[Intel-gfx] [PATCH v10 5/6] drm/i915/: Re-work clflush_write32

[Matt Roper]

On Thu, Feb 10, 2022 at 10:36:35AM -0800, Michael Cheng wrote:
> Use drm_clflush_virt_range instead of clflushopt and remove the memory
> barrier, since drm_clflush_virt_range takes care of that.
> 
> Signed-off-by: Michael Cheng <michael.cheng at intel.com>
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index 498b458fd784..0854276ff7ba 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -1332,10 +1332,8 @@ static void *reloc_vaddr(struct i915_vma *vma,
>  static void clflush_write32(u32 *addr, u32 value, unsigned int flushes)
>  {
>  	if (unlikely(flushes & (CLFLUSH_BEFORE | CLFLUSH_AFTER))) {
> -		if (flushes & CLFLUSH_BEFORE) {
> -			clflushopt(addr);
> -			mb();
> -		}
> +		if (flushes & CLFLUSH_BEFORE)
> +			drm_clflush_virt_range(addr, sizeof(addr));

This is another case where it should technically be sizeof(*addr),
although in practice it won't change the behavior.

>  
>  		*addr = value;
>  
> @@ -1347,7 +1345,7 @@ static void clflush_write32(u32 *addr, u32 value, unsigned int flushes)
>  		 * to ensure ordering of clflush wrt to the system.
>  		 */
>  		if (flushes & CLFLUSH_AFTER)
> -			clflushopt(addr);
> +			drm_clflush_virt_range(addr, sizeof(addr));

Ditto.


Aside from those,

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>


>  	} else
>  		*addr = value;
>  }
> -- 
> 2.25.1
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795