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 102
47static const struct agp_version agp_current_version =
48{
49	.major = AGPGART_VERSION_MAJOR,
50	.minor = AGPGART_VERSION_MINOR,
51};
52
53struct agp_bridge_data *(*agp_find_bridge)(struct pci_dev *) =
54	&agp_generic_find_bridge;
55
56struct agp_bridge_data *agp_bridge;
57LIST_HEAD(agp_bridges);
58EXPORT_SYMBOL(agp_bridge);
59EXPORT_SYMBOL(agp_bridges);
60EXPORT_SYMBOL(agp_find_bridge);
61
62/**
63 *	agp_backend_acquire  -  attempt to acquire an agp backend.
64 *
65 */
66struct 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}
80EXPORT_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 */
91void agp_backend_release(struct agp_bridge_data *bridge)
92{
93
94	if (bridge)
95		atomic_dec(&bridge->agp_in_use);
96}
97EXPORT_SYMBOL(agp_backend_release);
98
99
100static 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
112static 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
136static 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		flush_agp_mappings();
151
152		bridge->scratch_page_real = virt_to_gart(addr);
153		bridge->scratch_page =
154		    bridge->driver->mask_memory(bridge, bridge->scratch_page_real, 0);
155	}
156
157	size_value = bridge->driver->fetch_size();
158	if (size_value == 0) {
159		printk(KERN_ERR PFX "unable to determine aperture size.\n");
160		rc = -EINVAL;
161		goto err_out;
162	}
163	if (bridge->driver->create_gatt_table(bridge)) {
164		printk(KERN_ERR PFX
165		    "unable to get memory for graphics translation table.\n");
166		rc = -ENOMEM;
167		goto err_out;
168	}
169	got_gatt = 1;
170
171	bridge->key_list = vmalloc(PAGE_SIZE * 4);
172	if (bridge->key_list == NULL) {
173		printk(KERN_ERR PFX "error allocating memory for key lists.\n");
174		rc = -ENOMEM;
175		goto err_out;
176	}
177	got_keylist = 1;
178
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
189err_out:
190	if (bridge->driver->needs_scratch_page) {
191		bridge->driver->agp_destroy_page(
192				gart_to_virt(bridge->scratch_page_real));
193		flush_agp_mappings();
194	}
195	if (got_gatt)
196		bridge->driver->free_gatt_table(bridge);
197	if (got_keylist) {
198		vfree(bridge->key_list);
199		bridge->key_list = NULL;
200	}
201	return rc;
202}
203
204/* cannot be __exit b/c as it could be called from __init code */
205static void agp_backend_cleanup(struct agp_bridge_data *bridge)
206{
207	if (bridge->driver->cleanup)
208		bridge->driver->cleanup();
209	if (bridge->driver->free_gatt_table)
210		bridge->driver->free_gatt_table(bridge);
211
212	vfree(bridge->key_list);
213	bridge->key_list = NULL;
214
215	if (bridge->driver->agp_destroy_page &&
216	    bridge->driver->needs_scratch_page) {
217		bridge->driver->agp_destroy_page(
218				gart_to_virt(bridge->scratch_page_real));
219		flush_agp_mappings();
220	}
221}
222
223/* When we remove the global variable agp_bridge from all drivers
224 * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
225 */
226
227struct agp_bridge_data *agp_alloc_bridge(void)
228{
229	struct agp_bridge_data *bridge;
230
231	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
232	if (!bridge)
233		return NULL;
234
235	atomic_set(&bridge->agp_in_use, 0);
236	atomic_set(&bridge->current_memory_agp, 0);
237
238	if (list_empty(&agp_bridges))
239		agp_bridge = bridge;
240
241	return bridge;
242}
243EXPORT_SYMBOL(agp_alloc_bridge);
244
245
246void agp_put_bridge(struct agp_bridge_data *bridge)
247{
248        kfree(bridge);
249
250        if (list_empty(&agp_bridges))
251                agp_bridge = NULL;
252}
253EXPORT_SYMBOL(agp_put_bridge);
254
255
256int agp_add_bridge(struct agp_bridge_data *bridge)
257{
258	int error;
259
260	if (agp_off)
261		return -ENODEV;
262
263	if (!bridge->dev) {
264		printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
265		return -EINVAL;
266	}
267
268	/* Grab reference on the chipset driver. */
269	if (!try_module_get(bridge->driver->owner)) {
270		printk (KERN_INFO PFX "Couldn't lock chipset driver.\n");
271		return -EINVAL;
272	}
273
274	error = agp_backend_initialize(bridge);
275	if (error) {
276		printk (KERN_INFO PFX "agp_backend_initialize() failed.\n");
277		goto err_out;
278	}
279
280	if (list_empty(&agp_bridges)) {
281		error = agp_frontend_initialize();
282		if (error) {
283			printk (KERN_INFO PFX "agp_frontend_initialize() failed.\n");
284			goto frontend_err;
285		}
286
287		printk(KERN_INFO PFX "AGP aperture is %dM @ 0x%lx\n",
288			bridge->driver->fetch_size(), bridge->gart_bus_addr);
289
290	}
291
292	list_add(&bridge->list, &agp_bridges);
293	return 0;
294
295frontend_err:
296	agp_backend_cleanup(bridge);
297err_out:
298	module_put(bridge->driver->owner);
299	agp_put_bridge(bridge);
300	return error;
301}
302EXPORT_SYMBOL_GPL(agp_add_bridge);
303
304
305void agp_remove_bridge(struct agp_bridge_data *bridge)
306{
307	agp_backend_cleanup(bridge);
308	list_del(&bridge->list);
309	if (list_empty(&agp_bridges))
310		agp_frontend_cleanup();
311	module_put(bridge->driver->owner);
312}
313EXPORT_SYMBOL_GPL(agp_remove_bridge);
314
315int agp_off;
316int agp_try_unsupported_boot;
317EXPORT_SYMBOL(agp_off);
318EXPORT_SYMBOL(agp_try_unsupported_boot);
319
320static int __init agp_init(void)
321{
322	if (!agp_off)
323		printk(KERN_INFO "Linux agpgart interface v%d.%d (c) Dave Jones\n",
324			AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
325	return 0;
326}
327
328static void __exit agp_exit(void)
329{
330}
331
332#ifndef MODULE
333static __init int agp_setup(char *s)
334{
335	if (!strcmp(s,"off"))
336		agp_off = 1;
337	if (!strcmp(s,"try_unsupported"))
338		agp_try_unsupported_boot = 1;
339	return 1;
340}
341__setup("agp=", agp_setup);
342#endif
343
344MODULE_AUTHOR("Dave Jones <davej@codemonkey.org.uk>");
345MODULE_DESCRIPTION("AGP GART driver");
346MODULE_LICENSE("GPL and additional rights");
347MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
348
349module_init(agp_init);
350module_exit(agp_exit);
351