[PATCH v2 21/44] powerpc/64s/exception: remove 0xb00 handler

[Michael Ellerman]

Nicholas Piggin <npiggin at gmail.com> writes:
> This vector is not used by any supported processor, and has been
> implemented as an unknown exception going back to 2.6. There is
> nothing special about 0xb00, so remove it like other unused
> vectors.

Actually it goes back to the original ppc64 submission.

See (takes a while to load):
  https://github.com/mpe/linux-fullhistory/commit/c3aa9878533e724f639852c3d951e6a169e04081#diff-c7b0adae374819e9003279ff5f69226fR340


That commit had handlers for all the vectors from 0x100 through 0xf00,
with stubs for 0xa00, 0xb00 and 0xe00. But it's not at all clear why it
needed the stubs, possibly it was just being verbose.

0xa00 eventually became doorbell_super and 0xe00 became h_data_storage.
Leaving just 0xb00 as the lone relic.

</irrelevant-history>

Patch looks good.

cheers


> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 723c37f3da17..9c407392774c 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -1563,10 +1563,8 @@ EXC_COMMON_ASYNC(doorbell_super_common, 0xa00, unknown_exception)
>  #endif
>  
>  
> -EXC_REAL(trap_0b, 0xb00, 0x100)
> -EXC_VIRT(trap_0b, 0x4b00, 0x100, 0xb00)
> -TRAMP_KVM(PACA_EXGEN, 0xb00)
> -EXC_COMMON(trap_0b_common, 0xb00, unknown_exception)
> +EXC_REAL_NONE(0xb00, 0x100)
> +EXC_VIRT_NONE(0x4b00, 0x100)
>  
>  /*
>   * system call / hypercall (0xc00, 0x4c00)
> -- 
> 2.22.0