1 files changed, 24 insertions, 4 deletions

diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 5465dc183e5a..040b83de00ac 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -376,13 +376,33 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
                                 __cpu_name[cpu] = "R4000PC";
                         }
                 } else {
+                        int cca = read_c0_config() & CONF_CM_CMASK;
+                        int mc;
+
+                        /*
+                         * SC and MC versions can't be reliably told apart,
+                         * but only the latter support coherent caching
+                         * modes so assume the firmware has set the KSEG0
+                         * coherency attribute reasonably (if uncached, we
+                         * assume SC).
+                         */
+                        switch (cca) {
+                        case CONF_CM_CACHABLE_CE:
+                        case CONF_CM_CACHABLE_COW:
+                        case CONF_CM_CACHABLE_CUW:
+                                mc = 1;
+                                break;
+                        default:
+                                mc = 0;
+                                break;
+                        }
                         if ((c->processor_id & PRID_REV_MASK) >=
                             PRID_REV_R4400) {
-                                c->cputype = CPU_R4400SC;
-                                __cpu_name[cpu] = "R4400SC";
+                                c->cputype = mc ? CPU_R4400MC : CPU_R4400SC;
+                                __cpu_name[cpu] = mc ? "R4400MC" : "R4400SC";
                         } else {
-                                c->cputype = CPU_R4000SC;
-                                __cpu_name[cpu] = "R4000SC";
+                                c->cputype = mc ? CPU_R4000MC : CPU_R4000SC;
+                                __cpu_name[cpu] = mc ? "R4000MC" : "R4000SC";
                         }
                 }