drm/i915/selftests: Exercise some AB...BA preemption chains

Build a chain using 2 contexts (A, B) then request a preemption such
that a later A request runs before the spinner in B.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205123835.25331-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c b/drivers/gpu/drm/i915/selftests/intel_lrc.c
index fb35f53c9ce342266ee4ca58b592a9eb9cf8b0d0..58144e024751fced7c19649b2569f72ab350c310 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/intel_lrc.c
+++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c
@@ -4,6 +4,8 @@
  * Copyright © 2018 Intel Corporation
  */
 
+#include <linux/prime_numbers.h>
+
 #include "../i915_reset.h"
 
 #include "../i915_selftest.h"
@@ -405,6 +407,106 @@ static int live_suppress_self_preempt(void *arg)
        goto err_client_b;
 }
 
+static int live_chain_preempt(void *arg)
+{
+       struct drm_i915_private *i915 = arg;
+       struct intel_engine_cs *engine;
+       struct preempt_client hi, lo;
+       enum intel_engine_id id;
+       intel_wakeref_t wakeref;
+       int err = -ENOMEM;
+
+       /*
+        * Build a chain AB...BA between two contexts (A, B) and request
+        * preemption of the last request. It should then complete before
+        * the previously submitted spinner in B.
+        */
+
+       if (!HAS_LOGICAL_RING_PREEMPTION(i915))
+               return 0;
+
+       mutex_lock(&i915->drm.struct_mutex);
+       wakeref = intel_runtime_pm_get(i915);
+
+       if (preempt_client_init(i915, &hi))
+               goto err_unlock;
+
+       if (preempt_client_init(i915, &lo))
+               goto err_client_hi;
+
+       for_each_engine(engine, i915, id) {
+               struct i915_sched_attr attr = {
+                       .priority = I915_USER_PRIORITY(I915_PRIORITY_MAX),
+               };
+               int count, i;
+
+               for_each_prime_number_from(count, 1, 32) { /* must fit ring! */
+                       struct i915_request *rq;
+
+                       rq = igt_spinner_create_request(&hi.spin,
+                                                       hi.ctx, engine,
+                                                       MI_ARB_CHECK);
+                       if (IS_ERR(rq))
+                               goto err_wedged;
+                       i915_request_add(rq);
+                       if (!igt_wait_for_spinner(&hi.spin, rq))
+                               goto err_wedged;
+
+                       rq = igt_spinner_create_request(&lo.spin,
+                                                       lo.ctx, engine,
+                                                       MI_ARB_CHECK);
+                       if (IS_ERR(rq))
+                               goto err_wedged;
+                       i915_request_add(rq);
+
+                       for (i = 0; i < count; i++) {
+                               rq = i915_request_alloc(engine, lo.ctx);
+                               if (IS_ERR(rq))
+                                       goto err_wedged;
+                               i915_request_add(rq);
+                       }
+
+                       rq = i915_request_alloc(engine, hi.ctx);
+                       if (IS_ERR(rq))
+                               goto err_wedged;
+                       i915_request_add(rq);
+                       engine->schedule(rq, &attr);
+
+                       igt_spinner_end(&hi.spin);
+                       if (i915_request_wait(rq, I915_WAIT_LOCKED, HZ / 5) < 0) {
+                               struct drm_printer p =
+                                       drm_info_printer(i915->drm.dev);
+
+                               pr_err("Failed to preempt over chain of %d\n",
+                                      count);
+                               intel_engine_dump(engine, &p,
+                                                 "%s\n", engine->name);
+                               goto err_wedged;
+                       }
+                       igt_spinner_end(&lo.spin);
+               }
+       }
+
+       err = 0;
+err_client_lo:
+       preempt_client_fini(&lo);
+err_client_hi:
+       preempt_client_fini(&hi);
+err_unlock:
+       if (igt_flush_test(i915, I915_WAIT_LOCKED))
+               err = -EIO;
+       intel_runtime_pm_put(i915, wakeref);
+       mutex_unlock(&i915->drm.struct_mutex);
+       return err;
+
+err_wedged:
+       igt_spinner_end(&hi.spin);
+       igt_spinner_end(&lo.spin);
+       i915_gem_set_wedged(i915);
+       err = -EIO;
+       goto err_client_lo;
+}
+
 static int live_preempt_hang(void *arg)
 {
        struct drm_i915_private *i915 = arg;
@@ -785,6 +887,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915)
                SUBTEST(live_preempt),
                SUBTEST(live_late_preempt),
                SUBTEST(live_suppress_self_preempt),
+               SUBTEST(live_chain_preempt),
                SUBTEST(live_preempt_hang),
                SUBTEST(live_preempt_smoke),
        };