x86, mce: unify smp_thermal_interrupt
[linux-2.6.git] / arch / x86 / kernel / cpu / mcheck / therm_throt.c
1 /*
2  * Thermal throttle event support code (such as syslog messaging and rate
3  * limiting) that was factored out from x86_64 (mce_intel.c) and i386 (p4.c).
4  *
5  * This allows consistent reporting of CPU thermal throttle events.
6  *
7  * Maintains a counter in /sys that keeps track of the number of thermal
8  * events, such that the user knows how bad the thermal problem might be
9  * (since the logging to syslog and mcelog is rate limited).
10  *
11  * Author: Dmitriy Zavin (dmitriyz@google.com)
12  *
13  * Credits: Adapted from Zwane Mwaikambo's original code in mce_intel.c.
14  *          Inspired by Ross Biro's and Al Borchers' counter code.
15  */
16 #include <linux/interrupt.h>
17 #include <linux/notifier.h>
18 #include <linux/jiffies.h>
19 #include <linux/percpu.h>
20 #include <linux/sysdev.h>
21 #include <linux/cpu.h>
22
23 #include <asm/therm_throt.h>
24 #include <asm/idle.h>
25 #include <asm/mce.h>
26
27 /* How long to wait between reporting thermal events */
28 #define CHECK_INTERVAL          (300 * HZ)
29
30 static DEFINE_PER_CPU(__u64, next_check) = INITIAL_JIFFIES;
31 static DEFINE_PER_CPU(unsigned long, thermal_throttle_count);
32
33 atomic_t therm_throt_en         = ATOMIC_INIT(0);
34
35 #ifdef CONFIG_SYSFS
36 #define define_therm_throt_sysdev_one_ro(_name)                         \
37         static SYSDEV_ATTR(_name, 0444, therm_throt_sysdev_show_##_name, NULL)
38
39 #define define_therm_throt_sysdev_show_func(name)                       \
40 static ssize_t therm_throt_sysdev_show_##name(struct sys_device *dev,   \
41                                         struct sysdev_attribute *attr,  \
42                                               char *buf)                \
43 {                                                                       \
44         unsigned int cpu = dev->id;                                     \
45         ssize_t ret;                                                    \
46                                                                         \
47         preempt_disable();      /* CPU hotplug */                       \
48         if (cpu_online(cpu))                                            \
49                 ret = sprintf(buf, "%lu\n",                             \
50                               per_cpu(thermal_throttle_##name, cpu));   \
51         else                                                            \
52                 ret = 0;                                                \
53         preempt_enable();                                               \
54                                                                         \
55         return ret;                                                     \
56 }
57
58 define_therm_throt_sysdev_show_func(count);
59 define_therm_throt_sysdev_one_ro(count);
60
61 static struct attribute *thermal_throttle_attrs[] = {
62         &attr_count.attr,
63         NULL
64 };
65
66 static struct attribute_group thermal_throttle_attr_group = {
67         .attrs  = thermal_throttle_attrs,
68         .name   = "thermal_throttle"
69 };
70 #endif /* CONFIG_SYSFS */
71
72 /***
73  * therm_throt_process - Process thermal throttling event from interrupt
74  * @curr: Whether the condition is current or not (boolean), since the
75  *        thermal interrupt normally gets called both when the thermal
76  *        event begins and once the event has ended.
77  *
78  * This function is called by the thermal interrupt after the
79  * IRQ has been acknowledged.
80  *
81  * It will take care of rate limiting and printing messages to the syslog.
82  *
83  * Returns: 0 : Event should NOT be further logged, i.e. still in
84  *              "timeout" from previous log message.
85  *          1 : Event should be logged further, and a message has been
86  *              printed to the syslog.
87  */
88 int therm_throt_process(int curr)
89 {
90         unsigned int cpu = smp_processor_id();
91         __u64 tmp_jiffs = get_jiffies_64();
92
93         if (curr)
94                 __get_cpu_var(thermal_throttle_count)++;
95
96         if (time_before64(tmp_jiffs, __get_cpu_var(next_check)))
97                 return 0;
98
99         __get_cpu_var(next_check) = tmp_jiffs + CHECK_INTERVAL;
100
101         /* if we just entered the thermal event */
102         if (curr) {
103                 printk(KERN_CRIT "CPU%d: Temperature above threshold, "
104                        "cpu clock throttled (total events = %lu)\n", cpu,
105                        __get_cpu_var(thermal_throttle_count));
106
107                 add_taint(TAINT_MACHINE_CHECK);
108         } else {
109                 printk(KERN_CRIT "CPU%d: Temperature/speed normal\n", cpu);
110         }
111
112         return 1;
113 }
114
115 #ifdef CONFIG_SYSFS
116 /* Add/Remove thermal_throttle interface for CPU device: */
117 static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
118 {
119         return sysfs_create_group(&sys_dev->kobj,
120                                   &thermal_throttle_attr_group);
121 }
122
123 static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
124 {
125         sysfs_remove_group(&sys_dev->kobj, &thermal_throttle_attr_group);
126 }
127
128 /* Mutex protecting device creation against CPU hotplug: */
129 static DEFINE_MUTEX(therm_cpu_lock);
130
131 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
132 static __cpuinit int
133 thermal_throttle_cpu_callback(struct notifier_block *nfb,
134                               unsigned long action,
135                               void *hcpu)
136 {
137         unsigned int cpu = (unsigned long)hcpu;
138         struct sys_device *sys_dev;
139         int err = 0;
140
141         sys_dev = get_cpu_sysdev(cpu);
142
143         switch (action) {
144         case CPU_UP_PREPARE:
145         case CPU_UP_PREPARE_FROZEN:
146                 mutex_lock(&therm_cpu_lock);
147                 err = thermal_throttle_add_dev(sys_dev);
148                 mutex_unlock(&therm_cpu_lock);
149                 WARN_ON(err);
150                 break;
151         case CPU_UP_CANCELED:
152         case CPU_UP_CANCELED_FROZEN:
153         case CPU_DEAD:
154         case CPU_DEAD_FROZEN:
155                 mutex_lock(&therm_cpu_lock);
156                 thermal_throttle_remove_dev(sys_dev);
157                 mutex_unlock(&therm_cpu_lock);
158                 break;
159         }
160         return err ? NOTIFY_BAD : NOTIFY_OK;
161 }
162
163 static struct notifier_block thermal_throttle_cpu_notifier __cpuinitdata =
164 {
165         .notifier_call = thermal_throttle_cpu_callback,
166 };
167
168 static __init int thermal_throttle_init_device(void)
169 {
170         unsigned int cpu = 0;
171         int err;
172
173         if (!atomic_read(&therm_throt_en))
174                 return 0;
175
176         register_hotcpu_notifier(&thermal_throttle_cpu_notifier);
177
178 #ifdef CONFIG_HOTPLUG_CPU
179         mutex_lock(&therm_cpu_lock);
180 #endif
181         /* connect live CPUs to sysfs */
182         for_each_online_cpu(cpu) {
183                 err = thermal_throttle_add_dev(get_cpu_sysdev(cpu));
184                 WARN_ON(err);
185         }
186 #ifdef CONFIG_HOTPLUG_CPU
187         mutex_unlock(&therm_cpu_lock);
188 #endif
189
190         return 0;
191 }
192 device_initcall(thermal_throttle_init_device);
193
194 #endif /* CONFIG_SYSFS */
195
196 /* Thermal transition interrupt handler */
197 void intel_thermal_interrupt(void)
198 {
199         __u64 msr_val;
200
201         rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
202         if (therm_throt_process(msr_val & THERM_STATUS_PROCHOT))
203                 mce_log_therm_throt_event(msr_val);
204 }
205
206 static void unexpected_thermal_interrupt(void)
207 {
208         printk(KERN_ERR "CPU%d: Unexpected LVT TMR interrupt!\n",
209                         smp_processor_id());
210         add_taint(TAINT_MACHINE_CHECK);
211 }
212
213 static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
214
215 asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
216 {
217         exit_idle();
218         irq_enter();
219         inc_irq_stat(irq_thermal_count);
220         smp_thermal_vector();
221         irq_exit();
222         /* Ack only at the end to avoid potential reentry */
223         ack_APIC_irq();
224 }
225
226 void intel_set_thermal_handler(void)
227 {
228         smp_thermal_vector = intel_thermal_interrupt;
229 }