[Intel-gfx] [PATCH v5 09/10] drm/i915/perf: execute OA configuration from command stream

Lionel Landwerlin lionel.g.landwerlin at intel.com
Thu Jun 27 08:00:44 UTC 2019


We can't run into issues with doing writing the global OA/NOA
registers configuration from CPU so far, but HW engineers actually
recommend doing this from the command streamer.

Since we have a command buffer prepared for the execbuffer side of
things, we can reuse that approach here too.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
---
 drivers/gpu/drm/i915/i915_perf.c | 203 +++++++++++++++----------------
 1 file changed, 100 insertions(+), 103 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index bf4f5fee6764..7e636463e1f5 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -389,6 +389,19 @@ void i915_oa_config_release(struct kref *ref)
 	kfree(oa_config);
 }
 
+static void i915_oa_config_dispose_buffers(struct drm_i915_private *i915)
+{
+	struct i915_oa_config *oa_config, *next;
+
+	mutex_lock(&i915->perf.metrics_lock);
+	list_for_each_entry_safe(oa_config, next, &i915->perf.metrics_buffers, vma_link) {
+		list_del(&oa_config->vma_link);
+		i915_gem_object_put(oa_config->obj);
+		oa_config->obj = NULL;
+	}
+	mutex_unlock(&i915->perf.metrics_lock);
+}
+
 static u32 *write_cs_mi_lri(u32 *cs, const struct i915_oa_reg *reg_data, u32 n_regs)
 {
 	u32 i;
@@ -1813,67 +1826,86 @@ static int alloc_noa_wait(struct drm_i915_private *i915)
 	return ret;
 }
 
-static void config_oa_regs(struct drm_i915_private *dev_priv,
-			   const struct i915_oa_reg *regs,
-			   u32 n_regs)
+static int config_oa_regs(struct drm_i915_private *i915,
+			  struct i915_oa_config *oa_config)
 {
-	u32 i;
+	struct i915_request *rq;
+	struct i915_vma *vma;
+	long timeout;
+	u32 *cs;
+	int err;
 
-	for (i = 0; i < n_regs; i++) {
-		const struct i915_oa_reg *reg = regs + i;
+	rq = i915_request_create(i915->engine[RCS0]->kernel_context);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
 
-		I915_WRITE(reg->addr, reg->value);
+	err = i915_active_request_set(&i915->engine[RCS0]->last_oa_config,
+				      rq);
+	if (err) {
+		i915_request_add(rq);
+		return err;
+	}
+
+	vma = i915_vma_instance(oa_config->obj, &i915->ggtt.vm, NULL);
+	if (unlikely(IS_ERR(vma))) {
+		i915_request_add(rq);
+		return PTR_ERR(vma);
+	}
+
+	err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL);
+	if (err) {
+		i915_request_add(rq);
+		return err;
 	}
+
+	err = i915_vma_move_to_active(vma, rq, 0);
+	if (err) {
+		i915_vma_unpin(vma);
+		i915_request_add(rq);
+		return err;
+	}
+
+	cs = intel_ring_begin(rq, INTEL_GEN(i915) >= 8 ? 4 : 2);
+	if (IS_ERR(cs)) {
+		i915_vma_unpin(vma);
+		i915_request_add(rq);
+		return PTR_ERR(cs);
+	}
+
+	if (INTEL_GEN(i915) > 8) {
+		*cs++ = MI_BATCH_BUFFER_START_GEN8;
+		*cs++ = lower_32_bits(vma->node.start);
+		*cs++ = upper_32_bits(vma->node.start);
+		*cs++ = MI_NOOP;
+	} else {
+		*cs++ = MI_BATCH_BUFFER_START;
+		*cs++ = vma->node.start;
+	}
+
+	intel_ring_advance(rq, cs);
+
+	i915_vma_unpin(vma);
+
+	i915_request_add(rq);
+
+	i915_request_get(rq);
+	timeout = i915_request_wait(rq, I915_WAIT_INTERRUPTIBLE | I915_WAIT_LOCKED,
+				    MAX_SCHEDULE_TIMEOUT);
+	i915_request_put(rq);
+
+	return timeout < 0 ? err : 0;
 }
 
 static int hsw_enable_metric_set(struct i915_perf_stream *stream)
 {
 	struct drm_i915_private *dev_priv = stream->dev_priv;
-	const struct i915_oa_config *oa_config = stream->oa_config;
 
-	/* PRM:
-	 *
-	 * OA unit is using “crclk” for its functionality. When trunk
-	 * level clock gating takes place, OA clock would be gated,
-	 * unable to count the events from non-render clock domain.
-	 * Render clock gating must be disabled when OA is enabled to
-	 * count the events from non-render domain. Unit level clock
-	 * gating for RCS should also be disabled.
-	 */
 	I915_WRITE(GEN7_MISCCPCTL, (I915_READ(GEN7_MISCCPCTL) &
 				    ~GEN7_DOP_CLOCK_GATE_ENABLE));
 	I915_WRITE(GEN6_UCGCTL1, (I915_READ(GEN6_UCGCTL1) |
 				  GEN6_CSUNIT_CLOCK_GATE_DISABLE));
 
-	config_oa_regs(dev_priv, oa_config->mux_regs, oa_config->mux_regs_len);
-
-	/* It apparently takes a fairly long time for a new MUX
-	 * configuration to be be applied after these register writes.
-	 * This delay duration was derived empirically based on the
-	 * render_basic config but hopefully it covers the maximum
-	 * configuration latency.
-	 *
-	 * As a fallback, the checks in _append_oa_reports() to skip
-	 * invalid OA reports do also seem to work to discard reports
-	 * generated before this config has completed - albeit not
-	 * silently.
-	 *
-	 * Unfortunately this is essentially a magic number, since we
-	 * don't currently know of a reliable mechanism for predicting
-	 * how long the MUX config will take to apply and besides
-	 * seeing invalid reports we don't know of a reliable way to
-	 * explicitly check that the MUX config has landed.
-	 *
-	 * It's even possible we've miss characterized the underlying
-	 * problem - it just seems like the simplest explanation why
-	 * a delay at this location would mitigate any invalid reports.
-	 */
-	usleep_range(15000, 20000);
-
-	config_oa_regs(dev_priv, oa_config->b_counter_regs,
-		       oa_config->b_counter_regs_len);
-
-	return 0;
+	return config_oa_regs(dev_priv, stream->oa_config);
 }
 
 static void hsw_disable_metric_set(struct drm_i915_private *dev_priv)
@@ -1978,7 +2010,6 @@ static int gen8_configure_all_contexts(struct drm_i915_private *dev_priv,
 {
 	unsigned int map_type = i915_coherent_map_type(dev_priv);
 	struct i915_gem_context *ctx;
-	struct i915_request *rq;
 	int ret;
 
 	lockdep_assert_held(&dev_priv->drm.struct_mutex);
@@ -2037,14 +2068,9 @@ static int gen8_configure_all_contexts(struct drm_i915_private *dev_priv,
 	}
 
 	/*
-	 * Apply the configuration by doing one context restore of the edited
-	 * context image.
+	 * The above configuration will be applied when called
+	 * config_oa_regs().
 	 */
-	rq = i915_request_create(dev_priv->engine[RCS0]->kernel_context);
-	if (IS_ERR(rq))
-		return PTR_ERR(rq);
-
-	i915_request_add(rq);
 
 	return 0;
 }
@@ -2093,35 +2119,7 @@ static int gen8_enable_metric_set(struct i915_perf_stream *stream)
 	if (ret)
 		return ret;
 
-	config_oa_regs(dev_priv, oa_config->mux_regs, oa_config->mux_regs_len);
-
-	/* It apparently takes a fairly long time for a new MUX
-	 * configuration to be be applied after these register writes.
-	 * This delay duration was derived empirically based on the
-	 * render_basic config but hopefully it covers the maximum
-	 * configuration latency.
-	 *
-	 * As a fallback, the checks in _append_oa_reports() to skip
-	 * invalid OA reports do also seem to work to discard reports
-	 * generated before this config has completed - albeit not
-	 * silently.
-	 *
-	 * Unfortunately this is essentially a magic number, since we
-	 * don't currently know of a reliable mechanism for predicting
-	 * how long the MUX config will take to apply and besides
-	 * seeing invalid reports we don't know of a reliable way to
-	 * explicitly check that the MUX config has landed.
-	 *
-	 * It's even possible we've miss characterized the underlying
-	 * problem - it just seems like the simplest explanation why
-	 * a delay at this location would mitigate any invalid reports.
-	 */
-	usleep_range(15000, 20000);
-
-	config_oa_regs(dev_priv, oa_config->b_counter_regs,
-		       oa_config->b_counter_regs_len);
-
-	return 0;
+	return config_oa_regs(dev_priv, stream->oa_config);
 }
 
 static void gen8_disable_metric_set(struct drm_i915_private *dev_priv)
@@ -2292,6 +2290,7 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
 			       struct perf_open_properties *props)
 {
 	struct drm_i915_private *dev_priv = stream->dev_priv;
+	struct drm_i915_gem_object *obj;
 	int format_size;
 	int ret;
 
@@ -2376,13 +2375,6 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
 		}
 	}
 
-	ret = i915_perf_get_oa_config(dev_priv, props->metrics_set,
-				      &stream->oa_config, NULL);
-	if (ret) {
-		DRM_DEBUG("Invalid OA config id=%i\n", props->metrics_set);
-		goto err_config;
-	}
-
 	ret = alloc_noa_wait(dev_priv);
 	if (ret) {
 		DRM_DEBUG("Unable to allocate NOA wait batch buffer\n");
@@ -2412,6 +2404,19 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
 	if (ret)
 		goto err_lock;
 
+	ret = i915_perf_get_oa_config(dev_priv, props->metrics_set,
+				      &stream->oa_config, &obj);
+	if (ret) {
+		DRM_DEBUG("Invalid OA config id=%i\n", props->metrics_set);
+		goto err_config;
+	}
+
+	/*
+	 * We just need the buffer to be created, but not our own reference on
+	 * it as the oa_config already has one.
+	 */
+	i915_gem_object_put(obj);
+
 	stream->ops = &i915_oa_stream_ops;
 	dev_priv->perf.oa.exclusive_stream = stream;
 
@@ -2430,14 +2435,16 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
 err_enable:
 	dev_priv->perf.oa.exclusive_stream = NULL;
 	dev_priv->perf.oa.ops.disable_metric_set(dev_priv);
+
+err_config:
+	i915_oa_config_put(stream->oa_config);
+	i915_oa_config_dispose_buffers(dev_priv);
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 
 err_lock:
 	free_oa_buffer(dev_priv);
 
 err_oa_buf_alloc:
-	i915_oa_config_put(stream->oa_config);
-
 	intel_uncore_forcewake_put(&dev_priv->uncore, FORCEWAKE_ALL);
 	intel_runtime_pm_put(&dev_priv->runtime_pm, stream->wakeref);
 
@@ -2446,9 +2453,6 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 
 err_noa_wait_alloc:
-	i915_oa_config_put(stream->oa_config);
-
-err_config:
 	if (stream->ctx)
 		oa_put_render_ctx_id(stream);
 
@@ -2810,20 +2814,13 @@ static int i915_perf_release(struct inode *inode, struct file *file)
 {
 	struct i915_perf_stream *stream = file->private_data;
 	struct drm_i915_private *dev_priv = stream->dev_priv;
-	struct i915_oa_config *oa_config, *next;
 
 	mutex_lock(&dev_priv->perf.lock);
 
 	i915_perf_destroy_locked(stream);
 
 	/* Dispose of all oa config batch buffers. */
-	mutex_lock(&dev_priv->perf.metrics_lock);
-	list_for_each_entry_safe(oa_config, next, &dev_priv->perf.metrics_buffers, vma_link) {
-		list_del(&oa_config->vma_link);
-		i915_gem_object_put(oa_config->obj);
-		oa_config->obj = NULL;
-	}
-	mutex_unlock(&dev_priv->perf.metrics_lock);
+	i915_oa_config_dispose_buffers(dev_priv);
 
 	mutex_unlock(&dev_priv->perf.lock);
 
-- 
2.21.0.392.gf8f6787159e



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