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

drivers/gpu/drm/i915/gt/intel_engine_cs.c

@@ -1491,7 +1491,7 @@ static void intel_engine_print_registers(struct intel_engine_cs *engine,
 					intel_context_is_banned(rq->context) ? "*" : "");
 			len += print_ring(hdr + len, sizeof(hdr) - len, rq);
 			scnprintf(hdr + len, sizeof(hdr) - len, "rq: ");
-			i915_request_show(m, rq, hdr);
+			i915_request_show(m, rq, hdr, 0);
 		}
 		for (port = execlists->pending; (rq = *port); port++) {
 			char hdr[160];
@@ -1505,7 +1505,7 @@ static void intel_engine_print_registers(struct intel_engine_cs *engine,
 					intel_context_is_banned(rq->context) ? "*" : "");
 			len += print_ring(hdr + len, sizeof(hdr) - len, rq);
 			scnprintf(hdr + len, sizeof(hdr) - len, "rq: ");
-			i915_request_show(m, rq, hdr);
+			i915_request_show(m, rq, hdr, 0);
 		}
 		rcu_read_unlock();
 		execlists_active_unlock_bh(execlists);
@@ -1649,7 +1649,7 @@ void intel_engine_dump(struct intel_engine_cs *engine,
 	if (rq) {
 		struct intel_timeline *tl = get_timeline(rq);
 
-		i915_request_show(m, rq, "\t\tactive ");
+		i915_request_show(m, rq, "\t\tactive ", 0);
 
 		drm_printf(m, "\t\tring->start:  0x%08x\n",
 			   i915_ggtt_offset(rq->ring->vma));

drivers/gpu/drm/i915/gt/intel_lrc.c

@@ -5982,7 +5982,8 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 				   struct drm_printer *m,
 				   void (*show_request)(struct drm_printer *m,
 							const struct i915_request *rq,
-							const char *prefix),
+							const char *prefix,
+							int indent),
 				   unsigned int max)
 {
 	const struct intel_engine_execlists *execlists = &engine->execlists;
@@ -5997,7 +5998,7 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 	count = 0;
 	list_for_each_entry(rq, &engine->active.requests, sched.link) {
 		if (count++ < max - 1)
-			show_request(m, rq, "\t\tE ");
+			show_request(m, rq, "\t\t", 0);
 		else
 			last = rq;
 	}
@@ -6007,7 +6008,7 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 				   "\t\t...skipping %d executing requests...\n",
 				   count - max);
 		}
-		show_request(m, last, "\t\tE ");
+		show_request(m, last, "\t\t", 0);
 	}
 
 	if (execlists->switch_priority_hint != INT_MIN)
@@ -6025,7 +6026,7 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 
 		priolist_for_each_request(rq, p, i) {
 			if (count++ < max - 1)
-				show_request(m, rq, "\t\tQ ");
+				show_request(m, rq, "\t\t", 0);
 			else
 				last = rq;
 		}
@@ -6036,7 +6037,7 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 				   "\t\t...skipping %d queued requests...\n",
 				   count - max);
 		}
-		show_request(m, last, "\t\tQ ");
+		show_request(m, last, "\t\t", 0);
 	}
 
 	last = NULL;
@@ -6048,7 +6049,7 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 
 		if (rq) {
 			if (count++ < max - 1)
-				show_request(m, rq, "\t\tV ");
+				show_request(m, rq, "\t\t", 0);
 			else
 				last = rq;
 		}
@@ -6059,7 +6060,7 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 				   "\t\t...skipping %d virtual requests...\n",
 				   count - max);
 		}
-		show_request(m, last, "\t\tV ");
+		show_request(m, last, "\t\t", 0);
 	}
 
 	spin_unlock_irqrestore(&engine->active.lock, flags);

drivers/gpu/drm/i915/gt/intel_lrc.h

@@ -107,7 +107,8 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 				   struct drm_printer *m,
 				   void (*show_request)(struct drm_printer *m,
 							const struct i915_request *rq,
-							const char *prefix),
+							const char *prefix,
+							int indent),
 				   unsigned int max);
 
 struct intel_context *

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);

drivers/gpu/drm/i915/i915_request.h

@@ -372,7 +372,8 @@ long i915_request_wait(struct i915_request *rq,
 
 void i915_request_show(struct drm_printer *m,
 		       const struct i915_request *rq,
-		       const char *prefix);
+		       const char *prefix,
+		       int indent);
 
 static inline bool i915_request_signaled(const struct i915_request *rq)
 {