[PATCH] powerpc/mm/radix: Drop support for CPUs without lockless tlbie

[Nicholas Piggin]

On Wed,  3 May 2017 14:44:59 +1000
Michael Ellerman <mpe at ellerman.id.au> wrote:

> Currently the radix TLB code includes support for CPUs that do *not*
> have MMU_FTR_LOCKLESS_TLBIE. On those CPUs we are required to take a
> global spinlock before issuing a tlbie.
> 
> Radix can only be built for 64-bit Book3s CPUs, and of those, only
> POWER4, 970, Cell and PA6T do not have MMU_FTR_LOCKLESS_TLBIE. Although
> it's possible to build a kernel with Radix support that can also boot on
> those CPUs, we happen to know that in reality none of those CPUs support
> the Radix MMU, so the code can never actually run on those CPUs.
> 
> So remove the native_tlbie_lock in the Radix TLB code.
> 
> Note that there is another lock of the same name in the hash code, which
> is unaffected by this patch.
> 
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>

Good idea.

Reviewed-by: Nicholas Piggin <npiggin at gmail.com>