[U-Boot] [PATCH v2 01/10] arm: move flush_dcache_all() to just before disable cache

[R Sricharan]

Hi,

On Saturday 01 December 2012 04:31 AM, Simon Glass wrote:
> From: Arun Mankuzhi <arun.m at samsung.com>
>
> In Cortex-A15 architecture, when we run cache invalidate
> the cache clean operation executes automatically.
> So if there are any dirty cache lines before disabling the L2 cache
> these will be synchronized with the main memory when
> invalidate_dcache_all() runs in the last part of U-boot
>
> The two functions after flush_dcache_all is using the stack. So this
> data will be on the cache. After disable when invalidate is called the
> data will be flushed from cache to memory. This corrupts the stack in
> invalida_dcache_all. So this change is required to avoid the u-boot
> hang.
>
> So flush has to be done just before clearing CR_C bit
>
> Signed-off-by: Arun Mankuzhi <arun.m at samsung.com>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> Changes in v2: None
>
>   arch/arm/lib/cache-cp15.c |    5 ++++-
>   1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c
> index 939de10..06119c8 100644
> --- a/arch/arm/lib/cache-cp15.c
> +++ b/arch/arm/lib/cache-cp15.c
> @@ -124,8 +124,11 @@ static void cache_disable(uint32_t cache_bit)
>   			return;
>   		/* if disabling data cache, disable mmu too */
>   		cache_bit |= CR_M;
> -		flush_dcache_all();
>   	}
> +	reg = get_cr();
> +	cp_delay();
> +	if (cache_bit == (CR_C | CR_M))
> +		flush_dcache_all();
>   	set_cr(reg & ~cache_bit);
  Sorry for the late question.
  But are the two functions that is after flush_dcache_all currently ?

  There is only set_cr, which does not use the stack.

Regards,
  Sricharan