[Intel-gfx] [PATCH 1/5] drm/i915: Do not clear mappings beyond VMA size

[Tvrtko Ursulin]

On 04/24/2015 01:09 PM, Joonas Lahtinen wrote:
> Do not to clear mappings outside the allocated VMA under any
> circumstances. Only clear the smaller of VMA or object page count.
>
> This is required to allow creating partial object VMAs which in
> turn are needed for partial GGTT views.
>
> Signed-off-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> ---
>   drivers/gpu/drm/i915/i915_gem_gtt.c |    8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 6fae6bd..ee9ff8e 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -1947,19 +1947,23 @@ static void ggtt_unbind_vma(struct i915_vma *vma)
>   	struct drm_device *dev = vma->vm->dev;
>   	struct drm_i915_private *dev_priv = dev->dev_private;
>   	struct drm_i915_gem_object *obj = vma->obj;
> +	const uint64_t size = min_t(uint64_t,
> +				    obj->base.size,
> +				    vma->node.size);
>
>   	if (vma->bound & GLOBAL_BIND) {
>   		vma->vm->clear_range(vma->vm,
>   				     vma->node.start,
> -				     obj->base.size,
> +				     size,
>   				     true);
>   	}
>
>   	if (dev_priv->mm.aliasing_ppgtt && vma->bound & LOCAL_BIND) {
>   		struct i915_hw_ppgtt *appgtt = dev_priv->mm.aliasing_ppgtt;
> +
>   		appgtt->base.clear_range(&appgtt->base,
>   					 vma->node.start,
> -					 obj->base.size,
> +					 size,
>   					 true);
>   	}
>   }
>

Looks good to me,

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko