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Commit 5e5027bd authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

* 'acpi-pad' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  acpi_pad: build only on X86
  ACPI: create Processor Aggregator Device driver

Fixup trivial conflicts in MAINTAINERS file.
parents 6d5ee265 d91f79eb

MAINTAINERS

+7 −0
Original line number Diff line number Diff line
@@ -257,6 +257,13 @@ W: http://www.lesswatts.org/projects/acpi/ 
S:	Supported

F:	drivers/acpi/fan.c



ACPI PROCESSOR AGGREGATOR DRIVER

M:	Shaohua Li <shaohua.li@intel.com>

L:	linux-acpi@vger.kernel.org

W:	http://www.lesswatts.org/projects/acpi/

S:	Supported

F:	drivers/acpi/acpi_pad.c



ACPI THERMAL DRIVER

M:	Zhang Rui <rui.zhang@intel.com>

L:	linux-acpi@vger.kernel.org

drivers/acpi/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -211,6 +211,18 @@ config ACPI_HOTPLUG_CPU 
	select ACPI_CONTAINER

	default y



config ACPI_PROCESSOR_AGGREGATOR

	tristate "Processor Aggregator"

	depends on ACPI_PROCESSOR

	depends on EXPERIMENTAL

	depends on X86

	help

	  ACPI 4.0 defines processor Aggregator, which enables OS to perform

	  specfic processor configuration and control that applies to all

	  processors in the platform. Currently only logical processor idling

	  is defined, which is to reduce power consumption. This driver

	  support the new device.



config ACPI_THERMAL

	tristate "Thermal Zone"

	depends on ACPI_PROCESSOR

drivers/acpi/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -62,3 +62,5 @@ obj-$(CONFIG_ACPI_POWER_METER) += power_meter.o 
processor-y			:= processor_core.o processor_throttling.o

processor-y			+= processor_idle.o processor_thermal.o

processor-$(CONFIG_CPU_FREQ)	+= processor_perflib.o



obj-$(CONFIG_ACPI_PROCESSOR_AGGREGATOR) += acpi_pad.o

drivers/acpi/acpi_pad.c

0 → 100644
+514 −0
Original line number Diff line number Diff line 
/*

 * acpi_pad.c ACPI Processor Aggregator Driver

 *

 * Copyright (c) 2009, Intel Corporation.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */



#include <linux/kernel.h>

#include <linux/cpumask.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/types.h>

#include <linux/kthread.h>

#include <linux/freezer.h>

#include <linux/cpu.h>

#include <linux/clockchips.h>

#include <acpi/acpi_bus.h>

#include <acpi/acpi_drivers.h>



#define ACPI_PROCESSOR_AGGREGATOR_CLASS	"processor_aggregator"

#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"

#define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80

static DEFINE_MUTEX(isolated_cpus_lock);



#define MWAIT_SUBSTATE_MASK	(0xf)

#define MWAIT_CSTATE_MASK	(0xf)

#define MWAIT_SUBSTATE_SIZE	(4)

#define CPUID_MWAIT_LEAF (5)

#define CPUID5_ECX_EXTENSIONS_SUPPORTED (0x1)

#define CPUID5_ECX_INTERRUPT_BREAK	(0x2)

static unsigned long power_saving_mwait_eax;

static void power_saving_mwait_init(void)

{

	unsigned int eax, ebx, ecx, edx;

	unsigned int highest_cstate = 0;

	unsigned int highest_subcstate = 0;

	int i;



	if (!boot_cpu_has(X86_FEATURE_MWAIT))

		return;

	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)

		return;



	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx);



	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||

	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK))

		return;



	edx >>= MWAIT_SUBSTATE_SIZE;

	for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {

		if (edx & MWAIT_SUBSTATE_MASK) {

			highest_cstate = i;

			highest_subcstate = edx & MWAIT_SUBSTATE_MASK;

		}

	}

	power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |

		(highest_subcstate - 1);



	for_each_online_cpu(i)

		clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &i);



#if defined(CONFIG_GENERIC_TIME) && defined(CONFIG_X86)

	switch (boot_cpu_data.x86_vendor) {

	case X86_VENDOR_AMD:

	case X86_VENDOR_INTEL:

		/*

		 * AMD Fam10h TSC will tick in all

		 * C/P/S0/S1 states when this bit is set.

		 */

		if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))

			return;



		/*FALL THROUGH*/

	default:

		/* TSC could halt in idle, so notify users */

		mark_tsc_unstable("TSC halts in idle");

	}

#endif

}



static unsigned long cpu_weight[NR_CPUS];

static int tsk_in_cpu[NR_CPUS] = {[0 ... NR_CPUS-1] = -1};

static DECLARE_BITMAP(pad_busy_cpus_bits, NR_CPUS);

static void round_robin_cpu(unsigned int tsk_index)

{

	struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits);

	cpumask_var_t tmp;

	int cpu;

	unsigned long min_weight = -1, preferred_cpu;



	if (!alloc_cpumask_var(&tmp, GFP_KERNEL))

		return;



	mutex_lock(&isolated_cpus_lock);

	cpumask_clear(tmp);

	for_each_cpu(cpu, pad_busy_cpus)

		cpumask_or(tmp, tmp, topology_thread_cpumask(cpu));

	cpumask_andnot(tmp, cpu_online_mask, tmp);

	/* avoid HT sibilings if possible */

	if (cpumask_empty(tmp))

		cpumask_andnot(tmp, cpu_online_mask, pad_busy_cpus);

	if (cpumask_empty(tmp)) {

		mutex_unlock(&isolated_cpus_lock);

		return;

	}

	for_each_cpu(cpu, tmp) {

		if (cpu_weight[cpu] < min_weight) {

			min_weight = cpu_weight[cpu];

			preferred_cpu = cpu;

		}

	}



	if (tsk_in_cpu[tsk_index] != -1)

		cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus);

	tsk_in_cpu[tsk_index] = preferred_cpu;

	cpumask_set_cpu(preferred_cpu, pad_busy_cpus);

	cpu_weight[preferred_cpu]++;

	mutex_unlock(&isolated_cpus_lock);



	set_cpus_allowed_ptr(current, cpumask_of(preferred_cpu));

}



static void exit_round_robin(unsigned int tsk_index)

{

	struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits);

	cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus);

	tsk_in_cpu[tsk_index] = -1;

}



static unsigned int idle_pct = 5; /* percentage */

static unsigned int round_robin_time = 10; /* second */

static int power_saving_thread(void *data)

{

	struct sched_param param = {.sched_priority = 1};

	int do_sleep;

	unsigned int tsk_index = (unsigned long)data;

	u64 last_jiffies = 0;



	sched_setscheduler(current, SCHED_RR, &param);



	while (!kthread_should_stop()) {

		int cpu;

		u64 expire_time;



		try_to_freeze();



		/* round robin to cpus */

		if (last_jiffies + round_robin_time * HZ < jiffies) {

			last_jiffies = jiffies;

			round_robin_cpu(tsk_index);

		}



		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()) {

			local_irq_disable();

			cpu = smp_processor_id();

			clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER,

				&cpu);

			stop_critical_timings();



			__monitor((void *)&current_thread_info()->flags, 0, 0);

			smp_mb();

			if (!need_resched())

				__mwait(power_saving_mwait_eax, 1);



			start_critical_timings();

			clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT,

				&cpu);

			local_irq_enable();



			if (jiffies > expire_time) {

				do_sleep = 1;

				break;

			}

		}



		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

		 * scheduled out for 5% CPU time to not starve other tasks. But

		 * the mechanism only works when all CPUs have RT task running,

		 * as if one CPU hasn't RT task, RT task from other CPUs will

		 * borrow CPU time from this CPU and cause RT task use > 95%

		 * CPU time. To make 'avoid staration' work, takes a nap here.

		 */

		if (do_sleep)

			schedule_timeout_killable(HZ * idle_pct / 100);

	}



	exit_round_robin(tsk_index);

	return 0;

}



static struct task_struct *ps_tsks[NR_CPUS];

static unsigned int ps_tsk_num;

static int create_power_saving_task(void)

{

	ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread,

		(void *)(unsigned long)ps_tsk_num,

		"power_saving/%d", ps_tsk_num);

	if (ps_tsks[ps_tsk_num]) {

		ps_tsk_num++;

		return 0;

	}

	return -EINVAL;

}



static void destroy_power_saving_task(void)

{

	if (ps_tsk_num > 0) {

		ps_tsk_num--;

		kthread_stop(ps_tsks[ps_tsk_num]);

	}

}



static void set_power_saving_task_num(unsigned int num)

{

	if (num > ps_tsk_num) {

		while (ps_tsk_num < num) {

			if (create_power_saving_task())

				return;

		}

	} else if (num < ps_tsk_num) {

		while (ps_tsk_num > num)

			destroy_power_saving_task();

	}

}



static int acpi_pad_idle_cpus(unsigned int num_cpus)

{

	get_online_cpus();



	num_cpus = min_t(unsigned int, num_cpus, num_online_cpus());

	set_power_saving_task_num(num_cpus);



	put_online_cpus();

	return 0;

}



static uint32_t acpi_pad_idle_cpus_num(void)

{

	return ps_tsk_num;

}



static ssize_t acpi_pad_rrtime_store(struct device *dev,

	struct device_attribute *attr, const char *buf, size_t count)

{

	unsigned long num;

	if (strict_strtoul(buf, 0, &num))

		return -EINVAL;

	if (num < 1 || num >= 100)

		return -EINVAL;

	mutex_lock(&isolated_cpus_lock);

	round_robin_time = num;

	mutex_unlock(&isolated_cpus_lock);

	return count;

}



static ssize_t acpi_pad_rrtime_show(struct device *dev,

	struct device_attribute *attr, char *buf)

{

	return scnprintf(buf, PAGE_SIZE, "%d", round_robin_time);

}

static DEVICE_ATTR(rrtime, S_IRUGO|S_IWUSR,

	acpi_pad_rrtime_show,

	acpi_pad_rrtime_store);



static ssize_t acpi_pad_idlepct_store(struct device *dev,

	struct device_attribute *attr, const char *buf, size_t count)

{

	unsigned long num;

	if (strict_strtoul(buf, 0, &num))

		return -EINVAL;

	if (num < 1 || num >= 100)

		return -EINVAL;

	mutex_lock(&isolated_cpus_lock);

	idle_pct = num;

	mutex_unlock(&isolated_cpus_lock);

	return count;

}



static ssize_t acpi_pad_idlepct_show(struct device *dev,

	struct device_attribute *attr, char *buf)

{

	return scnprintf(buf, PAGE_SIZE, "%d", idle_pct);

}

static DEVICE_ATTR(idlepct, S_IRUGO|S_IWUSR,

	acpi_pad_idlepct_show,

	acpi_pad_idlepct_store);



static ssize_t acpi_pad_idlecpus_store(struct device *dev,

	struct device_attribute *attr, const char *buf, size_t count)

{

	unsigned long num;

	if (strict_strtoul(buf, 0, &num))

		return -EINVAL;

	mutex_lock(&isolated_cpus_lock);

	acpi_pad_idle_cpus(num);

	mutex_unlock(&isolated_cpus_lock);

	return count;

}



static ssize_t acpi_pad_idlecpus_show(struct device *dev,

	struct device_attribute *attr, char *buf)

{

	return cpumask_scnprintf(buf, PAGE_SIZE,

		to_cpumask(pad_busy_cpus_bits));

}

static DEVICE_ATTR(idlecpus, S_IRUGO|S_IWUSR,

	acpi_pad_idlecpus_show,

	acpi_pad_idlecpus_store);



static int acpi_pad_add_sysfs(struct acpi_device *device)

{

	int result;



	result = device_create_file(&device->dev, &dev_attr_idlecpus);

	if (result)

		return -ENODEV;

	result = device_create_file(&device->dev, &dev_attr_idlepct);

	if (result) {

		device_remove_file(&device->dev, &dev_attr_idlecpus);

		return -ENODEV;

	}

	result = device_create_file(&device->dev, &dev_attr_rrtime);

	if (result) {

		device_remove_file(&device->dev, &dev_attr_idlecpus);

		device_remove_file(&device->dev, &dev_attr_idlepct);

		return -ENODEV;

	}

	return 0;

}



static void acpi_pad_remove_sysfs(struct acpi_device *device)

{

	device_remove_file(&device->dev, &dev_attr_idlecpus);

	device_remove_file(&device->dev, &dev_attr_idlepct);

	device_remove_file(&device->dev, &dev_attr_rrtime);

}



/* Query firmware how many CPUs should be idle */

static int acpi_pad_pur(acpi_handle handle, int *num_cpus)

{

	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};

	acpi_status status;

	union acpi_object *package;

	int rev, num, ret = -EINVAL;



	status = acpi_evaluate_object(handle, "_PUR", NULL, &buffer);

	if (ACPI_FAILURE(status))

		return -EINVAL;

	package = buffer.pointer;

	if (package->type != ACPI_TYPE_PACKAGE || package->package.count != 2)

		goto out;

	rev = package->package.elements[0].integer.value;

	num = package->package.elements[1].integer.value;

	if (rev != 1)

		goto out;

	*num_cpus = num;

	ret = 0;

out:

	kfree(buffer.pointer);

	return ret;

}



/* Notify firmware how many CPUs are idle */

static void acpi_pad_ost(acpi_handle handle, int stat,

	uint32_t idle_cpus)

{

	union acpi_object params[3] = {

		{.type = ACPI_TYPE_INTEGER,},

		{.type = ACPI_TYPE_INTEGER,},

		{.type = ACPI_TYPE_BUFFER,},

	};

	struct acpi_object_list arg_list = {3, params};



	params[0].integer.value = ACPI_PROCESSOR_AGGREGATOR_NOTIFY;

	params[1].integer.value =  stat;

	params[2].buffer.length = 4;

	params[2].buffer.pointer = (void *)&idle_cpus;

	acpi_evaluate_object(handle, "_OST", &arg_list, NULL);

}



static void acpi_pad_handle_notify(acpi_handle handle)

{

	int num_cpus, ret;

	uint32_t idle_cpus;



	mutex_lock(&isolated_cpus_lock);

	if (acpi_pad_pur(handle, &num_cpus)) {

		mutex_unlock(&isolated_cpus_lock);

		return;

	}

	ret = acpi_pad_idle_cpus(num_cpus);

	idle_cpus = acpi_pad_idle_cpus_num();

	if (!ret)

		acpi_pad_ost(handle, 0, idle_cpus);

	else

		acpi_pad_ost(handle, 1, 0);

	mutex_unlock(&isolated_cpus_lock);

}



static void acpi_pad_notify(acpi_handle handle, u32 event,

	void *data)

{

	struct acpi_device *device = data;



	switch (event) {

	case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:

		acpi_pad_handle_notify(handle);

		acpi_bus_generate_proc_event(device, event, 0);

		acpi_bus_generate_netlink_event(device->pnp.device_class,

			dev_name(&device->dev), event, 0);

		break;

	default:

		printk(KERN_WARNING"Unsupported event [0x%x]\n", event);

		break;

	}

}



static int acpi_pad_add(struct acpi_device *device)

{

	acpi_status status;



	strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME);

	strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS);



	if (acpi_pad_add_sysfs(device))

		return -ENODEV;



	status = acpi_install_notify_handler(device->handle,

		ACPI_DEVICE_NOTIFY, acpi_pad_notify, device);

	if (ACPI_FAILURE(status)) {

		acpi_pad_remove_sysfs(device);

		return -ENODEV;

	}



	return 0;

}



static int acpi_pad_remove(struct acpi_device *device,

	int type)

{

	mutex_lock(&isolated_cpus_lock);

	acpi_pad_idle_cpus(0);

	mutex_unlock(&isolated_cpus_lock);



	acpi_remove_notify_handler(device->handle,

		ACPI_DEVICE_NOTIFY, acpi_pad_notify);

	acpi_pad_remove_sysfs(device);

	return 0;

}



static const struct acpi_device_id pad_device_ids[] = {

	{"ACPI000C", 0},

	{"", 0},

};

MODULE_DEVICE_TABLE(acpi, pad_device_ids);



static struct acpi_driver acpi_pad_driver = {

	.name = "processor_aggregator",

	.class = ACPI_PROCESSOR_AGGREGATOR_CLASS,

	.ids = pad_device_ids,

	.ops = {

		.add = acpi_pad_add,

		.remove = acpi_pad_remove,

	},

};



static int __init acpi_pad_init(void)

{

	power_saving_mwait_init();

	if (power_saving_mwait_eax == 0)

		return -EINVAL;



	return acpi_bus_register_driver(&acpi_pad_driver);

}



static void __exit acpi_pad_exit(void)

{

	acpi_bus_unregister_driver(&acpi_pad_driver);

}



module_init(acpi_pad_init);

module_exit(acpi_pad_exit);

MODULE_AUTHOR("Shaohua Li<shaohua.li@intel.com>");

MODULE_DESCRIPTION("ACPI Processor Aggregator Driver");

MODULE_LICENSE("GPL");