From: Jiaxun Yang <jiaxun.yang@flygoat.com>
To: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org, paul.burton@mips.com, stable@vger.kernel.org
Subject: Re: [PATCH] MIPS: elf_hwcap: Export microMIPS and vz
Date: Thu, 24 Oct 2019 14:32:05 +0800 [thread overview]
Message-ID: <B1A8B4BF-FF80-4E6D-9B4F-8E45B0EF5FE5@flygoat.com> (raw)
In-Reply-To: <20191024040624.eezpuusvhujfffud@lantea.localdomain>
于 2019年10月24日 GMT+08:00 下午12:06:24, Paul Burton <paulburton@kernel.org> 写到:
>Hi Jiaxun,
>
>On Wed, Oct 23, 2019 at 11:25:51PM +0800, Jiaxun Yang wrote:
>> After further discussion with userland library develpoer,
>> we addressed another two ASEs that can be used runtimely in programs.
>>
>> Export them in hwcap as well to benefit userspace programs.
>>
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> Cc: <stable@vger.kernel.org> # 4.4+
>> ---
>> arch/mips/include/uapi/asm/hwcap.h | 2 ++
>> arch/mips/kernel/cpu-probe.c | 7 ++++++-
>> 2 files changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/mips/include/uapi/asm/hwcap.h
>b/arch/mips/include/uapi/asm/hwcap.h
>> index 1ade1daa4921..e1a9bac62149 100644
>> --- a/arch/mips/include/uapi/asm/hwcap.h
>> +++ b/arch/mips/include/uapi/asm/hwcap.h
>> @@ -17,5 +17,7 @@
>> #define HWCAP_LOONGSON_MMI (1 << 11)
>> #define HWCAP_LOONGSON_EXT (1 << 12)
>> #define HWCAP_LOONGSON_EXT2 (1 << 13)
>> +#define HWCAP_MIPS_MICROMIPS (1 << 14)
>> +#define HWCAP_MIPS_VZ (1 << 15)
>
>What's the motivation for exposing VZ? Userland can't actually use it
>without something like KVM, which already exposes a means of detecting
>whether VZ is supported (try the creating a VM of type KVM_VM_MIPS_VZ &
>see if it works). I'm not sure what userland would be able to do with
>this information in AT_HWCAP
Hi Paul,
Well, that was preposed by a kvm developer from Loongson. They want to use it to implement CPU_AUTOPROBE and load required modules automatically.
As they said they will submit KVM support to mainline later, I'm just occupied a place for them.
Out of tree commit:
http://cgit.loongnix.org/cgit/linux-3.10/commit/?id=4db9301cca3b49358d46fd0da67c01ab2ae4a3e3
--
Jiaxun Yang
next prev parent reply other threads:[~2019-10-24 6:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-23 15:25 [PATCH] MIPS: elf_hwcap: Export microMIPS and vz Jiaxun Yang
2019-10-24 4:06 ` Paul Burton
2019-10-24 6:32 ` Jiaxun Yang [this message]
2019-10-24 8:13 ` Sergei Shtylyov
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