diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-01-25 10:05:20 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-01-25 11:19:39 +0000 |
| commit | e1a73a54a96e80dc6009e73c9209e4f81ae22285 (patch) | |
| tree | cadd51eb146190119e6fcd60916b77a2accc96a3 /drivers/gpu/drm/i915/intel_engine_cs.c | |
| parent | 8e525cb4a622148fbe30134ee3a1a34ad839a43a (diff) | |
drm/i915: Measure the required reserved size for request emission
Instead of tediously and fragilely counting up the number of dwords
required to emit the breadcrumb to seal a request, fake a request and
measure it automatically once during engine setup.
The downside is that this requires a fair amount of mocking to create a
proper breadcrumb. Still, should be less error prone in future as the
breadcrumb size fluctuates!
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125100520.20163-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/intel_engine_cs.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_engine_cs.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 2f3c71f6d313..8f738a7cd117 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -604,6 +604,47 @@ static void __intel_context_unpin(struct i915_gem_context *ctx, intel_context_unpin(to_intel_context(ctx, engine)); } +struct measure_breadcrumb { + struct i915_request rq; + struct i915_timeline timeline; + struct intel_ring ring; + u32 cs[1024]; +}; + +static int measure_breadcrumb_sz(struct intel_engine_cs *engine) +{ + struct measure_breadcrumb *frame; + unsigned int dw; + + GEM_BUG_ON(!engine->i915->gt.scratch); + + frame = kzalloc(sizeof(*frame), GFP_KERNEL); + if (!frame) + return -ENOMEM; + + i915_timeline_init(engine->i915, &frame->timeline, "measure"); + + INIT_LIST_HEAD(&frame->ring.request_list); + frame->ring.timeline = &frame->timeline; + frame->ring.vaddr = frame->cs; + frame->ring.size = sizeof(frame->cs); + frame->ring.effective_size = frame->ring.size; + intel_ring_update_space(&frame->ring); + + frame->rq.i915 = engine->i915; + frame->rq.engine = engine; + frame->rq.ring = &frame->ring; + frame->rq.timeline = &frame->timeline; + + dw = engine->emit_breadcrumb(&frame->rq, frame->cs) - frame->cs; + GEM_BUG_ON(dw != engine->emit_breadcrumb_sz); + + i915_timeline_fini(&frame->timeline); + kfree(frame); + + return dw; +} + /** * intel_engines_init_common - initialize cengine state which might require hw access * @engine: Engine to initialize. @@ -657,8 +698,16 @@ int intel_engine_init_common(struct intel_engine_cs *engine) if (ret) goto err_breadcrumbs; + ret = measure_breadcrumb_sz(engine); + if (ret < 0) + goto err_status_page; + + engine->emit_breadcrumb_sz = ret; + return 0; +err_status_page: + cleanup_status_page(engine); err_breadcrumbs: intel_engine_fini_breadcrumbs(engine); err_unpin_preempt: |