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Diffstat (limited to 'fs/yaffs2/yaffs_bitmap.c')
-rw-r--r--fs/yaffs2/yaffs_bitmap.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/fs/yaffs2/yaffs_bitmap.c b/fs/yaffs2/yaffs_bitmap.c
new file mode 100644
index 000000000000..7df42cd0066e
--- /dev/null
+++ b/fs/yaffs2/yaffs_bitmap.c
@@ -0,0 +1,98 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 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);
+ YBUG();
+ }
+ 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);
+ YBUG();
+ }
+}
+
+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;
+}