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Diffstat (limited to 'include/asm-powerpc/bitops.h')
| -rw-r--r-- | include/asm-powerpc/bitops.h | 437 |
1 files changed, 437 insertions, 0 deletions
diff --git a/include/asm-powerpc/bitops.h b/include/asm-powerpc/bitops.h new file mode 100644 index 000000000000..dc25c53704d5 --- /dev/null +++ b/include/asm-powerpc/bitops.h @@ -0,0 +1,437 @@ +/* + * PowerPC atomic bit operations. + * + * Merged version by David Gibson <david@gibson.dropbear.id.au>. + * Based on ppc64 versions by: Dave Engebretsen, Todd Inglett, Don + * Reed, Pat McCarthy, Peter Bergner, Anton Blanchard. They + * originally took it from the ppc32 code. + * + * Within a word, bits are numbered LSB first. Lot's of places make + * this assumption by directly testing bits with (val & (1<<nr)). + * This can cause confusion for large (> 1 word) bitmaps on a + * big-endian system because, unlike little endian, the number of each + * bit depends on the word size. + * + * The bitop functions are defined to work on unsigned longs, so for a + * ppc64 system the bits end up numbered: + * |63..............0|127............64|191...........128|255...........196| + * and on ppc32: + * |31.....0|63....31|95....64|127...96|159..128|191..160|223..192|255..224| + * + * There are a few little-endian macros used mostly for filesystem + * bitmaps, these work on similar bit arrays layouts, but + * byte-oriented: + * |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56| + * + * The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit + * number field needs to be reversed compared to the big-endian bit + * fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b). + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _ASM_POWERPC_BITOPS_H +#define _ASM_POWERPC_BITOPS_H + +#ifdef __KERNEL__ + +#include <linux/compiler.h> +#include <asm/atomic.h> +#include <asm/synch.h> + +/* + * clear_bit doesn't imply a memory barrier + */ +#define smp_mb__before_clear_bit() smp_mb() +#define smp_mb__after_clear_bit() smp_mb() + +#define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) +#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) +#define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) + +#ifdef CONFIG_PPC64 +#define LARXL "ldarx" +#define STCXL "stdcx." +#define CNTLZL "cntlzd" +#else +#define LARXL "lwarx" +#define STCXL "stwcx." +#define CNTLZL "cntlzw" +#endif + +static __inline__ void set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long old; + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + __asm__ __volatile__( +"1:" LARXL " %0,0,%3 # set_bit\n" + "or %0,%0,%2\n" + PPC405_ERR77(0,%3) + STCXL " %0,0,%3\n" + "bne- 1b" + : "=&r"(old), "=m"(*p) + : "r"(mask), "r"(p), "m"(*p) + : "cc" ); +} + +static __inline__ void clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long old; + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + __asm__ __volatile__( +"1:" LARXL " %0,0,%3 # set_bit\n" + "andc %0,%0,%2\n" + PPC405_ERR77(0,%3) + STCXL " %0,0,%3\n" + "bne- 1b" + : "=&r"(old), "=m"(*p) + : "r"(mask), "r"(p), "m"(*p) + : "cc" ); +} + +static __inline__ void change_bit(int nr, volatile unsigned long *addr) +{ + unsigned long old; + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + __asm__ __volatile__( +"1:" LARXL " %0,0,%3 # set_bit\n" + "xor %0,%0,%2\n" + PPC405_ERR77(0,%3) + STCXL " %0,0,%3\n" + "bne- 1b" + : "=&r"(old), "=m"(*p) + : "r"(mask), "r"(p), "m"(*p) + : "cc" ); +} + +static __inline__ int test_and_set_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long old, t; + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + __asm__ __volatile__( + EIEIO_ON_SMP +"1:" LARXL " %0,0,%3 # test_and_set_bit\n" + "or %1,%0,%2 \n" + PPC405_ERR77(0,%3) + STCXL " %1,0,%3 \n" + "bne- 1b" + ISYNC_ON_SMP + : "=&r" (old), "=&r" (t) + : "r" (mask), "r" (p) + : "cc", "memory"); + + return (old & mask) != 0; +} + +static __inline__ int test_and_clear_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long old, t; + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + __asm__ __volatile__( + EIEIO_ON_SMP +"1:" LARXL " %0,0,%3 # test_and_clear_bit\n" + "andc %1,%0,%2 \n" + PPC405_ERR77(0,%3) + STCXL " %1,0,%3 \n" + "bne- 1b" + ISYNC_ON_SMP + : "=&r" (old), "=&r" (t) + : "r" (mask), "r" (p) + : "cc", "memory"); + + return (old & mask) != 0; +} + +static __inline__ int test_and_change_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long old, t; + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + __asm__ __volatile__( + EIEIO_ON_SMP +"1:" LARXL " %0,0,%3 # test_and_change_bit\n" + "xor %1,%0,%2 \n" + PPC405_ERR77(0,%3) + STCXL " %1,0,%3 \n" + "bne- 1b" + ISYNC_ON_SMP + : "=&r" (old), "=&r" (t) + : "r" (mask), "r" (p) + : "cc", "memory"); + + return (old & mask) != 0; +} + +static __inline__ void set_bits(unsigned long mask, unsigned long *addr) +{ + unsigned long old; + + __asm__ __volatile__( +"1:" LARXL " %0,0,%3 # set_bit\n" + "or %0,%0,%2\n" + STCXL " %0,0,%3\n" + "bne- 1b" + : "=&r" (old), "=m" (*addr) + : "r" (mask), "r" (addr), "m" (*addr) + : "cc"); +} + +/* Non-atomic versions */ +static __inline__ int test_bit(unsigned long nr, + __const__ volatile unsigned long *addr) +{ + return 1UL & (addr[BITOP_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); +} + +static __inline__ void __set_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + *p |= mask; +} + +static __inline__ void __clear_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + *p &= ~mask; +} + +static __inline__ void __change_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + + *p ^= mask; +} + +static __inline__ int __test_and_set_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + unsigned long old = *p; + + *p = old | mask; + return (old & mask) != 0; +} + +static __inline__ int __test_and_clear_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + unsigned long old = *p; + + *p = old & ~mask; + return (old & mask) != 0; +} + +static __inline__ int __test_and_change_bit(unsigned long nr, + volatile unsigned long *addr) +{ + unsigned long mask = BITOP_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); + unsigned long old = *p; + + *p = old ^ mask; + return (old & mask) != 0; +} + +/* + * Return the zero-based bit position (LE, not IBM bit numbering) of + * the most significant 1-bit in a double word. + */ +static __inline__ int __ilog2(unsigned long x) +{ + int lz; + + asm (CNTLZL " %0,%1" : "=r" (lz) : "r" (x)); + return BITS_PER_LONG - 1 - lz; +} + +/* + * Determines the bit position of the least significant 0 bit in the + * specified double word. The returned bit position will be + * zero-based, starting from the right side (63/31 - 0). + */ +static __inline__ unsigned long ffz(unsigned long x) +{ + /* no zero exists anywhere in the 8 byte area. */ + if ((x = ~x) == 0) + return BITS_PER_LONG; + + /* + * Calculate the bit position of the least signficant '1' bit in x + * (since x has been changed this will actually be the least signficant + * '0' bit in * the original x). Note: (x & -x) gives us a mask that + * is the least significant * (RIGHT-most) 1-bit of the value in x. + */ + return __ilog2(x & -x); +} + +static __inline__ int __ffs(unsigned long x) +{ + return __ilog2(x & -x); +} + +/* + * ffs: find first bit set. 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) +{ + unsigned long i = (unsigned long)x; + return __ilog2(i & -i) + 1; +} + +/* + * fls: find last (most-significant) bit set. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ +static __inline__ int fls(unsigned int x) +{ + int lz; + + asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x)); + return 32 - lz; +} + +/* + * hweightN: returns the hamming weight (i.e. the number + * of bits set) of a N-bit word + */ +#define hweight64(x) generic_hweight64(x) +#define hweight32(x) generic_hweight32(x) +#define hweight16(x) generic_hweight16(x) +#define hweight8(x) generic_hweight8(x) + +#define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0) +unsigned long find_next_zero_bit(const unsigned long *addr, + unsigned long size, unsigned long offset); +/** + * find_first_bit - find the first set 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 set bit, not the number of the byte + * containing a bit. + */ +#define find_first_bit(addr, size) find_next_bit((addr), (size), 0) +unsigned long find_next_bit(const unsigned long *addr, + unsigned long size, unsigned long offset); + +/* Little-endian versions */ + +static __inline__ int test_le_bit(unsigned long nr, + __const__ unsigned long *addr) +{ + __const__ unsigned char *tmp = (__const__ unsigned char *) addr; + return (tmp[nr >> 3] >> (nr & 7)) & 1; +} + +#define __set_le_bit(nr, addr) \ + __set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) +#define __clear_le_bit(nr, addr) \ + __clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) + +#define test_and_set_le_bit(nr, addr) \ + test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) +#define test_and_clear_le_bit(nr, addr) \ + test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) + +#define __test_and_set_le_bit(nr, addr) \ + __test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) +#define __test_and_clear_le_bit(nr, addr) \ + __test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) + +#define find_first_zero_le_bit(addr, size) find_next_zero_le_bit((addr), (size), 0) +unsigned long find_next_zero_le_bit(const unsigned long *addr, + unsigned long size, unsigned long offset); + +/* Bitmap functions for the ext2 filesystem */ + +#define ext2_set_bit(nr,addr) \ + __test_and_set_le_bit((nr), (unsigned long*)addr) +#define ext2_clear_bit(nr, addr) \ + __test_and_clear_le_bit((nr), (unsigned long*)addr) + +#define ext2_set_bit_atomic(lock, nr, addr) \ + test_and_set_le_bit((nr), (unsigned long*)addr) +#define ext2_clear_bit_atomic(lock, nr, addr) \ + test_and_clear_le_bit((nr), (unsigned long*)addr) + +#define ext2_test_bit(nr, addr) test_le_bit((nr),(unsigned long*)addr) + +#define ext2_find_first_zero_bit(addr, size) \ + find_first_zero_le_bit((unsigned long*)addr, size) +#define ext2_find_next_zero_bit(addr, size, off) \ + find_next_zero_le_bit((unsigned long*)addr, size, off) + +/* Bitmap functions for the minix filesystem. */ + +#define minix_test_and_set_bit(nr,addr) \ + __test_and_set_le_bit(nr, (unsigned long *)addr) +#define minix_set_bit(nr,addr) \ + __set_le_bit(nr, (unsigned long *)addr) +#define minix_test_and_clear_bit(nr,addr) \ + __test_and_clear_le_bit(nr, (unsigned long *)addr) +#define minix_test_bit(nr,addr) \ + test_le_bit(nr, (unsigned long *)addr) + +#define minix_find_first_zero_bit(addr,size) \ + find_first_zero_le_bit((unsigned long *)addr, size) + +/* + * Every architecture must define this function. It's the fastest + * way of searching a 140-bit bitmap where the first 100 bits are + * unlikely to be set. It's guaranteed that at least one of the 140 + * bits is cleared. + */ +static inline int sched_find_first_bit(const unsigned long *b) +{ +#ifdef CONFIG_PPC64 + if (unlikely(b[0])) + return __ffs(b[0]); + if (unlikely(b[1])) + return __ffs(b[1]) + 64; + return __ffs(b[2]) + 128; +#else + 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 (b[3]) + return __ffs(b[3]) + 96; + return __ffs(b[4]) + 128; +#endif +} + +#endif /* __KERNEL__ */ + +#endif /* _ASM_POWERPC_BITOPS_H */ |