linux/drivers/char/agp/backend.c
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   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
  48static const struct agp_version agp_current_version =
  49{
  50        .major = AGPGART_VERSION_MAJOR,
  51        .minor = AGPGART_VERSION_MINOR,
  52};
  53
  54struct agp_bridge_data *(*agp_find_bridge)(struct pci_dev *) =
  55        &agp_generic_find_bridge;
  56
  57struct agp_bridge_data *agp_bridge;
  58LIST_HEAD(agp_bridges);
  59EXPORT_SYMBOL(agp_bridge);
  60EXPORT_SYMBOL(agp_bridges);
  61EXPORT_SYMBOL(agp_find_bridge);
  62
  63/**
  64 *      agp_backend_acquire  -  attempt to acquire an agp backend.
  65 *
  66 */
  67struct 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}
  81EXPORT_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 */
  92void agp_backend_release(struct agp_bridge_data *bridge)
  93{
  94
  95        if (bridge)
  96                atomic_dec(&bridge->agp_in_use);
  97}
  98EXPORT_SYMBOL(agp_backend_release);
  99
 100
 101static 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
 113static 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
 137static 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
 195err_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 */
 212static 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
 235struct 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}
 251EXPORT_SYMBOL(agp_alloc_bridge);
 252
 253
 254void agp_put_bridge(struct agp_bridge_data *bridge)
 255{
 256        kfree(bridge);
 257
 258        if (list_empty(&agp_bridges))
 259                agp_bridge = NULL;
 260}
 261EXPORT_SYMBOL(agp_put_bridge);
 262
 263
 264int 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
 309frontend_err:
 310        agp_backend_cleanup(bridge);
 311err_out:
 312        module_put(bridge->driver->owner);
 313err_put_bridge:
 314        agp_put_bridge(bridge);
 315        return error;
 316}
 317EXPORT_SYMBOL_GPL(agp_add_bridge);
 318
 319
 320void 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}
 328EXPORT_SYMBOL_GPL(agp_remove_bridge);
 329
 330int agp_off;
 331int agp_try_unsupported_boot;
 332EXPORT_SYMBOL(agp_off);
 333EXPORT_SYMBOL(agp_try_unsupported_boot);
 334
 335static 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
 343static void __exit agp_exit(void)
 344{
 345}
 346
 347#ifndef MODULE
 348static __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
 359MODULE_AUTHOR("Dave Jones, Jeff Hartmann");
 360MODULE_DESCRIPTION("AGP GART driver");
 361MODULE_LICENSE("GPL and additional rights");
 362MODULE_ALIAS_MISCDEV(AGPGART_MINOR);
 363
 364module_init(agp_init);
 365module_exit(agp_exit);
 366
 367