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/*
* 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>
#ifndef CONFIG_ARC_HAS_LLSC
#include <asm/smp.h>
#endif
#if defined(CONFIG_ARC_HAS_LLSC)
/*
* Hardware assisted Atomic-R-M-W
*/
#define BIT_OP(op, c_op, asm_op) \
static inline void op##_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 \
* 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 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 const @nr, but no code is generated due to gcc \
* const prop. \
*/ \
nr &= 0x1f; \
\
__asm__ __volatile__( \
"1: llock %0, [%1] \n" \
" " #asm_op " %0, %0, %2 \n" \
" scond %0, [%1] \n" \
" bnz 1b \n" \
: "=&r"(temp) /* Early clobber, to prevent reg reuse */ \
: "r"(m), /* Not "m": llock only supports reg direct addr mode */ \
"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
*/
#define TEST_N_BIT_OP(op, c_op, asm_op) \
static inline int test_and_##op##_bit(unsigned long nr, volatile unsigned long *m)\
{ \
unsigned long old, temp; \
\
m += nr >> 5; \
\
nr &= 0x1f; \
\
/* \
* Explicit full memory barrier needed before/after as \
* LLOCK/SCOND themselves don't provide any such smenatic \
*/ \
smp_mb(); \
\
__asm__ __volatile__( \
"1: llock %0, [%2] \n" \
" " #asm_op " %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 */
/*
* 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)
*/
#define BIT_OP(op, c_op, asm_op) \
static inline void op##_bit(unsigned long nr, volatile unsigned long *m)\
{ \
unsigned long temp, flags; \
m += nr >> 5; \
\
/* \
* spin lock/unlock provide the needed smp_mb() before/after \
*/ \
bitops_lock(flags); \
\
temp = *m; \
*m = temp c_op (1UL << (nr & 0x1f)); \
\
bitops_unlock(flags); \
}
#define TEST_N_BIT_OP(op, c_op, asm_op) \
static inline int test_and_##op##_bit(unsigned long nr, volatile unsigned long *m)\
{ \
unsigned long old, flags; \
m += nr >> 5; \
\
bitops_lock(flags); \
\
old = *m; \
*m = old c_op (1UL << (nr & 0x1f)); \
\
bitops_unlock(flags); \
\
return (old & (1UL << (nr & 0x1f))) != 0; \
}
#endif /* CONFIG_ARC_HAS_LLSC */
/***************************************
* Non atomic variants
**************************************/
#define __BIT_OP(op, c_op, asm_op) \
static inline void __##op##_bit(unsigned long nr, volatile unsigned long *m) \
{ \
unsigned long temp; \
m += nr >> 5; \
\
temp = *m; \
*m = temp c_op (1UL << (nr & 0x1f)); \
}
#define __TEST_N_BIT_OP(op, c_op, asm_op) \
static inline int __test_and_##op##_bit(unsigned long nr, volatile unsigned long *m)\
{ \
unsigned long old; \
m += nr >> 5; \
\
old = *m; \
*m = old c_op (1UL << (nr & 0x1f)); \
\
return (old & (1UL << (nr & 0x1f))) != 0; \
}
#define BIT_OPS(op, c_op, asm_op) \
\
/* set_bit(), clear_bit(), change_bit() */ \
BIT_OP(op, c_op, asm_op) \
\
/* test_and_set_bit(), test_and_clear_bit(), test_and_change_bit() */\
TEST_N_BIT_OP(op, c_op, asm_op) \
\
/* __set_bit(), __clear_bit(), __change_bit() */ \
__BIT_OP(op, c_op, asm_op) \
\
/* __test_and_set_bit(), __test_and_clear_bit(), __test_and_change_bit() */\
__TEST_N_BIT_OP(op, c_op, asm_op)
BIT_OPS(set, |, bset)
BIT_OPS(clear, & ~, bclr)
BIT_OPS(change, ^, bxor)
/*
* 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;
mask = 1UL << (nr & 0x1f);
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
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