linux/drivers/gpu/drm/drm_fops.c
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   1/**
   2 * \file drm_fops.c
   3 * File operations for DRM
   4 *
   5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6 * \author Daryll Strauss <daryll@valinux.com>
   7 * \author Gareth Hughes <gareth@valinux.com>
   8 */
   9
  10/*
  11 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
  12 *
  13 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  14 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  15 * All Rights Reserved.
  16 *
  17 * Permission is hereby granted, free of charge, to any person obtaining a
  18 * copy of this software and associated documentation files (the "Software"),
  19 * to deal in the Software without restriction, including without limitation
  20 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  21 * and/or sell copies of the Software, and to permit persons to whom the
  22 * Software is furnished to do so, subject to the following conditions:
  23 *
  24 * The above copyright notice and this permission notice (including the next
  25 * paragraph) shall be included in all copies or substantial portions of the
  26 * Software.
  27 *
  28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  29 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  30 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  31 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  32 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  33 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  34 * OTHER DEALINGS IN THE SOFTWARE.
  35 */
  36
  37#include "drmP.h"
  38#include "drm_sarea.h"
  39#include <linux/poll.h>
  40#include <linux/smp_lock.h>
  41
  42static int drm_open_helper(struct inode *inode, struct file *filp,
  43                           struct drm_device * dev);
  44
  45static int drm_setup(struct drm_device * dev)
  46{
  47        drm_local_map_t *map;
  48        int i;
  49        int ret;
  50        u32 sareapage;
  51
  52        if (dev->driver->firstopen) {
  53                ret = dev->driver->firstopen(dev);
  54                if (ret != 0)
  55                        return ret;
  56        }
  57
  58        dev->magicfree.next = NULL;
  59
  60        /* prebuild the SAREA */
  61        sareapage = max_t(unsigned, SAREA_MAX, PAGE_SIZE);
  62        i = drm_addmap(dev, 0, sareapage, _DRM_SHM, _DRM_CONTAINS_LOCK, &map);
  63        if (i != 0)
  64                return i;
  65
  66        atomic_set(&dev->ioctl_count, 0);
  67        atomic_set(&dev->vma_count, 0);
  68        dev->buf_use = 0;
  69        atomic_set(&dev->buf_alloc, 0);
  70
  71        if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
  72                i = drm_dma_setup(dev);
  73                if (i < 0)
  74                        return i;
  75        }
  76
  77        for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
  78                atomic_set(&dev->counts[i], 0);
  79
  80        drm_ht_create(&dev->magiclist, DRM_MAGIC_HASH_ORDER);
  81        INIT_LIST_HEAD(&dev->magicfree);
  82
  83        dev->sigdata.lock = NULL;
  84        init_waitqueue_head(&dev->lock.lock_queue);
  85        dev->queue_count = 0;
  86        dev->queue_reserved = 0;
  87        dev->queue_slots = 0;
  88        dev->queuelist = NULL;
  89        dev->irq_enabled = 0;
  90        dev->context_flag = 0;
  91        dev->interrupt_flag = 0;
  92        dev->dma_flag = 0;
  93        dev->last_context = 0;
  94        dev->last_switch = 0;
  95        dev->last_checked = 0;
  96        init_waitqueue_head(&dev->context_wait);
  97        dev->if_version = 0;
  98
  99        dev->ctx_start = 0;
 100        dev->lck_start = 0;
 101
 102        dev->buf_async = NULL;
 103        init_waitqueue_head(&dev->buf_readers);
 104        init_waitqueue_head(&dev->buf_writers);
 105
 106        DRM_DEBUG("\n");
 107
 108        /*
 109         * The kernel's context could be created here, but is now created
 110         * in drm_dma_enqueue.  This is more resource-efficient for
 111         * hardware that does not do DMA, but may mean that
 112         * drm_select_queue fails between the time the interrupt is
 113         * initialized and the time the queues are initialized.
 114         */
 115
 116        return 0;
 117}
 118
 119/**
 120 * Open file.
 121 *
 122 * \param inode device inode
 123 * \param filp file pointer.
 124 * \return zero on success or a negative number on failure.
 125 *
 126 * Searches the DRM device with the same minor number, calls open_helper(), and
 127 * increments the device open count. If the open count was previous at zero,
 128 * i.e., it's the first that the device is open, then calls setup().
 129 */
 130int drm_open(struct inode *inode, struct file *filp)
 131{
 132        struct drm_device *dev = NULL;
 133        int minor_id = iminor(inode);
 134        struct drm_minor *minor;
 135        int retcode = 0;
 136
 137        minor = idr_find(&drm_minors_idr, minor_id);
 138        if (!minor)
 139                return -ENODEV;
 140
 141        if (!(dev = minor->dev))
 142                return -ENODEV;
 143
 144        retcode = drm_open_helper(inode, filp, dev);
 145        if (!retcode) {
 146                atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 147                spin_lock(&dev->count_lock);
 148                if (!dev->open_count++) {
 149                        spin_unlock(&dev->count_lock);
 150                        return drm_setup(dev);
 151                }
 152                spin_unlock(&dev->count_lock);
 153        }
 154
 155        return retcode;
 156}
 157EXPORT_SYMBOL(drm_open);
 158
 159/**
 160 * File \c open operation.
 161 *
 162 * \param inode device inode.
 163 * \param filp file pointer.
 164 *
 165 * Puts the dev->fops corresponding to the device minor number into
 166 * \p filp, call the \c open method, and restore the file operations.
 167 */
 168int drm_stub_open(struct inode *inode, struct file *filp)
 169{
 170        struct drm_device *dev = NULL;
 171        struct drm_minor *minor;
 172        int minor_id = iminor(inode);
 173        int err = -ENODEV;
 174        const struct file_operations *old_fops;
 175
 176        DRM_DEBUG("\n");
 177
 178        /* BKL pushdown: note that nothing else serializes idr_find() */
 179        lock_kernel();
 180        minor = idr_find(&drm_minors_idr, minor_id);
 181        if (!minor)
 182                goto out;
 183
 184        if (!(dev = minor->dev))
 185                goto out;
 186
 187        old_fops = filp->f_op;
 188        filp->f_op = fops_get(&dev->driver->fops);
 189        if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 190                fops_put(filp->f_op);
 191                filp->f_op = fops_get(old_fops);
 192        }
 193        fops_put(old_fops);
 194
 195out:
 196        unlock_kernel();
 197        return err;
 198}
 199
 200/**
 201 * Check whether DRI will run on this CPU.
 202 *
 203 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 204 */
 205static int drm_cpu_valid(void)
 206{
 207#if defined(__i386__)
 208        if (boot_cpu_data.x86 == 3)
 209                return 0;       /* No cmpxchg on a 386 */
 210#endif
 211#if defined(__sparc__) && !defined(__sparc_v9__)
 212        return 0;               /* No cmpxchg before v9 sparc. */
 213#endif
 214        return 1;
 215}
 216
 217/**
 218 * Called whenever a process opens /dev/drm.
 219 *
 220 * \param inode device inode.
 221 * \param filp file pointer.
 222 * \param dev device.
 223 * \return zero on success or a negative number on failure.
 224 *
 225 * Creates and initializes a drm_file structure for the file private data in \p
 226 * filp and add it into the double linked list in \p dev.
 227 */
 228static int drm_open_helper(struct inode *inode, struct file *filp,
 229                           struct drm_device * dev)
 230{
 231        int minor_id = iminor(inode);
 232        struct drm_file *priv;
 233        int ret;
 234
 235        if (filp->f_flags & O_EXCL)
 236                return -EBUSY;  /* No exclusive opens */
 237        if (!drm_cpu_valid())
 238                return -EINVAL;
 239
 240        DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
 241
 242        priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 243        if (!priv)
 244                return -ENOMEM;
 245
 246        memset(priv, 0, sizeof(*priv));
 247        filp->private_data = priv;
 248        priv->filp = filp;
 249        priv->uid = current_euid();
 250        priv->pid = task_pid_nr(current);
 251        priv->minor = idr_find(&drm_minors_idr, minor_id);
 252        priv->ioctl_count = 0;
 253        /* for compatibility root is always authenticated */
 254        priv->authenticated = capable(CAP_SYS_ADMIN);
 255        priv->lock_count = 0;
 256
 257        INIT_LIST_HEAD(&priv->lhead);
 258
 259        if (dev->driver->driver_features & DRIVER_GEM)
 260                drm_gem_open(dev, priv);
 261
 262        if (dev->driver->open) {
 263                ret = dev->driver->open(dev, priv);
 264                if (ret < 0)
 265                        goto out_free;
 266        }
 267
 268        mutex_lock(&dev->struct_mutex);
 269        if (list_empty(&dev->filelist))
 270                priv->master = 1;
 271
 272        list_add(&priv->lhead, &dev->filelist);
 273        mutex_unlock(&dev->struct_mutex);
 274
 275#ifdef __alpha__
 276        /*
 277         * Default the hose
 278         */
 279        if (!dev->hose) {
 280                struct pci_dev *pci_dev;
 281                pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 282                if (pci_dev) {
 283                        dev->hose = pci_dev->sysdata;
 284                        pci_dev_put(pci_dev);
 285                }
 286                if (!dev->hose) {
 287                        struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 288                        if (b)
 289                                dev->hose = b->sysdata;
 290                }
 291        }
 292#endif
 293
 294        return 0;
 295      out_free:
 296        drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 297        filp->private_data = NULL;
 298        return ret;
 299}
 300
 301/** No-op. */
 302int drm_fasync(int fd, struct file *filp, int on)
 303{
 304        struct drm_file *priv = filp->private_data;
 305        struct drm_device *dev = priv->minor->dev;
 306        int retcode;
 307
 308        DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 309                  (long)old_encode_dev(priv->minor->device));
 310        retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 311        if (retcode < 0)
 312                return retcode;
 313        return 0;
 314}
 315EXPORT_SYMBOL(drm_fasync);
 316
 317/**
 318 * Release file.
 319 *
 320 * \param inode device inode
 321 * \param file_priv DRM file private.
 322 * \return zero on success or a negative number on failure.
 323 *
 324 * If the hardware lock is held then free it, and take it again for the kernel
 325 * context since it's necessary to reclaim buffers. Unlink the file private
 326 * data from its list and free it. Decreases the open count and if it reaches
 327 * zero calls drm_lastclose().
 328 */
 329int drm_release(struct inode *inode, struct file *filp)
 330{
 331        struct drm_file *file_priv = filp->private_data;
 332        struct drm_device *dev = file_priv->minor->dev;
 333        int retcode = 0;
 334
 335        lock_kernel();
 336
 337        DRM_DEBUG("open_count = %d\n", dev->open_count);
 338
 339        if (dev->driver->preclose)
 340                dev->driver->preclose(dev, file_priv);
 341
 342        /* ========================================================
 343         * Begin inline drm_release
 344         */
 345
 346        DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 347                  task_pid_nr(current),
 348                  (long)old_encode_dev(file_priv->minor->device),
 349                  dev->open_count);
 350
 351        if (dev->driver->reclaim_buffers_locked && dev->lock.hw_lock) {
 352                if (drm_i_have_hw_lock(dev, file_priv)) {
 353                        dev->driver->reclaim_buffers_locked(dev, file_priv);
 354                } else {
 355                        unsigned long endtime = jiffies + 3 * DRM_HZ;
 356                        int locked = 0;
 357
 358                        drm_idlelock_take(&dev->lock);
 359
 360                        /*
 361                         * Wait for a while.
 362                         */
 363
 364                        do{
 365                                spin_lock_bh(&dev->lock.spinlock);
 366                                locked = dev->lock.idle_has_lock;
 367                                spin_unlock_bh(&dev->lock.spinlock);
 368                                if (locked)
 369                                        break;
 370                                schedule();
 371                        } while (!time_after_eq(jiffies, endtime));
 372
 373                        if (!locked) {
 374                                DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
 375                                          "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
 376                                          "\tI will go on reclaiming the buffers anyway.\n");
 377                        }
 378
 379                        dev->driver->reclaim_buffers_locked(dev, file_priv);
 380                        drm_idlelock_release(&dev->lock);
 381                }
 382        }
 383
 384        if (dev->driver->reclaim_buffers_idlelocked && dev->lock.hw_lock) {
 385
 386                drm_idlelock_take(&dev->lock);
 387                dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
 388                drm_idlelock_release(&dev->lock);
 389
 390        }
 391
 392        if (drm_i_have_hw_lock(dev, file_priv)) {
 393                DRM_DEBUG("File %p released, freeing lock for context %d\n",
 394                          filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 395
 396                drm_lock_free(&dev->lock,
 397                              _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
 398        }
 399
 400
 401        if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 402            !dev->driver->reclaim_buffers_locked) {
 403                dev->driver->reclaim_buffers(dev, file_priv);
 404        }
 405
 406        if (dev->driver->driver_features & DRIVER_GEM)
 407                drm_gem_release(dev, file_priv);
 408
 409        mutex_lock(&dev->ctxlist_mutex);
 410        if (!list_empty(&dev->ctxlist)) {
 411                struct drm_ctx_list *pos, *n;
 412
 413                list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
 414                        if (pos->tag == file_priv &&
 415                            pos->handle != DRM_KERNEL_CONTEXT) {
 416                                if (dev->driver->context_dtor)
 417                                        dev->driver->context_dtor(dev,
 418                                                                  pos->handle);
 419
 420                                drm_ctxbitmap_free(dev, pos->handle);
 421
 422                                list_del(&pos->head);
 423                                drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 424                                --dev->ctx_count;
 425                        }
 426                }
 427        }
 428        mutex_unlock(&dev->ctxlist_mutex);
 429
 430        mutex_lock(&dev->struct_mutex);
 431        if (file_priv->remove_auth_on_close == 1) {
 432                struct drm_file *temp;
 433
 434                list_for_each_entry(temp, &dev->filelist, lhead)
 435                        temp->authenticated = 0;
 436        }
 437        list_del(&file_priv->lhead);
 438        mutex_unlock(&dev->struct_mutex);
 439
 440        if (dev->driver->postclose)
 441                dev->driver->postclose(dev, file_priv);
 442        drm_free(file_priv, sizeof(*file_priv), DRM_MEM_FILES);
 443
 444        /* ========================================================
 445         * End inline drm_release
 446         */
 447
 448        atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 449        spin_lock(&dev->count_lock);
 450        if (!--dev->open_count) {
 451                if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 452                        DRM_ERROR("Device busy: %d %d\n",
 453                                  atomic_read(&dev->ioctl_count), dev->blocked);
 454                        spin_unlock(&dev->count_lock);
 455                        unlock_kernel();
 456                        return -EBUSY;
 457                }
 458                spin_unlock(&dev->count_lock);
 459                unlock_kernel();
 460                return drm_lastclose(dev);
 461        }
 462        spin_unlock(&dev->count_lock);
 463
 464        unlock_kernel();
 465
 466        return retcode;
 467}
 468EXPORT_SYMBOL(drm_release);
 469
 470/** No-op. */
 471unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 472{
 473        return 0;
 474}
 475EXPORT_SYMBOL(drm_poll);
 476
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