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- #ifndef _I386_BITOPS_H
- #define _I386_BITOPS_H
- /*
- * Copyright 1992, Linus Torvalds.
- */
- /*
- * 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).
- */
- #include <asm-generic/bitops/fls.h>
- #include <asm-generic/bitops/__fls.h>
- #include <asm-generic/bitops/fls64.h>
- #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(int nr, volatile void * addr)
- {
- __asm__ __volatile__( LOCK_PREFIX
- "btsl %1,%0"
- :"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- __asm__(
- "btsl %1,%0"
- :"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- __asm__ __volatile__( LOCK_PREFIX
- "btrl %1,%0"
- :"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- __asm__ __volatile__(
- "btcl %1,%0"
- :"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- __asm__ __volatile__( LOCK_PREFIX
- "btcl %1,%0"
- :"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- int oldbit;
- __asm__ __volatile__( LOCK_PREFIX
- "btsl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- int oldbit;
- __asm__(
- "btsl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- int oldbit;
- __asm__ __volatile__( LOCK_PREFIX
- "btrl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- int oldbit;
- __asm__(
- "btrl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
- :"Ir" (nr));
- return oldbit;
- }
- /* WARNING: non atomic and it can be reordered! */
- static __inline__ int __test_and_change_bit(int nr, volatile void * addr)
- {
- int oldbit;
- __asm__ __volatile__(
- "btcl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
- :"Ir" (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(int nr, volatile void * addr)
- {
- int oldbit;
- __asm__ __volatile__( LOCK_PREFIX
- "btcl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit),"=m" (ADDR)
- :"Ir" (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(int nr, const volatile void * addr)
- {
- return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
- }
- static __inline__ int variable_test_bit(int nr, volatile void * addr)
- {
- int oldbit;
- __asm__ __volatile__(
- "btl %2,%1\n\tsbbl %0,%0"
- :"=r" (oldbit)
- :"m" (ADDR),"Ir" (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 size to search
- *
- * Returns the bit-number of the first zero bit, not the number of the byte
- * containing a bit.
- */
- static __inline__ int find_first_zero_bit(void * addr, unsigned size)
- {
- int d0, d1, d2;
- int res;
- if (!size)
- return 0;
- /* This looks at memory. Mark it volatile to tell gcc not to move it around */
- __asm__ __volatile__(
- "movl $-1,%%eax\n\t"
- "xorl %%edx,%%edx\n\t"
- "repe; scasl\n\t"
- "je 1f\n\t"
- "xorl -4(%%edi),%%eax\n\t"
- "subl $4,%%edi\n\t"
- "bsfl %%eax,%%edx\n"
- "1:\tsubl %%ebx,%%edi\n\t"
- "shll $3,%%edi\n\t"
- "addl %%edi,%%edx"
- :"=d" (res), "=&c" (d0), "=&D" (d1), "=&a" (d2)
- :"1" ((size + 31) >> 5), "2" (addr), "b" (addr));
- 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 long * p = ((unsigned long *) 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 long *) addr));
- return (offset + set + res);
- }
- /**
- * 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__("bsfl %1,%0"
- :"=r" (word)
- :"r" (~word));
- return word;
- }
- #ifdef __KERNEL__
- /**
- * __ffs - find first set 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__("rep; bsf %1,%0"
- : "=r" (word)
- : "rm" (word));
- return word;
- }
- /**
- * 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;
- }
- #define PLATFORM_FFS
- static inline int __ilog2(unsigned int x)
- {
- return generic_fls(x) - 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 /* _I386_BITOPS_H */
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