drm/i915: Move over to intel_context_lookup()

In preparation for an ever growing number of engines and so ever
increasing static array of HW contexts within the GEM context, move the
array over to an rbtree, allocated upon first use.

Unfortunately, this imposes an rbtree lookup at a few frequent callsites,
but we should be able to mitigate those by moving over to using the HW
context as our primary type and so only incur the lookup on the boundary
with the user GEM context and engines.

v2: Check for no HW context in guc_stage_desc_init

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/20190308132522.21573-4-chris@chris-wilson.co.uk

1 files changed, 19 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index b210a2764613..7aeff600f12e 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -628,8 +628,7 @@ static void port_assign(struct execlist_port *port, struct i915_request *rq)
 static void inject_preempt_context(struct intel_engine_cs *engine)
 {
 	struct intel_engine_execlists *execlists = &engine->execlists;
-	struct intel_context *ce =
-		to_intel_context(engine->i915->preempt_context, engine);
+	struct intel_context *ce = execlists->preempt_context;
 	unsigned int n;
 
 	GEM_BUG_ON(execlists->preempt_complete_status !=
@@ -1237,19 +1236,24 @@ static void execlists_submit_request(struct i915_request *request)
 	spin_unlock_irqrestore(&engine->timeline.lock, flags);
 }
 
-static void execlists_context_destroy(struct intel_context *ce)
+static void __execlists_context_fini(struct intel_context *ce)
 {
-	GEM_BUG_ON(ce->pin_count);
-
-	if (!ce->state)
-		return;
-
 	intel_ring_free(ce->ring);
 
 	GEM_BUG_ON(i915_gem_object_is_active(ce->state->obj));
 	i915_gem_object_put(ce->state->obj);
 }
 
+static void execlists_context_destroy(struct intel_context *ce)
+{
+	GEM_BUG_ON(ce->pin_count);
+
+	if (ce->state)
+		__execlists_context_fini(ce);
+
+	intel_context_free(ce);
+}
+
 static void execlists_context_unpin(struct intel_context *ce)
 {
 	struct intel_engine_cs *engine;
@@ -1390,7 +1394,11 @@ static struct intel_context *
 execlists_context_pin(struct intel_engine_cs *engine,
 		      struct i915_gem_context *ctx)
 {
-	struct intel_context *ce = to_intel_context(ctx, engine);
+	struct intel_context *ce;
+
+	ce = intel_context_instance(ctx, engine);
+	if (IS_ERR(ce))
+		return ce;
 
 	lockdep_assert_held(&ctx->i915->drm.struct_mutex);
 	GEM_BUG_ON(!ctx->ppgtt);
@@ -2441,8 +2449,9 @@ static int logical_ring_init(struct intel_engine_cs *engine)
 	execlists->preempt_complete_status = ~0u;
 	if (i915->preempt_context) {
 		struct intel_context *ce =
-			to_intel_context(i915->preempt_context, engine);
+			intel_context_lookup(i915->preempt_context, engine);
 
+		execlists->preempt_context = ce;
 		execlists->preempt_complete_status =
 			upper_32_bits(ce->lrc_desc);
 	}