[RFC v2 1/8] drm: provide management functions for drm_file

Noralf Trønnes
2018-01-03T22:21:03Z

From: David Herrmann <dh.herrmann@gmail.com>

Rather than doing drm_file allocation/destruction right in the fops, lets
provide separate helpers. This decouples drm_file management from the
still-mandatory drm-fops. It prepares for use of drm_file without the
fops, both by possible separate fops implementations and APIs (not that I
am aware of any such plans), and more importantly from in-kernel use where
no real file is available.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
[rebased]
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---
drivers/gpu/drm/drm_file.c | 309 +++++++++++++++++++++++------------------
drivers/gpu/drm/drm_internal.h | 2 +
2 files changed, 179 insertions(+), 132 deletions(-)

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index b3c6e997ccdb..d208faade27e 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -101,6 +101,179 @@ DEFINE_MUTEX(drm_global_mutex);

static int drm_open_helper(struct file *filp, struct drm_minor *minor);

+/**
+ * drm_file_alloc - allocate file context
+ * @minor: minor to allocate on
+ *
+ * This allocates a new DRM file context. It is not linked into any context and
+ * can be used by the caller freely. Note that the context keeps a pointer to
+ * @minor, so it must be freed before @minor is.
+ *
+ * The legacy paths might require the drm_global_mutex to be held.
+ *
+ * RETURNS:
+ * Pointer to newly allocated context, ERR_PTR on failure.
+ */
+struct drm_file *drm_file_alloc(struct drm_minor *minor)
+{
+ struct drm_device *dev = minor->dev;
+ struct drm_file *file;
+ int ret;
+
+ file = kzalloc(sizeof(*file), GFP_KERNEL);
+ if (!file)
+ return ERR_PTR(-ENOMEM);
+
+ file->pid = get_pid(task_pid(current));
+ file->minor = minor;
+
+ /* for compatibility root is always authenticated */
+ file->authenticated = capable(CAP_SYS_ADMIN);
+ file->lock_count = 0;
+
+ INIT_LIST_HEAD(&file->lhead);
+ INIT_LIST_HEAD(&file->fbs);
+ mutex_init(&file->fbs_lock);
+ INIT_LIST_HEAD(&file->blobs);
+ INIT_LIST_HEAD(&file->pending_event_list);
+ INIT_LIST_HEAD(&file->event_list);
+ init_waitqueue_head(&file->event_wait);
+ file->event_space = 4096; /* set aside 4k for event buffer */
+
+ mutex_init(&file->event_read_lock);
+
+ if (drm_core_check_feature(dev, DRIVER_GEM))
+ drm_gem_open(dev, file);
+
+ if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+ drm_syncobj_open(file);
+
+ if (drm_core_check_feature(dev, DRIVER_PRIME))
+ drm_prime_init_file_private(&file->prime);
+
+ if (dev->driver->open) {
+ ret = dev->driver->open(dev, file);
+ if (ret < 0)
+ goto out_prime_destroy;
+ }
+
+ if (drm_is_primary_client(file)) {
+ ret = drm_master_open(file);
+ if (ret)
+ goto out_close;
+ }
+
+ return file;
+
+out_close:
+ if (dev->driver->postclose)
+ dev->driver->postclose(dev, file);
+out_prime_destroy:
+ if (drm_core_check_feature(dev, DRIVER_PRIME))
+ drm_prime_destroy_file_private(&file->prime);
+ if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+ drm_syncobj_release(file);
+ if (drm_core_check_feature(dev, DRIVER_GEM))
+ drm_gem_release(dev, file);
+ put_pid(file->pid);
+ kfree(file);
+
+ return ERR_PTR(ret);
+}
+
+static void drm_events_release(struct drm_file *file_priv)
+{
+ struct drm_device *dev = file_priv->minor->dev;
+ struct drm_pending_event *e, *et;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->event_lock, flags);
+
+ /* Unlink pending events */
+ list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
+ pending_link) {
+ list_del(&e->pending_link);
+ e->file_priv = NULL;
+ }
+
+ /* Remove unconsumed events */
+ list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
+ list_del(&e->link);
+ kfree(e);
+ }
+
+ spin_unlock_irqrestore(&dev->event_lock, flags);
+}
+
+/**
+ * drm_file_free - free file context
+ * @file: context to free, or NULL
+ *
+ * This destroys and deallocates a DRM file context previously allocated via
+ * drm_file_alloc(). The caller must make sure to unlink it from any contexts
+ * before calling this.
+ *
+ * The legacy paths might require the drm_global_mutex to be held.
+ *
+ * If NULL is passed, this is a no-op.
+ *
+ * RETURNS:
+ * 0 on success, or error code on failure.
+ */
+void drm_file_free(struct drm_file *file)
+{
+ struct drm_device *dev;
+
+ if (!file)
+ return;
+
+ dev = file->minor->dev;
+
+ DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
+ task_pid_nr(current),
+ (long)old_encode_dev(file->minor->kdev->devt),
+ dev->open_count);
+
+ if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
+ dev->driver->preclose)
+ dev->driver->preclose(dev, file);
+
+ if (drm_core_check_feature(dev, DRIVER_LEGACY))
+ drm_legacy_lock_release(dev, file->filp);
+
+ if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
+ drm_legacy_reclaim_buffers(dev, file);
+
+ drm_events_release(file);
+
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+ drm_fb_release(file);
+ drm_property_destroy_user_blobs(dev, file);
+ }
+
+ if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+ drm_syncobj_release(file);
+
+ if (drm_core_check_feature(dev, DRIVER_GEM))
+ drm_gem_release(dev, file);
+
+ drm_legacy_ctxbitmap_flush(dev, file);
+
+ if (drm_is_primary_client(file))
+ drm_master_release(file);
+
+ if (dev->driver->postclose)
+ dev->driver->postclose(dev, file);
+
+ if (drm_core_check_feature(dev, DRIVER_PRIME))
+ drm_prime_destroy_file_private(&file->prime);
+
+ WARN_ON(!list_empty(&file->event_list));
+
+ put_pid(file->pid);
+ kfree(file);
+}
+
static int drm_setup(struct drm_device * dev)
{
int ret;
@@ -196,7 +369,6 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor)
{
struct drm_device *dev = minor->dev;
struct drm_file *priv;
- int ret;

if (filp->f_flags & O_EXCL)
return -EBUSY; /* No exclusive opens */
@@ -207,50 +379,12 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor)

DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);

- priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
+ priv = drm_file_alloc(minor);
+ if (IS_ERR(priv))
+ return PTR_ERR(priv);

filp->private_data = priv;
priv->filp = filp;
- priv->pid = get_pid(task_pid(current));
- priv->minor = minor;
-
- /* 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);
- mutex_init(&priv->fbs_lock);
- INIT_LIST_HEAD(&priv->blobs);
- INIT_LIST_HEAD(&priv->pending_event_list);
- INIT_LIST_HEAD(&priv->event_list);
- init_waitqueue_head(&priv->event_wait);
- priv->event_space = 4096; /* set aside 4k for event buffer */
-
- mutex_init(&priv->event_read_lock);
-
- if (drm_core_check_feature(dev, DRIVER_GEM))
- drm_gem_open(dev, priv);
-
- if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
- drm_syncobj_open(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_prime_destroy;
- }
-
- if (drm_is_primary_client(priv)) {
- ret = drm_master_open(priv);
- if (ret)
- goto out_close;
- }

mutex_lock(&dev->filelist_mutex);
list_add(&priv->lhead, &dev->filelist);
@@ -277,45 +411,6 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor)
#endif

return 0;
-
-out_close:
- if (dev->driver->postclose)
- dev->driver->postclose(dev, priv);
-out_prime_destroy:
- if (drm_core_check_feature(dev, DRIVER_PRIME))
- drm_prime_destroy_file_private(&priv->prime);
- if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
- drm_syncobj_release(priv);
- if (drm_core_check_feature(dev, DRIVER_GEM))
- drm_gem_release(dev, priv);
- put_pid(priv->pid);
- kfree(priv);
- filp->private_data = NULL;
- return ret;
-}
-
-static void drm_events_release(struct drm_file *file_priv)
-{
- struct drm_device *dev = file_priv->minor->dev;
- struct drm_pending_event *e, *et;
- unsigned long flags;
-
- spin_lock_irqsave(&dev->event_lock, flags);
-
- /* Unlink pending events */
- list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
- pending_link) {
- list_del(&e->pending_link);
- e->file_priv = NULL;
- }
-
- /* Remove unconsumed events */
- list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
- list_del(&e->link);
- kfree(e);
- }
-
- spin_unlock_irqrestore(&dev->event_lock, flags);
}

static void drm_legacy_dev_reinit(struct drm_device *dev)
@@ -382,57 +477,7 @@ int drm_release(struct inode *inode, struct file *filp)
list_del(&file_priv->lhead);
mutex_unlock(&dev->filelist_mutex);

- if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
- 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->kdev->devt),
- dev->open_count);
-
- if (drm_core_check_feature(dev, DRIVER_LEGACY))
- drm_legacy_lock_release(dev, filp);
-
- if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
- drm_legacy_reclaim_buffers(dev, file_priv);
-
- drm_events_release(file_priv);
-
- if (drm_core_check_feature(dev, DRIVER_MODESET)) {
- drm_fb_release(file_priv);
- drm_property_destroy_user_blobs(dev, file_priv);
- }
-
- if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
- drm_syncobj_release(file_priv);
-
- if (drm_core_check_feature(dev, DRIVER_GEM))
- drm_gem_release(dev, file_priv);
-
- drm_legacy_ctxbitmap_flush(dev, file_priv);
-
- if (drm_is_primary_client(file_priv))
- drm_master_release(file_priv);
-
- 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);
-
- WARN_ON(!list_empty(&file_priv->event_list));
-
- put_pid(file_priv->pid);
- kfree(file_priv);
-
- /* ========================================================
- * End inline drm_release
- */
+ drm_file_free(file_priv);

if (!--dev->open_count) {
drm_lastclose(dev);
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index b72242e93ea4..40179c5fc6b8 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -26,6 +26,8 @@

/* drm_file.c */
extern struct mutex drm_global_mutex;
+struct drm_file *drm_file_alloc(struct drm_minor *minor);
+void drm_file_free(struct drm_file *file);
void drm_lastclose(struct drm_device *dev);

/* drm_pci.c */
--
2.14.2