Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull SMP/hotplug changes from Ingo Molnar:
 "This is a pretty large, multi-arch series unifying and generalizing
  the various disjunct pieces of idle routines that architectures have
  historically copied from each other and have grown in random, wildly
  inconsistent and sometimes buggy directions:

   101 files changed, 455 insertions(+), 1328 deletions(-)

  this went through a number of review and test iterations before it was
  committed, it was tested on various architectures, was exposed to
  linux-next for quite some time - nevertheless it might cause problems
  on architectures that don't read the mailing lists and don't regularly
  test linux-next.

  This cat herding excercise was motivated by the -rt kernel, and was
  brought to you by Thomas "the Whip" Gleixner."

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  idle: Remove GENERIC_IDLE_LOOP config switch
  um: Use generic idle loop
  ia64: Make sure interrupts enabled when we "safe_halt()"
  sparc: Use generic idle loop
  idle: Remove unused ARCH_HAS_DEFAULT_IDLE
  bfin: Fix typo in arch_cpu_idle()
  xtensa: Use generic idle loop
  x86: Use generic idle loop
  unicore: Use generic idle loop
  tile: Use generic idle loop
  tile: Enter idle with preemption disabled
  sh: Use generic idle loop
  score: Use generic idle loop
  s390: Use generic idle loop
  powerpc: Use generic idle loop
  parisc: Use generic idle loop
  openrisc: Use generic idle loop
  mn10300: Use generic idle loop
  mips: Use generic idle loop
  microblaze: Use generic idle loop
  ...

101 files changed, 455 insertions, 1328 deletions

diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h
index 1f8c72959fb6..52cd2a4a3ff4 100644
--- a/arch/alpha/include/asm/thread_info.h
+++ b/arch/alpha/include/asm/thread_info.h
@@ -95,8 +95,6 @@ register struct thread_info *__current_thread_info __asm__("$8");
 #define TS_POLLING		0x0010	/* idle task polling need_resched,
 					   skip sending interrupt */
 
-#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
-
 #ifndef __ASSEMBLY__
 #define HAVE_SET_RESTORE_SIGMASK	1
 static inline void set_restore_sigmask(void)
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 63d27fb9b023..a3fd8a29ccac 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -46,25 +46,6 @@
 void (*pm_power_off)(void) = machine_power_off;
 EXPORT_SYMBOL(pm_power_off);
 
-void
-cpu_idle(void)
-{
-	current_thread_info()->status |= TS_POLLING;
-
-	while (1) {
-		/* FIXME -- EV6 and LCA45 know how to power down
-		   the CPU.  */
-
-		rcu_idle_enter();
-		while (!need_resched())
-			cpu_relax();
-
-		rcu_idle_exit();
-		schedule_preempt_disabled();
-	}
-}
-
-
 struct halt_info {
 	int mode;
 	char *restart_cmd;
diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index 9603bc234b47..7b60834fb4b2 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -167,8 +167,7 @@ smp_callin(void)
 	      cpuid, current, current->active_mm));
 
 	preempt_disable();
-	/* Do nothing.  */
-	cpu_idle();
+	cpu_startup_entry(CPUHP_ONLINE);
 }
 
 /* Wait until hwrpb->txrdy is clear for cpu.  Return -1 on timeout.  */
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index 0a7531d99294..cad66851e0c4 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -41,37 +41,12 @@ SYSCALL_DEFINE0(arc_gettls)
 	return task_thread_info(current)->thr_ptr;
 }
 
-static inline void arch_idle(void)
+void arch_cpu_idle(void)
 {
 	/* sleep, but enable all interrupts before committing */
 	__asm__("sleep 0x3");
 }
 
-void cpu_idle(void)
-{
-	/* Since we SLEEP in idle loop, TIF_POLLING_NRFLAG can't be set */
-
-	/* endless idle loop with no priority at all */
-	while (1) {
-		tick_nohz_idle_enter();
-		rcu_idle_enter();
-
-doze:
-		local_irq_disable();
-		if (!need_resched()) {
-			arch_idle();
-			goto doze;
-		} else {
-			local_irq_enable();
-		}
-
-		rcu_idle_exit();
-		tick_nohz_idle_exit();
-
-		schedule_preempt_disabled();
-	}
-}
-
 asmlinkage void ret_from_fork(void);
 
 /* Layout of Child kernel mode stack as setup at the end of this function is
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index 3af3e06dcf02..5c7fd603d216 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -141,7 +141,7 @@ void __cpuinit start_kernel_secondary(void)
 
 	local_irq_enable();
 	preempt_disable();
-	cpu_idle();
+	cpu_startup_entry(CPUHP_ONLINE);
 }
 
 /*
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index bbddefea77bb..a39e3214ea3d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -15,6 +15,7 @@ config ARM
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SMP_IDLE_THREAD
+	select GENERIC_IDLE_POLL_SETUP
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
 	select HARDIRQS_SW_RESEND
diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h
index 5a85f148b607..21a23e378bbe 100644
--- a/arch/arm/include/asm/system_misc.h
+++ b/arch/arm/include/asm/system_misc.h
@@ -21,9 +21,6 @@ extern void (*arm_pm_idle)(void);
 
 extern unsigned int user_debug;
 
-extern void disable_hlt(void);
-extern void enable_hlt(void);
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __ASM_ARM_SYSTEM_MISC_H */
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 047d3e40e470..c9a5e2ce8aa9 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -57,38 +57,6 @@ static const char *isa_modes[] = {
   "ARM" , "Thumb" , "Jazelle", "ThumbEE"
 };
 
-static volatile int hlt_counter;
-
-void disable_hlt(void)
-{
-	hlt_counter++;
-}
-
-EXPORT_SYMBOL(disable_hlt);
-
-void enable_hlt(void)
-{
-	hlt_counter--;
-	BUG_ON(hlt_counter < 0);
-}
-
-EXPORT_SYMBOL(enable_hlt);
-
-static int __init nohlt_setup(char *__unused)
-{
-	hlt_counter = 1;
-	return 1;
-}
-
-static int __init hlt_setup(char *__unused)
-{
-	hlt_counter = 0;
-	return 1;
-}
-
-__setup("nohlt", nohlt_setup);
-__setup("hlt", hlt_setup);
-
 extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
 typedef void (*phys_reset_t)(unsigned long);
 
@@ -172,54 +140,38 @@ static void default_idle(void)
 	local_irq_enable();
 }
 
-/*
- * The idle thread.
- * We always respect 'hlt_counter' to prevent low power idle.
- */
-void cpu_idle(void)
+void arch_cpu_idle_prepare(void)
 {
 	local_fiq_enable();
+}
 
-	/* endless idle loop with no priority at all */
-	while (1) {
-		tick_nohz_idle_enter();
-		rcu_idle_enter();
-		ledtrig_cpu(CPU_LED_IDLE_START);
-		while (!need_resched()) {
-#ifdef CONFIG_HOTPLUG_CPU
-			if (cpu_is_offline(smp_processor_id()))
-				cpu_die();
+void arch_cpu_idle_enter(void)
+{
+	ledtrig_cpu(CPU_LED_IDLE_START);
+#ifdef CONFIG_PL310_ERRATA_769419
+	wmb();
 #endif
+}
 
-			/*
-			 * We need to disable interrupts here
-			 * to ensure we don't miss a wakeup call.
-			 */
-			local_irq_disable();
-#ifdef CONFIG_PL310_ERRATA_769419
-			wmb();
+void arch_cpu_idle_exit(void)
+{
+	ledtrig_cpu(CPU_LED_IDLE_END);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void arch_cpu_idle_dead(void)
+{
+	cpu_die();
+}
 #endif
-			if (hlt_counter) {
-				local_irq_enable();
-				cpu_relax();
-			} else if (!need_resched()) {
-				stop_critical_timings();
-				if (cpuidle_idle_call())
-					default_idle();
-				start_critical_timings();
-				/*
-				 * default_idle functions must always
-				 * return with IRQs enabled.
-				 */
-				WARN_ON(irqs_disabled());
-			} else
-				local_irq_enable();
-		}
-		ledtrig_cpu(CPU_LED_IDLE_END);
-		rcu_idle_exit();
-		tick_nohz_idle_exit();
-		schedule_preempt_disabled();
-	}
+
+/*
+ * Called from the core idle loop.
+ */
+void arch_cpu_idle(void)
+{
+	if (cpuidle_idle_call())
+		default_idle();
 }
 
 static char reboot_mode = 'h';
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 1f2ccccaf009..4619177bcfe6 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -336,7 +336,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void)
 	/*
 	 * OK, it's off to the idle thread for us
 	 */
-	cpu_idle();
+	cpu_startup_entry(CPUHP_ONLINE);
 }
 
 void __init smp_cpus_done(unsigned int max_cpus)
diff --git a/arch/arm/mach-gemini/idle.c b/arch/arm/mach-gemini/idle.c
index 92bbd6bb600a..87dff4f5059e 100644
--- a/arch/arm/mach-gemini/idle.c
+++ b/arch/arm/mach-gemini/idle.c
@@ -13,9 +13,11 @@ static void gemini_idle(void)
 	 * will never wakeup... Acctualy it is not very good to enable
 	 * interrupts first since scheduler can miss a tick, but there is
 	 * no other way around this. Platforms that needs it for power saving
-	 * should call enable_hlt() in init code, since by default it is
+	 * should enable it in init code, since by default it is
 	 * disabled.
 	 */
+
+	/* FIXME: Enabling interrupts here is racy! */
 	local_irq_enable();
 	cpu_do_idle();
 }
diff --git a/arch/arm/mach-gemini/irq.c b/arch/arm/mach-gemini/irq.c
index 020852d3bdd8..6d8f6d1669ff 100644
--- a/arch/arm/mach-gemini/irq.c
+++ b/arch/arm/mach-gemini/irq.c
@@ -15,6 +15,8 @@
 #include <linux/stddef.h>
 #include <linux/list.h>
 #include <linux/sched.h>
+#include <linux/cpu.h>
+
 #include <asm/irq.h>
 #include <asm/mach/irq.h>
 #include <asm/system_misc.h>
@@ -77,7 +79,7 @@ void __init gemini_init_irq(void)
 	 * Disable the idle handler by default since it is buggy
 	 * For more info see arch/arm/mach-gemini/idle.c
 	 */
-	disable_hlt();
+	cpu_idle_poll_ctrl(true);
 
 	request_resource(&iomem_resource, &irq_resource);