writeback: fixups for !dirty_writeback_centisecs

[safe/jmp/linux-2.6] / include / linux / bitops.h

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 024f2b0..b796eab 100644 (file)
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -16,16 +16,15 @@
  */
 #include <asm/bitops.h>
 
-#define for_each_bit(bit, addr, size) \
+#define for_each_set_bit(bit, addr, size) \
        for ((bit) = find_first_bit((addr), (size)); \
             (bit) < (size); \
             (bit) = find_next_bit((addr), (size), (bit) + 1))
 
-
 static __inline__ int get_bitmask_order(unsigned int count)
 {
        int order;
-       
+
        order = fls(count);
        return order;   /* We could be slightly more clever with -1 here... */
 }
@@ -33,7 +32,7 @@ static __inline__ int get_bitmask_order(unsigned int count)
 static __inline__ int get_count_order(unsigned int count)
 {
        int order;
-       
+
        order = fls(count) - 1;
        if (count & (count - 1))
                order++;
@@ -45,6 +44,31 @@ static inline unsigned long hweight_long(unsigned long w)
        return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
 }
 
+/*
+ * Clearly slow versions of the hweightN() functions, their benefit is
+ * of course compile time evaluation of constant arguments.
+ */
+#define HWEIGHT8(w)                                    \
+      (        BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) +   \
+       (!!((w) & (1ULL << 0))) +                       \
+       (!!((w) & (1ULL << 1))) +                       \
+       (!!((w) & (1ULL << 2))) +                       \
+       (!!((w) & (1ULL << 3))) +                       \
+       (!!((w) & (1ULL << 4))) +                       \
+       (!!((w) & (1ULL << 5))) +                       \
+       (!!((w) & (1ULL << 6))) +                       \
+       (!!((w) & (1ULL << 7))) )
+
+#define HWEIGHT16(w) (HWEIGHT8(w)  + HWEIGHT8((w) >> 8))
+#define HWEIGHT32(w) (HWEIGHT16(w) + HWEIGHT16((w) >> 16))
+#define HWEIGHT64(w) (HWEIGHT32(w) + HWEIGHT32((w) >> 32))
+
+/*
+ * Type invariant version that simply casts things to the
+ * largest type.
+ */
+#define HWEIGHT(w)   HWEIGHT64((u64)(w))
+
 /**
  * rol32 - rotate a 32-bit value left
  * @word: value to rotate
@@ -112,6 +136,25 @@ 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
 
@@ -134,9 +177,20 @@ extern unsigned long find_first_bit(const unsigned long *addr,
  */
 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
 
 /**