Hi, > -----Original Message----- > From: lm-sensors-bounces@xxxxxxxxxxxxxx [mailto:lm-sensors-bounces@lm- > sensors.org] On Behalf Of Kirill A. Shutemov > Sent: Wednesday, May 02, 2012 8:41 PM > To: Yu, Fenghua; Guenter Roeck > Cc: Andi Kleen; linux-kernel@xxxxxxxxxxxxxxx; Kirill A. Shutemov; lm-sensors@lm- > sensors.org > Subject: [PATCH] hwmon: coretemp: use list instead of fixed size > array for temp data > > 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) The get_temp_data can return a NULL. So, you might want to do, if (tdata && tdata->cpu == cpu) to avoid a potential NULL ptr crash. In general, why are we using spin_locks instead of mutex_locks, for list manipulations .. ? Thanks, Durga _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
