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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_ARC_ATOMIC_H
#define _ASM_ARC_ATOMIC_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/compiler.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
#include <asm/smp.h>
#ifndef CONFIG_ARC_PLAT_EZNPS
#define atomic_read(v) READ_ONCE((v)->counter)
#ifdef CONFIG_ARC_HAS_LLSC
#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
#define ATOMIC_OP(op, c_op, asm_op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
unsigned int val; \
\
__asm__ __volatile__( \
"1: llock %[val], [%[ctr]] \n" \
" " #asm_op " %[val], %[val], %[i] \n" \
" scond %[val], [%[ctr]] \n" \
" bnz 1b \n" \
: [val] "=&r" (val) /* Early clobber to prevent reg reuse */ \
: [ctr] "r" (&v->counter), /* Not "m": llock only supports reg direct addr mode */ \
[i] "ir" (i) \
: "cc"); \
} \
#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
static inline int atomic_##op##_return(int i, atomic_t *v) \
{ \
unsigned int val; \
\
/* \
* Explicit full memory barrier needed before/after as \
* LLOCK/SCOND thmeselves don't provide any such semantics \
*/ \
smp_mb(); \
\
__asm__ __volatile__( \
"1: llock %[val], [%[ctr]] \n" \
" " #asm_op " %[val], %[val], %[i] \n" \
" scond %[val], [%[ctr]] \n" \
" bnz 1b \n" \
: [val] "=&r" (val) \
: [ctr] "r" (&v->counter), \
[i] "ir" (i) \
: "cc"); \
\
smp_mb(); \
\
return val; \
}
#else /* !CONFIG_ARC_HAS_LLSC */
#ifndef CONFIG_SMP
/* violating atomic_xxx API locking protocol in UP for optimization sake */
#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
#else
static inline void atomic_set(atomic_t *v, int i)
{
/*
* Independent of hardware support, all of the atomic_xxx() APIs need
* to follow the same locking rules to make sure that a "hardware"
* atomic insn (e.g. LD) doesn't clobber an "emulated" atomic insn
* sequence
*
* Thus atomic_set() despite being 1 insn (and seemingly atomic)
* requires the locking.
*/
unsigned long flags;
atomic_ops_lock(flags);
WRITE_ONCE(v->counter, i);
atomic_ops_unlock(flags);
}
#endif
/*
* Non hardware assisted Atomic-R-M-W
* Locking would change to irq-disabling only (UP) and spinlocks (SMP)
*/
#define ATOMIC_OP(op, c_op, asm_op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
unsigned long flags; \
\
atomic_ops_lock(flags); \
v->counter c_op i; \
atomic_ops_unlock(flags); \
}
#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
static inline int atomic_##op##_return(int i, atomic_t *v) \
{ \
unsigned long flags; \
unsigned long temp; \
\
/* \
* spin lock/unlock provides the needed smp_mb() before/after \
*/ \
atomic_ops_lock(flags); \
temp = v->counter; \
temp c_op i; \
v->counter = temp; \
atomic_ops_unlock(flags); \
\
return temp; \
}
#endif /* !CONFIG_ARC_HAS_LLSC */
#define ATOMIC_OPS(op, c_op, asm_op) \
ATOMIC_OP(op, c_op, asm_op) \
ATOMIC_OP_RETURN(op, c_op, asm_op)
ATOMIC_OPS(add, +=, add)
ATOMIC_OPS(sub, -=, sub)
#define atomic_andnot atomic_andnot
ATOMIC_OP(and, &=, and)
ATOMIC_OP(andnot, &= ~, bic)
ATOMIC_OP(or, |=, or)
ATOMIC_OP(xor, ^=, xor)
#undef SCOND_FAIL_RETRY_VAR_DEF
#undef SCOND_FAIL_RETRY_ASM
#undef SCOND_FAIL_RETRY_VARS
#else /* CONFIG_ARC_PLAT_EZNPS */
static inline int atomic_read(const atomic_t *v)
{
int temp;
__asm__ __volatile__(
" ld.di %0, [%1]"
: "=r"(temp)
: "r"(&v->counter)
: "memory");
return temp;
}
static inline void atomic_set(atomic_t *v, int i)
{
__asm__ __volatile__(
" st.di %0,[%1]"
:
: "r"(i), "r"(&v->counter)
: "memory");
}
#define ATOMIC_OP(op, c_op, asm_op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
__asm__ __volatile__( \
" mov r2, %0\n" \
" mov r3, %1\n" \
" .word %2\n" \
: \
: "r"(i), "r"(&v->counter), "i"(asm_op) \
: "r2", "r3", "memory"); \
} \
#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
static inline int atomic_##op##_return(int i, atomic_t *v) \
{ \
unsigned int temp = i; \
\
/* Explicit full memory barrier needed before/after */ \
smp_mb(); \
\
__asm__ __volatile__( \
" mov r2, %0\n" \
" mov r3, %1\n" \
" .word %2\n" \
" mov %0, r2" \
: "+r"(temp) \
: "r"(&v->counter), "i"(asm_op) \
: "r2", "r3", "memory"); \
\
smp_mb(); \
\
temp c_op i; \
\
return temp; \
}
#define ATOMIC_OPS(op, c_op, asm_op) \
ATOMIC_OP(op, c_op, asm_op) \
ATOMIC_OP_RETURN(op, c_op, asm_op)
ATOMIC_OPS(add, +=, CTOP_INST_AADD_DI_R2_R2_R3)
#define atomic_sub(i, v) atomic_add(-(i), (v))
#define atomic_sub_return(i, v) atomic_add_return(-(i), (v))
ATOMIC_OP(and, &=, CTOP_INST_AAND_DI_R2_R2_R3)
#define atomic_andnot(mask, v) atomic_and(~(mask), (v))
ATOMIC_OP(or, |=, CTOP_INST_AOR_DI_R2_R2_R3)
ATOMIC_OP(xor, ^=, CTOP_INST_AXOR_DI_R2_R2_R3)
#endif /* CONFIG_ARC_PLAT_EZNPS */
#undef ATOMIC_OPS
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
/**
* __atomic_add_unless - add unless the number is a given value
* @v: pointer of type atomic_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns the old value of @v
*/
#define __atomic_add_unless(v, a, u) \
({ \
int c, old; \
\
/* \
* Explicit full memory barrier needed before/after as \
* LLOCK/SCOND thmeselves don't provide any such semantics \
*/ \
smp_mb(); \
\
c = atomic_read(v); \
while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c)\
c = old; \
\
smp_mb(); \
\
c; \
})
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#define atomic_inc(v) atomic_add(1, v)
#define atomic_dec(v) atomic_sub(1, v)
#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
#define atomic_inc_return(v) atomic_add_return(1, (v))
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
#define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0)
#define ATOMIC_INIT(i) { (i) }
#include <asm-generic/atomic64.h>
#endif
#endif
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