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/*
* padata.c - generic interface to process data streams in parallel
*
* Copyright (C) 2008, 2009 secunet Security Networks AG
* Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/export.h>
#include <linux/cpumask.h>
#include <linux/err.h>
#include <linux/cpu.h>
#include <linux/padata.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/rcupdate.h>
#define MAX_SEQ_NR (INT_MAX - NR_CPUS)
#define MAX_OBJ_NUM 1000
static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
{
int cpu, target_cpu;
target_cpu = cpumask_first(pd->cpumask.pcpu);
for (cpu = 0; cpu < cpu_index; cpu++)
target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu);
return target_cpu;
}
static int padata_cpu_hash(struct padata_priv *padata)
{
int cpu_index;
struct parallel_data *pd;
pd = padata->pd;
/*
* Hash the sequence numbers to the cpus by taking
* seq_nr mod. number of cpus in use.
*/
cpu_index = padata->seq_nr % cpumask_weight(pd->cpumask.pcpu);
return padata_index_to_cpu(pd, cpu_index);
}
static void padata_parallel_worker(struct work_struct *parallel_work)
{
struct padata_parallel_queue *pqueue;
struct parallel_data *pd;
struct padata_instance *pinst;
LIST_HEAD(local_list);
local_bh_disable();
pqueue = container_of(parallel_work,
struct padata_parallel_queue, work);
pd = pqueue->pd;
pinst = pd->pinst;
spin_lock(&pqueue->parallel.lock);
list_replace_init(&pqueue->parallel.list, &local_list);
spin_unlock(&pqueue->parallel.lock);
while (!list_empty(&local_list)) {
struct padata_priv *padata;
padata = list_entry(local_list.next,
struct padata_priv, list);
list_del_init(&padata->list);
padata->parallel(padata);
}
local_bh_enable();
}
/**
* padata_do_parallel - padata parallelization function
*
* @pinst: padata instance
* @padata: object to be parallelized
* @cb_cpu: cpu the serialization callback function will run on,
* must be in the serial cpumask of padata(i.e. cpumask.cbcpu).
*
* The parallelization callback function will run with BHs off.
* Note: Every object which is parallelized by padata_do_parallel
* must be seen by padata_do_serial.
*/
int padata_do_parallel(struct padata_instance *pinst,
struct padata_priv *padata, int cb_cpu)
{
int target_cpu, err;
struct padata_parallel_queue *queue;
struct parallel_data *pd;
rcu_read_lock_bh();
pd = rcu_dereference(pinst->pd);
err = -EINVAL;
if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID)
goto out;
if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu))
goto out;
err = -EBUSY;
if ((pinst->flags & PADATA_RESET))
goto out;
if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
goto out;
err = 0;
atomic_inc(&pd->refcnt);
padata->pd = pd;
padata->cb_cpu = cb_cpu;
if (unlikely(atomic_read(&pd->seq_nr) == pd->max_seq_nr))
atomic_set(&pd->seq_nr, -1);
padata->seq_nr = atomic_inc_return(&pd->seq_nr);
target_cpu = padata_cpu_hash(padata);
queue = per_cpu_ptr(pd->pqueue, target_cpu);
spin_lock(&queue->parallel.lock);
list_add_tail(&padata->list, &queue->parallel.list);
spin_unlock(&queue->parallel.lock);
queue_work_on(target_cpu, pinst->wq, &queue->work);
out:
rcu_read_unlock_bh();
return err;
}
EXPORT_SYMBOL(padata_do_parallel);
/*
* padata_get_next - Get the next object that needs serialization.
*
* Return values are:
*
* A pointer to the control struct of the next object that needs
* serialization, if present in one of the percpu reorder queues.
*
* NULL, if all percpu reorder queues are empty.
*
* -EINPROGRESS, if the next object that needs serialization will
* be parallel processed by another cpu and is not yet present in
* the cpu's reorder queue.
*
* -ENODATA, if this cpu has to do the parallel processing for
* the next object.
*/
static struct padata_priv *padata_get_next(struct parallel_data *pd)
{
int cpu, num_cpus;
int next_nr, next_index;
struct padata_parallel_queue *queue, *next_queue;
struct padata_priv *padata;
struct padata_list *reorder;
num_cpus = cpumask_weight(pd->cpumask.pcpu);
/*
* Calculate the percpu reorder queue and the sequence
* number of the next object.
*/
next_nr = pd->processed;
next_index = next_nr % num_cpus;
cpu = padata_index_to_cpu(pd, next_index);
next_queue = per_cpu_ptr(pd->pqueue, cpu);
if (unlikely(next_nr > pd->max_seq_nr)) {
next_nr = next_nr - pd->max_seq_nr - 1;
next_index = next_nr % num_cpus;
cpu = padata_index_to_cpu(pd, next_index);
next_queue = per_cpu_ptr(pd->pqueue, cpu);
pd->processed = 0;
}
padata = NULL;
reorder = &next_queue->reorder;
if (!list_empty(&reorder->list)) {
padata = list_entry(reorder->list.next,
struct padata_priv, list);
BUG_ON(next_nr != padata->seq_nr);
spin_lock(&reorder->lock);
list_del_init(&padata->list);
atomic_dec(&pd->reorder_objects);
spin_unlock(&reorder->lock);
pd->processed++;
goto out;
}
queue = per_cpu_ptr(pd->pqueue, smp_processor_id());
if (queue->cpu_index == next_queue->cpu_index) {
padata = ERR_PTR(-ENODATA);
goto out;
}
padata = ERR_PTR(-EINPROGRESS);
out:
return padata;
}
static void padata_reorder(struct parallel_data *pd)
{
struct padata_priv *padata;
struct padata_serial_queue *squeue;
struct padata_instance *pinst = pd->pinst;
/*
* We need to ensure that only one cpu can work on dequeueing of
* the reorder queue the time. Calculating in which percpu reorder
* queue the next object will arrive takes some time. A spinlock
* would be highly contended. Also it is not clear in which order
* the objects arrive to the reorder queues. So a cpu could wait to
* get the lock just to notice that there is nothing to do at the
* moment. Therefore we use a trylock and let the holder of the lock
* care for all the objects enqueued during the holdtime of the lock.
*/
if (!spin_trylock_bh(&pd->lock))
return;
while (1) {
padata = padata_get_next(pd);
/*
* All reorder queues are empty, or the next object that needs
* serialization is parallel processed by another cpu and is
* still on it's way to the cpu's reorder queue, nothing to
* do for now.
*/
if (!padata || PTR_ERR(padata) == -EINPROGRESS)
break;
/*
* This cpu has to do the parallel processing of the next
* object. It's waiting in the cpu's parallelization queue,
* so exit immediately.
*/
if (PTR_ERR(padata) == -ENODATA) {
del_timer(&pd->timer);
spin_unlock_bh(&pd->lock);
return;
}
squeue = per_cpu_ptr(pd->squeue, padata->cb_cpu);
spin_lock(&squeue->serial.lock);
list_add_tail(&padata->list, &squeue->serial.list);
spin_unlock(&squeue->serial.lock);
queue_work_on(padata->cb_cpu, pinst->wq, &squeue->work);
}
spin_unlock_bh(&pd->lock);
/*
* The next object that needs serialization might have arrived to
* the reorder queues in the meantime, we will be called again
* from the timer function if no one else cares for it.
*/
if (atomic_read(&pd->reorder_objects)
&& !(pinst->flags & PADATA_RESET))
mod_timer(&pd->timer, jiffies + HZ);
else
del_timer(&pd->timer);
return;
}
static void padata_reorder_timer(unsigned long arg)
{
struct parallel_data *pd = (struct parallel_data *)arg;
padata_reorder(pd);
}
static void padata_serial_worker(struct work_struct *serial_work)
{
struct padata_serial_queue *squeue;
struct parallel_data *pd;
LIST_HEAD(local_list);
local_bh_disable();
squeue = container_of(serial_work, struct padata_serial_queue, work);
pd = squeue->pd;
spin_lock(&squeue->serial.lock);
list_replace_init(&squeue->serial.list, &local_list);
spin_unlock(&squeue->serial.lock);
while (!list_empty(&local_list)) {
struct padata_priv *padata;
padata = list_entry(local_list.next,
struct padata_priv, list);
list_del_init(&padata->list);
padata->serial(padata);
atomic_dec(&pd->refcnt);
}
local_bh_enable();
}
/**
* padata_do_serial - padata serialization function
*
* @padata: object to be serialized.
*
* padata_do_serial must be called for every parallelized object.
* The serialization callback function will run with BHs off.
*/
void padata_do_serial(struct padata_priv *padata)
{
int cpu;
struct padata_parallel_queue *pqueue;
struct parallel_data *pd;
pd = padata->pd;
cpu = get_cpu();
pqueue = per_cpu_ptr(pd->pqueue, cpu);
spin_lock(&pqueue->reorder.lock);
atomic_inc(&pd->reorder_objects);
list_add_tail(&padata->list, &pqueue->reorder.list);
spin_unlock(&pqueue->reorder.lock);
put_cpu();
padata_reorder(pd);
}
EXPORT_SYMBOL(padata_do_serial);
static int padata_setup_cpumasks(struct parallel_data *pd,
const struct cpumask *pcpumask,
const struct cpumask *cbcpumask)
{
if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
return -ENOMEM;
cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_active_mask);
if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) {
free_cpumask_var(pd->cpumask.cbcpu);
return -ENOMEM;
}
cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_active_mask);
return 0;
}
static void __padata_list_init(struct padata_list *pd_list)
{
INIT_LIST_HEAD(&pd_list->list);
spin_lock_init(&pd_list->lock);
}
/* Initialize all percpu queues used by serial workers */
static void padata_init_squeues(struct parallel_data *pd)
{
int cpu;
struct padata_serial_queue *squeue;
for_each_cpu(cpu, pd->cpumask.cbcpu) {
squeue = per_cpu_ptr(pd->squeue, cpu);
squeue->pd = pd;
__padata_list_init(&squeue->serial);
INIT_WORK(&squeue->work, padata_serial_worker);
}
}
/* Initialize all percpu queues used by parallel workers */
static void padata_init_pqueues(struct parallel_data *pd)
{
int cpu_index, num_cpus, cpu;
struct padata_parallel_queue *pqueue;
cpu_index = 0;
for_each_cpu(cpu, pd->cpumask.pcpu) {
pqueue = per_cpu_ptr(pd->pqueue, cpu);
pqueue->pd = pd;
pqueue->cpu_index = cpu_index;
cpu_index++;
__padata_list_init(&pqueue->reorder);
__padata_list_init(&pqueue->parallel);
INIT_WORK(&pqueue->work, padata_parallel_worker);
atomic_set(&pqueue->num_obj, 0);
}
num_cpus = cpumask_weight(pd->cpumask.pcpu);
pd->max_seq_nr = num_cpus ? (MAX_SEQ_NR / num_cpus) * num_cpus - 1 : 0;
}
/* Allocate and initialize the internal cpumask dependend resources. */
static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst,
const struct cpumask *pcpumask,
const struct cpumask *cbcpumask)
{
struct parallel_data *pd;
pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
if (!pd)
goto err;
pd->pqueue = alloc_percpu(struct padata_parallel_queue);
if (!pd->pqueue)
goto err_free_pd;
pd->squeue = alloc_percpu(struct padata_serial_queue);
if (!pd->squeue)
goto err_free_pqueue;
if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0)
goto err_free_squeue;
padata_init_pqueues(pd);
padata_init_squeues(pd);
setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd);
atomic_set(&pd->seq_nr, -1);
atomic_set(&pd->reorder_objects, 0);
atomic_set(&pd->refcnt, 0);
pd->pinst = pinst;
spin_lock_init(&pd->lock);
return pd;
err_free_squeue:
free_percpu(pd->squeue);
err_free_pqueue:
free_percpu(pd->pqueue);
err_free_pd:
kfree(pd);
err:
return NULL;
}
static void padata_free_pd(struct parallel_data *pd)
{
free_cpumask_var(pd->cpumask.pcpu);
free_cpumask_var(pd->cpumask.cbcpu);
free_percpu(pd->pqueue);
free_percpu(pd->squeue);
kfree(pd);
}
/* Flush all objects out of the padata queues. */
static void padata_flush_queues(struct parallel_data *pd)
{
int cpu;
struct padata_parallel_queue *pqueue;
struct padata_serial_queue *squeue;
for_each_cpu(cpu, pd->cpumask.pcpu) {
pqueue = per_cpu_ptr(pd->pqueue, cpu);
flush_work(&pqueue->work);
}
del_timer_sync(&pd->timer);
if (atomic_read(&pd->reorder_objects))
padata_reorder(pd);
for_each_cpu(cpu, pd->cpumask.cbcpu) {
squeue = per_cpu_ptr(pd->squeue, cpu);
flush_work(&squeue->work);
}
BUG_ON(atomic_read(&pd->refcnt) != 0);
}
static void __padata_start(struct padata_instance *pinst)
{
pinst->flags |= PADATA_INIT;
}
static void __padata_stop(struct padata_instance *pinst)
{
if (!(pinst->flags & PADATA_INIT))
return;
pinst->flags &= ~PADATA_INIT;
synchronize_rcu();
get_online_cpus();
padata_flush_queues(pinst->pd);
put_online_cpus();
}
/* Replace the internal control structure with a new one. */
static void padata_replace(struct padata_instance *pinst,
struct parallel_data *pd_new)
{
struct parallel_data *pd_old = pinst->pd;
int notification_mask = 0;
pinst->flags |= PADATA_RESET;
rcu_assign_pointer(pinst->pd, pd_new);
synchronize_rcu();
if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu))
notification_mask |= PADATA_CPU_PARALLEL;
if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu))
notification_mask |= PADATA_CPU_SERIAL;
padata_flush_queues(pd_old);
padata_free_pd(pd_old);
if (notification_mask)
blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
notification_mask,
&pd_new->cpumask);
pinst->flags &= ~PADATA_RESET;
}
/**
* padata_register_cpumask_notifier - Registers a notifier that will be called
* if either pcpu or cbcpu or both cpumasks change.
*
* @pinst: A poineter to padata instance
* @nblock: A pointer to notifier block.
*/
int padata_register_cpumask_notifier(struct padata_instance *pinst,
struct notifier_block *nblock)
{
return blocking_notifier_chain_register(&pinst->cpumask_change_notifier,
nblock);
}
EXPORT_SYMBOL(padata_register_cpumask_notifier);
/**
* padata_unregister_cpumask_notifier - Unregisters cpumask notifier
* registered earlier using padata_register_cpumask_notifier
*
* @pinst: A pointer to data instance.
* @nlock: A pointer to notifier block.
*/
int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
struct notifier_block *nblock)
{
return blocking_notifier_chain_unregister(
&pinst->cpumask_change_notifier,
nblock);
}
EXPORT_SYMBOL(padata_unregister_cpumask_notifier);
/* If cpumask contains no active cpu, we mark the instance as invalid. */
static bool padata_validate_cpumask(struct padata_instance *pinst,
const struct cpumask *cpumask)
{
if (!cpumask_intersects(cpumask, cpu_active_mask)) {
pinst->flags |= PADATA_INVALID;
return false;
}
pinst->flags &= ~PADATA_INVALID;
return true;
}
static int __padata_set_cpumasks(struct padata_instance *pinst,
cpumask_var_t pcpumask,
cpumask_var_t cbcpumask)
{
int valid;
struct parallel_data *pd;
valid = padata_validate_cpumask(pinst, pcpumask);
if (!valid) {
__padata_stop(pinst);
goto out_replace;
}
valid = padata_validate_cpumask(pinst, cbcpumask);
if (!valid)
__padata_stop(pinst);
out_replace:
pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
if (!pd)
return -ENOMEM;
cpumask_copy(pinst->cpumask.pcpu, pcpumask);
cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
padata_replace(pinst, pd);
if (valid)
__padata_start(pinst);
return 0;
}
/**
* padata_set_cpumasks - Set both parallel and serial cpumasks. The first
* one is used by parallel workers and the second one
* by the wokers doing serialization.
*
* @pinst: padata instance
* @pcpumask: the cpumask to use for parallel workers
* @cbcpumask: the cpumsak to use for serial workers
*/
int padata_set_cpumasks(struct padata_instance *pinst, cpumask_var_t pcpumask,
cpumask_var_t cbcpumask)
{
int err;
mutex_lock(&pinst->lock);
get_online_cpus();
err = __padata_set_cpumasks(pinst, pcpumask, cbcpumask);
put_online_cpus();
mutex_unlock(&pinst->lock);
return err;
}
EXPORT_SYMBOL(padata_set_cpumasks);
/**
* padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
* equivalent to @cpumask.
*
* @pinst: padata instance
* @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding
* to parallel and serial cpumasks respectively.
* @cpumask: the cpumask to use
*/
int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
cpumask_var_t cpumask)
{
struct cpumask *serial_mask, *parallel_mask;
int err = -EINVAL;
mutex_lock(&pinst->lock);
get_online_cpus();
switch (cpumask_type) {
case PADATA_CPU_PARALLEL:
serial_mask = pinst->cpumask.cbcpu;
parallel_mask = cpumask;
break;
case PADATA_CPU_SERIAL:
parallel_mask = pinst->cpumask.pcpu;
serial_mask = cpumask;
break;
default:
goto out;
}
err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
out:
put_online_cpus();
mutex_unlock(&pinst->lock);
return err;
}
EXPORT_SYMBOL(padata_set_cpumask);
static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
{
struct parallel_data *pd;
if (cpumask_test_cpu(cpu, cpu_active_mask)) {
pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
pinst->cpumask.cbcpu);
if (!pd)
return -ENOMEM;
padata_replace(pinst, pd);
if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
__padata_start(pinst);
}
return 0;
}
/**
* padata_add_cpu - add a cpu to one or both(parallel and serial)
* padata cpumasks.
*
* @pinst: padata instance
* @cpu: cpu to add
* @mask: bitmask of flags specifying to which cpumask @cpu shuld be added.
* The @mask may be any combination of the following flags:
* PADATA_CPU_SERIAL - serial cpumask
* PADATA_CPU_PARALLEL - parallel cpumask
*/
int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask)
{
int err;
if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
return -EINVAL;
mutex_lock(&pinst->lock);
get_online_cpus();
if (mask & PADATA_CPU_SERIAL)
cpumask_set_cpu(cpu, pinst->cpumask.cbcpu);
if (mask & PADATA_CPU_PARALLEL)
cpumask_set_cpu(cpu, pinst->cpumask.pcpu);
err = __padata_add_cpu(pinst, cpu);
put_online_cpus();
mutex_unlock(&pinst->lock);
return err;
}
EXPORT_SYMBOL(padata_add_cpu);
static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
{
struct parallel_data *pd = NULL;
if (cpumask_test_cpu(cpu, cpu_online_mask)) {
if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) ||
!padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
__padata_stop(pinst);
pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
pinst->cpumask.cbcpu);
if (!pd)
return -ENOMEM;
padata_replace(pinst, pd);
}
return 0;
}
/**
* padata_remove_cpu - remove a cpu from the one or both(serial and parallel)
* padata cpumasks.
*
* @pinst: padata instance
* @cpu: cpu to remove
* @mask: bitmask specifying from which cpumask @cpu should be removed
* The @mask may be any combination of the following flags:
* PADATA_CPU_SERIAL - serial cpumask
* PADATA_CPU_PARALLEL - parallel cpumask
*/
int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask)
{
int err;
if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL)))
return -EINVAL;
mutex_lock(&pinst->lock);
get_online_cpus();
if (mask & PADATA_CPU_SERIAL)
cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu);
if (mask & PADATA_CPU_PARALLEL)
cpumask_clear_cpu(cpu, pinst->cpumask.pcpu);
err = __padata_remove_cpu(pinst, cpu);
put_online_cpus();
mutex_unlock(&pinst->lock);
return err;
}
EXPORT_SYMBOL(padata_remove_cpu);
/**
* padata_start - start the parallel processing
*
* @pinst: padata instance to start
*/
int padata_start(struct padata_instance *pinst)
{
int err = 0;
mutex_lock(&pinst->lock);
if (pinst->flags & PADATA_INVALID)
err =-EINVAL;
__padata_start(pinst);
mutex_unlock(&pinst->lock);
return err;
}
EXPORT_SYMBOL(padata_start);
/**
* padata_stop - stop the parallel processing
*
* @pinst: padata instance to stop
*/
void padata_stop(struct padata_instance *pinst)
{
mutex_lock(&pinst->lock);
__padata_stop(pinst);
mutex_unlock(&pinst->lock);
}
EXPORT_SYMBOL(padata_stop);
#ifdef CONFIG_HOTPLUG_CPU
static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
{
return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) ||
cpumask_test_cpu(cpu, pinst->cpumask.cbcpu);
}
static int padata_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
int err;
struct padata_instance *pinst;
int cpu = (unsigned long)hcpu;
pinst = container_of(nfb, struct padata_instance, cpu_notifier);
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
if (!pinst_has_cpu(pinst, cpu))
break;
mutex_lock(&pinst->lock);
err = __padata_add_cpu(pinst, cpu);
mutex_unlock(&pinst->lock);
if (err)
return notifier_from_errno(err);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
if (!pinst_has_cpu(pinst, cpu))
break;
mutex_lock(&pinst->lock);
err = __padata_remove_cpu(pinst, cpu);
mutex_unlock(&pinst->lock);
if (err)
return notifier_from_errno(err);
break;
case CPU_UP_CANCELED:
case CPU_UP_CANCELED_FROZEN:
if (!pinst_has_cpu(pinst, cpu))
break;
mutex_lock(&pinst->lock);
__padata_remove_cpu(pinst, cpu);
mutex_unlock(&pinst->lock);
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
if (!pinst_has_cpu(pinst, cpu))
break;
mutex_lock(&pinst->lock);
__padata_add_cpu(pinst, cpu);
mutex_unlock(&pinst->lock);
}
return NOTIFY_OK;
}
#endif
static void __padata_free(struct padata_instance *pinst)
{
#ifdef CONFIG_HOTPLUG_CPU
unregister_hotcpu_notifier(&pinst->cpu_notifier);
#endif
padata_stop(pinst);
padata_free_pd(pinst->pd);
free_cpumask_var(pinst->cpumask.pcpu);
free_cpumask_var(pinst->cpumask.cbcpu);
kfree(pinst);
}
#define kobj2pinst(_kobj) \
container_of(_kobj, struct padata_instance, kobj)
#define attr2pentry(_attr) \
container_of(_attr, struct padata_sysfs_entry, attr)
static void padata_sysfs_release(struct kobject *kobj)
{
struct padata_instance *pinst = kobj2pinst(kobj);
__padata_free(pinst);
}
struct padata_sysfs_entry {
struct attribute attr;
ssize_t (*show)(struct padata_instance *, struct attribute *, char *);
ssize_t (*store)(struct padata_instance *, struct attribute *,
const char *, size_t);
};
static ssize_t show_cpumask(struct padata_instance *pinst,
struct attribute *attr, char *buf)
{
struct cpumask *cpumask;
ssize_t len;
mutex_lock(&pinst->lock);
if (!strcmp(attr->name, "serial_cpumask"))
cpumask = pinst->cpumask.cbcpu;
else
cpumask = pinst->cpumask.pcpu;
len = bitmap_scnprintf(buf, PAGE_SIZE, cpumask_bits(cpumask),
nr_cpu_ids);
if (PAGE_SIZE - len < 2)
len = -EINVAL;
else
len += sprintf(buf + len, "\n");
mutex_unlock(&pinst->lock);
return len;
}
static ssize_t store_cpumask(struct padata_instance *pinst,
struct attribute *attr,
const char *buf, size_t count)
{
cpumask_var_t new_cpumask;
ssize_t ret;
int mask_type;
if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL))
return -ENOMEM;
ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask),
nr_cpumask_bits);
if (ret < 0)
goto out;
mask_type = !strcmp(attr->name, "serial_cpumask") ?
PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL;
ret = padata_set_cpumask(pinst, mask_type, new_cpumask);
if (!ret)
ret = count;
out:
free_cpumask_var(new_cpumask);
return ret;
}
#define PADATA_ATTR_RW(_name, _show_name, _store_name) \
static struct padata_sysfs_entry _name##_attr = \
__ATTR(_name, 0644, _show_name, _store_name)
#define PADATA_ATTR_RO(_name, _show_name) \
static struct padata_sysfs_entry _name##_attr = \
__ATTR(_name, 0400, _show_name, NULL)
PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask);
PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask);
/*
* Padata sysfs provides the following objects:
* serial_cpumask [RW] - cpumask for serial workers
* parallel_cpumask [RW] - cpumask for parallel workers
*/
static struct attribute *padata_default_attrs[] = {
&serial_cpumask_attr.attr,
&parallel_cpumask_attr.attr,
NULL,
};
static ssize_t padata_sysfs_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
struct padata_instance *pinst;
struct padata_sysfs_entry *pentry;
ssize_t ret = -EIO;
pinst = kobj2pinst(kobj);
pentry = attr2pentry(attr);
if (pentry->show)
ret = pentry->show(pinst, attr, buf);
return ret;
}
static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t count)
{
struct padata_instance *pinst;
struct padata_sysfs_entry *pentry;
ssize_t ret = -EIO;
pinst = kobj2pinst(kobj);
pentry = attr2pentry(attr);
if (pentry->show)
ret = pentry->store(pinst, attr, buf, count);
return ret;
}
static const struct sysfs_ops padata_sysfs_ops = {
.show = padata_sysfs_show,
.store = padata_sysfs_store,
};
static struct kobj_type padata_attr_type = {
.sysfs_ops = &padata_sysfs_ops,
.default_attrs = padata_default_attrs,
.release = padata_sysfs_release,
};
/**
* padata_alloc_possible - Allocate and initialize padata instance.
* Use the cpu_possible_mask for serial and
* parallel workers.
*
* @wq: workqueue to use for the allocated padata instance
*/
struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq)
{
return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask);
}
EXPORT_SYMBOL(padata_alloc_possible);
/**
* padata_alloc - allocate and initialize a padata instance and specify
* cpumasks for serial and parallel workers.
*
* @wq: workqueue to use for the allocated padata instance
* @pcpumask: cpumask that will be used for padata parallelization
* @cbcpumask: cpumask that will be used for padata serialization
*/
struct padata_instance *padata_alloc(struct workqueue_struct *wq,
const struct cpumask *pcpumask,
const struct cpumask *cbcpumask)
{
struct padata_instance *pinst;
struct parallel_data *pd = NULL;
pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
if (!pinst)
goto err;
get_online_cpus();
if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
goto err_free_inst;
if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
free_cpumask_var(pinst->cpumask.pcpu);
goto err_free_inst;
}
if (!padata_validate_cpumask(pinst, pcpumask) ||
!padata_validate_cpumask(pinst, cbcpumask))
goto err_free_masks;
pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
if (!pd)
goto err_free_masks;
rcu_assign_pointer(pinst->pd, pd);
pinst->wq = wq;
cpumask_copy(pinst->cpumask.pcpu, pcpumask);
cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
pinst->flags = 0;
#ifdef CONFIG_HOTPLUG_CPU
pinst->cpu_notifier.notifier_call = padata_cpu_callback;
pinst->cpu_notifier.priority = 0;
register_hotcpu_notifier(&pinst->cpu_notifier);
#endif
put_online_cpus();
BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
kobject_init(&pinst->kobj, &padata_attr_type);
mutex_init(&pinst->lock);
return pinst;
err_free_masks:
free_cpumask_var(pinst->cpumask.pcpu);
free_cpumask_var(pinst->cpumask.cbcpu);
err_free_inst:
kfree(pinst);
put_online_cpus();
err:
return NULL;
}
EXPORT_SYMBOL(padata_alloc);
/**
* padata_free - free a padata instance
*
* @padata_inst: padata instance to free
*/
void padata_free(struct padata_instance *pinst)
{
kobject_put(&pinst->kobj);
}
EXPORT_SYMBOL(padata_free);
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