drm/i915: Implement inter-engine read-read optimisations

[deliverable/linux.git] / drivers / gpu / drm / i915 / i915_gem_context.c

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index f3e84c44d0091a00195d3b827c36de435d755ed5..8867818b140173fc3c107b299a7b553a6287f8f9 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -157,7 +157,9 @@ i915_gem_alloc_context_obj(struct drm_device *dev, size_t size)
        struct drm_i915_gem_object *obj;
        int ret;
 
-       obj = i915_gem_alloc_object(dev, size);
+       obj = i915_gem_object_create_stolen(dev, size);
+       if (obj == NULL)
+               obj = i915_gem_alloc_object(dev, size);
        if (obj == NULL)
                return ERR_PTR(-ENOMEM);
 
@@ -573,20 +575,12 @@ static inline bool should_skip_switch(struct intel_engine_cs *ring,
                                      struct intel_context *from,
                                      struct intel_context *to)
 {
-       struct drm_i915_private *dev_priv = ring->dev->dev_private;
-
        if (to->remap_slice)
                return false;
 
-       if (to->ppgtt) {
-               if (from == to && !test_bit(ring->id,
-                               &to->ppgtt->pd_dirty_rings))
-                       return true;
-       } else if (dev_priv->mm.aliasing_ppgtt) {
-               if (from == to && !test_bit(ring->id,
-                               &dev_priv->mm.aliasing_ppgtt->pd_dirty_rings))
-                       return true;
-       }
+       if (to->ppgtt && from == to &&
+           !(intel_ring_flag(ring) & to->ppgtt->pd_dirty_rings))
+               return true;
 
        return false;
 }
@@ -636,7 +630,6 @@ static int do_switch(struct intel_engine_cs *ring,
        struct intel_context *from = ring->last_context;
        u32 hw_flags = 0;
        bool uninitialized = false;
-       struct i915_vma *vma;
        int ret, i;
 
        if (from != NULL && ring == &dev_priv->ring[RCS]) {
@@ -673,7 +666,7 @@ static int do_switch(struct intel_engine_cs *ring,
                        goto unpin_out;
 
                /* Doing a PD load always reloads the page dirs */
-               clear_bit(ring->id, &to->ppgtt->pd_dirty_rings);
+               to->ppgtt->pd_dirty_rings &= ~intel_ring_flag(ring);
        }
 
        if (ring != &dev_priv->ring[RCS]) {
@@ -694,16 +687,6 @@ static int do_switch(struct intel_engine_cs *ring,
        if (ret)
                goto unpin_out;
 
-       vma = i915_gem_obj_to_ggtt(to->legacy_hw_ctx.rcs_state);
-       if (!(vma->bound & GLOBAL_BIND)) {
-               ret = i915_vma_bind(vma,
-                                   to->legacy_hw_ctx.rcs_state->cache_level,
-                                   GLOBAL_BIND);
-               /* This shouldn't ever fail. */
-               if (WARN_ONCE(ret, "GGTT context bind failed!"))
-                       goto unpin_out;
-       }
-
        if (!to->legacy_hw_ctx.initialized) {
                hw_flags |= MI_RESTORE_INHIBIT;
                /* NB: If we inhibit the restore, the context is not allowed to
@@ -711,12 +694,14 @@ static int do_switch(struct intel_engine_cs *ring,
                 * space. This means we must enforce that a page table load
                 * occur when this occurs. */
        } else if (to->ppgtt &&
-                       test_and_clear_bit(ring->id, &to->ppgtt->pd_dirty_rings))
+                  (intel_ring_flag(ring) & to->ppgtt->pd_dirty_rings)) {
                hw_flags |= MI_FORCE_RESTORE;
+               to->ppgtt->pd_dirty_rings &= ~intel_ring_flag(ring);
+       }
 
        /* We should never emit switch_mm more than once */
        WARN_ON(needs_pd_load_pre(ring, to) &&
-                       needs_pd_load_post(ring, to, hw_flags));
+               needs_pd_load_post(ring, to, hw_flags));
 
        ret = mi_set_context(ring, to, hw_flags);
        if (ret)
@@ -768,8 +753,6 @@ static int do_switch(struct intel_engine_cs *ring,
                 * swapped, but there is no way to do that yet.
                 */
                from->legacy_hw_ctx.rcs_state->dirty = 1;
-               BUG_ON(i915_gem_request_get_ring(
-                       from->legacy_hw_ctx.rcs_state->last_read_req) != ring);
 
                /* obj is kept alive until the next request by its active ref */
                i915_gem_object_ggtt_unpin(from->legacy_hw_ctx.rcs_state);