but the old version has been kept around for easier testing. Note this
doesn't impact the old P5 and WinChip machine check handlers.
Who: Andi Kleen <andi@firstfloor.org>
+
+----------------------------
+
+What: lock_policy_rwsem_* and unlock_policy_rwsem_* will not be
+ exported interface anymore.
+When: 2.6.33
+Why: cpu_policy_rwsem has a new cleaner definition making it local to
+ cpufreq core and contained inside cpufreq.c. Other dependent
+ drivers should not use it in order to safely avoid lockdep issues.
+Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
static int transition_fid_vid(struct powernow_k8_data *data,
u32 reqfid, u32 reqvid)
{
- if (core_voltage_pre_transition(data, reqvid))
+ if (core_voltage_pre_transition(data, reqvid, reqfid))
return 1;
if (core_frequency_transition(data, reqfid))
/* Phase 1 - core voltage transition ... setup voltage */
static int core_voltage_pre_transition(struct powernow_k8_data *data,
- u32 reqvid)
+ u32 reqvid, u32 reqfid)
{
u32 rvosteps = data->rvo;
u32 savefid = data->currfid;
- u32 maxvid, lo;
+ u32 maxvid, lo, rvomult = 1;
dprintk("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, "
"reqvid 0x%x, rvo 0x%x\n",
smp_processor_id(),
data->currfid, data->currvid, reqvid, data->rvo);
+ if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
+ rvomult = 2;
+ rvosteps *= rvomult;
rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
maxvid = 0x1f & (maxvid >> 16);
dprintk("ph1 maxvid=0x%x\n", maxvid);
return 1;
}
- while ((rvosteps > 0) && ((data->rvo + data->currvid) > reqvid)) {
+ while ((rvosteps > 0) &&
+ ((rvomult * data->rvo + data->currvid) > reqvid)) {
if (data->currvid == maxvid) {
rvosteps = 0;
} else {
u32 vcoreqfid, vcocurrfid, vcofiddiff;
u32 fid_interval, savevid = data->currvid;
- if ((reqfid < HI_FID_TABLE_BOTTOM) &&
- (data->currfid < HI_FID_TABLE_BOTTOM)) {
- printk(KERN_ERR PFX "ph2: illegal lo-lo transition "
- "0x%x 0x%x\n", reqfid, data->currfid);
- return 1;
- }
-
if (data->currfid == reqfid) {
printk(KERN_ERR PFX "ph2 null fid transition 0x%x\n",
data->currfid);
vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
: vcoreqfid - vcocurrfid;
+ if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
+ vcofiddiff = 0;
+
while (vcofiddiff > 2) {
(data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
return 0;
}
- if ((fid < HI_FID_TABLE_BOTTOM) &&
- (data->currfid < HI_FID_TABLE_BOTTOM)) {
- printk(KERN_ERR PFX
- "ignoring illegal change in lo freq table-%x to 0x%x\n",
- data->currfid, fid);
- return 1;
- }
-
dprintk("cpu %d, changing to fid 0x%x, vid 0x%x\n",
smp_processor_id(), fid, vid);
freqs.old = find_khz_freq_from_fid(data->currfid);
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "powernow-k8", msg)
-static int core_voltage_pre_transition(struct powernow_k8_data *data, u32 reqvid);
+static int core_voltage_pre_transition(struct powernow_k8_data *data,
+ u32 reqvid, u32 regfid);
static int core_voltage_post_transition(struct powernow_k8_data *data, u32 reqvid);
static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid);
* cpufreq_add_dev - add a CPU device
*
* Adds the cpufreq interface for a CPU device.
+ *
+ * The Oracle says: try running cpufreq registration/unregistration concurrently
+ * with with cpu hotplugging and all hell will break loose. Tried to clean this
+ * mess up, but more thorough testing is needed. - Mathieu
*/
static int cpufreq_add_dev(struct sys_device *sys_dev)
{
goto nomem_out;
}
if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) {
- kfree(policy);
ret = -ENOMEM;
- goto nomem_out;
+ goto err_free_policy;
}
if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) {
- free_cpumask_var(policy->cpus);
- kfree(policy);
ret = -ENOMEM;
- goto nomem_out;
+ goto err_free_cpumask;
}
policy->cpu = cpu;
/* Initially set CPU itself as the policy_cpu */
per_cpu(policy_cpu, cpu) = cpu;
- lock_policy_rwsem_write(cpu);
+ ret = (lock_policy_rwsem_write(cpu) < 0);
+ WARN_ON(ret);
init_completion(&policy->kobj_unregister);
INIT_WORK(&policy->update, handle_update);
ret = cpufreq_driver->init(policy);
if (ret) {
dprintk("initialization failed\n");
- goto err_out;
+ goto err_unlock_policy;
}
policy->user_policy.min = policy->min;
policy->user_policy.max = policy->max;
/* Check for existing affected CPUs.
* They may not be aware of it due to CPU Hotplug.
*/
- managed_policy = cpufreq_cpu_get(j); /* FIXME: Where is this released? What about error paths? */
+ managed_policy = cpufreq_cpu_get(j);
if (unlikely(managed_policy)) {
/* Set proper policy_cpu */
unlock_policy_rwsem_write(cpu);
per_cpu(policy_cpu, cpu) = managed_policy->cpu;
- if (lock_policy_rwsem_write(cpu) < 0)
- goto err_out_driver_exit;
+ if (lock_policy_rwsem_write(cpu) < 0) {
+ /* Should not go through policy unlock path */
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(policy);
+ ret = -EBUSY;
+ cpufreq_cpu_put(managed_policy);
+ goto err_free_cpumask;
+ }
spin_lock_irqsave(&cpufreq_driver_lock, flags);
cpumask_copy(managed_policy->cpus, policy->cpus);
ret = sysfs_create_link(&sys_dev->kobj,
&managed_policy->kobj,
"cpufreq");
- if (ret)
- goto err_out_driver_exit;
-
- cpufreq_debug_enable_ratelimit();
- ret = 0;
- goto err_out_driver_exit; /* call driver->exit() */
+ if (!ret)
+ cpufreq_cpu_put(managed_policy);
+ /*
+ * Success. We only needed to be added to the mask.
+ * Call driver->exit() because only the cpu parent of
+ * the kobj needed to call init().
+ */
+ goto out_driver_exit; /* call driver->exit() */
}
}
#endif
ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj,
"cpufreq");
if (ret)
- goto err_out_driver_exit;
+ goto out_driver_exit;
/* set up files for this cpu device */
drv_attr = cpufreq_driver->attr;
while ((drv_attr) && (*drv_attr)) {
ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
if (ret)
- goto err_out_driver_exit;
+ goto err_out_kobj_put;
drv_attr++;
}
if (cpufreq_driver->get) {
ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
if (ret)
- goto err_out_driver_exit;
+ goto err_out_kobj_put;
}
if (cpufreq_driver->target) {
ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
if (ret)
- goto err_out_driver_exit;
+ goto err_out_kobj_put;
}
spin_lock_irqsave(&cpufreq_driver_lock, flags);
continue;
dprintk("CPU %u already managed, adding link\n", j);
- cpufreq_cpu_get(cpu);
+ managed_policy = cpufreq_cpu_get(cpu);
cpu_sys_dev = get_cpu_sysdev(j);
ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
"cpufreq");
- if (ret)
+ if (ret) {
+ cpufreq_cpu_put(managed_policy);
goto err_out_unregister;
+ }
}
policy->governor = NULL; /* to assure that the starting sequence is
per_cpu(cpufreq_cpu_data, j) = NULL;
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+err_out_kobj_put:
kobject_put(&policy->kobj);
wait_for_completion(&policy->kobj_unregister);
-err_out_driver_exit:
+out_driver_exit:
if (cpufreq_driver->exit)
cpufreq_driver->exit(policy);
-err_out:
+err_unlock_policy:
unlock_policy_rwsem_write(cpu);
+err_free_cpumask:
+ free_cpumask_var(policy->cpus);
+err_free_policy:
kfree(policy);
-
nomem_out:
module_put(cpufreq_driver->owner);
module_out:
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
#endif
- unlock_policy_rwsem_write(cpu);
-
if (cpufreq_driver->target)
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
if (cpufreq_driver->exit)
cpufreq_driver->exit(data);
+ unlock_policy_rwsem_write(cpu);
+
free_cpumask_var(data->related_cpus);
free_cpumask_var(data->cpus);
kfree(data);
unsigned int down_skip;
unsigned int requested_freq;
int cpu;
- unsigned int enable:1;
+ /*
+ * percpu mutex that serializes governor limit change with
+ * do_dbs_timer invocation. We do not want do_dbs_timer to run
+ * when user is changing the governor or limits.
+ */
+ struct mutex timer_mutex;
};
static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
static unsigned int dbs_enable; /* number of CPUs using this policy */
/*
- * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug
- * lock and dbs_mutex. cpu_hotplug lock should always be held before
- * dbs_mutex. If any function that can potentially take cpu_hotplug lock
- * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then
- * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
- * is recursive for the same process. -Venki
- * DEADLOCK ALERT! (2) : do_dbs_timer() must not take the dbs_mutex, because it
- * would deadlock with cancel_delayed_work_sync(), which is needed for proper
- * raceless workqueue teardown.
+ * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on
+ * different CPUs. It protects dbs_enable in governor start/stop.
*/
static DEFINE_MUTEX(dbs_mutex);
struct cpufreq_policy *policy;
- if (!this_dbs_info->enable)
- return 0;
-
policy = this_dbs_info->cur_policy;
/*
delay -= jiffies % delay;
- if (lock_policy_rwsem_write(cpu) < 0)
- return;
-
- if (!dbs_info->enable) {
- unlock_policy_rwsem_write(cpu);
- return;
- }
+ mutex_lock(&dbs_info->timer_mutex);
dbs_check_cpu(dbs_info);
queue_delayed_work_on(cpu, kconservative_wq, &dbs_info->work, delay);
- unlock_policy_rwsem_write(cpu);
+ mutex_unlock(&dbs_info->timer_mutex);
}
static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
delay -= jiffies % delay;
- dbs_info->enable = 1;
INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer);
queue_delayed_work_on(dbs_info->cpu, kconservative_wq, &dbs_info->work,
delay);
static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
{
- dbs_info->enable = 0;
cancel_delayed_work_sync(&dbs_info->work);
}
if ((!cpu_online(cpu)) || (!policy->cur))
return -EINVAL;
- if (this_dbs_info->enable) /* Already enabled */
- break;
-
mutex_lock(&dbs_mutex);
rc = sysfs_create_group(&policy->kobj, &dbs_attr_group);
this_dbs_info->down_skip = 0;
this_dbs_info->requested_freq = policy->cur;
+ mutex_init(&this_dbs_info->timer_mutex);
dbs_enable++;
/*
* Start the timerschedule work, when this governor
&dbs_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}
- dbs_timer_init(this_dbs_info);
-
mutex_unlock(&dbs_mutex);
+ dbs_timer_init(this_dbs_info);
+
break;
case CPUFREQ_GOV_STOP:
- mutex_lock(&dbs_mutex);
dbs_timer_exit(this_dbs_info);
+
+ mutex_lock(&dbs_mutex);
sysfs_remove_group(&policy->kobj, &dbs_attr_group);
dbs_enable--;
+ mutex_destroy(&this_dbs_info->timer_mutex);
/*
* Stop the timerschedule work, when this governor
break;
case CPUFREQ_GOV_LIMITS:
- mutex_lock(&dbs_mutex);
+ mutex_lock(&this_dbs_info->timer_mutex);
if (policy->max < this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(
this_dbs_info->cur_policy,
__cpufreq_driver_target(
this_dbs_info->cur_policy,
policy->min, CPUFREQ_RELATION_L);
- mutex_unlock(&dbs_mutex);
+ mutex_unlock(&this_dbs_info->timer_mutex);
break;
}
unsigned int freq_lo_jiffies;
unsigned int freq_hi_jiffies;
int cpu;
- unsigned int enable:1,
- sample_type:1;
+ unsigned int sample_type:1;
+ /*
+ * percpu mutex that serializes governor limit change with
+ * do_dbs_timer invocation. We do not want do_dbs_timer to run
+ * when user is changing the governor or limits.
+ */
+ struct mutex timer_mutex;
};
static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
static unsigned int dbs_enable; /* number of CPUs using this policy */
/*
- * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug
- * lock and dbs_mutex. cpu_hotplug lock should always be held before
- * dbs_mutex. If any function that can potentially take cpu_hotplug lock
- * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then
- * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
- * is recursive for the same process. -Venki
- * DEADLOCK ALERT! (2) : do_dbs_timer() must not take the dbs_mutex, because it
- * would deadlock with cancel_delayed_work_sync(), which is needed for proper
- * raceless workqueue teardown.
+ * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on
+ * different CPUs. It protects dbs_enable in governor start/stop.
*/
static DEFINE_MUTEX(dbs_mutex);
return freq_hi;
}
+static void ondemand_powersave_bias_init_cpu(int cpu)
+{
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
+ dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
+ dbs_info->freq_lo = 0;
+}
+
static void ondemand_powersave_bias_init(void)
{
int i;
for_each_online_cpu(i) {
- struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, i);
- dbs_info->freq_table = cpufreq_frequency_get_table(i);
- dbs_info->freq_lo = 0;
+ ondemand_powersave_bias_init_cpu(i);
}
}
unsigned int input;
int ret;
ret = sscanf(buf, "%u", &input);
+ if (ret != 1)
+ return -EINVAL;
mutex_lock(&dbs_mutex);
- if (ret != 1) {
- mutex_unlock(&dbs_mutex);
- return -EINVAL;
- }
dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
mutex_unlock(&dbs_mutex);
int ret;
ret = sscanf(buf, "%u", &input);
- mutex_lock(&dbs_mutex);
if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
input < MIN_FREQUENCY_UP_THRESHOLD) {
- mutex_unlock(&dbs_mutex);
return -EINVAL;
}
+ mutex_lock(&dbs_mutex);
dbs_tuners_ins.up_threshold = input;
mutex_unlock(&dbs_mutex);
struct cpufreq_policy *policy;
unsigned int j;
- if (!this_dbs_info->enable)
- return;
-
this_dbs_info->freq_lo = 0;
policy = this_dbs_info->cur_policy;
int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
delay -= jiffies % delay;
-
- if (lock_policy_rwsem_write(cpu) < 0)
- return;
-
- if (!dbs_info->enable) {
- unlock_policy_rwsem_write(cpu);
- return;
- }
+ mutex_lock(&dbs_info->timer_mutex);
/* Common NORMAL_SAMPLE setup */
dbs_info->sample_type = DBS_NORMAL_SAMPLE;
dbs_info->freq_lo, CPUFREQ_RELATION_H);
}
queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay);
- unlock_policy_rwsem_write(cpu);
+ mutex_unlock(&dbs_info->timer_mutex);
}
static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
delay -= jiffies % delay;
- dbs_info->enable = 1;
- ondemand_powersave_bias_init();
dbs_info->sample_type = DBS_NORMAL_SAMPLE;
INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer);
queue_delayed_work_on(dbs_info->cpu, kondemand_wq, &dbs_info->work,
static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
{
- dbs_info->enable = 0;
cancel_delayed_work_sync(&dbs_info->work);
}
if ((!cpu_online(cpu)) || (!policy->cur))
return -EINVAL;
- if (this_dbs_info->enable) /* Already enabled */
- break;
-
mutex_lock(&dbs_mutex);
- dbs_enable++;
rc = sysfs_create_group(&policy->kobj, &dbs_attr_group);
if (rc) {
- dbs_enable--;
mutex_unlock(&dbs_mutex);
return rc;
}
+ dbs_enable++;
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(cpu_dbs_info, j);
}
}
this_dbs_info->cpu = cpu;
+ ondemand_powersave_bias_init_cpu(cpu);
+ mutex_init(&this_dbs_info->timer_mutex);
/*
* Start the timerschedule work, when this governor
* is used for first time
max(min_sampling_rate,
latency * LATENCY_MULTIPLIER);
}
- dbs_timer_init(this_dbs_info);
-
mutex_unlock(&dbs_mutex);
+
+ dbs_timer_init(this_dbs_info);
break;
case CPUFREQ_GOV_STOP:
- mutex_lock(&dbs_mutex);
dbs_timer_exit(this_dbs_info);
+
+ mutex_lock(&dbs_mutex);
sysfs_remove_group(&policy->kobj, &dbs_attr_group);
+ mutex_destroy(&this_dbs_info->timer_mutex);
dbs_enable--;
mutex_unlock(&dbs_mutex);
break;
case CPUFREQ_GOV_LIMITS:
- mutex_lock(&dbs_mutex);
+ mutex_lock(&this_dbs_info->timer_mutex);
if (policy->max < this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(this_dbs_info->cur_policy,
policy->max, CPUFREQ_RELATION_H);
else if (policy->min > this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(this_dbs_info->cur_policy,
policy->min, CPUFREQ_RELATION_L);
- mutex_unlock(&dbs_mutex);
+ mutex_unlock(&this_dbs_info->timer_mutex);
break;
}
return 0;