From bb7aa6d47fcd4f9ab18b4ade2ba078f7719f74ca Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Wed, 3 Oct 2007 15:05:20 +0200 Subject: [PATCH] [AVR32] Don't use __builtin_xchg() The implementation of __builtin_xchg() in at least some versions of avr32 gcc is buggy. Rather than find out exactly which versions that have this bug, let's just avoid the problem altogether by implementing xchg() in inline assembly. Also, in most architectures, xchg() seems to imply a memory barrier, while the existing avr32 implementation did not. This patch also fixes that discrepancy. Signed-off-by: Haavard Skinnemoen --- include/asm-avr32/system.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/include/asm-avr32/system.h b/include/asm-avr32/system.h index a8236bacc878..dc2d527cef41 100644 --- a/include/asm-avr32/system.h +++ b/include/asm-avr32/system.h @@ -73,11 +73,16 @@ extern struct task_struct *__switch_to(struct task_struct *, extern void __xchg_called_with_bad_pointer(void); -#ifdef __CHECKER__ -extern unsigned long __builtin_xchg(void *ptr, unsigned long x); -#endif +static inline unsigned long xchg_u32(u32 val, volatile u32 *m) +{ + u32 ret; -#define xchg_u32(val, m) __builtin_xchg((void *)m, val) + asm volatile("xchg %[ret], %[m], %[val]" + : [ret] "=&r"(ret), "=m"(*m) + : "m"(*m), [m] "r"(m), [val] "r"(val) + : "memory"); + return ret; +} static inline unsigned long __xchg(unsigned long x, volatile void *ptr,