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parisc: Implement __smp_store_release and __smp_load_acquire barriers

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This patch implements the __smp_store_release and __smp_load_acquire barriers
using ordered stores and loads.  This avoids the sync instruction present in
the generic implementation.

Cc: <stable@vger.kernel.org> # 4.14+
Signed-off-by: Dave Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
John David Anglin 2020-07-30 08:59:12 -04:00 committed by Helge Deller
parent 5b24993c21
commit e96ebd589d
1 changed files with 61 additions and 0 deletions
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61
arch/parisc/include/asm/barrier.h
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@ -26,6 +26,67 @@
#define __smp_rmb() mb()
#define __smp_wmb() mb()
#define __smp_store_release(p, v) \
do { \
typeof(p) __p = (p); \
union { typeof(*p) __val; char __c[1]; } __u = \
{ .__val = (__force typeof(*p)) (v) }; \
compiletime_assert_atomic_type(*p); \
switch (sizeof(*p)) { \
case 1: \
asm volatile("stb,ma %0,0(%1)" \
: : "r"(*(__u8 *)__u.__c), "r"(__p) \
: "memory"); \
break; \
case 2: \
asm volatile("sth,ma %0,0(%1)" \
: : "r"(*(__u16 *)__u.__c), "r"(__p) \
: "memory"); \
break; \
case 4: \
asm volatile("stw,ma %0,0(%1)" \
: : "r"(*(__u32 *)__u.__c), "r"(__p) \
: "memory"); \
break; \
case 8: \
if (IS_ENABLED(CONFIG_64BIT)) \
asm volatile("std,ma %0,0(%1)" \
: : "r"(*(__u64 *)__u.__c), "r"(__p) \
: "memory"); \
break; \
} \
} while (0)
#define __smp_load_acquire(p) \
({ \
union { typeof(*p) __val; char __c[1]; } __u; \
typeof(p) __p = (p); \
compiletime_assert_atomic_type(*p); \
switch (sizeof(*p)) { \
case 1: \
asm volatile("ldb,ma 0(%1),%0" \
: "=r"(*(__u8 *)__u.__c) : "r"(__p) \
: "memory"); \
break; \
case 2: \
asm volatile("ldh,ma 0(%1),%0" \
: "=r"(*(__u16 *)__u.__c) : "r"(__p) \
: "memory"); \
break; \
case 4: \
asm volatile("ldw,ma 0(%1),%0" \
: "=r"(*(__u32 *)__u.__c) : "r"(__p) \
: "memory"); \
break; \
case 8: \
if (IS_ENABLED(CONFIG_64BIT)) \
asm volatile("ldd,ma 0(%1),%0" \
: "=r"(*(__u64 *)__u.__c) : "r"(__p) \
: "memory"); \
break; \
} \
__u.__val; \
})
#include <asm-generic/barrier.h>
#endif /* !__ASSEMBLY__ */