	spin_lock_init(&bridge->mapped_lock);
202 
203 	return 0;
204 
205 err_out:
206 	if (bridge->driver->needs_scratch_page &&
207 	    bridge->driver->agp_unmap_page) {
208 		bridge->driver->agp_unmap_page(bridge->scratch_page_page,
209 					       bridge->scratch_page_dma);
210 	}
211 err_out_nounmap:
212 	if (bridge->driver->needs_scratch_page) {
213 		void *va = page_address(bridge->scratch_page_page);
214 
215 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
216 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
217 	}
218 	if (got_gatt)
219 		bridge->driver->free_gatt_table(bridge);
220 	if (got_keylist) {
221 		vfree(bridge->key_list);
222 		bridge->key_list = NULL;
223 	}
224 	return rc;
225 }
226 
227 /* cannot be __exit b/c as it could be called from __init code */
228 static void agp_backend_cleanup(struct agp_bridge_data *bridge)
229 {
230 	if (bridge->driver->cleanup)
231 		bridge->driver->cleanup();
232 	if (bridge->driver->free_gatt_table)
233 		bridge->driver->free_gatt_table(bridge);
234 
235 	vfree(bridge->key_list);
236 	bridge->key_list = NULL;
237 
238 	if (bridge->driver->agp_destroy_page &&
239 	    bridge->driver->needs_scratch_page) {
240 		void *va = page_address(bridge->scratch_page_page);
241 
242 		if (bridge->driver->agp_unmap_page)
243 			bridge->driver->agp_unmap_page(bridge->scratch_page_page,
244 						       bridge->scratch_page_dma);
245 
246 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
247 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
248 	}
249 }
250 
251 /* When we remove the global variable agp_bridge from all drivers
252  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
253  */
254 
255 struct agp_bridge_data *agp_alloc_bridge(void)
256 {
257 	struct agp_bridge_data *bridge;
258 
259 	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
260 	if (!bridge)
261 		return NULL;
262 
263 	atomic_set(&bridge->agp_in_use, 0);
264 	atomic_set(&bridge->current_memory_agp, 0);
265 
266 	if (list_empty(&agp_bridges))
267 		agp_bridge = bridge;
268 
269 	return bridge;
270 }
271 EXPORT_SYMBOL(agp_alloc_bridge);
272 
273 
274 void agp_put_bridge(struct agp_bridge_data *bridge)
275 {
276         kfree(bridge);
277 
278         if (list_empty(&agp_bridges))
279                 agp_bridge = NULL;
280 }
281 EXPORT_SYMBOL(agp_put_bridge);
282 
283 
284 int agp_add_bridge(struct agp_bridge_data *bridge)
285 {
286 	int error;
287 
288 	if (agp_off)
289 		return -ENODEV;
290 
291 	if (!bridge->dev) {
292 		printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
293 		return -EINVAL;
294 	}
295 
296 	/* Grab reference on the chipset driver. */
297 	if (!try_module_get(bridge->driver->owner)) {
298 		dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
299 		return -EINVAL;
300 	}
301 
302 	error = agp_backend_initialize(bridge);
303 	if (error) {
304 		dev_info(&bridge->dev->dev,
305 			 "agp_backend_initialize() failed\n");
306 		goto err_out;
307 	}
308 
309 	if (list_empty(&agp_bridges)) {
310 		error = agp_frontend_initialize();
311 		if (error) {
312 			dev_info(&bridge->dev->dev,
313 				 "agp_frontend_initialize() failed\n");
314 			goto frontend_err;
315 		}
316 
317 		dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
318 			 bridge->driver->fetch_size(), bridge->gart_bus_addr);
319 
320 	}
321 
322 	list_add(&bridge->list, &agp_bridges);
323 	return 0;
324 
325 frontend_err:
326 	agp_backend_cleanup(bridge);
327 err_out:
328 	module_put(bridge->driver->owner);
329 	agp_put_bridge(bridge);
330 	return error;
331 }
332 EXPORT_SYMBOL_GPL(agp_add_bridge);
333 
334 
335 void agp_remove_bridge(struct agp_bridge_data *bridge)
336 {
337 	agp_backend_cleanup(bridge);
338 	list_del(&bridge->list);
339 	if (list_empty(&agp_bridges))
340 		agp_frontend_cleanup();
341 	module_put(bridge->driver->owner);
342 }
343 EXPORT_SYMBOL_GPL(agp_remove_bridge);
344 
345 int agp_off;
346 int agp_try_unsupported_boot;
347 EXPORT_SYMBOL(agp_off);
348 EXPORT_SYMBOL(agp_try_unsupported_boot);
349 
350 static int __init agp_init(void)
351 {
352 	if (!agp_off)
353 		printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
354 			AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
355 	return 0;
356 }
357 
358 static void __exit agp_exit(void)
359 {
360 }
361 
362 #ifndef MODULE
363 static __init int agp_setup(char *s)
364 {
365 	if (!strcmp(s,"off"))
366 		agp_off = 1;
367 	if (!strcmp(s,"try_unsupported"))
368 		agp_try_unsupported_boot = 1;
369 	return 1;
370 }
371 __setup("agp=", agp_setup);
372 #endif
373 
374 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
375 MODULE_DESCRIPTION("AGP GART driver");
376 MODULE_LICENSE("GPL and additional rights");
377 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
378 
379 module_init(agp_init);
380 module_exit(agp_exit);
381 
382