1 files changed, 50 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 6836efb7e3d2..61f612454ce7 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1437,6 +1437,44 @@ static int context_pin(struct i915_gem_context *ctx)
                             PIN_GLOBAL | PIN_HIGH);
 }
 
+static struct i915_vma *
+alloc_context_vma(struct intel_engine_cs *engine)
+{
+        struct drm_i915_private *i915 = engine->i915;
+        struct drm_i915_gem_object *obj;
+        struct i915_vma *vma;
+
+        obj = i915_gem_object_create(i915, i915->hw_context_size);
+        if (IS_ERR(obj))
+                return ERR_CAST(obj);
+
+        /*
+         * Try to make the context utilize L3 as well as LLC.
+         *
+         * On VLV we don't have L3 controls in the PTEs so we
+         * shouldn't touch the cache level, especially as that
+         * would make the object snooped which might have a
+         * negative performance impact.
+         *
+         * Snooping is required on non-llc platforms in execlist
+         * mode, but since all GGTT accesses use PAT entry 0 we
+         * get snooping anyway regardless of cache_level.
+         *
+         * This is only applicable for Ivy Bridge devices since
+         * later platforms don't have L3 control bits in the PTE.
+         */
+        if (IS_IVYBRIDGE(i915)) {
+                /* Ignore any error, regard it as a simple optimisation */
+                i915_gem_object_set_cache_level(obj, I915_CACHE_L3_LLC);
+        }
+
+        vma = i915_vma_instance(obj, &i915->ggtt.base, NULL);
+        if (IS_ERR(vma))
+                i915_gem_object_put(obj);
+
+        return vma;
+}
+
 static int intel_ring_context_pin(struct intel_engine_cs *engine,
                                   struct i915_gem_context *ctx)
 {
@@ -1449,6 +1487,18 @@ static int intel_ring_context_pin(struct intel_engine_cs *engine,
                 return 0;
         GEM_BUG_ON(!ce->pin_count); /* no overflow please! */
 
+        if (engine->id == RCS && !ce->state && engine->i915->hw_context_size) {
+                struct i915_vma *vma;
+
+                vma = alloc_context_vma(engine);
+                if (IS_ERR(vma)) {
+                        ret = PTR_ERR(vma);
+                        goto error;
+                }
+
+                ce->state = vma;
+        }
+
         if (ce->state) {
                 ret = context_pin(ctx);
                 if (ret)