U-Boot-V2:Bitops: asm-generic bitops

This introduces selected generic bitop files from
kernel. We don't need minix, ext2, sched or lock
based bitops. Those have been dropped.

Signed-off-by: Nishanth Menon <x0nishan@ti.com>

3 files changed, 114 insertions, 0 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 2cbef7b7d0..c272078bb5 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -9,3 +9,7 @@ config CRC32
 
 config CRC16
 	bool
+
+config GENERIC_FIND_NEXT_BIT
+	def_bool n
+
diff --git a/lib/Makefile b/lib/Makefile
index 00e78ba7c0..2828fbe114 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -23,4 +23,5 @@ obj-$(CONFIG_CRC16)	+= crc16.o
 obj-$(CONFIG_CMDLINE_EDITING)	+= readline.o
 obj-$(CONFIG_SIMPLE_READLINE)	+= readline_simple.o
 obj-$(CONFIG_GLOB)		+= fnmatch.o
+obj-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
 obj-y			+= glob.o
diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c
new file mode 100644
index 0000000000..01873d8884
--- /dev/null
+++ b/lib/find_next_bit.c
@@ -0,0 +1,109 @@
+/* find_next_bit.c: fallback find next bit implementation
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <string.h>
+#include <init.h>
+#include <linux/bitops.h>
+#include <asm/types.h>
+#include <asm/byteorder.h>
+
+#define BITOP_WORD(nr)		((nr) / BITS_PER_LONG)
+
+#ifdef CONFIG_GENERIC_FIND_NEXT_BIT
+/*
+ * Find the next set bit in a memory region.
+ */
+unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
+			    unsigned long offset)
+{
+	const unsigned long *p = addr + BITOP_WORD(offset);
+	unsigned long result = offset & ~(BITS_PER_LONG-1);
+	unsigned long tmp;
+
+	if (offset >= size)
+		return size;
+	size -= result;
+	offset %= BITS_PER_LONG;
+	if (offset) {
+		tmp = *(p++);
+		tmp &= (~0UL << offset);
+		if (size < BITS_PER_LONG)
+			goto found_first;
+		if (tmp)
+			goto found_middle;
+		size -= BITS_PER_LONG;
+		result += BITS_PER_LONG;
+	}
+	while (size & ~(BITS_PER_LONG-1)) {
+		if ((tmp = *(p++)))
+			goto found_middle;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+	tmp = *p;
+
+found_first:
+	tmp &= (~0UL >> (BITS_PER_LONG - size));
+	if (tmp == 0UL)		/* Are any bits set? */
+		return result + size;	/* Nope. */
+found_middle:
+	return result + __ffs(tmp);
+}
+EXPORT_SYMBOL(find_next_bit);
+
+/*
+ * This implementation of find_{first,next}_zero_bit was stolen from
+ * Linus' asm-alpha/bitops.h.
+ */
+unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
+				 unsigned long offset)
+{
+	const unsigned long *p = addr + BITOP_WORD(offset);
+	unsigned long result = offset & ~(BITS_PER_LONG-1);
+	unsigned long tmp;
+
+	if (offset >= size)
+		return size;
+	size -= result;
+	offset %= BITS_PER_LONG;
+	if (offset) {
+		tmp = *(p++);
+		tmp |= ~0UL >> (BITS_PER_LONG - offset);
+		if (size < BITS_PER_LONG)
+			goto found_first;
+		if (~tmp)
+			goto found_middle;
+		size -= BITS_PER_LONG;
+		result += BITS_PER_LONG;
+	}
+	while (size & ~(BITS_PER_LONG-1)) {
+		if (~(tmp = *(p++)))
+			goto found_middle;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+	tmp = *p;
+
+found_first:
+	tmp |= ~0UL << size;
+	if (tmp == ~0UL)	/* Are any bits zero? */
+		return result + size;	/* Nope. */
+found_middle:
+	return result + ffz(tmp);
+}
+ EXPORT_SYMBOL(find_next_zero_bit);
+#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */