/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org) */ #ifndef __ASM_CMPXCHG_H #define __ASM_CMPXCHG_H #include <linux/irqflags.h> #define __HAVE_ARCH_CMPXCHG 1 #define __cmpxchg_asm(ld, st, m, old, new) \ ({ \ __typeof(*(m)) __ret; \ \ if (cpu_has_llsc && R10000_LLSC_WAR) { \ __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ " .set mips3 \n" \ "1: " ld " %0, %2 # __cmpxchg_asm \n" \ " bne %0, %z3, 2f \n" \ " .set mips0 \n" \ " move $1, %z4 \n" \ " .set mips3 \n" \ " " st " $1, %1 \n" \ " beqzl $1, 1b \n" \ "2: \n" \ " .set pop \n" \ : "=&r" (__ret), "=R" (*m) \ : "R" (*m), "Jr" (old), "Jr" (new) \ : "memory"); \ } else if (cpu_has_llsc) { \ __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ " .set mips3 \n" \ "1: " ld " %0, %2 # __cmpxchg_asm \n" \ " bne %0, %z3, 2f \n" \ " .set mips0 \n" \ " move $1, %z4 \n" \ " .set mips3 \n" \ " " st " $1, %1 \n" \ " beqz $1, 3f \n" \ "2: \n" \ " .subsection 2 \n" \ "3: b 1b \n" \ " .previous \n" \ " .set pop \n" \ : "=&r" (__ret), "=R" (*m) \ : "R" (*m), "Jr" (old), "Jr" (new) \ : "memory"); \ } else { \ unsigned long __flags; \ \ raw_local_irq_save(__flags); \ __ret = *m; \ if (__ret == old) \ *m = new; \ raw_local_irq_restore(__flags); \ } \ \ __ret; \ }) /* * This function doesn't exist, so you'll get a linker error * if something tries to do an invalid cmpxchg(). */ extern void __cmpxchg_called_with_bad_pointer(void); #define __cmpxchg(ptr, old, new, barrier) \ ({ \ __typeof__(ptr) __ptr = (ptr); \ __typeof__(*(ptr)) __old = (old); \ __typeof__(*(ptr)) __new = (new); \ __typeof__(*(ptr)) __res = 0; \ \ barrier; \ \ switch (sizeof(*(__ptr))) { \ case 4: \ __res = __cmpxchg_asm("ll", "sc", __ptr, __old, __new); \ break; \ case 8: \ if (sizeof(long) == 8) { \ __res = __cmpxchg_asm("lld", "scd", __ptr, \ __old, __new); \ break; \ } \ default: \ __cmpxchg_called_with_bad_pointer(); \ break; \ } \ \ barrier; \ \ __res; \ }) #define cmpxchg(ptr, old, new) __cmpxchg(ptr, old, new, smp_llsc_mb()) #define cmpxchg_local(ptr, old, new) __cmpxchg(ptr, old, new, ) #endif /* __ASM_CMPXCHG_H */