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, 7 insertions, 7 deletions

diff --git a/arch/mips/mti-malta/malta-init.c b/arch/mips/mti-malta/malta-init.c
index 31180c321a1a..4b988b9a30d5 100644
--- a/arch/mips/mti-malta/malta-init.c
+++ b/arch/mips/mti-malta/malta-init.c
@@ -28,6 +28,7 @@
 #include <asm/io.h>
 #include <asm/system.h>
 #include <asm/cacheflush.h>
+#include <asm/smp-ops.h>
 #include <asm/traps.h>
 
 #include <asm/gcmpregs.h>
@@ -358,15 +359,14 @@ void __init prom_init(void)
 #ifdef CONFIG_SERIAL_8250_CONSOLE
         console_config();
 #endif
-#ifdef CONFIG_MIPS_CMP
         /* Early detection of CMP support */
         if (gcmp_probe(GCMP_BASE_ADDR, GCMP_ADDRSPACE_SZ))
-                register_smp_ops(&cmp_smp_ops);
-        else
-#endif
-#ifdef CONFIG_MIPS_MT_SMP
-                register_smp_ops(&vsmp_smp_ops);
-#endif
+                if (!register_cmp_smp_ops())
+                        return;
+
+        if (!register_vsmp_smp_ops())
+                return;
+
 #ifdef CONFIG_MIPS_MT_SMTC
         register_smp_ops(&msmtc_smp_ops);
 #endif