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Diffstat (limited to 'include/asm-cris/bitops.h')
| -rw-r--r-- | include/asm-cris/bitops.h | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/include/asm-cris/bitops.h b/include/asm-cris/bitops.h new file mode 100644 index 00000000000..d7861115d73 --- /dev/null +++ b/include/asm-cris/bitops.h @@ -0,0 +1,387 @@ +/* asm/bitops.h for Linux/CRIS + * + * TODO: asm versions if speed is needed + * + * 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). + */ + +#ifndef _CRIS_BITOPS_H +#define _CRIS_BITOPS_H + +/* Currently this is unsuitable for consumption outside the kernel. */ +#ifdef __KERNEL__ + +#include <asm/arch/bitops.h> +#include <asm/system.h> +#include <linux/compiler.h> + +/* + * Some hacks to defeat gcc over-optimizations.. + */ +struct __dummy { unsigned long a[100]; }; +#define ADDR (*(struct __dummy *) addr) +#define CONST_ADDR (*(const struct __dummy *) 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. + */ + +#define set_bit(nr, addr) (void)test_and_set_bit(nr, addr) + +#define __set_bit(nr, addr) (void)__test_and_set_bit(nr, addr) + +/* + * 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. + */ + +#define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr) + +#define __clear_bit(nr, addr) (void)__test_and_clear_bit(nr, addr) + +/* + * 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. + */ + +#define change_bit(nr, addr) (void)test_and_change_bit(nr, addr) + +/* + * __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. + */ + +#define __change_bit(nr, addr) (void)__test_and_change_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 atomic and cannot be reordered. + * It also implies a memory barrier. + */ + +extern inline int test_and_set_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned long flags; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + local_save_flags(flags); + local_irq_disable(); + retval = (mask & *adr) != 0; + *adr |= mask; + local_irq_restore(flags); + return retval; +} + +extern inline int __test_and_set_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + retval = (mask & *adr) != 0; + *adr |= mask; + return retval; +} + +/* + * clear_bit() doesn't provide any barrier for the compiler. + */ +#define smp_mb__before_clear_bit() barrier() +#define smp_mb__after_clear_bit() barrier() + +/** + * 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. + */ + +extern inline int test_and_clear_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned long flags; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + local_save_flags(flags); + local_irq_disable(); + retval = (mask & *adr) != 0; + *adr &= ~mask; + local_irq_restore(flags); + return retval; +} + +/** + * __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. + */ + +extern inline int __test_and_clear_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + retval = (mask & *adr) != 0; + *adr &= ~mask; + return retval; +} +/** + * 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. + */ + +extern inline int test_and_change_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned long flags; + unsigned int *adr = (unsigned int *)addr; + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + local_save_flags(flags); + local_irq_disable(); + retval = (mask & *adr) != 0; + *adr ^= mask; + local_irq_restore(flags); + return retval; +} + +/* WARNING: non atomic and it can be reordered! */ + +extern inline int __test_and_change_bit(int nr, void *addr) +{ + unsigned int mask, retval; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + retval = (mask & *adr) != 0; + *adr ^= mask; + + return retval; +} + +/** + * test_bit - Determine whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + * + * This routine doesn't need to be atomic. + */ + +extern inline int test_bit(int nr, const void *addr) +{ + unsigned int mask; + unsigned int *adr = (unsigned int *)addr; + + adr += nr >> 5; + mask = 1 << (nr & 0x1f); + return ((mask & *adr) != 0); +} + +/* + * Find-bit routines.. + */ + +/* + * Since we define it "external", it collides with the built-in + * definition, which doesn't have the same semantics. We don't want to + * use -fno-builtin, so just hide the name ffs. + */ +#define ffs kernel_ffs + +/* + * fls: find last bit set. + */ + +#define fls(x) generic_fls(x) + +/* + * 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) + +/** + * 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 + */ +extern inline int find_next_zero_bit (void * addr, int size, int offset) +{ + unsigned long *p = ((unsigned long *) addr) + (offset >> 5); + unsigned long result = offset & ~31UL; + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 31UL; + if (offset) { + tmp = *(p++); + tmp |= ~0UL >> (32-offset); + if (size < 32) + goto found_first; + if (~tmp) + goto found_middle; + size -= 32; + result += 32; + } + while (size & ~31UL) { + if (~(tmp = *(p++))) + goto found_middle; + result += 32; + size -= 32; + } + if (!size) + return result; + tmp = *p; + + found_first: + tmp |= ~0UL >> size; + found_middle: + return result + ffz(tmp); +} + +/** + * find_next_bit - find the first set 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_bit(void *addr, int size, int offset) +{ + unsigned long *p = ((unsigned long *) addr) + (offset >> 5); + unsigned long result = offset & ~31UL; + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 31UL; + if (offset) { + tmp = *(p++); + tmp &= (~0UL << offset); + if (size < 32) + goto found_first; + if (tmp) + goto found_middle; + size -= 32; + result += 32; + } + while (size & ~31UL) { + if ((tmp = *(p++))) + goto found_middle; + result += 32; + size -= 32; + } + if (!size) + return result; + tmp = *p; + +found_first: + tmp &= (~0UL >> (32 - size)); + if (tmp == 0UL) /* Are any bits set? */ + return result + size; /* Nope. */ +found_middle: + return result + __ffs(tmp); +} + +/** + * 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. + */ + +#define find_first_zero_bit(addr, size) \ + find_next_zero_bit((addr), (size), 0) +#define find_first_bit(addr, size) \ + find_next_bit((addr), (size), 0) + +#define ext2_set_bit test_and_set_bit +#define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a) +#define ext2_clear_bit test_and_clear_bit +#define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a) +#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_set_bit(nr,addr) test_and_set_bit(nr,addr) +#define minix_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) + +extern inline int sched_find_first_bit(unsigned long *b) +{ + if (unlikely(b[0])) + return __ffs(b[0]); + if (unlikely(b[1])) + return __ffs(b[1]) + 32; + if (unlikely(b[2])) + return __ffs(b[2]) + 64; + if (unlikely(b[3])) + return __ffs(b[3]) + 96; + if (b[4]) + return __ffs(b[4]) + 128; + return __ffs(b[5]) + 32 + 128; +} + +#endif /* __KERNEL__ */ + +#endif /* _CRIS_BITOPS_H */ |