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![Ashok Raj](/assets/img/avatar_default.png)
There are some callers in cpufreq hotplug notify path that the lowest function calls lock_cpu_hotplug(). The lock is already held during cpu_up() and cpu_down() calls when the notify calls are broadcast to registered clients. Ideally if possible, we could disable_preempt() at the highest caller and make sure we dont sleep in the path down in cpufreq->driver_target() calls but the calls are so intertwined and cumbersome to cleanup. Hence we consistently use lock_cpu_hotplug() and unlock_cpu_hotplug() in all places. - Removed export of cpucontrol semaphore and made it static. - removed explicit uses of up/down with lock_cpu_hotplug() so we can keep track of the the callers in same thread context and just keep refcounts without calling a down() that causes a deadlock. - Removed current_in_hotplug() uses - Removed PF_HOTPLUG_CPU in sched.h introduced for the current_in_hotplug() temporary workaround. Tested with insmod of cpufreq_stat.ko, and logical online/offline to make sure we dont have any hang situations. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Cc: Zwane Mwaikambo <zwane@linuxpower.ca> Cc: Shaohua Li <shaohua.li@intel.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1553 lines
40 KiB
C
1553 lines
40 KiB
C
/*
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* linux/drivers/cpufreq/cpufreq.c
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*
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* Copyright (C) 2001 Russell King
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* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
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*
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* Oct 2005 - Ashok Raj <ashok.raj@intel.com>
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* Added handling for CPU hotplug
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/notifier.h>
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#include <linux/cpufreq.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/spinlock.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <linux/cpu.h>
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#include <linux/completion.h>
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#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg)
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/**
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* The "cpufreq driver" - the arch- or hardware-dependend low
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* level driver of CPUFreq support, and its spinlock. This lock
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* also protects the cpufreq_cpu_data array.
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*/
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static struct cpufreq_driver *cpufreq_driver;
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static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS];
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static DEFINE_SPINLOCK(cpufreq_driver_lock);
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/* internal prototypes */
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static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event);
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static void handle_update(void *data);
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static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci);
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/**
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* Two notifier lists: the "policy" list is involved in the
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* validation process for a new CPU frequency policy; the
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* "transition" list for kernel code that needs to handle
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* changes to devices when the CPU clock speed changes.
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* The mutex locks both lists.
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*/
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static struct notifier_block *cpufreq_policy_notifier_list;
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static struct notifier_block *cpufreq_transition_notifier_list;
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static DECLARE_RWSEM (cpufreq_notifier_rwsem);
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static LIST_HEAD(cpufreq_governor_list);
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static DECLARE_MUTEX (cpufreq_governor_sem);
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struct cpufreq_policy * cpufreq_cpu_get(unsigned int cpu)
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{
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struct cpufreq_policy *data;
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unsigned long flags;
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if (cpu >= NR_CPUS)
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goto err_out;
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/* get the cpufreq driver */
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spin_lock_irqsave(&cpufreq_driver_lock, flags);
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if (!cpufreq_driver)
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goto err_out_unlock;
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if (!try_module_get(cpufreq_driver->owner))
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goto err_out_unlock;
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/* get the CPU */
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data = cpufreq_cpu_data[cpu];
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if (!data)
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goto err_out_put_module;
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if (!kobject_get(&data->kobj))
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goto err_out_put_module;
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spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
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return data;
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err_out_put_module:
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module_put(cpufreq_driver->owner);
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err_out_unlock:
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spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
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err_out:
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return NULL;
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}
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EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
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void cpufreq_cpu_put(struct cpufreq_policy *data)
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{
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kobject_put(&data->kobj);
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module_put(cpufreq_driver->owner);
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}
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EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
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/*********************************************************************
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* UNIFIED DEBUG HELPERS *
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*********************************************************************/
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#ifdef CONFIG_CPU_FREQ_DEBUG
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/* what part(s) of the CPUfreq subsystem are debugged? */
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static unsigned int debug;
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/* is the debug output ratelimit'ed using printk_ratelimit? User can
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* set or modify this value.
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*/
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static unsigned int debug_ratelimit = 1;
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/* is the printk_ratelimit'ing enabled? It's enabled after a successful
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* loading of a cpufreq driver, temporarily disabled when a new policy
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* is set, and disabled upon cpufreq driver removal
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*/
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static unsigned int disable_ratelimit = 1;
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static DEFINE_SPINLOCK(disable_ratelimit_lock);
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static inline void cpufreq_debug_enable_ratelimit(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&disable_ratelimit_lock, flags);
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if (disable_ratelimit)
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disable_ratelimit--;
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spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
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}
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static inline void cpufreq_debug_disable_ratelimit(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&disable_ratelimit_lock, flags);
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disable_ratelimit++;
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spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
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}
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void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...)
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{
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char s[256];
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va_list args;
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unsigned int len;
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unsigned long flags;
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WARN_ON(!prefix);
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if (type & debug) {
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spin_lock_irqsave(&disable_ratelimit_lock, flags);
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if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) {
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spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
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return;
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}
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spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
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len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix);
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va_start(args, fmt);
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len += vsnprintf(&s[len], (256 - len), fmt, args);
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va_end(args);
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printk(s);
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WARN_ON(len < 5);
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}
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}
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EXPORT_SYMBOL(cpufreq_debug_printk);
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module_param(debug, uint, 0644);
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MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors.");
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module_param(debug_ratelimit, uint, 0644);
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MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting.");
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#else /* !CONFIG_CPU_FREQ_DEBUG */
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static inline void cpufreq_debug_enable_ratelimit(void) { return; }
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static inline void cpufreq_debug_disable_ratelimit(void) { return; }
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#endif /* CONFIG_CPU_FREQ_DEBUG */
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/*********************************************************************
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* EXTERNALLY AFFECTING FREQUENCY CHANGES *
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*********************************************************************/
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/**
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* adjust_jiffies - adjust the system "loops_per_jiffy"
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*
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* This function alters the system "loops_per_jiffy" for the clock
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* speed change. Note that loops_per_jiffy cannot be updated on SMP
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* systems as each CPU might be scaled differently. So, use the arch
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* per-CPU loops_per_jiffy value wherever possible.
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*/
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#ifndef CONFIG_SMP
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static unsigned long l_p_j_ref;
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static unsigned int l_p_j_ref_freq;
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static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
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{
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if (ci->flags & CPUFREQ_CONST_LOOPS)
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return;
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if (!l_p_j_ref_freq) {
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l_p_j_ref = loops_per_jiffy;
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l_p_j_ref_freq = ci->old;
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dprintk("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq);
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}
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if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) ||
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(val == CPUFREQ_POSTCHANGE && ci->old > ci->new) ||
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(val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) {
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loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new);
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dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new);
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}
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}
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#else
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static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { return; }
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#endif
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/**
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* cpufreq_notify_transition - call notifier chain and adjust_jiffies on frequency transition
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*
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* This function calls the transition notifiers and the "adjust_jiffies" function. It is called
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* twice on all CPU frequency changes that have external effects.
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*/
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void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
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{
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BUG_ON(irqs_disabled());
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freqs->flags = cpufreq_driver->flags;
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dprintk("notification %u of frequency transition to %u kHz\n", state, freqs->new);
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down_read(&cpufreq_notifier_rwsem);
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switch (state) {
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case CPUFREQ_PRECHANGE:
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/* detect if the driver reported a value as "old frequency" which
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* is not equal to what the cpufreq core thinks is "old frequency".
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*/
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if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
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if ((likely(cpufreq_cpu_data[freqs->cpu])) &&
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(likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)) &&
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(likely(cpufreq_cpu_data[freqs->cpu]->cur)) &&
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(unlikely(freqs->old != cpufreq_cpu_data[freqs->cpu]->cur)))
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{
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dprintk(KERN_WARNING "Warning: CPU frequency is %u, "
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"cpufreq assumed %u kHz.\n", freqs->old, cpufreq_cpu_data[freqs->cpu]->cur);
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freqs->old = cpufreq_cpu_data[freqs->cpu]->cur;
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}
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}
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notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_PRECHANGE, freqs);
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adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
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break;
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case CPUFREQ_POSTCHANGE:
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adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
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notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_POSTCHANGE, freqs);
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if ((likely(cpufreq_cpu_data[freqs->cpu])) &&
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(likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)))
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cpufreq_cpu_data[freqs->cpu]->cur = freqs->new;
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break;
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}
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up_read(&cpufreq_notifier_rwsem);
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}
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EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
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/*********************************************************************
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* SYSFS INTERFACE *
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*********************************************************************/
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/**
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* cpufreq_parse_governor - parse a governor string
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*/
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static int cpufreq_parse_governor (char *str_governor, unsigned int *policy,
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struct cpufreq_governor **governor)
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{
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if (!cpufreq_driver)
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return -EINVAL;
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if (cpufreq_driver->setpolicy) {
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if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
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*policy = CPUFREQ_POLICY_PERFORMANCE;
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return 0;
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} else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
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*policy = CPUFREQ_POLICY_POWERSAVE;
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return 0;
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}
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return -EINVAL;
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} else {
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struct cpufreq_governor *t;
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down(&cpufreq_governor_sem);
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if (!cpufreq_driver || !cpufreq_driver->target)
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goto out;
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list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
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if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) {
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*governor = t;
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up(&cpufreq_governor_sem);
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return 0;
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}
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}
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out:
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up(&cpufreq_governor_sem);
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}
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return -EINVAL;
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}
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EXPORT_SYMBOL_GPL(cpufreq_parse_governor);
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/* drivers/base/cpu.c */
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extern struct sysdev_class cpu_sysdev_class;
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/**
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* cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information
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*
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* Write out information from cpufreq_driver->policy[cpu]; object must be
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* "unsigned int".
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*/
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#define show_one(file_name, object) \
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static ssize_t show_##file_name \
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(struct cpufreq_policy * policy, char *buf) \
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{ \
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return sprintf (buf, "%u\n", policy->object); \
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}
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show_one(cpuinfo_min_freq, cpuinfo.min_freq);
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show_one(cpuinfo_max_freq, cpuinfo.max_freq);
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show_one(scaling_min_freq, min);
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show_one(scaling_max_freq, max);
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show_one(scaling_cur_freq, cur);
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/**
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* cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
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*/
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#define store_one(file_name, object) \
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static ssize_t store_##file_name \
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(struct cpufreq_policy * policy, const char *buf, size_t count) \
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{ \
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unsigned int ret = -EINVAL; \
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struct cpufreq_policy new_policy; \
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\
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ret = cpufreq_get_policy(&new_policy, policy->cpu); \
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if (ret) \
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return -EINVAL; \
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\
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ret = sscanf (buf, "%u", &new_policy.object); \
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if (ret != 1) \
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return -EINVAL; \
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\
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ret = cpufreq_set_policy(&new_policy); \
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\
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return ret ? ret : count; \
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}
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store_one(scaling_min_freq,min);
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store_one(scaling_max_freq,max);
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/**
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* show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
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*/
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static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf)
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{
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unsigned int cur_freq = cpufreq_get(policy->cpu);
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if (!cur_freq)
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return sprintf(buf, "<unknown>");
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return sprintf(buf, "%u\n", cur_freq);
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}
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/**
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* show_scaling_governor - show the current policy for the specified CPU
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*/
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static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf)
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{
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if(policy->policy == CPUFREQ_POLICY_POWERSAVE)
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return sprintf(buf, "powersave\n");
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else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
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return sprintf(buf, "performance\n");
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else if (policy->governor)
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return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name);
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return -EINVAL;
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}
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|
|
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/**
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* store_scaling_governor - store policy for the specified CPU
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*/
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static ssize_t store_scaling_governor (struct cpufreq_policy * policy,
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const char *buf, size_t count)
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{
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unsigned int ret = -EINVAL;
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char str_governor[16];
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struct cpufreq_policy new_policy;
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ret = cpufreq_get_policy(&new_policy, policy->cpu);
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if (ret)
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return ret;
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ret = sscanf (buf, "%15s", str_governor);
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if (ret != 1)
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return -EINVAL;
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|
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if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor))
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return -EINVAL;
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ret = cpufreq_set_policy(&new_policy);
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return ret ? ret : count;
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}
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/**
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* show_scaling_driver - show the cpufreq driver currently loaded
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*/
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static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf)
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{
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return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
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}
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|
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/**
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* show_scaling_available_governors - show the available CPUfreq governors
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*/
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static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy,
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char *buf)
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{
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ssize_t i = 0;
|
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struct cpufreq_governor *t;
|
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|
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if (!cpufreq_driver->target) {
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i += sprintf(buf, "performance powersave");
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goto out;
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}
|
|
|
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list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
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if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2)))
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goto out;
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i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
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}
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out:
|
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i += sprintf(&buf[i], "\n");
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return i;
|
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}
|
|
/**
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|
* show_affected_cpus - show the CPUs affected by each transition
|
|
*/
|
|
static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf)
|
|
{
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|
ssize_t i = 0;
|
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unsigned int cpu;
|
|
|
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for_each_cpu_mask(cpu, policy->cpus) {
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if (i)
|
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i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
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i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
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if (i >= (PAGE_SIZE - 5))
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break;
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}
|
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i += sprintf(&buf[i], "\n");
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return i;
|
|
}
|
|
|
|
|
|
#define define_one_ro(_name) \
|
|
static struct freq_attr _name = \
|
|
__ATTR(_name, 0444, show_##_name, NULL)
|
|
|
|
#define define_one_ro0400(_name) \
|
|
static struct freq_attr _name = \
|
|
__ATTR(_name, 0400, show_##_name, NULL)
|
|
|
|
#define define_one_rw(_name) \
|
|
static struct freq_attr _name = \
|
|
__ATTR(_name, 0644, show_##_name, store_##_name)
|
|
|
|
define_one_ro0400(cpuinfo_cur_freq);
|
|
define_one_ro(cpuinfo_min_freq);
|
|
define_one_ro(cpuinfo_max_freq);
|
|
define_one_ro(scaling_available_governors);
|
|
define_one_ro(scaling_driver);
|
|
define_one_ro(scaling_cur_freq);
|
|
define_one_ro(affected_cpus);
|
|
define_one_rw(scaling_min_freq);
|
|
define_one_rw(scaling_max_freq);
|
|
define_one_rw(scaling_governor);
|
|
|
|
static struct attribute * default_attrs[] = {
|
|
&cpuinfo_min_freq.attr,
|
|
&cpuinfo_max_freq.attr,
|
|
&scaling_min_freq.attr,
|
|
&scaling_max_freq.attr,
|
|
&affected_cpus.attr,
|
|
&scaling_governor.attr,
|
|
&scaling_driver.attr,
|
|
&scaling_available_governors.attr,
|
|
NULL
|
|
};
|
|
|
|
#define to_policy(k) container_of(k,struct cpufreq_policy,kobj)
|
|
#define to_attr(a) container_of(a,struct freq_attr,attr)
|
|
|
|
static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf)
|
|
{
|
|
struct cpufreq_policy * policy = to_policy(kobj);
|
|
struct freq_attr * fattr = to_attr(attr);
|
|
ssize_t ret;
|
|
policy = cpufreq_cpu_get(policy->cpu);
|
|
if (!policy)
|
|
return -EINVAL;
|
|
ret = fattr->show ? fattr->show(policy,buf) : -EIO;
|
|
cpufreq_cpu_put(policy);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t store(struct kobject * kobj, struct attribute * attr,
|
|
const char * buf, size_t count)
|
|
{
|
|
struct cpufreq_policy * policy = to_policy(kobj);
|
|
struct freq_attr * fattr = to_attr(attr);
|
|
ssize_t ret;
|
|
policy = cpufreq_cpu_get(policy->cpu);
|
|
if (!policy)
|
|
return -EINVAL;
|
|
ret = fattr->store ? fattr->store(policy,buf,count) : -EIO;
|
|
cpufreq_cpu_put(policy);
|
|
return ret;
|
|
}
|
|
|
|
static void cpufreq_sysfs_release(struct kobject * kobj)
|
|
{
|
|
struct cpufreq_policy * policy = to_policy(kobj);
|
|
dprintk("last reference is dropped\n");
|
|
complete(&policy->kobj_unregister);
|
|
}
|
|
|
|
static struct sysfs_ops sysfs_ops = {
|
|
.show = show,
|
|
.store = store,
|
|
};
|
|
|
|
static struct kobj_type ktype_cpufreq = {
|
|
.sysfs_ops = &sysfs_ops,
|
|
.default_attrs = default_attrs,
|
|
.release = cpufreq_sysfs_release,
|
|
};
|
|
|
|
|
|
/**
|
|
* cpufreq_add_dev - add a CPU device
|
|
*
|
|
* Adds the cpufreq interface for a CPU device.
|
|
*/
|
|
static int cpufreq_add_dev (struct sys_device * sys_dev)
|
|
{
|
|
unsigned int cpu = sys_dev->id;
|
|
int ret = 0;
|
|
struct cpufreq_policy new_policy;
|
|
struct cpufreq_policy *policy;
|
|
struct freq_attr **drv_attr;
|
|
unsigned long flags;
|
|
unsigned int j;
|
|
|
|
if (cpu_is_offline(cpu))
|
|
return 0;
|
|
|
|
cpufreq_debug_disable_ratelimit();
|
|
dprintk("adding CPU %u\n", cpu);
|
|
|
|
#ifdef CONFIG_SMP
|
|
/* check whether a different CPU already registered this
|
|
* CPU because it is in the same boat. */
|
|
policy = cpufreq_cpu_get(cpu);
|
|
if (unlikely(policy)) {
|
|
dprintk("CPU already managed, adding link\n");
|
|
sysfs_create_link(&sys_dev->kobj, &policy->kobj, "cpufreq");
|
|
cpufreq_debug_enable_ratelimit();
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
if (!try_module_get(cpufreq_driver->owner)) {
|
|
ret = -EINVAL;
|
|
goto module_out;
|
|
}
|
|
|
|
policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
|
|
if (!policy) {
|
|
ret = -ENOMEM;
|
|
goto nomem_out;
|
|
}
|
|
|
|
policy->cpu = cpu;
|
|
policy->cpus = cpumask_of_cpu(cpu);
|
|
|
|
init_MUTEX_LOCKED(&policy->lock);
|
|
init_completion(&policy->kobj_unregister);
|
|
INIT_WORK(&policy->update, handle_update, (void *)(long)cpu);
|
|
|
|
/* call driver. From then on the cpufreq must be able
|
|
* to accept all calls to ->verify and ->setpolicy for this CPU
|
|
*/
|
|
ret = cpufreq_driver->init(policy);
|
|
if (ret) {
|
|
dprintk("initialization failed\n");
|
|
goto err_out;
|
|
}
|
|
|
|
memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
|
|
|
|
/* prepare interface data */
|
|
policy->kobj.parent = &sys_dev->kobj;
|
|
policy->kobj.ktype = &ktype_cpufreq;
|
|
strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN);
|
|
|
|
ret = kobject_register(&policy->kobj);
|
|
if (ret)
|
|
goto err_out_driver_exit;
|
|
|
|
/* set up files for this cpu device */
|
|
drv_attr = cpufreq_driver->attr;
|
|
while ((drv_attr) && (*drv_attr)) {
|
|
sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
|
|
drv_attr++;
|
|
}
|
|
if (cpufreq_driver->get)
|
|
sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
|
|
if (cpufreq_driver->target)
|
|
sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
for_each_cpu_mask(j, policy->cpus)
|
|
cpufreq_cpu_data[j] = policy;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
policy->governor = NULL; /* to assure that the starting sequence is
|
|
* run in cpufreq_set_policy */
|
|
up(&policy->lock);
|
|
|
|
/* set default policy */
|
|
|
|
ret = cpufreq_set_policy(&new_policy);
|
|
if (ret) {
|
|
dprintk("setting policy failed\n");
|
|
goto err_out_unregister;
|
|
}
|
|
|
|
module_put(cpufreq_driver->owner);
|
|
dprintk("initialization complete\n");
|
|
cpufreq_debug_enable_ratelimit();
|
|
|
|
return 0;
|
|
|
|
|
|
err_out_unregister:
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
for_each_cpu_mask(j, policy->cpus)
|
|
cpufreq_cpu_data[j] = NULL;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
kobject_unregister(&policy->kobj);
|
|
wait_for_completion(&policy->kobj_unregister);
|
|
|
|
err_out_driver_exit:
|
|
if (cpufreq_driver->exit)
|
|
cpufreq_driver->exit(policy);
|
|
|
|
err_out:
|
|
kfree(policy);
|
|
|
|
nomem_out:
|
|
module_put(cpufreq_driver->owner);
|
|
module_out:
|
|
cpufreq_debug_enable_ratelimit();
|
|
return ret;
|
|
}
|
|
|
|
|
|
/**
|
|
* cpufreq_remove_dev - remove a CPU device
|
|
*
|
|
* Removes the cpufreq interface for a CPU device.
|
|
*/
|
|
static int cpufreq_remove_dev (struct sys_device * sys_dev)
|
|
{
|
|
unsigned int cpu = sys_dev->id;
|
|
unsigned long flags;
|
|
struct cpufreq_policy *data;
|
|
#ifdef CONFIG_SMP
|
|
struct sys_device *cpu_sys_dev;
|
|
unsigned int j;
|
|
#endif
|
|
|
|
cpufreq_debug_disable_ratelimit();
|
|
dprintk("unregistering CPU %u\n", cpu);
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
data = cpufreq_cpu_data[cpu];
|
|
|
|
if (!data) {
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
cpufreq_debug_enable_ratelimit();
|
|
return -EINVAL;
|
|
}
|
|
cpufreq_cpu_data[cpu] = NULL;
|
|
|
|
|
|
#ifdef CONFIG_SMP
|
|
/* if this isn't the CPU which is the parent of the kobj, we
|
|
* only need to unlink, put and exit
|
|
*/
|
|
if (unlikely(cpu != data->cpu)) {
|
|
dprintk("removing link\n");
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
sysfs_remove_link(&sys_dev->kobj, "cpufreq");
|
|
cpufreq_cpu_put(data);
|
|
cpufreq_debug_enable_ratelimit();
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
|
|
if (!kobject_get(&data->kobj)) {
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
cpufreq_debug_enable_ratelimit();
|
|
return -EFAULT;
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
/* if we have other CPUs still registered, we need to unlink them,
|
|
* or else wait_for_completion below will lock up. Clean the
|
|
* cpufreq_cpu_data[] while holding the lock, and remove the sysfs
|
|
* links afterwards.
|
|
*/
|
|
if (unlikely(cpus_weight(data->cpus) > 1)) {
|
|
for_each_cpu_mask(j, data->cpus) {
|
|
if (j == cpu)
|
|
continue;
|
|
cpufreq_cpu_data[j] = NULL;
|
|
}
|
|
}
|
|
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
if (unlikely(cpus_weight(data->cpus) > 1)) {
|
|
for_each_cpu_mask(j, data->cpus) {
|
|
if (j == cpu)
|
|
continue;
|
|
dprintk("removing link for cpu %u\n", j);
|
|
cpu_sys_dev = get_cpu_sysdev(j);
|
|
sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq");
|
|
cpufreq_cpu_put(data);
|
|
}
|
|
}
|
|
#else
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
#endif
|
|
|
|
down(&data->lock);
|
|
if (cpufreq_driver->target)
|
|
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
|
|
up(&data->lock);
|
|
|
|
kobject_unregister(&data->kobj);
|
|
|
|
kobject_put(&data->kobj);
|
|
|
|
/* we need to make sure that the underlying kobj is actually
|
|
* not referenced anymore by anybody before we proceed with
|
|
* unloading.
|
|
*/
|
|
dprintk("waiting for dropping of refcount\n");
|
|
wait_for_completion(&data->kobj_unregister);
|
|
dprintk("wait complete\n");
|
|
|
|
if (cpufreq_driver->exit)
|
|
cpufreq_driver->exit(data);
|
|
|
|
kfree(data);
|
|
|
|
cpufreq_debug_enable_ratelimit();
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void handle_update(void *data)
|
|
{
|
|
unsigned int cpu = (unsigned int)(long)data;
|
|
dprintk("handle_update for cpu %u called\n", cpu);
|
|
cpufreq_update_policy(cpu);
|
|
}
|
|
|
|
/**
|
|
* cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble.
|
|
* @cpu: cpu number
|
|
* @old_freq: CPU frequency the kernel thinks the CPU runs at
|
|
* @new_freq: CPU frequency the CPU actually runs at
|
|
*
|
|
* We adjust to current frequency first, and need to clean up later. So either call
|
|
* to cpufreq_update_policy() or schedule handle_update()).
|
|
*/
|
|
static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq)
|
|
{
|
|
struct cpufreq_freqs freqs;
|
|
|
|
dprintk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing "
|
|
"core thinks of %u, is %u kHz.\n", old_freq, new_freq);
|
|
|
|
freqs.cpu = cpu;
|
|
freqs.old = old_freq;
|
|
freqs.new = new_freq;
|
|
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
|
|
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
|
|
}
|
|
|
|
|
|
/**
|
|
* cpufreq_get - get the current CPU frequency (in kHz)
|
|
* @cpu: CPU number
|
|
*
|
|
* Get the CPU current (static) CPU frequency
|
|
*/
|
|
unsigned int cpufreq_get(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
|
|
unsigned int ret = 0;
|
|
|
|
if (!policy)
|
|
return 0;
|
|
|
|
if (!cpufreq_driver->get)
|
|
goto out;
|
|
|
|
down(&policy->lock);
|
|
|
|
ret = cpufreq_driver->get(cpu);
|
|
|
|
if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS))
|
|
{
|
|
/* verify no discrepancy between actual and saved value exists */
|
|
if (unlikely(ret != policy->cur)) {
|
|
cpufreq_out_of_sync(cpu, policy->cur, ret);
|
|
schedule_work(&policy->update);
|
|
}
|
|
}
|
|
|
|
up(&policy->lock);
|
|
|
|
out:
|
|
cpufreq_cpu_put(policy);
|
|
|
|
return (ret);
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_get);
|
|
|
|
|
|
/**
|
|
* cpufreq_suspend - let the low level driver prepare for suspend
|
|
*/
|
|
|
|
static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
|
|
{
|
|
int cpu = sysdev->id;
|
|
unsigned int ret = 0;
|
|
unsigned int cur_freq = 0;
|
|
struct cpufreq_policy *cpu_policy;
|
|
|
|
dprintk("resuming cpu %u\n", cpu);
|
|
|
|
if (!cpu_online(cpu))
|
|
return 0;
|
|
|
|
/* we may be lax here as interrupts are off. Nonetheless
|
|
* we need to grab the correct cpu policy, as to check
|
|
* whether we really run on this CPU.
|
|
*/
|
|
|
|
cpu_policy = cpufreq_cpu_get(cpu);
|
|
if (!cpu_policy)
|
|
return -EINVAL;
|
|
|
|
/* only handle each CPU group once */
|
|
if (unlikely(cpu_policy->cpu != cpu)) {
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return 0;
|
|
}
|
|
|
|
if (cpufreq_driver->suspend) {
|
|
ret = cpufreq_driver->suspend(cpu_policy, pmsg);
|
|
if (ret) {
|
|
printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
|
|
"step on CPU %u\n", cpu_policy->cpu);
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
|
|
if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)
|
|
goto out;
|
|
|
|
if (cpufreq_driver->get)
|
|
cur_freq = cpufreq_driver->get(cpu_policy->cpu);
|
|
|
|
if (!cur_freq || !cpu_policy->cur) {
|
|
printk(KERN_ERR "cpufreq: suspend failed to assert current "
|
|
"frequency is what timing core thinks it is.\n");
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(cur_freq != cpu_policy->cur)) {
|
|
struct cpufreq_freqs freqs;
|
|
|
|
if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
|
|
dprintk(KERN_DEBUG "Warning: CPU frequency is %u, "
|
|
"cpufreq assumed %u kHz.\n",
|
|
cur_freq, cpu_policy->cur);
|
|
|
|
freqs.cpu = cpu;
|
|
freqs.old = cpu_policy->cur;
|
|
freqs.new = cur_freq;
|
|
|
|
notifier_call_chain(&cpufreq_transition_notifier_list,
|
|
CPUFREQ_SUSPENDCHANGE, &freqs);
|
|
adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs);
|
|
|
|
cpu_policy->cur = cur_freq;
|
|
}
|
|
|
|
out:
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_resume - restore proper CPU frequency handling after resume
|
|
*
|
|
* 1.) resume CPUfreq hardware support (cpufreq_driver->resume())
|
|
* 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync
|
|
* 3.) schedule call cpufreq_update_policy() ASAP as interrupts are
|
|
* restored.
|
|
*/
|
|
static int cpufreq_resume(struct sys_device * sysdev)
|
|
{
|
|
int cpu = sysdev->id;
|
|
unsigned int ret = 0;
|
|
struct cpufreq_policy *cpu_policy;
|
|
|
|
dprintk("resuming cpu %u\n", cpu);
|
|
|
|
if (!cpu_online(cpu))
|
|
return 0;
|
|
|
|
/* we may be lax here as interrupts are off. Nonetheless
|
|
* we need to grab the correct cpu policy, as to check
|
|
* whether we really run on this CPU.
|
|
*/
|
|
|
|
cpu_policy = cpufreq_cpu_get(cpu);
|
|
if (!cpu_policy)
|
|
return -EINVAL;
|
|
|
|
/* only handle each CPU group once */
|
|
if (unlikely(cpu_policy->cpu != cpu)) {
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return 0;
|
|
}
|
|
|
|
if (cpufreq_driver->resume) {
|
|
ret = cpufreq_driver->resume(cpu_policy);
|
|
if (ret) {
|
|
printk(KERN_ERR "cpufreq: resume failed in ->resume "
|
|
"step on CPU %u\n", cpu_policy->cpu);
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
|
|
unsigned int cur_freq = 0;
|
|
|
|
if (cpufreq_driver->get)
|
|
cur_freq = cpufreq_driver->get(cpu_policy->cpu);
|
|
|
|
if (!cur_freq || !cpu_policy->cur) {
|
|
printk(KERN_ERR "cpufreq: resume failed to assert "
|
|
"current frequency is what timing core "
|
|
"thinks it is.\n");
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(cur_freq != cpu_policy->cur)) {
|
|
struct cpufreq_freqs freqs;
|
|
|
|
if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
|
|
dprintk(KERN_WARNING "Warning: CPU frequency"
|
|
"is %u, cpufreq assumed %u kHz.\n",
|
|
cur_freq, cpu_policy->cur);
|
|
|
|
freqs.cpu = cpu;
|
|
freqs.old = cpu_policy->cur;
|
|
freqs.new = cur_freq;
|
|
|
|
notifier_call_chain(&cpufreq_transition_notifier_list,
|
|
CPUFREQ_RESUMECHANGE, &freqs);
|
|
adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs);
|
|
|
|
cpu_policy->cur = cur_freq;
|
|
}
|
|
}
|
|
|
|
out:
|
|
schedule_work(&cpu_policy->update);
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return ret;
|
|
}
|
|
|
|
static struct sysdev_driver cpufreq_sysdev_driver = {
|
|
.add = cpufreq_add_dev,
|
|
.remove = cpufreq_remove_dev,
|
|
.suspend = cpufreq_suspend,
|
|
.resume = cpufreq_resume,
|
|
};
|
|
|
|
|
|
/*********************************************************************
|
|
* NOTIFIER LISTS INTERFACE *
|
|
*********************************************************************/
|
|
|
|
/**
|
|
* cpufreq_register_notifier - register a driver with cpufreq
|
|
* @nb: notifier function to register
|
|
* @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
|
|
*
|
|
* Add a driver to one of two lists: either a list of drivers that
|
|
* are notified about clock rate changes (once before and once after
|
|
* the transition), or a list of drivers that are notified about
|
|
* changes in cpufreq policy.
|
|
*
|
|
* This function may sleep, and has the same return conditions as
|
|
* notifier_chain_register.
|
|
*/
|
|
int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
|
|
{
|
|
int ret;
|
|
|
|
down_write(&cpufreq_notifier_rwsem);
|
|
switch (list) {
|
|
case CPUFREQ_TRANSITION_NOTIFIER:
|
|
ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb);
|
|
break;
|
|
case CPUFREQ_POLICY_NOTIFIER:
|
|
ret = notifier_chain_register(&cpufreq_policy_notifier_list, nb);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
up_write(&cpufreq_notifier_rwsem);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_register_notifier);
|
|
|
|
|
|
/**
|
|
* cpufreq_unregister_notifier - unregister a driver with cpufreq
|
|
* @nb: notifier block to be unregistered
|
|
* @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
|
|
*
|
|
* Remove a driver from the CPU frequency notifier list.
|
|
*
|
|
* This function may sleep, and has the same return conditions as
|
|
* notifier_chain_unregister.
|
|
*/
|
|
int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
|
|
{
|
|
int ret;
|
|
|
|
down_write(&cpufreq_notifier_rwsem);
|
|
switch (list) {
|
|
case CPUFREQ_TRANSITION_NOTIFIER:
|
|
ret = notifier_chain_unregister(&cpufreq_transition_notifier_list, nb);
|
|
break;
|
|
case CPUFREQ_POLICY_NOTIFIER:
|
|
ret = notifier_chain_unregister(&cpufreq_policy_notifier_list, nb);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
up_write(&cpufreq_notifier_rwsem);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_unregister_notifier);
|
|
|
|
|
|
/*********************************************************************
|
|
* GOVERNORS *
|
|
*********************************************************************/
|
|
|
|
|
|
int __cpufreq_driver_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
int retval = -EINVAL;
|
|
|
|
lock_cpu_hotplug();
|
|
dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
|
|
target_freq, relation);
|
|
if (cpu_online(policy->cpu) && cpufreq_driver->target)
|
|
retval = cpufreq_driver->target(policy, target_freq, relation);
|
|
|
|
unlock_cpu_hotplug();
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
|
|
|
|
int cpufreq_driver_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
int ret;
|
|
|
|
policy = cpufreq_cpu_get(policy->cpu);
|
|
if (!policy)
|
|
return -EINVAL;
|
|
|
|
down(&policy->lock);
|
|
|
|
ret = __cpufreq_driver_target(policy, target_freq, relation);
|
|
|
|
up(&policy->lock);
|
|
|
|
cpufreq_cpu_put(policy);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_driver_target);
|
|
|
|
|
|
static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
|
|
{
|
|
int ret;
|
|
|
|
if (!try_module_get(policy->governor->owner))
|
|
return -EINVAL;
|
|
|
|
dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event);
|
|
ret = policy->governor->governor(policy, event);
|
|
|
|
/* we keep one module reference alive for each CPU governed by this CPU */
|
|
if ((event != CPUFREQ_GOV_START) || ret)
|
|
module_put(policy->governor->owner);
|
|
if ((event == CPUFREQ_GOV_STOP) && !ret)
|
|
module_put(policy->governor->owner);
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
int cpufreq_governor(unsigned int cpu, unsigned int event)
|
|
{
|
|
int ret = 0;
|
|
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
|
|
|
|
if (!policy)
|
|
return -EINVAL;
|
|
|
|
down(&policy->lock);
|
|
ret = __cpufreq_governor(policy, event);
|
|
up(&policy->lock);
|
|
|
|
cpufreq_cpu_put(policy);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_governor);
|
|
|
|
|
|
int cpufreq_register_governor(struct cpufreq_governor *governor)
|
|
{
|
|
struct cpufreq_governor *t;
|
|
|
|
if (!governor)
|
|
return -EINVAL;
|
|
|
|
down(&cpufreq_governor_sem);
|
|
|
|
list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
|
|
if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) {
|
|
up(&cpufreq_governor_sem);
|
|
return -EBUSY;
|
|
}
|
|
}
|
|
list_add(&governor->governor_list, &cpufreq_governor_list);
|
|
|
|
up(&cpufreq_governor_sem);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_register_governor);
|
|
|
|
|
|
void cpufreq_unregister_governor(struct cpufreq_governor *governor)
|
|
{
|
|
if (!governor)
|
|
return;
|
|
|
|
down(&cpufreq_governor_sem);
|
|
list_del(&governor->governor_list);
|
|
up(&cpufreq_governor_sem);
|
|
return;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
|
|
|
|
|
|
|
|
/*********************************************************************
|
|
* POLICY INTERFACE *
|
|
*********************************************************************/
|
|
|
|
/**
|
|
* cpufreq_get_policy - get the current cpufreq_policy
|
|
* @policy: struct cpufreq_policy into which the current cpufreq_policy is written
|
|
*
|
|
* Reads the current cpufreq policy.
|
|
*/
|
|
int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *cpu_policy;
|
|
if (!policy)
|
|
return -EINVAL;
|
|
|
|
cpu_policy = cpufreq_cpu_get(cpu);
|
|
if (!cpu_policy)
|
|
return -EINVAL;
|
|
|
|
down(&cpu_policy->lock);
|
|
memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy));
|
|
up(&cpu_policy->lock);
|
|
|
|
cpufreq_cpu_put(cpu_policy);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_get_policy);
|
|
|
|
|
|
static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy)
|
|
{
|
|
int ret = 0;
|
|
|
|
cpufreq_debug_disable_ratelimit();
|
|
dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu,
|
|
policy->min, policy->max);
|
|
|
|
memcpy(&policy->cpuinfo,
|
|
&data->cpuinfo,
|
|
sizeof(struct cpufreq_cpuinfo));
|
|
|
|
/* verify the cpu speed can be set within this limit */
|
|
ret = cpufreq_driver->verify(policy);
|
|
if (ret)
|
|
goto error_out;
|
|
|
|
down_read(&cpufreq_notifier_rwsem);
|
|
|
|
/* adjust if necessary - all reasons */
|
|
notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST,
|
|
policy);
|
|
|
|
/* adjust if necessary - hardware incompatibility*/
|
|
notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_INCOMPATIBLE,
|
|
policy);
|
|
|
|
/* verify the cpu speed can be set within this limit,
|
|
which might be different to the first one */
|
|
ret = cpufreq_driver->verify(policy);
|
|
if (ret) {
|
|
up_read(&cpufreq_notifier_rwsem);
|
|
goto error_out;
|
|
}
|
|
|
|
/* notification of the new policy */
|
|
notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_NOTIFY,
|
|
policy);
|
|
|
|
up_read(&cpufreq_notifier_rwsem);
|
|
|
|
data->min = policy->min;
|
|
data->max = policy->max;
|
|
|
|
dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max);
|
|
|
|
if (cpufreq_driver->setpolicy) {
|
|
data->policy = policy->policy;
|
|
dprintk("setting range\n");
|
|
ret = cpufreq_driver->setpolicy(policy);
|
|
} else {
|
|
if (policy->governor != data->governor) {
|
|
/* save old, working values */
|
|
struct cpufreq_governor *old_gov = data->governor;
|
|
|
|
dprintk("governor switch\n");
|
|
|
|
/* end old governor */
|
|
if (data->governor)
|
|
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
|
|
|
|
/* start new governor */
|
|
data->governor = policy->governor;
|
|
if (__cpufreq_governor(data, CPUFREQ_GOV_START)) {
|
|
/* new governor failed, so re-start old one */
|
|
dprintk("starting governor %s failed\n", data->governor->name);
|
|
if (old_gov) {
|
|
data->governor = old_gov;
|
|
__cpufreq_governor(data, CPUFREQ_GOV_START);
|
|
}
|
|
ret = -EINVAL;
|
|
goto error_out;
|
|
}
|
|
/* might be a policy change, too, so fall through */
|
|
}
|
|
dprintk("governor: change or update limits\n");
|
|
__cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
|
|
}
|
|
|
|
error_out:
|
|
cpufreq_debug_enable_ratelimit();
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_set_policy - set a new CPUFreq policy
|
|
* @policy: policy to be set.
|
|
*
|
|
* Sets a new CPU frequency and voltage scaling policy.
|
|
*/
|
|
int cpufreq_set_policy(struct cpufreq_policy *policy)
|
|
{
|
|
int ret = 0;
|
|
struct cpufreq_policy *data;
|
|
|
|
if (!policy)
|
|
return -EINVAL;
|
|
|
|
data = cpufreq_cpu_get(policy->cpu);
|
|
if (!data)
|
|
return -EINVAL;
|
|
|
|
/* lock this CPU */
|
|
down(&data->lock);
|
|
|
|
ret = __cpufreq_set_policy(data, policy);
|
|
data->user_policy.min = data->min;
|
|
data->user_policy.max = data->max;
|
|
data->user_policy.policy = data->policy;
|
|
data->user_policy.governor = data->governor;
|
|
|
|
up(&data->lock);
|
|
cpufreq_cpu_put(data);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_set_policy);
|
|
|
|
|
|
/**
|
|
* cpufreq_update_policy - re-evaluate an existing cpufreq policy
|
|
* @cpu: CPU which shall be re-evaluated
|
|
*
|
|
* Usefull for policy notifiers which have different necessities
|
|
* at different times.
|
|
*/
|
|
int cpufreq_update_policy(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *data = cpufreq_cpu_get(cpu);
|
|
struct cpufreq_policy policy;
|
|
int ret = 0;
|
|
|
|
if (!data)
|
|
return -ENODEV;
|
|
|
|
down(&data->lock);
|
|
|
|
dprintk("updating policy for CPU %u\n", cpu);
|
|
memcpy(&policy,
|
|
data,
|
|
sizeof(struct cpufreq_policy));
|
|
policy.min = data->user_policy.min;
|
|
policy.max = data->user_policy.max;
|
|
policy.policy = data->user_policy.policy;
|
|
policy.governor = data->user_policy.governor;
|
|
|
|
ret = __cpufreq_set_policy(data, &policy);
|
|
|
|
up(&data->lock);
|
|
|
|
cpufreq_cpu_put(data);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_update_policy);
|
|
|
|
static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
unsigned int cpu = (unsigned long)hcpu;
|
|
struct cpufreq_policy *policy;
|
|
struct sys_device *sys_dev;
|
|
|
|
sys_dev = get_cpu_sysdev(cpu);
|
|
|
|
if (sys_dev) {
|
|
switch (action) {
|
|
case CPU_ONLINE:
|
|
cpufreq_add_dev(sys_dev);
|
|
break;
|
|
case CPU_DOWN_PREPARE:
|
|
/*
|
|
* We attempt to put this cpu in lowest frequency
|
|
* possible before going down. This will permit
|
|
* hardware-managed P-State to switch other related
|
|
* threads to min or higher speeds if possible.
|
|
*/
|
|
policy = cpufreq_cpu_data[cpu];
|
|
if (policy) {
|
|
cpufreq_driver_target(policy, policy->min,
|
|
CPUFREQ_RELATION_H);
|
|
}
|
|
break;
|
|
case CPU_DEAD:
|
|
cpufreq_remove_dev(sys_dev);
|
|
break;
|
|
}
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block cpufreq_cpu_notifier =
|
|
{
|
|
.notifier_call = cpufreq_cpu_callback,
|
|
};
|
|
|
|
/*********************************************************************
|
|
* REGISTER / UNREGISTER CPUFREQ DRIVER *
|
|
*********************************************************************/
|
|
|
|
/**
|
|
* cpufreq_register_driver - register a CPU Frequency driver
|
|
* @driver_data: A struct cpufreq_driver containing the values#
|
|
* submitted by the CPU Frequency driver.
|
|
*
|
|
* Registers a CPU Frequency driver to this core code. This code
|
|
* returns zero on success, -EBUSY when another driver got here first
|
|
* (and isn't unregistered in the meantime).
|
|
*
|
|
*/
|
|
int cpufreq_register_driver(struct cpufreq_driver *driver_data)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
if (!driver_data || !driver_data->verify || !driver_data->init ||
|
|
((!driver_data->setpolicy) && (!driver_data->target)))
|
|
return -EINVAL;
|
|
|
|
dprintk("trying to register driver %s\n", driver_data->name);
|
|
|
|
if (driver_data->setpolicy)
|
|
driver_data->flags |= CPUFREQ_CONST_LOOPS;
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
if (cpufreq_driver) {
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
return -EBUSY;
|
|
}
|
|
cpufreq_driver = driver_data;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver);
|
|
|
|
if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) {
|
|
int i;
|
|
ret = -ENODEV;
|
|
|
|
/* check for at least one working CPU */
|
|
for (i=0; i<NR_CPUS; i++)
|
|
if (cpufreq_cpu_data[i])
|
|
ret = 0;
|
|
|
|
/* if all ->init() calls failed, unregister */
|
|
if (ret) {
|
|
dprintk("no CPU initialized for driver %s\n", driver_data->name);
|
|
sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
cpufreq_driver = NULL;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
}
|
|
}
|
|
|
|
if (!ret) {
|
|
register_cpu_notifier(&cpufreq_cpu_notifier);
|
|
dprintk("driver %s up and running\n", driver_data->name);
|
|
cpufreq_debug_enable_ratelimit();
|
|
}
|
|
|
|
return (ret);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_register_driver);
|
|
|
|
|
|
/**
|
|
* cpufreq_unregister_driver - unregister the current CPUFreq driver
|
|
*
|
|
* Unregister the current CPUFreq driver. Only call this if you have
|
|
* the right to do so, i.e. if you have succeeded in initialising before!
|
|
* Returns zero if successful, and -EINVAL if the cpufreq_driver is
|
|
* currently not initialised.
|
|
*/
|
|
int cpufreq_unregister_driver(struct cpufreq_driver *driver)
|
|
{
|
|
unsigned long flags;
|
|
|
|
cpufreq_debug_disable_ratelimit();
|
|
|
|
if (!cpufreq_driver || (driver != cpufreq_driver)) {
|
|
cpufreq_debug_enable_ratelimit();
|
|
return -EINVAL;
|
|
}
|
|
|
|
dprintk("unregistering driver %s\n", driver->name);
|
|
|
|
sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
|
|
unregister_cpu_notifier(&cpufreq_cpu_notifier);
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
cpufreq_driver = NULL;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
|