X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=include%2Flinux%2Fbitops.h;h=c05a29cb9bb2540902fa1d553905cd3c7252e25a;hb=14d18a81b5171d4433e41129619c75748b4f4d26;hp=48bde600a2dbcf652715d0c97b4da756ceffad3d;hpb=3a48305028aa38afba93fc05066c71a6ee668ad8;p=safe%2Fjmp%2Flinux-2.6

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 48bde60..c05a29c 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -6,8 +6,8 @@
 #define BIT(nr)			(1UL << (nr))
 #define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
 #define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
-#define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_LONG)
 #define BITS_PER_BYTE		8
+#define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
 #endif
 
 /*
@@ -112,10 +112,27 @@ static inline unsigned fls_long(unsigned long l)
 	return fls64(l);
 }
 
+/**
+ * __ffs64 - find first set bit in a 64 bit word
+ * @word: The 64 bit word
+ *
+ * On 64 bit arches this is a synomyn for __ffs
+ * The result is not defined if no bits are set, so check that @word
+ * is non-zero before calling this.
+ */
+static inline unsigned long __ffs64(u64 word)
+{
+#if BITS_PER_LONG == 32
+	if (((u32)word) == 0UL)
+		return __ffs((u32)(word >> 32)) + 32;
+#elif BITS_PER_LONG != 64
+#error BITS_PER_LONG not 32 or 64
+#endif
+	return __ffs((unsigned long)word);
+}
+
 #ifdef __KERNEL__
 #ifdef CONFIG_GENERIC_FIND_FIRST_BIT
-extern unsigned long __find_first_bit(const unsigned long *addr,
-		unsigned long size);
 
 /**
  * find_first_bit - find the first set bit in a memory region
@@ -124,28 +141,8 @@ extern unsigned long __find_first_bit(const unsigned long *addr,
  *
  * Returns the bit number of the first set bit.
  */
-static __always_inline unsigned long
-find_first_bit(const unsigned long *addr, unsigned long size)
-{
-	/* Avoid a function call if the bitmap size is a constant */
-	/* and not bigger than BITS_PER_LONG. */
-
-	/* insert a sentinel so that __ffs returns size if there */
-	/* are no set bits in the bitmap */
-	if (__builtin_constant_p(size) && (size < BITS_PER_LONG))
-		return __ffs((*addr) | (1ul << size));
-
-	/* the result of __ffs(0) is undefined, so it needs to be */
-	/* handled separately */
-	if (__builtin_constant_p(size) && (size == BITS_PER_LONG))
-		return ((*addr) == 0) ? BITS_PER_LONG : __ffs(*addr);
-
-	/* size is not constant or too big */
-	return __find_first_bit(addr, size);
-}
-
-extern unsigned long __find_first_zero_bit(const unsigned long *addr,
-		unsigned long size);
+extern unsigned long find_first_bit(const unsigned long *addr,
+				    unsigned long size);
 
 /**
  * find_first_zero_bit - find the first cleared bit in a memory region
@@ -154,31 +151,23 @@ extern unsigned long __find_first_zero_bit(const unsigned long *addr,
  *
  * Returns the bit number of the first cleared bit.
  */
-static __always_inline unsigned long
-find_first_zero_bit(const unsigned long *addr, unsigned long size)
-{
-	/* Avoid a function call if the bitmap size is a constant */
-	/* and not bigger than BITS_PER_LONG. */
-
-	/* insert a sentinel so that __ffs returns size if there */
-	/* are no set bits in the bitmap */
-	if (__builtin_constant_p(size) && (size < BITS_PER_LONG)) {
-		return __ffs(~(*addr) | (1ul << size));
-	}
-
-	/* the result of __ffs(0) is undefined, so it needs to be */
-	/* handled separately */
-	if (__builtin_constant_p(size) && (size == BITS_PER_LONG))
-		return (~(*addr) == 0) ? BITS_PER_LONG : __ffs(~(*addr));
-
-	/* size is not constant or too big */
-	return __find_first_zero_bit(addr, size);
-}
+extern unsigned long find_first_zero_bit(const unsigned long *addr,
+					 unsigned long size);
 #endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
 
+#ifdef CONFIG_GENERIC_FIND_LAST_BIT
+/**
+ * find_last_bit - find the last set bit in a memory region
+ * @addr: The address to start the search at
+ * @size: The maximum size to search
+ *
+ * Returns the bit number of the first set bit, or size.
+ */
+extern unsigned long find_last_bit(const unsigned long *addr,
+				   unsigned long size);
+#endif /* CONFIG_GENERIC_FIND_LAST_BIT */
+
 #ifdef CONFIG_GENERIC_FIND_NEXT_BIT
-extern unsigned long __find_next_bit(const unsigned long *addr,
-		unsigned long size, unsigned long offset);
 
 /**
  * find_next_bit - find the next set bit in a memory region
@@ -186,36 +175,8 @@ extern unsigned long __find_next_bit(const unsigned long *addr,
  * @offset: The bitnumber to start searching at
  * @size: The bitmap size in bits
  */
-static __always_inline unsigned long
-find_next_bit(const unsigned long *addr, unsigned long size,
-		unsigned long offset)
-{
-	unsigned long value;
-
-	/* Avoid a function call if the bitmap size is a constant */
-	/* and not bigger than BITS_PER_LONG. */
-
-	/* insert a sentinel so that __ffs returns size if there */
-	/* are no set bits in the bitmap */
-	if (__builtin_constant_p(size) && (size < BITS_PER_LONG)) {
-		value = (*addr) & ((~0ul) << offset);
-		value |= (1ul << size);
-		return __ffs(value);
-	}
-
-	/* the result of __ffs(0) is undefined, so it needs to be */
-	/* handled separately */
-	if (__builtin_constant_p(size) && (size == BITS_PER_LONG)) {
-		value = (*addr) & ((~0ul) << offset);
-		return (value == 0) ? BITS_PER_LONG : __ffs(value);
-	}
-
-	/* size is not constant or too big */
-	return __find_next_bit(addr, size, offset);
-}
-
-extern unsigned long __find_next_zero_bit(const unsigned long *addr,
-		unsigned long size, unsigned long offset);
+extern unsigned long find_next_bit(const unsigned long *addr,
+				   unsigned long size, unsigned long offset);
 
 /**
  * find_next_zero_bit - find the next cleared bit in a memory region
@@ -223,33 +184,11 @@ extern unsigned long __find_next_zero_bit(const unsigned long *addr,
  * @offset: The bitnumber to start searching at
  * @size: The bitmap size in bits
  */
-static __always_inline unsigned long
-find_next_zero_bit(const unsigned long *addr, unsigned long size,
-		unsigned long offset)
-{
-	unsigned long value;
-
-	/* Avoid a function call if the bitmap size is a constant */
-	/* and not bigger than BITS_PER_LONG. */
-
-	/* insert a sentinel so that __ffs returns size if there */
-	/* are no set bits in the bitmap */
-	if (__builtin_constant_p(size) && (size < BITS_PER_LONG)) {
-		value = (~(*addr)) & ((~0ul) << offset);
-		value |= (1ul << size);
-		return __ffs(value);
-	}
-
-	/* the result of __ffs(0) is undefined, so it needs to be */
-	/* handled separately */
-	if (__builtin_constant_p(size) && (size == BITS_PER_LONG)) {
-		value = (~(*addr)) & ((~0ul) << offset);
-		return (value == 0) ? BITS_PER_LONG : __ffs(value);
-	}
-
-	/* size is not constant or too big */
-	return __find_next_zero_bit(addr, size, offset);
-}
+
+extern unsigned long find_next_zero_bit(const unsigned long *addr,
+					unsigned long size,
+					unsigned long offset);
+
 #endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
 #endif /* __KERNEL__ */
 #endif