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Diffstat (limited to 'kernel/arch/powerpc/include/asm/bitops.h')
| -rw-r--r-- | kernel/arch/powerpc/include/asm/bitops.h | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/include/asm/bitops.h b/kernel/arch/powerpc/include/asm/bitops.h new file mode 100644 index 000000000..59abc620f --- /dev/null +++ b/kernel/arch/powerpc/include/asm/bitops.h @@ -0,0 +1,289 @@ +/* + * 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...........192| + * and on ppc32: + * |31.....0|63....32|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__ + +#ifndef _LINUX_BITOPS_H +#error only <linux/bitops.h> can be included directly +#endif + +#include <linux/compiler.h> +#include <asm/asm-compat.h> +#include <asm/synch.h> + +/* PPC bit number conversion */ +#define PPC_BITLSHIFT(be) (BITS_PER_LONG - 1 - (be)) +#define PPC_BIT(bit) (1UL << PPC_BITLSHIFT(bit)) +#define PPC_BITMASK(bs, be) ((PPC_BIT(bs) - PPC_BIT(be)) | PPC_BIT(bs)) + +#include <asm/barrier.h> + +/* Macro for generating the ***_bits() functions */ +#define DEFINE_BITOP(fn, op, prefix) \ +static __inline__ void fn(unsigned long mask, \ + volatile unsigned long *_p) \ +{ \ + unsigned long old; \ + unsigned long *p = (unsigned long *)_p; \ + __asm__ __volatile__ ( \ + prefix \ +"1:" PPC_LLARX(%0,0,%3,0) "\n" \ + stringify_in_c(op) "%0,%0,%2\n" \ + PPC405_ERR77(0,%3) \ + PPC_STLCX "%0,0,%3\n" \ + "bne- 1b\n" \ + : "=&r" (old), "+m" (*p) \ + : "r" (mask), "r" (p) \ + : "cc", "memory"); \ +} + +DEFINE_BITOP(set_bits, or, "") +DEFINE_BITOP(clear_bits, andc, "") +DEFINE_BITOP(clear_bits_unlock, andc, PPC_RELEASE_BARRIER) +DEFINE_BITOP(change_bits, xor, "") + +static __inline__ void set_bit(int nr, volatile unsigned long *addr) +{ + set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)); +} + +static __inline__ void clear_bit(int nr, volatile unsigned long *addr) +{ + clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)); +} + +static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr) +{ + clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr)); +} + +static __inline__ void change_bit(int nr, volatile unsigned long *addr) +{ + change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)); +} + +/* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output + * operands. */ +#define DEFINE_TESTOP(fn, op, prefix, postfix, eh) \ +static __inline__ unsigned long fn( \ + unsigned long mask, \ + volatile unsigned long *_p) \ +{ \ + unsigned long old, t; \ + unsigned long *p = (unsigned long *)_p; \ + __asm__ __volatile__ ( \ + prefix \ +"1:" PPC_LLARX(%0,0,%3,eh) "\n" \ + stringify_in_c(op) "%1,%0,%2\n" \ + PPC405_ERR77(0,%3) \ + PPC_STLCX "%1,0,%3\n" \ + "bne- 1b\n" \ + postfix \ + : "=&r" (old), "=&r" (t) \ + : "r" (mask), "r" (p) \ + : "cc", "memory"); \ + return (old & mask); \ +} + +DEFINE_TESTOP(test_and_set_bits, or, PPC_ATOMIC_ENTRY_BARRIER, + PPC_ATOMIC_EXIT_BARRIER, 0) +DEFINE_TESTOP(test_and_set_bits_lock, or, "", + PPC_ACQUIRE_BARRIER, 1) +DEFINE_TESTOP(test_and_clear_bits, andc, PPC_ATOMIC_ENTRY_BARRIER, + PPC_ATOMIC_EXIT_BARRIER, 0) +DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER, + PPC_ATOMIC_EXIT_BARRIER, 0) + +static __inline__ int test_and_set_bit(unsigned long nr, + volatile unsigned long *addr) +{ + return test_and_set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0; +} + +static __inline__ int test_and_set_bit_lock(unsigned long nr, + volatile unsigned long *addr) +{ + return test_and_set_bits_lock(BIT_MASK(nr), + addr + BIT_WORD(nr)) != 0; +} + +static __inline__ int test_and_clear_bit(unsigned long nr, + volatile unsigned long *addr) +{ + return test_and_clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0; +} + +static __inline__ int test_and_change_bit(unsigned long nr, + volatile unsigned long *addr) +{ + return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0; +} + +#include <asm-generic/bitops/non-atomic.h> + +static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr) +{ + __asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory"); + __clear_bit(nr, addr); +} + +/* + * Return the zero-based bit position (LE, not IBM bit numbering) of + * the most significant 1-bit in a double word. + */ +static __inline__ __attribute__((const)) +int __ilog2(unsigned long x) +{ + int lz; + + asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x)); + return BITS_PER_LONG - 1 - lz; +} + +static inline __attribute__((const)) +int __ilog2_u32(u32 n) +{ + int bit; + asm ("cntlzw %0,%1" : "=r" (bit) : "r" (n)); + return 31 - bit; +} + +#ifdef __powerpc64__ +static inline __attribute__((const)) +int __ilog2_u64(u64 n) +{ + int bit; + asm ("cntlzd %0,%1" : "=r" (bit) : "r" (n)); + return 63 - bit; +} +#endif + +/* + * 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 significant '1' bit in x + * (since x has been changed this will actually be the least significant + * '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__ unsigned long __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; +} + +static __inline__ unsigned long __fls(unsigned long x) +{ + return __ilog2(x); +} + +/* + * 64-bit can do this using one cntlzd (count leading zeroes doubleword) + * instruction; for 32-bit we use the generic version, which does two + * 32-bit fls calls. + */ +#ifdef __powerpc64__ +static __inline__ int fls64(__u64 x) +{ + int lz; + + asm ("cntlzd %0,%1" : "=r" (lz) : "r" (x)); + return 64 - lz; +} +#else +#include <asm-generic/bitops/fls64.h> +#endif /* __powerpc64__ */ + +#ifdef CONFIG_PPC64 +unsigned int __arch_hweight8(unsigned int w); +unsigned int __arch_hweight16(unsigned int w); +unsigned int __arch_hweight32(unsigned int w); +unsigned long __arch_hweight64(__u64 w); +#include <asm-generic/bitops/const_hweight.h> +#else +#include <asm-generic/bitops/hweight.h> +#endif + +#include <asm-generic/bitops/find.h> + +/* Little-endian versions */ +#include <asm-generic/bitops/le.h> + +/* Bitmap functions for the ext2 filesystem */ + +#include <asm-generic/bitops/ext2-atomic-setbit.h> + +#include <asm-generic/bitops/sched.h> + +#endif /* __KERNEL__ */ + +#endif /* _ASM_POWERPC_BITOPS_H */ |