cmpxchg.h revision 6a846f3f821a252762897751fa0aeb68dda635f5
1/* 2 * Port on Texas Instruments TMS320C6x architecture 3 * 4 * Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated 5 * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com) 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11#ifndef _ASM_C6X_CMPXCHG_H 12#define _ASM_C6X_CMPXCHG_H 13 14#include <linux/irqflags.h> 15 16/* 17 * Misc. functions 18 */ 19static inline unsigned int __xchg(unsigned int x, volatile void *ptr, int size) 20{ 21 unsigned int tmp; 22 unsigned long flags; 23 24 local_irq_save(flags); 25 26 switch (size) { 27 case 1: 28 tmp = 0; 29 tmp = *((unsigned char *) ptr); 30 *((unsigned char *) ptr) = (unsigned char) x; 31 break; 32 case 2: 33 tmp = 0; 34 tmp = *((unsigned short *) ptr); 35 *((unsigned short *) ptr) = x; 36 break; 37 case 4: 38 tmp = 0; 39 tmp = *((unsigned int *) ptr); 40 *((unsigned int *) ptr) = x; 41 break; 42 } 43 local_irq_restore(flags); 44 return tmp; 45} 46 47#define xchg(ptr, x) \ 48 ((__typeof__(*(ptr)))__xchg((unsigned int)(x), (void *) (ptr), \ 49 sizeof(*(ptr)))) 50#define tas(ptr) xchg((ptr), 1) 51 52 53#include <asm-generic/cmpxchg-local.h> 54 55/* 56 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make 57 * them available. 58 */ 59#define cmpxchg_local(ptr, o, n) \ 60 ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), \ 61 (unsigned long)(o), \ 62 (unsigned long)(n), \ 63 sizeof(*(ptr)))) 64#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) 65 66#include <asm-generic/cmpxchg.h> 67 68#endif /* _ASM_C6X_CMPXCHG_H */ 69