/*
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* JFFS2 -- Journalling Flash File System, Version 2.
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*
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* Copyright © 2007 Nokia Corporation. All rights reserved.
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* Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
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*
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* Created by Richard Purdie <rpurdie@openedhand.com>
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*
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* For licensing information, see the file 'LICENCE' in this directory.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/lzo.h>
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#include "compr.h"
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static void *lzo_mem;
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static void *lzo_compress_buf;
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static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */
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static void free_workspace(void)
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{
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vfree(lzo_mem);
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vfree(lzo_compress_buf);
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}
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static int __init alloc_workspace(void)
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{
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lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
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lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
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if (!lzo_mem || !lzo_compress_buf) {
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free_workspace();
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return -ENOMEM;
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}
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return 0;
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}
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static int jffs2_lzo_compress(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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size_t compress_size;
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int ret;
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mutex_lock(&deflate_mutex);
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ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
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if (ret != LZO_E_OK)
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goto fail;
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if (compress_size > *dstlen)
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goto fail;
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memcpy(cpage_out, lzo_compress_buf, compress_size);
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mutex_unlock(&deflate_mutex);
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*dstlen = compress_size;
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return 0;
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fail:
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mutex_unlock(&deflate_mutex);
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return -1;
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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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size_t dl = destlen;
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int ret;
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ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
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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_compress,
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.decompress = &jffs2_lzo_decompress,
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.disabled = 0,
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};
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int __init jffs2_lzo_init(void)
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{
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int ret;
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ret = alloc_workspace();
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if (ret < 0)
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return ret;
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ret = jffs2_register_compressor(&jffs2_lzo_comp);
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if (ret)
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free_workspace();
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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_workspace();
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}
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