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- #ifndef _ASM_X86_BITOPS_H
- #define _ASM_X86_BITOPS_H
- /*
- * Copyright 1992, Linus Torvalds.
- *
- * Note: inlines with more than a single statement should be marked
- * __always_inline to avoid problems with older gcc's inlining heuristics.
- */
- #ifndef _LINUX_BITOPS_H
- #error only <linux/bitops.h> can be included directly
- #endif
- #include <linux/compiler.h>
- #include <asm/alternative.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).
- */
- #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
- /* Technically wrong, but this avoids compilation errors on some gcc
- versions. */
- #define BITOP_ADDR(x) "=m" (*(volatile long *) (x))
- #else
- #define BITOP_ADDR(x) "+m" (*(volatile long *) (x))
- #endif
- #define ADDR BITOP_ADDR(addr)
- /*
- * We do the locked ops that don't return the old value as
- * a mask operation on a byte.
- */
- #define IS_IMMEDIATE(nr) (__builtin_constant_p(nr))
- #define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3))
- #define CONST_MASK(nr) (1 << ((nr) & 7))
- /**
- * 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: there are no guarantees that this function will not be reordered
- * on non x86 architectures, so if you are writing 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.
- */
- static __always_inline void
- set_bit(unsigned int nr, volatile unsigned long *addr)
- {
- if (IS_IMMEDIATE(nr)) {
- asm volatile(LOCK_PREFIX "orb %1,%0"
- : CONST_MASK_ADDR(nr, addr)
- : "iq" ((u8)CONST_MASK(nr))
- : "memory");
- } else {
- asm volatile(LOCK_PREFIX "bts %1,%0"
- : BITOP_ADDR(addr) : "Ir" (nr) : "memory");
- }
- }
- /**
- * __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 unsigned long *addr)
- {
- asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory");
- }
- /**
- * 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 __always_inline void
- clear_bit(int nr, volatile unsigned long *addr)
- {
- if (IS_IMMEDIATE(nr)) {
- asm volatile(LOCK_PREFIX "andb %1,%0"
- : CONST_MASK_ADDR(nr, addr)
- : "iq" ((u8)~CONST_MASK(nr)));
- } else {
- asm volatile(LOCK_PREFIX "btr %1,%0"
- : BITOP_ADDR(addr)
- : "Ir" (nr));
- }
- }
- /*
- * clear_bit_unlock - Clears a bit in memory
- * @nr: Bit to clear
- * @addr: Address to start counting from
- *
- * clear_bit() is atomic and implies release semantics before the memory
- * operation. It can be used for an unlock.
- */
- static inline void clear_bit_unlock(unsigned nr, volatile unsigned long *addr)
- {
- barrier();
- clear_bit(nr, addr);
- }
- static inline void __clear_bit(int nr, volatile unsigned long *addr)
- {
- asm volatile("btr %1,%0" : ADDR : "Ir" (nr));
- }
- /*
- * __clear_bit_unlock - Clears a bit in memory
- * @nr: Bit to clear
- * @addr: Address to start counting from
- *
- * __clear_bit() is non-atomic and implies release semantics before the memory
- * operation. It can be used for an unlock if no other CPUs can concurrently
- * modify other bits in the word.
- *
- * No memory barrier is required here, because x86 cannot reorder stores past
- * older loads. Same principle as spin_unlock.
- */
- static inline void __clear_bit_unlock(unsigned nr, volatile unsigned long *addr)
- {
- barrier();
- __clear_bit(nr, addr);
- }
- #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 change
- * @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 unsigned long *addr)
- {
- asm volatile("btc %1,%0" : ADDR : "Ir" (nr));
- }
- /**
- * change_bit - Toggle a bit in memory
- * @nr: Bit to change
- * @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 unsigned long *addr)
- {
- if (IS_IMMEDIATE(nr)) {
- asm volatile(LOCK_PREFIX "xorb %1,%0"
- : CONST_MASK_ADDR(nr, addr)
- : "iq" ((u8)CONST_MASK(nr)));
- } else {
- asm volatile(LOCK_PREFIX "btc %1,%0"
- : BITOP_ADDR(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 unsigned long *addr)
- {
- int oldbit;
- asm volatile(LOCK_PREFIX "bts %2,%1\n\t"
- "sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
- return oldbit;
- }
- /**
- * test_and_set_bit_lock - Set a bit and return its old value for lock
- * @nr: Bit to set
- * @addr: Address to count from
- *
- * This is the same as test_and_set_bit on x86.
- */
- static __always_inline int
- test_and_set_bit_lock(int nr, volatile unsigned long *addr)
- {
- return test_and_set_bit(nr, addr);
- }
- /**
- * __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 unsigned long *addr)
- {
- int oldbit;
- asm("bts %2,%1\n\t"
- "sbb %0,%0"
- : "=r" (oldbit), ADDR
- : "Ir" (nr));
- return oldbit;
- }
- /**
- * test_and_clear_bit - Clear a bit and return its old value
- * @nr: Bit to clear
- * @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 unsigned long *addr)
- {
- int oldbit;
- asm volatile(LOCK_PREFIX "btr %2,%1\n\t"
- "sbb %0,%0"
- : "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
- return oldbit;
- }
- /**
- * __test_and_clear_bit - Clear a bit and return its old value
- * @nr: Bit to clear
- * @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 unsigned long *addr)
- {
- int oldbit;
- asm volatile("btr %2,%1\n\t"
- "sbb %0,%0"
- : "=r" (oldbit), ADDR
- : "Ir" (nr));
- return oldbit;
- }
- /* WARNING: non atomic and it can be reordered! */
- static inline int __test_and_change_bit(int nr, volatile unsigned long *addr)
- {
- int oldbit;
- asm volatile("btc %2,%1\n\t"
- "sbb %0,%0"
- : "=r" (oldbit), ADDR
- : "Ir" (nr) : "memory");
- return oldbit;
- }
- /**
- * test_and_change_bit - Change a bit and return its old value
- * @nr: Bit to change
- * @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 unsigned long *addr)
- {
- int oldbit;
- asm volatile(LOCK_PREFIX "btc %2,%1\n\t"
- "sbb %0,%0"
- : "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
- return oldbit;
- }
- static __always_inline int constant_test_bit(unsigned int nr, const volatile unsigned long *addr)
- {
- return ((1UL << (nr % BITS_PER_LONG)) &
- (addr[nr / BITS_PER_LONG])) != 0;
- }
- static inline int variable_test_bit(int nr, volatile const unsigned long *addr)
- {
- int oldbit;
- asm volatile("bt %2,%1\n\t"
- "sbb %0,%0"
- : "=r" (oldbit)
- : "m" (*(unsigned long *)addr), "Ir" (nr));
- 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 unsigned long *addr);
- #endif
- #define test_bit(nr, addr) \
- (__builtin_constant_p((nr)) \
- ? constant_test_bit((nr), (addr)) \
- : variable_test_bit((nr), (addr)))
- /**
- * __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("bsf %1,%0"
- : "=r" (word)
- : "rm" (word));
- return word;
- }
- /**
- * ffz - find first zero bit 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("bsf %1,%0"
- : "=r" (word)
- : "r" (~word));
- return word;
- }
- /*
- * __fls: find last set bit in word
- * @word: The word to search
- *
- * Undefined if no set bit exists, so code should check against 0 first.
- */
- static inline unsigned long __fls(unsigned long word)
- {
- asm("bsr %1,%0"
- : "=r" (word)
- : "rm" (word));
- return word;
- }
- #undef ADDR
- #ifdef __KERNEL__
- /**
- * ffs - find first set bit in word
- * @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 other bitops.
- *
- * ffs(value) returns 0 if value is 0 or the position of the first
- * set bit if value is nonzero. The first (least significant) bit
- * is at position 1.
- */
- static inline int ffs(int x)
- {
- int r;
- #ifdef CONFIG_X86_64
- /*
- * AMD64 says BSFL won't clobber the dest reg if x==0; Intel64 says the
- * dest reg is undefined if x==0, but their CPU architect says its
- * value is written to set it to the same as before, except that the
- * top 32 bits will be cleared.
- *
- * We cannot do this on 32 bits because at the very least some
- * 486 CPUs did not behave this way.
- */
- long tmp = -1;
- asm("bsfl %1,%0"
- : "=r" (r)
- : "rm" (x), "0" (tmp));
- #elif defined(CONFIG_X86_CMOV)
- asm("bsfl %1,%0\n\t"
- "cmovzl %2,%0"
- : "=&r" (r) : "rm" (x), "r" (-1));
- #else
- asm("bsfl %1,%0\n\t"
- "jnz 1f\n\t"
- "movl $-1,%0\n"
- "1:" : "=r" (r) : "rm" (x));
- #endif
- return r + 1;
- }
- /**
- * fls - find last set bit in word
- * @x: the word to search
- *
- * This is defined in a similar way as the libc and compiler builtin
- * ffs, but returns the position of the most significant set bit.
- *
- * fls(value) returns 0 if value is 0 or the position of the last
- * set bit if value is nonzero. The last (most significant) bit is
- * at position 32.
- */
- static inline int fls(int x)
- {
- int r;
- #ifdef CONFIG_X86_64
- /*
- * AMD64 says BSRL won't clobber the dest reg if x==0; Intel64 says the
- * dest reg is undefined if x==0, but their CPU architect says its
- * value is written to set it to the same as before, except that the
- * top 32 bits will be cleared.
- *
- * We cannot do this on 32 bits because at the very least some
- * 486 CPUs did not behave this way.
- */
- long tmp = -1;
- asm("bsrl %1,%0"
- : "=r" (r)
- : "rm" (x), "0" (tmp));
- #elif defined(CONFIG_X86_CMOV)
- asm("bsrl %1,%0\n\t"
- "cmovzl %2,%0"
- : "=&r" (r) : "rm" (x), "rm" (-1));
- #else
- asm("bsrl %1,%0\n\t"
- "jnz 1f\n\t"
- "movl $-1,%0\n"
- "1:" : "=r" (r) : "rm" (x));
- #endif
- return r + 1;
- }
- /**
- * fls64 - find last set bit in a 64-bit word
- * @x: the word to search
- *
- * This is defined in a similar way as the libc and compiler builtin
- * ffsll, but returns the position of the most significant set bit.
- *
- * fls64(value) returns 0 if value is 0 or the position of the last
- * set bit if value is nonzero. The last (most significant) bit is
- * at position 64.
- */
- #ifdef CONFIG_X86_64
- static __always_inline int fls64(__u64 x)
- {
- long bitpos = -1;
- /*
- * AMD64 says BSRQ won't clobber the dest reg if x==0; Intel64 says the
- * dest reg is undefined if x==0, but their CPU architect says its
- * value is written to set it to the same as before.
- */
- asm("bsrq %1,%0"
- : "+r" (bitpos)
- : "rm" (x));
- return bitpos + 1;
- }
- #else
- #include <asm-generic/bitops/fls64.h>
- #endif
- #include <asm-generic/bitops/find.h>
- #include <asm-generic/bitops/sched.h>
- #define ARCH_HAS_FAST_MULTIPLIER 1
- #include <asm/arch_hweight.h>
- #include <asm-generic/bitops/const_hweight.h>
- #include <asm-generic/bitops/le.h>
- #include <asm-generic/bitops/ext2-atomic-setbit.h>
- #endif /* __KERNEL__ */
- #endif /* _ASM_X86_BITOPS_H */
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