X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=lib%2Ffind_next_bit.c;h=24c59ded47a05d5617e2fe2501077f990de1ec4b;hp=5820e072b890269984dcfc7a5dec1cb10ed61930;hb=9a1607071c293e48b08bd703733480b1d55c7b93;hpb=6fd92b63d0626a8fe7eb8e2e50d19ecaa18cb412

diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c
index 5820e07..24c59de 100644
--- a/lib/find_next_bit.c
+++ b/lib/find_next_bit.c
@@ -15,17 +15,13 @@
 #include <asm/byteorder.h>
 
 #define BITOP_WORD(nr)		((nr) / BITS_PER_LONG)
-#undef find_next_bit
-#undef find_next_zero_bit
-
-/**
- * find_next_bit - find the next set bit in a memory region
- * @addr: The address to base the search on
- * @offset: The bitnumber to start searching at
- * @size: The maximum size to search
+
+#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)
+			    unsigned long offset)
 {
 	const unsigned long *p = addr + BITOP_WORD(offset);
 	unsigned long result = offset & ~(BITS_PER_LONG-1);
@@ -62,7 +58,6 @@ found_first:
 found_middle:
 	return result + __ffs(tmp);
 }
-
 EXPORT_SYMBOL(find_next_bit);
 
 /*
@@ -70,7 +65,7 @@ EXPORT_SYMBOL(find_next_bit);
  * Linus' asm-alpha/bitops.h.
  */
 unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
-		unsigned long offset)
+				 unsigned long offset)
 {
 	const unsigned long *p = addr + BITOP_WORD(offset);
 	unsigned long result = offset & ~(BITS_PER_LONG-1);
@@ -107,8 +102,62 @@ found_first:
 found_middle:
 	return result + ffz(tmp);
 }
-
 EXPORT_SYMBOL(find_next_zero_bit);
+#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
+
+#ifdef CONFIG_GENERIC_FIND_FIRST_BIT
+/*
+ * Find the first set bit in a memory region.
+ */
+unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
+{
+	const unsigned long *p = addr;
+	unsigned long result = 0;
+	unsigned long tmp;
+
+	while (size & ~(BITS_PER_LONG-1)) {
+		if ((tmp = *(p++)))
+			goto found;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+
+	tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));
+	if (tmp == 0UL)		/* Are any bits set? */
+		return result + size;	/* Nope. */
+found:
+	return result + __ffs(tmp);
+}
+EXPORT_SYMBOL(find_first_bit);
+
+/*
+ * Find the first cleared bit in a memory region.
+ */
+unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
+{
+	const unsigned long *p = addr;
+	unsigned long result = 0;
+	unsigned long tmp;
+
+	while (size & ~(BITS_PER_LONG-1)) {
+		if (~(tmp = *(p++)))
+			goto found;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+
+	tmp = (*p) | (~0UL << size);
+	if (tmp == ~0UL)	/* Are any bits zero? */
+		return result + size;	/* Nope. */
+found:
+	return result + ffz(tmp);
+}
+EXPORT_SYMBOL(find_first_zero_bit);
+#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
 
 #ifdef __BIG_ENDIAN