[people/ms/u-boot.git] / fs / yaffs2 / yaffs_checkptrw.c

/*
 * 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_checkptrw.h"
#include "yaffs_getblockinfo.h"

static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
{
	int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"checkpt blocks_avail = %d", blocks_avail);

	return (blocks_avail <= 0) ? 0 : 1;
}

static int yaffs_checkpt_erase(struct yaffs_dev *dev)
{
	int i;

	if (!dev->param.erase_fn)
		return 0;
	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"checking blocks %d to %d",
		dev->internal_start_block, dev->internal_end_block);

	for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
		struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
		if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
			yaffs_trace(YAFFS_TRACE_CHECKPOINT,
			"erasing checkpt block %d", i);

			dev->n_erasures++;

			if (dev->param.
			    erase_fn(dev,
				     i - dev->block_offset /* realign */)) {
				bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
				dev->n_erased_blocks++;
				dev->n_free_chunks +=
				    dev->param.chunks_per_block;
			} else {
				dev->param.bad_block_fn(dev, i);
				bi->block_state = YAFFS_BLOCK_STATE_DEAD;
			}
		}
	}

	dev->blocks_in_checkpt = 0;

	return 1;
}

static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
{
	int i;
	int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"allocating checkpt block: erased %d reserved %d avail %d next %d ",
		dev->n_erased_blocks, dev->param.n_reserved_blocks,
		blocks_avail, dev->checkpt_next_block);

	if (dev->checkpt_next_block >= 0 &&
	    dev->checkpt_next_block <= dev->internal_end_block &&
	    blocks_avail > 0) {

		for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
		     i++) {
			struct yaffs_block_info *bi =
			    yaffs_get_block_info(dev, i);
			if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
				dev->checkpt_next_block = i + 1;
				dev->checkpt_cur_block = i;
				yaffs_trace(YAFFS_TRACE_CHECKPOINT,
					"allocating checkpt block %d", i);
				return;
			}
		}
	}
	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "out of checkpt blocks");

	dev->checkpt_next_block = -1;
	dev->checkpt_cur_block = -1;
}

static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
{
	int i;
	struct yaffs_ext_tags tags;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"find next checkpt block: start:  blocks %d next %d",
		dev->blocks_in_checkpt, dev->checkpt_next_block);

	if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
		for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
		     i++) {
			int chunk = i * dev->param.chunks_per_block;
			int realigned_chunk = chunk - dev->chunk_offset;

			dev->param.read_chunk_tags_fn(dev, realigned_chunk,
						      NULL, &tags);
			yaffs_trace(YAFFS_TRACE_CHECKPOINT,
				"find next checkpt block: search: block %d oid %d seq %d eccr %d",
				i, tags.obj_id, tags.seq_number,
				tags.ecc_result);

			if (tags.seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA) {
				/* Right kind of block */
				dev->checkpt_next_block = tags.obj_id;
				dev->checkpt_cur_block = i;
				dev->checkpt_block_list[dev->
							blocks_in_checkpt] = i;
				dev->blocks_in_checkpt++;
				yaffs_trace(YAFFS_TRACE_CHECKPOINT,
					"found checkpt block %d", i);
				return;
			}
		}

	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");

	dev->checkpt_next_block = -1;
	dev->checkpt_cur_block = -1;
}

int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
{
	int i;

	dev->checkpt_open_write = writing;

	/* Got the functions we need? */
	if (!dev->param.write_chunk_tags_fn ||
	    !dev->param.read_chunk_tags_fn ||
	    !dev->param.erase_fn || !dev->param.bad_block_fn)
		return 0;

	if (writing && !yaffs2_checkpt_space_ok(dev))
		return 0;

	if (!dev->checkpt_buffer)
		dev->checkpt_buffer =
		    kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
	if (!dev->checkpt_buffer)
		return 0;

	dev->checkpt_page_seq = 0;
	dev->checkpt_byte_count = 0;
	dev->checkpt_sum = 0;
	dev->checkpt_xor = 0;
	dev->checkpt_cur_block = -1;
	dev->checkpt_cur_chunk = -1;
	dev->checkpt_next_block = dev->internal_start_block;

	/* Erase all the blocks in the checkpoint area */
	if (writing) {
		memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
		dev->checkpt_byte_offs = 0;
		return yaffs_checkpt_erase(dev);
	}

	/* Set to a value that will kick off a read */
	dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
	/* A checkpoint block list of 1 checkpoint block per 16 block is
	 * (hopefully) going to be way more than we need */
	dev->blocks_in_checkpt = 0;
	dev->checkpt_max_blocks =
	    (dev->internal_end_block - dev->internal_start_block) / 16 + 2;
	dev->checkpt_block_list =
	    kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);

	if (!dev->checkpt_block_list)
		return 0;

	for (i = 0; i < dev->checkpt_max_blocks; i++)
		dev->checkpt_block_list[i] = -1;

	return 1;
}

int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
{
	u32 composite_sum;

	composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xff);
	*sum = composite_sum;
	return 1;
}

static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
{
	int chunk;
	int realigned_chunk;
	struct yaffs_ext_tags tags;

	if (dev->checkpt_cur_block < 0) {
		yaffs2_checkpt_find_erased_block(dev);
		dev->checkpt_cur_chunk = 0;
	}

	if (dev->checkpt_cur_block < 0)
		return 0;

	tags.is_deleted = 0;
	tags.obj_id = dev->checkpt_next_block;	/* Hint to next place to look */
	tags.chunk_id = dev->checkpt_page_seq + 1;
	tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
	tags.n_bytes = dev->data_bytes_per_chunk;
	if (dev->checkpt_cur_chunk == 0) {
		/* First chunk we write for the block? Set block state to
		   checkpoint */
		struct yaffs_block_info *bi =
		    yaffs_get_block_info(dev, dev->checkpt_cur_block);
		bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
		dev->blocks_in_checkpt++;
	}

	chunk =
	    dev->checkpt_cur_block * dev->param.chunks_per_block +
	    dev->checkpt_cur_chunk;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
		chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
		tags.obj_id, tags.chunk_id);

	realigned_chunk = chunk - dev->chunk_offset;

	dev->n_page_writes++;

	dev->param.write_chunk_tags_fn(dev, realigned_chunk,
				       dev->checkpt_buffer, &tags);
	dev->checkpt_byte_offs = 0;
	dev->checkpt_page_seq++;
	dev->checkpt_cur_chunk++;
	if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
		dev->checkpt_cur_chunk = 0;
		dev->checkpt_cur_block = -1;
	}
	memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);

	return 1;
}

int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
{
	int i = 0;
	int ok = 1;
	u8 *data_bytes = (u8 *) data;

	if (!dev->checkpt_buffer)
		return 0;

	if (!dev->checkpt_open_write)
		return -1;

	while (i < n_bytes && ok) {
		dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
		dev->checkpt_sum += *data_bytes;
		dev->checkpt_xor ^= *data_bytes;

		dev->checkpt_byte_offs++;
		i++;
		data_bytes++;
		dev->checkpt_byte_count++;

		if (dev->checkpt_byte_offs < 0 ||
		    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
			ok = yaffs2_checkpt_flush_buffer(dev);
	}

	return i;
}

int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
{
	int i = 0;
	int ok = 1;
	struct yaffs_ext_tags tags;
	int chunk;
	int realigned_chunk;
	u8 *data_bytes = (u8 *) data;

	if (!dev->checkpt_buffer)
		return 0;

	if (dev->checkpt_open_write)
		return -1;

	while (i < n_bytes && ok) {

		if (dev->checkpt_byte_offs < 0 ||
		    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {

			if (dev->checkpt_cur_block < 0) {
				yaffs2_checkpt_find_block(dev);
				dev->checkpt_cur_chunk = 0;
			}

			if (dev->checkpt_cur_block < 0) {
				ok = 0;
				break;
			}

			chunk = dev->checkpt_cur_block *
			    dev->param.chunks_per_block +
			    dev->checkpt_cur_chunk;

			realigned_chunk = chunk - dev->chunk_offset;
			dev->n_page_reads++;

			/* read in the next chunk */
			dev->param.read_chunk_tags_fn(dev,
						realigned_chunk,
						dev->checkpt_buffer,
						&tags);

			if (tags.chunk_id != (dev->checkpt_page_seq + 1) ||
			    tags.ecc_result > YAFFS_ECC_RESULT_FIXED ||
			    tags.seq_number != YAFFS_SEQUENCE_CHECKPOINT_DATA) {
				ok = 0;
				break;
			}

			dev->checkpt_byte_offs = 0;
			dev->checkpt_page_seq++;
			dev->checkpt_cur_chunk++;

			if (dev->checkpt_cur_chunk >=
					dev->param.chunks_per_block)
				dev->checkpt_cur_block = -1;
		}

		*data_bytes = dev->checkpt_buffer[dev->checkpt_byte_offs];
		dev->checkpt_sum += *data_bytes;
		dev->checkpt_xor ^= *data_bytes;
		dev->checkpt_byte_offs++;
		i++;
		data_bytes++;
		dev->checkpt_byte_count++;
	}

	return i;
}

int yaffs_checkpt_close(struct yaffs_dev *dev)
{
	int i;

	if (dev->checkpt_open_write) {
		if (dev->checkpt_byte_offs != 0)
			yaffs2_checkpt_flush_buffer(dev);
	} else if (dev->checkpt_block_list) {
		for (i = 0;
		     i < dev->blocks_in_checkpt &&
		     dev->checkpt_block_list[i] >= 0; i++) {
			int blk = dev->checkpt_block_list[i];
			struct yaffs_block_info *bi = NULL;

			if (dev->internal_start_block <= blk &&
			    blk <= dev->internal_end_block)
				bi = yaffs_get_block_info(dev, blk);
			if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
				bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
		}
		kfree(dev->checkpt_block_list);
		dev->checkpt_block_list = NULL;
	}

	dev->n_free_chunks -=
		dev->blocks_in_checkpt * dev->param.chunks_per_block;
	dev->n_erased_blocks -= dev->blocks_in_checkpt;

	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "checkpoint byte count %d",
		dev->checkpt_byte_count);

	if (dev->checkpt_buffer) {
		/* free the buffer */
		kfree(dev->checkpt_buffer);
		dev->checkpt_buffer = NULL;
		return 1;
	} else {
		return 0;
	}
}

int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
{
	/* Erase the checkpoint data */

	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
		"checkpoint invalidate of %d blocks",
		dev->blocks_in_checkpt);

	return yaffs_checkpt_erase(dev);
}
Commit	Line	Data
0e8cc8bd WJ	1	/*
	2	* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
	3	*
753ac610	4	* Copyright (C) 2002-2011 Aleph One Ltd.
0e8cc8bd WJ	5	* for Toby Churchill Ltd and Brightstar Engineering
	6	*
	7	* Created by Charles Manning <charles@aleph1.co.uk>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
0e8cc8bd	14	#include "yaffs_checkptrw.h"
753ac610	15	#include "yaffs_getblockinfo.h"
0e8cc8bd	16
753ac610	17	static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
0e8cc8bd	18	{
753ac610	19	int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
0e8cc8bd	20
753ac610 CM	21	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
753ac610 CM	22	"checkpt blocks_avail = %d", blocks_avail);
4b070809	23
753ac610	24	return (blocks_avail <= 0) ? 0 : 1;
0e8cc8bd WJ	25	}
0e8cc8bd WJ	26
753ac610	27	static int yaffs_checkpt_erase(struct yaffs_dev *dev)
0e8cc8bd	28	{
0e8cc8bd	29	int i;
0e8cc8bd	30
753ac610	31	if (!dev->param.erase_fn)
0e8cc8bd	32	return 0;
753ac610 CM	33	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	34	"checking blocks %d to %d",
	35	dev->internal_start_block, dev->internal_end_block);
	36
	37	for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
	38	struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
	39	if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
	40	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	41	"erasing checkpt block %d", i);
	42
	43	dev->n_erasures++;
	44
	45	if (dev->param.
	46	erase_fn(dev,
	47	i - dev->block_offset /* realign */)) {
	48	bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
	49	dev->n_erased_blocks++;
	50	dev->n_free_chunks +=
	51	dev->param.chunks_per_block;
	52	} else {
	53	dev->param.bad_block_fn(dev, i);
	54	bi->block_state = YAFFS_BLOCK_STATE_DEAD;
0e8cc8bd WJ	55	}
	56	}
	57	}
4b070809	58
753ac610	59	dev->blocks_in_checkpt = 0;
4b070809	60
0e8cc8bd WJ	61	return 1;
	62	}
	63
753ac610	64	static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
0e8cc8bd	65	{
753ac610 CM	66	int i;
	67	int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
	68
	69	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	70	"allocating checkpt block: erased %d reserved %d avail %d next %d ",
	71	dev->n_erased_blocks, dev->param.n_reserved_blocks,
	72	blocks_avail, dev->checkpt_next_block);
	73
	74	if (dev->checkpt_next_block >= 0 &&
	75	dev->checkpt_next_block <= dev->internal_end_block &&
	76	blocks_avail > 0) {
	77
	78	for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
	79	i++) {
	80	struct yaffs_block_info *bi =
	81	yaffs_get_block_info(dev, i);
	82	if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
	83	dev->checkpt_next_block = i + 1;
	84	dev->checkpt_cur_block = i;
	85	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	86	"allocating checkpt block %d", i);
0e8cc8bd WJ	87	return;
	88	}
	89	}
	90	}
753ac610	91	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "out of checkpt blocks");
4b070809	92
753ac610 CM	93	dev->checkpt_next_block = -1;
753ac610 CM	94	dev->checkpt_cur_block = -1;
0e8cc8bd WJ	95	}
0e8cc8bd WJ	96
753ac610	97	static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
0e8cc8bd	98	{
753ac610 CM	99	int i;
	100	struct yaffs_ext_tags tags;
	101
	102	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	103	"find next checkpt block: start: blocks %d next %d",
	104	dev->blocks_in_checkpt, dev->checkpt_next_block);
	105
	106	if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
	107	for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
	108	i++) {
	109	int chunk = i * dev->param.chunks_per_block;
	110	int realigned_chunk = chunk - dev->chunk_offset;
	111
	112	dev->param.read_chunk_tags_fn(dev, realigned_chunk,
	113	NULL, &tags);
	114	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	115	"find next checkpt block: search: block %d oid %d seq %d eccr %d",
	116	i, tags.obj_id, tags.seq_number,
	117	tags.ecc_result);
	118
	119	if (tags.seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA) {
0e8cc8bd	120	/* Right kind of block */
753ac610 CM	121	dev->checkpt_next_block = tags.obj_id;
	122	dev->checkpt_cur_block = i;
	123	dev->checkpt_block_list[dev->
	124	blocks_in_checkpt] = i;
	125	dev->blocks_in_checkpt++;
	126	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	127	"found checkpt block %d", i);
0e8cc8bd WJ	128	return;
	129	}
	130	}
	131
753ac610	132	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");
0e8cc8bd	133
753ac610 CM	134	dev->checkpt_next_block = -1;
753ac610 CM	135	dev->checkpt_cur_block = -1;
0e8cc8bd WJ	136	}
0e8cc8bd WJ	137
753ac610	138	int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
0e8cc8bd	139	{
753ac610 CM	140	int i;
	141
	142	dev->checkpt_open_write = writing;
4b070809	143
0e8cc8bd	144	/* Got the functions we need? */
753ac610 CM	145	if (!dev->param.write_chunk_tags_fn \|\|
	146	!dev->param.read_chunk_tags_fn \|\|
	147	!dev->param.erase_fn \|\| !dev->param.bad_block_fn)
0e8cc8bd WJ	148	return 0;
0e8cc8bd WJ	149
753ac610	150	if (writing && !yaffs2_checkpt_space_ok(dev))
0e8cc8bd	151	return 0;
4b070809	152
753ac610 CM	153	if (!dev->checkpt_buffer)
	154	dev->checkpt_buffer =
	155	kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
	156	if (!dev->checkpt_buffer)
0e8cc8bd WJ	157	return 0;
0e8cc8bd WJ	158
753ac610 CM	159	dev->checkpt_page_seq = 0;
	160	dev->checkpt_byte_count = 0;
	161	dev->checkpt_sum = 0;
	162	dev->checkpt_xor = 0;
	163	dev->checkpt_cur_block = -1;
	164	dev->checkpt_cur_chunk = -1;
	165	dev->checkpt_next_block = dev->internal_start_block;
4b070809	166
0e8cc8bd	167	/* Erase all the blocks in the checkpoint area */
753ac610 CM	168	if (writing) {
	169	memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
	170	dev->checkpt_byte_offs = 0;
	171	return yaffs_checkpt_erase(dev);
	172	}
4b070809	173
753ac610 CM	174	/* Set to a value that will kick off a read */
	175	dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
	176	/* A checkpoint block list of 1 checkpoint block per 16 block is
	177	* (hopefully) going to be way more than we need */
	178	dev->blocks_in_checkpt = 0;
	179	dev->checkpt_max_blocks =
	180	(dev->internal_end_block - dev->internal_start_block) / 16 + 2;
	181	dev->checkpt_block_list =
	182	kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
	183
	184	if (!dev->checkpt_block_list)
	185	return 0;
4b070809	186
753ac610 CM	187	for (i = 0; i < dev->checkpt_max_blocks; i++)
753ac610 CM	188	dev->checkpt_block_list[i] = -1;
4b070809	189
0e8cc8bd WJ	190	return 1;
	191	}
	192
753ac610	193	int yaffs2_get_checkpt_sum(struct yaffs_dev dev, u32 sum)
0e8cc8bd	194	{
753ac610 CM	195	u32 composite_sum;
	196
	197	composite_sum = (dev->checkpt_sum << 8) \| (dev->checkpt_xor & 0xff);
	198	*sum = composite_sum;
0e8cc8bd WJ	199	return 1;
	200	}
	201
753ac610	202	static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
0e8cc8bd	203	{
0e8cc8bd	204	int chunk;
753ac610 CM	205	int realigned_chunk;
753ac610 CM	206	struct yaffs_ext_tags tags;
4b070809	207
753ac610 CM	208	if (dev->checkpt_cur_block < 0) {
	209	yaffs2_checkpt_find_erased_block(dev);
	210	dev->checkpt_cur_chunk = 0;
0e8cc8bd	211	}
4b070809	212
753ac610	213	if (dev->checkpt_cur_block < 0)
0e8cc8bd	214	return 0;
4b070809	215
753ac610 CM	216	tags.is_deleted = 0;
	217	tags.obj_id = dev->checkpt_next_block; /* Hint to next place to look */
	218	tags.chunk_id = dev->checkpt_page_seq + 1;
	219	tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
	220	tags.n_bytes = dev->data_bytes_per_chunk;
	221	if (dev->checkpt_cur_chunk == 0) {
0e8cc8bd WJ	222	/* First chunk we write for the block? Set block state to
0e8cc8bd WJ	223	checkpoint */
753ac610 CM	224	struct yaffs_block_info *bi =
	225	yaffs_get_block_info(dev, dev->checkpt_cur_block);
	226	bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
	227	dev->blocks_in_checkpt++;
0e8cc8bd	228	}
4b070809	229
753ac610 CM	230	chunk =
	231	dev->checkpt_cur_block * dev->param.chunks_per_block +
	232	dev->checkpt_cur_chunk;
0e8cc8bd	233
753ac610 CM	234	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	235	"checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
	236	chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
	237	tags.obj_id, tags.chunk_id);
4b070809	238
753ac610	239	realigned_chunk = chunk - dev->chunk_offset;
4b070809	240
753ac610	241	dev->n_page_writes++;
4b070809	242
753ac610 CM	243	dev->param.write_chunk_tags_fn(dev, realigned_chunk,
	244	dev->checkpt_buffer, &tags);
	245	dev->checkpt_byte_offs = 0;
	246	dev->checkpt_page_seq++;
	247	dev->checkpt_cur_chunk++;
	248	if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
	249	dev->checkpt_cur_chunk = 0;
	250	dev->checkpt_cur_block = -1;
0e8cc8bd	251	}
753ac610	252	memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
4b070809	253
0e8cc8bd WJ	254	return 1;
	255	}
	256
753ac610	257	int yaffs2_checkpt_wr(struct yaffs_dev dev, const void data, int n_bytes)
0e8cc8bd	258	{
753ac610	259	int i = 0;
0e8cc8bd	260	int ok = 1;
753ac610	261	u8 data_bytes = (u8 ) data;
0e8cc8bd	262
753ac610	263	if (!dev->checkpt_buffer)
0e8cc8bd	264	return 0;
4b070809	265
753ac610	266	if (!dev->checkpt_open_write)
0e8cc8bd WJ	267	return -1;
0e8cc8bd WJ	268
753ac610 CM	269	while (i < n_bytes && ok) {
	270	dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
	271	dev->checkpt_sum += *data_bytes;
	272	dev->checkpt_xor ^= *data_bytes;
4b070809	273
753ac610	274	dev->checkpt_byte_offs++;
0e8cc8bd	275	i++;
753ac610 CM	276	data_bytes++;
753ac610 CM	277	dev->checkpt_byte_count++;
0e8cc8bd	278
753ac610 CM	279	if (dev->checkpt_byte_offs < 0 \|\|
	280	dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
	281	ok = yaffs2_checkpt_flush_buffer(dev);
0e8cc8bd	282	}
4b070809	283
753ac610	284	return i;
0e8cc8bd WJ	285	}
0e8cc8bd WJ	286
753ac610	287	int yaffs2_checkpt_rd(struct yaffs_dev dev, void data, int n_bytes)
0e8cc8bd	288	{
753ac610	289	int i = 0;
0e8cc8bd	290	int ok = 1;
753ac610	291	struct yaffs_ext_tags tags;
0e8cc8bd	292	int chunk;
753ac610 CM	293	int realigned_chunk;
753ac610 CM	294	u8 data_bytes = (u8 ) data;
0e8cc8bd	295
753ac610	296	if (!dev->checkpt_buffer)
0e8cc8bd WJ	297	return 0;
0e8cc8bd WJ	298
753ac610	299	if (dev->checkpt_open_write)
0e8cc8bd WJ	300	return -1;
0e8cc8bd WJ	301
753ac610	302	while (i < n_bytes && ok) {
4b070809	303
753ac610 CM	304	if (dev->checkpt_byte_offs < 0 \|\|
753ac610 CM	305	dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
4b070809	306
753ac610 CM	307	if (dev->checkpt_cur_block < 0) {
	308	yaffs2_checkpt_find_block(dev);
	309	dev->checkpt_cur_chunk = 0;
0e8cc8bd	310	}
4b070809	311
753ac610	312	if (dev->checkpt_cur_block < 0) {
0e8cc8bd	313	ok = 0;
753ac610 CM	314	break;
753ac610 CM	315	}
4b070809	316
753ac610 CM	317	chunk = dev->checkpt_cur_block *
	318	dev->param.chunks_per_block +
	319	dev->checkpt_cur_chunk;
0e8cc8bd	320
753ac610 CM	321	realigned_chunk = chunk - dev->chunk_offset;
753ac610 CM	322	dev->n_page_reads++;
0e8cc8bd	323
753ac610 CM	324	/* read in the next chunk */
	325	dev->param.read_chunk_tags_fn(dev,
	326	realigned_chunk,
	327	dev->checkpt_buffer,
	328	&tags);
4b070809	329
753ac610 CM	330	if (tags.chunk_id != (dev->checkpt_page_seq + 1) \|\|
	331	tags.ecc_result > YAFFS_ECC_RESULT_FIXED \|\|
	332	tags.seq_number != YAFFS_SEQUENCE_CHECKPOINT_DATA) {
	333	ok = 0;
	334	break;
	335	}
0e8cc8bd	336
753ac610 CM	337	dev->checkpt_byte_offs = 0;
	338	dev->checkpt_page_seq++;
	339	dev->checkpt_cur_chunk++;
4b070809	340
753ac610 CM	341	if (dev->checkpt_cur_chunk >=
	342	dev->param.chunks_per_block)
	343	dev->checkpt_cur_block = -1;
0e8cc8bd	344	}
4b070809	345
753ac610 CM	346	*data_bytes = dev->checkpt_buffer[dev->checkpt_byte_offs];
	347	dev->checkpt_sum += *data_bytes;
	348	dev->checkpt_xor ^= *data_bytes;
	349	dev->checkpt_byte_offs++;
	350	i++;
	351	data_bytes++;
	352	dev->checkpt_byte_count++;
0e8cc8bd	353	}
4b070809	354
753ac610	355	return i;
0e8cc8bd WJ	356	}
0e8cc8bd WJ	357
753ac610	358	int yaffs_checkpt_close(struct yaffs_dev *dev)
0e8cc8bd	359	{
753ac610	360	int i;
0e8cc8bd	361
753ac610 CM	362	if (dev->checkpt_open_write) {
	363	if (dev->checkpt_byte_offs != 0)
	364	yaffs2_checkpt_flush_buffer(dev);
	365	} else if (dev->checkpt_block_list) {
	366	for (i = 0;
	367	i < dev->blocks_in_checkpt &&
	368	dev->checkpt_block_list[i] >= 0; i++) {
	369	int blk = dev->checkpt_block_list[i];
	370	struct yaffs_block_info *bi = NULL;
	371
	372	if (dev->internal_start_block <= blk &&
	373	blk <= dev->internal_end_block)
	374	bi = yaffs_get_block_info(dev, blk);
	375	if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
	376	bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
0e8cc8bd	377	}
753ac610 CM	378	kfree(dev->checkpt_block_list);
753ac610 CM	379	dev->checkpt_block_list = NULL;
0e8cc8bd WJ	380	}
0e8cc8bd WJ	381
753ac610 CM	382	dev->n_free_chunks -=
	383	dev->blocks_in_checkpt * dev->param.chunks_per_block;
	384	dev->n_erased_blocks -= dev->blocks_in_checkpt;
0e8cc8bd	385
753ac610 CM	386	yaffs_trace(YAFFS_TRACE_CHECKPOINT, "checkpoint byte count %d",
753ac610 CM	387	dev->checkpt_byte_count);
4b070809	388
753ac610	389	if (dev->checkpt_buffer) {
4b070809	390	/* free the buffer */
753ac610 CM	391	kfree(dev->checkpt_buffer);
753ac610 CM	392	dev->checkpt_buffer = NULL;
0e8cc8bd	393	return 1;
753ac610	394	} else {
0e8cc8bd	395	return 0;
753ac610	396	}
0e8cc8bd WJ	397	}
0e8cc8bd WJ	398
753ac610	399	int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
0e8cc8bd	400	{
753ac610	401	/* Erase the checkpoint data */
0e8cc8bd	402
753ac610 CM	403	yaffs_trace(YAFFS_TRACE_CHECKPOINT,
	404	"checkpoint invalidate of %d blocks",
	405	dev->blocks_in_checkpt);
0e8cc8bd	406
753ac610	407	return yaffs_checkpt_erase(dev);
0e8cc8bd	408	}