[Intel-gfx] [PATCH v4] drm/i915: Replace 4096 with PAGE_SIZE or I915_GTT_PAGE_SIZE

Joonas Lahtinen joonas.lahtinen at linux.intel.com
Tue Jan 10 16:17:42 UTC 2017

On ti, 2017-01-10 at 14:47 +0000, Chris Wilson wrote:
> Start converting over from the byte count to its semantic macro, either
> we want to allocate the size of a physical page in main memory or we
> want the size of a virtual page in the GTT. 4096 could mean either, but
> PAGE_SIZE and I915_GTT_PAGE_SIZE are explicit and should help improve
> code comprehension and future changes. In the future, we may want to use
> variable GTT page sizes and so have the challenge of knowing which
> hardcoded values were used to represent a physical page vs the virtual
> page.
> v2: Look for a few more 4096s to convert, discover IS_ALIGNED().
> v3: 4096ul paranoia, make fence alignment a distinct value of 4096, keep
> bdw stolen w/a as 4096 until we know better.
> v4: Add asserts that i915_vma_insert() start/end are aligned to GTT page
> sizes.
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>


> +++ b/drivers/gpu/drm/i915/i915_gem_fence_reg.h
> @@ -47,5 +47,7 @@ struct drm_i915_fence_reg {
> >  	bool dirty;
>  };
> +#define I965_FENCE_PAGE 4096UL

I'm pretty sure I'd look for this from the very top of the file before
structs. Any specific reason not there?

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

Regards, Joonas
Joonas Lahtinen
Open Source Technology Center
Intel Corporation

More information about the Intel-gfx mailing list