drm/i915: Track context current active time

Track context active (on hardware) status together with the start
timestamp.

This will be used to provide better granularity of context
runtime reporting in conjunction with already tracked pphwsp accumulated
runtime.

The latter is only updated on context save so does not give us visibility
to any currently executing work.

As part of the patch the existing runtime tracking data is moved under the
new ce->stats member and updated under the seqlock. This provides the
ability to atomically read out accumulated plus active runtime.

v2:
 * Rename and make __intel_context_get_active_time unlocked.

v3:
 * Use GRAPHICS_VER.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com> #  v1
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220401142205.3123159-6-tvrtko.ursulin@linux.intel.com

1 files changed, 14 insertions, 13 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index dffef6ab4baf..3f83a9038e13 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -778,7 +778,7 @@ static void init_common_regs(u32 * const regs,
 					   CTX_CTRL_RS_CTX_ENABLE);
 	regs[CTX_CONTEXT_CONTROL] = ctl;
 
-	regs[CTX_TIMESTAMP] = ce->runtime.last;
+	regs[CTX_TIMESTAMP] = ce->stats.runtime.last;
 }
 
 static void init_wa_bb_regs(u32 * const regs,
@@ -1734,11 +1734,12 @@ err:
 	}
 }
 
-static void st_update_runtime_underflow(struct intel_context *ce, s32 dt)
+static void st_runtime_underflow(struct intel_context_stats *stats, s32 dt)
 {
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
-	ce->runtime.num_underflow++;
-	ce->runtime.max_underflow = max_t(u32, ce->runtime.max_underflow, -dt);
+	stats->runtime.num_underflow++;
+	stats->runtime.max_underflow =
+		max_t(u32, stats->runtime.max_underflow, -dt);
 #endif
 }
 
@@ -1755,25 +1756,25 @@ static u32 lrc_get_runtime(const struct intel_context *ce)
 
 void lrc_update_runtime(struct intel_context *ce)
 {
+	struct intel_context_stats *stats = &ce->stats;
 	u32 old;
 	s32 dt;
 
-	if (intel_context_is_barrier(ce))
+	old = stats->runtime.last;
+	stats->runtime.last = lrc_get_runtime(ce);
+	dt = stats->runtime.last - old;
+	if (!dt)
 		return;
 
-	old = ce->runtime.last;
-	ce->runtime.last = lrc_get_runtime(ce);
-	dt = ce->runtime.last - old;
-
 	if (unlikely(dt < 0)) {
 		CE_TRACE(ce, "runtime underflow: last=%u, new=%u, delta=%d\n",
-			 old, ce->runtime.last, dt);
-		st_update_runtime_underflow(ce, dt);
+			 old, stats->runtime.last, dt);
+		st_runtime_underflow(stats, dt);
 		return;
 	}
 
-	ewma_runtime_add(&ce->runtime.avg, dt);
-	ce->runtime.total += dt;
+	ewma_runtime_add(&stats->runtime.avg, dt);
+	stats->runtime.total += dt;
 }
 
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)