v4.19.13 snapshot.
diff --git a/arch/powerpc/kernel/idle_book3e.S b/arch/powerpc/kernel/idle_book3e.S
new file mode 100644
index 0000000..4e0d94d
--- /dev/null
+++ b/arch/powerpc/kernel/idle_book3e.S
@@ -0,0 +1,107 @@
+/*
+ * Copyright 2010 IBM Corp, Benjamin Herrenschmidt <benh@kernel.crashing.org>
+ *
+ * Generic idle routine for Book3E processors
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/threads.h>
+#include <asm/reg.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/ppc-opcode.h>
+#include <asm/processor.h>
+#include <asm/thread_info.h>
+#include <asm/epapr_hcalls.h>
+#include <asm/hw_irq.h>
+
+/* 64-bit version only for now */
+#ifdef CONFIG_PPC64
+
+.macro BOOK3E_IDLE name loop
+_GLOBAL(\name)
+ /* Save LR for later */
+ mflr r0
+ std r0,16(r1)
+
+ /* Hard disable interrupts */
+ wrteei 0
+
+ /* Now check if an interrupt came in while we were soft disabled
+ * since we may otherwise lose it (doorbells etc...).
+ */
+ lbz r3,PACAIRQHAPPENED(r13)
+ cmpwi cr0,r3,0
+ bne 2f
+
+ /* Now we are going to mark ourselves as soft and hard enabled in
+ * order to be able to take interrupts while asleep. We inform lockdep
+ * of that. We don't actually turn interrupts on just yet tho.
+ */
+#ifdef CONFIG_TRACE_IRQFLAGS
+ stdu r1,-128(r1)
+ bl trace_hardirqs_on
+ addi r1,r1,128
+#endif
+ li r0,IRQS_ENABLED
+ stb r0,PACAIRQSOFTMASK(r13)
+
+ /* Interrupts will make use return to LR, so get something we want
+ * in there
+ */
+ bl 1f
+
+ /* And return (interrupts are on) */
+ ld r0,16(r1)
+ mtlr r0
+ blr
+
+1: /* Let's set the _TLF_NAPPING flag so interrupts make us return
+ * to the right spot
+ */
+ CURRENT_THREAD_INFO(r11, r1)
+ ld r10,TI_LOCAL_FLAGS(r11)
+ ori r10,r10,_TLF_NAPPING
+ std r10,TI_LOCAL_FLAGS(r11)
+
+ /* We can now re-enable hard interrupts and go to sleep */
+ wrteei 1
+ \loop
+
+2:
+ lbz r10,PACAIRQHAPPENED(r13)
+ ori r10,r10,PACA_IRQ_HARD_DIS
+ stb r10,PACAIRQHAPPENED(r13)
+ blr
+.endm
+
+.macro BOOK3E_IDLE_LOOP
+1:
+ PPC_WAIT(0)
+ b 1b
+.endm
+
+/* epapr_ev_idle_start below is patched with the proper hcall
+ opcodes during kernel initialization */
+.macro EPAPR_EV_IDLE_LOOP
+idle_loop:
+ LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
+
+.global epapr_ev_idle_start
+epapr_ev_idle_start:
+ li r3, -1
+ nop
+ nop
+ nop
+ b idle_loop
+.endm
+
+BOOK3E_IDLE epapr_ev_idle EPAPR_EV_IDLE_LOOP
+
+BOOK3E_IDLE book3e_idle BOOK3E_IDLE_LOOP
+
+#endif /* CONFIG_PPC64 */