Files
android/kernel/bpf/percpu_freelist.c
T
threeeye bc1d038eac REVVL 6 Pro kernel bring-up: full working tree snapshot (2026-09-12)
Squashed backup commit (no shallow-clone history issues) of
xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2 branch, upstream
commit 9eece662e) plus all fixes applied to get everpal_defconfig building
clean against a modern (GCC 15.2.0) toolchain -- see the previous commit
message on the lineage-23.2 branch (also in this repo history is not
available here since this is a squashed snapshot; full incremental history
lives in the local DL380 checkout and the upstream GitHub remote).

Upstream: https://github.com/xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2)
2026-09-12 13:36:46 +00:00

119 lines
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(struct pcpu_freelist_head *head,
struct pcpu_freelist_node *node)
{
raw_spin_lock(&head->lock);
node->next = head->first;
head->first = 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;
unsigned long flags;
int i, cpu, pcpu_entries;
pcpu_entries = nr_elems / num_possible_cpus() + 1;
i = 0;
/* disable irq to workaround lockdep false positive
* in bpf usage pcpu_freelist_populate() will never race
* with pcpu_freelist_push()
*/
local_irq_save(flags);
for_each_possible_cpu(cpu) {
again:
head = per_cpu_ptr(s->freelist, cpu);
___pcpu_freelist_push(head, buf);
i++;
buf += elem_size;
if (i == nr_elems)
break;
if (i % pcpu_entries)
goto again;
}
local_irq_restore(flags);
}
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;
}