powerpc: Unify the 32 and 64 bit idle loops

This unifies the 32-bit (ARCH=ppc and ARCH=powerpc) and 64-bit idle
loops.  It brings over the concept of having a ppc_md.power_save
function from 32-bit to ARCH=powerpc, which lets us get rid of
native_idle().  With this we will also be able to simplify the idle
handling for pSeries and cell.
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/Makefile

@@ -12,12 +12,12 @@ endif
 
 obj-y				:= semaphore.o cputable.o ptrace.o syscalls.o \
 				   irq.o align.o signal_32.o pmc.o vdso.o \
-				   init_task.o process.o systbl.o
+				   init_task.o process.o systbl.o idle.o
 obj-y				+= vdso32/
 obj-$(CONFIG_PPC64)		+= setup_64.o binfmt_elf32.o sys_ppc32.o \
 				   signal_64.o ptrace32.o \
 				   paca.o cpu_setup_power4.o \
-				   firmware.o sysfs.o idle_64.o
+				   firmware.o sysfs.o
 obj-$(CONFIG_PPC64)		+= vdso64/
 obj-$(CONFIG_ALTIVEC)		+= vecemu.o vector.o
 obj-$(CONFIG_POWER4)		+= idle_power4.o
@@ -34,6 +34,7 @@ obj-$(CONFIG_IBMEBUS)           += ibmebus.o
 obj-$(CONFIG_GENERIC_TBSYNC)	+= smp-tbsync.o
 obj64-$(CONFIG_PPC_MULTIPLATFORM) += nvram_64.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
+obj-$(CONFIG_6xx)		+= idle_6xx.o
 
 ifeq ($(CONFIG_PPC_MERGE),y)
 
@@ -51,7 +52,6 @@ obj-$(CONFIG_PPC64)		+= misc_64.o dma_64.o iommu.o
 obj-$(CONFIG_PPC_MULTIPLATFORM)	+= prom_init.o
 obj-$(CONFIG_MODULES)		+= ppc_ksyms.o
 obj-$(CONFIG_BOOTX_TEXT)	+= btext.o
-obj-$(CONFIG_6xx)		+= idle_6xx.o
 obj-$(CONFIG_SMP)		+= smp.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_PPC_UDBG_16550)	+= legacy_serial.o udbg_16550.o

arch/powerpc/kernel/entry_32.S

@@ -135,10 +135,10 @@ transfer_to_handler:
 	mfspr	r11,SPRN_HID0
 	mtcr	r11
 BEGIN_FTR_SECTION
-	bt-	8,power_save_6xx_restore	/* Check DOZE */
+	bt-	8,4f			/* Check DOZE */
 END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
 BEGIN_FTR_SECTION
-	bt-	9,power_save_6xx_restore	/* Check NAP */
+	bt-	9,4f			/* Check NAP */
 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
 #endif /* CONFIG_6xx */
 	.globl transfer_to_handler_cont
@@ -157,6 +157,10 @@ transfer_to_handler_cont:
 	SYNC
 	RFI				/* jump to handler, enable MMU */
 
+#ifdef CONFIG_6xx	
+4:	b	power_save_6xx_restore
+#endif
+
 /*
  * On kernel stack overflow, load up an initial stack pointer
  * and call StackOverflow(regs), which should not return.

arch/powerpc/kernel/idle_64.c → arch/powerpc/kernel/idle.c

@@ -2,13 +2,17 @@
  * Idle daemon for PowerPC.  Idle daemon will handle any action
  * that needs to be taken when the system becomes idle.
  *
- * Originally Written by Cort Dougan (cort@cs.nmt.edu)
+ * Originally written by Cort Dougan (cort@cs.nmt.edu).
+ * Subsequent 32-bit hacking by Tom Rini, Armin Kuster,
+ * Paul Mackerras and others.
  *
  * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
  *
  * Additional shared processor, SMT, and firmware support
  *    Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
  *
+ * 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org>
+ *
  * 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
@@ -29,18 +33,43 @@
 #include <asm/machdep.h>
 #include <asm/smp.h>
 
-extern void power4_idle(void);
+#ifdef CONFIG_HOTPLUG_CPU
+#define cpu_should_die()	(cpu_is_offline(smp_processor_id()) && \
+				 system_state == SYSTEM_RUNNING)
+#else
+#define cpu_should_die()	0
+#endif
 
-void default_idle(void)
+/*
+ * The body of the idle task.
+ */
+void cpu_idle(void)
 {
-	unsigned int cpu = smp_processor_id();
-	set_thread_flag(TIF_POLLING_NRFLAG);
+	if (ppc_md.idle_loop)
+		ppc_md.idle_loop();	/* doesn't return */
 
+	set_thread_flag(TIF_POLLING_NRFLAG);
 	while (1) {
-		if (!need_resched()) {
-			while (!need_resched() && !cpu_is_offline(cpu)) {
-				ppc64_runlatch_off();
+		ppc64_runlatch_off();
 
+		while (!need_resched() && !cpu_should_die()) {
+			if (ppc_md.power_save) {
+				clear_thread_flag(TIF_POLLING_NRFLAG);
+				/*
+				 * smp_mb is so clearing of TIF_POLLING_NRFLAG
+				 * is ordered w.r.t. need_resched() test.
+				 */
+				smp_mb();
+				local_irq_disable();
+
+				/* check again after disabling irqs */
+				if (!need_resched() && !cpu_should_die())
+					ppc_md.power_save();
+
+				local_irq_enable();
+				set_thread_flag(TIF_POLLING_NRFLAG);
+
+			} else {
 				/*
 				 * Go into low thread priority and possibly
 				 * low power mode.
@@ -48,46 +77,18 @@ void default_idle(void)
 				HMT_low();
 				HMT_very_low();
 			}
-
-			HMT_medium();
 		}
 
+		HMT_medium();
 		ppc64_runlatch_on();
+		if (cpu_should_die())
+			cpu_die();
 		preempt_enable_no_resched();
 		schedule();
 		preempt_disable();
-		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
-			cpu_die();
 	}
 }
 
-void native_idle(void)
-{
-	while (1) {
-		ppc64_runlatch_off();
-
-		if (!need_resched())
-			power4_idle();
-
-		if (need_resched()) {
-			ppc64_runlatch_on();
-			preempt_enable_no_resched();
-			schedule();
-			preempt_disable();
-		}
-
-		if (cpu_is_offline(smp_processor_id()) &&
-		    system_state == SYSTEM_RUNNING)
-			cpu_die();
-	}
-}
-
-void cpu_idle(void)
-{
-	BUG_ON(NULL == ppc_md.idle_loop);
-	ppc_md.idle_loop();
-}
-
 int powersave_nap;
 
 #ifdef CONFIG_SYSCTL

arch/powerpc/kernel/idle_6xx.S

@@ -87,19 +87,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
 	cmpwi	0,r3,0
 	beqlr
 
-	/* Clear MSR:EE */
-	mfmsr	r7
-	rlwinm	r0,r7,0,17,15
-	mtmsr	r0
-
-	/* Check current_thread_info()->flags */
-	rlwinm	r4,r1,0,0,18
-	lwz	r4,TI_FLAGS(r4)
-	andi.	r0,r4,_TIF_NEED_RESCHED
-	beq	1f
-	mtmsr	r7	/* out of line this ? */
-	blr
-1:	
 	/* Some pre-nap cleanups needed on some CPUs */
 	andis.	r0,r3,HID0_NAP@h
 	beq	2f
@@ -220,8 +207,6 @@ _GLOBAL(nap_save_msscr0)
 _GLOBAL(nap_save_hid1)
 	.space	4*NR_CPUS
 
-_GLOBAL(powersave_nap)
-	.long	0
 _GLOBAL(powersave_lowspeed)
 	.long	0
 

arch/powerpc/kernel/idle_power4.S

@@ -49,21 +49,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP)
 	cmpwi	0,r4,0
 	beqlr
 
-	/* Clear MSR:EE */
-	mfmsr	r7
-	li	r4,0
-	ori	r4,r4,MSR_EE
-	andc	r0,r7,r4
-	mtmsrd	r0
-
-	/* Check current_thread_info()->flags */
-	clrrdi	r4,r1,THREAD_SHIFT
-	ld	r4,TI_FLAGS(r4)
-	andi.	r0,r4,_TIF_NEED_RESCHED
-	beq	1f
-	mtmsrd	r7	/* out of line this ? */
-	blr
-1:
 	/* Go to NAP now */
 BEGIN_FTR_SECTION
 	DSSALL

arch/powerpc/kernel/setup_32.c

@@ -53,9 +53,6 @@
 extern void platform_init(void);
 extern void bootx_init(unsigned long r4, unsigned long phys);
 
-extern void ppc6xx_idle(void);
-extern void power4_idle(void);
-
 boot_infos_t *boot_infos;
 struct ide_machdep_calls ppc_ide_md;
 
@@ -194,7 +191,9 @@ void __init machine_init(unsigned long dt_ptr, unsigned long phys)
 	platform_init();
 
 #ifdef CONFIG_6xx
-	ppc_md.power_save = ppc6xx_idle;
+	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
+	    cpu_has_feature(CPU_FTR_CAN_NAP))
+		ppc_md.power_save = ppc6xx_idle;
 #endif
 
 	if (ppc_md.progress)

arch/powerpc/kernel/setup_64.c

@@ -607,12 +607,6 @@ void __init setup_arch(char **cmdline_p)
 
 	ppc_md.setup_arch();
 
-	/* Use the default idle loop if the platform hasn't provided one. */
-	if (NULL == ppc_md.idle_loop) {
-		ppc_md.idle_loop = default_idle;
-		printk(KERN_INFO "Using default idle loop\n");
-	}
-
 	paging_init();
 	ppc64_boot_msg(0x15, "Setup Done");
 }

arch/powerpc/platforms/maple/setup.c

@@ -290,7 +290,7 @@ struct machdep_calls __initdata maple_md = {
        	.get_rtc_time		= maple_get_rtc_time,
       	.calibrate_decr		= generic_calibrate_decr,
 	.progress		= maple_progress,
-	.idle_loop		= native_idle,
+	.power_save		= power4_idle,
 #ifdef CONFIG_KEXEC
 	.machine_kexec		= default_machine_kexec,
 	.machine_kexec_prepare	= default_machine_kexec_prepare,

arch/powerpc/platforms/powermac/setup.c

@@ -733,7 +733,7 @@ struct machdep_calls __initdata pmac_md = {
 	.progress		= udbg_progress,
 #ifdef CONFIG_PPC64
 	.pci_probe_mode		= pmac_pci_probe_mode,
-	.idle_loop		= native_idle,
+	.power_save		= power4_idle,
 	.enable_pmcs		= power4_enable_pmcs,
 #ifdef CONFIG_KEXEC
 	.machine_kexec		= default_machine_kexec,

arch/ppc/Makefile

@@ -59,8 +59,6 @@ head-$(CONFIG_4xx)		:= arch/ppc/kernel/head_4xx.o
 head-$(CONFIG_44x)		:= arch/ppc/kernel/head_44x.o
 head-$(CONFIG_FSL_BOOKE)	:= arch/ppc/kernel/head_fsl_booke.o
 
-head-$(CONFIG_6xx)		+= arch/ppc/kernel/idle_6xx.o
-head-$(CONFIG_POWER4)		+= arch/ppc/kernel/idle_power4.o
 head-$(CONFIG_PPC_FPU)		+= arch/powerpc/kernel/fpu.o
 
 core-y				+= arch/ppc/kernel/ arch/powerpc/kernel/ \

arch/ppc/kernel/Makefile

@@ -8,10 +8,9 @@ extra-$(CONFIG_40x)		:= head_4xx.o
 extra-$(CONFIG_44x)		:= head_44x.o
 extra-$(CONFIG_FSL_BOOKE)	:= head_fsl_booke.o
 extra-$(CONFIG_8xx)		:= head_8xx.o
-extra-$(CONFIG_6xx)		+= idle_6xx.o
 extra-y				+= vmlinux.lds
 
-obj-y				:= entry.o traps.o idle.o time.o misc.o \
+obj-y				:= entry.o traps.o time.o misc.o \
 					setup.o \
 					ppc_htab.o
 obj-$(CONFIG_6xx)		+= l2cr.o cpu_setup_6xx.o
@@ -35,7 +34,6 @@ endif
 # These are here while we do the architecture merge
 
 else
-obj-y				:= idle.o
 obj-$(CONFIG_6xx)		+= l2cr.o cpu_setup_6xx.o
 obj-$(CONFIG_SOFTWARE_SUSPEND)	+= swsusp.o
 obj-$(CONFIG_MODULES)		+= module.o

arch/ppc/kernel/entry.S

@@ -135,10 +135,10 @@ transfer_to_handler:
 	mfspr	r11,SPRN_HID0
 	mtcr	r11
 BEGIN_FTR_SECTION
-	bt-	8,power_save_6xx_restore	/* Check DOZE */
+	bt-	8,4f			/* Check DOZE */
 END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
 BEGIN_FTR_SECTION
-	bt-	9,power_save_6xx_restore	/* Check NAP */
+	bt-	9,4f			/* Check NAP */
 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
 #endif /* CONFIG_6xx */
 	.globl transfer_to_handler_cont
@@ -157,6 +157,10 @@ transfer_to_handler_cont:
 	SYNC
 	RFI				/* jump to handler, enable MMU */
 
+#ifdef CONFIG_6xx
+4:	b	power_save_6xx_restore
+#endif
+
 /*
  * On kernel stack overflow, load up an initial stack pointer
  * and call StackOverflow(regs), which should not return.

arch/ppc/kernel/idle.c

-/*
- * Idle daemon for PowerPC.  Idle daemon will handle any action
- * that needs to be taken when the system becomes idle.
- *
- * Written by Cort Dougan (cort@cs.nmt.edu).  Subsequently hacked
- * on by Tom Rini, Armin Kuster, Paul Mackerras and others.
- *
- * 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/config.h>
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/smp_lock.h>
-#include <linux/stddef.h>
-#include <linux/unistd.h>
-#include <linux/ptrace.h>
-#include <linux/slab.h>
-#include <linux/sysctl.h>
-#include <linux/cpu.h>
-
-#include <asm/pgtable.h>
-#include <asm/uaccess.h>
-#include <asm/system.h>
-#include <asm/io.h>
-#include <asm/mmu.h>
-#include <asm/cache.h>
-#include <asm/cputable.h>
-#include <asm/machdep.h>
-#include <asm/smp.h>
-
-void default_idle(void)
-{
-	void (*powersave)(void);
-
-	powersave = ppc_md.power_save;
-
-	if (!need_resched()) {
-		if (powersave != NULL)
-			powersave();
-#ifdef CONFIG_SMP
-		else {
-			set_thread_flag(TIF_POLLING_NRFLAG);
-			while (!need_resched() &&
-					!cpu_is_offline(smp_processor_id()))
-				barrier();
-			clear_thread_flag(TIF_POLLING_NRFLAG);
-		}
-#endif
-	}
-}
-
-/*
- * The body of the idle task.
- */
-void cpu_idle(void)
-{
-	int cpu = smp_processor_id();
-
-	for (;;) {
-		while (!need_resched()) {
-			if (ppc_md.idle != NULL)
-				ppc_md.idle();
-			else
-				default_idle();
-		}
-
-		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
-			cpu_die();
-		preempt_enable_no_resched();
-		schedule();
-		preempt_disable();
-	}
-}
-
-#if defined(CONFIG_SYSCTL) && defined(CONFIG_6xx)
-/*
- * Register the sysctl to set/clear powersave_nap.
- */
-extern int powersave_nap;
-
-static ctl_table powersave_nap_ctl_table[]={
-	{
-		.ctl_name	= KERN_PPC_POWERSAVE_NAP,
-		.procname	= "powersave-nap",
-		.data		= &powersave_nap,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= &proc_dointvec,
-	},
-	{ 0, },
-};
-static ctl_table powersave_nap_sysctl_root[] = {
-	{ 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, },
- 	{ 0,},
-};
-
-static int __init
-register_powersave_nap_sysctl(void)
-{
-	register_sysctl_table(powersave_nap_sysctl_root, 0);
-
-	return 0;
-}
-
-__initcall(register_powersave_nap_sysctl);
-#endif

arch/ppc/kernel/idle_6xx.S

-/*
- *  This file contains the power_save function for 6xx & 7xxx CPUs
- *  rewritten in assembler
- *
- *  Warning ! This code assumes that if your machine has a 750fx
- *  it will have PLL 1 set to low speed mode (used during NAP/DOZE).
- *  if this is not the case some additional changes will have to
- *  be done to check a runtime var (a bit like powersave-nap)
- *
- *  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/config.h>
-#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>
-
-#undef DEBUG
-
-	.text
-
-/*
- * Init idle, called at early CPU setup time from head.S for each CPU
- * Make sure no rest of NAP mode remains in HID0, save default
- * values for some CPU specific registers. Called with r24
- * containing CPU number and r3 reloc offset
- */
-_GLOBAL(init_idle_6xx)
-BEGIN_FTR_SECTION
-	mfspr	r4,SPRN_HID0
-	rlwinm	r4,r4,0,10,8	/* Clear NAP */
-	mtspr	SPRN_HID0, r4
-	b	1f
-END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
-	blr
-1:
-	slwi	r5,r24,2
-	add	r5,r5,r3
-BEGIN_FTR_SECTION
-	mfspr	r4,SPRN_MSSCR0
-	addis	r6,r5, nap_save_msscr0@ha
-	stw	r4,nap_save_msscr0@l(r6)
-END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR)
-BEGIN_FTR_SECTION
-	mfspr	r4,SPRN_HID1
-	addis	r6,r5,nap_save_hid1@ha
-	stw	r4,nap_save_hid1@l(r6)
-END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
-	blr
-
-/*
- * Here is the power_save_6xx function. This could eventually be
- * split into several functions & changing the function pointer
- * depending on the various features.
- */
-_GLOBAL(ppc6xx_idle)
-	/* Check if we can nap or doze, put HID0 mask in r3
-	 */
-	lis	r3, 0
-BEGIN_FTR_SECTION
-	lis	r3,HID0_DOZE@h
-END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
-BEGIN_FTR_SECTION
-	/* We must dynamically check for the NAP feature as it
-	 * can be cleared by CPU init after the fixups are done
-	 */
-	lis	r4,cur_cpu_spec@ha
-	lwz	r4,cur_cpu_spec@l(r4)
-	lwz	r4,CPU_SPEC_FEATURES(r4)
-	andi.	r0,r4,CPU_FTR_CAN_NAP
-	beq	1f
-	/* Now check if user or arch enabled NAP mode */
-	lis	r4,powersave_nap@ha
-	lwz	r4,powersave_nap@l(r4)
-	cmpwi	0,r4,0
-	beq	1f
-	lis	r3,HID0_NAP@h
-1:	
-END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
-	cmpwi	0,r3,0
-	beqlr
-
-	/* Clear MSR:EE */
-	mfmsr	r7
-	rlwinm	r0,r7,0,17,15
-	mtmsr	r0
-
-	/* Check current_thread_info()->flags */
-	rlwinm	r4,r1,0,0,18
-	lwz	r4,TI_FLAGS(r4)
-	andi.	r0,r4,_TIF_NEED_RESCHED
-	beq	1f
-	mtmsr	r7	/* out of line this ? */
-	blr
-1:	
-	/* Some pre-nap cleanups needed on some CPUs */
-	andis.	r0,r3,HID0_NAP@h
-	beq	2f
-BEGIN_FTR_SECTION
-	/* Disable L2 prefetch on some 745x and try to ensure
-	 * L2 prefetch engines are idle. As explained by errata
-	 * text, we can't be sure they are, we just hope very hard
-	 * that well be enough (sic !). At least I noticed Apple
-	 * doesn't even bother doing the dcbf's here...
-	 */
-	mfspr	r4,SPRN_MSSCR0
-	rlwinm	r4,r4,0,0,29
-	sync
-	mtspr	SPRN_MSSCR0,r4
-	sync
-	isync
-	lis	r4,KERNELBASE@h
-	dcbf	0,r4
-	dcbf	0,r4
-	dcbf	0,r4
-	dcbf	0,r4
-END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR)
-#ifdef DEBUG
-	lis	r6,nap_enter_count@ha
-	lwz	r4,nap_enter_count@l(r6)
-	addi	r4,r4,1
-	stw	r4,nap_enter_count@l(r6)
-#endif	
-2:
-BEGIN_FTR_SECTION
-	/* Go to low speed mode on some 750FX */
-	lis	r4,powersave_lowspeed@ha
-	lwz	r4,powersave_lowspeed@l(r4)
-	cmpwi	0,r4,0
-	beq	1f
-	mfspr	r4,SPRN_HID1
-	oris	r4,r4,0x0001
-	mtspr	SPRN_HID1,r4
-1:	
-END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
-
-	/* Go to NAP or DOZE now */	
-	mfspr	r4,SPRN_HID0
-	lis	r5,(HID0_NAP|HID0_SLEEP)@h
-BEGIN_FTR_SECTION
-	oris	r5,r5,HID0_DOZE@h
-END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
-	andc	r4,r4,r5
-	or	r4,r4,r3
-BEGIN_FTR_SECTION
-	oris	r4,r4,HID0_DPM@h	/* that should be done once for all  */
-END_FTR_SECTION_IFCLR(CPU_FTR_NO_DPM)
-	mtspr	SPRN_HID0,r4
-BEGIN_FTR_SECTION
-	DSSALL
-	sync
-END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
-	ori	r7,r7,MSR_EE /* Could be ommited (already set) */
-	oris	r7,r7,MSR_POW@h
-	sync
-	isync
-	mtmsr	r7
-	isync
-	sync
-	blr
-	
-/*
- * Return from NAP/DOZE mode, restore some CPU specific registers,
- * we are called with DR/IR still off and r2 containing physical
- * address of current.
- */
-_GLOBAL(power_save_6xx_restore)
-	mfspr	r11,SPRN_HID0
-	rlwinm.	r11,r11,0,10,8	/* Clear NAP & copy NAP bit !state to cr1 EQ */
-	cror	4*cr1+eq,4*cr0+eq,4*cr0+eq
-BEGIN_FTR_SECTION
-	rlwinm	r11,r11,0,9,7	/* Clear DOZE */
-END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
-	mtspr	SPRN_HID0, r11
-
-#ifdef DEBUG
-	beq	cr1,1f
-	lis	r11,(nap_return_count-KERNELBASE)@ha
-	lwz	r9,nap_return_count@l(r11)
-	addi	r9,r9,1
-	stw	r9,nap_return_count@l(r11)
-1:
-#endif
-	
-	rlwinm	r9,r1,0,0,18
-	tophys(r9,r9)
-	lwz	r11,TI_CPU(r9)
-	slwi	r11,r11,2
-	/* Todo make sure all these are in the same page
-	 * and load r22 (@ha part + CPU offset) only once
-	 */
-BEGIN_FTR_SECTION
-	beq	cr1,1f
-	addis	r9,r11,(nap_save_msscr0-KERNELBASE)@ha
-	lwz	r9,nap_save_msscr0@l(r9)
-	mtspr	SPRN_MSSCR0, r9
-	sync
-	isync
-1:
-END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR)
-BEGIN_FTR_SECTION
-	addis	r9,r11,(nap_save_hid1-KERNELBASE)@ha
-	lwz	r9,nap_save_hid1@l(r9)
-	mtspr	SPRN_HID1, r9
-END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
-	b	transfer_to_handler_cont
-
-	.data
-
-_GLOBAL(nap_save_msscr0)
-	.space	4*NR_CPUS
-
-_GLOBAL(nap_save_hid1)
-	.space	4*NR_CPUS
-
-_GLOBAL(powersave_nap)
-	.long	0
-_GLOBAL(powersave_lowspeed)
-	.long	0
-
-#ifdef DEBUG
-_GLOBAL(nap_enter_count)
-	.space	4
-_GLOBAL(nap_return_count)
-	.space	4
-#endif

arch/ppc/kernel/idle_power4.S

-/*
- *  This file contains the power_save function for 6xx & 7xxx CPUs
- *  rewritten in assembler
- *
- *  Warning ! This code assumes that if your machine has a 750fx
- *  it will have PLL 1 set to low speed mode (used during NAP/DOZE).
- *  if this is not the case some additional changes will have to
- *  be done to check a runtime var (a bit like powersave-nap)
- *
- *  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/config.h>
-#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>
-
-#undef DEBUG
-
-	.text
-
-/*
- * Init idle, called at early CPU setup time from head.S for each CPU
- * So nothing for now. Called with r24 containing CPU number and r3
- * reloc offset
- */
- 	.globl	init_idle_power4
-init_idle_power4:
-	blr
-
-/*
- * Here is the power_save_6xx function. This could eventually be
- * split into several functions & changing the function pointer
- * depending on the various features.
- */
-	.globl	power4_idle
-power4_idle:
-BEGIN_FTR_SECTION
-	blr
-END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP)
-	/* We must dynamically check for the NAP feature as it
-	 * can be cleared by CPU init after the fixups are done
-	 */
-	lis	r4,cur_cpu_spec@ha
-	lwz	r4,cur_cpu_spec@l(r4)
-	lwz	r4,CPU_SPEC_FEATURES(r4)
-	andi.	r0,r4,CPU_FTR_CAN_NAP
-	beqlr
-	/* Now check if user or arch enabled NAP mode */
-	lis	r4,powersave_nap@ha
-	lwz	r4,powersave_nap@l(r4)
-	cmpwi	0,r4,0
-	beqlr
-
-	/* Clear MSR:EE */
-	mfmsr	r7
-	rlwinm	r0,r7,0,17,15
-	mtmsr	r0
-
-	/* Check current_thread_info()->flags */
-	rlwinm	r4,r1,0,0,18
-	lwz	r4,TI_FLAGS(r4)
-	andi.	r0,r4,_TIF_NEED_RESCHED
-	beq	1f
-	mtmsr	r7	/* out of line this ? */
-	blr
-1:	
-	/* Go to NAP now */	
-BEGIN_FTR_SECTION
-	DSSALL
-	sync
-END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
-	ori	r7,r7,MSR_EE /* Could be ommited (already set) */
-	oris	r7,r7,MSR_POW@h
-	sync
-	isync
-	mtmsr	r7
-	isync
-	sync
-	blr
-	
-	.globl powersave_nap
-powersave_nap:
-	.long	0

include/asm-powerpc/machdep.h

@@ -158,6 +158,12 @@ struct machdep_calls {
 	/* Idle loop for this platform, leave empty for default idle loop */
 	void		(*idle_loop)(void);
 
+	/*
+	 * Function for waiting for work with reduced power in idle loop;
+	 * called with interrupts disabled.
+	 */
+	void		(*power_save)(void);
+
 	/* Function to enable performance monitor counters for this
 	   platform, called once per cpu. */
 	void		(*enable_pmcs)(void);
@@ -170,9 +176,6 @@ struct machdep_calls {
 	   May be NULL. */
 	void		(*init)(void);
 
-	void		(*idle)(void);
-	void		(*power_save)(void);
-
 	void		(*heartbeat)(void);
 	unsigned long	heartbeat_reset;
 	unsigned long	heartbeat_count;
@@ -242,8 +245,8 @@ struct machdep_calls {
 #endif /* CONFIG_KEXEC */
 };
 
-extern void default_idle(void);
-extern void native_idle(void);
+extern void power4_idle(void);
+extern void ppc6xx_idle(void);
 
 extern struct machdep_calls ppc_md;
 extern char cmd_line[COMMAND_LINE_SIZE];

include/asm-powerpc/reg.h

@@ -622,6 +622,10 @@ extern void ppc64_runlatch_off(void);
 extern unsigned long scom970_read(unsigned int address);
 extern void scom970_write(unsigned int address, unsigned long value);
 
+#else
+#define ppc64_runlatch_on()
+#define ppc64_runlatch_off()
+
 #endif /* CONFIG_PPC64 */
 
 #define __get_SP()	({unsigned long sp; \

include/asm-ppc/machdep.h

@@ -44,7 +44,7 @@ struct machdep_calls {
 	void		(*power_off)(void);
 	void		(*halt)(void);
 
-	void		(*idle)(void);
+	void		(*idle_loop)(void);
 	void		(*power_save)(void);
 
 	long		(*time_init)(void); /* Optional, may be NULL */