Since the system reset interrupt began to use its own stack, and machine check interrupts have done so for some time, r1 can be changed without clearing MSR[RI], provided no other interrupts (including SLB misses) are taken.
MSR[RI] does have to be cleared when using SCRATCH0, however. Signed-off-by: Nicholas Piggin <npig...@gmail.com> --- arch/powerpc/kernel/tm.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S index 9fabdce255cd..6ba0fdd1e7f8 100644 --- a/arch/powerpc/kernel/tm.S +++ b/arch/powerpc/kernel/tm.S @@ -148,7 +148,7 @@ _GLOBAL(tm_reclaim) /* Stash the stack pointer away for use after reclaim */ std r1, PACAR1(r13) - /* Clear MSR RI since we are about to change r1, EE is already off. */ + /* Clear MSR RI since we are about to use SCRATCH0, EE is already off */ li r5, 0 mtmsrd r5, 1 @@ -474,7 +474,7 @@ restore_gprs: REST_GPR(7, r7) - /* Clear MSR RI since we are about to change r1. EE is already off */ + /* Clear MSR RI since we are about to use SCRATCH0. EE is already off */ li r5, 0 mtmsrd r5, 1 -- 2.20.1