Messages in this thread | | | Subject | Re: [PATCH 1/6] MIPS: Loongson64: Do not write the read only field LPA of CP0_CONFIG3 | From | Jiaxun Yang <> | Date | Mon, 2 Nov 2020 18:47:50 +0800 |
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在 2020/10/30 20:13, Jiaxun Yang 写道: > > > 在 2020/10/30 14:22, Tiezhu Yang 写道: >> On 10/30/2020 12:00 PM, Jiaxun Yang wrote: >>> >>> >>> 在 2020/10/29 16:02, Tiezhu Yang 写道: >>>> The field LPA of CP0_CONFIG3 register is read only for Loongson64, >>>> so the >>>> write operations are meaningless, remove them. >>>> >>>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> >>>> --- >>>> arch/mips/include/asm/mach-loongson64/kernel-entry-init.h | 8 >>>> -------- >>>> arch/mips/loongson64/numa.c | 3 --- >>>> 2 files changed, 11 deletions(-) >>> Hi Tiezhu, >>> >>> AFAIK it's not read only on 3A1000. >>> Have you check with hardware guys? >> >> Hi Jiaxun, >> >> Yes, I checked it before send this patch, the field LPA of CP0_CONFIG3 >> on 3A1000 is also read only, we can see the related description in the >> chapter 3.22 of Loongson_3A1000_cpu_user_2. > > On page 36, it said: > "能否写ELPA位依赖于Config3寄存器的LPA域 。当Config3的LPA位为0时, > PageGrain的ELPA位被置位。" > > Don't know if it matters. > > @Huacai, Any comments? Do you know why it exists here?
Confirmed by another rev of the manual that it's only a tip for implementer. I guess my assumption was wrong. LPA should be read-only though.....
Thanks - Jiaxun
> > Thanks > > - Jiaxun
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