[PATCH 03/48] drm/i915: Don't unconditionally try to deref aliasing ppgtt

Ben Widawsky
2013-12-06T22:16:24Z

Since the beginning, the functions which try to properly reference the
aliasing PPGTT have deferences a potentially null aliasing_ppgtt member.
Since the accessors are meant to be global, this will not do.

Introduced originally in:
commit a70a3148b0c61cb7c588ea650db785b261b378a3
Author: Ben Widawsky <ben@bwidawsk.net>
Date: Wed Jul 31 16:59:56 2013 -0700

drm/i915: Make proper functions for VMs

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
drivers/gpu/drm/i915/i915_gem.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8b18c2a..5278b67 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4974,7 +4974,8 @@ unsigned long i915_gem_obj_offset(struct drm_i915_gem_object *o,
struct drm_i915_private *dev_priv = o->base.dev->dev_private;
struct i915_vma *vma;

- if (vm == &dev_priv->mm.aliasing_ppgtt->base)
+ if (!dev_priv->mm.aliasing_ppgtt ||
+ vm == &dev_priv->mm.aliasing_ppgtt->base)
vm = &dev_priv->gtt.base;

BUG_ON(list_empty(&o->vma_list));
@@ -5015,7 +5016,8 @@ unsigned long i915_gem_obj_size(struct drm_i915_gem_object *o,
struct drm_i915_private *dev_priv = o->base.dev->dev_private;
struct i915_vma *vma;

- if (vm == &dev_priv->mm.aliasing_ppgtt->base)
+ if (!dev_priv->mm.aliasing_ppgtt ||
+ vm == &dev_priv->mm.aliasing_ppgtt->base)
vm = &dev_priv->gtt.base;

BUG_ON(list_empty(&o->vma_list));
--
1.8.4.2