[U-Boot] [RFC] ARM: davinci: da850: Enable Caches for DA850-EVM

[Peter Howard]

On Sun, 2017-08-27 at 17:39 -0500, Adam Ford wrote:
> What starting up the DA850-EVM, U-Boot generates a warning:
>    WARNING: Caches not enabled
> 
> Looking at other arm926 processors, this is an attempt
> to enable the caches and remove the warning.
> 
> I am notsure who the proper TI or ARM people are to review this.
> 
> Signed-off-by: Adam Ford <aford173 at gmail.com>
> ---
>  board/davinci/da8xxevm/da850evm.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/board/davinci/da8xxevm/da850evm.c
> b/board/davinci/da8xxevm/da850evm.c
> index c2d2e8e..33a923c 100644
> --- a/board/davinci/da8xxevm/da850evm.c
> +++ b/board/davinci/da8xxevm/da850evm.c
> @@ -491,3 +491,29 @@ int board_eth_init(bd_t *bis)
>  	return 0;
>  }
>  #endif /* CONFIG_DRIVER_TI_EMAC */
> +
> +#ifndef CONFIG_SYS_ICACHE_OFF
> +/* Invalidate entire I-cache and branch predictor array */
> +void invalidate_icache_all(void)
> +{
> +	unsigned long i = 0;
> +
> +	asm ("mcr p15, 0, %0, c7, c5, 0" : : "r" (i));
> +}
> +#else
> +void invalidate_icache_all(void)
> +{
> +}
> +#endif
> +
> +#ifndef CONFIG_SYS_DCACHE_OFF
> +void enable_caches(void)
> +{
> +	/* Enable D-cache. I-cache is already enabled in start.S */
> +	dcache_enable();
> +}
> +#else
> +void enable_caches(void)
> +{
> +}
> +#endif /* CONFIG_SYS_DCACHE_OFF */

My 2c on this would be:

1) If it's going to be for the davinci specifically, I'd do it the same
way as for the at91 - i.e. under mach-davinci/arm926ejs

2) Is there any good reason _not_ to add it to
arch/arm/cpu/arm926ejs/cache.c rather than per-board?  Given it's a
feature of the arm core rather than anything specific to the davinci it
would make sense to me.



-- 
Peter Howard <pjh at northern-ridge.com.au>
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