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* [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation
@ 2020-02-24  9:59 Chris Wilson
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 02/14] drm/i915/selftests: Check recovery from corrupted LRC Chris Wilson
                   ` (14 more replies)
  0 siblings, 15 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24  9:59 UTC (permalink / raw)
  To: intel-gfx

Record the LRC registers before/after a preemption event to ensure that
the first context sees nothing from the second client; at least in the
normal per-context register state.

References: https://gitlab.freedesktop.org/drm/intel/issues/1233
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/selftest_lrc.c | 547 +++++++++++++++++++++++++
 1 file changed, 547 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index febd608c23a7..ee80b9d8a54b 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -4748,6 +4748,552 @@ static int live_lrc_timestamp(void *arg)
 	return 0;
 }
 
+static struct i915_vma *
+create_user_vma(struct i915_address_space *vm, unsigned long size)
+{
+	struct drm_i915_gem_object *obj;
+	struct i915_vma *vma;
+	int err;
+
+	obj = i915_gem_object_create_internal(vm->i915, size);
+	if (IS_ERR(obj))
+		return ERR_CAST(obj);
+
+	vma = i915_vma_instance(obj, vm, NULL);
+	if (IS_ERR(vma)) {
+		i915_gem_object_put(obj);
+		return vma;
+	}
+
+	err = i915_vma_pin(vma, 0, 0, PIN_USER);
+	if (err) {
+		i915_gem_object_put(obj);
+		return ERR_PTR(err);
+	}
+
+	return vma;
+}
+
+static struct i915_vma *
+store_context(struct intel_context *ce, struct i915_vma *scratch)
+{
+	struct i915_vma *batch;
+	u32 dw, x, *cs, *hw;
+
+	batch = create_user_vma(ce->vm, SZ_64K);
+	if (IS_ERR(batch))
+		return ERR_CAST(batch);
+
+	cs = i915_gem_object_pin_map(batch->obj, I915_MAP_WC);
+	if (IS_ERR(cs)) {
+		i915_vma_put(batch);
+		return ERR_CAST(cs);
+	}
+
+	x = 0;
+	dw = 0;
+	hw = ce->engine->pinned_default_state;
+	hw += LRC_STATE_PN * PAGE_SIZE / sizeof(*hw);
+	do {
+		u32 lri = hw[dw];
+
+		if (lri == 0) {
+			dw++;
+			continue;
+		}
+
+		if ((lri & GENMASK(31, 23)) != MI_INSTR(0x22, 0)) {
+			lri &= 0x7f;
+			dw += lri + 2;
+			continue;
+		}
+
+		lri &= 0x7f;
+		lri++;
+		dw++;
+
+		while (lri) {
+			*cs++ = MI_STORE_REGISTER_MEM_GEN8;
+			*cs++ = hw[dw];
+			*cs++ = lower_32_bits(scratch->node.start + x);
+			*cs++ = upper_32_bits(scratch->node.start + x);
+
+			dw += 2;
+			lri -= 2;
+			x += 4;
+		}
+	} while (dw < PAGE_SIZE / sizeof(u32) &&
+		 (hw[dw] & ~BIT(0)) != MI_BATCH_BUFFER_END);
+
+	*cs++ = MI_BATCH_BUFFER_END;
+
+	i915_gem_object_flush_map(batch->obj);
+	i915_gem_object_unpin_map(batch->obj);
+
+	return batch;
+}
+
+static int move_to_active(struct i915_request *rq,
+			  struct i915_vma *vma,
+			  unsigned int flags)
+{
+	int err;
+
+	i915_vma_lock(vma);
+	err = i915_request_await_object(rq, vma->obj, flags);
+	if (!err)
+		err = i915_vma_move_to_active(vma, rq, flags);
+	i915_vma_unlock(vma);
+
+	return err;
+}
+
+static struct i915_request *
+record_registers(struct intel_context *ce,
+		 struct i915_vma *before,
+		 struct i915_vma *after,
+		 u32 *sema)
+{
+	struct i915_vma *b_before, *b_after;
+	struct i915_request *rq;
+	u32 *cs;
+	int err;
+
+	b_before = store_context(ce, before);
+	if (IS_ERR(b_before))
+		return ERR_CAST(b_before);
+
+	b_after = store_context(ce, after);
+	if (IS_ERR(b_after)) {
+		err = PTR_ERR(b_after);
+		goto err_before;
+	}
+
+	rq = intel_context_create_request(ce);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto err_after;
+	}
+
+	err = move_to_active(rq, before, EXEC_OBJECT_WRITE);
+	if (err)
+		goto err_rq;
+
+	err = move_to_active(rq, b_before, 0);
+	if (err)
+		goto err_rq;
+
+	err = move_to_active(rq, after, EXEC_OBJECT_WRITE);
+	if (err)
+		goto err_rq;
+
+	err = move_to_active(rq, b_after, 0);
+	if (err)
+		goto err_rq;
+
+	cs = intel_ring_begin(rq, 14);
+	if (IS_ERR(cs)) {
+		err = PTR_ERR(cs);
+		goto err_rq;
+	}
+
+	*cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
+	*cs++ = MI_BATCH_BUFFER_START_GEN8 | BIT(8);
+	*cs++ = lower_32_bits(b_before->node.start);
+	*cs++ = upper_32_bits(b_before->node.start);
+
+	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
+	*cs++ = MI_SEMAPHORE_WAIT |
+		MI_SEMAPHORE_GLOBAL_GTT |
+		MI_SEMAPHORE_POLL |
+		MI_SEMAPHORE_SAD_NEQ_SDD;
+	*cs++ = 0;
+	*cs++ = i915_ggtt_offset(ce->engine->status_page.vma) +
+		offset_in_page(sema);
+	*cs++ = 0;
+	*cs++ = MI_NOOP;
+
+	*cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
+	*cs++ = MI_BATCH_BUFFER_START_GEN8 | BIT(8);
+	*cs++ = lower_32_bits(b_after->node.start);
+	*cs++ = upper_32_bits(b_after->node.start);
+
+	intel_ring_advance(rq, cs);
+
+	WRITE_ONCE(*sema, 0);
+	i915_request_get(rq);
+	i915_request_add(rq);
+err_after:
+	i915_vma_put(b_after);
+err_before:
+	i915_vma_put(b_before);
+	return rq;
+
+err_rq:
+	i915_request_add(rq);
+	rq = ERR_PTR(err);
+	goto err_after;
+}
+
+static struct i915_vma *load_context(struct intel_context *ce, u32 poison)
+{
+	struct i915_vma *batch;
+	u32 dw, *cs, *hw;
+
+	batch = create_user_vma(ce->vm, SZ_64K);
+	if (IS_ERR(batch))
+		return ERR_CAST(batch);
+
+	cs = i915_gem_object_pin_map(batch->obj, I915_MAP_WC);
+	if (IS_ERR(cs)) {
+		i915_vma_put(batch);
+		return ERR_CAST(cs);
+	}
+
+	dw = 0;
+	hw = ce->engine->pinned_default_state;
+	hw += LRC_STATE_PN * PAGE_SIZE / sizeof(*hw);
+	do {
+		u32 lri = hw[dw];
+
+		if (lri == 0) {
+			dw++;
+			continue;
+		}
+
+		if ((lri & GENMASK(31, 23)) != MI_INSTR(0x22, 0)) {
+			lri &= 0x7f;
+			dw += lri + 2;
+			continue;
+		}
+
+		lri &= 0x7f;
+		lri++;
+		dw++;
+
+		lri /= 2;
+		*cs++ = MI_LOAD_REGISTER_IMM(lri);
+		while (lri--) {
+			*cs++ = hw[dw];
+			*cs++ = poison;
+			dw += 2;
+		}
+	} while (dw < PAGE_SIZE / sizeof(u32) &&
+		 (hw[dw] & ~BIT(0)) != MI_BATCH_BUFFER_END);
+
+	*cs++ = MI_BATCH_BUFFER_END;
+
+	i915_gem_object_flush_map(batch->obj);
+	i915_gem_object_unpin_map(batch->obj);
+
+	return batch;
+}
+
+static int poison_registers(struct intel_context *ce, u32 poison, u32 *sema)
+{
+	struct i915_request *rq;
+	struct i915_vma *batch;
+	u32 *cs;
+	int err;
+
+	batch = load_context(ce, poison);
+	if (IS_ERR(batch))
+		return PTR_ERR(batch);
+
+	rq = intel_context_create_request(ce);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto err_batch;
+	}
+
+	err = move_to_active(rq, batch, 0);
+	if (err)
+		goto err_rq;
+
+	cs = intel_ring_begin(rq, 8);
+	if (IS_ERR(cs)) {
+		err = PTR_ERR(cs);
+		goto err_rq;
+	}
+
+	*cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
+	*cs++ = MI_BATCH_BUFFER_START_GEN8 | BIT(8);
+	*cs++ = lower_32_bits(batch->node.start);
+	*cs++ = upper_32_bits(batch->node.start);
+
+	*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
+	*cs++ = i915_ggtt_offset(ce->engine->status_page.vma) +
+		offset_in_page(sema);
+	*cs++ = 0;
+	*cs++ = 1;
+
+	intel_ring_advance(rq, cs);
+
+	rq->sched.attr.priority = I915_PRIORITY_BARRIER;
+err_rq:
+	i915_request_add(rq);
+err_batch:
+	i915_vma_put(batch);
+	return err;
+}
+
+static bool is_moving(u32 a, u32 b)
+{
+	return a != b;
+}
+
+static int compare_isolation(struct intel_engine_cs *engine,
+			     struct i915_vma *ref[2],
+			     struct i915_vma *result[2],
+			     struct intel_context *ce,
+			     u32 poison)
+{
+	u32 x, dw, *hw, *lrc;
+	u32 *A[2], *B[2];
+	int err = 0;
+
+	A[0] = i915_gem_object_pin_map(ref[0]->obj, I915_MAP_WC);
+	if (IS_ERR(A[0]))
+		return PTR_ERR(A[0]);
+
+	A[1] = i915_gem_object_pin_map(ref[1]->obj, I915_MAP_WC);
+	if (IS_ERR(A[1])) {
+		err = PTR_ERR(A[1]);
+		goto err_A0;
+	}
+
+	B[0] = i915_gem_object_pin_map(result[0]->obj, I915_MAP_WC);
+	if (IS_ERR(B[0])) {
+		err = PTR_ERR(B[0]);
+		goto err_A1;
+	}
+
+	B[1] = i915_gem_object_pin_map(result[1]->obj, I915_MAP_WC);
+	if (IS_ERR(B[1])) {
+		err = PTR_ERR(B[1]);
+		goto err_B0;
+	}
+
+	lrc = i915_gem_object_pin_map(ce->state->obj,
+				      i915_coherent_map_type(engine->i915));
+	if (IS_ERR(lrc)) {
+		err = PTR_ERR(lrc);
+		goto err_B1;
+	}
+	lrc += LRC_STATE_PN * PAGE_SIZE / sizeof(*hw);
+
+	x = 0;
+	dw = 0;
+	hw = engine->pinned_default_state;
+	hw += LRC_STATE_PN * PAGE_SIZE / sizeof(*hw);
+	do {
+		u32 lri = hw[dw];
+
+		if (lri == 0) {
+			dw++;
+			continue;
+		}
+
+		if ((lri & GENMASK(31, 23)) != MI_INSTR(0x22, 0)) {
+			lri &= 0x7f;
+			dw += lri + 2;
+			continue;
+		}
+
+		lri &= 0x7f;
+		lri++;
+		dw++;
+
+		while (lri) {
+			if (!is_moving(A[0][x], A[1][x]) &&
+			    (A[0][x] != B[0][x] || A[1][x] != B[1][x])) {
+				switch (hw[dw] & 4095) {
+				case 0x30: /* RING_HEAD */
+				case 0x34: /* RING_TAIL */
+					break;
+
+				default:
+					pr_err("%s[%d]: Mismatch for register %4x, default %08x, reference %08x, result (%08x, %08x), poison %08x, context %08x\n",
+					       engine->name, x,
+					       hw[dw], hw[dw + 1],
+					       A[0][x], B[0][x], B[1][x],
+					       poison, lrc[dw + 1]);
+					err = -EINVAL;
+					break;
+				}
+			}
+			dw += 2;
+			lri -= 2;
+			x++;
+		}
+	} while (dw < PAGE_SIZE / sizeof(u32) &&
+		 (hw[dw] & ~BIT(0)) != MI_BATCH_BUFFER_END);
+
+	i915_gem_object_unpin_map(ce->state->obj);
+err_B1:
+	i915_gem_object_unpin_map(result[1]->obj);
+err_B0:
+	i915_gem_object_unpin_map(result[0]->obj);
+err_A1:
+	i915_gem_object_unpin_map(ref[1]->obj);
+err_A0:
+	i915_gem_object_unpin_map(ref[0]->obj);
+	return err;
+}
+
+static int __lrc_isolation(struct intel_engine_cs *engine, u32 poison)
+{
+	u32 *sema = memset32(engine->status_page.addr + 1000, 0, 1);
+	struct i915_vma *ref[2], *result[2];
+	struct intel_context *A, *B;
+	struct i915_request *rq;
+	int err;
+
+	A = intel_context_create(engine);
+	if (IS_ERR(A))
+		return PTR_ERR(A);
+
+	B = intel_context_create(engine);
+	if (IS_ERR(B)) {
+		err = PTR_ERR(B);
+		goto err_A;
+	}
+
+	ref[0] = create_user_vma(A->vm, SZ_64K);
+	if (IS_ERR(ref[0])) {
+		err = PTR_ERR(ref[0]);
+		goto err_B;
+	}
+
+	ref[1] = create_user_vma(A->vm, SZ_64K);
+	if (IS_ERR(ref[1])) {
+		err = PTR_ERR(ref[1]);
+		goto err_ref0;
+	}
+
+	rq = record_registers(A, ref[0], ref[1], sema);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto err_ref1;
+	}
+
+	WRITE_ONCE(*sema, 1);
+	wmb();
+
+	if (i915_request_wait(rq, 0, HZ / 2) < 0) {
+		i915_request_put(rq);
+		err = -ETIME;
+		goto err_ref1;
+	}
+	i915_request_put(rq);
+
+	result[0] = create_user_vma(A->vm, SZ_64K);
+	if (IS_ERR(result[0])) {
+		err = PTR_ERR(result[0]);
+		goto err_ref1;
+	}
+
+	result[1] = create_user_vma(A->vm, SZ_64K);
+	if (IS_ERR(result[1])) {
+		err = PTR_ERR(result[1]);
+		goto err_result0;
+	}
+
+	rq = record_registers(A, result[0], result[1], sema);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto err_result1;
+	}
+
+	err = poison_registers(B, poison, sema);
+	if (err) {
+		WRITE_ONCE(*sema, -1);
+		i915_request_put(rq);
+		goto err_result1;
+	}
+
+	if (i915_request_wait(rq, 0, HZ / 2) < 0) {
+		i915_request_put(rq);
+		err = -ETIME;
+		goto err_result1;
+	}
+	i915_request_put(rq);
+
+	err = compare_isolation(engine, ref, result, A, poison);
+
+err_result1:
+	i915_vma_put(result[1]);
+err_result0:
+	i915_vma_put(result[0]);
+err_ref1:
+	i915_vma_put(ref[1]);
+err_ref0:
+	i915_vma_put(ref[0]);
+err_B:
+	intel_context_put(B);
+err_A:
+	intel_context_put(A);
+	return err;
+}
+
+static bool skip_isolation(const struct intel_engine_cs *engine)
+{
+	if (engine->class == COPY_ENGINE_CLASS && INTEL_GEN(engine->i915) == 9)
+		return true;
+
+	if (engine->class == RENDER_CLASS && INTEL_GEN(engine->i915) == 11)
+		return true;
+
+	return false;
+}
+
+static int live_lrc_isolation(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	const u32 poison[] = {
+		STACK_MAGIC,
+		0x3a3a3a3a,
+		0xc5c5c5c5,
+		0xffffffff,
+	};
+
+	/*
+	 * Our goal is try and verify that per-context state cannot be
+	 * tampered with by another non-privileged client.
+	 *
+	 * We take the list of context registers from the LRI in the default
+	 * context image and attempt to modify that list from a remote context.
+	 */
+
+	for_each_engine(engine, gt, id) {
+		int err = 0;
+		int i;
+
+		/* Just don't even ask */
+		if (!IS_ENABLED(CONFIG_DRM_I915_SELFTEST_BROKEN) &&
+		    skip_isolation(engine))
+			continue;
+
+		intel_engine_pm_get(engine);
+		if (engine->pinned_default_state) {
+			for (i = 0; i < ARRAY_SIZE(poison); i++) {
+				err = __lrc_isolation(engine, poison[i]);
+				if (err)
+					break;
+			}
+		}
+		if (igt_flush_test(gt->i915))
+			err = -EIO;
+		intel_engine_pm_put(engine);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
 static int __live_pphwsp_runtime(struct intel_engine_cs *engine)
 {
 	struct intel_context *ce;
@@ -4845,6 +5391,7 @@ int intel_lrc_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(live_lrc_fixed),
 		SUBTEST(live_lrc_state),
 		SUBTEST(live_lrc_gpr),
+		SUBTEST(live_lrc_isolation),
 		SUBTEST(live_lrc_timestamp),
 		SUBTEST(live_pphwsp_runtime),
 	};
-- 
2.25.1

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^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 02/14] drm/i915/selftests: Check recovery from corrupted LRC
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
@ 2020-02-24  9:59 ` Chris Wilson
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 03/14] drm/i915: Flush idle barriers when waiting Chris Wilson
                   ` (13 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24  9:59 UTC (permalink / raw)
  To: intel-gfx

Check that we can recover if the LRC is totally corrupted.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/selftest_lrc.c | 135 +++++++++++++++++++++++++
 1 file changed, 135 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index ee80b9d8a54b..5fdfb67c3bab 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -5294,6 +5294,140 @@ static int live_lrc_isolation(void *arg)
 	return 0;
 }
 
+static void garbage_reset(struct intel_engine_cs *engine,
+			  struct i915_request *rq)
+{
+	const unsigned int bit = I915_RESET_ENGINE + engine->id;
+	unsigned long *lock = &engine->gt->reset.flags;
+
+	if (test_and_set_bit(bit, lock))
+		return;
+
+	tasklet_disable(&engine->execlists.tasklet);
+
+	if (!rq->fence.error)
+		intel_engine_reset(engine, NULL);
+
+	tasklet_enable(&engine->execlists.tasklet);
+	clear_and_wake_up_bit(bit, lock);
+}
+
+static struct i915_request *garbage(struct intel_context *ce,
+				    struct rnd_state *prng)
+{
+	struct i915_request *rq;
+	int err;
+
+	err = intel_context_pin(ce);
+	if (err)
+		return ERR_PTR(err);
+
+	prandom_bytes_state(prng,
+			    ce->lrc_reg_state,
+			    ce->engine->context_size -
+			    LRC_STATE_PN * PAGE_SIZE);
+
+	rq = intel_context_create_request(ce);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto err_unpin;
+	}
+
+	i915_request_get(rq);
+	i915_request_add(rq);
+	return rq;
+
+err_unpin:
+	intel_context_unpin(ce);
+	return ERR_PTR(err);
+}
+
+static int __lrc_garbage(struct intel_engine_cs *engine, struct rnd_state *prng)
+{
+	struct intel_context *ce;
+	struct i915_request *hang;
+	int err;
+
+	ce = intel_context_create(engine);
+	if (IS_ERR(ce))
+		return PTR_ERR(ce);
+
+	hang = garbage(ce, prng);
+	if (IS_ERR(hang)) {
+		err = PTR_ERR(hang);
+		goto err_ce;
+	}
+
+	if (wait_for_submit(engine, hang, HZ / 2)) {
+		i915_request_put(hang);
+		err = -ETIME;
+		goto err_ce;
+	}
+
+	intel_context_set_banned(ce);
+	garbage_reset(engine, hang);
+
+	intel_engine_flush_submission(engine);
+	if (!hang->fence.error) {
+		i915_request_put(hang);
+		pr_err("%s: corrupted context was not reset\n",
+		       engine->name);
+		err = -EINVAL;
+		goto err_ce;
+	}
+
+	if (i915_request_wait(hang, 0, HZ / 2) < 0) {
+		pr_err("%s: corrupted context did not recover\n",
+		       engine->name);
+		i915_request_put(hang);
+		err = -EIO;
+		goto err_ce;
+	}
+	i915_request_put(hang);
+
+err_ce:
+	intel_context_put(ce);
+	return err;
+}
+
+static int live_lrc_garbage(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+
+	/*
+	 * Verify that we can recover if one context state is completely
+	 * corrupted.
+	 */
+
+	if (!IS_ENABLED(CONFIG_DRM_I915_SELFTEST_BROKEN))
+		return 0;
+
+	for_each_engine(engine, gt, id) {
+		I915_RND_STATE(prng);
+		int err = 0, i;
+
+		if (!intel_has_reset_engine(engine->gt))
+			continue;
+
+		intel_engine_pm_get(engine);
+		for (i = 0; i < 3; i++) {
+			err = __lrc_garbage(engine, &prng);
+			if (err)
+				break;
+		}
+		intel_engine_pm_put(engine);
+
+		if (igt_flush_test(gt->i915))
+			err = -EIO;
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
 static int __live_pphwsp_runtime(struct intel_engine_cs *engine)
 {
 	struct intel_context *ce;
@@ -5393,6 +5527,7 @@ int intel_lrc_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(live_lrc_gpr),
 		SUBTEST(live_lrc_isolation),
 		SUBTEST(live_lrc_timestamp),
+		SUBTEST(live_lrc_garbage),
 		SUBTEST(live_pphwsp_runtime),
 	};
 
-- 
2.25.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 03/14] drm/i915: Flush idle barriers when waiting
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 02/14] drm/i915/selftests: Check recovery from corrupted LRC Chris Wilson
@ 2020-02-24  9:59 ` Chris Wilson
  2020-02-25 19:07   ` Tvrtko Ursulin
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 04/14] drm/i915: Allow userspace to specify ringsize on construction Chris Wilson
                   ` (12 subsequent siblings)
  14 siblings, 1 reply; 18+ messages in thread
From: Chris Wilson @ 2020-02-24  9:59 UTC (permalink / raw)
  To: intel-gfx

If we do find ourselves with an idle barrier inside our active while
waiting, attempt to flush it by emitting a pulse using the kernel
context.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Steve Carbonari <steven.carbonari@intel.com>
---
 drivers/gpu/drm/i915/i915_active.c           | 42 ++++++++++++++----
 drivers/gpu/drm/i915/selftests/i915_active.c | 46 ++++++++++++++++++++
 2 files changed, 79 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index 9ccb931a733e..fae7e3820592 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -7,6 +7,7 @@
 #include <linux/debugobjects.h>
 
 #include "gt/intel_context.h"
+#include "gt/intel_engine_heartbeat.h"
 #include "gt/intel_engine_pm.h"
 #include "gt/intel_ring.h"
 
@@ -460,26 +461,49 @@ static void enable_signaling(struct i915_active_fence *active)
 	dma_fence_put(fence);
 }
 
-int i915_active_wait(struct i915_active *ref)
+static int flush_barrier(struct active_node *it)
 {
-	struct active_node *it, *n;
-	int err = 0;
+	struct intel_engine_cs *engine;
 
-	might_sleep();
+	if (!is_barrier(&it->base))
+		return 0;
 
-	if (!i915_active_acquire_if_busy(ref))
+	engine = __barrier_to_engine(it);
+	smp_rmb(); /* serialise with add_active_barriers */
+	if (!is_barrier(&it->base))
 		return 0;
 
-	/* Flush lazy signals */
+	return intel_engine_flush_barriers(engine);
+}
+
+static int flush_lazy_signals(struct i915_active *ref)
+{
+	struct active_node *it, *n;
+	int err = 0;
+
 	enable_signaling(&ref->excl);
 	rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
-		if (is_barrier(&it->base)) /* unconnected idle barrier */
-			continue;
+		err = flush_barrier(it); /* unconnected idle barrier? */
+		if (err)
+			break;
 
 		enable_signaling(&it->base);
 	}
-	/* Any fence added after the wait begins will not be auto-signaled */
 
+	return err;
+}
+
+int i915_active_wait(struct i915_active *ref)
+{
+	int err;
+
+	might_sleep();
+
+	if (!i915_active_acquire_if_busy(ref))
+		return 0;
+
+	/* Any fence added after the wait begins will not be auto-signaled */
+	err = flush_lazy_signals(ref);
 	i915_active_release(ref);
 	if (err)
 		return err;
diff --git a/drivers/gpu/drm/i915/selftests/i915_active.c b/drivers/gpu/drm/i915/selftests/i915_active.c
index ef572a0c2566..067e30b8927f 100644
--- a/drivers/gpu/drm/i915/selftests/i915_active.c
+++ b/drivers/gpu/drm/i915/selftests/i915_active.c
@@ -201,11 +201,57 @@ static int live_active_retire(void *arg)
 	return err;
 }
 
+static int live_active_barrier(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct intel_engine_cs *engine;
+	struct live_active *active;
+	int err = 0;
+
+	/* Check that we get a callback when requests retire upon waiting */
+
+	active = __live_alloc(i915);
+	if (!active)
+		return -ENOMEM;
+
+	err = i915_active_acquire(&active->base);
+	if (err)
+		goto out;
+
+	for_each_uabi_engine(engine, i915) {
+		err = i915_active_acquire_preallocate_barrier(&active->base,
+							      engine);
+		if (err)
+			break;
+
+		i915_active_acquire_barrier(&active->base);
+	}
+
+	i915_active_release(&active->base);
+
+	if (err == 0)
+		err = i915_active_wait(&active->base);
+
+	if (err == 0 && !READ_ONCE(active->retired)) {
+		pr_err("i915_active not retired after flushing barriers!\n");
+		err = -EINVAL;
+	}
+
+out:
+	__live_put(active);
+
+	if (igt_flush_test(i915))
+		err = -EIO;
+
+	return err;
+}
+
 int i915_active_live_selftests(struct drm_i915_private *i915)
 {
 	static const struct i915_subtest tests[] = {
 		SUBTEST(live_active_wait),
 		SUBTEST(live_active_retire),
+		SUBTEST(live_active_barrier),
 	};
 
 	if (intel_gt_is_wedged(&i915->gt))
-- 
2.25.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 04/14] drm/i915: Allow userspace to specify ringsize on construction
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 02/14] drm/i915/selftests: Check recovery from corrupted LRC Chris Wilson
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 03/14] drm/i915: Flush idle barriers when waiting Chris Wilson
@ 2020-02-24  9:59 ` Chris Wilson
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 05/14] drm/i915/gem: Honour O_NONBLOCK before throttling execbuf submissions Chris Wilson
                   ` (11 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24  9:59 UTC (permalink / raw)
  To: intel-gfx

No good reason why we must always use a static ringsize, so let
userspace select one during construction.

Link: https://github.com/intel/compute-runtime/pull/261
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Steve Carbonari <steven.carbonari@intel.com>
Reviewed-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
---
 drivers/gpu/drm/i915/Makefile                 |   1 +
 drivers/gpu/drm/i915/gem/i915_gem_context.c   | 110 ++++++++++++++++--
 drivers/gpu/drm/i915/gt/intel_context_param.c |  63 ++++++++++
 drivers/gpu/drm/i915/gt/intel_context_param.h |  14 +++
 drivers/gpu/drm/i915/gt/intel_lrc.c           |   1 +
 include/uapi/drm/i915_drm.h                   |  21 ++++
 6 files changed, 202 insertions(+), 8 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/gt/intel_context_param.c
 create mode 100644 drivers/gpu/drm/i915/gt/intel_context_param.h

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index b314d44ded5e..22a23134e98e 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -82,6 +82,7 @@ gt-y += \
 	gt/gen8_ppgtt.o \
 	gt/intel_breadcrumbs.o \
 	gt/intel_context.o \
+	gt/intel_context_param.o \
 	gt/intel_context_sseu.o \
 	gt/intel_engine_cs.o \
 	gt/intel_engine_heartbeat.o \
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index adcebf22a3d3..b24ee8e104cf 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -71,6 +71,7 @@
 
 #include "gt/gen6_ppgtt.h"
 #include "gt/intel_context.h"
+#include "gt/intel_context_param.h"
 #include "gt/intel_engine_heartbeat.h"
 #include "gt/intel_engine_user.h"
 #include "gt/intel_ring.h"
@@ -668,23 +669,30 @@ __create_context(struct drm_i915_private *i915)
 	return ERR_PTR(err);
 }
 
-static void
+static int
 context_apply_all(struct i915_gem_context *ctx,
-		  void (*fn)(struct intel_context *ce, void *data),
+		  int (*fn)(struct intel_context *ce, void *data),
 		  void *data)
 {
 	struct i915_gem_engines_iter it;
 	struct intel_context *ce;
+	int err = 0;
 
-	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it)
-		fn(ce, data);
+	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
+		err = fn(ce, data);
+		if (err)
+			break;
+	}
 	i915_gem_context_unlock_engines(ctx);
+
+	return err;
 }
 
-static void __apply_ppgtt(struct intel_context *ce, void *vm)
+static int __apply_ppgtt(struct intel_context *ce, void *vm)
 {
 	i915_vm_put(ce->vm);
 	ce->vm = i915_vm_get(vm);
+	return 0;
 }
 
 static struct i915_address_space *
@@ -722,9 +730,10 @@ static void __set_timeline(struct intel_timeline **dst,
 		intel_timeline_put(old);
 }
 
-static void __apply_timeline(struct intel_context *ce, void *timeline)
+static int __apply_timeline(struct intel_context *ce, void *timeline)
 {
 	__set_timeline(&ce->timeline, timeline);
+	return 0;
 }
 
 static void __assign_timeline(struct i915_gem_context *ctx,
@@ -1215,6 +1224,63 @@ static int set_ppgtt(struct drm_i915_file_private *file_priv,
 	return err;
 }
 
+static int __apply_ringsize(struct intel_context *ce, void *sz)
+{
+	return intel_context_set_ring_size(ce, (unsigned long)sz);
+}
+
+static int set_ringsize(struct i915_gem_context *ctx,
+			struct drm_i915_gem_context_param *args)
+{
+	if (!HAS_LOGICAL_RING_CONTEXTS(ctx->i915))
+		return -ENODEV;
+
+	if (args->size)
+		return -EINVAL;
+
+	if (!IS_ALIGNED(args->value, I915_GTT_PAGE_SIZE))
+		return -EINVAL;
+
+	if (args->value < I915_GTT_PAGE_SIZE)
+		return -EINVAL;
+
+	if (args->value > 128 * I915_GTT_PAGE_SIZE)
+		return -EINVAL;
+
+	return context_apply_all(ctx,
+				 __apply_ringsize,
+				 __intel_context_ring_size(args->value));
+}
+
+static int __get_ringsize(struct intel_context *ce, void *arg)
+{
+	long sz;
+
+	sz = intel_context_get_ring_size(ce);
+	GEM_BUG_ON(sz > INT_MAX);
+
+	return sz; /* stop on first engine */
+}
+
+static int get_ringsize(struct i915_gem_context *ctx,
+			struct drm_i915_gem_context_param *args)
+{
+	int sz;
+
+	if (!HAS_LOGICAL_RING_CONTEXTS(ctx->i915))
+		return -ENODEV;
+
+	if (args->size)
+		return -EINVAL;
+
+	sz = context_apply_all(ctx, __get_ringsize, NULL);
+	if (sz < 0)
+		return sz;
+
+	args->value = sz;
+	return 0;
+}
+
 static int
 user_to_context_sseu(struct drm_i915_private *i915,
 		     const struct drm_i915_gem_context_param_sseu *user,
@@ -1852,17 +1918,19 @@ set_persistence(struct i915_gem_context *ctx,
 	return __context_set_persistence(ctx, args->value);
 }
 
-static void __apply_priority(struct intel_context *ce, void *arg)
+static int __apply_priority(struct intel_context *ce, void *arg)
 {
 	struct i915_gem_context *ctx = arg;
 
 	if (!intel_engine_has_semaphores(ce->engine))
-		return;
+		return 0;
 
 	if (ctx->sched.priority >= I915_PRIORITY_NORMAL)
 		intel_context_set_use_semaphores(ce);
 	else
 		intel_context_clear_use_semaphores(ce);
+
+	return 0;
 }
 
 static int set_priority(struct i915_gem_context *ctx,
@@ -1955,6 +2023,10 @@ static int ctx_setparam(struct drm_i915_file_private *fpriv,
 		ret = set_persistence(ctx, args);
 		break;
 
+	case I915_CONTEXT_PARAM_RINGSIZE:
+		ret = set_ringsize(ctx, args);
+		break;
+
 	case I915_CONTEXT_PARAM_BAN_PERIOD:
 	default:
 		ret = -EINVAL;
@@ -1983,6 +2055,18 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data)
 	return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
 }
 
+static int copy_ring_size(struct intel_context *dst,
+			  struct intel_context *src)
+{
+	long sz;
+
+	sz = intel_context_get_ring_size(src);
+	if (sz < 0)
+		return sz;
+
+	return intel_context_set_ring_size(dst, sz);
+}
+
 static int clone_engines(struct i915_gem_context *dst,
 			 struct i915_gem_context *src)
 {
@@ -2026,6 +2110,12 @@ static int clone_engines(struct i915_gem_context *dst,
 		}
 
 		intel_context_set_gem(clone->engines[n], dst);
+
+		/* Copy across the preferred ringsize */
+		if (copy_ring_size(clone->engines[n], e->engines[n])) {
+			__free_engines(clone, n + 1);
+			goto err_unlock;
+		}
 	}
 	clone->num_engines = n;
 
@@ -2388,6 +2478,10 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
 		args->value = i915_gem_context_is_persistent(ctx);
 		break;
 
+	case I915_CONTEXT_PARAM_RINGSIZE:
+		ret = get_ringsize(ctx, args);
+		break;
+
 	case I915_CONTEXT_PARAM_BAN_PERIOD:
 	default:
 		ret = -EINVAL;
diff --git a/drivers/gpu/drm/i915/gt/intel_context_param.c b/drivers/gpu/drm/i915/gt/intel_context_param.c
new file mode 100644
index 000000000000..65dcd090245d
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_context_param.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include "i915_active.h"
+#include "intel_context.h"
+#include "intel_context_param.h"
+#include "intel_ring.h"
+
+int intel_context_set_ring_size(struct intel_context *ce, long sz)
+{
+	int err;
+
+	if (intel_context_lock_pinned(ce))
+		return -EINTR;
+
+	err = i915_active_wait(&ce->active);
+	if (err < 0)
+		goto unlock;
+
+	if (intel_context_is_pinned(ce)) {
+		err = -EBUSY; /* In active use, come back later! */
+		goto unlock;
+	}
+
+	if (test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
+		struct intel_ring *ring;
+
+		/* Replace the existing ringbuffer */
+		ring = intel_engine_create_ring(ce->engine, sz);
+		if (IS_ERR(ring)) {
+			err = PTR_ERR(ring);
+			goto unlock;
+		}
+
+		intel_ring_put(ce->ring);
+		ce->ring = ring;
+
+		/* Context image will be updated on next pin */
+	} else {
+		ce->ring = __intel_context_ring_size(sz);
+	}
+
+unlock:
+	intel_context_unlock_pinned(ce);
+	return err;
+}
+
+long intel_context_get_ring_size(struct intel_context *ce)
+{
+	long sz = (unsigned long)READ_ONCE(ce->ring);
+
+	if (test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
+		if (intel_context_lock_pinned(ce))
+			return -EINTR;
+
+		sz = ce->ring->size;
+		intel_context_unlock_pinned(ce);
+	}
+
+	return sz;
+}
diff --git a/drivers/gpu/drm/i915/gt/intel_context_param.h b/drivers/gpu/drm/i915/gt/intel_context_param.h
new file mode 100644
index 000000000000..f053d8633fe2
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_context_param.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef INTEL_CONTEXT_PARAM_H
+#define INTEL_CONTEXT_PARAM_H
+
+struct intel_context;
+
+int intel_context_set_ring_size(struct intel_context *ce, long sz);
+long intel_context_get_ring_size(struct intel_context *ce);
+
+#endif /* INTEL_CONTEXT_PARAM_H */
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 47561dc29304..39b0125b7143 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -2966,6 +2966,7 @@ __execlists_update_reg_state(const struct intel_context *ce,
 	regs[CTX_RING_START] = i915_ggtt_offset(ring->vma);
 	regs[CTX_RING_HEAD] = head;
 	regs[CTX_RING_TAIL] = ring->tail;
+	regs[CTX_RING_CTL] = RING_CTL_SIZE(ring->size) | RING_VALID;
 
 	/* RPCS */
 	if (engine->class == RENDER_CLASS) {
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 829c0a48577f..2813e579b480 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -1619,6 +1619,27 @@ struct drm_i915_gem_context_param {
  * By default, new contexts allow persistence.
  */
 #define I915_CONTEXT_PARAM_PERSISTENCE	0xb
+
+/*
+ * I915_CONTEXT_PARAM_RINGSIZE:
+ *
+ * Sets the size of the CS ringbuffer to use for logical ring contexts. This
+ * applies a limit of how many batches can be queued to HW before the caller
+ * is blocked due to lack of space for more commands.
+ *
+ * Only reliably possible to be set prior to first use, i.e. during
+ * construction. At any later point, the current execution must be flushed as
+ * the ring can only be changed while the context is idle. Note, the ringsize
+ * can be specified as a constructor property, see
+ * I915_CONTEXT_CREATE_EXT_SETPARAM, but can also be set later if required.
+ *
+ * Only applies to the current set of engine and lost when those engines
+ * are replaced by a new mapping (see I915_CONTEXT_PARAM_ENGINES).
+ *
+ * Must be between 4 - 512 KiB, in intervals of page size [4 KiB].
+ * Default is 16 KiB.
+ */
+#define I915_CONTEXT_PARAM_RINGSIZE	0xc
 /* Must be kept compact -- no holes and well documented */
 
 	__u64 value;
-- 
2.25.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 05/14] drm/i915/gem: Honour O_NONBLOCK before throttling execbuf submissions
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (2 preceding siblings ...)
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 04/14] drm/i915: Allow userspace to specify ringsize on construction Chris Wilson
@ 2020-02-24  9:59 ` Chris Wilson
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 06/14] drm/i915/selftests: Be a little more lenient for reset workers Chris Wilson
                   ` (10 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24  9:59 UTC (permalink / raw)
  To: intel-gfx

Check the user's flags on the struct file before deciding whether or not
to stall before submitting a request. This allows us to reasonably
cheaply honour O_NONBLOCK without checking at more critical phases
during request submission.

Suggested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Steve Carbonari <steven.carbonari@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 21 ++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 87fa5f42c39a..8646d76f4b6e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2327,15 +2327,22 @@ static int __eb_pin_engine(struct i915_execbuffer *eb, struct intel_context *ce)
 	intel_context_timeline_unlock(tl);
 
 	if (rq) {
-		if (i915_request_wait(rq,
-				      I915_WAIT_INTERRUPTIBLE,
-				      MAX_SCHEDULE_TIMEOUT) < 0) {
-			i915_request_put(rq);
-			err = -EINTR;
-			goto err_exit;
-		}
+		bool nonblock = eb->file->filp->f_flags & O_NONBLOCK;
+		long timeout;
+
+		timeout = MAX_SCHEDULE_TIMEOUT;
+		if (nonblock)
+			timeout = 0;
 
+		timeout = i915_request_wait(rq,
+					    I915_WAIT_INTERRUPTIBLE,
+					    timeout);
 		i915_request_put(rq);
+
+		if (timeout < 0) {
+			err = nonblock ? -EWOULDBLOCK : timeout;
+			goto err_exit;
+		}
 	}
 
 	eb->engine = ce->engine;
-- 
2.25.1

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^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 06/14] drm/i915/selftests: Be a little more lenient for reset workers
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (3 preceding siblings ...)
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 05/14] drm/i915/gem: Honour O_NONBLOCK before throttling execbuf submissions Chris Wilson
@ 2020-02-24  9:59 ` Chris Wilson
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 07/14] drm/i915: Protect i915_request_await_start from early waits Chris Wilson
                   ` (9 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24  9:59 UTC (permalink / raw)
  To: intel-gfx

Give the reset worker a kick before losing help when waiting for hang
recovery, as the CPU scheduler is a little unreliable.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/selftest_lrc.c | 74 ++++++++++++++++++--------
 1 file changed, 52 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 5fdfb67c3bab..83165bf9caaa 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -90,6 +90,48 @@ static int wait_for_submit(struct intel_engine_cs *engine,
 	return -ETIME;
 }
 
+static int wait_for_reset(struct intel_engine_cs *engine,
+			  struct i915_request *rq,
+			  unsigned long timeout)
+{
+	timeout += jiffies;
+	do {
+		cond_resched();
+		intel_engine_flush_submission(engine);
+
+		if (READ_ONCE(engine->execlists.pending[0]))
+			continue;
+
+		if (i915_request_completed(rq))
+			break;
+
+		if (READ_ONCE(rq->fence.error))
+			break;
+	} while (time_before(jiffies, timeout));
+
+	flush_scheduled_work();
+
+	if (rq->fence.error != -EIO) {
+		pr_err("%s: hanging request %llx:%lld not reset\n",
+		       engine->name,
+		       rq->fence.context,
+		       rq->fence.seqno);
+		return -EINVAL;
+	}
+
+	/* Give the request a jiffie to complete after flushing the worker */
+	if (i915_request_wait(rq, 0,
+			      max(0l, (long)(timeout - jiffies)) + 1) < 0) {
+		pr_err("%s: hanging request %llx:%lld did not complete\n",
+		       engine->name,
+		       rq->fence.context,
+		       rq->fence.seqno);
+		return -ETIME;
+	}
+
+	return 0;
+}
+
 static int live_sanitycheck(void *arg)
 {
 	struct intel_gt *gt = arg;
@@ -1805,14 +1847,9 @@ static int __cancel_active0(struct live_preempt_cancel *arg)
 	if (err)
 		goto out;
 
-	if (i915_request_wait(rq, 0, HZ / 5) < 0) {
-		err = -EIO;
-		goto out;
-	}
-
-	if (rq->fence.error != -EIO) {
-		pr_err("Cancelled inflight0 request did not report -EIO\n");
-		err = -EINVAL;
+	err = wait_for_reset(arg->engine, rq, HZ / 2);
+	if (err) {
+		pr_err("Cancelled inflight0 request did not reset\n");
 		goto out;
 	}
 
@@ -1870,10 +1907,9 @@ static int __cancel_active1(struct live_preempt_cancel *arg)
 		goto out;
 
 	igt_spinner_end(&arg->a.spin);
-	if (i915_request_wait(rq[1], 0, HZ / 5) < 0) {
-		err = -EIO;
+	err = wait_for_reset(arg->engine, rq[1], HZ / 2);
+	if (err)
 		goto out;
-	}
 
 	if (rq[0]->fence.error != 0) {
 		pr_err("Normal inflight0 request did not complete\n");
@@ -1953,10 +1989,9 @@ static int __cancel_queued(struct live_preempt_cancel *arg)
 	if (err)
 		goto out;
 
-	if (i915_request_wait(rq[2], 0, HZ / 5) < 0) {
-		err = -EIO;
+	err = wait_for_reset(arg->engine, rq[2], HZ / 2);
+	if (err)
 		goto out;
-	}
 
 	if (rq[0]->fence.error != -EIO) {
 		pr_err("Cancelled inflight0 request did not report -EIO\n");
@@ -2014,14 +2049,9 @@ static int __cancel_hostile(struct live_preempt_cancel *arg)
 	if (err)
 		goto out;
 
-	if (i915_request_wait(rq, 0, HZ / 5) < 0) {
-		err = -EIO;
-		goto out;
-	}
-
-	if (rq->fence.error != -EIO) {
-		pr_err("Cancelled inflight0 request did not report -EIO\n");
-		err = -EINVAL;
+	err = wait_for_reset(arg->engine, rq, HZ / 2);
+	if (err) {
+		pr_err("Cancelled inflight0 request did not reset\n");
 		goto out;
 	}
 
-- 
2.25.1

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https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 07/14] drm/i915: Protect i915_request_await_start from early waits
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (4 preceding siblings ...)
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 06/14] drm/i915/selftests: Be a little more lenient for reset workers Chris Wilson
@ 2020-02-24 10:00 ` Chris Wilson
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 08/14] drm/i915/gem: Consolidate ctx->engines[] release Chris Wilson
                   ` (8 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24 10:00 UTC (permalink / raw)
  To: intel-gfx

We need to be extremely careful inside i915_request_await_start() as it
needs to walk the list of requests in the foreign timeline with very
little protection. As we hold our own timeline mutex, we can not nest
inside the signaler's timeline mutex, so all that remains is our RCU
protection. However, to be safe we need to tell the compiler that we may
be traversing the list only under RCU protection, and furthermore we
need to start declaring requests as elements of the timeline from their
construction.

Fixes: 9ddc8ec027a3 ("drm/i915: Eliminate the trylock for awaiting an earlier request")
Fixes: 6a79d848403d ("drm/i915: Lock signaler timeline while navigating")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_request.c | 40 +++++++++++++++++++----------
 1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index d53af93b919b..8b22c8bb2fa8 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -290,7 +290,7 @@ bool i915_request_retire(struct i915_request *rq)
 	spin_unlock_irq(&rq->lock);
 
 	remove_from_client(rq);
-	list_del(&rq->link);
+	list_del_rcu(&rq->link);
 
 	intel_context_exit(rq->context);
 	intel_context_unpin(rq->context);
@@ -736,6 +736,8 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
 	rq->infix = rq->ring->emit; /* end of header; start of user payload */
 
 	intel_context_mark_active(ce);
+	list_add_tail_rcu(&rq->link, &tl->requests);
+
 	return rq;
 
 err_unwind:
@@ -792,13 +794,18 @@ i915_request_await_start(struct i915_request *rq, struct i915_request *signal)
 	GEM_BUG_ON(i915_request_timeline(rq) ==
 		   rcu_access_pointer(signal->timeline));
 
+	if (i915_request_started(signal))
+		return 0;
+
 	fence = NULL;
 	rcu_read_lock();
 	spin_lock_irq(&signal->lock);
-	if (!i915_request_started(signal) &&
-	    !list_is_first(&signal->link,
-			   &rcu_dereference(signal->timeline)->requests)) {
-		struct i915_request *prev = list_prev_entry(signal, link);
+	do {
+		struct list_head *pos = READ_ONCE(signal->link.prev);
+		struct i915_request *prev;
+
+		if (pos == &rcu_dereference(signal->timeline)->requests)
+			break;
 
 		/*
 		 * Peek at the request before us in the timeline. That
@@ -806,13 +813,22 @@ i915_request_await_start(struct i915_request *rq, struct i915_request *signal)
 		 * after acquiring a reference to it, confirm that it is
 		 * still part of the signaler's timeline.
 		 */
-		if (i915_request_get_rcu(prev)) {
-			if (list_next_entry(prev, link) == signal)
-				fence = &prev->fence;
-			else
-				i915_request_put(prev);
+		prev = list_entry(pos, typeof(*prev), link);
+		if (!i915_request_get_rcu(prev))
+			break;
+
+		if (unlikely(READ_ONCE(prev->link.next) != &signal->link)) {
+			i915_request_put(prev);
+			break;
 		}
-	}
+
+		if (unlikely(i915_request_started(signal))) {
+			i915_request_put(prev);
+			break;
+		}
+
+		fence = &prev->fence;
+	} while (0);
 	spin_unlock_irq(&signal->lock);
 	rcu_read_unlock();
 	if (!fence)
@@ -1253,8 +1269,6 @@ __i915_request_add_to_timeline(struct i915_request *rq)
 							 0);
 	}
 
-	list_add_tail(&rq->link, &timeline->requests);
-
 	/*
 	 * Make sure that no request gazumped us - if it was allocated after
 	 * our i915_request_alloc() and called __i915_request_add() before
-- 
2.25.1

_______________________________________________
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Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 08/14] drm/i915/gem: Consolidate ctx->engines[] release
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (5 preceding siblings ...)
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 07/14] drm/i915: Protect i915_request_await_start from early waits Chris Wilson
@ 2020-02-24 10:00 ` Chris Wilson
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 09/14] drm/i915/gt: Prevent allocation on a banned context Chris Wilson
                   ` (7 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24 10:00 UTC (permalink / raw)
  To: intel-gfx

Use the same engine_idle_release() routine for cleaning all old
ctx->engine[] state, closing any potential races with concurrent execbuf
submission.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/1241
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
Reorder set-closed/engine_idle_release to avoid premature killing
Take a reference to prevent racing context free with engine cleanup
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 190 ++++++++++----------
 1 file changed, 100 insertions(+), 90 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index b24ee8e104cf..3fd93ac911ef 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -244,7 +244,6 @@ static void __free_engines(struct i915_gem_engines *e, unsigned int count)
 		if (!e->engines[count])
 			continue;
 
-		RCU_INIT_POINTER(e->engines[count]->gem_context, NULL);
 		intel_context_put(e->engines[count]);
 	}
 	kfree(e);
@@ -271,8 +270,6 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx)
 	if (!e)
 		return ERR_PTR(-ENOMEM);
 
-	e->ctx = ctx;
-
 	for_each_engine(engine, gt, id) {
 		struct intel_context *ce;
 
@@ -306,7 +303,6 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
 	list_del(&ctx->link);
 	spin_unlock(&ctx->i915->gem.contexts.lock);
 
-	free_engines(rcu_access_pointer(ctx->engines));
 	mutex_destroy(&ctx->engines_mutex);
 
 	if (ctx->timeline)
@@ -493,30 +489,110 @@ static void kill_engines(struct i915_gem_engines *engines)
 static void kill_stale_engines(struct i915_gem_context *ctx)
 {
 	struct i915_gem_engines *pos, *next;
-	unsigned long flags;
 
-	spin_lock_irqsave(&ctx->stale.lock, flags);
+	spin_lock_irq(&ctx->stale.lock);
+	GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
 	list_for_each_entry_safe(pos, next, &ctx->stale.engines, link) {
-		if (!i915_sw_fence_await(&pos->fence))
+		if (!i915_sw_fence_await(&pos->fence)) {
+			list_del_init(&pos->link);
 			continue;
+		}
 
-		spin_unlock_irqrestore(&ctx->stale.lock, flags);
+		spin_unlock_irq(&ctx->stale.lock);
 
 		kill_engines(pos);
 
-		spin_lock_irqsave(&ctx->stale.lock, flags);
+		spin_lock_irq(&ctx->stale.lock);
+		GEM_BUG_ON(i915_sw_fence_signaled(&pos->fence));
 		list_safe_reset_next(pos, next, link);
 		list_del_init(&pos->link); /* decouple from FENCE_COMPLETE */
 
 		i915_sw_fence_complete(&pos->fence);
 	}
-	spin_unlock_irqrestore(&ctx->stale.lock, flags);
+	spin_unlock_irq(&ctx->stale.lock);
 }
 
 static void kill_context(struct i915_gem_context *ctx)
 {
 	kill_stale_engines(ctx);
-	kill_engines(__context_engines_static(ctx));
+}
+
+static int engines_notify(struct i915_sw_fence *fence,
+			  enum i915_sw_fence_notify state)
+{
+	struct i915_gem_engines *engines =
+		container_of(fence, typeof(*engines), fence);
+
+	switch (state) {
+	case FENCE_COMPLETE:
+		if (!list_empty(&engines->link)) {
+			struct i915_gem_context *ctx = engines->ctx;
+			unsigned long flags;
+
+			spin_lock_irqsave(&ctx->stale.lock, flags);
+			list_del(&engines->link);
+			spin_unlock_irqrestore(&ctx->stale.lock, flags);
+		}
+		break;
+
+	case FENCE_FREE:
+		i915_gem_context_put(engines->ctx);
+		init_rcu_head(&engines->rcu);
+		call_rcu(&engines->rcu, free_engines_rcu);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static void engines_idle_release(struct i915_gem_context *ctx,
+				 struct i915_gem_engines *engines)
+{
+	struct i915_gem_engines_iter it;
+	struct intel_context *ce;
+
+	i915_sw_fence_init(&engines->fence, engines_notify);
+	INIT_LIST_HEAD(&engines->link);
+
+	engines->ctx = i915_gem_context_get(ctx);
+
+	for_each_gem_engine(ce, engines, it) {
+		int err = 0;
+
+		RCU_INIT_POINTER(ce->gem_context, NULL);
+
+		if (!ce->timeline) { /* XXX serialisation with execbuf? */
+			intel_context_set_banned(ce);
+			continue;
+		}
+
+		mutex_lock(&ce->timeline->mutex);
+		if (!list_empty(&ce->timeline->requests)) {
+			struct i915_request *rq;
+
+			rq = list_last_entry(&ce->timeline->requests,
+					     typeof(*rq),
+					     link);
+
+			err = i915_sw_fence_await_dma_fence(&engines->fence,
+							    &rq->fence, 0,
+							    GFP_KERNEL);
+		}
+		mutex_unlock(&ce->timeline->mutex);
+		if (err < 0)
+			goto kill;
+	}
+
+	spin_lock_irq(&engines->ctx->stale.lock);
+	if (!i915_gem_context_is_closed(engines->ctx))
+		list_add_tail(&engines->link, &engines->ctx->stale.engines);
+	spin_unlock_irq(&engines->ctx->stale.lock);
+
+kill:
+	if (list_empty(&engines->link)) /* raced, already closed */
+		kill_engines(engines);
+
+	i915_sw_fence_commit(&engines->fence);
 }
 
 static void set_closed_name(struct i915_gem_context *ctx)
@@ -540,11 +616,16 @@ static void context_close(struct i915_gem_context *ctx)
 {
 	struct i915_address_space *vm;
 
+	/* Flush any concurrent set_engines() */
+	mutex_lock(&ctx->engines_mutex);
+	engines_idle_release(ctx, rcu_replace_pointer(ctx->engines, NULL, 1));
 	i915_gem_context_set_closed(ctx);
-	set_closed_name(ctx);
+	mutex_unlock(&ctx->engines_mutex);
 
 	mutex_lock(&ctx->mutex);
 
+	set_closed_name(ctx);
+
 	vm = i915_gem_context_vm(ctx);
 	if (vm)
 		i915_vm_close(vm);
@@ -1628,77 +1709,6 @@ static const i915_user_extension_fn set_engines__extensions[] = {
 	[I915_CONTEXT_ENGINES_EXT_BOND] = set_engines__bond,
 };
 
-static int engines_notify(struct i915_sw_fence *fence,
-			  enum i915_sw_fence_notify state)
-{
-	struct i915_gem_engines *engines =
-		container_of(fence, typeof(*engines), fence);
-
-	switch (state) {
-	case FENCE_COMPLETE:
-		if (!list_empty(&engines->link)) {
-			struct i915_gem_context *ctx = engines->ctx;
-			unsigned long flags;
-
-			spin_lock_irqsave(&ctx->stale.lock, flags);
-			list_del(&engines->link);
-			spin_unlock_irqrestore(&ctx->stale.lock, flags);
-		}
-		break;
-
-	case FENCE_FREE:
-		init_rcu_head(&engines->rcu);
-		call_rcu(&engines->rcu, free_engines_rcu);
-		break;
-	}
-
-	return NOTIFY_DONE;
-}
-
-static void engines_idle_release(struct i915_gem_engines *engines)
-{
-	struct i915_gem_engines_iter it;
-	struct intel_context *ce;
-	unsigned long flags;
-
-	GEM_BUG_ON(!engines);
-	i915_sw_fence_init(&engines->fence, engines_notify);
-
-	INIT_LIST_HEAD(&engines->link);
-	spin_lock_irqsave(&engines->ctx->stale.lock, flags);
-	if (!i915_gem_context_is_closed(engines->ctx))
-		list_add(&engines->link, &engines->ctx->stale.engines);
-	spin_unlock_irqrestore(&engines->ctx->stale.lock, flags);
-	if (list_empty(&engines->link)) /* raced, already closed */
-		goto kill;
-
-	for_each_gem_engine(ce, engines, it) {
-		struct dma_fence *fence;
-		int err;
-
-		if (!ce->timeline)
-			continue;
-
-		fence = i915_active_fence_get(&ce->timeline->last_request);
-		if (!fence)
-			continue;
-
-		err = i915_sw_fence_await_dma_fence(&engines->fence,
-						    fence, 0,
-						    GFP_KERNEL);
-
-		dma_fence_put(fence);
-		if (err < 0)
-			goto kill;
-	}
-	goto out;
-
-kill:
-	kill_engines(engines);
-out:
-	i915_sw_fence_commit(&engines->fence);
-}
-
 static int
 set_engines(struct i915_gem_context *ctx,
 	    const struct drm_i915_gem_context_param *args)
@@ -1741,8 +1751,6 @@ set_engines(struct i915_gem_context *ctx,
 	if (!set.engines)
 		return -ENOMEM;
 
-	set.engines->ctx = ctx;
-
 	for (n = 0; n < num_engines; n++) {
 		struct i915_engine_class_instance ci;
 		struct intel_engine_cs *engine;
@@ -1795,6 +1803,11 @@ set_engines(struct i915_gem_context *ctx,
 
 replace:
 	mutex_lock(&ctx->engines_mutex);
+	if (i915_gem_context_is_closed(ctx)) {
+		mutex_unlock(&ctx->engines_mutex);
+		free_engines(set.engines);
+		return -ENOENT;
+	}
 	if (args->size)
 		i915_gem_context_set_user_engines(ctx);
 	else
@@ -1803,7 +1816,7 @@ set_engines(struct i915_gem_context *ctx,
 	mutex_unlock(&ctx->engines_mutex);
 
 	/* Keep track of old engine sets for kill_context() */
-	engines_idle_release(set.engines);
+	engines_idle_release(ctx, set.engines);
 
 	return 0;
 }
@@ -2079,8 +2092,6 @@ static int clone_engines(struct i915_gem_context *dst,
 	if (!clone)
 		goto err_unlock;
 
-	clone->ctx = dst;
-
 	for (n = 0; n < e->num_engines; n++) {
 		struct intel_engine_cs *engine;
 
@@ -2123,8 +2134,7 @@ static int clone_engines(struct i915_gem_context *dst,
 	i915_gem_context_unlock_engines(src);
 
 	/* Serialised by constructor */
-	free_engines(__context_engines_static(dst));
-	RCU_INIT_POINTER(dst->engines, clone);
+	engines_idle_release(dst, rcu_replace_pointer(dst->engines, clone, 1));
 	if (user_engines)
 		i915_gem_context_set_user_engines(dst);
 	else
-- 
2.25.1

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https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 09/14] drm/i915/gt: Prevent allocation on a banned context
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (6 preceding siblings ...)
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 08/14] drm/i915/gem: Consolidate ctx->engines[] release Chris Wilson
@ 2020-02-24 10:00 ` Chris Wilson
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 10/14] drm/i915/gem: Check that the context wasn't closed during setup Chris Wilson
                   ` (6 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24 10:00 UTC (permalink / raw)
  To: intel-gfx; +Cc: Matthew Auld

If a context is banned even before we submit our first request to it,
report the failure before we attempt to allocate any resources for the
context.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_context.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 8bb444cda14f..01474d3a558b 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -51,6 +51,11 @@ int intel_context_alloc_state(struct intel_context *ce)
 		return -EINTR;
 
 	if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
+		if (intel_context_is_banned(ce)) {
+			err = -EIO;
+			goto unlock;
+		}
+
 		err = ce->ops->alloc(ce);
 		if (unlikely(err))
 			goto unlock;
-- 
2.25.1

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Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 10/14] drm/i915/gem: Check that the context wasn't closed during setup
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (7 preceding siblings ...)
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 09/14] drm/i915/gt: Prevent allocation on a banned context Chris Wilson
@ 2020-02-24 10:00 ` Chris Wilson
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 11/14] drm/i915/gt: Declare when we enabled timeslicing Chris Wilson
                   ` (5 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24 10:00 UTC (permalink / raw)
  To: intel-gfx; +Cc: Matthew Auld

As setup takes a long time, the user may close the context during the
construction of the execbuf. In order to make sure we correctly track
all outstanding work with non-persistent contexts, we need to serialise
the submission with the context closure and mop up any leaks.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 8646d76f4b6e..5200d5c1d732 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2736,6 +2736,12 @@ i915_gem_do_execbuffer(struct drm_device *dev,
 		goto err_batch_unpin;
 	}
 
+	/* Check that the context wasn't destroyed before setup */
+	if (!rcu_access_pointer(eb.context->gem_context)) {
+		err = -ENOENT;
+		goto err_request;
+	}
+
 	if (in_fence) {
 		err = i915_request_await_dma_fence(eb.request, in_fence);
 		if (err < 0)
-- 
2.25.1

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https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 11/14] drm/i915/gt: Declare when we enabled timeslicing
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (8 preceding siblings ...)
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 10/14] drm/i915/gem: Check that the context wasn't closed during setup Chris Wilson
@ 2020-02-24 10:00 ` Chris Wilson
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 12/14] drm/i915/gt: Yield the timeslice if caught waiting on a user semaphore Chris Wilson
                   ` (4 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24 10:00 UTC (permalink / raw)
  To: intel-gfx; +Cc: Kenneth Graunke

Let userspace know if they can trust timeslicing by including it as part
of the I915_PARAM_HAS_SCHEDULER::I915_SCHEDULER_CAP_TIMESLICING

v2: Only declare timeslicing if we can safely preempt userspace.

Fixes: 8ee36e048c98 ("drm/i915/execlists: Minimalistic timeslicing")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kenneth Graunke <kenneth@whitecape.org>
---
 drivers/gpu/drm/i915/gt/intel_engine.h      | 3 ++-
 drivers/gpu/drm/i915/gt/intel_engine_user.c | 5 +++++
 include/uapi/drm/i915_drm.h                 | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index 29c8c03c5caa..a32dc82a90d4 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -326,7 +326,8 @@ intel_engine_has_timeslices(const struct intel_engine_cs *engine)
 	if (!IS_ACTIVE(CONFIG_DRM_I915_TIMESLICE_DURATION))
 		return false;
 
-	return intel_engine_has_semaphores(engine);
+	return (intel_engine_has_semaphores(engine) &&
+		intel_engine_has_preemption(engine));
 }
 
 #endif /* _INTEL_RINGBUFFER_H_ */
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_user.c b/drivers/gpu/drm/i915/gt/intel_engine_user.c
index 848decee9066..b84fdd722781 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_user.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_user.c
@@ -121,6 +121,11 @@ static void set_scheduler_caps(struct drm_i915_private *i915)
 			else
 				disabled |= BIT(map[i].sched);
 		}
+
+		if (intel_engine_has_timeslices(engine))
+			enabled |= I915_SCHEDULER_CAP_TIMESLICING;
+		else
+			disabled |= I915_SCHEDULER_CAP_TIMESLICING;
 	}
 
 	i915->caps.scheduler = enabled & ~disabled;
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 2813e579b480..4f903431a3fe 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -523,6 +523,7 @@ typedef struct drm_i915_irq_wait {
 #define   I915_SCHEDULER_CAP_PREEMPTION	(1ul << 2)
 #define   I915_SCHEDULER_CAP_SEMAPHORES	(1ul << 3)
 #define   I915_SCHEDULER_CAP_ENGINE_BUSY_STATS	(1ul << 4)
+#define   I915_SCHEDULER_CAP_TIMESLICING	(1ul << 5)
 
 #define I915_PARAM_HUC_STATUS		 42
 
-- 
2.25.1

_______________________________________________
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Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 12/14] drm/i915/gt: Yield the timeslice if caught waiting on a user semaphore
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (9 preceding siblings ...)
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 11/14] drm/i915/gt: Declare when we enabled timeslicing Chris Wilson
@ 2020-02-24 10:00 ` Chris Wilson
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 13/14] drm/i915/execlists: Check the sentinel is alone in the ELSP Chris Wilson
                   ` (3 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24 10:00 UTC (permalink / raw)
  To: intel-gfx; +Cc: Kenneth Graunke

If we find ourselves waiting on a MI_SEMAPHORE_WAIT, either within the
user batch or in our own preamble, the engine raises a
GT_WAIT_ON_SEMAPHORE interrupt. We can unmask that interrupt and so
respond to a semaphore wait by yielding the timeslice, if we have
another context to yield to!

The only real complication is that the interrupt is only generated for
the start of the semaphore wait, and is asynchronous to our
process_csb() -- that is, we may not have registered the timeslice before
we see the interrupt. To ensure we don't miss a potential semaphore
blocking forward progress (e.g. selftests/live_timeslice_preempt) we mark
the interrupt and apply it to the next timeslice regardless of whether it
was active at the time.

v2: We use semaphores in preempt-to-busy, within the timeslicing
implementation itself! Ergo, when we do insert a preemption due to an
expired timeslice, the new context may start with the missed semaphore
flagged by the retired context and be yielded, ad infinitum. To avoid
this, read the context id at the time of the semaphore interrupt and
only yield if that context is still active.

Fixes: 8ee36e048c98 ("drm/i915/execlists: Minimalistic timeslicing")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
---
 drivers/gpu/drm/i915/gt/intel_engine_cs.c    |  6 +++
 drivers/gpu/drm/i915/gt/intel_engine_types.h |  9 +++++
 drivers/gpu/drm/i915/gt/intel_gt_irq.c       | 13 ++++++-
 drivers/gpu/drm/i915/gt/intel_lrc.c          | 40 +++++++++++++++++---
 drivers/gpu/drm/i915/i915_reg.h              |  1 +
 5 files changed, 61 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 119c9cb24fd4..eec6e3245a97 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -1288,6 +1288,12 @@ static void intel_engine_print_registers(struct intel_engine_cs *engine,
 
 	if (engine->id == RENDER_CLASS && IS_GEN_RANGE(dev_priv, 4, 7))
 		drm_printf(m, "\tCCID: 0x%08x\n", ENGINE_READ(engine, CCID));
+	if (HAS_EXECLISTS(dev_priv)) {
+		drm_printf(m, "\tEL_STAT_HI: 0x%08x\n",
+			   ENGINE_READ(engine, RING_EXECLIST_STATUS_HI));
+		drm_printf(m, "\tEL_STAT_LO: 0x%08x\n",
+			   ENGINE_READ(engine, RING_EXECLIST_STATUS_LO));
+	}
 	drm_printf(m, "\tRING_START: 0x%08x\n",
 		   ENGINE_READ(engine, RING_START));
 	drm_printf(m, "\tRING_HEAD:  0x%08x\n",
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
index b23366a81048..24cff658e6e5 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
@@ -156,6 +156,15 @@ struct intel_engine_execlists {
 	 */
 	struct i915_priolist default_priolist;
 
+	/**
+	 * @yield: CCID at the time of the last semaphore-wait interrupt.
+	 *
+	 * Instead of leaving a semaphore busy-spinning on an engine, we would
+	 * like to switch to another ready context, i.e. yielding the semaphore
+	 * timeslice.
+	 */
+	u32 yield;
+
 	/**
 	 * @error_interrupt: CS Master EIR
 	 *
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
index f0e7fd95165a..875bd0392ffc 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
@@ -39,6 +39,13 @@ cs_irq_handler(struct intel_engine_cs *engine, u32 iir)
 		}
 	}
 
+	if (iir & GT_WAIT_SEMAPHORE_INTERRUPT) {
+		WRITE_ONCE(engine->execlists.yield,
+			   ENGINE_READ_FW(engine, RING_EXECLIST_STATUS_HI));
+		if (del_timer(&engine->execlists.timer))
+			tasklet = true;
+	}
+
 	if (iir & GT_CONTEXT_SWITCH_INTERRUPT)
 		tasklet = true;
 
@@ -228,7 +235,8 @@ void gen11_gt_irq_postinstall(struct intel_gt *gt)
 	const u32 irqs =
 		GT_CS_MASTER_ERROR_INTERRUPT |
 		GT_RENDER_USER_INTERRUPT |
-		GT_CONTEXT_SWITCH_INTERRUPT;
+		GT_CONTEXT_SWITCH_INTERRUPT |
+		GT_WAIT_SEMAPHORE_INTERRUPT;
 	struct intel_uncore *uncore = gt->uncore;
 	const u32 dmask = irqs << 16 | irqs;
 	const u32 smask = irqs << 16;
@@ -366,7 +374,8 @@ void gen8_gt_irq_postinstall(struct intel_gt *gt)
 	const u32 irqs =
 		GT_CS_MASTER_ERROR_INTERRUPT |
 		GT_RENDER_USER_INTERRUPT |
-		GT_CONTEXT_SWITCH_INTERRUPT;
+		GT_CONTEXT_SWITCH_INTERRUPT |
+		GT_WAIT_SEMAPHORE_INTERRUPT;
 	const u32 gt_interrupts[] = {
 		irqs << GEN8_RCS_IRQ_SHIFT | irqs << GEN8_BCS_IRQ_SHIFT,
 		irqs << GEN8_VCS0_IRQ_SHIFT | irqs << GEN8_VCS1_IRQ_SHIFT,
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 39b0125b7143..0538731625ae 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1728,7 +1728,8 @@ static void defer_active(struct intel_engine_cs *engine)
 }
 
 static bool
-need_timeslice(struct intel_engine_cs *engine, const struct i915_request *rq)
+need_timeslice(const struct intel_engine_cs *engine,
+	       const struct i915_request *rq)
 {
 	int hint;
 
@@ -1744,6 +1745,31 @@ need_timeslice(struct intel_engine_cs *engine, const struct i915_request *rq)
 	return hint >= effective_prio(rq);
 }
 
+static bool
+timeslice_yield(const struct intel_engine_execlists *el,
+		const struct i915_request *rq)
+{
+	/*
+	 * Once bitten, forever smitten!
+	 *
+	 * If the active context ever busy-waited on a semaphore,
+	 * it will be treated as a hog until the end of its timeslice.
+	 * The HW only sends an interrupt on the first miss, and we
+	 * do know if that semaphore has been signaled, or even if it
+	 * is now stuck on another semaphore. Play safe, yield if it
+	 * might be stuck -- it will be given a fresh timeslice in
+	 * the near future.
+	 */
+	return upper_32_bits(rq->context->lrc_desc) == READ_ONCE(el->yield);
+}
+
+static bool
+timeslice_expired(const struct intel_engine_execlists *el,
+		  const struct i915_request *rq)
+{
+	return timer_expired(&el->timer) || timeslice_yield(el, rq);
+}
+
 static int
 switch_prio(struct intel_engine_cs *engine, const struct i915_request *rq)
 {
@@ -1759,8 +1785,7 @@ timeslice(const struct intel_engine_cs *engine)
 	return READ_ONCE(engine->props.timeslice_duration_ms);
 }
 
-static unsigned long
-active_timeslice(const struct intel_engine_cs *engine)
+static unsigned long active_timeslice(const struct intel_engine_cs *engine)
 {
 	const struct i915_request *rq = *engine->execlists.active;
 
@@ -1903,13 +1928,14 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 
 			last = NULL;
 		} else if (need_timeslice(engine, last) &&
-			   timer_expired(&engine->execlists.timer)) {
+			   timeslice_expired(execlists, last)) {
 			ENGINE_TRACE(engine,
-				     "expired last=%llx:%lld, prio=%d, hint=%d\n",
+				     "expired last=%llx:%lld, prio=%d, hint=%d, yield?=%s\n",
 				     last->fence.context,
 				     last->fence.seqno,
 				     last->sched.attr.priority,
-				     execlists->queue_priority_hint);
+				     execlists->queue_priority_hint,
+				     yesno(timeslice_yield(execlists, last)));
 
 			ring_set_paused(engine, 1);
 			defer_active(engine);
@@ -2169,6 +2195,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 		}
 		clear_ports(port + 1, last_port - port);
 
+		WRITE_ONCE(execlists->yield, -1);
 		execlists_submit_ports(engine);
 		set_preempt_timeout(engine);
 	} else {
@@ -4414,6 +4441,7 @@ logical_ring_default_irqs(struct intel_engine_cs *engine)
 	engine->irq_enable_mask = GT_RENDER_USER_INTERRUPT << shift;
 	engine->irq_keep_mask = GT_CONTEXT_SWITCH_INTERRUPT << shift;
 	engine->irq_keep_mask |= GT_CS_MASTER_ERROR_INTERRUPT << shift;
+	engine->irq_keep_mask |= GT_WAIT_SEMAPHORE_INTERRUPT << shift;
 }
 
 static void rcs_submission_override(struct intel_engine_cs *engine)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f45b5e86ec63..0b5e669c4867 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3092,6 +3092,7 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define GT_BSD_CS_ERROR_INTERRUPT		(1 << 15)
 #define GT_BSD_USER_INTERRUPT			(1 << 12)
 #define GT_RENDER_L3_PARITY_ERROR_INTERRUPT_S1	(1 << 11) /* hsw+; rsvd on snb, ivb, vlv */
+#define GT_WAIT_SEMAPHORE_INTERRUPT		REG_BIT(11) /* bdw+ */
 #define GT_CONTEXT_SWITCH_INTERRUPT		(1 <<  8)
 #define GT_RENDER_L3_PARITY_ERROR_INTERRUPT	(1 <<  5) /* !snb */
 #define GT_RENDER_PIPECTL_NOTIFY_INTERRUPT	(1 <<  4)
-- 
2.25.1

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https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 13/14] drm/i915/execlists: Check the sentinel is alone in the ELSP
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (10 preceding siblings ...)
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 12/14] drm/i915/gt: Yield the timeslice if caught waiting on a user semaphore Chris Wilson
@ 2020-02-24 10:00 ` Chris Wilson
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 14/14] drm/i915/execlists: Reduce preempt-to-busy roundtrip delay Chris Wilson
                   ` (2 subsequent siblings)
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24 10:00 UTC (permalink / raw)
  To: intel-gfx

We only use sentinel requests for "preempt-to-idle" passes, so assert
that they are the only request in a new submission.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_lrc.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 0538731625ae..51d0886c70f4 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1448,6 +1448,7 @@ assert_pending_valid(const struct intel_engine_execlists *execlists,
 {
 	struct i915_request * const *port, *rq;
 	struct intel_context *ce = NULL;
+	bool sentinel = false;
 
 	trace_ports(execlists, msg, execlists->pending);
 
@@ -1481,6 +1482,26 @@ assert_pending_valid(const struct intel_engine_execlists *execlists,
 		}
 		ce = rq->context;
 
+		/*
+		 * Sentinels are supposed to be lonely so they flush the
+		 * current exection off the HW. Check that they are the
+		 * only request in the pending submission.
+		 */
+		if (sentinel) {
+			GEM_TRACE_ERR("context:%llx after sentinel in pending[%zd]\n",
+				      ce->timeline->fence_context,
+				      port - execlists->pending);
+			return false;
+		}
+
+		sentinel = i915_request_has_sentinel(rq);
+		if (sentinel && port != execlists->pending) {
+			GEM_TRACE_ERR("sentinel context:%llx not in prime position[%zd]\n",
+				      ce->timeline->fence_context,
+				      port - execlists->pending);
+			return false;
+		}
+
 		/* Hold tightly onto the lock to prevent concurrent retires! */
 		if (!spin_trylock_irqsave(&rq->lock, flags))
 			continue;
-- 
2.25.1

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https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] [PATCH 14/14] drm/i915/execlists: Reduce preempt-to-busy roundtrip delay
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (11 preceding siblings ...)
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 13/14] drm/i915/execlists: Check the sentinel is alone in the ELSP Chris Wilson
@ 2020-02-24 10:00 ` Chris Wilson
  2020-02-24 10:59 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for series starting with [01/14] drm/i915/selftests: Verify LRC isolation Patchwork
  2020-02-24 13:17 ` [Intel-gfx] ✗ Fi.CI.BAT: failure " Patchwork
  14 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-24 10:00 UTC (permalink / raw)
  To: intel-gfx

To prevent the context from proceeding past the end of the request as we
unwind, we embed a semaphore into the footer of each request. (If the
context were to skip past the end of the request as we perform the
preemption, next time we reload the context it's RING_HEAD would be past
the RING_TAIL and instead of replaying the commands it would read the
read of the uninitialised ringbuffer.)

However, this requires us to keep the ring paused at the end of the
request until we have a change to process the preemption ack and remove
the semaphore. Our processing of acks is at the whim of ksoftirqd, and
so it is entirely possible that the GPU has to wait for the tasklet
before it can proceed with the next request.

It was suggested that we could also embed a MI_LOAD_REGISTER_MEM into
the footer to read the current RING_TAIL from the context, which would
allow us to not only avoid this round trip (and so release the context
as soon as we had submitted the preemption request to in ELSP), but also
skip using ELSP for lite-restores entirely. That has the nice benefit of
dramatically reducing contention and the frequency of interrupts when a
client submits two or more execbufs in rapid succession.

* This did not work out quite as well as anticipated due to us reloading
the new RING_TAIL from the context image moments before the HW acted
upon the ELSP. With the calamitous effect that we would submit a
preemption request with an identical RING_TAIL as the current RING_HEAD,
causing us to fail WaIdleLiteRestore and the HW stop working.

However, mmio access to RING_TAIL was defeatured in gen11 so we can only
employ this handy trick for gen8/gen9.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_engine_types.h | 23 +++--
 drivers/gpu/drm/i915/gt/intel_lrc.c          | 93 +++++++++++++++++++-
 2 files changed, 106 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
index 24cff658e6e5..ae8724915320 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
@@ -488,14 +488,15 @@ struct intel_engine_cs {
 	/* status_notifier: list of callbacks for context-switch changes */
 	struct atomic_notifier_head context_status_notifier;
 
-#define I915_ENGINE_USING_CMD_PARSER BIT(0)
-#define I915_ENGINE_SUPPORTS_STATS   BIT(1)
-#define I915_ENGINE_HAS_PREEMPTION   BIT(2)
-#define I915_ENGINE_HAS_SEMAPHORES   BIT(3)
-#define I915_ENGINE_NEEDS_BREADCRUMB_TASKLET BIT(4)
-#define I915_ENGINE_IS_VIRTUAL       BIT(5)
-#define I915_ENGINE_HAS_RELATIVE_MMIO BIT(6)
-#define I915_ENGINE_REQUIRES_CMD_PARSER BIT(7)
+#define I915_ENGINE_REQUIRES_CMD_PARSER		BIT(0)
+#define I915_ENGINE_USING_CMD_PARSER		BIT(1)
+#define I915_ENGINE_SUPPORTS_STATS		BIT(2)
+#define I915_ENGINE_HAS_PREEMPTION		BIT(3)
+#define I915_ENGINE_HAS_SEMAPHORES		BIT(4)
+#define I915_ENGINE_HAS_TAIL_LRM		BIT(5)
+#define I915_ENGINE_NEEDS_BREADCRUMB_TASKLET	BIT(6)
+#define I915_ENGINE_IS_VIRTUAL			BIT(7)
+#define I915_ENGINE_HAS_RELATIVE_MMIO		BIT(8)
 	unsigned int flags;
 
 	/*
@@ -592,6 +593,12 @@ intel_engine_has_semaphores(const struct intel_engine_cs *engine)
 	return engine->flags & I915_ENGINE_HAS_SEMAPHORES;
 }
 
+static inline bool
+intel_engine_has_tail_lrm(const struct intel_engine_cs *engine)
+{
+	return engine->flags & I915_ENGINE_HAS_TAIL_LRM;
+}
+
 static inline bool
 intel_engine_needs_breadcrumb_tasklet(const struct intel_engine_cs *engine)
 {
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 51d0886c70f4..9b3d4e0179da 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1861,6 +1861,76 @@ static inline void clear_ports(struct i915_request **ports, int count)
 	memset_p((void **)ports, NULL, count);
 }
 
+static struct i915_request *
+skip_lite_restore(struct intel_engine_cs *const engine,
+		  struct i915_request *first,
+		  bool *submit)
+{
+	struct intel_engine_execlists *const execlists = &engine->execlists;
+	struct i915_request *last = first;
+	struct rb_node *rb;
+
+	if (!intel_engine_has_tail_lrm(engine))
+		return last;
+
+	GEM_BUG_ON(*submit);
+	while ((rb = rb_first_cached(&execlists->queue))) {
+		struct i915_priolist *p = to_priolist(rb);
+		struct i915_request *rq, *rn;
+		int i;
+
+		priolist_for_each_request_consume(rq, rn, p, i) {
+			if (!can_merge_rq(last, rq))
+				goto out;
+
+			if (__i915_request_submit(rq)) {
+				*submit = true;
+				last = rq;
+			}
+		}
+
+		rb_erase_cached(&p->node, &execlists->queue);
+		i915_priolist_free(p);
+	}
+out:
+	if (*submit) {
+		ring_set_paused(engine, 1);
+
+		/*
+		 * If we are quick and the current context hasn't yet completed
+		 * its request, we can just tell it to extend the RING_TAIL
+		 * onto the next without having to submit a new ELSP.
+		 */
+		if (!i915_request_completed(first)) {
+			struct i915_request **port;
+
+			ENGINE_TRACE(engine,
+				     "eliding lite-restore last=%llx:%lld->%lld, current %d\n",
+				     first->fence.context,
+				     first->fence.seqno,
+				     last->fence.seqno,
+				     hwsp_seqno(last));
+			GEM_BUG_ON(first->context != last->context);
+
+			for (port = (struct i915_request **)execlists->active;
+			     *port != first;
+			     port++)
+				;
+
+			GEM_BUG_ON(first == last);
+			WRITE_ONCE(*port, i915_request_get(last));
+			execlists_update_context(last);
+
+			i915_request_put(first);
+			*submit = false;
+		}
+
+		ring_set_paused(engine, 0);
+	}
+
+	return last;
+}
+
 static void execlists_dequeue(struct intel_engine_cs *engine)
 {
 	struct intel_engine_execlists * const execlists = &engine->execlists;
@@ -1998,6 +2068,8 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 
 				return;
 			}
+
+			last = skip_lite_restore(engine, last, &submit);
 		}
 	}
 
@@ -4221,15 +4293,28 @@ static u32 *emit_preempt_busywait(struct i915_request *request, u32 *cs)
 	return cs;
 }
 
+static u32 *emit_lrm_tail(struct i915_request *request, u32 *cs)
+{
+	*cs++ = MI_LOAD_REGISTER_MEM_GEN8 | MI_USE_GGTT;
+	*cs++ = i915_mmio_reg_offset(RING_TAIL(request->engine->mmio_base));
+	*cs++ = i915_ggtt_offset(request->context->state) +
+		LRC_STATE_PN * PAGE_SIZE +
+		CTX_RING_TAIL * sizeof(u32);
+	*cs++ = 0;
+
+	return cs;
+}
+
 static __always_inline u32*
-gen8_emit_fini_breadcrumb_footer(struct i915_request *request,
-				 u32 *cs)
+gen8_emit_fini_breadcrumb_footer(struct i915_request *request, u32 *cs)
 {
 	*cs++ = MI_USER_INTERRUPT;
 
 	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
 	if (intel_engine_has_semaphores(request->engine))
 		cs = emit_preempt_busywait(request, cs);
+	if (intel_engine_has_tail_lrm(request->engine))
+		cs = emit_lrm_tail(request, cs);
 
 	request->tail = intel_ring_offset(request, cs);
 	assert_ring_tail_valid(request->ring, request->tail);
@@ -4318,6 +4403,8 @@ static u32 *gen12_emit_preempt_busywait(struct i915_request *request, u32 *cs)
 static __always_inline u32*
 gen12_emit_fini_breadcrumb_footer(struct i915_request *request, u32 *cs)
 {
+	GEM_BUG_ON(intel_engine_has_tail_lrm(request->engine));
+
 	*cs++ = MI_USER_INTERRUPT;
 
 	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
@@ -4384,6 +4471,8 @@ void intel_execlists_set_default_submission(struct intel_engine_cs *engine)
 		engine->flags |= I915_ENGINE_HAS_SEMAPHORES;
 		if (HAS_LOGICAL_RING_PREEMPTION(engine->i915))
 			engine->flags |= I915_ENGINE_HAS_PREEMPTION;
+		if (INTEL_GEN(engine->i915) < 11)
+			engine->flags |= I915_ENGINE_HAS_TAIL_LRM;
 	}
 
 	if (INTEL_GEN(engine->i915) >= 12)
-- 
2.25.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 18+ messages in thread

* [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for series starting with [01/14] drm/i915/selftests: Verify LRC isolation
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (12 preceding siblings ...)
  2020-02-24 10:00 ` [Intel-gfx] [PATCH 14/14] drm/i915/execlists: Reduce preempt-to-busy roundtrip delay Chris Wilson
@ 2020-02-24 10:59 ` Patchwork
  2020-02-24 13:17 ` [Intel-gfx] ✗ Fi.CI.BAT: failure " Patchwork
  14 siblings, 0 replies; 18+ messages in thread
From: Patchwork @ 2020-02-24 10:59 UTC (permalink / raw)
  To: Chris Wilson; +Cc: intel-gfx

== Series Details ==

Series: series starting with [01/14] drm/i915/selftests: Verify LRC isolation
URL   : https://patchwork.freedesktop.org/series/73840/
State : warning

== Summary ==

$ dim checkpatch origin/drm-tip
748167061786 drm/i915/selftests: Verify LRC isolation
-:451: WARNING:MEMORY_BARRIER: memory barrier without comment
#451: FILE: drivers/gpu/drm/i915/gt/selftest_lrc.c:5181:
+	wmb();

total: 0 errors, 1 warnings, 0 checks, 559 lines checked
43180ee37d91 drm/i915/selftests: Check recovery from corrupted LRC
91df47ab4b46 drm/i915: Flush idle barriers when waiting
9b9b9e729e66 drm/i915: Allow userspace to specify ringsize on construction
-:228: WARNING:FILE_PATH_CHANGES: added, moved or deleted file(s), does MAINTAINERS need updating?
#228: 
new file mode 100644

total: 0 errors, 1 warnings, 0 checks, 305 lines checked
78811038e2dc drm/i915/gem: Honour O_NONBLOCK before throttling execbuf submissions
f8a4a1a69d1e drm/i915/selftests: Be a little more lenient for reset workers
78e115ce3f07 drm/i915: Protect i915_request_await_start from early waits
0a2f475520dc drm/i915/gem: Consolidate ctx->engines[] release
7cb395eb4a69 drm/i915/gt: Prevent allocation on a banned context
cc42d7921f1b drm/i915/gem: Check that the context wasn't closed during setup
69ce6bbda208 drm/i915/gt: Declare when we enabled timeslicing
01288567a278 drm/i915/gt: Yield the timeslice if caught waiting on a user semaphore
b77c79afbfe7 drm/i915/execlists: Check the sentinel is alone in the ELSP
d3bd4cdb8f90 drm/i915/execlists: Reduce preempt-to-busy roundtrip delay

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply	[flat|nested] 18+ messages in thread

* [Intel-gfx] ✗ Fi.CI.BAT: failure for series starting with [01/14] drm/i915/selftests: Verify LRC isolation
  2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
                   ` (13 preceding siblings ...)
  2020-02-24 10:59 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for series starting with [01/14] drm/i915/selftests: Verify LRC isolation Patchwork
@ 2020-02-24 13:17 ` Patchwork
  14 siblings, 0 replies; 18+ messages in thread
From: Patchwork @ 2020-02-24 13:17 UTC (permalink / raw)
  To: Chris Wilson; +Cc: intel-gfx

== Series Details ==

Series: series starting with [01/14] drm/i915/selftests: Verify LRC isolation
URL   : https://patchwork.freedesktop.org/series/73840/
State : failure

== Summary ==

CI Bug Log - changes from CI_DRM_7993 -> Patchwork_16682
====================================================

Summary
-------

  **FAILURE**

  Serious unknown changes coming with Patchwork_16682 absolutely need to be
  verified manually.
  
  If you think the reported changes have nothing to do with the changes
  introduced in Patchwork_16682, please notify your bug team to allow them
  to document this new failure mode, which will reduce false positives in CI.

  External URL: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/index.html

Possible new issues
-------------------

  Here are the unknown changes that may have been introduced in Patchwork_16682:

### IGT changes ###

#### Possible regressions ####

  * igt@gem_exec_parallel@fds:
    - fi-cfl-8109u:       [PASS][1] -> [INCOMPLETE][2]
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-cfl-8109u/igt@gem_exec_parallel@fds.html
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-cfl-8109u/igt@gem_exec_parallel@fds.html

  * igt@i915_selftest@live_execlists:
    - fi-glk-dsi:         NOTRUN -> [DMESG-FAIL][3]
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-glk-dsi/igt@i915_selftest@live_execlists.html

  
#### Warnings ####

  * igt@runner@aborted:
    - fi-byt-j1900:       [FAIL][4] ([i915#816]) -> [FAIL][5]
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-byt-j1900/igt@runner@aborted.html
   [5]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-byt-j1900/igt@runner@aborted.html

  
#### Suppressed ####

  The following results come from untrusted machines, tests, or statuses.
  They do not affect the overall result.

  * igt@i915_selftest@live_gt_lrc:
    - {fi-tgl-u}:         [INCOMPLETE][6] ([i915#1233]) -> [DMESG-FAIL][7]
   [6]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-tgl-u/igt@i915_selftest@live_gt_lrc.html
   [7]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-tgl-u/igt@i915_selftest@live_gt_lrc.html

  
Known issues
------------

  Here are the changes found in Patchwork_16682 that come from known issues:

### IGT changes ###

#### Issues hit ####

  * igt@gem_close_race@basic-threads:
    - fi-hsw-peppy:       [PASS][8] -> [INCOMPLETE][9] ([i915#694] / [i915#816])
   [8]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-hsw-peppy/igt@gem_close_race@basic-threads.html
   [9]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-hsw-peppy/igt@gem_close_race@basic-threads.html

  * igt@gem_render_linear_blits@basic:
    - fi-tgl-y:           [PASS][10] -> [DMESG-WARN][11] ([CI#94] / [i915#402])
   [10]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-tgl-y/igt@gem_render_linear_blits@basic.html
   [11]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-tgl-y/igt@gem_render_linear_blits@basic.html

  * igt@i915_selftest@live_active:
    - fi-tgl-y:           [PASS][12] -> [DMESG-FAIL][13] ([CI#94])
   [12]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-tgl-y/igt@i915_selftest@live_active.html
   [13]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-tgl-y/igt@i915_selftest@live_active.html

  * igt@i915_selftest@live_gem_contexts:
    - fi-byt-n2820:       [PASS][14] -> [DMESG-FAIL][15] ([i915#722])
   [14]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-byt-n2820/igt@i915_selftest@live_gem_contexts.html
   [15]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-byt-n2820/igt@i915_selftest@live_gem_contexts.html

  * igt@kms_chamelium@hdmi-hpd-fast:
    - fi-icl-u2:          [PASS][16] -> [FAIL][17] ([i915#217])
   [16]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-icl-u2/igt@kms_chamelium@hdmi-hpd-fast.html
   [17]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-icl-u2/igt@kms_chamelium@hdmi-hpd-fast.html

  
#### Possible fixes ####

  * igt@gem_close_race@basic-threads:
    - fi-byt-j1900:       [INCOMPLETE][18] ([i915#45]) -> [PASS][19]
   [18]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-byt-j1900/igt@gem_close_race@basic-threads.html
   [19]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-byt-j1900/igt@gem_close_race@basic-threads.html

  * igt@gem_exec_suspend@basic-s4-devices:
    - fi-tgl-y:           [FAIL][20] ([CI#94]) -> [PASS][21]
   [20]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-tgl-y/igt@gem_exec_suspend@basic-s4-devices.html
   [21]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-tgl-y/igt@gem_exec_suspend@basic-s4-devices.html

  * igt@kms_addfb_basic@bad-pitch-999:
    - fi-tgl-y:           [DMESG-WARN][22] ([CI#94] / [i915#402]) -> [PASS][23] +1 similar issue
   [22]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-tgl-y/igt@kms_addfb_basic@bad-pitch-999.html
   [23]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-tgl-y/igt@kms_addfb_basic@bad-pitch-999.html

  * igt@kms_chamelium@hdmi-hpd-fast:
    - fi-kbl-7500u:       [FAIL][24] ([fdo#111407]) -> [PASS][25]
   [24]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-kbl-7500u/igt@kms_chamelium@hdmi-hpd-fast.html
   [25]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-kbl-7500u/igt@kms_chamelium@hdmi-hpd-fast.html

  
#### Warnings ####

  * igt@gem_exec_parallel@contexts:
    - fi-byt-n2820:       [TIMEOUT][26] ([fdo#112271] / [i915#1084]) -> [FAIL][27] ([i915#694])
   [26]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-byt-n2820/igt@gem_exec_parallel@contexts.html
   [27]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-byt-n2820/igt@gem_exec_parallel@contexts.html

  * igt@i915_selftest@live_gt_lrc:
    - fi-tgl-y:           [DMESG-FAIL][28] ([CI#94] / [i915#1233]) -> [DMESG-FAIL][29] ([CI#94])
   [28]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7993/fi-tgl-y/igt@i915_selftest@live_gt_lrc.html
   [29]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/fi-tgl-y/igt@i915_selftest@live_gt_lrc.html

  
  {name}: This element is suppressed. This means it is ignored when computing
          the status of the difference (SUCCESS, WARNING, or FAILURE).

  [CI#94]: https://gitlab.freedesktop.org/gfx-ci/i915-infra/issues/94
  [fdo#111407]: https://bugs.freedesktop.org/show_bug.cgi?id=111407
  [fdo#112271]: https://bugs.freedesktop.org/show_bug.cgi?id=112271
  [i915#1084]: https://gitlab.freedesktop.org/drm/intel/issues/1084
  [i915#1233]: https://gitlab.freedesktop.org/drm/intel/issues/1233
  [i915#217]: https://gitlab.freedesktop.org/drm/intel/issues/217
  [i915#402]: https://gitlab.freedesktop.org/drm/intel/issues/402
  [i915#45]: https://gitlab.freedesktop.org/drm/intel/issues/45
  [i915#694]: https://gitlab.freedesktop.org/drm/intel/issues/694
  [i915#722]: https://gitlab.freedesktop.org/drm/intel/issues/722
  [i915#816]: https://gitlab.freedesktop.org/drm/intel/issues/816


Participating hosts (45 -> 43)
------------------------------

  Additional (7): fi-ehl-1 fi-bdw-5557u fi-glk-dsi fi-ilk-650 fi-ivb-3770 fi-skl-lmem fi-skl-6600u 
  Missing    (9): fi-ilk-m540 fi-byt-squawks fi-bsw-cyan fi-snb-2520m fi-ctg-p8600 fi-icl-u3 fi-kbl-7560u fi-byt-clapper fi-bdw-samus 


Build changes
-------------

  * CI: CI-20190529 -> None
  * Linux: CI_DRM_7993 -> Patchwork_16682

  CI-20190529: 20190529
  CI_DRM_7993: db7cdbfad15a4b58edea31e516886081aeab188b @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_5459: ca5337002b52fe115cb871d5146543616fd1f207 @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
  Patchwork_16682: d3bd4cdb8f900b823a36d2743ac404e166588e09 @ git://anongit.freedesktop.org/gfx-ci/linux


== Linux commits ==

d3bd4cdb8f90 drm/i915/execlists: Reduce preempt-to-busy roundtrip delay
b77c79afbfe7 drm/i915/execlists: Check the sentinel is alone in the ELSP
01288567a278 drm/i915/gt: Yield the timeslice if caught waiting on a user semaphore
69ce6bbda208 drm/i915/gt: Declare when we enabled timeslicing
cc42d7921f1b drm/i915/gem: Check that the context wasn't closed during setup
7cb395eb4a69 drm/i915/gt: Prevent allocation on a banned context
0a2f475520dc drm/i915/gem: Consolidate ctx->engines[] release
78e115ce3f07 drm/i915: Protect i915_request_await_start from early waits
f8a4a1a69d1e drm/i915/selftests: Be a little more lenient for reset workers
78811038e2dc drm/i915/gem: Honour O_NONBLOCK before throttling execbuf submissions
9b9b9e729e66 drm/i915: Allow userspace to specify ringsize on construction
91df47ab4b46 drm/i915: Flush idle barriers when waiting
43180ee37d91 drm/i915/selftests: Check recovery from corrupted LRC
748167061786 drm/i915/selftests: Verify LRC isolation

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_16682/index.html
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^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [Intel-gfx] [PATCH 03/14] drm/i915: Flush idle barriers when waiting
  2020-02-24  9:59 ` [Intel-gfx] [PATCH 03/14] drm/i915: Flush idle barriers when waiting Chris Wilson
@ 2020-02-25 19:07   ` Tvrtko Ursulin
  2020-02-25 19:16     ` Chris Wilson
  0 siblings, 1 reply; 18+ messages in thread
From: Tvrtko Ursulin @ 2020-02-25 19:07 UTC (permalink / raw)
  To: Chris Wilson, intel-gfx


On 24/02/2020 09:59, Chris Wilson wrote:
> If we do find ourselves with an idle barrier inside our active while
> waiting, attempt to flush it by emitting a pulse using the kernel
> context.
> 
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Steve Carbonari <steven.carbonari@intel.com>
> ---
>   drivers/gpu/drm/i915/i915_active.c           | 42 ++++++++++++++----
>   drivers/gpu/drm/i915/selftests/i915_active.c | 46 ++++++++++++++++++++
>   2 files changed, 79 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
> index 9ccb931a733e..fae7e3820592 100644
> --- a/drivers/gpu/drm/i915/i915_active.c
> +++ b/drivers/gpu/drm/i915/i915_active.c
> @@ -7,6 +7,7 @@
>   #include <linux/debugobjects.h>
>   
>   #include "gt/intel_context.h"
> +#include "gt/intel_engine_heartbeat.h"
>   #include "gt/intel_engine_pm.h"
>   #include "gt/intel_ring.h"
>   
> @@ -460,26 +461,49 @@ static void enable_signaling(struct i915_active_fence *active)
>   	dma_fence_put(fence);
>   }
>   
> -int i915_active_wait(struct i915_active *ref)
> +static int flush_barrier(struct active_node *it)
>   {
> -	struct active_node *it, *n;
> -	int err = 0;
> +	struct intel_engine_cs *engine;
>   
> -	might_sleep();
> +	if (!is_barrier(&it->base))
> +		return 0;
>   
> -	if (!i915_active_acquire_if_busy(ref))
> +	engine = __barrier_to_engine(it);
> +	smp_rmb(); /* serialise with add_active_barriers */
> +	if (!is_barrier(&it->base))
>   		return 0;

What is the purpose of the first !is_barrier check? Just to kind of look 
better by not calling __bariier_to_engine on the wrong thing?

>   
> -	/* Flush lazy signals */
> +	return intel_engine_flush_barriers(engine);
> +}
> +
> +static int flush_lazy_signals(struct i915_active *ref)
> +{
> +	struct active_node *it, *n;
> +	int err = 0;
> +
>   	enable_signaling(&ref->excl);
>   	rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
> -		if (is_barrier(&it->base)) /* unconnected idle barrier */
> -			continue;
> +		err = flush_barrier(it); /* unconnected idle barrier? */
> +		if (err)
> +			break;
>   
>   		enable_signaling(&it->base);
>   	}
> -	/* Any fence added after the wait begins will not be auto-signaled */
>   
> +	return err;
> +}
> +
> +int i915_active_wait(struct i915_active *ref)
> +{
> +	int err;
> +
> +	might_sleep();
> +
> +	if (!i915_active_acquire_if_busy(ref))
> +		return 0;
> +
> +	/* Any fence added after the wait begins will not be auto-signaled */
> +	err = flush_lazy_signals(ref);
>   	i915_active_release(ref);
>   	if (err)
>   		return err;
> diff --git a/drivers/gpu/drm/i915/selftests/i915_active.c b/drivers/gpu/drm/i915/selftests/i915_active.c
> index ef572a0c2566..067e30b8927f 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_active.c
> +++ b/drivers/gpu/drm/i915/selftests/i915_active.c
> @@ -201,11 +201,57 @@ static int live_active_retire(void *arg)
>   	return err;
>   }
>   
> +static int live_active_barrier(void *arg)
> +{
> +	struct drm_i915_private *i915 = arg;
> +	struct intel_engine_cs *engine;
> +	struct live_active *active;
> +	int err = 0;
> +
> +	/* Check that we get a callback when requests retire upon waiting */
> +
> +	active = __live_alloc(i915);
> +	if (!active)
> +		return -ENOMEM;
> +
> +	err = i915_active_acquire(&active->base);
> +	if (err)
> +		goto out;
> +
> +	for_each_uabi_engine(engine, i915) {
> +		err = i915_active_acquire_preallocate_barrier(&active->base,
> +							      engine);
> +		if (err)
> +			break;
> +
> +		i915_active_acquire_barrier(&active->base);
> +	}
> +
> +	i915_active_release(&active->base);
> +
> +	if (err == 0)
> +		err = i915_active_wait(&active->base);
> +
> +	if (err == 0 && !READ_ONCE(active->retired)) {
> +		pr_err("i915_active not retired after flushing barriers!\n");
> +		err = -EINVAL;
> +	}
> +
> +out:
> +	__live_put(active);
> +
> +	if (igt_flush_test(i915))
> +		err = -EIO;
> +
> +	return err;
> +}
> +
>   int i915_active_live_selftests(struct drm_i915_private *i915)
>   {
>   	static const struct i915_subtest tests[] = {
>   		SUBTEST(live_active_wait),
>   		SUBTEST(live_active_retire),
> +		SUBTEST(live_active_barrier),
>   	};
>   
>   	if (intel_gt_is_wedged(&i915->gt))
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Regards,

Tvrtko
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^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [Intel-gfx] [PATCH 03/14] drm/i915: Flush idle barriers when waiting
  2020-02-25 19:07   ` Tvrtko Ursulin
@ 2020-02-25 19:16     ` Chris Wilson
  0 siblings, 0 replies; 18+ messages in thread
From: Chris Wilson @ 2020-02-25 19:16 UTC (permalink / raw)
  To: Tvrtko Ursulin, intel-gfx

Quoting Tvrtko Ursulin (2020-02-25 19:07:43)
> 
> On 24/02/2020 09:59, Chris Wilson wrote:
> > -int i915_active_wait(struct i915_active *ref)
> > +static int flush_barrier(struct active_node *it)
> >   {
> > -     struct active_node *it, *n;
> > -     int err = 0;
> > +     struct intel_engine_cs *engine;
> >   
> > -     might_sleep();
> > +     if (!is_barrier(&it->base))
> > +             return 0;
> >   
> > -     if (!i915_active_acquire_if_busy(ref))
> > +     engine = __barrier_to_engine(it);
> > +     smp_rmb(); /* serialise with add_active_barriers */
> > +     if (!is_barrier(&it->base))
> >               return 0;
> 
> What is the purpose of the first !is_barrier check? Just to kind of look 
> better by not calling __bariier_to_engine on the wrong thing?

Yeah, and that smp_rmb() is on the expensive side (enough to justify a
branch). If I was confident I would mark up that first !is_barrier() with
likely(). Hmm, does the kernel still have the infrastructure to warn
those annotations are wrong?
-Chris
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^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2020-02-25 19:16 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-24  9:59 [Intel-gfx] [PATCH 01/14] drm/i915/selftests: Verify LRC isolation Chris Wilson
2020-02-24  9:59 ` [Intel-gfx] [PATCH 02/14] drm/i915/selftests: Check recovery from corrupted LRC Chris Wilson
2020-02-24  9:59 ` [Intel-gfx] [PATCH 03/14] drm/i915: Flush idle barriers when waiting Chris Wilson
2020-02-25 19:07   ` Tvrtko Ursulin
2020-02-25 19:16     ` Chris Wilson
2020-02-24  9:59 ` [Intel-gfx] [PATCH 04/14] drm/i915: Allow userspace to specify ringsize on construction Chris Wilson
2020-02-24  9:59 ` [Intel-gfx] [PATCH 05/14] drm/i915/gem: Honour O_NONBLOCK before throttling execbuf submissions Chris Wilson
2020-02-24  9:59 ` [Intel-gfx] [PATCH 06/14] drm/i915/selftests: Be a little more lenient for reset workers Chris Wilson
2020-02-24 10:00 ` [Intel-gfx] [PATCH 07/14] drm/i915: Protect i915_request_await_start from early waits Chris Wilson
2020-02-24 10:00 ` [Intel-gfx] [PATCH 08/14] drm/i915/gem: Consolidate ctx->engines[] release Chris Wilson
2020-02-24 10:00 ` [Intel-gfx] [PATCH 09/14] drm/i915/gt: Prevent allocation on a banned context Chris Wilson
2020-02-24 10:00 ` [Intel-gfx] [PATCH 10/14] drm/i915/gem: Check that the context wasn't closed during setup Chris Wilson
2020-02-24 10:00 ` [Intel-gfx] [PATCH 11/14] drm/i915/gt: Declare when we enabled timeslicing Chris Wilson
2020-02-24 10:00 ` [Intel-gfx] [PATCH 12/14] drm/i915/gt: Yield the timeslice if caught waiting on a user semaphore Chris Wilson
2020-02-24 10:00 ` [Intel-gfx] [PATCH 13/14] drm/i915/execlists: Check the sentinel is alone in the ELSP Chris Wilson
2020-02-24 10:00 ` [Intel-gfx] [PATCH 14/14] drm/i915/execlists: Reduce preempt-to-busy roundtrip delay Chris Wilson
2020-02-24 10:59 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for series starting with [01/14] drm/i915/selftests: Verify LRC isolation Patchwork
2020-02-24 13:17 ` [Intel-gfx] ✗ Fi.CI.BAT: failure " Patchwork

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