From d9e0f8ea9f651a37a95ce8d3a650a9e16274aca8 Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Wed, 29 Jan 2014 10:18:02 +0100 Subject: [PATCH] drm: skip redundant minor-lookup in open path The drm_open_helper() function is only used internally for drm_open() so we can safely pass in the minor-object directly instead of the minor-id. This way, we avoid the additional minor IDR lookup, which we already do twice in drm_stub_open() and drm_open(). Signed-off-by: David Herrmann Reviewed-by: Daniel Vetter (cherry picked from commit f4aede2e3291896e7cb42755ecc5b6815b6cac97) Signed-off-by: Simon Horman --- drivers/gpu/drm/drm_fops.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 88ebc2b..1ec4498 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -44,7 +44,7 @@ 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) { @@ -100,7 +100,7 @@ int drm_open(struct inode *inode, struct file *filp) /* share address_space across all char-devs of a single device */ filp->f_mapping = dev->anon_inode->i_mapping; - retcode = drm_open_helper(inode, filp, dev); + retcode = drm_open_helper(inode, filp, minor); if (retcode) goto err_undo; if (need_setup) { @@ -182,16 +182,16 @@ 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; int ret; @@ -202,7 +202,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp, if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF) return -EINVAL; - DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id); + DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index); priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) @@ -212,11 +212,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp, priv->filp = filp; priv->uid = current_euid(); priv->pid = get_pid(task_pid(current)); - priv->minor = idr_find(&drm_minors_idr, minor_id); - if (!priv->minor) { - ret = -ENODEV; - goto out_put_pid; - } + priv->minor = minor; /* for compatibility root is always authenticated */ priv->always_authenticated = capable(CAP_SYS_ADMIN); @@ -322,7 +318,6 @@ out_prime_destroy: drm_prime_destroy_file_private(&priv->prime); if (dev->driver->driver_features & DRIVER_GEM) drm_gem_release(dev, priv); -out_put_pid: put_pid(priv->pid); kfree(priv); filp->private_data = NULL; -- 2.7.4