[PATCH] hwmon: coretemp: use list instead of fixed size array for temp data

From: Kirill A. Shutemov
Date: Wed May 02 2012 - 11:10:10 EST

From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>

Let's rework code to allow arbitrary number of cores on a CPU, not
limited by hardcoded array size.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
drivers/hwmon/coretemp.c | 176 +++++++++++++++++++++++++++++++++-------------
1 files changed, 127 insertions(+), 49 deletions(-)

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 54a70fe..f5f9108 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -36,6 +36,8 @@
#include <linux/cpu.h>
#include <linux/pci.h>
#include <linux/smp.h>
+#include <linux/list.h>
+#include <linux/kref.h>
#include <linux/moduleparam.h>
#include <asm/msr.h>
#include <asm/processor.h>
@@ -52,11 +54,9 @@ 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 16 /* Number of Real cores per cpu */
#define CORETEMP_NAME_LENGTH 17 /* 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)
@@ -82,6 +82,9 @@ MODULE_PARM_DESC(tjmax, "TjMax value in degrees Celsius");
* @valid: If this is 1, the current temperature is valid.
*/
struct temp_data {
+ struct list_head list;
+ struct kref refcount;
+ int id;
int temp;
int ttarget;
int tjmax;
@@ -101,7 +104,8 @@ struct temp_data {
struct platform_data {
struct device *hwmon_dev;
u16 phys_proc_id;
- struct temp_data *core_data[MAX_CORE_DATA];
+ struct list_head temp_data_list;
+ spinlock_t temp_data_lock;
struct device_attribute name_attr;
};

@@ -114,6 +118,29 @@ struct pdev_entry {
static LIST_HEAD(pdev_list);
static DEFINE_MUTEX(pdev_list_mutex);

+static void temp_data_release(struct kref *ref)
+{
+ struct temp_data *tdata = container_of(ref, struct temp_data, refcount);
+
+ kfree(tdata);
+}
+
+static struct temp_data *get_temp_data(struct platform_data *pdata, int id)
+{
+ struct temp_data *tdata;
+
+ spin_lock(&pdata->temp_data_lock);
+ list_for_each_entry(tdata, &pdata->temp_data_list, list)
+ if (tdata->id == id) {
+ kref_get(&tdata->refcount);
+ goto out;
+ }
+ tdata = NULL;
+out:
+ spin_unlock(&pdata->temp_data_lock);
+ return tdata;
+}
+
static ssize_t show_name(struct device *dev,
struct device_attribute *devattr, char *buf)
{
@@ -125,12 +152,19 @@ static ssize_t show_label(struct device *dev,
{
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];
+ struct temp_data *tdata = get_temp_data(pdata, attr->index);
+ ssize_t ret;
+
+ if (!tdata)
+ return -ENOENT;

if (tdata->is_pkg_data)
- return sprintf(buf, "Physical id %u\n", pdata->phys_proc_id);
+ ret = sprintf(buf, "Physical id %u\n", pdata->phys_proc_id);
+ else
+ ret = sprintf(buf, "Core %u\n", tdata->cpu_core_id);

- return sprintf(buf, "Core %u\n", tdata->cpu_core_id);
+ kref_put(&tdata->refcount, temp_data_release);
+ return ret;
}

static ssize_t show_crit_alarm(struct device *dev,
@@ -139,11 +173,18 @@ static ssize_t show_crit_alarm(struct device *dev,
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];
+ struct temp_data *tdata = get_temp_data(pdata, attr->index);
+ ssize_t ret;
+
+ if (!tdata)
+ return -ENOENT;

rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);

- return sprintf(buf, "%d\n", (eax >> 5) & 1);
+ ret = sprintf(buf, "%d\n", (eax >> 5) & 1);
+
+ kref_put(&tdata->refcount, temp_data_release);
+ return ret;
}

static ssize_t show_tjmax(struct device *dev,
@@ -151,8 +192,16 @@ static ssize_t show_tjmax(struct device *dev,
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct platform_data *pdata = dev_get_drvdata(dev);
+ struct temp_data *tdata = get_temp_data(pdata, attr->index);
+ ssize_t ret;
+
+ if (!tdata)
+ return -ENOENT;
+
+ ret = sprintf(buf, "%d\n", tdata->tjmax);

- return sprintf(buf, "%d\n", pdata->core_data[attr->index]->tjmax);
+ kref_put(&tdata->refcount, temp_data_release);
+ return ret;
}

static ssize_t show_ttarget(struct device *dev,
@@ -160,8 +209,16 @@ static ssize_t show_ttarget(struct device *dev,
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct platform_data *pdata = dev_get_drvdata(dev);
+ struct temp_data *tdata = get_temp_data(pdata, attr->index);
+ ssize_t ret;

- return sprintf(buf, "%d\n", pdata->core_data[attr->index]->ttarget);
+ if (!tdata)
+ return -ENOENT;
+
+ ret = sprintf(buf, "%d\n", tdata->ttarget);
+
+ kref_put(&tdata->refcount, temp_data_release);
+ return ret;
}

static ssize_t show_temp(struct device *dev,
@@ -170,7 +227,11 @@ static ssize_t show_temp(struct device *dev,
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];
+ struct temp_data *tdata = get_temp_data(pdata, attr->index);
+ ssize_t ret = -EAGAIN;
+
+ if (!tdata)
+ return -ENOENT;

mutex_lock(&tdata->update_lock);

@@ -188,7 +249,12 @@ static ssize_t show_temp(struct device *dev,
}

mutex_unlock(&tdata->update_lock);
- return tdata->valid ? sprintf(buf, "%d\n", tdata->temp) : -EAGAIN;
+
+ if (tdata->valid)
+ ret = sprintf(buf, "%d\n", tdata->temp);
+
+ kref_put(&tdata->refcount, temp_data_release);
+ return ret;
}

static int __cpuinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id,
@@ -412,6 +478,7 @@ static struct temp_data __cpuinit *init_temp_data(unsigned int cpu,
tdata = kzalloc(sizeof(struct temp_data), GFP_KERNEL);
if (!tdata)
return NULL;
+ kref_init(&tdata->refcount);

tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
MSR_IA32_THERM_STATUS;
@@ -423,7 +490,7 @@ static struct temp_data __cpuinit *init_temp_data(unsigned int cpu,
return tdata;
}

-static int __cpuinit create_core_data(struct platform_device *pdev,
+static int __cpuinit create_temp_data(struct platform_device *pdev,
unsigned int cpu, int pkg_flag)
{
struct temp_data *tdata;
@@ -440,9 +507,6 @@ static int __cpuinit create_core_data(struct platform_device *pdev,
*/
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
@@ -450,8 +514,14 @@ static int __cpuinit create_core_data(struct platform_device *pdev,
* 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;
+ spin_lock(&pdata->temp_data_lock);
+ list_for_each_entry(tdata, &pdata->temp_data_list, list) {
+ if (tdata->id == attr_no) {
+ spin_unlock(&pdata->temp_data_lock);
+ return 0;
+ }
+ }
+ spin_unlock(&pdata->temp_data_lock);

tdata = init_temp_data(cpu, pkg_flag);
if (!tdata)
@@ -480,16 +550,23 @@ static int __cpuinit create_core_data(struct platform_device *pdev,
}
}

- pdata->core_data[attr_no] = tdata;
+ tdata->id = attr_no;
+
+ spin_lock(&pdata->temp_data_lock);
+ list_add(&tdata->list, &pdata->temp_data_list);
+ spin_unlock(&pdata->temp_data_lock);

/* Create sysfs interfaces */
err = create_core_attrs(tdata, &pdev->dev, attr_no);
if (err)
- goto exit_free;
+ goto exit_list_del;

return 0;
+exit_list_del:
+ spin_lock(&pdata->temp_data_lock);
+ list_del(&tdata->list);
+ spin_unlock(&pdata->temp_data_lock);
exit_free:
- pdata->core_data[attr_no] = NULL;
kfree(tdata);
return err;
}
@@ -502,23 +579,21 @@ static void __cpuinit coretemp_add_core(unsigned int cpu, int pkg_flag)
if (!pdev)
return;

- err = create_core_data(pdev, cpu, pkg_flag);
+ err = create_temp_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,
- struct device *dev, int indx)
+static void coretemp_remove_core(struct temp_data *tdata, struct device *dev)
{
int i;
- struct temp_data *tdata = pdata->core_data[indx];

/* Remove the sysfs attributes */
for (i = 0; i < tdata->attr_size; i++)
device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);

- kfree(pdata->core_data[indx]);
- pdata->core_data[indx] = NULL;
+ list_del(&tdata->list);
+ kref_put(&tdata->refcount, temp_data_release);
}

static int __devinit coretemp_probe(struct platform_device *pdev)
@@ -536,6 +611,8 @@ static int __devinit coretemp_probe(struct platform_device *pdev)
goto exit_free;

pdata->phys_proc_id = pdev->id;
+ INIT_LIST_HEAD(&pdata->temp_data_list);
+ spin_lock_init(&pdata->temp_data_lock);
platform_set_drvdata(pdev, pdata);

pdata->hwmon_dev = hwmon_device_register(&pdev->dev);
@@ -557,11 +634,12 @@ exit_free:
static int __devexit coretemp_remove(struct platform_device *pdev)
{
struct platform_data *pdata = platform_get_drvdata(pdev);
- int i;
+ struct temp_data *cur, *tmp;

- for (i = MAX_CORE_DATA - 1; i >= 0; --i)
- if (pdata->core_data[i])
- coretemp_remove_core(pdata, &pdev->dev, i);
+ spin_lock(&pdata->temp_data_lock);
+ list_for_each_entry_safe(cur, tmp, &pdata->temp_data_list, list)
+ coretemp_remove_core(cur, &pdev->dev);
+ spin_unlock(&pdata->temp_data_lock);

device_remove_file(&pdev->dev, &pdata->name_attr);
hwmon_device_unregister(pdata->hwmon_dev);
@@ -641,16 +719,17 @@ static void __cpuinit coretemp_device_remove(unsigned int cpu)

static bool __cpuinit 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;
+ struct temp_data *tdata;
+ bool ret = true;
+
+ spin_lock(&pdata->temp_data_lock);
+ list_for_each_entry(tdata, &pdata->temp_data_list, list)
+ if (!tdata->is_pkg_data)
+ goto out;
+ ret = false;
+out:
+ spin_unlock(&pdata->temp_data_lock);
+ return ret;
}

static void __cpuinit get_core_online(unsigned int cpu)
@@ -697,9 +776,10 @@ static void __cpuinit get_core_online(unsigned int cpu)

static void __cpuinit put_core_offline(unsigned int cpu)
{
- int i, indx;
+ int i, attr_no;
struct platform_data *pdata;
struct platform_device *pdev = coretemp_get_pdev(cpu);
+ struct temp_data *tdata;

/* If the physical CPU device does not exist, just return */
if (!pdev)
@@ -707,14 +787,12 @@ static void __cpuinit put_core_offline(unsigned int cpu)

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;
+ attr_no = TO_ATTR_NO(cpu);

- if (pdata->core_data[indx] && pdata->core_data[indx]->cpu == cpu)
- coretemp_remove_core(pdata, &pdev->dev, indx);
+ tdata = get_temp_data(pdata, attr_no);
+ if (tdata->cpu == cpu)
+ coretemp_remove_core(tdata, &pdev->dev);
+ kref_put(&tdata->refcount, temp_data_release);

/*
* If a HT sibling of a core is taken offline, but another HT sibling
--
1.7.9.1

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