Re: [RFC] arch: Introduce new TSO memory barrier smp_tmb()

From: Peter Zijlstra
Date: Mon Nov 04 2013 - 14:12:04 EST

On Mon, Nov 04, 2013 at 08:27:32AM -0800, Paul E. McKenney wrote:
> All this is leading me to suggest the following shortenings of names:
>
> smp_load_with_acquire_semantics() -> smp_load_acquire()
>
> smp_store_with_release_semantics() -> smp_store_release()
>
> But names aside, the above gets rid of explicit barriers on TSO architectures,
> allows ARM to avoid full DMB, and allows PowerPC to use lwsync instead of
> the heavier-weight sync.

A little something like this? Completely guessed at the arm/arm64/ia64
asm, but at least for those archs I found proper instructions (I hope),
for x86,sparc,s390 which are TSO we can do with a barrier and PPC like
said can do with the lwsync, all others fall back to using a smp_mb().

Should probably come with a proper changelog and an addition to _The_
document.

---
arch/alpha/include/asm/barrier.h | 13 +++++++++++
arch/arc/include/asm/barrier.h | 13 +++++++++++
arch/arm/include/asm/barrier.h | 26 +++++++++++++++++++++
arch/arm64/include/asm/barrier.h | 28 +++++++++++++++++++++++
arch/avr32/include/asm/barrier.h | 12 ++++++++++
arch/blackfin/include/asm/barrier.h | 13 +++++++++++
arch/cris/include/asm/barrier.h | 13 +++++++++++
arch/frv/include/asm/barrier.h | 13 +++++++++++
arch/h8300/include/asm/barrier.h | 13 +++++++++++
arch/hexagon/include/asm/barrier.h | 13 +++++++++++
arch/ia64/include/asm/barrier.h | 43 +++++++++++++++++++++++++++++++++++
arch/m32r/include/asm/barrier.h | 13 +++++++++++
arch/m68k/include/asm/barrier.h | 13 +++++++++++
arch/metag/include/asm/barrier.h | 13 +++++++++++
arch/microblaze/include/asm/barrier.h | 13 +++++++++++
arch/mips/include/asm/barrier.h | 13 +++++++++++
arch/mn10300/include/asm/barrier.h | 13 +++++++++++
arch/parisc/include/asm/barrier.h | 13 +++++++++++
arch/powerpc/include/asm/barrier.h | 15 ++++++++++++
arch/s390/include/asm/barrier.h | 13 +++++++++++
arch/score/include/asm/barrier.h | 13 +++++++++++
arch/sh/include/asm/barrier.h | 13 +++++++++++
arch/sparc/include/asm/barrier_32.h | 13 +++++++++++
arch/sparc/include/asm/barrier_64.h | 13 +++++++++++
arch/tile/include/asm/barrier.h | 13 +++++++++++
arch/unicore32/include/asm/barrier.h | 13 +++++++++++
arch/x86/include/asm/barrier.h | 13 +++++++++++
arch/xtensa/include/asm/barrier.h | 13 +++++++++++
28 files changed, 423 insertions(+)

diff --git a/arch/alpha/include/asm/barrier.h b/arch/alpha/include/asm/barrier.h
index ce8860a0b32d..464139feee97 100644
--- a/arch/alpha/include/asm/barrier.h
+++ b/arch/alpha/include/asm/barrier.h
@@ -29,6 +29,19 @@ __asm__ __volatile__("mb": : :"memory")
#define smp_read_barrier_depends() do { } while (0)
#endif

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#define set_mb(var, value) \
do { var = value; mb(); } while (0)

diff --git a/arch/arc/include/asm/barrier.h b/arch/arc/include/asm/barrier.h
index f6cb7c4ffb35..a779da846fb5 100644
--- a/arch/arc/include/asm/barrier.h
+++ b/arch/arc/include/asm/barrier.h
@@ -30,6 +30,19 @@
#define smp_wmb() barrier()
#endif

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()
#define smp_mb__before_atomic_inc() barrier()
diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h
index 60f15e274e6d..a804093d6891 100644
--- a/arch/arm/include/asm/barrier.h
+++ b/arch/arm/include/asm/barrier.h
@@ -53,10 +53,36 @@
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
+
+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
#else
#define smp_mb() dmb(ish)
#define smp_rmb() smp_mb()
#define smp_wmb() dmb(ishst)
+
+#define smp_store_release(p, v) \
+do { \
+ asm volatile ("stlr %w0 [%1]" : : "r" (v), "r" (&p) : "memory");\
+} while (0)
+
+#define smp_load_acquire(p) \
+do { \
+ typeof(p) ___p1; \
+ asm volatile ("ldar %w0, [%1]" \
+ : "=r" (___p1) : "r" (&p) : "memory"); \
+ return ___p1; \
+} while (0)
#endif

#define read_barrier_depends() do { } while(0)
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index d4a63338a53c..0da2d4ebb9a8 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -35,10 +35,38 @@
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
+
+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#else
+
#define smp_mb() asm volatile("dmb ish" : : : "memory")
#define smp_rmb() asm volatile("dmb ishld" : : : "memory")
#define smp_wmb() asm volatile("dmb ishst" : : : "memory")
+
+#define smp_store_release(p, v) \
+do { \
+ asm volatile ("stlr %w0 [%1]" : : "r" (v), "r" (&p) : "memory");\
+} while (0)
+
+#define smp_load_acquire(p) \
+do { \
+ typeof(p) ___p1; \
+ asm volatile ("ldar %w0, [%1]" \
+ : "=r" (___p1) : "r" (&p) : "memory"); \
+ return ___p1; \
+} while (0)
#endif

#define read_barrier_depends() do { } while(0)
diff --git a/arch/avr32/include/asm/barrier.h b/arch/avr32/include/asm/barrier.h
index 0961275373db..a0c48ad684f8 100644
--- a/arch/avr32/include/asm/barrier.h
+++ b/arch/avr32/include/asm/barrier.h
@@ -25,5 +25,17 @@
# define smp_read_barrier_depends() do { } while(0)
#endif

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)

#endif /* __ASM_AVR32_BARRIER_H */
diff --git a/arch/blackfin/include/asm/barrier.h b/arch/blackfin/include/asm/barrier.h
index ebb189507dd7..67889d9225d9 100644
--- a/arch/blackfin/include/asm/barrier.h
+++ b/arch/blackfin/include/asm/barrier.h
@@ -45,4 +45,17 @@
#define set_mb(var, value) do { var = value; mb(); } while (0)
#define smp_read_barrier_depends() read_barrier_depends()

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _BLACKFIN_BARRIER_H */
diff --git a/arch/cris/include/asm/barrier.h b/arch/cris/include/asm/barrier.h
index 198ad7fa6b25..34243dc44ef1 100644
--- a/arch/cris/include/asm/barrier.h
+++ b/arch/cris/include/asm/barrier.h
@@ -22,4 +22,17 @@
#define smp_read_barrier_depends() do { } while(0)
#endif

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* __ASM_CRIS_BARRIER_H */
diff --git a/arch/frv/include/asm/barrier.h b/arch/frv/include/asm/barrier.h
index 06776ad9f5e9..92f89934d4ed 100644
--- a/arch/frv/include/asm/barrier.h
+++ b/arch/frv/include/asm/barrier.h
@@ -26,4 +26,17 @@
#define set_mb(var, value) \
do { var = (value); barrier(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _ASM_BARRIER_H */
diff --git a/arch/h8300/include/asm/barrier.h b/arch/h8300/include/asm/barrier.h
index 9e0aa9fc195d..516e9d379e25 100644
--- a/arch/h8300/include/asm/barrier.h
+++ b/arch/h8300/include/asm/barrier.h
@@ -26,4 +26,17 @@
#define smp_read_barrier_depends() do { } while(0)
#endif

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _H8300_BARRIER_H */
diff --git a/arch/hexagon/include/asm/barrier.h b/arch/hexagon/include/asm/barrier.h
index 1041a8e70ce8..838a2ebe07a5 100644
--- a/arch/hexagon/include/asm/barrier.h
+++ b/arch/hexagon/include/asm/barrier.h
@@ -38,4 +38,17 @@
#define set_mb(var, value) \
do { var = value; mb(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _ASM_BARRIER_H */
diff --git a/arch/ia64/include/asm/barrier.h b/arch/ia64/include/asm/barrier.h
index 60576e06b6fb..4598d390fabb 100644
--- a/arch/ia64/include/asm/barrier.h
+++ b/arch/ia64/include/asm/barrier.h
@@ -45,11 +45,54 @@
# define smp_rmb() rmb()
# define smp_wmb() wmb()
# define smp_read_barrier_depends() read_barrier_depends()
+
+#define smp_store_release(p, v) \
+do { \
+ switch (sizeof(p)) { \
+ case 4: \
+ asm volatile ("st4.acq [%0]=%1" \
+ :: "r" (&p), "r" (v) : "memory"); \
+ break; \
+ case 8: \
+ asm volatile ("st8.acq [%0]=%1" \
+ :: "r" (&p), "r" (v) : "memory"); \
+ break; \
+ } \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1; \
+ switch (sizeof(p)) { \
+ case 4: \
+ asm volatile ("ld4.rel %0=[%1]" \
+ : "=r"(___p1) : "r" (&p) : "memory"); \
+ break; \
+ case 8: \
+ asm volatile ("ld8.rel %0=[%1]" \
+ : "=r"(___p1) : "r" (&p) : "memory"); \
+ break; \
+ } \
+ return ___p1; \
+} while (0)
#else
# define smp_mb() barrier()
# define smp_rmb() barrier()
# define smp_wmb() barrier()
# define smp_read_barrier_depends() do { } while(0)
+
+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
#endif

/*
diff --git a/arch/m32r/include/asm/barrier.h b/arch/m32r/include/asm/barrier.h
index 6976621efd3f..e5d42bcf90c5 100644
--- a/arch/m32r/include/asm/barrier.h
+++ b/arch/m32r/include/asm/barrier.h
@@ -91,4 +91,17 @@
#define set_mb(var, value) do { var = value; barrier(); } while (0)
#endif

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _ASM_M32R_BARRIER_H */
diff --git a/arch/m68k/include/asm/barrier.h b/arch/m68k/include/asm/barrier.h
index 445ce22c23cb..eeb9ecf713cc 100644
--- a/arch/m68k/include/asm/barrier.h
+++ b/arch/m68k/include/asm/barrier.h
@@ -17,4 +17,17 @@
#define smp_wmb() barrier()
#define smp_read_barrier_depends() ((void)0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _M68K_BARRIER_H */
diff --git a/arch/metag/include/asm/barrier.h b/arch/metag/include/asm/barrier.h
index c90bfc6bf648..d8e6f2e4a27c 100644
--- a/arch/metag/include/asm/barrier.h
+++ b/arch/metag/include/asm/barrier.h
@@ -82,4 +82,17 @@ static inline void fence(void)
#define smp_read_barrier_depends() do { } while (0)
#define set_mb(var, value) do { var = value; smp_mb(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _ASM_METAG_BARRIER_H */
diff --git a/arch/microblaze/include/asm/barrier.h b/arch/microblaze/include/asm/barrier.h
index df5be3e87044..a890702061c9 100644
--- a/arch/microblaze/include/asm/barrier.h
+++ b/arch/microblaze/include/asm/barrier.h
@@ -24,4 +24,17 @@
#define smp_rmb() rmb()
#define smp_wmb() wmb()

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _ASM_MICROBLAZE_BARRIER_H */
diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h
index 314ab5532019..e59bcd051f36 100644
--- a/arch/mips/include/asm/barrier.h
+++ b/arch/mips/include/asm/barrier.h
@@ -180,4 +180,17 @@
#define nudge_writes() mb()
#endif

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* __ASM_BARRIER_H */
diff --git a/arch/mn10300/include/asm/barrier.h b/arch/mn10300/include/asm/barrier.h
index 2bd97a5c8af7..0e6a0608d4a1 100644
--- a/arch/mn10300/include/asm/barrier.h
+++ b/arch/mn10300/include/asm/barrier.h
@@ -34,4 +34,17 @@
#define read_barrier_depends() do {} while (0)
#define smp_read_barrier_depends() do {} while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _ASM_BARRIER_H */
diff --git a/arch/parisc/include/asm/barrier.h b/arch/parisc/include/asm/barrier.h
index e77d834aa803..f1145a8594a0 100644
--- a/arch/parisc/include/asm/barrier.h
+++ b/arch/parisc/include/asm/barrier.h
@@ -32,4 +32,17 @@

#define set_mb(var, value) do { var = value; mb(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* __PARISC_BARRIER_H */
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index ae782254e731..b5cc36791f42 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -65,4 +65,19 @@
#define data_barrier(x) \
asm volatile("twi 0,%0,0; isync" : : "r" (x) : "memory");

+/* use smp_rmb() as that is either lwsync or a barrier() depending on SMP */
+
+#define smp_store_release(p, v) \
+do { \
+ smp_rmb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_rmb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _ASM_POWERPC_BARRIER_H */
diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h
index 16760eeb79b0..e8989c40e11c 100644
--- a/arch/s390/include/asm/barrier.h
+++ b/arch/s390/include/asm/barrier.h
@@ -32,4 +32,17 @@

#define set_mb(var, value) do { var = value; mb(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ barrier(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ barrier(); \
+ return ___p1; \
+} while (0)
+
#endif /* __ASM_BARRIER_H */
diff --git a/arch/score/include/asm/barrier.h b/arch/score/include/asm/barrier.h
index 0eacb6471e6d..5f101ef8ade9 100644
--- a/arch/score/include/asm/barrier.h
+++ b/arch/score/include/asm/barrier.h
@@ -13,4 +13,17 @@

#define set_mb(var, value) do {var = value; wmb(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _ASM_SCORE_BARRIER_H */
diff --git a/arch/sh/include/asm/barrier.h b/arch/sh/include/asm/barrier.h
index 72c103dae300..611128c2f636 100644
--- a/arch/sh/include/asm/barrier.h
+++ b/arch/sh/include/asm/barrier.h
@@ -51,4 +51,17 @@

#define set_mb(var, value) do { (void)xchg(&var, value); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* __ASM_SH_BARRIER_H */
diff --git a/arch/sparc/include/asm/barrier_32.h b/arch/sparc/include/asm/barrier_32.h
index c1b76654ee76..f47f9d51f326 100644
--- a/arch/sparc/include/asm/barrier_32.h
+++ b/arch/sparc/include/asm/barrier_32.h
@@ -12,4 +12,17 @@
#define smp_wmb() __asm__ __volatile__("":::"memory")
#define smp_read_barrier_depends() do { } while(0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* !(__SPARC_BARRIER_H) */
diff --git a/arch/sparc/include/asm/barrier_64.h b/arch/sparc/include/asm/barrier_64.h
index 95d45986f908..77cbe6982ca0 100644
--- a/arch/sparc/include/asm/barrier_64.h
+++ b/arch/sparc/include/asm/barrier_64.h
@@ -53,4 +53,17 @@ do { __asm__ __volatile__("ba,pt %%xcc, 1f\n\t" \

#define smp_read_barrier_depends() do { } while(0)

+#define smp_store_release(p, v) \
+do { \
+ barrier(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ barrier(); \
+ return ___p1; \
+} while (0)
+
#endif /* !(__SPARC64_BARRIER_H) */
diff --git a/arch/tile/include/asm/barrier.h b/arch/tile/include/asm/barrier.h
index a9a73da5865d..4d5330d4fd31 100644
--- a/arch/tile/include/asm/barrier.h
+++ b/arch/tile/include/asm/barrier.h
@@ -140,5 +140,18 @@ mb_incoherent(void)
#define set_mb(var, value) \
do { var = value; mb(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_TILE_BARRIER_H */
diff --git a/arch/unicore32/include/asm/barrier.h b/arch/unicore32/include/asm/barrier.h
index a6620e5336b6..5471ff6aae10 100644
--- a/arch/unicore32/include/asm/barrier.h
+++ b/arch/unicore32/include/asm/barrier.h
@@ -25,4 +25,17 @@

#define set_mb(var, value) do { var = value; smp_mb(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* __UNICORE_BARRIER_H__ */
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index c6cd358a1eec..a7fd8201ab09 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -100,6 +100,19 @@
#define set_mb(var, value) do { var = value; barrier(); } while (0)
#endif

+#define smp_store_release(p, v) \
+do { \
+ barrier(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ barrier(); \
+ return ___p1; \
+} while (0)
+
/*
* Stop RDTSC speculation. This is needed when you need to use RDTSC
* (or get_cycles or vread that possibly accesses the TSC) in a defined
diff --git a/arch/xtensa/include/asm/barrier.h b/arch/xtensa/include/asm/barrier.h
index ef021677d536..703d511add49 100644
--- a/arch/xtensa/include/asm/barrier.h
+++ b/arch/xtensa/include/asm/barrier.h
@@ -26,4 +26,17 @@

#define set_mb(var, value) do { var = value; mb(); } while (0)

+#define smp_store_release(p, v) \
+do { \
+ smp_mb(); \
+ ACCESS_ONCE(p) = (v); \
+} while (0)
+
+#define smp_load_acquire(p, v) \
+do { \
+ typeof(p) ___p1 = ACCESS_ONCE(p); \
+ smp_mb(); \
+ return ___p1; \
+} while (0)
+
#endif /* _XTENSA_SYSTEM_H */
--
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