*
* This function is atomic and may not be reordered. See __set_bit()
* if you do not require the atomic guarantees.
+ *
+ * Note: there are no guarantees that this function will not be reordered
+ * on non x86 architectures, so if you are writting portable code,
+ * make sure not to rely on its reordering guarantees.
+ *
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
{
__asm__ __volatile__( LOCK_PREFIX
"btsl %1,%0"
- :"=m" (ADDR)
+ :"+m" (ADDR)
:"Ir" (nr));
}
{
__asm__(
"btsl %1,%0"
- :"=m" (ADDR)
+ :"+m" (ADDR)
:"Ir" (nr));
}
{
__asm__ __volatile__( LOCK_PREFIX
"btrl %1,%0"
- :"=m" (ADDR)
+ :"+m" (ADDR)
:"Ir" (nr));
}
{
__asm__ __volatile__(
"btrl %1,%0"
- :"=m" (ADDR)
+ :"+m" (ADDR)
:"Ir" (nr));
}
#define smp_mb__before_clear_bit() barrier()
{
__asm__ __volatile__(
"btcl %1,%0"
- :"=m" (ADDR)
+ :"+m" (ADDR)
:"Ir" (nr));
}
* @nr: Bit to change
* @addr: Address to start counting from
*
- * change_bit() is atomic and may not be reordered.
+ * change_bit() is atomic and may not be reordered. It may be
+ * reordered on other architectures than x86.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
{
__asm__ __volatile__( LOCK_PREFIX
"btcl %1,%0"
- :"=m" (ADDR)
+ :"+m" (ADDR)
:"Ir" (nr));
}
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
+ * It may be reordered on other architectures than x86.
* It also implies a memory barrier.
*/
static inline int test_and_set_bit(int nr, volatile unsigned long * addr)
__asm__ __volatile__( LOCK_PREFIX
"btsl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ :"=r" (oldbit),"+m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
__asm__(
"btsl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ :"=r" (oldbit),"+m" (ADDR)
:"Ir" (nr));
return oldbit;
}
* @nr: Bit to clear
* @addr: Address to count from
*
- * This operation is atomic and cannot be reordered.
+ * This operation is atomic and cannot be reordered.
+ * It can be reorderdered on other architectures other than x86.
* It also implies a memory barrier.
*/
static inline int test_and_clear_bit(int nr, volatile unsigned long * addr)
__asm__ __volatile__( LOCK_PREFIX
"btrl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ :"=r" (oldbit),"+m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
__asm__(
"btrl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ :"=r" (oldbit),"+m" (ADDR)
:"Ir" (nr));
return oldbit;
}
__asm__ __volatile__(
"btcl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ :"=r" (oldbit),"+m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
__asm__ __volatile__( LOCK_PREFIX
"btcl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
+ :"=r" (oldbit),"+m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
static int test_bit(int nr, const volatile void * addr);
#endif
-static inline int constant_test_bit(int nr, const volatile unsigned long *addr)
+static __always_inline int constant_test_bit(int nr, const volatile unsigned long *addr)
{
return ((1UL << (nr & 31)) & (addr[nr >> 5])) != 0;
}
*/
int find_next_zero_bit(const unsigned long *addr, int size, int offset);
+/**
+ * __ffs - find first bit in word.
+ * @word: The word to search
+ *
+ * Undefined if no bit exists, so code should check against 0 first.
+ */
+static inline unsigned long __ffs(unsigned long word)
+{
+ __asm__("bsfl %1,%0"
+ :"=r" (word)
+ :"rm" (word));
+ return word;
+}
+
/**
* find_first_bit - find the first set bit in a memory region
* @addr: The address to start the search at
* Returns the bit-number of the first set bit, not the number of the byte
* containing a bit.
*/
-static inline int find_first_bit(const unsigned long *addr, unsigned size)
+static inline unsigned find_first_bit(const unsigned long *addr, unsigned size)
{
- int d0, d1;
- int res;
-
- /* This looks at memory. Mark it volatile to tell gcc not to move it around */
- __asm__ __volatile__(
- "xorl %%eax,%%eax\n\t"
- "repe; scasl\n\t"
- "jz 1f\n\t"
- "leal -4(%%edi),%%edi\n\t"
- "bsfl (%%edi),%%eax\n"
- "1:\tsubl %%ebx,%%edi\n\t"
- "shll $3,%%edi\n\t"
- "addl %%edi,%%eax"
- :"=a" (res), "=&c" (d0), "=&D" (d1)
- :"1" ((size + 31) >> 5), "2" (addr), "b" (addr) : "memory");
- return res;
+ unsigned x = 0;
+
+ while (x < size) {
+ unsigned long val = *addr++;
+ if (val)
+ return __ffs(val) + x;
+ x += (sizeof(*addr)<<3);
+ }
+ return x;
}
/**
return word;
}
-/**
- * __ffs - find first bit in word.
- * @word: The word to search
- *
- * Undefined if no bit exists, so code should check against 0 first.
- */
-static inline unsigned long __ffs(unsigned long word)
-{
- __asm__("bsfl %1,%0"
- :"=r" (word)
- :"rm" (word));
- return word;
-}
-
-/*
- * fls: find last bit set.
- */
-
-#define fls(x) generic_fls(x)
+#define fls64(x) generic_fls64(x)
#ifdef __KERNEL__
return r+1;
}
+/**
+ * fls - find last bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as ffs.
+ */
+static inline int fls(int x)
+{
+ int r;
+
+ __asm__("bsrl %1,%0\n\t"
+ "jnz 1f\n\t"
+ "movl $-1,%0\n"
+ "1:" : "=r" (r) : "rm" (x));
+ return r+1;
+}
+
/**
* hweightN - returns the hamming weight of a N-bit word
* @x: the word to weigh
git://git.onelab.eu / linux-2.6.git / blobdiff