drivers: power: report battery voltage in AOSP compatible format

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / spinlock.h

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 7d537ced949aa83b33b4c20e32c991d2123ca5a5..75f34949d9ab998adf5941c0321ea45005cc7d62 100644 (file)
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -117,9 +117,17 @@ do {                                                               \
 #endif /*arch_spin_is_contended*/
 #endif
 
-/* The lock does not imply full memory barrier. */
-#ifndef ARCH_HAS_SMP_MB_AFTER_LOCK
-static inline void smp_mb__after_lock(void) { smp_mb(); }
+/*
+ * Despite its name it doesn't necessarily has to be a full barrier.
+ * It should only guarantee that a STORE before the critical section
+ * can not be reordered with a LOAD inside this section.
+ * spin_lock() is the one-way barrier, this LOAD can not escape out
+ * of the region. So the default implementation simply ensures that
+ * a STORE can not move into the critical section, smp_wmb() should
+ * serialize it with another STORE done by spin_lock().
+ */
+#ifndef smp_mb__before_spinlock
+#define smp_mb__before_spinlock()      smp_wmb()
 #endif
 
 /**