drm/i915: Only enforce fence limits inside the GTT.

So long as we adhere to the fence registers rules for alignment and no
overlaps (including with unfenced accesses to linear memory) and account
for the tiled access in our size allocation, we do not have to allocate
the full fenced region for the object. This allows us to fight the bloat
tiling imposed on pre-i965 chipsets and frees up RAM for real use. [Inside
the GTT we still suffer the additional alignment constraints, so it doesn't
magic allow us to render larger scenes without stalls -- we need the
expanded GTT and fence pipelining to overcome those...]

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index 8c641bed9bbd..b20dbb2d7174 100644
--- a/include/drm/i915_drm.h
+++ b/include/drm/i915_drm.h
@@ -287,6 +287,7 @@ typedef struct drm_i915_irq_wait {
 #define I915_PARAM_HAS_EXECBUF2          9
 #define I915_PARAM_HAS_BSD               10
 #define I915_PARAM_HAS_BLT               11
+#define I915_PARAM_HAS_RELAXED_FENCING   12
 
 typedef struct drm_i915_getparam {
         int param;