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Diffstat (limited to 'arch/powerpc/include/asm/bitops.h')
| -rw-r--r-- | arch/powerpc/include/asm/bitops.h | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/bitops.h b/arch/powerpc/include/asm/bitops.h new file mode 100644 index 000000000..7e0f03229 --- /dev/null +++ b/arch/powerpc/include/asm/bitops.h @@ -0,0 +1,346 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * 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). + */ + +#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)) + +/* Put a PPC bit into a "normal" bit position */ +#define PPC_BITEXTRACT(bits, ppc_bit, dst_bit) \ + ((((bits) >> PPC_BITLSHIFT(ppc_bit)) & 1) << (dst_bit)) + +#define PPC_BITLSHIFT32(be) (32 - 1 - (be)) +#define PPC_BIT32(bit) (1UL << PPC_BITLSHIFT32(bit)) +#define PPC_BITMASK32(bs, be) ((PPC_BIT32(bs) - PPC_BIT32(be))|PPC_BIT32(bs)) + +#define PPC_BITLSHIFT8(be) (8 - 1 - (be)) +#define PPC_BIT8(bit) (1UL << PPC_BITLSHIFT8(bit)) +#define PPC_BITMASK8(bs, be) ((PPC_BIT8(bs) - PPC_BIT8(be))|PPC_BIT8(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" \ + #op "%I2 %0,%0,%2\n" \ + PPC_STLCX "%0,0,%3\n" \ + "bne- 1b\n" \ + : "=&r" (old), "+m" (*p) \ + : "rK" (mask), "r" (p) \ + : "cc", "memory"); \ +} + +DEFINE_BITOP(set_bits, or, "") +DEFINE_BITOP(change_bits, xor, "") + +static __always_inline bool is_rlwinm_mask_valid(unsigned long x) +{ + if (!x) + return false; + if (x & 1) + x = ~x; // make the mask non-wrapping + x += x & -x; // adding the low set bit results in at most one bit set + + return !(x & (x - 1)); +} + +#define DEFINE_CLROP(fn, prefix) \ +static inline void fn(unsigned long mask, volatile unsigned long *_p) \ +{ \ + unsigned long old; \ + unsigned long *p = (unsigned long *)_p; \ + \ + if (IS_ENABLED(CONFIG_PPC32) && \ + __builtin_constant_p(mask) && is_rlwinm_mask_valid(~mask)) {\ + asm volatile ( \ + prefix \ + "1:" "lwarx %0,0,%3\n" \ + "rlwinm %0,%0,0,%2\n" \ + "stwcx. %0,0,%3\n" \ + "bne- 1b\n" \ + : "=&r" (old), "+m" (*p) \ + : "n" (~mask), "r" (p) \ + : "cc", "memory"); \ + } else { \ + asm volatile ( \ + prefix \ + "1:" PPC_LLARX "%0,0,%3,0\n" \ + "andc %0,%0,%2\n" \ + PPC_STLCX "%0,0,%3\n" \ + "bne- 1b\n" \ + : "=&r" (old), "+m" (*p) \ + : "r" (mask), "r" (p) \ + : "cc", "memory"); \ + } \ +} + +DEFINE_CLROP(clear_bits, "") +DEFINE_CLROP(clear_bits_unlock, PPC_RELEASE_BARRIER) + +static inline void arch_set_bit(int nr, volatile unsigned long *addr) +{ + set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)); +} + +static inline void arch_clear_bit(int nr, volatile unsigned long *addr) +{ + clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)); +} + +static inline void arch_clear_bit_unlock(int nr, volatile unsigned long *addr) +{ + clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr)); +} + +static inline void arch_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,%4\n" \ + #op "%I2 %1,%0,%2\n" \ + PPC_STLCX "%1,0,%3\n" \ + "bne- 1b\n" \ + postfix \ + : "=&r" (old), "=&r" (t) \ + : "rK" (mask), "r" (p), "n" (eh) \ + : "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, IS_ENABLED(CONFIG_PPC64)) +DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER, + PPC_ATOMIC_EXIT_BARRIER, 0) + +static inline unsigned long test_and_clear_bits(unsigned long mask, volatile unsigned long *_p) +{ + unsigned long old, t; + unsigned long *p = (unsigned long *)_p; + + if (IS_ENABLED(CONFIG_PPC32) && + __builtin_constant_p(mask) && is_rlwinm_mask_valid(~mask)) { + asm volatile ( + PPC_ATOMIC_ENTRY_BARRIER + "1:" "lwarx %0,0,%3\n" + "rlwinm %1,%0,0,%2\n" + "stwcx. %1,0,%3\n" + "bne- 1b\n" + PPC_ATOMIC_EXIT_BARRIER + : "=&r" (old), "=&r" (t) + : "n" (~mask), "r" (p) + : "cc", "memory"); + } else { + asm volatile ( + PPC_ATOMIC_ENTRY_BARRIER + "1:" PPC_LLARX "%0,0,%3,0\n" + "andc %1,%0,%2\n" + PPC_STLCX "%1,0,%3\n" + "bne- 1b\n" + PPC_ATOMIC_EXIT_BARRIER + : "=&r" (old), "=&r" (t) + : "r" (mask), "r" (p) + : "cc", "memory"); + } + + return (old & mask); +} + +static inline int arch_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 arch_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 arch_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 arch_test_and_change_bit(unsigned long nr, + volatile unsigned long *addr) +{ + return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0; +} + +#ifdef CONFIG_PPC64 +static inline unsigned long +clear_bit_unlock_return_word(int nr, volatile unsigned long *addr) +{ + unsigned long old, t; + unsigned long *p = (unsigned long *)addr + BIT_WORD(nr); + unsigned long mask = BIT_MASK(nr); + + __asm__ __volatile__ ( + PPC_RELEASE_BARRIER +"1:" PPC_LLARX "%0,0,%3,0\n" + "andc %1,%0,%2\n" + PPC_STLCX "%1,0,%3\n" + "bne- 1b\n" + : "=&r" (old), "=&r" (t) + : "r" (mask), "r" (p) + : "cc", "memory"); + + return old; +} + +/* + * This is a special function for mm/filemap.c + * Bit 7 corresponds to PG_waiters. + */ +#define arch_clear_bit_unlock_is_negative_byte(nr, addr) \ + (clear_bit_unlock_return_word(nr, addr) & BIT_MASK(7)) + +#endif /* CONFIG_PPC64 */ + +#include <asm-generic/bitops/non-atomic.h> + +static inline void arch___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. + */ +#define __ilog2(x) ilog2(x) + +#include <asm-generic/bitops/ffz.h> + +#include <asm-generic/bitops/builtin-__ffs.h> + +#include <asm-generic/bitops/builtin-ffs.h> + +/* + * fls: find last (most-significant) bit set. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ +static __always_inline int fls(unsigned int x) +{ + int lz; + + if (__builtin_constant_p(x)) + return x ? 32 - __builtin_clz(x) : 0; + asm("cntlzw %0,%1" : "=r" (lz) : "r" (x)); + return 32 - lz; +} + +#include <asm-generic/bitops/builtin-__fls.h> + +/* + * 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 CONFIG_PPC64 +static __always_inline int fls64(__u64 x) +{ + int lz; + + if (__builtin_constant_p(x)) + return x ? 64 - __builtin_clzll(x) : 0; + asm("cntlzd %0,%1" : "=r" (lz) : "r" (x)); + return 64 - lz; +} +#else +#include <asm-generic/bitops/fls64.h> +#endif + +#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 + +/* wrappers that deal with KASAN instrumentation */ +#include <asm-generic/bitops/instrumented-atomic.h> +#include <asm-generic/bitops/instrumented-lock.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 */ |