drm: extract legacy ctxbitmap flushing

The ctxbitmap code is only used by legacy drivers so lets try to keep it
as separated as possible. Furthermore, the locking is non-obvious and
kinda weird with ctxlist_mutex *and* struct_mutex. Keeping all ctxbitmap
access in one file is much easier to review and makes drm_release() more
readable.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_context.c b/drivers/gpu/drm/drm_context.c
index a4b017b6849e..c045505978f1 100644
--- a/drivers/gpu/drm/drm_context.c
+++ b/drivers/gpu/drm/drm_context.c
@@ -111,6 +111,36 @@ void drm_ctxbitmap_cleanup(struct drm_device * dev)
         mutex_unlock(&dev->struct_mutex);
 }
 
+/**
+ * drm_ctxbitmap_flush() - Flush all contexts owned by a file
+ * @dev: DRM device to operate on
+ * @file: Open file to flush contexts for
+ *
+ * This iterates over all contexts on @dev and drops them if they're owned by
+ * @file. Note that after this call returns, new contexts might be added if
+ * the file is still alive.
+ */
+void drm_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file)
+{
+        struct drm_ctx_list *pos, *tmp;
+
+        mutex_lock(&dev->ctxlist_mutex);
+
+        list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) {
+                if (pos->tag == file &&
+                    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);
+                }
+        }
+
+        mutex_unlock(&dev->ctxlist_mutex);
+}
+
 /*@}*/
 
 /******************************************************************/