[Intel-gfx] [PATCH v2 06/15] drm/i915: Populate ctx ID for periodic OA reports

[sourab.gupta at intel.com]

From: Sourab Gupta <sourab.gupta at intel.com>

This adds support for populating the ctx id for the periodic OA reports
when requested through the corresponding property.

For Gen8, the OA reports itself have the ctx ID and it is the one programmed
into HW while submitting workloads. Thus it's retrieved from reports itself.
For Gen7, the OA reports don't have any such field, and we can populate this
field with the last seen ctx ID while sending CS reports.

v2:
    - Corrected the ctx id mask bits (21 bits instead of 20) (Chris)
    - removed user-triggerable WARN_ONCE's. (Chris)

Signed-off-by: Sourab Gupta <sourab.gupta at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h  |  3 +++
 drivers/gpu/drm/i915/i915_perf.c | 52 +++++++++++++++++++++++++++++++++++++---
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e9cf939..853cc7db 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1859,6 +1859,8 @@ struct i915_oa_ops {
 		    u32 ts, u32 max_records);
 	int (*oa_buffer_num_samples)(struct drm_i915_private *dev_priv,
 					u32 *last_ts);
+	u32 (*oa_buffer_get_ctx_id)(struct i915_perf_stream *stream,
+					const u8 *report);
 };
 
 /*
@@ -2239,6 +2241,7 @@ struct drm_i915_private {
 			u32 status;
 		} command_stream_buf;
 
+		u32 last_ctx_id;
 		struct list_head node_list;
 		spinlock_t node_list_lock;
 	} perf;
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index e10e78f..7abbf30 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -637,6 +637,46 @@ gen7_oa_buffer_num_samples_fop_unlocked(struct drm_i915_private *dev_priv,
 	return num_samples;
 }
 
+static u32 gen7_oa_buffer_get_ctx_id(struct i915_perf_stream *stream,
+				    const u8 *report)
+{
+	struct drm_i915_private *dev_priv = stream->dev_priv;
+
+	if (!stream->cs_mode)
+		DRM_ERROR(
+			"CTX ID can't be retrieved if command stream mode not enabled");
+
+	/*
+	 * OA reports generated in Gen7 don't have the ctx ID information.
+	 * Therefore, just rely on the ctx ID information from the last CS
+	 * sample forwarded
+	 */
+	return dev_priv->perf.last_ctx_id;
+}
+
+static u32 gen8_oa_buffer_get_ctx_id(struct i915_perf_stream *stream,
+				    const u8 *report)
+{
+	struct drm_i915_private *dev_priv = stream->dev_priv;
+
+	/* The ctx ID present in the OA reports have intel_context::global_id
+	 * present, since this is programmed into the ELSP in execlist mode.
+	 * In non-execlist mode, fall back to retrieving the ctx ID from the
+	 * last saved ctx ID from command stream mode.
+	 */
+	if (i915.enable_execlists) {
+		u32 ctx_id = *(u32 *)(report + 12);
+		ctx_id &= 0x1fffff;
+		return ctx_id;
+	} else {
+		if (!stream->cs_mode)
+		DRM_ERROR(
+			"CTX ID can't be retrieved if command stream mode not enabled");
+
+		return dev_priv->perf.last_ctx_id;
+	}
+}
+
 /**
  * Appends a status record to a userspace read() buffer.
  */
@@ -733,9 +773,9 @@ static int append_oa_buffer_sample(struct i915_perf_stream *stream,
 		data.source = source;
 	}
 
-#warning "FIXME: append_oa_buffer_sample: read ctx ID from report and map that to an intel_context::global_id"
 	if (sample_flags & SAMPLE_CTX_ID)
-		data.ctx_id = 0;
+		data.ctx_id = dev_priv->perf.oa.ops.oa_buffer_get_ctx_id(
+						stream, report);
 
 	if (sample_flags & SAMPLE_OA_REPORT)
 		data.report = report;
@@ -1248,8 +1288,10 @@ static int append_oa_rcs_sample(struct i915_perf_stream *stream,
 	if (sample_flags & SAMPLE_OA_SOURCE_INFO)
 		data.source = I915_PERF_OA_EVENT_SOURCE_RCS;
 
-	if (sample_flags & SAMPLE_CTX_ID)
+	if (sample_flags & SAMPLE_CTX_ID) {
 		data.ctx_id = node->ctx_id;
+		dev_priv->perf.last_ctx_id = node->ctx_id;
+	}
 
 	if (sample_flags & SAMPLE_OA_REPORT)
 		data.report = report;
@@ -3092,6 +3134,8 @@ void i915_perf_init(struct drm_i915_private *dev_priv)
 		dev_priv->perf.oa.ops.read = gen7_oa_read;
 		dev_priv->perf.oa.ops.oa_buffer_num_samples =
 			gen7_oa_buffer_num_samples_fop_unlocked;
+		dev_priv->perf.oa.ops.oa_buffer_get_ctx_id =
+					gen7_oa_buffer_get_ctx_id;
 
 		dev_priv->perf.oa.timestamp_frequency = 12500000;
 
@@ -3106,6 +3150,8 @@ void i915_perf_init(struct drm_i915_private *dev_priv)
 		dev_priv->perf.oa.ops.read = gen8_oa_read;
 		dev_priv->perf.oa.ops.oa_buffer_num_samples =
 				gen8_oa_buffer_num_samples_fop_unlocked;
+		dev_priv->perf.oa.ops.oa_buffer_get_ctx_id =
+					gen8_oa_buffer_get_ctx_id;
 
 		dev_priv->perf.oa.oa_formats = gen8_plus_oa_formats;
 
-- 
1.9.1