drm/i915: Track GGTT writes on the vma

As writes through the GTT and GGTT PTE updates do not share the same
path, they are not strictly ordered and so we must explicitly flush the
indirect writes prior to modifying the PTE. We do track outstanding GGTT
writes on the object itself, but since the object may have multiple GGTT
vma, that is overly coarse as we can track and flush individual vma as
required.

Whilst here, update the GGTT flushing behaviour for Cannonlake.

v2: Hard-code ring offset to allow use during unload (after RCS may have
been freed, or never existed!)

References: https://bugs.freedesktop.org/show_bug.cgi?id=104002
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171206124914.19960-2-chris@chris-wilson.co.uk

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 1e2bc9b3c3ac..f636243eb8f7 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -90,6 +90,7 @@ struct i915_vma {
 #define I915_VMA_CLOSED		BIT(10)
 #define I915_VMA_USERFAULT_BIT	11
 #define I915_VMA_USERFAULT	BIT(I915_VMA_USERFAULT_BIT)
+#define I915_VMA_GGTT_WRITE	BIT(12)
 
 	unsigned int active;
 	struct i915_gem_active last_read[I915_NUM_ENGINES];
@@ -138,6 +139,24 @@ static inline bool i915_vma_is_ggtt(const struct i915_vma *vma)
 	return vma->flags & I915_VMA_GGTT;
 }
 
+static inline bool i915_vma_has_ggtt_write(const struct i915_vma *vma)
+{
+	return vma->flags & I915_VMA_GGTT_WRITE;
+}
+
+static inline void i915_vma_set_ggtt_write(struct i915_vma *vma)
+{
+	GEM_BUG_ON(!i915_vma_is_ggtt(vma));
+	vma->flags |= I915_VMA_GGTT_WRITE;
+}
+
+static inline void i915_vma_unset_ggtt_write(struct i915_vma *vma)
+{
+	vma->flags &= ~I915_VMA_GGTT_WRITE;
+}
+
+void i915_vma_flush_writes(struct i915_vma *vma);
+
 static inline bool i915_vma_is_map_and_fenceable(const struct i915_vma *vma)
 {
 	return vma->flags & I915_VMA_CAN_FENCE;