/**
 * \file drm_fops.c
 * File operations for DRM
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Daryll Strauss <daryll@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
 *
 * 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 <sys/cdefs.h>
#include <dev/drm2/drmP.h>

static int drm_open_helper(struct cdev *kdev, int flags, int fmt,
                           DRM_STRUCTPROC *p, 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;
        }

        /*
         * FIXME Linux<->FreeBSD: counter incremented in drm_open() and
         * reset to 0 here.
         */
#if 0
        for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
                atomic_set(&dev->counts[i], 0);
#endif

        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;
        DRM_INIT_WAITQUEUE(&dev->context_wait);
        dev->if_version = 0;

#ifdef FREEBSD_NOTYET
        dev->ctx_start = 0;
        dev->lck_start = 0;

        dev->buf_async = NULL;
        DRM_INIT_WAITQUEUE(&dev->buf_readers);
        DRM_INIT_WAITQUEUE(&dev->buf_writers);
#endif /* FREEBSD_NOTYET */

        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;
}

/**
 * Open file.
 *
 * \param inode device inode
 * \param filp file pointer.
 * \return zero on success or a negative number on failure.
 *
 * Searches the DRM device with the same minor number, calls open_helper(), and
 * increments the device open count. If the open count was previous at zero,
 * i.e., it's the first that the device is open, then calls setup().
 */
int drm_open(struct cdev *kdev, int flags, int fmt, DRM_STRUCTPROC *p)
{
        struct drm_device *dev = NULL;
        struct drm_minor *minor;
        int retcode = 0;
        int need_setup = 0;

        minor = kdev->si_drv1;
        if (!minor)
                return ENODEV;

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

        sx_xlock(&drm_global_mutex);

        /*
         * FIXME Linux<->FreeBSD: On Linux, counter updated outside
         * global mutex.
         */
        if (!dev->open_count++)
                need_setup = 1;

        retcode = drm_open_helper(kdev, flags, fmt, p, dev);
        if (retcode) {
                sx_xunlock(&drm_global_mutex);
                return (-retcode);
        }
        atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
        if (need_setup) {
                retcode = drm_setup(dev);
                if (retcode)
                        goto err_undo;
        }
        sx_xunlock(&drm_global_mutex);
        return 0;

err_undo:
        device_unbusy(dev->dev);
        dev->open_count--;
        sx_xunlock(&drm_global_mutex);
        return -retcode;
}
EXPORT_SYMBOL(drm_open);

/**
 * Called whenever a process opens /dev/drm.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param dev device.
 * \return zero on success or a negative number on failure.
 *
 * Creates and initializes a drm_file structure for the file private data in \p
 * filp and add it into the double linked list in \p dev.
 */
static int drm_open_helper(struct cdev *kdev, int flags, int fmt,
                           DRM_STRUCTPROC *p, struct drm_device *dev)
{
        struct drm_file *priv;
        int ret;

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

        DRM_DEBUG("pid = %d, device = %s\n", DRM_CURRENTPID, devtoname(kdev));

        priv = malloc(sizeof(*priv), DRM_MEM_FILES, M_NOWAIT | M_ZERO);
        if (!priv)
                return -ENOMEM;

        priv->uid = p->td_ucred->cr_svuid;
        priv->pid = p->td_proc->p_pid;
        priv->minor = kdev->si_drv1;
        priv->ioctl_count = 0;
        /* for compatibility root is always authenticated */
        priv->authenticated = DRM_SUSER(p);
        priv->lock_count = 0;

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

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

#ifdef FREEBSD_NOTYET
        if (drm_core_check_feature(dev, DRIVER_PRIME))
                drm_prime_init_file_private(&priv->prime);
#endif /* FREEBSD_NOTYET */

        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 */
        DRM_LOCK(dev);
        if (!priv->minor->master) {
                /* create a new master */
                priv->minor->master = drm_master_create(priv->minor);
                if (!priv->minor->master) {
                        DRM_UNLOCK(dev);
                        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;

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

        DRM_LOCK(dev);
        list_add(&priv->lhead, &dev->filelist);
        DRM_UNLOCK(dev);

        device_busy(dev->dev);

        ret = devfs_set_cdevpriv(priv, drm_release);
        if (ret != 0)
                drm_release(priv);

        return ret;
      out_free:
        free(priv, DRM_MEM_FILES);
        return ret;
}

static void drm_master_release(struct drm_device *dev, struct drm_file *file_priv)
{

        if (drm_i_have_hw_lock(dev, file_priv)) {
                DRM_DEBUG("File %p released, freeing lock for context %d\n",
                          file_priv, _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;

        DRM_SPINLOCK_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);

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

/**
 * Release file.
 *
 * \param inode device inode
 * \param file_priv DRM file private.
 * \return zero on success or a negative number on failure.
 *
 * If the hardware lock is held then free it, and take it again for the kernel
 * context since it's necessary to reclaim buffers. Unlink the file private
 * data from its list and free it. Decreases the open count and if it reaches
 * zero calls drm_lastclose().
 */
void drm_release(void *data)
{
        struct drm_file *file_priv = data;
        struct drm_device *dev = file_priv->minor->dev;

        sx_xlock(&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",
                  DRM_CURRENTPID,
                  (long)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, file_priv);

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

        drm_events_release(file_priv);

        seldrain(&file_priv->event_poll);

        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);

#ifdef FREEBSD_NOTYET
        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);
#endif /* FREEBSD_NOTYET */

        DRM_LOCK(dev);

        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;
                }

                /**
                 * Since the master is disappearing, so is the
                 * possibility to lock.
                 */

                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;
                        DRM_WAKEUP_INT(&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);
                }
        }

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

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

#ifdef FREEBSD_NOTYET
        if (drm_core_check_feature(dev, DRIVER_PRIME))
                drm_prime_destroy_file_private(&file_priv->prime);
#endif /* FREEBSD_NOTYET */

        free(file_priv, DRM_MEM_FILES);

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

        atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
        device_unbusy(dev->dev);
        if (!--dev->open_count) {
                if (atomic_read(&dev->ioctl_count)) {
                        DRM_ERROR("Device busy: %d\n",
                                  atomic_read(&dev->ioctl_count));
                } else
                        drm_lastclose(dev);
        }
        sx_xunlock(&drm_global_mutex);
}
EXPORT_SYMBOL(drm_release);

static bool
drm_dequeue_event(struct drm_file *file_priv, struct uio *uio,
    struct drm_pending_event **out)
{
        struct drm_pending_event *e;
        bool ret = false;

        /* Already locked in drm_read(). */
        /* DRM_SPINLOCK_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 > uio->uio_resid)
                goto out;

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

out:
        /* DRM_SPINUNLOCK_IRQRESTORE(&dev->event_lock, flags); */
        return ret;
}

int
drm_read(struct cdev *kdev, struct uio *uio, int ioflag)
{
        struct drm_file *file_priv;
        struct drm_device *dev;
        struct drm_pending_event *e;
        ssize_t error;

        error = devfs_get_cdevpriv((void **)&file_priv);
        if (error != 0) {
                DRM_ERROR("can't find authenticator\n");
                return (EINVAL);
        }

        dev = drm_get_device_from_kdev(kdev);
        mtx_lock(&dev->event_lock);
        while (list_empty(&file_priv->event_list)) {
                if ((ioflag & O_NONBLOCK) != 0) {
                        error = EAGAIN;
                        goto out;
                }
                error = msleep(&file_priv->event_space, &dev->event_lock,
                   PCATCH, "drmrea", 0);
               if (error != 0)
                       goto out;
        }

        while (drm_dequeue_event(file_priv, uio, &e)) {
                mtx_unlock(&dev->event_lock);
                error = uiomove(e->event, e->event->length, uio);
                CTR3(KTR_DRM, "drm_event_dequeued %d %d %d", curproc->p_pid,
                    e->event->type, e->event->length);

                e->destroy(e);
                if (error != 0)
                        return (error);
                mtx_lock(&dev->event_lock);
        }

out:
        mtx_unlock(&dev->event_lock);
        return (error);
}
EXPORT_SYMBOL(drm_read);

void
drm_event_wakeup(struct drm_pending_event *e)
{
        struct drm_file *file_priv;
        struct drm_device *dev __diagused;

        file_priv = e->file_priv;
        dev = file_priv->minor->dev;
        mtx_assert(&dev->event_lock, MA_OWNED);

        wakeup(&file_priv->event_space);
        selwakeup(&file_priv->event_poll);
}

int
drm_poll(struct cdev *kdev, int events, struct thread *td)
{
        struct drm_file *file_priv;
        struct drm_device *dev;
        int error, revents;

        error = devfs_get_cdevpriv((void **)&file_priv);
        if (error != 0) {
                DRM_ERROR("can't find authenticator\n");
                return (EINVAL);
        }

        dev = drm_get_device_from_kdev(kdev);

        revents = 0;
        mtx_lock(&dev->event_lock);
        if ((events & (POLLIN | POLLRDNORM)) != 0) {
                if (list_empty(&file_priv->event_list)) {
                        CTR0(KTR_DRM, "drm_poll empty list");
                        selrecord(td, &file_priv->event_poll);
                } else {
                        revents |= events & (POLLIN | POLLRDNORM);
                        CTR1(KTR_DRM, "drm_poll revents %x", revents);
                }
        }
        mtx_unlock(&dev->event_lock);
        return (revents);
}
EXPORT_SYMBOL(drm_poll);

int
drm_mmap_single(struct cdev *kdev, vm_ooffset_t *offset, vm_size_t size,
    struct vm_object **obj_res, int nprot)
{
        struct drm_device *dev;

        dev = drm_get_device_from_kdev(kdev);
        if (dev->drm_ttm_bdev != NULL) {
                return (-ttm_bo_mmap_single(dev->drm_ttm_bdev, offset, size,
                    obj_res, nprot));
        } else if ((dev->driver->driver_features & DRIVER_GEM) != 0) {
                return (-drm_gem_mmap_single(dev, offset, size, obj_res, nprot));
        } else {
                return (ENODEV);
        }
}