drm/i915/gt: Update request status flags for debug pretty-printer

We plan to expand upon the number of available statuses for when we
pretty-print the requests along the timelines, and so need a new set of
flags. We have settled upon:

	Unready [U]
	  - initial status after being submitted, the request is not
	    ready for execution as it is waiting for external fences

	Ready [R]
	  - all fences the request was waiting on have been signaled,
            and the request is now ready for execution and will be
	    in a backend queue

	  - a ready request may still need to wait on semaphores
	    [internal fences]

	Ready/virtual [V]
	  - same as ready, but queued over multiple backends

	Executing [E]
	  - the request has been transferred from the backend queue and
	    submitted for execution on HW

	  - a completed request may still be regarded as executing, its
	    status may not be updated until it is retired and removed
	    from the lists

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/20201119165616.10834-3-chris@chris-wilson.co.uk

1 files changed, 73 insertions, 12 deletions

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 673991718ae6..8d7d29c9e375 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1867,28 +1867,89 @@ static int print_sched_attr(const struct i915_sched_attr *attr,
 	return x;
 }
 
+static char queue_status(const struct i915_request *rq)
+{
+	if (i915_request_is_active(rq))
+		return 'E';
+
+	if (i915_request_is_ready(rq))
+		return intel_engine_is_virtual(rq->engine) ? 'V' : 'R';
+
+	return 'U';
+}
+
+static const char *run_status(const struct i915_request *rq)
+{
+	if (i915_request_completed(rq))
+		return "!";
+
+	if (i915_request_started(rq))
+		return "*";
+
+	if (!i915_sw_fence_signaled(&rq->semaphore))
+		return "&";
+
+	return "";
+}
+
+static const char *fence_status(const struct i915_request *rq)
+{
+	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))
+		return "+";
+
+	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &rq->fence.flags))
+		return "-";
+
+	return "";
+}
+
 void i915_request_show(struct drm_printer *m,
 		       const struct i915_request *rq,
-		       const char *prefix)
+		       const char *prefix,
+		       int indent)
 {
 	const char *name = rq->fence.ops->get_timeline_name((struct dma_fence *)&rq->fence);
 	char buf[80] = "";
 	int x = 0;
 
+	/*
+	 * The prefix is used to show the queue status, for which we use
+	 * the following flags:
+	 *
+	 *  U [Unready]
+	 *    - initial status upon being submitted by the user
+	 *
+	 *    - the request is not ready for execution as it is waiting
+	 *      for external fences
+	 *
+	 *  R [Ready]
+	 *    - all fences the request was waiting on have been signaled,
+	 *      and the request is now ready for execution and will be
+	 *      in a backend queue
+	 *
+	 *    - a ready request may still need to wait on semaphores
+	 *      [internal fences]
+	 *
+	 *  V [Ready/virtual]
+	 *    - same as ready, but queued over multiple backends
+	 *
+	 *  E [Executing]
+	 *    - the request has been transferred from the backend queue and
+	 *      submitted for execution on HW
+	 *
+	 *    - a completed request may still be regarded as executing, its
+	 *      status may not be updated until it is retired and removed
+	 *      from the lists
+	 */
+
 	x = print_sched_attr(&rq->sched.attr, buf, x, sizeof(buf));
 
-	drm_printf(m, "%s %llx:%lld%s%s %s @ %dms: %s\n",
-		   prefix,
+	drm_printf(m, "%s%.*s%c %llx:%lld%s%s %s @ %dms: %s\n",
+		   prefix, indent, "                ",
+		   queue_status(rq),
 		   rq->fence.context, rq->fence.seqno,
-		   i915_request_completed(rq) ? "!" :
-		   i915_request_started(rq) ? "*" :
-		   !i915_sw_fence_signaled(&rq->semaphore) ? "&" :
-		   "",
-		   test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
-			    &rq->fence.flags) ? "+" :
-		   test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
-			    &rq->fence.flags) ? "-" :
-		   "",
+		   run_status(rq),
+		   fence_status(rq),
 		   buf,
 		   jiffies_to_msecs(jiffies - rq->emitted_jiffies),
 		   name);