From: Mathieu Desnoyers mathieu.desnoyers@efficios.com
Backport for 4.4
(cherry picked from commit d85be8a49e733dcd23674aa6202870d54bf5600d)
The placeholder for instruction selection should use the second argument's operand, which is %1, not %0. This could generate incorrect assembly code if the memory addressing of operand %0 is a different form from that of operand %1.
Also remove the %Un placeholder because having %Un placeholders for two operands which are based on the same local var (ptep) doesn't make much sense. By the way, it doesn't change the current behaviour because "<>" constraint is missing for the associated "=m".
[chleroy: revised commit log iaw segher's comments and removed %U0]
Fixes: 9bf2b5cdc5fe ("powerpc: Fixes for CONFIG_PTE_64BIT for SMP support") Cc: stable@vger.kernel.org # v2.6.28+ Signed-off-by: Mathieu Desnoyers mathieu.desnoyers@efficios.com Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Acked-by: Segher Boessenkool segher@kernel.crashing.org Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/96354bd77977a6a933fe9020da57629007fdb920.160335894... --- arch/powerpc/include/asm/pgtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index b64b4212b71f..408f9e1fa24a 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -149,9 +149,9 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, flush_hash_entry(mm, ptep, addr); #endif __asm__ __volatile__("\ - stw%U0%X0 %2,%0\n\ + stw%X0 %2,%0\n\ eieio\n\ - stw%U0%X0 %L2,%1" + stw%X1 %L2,%1" : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4)) : "r" (pte) : "memory");