[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>

1 files changed, 426 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_core.c b/drivers/macintosh/windfarm_core.c
new file mode 100644
index 000000000000..6c2a471ea6c0
--- /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");
+