powerpc/64s/hash: Fix assert_slb_presence() use of the slbfee. instruction

[Michael Ellerman]

On Fri, 2019-02-15 at 10:20:20 UTC, Nicholas Piggin wrote:
> The slbfee. instruction must have bit 24 of RB clear, failure to do
> so can result in false negatives that result in incorrect assertions.
> 
> This is not obvious from the ISA v3.0B document, which only says:
> 
>     The hardware ignores the contents of RB 36:38 40:63 -- p.1032
> 
> This patch fixes the bug and also clears all other bits from PPC bit
> 36-63, which is good practice when dealing with reserved or ignored
> bits.
> 
> Fixes: e15a4fea4d ("powerpc/64s/hash: Add some SLB debugging tests")
> Reported-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
> Tested-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/7104dccfd052fde51eecc9972dad9c40

cheers