X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=include%2Fasm-ia64%2Fbitops.h;h=e2ca800373351d26b1042394275ebe10f6c8d23e;hb=a0abb93bf9dc590b031a1123f3e6c6c225c1cdd1;hp=a1b9719f5fbb7ba11071a92ddcd611e6945e2c2e;hpb=03bbe082cffc4533f6557bf23f0c672307067246;p=linux-2.6-omap-h63xx.git

diff --git a/include/asm-ia64/bitops.h b/include/asm-ia64/bitops.h
index a1b9719f5fb..e2ca8003733 100644
--- a/include/asm-ia64/bitops.h
+++ b/include/asm-ia64/bitops.h
@@ -122,38 +122,40 @@ clear_bit_unlock (int nr, volatile void *addr)
 }
 
 /**
- * __clear_bit_unlock - Non-atomically clear a bit with release
+ * __clear_bit_unlock - Non-atomically clears a bit in memory with release
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
  *
- * This is like clear_bit_unlock, but the implementation uses a store
+ * Similarly to clear_bit_unlock, the implementation uses a store
  * with release semantics. See also __raw_spin_unlock().
  */
 static __inline__ void
-__clear_bit_unlock(int nr, volatile void *addr)
+__clear_bit_unlock(int nr, void *addr)
 {
-	__u32 mask, new;
-	volatile __u32 *m;
+	__u32 * const m = (__u32 *) addr + (nr >> 5);
+	__u32 const new = *m & ~(1 << (nr & 31));
 
-	m = (volatile __u32 *)addr + (nr >> 5);
-	mask = ~(1 << (nr & 31));
-	new = *m & mask;
-	barrier();
 	ia64_st4_rel_nta(m, new);
 }
 
 /**
  * __clear_bit - Clears a bit in memory (non-atomic version)
+ * @nr: the bit to clear
+ * @addr: the address to start counting from
+ *
+ * Unlike clear_bit(), this function is non-atomic and may be reordered.
+ * If it's called on the same region of memory simultaneously, the effect
+ * may be that only one operation succeeds.
  */
 static __inline__ void
 __clear_bit (int nr, volatile void *addr)
 {
-	volatile __u32 *p = (__u32 *) addr + (nr >> 5);
-	__u32 m = 1 << (nr & 31);
-	*p &= ~m;
+	*((__u32 *) addr + (nr >> 5)) &= ~(1 << (nr & 31));
 }
 
 /**
  * change_bit - Toggle a bit in memory
- * @nr: Bit to clear
+ * @nr: Bit to toggle
  * @addr: Address to start counting from
  *
  * change_bit() is atomic and may not be reordered.
@@ -178,7 +180,7 @@ change_bit (int nr, volatile void *addr)
 
 /**
  * __change_bit - Toggle a bit in memory
- * @nr: the bit to set
+ * @nr: the bit to toggle
  * @addr: the address to start counting from
  *
  * Unlike change_bit(), this function is non-atomic and may be reordered.
@@ -197,7 +199,7 @@ __change_bit (int nr, volatile void *addr)
  * @addr: Address to count from
  *
  * This operation is atomic and cannot be reordered.  
- * It also implies a memory barrier.
+ * It also implies the acquisition side of the memory barrier.
  */
 static __inline__ int
 test_and_set_bit (int nr, volatile void *addr)
@@ -247,11 +249,11 @@ __test_and_set_bit (int nr, volatile void *addr)
 
 /**
  * test_and_clear_bit - Clear a bit and return its old value
- * @nr: Bit to set
+ * @nr: Bit to clear
  * @addr: Address to count from
  *
  * This operation is atomic and cannot be reordered.  
- * It also implies a memory barrier.
+ * It also implies the acquisition side of the memory barrier.
  */
 static __inline__ int
 test_and_clear_bit (int nr, volatile void *addr)
@@ -272,7 +274,7 @@ test_and_clear_bit (int nr, volatile void *addr)
 
 /**
  * __test_and_clear_bit - Clear a bit and return its old value
- * @nr: Bit to set
+ * @nr: Bit to clear
  * @addr: Address to count from
  *
  * This operation is non-atomic and can be reordered.  
@@ -292,11 +294,11 @@ __test_and_clear_bit(int nr, volatile void * addr)
 
 /**
  * test_and_change_bit - Change a bit and return its old value
- * @nr: Bit to set
+ * @nr: Bit to change
  * @addr: Address to count from
  *
  * This operation is atomic and cannot be reordered.  
- * It also implies a memory barrier.
+ * It also implies the acquisition side of the memory barrier.
  */
 static __inline__ int
 test_and_change_bit (int nr, volatile void *addr)
@@ -315,8 +317,12 @@ test_and_change_bit (int nr, volatile void *addr)
 	return (old & bit) != 0;
 }
 
-/*
- * WARNING: non atomic version.
+/**
+ * __test_and_change_bit - Change a bit and return its old value
+ * @nr: Bit to change
+ * @addr: Address to count from
+ *
+ * This operation is non-atomic and can be reordered.
  */
 static __inline__ int
 __test_and_change_bit (int nr, void *addr)
@@ -401,6 +407,22 @@ fls (int t)
 	return ia64_popcnt(x);
 }
 
+/*
+ * Find the last (most significant) bit set.  Undefined for x==0.
+ * Bits are numbered from 0..63 (e.g., __fls(9) == 3).
+ */
+static inline unsigned long
+__fls (unsigned long x)
+{
+	x |= x >> 1;
+	x |= x >> 2;
+	x |= x >> 4;
+	x |= x >> 8;
+	x |= x >> 16;
+	x |= x >> 32;
+	return ia64_popcnt(x) - 1;
+}
+
 #include <asm-generic/bitops/fls64.h>
 
 /*