make: mufs: re-organise code and add separate Makefile

source/mufs/block.c

@@ -0,0 +1,93 @@
+#include <bitops.h>
+#include <flash.h>
+#include <macros.h>
+
+#include <fs/mufs.h>
+
+#include "block.h"
+
+int mufs_mark_block(struct mufs *fs, uint32_t block, int status)
+{
+	struct flash_dev *dev = fs->dev;
+	uint32_t data;
+	size_t offset, index;
+
+	if (block >= fs->nblocks)
+		return -1;
+
+	offset = align(block >> ilog2(8), ilog2(4));
+	index = mask(block, ilog2(8) + ilog2(4));
+
+	if (flash_read(fs->dev, (1 << dev->log2_block_size) + offset, &data,
+		sizeof data) ==0)
+		return -1;
+
+	if (status) {
+		data |= 1 << index;
+	} else {
+		data = data & ~(1 << index);
+	}
+
+	if (flash_write(fs->dev, (1 << dev->log2_block_size) + offset, &data,
+		sizeof data) == 0)
+		return -1;
+
+	if (flash_sync(fs->dev) < 0)
+		return -1;
+
+	return 0;
+}
+
+static size_t mufs_next_free_block(struct mufs *fs)
+{
+	struct flash_dev *dev = fs->dev;
+	char data[32];
+	size_t nblocks = fs->nblocks;
+	size_t offset, index, bitlen, len;
+
+	offset = 0;
+
+	while (nblocks) {
+		bitlen = min(BIT_SIZE(data), nblocks);
+		len = bitlen >> ilog2(8);
+
+		if (flash_read(fs->dev, (1 << dev->log2_block_size) + offset, data,
+			len) == 0)
+			return SIZE_MAX;
+
+		if ((index = next_clear_bit(data, bitlen)) != SIZE_MAX)
+			return (offset >> (ilog2(8) + ilog2(32))) + index;
+
+		offset += len;
+		nblocks -= bitlen;
+	}
+
+	return SIZE_MAX;
+}
+
+int mufs_alloc_block(struct mufs *fs, uint32_t *found)
+{
+	size_t index;
+
+	if ((index = mufs_next_free_block(fs)) == SIZE_MAX)
+		return -1;
+
+	flash_erase(fs->dev, index, 1);
+
+	*found = index;
+
+	return mufs_mark_block(fs, index, 1);
+}
+
+int mufs_free_block(struct mufs *fs, uint32_t block)
+{
+	struct flash_dev *dev = fs->dev;
+	uint8_t log2_bits_per_block = dev->log2_block_size + ilog2(8);
+	size_t nbitmap_size = align_up(fs->nblocks, log2_bits_per_block) >>
+		log2_bits_per_block;
+
+	if (block < 1 + nbitmap_size)
+		return -1;
+
+	return mufs_mark_block(fs, block, 0);
+}