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Diffstat (limited to 'arch/frv/include/asm/atomic.h')
| -rw-r--r-- | arch/frv/include/asm/atomic.h | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/arch/frv/include/asm/atomic.h b/arch/frv/include/asm/atomic.h new file mode 100644 index 000000000000..296c35cfb207 --- /dev/null +++ b/arch/frv/include/asm/atomic.h @@ -0,0 +1,198 @@ +/* atomic.h: atomic operation emulation for FR-V + * + * For an explanation of how atomic ops work in this arch, see: + * Documentation/frv/atomic-ops.txt + * + * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * 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_ATOMIC_H +#define _ASM_ATOMIC_H + +#include <linux/types.h> +#include <asm/spr-regs.h> +#include <asm/system.h> + +#ifdef CONFIG_SMP +#error not SMP safe +#endif + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + * + * We do not have SMP systems, so we don't have to deal with that. + */ + +/* Atomic operations are already serializing */ +#define smp_mb__before_atomic_dec() barrier() +#define smp_mb__after_atomic_dec() barrier() +#define smp_mb__before_atomic_inc() barrier() +#define smp_mb__after_atomic_inc() barrier() + +#define ATOMIC_INIT(i) { (i) } +#define atomic_read(v) ((v)->counter) +#define atomic_set(v, i) (((v)->counter) = (i)) + +#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS +static inline int atomic_add_return(int i, atomic_t *v) +{ + unsigned long val; + + asm("0: \n" + " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ + " ckeq icc3,cc7 \n" + " ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ + " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ + " add%I2 %1,%2,%1 \n" + " cst.p %1,%M0 ,cc3,#1 \n" + " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ + " beq icc3,#0,0b \n" + : "+U"(v->counter), "=&r"(val) + : "NPr"(i) + : "memory", "cc7", "cc3", "icc3" + ); + + return val; +} + +static inline int atomic_sub_return(int i, atomic_t *v) +{ + unsigned long val; + + asm("0: \n" + " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ + " ckeq icc3,cc7 \n" + " ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ + " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ + " sub%I2 %1,%2,%1 \n" + " cst.p %1,%M0 ,cc3,#1 \n" + " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ + " beq icc3,#0,0b \n" + : "+U"(v->counter), "=&r"(val) + : "NPr"(i) + : "memory", "cc7", "cc3", "icc3" + ); + + return val; +} + +#else + +extern int atomic_add_return(int i, atomic_t *v); +extern int atomic_sub_return(int i, atomic_t *v); + +#endif + +static inline int atomic_add_negative(int i, atomic_t *v) +{ + return atomic_add_return(i, v) < 0; +} + +static inline void atomic_add(int i, atomic_t *v) +{ + atomic_add_return(i, v); +} + +static inline void atomic_sub(int i, atomic_t *v) +{ + atomic_sub_return(i, v); +} + +static inline void atomic_inc(atomic_t *v) +{ + atomic_add_return(1, v); +} + +static inline void atomic_dec(atomic_t *v) +{ + atomic_sub_return(1, v); +} + +#define atomic_dec_return(v) atomic_sub_return(1, (v)) +#define atomic_inc_return(v) atomic_add_return(1, (v)) + +#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) +#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) +#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) + +/*****************************************************************************/ +/* + * exchange value with memory + */ +#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS + +#define xchg(ptr, x) \ +({ \ + __typeof__(ptr) __xg_ptr = (ptr); \ + __typeof__(*(ptr)) __xg_orig; \ + \ + switch (sizeof(__xg_orig)) { \ + case 4: \ + asm volatile( \ + "swap%I0 %M0,%1" \ + : "+m"(*__xg_ptr), "=r"(__xg_orig) \ + : "1"(x) \ + : "memory" \ + ); \ + break; \ + \ + default: \ + __xg_orig = (__typeof__(__xg_orig))0; \ + asm volatile("break"); \ + break; \ + } \ + \ + __xg_orig; \ +}) + +#else + +extern uint32_t __xchg_32(uint32_t i, volatile void *v); + +#define xchg(ptr, x) \ +({ \ + __typeof__(ptr) __xg_ptr = (ptr); \ + __typeof__(*(ptr)) __xg_orig; \ + \ + switch (sizeof(__xg_orig)) { \ + case 4: __xg_orig = (__typeof__(*(ptr))) __xchg_32((uint32_t) x, __xg_ptr); break; \ + default: \ + __xg_orig = (__typeof__(__xg_orig))0; \ + asm volatile("break"); \ + break; \ + } \ + __xg_orig; \ +}) + +#endif + +#define tas(ptr) (xchg((ptr), 1)) + +#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) +#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) + +static __inline__ int atomic_add_unless(atomic_t *v, int a, int u) +{ + int c, old; + c = atomic_read(v); + for (;;) { + if (unlikely(c == (u))) + break; + old = atomic_cmpxchg((v), c, c + (a)); + if (likely(old == c)) + break; + c = old; + } + return c != (u); +} + +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + +#include <asm-generic/atomic.h> +#endif /* _ASM_ATOMIC_H */ |