[PATCH v3 3/4] drm/i915: pre-alloc instead of drm_mm search/get_block

[Daniel Vetter]

On Sat, Jul 27, 2013 at 04:21:27PM +0200, David Herrmann wrote:
> i915 is the last user of the weird search+get_block drm_mm API. Convert it
> to an explicit kmalloc()+insert_node(). This drops the last user of the
> node-cache in drm_mm. We can remove it now in a follow-up patch.
> 
> v2:
>  - simplify error path in i915_setup_compression()
> v3:
>  - simplify error path even more
> 
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: David Herrmann <dh.herrmann at gmail.com>

I think this won't conflict badly with the ongoing VMA rework in drm/i915,
so

Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>

for merging through drm-next directly.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem_stolen.c | 78 ++++++++++++++++++++--------------
>  1 file changed, 47 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
> index e355170..a3d1a12 100644
> --- a/drivers/gpu/drm/i915/i915_gem_stolen.c
> +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
> @@ -112,34 +112,36 @@ static int i915_setup_compression(struct drm_device *dev, int size)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
> +	int ret;
>  
> -	/* Try to over-allocate to reduce reallocations and fragmentation */
> -	compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
> -					   size <<= 1, 4096,
> -					   DRM_MM_SEARCH_DEFAULT);
> -	if (!compressed_fb)
> -		compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
> -						   size >>= 1, 4096,
> -						   DRM_MM_SEARCH_DEFAULT);
> -	if (compressed_fb)
> -		compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
> +	compressed_fb = kzalloc(sizeof(*compressed_fb), GFP_KERNEL);
>  	if (!compressed_fb)
> -		goto err;
> +		goto err_llb;
> +
> +	/* Try to over-allocate to reduce reallocations and fragmentation */
> +	ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_fb,
> +				 size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);
> +	if (ret)
> +		ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_fb,
> +					 size >>= 1, 4096,
> +					 DRM_MM_SEARCH_DEFAULT);
> +	if (ret)
> +		goto err_llb;
>  
>  	if (HAS_PCH_SPLIT(dev))
>  		I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
>  	else if (IS_GM45(dev)) {
>  		I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
>  	} else {
> -		compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
> -						    4096, 4096,
> -						    DRM_MM_SEARCH_DEFAULT);
> -		if (compressed_llb)
> -			compressed_llb = drm_mm_get_block(compressed_llb,
> -							  4096, 4096);
> +		compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
>  		if (!compressed_llb)
>  			goto err_fb;
>  
> +		ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
> +					 4096, 4096, DRM_MM_SEARCH_DEFAULT);
> +		if (ret)
> +			goto err_fb;
> +
>  		dev_priv->fbc.compressed_llb = compressed_llb;
>  
>  		I915_WRITE(FBC_CFB_BASE,
> @@ -157,8 +159,10 @@ static int i915_setup_compression(struct drm_device *dev, int size)
>  	return 0;
>  
>  err_fb:
> -	drm_mm_put_block(compressed_fb);
> -err:
> +	kfree(compressed_llb);
> +	drm_mm_remove_node(compressed_fb);
> +err_llb:
> +	kfree(compressed_fb);
>  	pr_info_once("drm: not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size);
>  	return -ENOSPC;
>  }
> @@ -186,11 +190,15 @@ void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
>  	if (dev_priv->fbc.size == 0)
>  		return;
>  
> -	if (dev_priv->fbc.compressed_fb)
> -		drm_mm_put_block(dev_priv->fbc.compressed_fb);
> +	if (dev_priv->fbc.compressed_fb) {
> +		drm_mm_remove_node(dev_priv->fbc.compressed_fb);
> +		kfree(dev_priv->fbc.compressed_fb);
> +	}
>  
> -	if (dev_priv->fbc.compressed_llb)
> -		drm_mm_put_block(dev_priv->fbc.compressed_llb);
> +	if (dev_priv->fbc.compressed_llb) {
> +		drm_mm_remove_node(dev_priv->fbc.compressed_llb);
> +		kfree(dev_priv->fbc.compressed_llb);
> +	}
>  
>  	dev_priv->fbc.size = 0;
>  }
> @@ -323,6 +331,7 @@ i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	struct drm_i915_gem_object *obj;
>  	struct drm_mm_node *stolen;
> +	int ret;
>  
>  	if (!drm_mm_initialized(&dev_priv->mm.stolen))
>  		return NULL;
> @@ -331,18 +340,23 @@ i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
>  	if (size == 0)
>  		return NULL;
>  
> -	stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096,
> -				    DRM_MM_SEARCH_DEFAULT);
> -	if (stolen)
> -		stolen = drm_mm_get_block(stolen, size, 4096);
> -	if (stolen == NULL)
> +	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
> +	if (!stolen)
>  		return NULL;
>  
> +	ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
> +				 4096, DRM_MM_SEARCH_DEFAULT);
> +	if (ret) {
> +		kfree(stolen);
> +		return NULL;
> +	}
> +
>  	obj = _i915_gem_object_create_stolen(dev, stolen);
>  	if (obj)
>  		return obj;
>  
> -	drm_mm_put_block(stolen);
> +	drm_mm_remove_node(stolen);
> +	kfree(stolen);
>  	return NULL;
>  }
>  
> @@ -386,7 +400,8 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
>  	obj = _i915_gem_object_create_stolen(dev, stolen);
>  	if (obj == NULL) {
>  		DRM_DEBUG_KMS("failed to allocate stolen object\n");
> -		drm_mm_put_block(stolen);
> +		drm_mm_remove_node(stolen);
> +		kfree(stolen);
>  		return NULL;
>  	}
>  
> @@ -426,7 +441,8 @@ void
>  i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
>  {
>  	if (obj->stolen) {
> -		drm_mm_put_block(obj->stolen);
> +		drm_mm_remove_node(obj->stolen);
> +		kfree(obj->stolen);
>  		obj->stolen = NULL;
>  	}
>  }
> -- 
> 1.8.3.4
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch