136 lines
3.0 KiB
C
136 lines
3.0 KiB
C
/*
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* JFFS2 LZO Compression Interface.
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*
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* Copyright (C) 2007 Nokia Corporation. All rights reserved.
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*
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* Author: Richard Purdie <rpurdie@openedhand.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*
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*/
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#include <stdint.h>
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#include <stdio.h>
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#include <string.h>
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#ifndef WITHOUT_LZO
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#include <asm/types.h>
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#include <linux/jffs2.h>
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#include <lzo/lzo1x.h>
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#include "compr.h"
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extern int page_size;
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static void *lzo_mem;
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static void *lzo_compress_buf;
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/*
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* Note about LZO compression.
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*
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* We want to use the _999_ compression routine which gives better compression
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* rates at the expense of time. Decompression time is unaffected. We might as
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* well use the standard lzo library routines for this but they will overflow
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* the destination buffer since they don't check the destination size.
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*
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* We therefore compress to a temporary buffer and copy if it will fit.
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*
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*/
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static int jffs2_lzo_cmpr(unsigned char *data_in, unsigned char *cpage_out,
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uint32_t *sourcelen, uint32_t *dstlen)
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{
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lzo_uint compress_size;
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int ret;
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ret = lzo1x_999_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
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if (ret != LZO_E_OK)
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return -1;
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if (compress_size > *dstlen)
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return -1;
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memcpy(cpage_out, lzo_compress_buf, compress_size);
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*dstlen = compress_size;
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return 0;
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}
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static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
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uint32_t srclen, uint32_t destlen)
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{
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int ret;
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lzo_uint dl;
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ret = lzo1x_decompress_safe(data_in,srclen,cpage_out,&dl,NULL);
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if (ret != LZO_E_OK || dl != destlen)
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return -1;
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return 0;
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}
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static struct jffs2_compressor jffs2_lzo_comp = {
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.priority = JFFS2_LZO_PRIORITY,
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.name = "lzo",
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.compr = JFFS2_COMPR_LZO,
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.compress = &jffs2_lzo_cmpr,
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.decompress = &jffs2_lzo_decompress,
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.disabled = 1,
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};
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int jffs2_lzo_init(void)
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{
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int ret;
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lzo_mem = malloc(LZO1X_999_MEM_COMPRESS);
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if (!lzo_mem)
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return -1;
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/* Worse case LZO compression size from their FAQ */
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lzo_compress_buf = malloc(page_size + (page_size / 16) + 64 + 3);
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if (!lzo_compress_buf) {
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free(lzo_mem);
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return -1;
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}
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ret = jffs2_register_compressor(&jffs2_lzo_comp);
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if (ret < 0) {
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free(lzo_compress_buf);
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free(lzo_mem);
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}
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return ret;
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}
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void jffs2_lzo_exit(void)
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{
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jffs2_unregister_compressor(&jffs2_lzo_comp);
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free(lzo_compress_buf);
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free(lzo_mem);
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}
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#else
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int jffs2_lzo_init(void)
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{
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return 0;
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}
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void jffs2_lzo_exit(void)
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{
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}
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#endif
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