yaffs Reactoring WIP

[yaffs2.git] / yaffs_bitmap.c

diff --git a/yaffs_bitmap.c b/yaffs_bitmap.c
new file mode 100644 (file)
index 0000000..c7e9e8c
--- /dev/null
+++ b/yaffs_bitmap.c
@@ -0,0 +1,105 @@
+/*
+ * 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 Y_INLINE __u8 *yaffs_BlockBits(yaffs_Device *dev, int blk)
+{
+       if (blk < dev->internalStartBlock || blk > dev->internalEndBlock) {
+               T(YAFFS_TRACE_ERROR,
+                       (TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR),
+                       blk));
+               YBUG();
+       }
+       return dev->chunkBits +
+               (dev->chunkBitmapStride * (blk - dev->internalStartBlock));
+}
+
+void yaffs_VerifyChunkBitId(yaffs_Device *dev, int blk, int chunk)
+{
+       if (blk < dev->internalStartBlock || blk > dev->internalEndBlock ||
+                       chunk < 0 || chunk >= dev->param.nChunksPerBlock) {
+               T(YAFFS_TRACE_ERROR,
+               (TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR),
+                       blk, chunk));
+               YBUG();
+       }
+}
+
+void yaffs_ClearChunkBits(yaffs_Device *dev, int blk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+
+       memset(blkBits, 0, dev->chunkBitmapStride);
+}
+
+void yaffs_ClearChunkBit(yaffs_Device *dev, int blk, int chunk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+
+       yaffs_VerifyChunkBitId(dev, blk, chunk);
+
+       blkBits[chunk / 8] &= ~(1 << (chunk & 7));
+}
+
+void yaffs_SetChunkBit(yaffs_Device *dev, int blk, int chunk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+
+       yaffs_VerifyChunkBitId(dev, blk, chunk);
+
+       blkBits[chunk / 8] |= (1 << (chunk & 7));
+}
+
+int yaffs_CheckChunkBit(yaffs_Device *dev, int blk, int chunk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       yaffs_VerifyChunkBitId(dev, blk, chunk);
+
+       return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
+}
+
+int yaffs_StillSomeChunkBits(yaffs_Device *dev, int blk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       int i;
+       for (i = 0; i < dev->chunkBitmapStride; i++) {
+               if (*blkBits)
+                       return 1;
+               blkBits++;
+       }
+       return 0;
+}
+
+int yaffs_CountChunkBits(yaffs_Device *dev, int blk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       int i;
+       int n = 0;
+       for (i = 0; i < dev->chunkBitmapStride; i++) {
+               __u8 x = *blkBits;
+               while (x) {
+                       if (x & 1)
+                               n++;
+                       x >>= 1;
+               }
+
+               blkBits++;
+       }
+       return n;
+}
+