From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 22 Mar 2018 13:10:34 +0000
Subject: drm/i915: Remove local timeline var from submit/unsubmit
Git-commit: 4ccfee92f4b6fbbedee1eb68f110a66f03edf7c6
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Both request_submit and request_unsubmit deal with transferring the
request from the client's timeline onto the execution timeline and back
again. As both functions deal with a pair of timeline's, using a
shorthand for just one of them is slightly confusing, especially as the
different functions use the shorthand for the alternate timeline.
Instead, use the full version of each timeline so it should be easier to
keep track of the transfer between the request/client and the engine.

v2: Refactor the common lock+list_move
v3: Be clear we require the other timeline list to be locked as well.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180322131034.6036-1-chris@chris-wilson.co.uk

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/i915_request.c |   30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -492,10 +492,20 @@ static u32 timeline_get_seqno(struct int
 	return ++tl->seqno;
 }
 
+static void move_to_timeline(struct i915_request *request,
+			     struct intel_timeline *timeline)
+{
+	GEM_BUG_ON(request->timeline == request->engine->timeline);
+	lockdep_assert_held(&request->engine->timeline->lock);
+
+	spin_lock(&request->timeline->lock);
+	list_move_tail(&request->link, &timeline->requests);
+	spin_unlock(&request->timeline->lock);
+}
+
 void __i915_request_submit(struct i915_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
-	struct intel_timeline *timeline;
 	u32 seqno;
 
 	GEM_TRACE("%s fence %llx:%d -> global_seqno %d\n",
@@ -506,12 +516,9 @@ void __i915_request_submit(struct i915_r
 	GEM_BUG_ON(!irqs_disabled());
 	lockdep_assert_held(&engine->timeline->lock);
 
-	/* Transfer from per-context onto the global per-engine timeline */
-	timeline = engine->timeline;
-	GEM_BUG_ON(timeline == request->timeline);
 	GEM_BUG_ON(request->global_seqno);
 
-	seqno = timeline_get_seqno(timeline);
+	seqno = timeline_get_seqno(engine->timeline);
 	GEM_BUG_ON(!seqno);
 	GEM_BUG_ON(i915_seqno_passed(intel_engine_get_seqno(engine), seqno));
 
@@ -525,9 +532,8 @@ void __i915_request_submit(struct i915_r
 	engine->emit_breadcrumb(request,
 				request->ring->vaddr + request->postfix);
 
-	spin_lock(&request->timeline->lock);
-	list_move_tail(&request->link, &timeline->requests);
-	spin_unlock(&request->timeline->lock);
+	/* Transfer from per-context onto the global per-engine timeline */
+	move_to_timeline(request, engine->timeline);
 
 	trace_i915_request_execute(request);
 
@@ -550,7 +556,6 @@ void i915_request_submit(struct i915_req
 void __i915_request_unsubmit(struct i915_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
-	struct intel_timeline *timeline;
 
 	GEM_TRACE("%s fence %llx:%d <- global_seqno %d\n",
 		  request->engine->name,
@@ -578,12 +583,7 @@ void __i915_request_unsubmit(struct i915
 	spin_unlock(&request->lock);
 
 	/* Transfer back from the global per-engine timeline to per-context */
-	timeline = request->timeline;
-	GEM_BUG_ON(timeline == engine->timeline);
-
-	spin_lock(&timeline->lock);
-	list_move(&request->link, &timeline->requests);
-	spin_unlock(&timeline->lock);
+	move_to_timeline(request, request->timeline);
 
 	/*
 	 * We don't need to wake_up any waiters on request->execute, they