[Intel-gfx] [PATCH 3/8] drm/i915: Framework for capturing command stream based OA reports

[sourab gupta]

On Thu, 2017-03-16 at 01:31 -0700, Chris Wilson wrote:
> On Thu, Mar 16, 2017 at 11:44:10AM +0530, sourab.gupta at intel.com wrote:
> > +static void i915_perf_command_stream_hook_oa(struct i915_perf_stream *stream,
> > +					struct drm_i915_gem_request *request)
> > +{
> > +	struct drm_i915_private *dev_priv = request->i915;
> > +	struct i915_gem_context *ctx = request->ctx;
> > +	struct i915_perf_cs_sample *sample;
> > +	u32 addr = 0;
> > +	u32 cmd, *cs;
> > +
> > +	sample = kzalloc(sizeof(*sample), GFP_KERNEL);
> > +	if (sample == NULL) {
> > +		DRM_ERROR("Perf sample alloc failed\n");
> > +		return;
> > +	}
> > +
> > +	cs = intel_ring_begin(request, 4);
> > +	if (IS_ERR(cs)) {
> > +		kfree(sample);
> > +		return;
> > +	}
> > +
> > +	sample->ctx_id = ctx->hw_id;
> > +	i915_gem_request_assign(&sample->request, request);
> > +
> > +	insert_perf_sample(dev_priv, sample);
> > +
> > +	addr = dev_priv->perf.command_stream_buf.vma->node.start +
> > +		sample->offset;
> > +
> > +	if (WARN_ON(addr & 0x3f)) {
> > +		DRM_ERROR("OA buffer address not aligned to 64 byte");
> > +		return;
> > +	}
> > +
> > +	cmd = MI_REPORT_PERF_COUNT | (1<<0);
> > +	if (INTEL_GEN(dev_priv) >= 8)
> > +		cmd |= (2<<0);
> > +
> > +	*cs++ = cmd;
> > +	*cs++ = addr | MI_REPORT_PERF_COUNT_GGTT;
> > +	*cs++ = request->global_seqno;
> 
> request->global_seqno is always zero at this point, and is subject to
> change after assignment.
> 
> [ctx:engine or request->fence.context]:request->fence.seqno is permanent.
> -Chris
> 
Thanks for pointing out. I'll use request->fence.seqno instead.

Regards,
Sourab