MIPS: Malta: Fix crash in SMP kernel on non-CMP systems.

Since 6be63bbbdab66b9185dc6f67c8b1bacb6f37f946 (lmo) rsp.
af3a1f6f4813907e143f87030cde67a9971db533 (kernel.org) the Malta code does
no longer probe for presence of GCMP if CMP is not configured.  This means
that the variable gcmp_present well be left at its default value of -1
which normally is meant to indicate that GCMP has not yet been mmapped.
This non-zero value is now interpreted as GCMP being present resulting
in a write attempt to a GCMP register resulting in a crash.

Reported and a build fix on top of my fix by Rob Landley <rob@landley.net>.

Reported-by: Rob Landley <rob@landley.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2413/

1 files changed, 3 insertions, 5 deletions

diff --git a/arch/mips/pmc-sierra/msp71xx/msp_setup.c b/arch/mips/pmc-sierra/msp71xx/msp_setup.c
index 2413ea67877e..0abfbe04ffc9 100644
--- a/arch/mips/pmc-sierra/msp71xx/msp_setup.c
+++ b/arch/mips/pmc-sierra/msp71xx/msp_setup.c
@@ -228,13 +228,11 @@ void __init prom_init(void)
          */
         msp_serial_setup();
 
-#ifdef CONFIG_MIPS_MT_SMP
-        register_smp_ops(&vsmp_smp_ops);
-#endif
-
+        if (register_vsmp_smp_ops()) {
 #ifdef CONFIG_MIPS_MT_SMTC
-        register_smp_ops(&msp_smtc_smp_ops);
+                register_smp_ops(&msp_smtc_smp_ops);
 #endif
+        }
 
 #ifdef CONFIG_PMCTWILED
         /*