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/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                 error = -ENODEV;
 290                 goto err_put_bridge;
 291         }
 292
 293         if (!bridge->dev) {
 294                 printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
 295                 error = -EINVAL;
 296                 goto err_put_bridge;
 297         }
 298
 299         /* Grab reference on the chipset driver. */
 300         if (!try_module_get(bridge->driver->owner)) {
 301                 dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
 302                 error = -EINVAL;
 303                 goto err_put_bridge;
 304         }
 305
 306         error = agp_backend_initialize(bridge);
 307         if (error) {
 308                 dev_info(&bridge->dev->dev,
 309                          "agp_backend_initialize() failed\n");
 310                 goto err_out;
 311         }
 312
 313         if (list_empty(&agp_bridges)) {
 314                 error = agp_frontend_initialize();
 315                 if (error) {
 316                         dev_info(&bridge->dev->dev,
 317                                  "agp_frontend_initialize() failed\n");
 318                         goto frontend_err;
 319                 }
 320
 321                 dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
 322                          bridge->driver->fetch_size(), bridge->gart_bus_addr);
 323
 324         }
 325
 326         list_add(&bridge->list, &agp_bridges);
 327         return 0;
 328
 329 frontend_err:
 330         agp_backend_cleanup(bridge);
 331 err_out:
 332         module_put(bridge->driver->owner);
 333 err_put_bridge:
 334         agp_put_bridge(bridge);
 335         return error;
 336 }
 337 EXPORT_SYMBOL_GPL(agp_add_bridge);
 338
 339
 340 void agp_remove_bridge(struct agp_bridge_data *bridge)
 341 {
 342         agp_backend_cleanup(bridge);
 343         list_del(&bridge->list);
 344         if (list_empty(&agp_bridges))
 345                 agp_frontend_cleanup();
 346         module_put(bridge->driver->owner);
 347 }
 348 EXPORT_SYMBOL_GPL(agp_remove_bridge);
 349
 350 int agp_off;
 351 int agp_try_unsupported_boot;
 352 EXPORT_SYMBOL(agp_off);
 353 EXPORT_SYMBOL(agp_try_unsupported_boot);
 354
 355 static int __init agp_init(void)
 356 {
 357         if (!agp_off)
 358                 printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
 359                         AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
 360         return 0;
 361 }
 362
 363 static void __exit agp_exit(void)
 364 {
 365 }
 366
 367 #ifndef MODULE
 368 static __init int agp_setup(char *s)
 369 {
 370         if (!strcmp(s,"off"))
 371                 agp_off = 1;
 372         if (!strcmp(s,"try_unsupported"))
 373                 agp_try_unsupported_boot = 1;
 374         return 1;
 375 }
 376 __setup("agp=", agp_setup);
 377 #endif
 378
 379 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
 380 MODULE_DESCRIPTION("AGP GART driver");
 381 MODULE_LICENSE("GPL and additional rights");
 382 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
 383
 384 module_init(agp_init);
 385 module_exit(agp_exit);
 386