Re: [PATCH master 1/4] ARM: mmu64: request TTB region

[Sascha Hauer <sha@pengutronix.de>]

On Fri, May 26, 2023 at 08:33:51AM +0200, Ahmad Fatoum wrote:
> ARM64 MMU code used to disable early MMU, reallocate TTB from malloc
> area and then reenable it. This has recently been changed, so MMU is
> left enabled like on ARM32, but unlike ARM32, the SDRAM region used in
> PBL is not requested in barebox proper. Do that now.
> 
> Fixes: b53744ffe333 ("ARM: mmu64: Use two level pagetables in early code")
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  arch/arm/cpu/mmu_64.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)

Applied, thanks

Sascha

> 
> diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c
> index cdc482542202..1d5a5355c6be 100644
> --- a/arch/arm/cpu/mmu_64.c
> +++ b/arch/arm/cpu/mmu_64.c
> @@ -192,8 +192,20 @@ static void mmu_enable(void)
>   */
>  void __mmu_init(bool mmu_on)
>  {
> +	uint64_t *ttb = get_ttb();
>  	struct memory_bank *bank;
>  
> +	if (!request_sdram_region("ttb", (unsigned long)ttb,
> +				  ARM_EARLY_PAGETABLE_SIZE))
> +		/*
> +		 * This can mean that:
> +		 * - the early MMU code has put the ttb into a place
> +		 *   which we don't have inside our available memory
> +		 * - Somebody else has occupied the ttb region which means
> +		 *   the ttb will get corrupted.
> +		 */
> +		pr_crit("Can't request SDRAM region for ttb at %p\n", ttb);
> +
>  	for_each_memory_bank(bank) {
>  		struct resource *rsv;
>  		resource_size_t pos;
> -- 
> 2.39.2
> 
> 
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |