advsync: Use READ_ONCE()/WRITE_ONCE() in sequence of 'Device Operations'
Using pseudo-asm code here results in a redundant look. In this
section, using READ_ONCE()/WRITE_ONCE() in code sequence gives
a good contrast with the resulting ordering of memory accesses.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/advsync/memorybarriers.tex b/advsync/memorybarriers.tex
index 7b50511..f94b113 100644
--- a/advsync/memorybarriers.tex
+++ b/advsync/memorybarriers.tex
@@ -1261,15 +1261,15 @@
locations, but the order in which the control registers are accessed is very
important. For instance, imagine an Ethernet card with a set of internal
registers that are accessed through an address port register~(A) and a data
-port register~(D). To read internal register~5, the following code might then
-be used:
+port register~(D). To read internal register~5, the following code (in C)
+might then be used:
\vspace{5pt}
\begin{minipage}[t]{\columnwidth}
\scriptsize
\begin{verbatim}
-*A = 5;
-x = *D;
+WRITE_ONCE(*A, 5);
+x = READ_ONCE(*D);
\end{verbatim}
\vspace{1pt}
\end{minipage}
