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// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/cpu.h>
#include <linux/crypto.h>
#include <linux/vmalloc.h>
#include "zcomp.h"
#include "backend_lzo.h"
#include "backend_lzorle.h"
#include "backend_lz4.h"
#include "backend_lz4hc.h"
#include "backend_zstd.h"
#include "backend_deflate.h"
static const struct zcomp_ops *backends[] = {
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
&backend_lzorle,
&backend_lzo,
#endif
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4)
&backend_lz4,
#endif
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4HC)
&backend_lz4hc,
#endif
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_ZSTD)
&backend_zstd,
#endif
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_DEFLATE)
&backend_deflate,
#endif
NULL
};
static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *zstrm)
{
if (zstrm->ctx)
comp->ops->destroy_ctx(zstrm->ctx);
vfree(zstrm->buffer);
zstrm->ctx = NULL;
zstrm->buffer = NULL;
}
static int zcomp_strm_init(struct zcomp *comp, struct zcomp_strm *zstrm)
{
zstrm->ctx = comp->ops->create_ctx();
/*
* allocate 2 pages. 1 for compressed data, plus 1 extra for the
* case when compressed size is larger than the original one
*/
zstrm->buffer = vzalloc(2 * PAGE_SIZE);
if (!zstrm->ctx || !zstrm->buffer) {
zcomp_strm_free(comp, zstrm);
return -ENOMEM;
}
return 0;
}
static const struct zcomp_ops *lookup_backend_ops(const char *comp)
{
int i = 0;
while (backends[i]) {
if (sysfs_streq(comp, backends[i]->name))
break;
i++;
}
return backends[i];
}
bool zcomp_available_algorithm(const char *comp)
{
return lookup_backend_ops(comp) != NULL;
}
/* show available compressors */
ssize_t zcomp_available_show(const char *comp, char *buf)
{
ssize_t sz = 0;
int i;
for (i = 0; i < ARRAY_SIZE(backends) - 1; i++) {
if (!strcmp(comp, backends[i]->name)) {
sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
"[%s] ", backends[i]->name);
} else {
sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
"%s ", backends[i]->name);
}
}
sz += scnprintf(buf + sz, PAGE_SIZE - sz, "\n");
return sz;
}
struct zcomp_strm *zcomp_stream_get(struct zcomp *comp)
{
local_lock(&comp->stream->lock);
return this_cpu_ptr(comp->stream);
}
void zcomp_stream_put(struct zcomp *comp)
{
local_unlock(&comp->stream->lock);
}
int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
const void *src, unsigned int *dst_len)
{
/* The dst buffer should always be 2 * PAGE_SIZE */
size_t dlen = 2 * PAGE_SIZE;
int ret;
ret = comp->ops->compress(zstrm->ctx, src, PAGE_SIZE,
zstrm->buffer, &dlen);
if (!ret)
*dst_len = dlen;
return ret;
}
int zcomp_decompress(struct zcomp *comp, struct zcomp_strm *zstrm,
const void *src, unsigned int src_len, void *dst)
{
return comp->ops->decompress(zstrm->ctx, src, src_len,
dst, PAGE_SIZE);
}
int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
{
struct zcomp *comp = hlist_entry(node, struct zcomp, node);
struct zcomp_strm *zstrm;
int ret;
zstrm = per_cpu_ptr(comp->stream, cpu);
local_lock_init(&zstrm->lock);
ret = zcomp_strm_init(comp, zstrm);
if (ret)
pr_err("Can't allocate a compression stream\n");
return ret;
}
int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node)
{
struct zcomp *comp = hlist_entry(node, struct zcomp, node);
struct zcomp_strm *zstrm;
zstrm = per_cpu_ptr(comp->stream, cpu);
zcomp_strm_free(comp, zstrm);
return 0;
}
static int zcomp_init(struct zcomp *comp)
{
int ret;
comp->stream = alloc_percpu(struct zcomp_strm);
if (!comp->stream)
return -ENOMEM;
ret = cpuhp_state_add_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
if (ret < 0)
goto cleanup;
return 0;
cleanup:
free_percpu(comp->stream);
return ret;
}
void zcomp_destroy(struct zcomp *comp)
{
cpuhp_state_remove_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
free_percpu(comp->stream);
kfree(comp);
}
struct zcomp *zcomp_create(const char *alg)
{
struct zcomp *comp;
int error;
comp = kzalloc(sizeof(struct zcomp), GFP_KERNEL);
if (!comp)
return ERR_PTR(-ENOMEM);
comp->ops = lookup_backend_ops(alg);
if (!comp->ops) {
kfree(comp);
return ERR_PTR(-EINVAL);
}
error = zcomp_init(comp);
if (error) {
kfree(comp);
return ERR_PTR(error);
}
return comp;
}
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