| David Howells | 1c80f22 | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 1 | /* MN10300 Atomic xchg/cmpxchg operations |
| 2 | * |
| 3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public Licence |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the Licence, or (at your option) any later version. |
| 10 | */ |
| 11 | #ifndef _ASM_CMPXCHG_H |
| 12 | #define _ASM_CMPXCHG_H |
| 13 | |
| 14 | #include <asm/irqflags.h> |
| 15 | |
| 16 | #ifdef CONFIG_SMP |
| 17 | #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT |
| 18 | static inline |
| 19 | unsigned long __xchg(volatile unsigned long *m, unsigned long val) |
| 20 | { |
| 21 | unsigned long status; |
| 22 | unsigned long oldval; |
| 23 | |
| 24 | asm volatile( |
| 25 | "1: mov %4,(_AAR,%3) \n" |
| 26 | " mov (_ADR,%3),%1 \n" |
| 27 | " mov %5,(_ADR,%3) \n" |
| 28 | " mov (_ADR,%3),%0 \n" /* flush */ |
| 29 | " mov (_ASR,%3),%0 \n" |
| 30 | " or %0,%0 \n" |
| 31 | " bne 1b \n" |
| 32 | : "=&r"(status), "=&r"(oldval), "=m"(*m) |
| 33 | : "a"(ATOMIC_OPS_BASE_ADDR), "r"(m), "r"(val) |
| 34 | : "memory", "cc"); |
| 35 | |
| 36 | return oldval; |
| 37 | } |
| 38 | |
| 39 | static inline unsigned long __cmpxchg(volatile unsigned long *m, |
| 40 | unsigned long old, unsigned long new) |
| 41 | { |
| 42 | unsigned long status; |
| 43 | unsigned long oldval; |
| 44 | |
| 45 | asm volatile( |
| 46 | "1: mov %4,(_AAR,%3) \n" |
| 47 | " mov (_ADR,%3),%1 \n" |
| 48 | " cmp %5,%1 \n" |
| 49 | " bne 2f \n" |
| 50 | " mov %6,(_ADR,%3) \n" |
| 51 | "2: mov (_ADR,%3),%0 \n" /* flush */ |
| 52 | " mov (_ASR,%3),%0 \n" |
| 53 | " or %0,%0 \n" |
| 54 | " bne 1b \n" |
| 55 | : "=&r"(status), "=&r"(oldval), "=m"(*m) |
| 56 | : "a"(ATOMIC_OPS_BASE_ADDR), "r"(m), |
| 57 | "r"(old), "r"(new) |
| 58 | : "memory", "cc"); |
| 59 | |
| 60 | return oldval; |
| 61 | } |
| 62 | #else /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */ |
| 63 | #error "No SMP atomic operation support!" |
| 64 | #endif /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */ |
| 65 | |
| 66 | #else /* CONFIG_SMP */ |
| 67 | |
| 68 | /* |
| 69 | * Emulate xchg for non-SMP MN10300 |
| 70 | */ |
| 71 | struct __xchg_dummy { unsigned long a[100]; }; |
| 72 | #define __xg(x) ((struct __xchg_dummy *)(x)) |
| 73 | |
| 74 | static inline |
| 75 | unsigned long __xchg(volatile unsigned long *m, unsigned long val) |
| 76 | { |
| 77 | unsigned long oldval; |
| 78 | unsigned long flags; |
| 79 | |
| 80 | flags = arch_local_cli_save(); |
| 81 | oldval = *m; |
| 82 | *m = val; |
| 83 | arch_local_irq_restore(flags); |
| 84 | return oldval; |
| 85 | } |
| 86 | |
| 87 | /* |
| 88 | * Emulate cmpxchg for non-SMP MN10300 |
| 89 | */ |
| 90 | static inline unsigned long __cmpxchg(volatile unsigned long *m, |
| 91 | unsigned long old, unsigned long new) |
| 92 | { |
| 93 | unsigned long oldval; |
| 94 | unsigned long flags; |
| 95 | |
| 96 | flags = arch_local_cli_save(); |
| 97 | oldval = *m; |
| 98 | if (oldval == old) |
| 99 | *m = new; |
| 100 | arch_local_irq_restore(flags); |
| 101 | return oldval; |
| 102 | } |
| 103 | |
| 104 | #endif /* CONFIG_SMP */ |
| 105 | |
| 106 | #define xchg(ptr, v) \ |
| 107 | ((__typeof__(*(ptr))) __xchg((unsigned long *)(ptr), \ |
| 108 | (unsigned long)(v))) |
| 109 | |
| 110 | #define cmpxchg(ptr, o, n) \ |
| 111 | ((__typeof__(*(ptr))) __cmpxchg((unsigned long *)(ptr), \ |
| 112 | (unsigned long)(o), \ |
| 113 | (unsigned long)(n))) |
| 114 | |
| 115 | #endif /* _ASM_CMPXCHG_H */ |