drivers/block/zram/backend_deflate.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 #include <linux/kernel.h>
   4 #include <linux/slab.h>
   5 #include <linux/vmalloc.h>
   6 #include <linux/zlib.h>
   7
   8 #include "backend_deflate.h"
   9
  10 /* Use the same value as crypto API */
  11 #define DEFLATE_DEF_WINBITS             11
  12 #define DEFLATE_DEF_MEMLEVEL            MAX_MEM_LEVEL
  13
  14 struct deflate_ctx {
  15         struct z_stream_s cctx;
  16         struct z_stream_s dctx;
  17 };
  18
  19 static void deflate_release_params(struct zcomp_params *params)
  20 {
  21 }
  22
  23 static int deflate_setup_params(struct zcomp_params *params)
  24 {
  25         if (params->level == ZCOMP_PARAM_NO_LEVEL)
  26                 params->level = Z_DEFAULT_COMPRESSION;
  27
  28         return 0;
  29 }
  30
  31 static void deflate_destroy(struct zcomp_ctx *ctx)
  32 {
  33         struct deflate_ctx *zctx = ctx->context;
  34
  35         if (!zctx)
  36                 return;
  37
  38         if (zctx->cctx.workspace) {
  39                 zlib_deflateEnd(&zctx->cctx);
  40                 vfree(zctx->cctx.workspace);
  41         }
  42         if (zctx->dctx.workspace) {
  43                 zlib_inflateEnd(&zctx->dctx);
  44                 vfree(zctx->dctx.workspace);
  45         }
  46         kfree(zctx);
  47 }
  48
  49 static int deflate_create(struct zcomp_params *params, struct zcomp_ctx *ctx)
  50 {
  51         struct deflate_ctx *zctx;
  52         size_t sz;
  53         int ret;
  54
  55         zctx = kzalloc(sizeof(*zctx), GFP_KERNEL);
  56         if (!zctx)
  57                 return -ENOMEM;
  58
  59         ctx->context = zctx;
  60         sz = zlib_deflate_workspacesize(-DEFLATE_DEF_WINBITS, MAX_MEM_LEVEL);
  61         zctx->cctx.workspace = vzalloc(sz);
  62         if (!zctx->cctx.workspace)
  63                 goto error;
  64
  65         ret = zlib_deflateInit2(&zctx->cctx, params->level, Z_DEFLATED,
  66                                 -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
  67                                 Z_DEFAULT_STRATEGY);
  68         if (ret != Z_OK)
  69                 goto error;
  70
  71         sz = zlib_inflate_workspacesize();
  72         zctx->dctx.workspace = vzalloc(sz);
  73         if (!zctx->dctx.workspace)
  74                 goto error;
  75
  76         ret = zlib_inflateInit2(&zctx->dctx, -DEFLATE_DEF_WINBITS);
  77         if (ret != Z_OK)
  78                 goto error;
  79
  80         return 0;
  81
  82 error:
  83         deflate_destroy(ctx);
  84         return -EINVAL;
  85 }
  86
  87 static int deflate_compress(struct zcomp_params *params, struct zcomp_ctx *ctx,
  88                             struct zcomp_req *req)
  89 {
  90         struct deflate_ctx *zctx = ctx->context;
  91         struct z_stream_s *deflate;
  92         int ret;
  93
  94         deflate = &zctx->cctx;
  95         ret = zlib_deflateReset(deflate);
  96         if (ret != Z_OK)
  97                 return -EINVAL;
  98
  99         deflate->next_in = (u8 *)req->src;
 100         deflate->avail_in = req->src_len;
 101         deflate->next_out = (u8 *)req->dst;
 102         deflate->avail_out = req->dst_len;
 103
 104         ret = zlib_deflate(deflate, Z_FINISH);
 105         if (ret != Z_STREAM_END)
 106                 return -EINVAL;
 107
 108         req->dst_len = deflate->total_out;
 109         return 0;
 110 }
 111
 112 static int deflate_decompress(struct zcomp_params *params,
 113                               struct zcomp_ctx *ctx,
 114                               struct zcomp_req *req)
 115 {
 116         struct deflate_ctx *zctx = ctx->context;
 117         struct z_stream_s *inflate;
 118         int ret;
 119
 120         inflate = &zctx->dctx;
 121
 122         ret = zlib_inflateReset(inflate);
 123         if (ret != Z_OK)
 124                 return -EINVAL;
 125
 126         inflate->next_in = (u8 *)req->src;
 127         inflate->avail_in = req->src_len;
 128         inflate->next_out = (u8 *)req->dst;
 129         inflate->avail_out = req->dst_len;
 130
 131         ret = zlib_inflate(inflate, Z_SYNC_FLUSH);
 132         if (ret != Z_STREAM_END)
 133                 return -EINVAL;
 134
 135         return 0;
 136 }
 137
 138 const struct zcomp_ops backend_deflate = {
 139         .compress       = deflate_compress,
 140         .decompress     = deflate_decompress,
 141         .create_ctx     = deflate_create,
 142         .destroy_ctx    = deflate_destroy,
 143         .setup_params   = deflate_setup_params,
 144         .release_params = deflate_release_params,
 145         .name           = "deflate",
 146 };