blob: 33c625329078f0d802bdeef0d49cd485ff1414dc [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* This file contains the power_save function for 970-family CPUs.
*/
#include <linux/threads.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/cputable.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/irqflags.h>
#include <asm/hw_irq.h>
#include <asm/feature-fixups.h>
#undef DEBUG
.text
_GLOBAL(power4_idle)
BEGIN_FTR_SECTION
blr
END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP)
/* Now check if user or arch enabled NAP mode */
LOAD_REG_ADDRBASE(r3,powersave_nap)
lwz r4,ADDROFF(powersave_nap)(r3)
cmpwi 0,r4,0
beqlr
/* This sequence is similar to prep_irq_for_idle() */
/* Hard disable interrupts */
mfmsr r7
rldicl r0,r7,48,1
rotldi r0,r0,16
mtmsrd r0,1
/* Check if something happened while soft-disabled */
lbz r0,PACAIRQHAPPENED(r13)
cmpwi cr0,r0,0
bne- 2f
/*
* Soft-enable interrupts. This will make power4_fixup_nap return
* to our caller with interrupts enabled (soft and hard). The caller
* can cope with either interrupts disabled or enabled upon return.
*/
#ifdef CONFIG_TRACE_IRQFLAGS
/* Tell the tracer interrupts are on, because idle responds to them. */
mflr r0
std r0,16(r1)
stdu r1,-128(r1)
bl trace_hardirqs_on
addi r1,r1,128
ld r0,16(r1)
mtlr r0
mfmsr r7
#endif /* CONFIG_TRACE_IRQFLAGS */
li r0,IRQS_ENABLED
stb r0,PACAIRQSOFTMASK(r13) /* we'll hard-enable shortly */
BEGIN_FTR_SECTION
DSSALL
sync
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
ld r9, PACA_THREAD_INFO(r13)
ld r8,TI_LOCAL_FLAGS(r9) /* set napping bit */
ori r8,r8,_TLF_NAPPING /* so when we take an exception */
std r8,TI_LOCAL_FLAGS(r9) /* it will return to our caller */
ori r7,r7,MSR_EE
oris r7,r7,MSR_POW@h
1: sync
isync
mtmsrd r7
isync
b 1b
2: /* Return if an interrupt had happened while soft disabled */
/* Set the HARD_DIS flag because interrupts are now hard disabled */
ori r0,r0,PACA_IRQ_HARD_DIS
stb r0,PACAIRQHAPPENED(r13)
blr