.emit = upload_sol_state,
};
+/**
+ * Tally the number of primitives generated so far.
+ *
+ * The buffer contains a series of pairs:
+ * (<start0, start1, start2, start3>, <end0, end1, end2, end3>) ;
+ * (<start0, start1, start2, start3>, <end0, end1, end2, end3>) ;
+ *
+ * For each stream, we subtract the pair of values (end - start) to get the
+ * number of primitives generated during one section. We accumulate these
+ * values, adding them up to get the total number of primitives generated.
+ */
+static void
+gen7_tally_prims_generated(struct brw_context *brw,
+ struct brw_transform_feedback_object *obj)
+{
+ /* If the current batch is still contributing to the number of primitives
+ * generated, flush it now so the results will be present when mapped.
+ */
+ if (drm_intel_bo_references(brw->batch.bo, obj->prim_count_bo))
+ intel_batchbuffer_flush(brw);
+
+ if (unlikely(brw->perf_debug && drm_intel_bo_busy(obj->prim_count_bo)))
+ perf_debug("Stalling for # of transform feedback primitives written.\n");
+
+ drm_intel_bo_map(obj->prim_count_bo, false);
+ uint64_t *prim_counts = obj->prim_count_bo->virtual;
+
+ assert(obj->prim_count_buffer_index % (2 * BRW_MAX_XFB_STREAMS) == 0);
+ int pairs = obj->prim_count_buffer_index / (2 * BRW_MAX_XFB_STREAMS);
+
+ for (int i = 0; i < pairs; i++) {
+ for (int s = 0; s < BRW_MAX_XFB_STREAMS; s++) {
+ obj->prims_generated[s] +=
+ prim_counts[BRW_MAX_XFB_STREAMS + s] - prim_counts[s];
+ }
+ prim_counts += 2 * BRW_MAX_XFB_STREAMS; /* move to the next pair */
+ }
+
+ drm_intel_bo_unmap(obj->prim_count_bo);
+
+ /* We've already gathered up the old data; we can safely overwrite it now. */
+ obj->prim_count_buffer_index = 0;
+}
+
+/**
+ * Store the SO_NUM_PRIMS_WRITTEN counters for each stream (4 uint64_t values)
+ * to prim_count_bo.
+ *
+ * If prim_count_bo is out of space, gather up the results so far into
+ * prims_generated[] and allocate a new buffer with enough space.
+ *
+ * The number of primitives written is used to compute the number of vertices
+ * written to a transform feedback stream, which is required to implement
+ * DrawTransformFeedback().
+ */
+static void
+gen7_save_primitives_written_counters(struct brw_context *brw,
+ struct brw_transform_feedback_object *obj)
+{
+ const int streams = BRW_MAX_XFB_STREAMS;
+
+ /* Check if there's enough space for a new pair of four values. */
+ if (obj->prim_count_bo != NULL &&
+ obj->prim_count_buffer_index + 2 * streams >= 4096 / sizeof(uint64_t)) {
+ /* Gather up the results so far and release the BO. */
+ gen7_tally_prims_generated(brw, obj);
+ }
+
+ /* Flush any drawing so that the counters have the right values. */
+ intel_batchbuffer_emit_mi_flush(brw);
+
+ /* Emit MI_STORE_REGISTER_MEM commands to write the values. */
+ for (int i = 0; i < streams; i++) {
+ brw_store_register_mem64(brw, obj->prim_count_bo,
+ GEN7_SO_NUM_PRIMS_WRITTEN(i),
+ obj->prim_count_buffer_index + i);
+ }
+
+ /* Update where to write data to. */
+ obj->prim_count_buffer_index += streams;
+}
+
+/**
+ * Compute the number of vertices written by this transform feedback operation.
+ */
+static void
+brw_compute_xfb_vertices_written(struct brw_context *brw,
+ struct brw_transform_feedback_object *obj)
+{
+ if (obj->vertices_written_valid || !obj->base.EndedAnytime)
+ return;
+
+ unsigned vertices_per_prim = 0;
+
+ switch (obj->primitive_mode) {
+ case GL_POINTS:
+ vertices_per_prim = 1;
+ break;
+ case GL_LINES:
+ vertices_per_prim = 2;
+ break;
+ case GL_TRIANGLES:
+ vertices_per_prim = 3;
+ break;
+ default:
+ assert(!"Invalid transform feedback primitive mode.");
+ }
+
+ /* Get the number of primitives generated. */
+ gen7_tally_prims_generated(brw, obj);
+
+ for (int i = 0; i < BRW_MAX_XFB_STREAMS; i++) {
+ obj->vertices_written[i] = vertices_per_prim * obj->prims_generated[i];
+ }
+ obj->vertices_written_valid = true;
+}
+
+/**
+ * GetTransformFeedbackVertexCount() driver hook.
+ *
+ * Returns the number of vertices written to a particular stream by the last
+ * Begin/EndTransformFeedback block. Used to implement DrawTransformFeedback().
+ */
+GLsizei
+brw_get_transform_feedback_vertex_count(struct gl_context *ctx,
+ struct gl_transform_feedback_object *obj,
+ GLuint stream)
+{
+ struct brw_context *brw = brw_context(ctx);
+ struct brw_transform_feedback_object *brw_obj =
+ (struct brw_transform_feedback_object *) obj;
+
+ assert(obj->EndedAnytime);
+ assert(stream < BRW_MAX_XFB_STREAMS);
+
+ brw_compute_xfb_vertices_written(brw, brw_obj);
+ return brw_obj->vertices_written[stream];
+}
+
void
gen7_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
struct gl_transform_feedback_object *obj)
{
struct brw_context *brw = brw_context(ctx);
+ struct brw_transform_feedback_object *brw_obj =
+ (struct brw_transform_feedback_object *) obj;
intel_batchbuffer_flush(brw);
brw->batch.needs_sol_reset = true;
+
+ /* We're about to lose the information needed to compute the number of
+ * vertices written during the last Begin/EndTransformFeedback section,
+ * so we can't delay it any further.
+ */
+ brw_compute_xfb_vertices_written(brw, brw_obj);
+
+ /* No primitives have been generated yet. */
+ for (int i = 0; i < BRW_MAX_XFB_STREAMS; i++) {
+ brw_obj->prims_generated[i] = 0;
+ }
+
+ /* Store the starting value of the SO_NUM_PRIMS_WRITTEN counters. */
+ gen7_save_primitives_written_counters(brw, brw_obj);
+
+ brw_obj->primitive_mode = mode;
}
void
* simplicity, just do a full flush.
*/
struct brw_context *brw = brw_context(ctx);
+ struct brw_transform_feedback_object *brw_obj =
+ (struct brw_transform_feedback_object *) obj;
- intel_batchbuffer_emit_mi_flush(brw);
+ /* Store the ending value of the SO_NUM_PRIMS_WRITTEN counters. */
+ gen7_save_primitives_written_counters(brw, brw_obj);
+
+ /* EndTransformFeedback() means that we need to update the number of
+ * vertices written. Since it's only necessary if DrawTransformFeedback()
+ * is called and it means mapping a buffer object, we delay computing it
+ * until it's absolutely necessary to try and avoid stalls.
+ */
+ brw_obj->vertices_written_valid = false;
}
void
struct brw_transform_feedback_object *brw_obj =
(struct brw_transform_feedback_object *) obj;
+ /* Flush any drawing so that the counters have the right values. */
+ intel_batchbuffer_emit_mi_flush(brw);
+
/* Save the SOL buffer offset register values. */
for (int i = 0; i < 4; i++) {
BEGIN_BATCH(3);
i * sizeof(uint32_t));
ADVANCE_BATCH();
}
+
+ /* Store the temporary ending value of the SO_NUM_PRIMS_WRITTEN counters.
+ * While this operation is paused, other transform feedback actions may
+ * occur, which will contribute to the counters. We need to exclude that
+ * from our counts.
+ */
+ gen7_save_primitives_written_counters(brw, brw_obj);
}
void
i * sizeof(uint32_t));
ADVANCE_BATCH();
}
+
+ /* Store the new starting value of the SO_NUM_PRIMS_WRITTEN counters. */
+ gen7_save_primitives_written_counters(brw, brw_obj);
}
projects / mesa.git / commitdiff