[Intel-gfx] [PATCH] drm/i915: Move Braswell stop_machine GGTT insertion workaround

[Chris Wilson]

There was a silent conflict between

commit 0a878716265e9af9f697264dc2e858fcc060d833
Author: Daniel Vetter <daniel.vetter at ffwll.ch>
Date:   Thu Oct 15 14:23:01 2015 +0200

    drm/i915: restore ggtt double-bind avoidance

and

commit 5bab6f60cb4d1417ad7c599166bcfec87529c1a2
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Fri Oct 23 18:43:32 2015 +0100

    drm/i915: Serialise updates to GGTT with access through GGTT on Braswell

thankfully caught by the extra WARN safegaurd in 0a878716. Since we now
override the GGTT insert_pages callback when installing the aliasing
ppgtt, we assert that the callback is the original ggtt routine.
However, on Braswell we now use a different insertion routine to
serialise access through the GGTT with updating the PTE and hence the
conflict. To avoid the conflict, move the custom insertion routine for
Braswell down a level.

Reported-by: Ville Syrjälä <ville.syrjala at linux.intel.com
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Michel Thierry <michel.thierry at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 50 +++++++++++++++++++++----------------
 1 file changed, 28 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 4d357e18e5d1..8cd271fa2396 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2386,6 +2386,32 @@ static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
 	POSTING_READ(GFX_FLSH_CNTL_GEN6);
 }
 
+struct insert_entries {
+	struct i915_address_space *vm;
+	struct sg_table *st;
+	uint64_t start;
+	enum i915_cache_level level;
+	u32 flags;
+};
+
+static int gen8_ggtt_insert_entries__cb(void *_arg)
+{
+	struct insert_entries *arg = _arg;
+	gen8_ggtt_insert_entries(arg->vm, arg->st,
+				 arg->start, arg->level, arg->flags);
+	return 0;
+}
+
+static void gen8_ggtt_insert_entries__BKL(struct i915_address_space *vm,
+					  struct sg_table *st,
+					  uint64_t start,
+					  enum i915_cache_level level,
+					  u32 flags)
+{
+	struct insert_entries arg = { vm, st, start, level, flags };
+	stop_machine(gen8_ggtt_insert_entries__cb, &arg, NULL);
+}
+
 /*
  * Binds an object into the global gtt with the specified cache level. The object
  * will be accessible to the GPU via commands whose operands reference offsets
@@ -2534,26 +2560,6 @@ static int ggtt_bind_vma(struct i915_vma *vma,
 	return 0;
 }
 
-struct ggtt_bind_vma__cb {
-	struct i915_vma *vma;
-	enum i915_cache_level cache_level;
-	u32 flags;
-};
-
-static int ggtt_bind_vma__cb(void *_arg)
-{
-	struct ggtt_bind_vma__cb *arg = _arg;
-	return ggtt_bind_vma(arg->vma, arg->cache_level, arg->flags);
-}
-
-static int ggtt_bind_vma__BKL(struct i915_vma *vma,
-			      enum i915_cache_level cache_level,
-			      u32 flags)
-{
-	struct ggtt_bind_vma__cb arg = { vma, cache_level, flags };
-	return stop_machine(ggtt_bind_vma__cb, &arg, NULL);
-}
-
 static int aliasing_gtt_bind_vma(struct i915_vma *vma,
 				 enum i915_cache_level cache_level,
 				 u32 flags)
@@ -3021,8 +3027,8 @@ static int gen8_gmch_probe(struct drm_device *dev,
 	dev_priv->gtt.base.bind_vma = ggtt_bind_vma;
 	dev_priv->gtt.base.unbind_vma = ggtt_unbind_vma;
 
-	if (IS_CHERRYVIEW(dev))
-		dev_priv->gtt.base.bind_vma = ggtt_bind_vma__BKL;
+	if (IS_CHERRYVIEW(dev_priv))
+		dev_priv->gtt.base.insert_entries = gen8_ggtt_insert_entries__BKL;
 
 	return ret;
 }
-- 
2.6.2