Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 857 insertions, 0 deletions

diff --git a/kernel/drivers/hwmon/coretemp.c b/kernel/drivers/hwmon/coretemp.c
new file mode 100644
index 000000000..ed303ba3a
--- /dev/null
+++ b/kernel/drivers/hwmon/coretemp.c
@@ -0,0 +1,857 @@
+/*
+ * coretemp.c - Linux kernel module for hardware monitoring
+ *
+ * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
+ *
+ * Inspired from many hwmon drivers
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that 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 Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/hwmon.h>
+#include <linux/sysfs.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/platform_device.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/moduleparam.h>
+#include <linux/pci.h>
+#include <asm/msr.h>
+#include <asm/processor.h>
+#include <asm/cpu_device_id.h>
+
+#define DRVNAME	"coretemp"
+
+/*
+ * force_tjmax only matters when TjMax can't be read from the CPU itself.
+ * When set, it replaces the driver's suboptimal heuristic.
+ */
+static int force_tjmax;
+module_param_named(tjmax, force_tjmax, int, 0444);
+MODULE_PARM_DESC(tjmax, "TjMax value in degrees Celsius");
+
+#define BASE_SYSFS_ATTR_NO	2	/* Sysfs Base attr no for coretemp */
+#define NUM_REAL_CORES		32	/* Number of Real cores per cpu */
+#define CORETEMP_NAME_LENGTH	19	/* String Length of attrs */
+#define MAX_CORE_ATTRS		4	/* Maximum no of basic attrs */
+#define TOTAL_ATTRS		(MAX_CORE_ATTRS + 1)
+#define MAX_CORE_DATA		(NUM_REAL_CORES + BASE_SYSFS_ATTR_NO)
+
+#define TO_PHYS_ID(cpu)		(cpu_data(cpu).phys_proc_id)
+#define TO_CORE_ID(cpu)		(cpu_data(cpu).cpu_core_id)
+#define TO_ATTR_NO(cpu)		(TO_CORE_ID(cpu) + BASE_SYSFS_ATTR_NO)
+
+#ifdef CONFIG_SMP
+#define for_each_sibling(i, cpu)	for_each_cpu(i, cpu_sibling_mask(cpu))
+#else
+#define for_each_sibling(i, cpu)	for (i = 0; false; )
+#endif
+
+/*
+ * Per-Core Temperature Data
+ * @last_updated: The time when the current temperature value was updated
+ *		earlier (in jiffies).
+ * @cpu_core_id: The CPU Core from which temperature values should be read
+ *		This value is passed as "id" field to rdmsr/wrmsr functions.
+ * @status_reg: One of IA32_THERM_STATUS or IA32_PACKAGE_THERM_STATUS,
+ *		from where the temperature values should be read.
+ * @attr_size:  Total number of pre-core attrs displayed in the sysfs.
+ * @is_pkg_data: If this is 1, the temp_data holds pkgtemp data.
+ *		Otherwise, temp_data holds coretemp data.
+ * @valid: If this is 1, the current temperature is valid.
+ */
+struct temp_data {
+	int temp;
+	int ttarget;
+	int tjmax;
+	unsigned long last_updated;
+	unsigned int cpu;
+	u32 cpu_core_id;
+	u32 status_reg;
+	int attr_size;
+	bool is_pkg_data;
+	bool valid;
+	struct sensor_device_attribute sd_attrs[TOTAL_ATTRS];
+	char attr_name[TOTAL_ATTRS][CORETEMP_NAME_LENGTH];
+	struct attribute *attrs[TOTAL_ATTRS + 1];
+	struct attribute_group attr_group;
+	struct mutex update_lock;
+};
+
+/* Platform Data per Physical CPU */
+struct platform_data {
+	struct device *hwmon_dev;
+	u16 phys_proc_id;
+	struct temp_data *core_data[MAX_CORE_DATA];
+	struct device_attribute name_attr;
+};
+
+struct pdev_entry {
+	struct list_head list;
+	struct platform_device *pdev;
+	u16 phys_proc_id;
+};
+
+static LIST_HEAD(pdev_list);
+static DEFINE_MUTEX(pdev_list_mutex);
+
+static ssize_t show_label(struct device *dev,
+				struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct platform_data *pdata = dev_get_drvdata(dev);
+	struct temp_data *tdata = pdata->core_data[attr->index];
+
+	if (tdata->is_pkg_data)
+		return sprintf(buf, "Physical id %u\n", pdata->phys_proc_id);
+
+	return sprintf(buf, "Core %u\n", tdata->cpu_core_id);
+}
+
+static ssize_t show_crit_alarm(struct device *dev,
+				struct device_attribute *devattr, char *buf)
+{
+	u32 eax, edx;
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct platform_data *pdata = dev_get_drvdata(dev);
+	struct temp_data *tdata = pdata->core_data[attr->index];
+
+	rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
+
+	return sprintf(buf, "%d\n", (eax >> 5) & 1);
+}
+
+static ssize_t show_tjmax(struct device *dev,
+			struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct platform_data *pdata = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", pdata->core_data[attr->index]->tjmax);
+}
+
+static ssize_t show_ttarget(struct device *dev,
+				struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct platform_data *pdata = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", pdata->core_data[attr->index]->ttarget);
+}
+
+static ssize_t show_temp(struct device *dev,
+			struct device_attribute *devattr, char *buf)
+{
+	u32 eax, edx;
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct platform_data *pdata = dev_get_drvdata(dev);
+	struct temp_data *tdata = pdata->core_data[attr->index];
+
+	mutex_lock(&tdata->update_lock);
+
+	/* Check whether the time interval has elapsed */
+	if (!tdata->valid || time_after(jiffies, tdata->last_updated + HZ)) {
+		rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
+		/*
+		 * Ignore the valid bit. In all observed cases the register
+		 * value is either low or zero if the valid bit is 0.
+		 * Return it instead of reporting an error which doesn't
+		 * really help at all.
+		 */
+		tdata->temp = tdata->tjmax - ((eax >> 16) & 0x7f) * 1000;
+		tdata->valid = 1;
+		tdata->last_updated = jiffies;
+	}
+
+	mutex_unlock(&tdata->update_lock);
+	return sprintf(buf, "%d\n", tdata->temp);
+}
+
+struct tjmax_pci {
+	unsigned int device;
+	int tjmax;
+};
+
+static const struct tjmax_pci tjmax_pci_table[] = {
+	{ 0x0708, 110000 },	/* CE41x0 (Sodaville ) */
+	{ 0x0c72, 102000 },	/* Atom S1240 (Centerton) */
+	{ 0x0c73, 95000 },	/* Atom S1220 (Centerton) */
+	{ 0x0c75, 95000 },	/* Atom S1260 (Centerton) */
+};
+
+struct tjmax {
+	char const *id;
+	int tjmax;
+};
+
+static const struct tjmax tjmax_table[] = {
+	{ "CPU  230", 100000 },		/* Model 0x1c, stepping 2	*/
+	{ "CPU  330", 125000 },		/* Model 0x1c, stepping 2	*/
+};
+
+struct tjmax_model {
+	u8 model;
+	u8 mask;
+	int tjmax;
+};
+
+#define ANY 0xff
+
+static const struct tjmax_model tjmax_model_table[] = {
+	{ 0x1c, 10, 100000 },	/* D4xx, K4xx, N4xx, D5xx, K5xx, N5xx */
+	{ 0x1c, ANY, 90000 },	/* Z5xx, N2xx, possibly others
+				 * Note: Also matches 230 and 330,
+				 * which are covered by tjmax_table
+				 */
+	{ 0x26, ANY, 90000 },	/* Atom Tunnel Creek (Exx), Lincroft (Z6xx)
+				 * Note: TjMax for E6xxT is 110C, but CPU type
+				 * is undetectable by software
+				 */
+	{ 0x27, ANY, 90000 },	/* Atom Medfield (Z2460) */
+	{ 0x35, ANY, 90000 },	/* Atom Clover Trail/Cloverview (Z27x0) */
+	{ 0x36, ANY, 100000 },	/* Atom Cedar Trail/Cedarview (N2xxx, D2xxx)
+				 * Also matches S12x0 (stepping 9), covered by
+				 * PCI table
+				 */
+};
+
+static int adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
+{
+	/* The 100C is default for both mobile and non mobile CPUs */
+
+	int tjmax = 100000;
+	int tjmax_ee = 85000;
+	int usemsr_ee = 1;
+	int err;
+	u32 eax, edx;
+	int i;
+	struct pci_dev *host_bridge = pci_get_bus_and_slot(0, PCI_DEVFN(0, 0));
+
+	/*
+	 * Explicit tjmax table entries override heuristics.
+	 * First try PCI host bridge IDs, followed by model ID strings
+	 * and model/stepping information.
+	 */
+	if (host_bridge && host_bridge->vendor == PCI_VENDOR_ID_INTEL) {
+		for (i = 0; i < ARRAY_SIZE(tjmax_pci_table); i++) {
+			if (host_bridge->device == tjmax_pci_table[i].device)
+				return tjmax_pci_table[i].tjmax;
+		}
+	}
+
+	for (i = 0; i < ARRAY_SIZE(tjmax_table); i++) {
+		if (strstr(c->x86_model_id, tjmax_table[i].id))
+			return tjmax_table[i].tjmax;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(tjmax_model_table); i++) {
+		const struct tjmax_model *tm = &tjmax_model_table[i];
+		if (c->x86_model == tm->model &&
+		    (tm->mask == ANY || c->x86_mask == tm->mask))
+			return tm->tjmax;
+	}
+
+	/* Early chips have no MSR for TjMax */
+
+	if (c->x86_model == 0xf && c->x86_mask < 4)
+		usemsr_ee = 0;
+
+	if (c->x86_model > 0xe && usemsr_ee) {
+		u8 platform_id;
+
+		/*
+		 * Now we can detect the mobile CPU using Intel provided table
+		 * http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
+		 * For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
+		 */
+		err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
+		if (err) {
+			dev_warn(dev,
+				 "Unable to access MSR 0x17, assuming desktop"
+				 " CPU\n");
+			usemsr_ee = 0;
+		} else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
+			/*
+			 * Trust bit 28 up to Penryn, I could not find any
+			 * documentation on that; if you happen to know
+			 * someone at Intel please ask
+			 */
+			usemsr_ee = 0;
+		} else {
+			/* Platform ID bits 52:50 (EDX starts at bit 32) */
+			platform_id = (edx >> 18) & 0x7;
+
+			/*
+			 * Mobile Penryn CPU seems to be platform ID 7 or 5
+			 * (guesswork)
+			 */
+			if (c->x86_model == 0x17 &&
+			    (platform_id == 5 || platform_id == 7)) {
+				/*
+				 * If MSR EE bit is set, set it to 90 degrees C,
+				 * otherwise 105 degrees C
+				 */
+				tjmax_ee = 90000;
+				tjmax = 105000;
+			}
+		}
+	}
+
+	if (usemsr_ee) {
+		err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
+		if (err) {
+			dev_warn(dev,
+				 "Unable to access MSR 0xEE, for Tjmax, left"
+				 " at default\n");
+		} else if (eax & 0x40000000) {
+			tjmax = tjmax_ee;
+		}
+	} else if (tjmax == 100000) {
+		/*
+		 * If we don't use msr EE it means we are desktop CPU
+		 * (with exeception of Atom)
+		 */
+		dev_warn(dev, "Using relative temperature scale!\n");
+	}
+
+	return tjmax;
+}
+
+static bool cpu_has_tjmax(struct cpuinfo_x86 *c)
+{
+	u8 model = c->x86_model;
+
+	return model > 0xe &&
+	       model != 0x1c &&
+	       model != 0x26 &&
+	       model != 0x27 &&
+	       model != 0x35 &&
+	       model != 0x36;
+}
+
+static int get_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
+{
+	int err;
+	u32 eax, edx;
+	u32 val;
+
+	/*
+	 * A new feature of current Intel(R) processors, the
+	 * IA32_TEMPERATURE_TARGET contains the TjMax value
+	 */
+	err = rdmsr_safe_on_cpu(id, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
+	if (err) {
+		if (cpu_has_tjmax(c))
+			dev_warn(dev, "Unable to read TjMax from CPU %u\n", id);
+	} else {
+		val = (eax >> 16) & 0xff;
+		/*
+		 * If the TjMax is not plausible, an assumption
+		 * will be used
+		 */
+		if (val) {
+			dev_dbg(dev, "TjMax is %d degrees C\n", val);
+			return val * 1000;
+		}
+	}
+
+	if (force_tjmax) {
+		dev_notice(dev, "TjMax forced to %d degrees C by user\n",
+			   force_tjmax);
+		return force_tjmax * 1000;
+	}
+
+	/*
+	 * An assumption is made for early CPUs and unreadable MSR.
+	 * NOTE: the calculated value may not be correct.
+	 */
+	return adjust_tjmax(c, id, dev);
+}
+
+static int create_core_attrs(struct temp_data *tdata, struct device *dev,
+			     int attr_no)
+{
+	int i;
+	static ssize_t (*const rd_ptr[TOTAL_ATTRS]) (struct device *dev,
+			struct device_attribute *devattr, char *buf) = {
+			show_label, show_crit_alarm, show_temp, show_tjmax,
+			show_ttarget };
+	static const char *const suffixes[TOTAL_ATTRS] = {
+		"label", "crit_alarm", "input", "crit", "max"
+	};
+
+	for (i = 0; i < tdata->attr_size; i++) {
+		snprintf(tdata->attr_name[i], CORETEMP_NAME_LENGTH,
+			 "temp%d_%s", attr_no, suffixes[i]);
+		sysfs_attr_init(&tdata->sd_attrs[i].dev_attr.attr);
+		tdata->sd_attrs[i].dev_attr.attr.name = tdata->attr_name[i];
+		tdata->sd_attrs[i].dev_attr.attr.mode = S_IRUGO;
+		tdata->sd_attrs[i].dev_attr.show = rd_ptr[i];
+		tdata->sd_attrs[i].index = attr_no;
+		tdata->attrs[i] = &tdata->sd_attrs[i].dev_attr.attr;
+	}
+	tdata->attr_group.attrs = tdata->attrs;
+	return sysfs_create_group(&dev->kobj, &tdata->attr_group);
+}
+
+
+static int chk_ucode_version(unsigned int cpu)
+{
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+
+	/*
+	 * Check if we have problem with errata AE18 of Core processors:
+	 * Readings might stop update when processor visited too deep sleep,
+	 * fixed for stepping D0 (6EC).
+	 */
+	if (c->x86_model == 0xe && c->x86_mask < 0xc && c->microcode < 0x39) {
+		pr_err("Errata AE18 not fixed, update BIOS or microcode of the CPU!\n");
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static struct platform_device *coretemp_get_pdev(unsigned int cpu)
+{
+	u16 phys_proc_id = TO_PHYS_ID(cpu);
+	struct pdev_entry *p;
+
+	mutex_lock(&pdev_list_mutex);
+
+	list_for_each_entry(p, &pdev_list, list)
+		if (p->phys_proc_id == phys_proc_id) {
+			mutex_unlock(&pdev_list_mutex);
+			return p->pdev;
+		}
+
+	mutex_unlock(&pdev_list_mutex);
+	return NULL;
+}
+
+static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
+{
+	struct temp_data *tdata;
+
+	tdata = kzalloc(sizeof(struct temp_data), GFP_KERNEL);
+	if (!tdata)
+		return NULL;
+
+	tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
+							MSR_IA32_THERM_STATUS;
+	tdata->is_pkg_data = pkg_flag;
+	tdata->cpu = cpu;
+	tdata->cpu_core_id = TO_CORE_ID(cpu);
+	tdata->attr_size = MAX_CORE_ATTRS;
+	mutex_init(&tdata->update_lock);
+	return tdata;
+}
+
+static int create_core_data(struct platform_device *pdev, unsigned int cpu,
+			    int pkg_flag)
+{
+	struct temp_data *tdata;
+	struct platform_data *pdata = platform_get_drvdata(pdev);
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+	u32 eax, edx;
+	int err, attr_no;
+
+	/*
+	 * Find attr number for sysfs:
+	 * We map the attr number to core id of the CPU
+	 * The attr number is always core id + 2
+	 * The Pkgtemp will always show up as temp1_*, if available
+	 */
+	attr_no = pkg_flag ? 1 : TO_ATTR_NO(cpu);
+
+	if (attr_no > MAX_CORE_DATA - 1)
+		return -ERANGE;
+
+	/*
+	 * Provide a single set of attributes for all HT siblings of a core
+	 * to avoid duplicate sensors (the processor ID and core ID of all
+	 * HT siblings of a core are the same).
+	 * Skip if a HT sibling of this core is already registered.
+	 * This is not an error.
+	 */
+	if (pdata->core_data[attr_no] != NULL)
+		return 0;
+
+	tdata = init_temp_data(cpu, pkg_flag);
+	if (!tdata)
+		return -ENOMEM;
+
+	/* Test if we can access the status register */
+	err = rdmsr_safe_on_cpu(cpu, tdata->status_reg, &eax, &edx);
+	if (err)
+		goto exit_free;
+
+	/* We can access status register. Get Critical Temperature */
+	tdata->tjmax = get_tjmax(c, cpu, &pdev->dev);
+
+	/*
+	 * Read the still undocumented bits 8:15 of IA32_TEMPERATURE_TARGET.
+	 * The target temperature is available on older CPUs but not in this
+	 * register. Atoms don't have the register at all.
+	 */
+	if (c->x86_model > 0xe && c->x86_model != 0x1c) {
+		err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET,
+					&eax, &edx);
+		if (!err) {
+			tdata->ttarget
+			  = tdata->tjmax - ((eax >> 8) & 0xff) * 1000;
+			tdata->attr_size++;
+		}
+	}
+
+	pdata->core_data[attr_no] = tdata;
+
+	/* Create sysfs interfaces */
+	err = create_core_attrs(tdata, pdata->hwmon_dev, attr_no);
+	if (err)
+		goto exit_free;
+
+	return 0;
+exit_free:
+	pdata->core_data[attr_no] = NULL;
+	kfree(tdata);
+	return err;
+}
+
+static void coretemp_add_core(unsigned int cpu, int pkg_flag)
+{
+	struct platform_device *pdev = coretemp_get_pdev(cpu);
+	int err;
+
+	if (!pdev)
+		return;
+
+	err = create_core_data(pdev, cpu, pkg_flag);
+	if (err)
+		dev_err(&pdev->dev, "Adding Core %u failed\n", cpu);
+}
+
+static void coretemp_remove_core(struct platform_data *pdata,
+				 int indx)
+{
+	struct temp_data *tdata = pdata->core_data[indx];
+
+	/* Remove the sysfs attributes */
+	sysfs_remove_group(&pdata->hwmon_dev->kobj, &tdata->attr_group);
+
+	kfree(pdata->core_data[indx]);
+	pdata->core_data[indx] = NULL;
+}
+
+static int coretemp_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct platform_data *pdata;
+
+	/* Initialize the per-package data structures */
+	pdata = devm_kzalloc(dev, sizeof(struct platform_data), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	pdata->phys_proc_id = pdev->id;
+	platform_set_drvdata(pdev, pdata);
+
+	pdata->hwmon_dev = devm_hwmon_device_register_with_groups(dev, DRVNAME,
+								  pdata, NULL);
+	return PTR_ERR_OR_ZERO(pdata->hwmon_dev);
+}
+
+static int coretemp_remove(struct platform_device *pdev)
+{
+	struct platform_data *pdata = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = MAX_CORE_DATA - 1; i >= 0; --i)
+		if (pdata->core_data[i])
+			coretemp_remove_core(pdata, i);
+
+	return 0;
+}
+
+static struct platform_driver coretemp_driver = {
+	.driver = {
+		.name = DRVNAME,
+	},
+	.probe = coretemp_probe,
+	.remove = coretemp_remove,
+};
+
+static int coretemp_device_add(unsigned int cpu)
+{
+	int err;
+	struct platform_device *pdev;
+	struct pdev_entry *pdev_entry;
+
+	mutex_lock(&pdev_list_mutex);
+
+	pdev = platform_device_alloc(DRVNAME, TO_PHYS_ID(cpu));
+	if (!pdev) {
+		err = -ENOMEM;
+		pr_err("Device allocation failed\n");
+		goto exit;
+	}
+
+	pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
+	if (!pdev_entry) {
+		err = -ENOMEM;
+		goto exit_device_put;
+	}
+
+	err = platform_device_add(pdev);
+	if (err) {
+		pr_err("Device addition failed (%d)\n", err);
+		goto exit_device_free;
+	}
+
+	pdev_entry->pdev = pdev;
+	pdev_entry->phys_proc_id = pdev->id;
+
+	list_add_tail(&pdev_entry->list, &pdev_list);
+	mutex_unlock(&pdev_list_mutex);
+
+	return 0;
+
+exit_device_free:
+	kfree(pdev_entry);
+exit_device_put:
+	platform_device_put(pdev);
+exit:
+	mutex_unlock(&pdev_list_mutex);
+	return err;
+}
+
+static void coretemp_device_remove(unsigned int cpu)
+{
+	struct pdev_entry *p, *n;
+	u16 phys_proc_id = TO_PHYS_ID(cpu);
+
+	mutex_lock(&pdev_list_mutex);
+	list_for_each_entry_safe(p, n, &pdev_list, list) {
+		if (p->phys_proc_id != phys_proc_id)
+			continue;
+		platform_device_unregister(p->pdev);
+		list_del(&p->list);
+		kfree(p);
+	}
+	mutex_unlock(&pdev_list_mutex);
+}
+
+static bool is_any_core_online(struct platform_data *pdata)
+{
+	int i;
+
+	/* Find online cores, except pkgtemp data */
+	for (i = MAX_CORE_DATA - 1; i >= 0; --i) {
+		if (pdata->core_data[i] &&
+			!pdata->core_data[i]->is_pkg_data) {
+			return true;
+		}
+	}
+	return false;
+}
+
+static void get_core_online(unsigned int cpu)
+{
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+	struct platform_device *pdev = coretemp_get_pdev(cpu);
+	int err;
+
+	/*
+	 * CPUID.06H.EAX[0] indicates whether the CPU has thermal
+	 * sensors. We check this bit only, all the early CPUs
+	 * without thermal sensors will be filtered out.
+	 */
+	if (!cpu_has(c, X86_FEATURE_DTHERM))
+		return;
+
+	if (!pdev) {
+		/* Check the microcode version of the CPU */
+		if (chk_ucode_version(cpu))
+			return;
+
+		/*
+		 * Alright, we have DTS support.
+		 * We are bringing the _first_ core in this pkg
+		 * online. So, initialize per-pkg data structures and
+		 * then bring this core online.
+		 */
+		err = coretemp_device_add(cpu);
+		if (err)
+			return;
+		/*
+		 * Check whether pkgtemp support is available.
+		 * If so, add interfaces for pkgtemp.
+		 */
+		if (cpu_has(c, X86_FEATURE_PTS))
+			coretemp_add_core(cpu, 1);
+	}
+	/*
+	 * Physical CPU device already exists.
+	 * So, just add interfaces for this core.
+	 */
+	coretemp_add_core(cpu, 0);
+}
+
+static void put_core_offline(unsigned int cpu)
+{
+	int i, indx;
+	struct platform_data *pdata;
+	struct platform_device *pdev = coretemp_get_pdev(cpu);
+
+	/* If the physical CPU device does not exist, just return */
+	if (!pdev)
+		return;
+
+	pdata = platform_get_drvdata(pdev);
+
+	indx = TO_ATTR_NO(cpu);
+
+	/* The core id is too big, just return */
+	if (indx > MAX_CORE_DATA - 1)
+		return;
+
+	if (pdata->core_data[indx] && pdata->core_data[indx]->cpu == cpu)
+		coretemp_remove_core(pdata, indx);
+
+	/*
+	 * If a HT sibling of a core is taken offline, but another HT sibling
+	 * of the same core is still online, register the alternate sibling.
+	 * This ensures that exactly one set of attributes is provided as long
+	 * as at least one HT sibling of a core is online.
+	 */
+	for_each_sibling(i, cpu) {
+		if (i != cpu) {
+			get_core_online(i);
+			/*
+			 * Display temperature sensor data for one HT sibling
+			 * per core only, so abort the loop after one such
+			 * sibling has been found.
+			 */
+			break;
+		}
+	}
+	/*
+	 * If all cores in this pkg are offline, remove the device.
+	 * coretemp_device_remove calls unregister_platform_device,
+	 * which in turn calls coretemp_remove. This removes the
+	 * pkgtemp entry and does other clean ups.
+	 */
+	if (!is_any_core_online(pdata))
+		coretemp_device_remove(cpu);
+}
+
+static int coretemp_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 coretemp_cpu_notifier __refdata = {
+	.notifier_call = coretemp_cpu_callback,
+};
+
+static const struct x86_cpu_id __initconst coretemp_ids[] = {
+	{ X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_DTHERM },
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, coretemp_ids);
+
+static int __init coretemp_init(void)
+{
+	int i, err;
+
+	/*
+	 * CPUID.06H.EAX[0] indicates whether the CPU has thermal
+	 * sensors. We check this bit only, all the early CPUs
+	 * without thermal sensors will be filtered out.
+	 */
+	if (!x86_match_cpu(coretemp_ids))
+		return -ENODEV;
+
+	err = platform_driver_register(&coretemp_driver);
+	if (err)
+		goto exit;
+
+	cpu_notifier_register_begin();
+	for_each_online_cpu(i)
+		get_core_online(i);
+
+#ifndef CONFIG_HOTPLUG_CPU
+	if (list_empty(&pdev_list)) {
+		cpu_notifier_register_done();
+		err = -ENODEV;
+		goto exit_driver_unreg;
+	}
+#endif
+
+	__register_hotcpu_notifier(&coretemp_cpu_notifier);
+	cpu_notifier_register_done();
+	return 0;
+
+#ifndef CONFIG_HOTPLUG_CPU
+exit_driver_unreg:
+	platform_driver_unregister(&coretemp_driver);
+#endif
+exit:
+	return err;
+}
+
+static void __exit coretemp_exit(void)
+{
+	struct pdev_entry *p, *n;
+
+	cpu_notifier_register_begin();
+	__unregister_hotcpu_notifier(&coretemp_cpu_notifier);
+	mutex_lock(&pdev_list_mutex);
+	list_for_each_entry_safe(p, n, &pdev_list, list) {
+		platform_device_unregister(p->pdev);
+		list_del(&p->list);
+		kfree(p);
+	}
+	mutex_unlock(&pdev_list_mutex);
+	cpu_notifier_register_done();
+	platform_driver_unregister(&coretemp_driver);
+}
+
+MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
+MODULE_DESCRIPTION("Intel Core temperature monitor");
+MODULE_LICENSE("GPL");
+
+module_init(coretemp_init)
+module_exit(coretemp_exit)