Re: [PATCH v2 3/4 RESEND] MIPS: Loongson64: Add /proc/boardinfo

From: Tiezhu Yang <yangtiezhu@loongson.cn>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Jonathan Corbet <corbet@lwn.net>, Huacai Chen <chenhc@lemote.com>,
	Jiaxun Yang <jiaxun.yang@flygoat.com>,
	linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org, Xuefeng Li <lixuefeng@loongson.cn>
Subject: Re: [PATCH v2 3/4 RESEND] MIPS: Loongson64: Add /proc/boardinfo
Date: Mon, 12 Oct 2020 20:02:25 +0800	[thread overview]
Message-ID: <95060519-530b-c5f5-537d-a7b217b39003@loongson.cn> (raw)
In-Reply-To: <20201012103805.GC7953@alpha.franken.de>

On 10/12/2020 06:38 PM, Thomas Bogendoerfer wrote:
> On Sun, Oct 11, 2020 at 07:47:53AM +0800, Tiezhu Yang wrote:
>> Add /proc/boardinfo to get mainboard and BIOS info easily on the Loongson
>> platform, this is useful to point out the current used mainboard type and
>> BIOS version when there exists problems related with hardware or firmware.
>>
>> E.g. with this patch:
>>
>> [loongson@linux ~]$ cat /proc/boardinfo
>> Board Info
>> Manufacturer            : LEMOTE
>> Board Name              : LEMOTE-LS3A4000-7A1000-1w-V01-pc
>> Family                  : LOONGSON3
>>
>> BIOS Info
>> Vendor                  : Kunlun
>> Version                 : Kunlun-A1901-V4.1.3-20200414093938
>> ROM Size                : 4 KB
>> Release Date            : 2020-04-14
> Why does Loongson64 need this extra file no other architecture or MIPS
> platform need ? Do others provide this information via a different method ?
> If yes, why can't Loongson64 do the same ?

Hi Thomas,

This is related with the implementation of firmware.

Using dmidecode command can get the similar info if there exists SMBIOS
in firmware, but the fact is there is no SMBIOS on some machines, we can
see nothing when execute dmidecode, like this:

[root@linux loongson]# dmidecode
# dmidecode 2.12
# No SMBIOS nor DMI entry point found, sorry.

The following three structures are already defined in the interface
specification about firmware and kernel on the Loongson platform,
this is common requirement and specific for Loongson64, so add a
new boardinfo.c file in arch/mips/loongson64.

arch/mips/include/asm/mach-loongson64/boot_param.h
struct interface_info {
     u16 vers; /* version of the specificition */
     u16 size;
     u8  flag;
     char description[64];
} __packed;

struct board_devices {
     char name[64];    /* hold the device name */
     u32 num_resources; /* number of device_resource */
     /* for each device's resource */
     struct resource_loongson resource[MAX_RESOURCE_NUMBER];
     /* arch specific additions */
     struct archdev_data archdata;
};

struct loongson_special_attribute {
     u16 vers;     /* version of this special */
     char special_name[64]; /* special_atribute_name */
     u32 loongson_special_type; /* type of special device */
     /* for each device's resource */
     struct resource_loongson resource[MAX_RESOURCE_NUMBER];
};

Thanks,
Tiezhu

>
> Thomas.
>