checkpatch: Add warnings for {smp_,}read_barrier_depends()

Now that both smp_read_barrier_depends() and read_barrier_depends()
are being de-emphasized, warn if any are added.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
[ paulmck: Skipped checking files and handled whitespace per Joe Perches. ]

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 95cda3e..9a384bf 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5586,6 +5586,12 @@ sub process {
                        }
                }
 
+# check for smp_read_barrier_depends and read_barrier_depends
+               if (!$file && $line =~ /\b(smp_|)read_barrier_depends\s*\(/) {
+                       WARN("READ_BARRIER_DEPENDS",
+                            "$1read_barrier_depends should only be used in READ_ONCE or DEC Alpha code\n" . $herecurr);
+               }
+
 # check of hardware specific defines
                if ($line =~ m@^.\s*\#\s*if.*\b(__i386__|__powerpc64__|__sun__|__s390x__)\b@ && $realfile !~ m@include/asm-@) {
                        CHK("ARCH_DEFINES",