From 716ca530e1c4515d8683c9d5be3d56b301758b66 Mon Sep 17 00:00:00 2001
From: James <>
Date: Wed, 4 Nov 2015 11:49:21 +0000
Subject: trunk-47381

---
 .../linux/generic/files/fs/yaffs2/yaffs_bitmap.c   | 97 ++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c

(limited to 'target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c')

diff --git a/target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c b/target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c
new file mode 100644
index 0000000..4440e93
--- /dev/null
+++ b/target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c
@@ -0,0 +1,97 @@
+/*
+ * 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_bitmap.h"
+#include "yaffs_trace.h"
+/*
+ * Chunk bitmap manipulations
+ */
+
+static inline u8 *yaffs_block_bits(struct yaffs_dev *dev, int blk)
+{
+	if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
+		yaffs_trace(YAFFS_TRACE_ERROR,
+			"BlockBits block %d is not valid",
+			blk);
+		BUG();
+	}
+	return dev->chunk_bits +
+	    (dev->chunk_bit_stride * (blk - dev->internal_start_block));
+}
+
+void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk)
+{
+	if (blk < dev->internal_start_block || blk > dev->internal_end_block ||
+	    chunk < 0 || chunk >= dev->param.chunks_per_block) {
+		yaffs_trace(YAFFS_TRACE_ERROR,
+			"Chunk Id (%d:%d) invalid",
+			blk, chunk);
+		BUG();
+	}
+}
+
+void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk)
+{
+	u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+	memset(blk_bits, 0, dev->chunk_bit_stride);
+}
+
+void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+	u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+	yaffs_verify_chunk_bit_id(dev, blk, chunk);
+	blk_bits[chunk / 8] &= ~(1 << (chunk & 7));
+}
+
+void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+	u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+	yaffs_verify_chunk_bit_id(dev, blk, chunk);
+	blk_bits[chunk / 8] |= (1 << (chunk & 7));
+}
+
+int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+	u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+	yaffs_verify_chunk_bit_id(dev, blk, chunk);
+	return (blk_bits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
+}
+
+int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk)
+{
+	u8 *blk_bits = yaffs_block_bits(dev, blk);
+	int i;
+
+	for (i = 0; i < dev->chunk_bit_stride; i++) {
+		if (*blk_bits)
+			return 1;
+		blk_bits++;
+	}
+	return 0;
+}
+
+int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk)
+{
+	u8 *blk_bits = yaffs_block_bits(dev, blk);
+	int i;
+	int n = 0;
+
+	for (i = 0; i < dev->chunk_bit_stride; i++, blk_bits++)
+		n += hweight8(*blk_bits);
+
+	return n;
+}
-- 
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