diff options
author | Ralf Baechle <ralf@linux-mips.org> | 2007-10-01 04:15:00 +0100 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 2007-10-03 14:30:52 +0100 |
commit | fef74705ea310acd716c2722bfeb0f796cf23640 (patch) | |
tree | 95f48dfc2f53edd15fc5246250444c46fca22010 /include/asm-mips/cmpxchg.h | |
parent | f6a9e6dec537dc1d9d2c62d7b8ad205d0993bddc (diff) |
[MIPS] Type proof reimplementation of cmpxchg.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'include/asm-mips/cmpxchg.h')
-rw-r--r-- | include/asm-mips/cmpxchg.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/include/asm-mips/cmpxchg.h b/include/asm-mips/cmpxchg.h new file mode 100644 index 000000000000..c5b4708e003b --- /dev/null +++ b/include/asm-mips/cmpxchg.h @@ -0,0 +1,107 @@ +/* + * 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 */ |