lib/igt_dummyload: Introduce igt_spin_reset

Libify resetting a spin for reuse.

v2: use also in perf_pmu
v3: s/cmd_spin/cmd_precondition
v4: remove early return for !spin (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

5 files changed, 38 insertions, 44 deletions

diff --git a/lib/igt_dummyload.c b/lib/igt_dummyload.c
index 1d57a53c..65957ed1 100644
--- a/lib/igt_dummyload.c
+++ b/lib/igt_dummyload.c
@@ -260,6 +260,8 @@ emit_recursive_batch(igt_spin_t *spin,
 	obj[SCRATCH].flags = EXEC_OBJECT_PINNED;
 	obj[BATCH].flags = EXEC_OBJECT_PINNED;
 
+	spin->cmd_precondition = *spin->batch;
+
 	return fence_fd;
 }
 
@@ -367,6 +369,21 @@ void igt_spin_set_timeout(igt_spin_t *spin, int64_t ns)
 }
 
 /**
+ * igt_spin_reset:
+ * @spin: spin state from igt_spin_new()
+ *
+ * Reset the state of spin, allowing its reuse.
+ */
+void igt_spin_reset(igt_spin_t *spin)
+{
+	if (igt_spin_has_poll(spin))
+		spin->poll[SPIN_POLL_START_IDX] = 0;
+
+	*spin->batch = spin->cmd_precondition;
+	__sync_synchronize();
+}
+
+/**
  * igt_spin_end:
  * @spin: spin state from igt_spin_new()
  *
diff --git a/lib/igt_dummyload.h b/lib/igt_dummyload.h
index d6482089..34537f27 100644
--- a/lib/igt_dummyload.h
+++ b/lib/igt_dummyload.h
@@ -37,6 +37,7 @@ typedef struct igt_spin {
 	timer_t timer;
 	struct igt_list link;
 	uint32_t *batch;
+	uint32_t cmd_precondition;
 	int out_fence;
 	struct drm_i915_gem_exec_object2 obj[2];
 	struct drm_i915_gem_execbuffer2 execbuf;
@@ -68,6 +69,7 @@ igt_spin_factory(int fd, const struct igt_spin_factory *opts);
 	igt_spin_factory(fd, &((struct igt_spin_factory){__VA_ARGS__}))
 
 void igt_spin_set_timeout(igt_spin_t *spin, int64_t ns);
+void igt_spin_reset(igt_spin_t *spin);
 void igt_spin_end(igt_spin_t *spin);
 void igt_spin_free(int fd, igt_spin_t *spin);
 
diff --git a/tests/i915/gem_exec_latency.c b/tests/i915/gem_exec_latency.c
index 6b7dfbc0..2cfb78bf 100644
--- a/tests/i915/gem_exec_latency.c
+++ b/tests/i915/gem_exec_latency.c
@@ -73,19 +73,17 @@ poll_ring(int fd, unsigned ring, const char *name)
 	unsigned long cycles;
 	igt_spin_t *spin[2];
 	uint64_t elapsed;
-	uint32_t cmd;
 
 	gem_require_ring(fd, ring);
 	igt_require(gem_can_store_dword(fd, ring));
 
 	spin[0] = __igt_spin_factory(fd, &opts);
 	igt_assert(igt_spin_has_poll(spin[0]));
-	cmd = *spin[0]->batch;
 
 	spin[1] = __igt_spin_factory(fd, &opts);
 	igt_assert(igt_spin_has_poll(spin[1]));
 
-	igt_assert(cmd == *spin[1]->batch);
+	igt_assert(*spin[0]->batch == *spin[1]->batch);
 
 	igt_spin_end(spin[0]);
 	igt_spin_busywait_until_started(spin[1]);
@@ -96,8 +94,8 @@ poll_ring(int fd, unsigned ring, const char *name)
 	while ((elapsed = igt_nsec_elapsed(&tv)) < 2ull << 30) {
 		const unsigned int idx = cycles++ & 1;
 
-		*spin[idx]->batch = cmd;
-		spin[idx]->poll[SPIN_POLL_START_IDX] = 0;
+		igt_spin_reset(spin[idx]);
+
 		gem_execbuf(fd, &spin[idx]->execbuf);
 
 		igt_spin_end(spin[!idx]);
@@ -414,15 +412,6 @@ static void latency_from_ring(int fd,
 	}
 }
 
-static void __rearm_spin(igt_spin_t *spin)
-{
-	const uint32_t mi_arb_chk = 0x5 << 23;
-
-       *spin->batch = mi_arb_chk;
-       spin->poll[SPIN_POLL_START_IDX] = 0;
-       __sync_synchronize();
-}
-
 static void
 __submit_spin(int fd, igt_spin_t *spin, unsigned int flags)
 {
@@ -557,7 +546,7 @@ rthog_latency_on_ring(int fd, unsigned int engine, const char *name, unsigned in
 				if (nengine > 1)
 					usleep(10*nengine);
 
-				__rearm_spin(spin);
+				igt_spin_reset(spin);
 
 				igt_nsec_elapsed(&ts);
 				__submit_spin(fd, spin, engine);
diff --git a/tests/i915/gem_sync.c b/tests/i915/gem_sync.c
index f17ecd0b..8c5aaa14 100644
--- a/tests/i915/gem_sync.c
+++ b/tests/i915/gem_sync.c
@@ -209,7 +209,6 @@ wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 		struct drm_i915_gem_execbuffer2 execbuf;
 		double end, this, elapsed, now, baseline;
 		unsigned long cycles;
-		uint32_t cmd;
 		igt_spin_t *spin;
 
 		memset(&object, 0, sizeof(object));
@@ -226,7 +225,6 @@ wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 				      .flags = (IGT_SPIN_POLL_RUN |
 						IGT_SPIN_FAST));
 		igt_assert(igt_spin_has_poll(spin));
-		cmd = *spin->batch;
 
 		gem_execbuf(fd, &execbuf);
 
@@ -238,8 +236,8 @@ wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 			elapsed = 0;
 			cycles = 0;
 			do {
-				*spin->batch = cmd;
-				spin->poll[SPIN_POLL_START_IDX] = 0;
+				igt_spin_reset(spin);
+
 				gem_execbuf(fd, &spin->execbuf);
 				igt_spin_busywait_until_started(spin);
 
@@ -262,8 +260,8 @@ wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 		elapsed = 0;
 		cycles = 0;
 		do {
-			*spin->batch = cmd;
-			spin->poll[SPIN_POLL_START_IDX] = 0;
+			igt_spin_reset(spin);
+
 			gem_execbuf(fd, &spin->execbuf);
 			igt_spin_busywait_until_started(spin);
 
@@ -321,17 +319,14 @@ static void active_ring(int fd, unsigned ring, int timeout)
 		double start, end, elapsed;
 		unsigned long cycles;
 		igt_spin_t *spin[2];
-		uint32_t cmd;
 
 		spin[0] = __igt_spin_new(fd,
 					 .engine = ring,
 					 .flags = IGT_SPIN_FAST);
-		cmd = *spin[0]->batch;
 
 		spin[1] = __igt_spin_new(fd,
 					 .engine = ring,
 					 .flags = IGT_SPIN_FAST);
-		igt_assert(*spin[1]->batch == cmd);
 
 		start = gettime();
 		end = start + timeout;
@@ -343,7 +338,8 @@ static void active_ring(int fd, unsigned ring, int timeout)
 				igt_spin_end(s);
 				gem_sync(fd, s->handle);
 
-				*s->batch = cmd;
+				igt_spin_reset(s);
+
 				gem_execbuf(fd, &s->execbuf);
 			}
 			cycles += 1024;
@@ -393,7 +389,6 @@ active_wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 		double end, this, elapsed, now, baseline;
 		unsigned long cycles;
 		igt_spin_t *spin[2];
-		uint32_t cmd;
 
 		memset(&object, 0, sizeof(object));
 		object.handle = gem_create(fd, 4096);
@@ -409,7 +404,6 @@ active_wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 					 .flags = (IGT_SPIN_POLL_RUN |
 						   IGT_SPIN_FAST));
 		igt_assert(igt_spin_has_poll(spin[0]));
-		cmd = *spin[0]->batch;
 
 		spin[1] = __igt_spin_new(fd,
 					 .engine = execbuf.flags,
@@ -423,8 +417,8 @@ active_wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 		gem_sync(fd, object.handle);
 
 		for (int warmup = 0; warmup <= 1; warmup++) {
-			*spin[0]->batch = cmd;
-			spin[0]->poll[SPIN_POLL_START_IDX] = 0;
+			igt_spin_reset(spin[0]);
+
 			gem_execbuf(fd, &spin[0]->execbuf);
 
 			end = gettime() + timeout/10.;
@@ -433,8 +427,8 @@ active_wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 			do {
 				igt_spin_busywait_until_started(spin[0]);
 
-				*spin[1]->batch = cmd;
-				spin[1]->poll[SPIN_POLL_START_IDX] = 0;
+				igt_spin_reset(spin[1]);
+
 				gem_execbuf(fd, &spin[1]->execbuf);
 
 				this = gettime();
@@ -454,8 +448,8 @@ active_wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 			 names[child % num_engines] ? " b" : "B",
 			 cycles, elapsed*1e6/cycles);
 
-		*spin[0]->batch = cmd;
-		spin[0]->poll[SPIN_POLL_START_IDX] = 0;
+		igt_spin_reset(spin[0]);
+
 		gem_execbuf(fd, &spin[0]->execbuf);
 
 		end = gettime() + timeout;
@@ -467,8 +461,8 @@ active_wakeup_ring(int fd, unsigned ring, int timeout, int wlen)
 			for (int n = 0; n < wlen; n++)
 				gem_execbuf(fd, &execbuf);
 
-			*spin[1]->batch = cmd;
-			spin[1]->poll[SPIN_POLL_START_IDX] = 0;
+			igt_spin_reset(spin[1]);
+
 			gem_execbuf(fd, &spin[1]->execbuf);
 
 			this = gettime();
diff --git a/tests/perf_pmu.c b/tests/perf_pmu.c
index a8ad86ce..e719a292 100644
--- a/tests/perf_pmu.c
+++ b/tests/perf_pmu.c
@@ -1501,14 +1501,6 @@ test_enable_race(int gem_fd, const struct intel_execution_engine2 *e)
 	gem_quiescent_gpu(gem_fd);
 }
 
-static void __rearm_spin(igt_spin_t *spin)
-{
-	const uint32_t mi_arb_chk = 0x5 << 23;
-
-       *spin->batch = mi_arb_chk;
-       __sync_synchronize();
-}
-
 #define __assert_within(x, ref, tol_up, tol_down) \
 	igt_assert_f((double)(x) <= ((double)(ref) + (tol_up)) && \
 		     (double)(x) >= ((double)(ref) - (tol_down)), \
@@ -1596,7 +1588,7 @@ accuracy(int gem_fd, const struct intel_execution_engine2 *e,
 				nanosleep(&_ts, NULL);
 
 				/* Restart the spinbatch. */
-				__rearm_spin(spin);
+				igt_spin_reset(spin);
 				__submit_spin(gem_fd, spin, e, 0);
 
 				/* PWM busy sleep. */