[PATCH] ppc64: Thermal control for SMU based machines
This adds a new thermal control framework for PowerMac, along with the
implementation for PowerMac8,1, PowerMac8,2 (iMac G5 rev 1 and 2), and
PowerMac9,1 (latest single CPU desktop). In the future, I expect to move
the older G5 thermal control to the new framework as well.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/drivers/macintosh/windfarm_core.c b/drivers/macintosh/windfarm_core.c
new file mode 100644
index 0000000..6c2a471
--- /dev/null
+++ b/drivers/macintosh/windfarm_core.c
@@ -0,0 +1,426 @@
+/*
+ * Windfarm PowerMac thermal control. Core
+ *
+ * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
+ * <benh@kernel.crashing.org>
+ *
+ * Released under the term of the GNU GPL v2.
+ *
+ * This core code tracks the list of sensors & controls, register
+ * clients, and holds the kernel thread used for control.
+ *
+ * TODO:
+ *
+ * Add some information about sensor/control type and data format to
+ * sensors/controls, and have the sysfs attribute stuff be moved
+ * generically here instead of hard coded in the platform specific
+ * driver as it us currently
+ *
+ * This however requires solving some annoying lifetime issues with
+ * sysfs which doesn't seem to have lifetime rules for struct attribute,
+ * I may have to create full features kobjects for every sensor/control
+ * instead which is a bit of an overkill imho
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/smp_lock.h>
+#include <linux/kthread.h>
+#include <linux/jiffies.h>
+#include <linux/reboot.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+
+#include "windfarm.h"
+
+#define VERSION "0.2"
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(args...) printk(args)
+#else
+#define DBG(args...) do { } while(0)
+#endif
+
+static LIST_HEAD(wf_controls);
+static LIST_HEAD(wf_sensors);
+static DECLARE_MUTEX(wf_lock);
+static struct notifier_block *wf_client_list;
+static int wf_client_count;
+static unsigned int wf_overtemp;
+static unsigned int wf_overtemp_counter;
+struct task_struct *wf_thread;
+
+/*
+ * Utilities & tick thread
+ */
+
+static inline void wf_notify(int event, void *param)
+{
+ notifier_call_chain(&wf_client_list, event, param);
+}
+
+int wf_critical_overtemp(void)
+{
+ static char * critical_overtemp_path = "/sbin/critical_overtemp";
+ char *argv[] = { critical_overtemp_path, NULL };
+ static char *envp[] = { "HOME=/",
+ "TERM=linux",
+ "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+ NULL };
+
+ return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
+}
+EXPORT_SYMBOL_GPL(wf_critical_overtemp);
+
+static int wf_thread_func(void *data)
+{
+ unsigned long next, delay;
+
+ next = jiffies;
+
+ DBG("wf: thread started\n");
+
+ while(!kthread_should_stop()) {
+ try_to_freeze();
+
+ if (time_after_eq(jiffies, next)) {
+ wf_notify(WF_EVENT_TICK, NULL);
+ if (wf_overtemp) {
+ wf_overtemp_counter++;
+ /* 10 seconds overtemp, notify userland */
+ if (wf_overtemp_counter > 10)
+ wf_critical_overtemp();
+ /* 30 seconds, shutdown */
+ if (wf_overtemp_counter > 30) {
+ printk(KERN_ERR "windfarm: Overtemp "
+ "for more than 30"
+ " seconds, shutting down\n");
+ machine_power_off();
+ }
+ }
+ next += HZ;
+ }
+
+ delay = next - jiffies;
+ if (delay <= HZ)
+ schedule_timeout_interruptible(delay);
+
+ /* there should be no signal, but oh well */
+ if (signal_pending(current)) {
+ printk(KERN_WARNING "windfarm: thread got sigl !\n");
+ break;
+ }
+ }
+
+ DBG("wf: thread stopped\n");
+
+ return 0;
+}
+
+static void wf_start_thread(void)
+{
+ wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
+ if (IS_ERR(wf_thread)) {
+ printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
+ PTR_ERR(wf_thread));
+ wf_thread = NULL;
+ }
+}
+
+
+static void wf_stop_thread(void)
+{
+ if (wf_thread)
+ kthread_stop(wf_thread);
+ wf_thread = NULL;
+}
+
+/*
+ * Controls
+ */
+
+static void wf_control_release(struct kref *kref)
+{
+ struct wf_control *ct = container_of(kref, struct wf_control, ref);
+
+ DBG("wf: Deleting control %s\n", ct->name);
+
+ if (ct->ops && ct->ops->release)
+ ct->ops->release(ct);
+ else
+ kfree(ct);
+}
+
+int wf_register_control(struct wf_control *new_ct)
+{
+ struct wf_control *ct;
+
+ down(&wf_lock);
+ list_for_each_entry(ct, &wf_controls, link) {
+ if (!strcmp(ct->name, new_ct->name)) {
+ printk(KERN_WARNING "windfarm: trying to register"
+ " duplicate control %s\n", ct->name);
+ up(&wf_lock);
+ return -EEXIST;
+ }
+ }
+ kref_init(&new_ct->ref);
+ list_add(&new_ct->link, &wf_controls);
+
+ DBG("wf: Registered control %s\n", new_ct->name);
+
+ wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
+ up(&wf_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wf_register_control);
+
+void wf_unregister_control(struct wf_control *ct)
+{
+ down(&wf_lock);
+ list_del(&ct->link);
+ up(&wf_lock);
+
+ DBG("wf: Unregistered control %s\n", ct->name);
+
+ kref_put(&ct->ref, wf_control_release);
+}
+EXPORT_SYMBOL_GPL(wf_unregister_control);
+
+struct wf_control * wf_find_control(const char *name)
+{
+ struct wf_control *ct;
+
+ down(&wf_lock);
+ list_for_each_entry(ct, &wf_controls, link) {
+ if (!strcmp(ct->name, name)) {
+ if (wf_get_control(ct))
+ ct = NULL;
+ up(&wf_lock);
+ return ct;
+ }
+ }
+ up(&wf_lock);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(wf_find_control);
+
+int wf_get_control(struct wf_control *ct)
+{
+ if (!try_module_get(ct->ops->owner))
+ return -ENODEV;
+ kref_get(&ct->ref);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wf_get_control);
+
+void wf_put_control(struct wf_control *ct)
+{
+ struct module *mod = ct->ops->owner;
+ kref_put(&ct->ref, wf_control_release);
+ module_put(mod);
+}
+EXPORT_SYMBOL_GPL(wf_put_control);
+
+
+/*
+ * Sensors
+ */
+
+
+static void wf_sensor_release(struct kref *kref)
+{
+ struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
+
+ DBG("wf: Deleting sensor %s\n", sr->name);
+
+ if (sr->ops && sr->ops->release)
+ sr->ops->release(sr);
+ else
+ kfree(sr);
+}
+
+int wf_register_sensor(struct wf_sensor *new_sr)
+{
+ struct wf_sensor *sr;
+
+ down(&wf_lock);
+ list_for_each_entry(sr, &wf_sensors, link) {
+ if (!strcmp(sr->name, new_sr->name)) {
+ printk(KERN_WARNING "windfarm: trying to register"
+ " duplicate sensor %s\n", sr->name);
+ up(&wf_lock);
+ return -EEXIST;
+ }
+ }
+ kref_init(&new_sr->ref);
+ list_add(&new_sr->link, &wf_sensors);
+
+ DBG("wf: Registered sensor %s\n", new_sr->name);
+
+ wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
+ up(&wf_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wf_register_sensor);
+
+void wf_unregister_sensor(struct wf_sensor *sr)
+{
+ down(&wf_lock);
+ list_del(&sr->link);
+ up(&wf_lock);
+
+ DBG("wf: Unregistered sensor %s\n", sr->name);
+
+ wf_put_sensor(sr);
+}
+EXPORT_SYMBOL_GPL(wf_unregister_sensor);
+
+struct wf_sensor * wf_find_sensor(const char *name)
+{
+ struct wf_sensor *sr;
+
+ down(&wf_lock);
+ list_for_each_entry(sr, &wf_sensors, link) {
+ if (!strcmp(sr->name, name)) {
+ if (wf_get_sensor(sr))
+ sr = NULL;
+ up(&wf_lock);
+ return sr;
+ }
+ }
+ up(&wf_lock);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(wf_find_sensor);
+
+int wf_get_sensor(struct wf_sensor *sr)
+{
+ if (!try_module_get(sr->ops->owner))
+ return -ENODEV;
+ kref_get(&sr->ref);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wf_get_sensor);
+
+void wf_put_sensor(struct wf_sensor *sr)
+{
+ struct module *mod = sr->ops->owner;
+ kref_put(&sr->ref, wf_sensor_release);
+ module_put(mod);
+}
+EXPORT_SYMBOL_GPL(wf_put_sensor);
+
+
+/*
+ * Client & notification
+ */
+
+int wf_register_client(struct notifier_block *nb)
+{
+ int rc;
+ struct wf_control *ct;
+ struct wf_sensor *sr;
+
+ down(&wf_lock);
+ rc = notifier_chain_register(&wf_client_list, nb);
+ if (rc != 0)
+ goto bail;
+ wf_client_count++;
+ list_for_each_entry(ct, &wf_controls, link)
+ wf_notify(WF_EVENT_NEW_CONTROL, ct);
+ list_for_each_entry(sr, &wf_sensors, link)
+ wf_notify(WF_EVENT_NEW_SENSOR, sr);
+ if (wf_client_count == 1)
+ wf_start_thread();
+ bail:
+ up(&wf_lock);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(wf_register_client);
+
+int wf_unregister_client(struct notifier_block *nb)
+{
+ down(&wf_lock);
+ notifier_chain_unregister(&wf_client_list, nb);
+ wf_client_count++;
+ if (wf_client_count == 0)
+ wf_stop_thread();
+ up(&wf_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wf_unregister_client);
+
+void wf_set_overtemp(void)
+{
+ down(&wf_lock);
+ wf_overtemp++;
+ if (wf_overtemp == 1) {
+ printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
+ wf_overtemp_counter = 0;
+ wf_notify(WF_EVENT_OVERTEMP, NULL);
+ }
+ up(&wf_lock);
+}
+EXPORT_SYMBOL_GPL(wf_set_overtemp);
+
+void wf_clear_overtemp(void)
+{
+ down(&wf_lock);
+ WARN_ON(wf_overtemp == 0);
+ if (wf_overtemp == 0) {
+ up(&wf_lock);
+ return;
+ }
+ wf_overtemp--;
+ if (wf_overtemp == 0) {
+ printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
+ wf_notify(WF_EVENT_NORMALTEMP, NULL);
+ }
+ up(&wf_lock);
+}
+EXPORT_SYMBOL_GPL(wf_clear_overtemp);
+
+int wf_is_overtemp(void)
+{
+ return (wf_overtemp != 0);
+}
+EXPORT_SYMBOL_GPL(wf_is_overtemp);
+
+static struct platform_device wf_platform_device = {
+ .name = "windfarm",
+};
+
+static int __init windfarm_core_init(void)
+{
+ DBG("wf: core loaded\n");
+
+ platform_device_register(&wf_platform_device);
+ return 0;
+}
+
+static void __exit windfarm_core_exit(void)
+{
+ BUG_ON(wf_client_count != 0);
+
+ DBG("wf: core unloaded\n");
+
+ platform_device_unregister(&wf_platform_device);
+}
+
+
+module_init(windfarm_core_init);
+module_exit(windfarm_core_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("Core component of PowerMac thermal control");
+MODULE_LICENSE("GPL");
+