[Intel-gfx] [RFC] drm/i915: Framebuffers need not be limited to 256MB on gen8+.

[deepak.s at linux.intel.com]

From: Deepak S <deepak.s at linux.intel.com>

The restriction of pinningFramebuffer to first 256MB is removed from gen8+.
Removing the restriction so that FB can be pinned in any space within
GTT/PPGTT. Also, for gen8+ no need to use pin_mappable for Framebuffer &
also we do not take fence as Framebuffer compression is not enabled.

Signed-off-by: Satyanantha, Rama Gopal M <rama.gopal.m.satyanantha at intel.com>
Signed-off-by: Deepak S <deepak.s at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c      |  9 +++++++--
 drivers/gpu/drm/i915/intel_display.c | 11 +++++++----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 77a7315..c9f5b06 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3941,6 +3941,7 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
 				     struct intel_engine_cs *pipelined)
 {
 	u32 old_read_domains, old_write_domain;
+	struct drm_device *dev = obj->base.dev;
 	bool was_pin_display;
 	int ret;
 
@@ -3972,9 +3973,13 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
 
 	/* As the user may map the buffer once pinned in the display plane
 	 * (e.g. libkms for the bootup splash), we have to ensure that we
-	 * always use map_and_fenceable for all scanout buffers.
+	 * always use map_and_fenceable for all scanout buffers. No need
+	 * of map_fenceable for >= gen8
 	 */
-	ret = i915_gem_obj_ggtt_pin(obj, alignment, PIN_MAPPABLE);
+	if ((INTEL_INFO(dev)->gen >= 8))
+		ret = i915_gem_obj_ggtt_pin(obj, alignment, 0);
+	else
+		ret = i915_gem_obj_ggtt_pin(obj, alignment, PIN_MAPPABLE);
 	if (ret)
 		goto err_unpin_display;
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index fad5f76..d3067be 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2267,11 +2267,14 @@ intel_pin_and_fence_fb_obj(struct drm_plane *plane,
 	/* Install a fence for tiled scan-out. Pre-i965 always needs a
 	 * fence, whereas 965+ only requires a fence if using
 	 * framebuffer compression.  For simplicity, we always install
-	 * a fence as the cost is not that onerous.
+	 * a fence as the cost is not that onerous. Fence is only required
+	 * for gen 7 & below
 	 */
-	ret = i915_gem_object_get_fence(obj);
-	if (ret)
-		goto err_unpin;
+	if ((INTEL_INFO(dev)->gen <= 7)) {
+		ret = i915_gem_object_get_fence(obj);
+		if (ret)
+			goto err_unpin;
+	}
 
 	i915_gem_object_pin_fence(obj);
 
-- 
1.9.1