Commit 2a7d4eed authored by John David Anglin's avatar John David Anglin Committed by Helge Deller
Browse files

parisc: Mark pointers volatile in __xchg8(), __xchg32() and __xchg64() 



Let the complier treat the pointers volatile to ensure that they get
accessed atomicly.

Signed-off-by: default avatarJohn David Anglin <dave.anglin@bell.net>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 4df82ce7

arch/parisc/include/asm/cmpxchg.h

+7 −7
Original line number Diff line number Diff line
@@ -14,22 +14,22 @@ 
extern void __xchg_called_with_bad_pointer(void);



/* __xchg32/64 defined in arch/parisc/lib/bitops.c */

extern unsigned long __xchg8(char, char *);

extern unsigned long __xchg32(int, int *);

extern unsigned long __xchg8(char, volatile char *);

extern unsigned long __xchg32(int, volatile int *);

#ifdef CONFIG_64BIT

extern unsigned long __xchg64(unsigned long, unsigned long *);

extern unsigned long __xchg64(unsigned long, volatile unsigned long *);

#endif



/* optimizer better get rid of switch since size is a constant */

static inline unsigned long

__xchg(unsigned long x, __volatile__ void *ptr, int size)

__xchg(unsigned long x, volatile void *ptr, int size)

{

	switch (size) {

#ifdef CONFIG_64BIT

	case 8: return __xchg64(x, (unsigned long *) ptr);

	case 8: return __xchg64(x, (volatile unsigned long *) ptr);

#endif

	case 4: return __xchg32((int) x, (int *) ptr);

	case 1: return __xchg8((char) x, (char *) ptr);

	case 4: return __xchg32((int) x, (volatile int *) ptr);

	case 1: return __xchg8((char) x, (volatile char *) ptr);

	}

	__xchg_called_with_bad_pointer();

	return x;

arch/parisc/lib/bitops.c

+3 −3
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = { 
#endif



#ifdef CONFIG_64BIT

unsigned long __xchg64(unsigned long x, unsigned long *ptr)

unsigned long __xchg64(unsigned long x, volatile unsigned long *ptr)

{

	unsigned long temp, flags;
@@ -30,7 +30,7 @@ unsigned long __xchg64(unsigned long x, unsigned long *ptr) 
}

#endif



unsigned long __xchg32(int x, int *ptr)

unsigned long __xchg32(int x, volatile int *ptr)

{

	unsigned long flags;

	long temp;
@@ -43,7 +43,7 @@ unsigned long __xchg32(int x, int *ptr) 
}





unsigned long __xchg8(char x, char *ptr)

unsigned long __xchg8(char x, volatile char *ptr)

{

	unsigned long flags;

	long temp;