/* * 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. */ #include <linux/module.h> #include <linux/delay.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 <asm/msr.h> #include <asm/processor.h> #define DRVNAME "coretemp" typedef enum { SHOW_TEMP, SHOW_TJMAX, SHOW_TTARGET, SHOW_LABEL, SHOW_NAME } SHOW; /* * Functions declaration */ 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; char valid; /* zero until following fields are valid */ unsigned long last_updated; /* in jiffies */ int temp; int tjmax; int ttarget; u8 alarm; }; /* * Sysfs stuff */ static ssize_t show_name(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); if (attr->index == SHOW_NAME) ret = sprintf(buf, "%s\n", data->name); else /* show label */ ret = sprintf(buf, "Core %d\n", data->id); return ret; } static ssize_t show_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); } static ssize_t show_temp(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; 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; } 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 const struct attribute_group coretemp_group = { .attrs = coretemp_attributes, }; static struct coretemp_data *coretemp_update_device(struct device *dev) { struct coretemp_data *data = dev_get_drvdata(dev); mutex_lock(&data->update_lock); if (!data->valid || time_after(jiffies, data->last_updated + HZ)) { u32 eax, edx; 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 */ 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); } data->last_updated = jiffies; } mutex_unlock(&data->update_lock); return data; } static int __devinit 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 ismobile = 1; int err; u32 eax, edx; /* Early chips have no MSR for TjMax */ if ((c->x86_model == 0xf) && (c->x86_mask < 4)) { ismobile = 0; } if ((c->x86_model > 0xe) && (ismobile)) { /* 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"); ismobile = 0; } else if (!(eax & 0x10000000)) { ismobile = 0; } } if (ismobile) { err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx); if (err) { dev_warn(dev, "Unable to access MSR 0xEE, for Tjmax, left" " at default"); } else if (eax & 0x40000000) { tjmax = 85000; } } else { dev_warn(dev, "Using relative temperature scale!\n"); } return tjmax; } static int __devinit coretemp_probe(struct platform_device *pdev) { struct coretemp_data *data; struct cpuinfo_x86 *c = &cpu_data(pdev->id); int err; u32 eax, edx; if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) { err = -ENOMEM; dev_err(&pdev->dev, "Out of memory\n"); goto exit; } data->id = pdev->id; data->name = "coretemp"; mutex_init(&data->update_lock); /* 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; } /* 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 */ rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx); if (edx < 0x39) { err = -ENODEV; dev_err(&pdev->dev, "Errata AE18 not fixed, update BIOS or " "microcode of the CPU!\n"); goto exit_free; } } data->tjmax = adjust_tjmax(c, data->id, &pdev->dev); platform_set_drvdata(pdev, data); /* read the still undocumented IA32_TEMPERATURE_TARGET it exists on older CPUs but not in this register */ if (c->x86_model > 0xe) { err = rdmsr_safe_on_cpu(data->id, 0x1a2, &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 ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group))) goto exit_dev; 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; } return 0; exit_class: sysfs_remove_group(&pdev->dev.kobj, &coretemp_group); exit_dev: device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr); exit_free: kfree(data); exit: return err; } static int __devexit coretemp_remove(struct platform_device *pdev) { struct coretemp_data *data = platform_get_drvdata(pdev); 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); platform_set_drvdata(pdev, NULL); kfree(data); return 0; } static struct platform_driver coretemp_driver = { .driver = { .owner = THIS_MODULE, .name = DRVNAME, }, .probe = coretemp_probe, .remove = __devexit_p(coretemp_remove), }; struct pdev_entry { struct list_head list; struct platform_device *pdev; unsigned int cpu; }; 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; pdev = platform_device_alloc(DRVNAME, cpu); if (!pdev) { err = -ENOMEM; printk(KERN_ERR DRVNAME ": 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) { printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n", err); goto exit_device_free; } pdev_entry->pdev = pdev; pdev_entry->cpu = cpu; mutex_lock(&pdev_list_mutex); 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: return err; } #ifdef CONFIG_HOTPLUG_CPU static void coretemp_device_remove(unsigned int cpu) { struct pdev_entry *p, *n; mutex_lock(&pdev_list_mutex); list_for_each_entry_safe(p, n, &pdev_list, list) { if (p->cpu == cpu) { platform_device_unregister(p->pdev); list_del(&p->list); kfree(p); } } mutex_unlock(&pdev_list_mutex); } static int __cpuinit 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: coretemp_device_add(cpu); break; case CPU_DOWN_PREPARE: coretemp_device_remove(cpu); break; } return NOTIFY_OK; } static struct notifier_block coretemp_cpu_notifier __refdata = { .notifier_call = coretemp_cpu_callback, }; #endif /* !CONFIG_HOTPLUG_CPU */ static int __init coretemp_init(void) { int i, err = -ENODEV; struct pdev_entry *p, *n; /* quick check if we run Intel */ if (cpu_data(0).x86_vendor != X86_VENDOR_INTEL) goto exit; err = platform_driver_register(&coretemp_driver); if (err) goto exit; for_each_online_cpu(i) { struct cpuinfo_x86 *c = &cpu_data(i); /* check if family 6, models 0xe, 0xf, 0x16, 0x17, 0x1A */ if ((c->cpuid_level < 0) || (c->x86 != 0x6) || !((c->x86_model == 0xe) || (c->x86_model == 0xf) || (c->x86_model == 0x16) || (c->x86_model == 0x17) || (c->x86_model == 0x1A))) { /* supported CPU not found, but report the unknown family 6 CPU */ if ((c->x86 == 0x6) && (c->x86_model > 0xf)) printk(KERN_WARNING DRVNAME ": Unknown CPU " "model %x\n", c->x86_model); continue; } err = coretemp_device_add(i); if (err) goto exit_devices_unreg; } if (list_empty(&pdev_list)) { err = -ENODEV; goto exit_driver_unreg; } #ifdef CONFIG_HOTPLUG_CPU register_hotcpu_notifier(&coretemp_cpu_notifier); #endif return 0; exit_devices_unreg: 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); exit_driver_unreg: platform_driver_unregister(&coretemp_driver); exit: return err; } static void __exit coretemp_exit(void) { struct pdev_entry *p, *n; #ifdef CONFIG_HOTPLUG_CPU unregister_hotcpu_notifier(&coretemp_cpu_notifier); #endif 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); 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)