linux/arch/powerpc/kernel/idle_book3e.S
Stuart Yoder f070986a07 powerpc: Add paravirt idle loop for 64-bit Book-E
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2013-03-13 14:19:36 -05:00

102 lines
2.2 KiB
ArmAsm

/*
* 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>
/* 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
bnelr
/* 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 r0,1
stb r0,PACASOFTIRQEN(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
.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 */