diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 6f70ea821a07d86955a80be14dcd44d42f1da005..91f9fdc2d027df702c5d2768f215fef2f01ba90c 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 5cbb8b1faf7e5073262381e76ddb975c1f845ed5..45faa9a32a0190325908e5986daed62972bf4296 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