[PATCH 7/7] ARM: dma-mapping: no need to clean overlapping cache lines on invalidate

[Nicolas Pitre]

On Fri, 20 Nov 2009, Russell King - ARM Linux wrote:

> Since we now clean the DMA buffers on map, there's no need to clean
> overlapping cache lines on invalidation anymore.  (Note: the DMA API
> prohibits other data sharing the same cache line as a DMA buffer
> anyway.)
> 
> Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> ---
[...]

> diff --git a/arch/arm/mm/proc-feroceon.S b/arch/arm/mm/proc-feroceon.S
> index d0d7795..b2f264e 100644
> --- a/arch/arm/mm/proc-feroceon.S
> +++ b/arch/arm/mm/proc-feroceon.S
> @@ -274,11 +274,7 @@ ENTRY(feroceon_range_flush_kern_dcache_page)
>   */
>  	.align	5
>  ENTRY(feroceon_dma_inv_range)
> -	tst	r0, #CACHE_DLINESIZE - 1
>  	bic	r0, r0, #CACHE_DLINESIZE - 1
> -	mcrne	p15, 0, r0, c7, c10, 1		@ clean D entry
> -	tst	r1, #CACHE_DLINESIZE - 1
> -	mcrne	p15, 0, r1, c7, c10, 1		@ clean D entry
>  1:	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D entry
>  	add	r0, r0, #CACHE_DLINESIZE
>  	cmp	r0, r1

The code in feroceon_range_dma_inv_range is likely to require the same 
cleanup.


Nicolas