1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (c) 2013
4*4882a593Smuzhiyun * Phillip Lougher <phillip@squashfs.org.uk>
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <linux/types.h>
8*4882a593Smuzhiyun #include <linux/slab.h>
9*4882a593Smuzhiyun #include <linux/percpu.h>
10*4882a593Smuzhiyun #include <linux/buffer_head.h>
11*4882a593Smuzhiyun #include <linux/local_lock.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include "squashfs_fs.h"
14*4882a593Smuzhiyun #include "squashfs_fs_sb.h"
15*4882a593Smuzhiyun #include "decompressor.h"
16*4882a593Smuzhiyun #include "squashfs.h"
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun /*
19*4882a593Smuzhiyun * This file implements multi-threaded decompression using percpu
20*4882a593Smuzhiyun * variables, one thread per cpu core.
21*4882a593Smuzhiyun */
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun struct squashfs_stream {
24*4882a593Smuzhiyun void *stream;
25*4882a593Smuzhiyun local_lock_t lock;
26*4882a593Smuzhiyun };
27*4882a593Smuzhiyun
squashfs_decompressor_create(struct squashfs_sb_info * msblk,void * comp_opts)28*4882a593Smuzhiyun void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
29*4882a593Smuzhiyun void *comp_opts)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun struct squashfs_stream *stream;
32*4882a593Smuzhiyun struct squashfs_stream __percpu *percpu;
33*4882a593Smuzhiyun int err, cpu;
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun percpu = alloc_percpu(struct squashfs_stream);
36*4882a593Smuzhiyun if (percpu == NULL)
37*4882a593Smuzhiyun return ERR_PTR(-ENOMEM);
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun for_each_possible_cpu(cpu) {
40*4882a593Smuzhiyun stream = per_cpu_ptr(percpu, cpu);
41*4882a593Smuzhiyun stream->stream = msblk->decompressor->init(msblk, comp_opts);
42*4882a593Smuzhiyun if (IS_ERR(stream->stream)) {
43*4882a593Smuzhiyun err = PTR_ERR(stream->stream);
44*4882a593Smuzhiyun goto out;
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun local_lock_init(&stream->lock);
47*4882a593Smuzhiyun }
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun kfree(comp_opts);
50*4882a593Smuzhiyun return (__force void *) percpu;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun out:
53*4882a593Smuzhiyun for_each_possible_cpu(cpu) {
54*4882a593Smuzhiyun stream = per_cpu_ptr(percpu, cpu);
55*4882a593Smuzhiyun if (!IS_ERR_OR_NULL(stream->stream))
56*4882a593Smuzhiyun msblk->decompressor->free(stream->stream);
57*4882a593Smuzhiyun }
58*4882a593Smuzhiyun free_percpu(percpu);
59*4882a593Smuzhiyun return ERR_PTR(err);
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun
squashfs_decompressor_destroy(struct squashfs_sb_info * msblk)62*4882a593Smuzhiyun void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun struct squashfs_stream __percpu *percpu =
65*4882a593Smuzhiyun (struct squashfs_stream __percpu *) msblk->stream;
66*4882a593Smuzhiyun struct squashfs_stream *stream;
67*4882a593Smuzhiyun int cpu;
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun if (msblk->stream) {
70*4882a593Smuzhiyun for_each_possible_cpu(cpu) {
71*4882a593Smuzhiyun stream = per_cpu_ptr(percpu, cpu);
72*4882a593Smuzhiyun msblk->decompressor->free(stream->stream);
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun free_percpu(percpu);
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun
squashfs_decompress(struct squashfs_sb_info * msblk,struct bio * bio,int offset,int length,struct squashfs_page_actor * output)78*4882a593Smuzhiyun int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
79*4882a593Smuzhiyun int offset, int length, struct squashfs_page_actor *output)
80*4882a593Smuzhiyun {
81*4882a593Smuzhiyun struct squashfs_stream *stream;
82*4882a593Smuzhiyun int res;
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun local_lock(&msblk->stream->lock);
85*4882a593Smuzhiyun stream = this_cpu_ptr(msblk->stream);
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun res = msblk->decompressor->decompress(msblk, stream->stream, bio,
88*4882a593Smuzhiyun offset, length, output);
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun local_unlock(&msblk->stream->lock);
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun if (res < 0)
93*4882a593Smuzhiyun ERROR("%s decompression failed, data probably corrupt\n",
94*4882a593Smuzhiyun msblk->decompressor->name);
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun return res;
97*4882a593Smuzhiyun }
98*4882a593Smuzhiyun
squashfs_max_decompressors(void)99*4882a593Smuzhiyun int squashfs_max_decompressors(void)
100*4882a593Smuzhiyun {
101*4882a593Smuzhiyun return num_possible_cpus();
102*4882a593Smuzhiyun }
103