Re: [PATCH v2 RESEND 4/4] MIPS: emulate CPUCFG instruction on older Loongson64 cores

[WANG Xuerui <kernel@xen0n.name>]

On 5/17/20 4:37 PM, Thomas Bogendoerfer wrote:

> On Sun, May 03, 2020 at 06:50:13PM +0800, WANG Xuerui wrote:
>> +#endif
>> +
>> +#endif /* _ASM_MACH_LOONGSON64_CPUCFG_EMUL_H_ */
>> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
>> index ca2e6f1af4fe..907e31ff562f 100644
>> --- a/arch/mips/kernel/cpu-probe.c
>> +++ b/arch/mips/kernel/cpu-probe.c
>> @@ -28,6 +28,8 @@
>>   #include <asm/spram.h>
>>   #include <linux/uaccess.h>
>>   
>> +#include <asm/mach-loongson64/cpucfg-emul.h>
>> +
> this doesn't fly:
>
> In file included from /local/tbogendoerfer/korg/linux/arch/mips/kernel/cpu-probe.c:31:0:
> /local/tbogendoerfer/korg/linux/arch/mips/include/asm/mach-loongson64/cpucfg-emul.h:7:27: fatal error: loongson_regs.h: No such file or directory
>   #include <loongson_regs.h>
>                             ^
> compilation terminated.
>
> Is there a chance to put this code in a loongsoon specific file ?

Oops... I'll rebase tonight to fix this. Might be caused by the build 
system changes merged in the meantime.

As for the logic separation, I'm 100% in agreement with this, but I 
don't know of any way to invoke mach-specific bits from inside 
cpu-probe. Plus all the PRId matching logic have to be duplicated if the 
code is to be moved to the loongson64/ sub-directory. I didn't find any 
other platform that does this, so I just extended the probing code.

Other way is to treat the whole CPUCFG thing just like the r2-to-r6-emul 
thing, which means moving all the logic to kernel/ sub-directory. But 
I'd rather not do this, for reasons explained in the cover letter.

>
> Thomas.
>