hwmon: (coretemp) Merge pkgtemp with coretemp

This patch merges the pkgtemp with coretemp driver.
The sysfs interfaces for all cores in the same pkg
are shown under one directory, in hwmon. It also
supports CONFIG_HOTPLUG_CPU. So, the sysfs interfaces
are created when each core comes online and are
removed when it goes offline.

Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
[guenter.roeck@ericsson.com: Fixed section reference errors]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

1 files changed, 455 insertions, 210 deletions

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 194ca0aa8b0c..ece3b7da6538 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -41,122 +41,146 @@
 
 #define DRVNAME	"coretemp"
 
-typedef enum { SHOW_TEMP, SHOW_TJMAX, SHOW_TTARGET, SHOW_LABEL,
-		SHOW_NAME } SHOW;
+#define BASE_SYSFS_ATTR_NO	2	/* Sysfs Base attr no for coretemp */
+#define NUM_REAL_CORES		16	/* Number of Real cores per cpu */
+#define CORETEMP_NAME_LENGTH	17	/* String Length of attrs */
+#define MAX_ATTRS		5	/* Maximum no of per-core attrs */
+#define MAX_CORE_DATA		(NUM_REAL_CORES + BASE_SYSFS_ATTR_NO)
+
+#ifdef CONFIG_SMP
+#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)
+#else
+#define TO_PHYS_ID(cpu)		(cpu)
+#define TO_CORE_ID(cpu)		(cpu)
+#define TO_ATTR_NO(cpu)		(cpu)
+#endif
 
 /*
- * Functions declaration
+ * 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.
+ * @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.
  */
-
-static struct coretemp_data *coretemp_update_device(struct device *dev);
-
-struct coretemp_data {
-	struct device *hwmon_dev;
-	struct mutex update_lock;
-	const char *name;
-	u32 id;
-	u16 core_id;
-	char valid;		/* zero until following fields are valid */
-	unsigned long last_updated;	/* in jiffies */
+struct temp_data {
 	int temp;
-	int tjmax;
 	int ttarget;
-	u8 alarm;
+	int tjmax;
+	unsigned long last_updated;
+	unsigned int cpu;
+	u32 cpu_core_id;
+	u32 status_reg;
+	bool is_pkg_data;
+	bool valid;
+	struct sensor_device_attribute sd_attrs[MAX_ATTRS];
+	char attr_name[MAX_ATTRS][CORETEMP_NAME_LENGTH];
+	struct mutex update_lock;
 };
 
-/*
- * Sysfs stuff
- */
+/* 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;
+};
 
-static ssize_t show_name(struct device *dev, struct device_attribute
-			  *devattr, char *buf)
+struct pdev_entry {
+	struct list_head list;
+	struct platform_device *pdev;
+	unsigned int cpu;
+	u16 phys_proc_id;
+	u16 cpu_core_id;
+};
+
+static LIST_HEAD(pdev_list);
+static DEFINE_MUTEX(pdev_list_mutex);
+
+static ssize_t show_name(struct device *dev,
+			struct device_attribute *devattr, char *buf)
+{
+	return sprintf(buf, "%s\n", DRVNAME);
+}
+
+static ssize_t show_label(struct device *dev,
+				struct device_attribute *devattr, char *buf)
 {
-	int ret;
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-	struct coretemp_data *data = dev_get_drvdata(dev);
+	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);
 
-	if (attr->index == SHOW_NAME)
-		ret = sprintf(buf, "%s\n", data->name);
-	else	/* show label */
-		ret = sprintf(buf, "Core %d\n", data->core_id);
-	return ret;
+	return sprintf(buf, "Core %u\n", tdata->cpu_core_id);
 }
 
-static ssize_t show_alarm(struct device *dev, struct device_attribute
-			  *devattr, char *buf)
+static ssize_t show_crit_alarm(struct device *dev,
+				struct device_attribute *devattr, char *buf)
 {
-	struct coretemp_data *data = coretemp_update_device(dev);
-	/* read the Out-of-spec log, never clear */
-	return sprintf(buf, "%d\n", data->alarm);
+	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_temp(struct device *dev,
-			 struct device_attribute *devattr, char *buf)
+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 coretemp_data *data = coretemp_update_device(dev);
-	int err;
+	struct platform_data *pdata = dev_get_drvdata(dev);
 
-	if (attr->index == SHOW_TEMP)
-		err = data->valid ? sprintf(buf, "%d\n", data->temp) : -EAGAIN;
-	else if (attr->index == SHOW_TJMAX)
-		err = sprintf(buf, "%d\n", data->tjmax);
-	else
-		err = sprintf(buf, "%d\n", data->ttarget);
-	return err;
+	return sprintf(buf, "%d\n", pdata->core_data[attr->index]->tjmax);
 }
 
-static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
-			  SHOW_TEMP);
-static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
-			  SHOW_TJMAX);
-static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL,
-			  SHOW_TTARGET);
-static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
-static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
-static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
-
-static struct attribute *coretemp_attributes[] = {
-	&sensor_dev_attr_name.dev_attr.attr,
-	&sensor_dev_attr_temp1_label.dev_attr.attr,
-	&dev_attr_temp1_crit_alarm.attr,
-	&sensor_dev_attr_temp1_input.dev_attr.attr,
-	&sensor_dev_attr_temp1_crit.dev_attr.attr,
-	NULL
-};
+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);
 
-static const struct attribute_group coretemp_group = {
-	.attrs = coretemp_attributes,
-};
+	return sprintf(buf, "%d\n", pdata->core_data[attr->index]->ttarget);
+}
 
-static struct coretemp_data *coretemp_update_device(struct device *dev)
+static ssize_t show_temp(struct device *dev,
+			struct device_attribute *devattr, char *buf)
 {
-	struct coretemp_data *data = dev_get_drvdata(dev);
-
-	mutex_lock(&data->update_lock);
+	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];
 
-	if (!data->valid || time_after(jiffies, data->last_updated + HZ)) {
-		u32 eax, edx;
+	mutex_lock(&tdata->update_lock);
 
-		data->valid = 0;
-		rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
-		data->alarm = (eax >> 5) & 1;
-		/* update only if data has been valid */
+	/* 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);
+		tdata->valid = 0;
+		/* Check whether the data is valid */
 		if (eax & 0x80000000) {
-			data->temp = data->tjmax - (((eax >> 16)
-							& 0x7f) * 1000);
-			data->valid = 1;
-		} else {
-			dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
+			tdata->temp = tdata->tjmax -
+					(((eax >> 16) & 0x7f) * 1000);
+			tdata->valid = 1;
 		}
-		data->last_updated = jiffies;
+		tdata->last_updated = jiffies;
 	}
 
-	mutex_unlock(&data->update_lock);
-	return data;
+	mutex_unlock(&tdata->update_lock);
+	return tdata->valid ? sprintf(buf, "%d\n", tdata->temp) : -EAGAIN;
 }
 
-static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
+static int adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
 {
 	/* The 100C is default for both mobile and non mobile CPUs */
 
@@ -244,8 +268,7 @@ static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *
 	return tjmax;
 }
 
-static int __devinit get_tjmax(struct cpuinfo_x86 *c, u32 id,
-			       struct device *dev)
+static int get_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
 {
 	/* The 100C is default for both mobile and non mobile CPUs */
 	int err;
@@ -300,115 +323,293 @@ static void __devinit get_ucode_rev_on_cpu(void *edx)
 	rdmsr(MSR_IA32_UCODE_REV, eax, *(u32 *)edx);
 }
 
-static int __devinit coretemp_probe(struct platform_device *pdev)
+static int get_pkg_tjmax(unsigned int cpu, struct device *dev)
 {
-	struct coretemp_data *data;
-	struct cpuinfo_x86 *c = &cpu_data(pdev->id);
 	int err;
-	u32 eax, edx;
+	u32 eax, edx, val;
 
-	if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
-		err = -ENOMEM;
-		dev_err(&pdev->dev, "Out of memory\n");
-		goto exit;
+	err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
+	if (!err) {
+		val = (eax >> 16) & 0xff;
+		if ((val > 80) && (val < 120))
+			return val * 1000;
 	}
+	dev_warn(dev, "Unable to read Pkg-TjMax from CPU:%u\n", cpu);
+	return 100000; /* Default TjMax: 100 degree celsius */
+}
 
-	data->id = pdev->id;
-#ifdef CONFIG_SMP
-	data->core_id = c->cpu_core_id;
-#endif
-	data->name = "coretemp";
-	mutex_init(&data->update_lock);
+static int create_name_attr(struct platform_data *pdata, struct device *dev)
+{
+	pdata->name_attr.attr.name = "name";
+	pdata->name_attr.attr.mode = S_IRUGO;
+	pdata->name_attr.show = show_name;
+	return device_create_file(dev, &pdata->name_attr);
+}
 
-	/* test if we can access the THERM_STATUS MSR */
-	err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
-	if (err) {
-		dev_err(&pdev->dev,
-			"Unable to access THERM_STATUS MSR, giving up\n");
-		goto exit_free;
+static int create_core_attrs(struct temp_data *tdata, struct device *dev,
+				int attr_no)
+{
+	int err, i;
+	static ssize_t (*rd_ptr[MAX_ATTRS]) (struct device *dev,
+			struct device_attribute *devattr, char *buf) = {
+			show_label, show_crit_alarm, show_ttarget,
+			show_temp, show_tjmax };
+	static const char *names[MAX_ATTRS] = {
+					"temp%d_label", "temp%d_crit_alarm",
+					"temp%d_max", "temp%d_input",
+					"temp%d_crit" };
+
+	for (i = 0; i < MAX_ATTRS; i++) {
+		snprintf(tdata->attr_name[i], CORETEMP_NAME_LENGTH, names[i],
+			attr_no);
+		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].dev_attr.store = NULL;
+		tdata->sd_attrs[i].index = attr_no;
+		err = device_create_file(dev, &tdata->sd_attrs[i].dev_attr);
+		if (err)
+			goto exit_free;
 	}
+	return 0;
+
+exit_free:
+	while (--i >= 0)
+		device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);
+	return err;
+}
+
+static void update_ttarget(__u8 cpu_model, struct temp_data *tdata,
+				struct device *dev)
+{
+	int err;
+	u32 eax, edx;
+
+	/*
+	 * Initialize ttarget value. Eventually this will be
+	 * initialized with the value from MSR_IA32_THERM_INTERRUPT
+	 * register. If IA32_TEMPERATURE_TARGET is supported, this
+	 * value will be over written below.
+	 * To Do: Patch to initialize ttarget from MSR_IA32_THERM_INTERRUPT
+	 */
+	tdata->ttarget = tdata->tjmax - 20000;
 
-	/* 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).
-	*/
+	/*
+	 * Read the still undocumented IA32_TEMPERATURE_TARGET. It exists
+	 * on older CPUs but not in this register,
+	 * Atoms don't have it either.
+	 */
+	if ((cpu_model > 0xe) && (cpu_model != 0x1c)) {
+		err = rdmsr_safe_on_cpu(tdata->cpu,
+				MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
+		if (err) {
+			dev_warn(dev,
+			"Unable to read IA32_TEMPERATURE_TARGET MSR\n");
+		} else {
+			tdata->ttarget = tdata->tjmax -
+					(((eax >> 8) & 0xff) * 1000);
+		}
+	}
+}
+
+static int chk_ucode_version(struct platform_device *pdev)
+{
+	struct cpuinfo_x86 *c = &cpu_data(pdev->id);
+	int err;
+	u32 edx;
 
+	/*
+	 * 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)) {
 		/* check for microcode update */
-		err = smp_call_function_single(data->id, get_ucode_rev_on_cpu,
+		err = smp_call_function_single(pdev->id, get_ucode_rev_on_cpu,
 					       &edx, 1);
 		if (err) {
 			dev_err(&pdev->dev,
 				"Cannot determine microcode revision of "
-				"CPU#%u (%d)!\n", data->id, err);
-			err = -ENODEV;
-			goto exit_free;
+				"CPU#%u (%d)!\n", pdev->id, err);
+			return -ENODEV;
 		} else if (edx < 0x39) {
-			err = -ENODEV;
 			dev_err(&pdev->dev,
 				"Errata AE18 not fixed, update BIOS or "
 				"microcode of the CPU!\n");
-			goto exit_free;
+			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);
+	mutex_init(&tdata->update_lock);
+	return tdata;
+}
 
-	data->tjmax = get_tjmax(c, data->id, &pdev->dev);
-	platform_set_drvdata(pdev, data);
+static int create_core_data(struct platform_data *pdata,
+				struct platform_device *pdev,
+				unsigned int cpu, int pkg_flag)
+{
+	struct temp_data *tdata;
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+	u32 eax, edx;
+	int err, attr_no;
 
 	/*
-	 * read the still undocumented IA32_TEMPERATURE_TARGET. It exists
-	 * on older CPUs but not in this register,
-	 * Atoms don't have it either.
+	 * 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 ((c->x86_model > 0xe) && (c->x86_model != 0x1c)) {
-		err = rdmsr_safe_on_cpu(data->id, MSR_IA32_TEMPERATURE_TARGET,
-		    &eax, &edx);
-		if (err) {
-			dev_warn(&pdev->dev, "Unable to read"
-					" IA32_TEMPERATURE_TARGET MSR\n");
-		} else {
-			data->ttarget = data->tjmax -
-					(((eax >> 8) & 0xff) * 1000);
-			err = device_create_file(&pdev->dev,
-					&sensor_dev_attr_temp1_max.dev_attr);
-			if (err)
-				goto exit_free;
-		}
-	}
+	if (attr_no > MAX_CORE_DATA - 1)
+		return -ERANGE;
+
+	/* Skip if it is a HT core, Not an error */
+	if (pdata->core_data[attr_no] != NULL)
+		return 0;
 
-	if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
-		goto exit_dev;
+	tdata = init_temp_data(cpu, pkg_flag);
+	if (!tdata)
+		return -ENOMEM;
 
-	data->hwmon_dev = hwmon_device_register(&pdev->dev);
-	if (IS_ERR(data->hwmon_dev)) {
-		err = PTR_ERR(data->hwmon_dev);
-		dev_err(&pdev->dev, "Class registration failed (%d)\n",
-			err);
-		goto exit_class;
-	}
+	/* 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 */
+	if (pkg_flag)
+		tdata->tjmax = get_pkg_tjmax(pdev->id, &pdev->dev);
+	else
+		tdata->tjmax = get_tjmax(c, cpu, &pdev->dev);
+
+	update_ttarget(c->x86_model, tdata, &pdev->dev);
+	pdata->core_data[attr_no] = tdata;
+
+	/* Create sysfs interfaces */
+	err = create_core_attrs(tdata, &pdev->dev, attr_no);
+	if (err)
+		goto exit_free;
 
 	return 0;
+exit_free:
+	kfree(tdata);
+	return err;
+}
+
+static void coretemp_add_core(unsigned int cpu, int pkg_flag)
+{
+	struct platform_data *pdata;
+	struct platform_device *pdev = coretemp_get_pdev(cpu);
+	int err;
+
+	if (!pdev)
+		return;
+
+	pdata = platform_get_drvdata(pdev);
+
+	err = create_core_data(pdata, 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,
+				struct device *dev, int indx)
+{
+	int i;
+	struct temp_data *tdata = pdata->core_data[indx];
+
+	/* Remove the sysfs attributes */
+	for (i = 0; i < MAX_ATTRS; i++)
+		device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);
+
+	kfree(pdata->core_data[indx]);
+	pdata->core_data[indx] = NULL;
+}
+
+static int __devinit coretemp_probe(struct platform_device *pdev)
+{
+	struct platform_data *pdata;
+	int err;
 
-exit_class:
-	sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
-exit_dev:
-	device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
+	/* Check the microcode version of the CPU */
+	err = chk_ucode_version(pdev);
+	if (err)
+		return err;
+
+	/* Initialize the per-package data structures */
+	pdata = kzalloc(sizeof(struct platform_data), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	err = create_name_attr(pdata, &pdev->dev);
+	if (err)
+		goto exit_free;
+
+	pdata->phys_proc_id = TO_PHYS_ID(pdev->id);
+	platform_set_drvdata(pdev, pdata);
+
+	pdata->hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(pdata->hwmon_dev)) {
+		err = PTR_ERR(pdata->hwmon_dev);
+		dev_err(&pdev->dev, "Class registration failed (%d)\n", err);
+		goto exit_name;
+	}
+	return 0;
+
+exit_name:
+	device_remove_file(&pdev->dev, &pdata->name_attr);
+	platform_set_drvdata(pdev, NULL);
 exit_free:
-	kfree(data);
-exit:
+	kfree(pdata);
 	return err;
 }
 
 static int __devexit coretemp_remove(struct platform_device *pdev)
 {
-	struct coretemp_data *data = platform_get_drvdata(pdev);
+	struct platform_data *pdata = platform_get_drvdata(pdev);
+	int i;
 
-	hwmon_device_unregister(data->hwmon_dev);
-	sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
-	device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
+	for (i = MAX_CORE_DATA - 1; i >= 0; --i)
+		if (pdata->core_data[i])
+			coretemp_remove_core(pdata, &pdev->dev, i);
+
+	device_remove_file(&pdev->dev, &pdata->name_attr);
+	hwmon_device_unregister(pdata->hwmon_dev);
 	platform_set_drvdata(pdev, NULL);
-	kfree(data);
+	kfree(pdata);
 	return 0;
 }
 
@@ -421,50 +622,14 @@ static struct platform_driver coretemp_driver = {
 	.remove = __devexit_p(coretemp_remove),
 };
 
-struct pdev_entry {
-	struct list_head list;
-	struct platform_device *pdev;
-	unsigned int cpu;
-#ifdef CONFIG_SMP
-	u16 phys_proc_id;
-	u16 cpu_core_id;
-#endif
-};
-
-static LIST_HEAD(pdev_list);
-static DEFINE_MUTEX(pdev_list_mutex);
-
 static int __cpuinit coretemp_device_add(unsigned int cpu)
 {
 	int err;
 	struct platform_device *pdev;
 	struct pdev_entry *pdev_entry;
-	struct cpuinfo_x86 *c = &cpu_data(cpu);
-
-	/*
-	 * 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_DTS)) {
-		pr_info("CPU (model=0x%x) has no thermal sensor\n",
-			c->x86_model);
-		return 0;
-	}
 
 	mutex_lock(&pdev_list_mutex);
 
-#ifdef CONFIG_SMP
-	/* Skip second HT entry of each core */
-	list_for_each_entry(pdev_entry, &pdev_list, list) {
-		if (c->phys_proc_id == pdev_entry->phys_proc_id &&
-		    c->cpu_core_id == pdev_entry->cpu_core_id) {
-			err = 0;	/* Not an error */
-			goto exit;
-		}
-	}
-#endif
-
 	pdev = platform_device_alloc(DRVNAME, cpu);
 	if (!pdev) {
 		err = -ENOMEM;
@@ -486,10 +651,9 @@ static int __cpuinit coretemp_device_add(unsigned int cpu)
 
 	pdev_entry->pdev = pdev;
 	pdev_entry->cpu = cpu;
-#ifdef CONFIG_SMP
-	pdev_entry->phys_proc_id = c->phys_proc_id;
-	pdev_entry->cpu_core_id = c->cpu_core_id;
-#endif
+	pdev_entry->phys_proc_id = TO_PHYS_ID(cpu);
+	pdev_entry->cpu_core_id = TO_CORE_ID(cpu);
+
 	list_add_tail(&pdev_entry->list, &pdev_list);
 	mutex_unlock(&pdev_list_mutex);
 
@@ -504,28 +668,108 @@ exit:
 	return err;
 }
 
-static void __cpuinit coretemp_device_remove(unsigned int cpu)
+static void coretemp_device_remove(unsigned int cpu)
 {
-	struct pdev_entry *p;
-	unsigned int i;
+	struct pdev_entry *p, *n;
+	u16 phys_proc_id = TO_PHYS_ID(cpu);
 
 	mutex_lock(&pdev_list_mutex);
-	list_for_each_entry(p, &pdev_list, list) {
-		if (p->cpu != cpu)
+	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);
-		mutex_unlock(&pdev_list_mutex);
 		kfree(p);
-		for_each_cpu(i, cpu_sibling_mask(cpu))
-			if (i != cpu && !coretemp_device_add(i))
-				break;
-		return;
 	}
 	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 __cpuinit 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_DTS))
+		return;
+
+	if (!pdev) {
+		/*
+		 * 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 __cpuinit 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);
+
+	if (pdata->core_data[indx] && pdata->core_data[indx]->cpu == cpu)
+		coretemp_remove_core(pdata, &pdev->dev, indx);
+
+	/* Online the HT version of this core, if any */
+	for_each_cpu(i, cpu_sibling_mask(cpu)) {
+		if (i != cpu) {
+			get_core_online(i);
+			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 __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
 				 unsigned long action, void *hcpu)
 {
@@ -534,10 +778,10 @@ static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
 	switch (action) {
 	case CPU_ONLINE:
 	case CPU_DOWN_FAILED:
-		coretemp_device_add(cpu);
+		get_core_online(cpu);
 		break;
 	case CPU_DOWN_PREPARE:
-		coretemp_device_remove(cpu);
+		put_core_offline(cpu);
 		break;
 	}
 	return NOTIFY_OK;
@@ -547,6 +791,7 @@ static struct notifier_block coretemp_cpu_notifier __refdata = {
 	.notifier_call = coretemp_cpu_callback,
 };
 
+
 static int __init coretemp_init(void)
 {
 	int i, err = -ENODEV;
@@ -560,7 +805,7 @@ static int __init coretemp_init(void)
 		goto exit;
 
 	for_each_online_cpu(i)
-		coretemp_device_add(i);
+		get_core_online(i);
 
 #ifndef CONFIG_HOTPLUG_CPU
 	if (list_empty(&pdev_list)) {