/* Copyright (c) 2016 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#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_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;
}
}
/ipv6
Merge tag 'docs-4.10' of git://git.lwn.net/linux
HEADmasterPull documentation update from Jonathan Corbet:
"These are the documentation changes for 4.10.
It's another busy cycle for the docs tree, as the sphinx conversion
continues. Highlights include:
- Further work on PDF output, which remains a bit of a pain but
should be more solid now.
- Five more DocBook template files converted to Sphinx. Only 27 to
go... Lots of plain-text files have also been converted and
integrated.
- Images in binary formats have been replaced with more
source-friendly versions.
- Various bits of organizational work, including the renaming of
various files discussed at the kernel summit.
- New documentation for the device_link mechanism.
... and, of course, lots of typo fixes and small updates"
* tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits)
dma-buf: Extract dma-buf.rst
Update Documentation/00-INDEX
docs: 00-INDEX: document directories/files with no docs
docs: 00-INDEX: remove non-existing entries
docs: 00-INDEX: add missing entries for documentation files/dirs
docs: 00-INDEX: consolidate process/ and admin-guide/ description
scripts: add a script to check if Documentation/00-INDEX is sane
Docs: change sh -> awk in REPORTING-BUGS
Documentation/core-api/device_link: Add initial documentation
core-api: remove an unexpected unident
ppc/idle: Add documentation for powersave=off
Doc: Correct typo, "Introdution" => "Introduction"
Documentation/atomic_ops.txt: convert to ReST markup
Documentation/local_ops.txt: convert to ReST markup
Documentation/assoc_array.txt: convert to ReST markup
docs-rst: parse-headers.pl: cleanup the documentation
docs-rst: fix media cleandocs target
docs-rst: media/Makefile: reorganize the rules
docs-rst: media: build SVG from graphviz files
docs-rst: replace bayer.png by a SVG image
...