[Intel-gfx] [PATCH] drm/i915: Mark PIN_USER binding as GLOBAL_BIND without the aliasing ppgtt

[Daniel Vetter]

On Wed, Jul 29, 2015 at 08:02:48PM +0100, Chris Wilson wrote:
> If the device does not support the aliasing ppgtt, we must translate
> user bind requests (PIN_USER) from LOCAL_BIND to a GLOBAL_BIND. However,
> since this is device specific we cannot do this conveniently in the
> upper layers and so must manage the vma->bound flags in the backend.
> 
> Partial revert of commit 75d04a3773ecee617847de963ae4195d6aa74c28 [4.2-rc1]
> Author: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Date:   Tue Apr 28 17:56:17 2015 +0300
> 
>     drm/i915/gtt: Allocate va range only if vma is not bound
> 
> Note this was spotted by Daniel originally, but we dropped the ball in
> getting the fix in before the bug going wild. Sorry all.
> 
> Reported-by: Vincent Legoll vincent.legoll at gmail.com
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91133
> References: https://bugs.freedesktop.org/show_bug.cgi?id=90224
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michel Thierry <michel.thierry at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
Picked up for -fixes, thanks for the patch.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 9d3852c521c7..c0d8e1f5b5c2 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -1928,6 +1928,17 @@ static int ggtt_bind_vma(struct i915_vma *vma,
>  		vma->vm->insert_entries(vma->vm, pages,
>  					vma->node.start,
>  					cache_level, pte_flags);
> +
> +		/* Note the inconsistency here is due to absence of the
> +		 * aliasing ppgtt on gen4 and earlier. Though we always
> +		 * request PIN_USER for execbuffer (translated to LOCAL_BIND),
> +		 * without the appgtt, we cannot honour that request and so
> +		 * must substitute it with a global binding. Since we do this
> +		 * behind the upper layers back, we need to explicitly set
> +		 * the bound flag ourselves.
> +		 */
> +		vma->bound |= GLOBAL_BIND;
> +
>  	}
>  
>  	if (dev_priv->mm.aliasing_ppgtt && flags & LOCAL_BIND) {
> -- 
> 2.4.6
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch