patch-2.4.0-test12 linux/include/asm-parisc/bitops.h

• Lines: 248
• Date: Tue Dec 5 12:29:39 2000
• Orig file: v2.4.0-test11/linux/include/asm-parisc/bitops.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test11/linux/include/asm-parisc/bitops.h linux/include/asm-parisc/bitops.h
@@ -0,0 +1,247 @@
+#ifndef _PARISC_BITOPS_H
+#define _PARISC_BITOPS_H
+
+#include <linux/spinlock.h>
+#include <asm/system.h>
+#include <asm/byteorder.h>
+#include <asm/atomic.h>
+
+#ifdef __LP64__
+#   define SHIFT_PER_LONG 6
+#ifndef BITS_PER_LONG
+#   define BITS_PER_LONG 64
+#endif
+#else
+#   define SHIFT_PER_LONG 5
+#ifndef BITS_PER_LONG
+#   define BITS_PER_LONG 32
+#endif
+#endif
+
+#define CHOP_SHIFTCOUNT(x) ((x) & (BITS_PER_LONG - 1))
+
+static __inline__ int test_and_set_bit(int nr, void * address)
+{
+	unsigned long mask;
+	unsigned long *addr = (unsigned long *) address;
+	int oldbit;
+	unsigned long flags;
+
+	addr += (nr >> SHIFT_PER_LONG);
+	SPIN_LOCK_IRQSAVE(ATOMIC_HASH(addr), flags);
+
+	mask = 1L << CHOP_SHIFTCOUNT(nr);
+	oldbit = (*addr & mask) ? 1 : 0;
+	*addr |= mask;
+
+	SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(addr), flags);
+
+	return oldbit;
+}
+
+static __inline__ int test_and_clear_bit(int nr, void * address)
+{
+	unsigned long mask;
+	unsigned long *addr = (unsigned long *) address;
+	int oldbit;
+	unsigned long flags;
+
+	addr += (nr >> SHIFT_PER_LONG);
+	SPIN_LOCK_IRQSAVE(ATOMIC_HASH(addr), flags);
+
+	mask = 1L << CHOP_SHIFTCOUNT(nr);
+	oldbit = (*addr & mask) ? 1 : 0;
+	*addr &= ~mask;
+
+	SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(addr), flags);
+
+	return oldbit;
+}
+
+static __inline__ int test_and_change_bit(int nr, void * address)
+{
+	unsigned long mask;
+	unsigned long *addr = (unsigned long *) address;
+	int oldbit;
+	unsigned long flags;
+
+	addr += (nr >> SHIFT_PER_LONG);
+	SPIN_LOCK_IRQSAVE(ATOMIC_HASH(addr), flags);
+
+	mask = 1L << CHOP_SHIFTCOUNT(nr);
+	oldbit = (*addr & mask) ? 1 : 0;
+	*addr ^= mask;
+
+	SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(addr), flags);
+
+	return oldbit;
+}
+
+/* again, the read-only case doesn't have to do any locking */
+
+static __inline__ int test_bit(int nr, const volatile void *address)
+{
+	unsigned long mask;
+	unsigned long *addr = (unsigned long *) address;
+	
+	addr += (nr >> SHIFT_PER_LONG);
+	mask = 1L << CHOP_SHIFTCOUNT(nr);
+	
+	return !!(*addr & mask);
+}
+
+/* sparc does this, other arch's don't -- what's the right answer? XXX */
+#define smp_mb__before_clear_bit()	do { } while(0)
+#define smp_mb__after_clear_bit()	do { } while(0)
+#define set_bit(nr,addr)	((void)test_and_set_bit(nr,addr))
+#define clear_bit(nr,addr)	((void)test_and_clear_bit(nr,addr))
+#define change_bit(nr,addr)	((void)test_and_change_bit(nr,addr))
+
+/* XXX We'd need some binary search here */
+
+extern __inline__ unsigned long ffz(unsigned long word)
+{
+	unsigned long result;
+
+	result = 0;
+	while(word & 1) {
+		result++;
+		word >>= 1;
+	}
+
+	return result;
+}
+
+#ifdef __KERNEL__
+
+/*
+ * ffs: find first bit set. This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from the above ffz (man ffs).
+ */
+
+#define ffs(x) generic_ffs(x)
+
+/*
+ * hweightN: returns the hamming weight (i.e. the number
+ * of bits set) of a N-bit word
+ */
+
+#define hweight32(x) generic_hweight32(x)
+#define hweight16(x) generic_hweight16(x)
+#define hweight8(x) generic_hweight8(x)
+
+#endif /* __KERNEL__ */
+
+/*
+ * This implementation of find_{first,next}_zero_bit was stolen from
+ * Linus' asm-alpha/bitops.h.
+ */
+#define find_first_zero_bit(addr, size) \
+	find_next_zero_bit((addr), (size), 0)
+
+static __inline__ unsigned long find_next_zero_bit(void * addr, unsigned long size, unsigned long offset)
+{
+	unsigned long * p = ((unsigned long *) addr) + (offset >> SHIFT_PER_LONG);
+	unsigned long result = offset & ~(BITS_PER_LONG-1);
+	unsigned long tmp;
+
+	if (offset >= size)
+		return size;
+	size -= result;
+	offset &= (BITS_PER_LONG-1);
+	if (offset) {
+		tmp = *(p++);
+		tmp |= ~0UL >> (BITS_PER_LONG-offset);
+		if (size < BITS_PER_LONG)
+			goto found_first;
+		if (~tmp)
+			goto found_middle;
+		size -= BITS_PER_LONG;
+		result += BITS_PER_LONG;
+	}
+	while (size & ~(BITS_PER_LONG -1)) {
+		if (~(tmp = *(p++)))
+			goto found_middle;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+	tmp = *p;
+found_first:
+	tmp |= ~0UL << size;
+found_middle:
+	return result + ffz(tmp);
+}
+
+#define _EXT2_HAVE_ASM_BITOPS_
+
+#ifdef __KERNEL__
+/*
+ * test_and_{set,clear}_bit guarantee atomicity without
+ * disabling interrupts.
+ */
+#define ext2_set_bit(nr, addr)		test_and_set_bit((nr) ^ 0x18, addr)
+#define ext2_clear_bit(nr, addr)	test_and_clear_bit((nr) ^ 0x18, addr)
+
+#endif	/* __KERNEL__ */
+
+static __inline__ int ext2_test_bit(int nr, __const__ void * addr)
+{
+	__const__ unsigned char	*ADDR = (__const__ unsigned char *) addr;
+
+	return (ADDR[nr >> 3] >> (nr & 7)) & 1;
+}
+
+/*
+ * This implementation of ext2_find_{first,next}_zero_bit was stolen from
+ * Linus' asm-alpha/bitops.h and modified for a big-endian machine.
+ */
+
+#define ext2_find_first_zero_bit(addr, size) \
+        ext2_find_next_zero_bit((addr), (size), 0)
+
+extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr,
+	unsigned long size, unsigned long offset)
+{
+	unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
+	unsigned int result = offset & ~31UL;
+	unsigned int tmp;
+
+	if (offset >= size)
+		return size;
+	size -= result;
+	offset &= 31UL;
+	if (offset) {
+		tmp = cpu_to_le32p(p++);
+		tmp |= ~0UL >> (32-offset);
+		if (size < 32)
+			goto found_first;
+		if (tmp != ~0U)
+			goto found_middle;
+		size -= 32;
+		result += 32;
+	}
+	while (size >= 32) {
+		if ((tmp = cpu_to_le32p(p++)) != ~0U)
+			goto found_middle;
+		result += 32;
+		size -= 32;
+	}
+	if (!size)
+		return result;
+	tmp = cpu_to_le32p(p);
+found_first:
+	tmp |= ~0U << size;
+found_middle:
+	return result + ffz(tmp);
+}
+
+/* Bitmap functions for the minix filesystem.  */
+#define minix_set_bit(nr,addr) ext2_set_bit(nr,addr)
+#define minix_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
+#define minix_test_bit(nr,addr) ext2_test_bit(nr,addr)
+#define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size)
+
+#endif /* _PARISC_BITOPS_H */