[linux-2.6-block.git] / arch / powerpc / kernel / idle_power4.S

/*
 *  This file contains the power_save function for 970-family CPUs.
 *
 *  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/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)
	CURRENT_THREAD_INFO(r9, r1)
	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
Commit	Line	Data
1da177e4	1	/*
ff2e6d7e	2	* This file contains the power_save function for 970-family CPUs.
1da177e4 LT	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*/
	9
1da177e4 LT	10	#include <linux/threads.h>
	11	#include <asm/processor.h>
	12	#include <asm/page.h>
	13	#include <asm/cputable.h>
	14	#include <asm/thread_info.h>
	15	#include <asm/ppc_asm.h>
0013a854	16	#include <asm/asm-offsets.h>
7230c564	17	#include <asm/irqflags.h>
c2e480ba	18	#include <asm/hw_irq.h>
2c86cd18	19	#include <asm/feature-fixups.h>
1da177e4 LT	20
	21	#undef DEBUG
	22
	23	.text
	24
1da177e4 LT	25	_GLOBAL(power4_idle)
	26	BEGIN_FTR_SECTION
	27	blr
	28	END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP)
1da177e4	29	/* Now check if user or arch enabled NAP mode */
e58c3495 DG	30	LOAD_REG_ADDRBASE(r3,powersave_nap)
e58c3495 DG	31	lwz r4,ADDROFF(powersave_nap)(r3)
1da177e4 LT	32	cmpwi 0,r4,0
	33	beqlr
	34
993ff6d9 NP	35	/* This sequence is similar to prep_irq_for_idle() */
993ff6d9 NP	36
7230c564	37	/* Hard disable interrupts */
d04c56f7 PM	38	mfmsr r7
	39	rldicl r0,r7,48,1
	40	rotldi r0,r0,16
7230c564 BH	41	mtmsrd r0,1
	42
	43	/* Check if something happened while soft-disabled */
	44	lbz r0,PACAIRQHAPPENED(r13)
	45	cmpwi cr0,r0,0
993ff6d9	46	bne- 2f
7230c564	47
993ff6d9 NP	48	/*
	49	* Soft-enable interrupts. This will make power4_fixup_nap return
	50	* to our caller with interrupts enabled (soft and hard). The caller
	51	* can cope with either interrupts disabled or enabled upon return.
	52	*/
7230c564	53	#ifdef CONFIG_TRACE_IRQFLAGS
993ff6d9	54	/* Tell the tracer interrupts are on, because idle responds to them. */
7230c564 BH	55	mflr r0
	56	std r0,16(r1)
	57	stdu r1,-128(r1)
b1576fec	58	bl trace_hardirqs_on
7230c564 BH	59	addi r1,r1,128
	60	ld r0,16(r1)
	61	mtlr r0
01e8ec44	62	mfmsr r7
7230c564 BH	63	#endif /* CONFIG_TRACE_IRQFLAGS */
7230c564 BH	64
c2e480ba	65	li r0,IRQS_ENABLED
4e26bc4a	66	stb r0,PACAIRQSOFTMASK(r13) /* we'll hard-enable shortly */
1da177e4 LT	67	BEGIN_FTR_SECTION
	68	DSSALL
	69	sync
	70	END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
9778b696	71	CURRENT_THREAD_INFO(r9, r1)
f39224a8 PM	72	ld r8,TI_LOCAL_FLAGS(r9) /* set napping bit */
	73	ori r8,r8,_TLF_NAPPING /* so when we take an exception */
	74	std r8,TI_LOCAL_FLAGS(r9) /* it will return to our caller */
ff2e6d7e	75	ori r7,r7,MSR_EE
1da177e4	76	oris r7,r7,MSR_POW@h
f39224a8	77	1: sync
1da177e4 LT	78	isync
	79	mtmsrd r7
	80	isync
f39224a8 PM	81	b 1b
f39224a8 PM	82
993ff6d9 NP	83	2: /* Return if an interrupt had happened while soft disabled */
	84	/* Set the HARD_DIS flag because interrupts are now hard disabled */
	85	ori r0,r0,PACA_IRQ_HARD_DIS
	86	stb r0,PACAIRQHAPPENED(r13)
	87	blr