[Intel-gfx] [PATCH v2 4/4] drm/i915/: Re-work clflush_write32

[Bowman, Casey G]

> -----Original Message-----
> From: Cheng, Michael <michael.cheng at intel.com>
> Sent: Friday, January 28, 2022 2:10 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: Cheng, Michael <michael.cheng at intel.com>; Bowman, Casey G
> <casey.g.bowman at intel.com>; De Marchi, Lucas
> <lucas.demarchi at intel.com>; Boyer, Wayne <wayne.boyer at intel.com>;
> ville.syrjala at linux.intel.com; Kuoppala, Mika <mika.kuoppala at intel.com>;
> Auld, Matthew <matthew.auld at intel.com>
> Subject: [PATCH v2 4/4] drm/i915/: Re-work clflush_write32
> 
> 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>

Reviewed-by: Casey Bowman <casey.g.bowman 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));
> 
>  		*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));
>  	} else
>  		*addr = value;
>  }
> --
> 2.25.1