[PATCH 1/1] imx8m: Restrict usable memory based on rom_pointer[0]

[Frieder Schrempf]

On 23.08.21 04:43, Ying-Chun Liu wrote:
> From: "Ying-Chun Liu (PaulLiu)" <paulliu at debian.org>
> 
> When TEE is loaded, we need to restrict the memory usage based
> on rom_pointer[0]
> 
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu at debian.org>
> Cc: Fabio Estevam <festevam at denx.de>
> Cc: Frieder Schrempf <frieder.schrempf at kontron.de>
> Cc: uboot-imx <uboot-imx at nxp.com>

Reviewed-by: Frieder Schrempf <frieder.schrempf at kontron.de>

> ---
>  arch/arm/mach-imx/imx8m/soc.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
> index f2ddc834d4..863508776d 100644
> --- a/arch/arm/mach-imx/imx8m/soc.c
> +++ b/arch/arm/mach-imx/imx8m/soc.c
> @@ -298,16 +298,26 @@ phys_size_t get_effective_memsize(void)
>  
>  ulong board_get_usable_ram_top(ulong total_size)
>  {
> +	ulong top_addr = PHYS_SDRAM + gd->ram_size;
> +
>  	/*
>  	 * Some IPs have their accessible address space restricted by
>  	 * the interconnect. Let's make sure U-Boot only ever uses the
>  	 * space below the 4G address boundary (which is 3GiB big),
>  	 * even when the effective available memory is bigger.
>  	 */
> -	if (PHYS_SDRAM + gd->ram_size > 0x80000000)
> -		return 0x80000000;
> +	if (top_addr > 0x80000000)
> +		top_addr = 0x80000000;
> +
> +	/*
> +	 * rom_pointer[0] stores the TEE memory start address.
> +	 * rom_pointer[1] stores the size TEE uses.
> +	 * We need to reserve the memory region for TEE.
> +	 */
> +	if (rom_pointer[0] && rom_pointer[1] && top_addr > rom_pointer[0])
> +		top_addr = rom_pointer[0];
>  
> -	return PHYS_SDRAM + gd->ram_size;
> +	return top_addr;
>  }
>  
>  static u32 get_cpu_variant_type(u32 type)
>