diff --git a/include/asm-nios2/bitops.h b/include/asm-nios2/bitops.h index 5776bda3e3..cf48ff7a1a 100644 --- a/include/asm-nios2/bitops.h +++ b/include/asm-nios2/bitops.h @@ -24,15 +24,9 @@ #ifndef __ASM_NIOS2_BITOPS_H_ #define __ASM_NIOS2_BITOPS_H_ - -extern void set_bit(int nr, volatile void * a); -extern void clear_bit(int nr, volatile void * a); -extern int test_and_clear_bit(int nr, volatile void * a); -extern void change_bit(unsigned long nr, volatile void *addr); -extern int test_and_set_bit(int nr, volatile void * a); -extern int test_and_change_bit(int nr, volatile void * addr); -extern int test_bit(int nr, volatile void * a); -extern int ffs(int i); -#define PLATFORM_FFS +/* copied from linux-2.6/include/asm-generic/bitops */ +#include +#include +#include #endif /* __ASM_NIOS2_BITOPS_H */ diff --git a/include/asm-nios2/bitops/atomic.h b/include/asm-nios2/bitops/atomic.h new file mode 100644 index 0000000000..c8946465e6 --- /dev/null +++ b/include/asm-nios2/bitops/atomic.h @@ -0,0 +1,189 @@ +#ifndef _ASM_GENERIC_BITOPS_ATOMIC_H_ +#define _ASM_GENERIC_BITOPS_ATOMIC_H_ + +#include +#include + +#ifdef CONFIG_SMP +#include +#include /* we use L1_CACHE_BYTES */ + +/* Use an array of spinlocks for our atomic_ts. + * Hash function to index into a different SPINLOCK. + * Since "a" is usually an address, use one spinlock per cacheline. + */ +# define ATOMIC_HASH_SIZE 4 +# define ATOMIC_HASH(a) (&(__atomic_hash[ (((unsigned long) a)/L1_CACHE_BYTES) & (ATOMIC_HASH_SIZE-1) ])) + +extern raw_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned; + +/* Can't use raw_spin_lock_irq because of #include problems, so + * this is the substitute */ +#define _atomic_spin_lock_irqsave(l,f) do { \ + raw_spinlock_t *s = ATOMIC_HASH(l); \ + local_irq_save(f); \ + __raw_spin_lock(s); \ +} while(0) + +#define _atomic_spin_unlock_irqrestore(l,f) do { \ + raw_spinlock_t *s = ATOMIC_HASH(l); \ + __raw_spin_unlock(s); \ + local_irq_restore(f); \ +} while(0) + + +#else +# define _atomic_spin_lock_irqsave(l,f) do { local_irq_save(f); } while (0) +# define _atomic_spin_unlock_irqrestore(l,f) do { local_irq_restore(f); } while (0) +#endif + +/* + * NMI events can occur at any time, including when interrupts have been + * disabled by *_irqsave(). So you can get NMI events occurring while a + * *_bit function is holding a spin lock. If the NMI handler also wants + * to do bit manipulation (and they do) then you can get a deadlock + * between the original caller of *_bit() and the NMI handler. + * + * by Keith Owens + */ + +/** + * 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 inline void set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long flags; + + _atomic_spin_lock_irqsave(p, flags); + *p |= mask; + _atomic_spin_unlock_irqrestore(p, flags); +} + +/** + * 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 unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long flags; + + _atomic_spin_lock_irqsave(p, flags); + *p &= ~mask; + _atomic_spin_unlock_irqrestore(p, flags); +} + +/** + * 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. It may be + * reordered on other architectures than x86. + * 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) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long flags; + + _atomic_spin_lock_irqsave(p, flags); + *p ^= mask; + _atomic_spin_unlock_irqrestore(p, flags); +} + +/** + * 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 may be reordered on other architectures than x86. + * It also implies a memory barrier. + */ +static inline int test_and_set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old; + unsigned long flags; + + _atomic_spin_lock_irqsave(p, flags); + old = *p; + *p = old | mask; + _atomic_spin_unlock_irqrestore(p, flags); + + return (old & mask) != 0; +} + +/** + * 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 can be reorderdered on other architectures other than x86. + * It also implies a memory barrier. + */ +static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old; + unsigned long flags; + + _atomic_spin_lock_irqsave(p, flags); + old = *p; + *p = old & ~mask; + _atomic_spin_unlock_irqrestore(p, flags); + + return (old & mask) != 0; +} + +/** + * 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) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old; + unsigned long flags; + + _atomic_spin_lock_irqsave(p, flags); + old = *p; + *p = old ^ mask; + _atomic_spin_unlock_irqrestore(p, flags); + + return (old & mask) != 0; +} + +#endif /* _ASM_GENERIC_BITOPS_ATOMIC_H */ diff --git a/include/asm-nios2/bitops/ffs.h b/include/asm-nios2/bitops/ffs.h new file mode 100644 index 0000000000..fbbb43af7d --- /dev/null +++ b/include/asm-nios2/bitops/ffs.h @@ -0,0 +1,41 @@ +#ifndef _ASM_GENERIC_BITOPS_FFS_H_ +#define _ASM_GENERIC_BITOPS_FFS_H_ + +/** + * 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 = 1; + + if (!x) + return 0; + if (!(x & 0xffff)) { + x >>= 16; + r += 16; + } + if (!(x & 0xff)) { + x >>= 8; + r += 8; + } + if (!(x & 0xf)) { + x >>= 4; + r += 4; + } + if (!(x & 3)) { + x >>= 2; + r += 2; + } + if (!(x & 1)) { + x >>= 1; + r += 1; + } + return r; +} + +#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */ diff --git a/include/asm-nios2/bitops/non-atomic.h b/include/asm-nios2/bitops/non-atomic.h new file mode 100644 index 0000000000..697cc2b7e0 --- /dev/null +++ b/include/asm-nios2/bitops/non-atomic.h @@ -0,0 +1,108 @@ +#ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ +#define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ + +#include + +/** + * __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) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p |= mask; +} + +static inline void __clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p &= ~mask; +} + +/** + * __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) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p ^= mask; +} + +/** + * __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) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old | mask; + return (old & mask) != 0; +} + +/** + * __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) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old & ~mask; + return (old & mask) != 0; +} + +/* WARNING: non atomic and it can be reordered! */ +static inline int __test_and_change_bit(int nr, + volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old ^ mask; + return (old & mask) != 0; +} + +/** + * test_bit - Determine whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + */ +static inline int test_bit(int nr, const volatile unsigned long *addr) +{ + return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); +} + +#endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */