drm/i915/guc: rework guc_add_workqueue_item()
Mostly little optimisations and future-proofing against code breakage.
For instance, if the driver is correctly following the submission
protocol, the "out of space" condition is impossible, so the previous
runtime WARN_ON() is promoted to a GEM_BUG_ON() for a more dramatic
effect in development and less impact in end-user systems.
Similarly we can make alignment checking more stringent and replace
other WARN_ON() conditions that don't relate to the runtime hardware
state with either BUILD_BUG_ON() for compile-time-detectable issues, or
GEM_BUG_ON() for logical "can't happen" errors.
With those changes, we can convert it to void, as suggested by Chris
Wilson, and update the calling code appropriately.
v2:
Note that we're now putting the request seqno in the "fence_id"
field of each GuC-work-item, in case it turns up somewhere useful
(e.g. in a GuC log) [Tvrtko Ursulin].
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_guc_fwif.h b/drivers/gpu/drm/i915/intel_guc_fwif.h
index 2de57ff..944786d 100644
--- a/drivers/gpu/drm/i915/intel_guc_fwif.h
+++ b/drivers/gpu/drm/i915/intel_guc_fwif.h
@@ -71,7 +71,8 @@
#define WQ_WORKLOAD_TOUCH (2 << WQ_WORKLOAD_SHIFT)
#define WQ_RING_TAIL_SHIFT 20
-#define WQ_RING_TAIL_MASK (0x7FF << WQ_RING_TAIL_SHIFT)
+#define WQ_RING_TAIL_MAX 0x7FF /* 2^11 QWords */
+#define WQ_RING_TAIL_MASK (WQ_RING_TAIL_MAX << WQ_RING_TAIL_SHIFT)
#define GUC_DOORBELL_ENABLED 1
#define GUC_DOORBELL_DISABLED 0