drm/i915: Move GEM activity tracking into a common struct reservation_object

In preparation to support many distinct timelines, we need to expand the
activity tracking on the GEM object to handle more than just a request
per engine. We already use the struct reservation_object on the dma-buf
to handle many fence contexts, so integrating that into the GEM object
itself is the preferred solution. (For example, we can now share the same
reservation_object between every consumer/producer using this buffer and
skip the manual import/export via dma-buf.)

v2: Reimplement busy-ioctl (by walking the reservation object), postpone
the ABI change for another day. Similarly use the reservation object to
find the last_write request (if active and from i915) for choosing
display CS flips.

Caveats:

 * busy-ioctl: busy-ioctl only reports on the native fences, it will not
warn of stalls (in set-domain-ioctl, pread/pwrite etc) if the object is
being rendered to by external fences. It also will not report the same
busy state as wait-ioctl (or polling on the dma-buf) in the same
circumstances. On the plus side, it does retain reporting of which
*i915* engines are engaged with this object.

 * non-blocking atomic modesets take a step backwards as the wait for
render completion blocks the ioctl. This is fixed in a subsequent
patch to use a fence instead for awaiting on the rendering, see
"drm/i915: Restore nonblocking awaits for modesetting"

 * dynamic array manipulation for shared-fences in reservation is slower
than the previous lockless static assignment (e.g. gem_exec_lut_handle
runtime on ivb goes from 42s to 66s), mainly due to atomic operations
(maintaining the fence refcounts).

 * loss of object-level retirement callbacks, emulated by VMA retirement
tracking.

 * minor loss of object-level last activity information from debugfs,
could be replaced with per-vma information if desired

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-21-chris@chris-wilson.co.uk

1 files changed, 1 insertions, 34 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
index 602234f91583..a51d596a60ac 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.h
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -554,22 +554,7 @@ i915_gem_active_isset(const struct i915_gem_active *active)
 }
 
 /**
- * i915_gem_active_is_idle - report whether the active tracker is idle
- * @active - the active tracker
- *
- * i915_gem_active_is_idle() returns true if the active tracker is currently
- * unassigned or if the request is complete (but not yet retired). Requires
- * the caller to hold struct_mutex (but that can be relaxed if desired).
- */
-static inline bool
-i915_gem_active_is_idle(const struct i915_gem_active *active,
-			struct mutex *mutex)
-{
-	return !i915_gem_active_peek(active, mutex);
-}
-
-/**
- * i915_gem_active_wait- waits until the request is completed
+ * i915_gem_active_wait - waits until the request is completed
  * @active - the active request on which to wait
  * @flags - how to wait
  * @timeout - how long to wait at most
@@ -639,24 +624,6 @@ i915_gem_active_retire(struct i915_gem_active *active,
 	return 0;
 }
 
-/* Convenience functions for peeking at state inside active's request whilst
- * guarded by the struct_mutex.
- */
-
-static inline uint32_t
-i915_gem_active_get_seqno(const struct i915_gem_active *active,
-			  struct mutex *mutex)
-{
-	return i915_gem_request_get_seqno(i915_gem_active_peek(active, mutex));
-}
-
-static inline struct intel_engine_cs *
-i915_gem_active_get_engine(const struct i915_gem_active *active,
-			   struct mutex *mutex)
-{
-	return i915_gem_request_get_engine(i915_gem_active_peek(active, mutex));
-}
-
 #define for_each_active(mask, idx) \
 	for (; mask ? idx = ffs(mask) - 1, 1 : 0; mask &= ~BIT(idx))