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![Jeremy Fitzhardinge](/assets/img/avatar_default.png)
Rather than using a tri-state integer for the wait flag in call_usermodehelper_exec, define a proper enum, and use that. I've preserved the integer values so that any callers I've missed should still work OK. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Andi Kleen <ak@suse.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: David Howells <dhowells@redhat.com>
499 lines
11 KiB
C
499 lines
11 KiB
C
/*
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* Windfarm PowerMac thermal control. Core
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*
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* (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
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* <benh@kernel.crashing.org>
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*
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* Released under the term of the GNU GPL v2.
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*
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* This core code tracks the list of sensors & controls, register
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* clients, and holds the kernel thread used for control.
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*
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* TODO:
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*
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* Add some information about sensor/control type and data format to
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* sensors/controls, and have the sysfs attribute stuff be moved
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* generically here instead of hard coded in the platform specific
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* driver as it us currently
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*
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* This however requires solving some annoying lifetime issues with
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* sysfs which doesn't seem to have lifetime rules for struct attribute,
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* I may have to create full features kobjects for every sensor/control
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* instead which is a bit of an overkill imho
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*/
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/kthread.h>
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#include <linux/jiffies.h>
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#include <linux/reboot.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/mutex.h>
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#include <linux/freezer.h>
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#include <asm/prom.h>
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#include "windfarm.h"
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#define VERSION "0.2"
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#undef DEBUG
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#ifdef DEBUG
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#define DBG(args...) printk(args)
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#else
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#define DBG(args...) do { } while(0)
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#endif
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static LIST_HEAD(wf_controls);
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static LIST_HEAD(wf_sensors);
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static DEFINE_MUTEX(wf_lock);
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static BLOCKING_NOTIFIER_HEAD(wf_client_list);
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static int wf_client_count;
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static unsigned int wf_overtemp;
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static unsigned int wf_overtemp_counter;
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struct task_struct *wf_thread;
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static struct platform_device wf_platform_device = {
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.name = "windfarm",
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};
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/*
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* Utilities & tick thread
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*/
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static inline void wf_notify(int event, void *param)
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{
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blocking_notifier_call_chain(&wf_client_list, event, param);
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}
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int wf_critical_overtemp(void)
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{
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static char * critical_overtemp_path = "/sbin/critical_overtemp";
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char *argv[] = { critical_overtemp_path, NULL };
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static char *envp[] = { "HOME=/",
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"TERM=linux",
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"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
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NULL };
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return call_usermodehelper(critical_overtemp_path,
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argv, envp, UMH_WAIT_EXEC);
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}
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EXPORT_SYMBOL_GPL(wf_critical_overtemp);
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static int wf_thread_func(void *data)
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{
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unsigned long next, delay;
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next = jiffies;
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DBG("wf: thread started\n");
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set_freezable();
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while(!kthread_should_stop()) {
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if (time_after_eq(jiffies, next)) {
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wf_notify(WF_EVENT_TICK, NULL);
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if (wf_overtemp) {
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wf_overtemp_counter++;
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/* 10 seconds overtemp, notify userland */
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if (wf_overtemp_counter > 10)
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wf_critical_overtemp();
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/* 30 seconds, shutdown */
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if (wf_overtemp_counter > 30) {
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printk(KERN_ERR "windfarm: Overtemp "
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"for more than 30"
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" seconds, shutting down\n");
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machine_power_off();
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}
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}
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next += HZ;
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}
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delay = next - jiffies;
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if (delay <= HZ)
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schedule_timeout_interruptible(delay);
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/* there should be no non-suspend signal, but oh well */
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if (signal_pending(current) && !try_to_freeze()) {
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printk(KERN_WARNING "windfarm: thread got sigl !\n");
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break;
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}
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}
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DBG("wf: thread stopped\n");
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return 0;
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}
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static void wf_start_thread(void)
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{
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wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
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if (IS_ERR(wf_thread)) {
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printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
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PTR_ERR(wf_thread));
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wf_thread = NULL;
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}
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}
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static void wf_stop_thread(void)
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{
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if (wf_thread)
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kthread_stop(wf_thread);
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wf_thread = NULL;
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}
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/*
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* Controls
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*/
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static void wf_control_release(struct kref *kref)
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{
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struct wf_control *ct = container_of(kref, struct wf_control, ref);
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DBG("wf: Deleting control %s\n", ct->name);
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if (ct->ops && ct->ops->release)
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ct->ops->release(ct);
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else
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kfree(ct);
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}
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static ssize_t wf_show_control(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
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s32 val = 0;
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int err;
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err = ctrl->ops->get_value(ctrl, &val);
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if (err < 0)
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return err;
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return sprintf(buf, "%d\n", val);
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}
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/* This is really only for debugging... */
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static ssize_t wf_store_control(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
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int val;
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int err;
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char *endp;
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val = simple_strtoul(buf, &endp, 0);
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while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
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++endp;
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if (endp - buf < count)
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return -EINVAL;
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err = ctrl->ops->set_value(ctrl, val);
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if (err < 0)
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return err;
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return count;
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}
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int wf_register_control(struct wf_control *new_ct)
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{
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struct wf_control *ct;
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mutex_lock(&wf_lock);
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list_for_each_entry(ct, &wf_controls, link) {
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if (!strcmp(ct->name, new_ct->name)) {
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printk(KERN_WARNING "windfarm: trying to register"
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" duplicate control %s\n", ct->name);
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mutex_unlock(&wf_lock);
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return -EEXIST;
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}
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}
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kref_init(&new_ct->ref);
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list_add(&new_ct->link, &wf_controls);
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new_ct->attr.attr.name = new_ct->name;
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new_ct->attr.attr.mode = 0644;
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new_ct->attr.show = wf_show_control;
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new_ct->attr.store = wf_store_control;
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if (device_create_file(&wf_platform_device.dev, &new_ct->attr))
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printk(KERN_WARNING "windfarm: device_create_file failed"
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" for %s\n", new_ct->name);
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/* the subsystem still does useful work without the file */
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DBG("wf: Registered control %s\n", new_ct->name);
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wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
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mutex_unlock(&wf_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(wf_register_control);
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void wf_unregister_control(struct wf_control *ct)
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{
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mutex_lock(&wf_lock);
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list_del(&ct->link);
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mutex_unlock(&wf_lock);
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DBG("wf: Unregistered control %s\n", ct->name);
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kref_put(&ct->ref, wf_control_release);
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}
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EXPORT_SYMBOL_GPL(wf_unregister_control);
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struct wf_control * wf_find_control(const char *name)
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{
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struct wf_control *ct;
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mutex_lock(&wf_lock);
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list_for_each_entry(ct, &wf_controls, link) {
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if (!strcmp(ct->name, name)) {
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if (wf_get_control(ct))
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ct = NULL;
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mutex_unlock(&wf_lock);
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return ct;
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}
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}
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mutex_unlock(&wf_lock);
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return NULL;
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}
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EXPORT_SYMBOL_GPL(wf_find_control);
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int wf_get_control(struct wf_control *ct)
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{
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if (!try_module_get(ct->ops->owner))
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return -ENODEV;
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kref_get(&ct->ref);
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return 0;
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}
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EXPORT_SYMBOL_GPL(wf_get_control);
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void wf_put_control(struct wf_control *ct)
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{
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struct module *mod = ct->ops->owner;
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kref_put(&ct->ref, wf_control_release);
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module_put(mod);
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}
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EXPORT_SYMBOL_GPL(wf_put_control);
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/*
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* Sensors
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*/
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static void wf_sensor_release(struct kref *kref)
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{
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struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
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DBG("wf: Deleting sensor %s\n", sr->name);
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if (sr->ops && sr->ops->release)
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sr->ops->release(sr);
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else
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kfree(sr);
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}
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static ssize_t wf_show_sensor(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
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s32 val = 0;
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int err;
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err = sens->ops->get_value(sens, &val);
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if (err < 0)
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return err;
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return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
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}
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int wf_register_sensor(struct wf_sensor *new_sr)
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{
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struct wf_sensor *sr;
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mutex_lock(&wf_lock);
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list_for_each_entry(sr, &wf_sensors, link) {
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if (!strcmp(sr->name, new_sr->name)) {
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printk(KERN_WARNING "windfarm: trying to register"
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" duplicate sensor %s\n", sr->name);
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mutex_unlock(&wf_lock);
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return -EEXIST;
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}
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}
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kref_init(&new_sr->ref);
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list_add(&new_sr->link, &wf_sensors);
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new_sr->attr.attr.name = new_sr->name;
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new_sr->attr.attr.mode = 0444;
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new_sr->attr.show = wf_show_sensor;
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new_sr->attr.store = NULL;
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if (device_create_file(&wf_platform_device.dev, &new_sr->attr))
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printk(KERN_WARNING "windfarm: device_create_file failed"
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" for %s\n", new_sr->name);
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/* the subsystem still does useful work without the file */
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DBG("wf: Registered sensor %s\n", new_sr->name);
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wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
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mutex_unlock(&wf_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(wf_register_sensor);
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void wf_unregister_sensor(struct wf_sensor *sr)
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{
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mutex_lock(&wf_lock);
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list_del(&sr->link);
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mutex_unlock(&wf_lock);
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DBG("wf: Unregistered sensor %s\n", sr->name);
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wf_put_sensor(sr);
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}
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EXPORT_SYMBOL_GPL(wf_unregister_sensor);
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struct wf_sensor * wf_find_sensor(const char *name)
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{
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struct wf_sensor *sr;
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mutex_lock(&wf_lock);
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list_for_each_entry(sr, &wf_sensors, link) {
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if (!strcmp(sr->name, name)) {
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if (wf_get_sensor(sr))
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sr = NULL;
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mutex_unlock(&wf_lock);
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return sr;
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}
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}
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mutex_unlock(&wf_lock);
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return NULL;
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}
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EXPORT_SYMBOL_GPL(wf_find_sensor);
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int wf_get_sensor(struct wf_sensor *sr)
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{
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if (!try_module_get(sr->ops->owner))
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return -ENODEV;
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kref_get(&sr->ref);
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return 0;
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}
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EXPORT_SYMBOL_GPL(wf_get_sensor);
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void wf_put_sensor(struct wf_sensor *sr)
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{
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struct module *mod = sr->ops->owner;
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kref_put(&sr->ref, wf_sensor_release);
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module_put(mod);
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}
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EXPORT_SYMBOL_GPL(wf_put_sensor);
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/*
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* Client & notification
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*/
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int wf_register_client(struct notifier_block *nb)
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{
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int rc;
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struct wf_control *ct;
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struct wf_sensor *sr;
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mutex_lock(&wf_lock);
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rc = blocking_notifier_chain_register(&wf_client_list, nb);
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if (rc != 0)
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goto bail;
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wf_client_count++;
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list_for_each_entry(ct, &wf_controls, link)
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wf_notify(WF_EVENT_NEW_CONTROL, ct);
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list_for_each_entry(sr, &wf_sensors, link)
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wf_notify(WF_EVENT_NEW_SENSOR, sr);
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if (wf_client_count == 1)
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wf_start_thread();
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bail:
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mutex_unlock(&wf_lock);
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return rc;
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}
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EXPORT_SYMBOL_GPL(wf_register_client);
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int wf_unregister_client(struct notifier_block *nb)
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{
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mutex_lock(&wf_lock);
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blocking_notifier_chain_unregister(&wf_client_list, nb);
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wf_client_count++;
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if (wf_client_count == 0)
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wf_stop_thread();
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mutex_unlock(&wf_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(wf_unregister_client);
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void wf_set_overtemp(void)
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{
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mutex_lock(&wf_lock);
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wf_overtemp++;
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if (wf_overtemp == 1) {
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printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
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wf_overtemp_counter = 0;
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wf_notify(WF_EVENT_OVERTEMP, NULL);
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}
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mutex_unlock(&wf_lock);
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}
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EXPORT_SYMBOL_GPL(wf_set_overtemp);
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void wf_clear_overtemp(void)
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{
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mutex_lock(&wf_lock);
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WARN_ON(wf_overtemp == 0);
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if (wf_overtemp == 0) {
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mutex_unlock(&wf_lock);
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return;
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}
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wf_overtemp--;
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if (wf_overtemp == 0) {
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printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
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wf_notify(WF_EVENT_NORMALTEMP, NULL);
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}
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mutex_unlock(&wf_lock);
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}
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EXPORT_SYMBOL_GPL(wf_clear_overtemp);
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int wf_is_overtemp(void)
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{
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return (wf_overtemp != 0);
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}
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EXPORT_SYMBOL_GPL(wf_is_overtemp);
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static int __init windfarm_core_init(void)
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{
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DBG("wf: core loaded\n");
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/* Don't register on old machines that use therm_pm72 for now */
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if (machine_is_compatible("PowerMac7,2") ||
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machine_is_compatible("PowerMac7,3") ||
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machine_is_compatible("RackMac3,1"))
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return -ENODEV;
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platform_device_register(&wf_platform_device);
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return 0;
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}
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static void __exit windfarm_core_exit(void)
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{
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BUG_ON(wf_client_count != 0);
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DBG("wf: core unloaded\n");
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platform_device_unregister(&wf_platform_device);
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}
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module_init(windfarm_core_init);
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module_exit(windfarm_core_exit);
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MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
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MODULE_DESCRIPTION("Core component of PowerMac thermal control");
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MODULE_LICENSE("GPL");
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