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From:   Damien Le Moal <Damien.LeMoal@wdc.com>
To:     Vitaly Wool <vitaly.wool@konsulko.com>,
        "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>
CC:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Anup Patel <anup@brainfault.org>,
        Palmer Dabbelt <palmerdabbelt@google.com>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
Subject: Re: [PATCH] RISC-V: simplify BUILTIN_DTB processing
Thread-Topic: [PATCH] RISC-V: simplify BUILTIN_DTB processing
Thread-Index: AQHW6F+wb8gN2NR8V0SpNievsT3NMA==
Date:   Tue, 12 Jan 2021 04:56:42 +0000
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References: <20210111212031.2422-1-vitaly.wool@konsulko.com>
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On 2021/01/12 6:21, Vitaly Wool wrote:=0A=
> Provide __dtb_start as a parameter to setup_vm() in case=0A=
> CONFIG_BUILTIN_DTB is true, so we don't have to duplicate=0A=
> BUILTIN_DTB specific processing in MMU-enabled and MMU-disabled=0A=
> versions of setup_vm().=0A=
> =0A=
> Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>=0A=
> ---=0A=
>  arch/riscv/kernel/head.S | 4 ++++=0A=
>  arch/riscv/mm/init.c     | 4 ----=0A=
>  2 files changed, 4 insertions(+), 4 deletions(-)=0A=
> =0A=
> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S=0A=
> index 16e9941900c4..f5a9bad86e58 100644=0A=
> --- a/arch/riscv/kernel/head.S=0A=
> +++ b/arch/riscv/kernel/head.S=0A=
> @@ -260,7 +260,11 @@ clear_bss_done:=0A=
>  =0A=
>  	/* Initialize page tables and relocate to virtual addresses */=0A=
>  	la sp, init_thread_union + THREAD_SIZE=0A=
> +#ifdef CONFIG_BUILTIN_DTB=0A=
> +	la a0, __dtb_start=0A=
> +#else=0A=
>  	mv a0, s1=0A=
> +#endif /* CONFIG_BUILTIN_DTB */=0A=
>  	call setup_vm=0A=
>  #ifdef CONFIG_MMU=0A=
>  	la a0, early_pg_dir=0A=
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c=0A=
> index 5b17f8d22f91..45faad7c4291 100644=0A=
> --- a/arch/riscv/mm/init.c=0A=
> +++ b/arch/riscv/mm/init.c=0A=
> @@ -615,11 +615,7 @@ static void __init setup_vm_final(void)=0A=
>  #else=0A=
>  asmlinkage void __init setup_vm(uintptr_t dtb_pa)=0A=
>  {=0A=
> -#ifdef CONFIG_BUILTIN_DTB=0A=
> -	dtb_early_va =3D (void *) __dtb_start;=0A=
> -#else=0A=
>  	dtb_early_va =3D (void *)dtb_pa;=0A=
> -#endif=0A=
>  	dtb_early_pa =3D dtb_pa;=0A=
>  }=0A=
>  =0A=
> =0A=
=0A=
Tested this with a nommu kernel on a MAIX bit board (K210 SoC). No problems=
=0A=
detected.=0A=
=0A=
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>=0A=
=0A=
-- =0A=
Damien Le Moal=0A=
Western Digital Research=0A=