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