drivers/block/zram/zcomp_lzo.c

   1 /*
   2  * Copyright (C) 2014 Sergey Senozhatsky.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version
   7  * 2 of the License, or (at your option) any later version.
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/slab.h>
  12 #include <linux/lzo.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/mm.h>
  15
  16 #include "zcomp_lzo.h"
  17
  18 static void *lzo_create(gfp_t flags)
  19 {
  20         void *ret;
  21
  22         ret = kmalloc(LZO1X_MEM_COMPRESS, flags);
  23         if (!ret)
  24                 ret = __vmalloc(LZO1X_MEM_COMPRESS,
  25                                 flags | __GFP_HIGHMEM,
  26                                 PAGE_KERNEL);
  27         return ret;
  28 }
  29
  30 static void lzo_destroy(void *private)
  31 {
  32         kvfree(private);
  33 }
  34
  35 static int lzo_compress(const unsigned char *src, unsigned char *dst,
  36                 size_t *dst_len, void *private)
  37 {
  38         int ret = lzo1x_1_compress(src, PAGE_SIZE, dst, dst_len, private);
  39         return ret == LZO_E_OK ? 0 : ret;
  40 }
  41
  42 static int lzo_decompress(const unsigned char *src, size_t src_len,
  43                 unsigned char *dst)
  44 {
  45         size_t dst_len = PAGE_SIZE;
  46         int ret = lzo1x_decompress_safe(src, src_len, dst, &dst_len);
  47         return ret == LZO_E_OK ? 0 : ret;
  48 }
  49
  50 struct zcomp_backend zcomp_lzo = {
  51         .compress = lzo_compress,
  52         .decompress = lzo_decompress,
  53         .create = lzo_create,
  54         .destroy = lzo_destroy,
  55         .name = "lzo",
  56 };