Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Subject: Re: [PATCH 3/3] MIPS: Use memblock_add_node() in early_parse_mem()
 under CONFIG_NUMA
To:     Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>
References: <1647615920-23103-1-git-send-email-yangtiezhu@loongson.cn>
 <1647615920-23103-4-git-send-email-yangtiezhu@loongson.cn>
 <33241bd3-2f12-954c-6701-56cf563060bb@flygoat.com>
Cc:     Xuefeng Li <lixuefeng@loongson.cn>, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org
From:   Tiezhu Yang <yangtiezhu@loongson.cn>
Message-ID: <fb188614-0301-3255-c31c-3d443cf17b91@loongson.cn>
Date:   Wed, 23 Mar 2022 10:42:28 +0800
User-Agent: Mozilla/5.0 (X11; Linux mips64; rv:45.0) Gecko/20100101
 Thunderbird/45.4.0
MIME-Version: 1.0
In-Reply-To: <33241bd3-2f12-954c-6701-56cf563060bb@flygoat.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


On 03/22/2022 09:19 PM, Jiaxun Yang wrote:
>
>
> 在 2022/3/18 15:05, Tiezhu Yang 写道:
>> Use memblock_add_node to add new memblock region within a NUMA node
>> in early_parse_mem() under CONFIG_NUMA, otherwise the mem parameter
>> can not work well.
>
> Hi Tiezhu,
>
> pa_to_nid doesn't exist when CONFIG_NUME is disabled.
> So probably you want #ifdef macro instead ？

Hi Jiaxun,

Thank you for your reply.

As far as I can tell, if CONFIG_NUMA is set, IS_ENABLED(CONFIG_NUMA)
is 1, pa_to_nid() is defined in the platform dependent header file:

	arch/mips/include/asm/mach-ip27/mmzone.h
	arch/mips/include/asm/mach-loongson64/mmzone.h

if CONFIG_NUMA is not set, IS_ENABLED(CONFIG_NUMA) is 0, pa_to_nid()
is always 0 which is defined in arch/mips/include/asm/mmzone.h:

	#ifdef CONFIG_NUMA
	# include <mmzone.h>
	#endif

	#ifndef pa_to_nid
	#define pa_to_nid(addr) 0
	#endif

So pa_to_nid() is defined under both CONFIG_NUMA and !CONFIG_NUMA,
there is no build error.

Additionally, use #ifdef CONFIG_NUMA is also OK, but I prefer to
use IS_ENABLED(CONFIG_NUMA).

If I am missing something, please let me know, thank you.

Thanks,
Tiezhu

>
> Thanks.
> - Jiaxun
>
>>
>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>> ---
>>   arch/mips/kernel/setup.c | 6 +++++-
>>   1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
>> index c8c8f60..50cdc08 100644
>> --- a/arch/mips/kernel/setup.c
>> +++ b/arch/mips/kernel/setup.c
>> @@ -37,6 +37,7 @@
>>   #include <asm/cdmm.h>
>>   #include <asm/cpu.h>
>>   #include <asm/debug.h>
>> +#include <asm/mmzone.h>
>>   #include <asm/sections.h>
>>   #include <asm/setup.h>
>>   #include <asm/smp-ops.h>
>> @@ -378,7 +379,10 @@ static int __init early_parse_mem(char *p)
>>               memblock_end_of_DRAM() - memblock_start_of_DRAM());
>>       }
>>   -    memblock_add(start, size);
>> +    if (IS_ENABLED(CONFIG_NUMA))
>> +        memblock_add_node(start, size, pa_to_nid(start), MEMBLOCK_NONE);
>> +    else
>> +        memblock_add(start, size);
>>         return 0;
>>   }