[Intel-gfx] [PATCH v4 10/24] drm/i915: Extract context switch skip and pd load logic

[Michel Thierry]

From: Ben Widawsky <benjamin.widawsky at intel.com>

We have some fanciness coming up. This patch just breaks out the logic
of context switch skip, pd load pre, and pd load post.

v2: Use new functions to replace the logic right away (Daniel)

Cc: Daniel Vetter <daniel at ffwll.ch>
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry at intel.com> (v2)
---
 drivers/gpu/drm/i915/i915_gem_context.c | 40 +++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 755b415..6206d27 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -565,6 +565,33 @@ mi_set_context(struct intel_engine_cs *ring,
 	return ret;
 }
 
+static inline bool should_skip_switch(struct intel_engine_cs *ring,
+				      struct intel_context *from,
+				      struct intel_context *to)
+{
+	if (from == to && !to->remap_slice)
+		return true;
+
+	return false;
+}
+
+static bool
+needs_pd_load_pre(struct intel_engine_cs *ring, struct intel_context *to)
+{
+	struct drm_i915_private *dev_priv = ring->dev->dev_private;
+
+	return ((INTEL_INFO(ring->dev)->gen < 8) ||
+			(ring != &dev_priv->ring[RCS])) && to->ppgtt;
+}
+
+static bool
+needs_pd_load_post(struct intel_engine_cs *ring, struct intel_context *to)
+{
+	return (!to->legacy_hw_ctx.initialized ||
+			i915_gem_context_is_default(to)) &&
+			to->ppgtt && IS_GEN8(ring->dev);
+}
+
 static int do_switch(struct intel_engine_cs *ring,
 		     struct intel_context *to)
 {
@@ -573,9 +600,6 @@ static int do_switch(struct intel_engine_cs *ring,
 	u32 hw_flags = 0;
 	bool uninitialized = false;
 	struct i915_vma *vma;
-	bool needs_pd_load_pre = ((INTEL_INFO(ring->dev)->gen < 8) ||
-			(ring != &dev_priv->ring[RCS])) && to->ppgtt;
-	bool needs_pd_load_post = false;
 	int ret, i;
 
 	if (from != NULL && ring == &dev_priv->ring[RCS]) {
@@ -583,7 +607,7 @@ static int do_switch(struct intel_engine_cs *ring,
 		BUG_ON(!i915_gem_obj_is_pinned(from->legacy_hw_ctx.rcs_state));
 	}
 
-	if (from == to && !to->remap_slice)
+	if (should_skip_switch(ring, from, to))
 		return 0;
 
 	/* Trying to pin first makes error handling easier. */
@@ -601,7 +625,7 @@ static int do_switch(struct intel_engine_cs *ring,
 	 */
 	from = ring->last_context;
 
-	if (needs_pd_load_pre) {
+	if (needs_pd_load_pre(ring, to)) {
 		/* Older GENs and non render rings still want the load first,
 		 * "PP_DCLV followed by PP_DIR_BASE register through Load
 		 * Register Immediate commands in Ring Buffer before submitting
@@ -646,16 +670,14 @@ static int do_switch(struct intel_engine_cs *ring,
 	 * XXX: If we implemented page directory eviction code, this
 	 * optimization needs to be removed.
 	 */
-	if (!to->legacy_hw_ctx.initialized || i915_gem_context_is_default(to)) {
+	if (!to->legacy_hw_ctx.initialized || i915_gem_context_is_default(to))
 		hw_flags |= MI_RESTORE_INHIBIT;
-		needs_pd_load_post = to->ppgtt && IS_GEN8(ring->dev);
-	}
 
 	ret = mi_set_context(ring, to, hw_flags);
 	if (ret)
 		goto unpin_out;
 
-	if (needs_pd_load_post) {
+	if (needs_pd_load_post(ring, to)) {
 		ret = to->ppgtt->switch_mm(to->ppgtt, ring);
 		/* The hardware context switch is emitted, but we haven't
 		 * actually changed the state - so it's probably safe to bail
-- 
2.1.1