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                 if (bridge->driver->agp_map_page) {
 155                         if (bridge->driver->agp_map_page(page,
 156                                                          &bridge->scratch_page_dma)) {
 157                                 dev_err(&bridge->dev->dev,
 158                                         "unable to dma-map scratch page\n");
 159                                 rc = -ENOMEM;
 160                                 goto err_out_nounmap;
 161                         }
 162                 } else {
 163                         bridge->scratch_page_dma = page_to_phys(page);
 164                 }
 165
 166                 bridge->scratch_page = bridge->driver->mask_memory(bridge,
 167                                                    bridge->scratch_page_dma, 0);
 168         }
 169
 170         size_value = bridge->driver->fetch_size();
 171         if (size_value == 0) {
 172                 dev_err(&bridge->dev->dev, "can't determine aperture size\n");
 173                 rc = -EINVAL;
 174                 goto err_out;
 175         }
 176         if (bridge->driver->create_gatt_table(bridge)) {
 177                 dev_err(&bridge->dev->dev,
 178                         "can't get memory for graphics translation table\n");
 179                 rc = -ENOMEM;
 180                 goto err_out;
 181         }
 182         got_gatt = 1;
 183
 184         bridge->key_list = vmalloc(PAGE_SIZE * 4);
 185         if (bridge->key_list == NULL) {
 186                 dev_err(&bridge->dev->dev,
 187                         "can't allocate memory for key lists\n");
 188                 rc = -ENOMEM;
 189                 goto err_out;
 190         }
 191         got_keylist = 1;
 192
 193         /* FIXME vmalloc'd memory not guaranteed contiguous */
 194         memset(bridge->key_list, 0, PAGE_SIZE * 4);
 195
 196         if (bridge->driver->configure()) {
 197                 dev_err(&bridge->dev->dev, "error configuring host chipset\n");
 198                 rc = -EINVAL;
 199                 goto err_out;
 200         }
 201         INIT_LIST_HEAD(&bridge->mapped_list);
 202         spin_lock_init(&bridge->mapped_lock);
 203
 204         return 0;
 205
 206 err_out:
 207         if (bridge->driver->needs_scratch_page &&
 208             bridge->driver->agp_unmap_page) {
 209                 bridge->driver->agp_unmap_page(bridge->scratch_page_page,
 210                                                bridge->scratch_page_dma);
 211         }
 212 err_out_nounmap:
 213         if (bridge->driver->needs_scratch_page) {
 214                 void *va = page_address(bridge->scratch_page_page);
 215
 216                 bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
 217                 bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
 218         }
 219         if (got_gatt)
 220                 bridge->driver->free_gatt_table(bridge);
 221         if (got_keylist) {
 222                 vfree(bridge->key_list);
 223                 bridge->key_list = NULL;
 224         }
 225         return rc;
 226 }
 227
 228 /* cannot be __exit b/c as it could be called from __init code */
 229 static void agp_backend_cleanup(struct agp_bridge_data *bridge)
 230 {
 231         if (bridge->driver->cleanup)
 232                 bridge->driver->cleanup();
 233         if (bridge->driver->free_gatt_table)
 234                 bridge->driver->free_gatt_table(bridge);
 235
 236         vfree(bridge->key_list);
 237         bridge->key_list = NULL;
 238
 239         if (bridge->driver->agp_destroy_page &&
 240             bridge->driver->needs_scratch_page) {
 241                 void *va = page_address(bridge->scratch_page_page);
 242
 243                 if (bridge->driver->agp_unmap_page)
 244                         bridge->driver->agp_unmap_page(bridge->scratch_page_page,
 245                                                        bridge->scratch_page_dma);
 246
 247                 bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
 248                 bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
 249         }
 250 }
 251
 252 /* When we remove the global variable agp_bridge from all drivers
 253  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
 254  */
 255
 256 struct agp_bridge_data *agp_alloc_bridge(void)
 257 {
 258         struct agp_bridge_data *bridge;
 259
 260         bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
 261         if (!bridge)
 262                 return NULL;
 263
 264         atomic_set(&bridge->agp_in_use, 0);
 265         atomic_set(&bridge->current_memory_agp, 0);
 266
 267         if (list_empty(&agp_bridges))
 268                 agp_bridge = bridge;
 269
 270         return bridge;
 271 }
 272 EXPORT_SYMBOL(agp_alloc_bridge);
 273
 274
 275 void agp_put_bridge(struct agp_bridge_data *bridge)
 276 {
 277         kfree(bridge);
 278
 279         if (list_empty(&agp_bridges))
 280                 agp_bridge = NULL;
 281 }
 282 EXPORT_SYMBOL(agp_put_bridge);
 283
 284
 285 int agp_add_bridge(struct agp_bridge_data *bridge)
 286 {
 287         int error;
 288
 289         if (agp_off) {
 290                 error = -ENODEV;
 291                 goto err_put_bridge;
 292         }
 293
 294         if (!bridge->dev) {
 295                 printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
 296                 error = -EINVAL;
 297                 goto err_put_bridge;
 298         }
 299
 300         /* Grab reference on the chipset driver. */
 301         if (!try_module_get(bridge->driver->owner)) {
 302                 dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
 303                 error = -EINVAL;
 304                 goto err_put_bridge;
 305         }
 306
 307         error = agp_backend_initialize(bridge);
 308         if (error) {
 309                 dev_info(&bridge->dev->dev,
 310                          "agp_backend_initialize() failed\n");
 311                 goto err_out;
 312         }
 313
 314         if (list_empty(&agp_bridges)) {
 315                 error = agp_frontend_initialize();
 316                 if (error) {
 317                         dev_info(&bridge->dev->dev,
 318                                  "agp_frontend_initialize() failed\n");
 319                         goto frontend_err;
 320                 }
 321
 322                 dev_info(&bridge->dev->dev, "AGP aperture is %dM @ 0x%lx\n",
 323                          bridge->driver->fetch_size(), bridge->gart_bus_addr);
 324
 325         }
 326
 327         list_add(&bridge->list, &agp_bridges);
 328         return 0;
 329
 330 frontend_err:
 331         agp_backend_cleanup(bridge);
 332 err_out:
 333         module_put(bridge->driver->owner);
 334 err_put_bridge:
 335         agp_put_bridge(bridge);
 336         return error;
 337 }
 338 EXPORT_SYMBOL_GPL(agp_add_bridge);
 339
 340
 341 void agp_remove_bridge(struct agp_bridge_data *bridge)
 342 {
 343         agp_backend_cleanup(bridge);
 344         list_del(&bridge->list);
 345         if (list_empty(&agp_bridges))
 346                 agp_frontend_cleanup();
 347         module_put(bridge->driver->owner);
 348 }
 349 EXPORT_SYMBOL_GPL(agp_remove_bridge);
 350
 351 int agp_off;
 352 int agp_try_unsupported_boot;
 353 EXPORT_SYMBOL(agp_off);
 354 EXPORT_SYMBOL(agp_try_unsupported_boot);
 355
 356 static int __init agp_init(void)
 357 {
 358         if (!agp_off)
 359                 printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
 360                         AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
 361         return 0;
 362 }
 363
 364 static void __exit agp_exit(void)
 365 {
 366 }
 367
 368 #ifndef MODULE
 369 static __init int agp_setup(char *s)
 370 {
 371         if (!strcmp(s,"off"))
 372                 agp_off = 1;
 373         if (!strcmp(s,"try_unsupported"))
 374                 agp_try_unsupported_boot = 1;
 375         return 1;
 376 }
 377 __setup("agp=", agp_setup);
 378 #endif
 379
 380 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
 381 MODULE_DESCRIPTION("AGP GART driver");
 382 MODULE_LICENSE("GPL and additional rights");
 383 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
 384
 385 module_init(agp_init);
 386 module_exit(agp_exit);
 387