Re: [PATCH] RISC-V: simplify BUILTIN_DTB processing

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2021/01/12 6:21, Vitaly Wool wrote:
> Provide __dtb_start as a parameter to setup_vm() in case
> CONFIG_BUILTIN_DTB is true, so we don't have to duplicate
> BUILTIN_DTB specific processing in MMU-enabled and MMU-disabled
> versions of setup_vm().
> 
> Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
> ---
>  arch/riscv/kernel/head.S | 4 ++++
>  arch/riscv/mm/init.c     | 4 ----
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
> index 16e9941900c4..f5a9bad86e58 100644
> --- a/arch/riscv/kernel/head.S
> +++ b/arch/riscv/kernel/head.S
> @@ -260,7 +260,11 @@ clear_bss_done:
>  
>  	/* Initialize page tables and relocate to virtual addresses */
>  	la sp, init_thread_union + THREAD_SIZE
> +#ifdef CONFIG_BUILTIN_DTB
> +	la a0, __dtb_start
> +#else
>  	mv a0, s1
> +#endif /* CONFIG_BUILTIN_DTB */
>  	call setup_vm
>  #ifdef CONFIG_MMU
>  	la a0, early_pg_dir
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 5b17f8d22f91..45faad7c4291 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -615,11 +615,7 @@ static void __init setup_vm_final(void)
>  #else
>  asmlinkage void __init setup_vm(uintptr_t dtb_pa)
>  {
> -#ifdef CONFIG_BUILTIN_DTB
> -	dtb_early_va = (void *) __dtb_start;
> -#else
>  	dtb_early_va = (void *)dtb_pa;
> -#endif
>  	dtb_early_pa = dtb_pa;
>  }
>  
> 

Tested this with a nommu kernel on a MAIX bit board (K210 SoC). No problems
detected.

Tested-by: Damien Le Moal <damien.lemoal@wdc.com>

-- 
Damien Le Moal
Western Digital Research