[U-Boot] [PATCH v2 01/10] arm: move flush_dcache_all() to just before disable cache
Albert ARIBAUD
albert.u.boot at aribaud.net
Thu Jan 10 23:27:49 CET 2013
Hi Simon,
On Fri, 30 Nov 2012 15:01:14 -0800, Simon Glass <sjg at chromium.org>
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);
> }
> #endif
Applied the whole series to u-boot-arm/master, thanks!
Amicalement,
--
Albert.
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