[CI] drm/i915: Track hw reported context runtime
diff mbox series

Message ID 20200215212226.18507-1-chris@chris-wilson.co.uk
State New
Headers show
Series
  • [CI] drm/i915: Track hw reported context runtime
Related show

Commit Message

Chris Wilson Feb. 15, 2020, 9:22 p.m. UTC
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

GPU saves accumulated context runtime (in CS timestamp units) in PPHWSP
which will be useful for us in cases when we are not able to track context
busyness ourselves (like with GuC). Keep a copy of this in struct
intel_context from where it can be easily read even if the context is not
pinned.

QQQ: Do we want to make this accounting conditional / able to turn on/off?

v2:
 (Chris)
 * Do not store pphwsp address in intel_context.
 * Log CS wrap-around.
 * Simplify calculation by relying on integer wraparound.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_context.h       |  9 ++
 drivers/gpu/drm/i915/gt/intel_context_types.h |  7 ++
 drivers/gpu/drm/i915/gt/intel_lrc.c           | 41 ++++++++-
 drivers/gpu/drm/i915/gt/selftest_lrc.c        | 85 +++++++++++++++++++
 drivers/gpu/drm/i915/intel_device_info.c      |  6 ++
 drivers/gpu/drm/i915/intel_device_info.h      |  1 +
 6 files changed, 147 insertions(+), 2 deletions(-)

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index 604d5cfc46ba..502cf7361a29 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -12,6 +12,7 @@ 
 #include <linux/types.h>
 
 #include "i915_active.h"
+#include "i915_drv.h"
 #include "intel_context_types.h"
 #include "intel_engine_types.h"
 #include "intel_ring_types.h"
@@ -227,4 +228,12 @@  intel_context_clear_nopreempt(struct intel_context *ce)
 	clear_bit(CONTEXT_NOPREEMPT, &ce->flags);
 }
 
+static inline u64 intel_context_get_hw_runtime_ns(struct intel_context *ce)
+{
+	const u32 period =
+		RUNTIME_INFO(ce->engine->i915)->cs_timestamp_period_ns;
+
+	return mul_u32_u32(ce->runtime.total, period);
+}
+
 #endif /* __INTEL_CONTEXT_H__ */
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index ca1420fb8b53..3100823b16c3 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -68,6 +68,13 @@  struct intel_context {
 	u64 lrc_desc;
 	u32 tag; /* cookie passed to HW to track this context on submission */
 
+	/* Time on GPU as tracked by the hw. */
+	struct {
+		u64 total;
+		u32 last;
+		I915_SELFTEST_DECLARE(unsigned long underflow);
+	} runtime;
+
 	unsigned int active_count; /* protected by timeline->mutex */
 
 	atomic_t pin_count;
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index c3d7727021db..a505e98c8854 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1195,6 +1195,37 @@  static void reset_active(struct i915_request *rq,
 	ce->lrc_desc |= CTX_DESC_FORCE_RESTORE;
 }
 
+static u32 intel_context_get_runtime(const struct intel_context *ce)
+{
+	/*
+	 * PPHWSP is one page before the lrc state page and in it at
+	 * dword 16 we have cumulative context runtime in CS timestamp ticks.
+	 */
+	BUILD_BUG_ON((LRC_STATE_PN - LRC_PPHWSP_PN) != 1);
+	return ce->lrc_reg_state[-1024 + 16];
+}
+
+static void intel_context_update_runtime(struct intel_context *ce)
+{
+	u32 new, old;
+
+	if (intel_context_is_barrier(ce))
+		return;
+
+	old = ce->runtime.last;
+	new = intel_context_get_runtime(ce);
+	if ((s32)(new - old) <= 0) {
+		CE_TRACE(ce, "runtime underflow: last=%u, new=%u, delta=%d\n",
+			 old, new, new - old);
+		I915_SELFTEST_ONLY(ce->runtime.underflow++);
+		GEM_TRACE_DUMP();
+		return;
+	}
+
+	ce->runtime.total += new - old;
+	ce->runtime.last = new;
+}
+
 static inline struct intel_engine_cs *
 __execlists_schedule_in(struct i915_request *rq)
 {
@@ -1278,6 +1309,7 @@  __execlists_schedule_out(struct i915_request *rq,
 	    i915_request_completed(rq))
 		intel_engine_add_retire(engine, ce->timeline);
 
+	intel_context_update_runtime(ce);
 	intel_engine_context_out(engine);
 	execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT);
 	intel_gt_pm_put_async(engine->gt);
@@ -4607,8 +4639,13 @@  populate_lr_context(struct intel_context *ce,
 		inhibit = false;
 	}
 
-	/* The second page of the context object contains some fields which must
-	 * be set up prior to the first execution. */
+	/* Clear the ppHWSP (inc. per-context counters) */
+	memset(vaddr, 0, PAGE_SIZE);
+
+	/*
+	 * The second page of the context object contains some registers which
+	 * must be set up prior to the first execution.
+	 */
 	execlists_init_reg_state(vaddr + LRC_STATE_PN * PAGE_SIZE,
 				 ce, engine, ring, inhibit);
 
diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 64761e619876..d71bcd959d48 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -4450,6 +4450,90 @@  static int live_gpr_clear(void *arg)
 	return err;
 }
 
+static int __live_pphwsp_runtime(struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+	struct i915_request *rq;
+	IGT_TIMEOUT(end_time);
+	bool timeout = false;
+	int err;
+
+	ce = intel_context_create(engine);
+	if (IS_ERR(ce))
+		return PTR_ERR(ce);
+
+	ce->runtime.underflow = 0;
+
+	while (!timeout) {
+		unsigned int loop = 1024;
+
+		while (loop) {
+			rq = intel_context_create_request(ce);
+			if (IS_ERR(rq)) {
+				err = PTR_ERR(rq);
+				goto err_rq;
+			}
+
+			if (--loop == 0)
+				i915_request_get(rq);
+
+			i915_request_add(rq);
+		}
+		timeout = __igt_timeout(end_time, NULL);
+		if (!timeout)
+			i915_request_put(rq);
+	}
+
+	err = i915_request_wait(rq, 0, HZ / 5);
+	if (err < 0) {
+		pr_err("%s: request not completed! (err=%d)\n",
+		       engine->name, err);
+		goto err_wait;
+	}
+
+	igt_flush_test(engine->i915);
+
+	pr_info("%s: pphwsp runtime %lluns\n",
+		engine->name, intel_context_get_hw_runtime_ns(ce));
+
+	err = 0;
+	if (ce->runtime.underflow) {
+		pr_err("%s: pphwsp underflow %lu time(s)!\n",
+		       engine->name, ce->runtime.underflow);
+		err = -EOVERFLOW;
+	}
+
+err_wait:
+	i915_request_put(rq);
+err_rq:
+	intel_context_put(ce);
+	return err;
+}
+
+static int live_pphwsp_runtime(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err = 0;
+
+	/*
+	 * Check that cumulative context runtime as stored in the pphwsp[16]
+	 * is monotonic.
+	 */
+
+	for_each_engine(engine, gt, id) {
+		err = __live_pphwsp_runtime(engine);
+		if (err)
+			break;
+	}
+
+	if (igt_flush_test(gt->i915))
+		err = -EIO;
+
+	return err;
+}
+
 int intel_lrc_live_selftests(struct drm_i915_private *i915)
 {
 	static const struct i915_subtest tests[] = {
@@ -4457,6 +4541,7 @@  int intel_lrc_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(live_lrc_fixed),
 		SUBTEST(live_lrc_state),
 		SUBTEST(live_gpr_clear),
+		SUBTEST(live_pphwsp_runtime),
 	};
 
 	if (!HAS_LOGICAL_RING_CONTEXTS(i915))
diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
index fcdacd6d4aa5..113decd59b40 100644
--- a/drivers/gpu/drm/i915/intel_device_info.c
+++ b/drivers/gpu/drm/i915/intel_device_info.c
@@ -1045,6 +1045,12 @@  void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
 
 	/* Initialize command stream timestamp frequency */
 	runtime->cs_timestamp_frequency_khz = read_timestamp_frequency(dev_priv);
+	runtime->cs_timestamp_period_ns =
+		div_u64(1e6, runtime->cs_timestamp_frequency_khz);
+	drm_dbg(&dev_priv->drm,
+		"CS timestamp wraparound in %lldms\n",
+		div_u64(mul_u32_u32(runtime->cs_timestamp_period_ns, U32_MAX),
+			USEC_PER_SEC));
 }
 
 void intel_driver_caps_print(const struct intel_driver_caps *caps,
diff --git a/drivers/gpu/drm/i915/intel_device_info.h b/drivers/gpu/drm/i915/intel_device_info.h
index 7d4d122d2182..f8bfa26388c1 100644
--- a/drivers/gpu/drm/i915/intel_device_info.h
+++ b/drivers/gpu/drm/i915/intel_device_info.h
@@ -217,6 +217,7 @@  struct intel_runtime_info {
 	struct sseu_dev_info sseu;
 
 	u32 cs_timestamp_frequency_khz;
+	u32 cs_timestamp_period_ns;
 
 	/* Media engine access to SFC per instance */
 	u8 vdbox_sfc_access;