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

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

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
John David Anglin 2020-10-02 21:16:49 +02:00 committed by Helge Deller
parent 4df82ce78a
commit 2a7d4eed57
2 changed files with 10 additions and 10 deletions
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14
arch/parisc/include/asm/cmpxchg.h
View File

@ -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;

6
arch/parisc/lib/bitops.c
View File

@ -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;