Add the acquire variant of smp_cond_load_relaxed_timewait(). This
reuses the relaxed variant, with an additional LOAD->LOAD
ordering via smp_acquire__after_ctrl_dep().
Also, the rqspinlock implementation has a locally cached copy of
this interface. Fixup the parameters used there.
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
---
arch/arm64/include/asm/rqspinlock.h | 2 +-
include/asm-generic/barrier.h | 22 ++++++++++++++++++++++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/rqspinlock.h b/arch/arm64/include/asm/rqspinlock.h
index 9ea0a74e5892..f1b6a428013e 100644
--- a/arch/arm64/include/asm/rqspinlock.h
+++ b/arch/arm64/include/asm/rqspinlock.h
@@ -86,7 +86,7 @@
#endif
-#define res_smp_cond_load_acquire(v, c) smp_cond_load_acquire_timewait(v, c, 0, 1)
+#define res_smp_cond_load_acquire(v, c) smp_cond_load_acquire_timewait(v, c, 0ULL, 1ULL, 0)
#include <asm-generic/rqspinlock.h>
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index 8299c57d1110..dd7c9ca2dff3 100644
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -388,6 +388,28 @@ static inline u64 ___smp_cond_spinwait(u64 now, u64 prev, u64 end,
(typeof(*ptr))_val; \
})
+/**
+ * smp_cond_load_acquire_timewait() - (Spin) wait for cond with ACQUIRE ordering
+ * until a timeout expires.
+ *
+ * Arguments: same as smp_cond_load_relaxed_timeout().
+ *
+ * Equivalent to using smp_cond_load_acquire() on the condition variable with
+ * a timeout.
+ */
+#ifndef smp_cond_load_acquire_timewait
+#define smp_cond_load_acquire_timewait(ptr, cond_expr, \
+ time_expr, time_end, \
+ slack) ({ \
+ __unqual_scalar_typeof(*ptr) _val; \
+ _val = smp_cond_load_relaxed_timewait(ptr, cond_expr, \
+ time_expr, time_end, \
+ slack); \
+ /* Depends on the control dependency of the wait above. */ \
+ smp_acquire__after_ctrl_dep(); \
+ (typeof(*ptr))_val; \
+})
+#endif
/*
* pmem_wmb() ensures that all stores for which the modification
* are written to persistent storage by preceding instructions have
--
2.43.5
