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 102
  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 = 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
 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                 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         /* FIXME vmalloc'd memory not guaranteed contiguous */
 180         memset(bridge->key_list, 0, PAGE_SIZE * 4);
 181
 182         if (bridge->driver->configure()) {
 183                 printk(KERN_ERR PFX "error configuring host chipset.\n");
 184                 rc = -EINVAL;
 185                 goto err_out;
 186         }
 187
 188         return 0;
 189
 190 err_out:
 191         if (bridge->driver->needs_scratch_page) {
 192                 bridge->driver->agp_destroy_page(gart_to_virt(bridge->scratch_page_real),
 193                                                  AGP_PAGE_DESTROY_UNMAP);
 194                 flush_agp_mappings();
 195                 bridge->driver->agp_destroy_page(gart_to_virt(bridge->scratch_page_real),
 196                                                  AGP_PAGE_DESTROY_FREE);
 197         }
 198         if (got_gatt)
 199                 bridge->driver->free_gatt_table(bridge);
 200         if (got_keylist) {
 201                 vfree(bridge->key_list);
 202                 bridge->key_list = NULL;
 203         }
 204         return rc;
 205 }
 206
 207 /* cannot be __exit b/c as it could be called from __init code */
 208 static void agp_backend_cleanup(struct agp_bridge_data *bridge)
 209 {
 210         if (bridge->driver->cleanup)
 211                 bridge->driver->cleanup();
 212         if (bridge->driver->free_gatt_table)
 213                 bridge->driver->free_gatt_table(bridge);
 214
 215         vfree(bridge->key_list);
 216         bridge->key_list = NULL;
 217
 218         if (bridge->driver->agp_destroy_page &&
 219             bridge->driver->needs_scratch_page) {
 220                 bridge->driver->agp_destroy_page(gart_to_virt(bridge->scratch_page_real),
 221                                                  AGP_PAGE_DESTROY_UNMAP);
 222                 flush_agp_mappings();
 223                 bridge->driver->agp_destroy_page(gart_to_virt(bridge->scratch_page_real),
 224                                                  AGP_PAGE_DESTROY_FREE);
 225         }
 226 }
 227
 228 /* When we remove the global variable agp_bridge from all drivers
 229  * then agp_alloc_bridge and agp_generic_find_bridge need to be updated
 230  */
 231
 232 struct agp_bridge_data *agp_alloc_bridge(void)
 233 {
 234         struct agp_bridge_data *bridge;
 235
 236         bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
 237         if (!bridge)
 238                 return NULL;
 239
 240         atomic_set(&bridge->agp_in_use, 0);
 241         atomic_set(&bridge->current_memory_agp, 0);
 242
 243         if (list_empty(&agp_bridges))
 244                 agp_bridge = bridge;
 245
 246         return bridge;
 247 }
 248 EXPORT_SYMBOL(agp_alloc_bridge);
 249
 250
 251 void agp_put_bridge(struct agp_bridge_data *bridge)
 252 {
 253         kfree(bridge);
 254
 255         if (list_empty(&agp_bridges))
 256                 agp_bridge = NULL;
 257 }
 258 EXPORT_SYMBOL(agp_put_bridge);
 259
 260
 261 int agp_add_bridge(struct agp_bridge_data *bridge)
 262 {
 263         int error;
 264
 265         if (agp_off)
 266                 return -ENODEV;
 267
 268         if (!bridge->dev) {
 269                 printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
 270                 return -EINVAL;
 271         }
 272
 273         /* Grab reference on the chipset driver. */
 274         if (!try_module_get(bridge->driver->owner)) {
 275                 printk (KERN_INFO PFX "Couldn't lock chipset driver.\n");
 276                 return -EINVAL;
 277         }
 278
 279         error = agp_backend_initialize(bridge);
 280         if (error) {
 281                 printk (KERN_INFO PFX "agp_backend_initialize() failed.\n");
 282                 goto err_out;
 283         }
 284
 285         if (list_empty(&agp_bridges)) {
 286                 error = agp_frontend_initialize();
 287                 if (error) {
 288                         printk (KERN_INFO PFX "agp_frontend_initialize() failed.\n");
 289                         goto frontend_err;
 290                 }
 291
 292                 printk(KERN_INFO PFX "AGP aperture is %dM @ 0x%lx\n",
 293                         bridge->driver->fetch_size(), bridge->gart_bus_addr);
 294
 295         }
 296
 297         list_add(&bridge->list, &agp_bridges);
 298         return 0;
 299
 300 frontend_err:
 301         agp_backend_cleanup(bridge);
 302 err_out:
 303         module_put(bridge->driver->owner);
 304         agp_put_bridge(bridge);
 305         return error;
 306 }
 307 EXPORT_SYMBOL_GPL(agp_add_bridge);
 308
 309
 310 void agp_remove_bridge(struct agp_bridge_data *bridge)
 311 {
 312         agp_backend_cleanup(bridge);
 313         list_del(&bridge->list);
 314         if (list_empty(&agp_bridges))
 315                 agp_frontend_cleanup();
 316         module_put(bridge->driver->owner);
 317 }
 318 EXPORT_SYMBOL_GPL(agp_remove_bridge);
 319
 320 int agp_off;
 321 int agp_try_unsupported_boot;
 322 EXPORT_SYMBOL(agp_off);
 323 EXPORT_SYMBOL(agp_try_unsupported_boot);
 324
 325 static int __init agp_init(void)
 326 {
 327         if (!agp_off)
 328                 printk(KERN_INFO "Linux agpgart interface v%d.%d\n",
 329                         AGPGART_VERSION_MAJOR, AGPGART_VERSION_MINOR);
 330         return 0;
 331 }
 332
 333 static void __exit agp_exit(void)
 334 {
 335 }
 336
 337 #ifndef MODULE
 338 static __init int agp_setup(char *s)
 339 {
 340         if (!strcmp(s,"off"))
 341                 agp_off = 1;
 342         if (!strcmp(s,"try_unsupported"))
 343                 agp_try_unsupported_boot = 1;
 344         return 1;
 345 }
 346 __setup("agp=", agp_setup);
 347 #endif
 348
 349 MODULE_AUTHOR("Dave Jones <davej@codemonkey.org.uk>");
 350 MODULE_DESCRIPTION("AGP GART driver");
 351 MODULE_LICENSE("GPL and additional rights");
 352 MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
 353
 354 module_init(agp_init);
 355 module_exit(agp_exit);
 356