locking/barriers: Move smp_cond_load_acquire() to asm-generic/barrier.h
Since all asm/barrier.h should/must include asm-generic/barrier.h the
latter is a good place for generic infrastructure like this.
This also allows archs to override the new smp_acquire__after_ctrl_dep().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index 1cceca14..ab7b0bd 100644
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -207,5 +207,44 @@
#define virt_store_release(p, v) __smp_store_release(p, v)
#define virt_load_acquire(p) __smp_load_acquire(p)
+/**
+ * smp_acquire__after_ctrl_dep() - Provide ACQUIRE ordering after a control dependency
+ *
+ * A control dependency provides a LOAD->STORE order, the additional RMB
+ * provides LOAD->LOAD order, together they provide LOAD->{LOAD,STORE} order,
+ * aka. (load)-ACQUIRE.
+ *
+ * Architectures that do not do load speculation can have this be barrier().
+ */
+#ifndef smp_acquire__after_ctrl_dep
+#define smp_acquire__after_ctrl_dep() smp_rmb()
+#endif
+
+/**
+ * smp_cond_load_acquire() - (Spin) wait for cond with ACQUIRE ordering
+ * @ptr: pointer to the variable to wait on
+ * @cond: boolean expression to wait for
+ *
+ * Equivalent to using smp_load_acquire() on the condition variable but employs
+ * the control dependency of the wait to reduce the barrier on many platforms.
+ *
+ * Due to C lacking lambda expressions we load the value of *ptr into a
+ * pre-named variable @VAL to be used in @cond.
+ */
+#ifndef smp_cond_load_acquire
+#define smp_cond_load_acquire(ptr, cond_expr) ({ \
+ typeof(ptr) __PTR = (ptr); \
+ typeof(*ptr) VAL; \
+ for (;;) { \
+ VAL = READ_ONCE(*__PTR); \
+ if (cond_expr) \
+ break; \
+ cpu_relax(); \
+ } \
+ smp_acquire__after_ctrl_dep(); \
+ VAL; \
+})
+#endif
+
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_GENERIC_BARRIER_H */
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 59a7004..2e853b6 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -304,43 +304,6 @@
__u.__val; \
})
-/**
- * smp_acquire__after_ctrl_dep() - Provide ACQUIRE ordering after a control dependency
- *
- * A control dependency provides a LOAD->STORE order, the additional RMB
- * provides LOAD->LOAD order, together they provide LOAD->{LOAD,STORE} order,
- * aka. (load)-ACQUIRE.
- *
- * Architectures that do not do load speculation can have this be barrier().
- */
-#define smp_acquire__after_ctrl_dep() smp_rmb()
-
-/**
- * smp_cond_load_acquire() - (Spin) wait for cond with ACQUIRE ordering
- * @ptr: pointer to the variable to wait on
- * @cond: boolean expression to wait for
- *
- * Equivalent to using smp_load_acquire() on the condition variable but employs
- * the control dependency of the wait to reduce the barrier on many platforms.
- *
- * Due to C lacking lambda expressions we load the value of *ptr into a
- * pre-named variable @VAL to be used in @cond.
- */
-#ifndef smp_cond_load_acquire
-#define smp_cond_load_acquire(ptr, cond_expr) ({ \
- typeof(ptr) __PTR = (ptr); \
- typeof(*ptr) VAL; \
- for (;;) { \
- VAL = READ_ONCE(*__PTR); \
- if (cond_expr) \
- break; \
- cpu_relax(); \
- } \
- smp_acquire__after_ctrl_dep(); \
- VAL; \
-})
-#endif
-
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
