[PATCH] arm64: mvebu: handle non-zero base address for RAM

[Stefan Roese]

On 20.05.22 06:39, Chris Packham wrote:
> board_get_usable_ram_top() conflated the RAM size with the top address
> of RAM. On systems where RAM starts at address 0 these numbers are the
> same so it went unnoticed. Update board_get_usable_ram_top() to take
> CONFIG_SYS_SDRAM_BASE into account when determining the top address.
> 
> Signed-off-by: Chris Packham <judge.packham at gmail.com>
> ---
> I've got a 64-bit mvebu SoC/board that I plan on submitting in a few
> weeks. One of the gotchas with this board is that the physical address
> of the RAM starts at 0x2_00000000 (there's some seemingly unmovable I/O
> occupying the lower addresses).
> 
> This was one of the earlier issues I hit with porting. I figured it was
> independent enough that I could send it out while I'm still working on
> the rest of the series.
> 
>   arch/arm/mach-mvebu/arm64-common.c | 7 +++----
>   1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/mach-mvebu/arm64-common.c b/arch/arm/mach-mvebu/arm64-common.c
> index 5357aa554db4..238edbe6ba56 100644
> --- a/arch/arm/mach-mvebu/arm64-common.c
> +++ b/arch/arm/mach-mvebu/arm64-common.c
> @@ -28,14 +28,13 @@ DECLARE_GLOBAL_DATA_PTR;
>    * Currently only 2GiB are mapped for system memory. This is what
>    * we pass to the U-Boot subsystem here.
>    */
> -#define USABLE_RAM_SIZE		0x80000000
> +#define USABLE_RAM_SIZE		0x80000000ULL
>   
>   ulong board_get_usable_ram_top(ulong total_size)
>   {
> -	if (gd->ram_size > USABLE_RAM_SIZE)
> -		return USABLE_RAM_SIZE;
> +	unsigned long top = CONFIG_SYS_SDRAM_BASE + min(gd->ram_size, USABLE_RAM_SIZE);
>   
> -	return gd->ram_size;
> +	return (gd->ram_top > top) ? top : gd->ram_top;
>   }

Reviewed-by: Stefan Roese <sr at denx.de>

Thanks,
Stefan