4 files changed, 82 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/idle_power4.S b/arch/powerpc/kernel/idle_power4.S
index ba3195478600..5328709eeedc 100644
--- a/arch/powerpc/kernel/idle_power4.S
+++ b/arch/powerpc/kernel/idle_power4.S
@@ -53,3 +53,24 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
         isync
         b       1b
 
+_GLOBAL(power4_cpu_offline_powersave)
+        /* Go to NAP now */
+        mfmsr   r7
+        rldicl  r0,r7,48,1
+        rotldi  r0,r0,16
+        mtmsrd  r0,1                    /* hard-disable interrupts */
+        li      r0,1
+        li      r6,0
+        stb     r0,PACAHARDIRQEN(r13)   /* we'll hard-enable shortly */
+        stb     r6,PACASOFTIRQEN(r13)   /* soft-disable irqs */
+BEGIN_FTR_SECTION
+        DSSALL
+        sync
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+        ori     r7,r7,MSR_EE
+        oris    r7,r7,MSR_POW@h
+        sync
+        isync
+        mtmsrd  r7
+        isync
+        blr
diff --git a/arch/powerpc/platforms/powermac/setup.c b/arch/powerpc/platforms/powermac/setup.c
index 5ae57e17d2ba..e365bff74d83 100644
--- a/arch/powerpc/platforms/powermac/setup.c
+++ b/arch/powerpc/platforms/powermac/setup.c
@@ -444,6 +444,9 @@ static int initializing = 1;
 static int pmac_late_init(void)
 {
         initializing = 0;
+        /* this is udbg (which is __init) and we can later use it during
+         * cpu hotplug (in smp_core99_kick_cpu) */
+        ppc_md.progress = NULL;
         return 0;
 }
 
@@ -661,7 +664,52 @@ static int pmac_pci_probe_mode(struct pci_bus *bus)
                 return PCI_PROBE_NORMAL;
         return PCI_PROBE_DEVTREE;
 }
-#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+/* access per cpu vars from generic smp.c */
+DECLARE_PER_CPU(int, cpu_state);
+
+static void pmac_cpu_die(void)
+{
+        /*
+         * turn off as much as possible, we'll be
+         * kicked out as this will only be invoked
+         * on core99 platforms for now ...
+         */
+
+        printk(KERN_INFO "CPU#%d offline\n", smp_processor_id());
+        __get_cpu_var(cpu_state) = CPU_DEAD;
+        smp_wmb();
+
+        /*
+         * during the path that leads here preemption is disabled,
+         * reenable it now so that when coming up preempt count is
+         * zero correctly
+         */
+        preempt_enable();
+
+        /*
+         * hard-disable interrupts for the non-NAP case, the NAP code
+         * needs to re-enable interrupts (but soft-disables them)
+         */
+        hard_irq_disable();
+
+        while (1) {
+                /* let's not take timer interrupts too often ... */
+                set_dec(0x7fffffff);
+
+                /* should always be true at this point */
+                if (cpu_has_feature(CPU_FTR_CAN_NAP))
+                        power4_cpu_offline_powersave();
+                else {
+                        HMT_low();
+                        HMT_very_low();
+                }
+        }
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#endif /* CONFIG_PPC64 */
 
 define_machine(powermac) {
         .name                   = "PowerMac",
@@ -698,6 +746,6 @@ define_machine(powermac) {
         .phys_mem_access_prot   = pci_phys_mem_access_prot,
 #endif
 #if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PPC64)
-        .cpu_die                = generic_mach_cpu_die,
+        .cpu_die                = pmac_cpu_die,
 #endif
 };
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 6f32c4eca6e5..330354113186 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -900,7 +900,7 @@ void smp_core99_cpu_die(unsigned int cpu)
         cpu_dead[cpu] = 0;
 }
 
-#endif
+#endif /* CONFIG_HOTPLUG_CPU && CONFIG_PP32 */
 
 /* Core99 Macs (dual G4s and G5s) */
 struct smp_ops_t core99_smp_ops = {
@@ -910,8 +910,16 @@ struct smp_ops_t core99_smp_ops = {
         .setup_cpu      = smp_core99_setup_cpu,
         .give_timebase  = smp_core99_give_timebase,
         .take_timebase  = smp_core99_take_timebase,
-#if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PPC32)
+#if defined(CONFIG_HOTPLUG_CPU)
+# if defined(CONFIG_PPC32)
         .cpu_disable    = smp_core99_cpu_disable,
         .cpu_die        = smp_core99_cpu_die,
+# endif
+# if defined(CONFIG_PPC64)
+        .cpu_disable    = generic_cpu_disable,
+        .cpu_die        = generic_cpu_die,
+        /* intentionally do *NOT* assign cpu_enable,
+         * the generic code will use kick_cpu then! */
+# endif
 #endif
 };
diff --git a/include/asm-powerpc/machdep.h b/include/asm-powerpc/machdep.h
index b204926ce913..bbd17d0e170d 100644
--- a/include/asm-powerpc/machdep.h
+++ b/include/asm-powerpc/machdep.h
@@ -248,6 +248,7 @@ struct machdep_calls {
 };
 
 extern void power4_idle(void);
+extern void power4_cpu_offline_powersave(void);
 extern void ppc6xx_idle(void);
 
 /*