X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=include%2Flinux%2Fbitops.h;h=8340a3aba49adbaf9eadf234dbc3fc19d844685b;hb=29f2a4dac856e9433a502b05b40e8e90385d8e27;hp=69c1edb9fe54a345f061cf983fe8311805c83154;hpb=14ed9d23aa9acd79210a92ac561a728b42a8e281;p=safe%2Fjmp%2Flinux-2.6

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 69c1edb..8340a3a 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
 
 /*
@@ -65,6 +65,46 @@ static inline __u32 ror32(__u32 word, unsigned int shift)
 	return (word >> shift) | (word << (32 - shift));
 }
 
+/**
+ * rol16 - rotate a 16-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u16 rol16(__u16 word, unsigned int shift)
+{
+	return (word << shift) | (word >> (16 - shift));
+}
+
+/**
+ * ror16 - rotate a 16-bit value right
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u16 ror16(__u16 word, unsigned int shift)
+{
+	return (word >> shift) | (word << (16 - shift));
+}
+
+/**
+ * rol8 - rotate an 8-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u8 rol8(__u8 word, unsigned int shift)
+{
+	return (word << shift) | (word >> (8 - shift));
+}
+
+/**
+ * ror8 - rotate an 8-bit value right
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u8 ror8(__u8 word, unsigned int shift)
+{
+	return (word >> shift) | (word << (8 - shift));
+}
+
 static inline unsigned fls_long(unsigned long l)
 {
 	if (sizeof(l) == 4)
@@ -72,4 +112,144 @@ static inline unsigned fls_long(unsigned long l)
 	return fls64(l);
 }
 
+#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
+ * @addr: The address to start the search at
+ * @size: The maximum size to search
+ *
+ * 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);
+
+/**
+ * find_first_zero_bit - find the first cleared 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 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);
+}
+#endif /* CONFIG_GENERIC_FIND_FIRST_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
+ * @addr: The address to base the search on
+ * @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);
+
+/**
+ * find_next_zero_bit - find the next cleared bit in a memory region
+ * @addr: The address to base the search on
+ * @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);
+}
+#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
+#endif /* __KERNEL__ */
 #endif