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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2007-10-03 15:05:20 +0200
committerHaavard Skinnemoen <hskinnemoen@atmel.com>2007-10-11 13:32:56 +0200
commitbb7aa6d47fcd4f9ab18b4ade2ba078f7719f74ca (patch)
treef44d5d49cf4d95c57e067bd004fe99d072625d7d
parent82c54f864fea26c4c44f27e2b4c4d9a811dde299 (diff)
downloadop-kernel-dev-bb7aa6d47fcd4f9ab18b4ade2ba078f7719f74ca.zip
op-kernel-dev-bb7aa6d47fcd4f9ab18b4ade2ba078f7719f74ca.tar.gz
[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 <hskinnemoen@atmel.com>
-rw-r--r--include/asm-avr32/system.h13
1 files changed, 9 insertions, 4 deletions
diff --git a/include/asm-avr32/system.h b/include/asm-avr32/system.h
index a8236ba..dc2d527 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,
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