[Intel-gfx] [PATCH] drm/i915: Don't use a special stolen reserve offset

[Ben Widawsky]

Setting the node directly is good enough. We don't need a special value
to store the gtt_offset, and we no longer have the pointer to tuck
things away neatly.

This is temporarily broken since:
commit 7dedae28b41000539b6c18bcf72107c97e4937e4
Author: Ben Widawsky <ben at bwidawsk.net>
Date:   Wed Jul 3 14:45:24 2013 -0700

    drm/i915: Use gtt_space->start for stolen reservation

However with no userspace currently, the bisection problem shouldn't be
a concern.

CC: Chris Wilson <chris at chris-wilson.co.uk>
Reported-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_drv.h        | 1 -
 drivers/gpu/drm/i915/i915_gem_gtt.c    | 1 -
 drivers/gpu/drm/i915/i915_gem_stolen.c | 8 ++++++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ea86ad6..b9e8ba1 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1201,7 +1201,6 @@ enum hdmi_force_audio {
 	HDMI_AUDIO_ON,			/* force turn on HDMI audio */
 };
 
-#define I915_GTT_RESERVED (ULONG_MAX)
 #define I915_GTT_OFFSET_NONE ((u32)-1)
 
 struct drm_i915_gem_object_ops {
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index f075831..c0ca103 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -632,7 +632,6 @@ void i915_gem_setup_global_gtt(struct drm_device *dev,
 		DRM_DEBUG_KMS("reserving preallocated space: %lx + %zx\n",
 			      i915_gem_obj_ggtt_offset(obj), obj->base.size);
 
-		BUG_ON(obj->gtt_space->start != I915_GTT_RESERVED);
 		obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
 						     i915_gem_obj_ggtt_offset(obj),
 						     obj->base.size,
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index c6b70312..289d511d 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -397,8 +397,12 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 			drm_gem_object_unreference(&obj->base);
 			return NULL;
 		}
-	} else
-		obj->gtt_space->start = I915_GTT_RESERVED;
+	} else {
+		/* Generally it isn't safe to directly set attributes of the
+		 * drm_mm_node, however this is a special case where we'll
+		 * promise to handle everything properly later. */
+		obj->gtt_space->start = gtt_offset;
+	}
 
 	obj->has_global_gtt_mapping = 1;
 
-- 
1.8.3.2