MIPS: GCMP: Avoid accessing registers when they are not present

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 13 insertions, 3 deletions

diff --git a/arch/mips/mti-malta/malta-int.c b/arch/mips/mti-malta/malta-int.c
index 377a925e8cc6..4c3fca18a171 100644
--- a/arch/mips/mti-malta/malta-int.c
+++ b/arch/mips/mti-malta/malta-int.c
@@ -411,6 +411,11 @@ static struct gic_intr_map gic_intr_map[GIC_NUM_INTRS] = {
  */
 int __init gcmp_probe(unsigned long addr, unsigned long size)
 {
+        if (mips_revision_sconid != MIPS_REVISION_SCON_ROCIT) {
+                gcmp_present = 0;
+                return gcmp_present;
+        }
+
         if (gcmp_present >= 0)
                 return gcmp_present;
 
@@ -479,9 +484,14 @@ void __init arch_init_irq(void)
                 GCMPGCB(GICBA) = GIC_BASE_ADDR | GCMP_GCB_GICBA_EN_MSK;
                 gic_present = 1;
         } else {
-                _msc01_biu_base = (unsigned long) ioremap_nocache(MSC01_BIU_REG_BASE, MSC01_BIU_ADDRSPACE_SZ);
-                gic_present = (REG(_msc01_biu_base, MSC01_SC_CFG) &
-                MSC01_SC_CFG_GICPRES_MSK) >> MSC01_SC_CFG_GICPRES_SHF;
+                if (mips_revision_sconid == MIPS_REVISION_SCON_ROCIT) {
+                        _msc01_biu_base = (unsigned long)
+                                        ioremap_nocache(MSC01_BIU_REG_BASE,
+                                                MSC01_BIU_ADDRSPACE_SZ);
+                        gic_present = (REG(_msc01_biu_base, MSC01_SC_CFG) &
+                                        MSC01_SC_CFG_GICPRES_MSK) >>
+                                        MSC01_SC_CFG_GICPRES_SHF;
+                }
         }
         if (gic_present)
                 pr_debug("GIC present\n");