MN10300: Introduce barriers to replace removed volatiles in gdbstub
Introduce into the MN10300 gdbstub a couple of barrier() calls to replace the
removed volatility of the input/output index variables for the Rx ring buffer.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/mn10300/kernel/gdb-io-ttysm.c b/arch/mn10300/kernel/gdb-io-ttysm.c
index c545159..e94c25e 100644
--- a/arch/mn10300/kernel/gdb-io-ttysm.c
+++ b/arch/mn10300/kernel/gdb-io-ttysm.c
@@ -196,6 +196,7 @@
try_again:
/* pull chars out of the buffer */
ix = gdbstub_rx_outp;
+ barrier();
if (ix == gdbstub_rx_inp) {
if (nonblock)
return -EAGAIN;
@@ -207,6 +208,7 @@
ch = gdbstub_rx_buffer[ix++];
st = gdbstub_rx_buffer[ix++];
+ barrier();
gdbstub_rx_outp = ix & (PAGE_SIZE - 1);
st &= SC01STR_RXF | SC01STR_RBF | SC01STR_FEF | SC01STR_PEF |