drm/i915: Switch back to an array of logical per-engine HW contexts

We switched to a tree of per-engine HW context to accommodate the
introduction of virtual engines. However, we plan to also support
multiple instances of the same engine within the GEM context, defeating
our use of the engine as a key to looking up the HW context. Just
allocate a logical per-engine instance and always use an index into the
ctx->engines[]. Later on, this ctx->engines[] may be replaced by a user
specified map.

v2: Add for_each_gem_engine() helper to iterator within the engines lock
v3: intel_context_create_request() helper
v4: s/unsigned long/unsigned int/ 4 billion engines is quite enough.
v5: Push iterator locking to caller

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-7-chris@chris-wilson.co.uk

1 files changed, 5 insertions, 22 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index b746add6b71d..63392c88cd98 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -12,24 +12,16 @@
 #include "intel_context_types.h"
 #include "intel_engine_types.h"
 
-struct intel_context *intel_context_alloc(void);
-void intel_context_free(struct intel_context *ce);
-
 void intel_context_init(struct intel_context *ce,
 			struct i915_gem_context *ctx,
 			struct intel_engine_cs *engine);
 
-/**
- * intel_context_lookup - Find the matching HW context for this (ctx, engine)
- * @ctx - the parent GEM context
- * @engine - the target HW engine
- *
- * May return NULL if the HW context hasn't been instantiated (i.e. unused).
- */
 struct intel_context *
-intel_context_lookup(struct i915_gem_context *ctx,
+intel_context_create(struct i915_gem_context *ctx,
 		     struct intel_engine_cs *engine);
 
+void intel_context_free(struct intel_context *ce);
+
 /**
  * intel_context_lock_pinned - Stablises the 'pinned' status of the HW context
  * @ce - the context
@@ -71,17 +63,6 @@ static inline void intel_context_unlock_pinned(struct intel_context *ce)
 	mutex_unlock(&ce->pin_mutex);
 }
 
-struct intel_context *
-__intel_context_insert(struct i915_gem_context *ctx,
-		       struct intel_engine_cs *engine,
-		       struct intel_context *ce);
-void
-__intel_context_remove(struct intel_context *ce);
-
-struct intel_context *
-intel_context_instance(struct i915_gem_context *ctx,
-		       struct intel_engine_cs *engine);
-
 int __intel_context_do_pin(struct intel_context *ce);
 
 static inline int intel_context_pin(struct intel_context *ce)
@@ -144,4 +125,6 @@ static inline void intel_context_timeline_unlock(struct intel_context *ce)
 	mutex_unlock(&ce->ring->timeline->mutex);
 }
 
+struct i915_request *intel_context_create_request(struct intel_context *ce);
+
 #endif /* __INTEL_CONTEXT_H__ */