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/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  *      @pdev: the PCI device
  66  *
  67  */
  68 struct agp_bridge_data *agp_backend_acquire(struct pci_dev *pdev)
  69 {
  70         struct agp_bridge_data *bridge;
  71
  72         bridge = agp_find_bridge(pdev);
  73
  74         if (!bridge)
  75                 return NULL;
  76
  77         if (atomic_read(&bridge->agp_in_use))
  78                 return NULL;
  79         atomic_inc(&bridge->agp_in_use);
  80         return bridge;
  81 }
  82 EXPORT_SYMBOL(agp_backend_acquire);
  83
  84
  85 /**
  86  *      agp_backend_release  -  release the lock on the agp backend.
  87  *      @bridge: the AGP backend to release
  88  *
  89  *      The caller must insure that the graphics aperture translation table
  90  *      is read for use by another entity.
  91  *
  92  *      (Ensure that all memory it bound is unbound.)
  93  */
  94 void agp_backend_release(struct agp_bridge_data *bridge)
  95 {
  96
  97         if (bridge)
  98                 atomic_dec(&bridge->agp_in_use);
  99 }
 100 EXPORT_SYMBOL(agp_backend_release);
 101
 102
 103 static const struct { int mem, agp; } maxes_table[] = {
 104         {0, 0},
 105         {32, 4},
 106         {64, 28},
 107         {128, 96},
 108         {256, 204},
 109         {512, 440},
 110         {1024, 942},
 111         {2048, 1920},
 112         {4096, 3932}
 113 };
 114
 115 static int agp_find_max(void)
 116 {
 117         long memory, index, result;
 118
 119 #if PAGE_SHIFT < 20
 120         memory = totalram_pages() >> (20 - PAGE_SHIFT);
 121 #else
 122         memory = totalram_pages() << (PAGE_SHIFT - 20);
 123 #endif
 124         index = 1;
 125
 126         while ((memory > maxes_table[index].mem) && (index < 8))
 127                 index++;
 128
 129         result = maxes_table[index - 1].agp +
 130            ( (memory - maxes_table[index - 1].mem)  *
 131              (maxes_table[index].agp - maxes_table[index - 1].agp)) /
 132            (maxes_table[index].mem - maxes_table[index - 1].mem);
 133
 134         result = result << (20 - PAGE_SHIFT);
 135         return result;
 136 }
 137
 138
 139 static int agp_backend_initialize(struct agp_bridge_data *bridge)
 140 {
 141         int size_value, rc, got_gatt=0, got_keylist=0;
 142
 143         bridge->max_memory_agp = agp_find_max();
 144         bridge->version = &agp_current_version;
 145
 146         if (bridge->driver->needs_scratch_page) {
 147                 struct page *page = bridge->driver->agp_alloc_page(bridge);
 148
 149                 if (!page) {
 150                         dev_err(&bridge->dev->dev,
 151                                 "can't get memory for scratch page\n");
 152                         return -ENOMEM;
 153                 }
 154
 155                 bridge->scratch_page_page = page;
 156                 bridge->scratch_page_dma = page_to_phys(page);
 157
 158                 bridge->scratch_page = bridge->driver->mask_memory(bridge,
 159                                                    bridge->scratch_page_dma, 0);
 160         }
 161
 162         size_value = bridge->driver->fetch_size();
 163         if (size_value == 0) {
 164                 dev_err(&bridge->dev->dev, "can't determine aperture size\n");
 165                 rc = -EINVAL;
 166                 goto err_out;
 167         }
 168         if (bridge->driver->create_gatt_table(bridge)) {
 169                 dev_err(&bridge->dev->dev,
 170                         "can't get memory for graphics translation table\n");
 171                 rc = -ENOMEM;
 172                 goto err_out;
 173         }
 174         got_gatt = 1;
 175
 176         bridge->key_list = vzalloc(PAGE_SIZE * 4);
 177         if (bridge->key_list == NULL) {
 178                 dev_err(&bridge->dev->dev,
 179                         "can't allocate memory for key lists\n");
 180                 rc = -ENOMEM;
 181                 goto err_out;
 182         }
 183         got_keylist = 1;
 184
 185         /* FIXME vmalloc'd memory not guaranteed contiguous */
 186
 187         if (bridge->driver->configure()) {
 188                 dev_err(&bridge->dev->dev, "error configuring host chipset\n");
 189                 rc = -EINVAL;
 190                 goto err_out;
 191         }
 192         INIT_LIST_HEAD(&bridge->mapped_list);
 193         spin_lock_init(&bridge->mapped_lock);
 194
 195         return 0;
 196
 197 err_out:
 198         if (bridge->driver->needs_scratch_page) {
 199                 struct page *page = bridge->scratch_page_page;
 200
 201                 bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_UNMAP);
 202                 bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_FREE);
 203         }
 204         if (got_gatt)
 205                 bridge->driver->free_gatt_table(bridge);
 206         if (got_keylist) {
 207                 vfree(bridge->key_list);
 208                 bridge->key_list = NULL;
 209         }
 210         return rc;
 211 }
 212
 213 /* cannot be __exit b/c as it could be called from __init code */
 214 static void agp_backend_cleanup(struct agp_bridge_data *bridge)
 215 {
 216         if (bridge->driver->cleanup)
 217                 bridge->driver->cleanup();
 218         if (bridge->driver->free_gatt_table)
 219                 bridge->driver->free_gatt_table(bridge);
 220
 221         vfree(bridge->key_list);
 222         bridge->key_list = NULL;
 223
 224         if (bridge->driver->agp_destroy_page &&
 225             bridge->driver->needs_scratch_page) {
 226                 struct page *page = bridge->scratch_page_page;
 227
 228                 bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_UNMAP);
 229                 bridge->driver->agp_destroy_page(page, AGP_PAGE_DESTROY_FREE);
 230         }
 231 }
 232
 233 /* When we remove the global variable agp_bridge from all drivers
 234  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
 235  */
 236
 237 struct agp_bridge_data *agp_alloc_bridge(void)
 238 {
 239         struct agp_bridge_data *bridge;
 240
 241         bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
 242         if (!bridge)
 243                 return NULL;
 244
 245         atomic_set(&bridge->agp_in_use, 0);
 246         atomic_set(&bridge->current_memory_agp, 0);
 247
 248         if (list_empty(&agp_bridges))
 249                 agp_bridge = bridge;
 250
 251         return bridge;
 252 }
 253 EXPORT_SYMBOL(agp_alloc_bridge);
 254
 255
 256 void agp_put_bridge(struct agp_bridge_data *bridge)
 257 {
 258         kfree(bridge);
 259
 260         if (list_empty(&agp_bridges))
 261                 agp_bridge = NULL;
 262 }
 263 EXPORT_SYMBOL(agp_put_bridge);
 264
 265
 266 int agp_add_bridge(struct agp_bridge_data *bridge)
 267 {
 268         int error;
 269
 270         if (agp_off) {
 271                 error = -ENODEV;
 272                 goto err_put_bridge;
 273         }
 274
 275         if (!bridge->dev) {
 276                 printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
 277                 error = -EINVAL;
 278                 goto err_put_bridge;
 279         }
 280
 281         /* Grab reference on the chipset driver. */
 282         if (!try_module_get(bridge->driver->owner)) {
 283                 dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
 284                 error = -EINVAL;
 285                 goto err_put_bridge;
 286         }
 287
 288         error = agp_backend_initialize(bridge);
 289         if (error) {
 290                 dev_info(&bridge->dev->dev,
 291                          "agp_backend_initialize() failed\n");
 292                 goto err_out;
 293         }
 294
 295         if (list_empty(&agp_bridges)) {
 296                 dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
 297                          bridge->driver->fetch_size(), bridge->gart_bus_addr);
 298
 299         }
 300
 301         list_add(&bridge->list, &agp_bridges);
 302         return 0;
 303
 304 err_out:
 305         module_put(bridge->driver->owner);
 306 err_put_bridge:
 307         agp_put_bridge(bridge);
 308         return error;
 309 }
 310 EXPORT_SYMBOL_GPL(agp_add_bridge);
 311
 312
 313 void agp_remove_bridge(struct agp_bridge_data *bridge)
 314 {
 315         agp_backend_cleanup(bridge);
 316         list_del(&bridge->list);
 317         module_put(bridge->driver->owner);
 318 }
 319 EXPORT_SYMBOL_GPL(agp_remove_bridge);
 320
 321 int agp_off;
 322 int agp_try_unsupported_boot;
 323 EXPORT_SYMBOL(agp_off);
 324 EXPORT_SYMBOL(agp_try_unsupported_boot);
 325
 326 static int __init agp_init(void)
 327 {
 328         if (!agp_off)
 329                 printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
 330                         AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
 331         return 0;
 332 }
 333
 334 static void __exit agp_exit(void)
 335 {
 336 }
 337
 338 #ifndef MODULE
 339 static __init int agp_setup(char *s)
 340 {
 341         if (!strcmp(s,"off"))
 342                 agp_off = 1;
 343         if (!strcmp(s,"try_unsupported"))
 344                 agp_try_unsupported_boot = 1;
 345         return 1;
 346 }
 347 __setup("agp=", agp_setup);
 348 #endif
 349
 350 MODULE_AUTHOR("Dave Jones, Jeff Hartmann");
 351 MODULE_DESCRIPTION("AGP GART driver");
 352 MODULE_LICENSE("GPL and additional rights");
 353 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
 354
 355 module_init(agp_init);
 356 module_exit(agp_exit);
 357