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linux/drivers/block/zram/zcomp.h
Sergey Senozhatsky b8f03cb703 zram: move immutable comp params away from per-CPU context
Immutable params never change once comp has been allocated and setup, so
we don't need to store multiple copies of them in each per-CPU backend
context.  Move those to per-comp zcomp_params and pass it to backends
callbacks for requests execution.  Basically, this means parameters
sharing between different contexts.

Also introduce two new backends callbacks: setup_params() and
release_params().  First, we need to validate params in a driver-specific
way; second, driver may want to allocate its specific representation of
the params which is needed to execute requests.

Link: https://lkml.kernel.org/r/20240902105656.1383858-20-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:10 -07:00

88 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _ZCOMP_H_
#define _ZCOMP_H_
#include <linux/local_lock.h>
#define ZCOMP_PARAM_NO_LEVEL INT_MIN
/*
* Immutable driver (backend) parameters. The driver may attach private
* data to it (e.g. driver representation of the dictionary, etc.).
*
* This data is kept per-comp and is shared among execution contexts.
*/
struct zcomp_params {
void *dict;
size_t dict_sz;
s32 level;
void *drv_data;
};
/*
* Run-time driver context - scratch buffers, etc. It is modified during
* request execution (compression/decompression), cannot be shared, so
* it's in per-CPU area.
*/
struct zcomp_ctx {
void *context;
};
struct zcomp_strm {
local_lock_t lock;
/* compression buffer */
void *buffer;
struct zcomp_ctx ctx;
};
struct zcomp_req {
const unsigned char *src;
const size_t src_len;
unsigned char *dst;
size_t dst_len;
};
struct zcomp_ops {
int (*compress)(struct zcomp_params *params, struct zcomp_ctx *ctx,
struct zcomp_req *req);
int (*decompress)(struct zcomp_params *params, struct zcomp_ctx *ctx,
struct zcomp_req *req);
int (*create_ctx)(struct zcomp_params *params, struct zcomp_ctx *ctx);
void (*destroy_ctx)(struct zcomp_ctx *ctx);
int (*setup_params)(struct zcomp_params *params);
void (*release_params)(struct zcomp_params *params);
const char *name;
};
/* dynamic per-device compression frontend */
struct zcomp {
struct zcomp_strm __percpu *stream;
const struct zcomp_ops *ops;
struct zcomp_params *params;
struct hlist_node node;
};
int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node);
int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node);
ssize_t zcomp_available_show(const char *comp, char *buf);
bool zcomp_available_algorithm(const char *comp);
struct zcomp *zcomp_create(const char *alg, struct zcomp_params *params);
void zcomp_destroy(struct zcomp *comp);
struct zcomp_strm *zcomp_stream_get(struct zcomp *comp);
void zcomp_stream_put(struct zcomp *comp);
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_ */