diff options
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 8 | ||||
| -rw-r--r-- | arch/powerpc/kernel/process.c | 14 |
2 files changed, 16 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 6f70ea821a07..91f9fdc2d027 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -607,6 +607,14 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT) top of the kernel stack. */ addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE + /* + * PMU interrupts in radix may come in here. They will use r1, not + * PACAKSAVE, so this stack switch will not cause a problem. They + * will store to the process stack, which may then be migrated to + * another CPU. However the rq lock release on this CPU paired with + * the rq lock acquire on the new CPU before the stack becomes + * active on the new CPU, will order those stores. + */ mr r1,r8 /* start using new stack pointer */ std r7,PACAKSAVE(r13) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 5cbb8b1faf7e..45faa9a32a01 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1199,12 +1199,14 @@ struct task_struct *__switch_to(struct task_struct *prev, __switch_to_tm(prev, new); - /* - * We can't take a PMU exception inside _switch() since there is a - * window where the kernel stack SLB and the kernel stack are out - * of sync. Hard disable here. - */ - hard_irq_disable(); + if (!radix_enabled()) { + /* + * We can't take a PMU exception inside _switch() since there + * is a window where the kernel stack SLB and the kernel stack + * are out of sync. Hard disable here. + */ + hard_irq_disable(); + } /* * Call restore_sprs() before calling _switch(). If we move it after |