diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/thermal/x86_pkg_temp_thermal.c | 558 |
1 files changed, 558 insertions, 0 deletions
diff --git a/drivers/thermal/x86_pkg_temp_thermal.c b/drivers/thermal/x86_pkg_temp_thermal.c new file mode 100644 index 000000000..1ef937d79 --- /dev/null +++ b/drivers/thermal/x86_pkg_temp_thermal.c @@ -0,0 +1,558 @@ +/* + * x86_pkg_temp_thermal driver + * Copyright (c) 2013, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/param.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/cpu.h> +#include <linux/smp.h> +#include <linux/slab.h> +#include <linux/pm.h> +#include <linux/thermal.h> +#include <linux/debugfs.h> +#include <asm/cpu_device_id.h> +#include <asm/mce.h> + +/* +* Rate control delay: Idea is to introduce denounce effect +* This should be long enough to avoid reduce events, when +* threshold is set to a temperature, which is constantly +* violated, but at the short enough to take any action. +* The action can be remove threshold or change it to next +* interesting setting. Based on experiments, in around +* every 5 seconds under load will give us a significant +* temperature change. +*/ +#define PKG_TEMP_THERMAL_NOTIFY_DELAY 5000 +static int notify_delay_ms = PKG_TEMP_THERMAL_NOTIFY_DELAY; +module_param(notify_delay_ms, int, 0644); +MODULE_PARM_DESC(notify_delay_ms, + "User space notification delay in milli seconds."); + +/* Number of trip points in thermal zone. Currently it can't +* be more than 2. MSR can allow setting and getting notifications +* for only 2 thresholds. This define enforces this, if there +* is some wrong values returned by cpuid for number of thresholds. +*/ +#define MAX_NUMBER_OF_TRIPS 2 + +struct pkg_device { + int cpu; + bool work_scheduled; + u32 tj_max; + u32 msr_pkg_therm_low; + u32 msr_pkg_therm_high; + struct delayed_work work; + struct thermal_zone_device *tzone; + struct cpumask cpumask; +}; + +static struct thermal_zone_params pkg_temp_tz_params = { + .no_hwmon = true, +}; + +/* Keep track of how many package pointers we allocated in init() */ +static int max_packages __read_mostly; +/* Array of package pointers */ +static struct pkg_device **packages; +/* Serializes interrupt notification, work and hotplug */ +static DEFINE_SPINLOCK(pkg_temp_lock); +/* Protects zone operation in the work function against hotplug removal */ +static DEFINE_MUTEX(thermal_zone_mutex); + +/* The dynamically assigned cpu hotplug state for module_exit() */ +static enum cpuhp_state pkg_thermal_hp_state __read_mostly; + +/* Debug counters to show using debugfs */ +static struct dentry *debugfs; +static unsigned int pkg_interrupt_cnt; +static unsigned int pkg_work_cnt; + +static int pkg_temp_debugfs_init(void) +{ + struct dentry *d; + + debugfs = debugfs_create_dir("pkg_temp_thermal", NULL); + if (!debugfs) + return -ENOENT; + + d = debugfs_create_u32("pkg_thres_interrupt", S_IRUGO, debugfs, + &pkg_interrupt_cnt); + if (!d) + goto err_out; + + d = debugfs_create_u32("pkg_thres_work", S_IRUGO, debugfs, + &pkg_work_cnt); + if (!d) + goto err_out; + + return 0; + +err_out: + debugfs_remove_recursive(debugfs); + return -ENOENT; +} + +/* + * Protection: + * + * - cpu hotplug: Read serialized by cpu hotplug lock + * Write must hold pkg_temp_lock + * + * - Other callsites: Must hold pkg_temp_lock + */ +static struct pkg_device *pkg_temp_thermal_get_dev(unsigned int cpu) +{ + int pkgid = topology_logical_package_id(cpu); + + if (pkgid >= 0 && pkgid < max_packages) + return packages[pkgid]; + return NULL; +} + +/* +* tj-max is is interesting because threshold is set relative to this +* temperature. +*/ +static int get_tj_max(int cpu, u32 *tj_max) +{ + u32 eax, edx, val; + int err; + + err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx); + if (err) + return err; + + val = (eax >> 16) & 0xff; + *tj_max = val * 1000; + + return val ? 0 : -EINVAL; +} + +static int sys_get_curr_temp(struct thermal_zone_device *tzd, int *temp) +{ + struct pkg_device *pkgdev = tzd->devdata; + u32 eax, edx; + + rdmsr_on_cpu(pkgdev->cpu, MSR_IA32_PACKAGE_THERM_STATUS, &eax, &edx); + if (eax & 0x80000000) { + *temp = pkgdev->tj_max - ((eax >> 16) & 0x7f) * 1000; + pr_debug("sys_get_curr_temp %d\n", *temp); + return 0; + } + return -EINVAL; +} + +static int sys_get_trip_temp(struct thermal_zone_device *tzd, + int trip, int *temp) +{ + struct pkg_device *pkgdev = tzd->devdata; + unsigned long thres_reg_value; + u32 mask, shift, eax, edx; + int ret; + + if (trip >= MAX_NUMBER_OF_TRIPS) + return -EINVAL; + + if (trip) { + mask = THERM_MASK_THRESHOLD1; + shift = THERM_SHIFT_THRESHOLD1; + } else { + mask = THERM_MASK_THRESHOLD0; + shift = THERM_SHIFT_THRESHOLD0; + } + + ret = rdmsr_on_cpu(pkgdev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, + &eax, &edx); + if (ret < 0) + return ret; + + thres_reg_value = (eax & mask) >> shift; + if (thres_reg_value) + *temp = pkgdev->tj_max - thres_reg_value * 1000; + else + *temp = 0; + pr_debug("sys_get_trip_temp %d\n", *temp); + + return 0; +} + +static int +sys_set_trip_temp(struct thermal_zone_device *tzd, int trip, int temp) +{ + struct pkg_device *pkgdev = tzd->devdata; + u32 l, h, mask, shift, intr; + int ret; + + if (trip >= MAX_NUMBER_OF_TRIPS || temp >= pkgdev->tj_max) + return -EINVAL; + + ret = rdmsr_on_cpu(pkgdev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, + &l, &h); + if (ret < 0) + return ret; + + if (trip) { + mask = THERM_MASK_THRESHOLD1; + shift = THERM_SHIFT_THRESHOLD1; + intr = THERM_INT_THRESHOLD1_ENABLE; + } else { + mask = THERM_MASK_THRESHOLD0; + shift = THERM_SHIFT_THRESHOLD0; + intr = THERM_INT_THRESHOLD0_ENABLE; + } + l &= ~mask; + /* + * When users space sets a trip temperature == 0, which is indication + * that, it is no longer interested in receiving notifications. + */ + if (!temp) { + l &= ~intr; + } else { + l |= (pkgdev->tj_max - temp)/1000 << shift; + l |= intr; + } + + return wrmsr_on_cpu(pkgdev->cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); +} + +static int sys_get_trip_type(struct thermal_zone_device *thermal, int trip, + enum thermal_trip_type *type) +{ + *type = THERMAL_TRIP_PASSIVE; + return 0; +} + +/* Thermal zone callback registry */ +static struct thermal_zone_device_ops tzone_ops = { + .get_temp = sys_get_curr_temp, + .get_trip_temp = sys_get_trip_temp, + .get_trip_type = sys_get_trip_type, + .set_trip_temp = sys_set_trip_temp, +}; + +static bool pkg_thermal_rate_control(void) +{ + return true; +} + +/* Enable threshold interrupt on local package/cpu */ +static inline void enable_pkg_thres_interrupt(void) +{ + u8 thres_0, thres_1; + u32 l, h; + + rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); + /* only enable/disable if it had valid threshold value */ + thres_0 = (l & THERM_MASK_THRESHOLD0) >> THERM_SHIFT_THRESHOLD0; + thres_1 = (l & THERM_MASK_THRESHOLD1) >> THERM_SHIFT_THRESHOLD1; + if (thres_0) + l |= THERM_INT_THRESHOLD0_ENABLE; + if (thres_1) + l |= THERM_INT_THRESHOLD1_ENABLE; + wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); +} + +/* Disable threshold interrupt on local package/cpu */ +static inline void disable_pkg_thres_interrupt(void) +{ + u32 l, h; + + rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); + + l &= ~(THERM_INT_THRESHOLD0_ENABLE | THERM_INT_THRESHOLD1_ENABLE); + wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h); +} + +static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work) +{ + struct thermal_zone_device *tzone = NULL; + int cpu = smp_processor_id(); + struct pkg_device *pkgdev; + u64 msr_val, wr_val; + + mutex_lock(&thermal_zone_mutex); + spin_lock_irq(&pkg_temp_lock); + ++pkg_work_cnt; + + pkgdev = pkg_temp_thermal_get_dev(cpu); + if (!pkgdev) { + spin_unlock_irq(&pkg_temp_lock); + mutex_unlock(&thermal_zone_mutex); + return; + } + pkgdev->work_scheduled = false; + + rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val); + wr_val = msr_val & ~(THERM_LOG_THRESHOLD0 | THERM_LOG_THRESHOLD1); + if (wr_val != msr_val) { + wrmsrl(MSR_IA32_PACKAGE_THERM_STATUS, wr_val); + tzone = pkgdev->tzone; + } + + enable_pkg_thres_interrupt(); + spin_unlock_irq(&pkg_temp_lock); + + /* + * If tzone is not NULL, then thermal_zone_mutex will prevent the + * concurrent removal in the cpu offline callback. + */ + if (tzone) + thermal_zone_device_update(tzone, THERMAL_EVENT_UNSPECIFIED); + + mutex_unlock(&thermal_zone_mutex); +} + +static void pkg_thermal_schedule_work(int cpu, struct delayed_work *work) +{ + unsigned long ms = msecs_to_jiffies(notify_delay_ms); + + schedule_delayed_work_on(cpu, work, ms); +} + +static int pkg_thermal_notify(u64 msr_val) +{ + int cpu = smp_processor_id(); + struct pkg_device *pkgdev; + unsigned long flags; + + spin_lock_irqsave(&pkg_temp_lock, flags); + ++pkg_interrupt_cnt; + + disable_pkg_thres_interrupt(); + + /* Work is per package, so scheduling it once is enough. */ + pkgdev = pkg_temp_thermal_get_dev(cpu); + if (pkgdev && !pkgdev->work_scheduled) { + pkgdev->work_scheduled = true; + pkg_thermal_schedule_work(pkgdev->cpu, &pkgdev->work); + } + + spin_unlock_irqrestore(&pkg_temp_lock, flags); + return 0; +} + +static int pkg_temp_thermal_device_add(unsigned int cpu) +{ + int pkgid = topology_logical_package_id(cpu); + u32 tj_max, eax, ebx, ecx, edx; + struct pkg_device *pkgdev; + int thres_count, err; + + if (pkgid >= max_packages) + return -ENOMEM; + + cpuid(6, &eax, &ebx, &ecx, &edx); + thres_count = ebx & 0x07; + if (!thres_count) + return -ENODEV; + + thres_count = clamp_val(thres_count, 0, MAX_NUMBER_OF_TRIPS); + + err = get_tj_max(cpu, &tj_max); + if (err) + return err; + + pkgdev = kzalloc(sizeof(*pkgdev), GFP_KERNEL); + if (!pkgdev) + return -ENOMEM; + + INIT_DELAYED_WORK(&pkgdev->work, pkg_temp_thermal_threshold_work_fn); + pkgdev->cpu = cpu; + pkgdev->tj_max = tj_max; + pkgdev->tzone = thermal_zone_device_register("x86_pkg_temp", + thres_count, + (thres_count == MAX_NUMBER_OF_TRIPS) ? 0x03 : 0x01, + pkgdev, &tzone_ops, &pkg_temp_tz_params, 0, 0); + if (IS_ERR(pkgdev->tzone)) { + err = PTR_ERR(pkgdev->tzone); + kfree(pkgdev); + return err; + } + /* Store MSR value for package thermal interrupt, to restore at exit */ + rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, pkgdev->msr_pkg_therm_low, + pkgdev->msr_pkg_therm_high); + + cpumask_set_cpu(cpu, &pkgdev->cpumask); + spin_lock_irq(&pkg_temp_lock); + packages[pkgid] = pkgdev; + spin_unlock_irq(&pkg_temp_lock); + return 0; +} + +static int pkg_thermal_cpu_offline(unsigned int cpu) +{ + struct pkg_device *pkgdev = pkg_temp_thermal_get_dev(cpu); + bool lastcpu, was_target; + int target; + + if (!pkgdev) + return 0; + + target = cpumask_any_but(&pkgdev->cpumask, cpu); + cpumask_clear_cpu(cpu, &pkgdev->cpumask); + lastcpu = target >= nr_cpu_ids; + /* + * Remove the sysfs files, if this is the last cpu in the package + * before doing further cleanups. + */ + if (lastcpu) { + struct thermal_zone_device *tzone = pkgdev->tzone; + + /* + * We must protect against a work function calling + * thermal_zone_update, after/while unregister. We null out + * the pointer under the zone mutex, so the worker function + * won't try to call. + */ + mutex_lock(&thermal_zone_mutex); + pkgdev->tzone = NULL; + mutex_unlock(&thermal_zone_mutex); + + thermal_zone_device_unregister(tzone); + } + + /* Protect against work and interrupts */ + spin_lock_irq(&pkg_temp_lock); + + /* + * Check whether this cpu was the current target and store the new + * one. When we drop the lock, then the interrupt notify function + * will see the new target. + */ + was_target = pkgdev->cpu == cpu; + pkgdev->cpu = target; + + /* + * If this is the last CPU in the package remove the package + * reference from the array and restore the interrupt MSR. When we + * drop the lock neither the interrupt notify function nor the + * worker will see the package anymore. + */ + if (lastcpu) { + packages[topology_logical_package_id(cpu)] = NULL; + /* After this point nothing touches the MSR anymore. */ + wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, + pkgdev->msr_pkg_therm_low, pkgdev->msr_pkg_therm_high); + } + + /* + * Check whether there is work scheduled and whether the work is + * targeted at the outgoing CPU. + */ + if (pkgdev->work_scheduled && was_target) { + /* + * To cancel the work we need to drop the lock, otherwise + * we might deadlock if the work needs to be flushed. + */ + spin_unlock_irq(&pkg_temp_lock); + cancel_delayed_work_sync(&pkgdev->work); + spin_lock_irq(&pkg_temp_lock); + /* + * If this is not the last cpu in the package and the work + * did not run after we dropped the lock above, then we + * need to reschedule the work, otherwise the interrupt + * stays disabled forever. + */ + if (!lastcpu && pkgdev->work_scheduled) + pkg_thermal_schedule_work(target, &pkgdev->work); + } + + spin_unlock_irq(&pkg_temp_lock); + + /* Final cleanup if this is the last cpu */ + if (lastcpu) + kfree(pkgdev); + return 0; +} + +static int pkg_thermal_cpu_online(unsigned int cpu) +{ + struct pkg_device *pkgdev = pkg_temp_thermal_get_dev(cpu); + struct cpuinfo_x86 *c = &cpu_data(cpu); + + /* Paranoia check */ + if (!cpu_has(c, X86_FEATURE_DTHERM) || !cpu_has(c, X86_FEATURE_PTS)) + return -ENODEV; + + /* If the package exists, nothing to do */ + if (pkgdev) { + cpumask_set_cpu(cpu, &pkgdev->cpumask); + return 0; + } + return pkg_temp_thermal_device_add(cpu); +} + +static const struct x86_cpu_id __initconst pkg_temp_thermal_ids[] = { + { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_PTS }, + {} +}; +MODULE_DEVICE_TABLE(x86cpu, pkg_temp_thermal_ids); + +static int __init pkg_temp_thermal_init(void) +{ + int ret; + + if (!x86_match_cpu(pkg_temp_thermal_ids)) + return -ENODEV; + + max_packages = topology_max_packages(); + packages = kcalloc(max_packages, sizeof(struct pkg_device *), + GFP_KERNEL); + if (!packages) + return -ENOMEM; + + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "thermal/x86_pkg:online", + pkg_thermal_cpu_online, pkg_thermal_cpu_offline); + if (ret < 0) + goto err; + + /* Store the state for module exit */ + pkg_thermal_hp_state = ret; + + platform_thermal_package_notify = pkg_thermal_notify; + platform_thermal_package_rate_control = pkg_thermal_rate_control; + + /* Don't care if it fails */ + pkg_temp_debugfs_init(); + return 0; + +err: + kfree(packages); + return ret; +} +module_init(pkg_temp_thermal_init) + +static void __exit pkg_temp_thermal_exit(void) +{ + platform_thermal_package_notify = NULL; + platform_thermal_package_rate_control = NULL; + + cpuhp_remove_state(pkg_thermal_hp_state); + debugfs_remove_recursive(debugfs); + kfree(packages); +} +module_exit(pkg_temp_thermal_exit) + +MODULE_DESCRIPTION("X86 PKG TEMP Thermal Driver"); +MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>"); +MODULE_LICENSE("GPL v2"); |