drm/i915/selftests: Add basic sanitychecks for execlists

Before adding a new feature to execlists submission, we should endeavour
to cover the baseline behaviour with selftests. So start the ball
rolling.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
CC: Michel Thierry <michel.thierry@intel.com>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180404093329.5383-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/intel_lrc.c

@@ -2609,3 +2609,7 @@ void intel_lr_context_resume(struct drm_i915_private *dev_priv)
 		}
 	}
 }
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/intel_lrc.c"
+#endif

drivers/gpu/drm/i915/selftests/i915_live_selftests.h

@@ -20,4 +20,5 @@ selftest(evict, i915_gem_evict_live_selftests)
 selftest(hugepages, i915_gem_huge_page_live_selftests)
 selftest(contexts, i915_gem_context_live_selftests)
 selftest(hangcheck, intel_hangcheck_live_selftests)
+selftest(execlists, intel_execlists_live_selftests)
 selftest(guc, intel_guc_live_selftest)

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

@@ -0,0 +1,507 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2018 Intel Corporation
+ */
+
+#include "../i915_selftest.h"
+
+#include "mock_context.h"
+
+struct spinner {
+	struct drm_i915_private *i915;
+	struct drm_i915_gem_object *hws;
+	struct drm_i915_gem_object *obj;
+	u32 *batch;
+	void *seqno;
+};
+
+static int spinner_init(struct spinner *spin, struct drm_i915_private *i915)
+{
+	unsigned int mode;
+	void *vaddr;
+	int err;
+
+	GEM_BUG_ON(INTEL_GEN(i915) < 8);
+
+	memset(spin, 0, sizeof(*spin));
+	spin->i915 = i915;
+
+	spin->hws = i915_gem_object_create_internal(i915, PAGE_SIZE);
+	if (IS_ERR(spin->hws)) {
+		err = PTR_ERR(spin->hws);
+		goto err;
+	}
+
+	spin->obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
+	if (IS_ERR(spin->obj)) {
+		err = PTR_ERR(spin->obj);
+		goto err_hws;
+	}
+
+	i915_gem_object_set_cache_level(spin->hws, I915_CACHE_LLC);
+	vaddr = i915_gem_object_pin_map(spin->hws, I915_MAP_WB);
+	if (IS_ERR(vaddr)) {
+		err = PTR_ERR(vaddr);
+		goto err_obj;
+	}
+	spin->seqno = memset(vaddr, 0xff, PAGE_SIZE);
+
+	mode = HAS_LLC(i915) ? I915_MAP_WB : I915_MAP_WC;
+	vaddr = i915_gem_object_pin_map(spin->obj, mode);
+	if (IS_ERR(vaddr)) {
+		err = PTR_ERR(vaddr);
+		goto err_unpin_hws;
+	}
+	spin->batch = vaddr;
+
+	return 0;
+
+err_unpin_hws:
+	i915_gem_object_unpin_map(spin->hws);
+err_obj:
+	i915_gem_object_put(spin->obj);
+err_hws:
+	i915_gem_object_put(spin->hws);
+err:
+	return err;
+}
+
+static unsigned int seqno_offset(u64 fence)
+{
+	return offset_in_page(sizeof(u32) * fence);
+}
+
+static u64 hws_address(const struct i915_vma *hws,
+		       const struct i915_request *rq)
+{
+	return hws->node.start + seqno_offset(rq->fence.context);
+}
+
+static int emit_recurse_batch(struct spinner *spin,
+			      struct i915_request *rq,
+			      u32 arbitration_command)
+{
+	struct i915_address_space *vm = &rq->ctx->ppgtt->base;
+	struct i915_vma *hws, *vma;
+	u32 *batch;
+	int err;
+
+	vma = i915_vma_instance(spin->obj, vm, NULL);
+	if (IS_ERR(vma))
+		return PTR_ERR(vma);
+
+	hws = i915_vma_instance(spin->hws, vm, NULL);
+	if (IS_ERR(hws))
+		return PTR_ERR(hws);
+
+	err = i915_vma_pin(vma, 0, 0, PIN_USER);
+	if (err)
+		return err;
+
+	err = i915_vma_pin(hws, 0, 0, PIN_USER);
+	if (err)
+		goto unpin_vma;
+
+	i915_vma_move_to_active(vma, rq, 0);
+	if (!i915_gem_object_has_active_reference(vma->obj)) {
+		i915_gem_object_get(vma->obj);
+		i915_gem_object_set_active_reference(vma->obj);
+	}
+
+	i915_vma_move_to_active(hws, rq, 0);
+	if (!i915_gem_object_has_active_reference(hws->obj)) {
+		i915_gem_object_get(hws->obj);
+		i915_gem_object_set_active_reference(hws->obj);
+	}
+
+	batch = spin->batch;
+
+	*batch++ = MI_STORE_DWORD_IMM_GEN4;
+	*batch++ = lower_32_bits(hws_address(hws, rq));
+	*batch++ = upper_32_bits(hws_address(hws, rq));
+	*batch++ = rq->fence.seqno;
+
+	*batch++ = arbitration_command;
+
+	*batch++ = MI_BATCH_BUFFER_START | 1 << 8 | 1;
+	*batch++ = lower_32_bits(vma->node.start);
+	*batch++ = upper_32_bits(vma->node.start);
+	*batch++ = MI_BATCH_BUFFER_END; /* not reached */
+
+	i915_gem_chipset_flush(spin->i915);
+
+	err = rq->engine->emit_bb_start(rq, vma->node.start, PAGE_SIZE, 0);
+
+	i915_vma_unpin(hws);
+unpin_vma:
+	i915_vma_unpin(vma);
+	return err;
+}
+
+static struct i915_request *
+spinner_create_request(struct spinner *spin,
+		       struct i915_gem_context *ctx,
+		       struct intel_engine_cs *engine,
+		       u32 arbitration_command)
+{
+	struct i915_request *rq;
+	int err;
+
+	rq = i915_request_alloc(engine, ctx);
+	if (IS_ERR(rq))
+		return rq;
+
+	err = emit_recurse_batch(spin, rq, arbitration_command);
+	if (err) {
+		__i915_request_add(rq, false);
+		return ERR_PTR(err);
+	}
+
+	return rq;
+}
+
+static u32 hws_seqno(const struct spinner *spin, const struct i915_request *rq)
+{
+	u32 *seqno = spin->seqno + seqno_offset(rq->fence.context);
+
+	return READ_ONCE(*seqno);
+}
+
+struct wedge_me {
+	struct delayed_work work;
+	struct drm_i915_private *i915;
+	const void *symbol;
+};
+
+static void wedge_me(struct work_struct *work)
+{
+	struct wedge_me *w = container_of(work, typeof(*w), work.work);
+
+	pr_err("%pS timed out, cancelling all further testing.\n", w->symbol);
+
+	GEM_TRACE("%pS timed out.\n", w->symbol);
+	GEM_TRACE_DUMP();
+
+	i915_gem_set_wedged(w->i915);
+}
+
+static void __init_wedge(struct wedge_me *w,
+			 struct drm_i915_private *i915,
+			 long timeout,
+			 const void *symbol)
+{
+	w->i915 = i915;
+	w->symbol = symbol;
+
+	INIT_DELAYED_WORK_ONSTACK(&w->work, wedge_me);
+	schedule_delayed_work(&w->work, timeout);
+}
+
+static void __fini_wedge(struct wedge_me *w)
+{
+	cancel_delayed_work_sync(&w->work);
+	destroy_delayed_work_on_stack(&w->work);
+	w->i915 = NULL;
+}
+
+#define wedge_on_timeout(W, DEV, TIMEOUT)				\
+	for (__init_wedge((W), (DEV), (TIMEOUT), __builtin_return_address(0)); \
+	     (W)->i915;							\
+	     __fini_wedge((W)))
+
+static noinline int
+flush_test(struct drm_i915_private *i915, unsigned int flags)
+{
+	struct wedge_me w;
+
+	cond_resched();
+
+	wedge_on_timeout(&w, i915, HZ)
+		i915_gem_wait_for_idle(i915, flags);
+
+	return i915_terminally_wedged(&i915->gpu_error) ? -EIO : 0;
+}
+
+static void spinner_end(struct spinner *spin)
+{
+	*spin->batch = MI_BATCH_BUFFER_END;
+	i915_gem_chipset_flush(spin->i915);
+}
+
+static void spinner_fini(struct spinner *spin)
+{
+	spinner_end(spin);
+
+	i915_gem_object_unpin_map(spin->obj);
+	i915_gem_object_put(spin->obj);
+
+	i915_gem_object_unpin_map(spin->hws);
+	i915_gem_object_put(spin->hws);
+}
+
+static bool wait_for_spinner(struct spinner *spin, struct i915_request *rq)
+{
+	if (!wait_event_timeout(rq->execute,
+				READ_ONCE(rq->global_seqno),
+				msecs_to_jiffies(10)))
+		return false;
+
+	return !(wait_for_us(i915_seqno_passed(hws_seqno(spin, rq),
+					       rq->fence.seqno),
+			     10) &&
+		 wait_for(i915_seqno_passed(hws_seqno(spin, rq),
+					    rq->fence.seqno),
+			  1000));
+}
+
+static int live_sanitycheck(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct intel_engine_cs *engine;
+	struct i915_gem_context *ctx;
+	enum intel_engine_id id;
+	struct spinner spin;
+	int err = -ENOMEM;
+
+	if (!HAS_LOGICAL_RING_CONTEXTS(i915))
+		return 0;
+
+	mutex_lock(&i915->drm.struct_mutex);
+
+	if (spinner_init(&spin, i915))
+		goto err_unlock;
+
+	ctx = kernel_context(i915);
+	if (!ctx)
+		goto err_spin;
+
+	for_each_engine(engine, i915, id) {
+		struct i915_request *rq;
+
+		rq = spinner_create_request(&spin, ctx, engine, MI_NOOP);
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			goto err_ctx;
+		}
+
+		i915_request_add(rq);
+		if (!wait_for_spinner(&spin, rq)) {
+			GEM_TRACE("spinner failed to start\n");
+			GEM_TRACE_DUMP();
+			i915_gem_set_wedged(i915);
+			err = -EIO;
+			goto err_ctx;
+		}
+
+		spinner_end(&spin);
+		if (flush_test(i915, I915_WAIT_LOCKED)) {
+			err = -EIO;
+			goto err_ctx;
+		}
+	}
+
+	err = 0;
+err_ctx:
+	kernel_context_close(ctx);
+err_spin:
+	spinner_fini(&spin);
+err_unlock:
+	flush_test(i915, I915_WAIT_LOCKED);
+	mutex_unlock(&i915->drm.struct_mutex);
+	return err;
+}
+
+static int live_preempt(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct i915_gem_context *ctx_hi, *ctx_lo;
+	struct spinner spin_hi, spin_lo;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err = -ENOMEM;
+
+	if (!HAS_LOGICAL_RING_PREEMPTION(i915))
+		return 0;
+
+	mutex_lock(&i915->drm.struct_mutex);
+
+	if (spinner_init(&spin_hi, i915))
+		goto err_unlock;
+
+	if (spinner_init(&spin_lo, i915))
+		goto err_spin_hi;
+
+	ctx_hi = kernel_context(i915);
+	if (!ctx_hi)
+		goto err_spin_lo;
+	ctx_hi->priority = I915_CONTEXT_MAX_USER_PRIORITY;
+
+	ctx_lo = kernel_context(i915);
+	if (!ctx_lo)
+		goto err_ctx_hi;
+	ctx_lo->priority = I915_CONTEXT_MIN_USER_PRIORITY;
+
+	for_each_engine(engine, i915, id) {
+		struct i915_request *rq;
+
+		rq = spinner_create_request(&spin_lo, ctx_lo, engine,
+					    MI_ARB_CHECK);
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			goto err_ctx_lo;
+		}
+
+		i915_request_add(rq);
+		if (!wait_for_spinner(&spin_lo, rq)) {
+			GEM_TRACE("lo spinner failed to start\n");
+			GEM_TRACE_DUMP();
+			i915_gem_set_wedged(i915);
+			err = -EIO;
+			goto err_ctx_lo;
+		}
+
+		rq = spinner_create_request(&spin_hi, ctx_hi, engine,
+					    MI_ARB_CHECK);
+		if (IS_ERR(rq)) {
+			spinner_end(&spin_lo);
+			err = PTR_ERR(rq);
+			goto err_ctx_lo;
+		}
+
+		i915_request_add(rq);
+		if (!wait_for_spinner(&spin_hi, rq)) {
+			GEM_TRACE("hi spinner failed to start\n");
+			GEM_TRACE_DUMP();
+			i915_gem_set_wedged(i915);
+			err = -EIO;
+			goto err_ctx_lo;
+		}
+
+		spinner_end(&spin_hi);
+		spinner_end(&spin_lo);
+		if (flush_test(i915, I915_WAIT_LOCKED)) {
+			err = -EIO;
+			goto err_ctx_lo;
+		}
+	}
+
+	err = 0;
+err_ctx_lo:
+	kernel_context_close(ctx_lo);
+err_ctx_hi:
+	kernel_context_close(ctx_hi);
+err_spin_lo:
+	spinner_fini(&spin_lo);
+err_spin_hi:
+	spinner_fini(&spin_hi);
+err_unlock:
+	flush_test(i915, I915_WAIT_LOCKED);
+	mutex_unlock(&i915->drm.struct_mutex);
+	return err;
+}
+
+static int live_late_preempt(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct i915_gem_context *ctx_hi, *ctx_lo;
+	struct spinner spin_hi, spin_lo;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err = -ENOMEM;
+
+	if (!HAS_LOGICAL_RING_PREEMPTION(i915))
+		return 0;
+
+	mutex_lock(&i915->drm.struct_mutex);
+
+	if (spinner_init(&spin_hi, i915))
+		goto err_unlock;
+
+	if (spinner_init(&spin_lo, i915))
+		goto err_spin_hi;
+
+	ctx_hi = kernel_context(i915);
+	if (!ctx_hi)
+		goto err_spin_lo;
+
+	ctx_lo = kernel_context(i915);
+	if (!ctx_lo)
+		goto err_ctx_hi;
+
+	for_each_engine(engine, i915, id) {
+		struct i915_request *rq;
+
+		rq = spinner_create_request(&spin_lo, ctx_lo, engine,
+					    MI_ARB_CHECK);
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			goto err_ctx_lo;
+		}
+
+		i915_request_add(rq);
+		if (!wait_for_spinner(&spin_lo, rq)) {
+			pr_err("First context failed to start\n");
+			goto err_wedged;
+		}
+
+		rq = spinner_create_request(&spin_hi, ctx_hi, engine, MI_NOOP);
+		if (IS_ERR(rq)) {
+			spinner_end(&spin_lo);
+			err = PTR_ERR(rq);
+			goto err_ctx_lo;
+		}
+
+		i915_request_add(rq);
+		if (wait_for_spinner(&spin_hi, rq)) {
+			pr_err("Second context overtook first?\n");
+			goto err_wedged;
+		}
+
+		engine->schedule(rq, I915_PRIORITY_MAX);
+
+		if (!wait_for_spinner(&spin_hi, rq)) {
+			pr_err("High priority context failed to preempt the low priority context\n");
+			GEM_TRACE_DUMP();
+			goto err_wedged;
+		}
+
+		spinner_end(&spin_hi);
+		spinner_end(&spin_lo);
+		if (flush_test(i915, I915_WAIT_LOCKED)) {
+			err = -EIO;
+			goto err_ctx_lo;
+		}
+	}
+
+	err = 0;
+err_ctx_lo:
+	kernel_context_close(ctx_lo);
+err_ctx_hi:
+	kernel_context_close(ctx_hi);
+err_spin_lo:
+	spinner_fini(&spin_lo);
+err_spin_hi:
+	spinner_fini(&spin_hi);
+err_unlock:
+	flush_test(i915, I915_WAIT_LOCKED);
+	mutex_unlock(&i915->drm.struct_mutex);
+	return err;
+
+err_wedged:
+	spinner_end(&spin_hi);
+	spinner_end(&spin_lo);
+	i915_gem_set_wedged(i915);
+	err = -EIO;
+	goto err_ctx_lo;
+}
+
+int intel_execlists_live_selftests(struct drm_i915_private *i915)
+{
+	static const struct i915_subtest tests[] = {
+		SUBTEST(live_sanitycheck),
+		SUBTEST(live_preempt),
+		SUBTEST(live_late_preempt),
+	};
+	return i915_subtests(tests, i915);
+}