Re: [PATCH 3/5] drm/i915: Extract gen6 aliasing ppgtt code

[Chris Wilson <chris@chris-wilson.co.uk>]

On Fri, 28 Dec 2012 20:27:27 -0800, Ben Widawsky <ben@bwidawsk.net> wrote:
> This refactor clearly identifies the GEN specific portion of the aliased
> ppgtt code. Aside from some of the gen specific parts being extracted,
> it also preps us for an upcoming patch that pulls out the size, which
> has some nice benefits.

Error handling looks a little wonky.

> 
> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c | 51 ++++++++++++++++++++++---------------
>  1 file changed, 30 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 94d21aa..3b1bff1 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -108,29 +108,20 @@ static void i915_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
>  	}
>  }
>  
> -static int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
> +static int gen6_init_aliasing_ppgtt(struct i915_hw_ppgtt *ppgtt)
>  {
> +	struct drm_device *dev = ppgtt->dev;
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> -	struct i915_hw_ppgtt *ppgtt;
>  	unsigned first_pd_entry_in_global_pt;
> -	int i;
> -	int ret = -ENOMEM;
> +	int i, ret = -ENOMEM;
>  
>  	/* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
>  	 * entries. For aliasing ppgtt support we just steal them at the end for
>  	 * now. */
>  	first_pd_entry_in_global_pt = dev_priv->mm.gtt->gtt_total_entries - I915_PPGTT_PD_ENTRIES;
> -
> -	ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
> -	if (!ppgtt)
> -		return ret;
> -
> -	ppgtt->dev = dev;
>  	ppgtt->num_pd_entries = I915_PPGTT_PD_ENTRIES;
>  	ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
>  				  GFP_KERNEL);
> -	if (!ppgtt->pt_pages)
> -		goto err_ppgtt;

I think you still want this...
  
> @@ -185,9 +171,32 @@ err_pt_alloc:
>  		if (ppgtt->pt_pages[i])
>  			__free_page(ppgtt->pt_pages[i]);
>  	}
> -	kfree(ppgtt->pt_pages);
> -err_ppgtt:
> -	kfree(ppgtt);
> +
> +	if (!ppgtt->pt_pages)
> +		kfree(ppgtt->pt_pages);

And will want to reconsider this chunk.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre