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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/completion.h>#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 PADATA_WORK_ONSTACK 1 /* Work's memory is on stack */
struct padata_work { struct work_struct pw_work; struct list_head pw_list; /* padata_free_works linkage */ void *pw_data;};
static DEFINE_SPINLOCK(padata_works_lock);static struct padata_work *padata_works;static LIST_HEAD(padata_free_works);
struct padata_mt_job_state { spinlock_t lock; struct completion completion; struct padata_mt_job *job; int nworks; int nworks_fini; unsigned long chunk_size;};
static void padata_free_pd(struct parallel_data *pd);static void __init padata_mt_helper(struct work_struct *work);
static inline void padata_get_pd(struct parallel_data *pd){ refcount_inc(&pd->refcnt);}
static inline void padata_put_pd_cnt(struct parallel_data *pd, int cnt){ if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd);}
static inline void padata_put_pd(struct parallel_data *pd){ padata_put_pd_cnt(pd, 1);}
static int padata_cpu_hash(struct parallel_data *pd, unsigned int seq_nr){ /* * Hash the sequence numbers to the cpus by taking * seq_nr mod. number of cpus in use. */ int cpu_index = seq_nr % cpumask_weight(pd->cpumask.pcpu);
return cpumask_nth(cpu_index, pd->cpumask.pcpu);}
static struct padata_work *padata_work_alloc(void){ struct padata_work *pw;
lockdep_assert_held(&padata_works_lock);
if (list_empty(&padata_free_works)) return NULL; /* No more work items allowed to be queued. */
pw = list_first_entry(&padata_free_works, struct padata_work, pw_list); list_del(&pw->pw_list); return pw;}
/* * This function is marked __ref because this function may be optimized in such * a way that it directly refers to work_fn's address, which causes modpost to * complain when work_fn is marked __init. This scenario was observed with clang * LTO, where padata_work_init() was optimized to refer directly to * padata_mt_helper() because the calls to padata_work_init() with other work_fn * values were eliminated or inlined. */static void __ref padata_work_init(struct padata_work *pw, work_func_t work_fn, void *data, int flags){ if (flags & PADATA_WORK_ONSTACK) INIT_WORK_ONSTACK(&pw->pw_work, work_fn); else INIT_WORK(&pw->pw_work, work_fn); pw->pw_data = data;}
static int __init padata_work_alloc_mt(int nworks, void *data, struct list_head *head){ int i;
spin_lock_bh(&padata_works_lock); /* Start at 1 because the current task participates in the job. */ for (i = 1; i < nworks; ++i) { struct padata_work *pw = padata_work_alloc();
if (!pw) break; padata_work_init(pw, padata_mt_helper, data, 0); list_add(&pw->pw_list, head); } spin_unlock_bh(&padata_works_lock);
return i;}
static void padata_work_free(struct padata_work *pw){ lockdep_assert_held(&padata_works_lock); list_add(&pw->pw_list, &padata_free_works);}
static void __init padata_works_free(struct list_head *works){ struct padata_work *cur, *next;
if (list_empty(works)) return;
spin_lock_bh(&padata_works_lock); list_for_each_entry_safe(cur, next, works, pw_list) { list_del(&cur->pw_list); padata_work_free(cur); } spin_unlock_bh(&padata_works_lock);}
static void padata_parallel_worker(struct work_struct *parallel_work){ struct padata_work *pw = container_of(parallel_work, struct padata_work, pw_work); struct padata_priv *padata = pw->pw_data;
local_bh_disable(); padata->parallel(padata); spin_lock(&padata_works_lock); padata_work_free(pw); spin_unlock(&padata_works_lock); local_bh_enable();}
/** * padata_do_parallel - padata parallelization function * * @ps: padatashell * @padata: object to be parallelized * @cb_cpu: pointer to the CPU that the serialization callback function should * run on. If it's not in the serial cpumask of @pinst * (i.e. cpumask.cbcpu), this function selects a fallback CPU and if * none found, returns -EINVAL. * * 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. * * Return: 0 on success or else negative error code. */int padata_do_parallel(struct padata_shell *ps, struct padata_priv *padata, int *cb_cpu){ struct padata_instance *pinst = ps->pinst; struct parallel_data *pd; struct padata_work *pw; int cpu_index, err;
rcu_read_lock_bh();
pd = rcu_dereference_bh(ps->pd);
err = -EINVAL; if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID) goto out;
if (!cpumask_test_cpu(*cb_cpu, pd->cpumask.cbcpu)) { if (cpumask_empty(pd->cpumask.cbcpu)) goto out;
/* Select an alternate fallback CPU and notify the caller. */ cpu_index = *cb_cpu % cpumask_weight(pd->cpumask.cbcpu); *cb_cpu = cpumask_nth(cpu_index, pd->cpumask.cbcpu); }
err = -EBUSY; if ((pinst->flags & PADATA_RESET)) goto out;
padata_get_pd(pd); padata->pd = pd; padata->cb_cpu = *cb_cpu;
spin_lock(&padata_works_lock); padata->seq_nr = ++pd->seq_nr; pw = padata_work_alloc(); spin_unlock(&padata_works_lock);
if (!pw) { /* Maximum works limit exceeded, run in the current task. */ padata->parallel(padata); }
rcu_read_unlock_bh();
if (pw) { padata_work_init(pw, padata_parallel_worker, padata, 0); queue_work(pinst->parallel_wq, &pw->pw_work); }
return 0;out: rcu_read_unlock_bh();
return err;}EXPORT_SYMBOL(padata_do_parallel);
/* * padata_find_next - Find the next object that needs serialization. * * Return: * * A pointer to the control struct of the next object that needs * serialization, if present in one of the percpu reorder queues. * * NULL, 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. */static struct padata_priv *padata_find_next(struct parallel_data *pd, int cpu, unsigned int processed){ struct padata_priv *padata; struct padata_list *reorder;
reorder = per_cpu_ptr(pd->reorder_list, cpu);
spin_lock(&reorder->lock); if (list_empty(&reorder->list)) goto notfound;
padata = list_entry(reorder->list.next, struct padata_priv, list);
/* * Checks the rare case where two or more parallel jobs have hashed to * the same CPU and one of the later ones finishes first. */ if (padata->seq_nr != processed) goto notfound;
list_del_init(&padata->list); spin_unlock(&reorder->lock); return padata;
notfound: pd->processed = processed; pd->cpu = cpu; spin_unlock(&reorder->lock); return NULL;}
static void padata_reorder(struct padata_priv *padata){ struct parallel_data *pd = padata->pd; struct padata_instance *pinst = pd->ps->pinst; unsigned int processed; int cpu;
processed = pd->processed; cpu = pd->cpu;
do { struct padata_serial_queue *squeue; int cb_cpu;
processed++; /* When sequence wraps around, reset to the first CPU. */ if (unlikely(processed == 0)) cpu = cpumask_first(pd->cpumask.pcpu); else cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
cb_cpu = padata->cb_cpu; squeue = per_cpu_ptr(pd->squeue, cb_cpu);
spin_lock(&squeue->serial.lock); list_add_tail(&padata->list, &squeue->serial.list); queue_work_on(cb_cpu, pinst->serial_wq, &squeue->work);
/* * If 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, end the loop. */ padata = padata_find_next(pd, cpu, processed); spin_unlock(&squeue->serial.lock); } while (padata);}
static void padata_serial_worker(struct work_struct *serial_work){ struct padata_serial_queue *squeue; struct parallel_data *pd; LIST_HEAD(local_list); int cnt;
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);
cnt = 0;
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); cnt++; } local_bh_enable();
padata_put_pd_cnt(pd, cnt);}
/** * 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){ struct parallel_data *pd = padata->pd; int hashed_cpu = padata_cpu_hash(pd, padata->seq_nr); struct padata_list *reorder = per_cpu_ptr(pd->reorder_list, hashed_cpu); struct padata_priv *cur; struct list_head *pos; bool gotit = true;
spin_lock(&reorder->lock); /* Sort in ascending order of sequence number. */ list_for_each_prev(pos, &reorder->list) { cur = list_entry(pos, struct padata_priv, list); /* Compare by difference to consider integer wrap around */ if ((signed int)(cur->seq_nr - padata->seq_nr) < 0) break; } if (padata->seq_nr != pd->processed) { gotit = false; list_add(&padata->list, pos); } spin_unlock(&reorder->lock);
if (gotit) padata_reorder(padata);}EXPORT_SYMBOL(padata_do_serial);
static int padata_setup_cpumasks(struct padata_instance *pinst){ struct workqueue_attrs *attrs; int err;
attrs = alloc_workqueue_attrs(); if (!attrs) return -ENOMEM;
/* Restrict parallel_wq workers to pd->cpumask.pcpu. */ cpumask_copy(attrs->cpumask, pinst->cpumask.pcpu); err = apply_workqueue_attrs(pinst->parallel_wq, attrs); free_workqueue_attrs(attrs);
return err;}
static void __init padata_mt_helper(struct work_struct *w){ struct padata_work *pw = container_of(w, struct padata_work, pw_work); struct padata_mt_job_state *ps = pw->pw_data; struct padata_mt_job *job = ps->job; bool done;
spin_lock(&ps->lock);
while (job->size > 0) { unsigned long start, size, end;
start = job->start; /* So end is chunk size aligned if enough work remains. */ size = roundup(start + 1, ps->chunk_size) - start; size = min(size, job->size); end = start + size;
job->start = end; job->size -= size;
spin_unlock(&ps->lock); job->thread_fn(start, end, job->fn_arg); spin_lock(&ps->lock); }
++ps->nworks_fini; done = (ps->nworks_fini == ps->nworks); spin_unlock(&ps->lock);
if (done) complete(&ps->completion);}
/** * padata_do_multithreaded - run a multithreaded job * @job: Description of the job. * * See the definition of struct padata_mt_job for more details. */void __init padata_do_multithreaded(struct padata_mt_job *job){ /* In case threads finish at different times. */ static const unsigned long load_balance_factor = 4; struct padata_work my_work, *pw; struct padata_mt_job_state ps; LIST_HEAD(works); int nworks, nid; static atomic_t last_used_nid __initdata;
if (job->size == 0) return;
/* Ensure at least one thread when size < min_chunk. */ nworks = max(job->size / max(job->min_chunk, job->align), 1ul); nworks = min(nworks, job->max_threads);
if (nworks == 1) { /* Single thread, no coordination needed, cut to the chase. */ job->thread_fn(job->start, job->start + job->size, job->fn_arg); return; }
spin_lock_init(&ps.lock); init_completion(&ps.completion); ps.job = job; ps.nworks = padata_work_alloc_mt(nworks, &ps, &works); ps.nworks_fini = 0;
/* * Chunk size is the amount of work a helper does per call to the * thread function. Load balance large jobs between threads by * increasing the number of chunks, guarantee at least the minimum * chunk size from the caller, and honor the caller's alignment. * Ensure chunk_size is at least 1 to prevent divide-by-0 * panic in padata_mt_helper(). */ ps.chunk_size = job->size / (ps.nworks * load_balance_factor); ps.chunk_size = max(ps.chunk_size, job->min_chunk); ps.chunk_size = max(ps.chunk_size, 1ul); ps.chunk_size = roundup(ps.chunk_size, job->align);
list_for_each_entry(pw, &works, pw_list) if (job->numa_aware) { int old_node = atomic_read(&last_used_nid);
do { nid = next_node_in(old_node, node_states[N_CPU]); } while (!atomic_try_cmpxchg(&last_used_nid, &old_node, nid)); queue_work_node(nid, system_dfl_wq, &pw->pw_work); } else { queue_work(system_dfl_wq, &pw->pw_work); }
/* Use the current thread, which saves starting a workqueue worker. */ padata_work_init(&my_work, padata_mt_helper, &ps, PADATA_WORK_ONSTACK); padata_mt_helper(&my_work.pw_work);
/* Wait for all the helpers to finish. */ wait_for_completion(&ps.completion);
destroy_work_on_stack(&my_work.pw_work); padata_works_free(&works);}
/* 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; INIT_LIST_HEAD(&squeue->serial.list); spin_lock_init(&squeue->serial.lock); INIT_WORK(&squeue->work, padata_serial_worker); }}
/* Initialize per-CPU reorder lists */static void padata_init_reorder_list(struct parallel_data *pd){ int cpu; struct padata_list *list;
for_each_cpu(cpu, pd->cpumask.pcpu) { list = per_cpu_ptr(pd->reorder_list, cpu); INIT_LIST_HEAD(&list->list); spin_lock_init(&list->lock); }}
/* Allocate and initialize the internal cpumask dependend resources. */static struct parallel_data *padata_alloc_pd(struct padata_shell *ps, int offlining_cpu){ struct padata_instance *pinst = ps->pinst; struct parallel_data *pd;
pd = kzalloc_obj(struct parallel_data); if (!pd) goto err;
pd->reorder_list = alloc_percpu(struct padata_list); if (!pd->reorder_list) goto err_free_pd;
pd->squeue = alloc_percpu(struct padata_serial_queue); if (!pd->squeue) goto err_free_reorder_list;
pd->ps = ps;
if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL)) goto err_free_squeue; if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) goto err_free_pcpu;
cpumask_and(pd->cpumask.pcpu, pinst->cpumask.pcpu, cpu_online_mask); cpumask_and(pd->cpumask.cbcpu, pinst->cpumask.cbcpu, cpu_online_mask); if (offlining_cpu >= 0) { __cpumask_clear_cpu(offlining_cpu, pd->cpumask.pcpu); __cpumask_clear_cpu(offlining_cpu, pd->cpumask.cbcpu); }
padata_init_reorder_list(pd); padata_init_squeues(pd); pd->seq_nr = -1; refcount_set(&pd->refcnt, 1); pd->cpu = cpumask_first(pd->cpumask.pcpu);
return pd;
err_free_pcpu: free_cpumask_var(pd->cpumask.pcpu);err_free_squeue: free_percpu(pd->squeue);err_free_reorder_list: free_percpu(pd->reorder_list);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->reorder_list); free_percpu(pd->squeue); kfree(pd);}
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();}
/* Replace the internal control structure with a new one. */static int padata_replace_one(struct padata_shell *ps, int offlining_cpu){ struct parallel_data *pd_new;
pd_new = padata_alloc_pd(ps, offlining_cpu); if (!pd_new) return -ENOMEM;
ps->opd = rcu_dereference_protected(ps->pd, 1); rcu_assign_pointer(ps->pd, pd_new);
return 0;}
static int padata_replace(struct padata_instance *pinst, int offlining_cpu){ struct padata_shell *ps; int err = 0;
pinst->flags |= PADATA_RESET;
list_for_each_entry(ps, &pinst->pslist, list) { err = padata_replace_one(ps, offlining_cpu); if (err) break; }
synchronize_rcu();
list_for_each_entry_continue_reverse(ps, &pinst->pslist, list) padata_put_pd(ps->opd);
pinst->flags &= ~PADATA_RESET;
return err;}
/* 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, int offlining_cpu){ cpumask_copy(pinst->validate_cpumask, cpu_online_mask);
/* * @offlining_cpu is still in cpu_online_mask, so remove it here for * validation. Using a sub-CPUHP_TEARDOWN_CPU hotplug state where * @offlining_cpu wouldn't be in the online mask doesn't work because * padata_cpu_offline() can fail but such a state doesn't allow failure. */ if (offlining_cpu >= 0) __cpumask_clear_cpu(offlining_cpu, pinst->validate_cpumask);
if (!cpumask_intersects(cpumask, pinst->validate_cpumask)) { 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; int err;
valid = padata_validate_cpumask(pinst, pcpumask, -1); if (!valid) { __padata_stop(pinst); goto out_replace; }
valid = padata_validate_cpumask(pinst, cbcpumask, -1); if (!valid) __padata_stop(pinst);
out_replace: cpumask_copy(pinst->cpumask.pcpu, pcpumask); cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
err = padata_setup_cpumasks(pinst) ?: padata_replace(pinst, -1);
if (valid) __padata_start(pinst);
return err;}
/** * 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 * * Return: 0 on success or negative error code */int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, cpumask_var_t cpumask){ struct cpumask *serial_mask, *parallel_mask; int err = -EINVAL;
cpus_read_lock(); mutex_lock(&pinst->lock);
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: mutex_unlock(&pinst->lock); cpus_read_unlock();
return err;}EXPORT_SYMBOL(padata_set_cpumask);
#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_online(unsigned int cpu, struct hlist_node *node){ struct padata_instance *pinst; int ret;
pinst = hlist_entry_safe(node, struct padata_instance, cpuhp_node); if (!pinst_has_cpu(pinst, cpu)) return 0;
mutex_lock(&pinst->lock);
ret = padata_replace(pinst, -1);
if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu, -1) && padata_validate_cpumask(pinst, pinst->cpumask.cbcpu, -1)) __padata_start(pinst);
mutex_unlock(&pinst->lock); return ret;}
static int padata_cpu_offline(unsigned int cpu, struct hlist_node *node){ struct padata_instance *pinst; int ret;
pinst = hlist_entry_safe(node, struct padata_instance, cpuhp_node); if (!pinst_has_cpu(pinst, cpu)) return 0;
mutex_lock(&pinst->lock);
if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu, cpu) || !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu, cpu)) __padata_stop(pinst);
ret = padata_replace(pinst, cpu);
mutex_unlock(&pinst->lock); return ret;}
static enum cpuhp_state hp_online;#endif
static void __padata_free(struct padata_instance *pinst){#ifdef CONFIG_HOTPLUG_CPU cpuhp_state_remove_instance_nocalls(hp_online, &pinst->cpuhp_node);#endif
WARN_ON(!list_empty(&pinst->pslist));
free_cpumask_var(pinst->cpumask.pcpu); free_cpumask_var(pinst->cpumask.cbcpu); free_cpumask_var(pinst->validate_cpumask); destroy_workqueue(pinst->serial_wq); destroy_workqueue(pinst->parallel_wq); kfree(pinst);}
#define kobj2pinst(_kobj) \ container_of(_kobj, struct padata_instance, kobj)#define attr2pentry(_attr) \ container_of_const(_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 *, const struct attribute *, char *); ssize_t (*store)(struct padata_instance *, const struct attribute *, const char *, size_t);};
static ssize_t show_cpumask(struct padata_instance *pinst, const 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 = snprintf(buf, PAGE_SIZE, "%*pb\n", nr_cpu_ids, cpumask_bits(cpumask)); mutex_unlock(&pinst->lock); return len < PAGE_SIZE ? len : -EINVAL;}
static ssize_t store_cpumask(struct padata_instance *pinst, const 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 const struct padata_sysfs_entry _name##_attr = \ __ATTR(_name, 0644, _show_name, _store_name)#define PADATA_ATTR_RO(_name, _show_name) \ static const 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 const struct attribute *const padata_default_attrs[] = { &serial_cpumask_attr.attr, ¶llel_cpumask_attr.attr, NULL,};ATTRIBUTE_GROUPS(padata_default);
static ssize_t padata_sysfs_show(struct kobject *kobj, struct attribute *attr, char *buf){ const struct padata_sysfs_entry *pentry; struct padata_instance *pinst; 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){ const struct padata_sysfs_entry *pentry; struct padata_instance *pinst; ssize_t ret = -EIO;
pinst = kobj2pinst(kobj); pentry = attr2pentry(attr); if (pentry->store) 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 const struct kobj_type padata_attr_type = { .sysfs_ops = &padata_sysfs_ops, .default_groups = padata_default_groups, .release = padata_sysfs_release,};
/** * padata_alloc - allocate and initialize a padata instance * @name: used to identify the instance * * Return: new instance on success, NULL on error */struct padata_instance *padata_alloc(const char *name){ struct padata_instance *pinst;
pinst = kzalloc_obj(struct padata_instance); if (!pinst) goto err;
pinst->parallel_wq = alloc_workqueue("%s_parallel", WQ_UNBOUND, 0, name); if (!pinst->parallel_wq) goto err_free_inst;
cpus_read_lock();
pinst->serial_wq = alloc_workqueue("%s_serial", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE | WQ_PERCPU, 1, name); if (!pinst->serial_wq) goto err_put_cpus;
if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL)) goto err_free_serial_wq; if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) goto err_free_p_mask; if (!alloc_cpumask_var(&pinst->validate_cpumask, GFP_KERNEL)) goto err_free_cb_mask;
INIT_LIST_HEAD(&pinst->pslist);
cpumask_copy(pinst->cpumask.pcpu, cpu_possible_mask); cpumask_copy(pinst->cpumask.cbcpu, cpu_possible_mask);
if (padata_setup_cpumasks(pinst)) goto err_free_v_mask;
__padata_start(pinst);
kobject_init(&pinst->kobj, &padata_attr_type); mutex_init(&pinst->lock);
#ifdef CONFIG_HOTPLUG_CPU cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, &pinst->cpuhp_node);#endif
cpus_read_unlock();
return pinst;
err_free_v_mask: free_cpumask_var(pinst->validate_cpumask);err_free_cb_mask: free_cpumask_var(pinst->cpumask.cbcpu);err_free_p_mask: free_cpumask_var(pinst->cpumask.pcpu);err_free_serial_wq: destroy_workqueue(pinst->serial_wq);err_put_cpus: cpus_read_unlock(); destroy_workqueue(pinst->parallel_wq);err_free_inst: kfree(pinst);err: return NULL;}EXPORT_SYMBOL(padata_alloc);
/** * padata_free - free a padata instance * * @pinst: padata instance to free */void padata_free(struct padata_instance *pinst){ kobject_put(&pinst->kobj);}EXPORT_SYMBOL(padata_free);
/** * padata_alloc_shell - Allocate and initialize padata shell. * * @pinst: Parent padata_instance object. * * Return: new shell on success, NULL on error */struct padata_shell *padata_alloc_shell(struct padata_instance *pinst){ struct parallel_data *pd; struct padata_shell *ps;
ps = kzalloc_obj(*ps); if (!ps) goto out;
ps->pinst = pinst;
cpus_read_lock(); pd = padata_alloc_pd(ps, -1); cpus_read_unlock();
if (!pd) goto out_free_ps;
mutex_lock(&pinst->lock); RCU_INIT_POINTER(ps->pd, pd); list_add(&ps->list, &pinst->pslist); mutex_unlock(&pinst->lock);
return ps;
out_free_ps: kfree(ps);out: return NULL;}EXPORT_SYMBOL(padata_alloc_shell);
/** * padata_free_shell - free a padata shell * * @ps: padata shell to free */void padata_free_shell(struct padata_shell *ps){ struct parallel_data *pd;
if (!ps) return;
mutex_lock(&ps->pinst->lock); list_del(&ps->list); pd = rcu_dereference_protected(ps->pd, 1); padata_put_pd(pd); mutex_unlock(&ps->pinst->lock);
kfree(ps);}EXPORT_SYMBOL(padata_free_shell);
void __init padata_init(void){ unsigned int i, possible_cpus;#ifdef CONFIG_HOTPLUG_CPU int ret;
ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online", padata_cpu_online, padata_cpu_offline); if (ret < 0) goto err; hp_online = ret;#endif
possible_cpus = num_possible_cpus(); padata_works = kmalloc_objs(struct padata_work, possible_cpus); if (!padata_works) goto remove_online_state;
for (i = 0; i < possible_cpus; ++i) list_add(&padata_works[i].pw_list, &padata_free_works);
return;
remove_online_state:#ifdef CONFIG_HOTPLUG_CPU cpuhp_remove_multi_state(hp_online);err:#endif pr_warn("padata: initialization failed\n");}