patch-2.4.20 linux-2.4.20/include/asm-x86_64/bitops.h

• Lines: 410
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/asm-x86_64/bitops.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/include/asm-x86_64/bitops.h linux-2.4.20/include/asm-x86_64/bitops.h
@@ -0,0 +1,409 @@
+#ifndef _X86_64_BITOPS_H
+#define _X86_64_BITOPS_H
+
+/*
+ * Copyright 1992, Linus Torvalds.
+ */
+
+#include <linux/config.h>
+
+/*
+ * These have to be done with inline assembly: that way the bit-setting
+ * is guaranteed to be atomic. All bit operations return 0 if the bit
+ * was cleared before the operation and != 0 if it was not.
+ *
+ * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
+ */
+
+#ifdef CONFIG_SMP
+#define LOCK_PREFIX "lock ; "
+#else
+#define LOCK_PREFIX ""
+#endif
+
+#define ADDR (*(volatile long *) addr)
+
+/**
+ * set_bit - Atomically set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * This function is atomic and may not be reordered.  See __set_bit()
+ * if you do not require the atomic guarantees.
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static __inline__ void set_bit(long nr, volatile void * addr)
+{
+	__asm__ __volatile__( LOCK_PREFIX
+		"btsq %1,%0"
+		:"=m" (ADDR)
+		:"dIr" (nr));
+}
+
+/**
+ * __set_bit - Set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * Unlike set_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 __set_bit(long nr, volatile void * addr)
+{
+	__asm__(
+		"btsq %1,%0"
+		:"=m" (ADDR)
+		:"dIr" (nr));
+}
+
+/**
+ * clear_bit - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * clear_bit() is atomic and may not be reordered.  However, it does
+ * not contain a memory barrier, so if it is used for locking purposes,
+ * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
+ * in order to ensure changes are visible on other processors.
+ */
+static __inline__ void clear_bit(long nr, volatile void * addr)
+{
+	__asm__ __volatile__( LOCK_PREFIX
+		"btrq %1,%0"
+		:"=m" (ADDR)
+		:"dIr" (nr));
+}
+#define smp_mb__before_clear_bit()	barrier()
+#define smp_mb__after_clear_bit()	barrier()
+
+/**
+ * __change_bit - Toggle a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * Unlike change_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 __change_bit(long nr, volatile void * addr)
+{
+	__asm__ __volatile__(
+		"btcq %1,%0"
+		:"=m" (ADDR)
+		:"dIr" (nr));
+}
+
+/**
+ * change_bit - Toggle a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * change_bit() is atomic and may not be reordered.
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static __inline__ void change_bit(long nr, volatile void * addr)
+{
+	__asm__ __volatile__( LOCK_PREFIX
+		"btcq %1,%0"
+		:"=m" (ADDR)
+		:"dIr" (nr));
+}
+
+/**
+ * test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.  
+ * It also implies a memory barrier.
+ */
+static __inline__ int test_and_set_bit(long nr, volatile void * addr)
+{
+        long oldbit;
+
+	__asm__ __volatile__( LOCK_PREFIX
+		"btsq %2,%1\n\tsbbq %0,%0"
+		:"=r" (oldbit),"=m" (ADDR)
+		:"dIr" (nr) : "memory");
+	return oldbit;
+}
+
+/**
+ * __test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is non-atomic and can be reordered.  
+ * If two examples of this operation race, one can appear to succeed
+ * but actually fail.  You must protect multiple accesses with a lock.
+ */
+static __inline__ int __test_and_set_bit(long nr, volatile void * addr)
+{
+	long oldbit;
+
+	__asm__(
+		"btsq %2,%1\n\tsbbq %0,%0"
+		:"=r" (oldbit),"=m" (ADDR)
+		:"dIr" (nr));
+	return oldbit;
+}
+
+/**
+ * test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.  
+ * It also implies a memory barrier.
+ */
+static __inline__ int test_and_clear_bit(long nr, volatile void * addr)
+{
+	long oldbit;
+
+	__asm__ __volatile__( LOCK_PREFIX
+		"btrq %2,%1\n\tsbbq %0,%0"
+		:"=r" (oldbit),"=m" (ADDR)
+		:"dIr" (nr) : "memory");
+	return oldbit;
+}
+
+/**
+ * __test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is non-atomic and can be reordered.  
+ * If two examples of this operation race, one can appear to succeed
+ * but actually fail.  You must protect multiple accesses with a lock.
+ */
+static __inline__ int __test_and_clear_bit(long nr, volatile void * addr)
+{
+	long oldbit;
+
+	__asm__(
+		"btrq %2,%1\n\tsbbq %0,%0"
+		:"=r" (oldbit),"=m" (ADDR)
+		:"dIr" (nr));
+	return oldbit;
+}
+
+/* WARNING: non atomic and it can be reordered! */
+static __inline__ int __test_and_change_bit(long nr, volatile void * addr)
+{
+	long oldbit;
+
+	__asm__ __volatile__(
+		"btcq %2,%1\n\tsbbq %0,%0"
+		:"=r" (oldbit),"=m" (ADDR)
+		:"dIr" (nr) : "memory");
+	return oldbit;
+}
+
+/**
+ * test_and_change_bit - Change a bit and return its new value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.  
+ * It also implies a memory barrier.
+ */
+static __inline__ int test_and_change_bit(long nr, volatile void * addr)
+{
+	long oldbit;
+
+	__asm__ __volatile__( LOCK_PREFIX
+		"btcq %2,%1\n\tsbbq %0,%0"
+		:"=r" (oldbit),"=m" (ADDR)
+		:"dIr" (nr) : "memory");
+	return oldbit;
+}
+
+#if 0 /* Fool kernel-doc since it doesn't do macros yet */
+/**
+ * test_bit - Determine whether a bit is set
+ * @nr: bit number to test
+ * @addr: Address to start counting from
+ */
+static int test_bit(int nr, const volatile void * addr);
+#endif
+
+static __inline__ int constant_test_bit(long nr, const volatile void * addr)
+{
+	return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
+}
+
+static __inline__ int variable_test_bit(long nr, volatile void * addr)
+{
+	long oldbit;
+
+	__asm__ __volatile__(
+		"btq %2,%1\n\tsbbq %0,%0"
+		:"=r" (oldbit)
+		:"m" (ADDR),"dIr" (nr));
+	return oldbit;
+}
+
+#define test_bit(nr,addr) \
+(__builtin_constant_p(nr) ? \
+ constant_test_bit((nr),(addr)) : \
+ variable_test_bit((nr),(addr)))
+
+/**
+ * find_first_zero_bit - find the first zero bit in a memory region
+ * @addr: The address to start the search at
+ * @size: The maximum bitnumber to search
+ *
+ * Returns the bit-number of the first zero bit, not the number of the byte
+ * containing a bit. -1 when none found.
+ */
+static __inline__ int find_first_zero_bit(void * addr, unsigned size)
+{
+	int d0, d1, d2;
+	int res;
+
+	if (!size)
+		return 0;
+	__asm__ __volatile__(
+		"movl $-1,%%eax\n\t"
+		"xorl %%edx,%%edx\n\t"
+		"repe; scasl\n\t"
+		"je 1f\n\t"
+		"xorl -4(%%rdi),%%eax\n\t"
+		"subq $4,%%rdi\n\t"
+		"bsfl %%eax,%%edx\n"
+		"1:\tsubq %%rbx,%%rdi\n\t"
+		"shlq $3,%%rdi\n\t"
+		"addq %%rdi,%%rdx"
+		:"=d" (res), "=&c" (d0), "=&D" (d1), "=&a" (d2)
+		:"1" ((size + 31) >> 5), "2" (addr), "b" (addr) : "memory");
+	return res;
+}
+
+/**
+ * find_next_zero_bit - find the first zero bit in a memory region
+ * @addr: The address to base the search on
+ * @offset: The bitnumber to start searching at
+ * @size: The maximum size to search
+ */
+static __inline__ int find_next_zero_bit (void * addr, int size, int offset)
+{
+	unsigned int * p = ((unsigned int *) addr) + (offset >> 5);
+	int set = 0, bit = offset & 31, res;
+	
+	if (bit) {
+		/*
+		 * Look for zero in first byte
+		 */
+		__asm__("bsfl %1,%0\n\t"
+			"jne 1f\n\t"
+			"movl $32, %0\n"
+			"1:"
+			: "=r" (set)
+			: "r" (~(*p >> bit)));
+		if (set < (32 - bit))
+			return set + offset;
+		set = 32 - bit;
+		p++;
+	}
+	/*
+	 * No zero yet, search remaining full bytes for a zero
+	 */
+	res = find_first_zero_bit (p, size - 32 * (p - (unsigned int *) addr));
+	return (offset + set + res);
+}
+
+/* 
+ * Find string of zero bits in a bitmap. -1 when not found.
+ */ 
+extern unsigned long 
+find_next_zero_string(unsigned long *bitmap, long start, long nbits, int len);
+
+static inline void set_bit_string(unsigned long *bitmap, unsigned long i, 
+				  int len) 
+{ 
+	unsigned long end = i + len; 
+	while (i < end) {
+		__set_bit(i, bitmap); 
+		i++;
+	}
+} 
+
+static inline void clear_bit_string(unsigned long *bitmap, unsigned long i, 
+				    int len) 
+{ 
+	unsigned long end = i + len; 
+	while (i < end) {
+		clear_bit(i, bitmap); 
+		i++;
+	}
+} 
+
+/**
+ * ffz - find first zero in word.
+ * @word: The word to search
+ *
+ * Undefined if no zero exists, so code should check against ~0UL first.
+ */
+static __inline__ unsigned long ffz(unsigned long word)
+{
+	__asm__("bsfq %1,%0"
+		:"=r" (word)
+		:"r" (~word));
+	return word;
+}
+
+#ifdef __KERNEL__
+
+/**
+ * ffs - find first bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from the above ffz (man ffs).
+ */
+static __inline__ int ffs(int x)
+{
+	int r;
+
+	__asm__("bsfl %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
+ *
+ * The Hamming Weight of a number is the total number of bits set in it.
+ */
+
+#define hweight32(x) generic_hweight32(x)
+#define hweight16(x) generic_hweight16(x)
+#define hweight8(x) generic_hweight8(x)
+
+#endif /* __KERNEL__ */
+
+#ifdef __KERNEL__
+
+#define ext2_set_bit                 __test_and_set_bit
+#define ext2_clear_bit               __test_and_clear_bit
+#define ext2_test_bit                test_bit
+#define ext2_find_first_zero_bit     find_first_zero_bit
+#define ext2_find_next_zero_bit      find_next_zero_bit
+
+/* Bitmap functions for the minix filesystem.  */
+#define minix_test_and_set_bit(nr,addr) __test_and_set_bit(nr,addr)
+#define minix_set_bit(nr,addr) __set_bit(nr,addr)
+#define minix_test_and_clear_bit(nr,addr) __test_and_clear_bit(nr,addr)
+#define minix_test_bit(nr,addr) test_bit(nr,addr)
+#define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size)
+
+#endif /* __KERNEL__ */
+
+#endif /* _X86_64_BITOPS_H */