Re: [PATCH] riscv: mm: fix wrong phys_ram_base value for RV64

From: Alexandre ghiti <alex@ghiti.fr>
To: Jisheng Zhang <jszhang@kernel.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] riscv: mm: fix wrong phys_ram_base value for RV64
Date: Thu, 2 Dec 2021 16:52:08 +0100	[thread overview]
Message-ID: <baa3e6dc-cfbc-c491-384a-639867734a7f@ghiti.fr> (raw)
In-Reply-To: <20211202153641.1961-1-jszhang@kernel.org>

On 12/2/21 16:36, Jisheng Zhang wrote:
> Currently, if 64BIT and !XIP_KERNEL, the phys_ram_base is always 0,
> no matter the real start of dram reported by memblock is. The original
> patch[1] is correct, I believe it's not corrected merged due to lots
> of #ifdef in arch/riscv/mm/init.c, I plan to send a clean up series
> soon.
>
> [1] http://lists.infradead.org/pipermail/linux-riscv/2021-July/007650.html
>
> Fixes: 6d7f91d914bc ("riscv: Get rid of CONFIG_PHYS_RAM_BASE in kernel physical address conversion")
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> ---
>   arch/riscv/mm/init.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 24b2b8044602..3c0649dba4ff 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -187,10 +187,10 @@ static void __init setup_bootmem(void)
>   
>   
>   	phys_ram_end = memblock_end_of_DRAM();
> -#ifndef CONFIG_64BIT
>   #ifndef CONFIG_XIP_KERNEL
>   	phys_ram_base = memblock_start_of_DRAM();
>   #endif
> +#ifndef CONFIG_64BIT
>   	/*
>   	 * memblock allocator is not aware of the fact that last 4K bytes of
>   	 * the addressable memory can not be mapped because of IS_ERR_VALUE

Good catch, you can add:

Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>

And looking forward to your cleanup patch ;)

Thanks,

Alex