Thermal: CPU Package temperature thermal

This driver register CPU digital temperature sensor as a thermal
zone at package level.
Each package will show up as one zone with at max two trip points.
These trip points can be both read and updated. Once a non zero
value is set in the trip point, if the package package temperature
goes above or below this setting, a thermal notification is
generated.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 642 insertions, 0 deletions

diff --git a/drivers/thermal/x86_pkg_temp_thermal.c b/drivers/thermal/x86_pkg_temp_thermal.c
new file mode 100644
index 0000000..5de56f6
--- /dev/null
+++ b/drivers/thermal/x86_pkg_temp_thermal.c
@@ -0,0 +1,642 @@
+/*
+ * x86_pkg_temp_thermal driver
+ * Copyright (c) 2013, 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.
+ *
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/param.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/slab.h>
+#include <linux/pm.h>
+#include <linux/thermal.h>
+#include <linux/debugfs.h>
+#include <asm/cpu_device_id.h>
+#include <asm/mce.h>
+
+/*
+* Rate control delay: Idea is to introduce denounce effect
+* This should be long enough to avoid reduce events, when
+* threshold is set to a temperature, which is constantly
+* violated, but at the short enough to take any action.
+* The action can be remove threshold or change it to next
+* interesting setting. Based on experiments, in around
+* every 5 seconds under load will give us a significant
+* temperature change.
+*/
+#define PKG_TEMP_THERMAL_NOTIFY_DELAY	5000
+static int notify_delay_ms = PKG_TEMP_THERMAL_NOTIFY_DELAY;
+module_param(notify_delay_ms, int, 0644);
+MODULE_PARM_DESC(notify_delay_ms,
+	"User space notification delay in milli seconds.");
+
+/* Number of trip points in thermal zone. Currently it can't
+* be more than 2. MSR can allow setting and getting notifications
+* for only 2 thresholds. This define enforces this, if there
+* is some wrong values returned by cpuid for number of thresholds.
+*/
+#define MAX_NUMBER_OF_TRIPS	2
+
+struct phy_dev_entry {
+	struct list_head list;
+	u16 phys_proc_id;
+	u16 first_cpu;
+	u32 tj_max;
+	int ref_cnt;
+	u32 start_pkg_therm_low;
+	u32 start_pkg_therm_high;
+	struct thermal_zone_device *tzone;
+};
+
+/* List maintaining number of package instances */
+static LIST_HEAD(phy_dev_list);
+static DEFINE_MUTEX(phy_dev_list_mutex);
+
+/* Interrupt to work function schedule queue */
+static DEFINE_PER_CPU(struct delayed_work, pkg_temp_thermal_threshold_work);
+
+/* To track if the work is already scheduled on a package */
+static u8 *pkg_work_scheduled;
+
+/* Spin lock to prevent races with pkg_work_scheduled */
+static spinlock_t pkg_work_lock;
+static u16 max_phy_id;
+
+/* Debug counters to show using debugfs */
+static struct dentry *debugfs;
+static unsigned int pkg_interrupt_cnt;
+static unsigned int pkg_work_cnt;
+
+static int pkg_temp_debugfs_init(void)
+{
+	struct dentry *d;
+
+	debugfs = debugfs_create_dir("pkg_temp_thermal", NULL);
+	if (!debugfs)
+		return -ENOENT;
+
+	d = debugfs_create_u32("pkg_thres_interrupt", S_IRUGO, debugfs,
+				(u32 *)&pkg_interrupt_cnt);
+	if (!d)
+		goto err_out;
+
+	d = debugfs_create_u32("pkg_thres_work", S_IRUGO, debugfs,
+				(u32 *)&pkg_work_cnt);
+	if (!d)
+		goto err_out;
+
+	return 0;
+
+err_out:
+	debugfs_remove_recursive(debugfs);
+	return -ENOENT;
+}
+
+static struct phy_dev_entry
+			*pkg_temp_thermal_get_phy_entry(unsigned int cpu)
+{
+	u16 phys_proc_id = topology_physical_package_id(cpu);
+	struct phy_dev_entry *phy_ptr;
+
+	mutex_lock(&phy_dev_list_mutex);
+
+	list_for_each_entry(phy_ptr, &phy_dev_list, list)
+		if (phy_ptr->phys_proc_id == phys_proc_id) {
+			mutex_unlock(&phy_dev_list_mutex);
+			return phy_ptr;
+		}
+
+	mutex_unlock(&phy_dev_list_mutex);
+
+	return NULL;
+}
+
+/*
+* tj-max is is interesting because threshold is set relative to this
+* temperature.
+*/
+static int get_tj_max(int cpu, u32 *tj_max)
+{
+	u32 eax, edx;
+	u32 val;
+	int err;
+
+	err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
+	if (err)
+		goto err_ret;
+	else {
+		val = (eax >> 16) & 0xff;
+		if (val)
+			*tj_max = val * 1000;
+		else {
+			err = -EINVAL;
+			goto err_ret;
+		}
+	}
+
+	return 0;
+err_ret:
+	*tj_max = 0;
+	return err;
+}
+
+static int sys_get_curr_temp(struct thermal_zone_device *tzd, unsigned long *temp)
+{
+	u32 eax, edx;
+	struct phy_dev_entry *phy_dev_entry;
+
+	phy_dev_entry = tzd->devdata;
+	rdmsr_on_cpu(phy_dev_entry->first_cpu, MSR_IA32_PACKAGE_THERM_STATUS,
+			&eax, &edx);
+	if (eax & 0x80000000) {
+		*temp = phy_dev_entry->tj_max -
+				((eax >> 16) & 0x7f) * 1000;
+		pr_debug("sys_get_curr_temp %ld\n", *temp);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int sys_get_trip_temp(struct thermal_zone_device *tzd,
+		int trip, unsigned long *temp)
+{
+	u32 eax, edx;
+	struct phy_dev_entry *phy_dev_entry;
+	u32 mask, shift;
+	unsigned long thres_reg_value;
+	int ret;
+
+	if (trip >= MAX_NUMBER_OF_TRIPS)
+		return -EINVAL;
+
+	phy_dev_entry = tzd->devdata;
+
+	if (trip) {
+		mask = THERM_MASK_THRESHOLD1;
+		shift = THERM_SHIFT_THRESHOLD1;
+	} else {
+		mask = THERM_MASK_THRESHOLD0;
+		shift = THERM_SHIFT_THRESHOLD0;
+	}
+
+	ret = rdmsr_on_cpu(phy_dev_entry->first_cpu,
+				MSR_IA32_PACKAGE_THERM_INTERRUPT, &eax, &edx);
+	if (ret < 0)
+		return -EINVAL;
+
+	thres_reg_value = (eax & mask) >> shift;
+	if (thres_reg_value)
+		*temp = phy_dev_entry->tj_max - thres_reg_value * 1000;
+	else
+		*temp = 0;
+	pr_debug("sys_get_trip_temp %ld\n", *temp);
+
+	return 0;
+}
+
+int sys_set_trip_temp(struct thermal_zone_device *tzd, int trip,
+							unsigned long temp)
+{
+	u32 l, h;
+	struct phy_dev_entry *phy_dev_entry;
+	u32 mask, shift, intr;
+	int ret;
+
+	phy_dev_entry = tzd->devdata;
+
+	if (trip >= MAX_NUMBER_OF_TRIPS || temp >= phy_dev_entry->tj_max)
+		return -EINVAL;
+
+	ret = rdmsr_on_cpu(phy_dev_entry->first_cpu,
+					MSR_IA32_PACKAGE_THERM_INTERRUPT,
+					&l, &h);
+	if (ret < 0)
+		return -EINVAL;
+
+	if (trip) {
+		mask = THERM_MASK_THRESHOLD1;
+		shift = THERM_SHIFT_THRESHOLD1;
+		intr = THERM_INT_THRESHOLD1_ENABLE;
+	} else {
+		mask = THERM_MASK_THRESHOLD0;
+		shift = THERM_SHIFT_THRESHOLD0;
+		intr = THERM_INT_THRESHOLD0_ENABLE;
+	}
+	l &= ~mask;
+	/*
+	* When users space sets a trip temperature == 0, which is indication
+	* that, it is no longer interested in receiving notifications.
+	*/
+	if (!temp)
+		l &= ~intr;
+	else {
+		l |= (phy_dev_entry->tj_max - temp)/1000 << shift;
+		l |= intr;
+	}
+
+	return wrmsr_on_cpu(phy_dev_entry->first_cpu,
+					MSR_IA32_PACKAGE_THERM_INTERRUPT,
+					l, h);
+}
+
+static int sys_get_trip_type(struct thermal_zone_device *thermal,
+		int trip, enum thermal_trip_type *type)
+{
+
+	*type = THERMAL_TRIP_PASSIVE;
+
+	return 0;
+}
+
+/* Thermal zone callback registry */
+static struct thermal_zone_device_ops tzone_ops = {
+	.get_temp = sys_get_curr_temp,
+	.get_trip_temp = sys_get_trip_temp,
+	.get_trip_type = sys_get_trip_type,
+	.set_trip_temp = sys_set_trip_temp,
+};
+
+static bool pkg_temp_thermal_platform_thermal_rate_control(void)
+{
+	return true;
+}
+
+/* Enable threshold interrupt on local package/cpu */
+static inline void enable_pkg_thres_interrupt(void)
+{
+	u32 l, h;
+	u8 thres_0, thres_1;
+
+	rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
+	/* only enable/disable if it had valid threshold value */
+	thres_0 = (l & THERM_MASK_THRESHOLD0) >> THERM_SHIFT_THRESHOLD0;
+	thres_1 = (l & THERM_MASK_THRESHOLD1) >> THERM_SHIFT_THRESHOLD1;
+	if (thres_0)
+		l |= THERM_INT_THRESHOLD0_ENABLE;
+	if (thres_1)
+		l |= THERM_INT_THRESHOLD1_ENABLE;
+	wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
+}
+
+/* Disable threshold interrupt on local package/cpu */
+static inline void disable_pkg_thres_interrupt(void)
+{
+	u32 l, h;
+	rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
+	wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
+			l & (~THERM_INT_THRESHOLD0_ENABLE) &
+				(~THERM_INT_THRESHOLD1_ENABLE), h);
+}
+
+static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work)
+{
+	__u64 msr_val;
+	int cpu = smp_processor_id();
+	int phy_id = topology_physical_package_id(cpu);
+	struct phy_dev_entry *phdev = pkg_temp_thermal_get_phy_entry(cpu);
+	bool notify = false;
+
+	if (!phdev)
+		return;
+
+	spin_lock(&pkg_work_lock);
+	++pkg_work_cnt;
+	if (unlikely(phy_id > max_phy_id)) {
+		spin_unlock(&pkg_work_lock);
+		return;
+	}
+	pkg_work_scheduled[phy_id] = 0;
+	spin_unlock(&pkg_work_lock);
+
+	enable_pkg_thres_interrupt();
+	rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
+	if (msr_val & THERM_LOG_THRESHOLD0) {
+		wrmsrl(MSR_IA32_PACKAGE_THERM_STATUS,
+				msr_val & ~THERM_LOG_THRESHOLD0);
+		notify = true;
+	}
+	if (msr_val & THERM_LOG_THRESHOLD1) {
+		wrmsrl(MSR_IA32_PACKAGE_THERM_STATUS,
+				msr_val & ~THERM_LOG_THRESHOLD1);
+		notify = true;
+	}
+	if (notify) {
+		pr_debug("thermal_zone_device_update\n");
+		thermal_zone_device_update(phdev->tzone);
+	}
+}
+
+static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+{
+	unsigned long flags;
+	int cpu = smp_processor_id();
+	int phy_id = topology_physical_package_id(cpu);
+
+	/*
+	* When a package is in interrupted state, all CPU's in that package
+	* are in the same interrupt state. So scheduling on any one CPU in
+	* the package is enough and simply return for others.
+	*/
+	spin_lock_irqsave(&pkg_work_lock, flags);
+	++pkg_interrupt_cnt;
+	if (unlikely(phy_id > max_phy_id) || unlikely(!pkg_work_scheduled) ||
+			pkg_work_scheduled[phy_id]) {
+		disable_pkg_thres_interrupt();
+		spin_unlock_irqrestore(&pkg_work_lock, flags);
+		return -EINVAL;
+	}
+	pkg_work_scheduled[phy_id] = 1;
+	spin_unlock_irqrestore(&pkg_work_lock, flags);
+
+	disable_pkg_thres_interrupt();
+	schedule_delayed_work_on(cpu,
+				&per_cpu(pkg_temp_thermal_threshold_work, cpu),
+				msecs_to_jiffies(notify_delay_ms));
+	return 0;
+}
+
+static int find_siblings_cpu(int cpu)
+{
+	int i;
+	int id = topology_physical_package_id(cpu);
+
+	for_each_online_cpu(i)
+		if (i != cpu && topology_physical_package_id(i) == id)
+			return i;
+
+	return 0;
+}
+
+static int pkg_temp_thermal_device_add(unsigned int cpu)
+{
+	int err;
+	u32 tj_max;
+	struct phy_dev_entry *phy_dev_entry;
+	char buffer[30];
+	int thres_count;
+	u32 eax, ebx, ecx, edx;
+
+	cpuid(6, &eax, &ebx, &ecx, &edx);
+	thres_count = ebx & 0x07;
+	if (!thres_count)
+		return -ENODEV;
+
+	thres_count = clamp_val(thres_count, 0, MAX_NUMBER_OF_TRIPS);
+
+	err = get_tj_max(cpu, &tj_max);
+	if (err)
+		goto err_ret;
+
+	mutex_lock(&phy_dev_list_mutex);
+
+	phy_dev_entry = kzalloc(sizeof(*phy_dev_entry), GFP_KERNEL);
+	if (!phy_dev_entry) {
+		err = -ENOMEM;
+		goto err_ret_unlock;
+	}
+
+	spin_lock(&pkg_work_lock);
+	if (topology_physical_package_id(cpu) > max_phy_id)
+		max_phy_id = topology_physical_package_id(cpu);
+	pkg_work_scheduled = krealloc(pkg_work_scheduled,
+				(max_phy_id+1) * sizeof(u8), GFP_ATOMIC);
+	if (!pkg_work_scheduled) {
+		spin_unlock(&pkg_work_lock);
+		err = -ENOMEM;
+		goto err_ret_free;
+	}
+	pkg_work_scheduled[topology_physical_package_id(cpu)] = 0;
+	spin_unlock(&pkg_work_lock);
+
+	phy_dev_entry->phys_proc_id = topology_physical_package_id(cpu);
+	phy_dev_entry->first_cpu = cpu;
+	phy_dev_entry->tj_max = tj_max;
+	phy_dev_entry->ref_cnt = 1;
+	snprintf(buffer, sizeof(buffer), "pkg-temp-%d\n",
+					phy_dev_entry->phys_proc_id);
+	phy_dev_entry->tzone = thermal_zone_device_register(buffer,
+			thres_count,
+			(thres_count == MAX_NUMBER_OF_TRIPS) ?
+				0x03 : 0x01,
+			phy_dev_entry, &tzone_ops, NULL, 0, 0);
+	if (IS_ERR(phy_dev_entry->tzone)) {
+		err = PTR_ERR(phy_dev_entry->tzone);
+		goto err_ret_free;
+	}
+	/* Store MSR value for package thermal interrupt, to restore at exit */
+	rdmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT,
+				&phy_dev_entry->start_pkg_therm_low,
+				&phy_dev_entry->start_pkg_therm_high);
+
+	list_add_tail(&phy_dev_entry->list, &phy_dev_list);
+	pr_debug("pkg_temp_thermal_device_add :phy_id %d cpu %d\n",
+			phy_dev_entry->phys_proc_id, cpu);
+
+	mutex_unlock(&phy_dev_list_mutex);
+
+	return 0;
+
+err_ret_free:
+	kfree(phy_dev_entry);
+err_ret_unlock:
+	mutex_unlock(&phy_dev_list_mutex);
+
+err_ret:
+	return err;
+}
+
+static int pkg_temp_thermal_device_remove(unsigned int cpu)
+{
+	struct phy_dev_entry *n;
+	u16 phys_proc_id = topology_physical_package_id(cpu);
+	struct phy_dev_entry *phdev =
+			pkg_temp_thermal_get_phy_entry(cpu);
+
+	if (!phdev)
+		return -ENODEV;
+
+	mutex_lock(&phy_dev_list_mutex);
+	/* If we are loosing the first cpu for this package, we need change */
+	if (phdev->first_cpu == cpu) {
+		phdev->first_cpu = find_siblings_cpu(cpu);
+		pr_debug("thermal_device_remove: first cpu switched %d\n",
+					phdev->first_cpu);
+	}
+	/*
+	* It is possible that no siblings left as this was the last cpu
+	* going offline. We don't need to worry about this assignment
+	* as the phydev entry will be removed in this case and
+	* thermal zone is removed.
+	*/
+	--phdev->ref_cnt;
+	pr_debug("thermal_device_remove: pkg: %d cpu %d ref_cnt %d\n",
+					phys_proc_id, cpu, phdev->ref_cnt);
+	if (!phdev->ref_cnt)
+		list_for_each_entry_safe(phdev, n, &phy_dev_list, list) {
+			if (phdev->phys_proc_id == phys_proc_id) {
+				thermal_zone_device_unregister(phdev->tzone);
+				list_del(&phdev->list);
+				kfree(phdev);
+				break;
+			}
+		}
+	mutex_unlock(&phy_dev_list_mutex);
+
+	return 0;
+}
+
+static int get_core_online(unsigned int cpu)
+{
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+	struct phy_dev_entry *phdev = pkg_temp_thermal_get_phy_entry(cpu);
+
+	/* Check if there is already an instance for this package */
+	if (!phdev) {
+		if (!cpu_has(c, X86_FEATURE_DTHERM) &&
+					!cpu_has(c, X86_FEATURE_PTS))
+			return -ENODEV;
+		if (pkg_temp_thermal_device_add(cpu))
+			return -ENODEV;
+	} else {
+		mutex_lock(&phy_dev_list_mutex);
+		++phdev->ref_cnt;
+		pr_debug("get_core_online: cpu %d ref_cnt %d\n",
+						cpu, phdev->ref_cnt);
+		mutex_unlock(&phy_dev_list_mutex);
+	}
+	INIT_DELAYED_WORK(&per_cpu(pkg_temp_thermal_threshold_work, cpu),
+			pkg_temp_thermal_threshold_work_fn);
+
+	pr_debug("get_core_online: cpu %d successful\n", cpu);
+
+	return 0;
+}
+
+static void put_core_offline(unsigned int cpu)
+{
+	if (!pkg_temp_thermal_device_remove(cpu))
+		cancel_delayed_work_sync(
+			&per_cpu(pkg_temp_thermal_threshold_work, cpu));
+
+	pr_debug("put_core_offline: cpu %d\n", cpu);
+}
+
+static int pkg_temp_thermal_cpu_callback(struct notifier_block *nfb,
+				 unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (unsigned long) hcpu;
+
+	switch (action) {
+	case CPU_ONLINE:
+	case CPU_DOWN_FAILED:
+		get_core_online(cpu);
+		break;
+	case CPU_DOWN_PREPARE:
+		put_core_offline(cpu);
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block pkg_temp_thermal_notifier __refdata = {
+	.notifier_call = pkg_temp_thermal_cpu_callback,
+};
+
+static const struct x86_cpu_id __initconst pkg_temp_thermal_ids[] = {
+	{ X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_DTHERM },
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, pkg_temp_thermal_ids);
+
+static int __init pkg_temp_thermal_init(void)
+{
+	int i;
+
+	if (!x86_match_cpu(pkg_temp_thermal_ids))
+		return -ENODEV;
+
+	spin_lock_init(&pkg_work_lock);
+	platform_thermal_package_notify =
+			pkg_temp_thermal_platform_thermal_notify;
+	platform_thermal_package_rate_control =
+			pkg_temp_thermal_platform_thermal_rate_control;
+
+	get_online_cpus();
+	for_each_online_cpu(i)
+		if (get_core_online(i))
+			goto err_ret;
+	register_hotcpu_notifier(&pkg_temp_thermal_notifier);
+	put_online_cpus();
+
+	pkg_temp_debugfs_init(); /* Don't care if fails */
+
+	return 0;
+
+err_ret:
+	get_online_cpus();
+	for_each_online_cpu(i)
+		put_core_offline(i);
+	put_online_cpus();
+	kfree(pkg_work_scheduled);
+	platform_thermal_package_notify = NULL;
+	platform_thermal_package_rate_control = NULL;
+
+	return -ENODEV;
+}
+
+static void __exit pkg_temp_thermal_exit(void)
+{
+	struct phy_dev_entry *phdev, *n;
+	int i;
+
+	get_online_cpus();
+	unregister_hotcpu_notifier(&pkg_temp_thermal_notifier);
+	mutex_lock(&phy_dev_list_mutex);
+	list_for_each_entry_safe(phdev, n, &phy_dev_list, list) {
+		/* Retore old MSR value for package thermal interrupt */
+		wrmsr_on_cpu(phdev->first_cpu,
+			MSR_IA32_PACKAGE_THERM_INTERRUPT,
+			phdev->start_pkg_therm_low,
+			phdev->start_pkg_therm_high);
+		thermal_zone_device_unregister(phdev->tzone);
+		list_del(&phdev->list);
+		kfree(phdev);
+	}
+	mutex_unlock(&phy_dev_list_mutex);
+	platform_thermal_package_notify = NULL;
+	platform_thermal_package_rate_control = NULL;
+	for_each_online_cpu(i)
+		cancel_delayed_work_sync(
+			&per_cpu(pkg_temp_thermal_threshold_work, i));
+	put_online_cpus();
+
+	kfree(pkg_work_scheduled);
+
+	debugfs_remove_recursive(debugfs);
+}
+
+module_init(pkg_temp_thermal_init)
+module_exit(pkg_temp_thermal_exit)
+
+MODULE_DESCRIPTION("X86 PKG TEMP Thermal Driver");
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
+MODULE_LICENSE("GPL v2");