119 строки
2.5 KiB
C
119 строки
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* Copyright (c) 2016 Facebook
|
|
*/
|
|
#include "percpu_freelist.h"
|
|
|
|
int pcpu_freelist_init(struct pcpu_freelist *s)
|
|
{
|
|
int cpu;
|
|
|
|
s->freelist = alloc_percpu(struct pcpu_freelist_head);
|
|
if (!s->freelist)
|
|
return -ENOMEM;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct pcpu_freelist_head *head = per_cpu_ptr(s->freelist, cpu);
|
|
|
|
raw_spin_lock_init(&head->lock);
|
|
head->first = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void pcpu_freelist_destroy(struct pcpu_freelist *s)
|
|
{
|
|
free_percpu(s->freelist);
|
|
}
|
|
|
|
static inline void pcpu_freelist_push_node(struct pcpu_freelist_head *head,
|
|
struct pcpu_freelist_node *node)
|
|
{
|
|
node->next = head->first;
|
|
head->first = node;
|
|
}
|
|
|
|
static inline void ___pcpu_freelist_push(struct pcpu_freelist_head *head,
|
|
struct pcpu_freelist_node *node)
|
|
{
|
|
raw_spin_lock(&head->lock);
|
|
pcpu_freelist_push_node(head, node);
|
|
raw_spin_unlock(&head->lock);
|
|
}
|
|
|
|
void __pcpu_freelist_push(struct pcpu_freelist *s,
|
|
struct pcpu_freelist_node *node)
|
|
{
|
|
struct pcpu_freelist_head *head = this_cpu_ptr(s->freelist);
|
|
|
|
___pcpu_freelist_push(head, node);
|
|
}
|
|
|
|
void pcpu_freelist_push(struct pcpu_freelist *s,
|
|
struct pcpu_freelist_node *node)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
__pcpu_freelist_push(s, node);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
|
|
u32 nr_elems)
|
|
{
|
|
struct pcpu_freelist_head *head;
|
|
int i, cpu, pcpu_entries;
|
|
|
|
pcpu_entries = nr_elems / num_possible_cpus() + 1;
|
|
i = 0;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
again:
|
|
head = per_cpu_ptr(s->freelist, cpu);
|
|
/* No locking required as this is not visible yet. */
|
|
pcpu_freelist_push_node(head, buf);
|
|
i++;
|
|
buf += elem_size;
|
|
if (i == nr_elems)
|
|
break;
|
|
if (i % pcpu_entries)
|
|
goto again;
|
|
}
|
|
}
|
|
|
|
struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
|
|
{
|
|
struct pcpu_freelist_head *head;
|
|
struct pcpu_freelist_node *node;
|
|
int orig_cpu, cpu;
|
|
|
|
orig_cpu = cpu = raw_smp_processor_id();
|
|
while (1) {
|
|
head = per_cpu_ptr(s->freelist, cpu);
|
|
raw_spin_lock(&head->lock);
|
|
node = head->first;
|
|
if (node) {
|
|
head->first = node->next;
|
|
raw_spin_unlock(&head->lock);
|
|
return node;
|
|
}
|
|
raw_spin_unlock(&head->lock);
|
|
cpu = cpumask_next(cpu, cpu_possible_mask);
|
|
if (cpu >= nr_cpu_ids)
|
|
cpu = 0;
|
|
if (cpu == orig_cpu)
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s)
|
|
{
|
|
struct pcpu_freelist_node *ret;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
ret = __pcpu_freelist_pop(s);
|
|
local_irq_restore(flags);
|
|
return ret;
|
|
}
|