Re: [PATCH v2 3/4] drm/i915: Introduce i915_vm_to_ggtt()

Joonas Lahtinen
2016-04-18T13:36:02Z

On ma, 2016-04-18 at 12:14 +0100, Chris Wilson wrote:
> In a couple of places, we have an i915_address_space that we know is
> really an i915_ggtt that we want to use. Create an inline helper to
> convert from the i915_address_space subclass into its container.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Comment below.

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 9f165feb54ae..b3af2e808b49 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -93,6 +93,13 @@
>   *
>   */
>
> +static inline struct i915_ggtt *
> +i915_vm_to_ggtt(struct i915_address_space *vm)
> +{
> + GEM_BUG_ON(!i915_is_ggtt(vm));
> + return container_of(vm, struct i915_ggtt, base);
> +}
> +
>  static int
>  i915_get_ggtt_vma_pages(struct i915_vma *vma);
>
> @@ -2359,7 +2366,7 @@ static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
>        enum i915_cache_level level, u32 unused)
>  {
>   struct drm_i915_private *dev_priv = to_i915(vm->dev);
> - struct i915_ggtt *ggtt = &dev_priv->ggtt;
> + struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);

I do not see this as a very necessary change, because we are going to
have only one Global XYZ per device by definiton of "global".

Especially after the rename it's going to be;

struct i915_ggtt *ggtt = &i915->ggtt;

But regardless my R-b.

Regards, Joonas

>   unsigned first_entry = start >> PAGE_SHIFT;
>   gen8_pte_t __iomem *gtt_entries =
>   (gen8_pte_t __iomem *)ggtt->gsm + first_entry;
> @@ -2437,7 +2444,7 @@ static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
>        enum i915_cache_level level, u32 flags)
>  {
>   struct drm_i915_private *dev_priv = to_i915(vm->dev);
> - struct i915_ggtt *ggtt = &dev_priv->ggtt;
> + struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>   unsigned first_entry = start >> PAGE_SHIFT;
>   gen6_pte_t __iomem *gtt_entries =
>   (gen6_pte_t __iomem *)ggtt->gsm + first_entry;
> @@ -2481,7 +2488,7 @@ static void gen8_ggtt_clear_range(struct i915_address_space *vm,
>     bool use_scratch)
>  {
>   struct drm_i915_private *dev_priv = to_i915(vm->dev);
> - struct i915_ggtt *ggtt = &dev_priv->ggtt;
> + struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>   unsigned first_entry = start >> PAGE_SHIFT;
>   unsigned num_entries = length >> PAGE_SHIFT;
>   gen8_pte_t scratch_pte, __iomem *gtt_base =
> @@ -2513,7 +2520,7 @@ static void gen6_ggtt_clear_range(struct i915_address_space *vm,
>     bool use_scratch)
>  {
>   struct drm_i915_private *dev_priv = to_i915(vm->dev);
> - struct i915_ggtt *ggtt = &dev_priv->ggtt;
> + struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>   unsigned first_entry = start >> PAGE_SHIFT;
>   unsigned num_entries = length >> PAGE_SHIFT;
>   gen6_pte_t scratch_pte, __iomem *gtt_base =
--
Joonas Lahtinen
Open Source Technology Center
Intel Corporation