linux/drivers/block/zram/backend_deflate.c
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

147 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/zlib.h>
#include "backend_deflate.h"
/* Use the same value as crypto API */
#define DEFLATE_DEF_WINBITS 11
#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL
struct deflate_ctx {
struct z_stream_s cctx;
struct z_stream_s dctx;
};
static void deflate_release_params(struct zcomp_params *params)
{
}
static int deflate_setup_params(struct zcomp_params *params)
{
if (params->level == ZCOMP_PARAM_NO_LEVEL)
params->level = Z_DEFAULT_COMPRESSION;
return 0;
}
static void deflate_destroy(struct zcomp_ctx *ctx)
{
struct deflate_ctx *zctx = ctx->context;
if (!zctx)
return;
if (zctx->cctx.workspace) {
zlib_deflateEnd(&zctx->cctx);
vfree(zctx->cctx.workspace);
}
if (zctx->dctx.workspace) {
zlib_inflateEnd(&zctx->dctx);
vfree(zctx->dctx.workspace);
}
kfree(zctx);
}
static int deflate_create(struct zcomp_params *params, struct zcomp_ctx *ctx)
{
struct deflate_ctx *zctx;
size_t sz;
int ret;
zctx = kzalloc(sizeof(*zctx), GFP_KERNEL);
if (!zctx)
return -ENOMEM;
ctx->context = zctx;
sz = zlib_deflate_workspacesize(-DEFLATE_DEF_WINBITS, MAX_MEM_LEVEL);
zctx->cctx.workspace = vzalloc(sz);
if (!zctx->cctx.workspace)
goto error;
ret = zlib_deflateInit2(&zctx->cctx, params->level, Z_DEFLATED,
-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
Z_DEFAULT_STRATEGY);
if (ret != Z_OK)
goto error;
sz = zlib_inflate_workspacesize();
zctx->dctx.workspace = vzalloc(sz);
if (!zctx->dctx.workspace)
goto error;
ret = zlib_inflateInit2(&zctx->dctx, -DEFLATE_DEF_WINBITS);
if (ret != Z_OK)
goto error;
return 0;
error:
deflate_destroy(ctx);
return -EINVAL;
}
static int deflate_compress(struct zcomp_params *params, struct zcomp_ctx *ctx,
struct zcomp_req *req)
{
struct deflate_ctx *zctx = ctx->context;
struct z_stream_s *deflate;
int ret;
deflate = &zctx->cctx;
ret = zlib_deflateReset(deflate);
if (ret != Z_OK)
return -EINVAL;
deflate->next_in = (u8 *)req->src;
deflate->avail_in = req->src_len;
deflate->next_out = (u8 *)req->dst;
deflate->avail_out = req->dst_len;
ret = zlib_deflate(deflate, Z_FINISH);
if (ret != Z_STREAM_END)
return -EINVAL;
req->dst_len = deflate->total_out;
return 0;
}
static int deflate_decompress(struct zcomp_params *params,
struct zcomp_ctx *ctx,
struct zcomp_req *req)
{
struct deflate_ctx *zctx = ctx->context;
struct z_stream_s *inflate;
int ret;
inflate = &zctx->dctx;
ret = zlib_inflateReset(inflate);
if (ret != Z_OK)
return -EINVAL;
inflate->next_in = (u8 *)req->src;
inflate->avail_in = req->src_len;
inflate->next_out = (u8 *)req->dst;
inflate->avail_out = req->dst_len;
ret = zlib_inflate(inflate, Z_SYNC_FLUSH);
if (ret != Z_STREAM_END)
return -EINVAL;
return 0;
}
const struct zcomp_ops backend_deflate = {
.compress = deflate_compress,
.decompress = deflate_decompress,
.create_ctx = deflate_create,
.destroy_ctx = deflate_destroy,
.setup_params = deflate_setup_params,
.release_params = deflate_release_params,
.name = "deflate",
};