[PATCH v2 0/4] powerpc/64: syscalls in C

[Christophe Leroy]

Le 28/08/2019 à 11:49, Nicholas Piggin a écrit :
> Christophe Leroy's on August 28, 2019 7:06 pm:
>>
>>
>> Le 27/08/2019 à 15:55, Nicholas Piggin a écrit :
>>> Accounted for some feedback.
>>>
>>> Nicholas Piggin (4):
>>>     powerpc: convert to copy_thread_tls
>>>     powerpc/64: remove support for kernel-mode syscalls
>>>     powerpc/64: system call remove non-volatile GPR save optimisation
>>>     powerpc/64: system call implement the bulk of the logic in C
>>
>> Would it be possible to split in the following parts:
>>
>> 1/ Implement in C whatever can be implemented without removing
>> non-volatile GPR save optimisation
>> 2/ Remove non-volatile GPR save optimisation
>> 3/ Implement in C everything else
> 
> Hmm. I'll have a look but I would rather not go back and add the
> intermediate state I was hoping to avoid. I'll think about it and
> if it's not too difficult I will try to add something. I have an
> idea.
> 
> With your nvregs performance test on ppc32, are you doing the
> nvgpr restore? The fast path should be able to avoid that.

I only added the SAVE_NVGPRS call in the syscall entry macro just after 
the saving of volatile regs, and changed the trap from \trapno+1 to \trapno

Christophe