[PATCH v2 2/2] rockchip: sdram: add dram bank with usable memory beyond 4GB

[Kever Yang]

On 2023/2/8 01:27, Jonas Karlman wrote:
> Add a second dram bank of usable memory beyond the blob of space for
> peripheral near 4GB. Any memory that exists beyond the 4GB mark is added
> to the second bank.
>
> Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
Reviewed-by: Kever Yang <kever.yang at rock-chips.com>

Thanks,
- Kever
> ---
> v2:
> - Change CONFIG_SYS_SDRAM_BASE to CFG_SYS_SDRAM_BASE
>
>   arch/arm/mach-rockchip/sdram.c | 12 +++++++++---
>   1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/mach-rockchip/sdram.c b/arch/arm/mach-rockchip/sdram.c
> index 91951e4b8ccf..1d17a740ade9 100644
> --- a/arch/arm/mach-rockchip/sdram.c
> +++ b/arch/arm/mach-rockchip/sdram.c
> @@ -37,13 +37,19 @@ struct tos_parameter_t {
>   
>   int dram_init_banksize(void)
>   {
> -	size_t top = min((unsigned long)(gd->ram_size + CFG_SYS_SDRAM_BASE),
> -			 (unsigned long)(gd->ram_top));
> +	size_t ram_top = (unsigned long)(gd->ram_size + CFG_SYS_SDRAM_BASE);
> +	size_t top = min((unsigned long)ram_top, (unsigned long)(gd->ram_top));
>   
>   #ifdef CONFIG_ARM64
>   	/* Reserve 0x200000 for ATF bl31 */
>   	gd->bd->bi_dram[0].start = 0x200000;
>   	gd->bd->bi_dram[0].size = top - gd->bd->bi_dram[0].start;
> +
> +	/* Add usable memory beyond the blob of space for peripheral near 4GB */
> +	if (ram_top > SZ_4G && top < SZ_4G) {
> +		gd->bd->bi_dram[1].start = SZ_4G;
> +		gd->bd->bi_dram[1].size = ram_top - gd->bd->bi_dram[1].start;
> +	}
>   #else
>   #ifdef CONFIG_SPL_OPTEE_IMAGE
>   	struct tos_parameter_t *tos_parameter;
> @@ -181,7 +187,7 @@ size_t rockchip_sdram_size(phys_addr_t reg)
>   	 *   2. update board_get_usable_ram_top() and dram_init_banksize()
>   	 *   to reserve memory for peripheral space after previous update.
>   	 */
> -	if (size_mb > (SDRAM_MAX_SIZE >> 20))
> +	if (!IS_ENABLED(CONFIG_ARM64) && size_mb > (SDRAM_MAX_SIZE >> 20))
>   		size_mb = (SDRAM_MAX_SIZE >> 20);
>   
>   	return (size_t)size_mb << 20;