[PATCH 08/20] rockchip: sdram: honor CFG_SYS_SDRAM_BASE when defining ram regions

[Quentin Schulz]

Hi Heiko,

On 11/21/24 3:27 PM, Heiko Stuebner wrote:
> Currently the sdram code for arm64 expects CFG_SYS_SDRAM_BASE to be 0.
> The ram being in front and the device-area behind it.
> 
> The upcoming RK3576 uses a different layout, with the device area
> in front the ram, which then also extends past the 4G mark.
> 
> Adapt both the generic zone definitions as well as the ATAG parser
> to be usable on devices where CFG_SYS_SDRAM_BASE is not 0.
> 
> Signed-off-by: Heiko Stuebner <heiko at sntech.de>
> ---
>   arch/arm/mach-rockchip/sdram.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm/mach-rockchip/sdram.c b/arch/arm/mach-rockchip/sdram.c
> index 1fb01e1c4b1..4e2af55d6e1 100644
> --- a/arch/arm/mach-rockchip/sdram.c
> +++ b/arch/arm/mach-rockchip/sdram.c
> @@ -181,9 +181,9 @@ static int rockchip_dram_init_banksize(void)
>   		 * BL31 (TF-A) reserves the first 2MB but DDR_MEM tag may not
>   		 * have it, so force this space as reserved.
>   		 */
> -		if (start_addr < SZ_2M) {
> -			size -= SZ_2M - start_addr;
> -			start_addr = SZ_2M;
> +		if (start_addr < SZ_2M + CFG_SYS_SDRAM_BASE) {
> +			size -= SZ_2M - (start_addr - CFG_SYS_SDRAM_BASE);
> +			start_addr = SZ_2M + CFG_SYS_SDRAM_BASE;

I would just put CFG_SYS_SDRAM_BASE on the left side of SZ_2M.

I would also do

size -= CFG_SYS_SDRAM_BASE + SZ_2M - start_addr;

But those nitpicks are just a matter of taste, therefore

Reviewed-by: Quentin Schulz <quentin.schulz at cherry.de>

Thanks!
Quentin