// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Copyright (C) 2014 Sergey Senozhatsky.
- */
#include <linux/kernel.h>
#include <linux/string.h>
#include "zcomp.h"
-static const char * const backends[] = {
-#if IS_ENABLED(CONFIG_CRYPTO_LZO)
- "lzo",
- "lzo-rle",
-#endif
-#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
- "lz4",
-#endif
-#if IS_ENABLED(CONFIG_CRYPTO_LZ4HC)
- "lz4hc",
-#endif
-#if IS_ENABLED(CONFIG_CRYPTO_842)
- "842",
-#endif
-#if IS_ENABLED(CONFIG_CRYPTO_ZSTD)
- "zstd",
-#endif
+static const struct zcomp_ops *backends[] = {
+ NULL
};
-static void zcomp_strm_free(struct zcomp_strm *zstrm)
+static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *zstrm)
{
- if (!IS_ERR_OR_NULL(zstrm->tfm))
- crypto_free_comp(zstrm->tfm);
+ if (zstrm->ctx)
+ comp->ops->destroy_ctx(zstrm->ctx);
vfree(zstrm->buffer);
- zstrm->tfm = NULL;
+ zstrm->ctx = NULL;
zstrm->buffer = NULL;
}
-/*
- * Initialize zcomp_strm structure with ->tfm initialized by backend, and
- * ->buffer. Return a negative value on error.
- */
-static int zcomp_strm_init(struct zcomp_strm *zstrm, struct zcomp *comp)
+static int zcomp_strm_init(struct zcomp *comp, struct zcomp_strm *zstrm)
{
- zstrm->tfm = crypto_alloc_comp(comp->name, 0, 0);
+ 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 (IS_ERR_OR_NULL(zstrm->tfm) || !zstrm->buffer) {
- zcomp_strm_free(zstrm);
+ 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)
{
- /*
- * Crypto does not ignore a trailing new line symbol,
- * so make sure you don't supply a string containing
- * one.
- * This also means that we permit zcomp initialisation
- * with any compressing algorithm known to crypto api.
- */
- return crypto_has_comp(comp, 0, 0) == 1;
+ return lookup_backend_ops(comp) != NULL;
}
/* show available compressors */
ssize_t zcomp_available_show(const char *comp, char *buf)
{
- bool known_algorithm = false;
ssize_t sz = 0;
int i;
- for (i = 0; i < ARRAY_SIZE(backends); i++) {
- if (!strcmp(comp, backends[i])) {
- known_algorithm = true;
+ 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]);
+ "[%s] ", backends[i]->name);
} else {
sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
- "%s ", backends[i]);
+ "%s ", backends[i]->name);
}
}
- /*
- * Out-of-tree module known to crypto api or a missing
- * entry in `backends'.
- */
- if (!known_algorithm && crypto_has_comp(comp, 0, 0) == 1)
- sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
- "[%s] ", comp);
-
sz += scnprintf(buf + sz, PAGE_SIZE - sz, "\n");
return sz;
}
local_unlock(&comp->stream->lock);
}
-int zcomp_compress(struct zcomp_strm *zstrm,
- const void *src, unsigned int *dst_len)
+int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
+ const void *src, unsigned int *dst_len)
{
- /*
- * Our dst memory (zstrm->buffer) is always `2 * PAGE_SIZE' sized
- * because sometimes we can endup having a bigger compressed data
- * due to various reasons: for example compression algorithms tend
- * to add some padding to the compressed buffer. Speaking of padding,
- * comp algorithm `842' pads the compressed length to multiple of 8
- * and returns -ENOSP when the dst memory is not big enough, which
- * is not something that ZRAM wants to see. We can handle the
- * `compressed_size > PAGE_SIZE' case easily in ZRAM, but when we
- * receive -ERRNO from the compressing backend we can't help it
- * anymore. To make `842' happy we need to tell the exact size of
- * the dst buffer, zram_drv will take care of the fact that
- * compressed buffer is too big.
- */
- *dst_len = PAGE_SIZE * 2;
+ /* The dst buffer should always be 2 * PAGE_SIZE */
+ size_t dlen = 2 * PAGE_SIZE;
+ int ret;
- return crypto_comp_compress(zstrm->tfm,
- src, PAGE_SIZE,
- zstrm->buffer, dst_len);
+ ret = comp->ops->compress(zstrm->ctx, src, PAGE_SIZE,
+ zstrm->buffer, &dlen);
+ if (!ret)
+ *dst_len = dlen;
+ return ret;
}
-int zcomp_decompress(struct zcomp_strm *zstrm,
- const void *src, unsigned int src_len, void *dst)
+int zcomp_decompress(struct zcomp *comp, struct zcomp_strm *zstrm,
+ const void *src, unsigned int src_len, void *dst)
{
- unsigned int dst_len = PAGE_SIZE;
-
- return crypto_comp_decompress(zstrm->tfm,
- src, src_len,
- dst, &dst_len);
+ return comp->ops->decompress(zstrm->ctx, src, src_len,
+ dst, PAGE_SIZE);
}
int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
zstrm = per_cpu_ptr(comp->stream, cpu);
local_lock_init(&zstrm->lock);
- ret = zcomp_strm_init(zstrm, comp);
+ ret = zcomp_strm_init(comp, zstrm);
if (ret)
pr_err("Can't allocate a compression stream\n");
return ret;
struct zcomp_strm *zstrm;
zstrm = per_cpu_ptr(comp->stream, cpu);
- zcomp_strm_free(zstrm);
+ zcomp_strm_free(comp, zstrm);
return 0;
}
kfree(comp);
}
-/*
- * search available compressors for requested algorithm.
- * allocate new zcomp and initialize it. return compressing
- * backend pointer or ERR_PTR if things went bad. ERR_PTR(-EINVAL)
- * if requested algorithm is not supported, ERR_PTR(-ENOMEM) in
- * case of allocation error, or any other error potentially
- * returned by zcomp_init().
- */
struct zcomp *zcomp_create(const char *alg)
{
struct zcomp *comp;
int error;
- /*
- * Crypto API will execute /sbin/modprobe if the compression module
- * is not loaded yet. We must do it here, otherwise we are about to
- * call /sbin/modprobe under CPU hot-plug lock.
- */
- if (!zcomp_available_algorithm(alg))
- return ERR_PTR(-EINVAL);
-
comp = kzalloc(sizeof(struct zcomp), GFP_KERNEL);
if (!comp)
return ERR_PTR(-ENOMEM);
- comp->name = alg;
+ comp->ops = lookup_backend_ops(alg);
+ if (!comp->ops) {
+ kfree(comp);
+ return ERR_PTR(-EINVAL);
+ }
+
error = zcomp_init(comp);
if (error) {
kfree(comp);
/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Copyright (C) 2014 Sergey Senozhatsky.
- */
#ifndef _ZCOMP_H_
#define _ZCOMP_H_
local_lock_t lock;
/* compression/decompression buffer */
void *buffer;
- struct crypto_comp *tfm;
+ void *ctx;
+};
+
+struct zcomp_ops {
+ int (*compress)(void *ctx, const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len);
+
+ int (*decompress)(void *ctx, const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t dst_len);
+
+ void *(*create_ctx)(void);
+ void (*destroy_ctx)(void *ctx);
+
+ const char *name;
};
/* dynamic per-device compression frontend */
struct zcomp {
struct zcomp_strm __percpu *stream;
- const char *name;
+ const struct zcomp_ops *ops;
struct hlist_node node;
};
struct zcomp_strm *zcomp_stream_get(struct zcomp *comp);
void zcomp_stream_put(struct zcomp *comp);
-int zcomp_compress(struct zcomp_strm *zstrm,
- const void *src, unsigned int *dst_len);
-
-int zcomp_decompress(struct zcomp_strm *zstrm,
- const void *src, unsigned int src_len, void *dst);
+int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
+ const void *src, unsigned int *dst_len);
+int zcomp_decompress(struct zcomp *comp, struct zcomp_strm *zstrm,
+ const void *src, unsigned int src_len, void *dst);
#endif /* _ZCOMP_H_ */
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