drm/i915: Add initial selftests for hang detection and resets

Check that we can reset the GPU and continue executing from the next
request.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-47-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -3377,7 +3377,7 @@ int __must_check i915_gem_init(struct drm_i915_private *dev_priv);
 int __must_check i915_gem_init_hw(struct drm_i915_private *dev_priv);
 void i915_gem_init_swizzling(struct drm_i915_private *dev_priv);
 void i915_gem_cleanup_engines(struct drm_i915_private *dev_priv);
-int __must_check i915_gem_wait_for_idle(struct drm_i915_private *dev_priv,
+int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv,
 			   unsigned int flags);
 int __must_check i915_gem_suspend(struct drm_i915_private *dev_priv);
 void i915_gem_resume(struct drm_i915_private *dev_priv);

drivers/gpu/drm/i915/intel_hangcheck.c

@@ -480,3 +480,7 @@ void intel_hangcheck_init(struct drm_i915_private *i915)
 	INIT_DELAYED_WORK(&i915->gpu_error.hangcheck_work,
 			  i915_hangcheck_elapsed);
 }
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/intel_hangcheck.c"
+#endif

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

@@ -16,3 +16,4 @@ selftest(dmabuf, i915_gem_dmabuf_live_selftests)
 selftest(coherency, i915_gem_coherency_live_selftests)
 selftest(gtt, i915_gem_gtt_live_selftests)
 selftest(contexts, i915_gem_context_live_selftests)
+selftest(hangcheck, intel_hangcheck_live_selftests)

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

+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include "../i915_selftest.h"
+
+struct hang {
+	struct drm_i915_private *i915;
+	struct drm_i915_gem_object *hws;
+	struct drm_i915_gem_object *obj;
+	u32 *seqno;
+	u32 *batch;
+};
+
+static int hang_init(struct hang *h, struct drm_i915_private *i915)
+{
+	void *vaddr;
+	int err;
+
+	memset(h, 0, sizeof(*h));
+	h->i915 = i915;
+
+	h->hws = i915_gem_object_create_internal(i915, PAGE_SIZE);
+	if (IS_ERR(h->hws))
+		return PTR_ERR(h->hws);
+
+	h->obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
+	if (IS_ERR(h->obj)) {
+		err = PTR_ERR(h->obj);
+		goto err_hws;
+	}
+
+	i915_gem_object_set_cache_level(h->hws, I915_CACHE_LLC);
+	vaddr = i915_gem_object_pin_map(h->hws, I915_MAP_WB);
+	if (IS_ERR(vaddr)) {
+		err = PTR_ERR(vaddr);
+		goto err_obj;
+	}
+	h->seqno = memset(vaddr, 0xff, PAGE_SIZE);
+
+	vaddr = i915_gem_object_pin_map(h->obj,
+					HAS_LLC(i915) ? I915_MAP_WB : I915_MAP_WC);
+	if (IS_ERR(vaddr)) {
+		err = PTR_ERR(vaddr);
+		goto err_unpin_hws;
+	}
+	h->batch = vaddr;
+
+	return 0;
+
+err_unpin_hws:
+	i915_gem_object_unpin_map(h->hws);
+err_obj:
+	i915_gem_object_put(h->obj);
+err_hws:
+	i915_gem_object_put(h->hws);
+	return err;
+}
+
+static u64 hws_address(const struct i915_vma *hws,
+		       const struct drm_i915_gem_request *rq)
+{
+	return hws->node.start + offset_in_page(sizeof(u32)*rq->fence.context);
+}
+
+static int emit_recurse_batch(struct hang *h,
+			      struct drm_i915_gem_request *rq)
+{
+	struct drm_i915_private *i915 = h->i915;
+	struct i915_address_space *vm = rq->ctx->ppgtt ? &rq->ctx->ppgtt->base : &i915->ggtt.base;
+	struct i915_vma *hws, *vma;
+	unsigned int flags;
+	u32 *batch;
+	int err;
+
+	vma = i915_vma_instance(h->obj, vm, NULL);
+	if (IS_ERR(vma))
+		return PTR_ERR(vma);
+
+	hws = i915_vma_instance(h->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;
+
+	err = rq->engine->emit_flush(rq, EMIT_INVALIDATE);
+	if (err)
+		goto unpin_hws;
+
+	err = i915_switch_context(rq);
+	if (err)
+		goto unpin_hws;
+
+	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 = h->batch;
+	if (INTEL_GEN(i915) >= 8) {
+		*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++ = MI_BATCH_BUFFER_START | 1 << 8 | 1;
+		*batch++ = lower_32_bits(vma->node.start);
+		*batch++ = upper_32_bits(vma->node.start);
+	} else if (INTEL_GEN(i915) >= 6) {
+		*batch++ = MI_STORE_DWORD_IMM_GEN4;
+		*batch++ = 0;
+		*batch++ = lower_32_bits(hws_address(hws, rq));
+		*batch++ = rq->fence.seqno;
+		*batch++ = MI_BATCH_BUFFER_START | 1 << 8;
+		*batch++ = lower_32_bits(vma->node.start);
+	} else if (INTEL_GEN(i915) >= 4) {
+		*batch++ = MI_STORE_DWORD_IMM_GEN4 | 1 << 22;
+		*batch++ = 0;
+		*batch++ = lower_32_bits(hws_address(hws, rq));
+		*batch++ = rq->fence.seqno;
+		*batch++ = MI_BATCH_BUFFER_START | 2 << 6;
+		*batch++ = lower_32_bits(vma->node.start);
+	} else {
+		*batch++ = MI_STORE_DWORD_IMM;
+		*batch++ = lower_32_bits(hws_address(hws, rq));
+		*batch++ = rq->fence.seqno;
+		*batch++ = MI_BATCH_BUFFER_START | 2 << 6 | 1;
+		*batch++ = lower_32_bits(vma->node.start);
+	}
+	*batch++ = MI_BATCH_BUFFER_END; /* not reached */
+
+	flags = 0;
+	if (INTEL_GEN(vm->i915) <= 5)
+		flags |= I915_DISPATCH_SECURE;
+
+	err = rq->engine->emit_bb_start(rq, vma->node.start, PAGE_SIZE, flags);
+
+unpin_hws:
+	i915_vma_unpin(hws);
+unpin_vma:
+	i915_vma_unpin(vma);
+	return err;
+}
+
+static struct drm_i915_gem_request *
+hang_create_request(struct hang *h,
+		    struct intel_engine_cs *engine,
+		    struct i915_gem_context *ctx)
+{
+	struct drm_i915_gem_request *rq;
+	int err;
+
+	if (i915_gem_object_is_active(h->obj)) {
+		struct drm_i915_gem_object *obj;
+		void *vaddr;
+
+		obj = i915_gem_object_create_internal(h->i915, PAGE_SIZE);
+		if (IS_ERR(obj))
+			return ERR_CAST(obj);
+
+		vaddr = i915_gem_object_pin_map(obj,
+						HAS_LLC(h->i915) ? I915_MAP_WB : I915_MAP_WC);
+		if (IS_ERR(vaddr)) {
+			i915_gem_object_put(obj);
+			return ERR_CAST(vaddr);
+		}
+
+		i915_gem_object_unpin_map(h->obj);
+		i915_gem_object_put(h->obj);
+
+		h->obj = obj;
+		h->batch = vaddr;
+	}
+
+	rq = i915_gem_request_alloc(engine, ctx);
+	if (IS_ERR(rq))
+		return rq;
+
+	err = emit_recurse_batch(h, rq);
+	if (err) {
+		__i915_add_request(rq, false);
+		return ERR_PTR(err);
+	}
+
+	return rq;
+}
+
+static u32 hws_seqno(const struct hang *h,
+		     const struct drm_i915_gem_request *rq)
+{
+	return READ_ONCE(h->seqno[rq->fence.context % (PAGE_SIZE/sizeof(u32))]);
+}
+
+static void hang_fini(struct hang *h)
+{
+	*h->batch = MI_BATCH_BUFFER_END;
+	wmb();
+
+	i915_gem_object_unpin_map(h->obj);
+	i915_gem_object_put(h->obj);
+
+	i915_gem_object_unpin_map(h->hws);
+	i915_gem_object_put(h->hws);
+
+	i915_gem_wait_for_idle(h->i915, I915_WAIT_LOCKED);
+	i915_gem_retire_requests(h->i915);
+}
+
+static int igt_hang_sanitycheck(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct drm_i915_gem_request *rq;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	struct hang h;
+	int err;
+
+	/* Basic check that we can execute our hanging batch */
+
+	if (!igt_can_mi_store_dword_imm(i915))
+		return 0;
+
+	mutex_lock(&i915->drm.struct_mutex);
+	err = hang_init(&h, i915);
+	if (err)
+		goto unlock;
+
+	for_each_engine(engine, i915, id) {
+		long timeout;
+
+		rq = hang_create_request(&h, engine, i915->kernel_context);
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			pr_err("Failed to create request for %s, err=%d\n",
+			       engine->name, err);
+			goto fini;
+		}
+
+		i915_gem_request_get(rq);
+
+		*h.batch = MI_BATCH_BUFFER_END;
+		__i915_add_request(rq, true);
+
+		timeout = i915_wait_request(rq,
+					    I915_WAIT_LOCKED,
+					    MAX_SCHEDULE_TIMEOUT);
+		i915_gem_request_put(rq);
+
+		if (timeout < 0) {
+			err = timeout;
+			pr_err("Wait for request failed on %s, err=%d\n",
+			       engine->name, err);
+			goto fini;
+		}
+	}
+
+fini:
+	hang_fini(&h);
+unlock:
+	mutex_unlock(&i915->drm.struct_mutex);
+	return err;
+}
+
+static int igt_global_reset(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	unsigned int reset_count;
+	int err = 0;
+
+	/* Check that we can issue a global GPU reset */
+
+	set_bit(I915_RESET_IN_PROGRESS, &i915->gpu_error.flags);
+
+	mutex_lock(&i915->drm.struct_mutex);
+	reset_count = i915_reset_count(&i915->gpu_error);
+
+	i915_reset(i915);
+
+	if (i915_reset_count(&i915->gpu_error) == reset_count) {
+		pr_err("No GPU reset recorded!\n");
+		err = -EINVAL;
+	}
+	mutex_unlock(&i915->drm.struct_mutex);
+
+	GEM_BUG_ON(test_bit(I915_RESET_IN_PROGRESS, &i915->gpu_error.flags));
+	if (i915_terminally_wedged(&i915->gpu_error))
+		err = -EIO;
+
+	return err;
+}
+
+static u32 fake_hangcheck(struct drm_i915_gem_request *rq)
+{
+	u32 reset_count;
+
+	rq->engine->hangcheck.stalled = true;
+	rq->engine->hangcheck.seqno = intel_engine_get_seqno(rq->engine);
+
+	reset_count = i915_reset_count(&rq->i915->gpu_error);
+
+	set_bit(I915_RESET_IN_PROGRESS, &rq->i915->gpu_error.flags);
+	wake_up_all(&rq->i915->gpu_error.wait_queue);
+
+	return reset_count;
+}
+
+static bool wait_for_hang(struct hang *h, struct drm_i915_gem_request *rq)
+{
+	return !(wait_for_us(i915_seqno_passed(hws_seqno(h, rq),
+					       rq->fence.seqno),
+			     10) &&
+		 wait_for(i915_seqno_passed(hws_seqno(h, rq),
+					    rq->fence.seqno),
+			  1000));
+}
+
+static int igt_wait_reset(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct drm_i915_gem_request *rq;
+	unsigned int reset_count;
+	struct hang h;
+	long timeout;
+	int err;
+
+	/* Check that we detect a stuck waiter and issue a reset */
+
+	set_bit(I915_RESET_IN_PROGRESS, &i915->gpu_error.flags);
+
+	mutex_lock(&i915->drm.struct_mutex);
+	err = hang_init(&h, i915);
+	if (err)
+		goto unlock;
+
+	rq = hang_create_request(&h, i915->engine[RCS], i915->kernel_context);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto fini;
+	}
+
+	i915_gem_request_get(rq);
+	__i915_add_request(rq, true);
+
+	if (!wait_for_hang(&h, rq)) {
+		pr_err("Failed to start request %x\n", rq->fence.seqno);
+		err = -EIO;
+		goto out_rq;
+	}
+
+	reset_count = fake_hangcheck(rq);
+
+	timeout = i915_wait_request(rq, I915_WAIT_LOCKED, 10);
+	if (timeout < 0) {
+		pr_err("i915_wait_request failed on a stuck request: err=%ld\n",
+		       timeout);
+		err = timeout;
+		goto out_rq;
+	}
+	GEM_BUG_ON(test_bit(I915_RESET_IN_PROGRESS, &i915->gpu_error.flags));
+
+	if (i915_reset_count(&i915->gpu_error) == reset_count) {
+		pr_err("No GPU reset recorded!\n");
+		err = -EINVAL;
+		goto out_rq;
+	}
+
+out_rq:
+	i915_gem_request_put(rq);
+fini:
+	hang_fini(&h);
+unlock:
+	mutex_unlock(&i915->drm.struct_mutex);
+
+	if (i915_terminally_wedged(&i915->gpu_error))
+		return -EIO;
+
+	return err;
+}
+
+static int igt_reset_queue(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	struct hang h;
+	int err;
+
+	/* Check that we replay pending requests following a hang */
+
+	if (!igt_can_mi_store_dword_imm(i915))
+		return 0;
+
+	mutex_lock(&i915->drm.struct_mutex);
+	err = hang_init(&h, i915);
+	if (err)
+		goto unlock;
+
+	for_each_engine(engine, i915, id) {
+		struct drm_i915_gem_request *prev;
+		IGT_TIMEOUT(end_time);
+		unsigned int count;
+
+		prev = hang_create_request(&h, engine, i915->kernel_context);
+		if (IS_ERR(prev)) {
+			err = PTR_ERR(prev);
+			goto fini;
+		}
+
+		i915_gem_request_get(prev);
+		__i915_add_request(prev, true);
+
+		count = 0;
+		do {
+			struct drm_i915_gem_request *rq;
+			unsigned int reset_count;
+
+			rq = hang_create_request(&h,
+						 engine,
+						 i915->kernel_context);
+			if (IS_ERR(rq)) {
+				err = PTR_ERR(rq);
+				goto fini;
+			}
+
+			i915_gem_request_get(rq);
+			__i915_add_request(rq, true);
+
+			if (!wait_for_hang(&h, prev)) {
+				pr_err("Failed to start request %x\n",
+				       prev->fence.seqno);
+				i915_gem_request_put(rq);
+				i915_gem_request_put(prev);
+				err = -EIO;
+				goto fini;
+			}
+
+			reset_count = fake_hangcheck(prev);
+
+			i915_reset(i915);
+
+			GEM_BUG_ON(test_bit(I915_RESET_IN_PROGRESS,
+					    &i915->gpu_error.flags));
+			if (prev->fence.error != -EIO) {
+				pr_err("GPU reset not recorded on hanging request [fence.error=%d]!\n",
+				       prev->fence.error);
+				i915_gem_request_put(rq);
+				i915_gem_request_put(prev);
+				err = -EINVAL;
+				goto fini;
+			}
+
+			if (rq->fence.error) {
+				pr_err("Fence error status not zero [%d] after unrelated reset\n",
+				       rq->fence.error);
+				i915_gem_request_put(rq);
+				i915_gem_request_put(prev);
+				err = -EINVAL;
+				goto fini;
+			}
+
+			if (i915_reset_count(&i915->gpu_error) == reset_count) {
+				pr_err("No GPU reset recorded!\n");
+				i915_gem_request_put(rq);
+				i915_gem_request_put(prev);
+				err = -EINVAL;
+				goto fini;
+			}
+
+			i915_gem_request_put(prev);
+			prev = rq;
+			count++;
+		} while (time_before(jiffies, end_time));
+		pr_info("%s: Completed %d resets\n", engine->name, count);
+
+		*h.batch = MI_BATCH_BUFFER_END;
+		wmb();
+
+		i915_gem_request_put(prev);
+	}
+
+fini:
+	hang_fini(&h);
+unlock:
+	mutex_unlock(&i915->drm.struct_mutex);
+
+	if (i915_terminally_wedged(&i915->gpu_error))
+		return -EIO;
+
+	return err;
+}
+
+int intel_hangcheck_live_selftests(struct drm_i915_private *i915)
+{
+	static const struct i915_subtest tests[] = {
+		SUBTEST(igt_hang_sanitycheck),
+		SUBTEST(igt_global_reset),
+		SUBTEST(igt_wait_reset),
+		SUBTEST(igt_reset_queue),
+	};
+
+	if (!intel_has_gpu_reset(i915))
+		return 0;
+
+	return i915_subtests(tests, i915);
+}