text: /*
   * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   *
   * Copyright (C) 2002-2011 Aleph One Ltd.
   *   for Toby Churchill Ltd and Brightstar Engineering
   *
   * Created by Charles Manning <charles@aleph1.co.uk>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include "yaffs_guts.h"
  #include "yaffs_trace.h"
  #include "yaffs_packedtags2.h"
  
  static int yaffs_tags_marshall_write(struct yaffs_dev *dev,
  				    int nand_chunk, const u8 *data,
  				    const struct yaffs_ext_tags *tags)
  {
  	struct yaffs_packed_tags2 pt;
  	int retval;
  
  	int packed_tags_size =
  	    dev->param.no_tags_ecc ? sizeof(pt.t) : sizeof(pt);
  	void *packed_tags_ptr =
  	    dev->param.no_tags_ecc ? (void *)&pt.t : (void *)&pt;
  
  	yaffs_trace(YAFFS_TRACE_MTD,
  		"yaffs_tags_marshall_write chunk %d data %p tags %p",
  		nand_chunk, data, tags);
  
  	/* For yaffs2 writing there must be both data and tags.
  	 * If we're using inband tags, then the tags are stuffed into
  	 * the end of the data buffer.
  	 */
  	if (!data || !tags)
  		BUG();
  	else if (dev->param.inband_tags) {
  		struct yaffs_packed_tags2_tags_only *pt2tp;
  		pt2tp =
  		    (struct yaffs_packed_tags2_tags_only *)(data +
  							dev->
  							data_bytes_per_chunk);
  		yaffs_pack_tags2_tags_only(pt2tp, tags);
  	} else {
  		yaffs_pack_tags2(&pt, tags, !dev->param.no_tags_ecc);
  	}
  
  	retval = dev->drv.drv_write_chunk_fn(dev, nand_chunk,
  			data, dev->param.total_bytes_per_chunk,
  			(dev->param.inband_tags) ? NULL : packed_tags_ptr,
  			(dev->param.inband_tags) ? 0 : packed_tags_size);
  
  	return retval;
  }
  
  static int yaffs_tags_marshall_read(struct yaffs_dev *dev,
  				   int nand_chunk, u8 *data,
  				   struct yaffs_ext_tags *tags)
  {
  	int retval = 0;
  	int local_data = 0;
  	u8 spare_buffer[100];
  	enum yaffs_ecc_result ecc_result;
  
  	struct yaffs_packed_tags2 pt;
  
  	int packed_tags_size =
  	    dev->param.no_tags_ecc ? sizeof(pt.t) : sizeof(pt);
  	void *packed_tags_ptr =
  	    dev->param.no_tags_ecc ? (void *)&pt.t : (void *)&pt;
  
  	yaffs_trace(YAFFS_TRACE_MTD,
  		"yaffs_tags_marshall_read chunk %d data %p tags %p",
  		nand_chunk, data, tags);
  
  	if (dev->param.inband_tags) {
  		if (!data) {
  			local_data = 1;
  			data = yaffs_get_temp_buffer(dev);
  		}
  	}
  
  	if (dev->param.inband_tags || (data && !tags))
  		retval = dev->drv.drv_read_chunk_fn(dev, nand_chunk,
  					data, dev->param.total_bytes_per_chunk,
  					NULL, 0,
  					&ecc_result);
  	else if (tags)
  		retval = dev->drv.drv_read_chunk_fn(dev, nand_chunk,
  					data, dev->param.total_bytes_per_chunk,
  					spare_buffer, packed_tags_size,
  					&ecc_result);
  	else
  		BUG();
  
  
  	if (dev->param.inband_tags) {
  		if (tags) {
  			struct yaffs_packed_tags2_tags_only *pt2tp;
  			pt2tp =
  				(struct yaffs_packed_tags2_tags_only *)
  				&data[dev->data_bytes_per_chunk];
  			yaffs_unpack_tags2_tags_only(tags, pt2tp);
  		}
  	} else if (tags) {
  		memcpy(packed_tags_ptr, spare_buffer, packed_tags_size);
  		yaffs_unpack_tags2(tags, &pt, !dev->param.no_tags_ecc);
  	}
  
  	if (local_data)
  		yaffs_release_temp_buffer(dev, data);
  
  	if (tags && ecc_result == YAFFS_ECC_RESULT_UNFIXED) {
  		tags->ecc_result = YAFFS_ECC_RESULT_UNFIXED;
  		dev->n_ecc_unfixed++;
  	}
  
  	if (tags && ecc_result == -YAFFS_ECC_RESULT_FIXED) {
  		if (tags->ecc_result <= YAFFS_ECC_RESULT_NO_ERROR)
  			tags->ecc_result = YAFFS_ECC_RESULT_FIXED;
  		dev->n_ecc_fixed++;
  	}
  
  	if (ecc_result < YAFFS_ECC_RESULT_UNFIXED)
  		return YAFFS_OK;
  	else
  		return YAFFS_FAIL;
  }
  
  static int yaffs_tags_marshall_query_block(struct yaffs_dev *dev, int block_no,
  			       enum yaffs_block_state *state,
  			       u32 *seq_number)
  {
  	int retval;
  
  	yaffs_trace(YAFFS_TRACE_MTD, "yaffs_tags_marshall_query_block %d",
  			block_no);
  
  	retval = dev->drv.drv_check_bad_fn(dev, block_no);
  
  	if (retval== YAFFS_FAIL) {
  		yaffs_trace(YAFFS_TRACE_MTD, "block is bad");
  
  		*state = YAFFS_BLOCK_STATE_DEAD;
  		*seq_number = 0;
  	} else {
  		struct yaffs_ext_tags t;
  
  		yaffs_tags_marshall_read(dev,
  				    block_no * dev->param.chunks_per_block,
  				    NULL, &t);
  
  		if (t.chunk_used) {
  			*seq_number = t.seq_number;
  			*state = YAFFS_BLOCK_STATE_NEEDS_SCAN;
  		} else {
  			*seq_number = 0;
  			*state = YAFFS_BLOCK_STATE_EMPTY;
  		}
  	}
  
  	yaffs_trace(YAFFS_TRACE_MTD,
  		"block query returns  seq %d state %d",
  		*seq_number, *state);
  
  	if (retval == 0)
  		return YAFFS_OK;
  	else
  		return YAFFS_FAIL;
  }
  
  static int yaffs_tags_marshall_mark_bad(struct yaffs_dev *dev, int block_no)
  {
  	return dev->drv.drv_mark_bad_fn(dev, block_no);
  
  }
  
  
  void yaffs_tags_marshall_install(struct yaffs_dev *dev)
  {
  	if (!dev->param.is_yaffs2)
  		return;
  
  	if (!dev->tagger.write_chunk_tags_fn)
  		dev->tagger.write_chunk_tags_fn = yaffs_tags_marshall_write;
  
  	if (!dev->tagger.read_chunk_tags_fn)
  		dev->tagger.read_chunk_tags_fn = yaffs_tags_marshall_read;
  
  	if (!dev->tagger.query_block_fn)
  		dev->tagger.query_block_fn = yaffs_tags_marshall_query_block;
  
  	if (!dev->tagger.mark_bad_fn)
  		dev->tagger.mark_bad_fn = yaffs_tags_marshall_mark_bad;
  
  }
  