1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2016 Facebook
4 #include "percpu_freelist.h"
6 int pcpu_freelist_init(struct pcpu_freelist *s)
10 s->freelist = alloc_percpu(struct pcpu_freelist_head);
14 for_each_possible_cpu(cpu) {
15 struct pcpu_freelist_head *head = per_cpu_ptr(s->freelist, cpu);
17 raw_spin_lock_init(&head->lock);
23 void pcpu_freelist_destroy(struct pcpu_freelist *s)
25 free_percpu(s->freelist);
28 static inline void ___pcpu_freelist_push(struct pcpu_freelist_head *head,
29 struct pcpu_freelist_node *node)
31 raw_spin_lock(&head->lock);
32 node->next = head->first;
34 raw_spin_unlock(&head->lock);
37 void __pcpu_freelist_push(struct pcpu_freelist *s,
38 struct pcpu_freelist_node *node)
40 struct pcpu_freelist_head *head = this_cpu_ptr(s->freelist);
42 ___pcpu_freelist_push(head, node);
45 void pcpu_freelist_push(struct pcpu_freelist *s,
46 struct pcpu_freelist_node *node)
50 local_irq_save(flags);
51 __pcpu_freelist_push(s, node);
52 local_irq_restore(flags);
55 void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
58 struct pcpu_freelist_head *head;
60 int i, cpu, pcpu_entries;
62 pcpu_entries = nr_elems / num_possible_cpus() + 1;
65 /* disable irq to workaround lockdep false positive
66 * in bpf usage pcpu_freelist_populate() will never race
67 * with pcpu_freelist_push()
69 local_irq_save(flags);
70 for_each_possible_cpu(cpu) {
72 head = per_cpu_ptr(s->freelist, cpu);
73 ___pcpu_freelist_push(head, buf);
81 local_irq_restore(flags);
84 struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
86 struct pcpu_freelist_head *head;
87 struct pcpu_freelist_node *node;
90 orig_cpu = cpu = raw_smp_processor_id();
92 head = per_cpu_ptr(s->freelist, cpu);
93 raw_spin_lock(&head->lock);
96 head->first = node->next;
97 raw_spin_unlock(&head->lock);
100 raw_spin_unlock(&head->lock);
101 cpu = cpumask_next(cpu, cpu_possible_mask);
102 if (cpu >= nr_cpu_ids)
109 struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s)
111 struct pcpu_freelist_node *ret;
114 local_irq_save(flags);
115 ret = __pcpu_freelist_pop(s);
116 local_irq_restore(flags);