diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 130 |
1 files changed, 74 insertions, 56 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 0128de3603df..02ab56b2a0d8 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -50,7 +50,9 @@ static LIST_HEAD(cpufreq_governor_list); #define for_each_governor(__governor) \ list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) -/** +static char default_governor[CPUFREQ_NAME_LEN]; + +/* * The "cpufreq driver" - the arch- or hardware-dependent low * level driver of CPUFreq support, and its spinlock. This lock * also protects the cpufreq_cpu_data array. @@ -71,14 +73,12 @@ static inline bool has_target(void) static unsigned int __cpufreq_get(struct cpufreq_policy *policy); static int cpufreq_init_governor(struct cpufreq_policy *policy); static void cpufreq_exit_governor(struct cpufreq_policy *policy); -static int cpufreq_start_governor(struct cpufreq_policy *policy); -static void cpufreq_stop_governor(struct cpufreq_policy *policy); static void cpufreq_governor_limits(struct cpufreq_policy *policy); static int cpufreq_set_policy(struct cpufreq_policy *policy, struct cpufreq_governor *new_gov, unsigned int new_pol); -/** +/* * Two notifier lists: the "policy" list is involved in the * validation process for a new CPU frequency policy; the * "transition" list for kernel code that needs to handle @@ -298,7 +298,7 @@ struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu) * EXTERNALLY AFFECTING FREQUENCY CHANGES * *********************************************************************/ -/** +/* * adjust_jiffies - adjust the system "loops_per_jiffy" * * This function alters the system "loops_per_jiffy" for the clock @@ -524,6 +524,7 @@ EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); /** * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported * one. + * @policy: associated policy to interrogate * @target_freq: target frequency to resolve. * * The target to driver frequency mapping is cached in the policy. @@ -538,7 +539,7 @@ unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, policy->cached_target_freq = target_freq; if (cpufreq_driver->target_index) { - int idx; + unsigned int idx; idx = cpufreq_frequency_table_target(policy, target_freq, CPUFREQ_RELATION_L); @@ -621,6 +622,24 @@ static struct cpufreq_governor *find_governor(const char *str_governor) return NULL; } +static struct cpufreq_governor *get_governor(const char *str_governor) +{ + struct cpufreq_governor *t; + + mutex_lock(&cpufreq_governor_mutex); + t = find_governor(str_governor); + if (!t) + goto unlock; + + if (!try_module_get(t->owner)) + t = NULL; + +unlock: + mutex_unlock(&cpufreq_governor_mutex); + + return t; +} + static unsigned int cpufreq_parse_policy(char *str_governor) { if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) @@ -640,31 +659,17 @@ static struct cpufreq_governor *cpufreq_parse_governor(char *str_governor) { struct cpufreq_governor *t; - mutex_lock(&cpufreq_governor_mutex); - - t = find_governor(str_governor); - if (!t) { - int ret; - - mutex_unlock(&cpufreq_governor_mutex); - - ret = request_module("cpufreq_%s", str_governor); - if (ret) - return NULL; + t = get_governor(str_governor); + if (t) + return t; - mutex_lock(&cpufreq_governor_mutex); - - t = find_governor(str_governor); - } - if (t && !try_module_get(t->owner)) - t = NULL; - - mutex_unlock(&cpufreq_governor_mutex); + if (request_module("cpufreq_%s", str_governor)) + return NULL; - return t; + return get_governor(str_governor); } -/** +/* * cpufreq_per_cpu_attr_read() / show_##file_name() - * print out cpufreq information * @@ -706,7 +711,7 @@ static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) return ret; } -/** +/* * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access */ #define store_one(file_name, object) \ @@ -727,7 +732,7 @@ static ssize_t store_##file_name \ store_one(scaling_min_freq, min); store_one(scaling_max_freq, max); -/** +/* * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware */ static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, @@ -741,7 +746,7 @@ static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, return sprintf(buf, "<unknown>\n"); } -/** +/* * show_scaling_governor - show the current policy for the specified CPU */ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) @@ -756,7 +761,7 @@ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) return -EINVAL; } -/** +/* * store_scaling_governor - store policy for the specified CPU */ static ssize_t store_scaling_governor(struct cpufreq_policy *policy, @@ -793,7 +798,7 @@ static ssize_t store_scaling_governor(struct cpufreq_policy *policy, return ret ? ret : count; } -/** +/* * show_scaling_driver - show the cpufreq driver currently loaded */ static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) @@ -801,7 +806,7 @@ static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); } -/** +/* * show_scaling_available_governors - show the available CPUfreq governors */ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, @@ -815,12 +820,14 @@ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, goto out; } + mutex_lock(&cpufreq_governor_mutex); for_each_governor(t) { if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) - goto out; + break; i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); } + mutex_unlock(&cpufreq_governor_mutex); out: i += sprintf(&buf[i], "\n"); return i; @@ -843,7 +850,7 @@ ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) } EXPORT_SYMBOL_GPL(cpufreq_show_cpus); -/** +/* * show_related_cpus - show the CPUs affected by each transition even if * hw coordination is in use */ @@ -852,7 +859,7 @@ static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) return cpufreq_show_cpus(policy->related_cpus, buf); } -/** +/* * show_affected_cpus - show the CPUs affected by each transition */ static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) @@ -886,7 +893,7 @@ static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) return policy->governor->show_setspeed(policy, buf); } -/** +/* * show_bios_limit - show the current cpufreq HW/BIOS limitation */ static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) @@ -1048,36 +1055,36 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) return 0; } -__weak struct cpufreq_governor *cpufreq_default_governor(void) -{ - return NULL; -} - static int cpufreq_init_policy(struct cpufreq_policy *policy) { - struct cpufreq_governor *def_gov = cpufreq_default_governor(); struct cpufreq_governor *gov = NULL; unsigned int pol = CPUFREQ_POLICY_UNKNOWN; + int ret; if (has_target()) { /* Update policy governor to the one used before hotplug. */ - gov = find_governor(policy->last_governor); + gov = get_governor(policy->last_governor); if (gov) { pr_debug("Restoring governor %s for cpu %d\n", - policy->governor->name, policy->cpu); - } else if (def_gov) { - gov = def_gov; + gov->name, policy->cpu); } else { - return -ENODATA; + gov = get_governor(default_governor); + } + + if (!gov) { + gov = cpufreq_default_governor(); + __module_get(gov->owner); } + } else { + /* Use the default policy if there is no last_policy. */ if (policy->last_policy) { pol = policy->last_policy; - } else if (def_gov) { - pol = cpufreq_parse_policy(def_gov->name); + } else { + pol = cpufreq_parse_policy(default_governor); /* - * In case the default governor is neiter "performance" + * In case the default governor is neither "performance" * nor "powersave", fall back to the initial policy * value set by the driver. */ @@ -1089,7 +1096,11 @@ static int cpufreq_init_policy(struct cpufreq_policy *policy) return -ENODATA; } - return cpufreq_set_policy(policy, gov, pol); + ret = cpufreq_set_policy(policy, gov, pol); + if (gov) + module_put(gov->owner); + + return ret; } static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) @@ -1604,7 +1615,7 @@ unlock: return 0; } -/** +/* * cpufreq_remove_dev - remove a CPU device * * Removes the cpufreq interface for a CPU device. @@ -2253,7 +2264,7 @@ static void cpufreq_exit_governor(struct cpufreq_policy *policy) module_put(policy->governor->owner); } -static int cpufreq_start_governor(struct cpufreq_policy *policy) +int cpufreq_start_governor(struct cpufreq_policy *policy) { int ret; @@ -2280,7 +2291,7 @@ static int cpufreq_start_governor(struct cpufreq_policy *policy) return 0; } -static void cpufreq_stop_governor(struct cpufreq_policy *policy) +void cpufreq_stop_governor(struct cpufreq_policy *policy) { if (cpufreq_suspended || !policy->governor) return; @@ -2361,6 +2372,7 @@ EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); * cpufreq_get_policy - get the current cpufreq_policy * @policy: struct cpufreq_policy into which the current cpufreq_policy * is written + * @cpu: CPU to find the policy for * * Reads the current cpufreq policy. */ @@ -2747,7 +2759,7 @@ out: } 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 @@ -2783,13 +2795,19 @@ EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); static int __init cpufreq_core_init(void) { + struct cpufreq_governor *gov = cpufreq_default_governor(); + if (cpufreq_disabled()) return -ENODEV; cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); BUG_ON(!cpufreq_global_kobject); + if (!strlen(default_governor)) + strncpy(default_governor, gov->name, CPUFREQ_NAME_LEN); + return 0; } module_param(off, int, 0444); +module_param_string(default_governor, default_governor, CPUFREQ_NAME_LEN, 0444); core_initcall(cpufreq_core_init); |