Merge branch 'drm-minor' of git://people.freedesktop.org/~dvdhrm/linux into drm-next

This series contains several cleanups for the DRM-minor handling. All but the
last one reviewed by Daniel and tested by Thierry. Initially, the series
included patches to convert minor-handling to a common base-ID, but have
been NACKed by Daniel so I dropped them and only included the main part in the
last patch. With this in place, drm_global_mutex is no longer needed for
minor-handling (but still for device unregistration..).
There are some pending patches that try to remove the global mutex entirely, but
they need some more reviews and thus are not included.
* 'drm-minor' of git://people.freedesktop.org/~dvdhrm/linux:
  drm: make minors independent of global lock
  drm: inline drm_minor_get_id()
  drm: coding-style fixes in minor handling
  drm: remove redundant minor->device field
  drm: remove unneeded #ifdef CONFIG_DEBUGFS
  drm: rename drm_unplug/get_minor() to drm_minor_register/unregister()
  drm: move drm_put_minor() to drm_minor_free()
  drm: allocate minors early
  drm: add minor-lookup/release helpers
  drm: provide device-refcount
  drm: turn DRM_MINOR_* into enum
  drm: remove unused DRM_MINOR_UNASSIGNED
  drm: skip redundant minor-lookup in open path
  drm: group dev-lifetime related members

8 files changed, 278 insertions, 193 deletions

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 345be03c23db..ec651be2f3cb 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -344,7 +344,7 @@ long drm_ioctl(struct file *filp,
 
         DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
                   task_pid_nr(current),
-                  (long)old_encode_dev(file_priv->minor->device),
+                  (long)old_encode_dev(file_priv->minor->kdev->devt),
                   file_priv->authenticated, ioctl->name);
 
         /* Do not trust userspace, use our own definition */
@@ -402,7 +402,7 @@ long drm_ioctl(struct file *filp,
         if (!ioctl)
                 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
                           task_pid_nr(current),
-                          (long)old_encode_dev(file_priv->minor->device),
+                          (long)old_encode_dev(file_priv->minor->kdev->devt),
                           file_priv->authenticated, cmd, nr);
 
         if (kdata != stack_kdata)
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 7f2af9aca038..8f46fe273ba3 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -39,12 +39,12 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 
-/* from BKL pushdown: note that nothing else serializes idr_find() */
+/* from BKL pushdown */
 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);
+                           struct drm_minor *minor);
 
 static int drm_setup(struct drm_device * dev)
 {
@@ -79,24 +79,18 @@ static int drm_setup(struct drm_device * dev)
  */
 int drm_open(struct inode *inode, struct file *filp)
 {
-        struct drm_device *dev = NULL;
-        int minor_id = iminor(inode);
+        struct drm_device *dev;
         struct drm_minor *minor;
-        int retcode = 0;
+        int retcode;
         int need_setup = 0;
         struct address_space *old_mapping;
         struct address_space *old_imapping;
 
-        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;
+        minor = drm_minor_acquire(iminor(inode));
+        if (IS_ERR(minor))
+                return PTR_ERR(minor);
 
+        dev = minor->dev;
         if (!dev->open_count++)
                 need_setup = 1;
         mutex_lock(&dev->struct_mutex);
@@ -110,7 +104,7 @@ int drm_open(struct inode *inode, struct file *filp)
         filp->f_mapping = dev->dev_mapping;
         mutex_unlock(&dev->struct_mutex);
 
-        retcode = drm_open_helper(inode, filp, dev);
+        retcode = drm_open_helper(inode, filp, minor);
         if (retcode)
                 goto err_undo;
         if (need_setup) {
@@ -128,6 +122,7 @@ err_undo:
         dev->dev_mapping = old_mapping;
         mutex_unlock(&dev->struct_mutex);
         dev->open_count--;
+        drm_minor_release(minor);
         return retcode;
 }
 EXPORT_SYMBOL(drm_open);
@@ -143,33 +138,30 @@ EXPORT_SYMBOL(drm_open);
  */
 int drm_stub_open(struct inode *inode, struct file *filp)
 {
-        struct drm_device *dev = NULL;
+        struct drm_device *dev;
         struct drm_minor *minor;
-        int minor_id = iminor(inode);
         int err = -ENODEV;
         const struct file_operations *new_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;
+        minor = drm_minor_acquire(iminor(inode));
+        if (IS_ERR(minor))
+                goto out_unlock;
 
+        dev = minor->dev;
         new_fops = fops_get(dev->driver->fops);
         if (!new_fops)
-                goto out;
+                goto out_release;
 
         replace_fops(filp, new_fops);
         if (filp->f_op->open)
                 err = filp->f_op->open(inode, filp);
-out:
+
+out_release:
+        drm_minor_release(minor);
+out_unlock:
         mutex_unlock(&drm_global_mutex);
         return err;
 }
@@ -196,16 +188,16 @@ static int drm_cpu_valid(void)
  *
  * \param inode device inode.
  * \param filp file pointer.
- * \param dev device.
+ * \param minor acquired minor-object.
  * \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 inode *inode, struct file *filp,
-                           struct drm_device * dev)
+                           struct drm_minor *minor)
 {
-        int minor_id = iminor(inode);
+        struct drm_device *dev = minor->dev;
         struct drm_file *priv;