drm/i915: Stop mapping the scratch page into CPU space

After the elimination of using the scratch page for Ironlake's
breadcrumb, we no longer need to kmap the object. We therefore can move
it into the high unmappable space and do not need to force the object to
be coherent (i.e. snooped on !llc platforms).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467390209-3576-9-git-send-email-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 02104fbf9045e402a9a8c6401a60e6d833428e7a..7ccfb1e57d121fa3af45606290f33e916e1b8730 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -648,58 +648,40 @@ out:
        return ret;
 }
 
-void
-intel_fini_pipe_control(struct intel_engine_cs *engine)
+void intel_fini_pipe_control(struct intel_engine_cs *engine)
 {
        if (engine->scratch.obj == NULL)
                return;
 
-       if (INTEL_GEN(engine->i915) >= 5) {
-               kunmap(sg_page(engine->scratch.obj->pages->sgl));
-               i915_gem_object_ggtt_unpin(engine->scratch.obj);
-       }
-
+       i915_gem_object_ggtt_unpin(engine->scratch.obj);
        drm_gem_object_unreference(&engine->scratch.obj->base);
        engine->scratch.obj = NULL;
 }
 
-int
-intel_init_pipe_control(struct intel_engine_cs *engine)
+int intel_init_pipe_control(struct intel_engine_cs *engine)
 {
+       struct drm_i915_gem_object *obj;
        int ret;
 
        WARN_ON(engine->scratch.obj);
 
-       engine->scratch.obj = i915_gem_object_create(engine->i915->dev, 4096);
-       if (IS_ERR(engine->scratch.obj)) {
-               DRM_ERROR("Failed to allocate seqno page\n");
-               ret = PTR_ERR(engine->scratch.obj);
-               engine->scratch.obj = NULL;
+       obj = i915_gem_object_create(engine->i915->dev, 4096);
+       if (IS_ERR(obj)) {
+               DRM_ERROR("Failed to allocate scratch page\n");
+               ret = PTR_ERR(obj);
                goto err;
        }
 
-       ret = i915_gem_object_set_cache_level(engine->scratch.obj,
-                                             I915_CACHE_LLC);
+       ret = i915_gem_obj_ggtt_pin(obj, 4096, PIN_HIGH);
        if (ret)
                goto err_unref;
 
-       ret = i915_gem_obj_ggtt_pin(engine->scratch.obj, 4096, 0);
-       if (ret)
-               goto err_unref;
-
-       engine->scratch.gtt_offset = i915_gem_obj_ggtt_offset(engine->scratch.obj);
-       engine->scratch.cpu_page = kmap(sg_page(engine->scratch.obj->pages->sgl));
-       if (engine->scratch.cpu_page == NULL) {
-               ret = -ENOMEM;
-               goto err_unpin;
-       }
-
+       engine->scratch.obj = obj;
+       engine->scratch.gtt_offset = i915_gem_obj_ggtt_offset(obj);
        DRM_DEBUG_DRIVER("%s pipe control offset: 0x%08x\n",
                         engine->name, engine->scratch.gtt_offset);
        return 0;
 
-err_unpin:
-       i915_gem_object_ggtt_unpin(engine->scratch.obj);
 err_unref:
        drm_gem_object_unreference(&engine->scratch.obj->base);
 err:

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index b03931f6dde530dd3867277229d6f4d02ce787c5..2ae6e3c8eb0f3521b1b0863823b4410bff6fd812 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -326,7 +326,6 @@ struct intel_engine_cs {
        struct {
                struct drm_i915_gem_object *obj;
                u32 gtt_offset;
-               volatile u32 *cpu_page;
        } scratch;
 
        bool needs_cmd_parser;