drm/i915: Pull i915_gem_active into the i915_active family

Looking forward, we need to break the struct_mutex dependency on
i915_gem_active. In the meantime, external use of i915_gem_active is
quite beguiling, little do new users suspect that it implies a barrier
as each request it tracks must be ordered wrt the previous one. As one
of many, it can be used to track activity across multiple timelines, a
shared fence, which fits our unordered request submission much better. We
need to steer external users away from the singular, exclusive fence
imposed by i915_gem_active to i915_active instead. As part of that
process, we move i915_gem_active out of i915_request.c into
i915_active.c to start separating the two concepts, and rename it to
i915_active_request (both to tie it to the concept of tracking just one
request, and to give it a longer, less appealing name).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205130005.2807-5-chris@chris-wilson.co.uk

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_active_types.h b/drivers/gpu/drm/i915/i915_active_types.h
index 411e502ed8dd..b679253b53a5 100644
--- a/drivers/gpu/drm/i915/i915_active_types.h
+++ b/drivers/gpu/drm/i915/i915_active_types.h
@@ -8,16 +8,26 @@
 #define _I915_ACTIVE_TYPES_H_
 
 #include <linux/rbtree.h>
-
-#include "i915_request.h"
+#include <linux/rcupdate.h>
 
 struct drm_i915_private;
+struct i915_active_request;
+struct i915_request;
+
+typedef void (*i915_active_retire_fn)(struct i915_active_request *,
+				      struct i915_request *);
+
+struct i915_active_request {
+	struct i915_request __rcu *request;
+	struct list_head link;
+	i915_active_retire_fn retire;
+};
 
 struct i915_active {
 	struct drm_i915_private *i915;
 
 	struct rb_root tree;
-	struct i915_gem_active last;
+	struct i915_active_request last;
 	unsigned int count;
 
 	void (*retire)(struct i915_active *ref);