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>

18 files changed, 74 insertions, 535 deletions

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 80e9fe2632b8..f2c47e907037 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/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
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 4827ca1ec89b..b3a979467225 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/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.
diff --git a/arch/powerpc/kernel/idle_64.c b/arch/powerpc/kernel/idle.c
index b879d3057ef8..e9f321d74d85 100644
--- a/arch/powerpc/kernel/idle_64.c
+++ b/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();
                         }
-