Merge branch 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6

* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
  intel_idle: native hardware cpuidle driver for latest Intel processors
  ACPI: acpi_idle: touch TS_POLLING only in the non-MWAIT case
  acpi_pad: uses MONITOR/MWAIT, so it doesn't need to clear TS_POLLING
  sched: clarify commment for TS_POLLING
  ACPI: allow a native cpuidle driver to displace ACPI
  cpuidle: make cpuidle_curr_driver static
  cpuidle: add cpuidle_unregister_driver() error check
  cpuidle: fail to register if !CONFIG_CPU_IDLE

MAINTAINERS

@@ -2887,6 +2887,13 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git
 S:	Maintained
 F:	drivers/input/
 
+INTEL IDLE DRIVER
+M:	Len Brown <lenb@kernel.org>
+L:	linux-pm@lists.linux-foundation.org
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6.git
+S:	Supported
+F:	drivers/idle/intel_idle.c
+
 INTEL FRAMEBUFFER DRIVER (excluding 810 and 815)
 M:	Maik Broemme <mbroemme@plusserver.de>
 L:	linux-fbdev@vger.kernel.org

arch/x86/include/asm/thread_info.h

@@ -239,8 +239,8 @@ static inline struct thread_info *current_thread_info(void)
 #define TS_USEDFPU		0x0001	/* FPU was used by this task
 					   this quantum (SMP) */
 #define TS_COMPAT		0x0002	/* 32bit syscall active (64BIT)*/
-#define TS_POLLING		0x0004	/* true if in idle loop
-					   and not sleeping */
+#define TS_POLLING		0x0004	/* idle task polling need_resched,
+					   skip sending interrupt */
 #define TS_RESTORE_SIGMASK	0x0008	/* restore signal mask in do_signal() */
 
 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)

drivers/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_PCI)		+= pci/
 obj-$(CONFIG_PARISC)		+= parisc/
 obj-$(CONFIG_RAPIDIO)		+= rapidio/
 obj-y				+= video/
+obj-y				+= idle/
 obj-$(CONFIG_ACPI)		+= acpi/
 obj-$(CONFIG_SFI)		+= sfi/
 # PnP must come after ACPI since it will eventually need to check if acpi
@@ -91,7 +92,6 @@ obj-$(CONFIG_EISA)		+= eisa/
 obj-y				+= lguest/
 obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
 obj-$(CONFIG_CPU_IDLE)		+= cpuidle/
-obj-y				+= idle/
 obj-$(CONFIG_MMC)		+= mmc/
 obj-$(CONFIG_MEMSTICK)		+= memstick/
 obj-$(CONFIG_NEW_LEDS)		+= leds/

drivers/acpi/acpi_pad.c

@@ -172,13 +172,6 @@ static int power_saving_thread(void *data)
 
 		do_sleep = 0;
 
-		current_thread_info()->status &= ~TS_POLLING;
-		/*
-		 * TS_POLLING-cleared state must be visible before we test
-		 * NEED_RESCHED:
-		 */
-		smp_mb();
-
 		expire_time = jiffies + HZ * (100 - idle_pct) / 100;
 
 		while (!need_resched()) {
@@ -209,8 +202,6 @@ static int power_saving_thread(void *data)
 			}
 		}
 
-		current_thread_info()->status |= TS_POLLING;
-
 		/*
 		 * current sched_rt has threshold for rt task running time.
 		 * When a rt task uses 95% CPU time, the rt thread will be

drivers/acpi/processor_driver.c

@@ -616,7 +616,8 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device)
 	acpi_processor_get_limit_info(pr);
 
 
-	acpi_processor_power_init(pr, device);
+	if (cpuidle_get_driver() == &acpi_idle_driver)
+		acpi_processor_power_init(pr, device);
 
 	pr->cdev = thermal_cooling_device_register("Processor", device,
 						&processor_cooling_ops);
@@ -920,9 +921,14 @@ static int __init acpi_processor_init(void)
 	if (!acpi_processor_dir)
 		return -ENOMEM;
 #endif
-	result = cpuidle_register_driver(&acpi_idle_driver);
-	if (result < 0)
-		goto out_proc;
+
+	if (!cpuidle_register_driver(&acpi_idle_driver)) {
+		printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
+			acpi_idle_driver.name);
+	} else {
+		printk(KERN_DEBUG "ACPI: acpi_idle yielding to %s",
+			cpuidle_get_driver()->name);
+	}
 
 	result = acpi_bus_register_driver(&acpi_processor_driver);
 	if (result < 0)
@@ -941,7 +947,6 @@ static int __init acpi_processor_init(void)
 out_cpuidle:
 	cpuidle_unregister_driver(&acpi_idle_driver);
 
-out_proc:
 #ifdef CONFIG_ACPI_PROCFS
 	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
 #endif

drivers/acpi/processor_idle.c

@@ -872,6 +872,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 		return(acpi_idle_enter_c1(dev, state));
 
 	local_irq_disable();
+
 	if (cx->entry_method != ACPI_CSTATE_FFH) {
 		current_thread_info()->status &= ~TS_POLLING;
 		/*
@@ -879,12 +880,12 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 		 * NEED_RESCHED:
 		 */
 		smp_mb();
-	}
 
-	if (unlikely(need_resched())) {
-		current_thread_info()->status |= TS_POLLING;
-		local_irq_enable();
-		return 0;
+		if (unlikely(need_resched())) {
+			current_thread_info()->status |= TS_POLLING;
+			local_irq_enable();
+			return 0;
+		}
 	}
 
 	/*
@@ -911,7 +912,8 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 	sched_clock_idle_wakeup_event(idle_time_ns);
 
 	local_irq_enable();
-	current_thread_info()->status |= TS_POLLING;
+	if (cx->entry_method != ACPI_CSTATE_FFH)
+		current_thread_info()->status |= TS_POLLING;
 
 	cx->usage++;
 
@@ -962,6 +964,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 	}
 
 	local_irq_disable();
+
 	if (cx->entry_method != ACPI_CSTATE_FFH) {
 		current_thread_info()->status &= ~TS_POLLING;
 		/*
@@ -969,12 +972,12 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 		 * NEED_RESCHED:
 		 */
 		smp_mb();
-	}
 
-	if (unlikely(need_resched())) {
-		current_thread_info()->status |= TS_POLLING;
-		local_irq_enable();
-		return 0;
+		if (unlikely(need_resched())) {
+			current_thread_info()->status |= TS_POLLING;
+			local_irq_enable();
+			return 0;
+		}
 	}
 
 	acpi_unlazy_tlb(smp_processor_id());
@@ -1028,7 +1031,8 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 	sched_clock_idle_wakeup_event(idle_time_ns);
 
 	local_irq_enable();
-	current_thread_info()->status |= TS_POLLING;
+	if (cx->entry_method != ACPI_CSTATE_FFH)
+		current_thread_info()->status |= TS_POLLING;
 
 	cx->usage++;
 

drivers/cpuidle/cpuidle.c

@@ -156,7 +156,7 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
 
 	if (dev->enabled)
 		return 0;
-	if (!cpuidle_curr_driver || !cpuidle_curr_governor)
+	if (!cpuidle_get_driver() || !cpuidle_curr_governor)
 		return -EIO;
 	if (!dev->state_count)
 		return -EINVAL;
@@ -207,7 +207,7 @@ void cpuidle_disable_device(struct cpuidle_device *dev)
 {
 	if (!dev->enabled)
 		return;
-	if (!cpuidle_curr_driver || !cpuidle_curr_governor)
+	if (!cpuidle_get_driver() || !cpuidle_curr_governor)
 		return;
 
 	dev->enabled = 0;
@@ -271,10 +271,11 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
 {
 	int ret;
 	struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);
+	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
 
 	if (!sys_dev)
 		return -EINVAL;
-	if (!try_module_get(cpuidle_curr_driver->owner))
+	if (!try_module_get(cpuidle_driver->owner))
 		return -EINVAL;
 
 	init_completion(&dev->kobj_unregister);
@@ -284,7 +285,7 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
 	per_cpu(cpuidle_devices, dev->cpu) = dev;
 	list_add(&dev->device_list, &cpuidle_detected_devices);
 	if ((ret = cpuidle_add_sysfs(sys_dev))) {
-		module_put(cpuidle_curr_driver->owner);
+		module_put(cpuidle_driver->owner);
 		return ret;
 	}
 
@@ -325,6 +326,7 @@ EXPORT_SYMBOL_GPL(cpuidle_register_device);
 void cpuidle_unregister_device(struct cpuidle_device *dev)
 {
 	struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);
+	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
 
 	if (dev->registered == 0)
 		return;
@@ -340,7 +342,7 @@ void cpuidle_unregister_device(struct cpuidle_device *dev)
 
 	cpuidle_resume_and_unlock();
 
-	module_put(cpuidle_curr_driver->owner);
+	module_put(cpuidle_driver->owner);
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_unregister_device);

drivers/cpuidle/cpuidle.h

@@ -9,7 +9,6 @@
 
 /* For internal use only */
 extern struct cpuidle_governor *cpuidle_curr_governor;
-extern struct cpuidle_driver *cpuidle_curr_driver;
 extern struct list_head cpuidle_governors;
 extern struct list_head cpuidle_detected_devices;
 extern struct mutex cpuidle_lock;

drivers/cpuidle/driver.c

@@ -14,7 +14,7 @@
 
 #include "cpuidle.h"
 
-struct cpuidle_driver *cpuidle_curr_driver;
+static struct cpuidle_driver *cpuidle_curr_driver;
 DEFINE_SPINLOCK(cpuidle_driver_lock);
 
 /**
@@ -39,14 +39,26 @@ int cpuidle_register_driver(struct cpuidle_driver *drv)
 
 EXPORT_SYMBOL_GPL(cpuidle_register_driver);
 
+/**
+ * cpuidle_get_driver - return the current driver
+ */
+struct cpuidle_driver *cpuidle_get_driver(void)
+{
+	return cpuidle_curr_driver;
+}
+EXPORT_SYMBOL_GPL(cpuidle_get_driver);
+
 /**
  * cpuidle_unregister_driver - unregisters a driver
  * @drv: the driver
  */
 void cpuidle_unregister_driver(struct cpuidle_driver *drv)
 {
-	if (!drv)
+	if (drv != cpuidle_curr_driver) {
+		WARN(1, "invalid cpuidle_unregister_driver(%s)\n",
+			drv->name);
 		return;
+	}
 
 	spin_lock(&cpuidle_driver_lock);
 	cpuidle_curr_driver = NULL;

drivers/cpuidle/sysfs.c

@@ -47,10 +47,11 @@ static ssize_t show_current_driver(struct sysdev_class *class,
 				   char *buf)
 {
 	ssize_t ret;
+	struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
 
 	spin_lock(&cpuidle_driver_lock);
-	if (cpuidle_curr_driver)
-		ret = sprintf(buf, "%s\n", cpuidle_curr_driver->name);
+	if (cpuidle_driver)
+		ret = sprintf(buf, "%s\n", cpuidle_driver->name);
 	else
 		ret = sprintf(buf, "none\n");
 	spin_unlock(&cpuidle_driver_lock);

drivers/idle/Kconfig

+config INTEL_IDLE
+	tristate "Cpuidle Driver for Intel Processors"
+	depends on CPU_IDLE
+	depends on X86
+	depends on CPU_SUP_INTEL
+	depends on EXPERIMENTAL
+	help
+	  Enable intel_idle, a cpuidle driver that includes knowledge of
+	  native Intel hardware idle features.  The acpi_idle driver
+	  can be configured at the same time, in order to handle
+	  processors intel_idle does not support.
 
 menu "Memory power savings"
 depends on X86_64

drivers/idle/Makefile

 obj-$(CONFIG_I7300_IDLE)			+= i7300_idle.o
+obj-$(CONFIG_INTEL_IDLE)			+= intel_idle.o
 

include/linux/cpuidle.h

@@ -125,6 +125,7 @@ struct cpuidle_driver {
 #ifdef CONFIG_CPU_IDLE
 
 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
+struct cpuidle_driver *cpuidle_get_driver(void);
 extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
 extern int cpuidle_register_device(struct cpuidle_device *dev);
 extern void cpuidle_unregister_device(struct cpuidle_device *dev);
@@ -137,16 +138,17 @@ extern void cpuidle_disable_device(struct cpuidle_device *dev);
 #else
 
 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
-{return 0;}
+{return -ENODEV; }
+static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
 static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
 static inline int cpuidle_register_device(struct cpuidle_device *dev)
-{return 0;}
+{return -ENODEV; }
 static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
 
 static inline void cpuidle_pause_and_lock(void) { }
 static inline void cpuidle_resume_and_unlock(void) { }
 static inline int cpuidle_enable_device(struct cpuidle_device *dev)
-{return 0;}
+{return -ENODEV; }
 static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
 
 #endif