169 lines
4.4 KiB
C
169 lines
4.4 KiB
C
/* asm/bitops.h for Linux/CRIS
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*
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* TODO: asm versions if speed is needed
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*
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* All bit operations return 0 if the bit was cleared before the
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* operation and != 0 if it was not.
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*
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* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
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*/
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#ifndef _CRIS_BITOPS_H
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#define _CRIS_BITOPS_H
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/* Currently this is unsuitable for consumption outside the kernel. */
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#ifdef __KERNEL__
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#include <asm/arch/bitops.h>
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#include <asm/system.h>
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#include <asm/atomic.h>
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#include <linux/compiler.h>
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/*
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* Some hacks to defeat gcc over-optimizations..
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*/
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struct __dummy { unsigned long a[100]; };
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#define ADDR (*(struct __dummy *) addr)
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#define CONST_ADDR (*(const struct __dummy *) addr)
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/*
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* set_bit - Atomically set a bit in memory
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* @nr: the bit to set
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* @addr: the address to start counting from
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*
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* This function is atomic and may not be reordered. See __set_bit()
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* if you do not require the atomic guarantees.
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* Note that @nr may be almost arbitrarily large; this function is not
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* restricted to acting on a single-word quantity.
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*/
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#define set_bit(nr, addr) (void)test_and_set_bit(nr, addr)
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/*
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* clear_bit - Clears a bit in memory
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* @nr: Bit to clear
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* @addr: Address to start counting from
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*
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* clear_bit() is atomic and may not be reordered. However, it does
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* not contain a memory barrier, so if it is used for locking purposes,
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* you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
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* in order to ensure changes are visible on other processors.
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*/
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#define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr)
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/*
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* change_bit - Toggle a bit in memory
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* @nr: Bit to change
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* @addr: Address to start counting from
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*
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* change_bit() is atomic and may not be reordered.
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* Note that @nr may be almost arbitrarily large; this function is not
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* restricted to acting on a single-word quantity.
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*/
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#define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
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/**
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* test_and_set_bit - Set a bit and return its old value
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* @nr: Bit to set
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* @addr: Address to count from
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*
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* This operation is atomic and cannot be reordered.
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* It also implies a memory barrier.
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*/
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static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
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{
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unsigned int mask, retval;
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unsigned long flags;
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unsigned int *adr = (unsigned int *)addr;
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adr += nr >> 5;
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mask = 1 << (nr & 0x1f);
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cris_atomic_save(addr, flags);
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retval = (mask & *adr) != 0;
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*adr |= mask;
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cris_atomic_restore(addr, flags);
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return retval;
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}
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/*
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* clear_bit() doesn't provide any barrier for the compiler.
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*/
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#define smp_mb__before_clear_bit() barrier()
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#define smp_mb__after_clear_bit() barrier()
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/**
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* test_and_clear_bit - Clear a bit and return its old value
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* @nr: Bit to clear
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* @addr: Address to count from
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*
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* This operation is atomic and cannot be reordered.
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* It also implies a memory barrier.
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*/
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static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
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{
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unsigned int mask, retval;
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unsigned long flags;
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unsigned int *adr = (unsigned int *)addr;
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adr += nr >> 5;
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mask = 1 << (nr & 0x1f);
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cris_atomic_save(addr, flags);
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retval = (mask & *adr) != 0;
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*adr &= ~mask;
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cris_atomic_restore(addr, flags);
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return retval;
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}
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/**
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* test_and_change_bit - Change a bit and return its old value
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* @nr: Bit to change
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* @addr: Address to count from
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*
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* This operation is atomic and cannot be reordered.
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* It also implies a memory barrier.
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*/
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static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
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{
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unsigned int mask, retval;
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unsigned long flags;
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unsigned int *adr = (unsigned int *)addr;
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adr += nr >> 5;
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mask = 1 << (nr & 0x1f);
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cris_atomic_save(addr, flags);
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retval = (mask & *adr) != 0;
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*adr ^= mask;
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cris_atomic_restore(addr, flags);
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return retval;
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}
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#include <asm-generic/bitops/non-atomic.h>
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/*
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* Since we define it "external", it collides with the built-in
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* definition, which doesn't have the same semantics. We don't want to
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* use -fno-builtin, so just hide the name ffs.
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*/
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#define ffs kernel_ffs
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#include <asm-generic/bitops/fls.h>
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#include <asm-generic/bitops/fls64.h>
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#include <asm-generic/bitops/hweight.h>
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#include <asm-generic/bitops/find.h>
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#include <asm-generic/bitops/ext2-non-atomic.h>
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#define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a)
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#define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
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#include <asm-generic/bitops/minix.h>
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#include <asm-generic/bitops/sched.h>
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#endif /* __KERNEL__ */
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#endif /* _CRIS_BITOPS_H */
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