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Diffstat (limited to 'kernel/arch/arc/include/asm/bitops.h')
-rw-r--r-- | kernel/arch/arc/include/asm/bitops.h | 533 |
1 files changed, 533 insertions, 0 deletions
diff --git a/kernel/arch/arc/include/asm/bitops.h b/kernel/arch/arc/include/asm/bitops.h new file mode 100644 index 000000000..624a9d048 --- /dev/null +++ b/kernel/arch/arc/include/asm/bitops.h @@ -0,0 +1,533 @@ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _ASM_BITOPS_H +#define _ASM_BITOPS_H + +#ifndef _LINUX_BITOPS_H +#error only <linux/bitops.h> can be included directly +#endif + +#ifndef __ASSEMBLY__ + +#include <linux/types.h> +#include <linux/compiler.h> +#include <asm/barrier.h> + +/* + * Hardware assisted read-modify-write using ARC700 LLOCK/SCOND insns. + * The Kconfig glue ensures that in SMP, this is only set if the container + * SoC/platform has cross-core coherent LLOCK/SCOND + */ +#if defined(CONFIG_ARC_HAS_LLSC) + +static inline void set_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned int temp; + + m += nr >> 5; + + /* + * ARC ISA micro-optimization: + * + * Instructions dealing with bitpos only consider lower 5 bits (0-31) + * e.g (x << 33) is handled like (x << 1) by ASL instruction + * (mem pointer still needs adjustment to point to next word) + * + * Hence the masking to clamp @nr arg can be elided in general. + * + * However if @nr is a constant (above assumed it in a register), + * and greater than 31, gcc can optimize away (x << 33) to 0, + * as overflow, given the 32-bit ISA. Thus masking needs to be done + * for constant @nr, but no code is generated due to const prop. + */ + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + __asm__ __volatile__( + "1: llock %0, [%1] \n" + " bset %0, %0, %2 \n" + " scond %0, [%1] \n" + " bnz 1b \n" + : "=&r"(temp) + : "r"(m), "ir"(nr) + : "cc"); +} + +static inline void clear_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned int temp; + + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + __asm__ __volatile__( + "1: llock %0, [%1] \n" + " bclr %0, %0, %2 \n" + " scond %0, [%1] \n" + " bnz 1b \n" + : "=&r"(temp) + : "r"(m), "ir"(nr) + : "cc"); +} + +static inline void change_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned int temp; + + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + __asm__ __volatile__( + "1: llock %0, [%1] \n" + " bxor %0, %0, %2 \n" + " scond %0, [%1] \n" + " bnz 1b \n" + : "=&r"(temp) + : "r"(m), "ir"(nr) + : "cc"); +} + +/* + * Semantically: + * Test the bit + * if clear + * set it and return 0 (old value) + * else + * return 1 (old value). + * + * Since ARC lacks a equivalent h/w primitive, the bit is set unconditionally + * and the old value of bit is returned + */ +static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long old, temp; + + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + /* + * Explicit full memory barrier needed before/after as + * LLOCK/SCOND themselves don't provide any such semantics + */ + smp_mb(); + + __asm__ __volatile__( + "1: llock %0, [%2] \n" + " bset %1, %0, %3 \n" + " scond %1, [%2] \n" + " bnz 1b \n" + : "=&r"(old), "=&r"(temp) + : "r"(m), "ir"(nr) + : "cc"); + + smp_mb(); + + return (old & (1 << nr)) != 0; +} + +static inline int +test_and_clear_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned int old, temp; + + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + smp_mb(); + + __asm__ __volatile__( + "1: llock %0, [%2] \n" + " bclr %1, %0, %3 \n" + " scond %1, [%2] \n" + " bnz 1b \n" + : "=&r"(old), "=&r"(temp) + : "r"(m), "ir"(nr) + : "cc"); + + smp_mb(); + + return (old & (1 << nr)) != 0; +} + +static inline int +test_and_change_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned int old, temp; + + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + smp_mb(); + + __asm__ __volatile__( + "1: llock %0, [%2] \n" + " bxor %1, %0, %3 \n" + " scond %1, [%2] \n" + " bnz 1b \n" + : "=&r"(old), "=&r"(temp) + : "r"(m), "ir"(nr) + : "cc"); + + smp_mb(); + + return (old & (1 << nr)) != 0; +} + +#else /* !CONFIG_ARC_HAS_LLSC */ + +#include <asm/smp.h> + +/* + * Non hardware assisted Atomic-R-M-W + * Locking would change to irq-disabling only (UP) and spinlocks (SMP) + * + * There's "significant" micro-optimization in writing our own variants of + * bitops (over generic variants) + * + * (1) The generic APIs have "signed" @nr while we have it "unsigned" + * This avoids extra code to be generated for pointer arithmatic, since + * is "not sure" that index is NOT -ve + * (2) Utilize the fact that ARCompact bit fidding insn (BSET/BCLR/ASL) etc + * only consider bottom 5 bits of @nr, so NO need to mask them off. + * (GCC Quirk: however for constant @nr we still need to do the masking + * at compile time) + */ + +static inline void set_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long temp, flags; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + bitops_lock(flags); + + temp = *m; + *m = temp | (1UL << nr); + + bitops_unlock(flags); +} + +static inline void clear_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long temp, flags; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + bitops_lock(flags); + + temp = *m; + *m = temp & ~(1UL << nr); + + bitops_unlock(flags); +} + +static inline void change_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long temp, flags; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + bitops_lock(flags); + + temp = *m; + *m = temp ^ (1UL << nr); + + bitops_unlock(flags); +} + +static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long old, flags; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + /* + * spin lock/unlock provide the needed smp_mb() before/after + */ + bitops_lock(flags); + + old = *m; + *m = old | (1 << nr); + + bitops_unlock(flags); + + return (old & (1 << nr)) != 0; +} + +static inline int +test_and_clear_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long old, flags; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + bitops_lock(flags); + + old = *m; + *m = old & ~(1 << nr); + + bitops_unlock(flags); + + return (old & (1 << nr)) != 0; +} + +static inline int +test_and_change_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long old, flags; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + bitops_lock(flags); + + old = *m; + *m = old ^ (1 << nr); + + bitops_unlock(flags); + + return (old & (1 << nr)) != 0; +} + +#endif /* CONFIG_ARC_HAS_LLSC */ + +/*************************************** + * Non atomic variants + **************************************/ + +static inline void __set_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long temp; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + temp = *m; + *m = temp | (1UL << nr); +} + +static inline void __clear_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long temp; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + temp = *m; + *m = temp & ~(1UL << nr); +} + +static inline void __change_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long temp; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + temp = *m; + *m = temp ^ (1UL << nr); +} + +static inline int +__test_and_set_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long old; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + old = *m; + *m = old | (1 << nr); + + return (old & (1 << nr)) != 0; +} + +static inline int +__test_and_clear_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long old; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + old = *m; + *m = old & ~(1 << nr); + + return (old & (1 << nr)) != 0; +} + +static inline int +__test_and_change_bit(unsigned long nr, volatile unsigned long *m) +{ + unsigned long old; + m += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + old = *m; + *m = old ^ (1 << nr); + + return (old & (1 << nr)) != 0; +} + +/* + * This routine doesn't need to be atomic. + */ +static inline int +test_bit(unsigned int nr, const volatile unsigned long *addr) +{ + unsigned long mask; + + addr += nr >> 5; + + if (__builtin_constant_p(nr)) + nr &= 0x1f; + + mask = 1 << nr; + + return ((mask & *addr) != 0); +} + +/* + * Count the number of zeros, starting from MSB + * Helper for fls( ) friends + * This is a pure count, so (1-32) or (0-31) doesn't apply + * It could be 0 to 32, based on num of 0's in there + * clz(0x8000_0000) = 0, clz(0xFFFF_FFFF)=0, clz(0) = 32, clz(1) = 31 + */ +static inline __attribute__ ((const)) int clz(unsigned int x) +{ + unsigned int res; + + __asm__ __volatile__( + " norm.f %0, %1 \n" + " mov.n %0, 0 \n" + " add.p %0, %0, 1 \n" + : "=r"(res) + : "r"(x) + : "cc"); + + return res; +} + +static inline int constant_fls(int x) +{ + int r = 32; + + if (!x) + return 0; + if (!(x & 0xffff0000u)) { + x <<= 16; + r -= 16; + } + if (!(x & 0xff000000u)) { + x <<= 8; + r -= 8; + } + if (!(x & 0xf0000000u)) { + x <<= 4; + r -= 4; + } + if (!(x & 0xc0000000u)) { + x <<= 2; + r -= 2; + } + if (!(x & 0x80000000u)) { + x <<= 1; + r -= 1; + } + return r; +} + +/* + * fls = Find Last Set in word + * @result: [1-32] + * fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0 + */ +static inline __attribute__ ((const)) int fls(unsigned long x) +{ + if (__builtin_constant_p(x)) + return constant_fls(x); + + return 32 - clz(x); +} + +/* + * __fls: Similar to fls, but zero based (0-31) + */ +static inline __attribute__ ((const)) int __fls(unsigned long x) +{ + if (!x) + return 0; + else + return fls(x) - 1; +} + +/* + * ffs = Find First Set in word (LSB to MSB) + * @result: [1-32], 0 if all 0's + */ +#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); }) + +/* + * __ffs: Similar to ffs, but zero based (0-31) + */ +static inline __attribute__ ((const)) int __ffs(unsigned long word) +{ + if (!word) + return word; + + return ffs(word) - 1; +} + +/* + * ffz = Find First Zero in word. + * @return:[0-31], 32 if all 1's + */ +#define ffz(x) __ffs(~(x)) + +#include <asm-generic/bitops/hweight.h> +#include <asm-generic/bitops/fls64.h> +#include <asm-generic/bitops/sched.h> +#include <asm-generic/bitops/lock.h> + +#include <asm-generic/bitops/find.h> +#include <asm-generic/bitops/le.h> +#include <asm-generic/bitops/ext2-atomic-setbit.h> + +#endif /* !__ASSEMBLY__ */ + +#endif |