[Patch 1/2] cpufreq: unexport (un)lock_policy_rwsem* functions
Amerigo Wang
lock_policy_rwsem_* and unlock_policy_rwsem_* functions are scheduled
to be unexported when 2.6.33. Now there are no other callers of them
out of cpufreq.c, unexport them and make them static.
Signed-off-by: WANG Cong <amw...@redhat.com>
Cc: Venkatesh Pallipadi <venkatesh...@intel.com>
Cc: Dave Jones <da...@redhat.com>
---
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 73ef30d..13b338f 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -381,16 +381,6 @@ Who: Eric Paris <epa...@redhat.com>
----------------------------
-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...@intel.com>
-
-----------------------------
-
What: sound-slot/service-* module aliases and related clutters in
sound/sound_core.c
When: August 2010
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 67bc2ec..4de1e5f 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -68,7 +68,7 @@ static DEFINE_PER_CPU(int, cpufreq_policy_cpu);
static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem);
#define lock_policy_rwsem(mode, cpu) \
-int lock_policy_rwsem_##mode \
+static int lock_policy_rwsem_##mode \
(int cpu) \
{ \
int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \
@@ -83,26 +83,22 @@ int lock_policy_rwsem_##mode \
}
lock_policy_rwsem(read, cpu);
-EXPORT_SYMBOL_GPL(lock_policy_rwsem_read);
lock_policy_rwsem(write, cpu);
-EXPORT_SYMBOL_GPL(lock_policy_rwsem_write);
-void unlock_policy_rwsem_read(int cpu)
+static void unlock_policy_rwsem_read(int cpu)
{
int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);
BUG_ON(policy_cpu == -1);
up_read(&per_cpu(cpu_policy_rwsem, policy_cpu));
}
-EXPORT_SYMBOL_GPL(unlock_policy_rwsem_read);
-void unlock_policy_rwsem_write(int cpu)
+static void unlock_policy_rwsem_write(int cpu)
{
int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);
BUG_ON(policy_cpu == -1);
up_write(&per_cpu(cpu_policy_rwsem, policy_cpu));
}
-EXPORT_SYMBOL_GPL(unlock_policy_rwsem_write);
/* internal prototypes */
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 4de02b1..7a4a5ff 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -196,11 +196,6 @@ extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
int cpufreq_register_governor(struct cpufreq_governor *governor);
void cpufreq_unregister_governor(struct cpufreq_governor *governor);
-int lock_policy_rwsem_read(int cpu);
-int lock_policy_rwsem_write(int cpu);
-void unlock_policy_rwsem_read(int cpu);
-void unlock_policy_rwsem_write(int cpu);
-
/*********************************************************************
* CPUFREQ DRIVER INTERFACE *
--
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Amerigo Wang
There is no need to do sysfs_remove_link() or kobject_put() etc.
when policy_rwsem_write is held, move them after releasing the lock.
This fixes the lockdep warning:
halt/4071 is trying to acquire lock:
(s_active){++++.+}, at: [<c0000000001ef868>] .sysfs_addrm_finish+0x58/0xc0
but task is already holding lock:
(&per_cpu(cpu_policy_rwsem, cpu)){+.+.+.}, at: [<c0000000004cd6ac>] .lock_policy_rwsem_write+0x84/0xf4
Reported-by: Benjamin Herrenschmidt <be...@kernel.crashing.org>
Signed-off-by: WANG Cong <amw...@redhat.com>
Cc: Johannes Berg <joha...@sipsolutions.net>
Cc: Venkatesh Pallipadi <venkatesh...@intel.com>
Cc: Dave Jones <da...@redhat.com>
---
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 67bc2ec..e196084 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1113,6 +1113,8 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev)
unsigned int cpu = sys_dev->id;
unsigned long flags;
struct cpufreq_policy *data;
+ struct kobject *kobj;
+ struct completion *cmp;
#ifdef CONFIG_SMP
struct sys_device *cpu_sys_dev;
unsigned int j;
@@ -1141,10 +1143,11 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev)
dprintk("removing link\n");
cpumask_clear_cpu(cpu, data->cpus);
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
- sysfs_remove_link(&sys_dev->kobj, "cpufreq");
+ kobj = &sys_dev->kobj;
cpufreq_cpu_put(data);
cpufreq_debug_enable_ratelimit();
unlock_policy_rwsem_write(cpu);
+ sysfs_remove_link(kobj, "cpufreq");
return 0;
}
#endif
@@ -1181,7 +1184,10 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev)
data->governor->name, CPUFREQ_NAME_LEN);
#endif
cpu_sys_dev = get_cpu_sysdev(j);
- sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq");
+ kobj = &cpu_sys_dev->kobj;
+ unlock_policy_rwsem_write(cpu);
+ sysfs_remove_link(kobj, "cpufreq");
+ lock_policy_rwsem_write(cpu);
cpufreq_cpu_put(data);
}
}
@@ -1192,19 +1198,22 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev)
if (cpufreq_driver->target)
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
- kobject_put(&data->kobj);
+ kobj = &data->kobj;
+ cmp = &data->kobj_unregister;
+ unlock_policy_rwsem_write(cpu);
+ kobject_put(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);
+ wait_for_completion(cmp);
dprintk("wait complete\n");
+ lock_policy_rwsem_write(cpu);
if (cpufreq_driver->exit)
cpufreq_driver->exit(data);
-
unlock_policy_rwsem_write(cpu);
free_cpumask_var(data->related_cpus);