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Merge branch 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux into master

Browse Source 
Pull parisc fixes from Helge Deller:
 "Two fixes:

   - Add the cmpxchg() function for pointers to u8 values. This fixes a
     kernel linking error when building the tusb1210 driver (from Liam
     Beguin).

   - Add a define for atomic64_set_release() to fix CPU soft lockups
     which happen because of missing unlocks while processing bit
     operations (from John David Anglin)"

* 'parisc-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Add atomic64_set_release() define to avoid CPU soft lockups
  parisc: add support for cmpxchg on u8 pointers
This commit is contained in:
Linus Torvalds 2020-07-26 12:14:46 -07:00
commit 40c60ac321
3 changed files with 16 additions and 0 deletions
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2
arch/parisc/include/asm/atomic.h
View File

@ -212,6 +212,8 @@ atomic64_set(atomic64_t *v, s64 i)
_atomic_spin_unlock_irqrestore(v, flags);
}
#define atomic64_set_release(v, i) atomic64_set((v), (i))
static __inline__ s64
atomic64_read(const atomic64_t *v)
{

2
arch/parisc/include/asm/cmpxchg.h
View File

@ -60,6 +60,7 @@ extern void __cmpxchg_called_with_bad_pointer(void);
extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old,
unsigned int new_);
extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_);
extern u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new_);
/* don't worry...optimizer will get rid of most of this */
static inline unsigned long
@ -71,6 +72,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
#endif
case 4: return __cmpxchg_u32((unsigned int *)ptr,
(unsigned int)old, (unsigned int)new_);
case 1: return __cmpxchg_u8((u8 *)ptr, (u8)old, (u8)new_);
}
__cmpxchg_called_with_bad_pointer();
return old;

12
arch/parisc/lib/bitops.c
View File

@ -79,3 +79,15 @@ unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsign
_atomic_spin_unlock_irqrestore(ptr, flags);
return (unsigned long)prev;
}
u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new)
{
unsigned long flags;
u8 prev;
_atomic_spin_lock_irqsave(ptr, flags);
if ((prev = *ptr) == old)
*ptr = new;
_atomic_spin_unlock_irqrestore(ptr, flags);
return prev;
}