drm_fops.c

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/*
 * Created: Mon Jan  4 08:58:31 1999 by [email protected]
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <drm/drmP.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/module.h>

/* from BKL pushdown: note that nothing else serializes idr_find() */
DEFINE_MUTEX(drm_global_mutex);
EXPORT_SYMBOL(drm_global_mutex);

static int drm_open_helper(struct inode *inode, struct file *filp,
               struct drm_device * dev);

static int drm_setup(struct drm_device * dev)
{
    int i;
    int ret;

    if (dev->driver->firstopen) {
        ret = dev->driver->firstopen(dev);
        if (ret != 0)
            return ret;
    }

    atomic_set(&dev->ioctl_count, 0);
    atomic_set(&dev->vma_count, 0);

    if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
        !drm_core_check_feature(dev, DRIVER_MODESET)) {
        dev->buf_use = 0;
        atomic_set(&dev->buf_alloc, 0);

        i = drm_dma_setup(dev);
        if (i < 0)
            return i;
    }

    for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
        atomic_set(&dev->counts[i], 0);

    dev->sigdata.lock = NULL;

    dev->context_flag = 0;
    dev->interrupt_flag = 0;
    dev->dma_flag = 0;
    dev->last_context = 0;
    dev->last_switch = 0;
    dev->last_checked = 0;
    init_waitqueue_head(&dev->context_wait);
    dev->if_version = 0;

    dev->ctx_start = 0;
    dev->lck_start = 0;

    dev->buf_async = NULL;
    init_waitqueue_head(&dev->buf_readers);
    init_waitqueue_head(&dev->buf_writers);

    DRM_DEBUG("\n");

    /*
     * The kernel's context could be created here, but is now created
     * in drm_dma_enqueue.  This is more resource-efficient for
     * hardware that does not do DMA, but may mean that
     * drm_select_queue fails between the time the interrupt is
     * initialized and the time the queues are initialized.
     */

    return 0;
}

int drm_open(struct inode *inode, struct file *filp)
{
    struct drm_device *dev = NULL;
    int minor_id = iminor(inode);
    struct drm_minor *minor;
    int retcode = 0;
    int need_setup = 0;
    struct address_space *old_mapping;

    minor = idr_find(&drm_minors_idr, minor_id);
    if (!minor)
        return -ENODEV;

    if (!(dev = minor->dev))
        return -ENODEV;

    if (drm_device_is_unplugged(dev))
        return -ENODEV;

    if (!dev->open_count++)
        need_setup = 1;
    mutex_lock(&dev->struct_mutex);
    old_mapping = dev->dev_mapping;
    if (old_mapping == NULL)
        dev->dev_mapping = &inode->i_data;
    /* ihold ensures nobody can remove inode with our i_data */
    ihold(container_of(dev->dev_mapping, struct inode, i_data));
    inode->i_mapping = dev->dev_mapping;
    filp->f_mapping = dev->dev_mapping;
    mutex_unlock(&dev->struct_mutex);

    retcode = drm_open_helper(inode, filp, dev);
    if (retcode)
        goto err_undo;
    atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
    if (need_setup) {
        retcode = drm_setup(dev);
        if (retcode)
            goto err_undo;
    }
    return 0;

err_undo:
    mutex_lock(&dev->struct_mutex);
    filp->f_mapping = old_mapping;
    inode->i_mapping = old_mapping;
    iput(container_of(dev->dev_mapping, struct inode, i_data));
    dev->dev_mapping = old_mapping;
    mutex_unlock(&dev->struct_mutex);
    dev->open_count--;
    return retcode;
}
EXPORT_SYMBOL(drm_open);

int drm_stub_open(struct inode *inode, struct file *filp)
{
    struct drm_device *dev = NULL;
    struct drm_minor *minor;
    int minor_id = iminor(inode);
    int err = -ENODEV;
    const struct file_operations *old_fops;

    DRM_DEBUG("\n");

    mutex_lock(&drm_global_mutex);
    minor = idr_find(&drm_minors_idr, minor_id);
    if (!minor)
        goto out;

    if (!(dev = minor->dev))
        goto out;

    if (drm_device_is_unplugged(dev))
        goto out;

    old_fops = filp->f_op;
    filp->f_op = fops_get(dev->driver->fops);
    if (filp->f_op == NULL) {
        filp->f_op = old_fops;
        goto out;
    }
    if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
        fops_put(filp->f_op);
        filp->f_op = fops_get(old_fops);
    }
    fops_put(old_fops);

out:
    mutex_unlock(&drm_global_mutex);
    return err;
}

static int drm_cpu_valid(void)
{
#if defined(__i386__)
    if (boot_cpu_data.x86 == 3)
        return 0;   /* No cmpxchg on a 386 */
#endif
#if defined(__sparc__) && !defined(__sparc_v9__)
    return 0;       /* No cmpxchg before v9 sparc. */
#endif
    return 1;
}

static int drm_open_helper(struct inode *inode, struct file *filp,
               struct drm_device * dev)
{
    int minor_id = iminor(inode);
    struct drm_file *priv;
    int ret;

    if (filp->f_flags & O_EXCL)
        return -EBUSY;  /* No exclusive opens */
    if (!drm_cpu_valid())
        return -EINVAL;
    if (dev->switch_power_state != DRM_SWITCH_POWER_ON)
        return -EINVAL;

    DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);

    priv = kzalloc(sizeof(*priv), GFP_KERNEL);
    if (!priv)
        return -ENOMEM;

    filp->private_data = priv;
    priv->filp = filp;
    priv->uid = current_euid();
    priv->pid = get_pid(task_pid(current));
    priv->minor = idr_find(&drm_minors_idr, minor_id);
    priv->ioctl_count = 0;
    /* for compatibility root is always authenticated */
    priv->authenticated = capable(CAP_SYS_ADMIN);
    priv->lock_count = 0;

    INIT_LIST_HEAD(&priv->lhead);
    INIT_LIST_HEAD(&priv->fbs);
    INIT_LIST_HEAD(&priv->event_list);
    init_waitqueue_head(&priv->event_wait);
    priv->event_space = 4096; /* set aside 4k for event buffer */

    if (dev->driver->driver_features & DRIVER_GEM)
        drm_gem_open(dev, priv);

    if (drm_core_check_feature(dev, DRIVER_PRIME))
        drm_prime_init_file_private(&priv->prime);

    if (dev->driver->open) {
        ret = dev->driver->open(dev, priv);
        if (ret < 0)
            goto out_free;
    }


    /* if there is no current master make this fd it */
    mutex_lock(&dev->struct_mutex);
    if (!priv->minor->master) {
        /* create a new master */
        priv->minor->master = drm_master_create(priv->minor);
        if (!priv->minor->master) {
            mutex_unlock(&dev->struct_mutex);
            ret = -ENOMEM;
            goto out_free;
        }

        priv->is_master = 1;
        /* take another reference for the copy in the local file priv */
        priv->master = drm_master_get(priv->minor->master);

        priv->authenticated = 1;

        mutex_unlock(&dev->struct_mutex);
        if (dev->driver->master_create) {
            ret = dev->driver->master_create(dev, priv->master);
            if (ret) {
                mutex_lock(&dev->struct_mutex);
                /* drop both references if this fails */
                drm_master_put(&priv->minor->master);
                drm_master_put(&priv->master);
                mutex_unlock(&dev->struct_mutex);
                goto out_free;
            }
        }
        mutex_lock(&dev->struct_mutex);
        if (dev->driver->master_set) {
            ret = dev->driver->master_set(dev, priv, true);
            if (ret) {
                /* drop both references if this fails */
                drm_master_put(&priv->minor->master);
                drm_master_put(&priv->master);
                mutex_unlock(&dev->struct_mutex);
                goto out_free;
            }
        }
        mutex_unlock(&dev->struct_mutex);
    } else {
        /* get a reference to the master */
        priv->master = drm_master_get(priv->minor->master);
        mutex_unlock(&dev->struct_mutex);
    }

    mutex_lock(&dev->struct_mutex);
    list_add(&priv->lhead, &dev->filelist);
    mutex_unlock(&dev->struct_mutex);

#ifdef __alpha__
    /*
     * Default the hose
     */
    if (!dev->hose) {
        struct pci_dev *pci_dev;
        pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
        if (pci_dev) {
            dev->hose = pci_dev->sysdata;
            pci_dev_put(pci_dev);
        }
        if (!dev->hose) {
            struct pci_bus *b = pci_bus_b(pci_root_buses.next);
            if (b)
                dev->hose = b->sysdata;
        }
    }
#endif

    return 0;
      out_free:
    kfree(priv);
    filp->private_data = NULL;
    return ret;
}

int drm_fasync(int fd, struct file *filp, int on)
{
    struct drm_file *priv = filp->private_data;
    struct drm_device *dev = priv->minor->dev;

    DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
          (long)old_encode_dev(priv->minor->device));
    return fasync_helper(fd, filp, on, &dev->buf_async);
}
EXPORT_SYMBOL(drm_fasync);

static void drm_master_release(struct drm_device *dev, struct file *filp)
{
    struct drm_file *file_priv = filp->private_data;

    if (drm_i_have_hw_lock(dev, file_priv)) {
        DRM_DEBUG("File %p released, freeing lock for context %d\n",
              filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
        drm_lock_free(&file_priv->master->lock,
                  _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
    }
}

static void drm_events_release(struct drm_file *file_priv)
{
    struct drm_device *dev = file_priv->minor->dev;
    struct drm_pending_event *e, *et;
    struct drm_pending_vblank_event *v, *vt;
    unsigned long flags;

    spin_lock_irqsave(&dev->event_lock, flags);

    /* Remove pending flips */
    list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
        if (v->base.file_priv == file_priv) {
            list_del(&v->base.link);
            drm_vblank_put(dev, v->pipe);
            v->base.destroy(&v->base);
        }

    /* Remove unconsumed events */
    list_for_each_entry_safe(e, et, &file_priv->event_list, link)
        e->destroy(e);

    spin_unlock_irqrestore(&dev->event_lock, flags);
}

int drm_release(struct inode *inode, struct file *filp)
{
    struct drm_file *file_priv = filp->private_data;
    struct drm_device *dev = file_priv->minor->dev;
    int retcode = 0;

    mutex_lock(&drm_global_mutex);

    DRM_DEBUG("open_count = %d\n", dev->open_count);

    if (dev->driver->preclose)
        dev->driver->preclose(dev, file_priv);

    /* ========================================================
     * Begin inline drm_release
     */

    DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
          task_pid_nr(current),
          (long)old_encode_dev(file_priv->minor->device),
          dev->open_count);

    /* Release any auth tokens that might point to this file_priv,
       (do that under the drm_global_mutex) */
    if (file_priv->magic)
        (void) drm_remove_magic(file_priv->master, file_priv->magic);

    /* if the master has gone away we can't do anything with the lock */
    if (file_priv->minor->master)
        drm_master_release(dev, filp);

    if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
        drm_core_reclaim_buffers(dev, file_priv);

    drm_events_release(file_priv);

    if (dev->driver->driver_features & DRIVER_MODESET)
        drm_fb_release(file_priv);

    if (dev->driver->driver_features & DRIVER_GEM)
        drm_gem_release(dev, file_priv);

    mutex_lock(&dev->ctxlist_mutex);
    if (!list_empty(&dev->ctxlist)) {
        struct drm_ctx_list *pos, *n;

        list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
            if (pos->tag == file_priv &&
                pos->handle != DRM_KERNEL_CONTEXT) {
                if (dev->driver->context_dtor)
                    dev->driver->context_dtor(dev,
                                  pos->handle);

                drm_ctxbitmap_free(dev, pos->handle);

                list_del(&pos->head);
                kfree(pos);
                --dev->ctx_count;
            }
        }
    }
    mutex_unlock(&dev->ctxlist_mutex);

    mutex_lock(&dev->struct_mutex);

    if (file_priv->is_master) {
        struct drm_master *master = file_priv->master;
        struct drm_file *temp;
        list_for_each_entry(temp, &dev->filelist, lhead) {
            if ((temp->master == file_priv->master) &&
                (temp != file_priv))
                temp->authenticated = 0;
        }

        if (master->lock.hw_lock) {
            if (dev->sigdata.lock == master->lock.hw_lock)
                dev->sigdata.lock = NULL;
            master->lock.hw_lock = NULL;
            master->lock.file_priv = NULL;
            wake_up_interruptible_all(&master->lock.lock_queue);
        }

        if (file_priv->minor->master == file_priv->master) {
            /* drop the reference held my the minor */
            if (dev->driver->master_drop)
                dev->driver->master_drop(dev, file_priv, true);
            drm_master_put(&file_priv->minor->master);
        }
    }

    BUG_ON(dev->dev_mapping == NULL);
    iput(container_of(dev->dev_mapping, struct inode, i_data));

    /* drop the reference held my the file priv */
    drm_master_put(&file_priv->master);
    file_priv->is_master = 0;
    list_del(&file_priv->lhead);
    mutex_unlock(&dev->struct_mutex);

    if (dev->driver->postclose)
        dev->driver->postclose(dev, file_priv);

    if (drm_core_check_feature(dev, DRIVER_PRIME))
        drm_prime_destroy_file_private(&file_priv->prime);

    put_pid(file_priv->pid);
    kfree(file_priv);

    /* ========================================================
     * End inline drm_release
     */

    atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
    if (!--dev->open_count) {
        if (atomic_read(&dev->ioctl_count)) {
            DRM_ERROR("Device busy: %d\n",
                  atomic_read(&dev->ioctl_count));
            retcode = -EBUSY;
        } else
            retcode = drm_lastclose(dev);
        if (drm_device_is_unplugged(dev))
            drm_put_dev(dev);
    }
    mutex_unlock(&drm_global_mutex);

    return retcode;
}
EXPORT_SYMBOL(drm_release);

static bool
drm_dequeue_event(struct drm_file *file_priv,
          size_t total, size_t max, struct drm_pending_event **out)
{
    struct drm_device *dev = file_priv->minor->dev;
    struct drm_pending_event *e;
    unsigned long flags;
    bool ret = false;

    spin_lock_irqsave(&dev->event_lock, flags);

    *out = NULL;
    if (list_empty(&file_priv->event_list))
        goto out;
    e = list_first_entry(&file_priv->event_list,
                 struct drm_pending_event, link);
    if (e->event->length + total > max)
        goto out;

    file_priv->event_space += e->event->length;
    list_del(&e->link);
    *out = e;
    ret = true;

out:
    spin_unlock_irqrestore(&dev->event_lock, flags);
    return ret;
}

ssize_t drm_read(struct file *filp, char __user *buffer,
         size_t count, loff_t *offset)
{
    struct drm_file *file_priv = filp->private_data;
    struct drm_pending_event *e;
    size_t total;
    ssize_t ret;

    ret = wait_event_interruptible(file_priv->event_wait,
                       !list_empty(&file_priv->event_list));
    if (ret < 0)
        return ret;

    total = 0;
    while (drm_dequeue_event(file_priv, total, count, &e)) {
        if (copy_to_user(buffer + total,
                 e->event, e->event->length)) {
            total = -EFAULT;
            break;
        }

        total += e->event->length;
        e->destroy(e);
    }

    return total;
}
EXPORT_SYMBOL(drm_read);

unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
{
    struct drm_file *file_priv = filp->private_data;
    unsigned int mask = 0;

    poll_wait(filp, &file_priv->event_wait, wait);

    if (!list_empty(&file_priv->event_list))
        mask |= POLLIN | POLLRDNORM;

    return mask;
}
EXPORT_SYMBOL(drm_poll);