MIPS: Fix FTLB detection for R6

[linux-drm-fsl-dcu.git] / arch / mips / kernel / cpu-probe.c

diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 397551cf2e7bc3235d4dcf4d55b22485a846d79e..09a51d091941be3aa75ae37b53b386714a6d3db5 100644 (file)
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -561,15 +561,18 @@ static inline unsigned int decode_config4(struct cpuinfo_mips *c)
        if (cpu_has_tlb) {
                if (((config4 & MIPS_CONF4_IE) >> 29) == 2)
                        c->options |= MIPS_CPU_TLBINV;
+
                /*
-                * This is a bit ugly. R6 has dropped that field from
-                * config4 and the only valid configuration is VTLB+FTLB so
-                * set a good value for mmuextdef for that case.
+                * R6 has dropped the MMUExtDef field from config4.
+                * On R6 the fields always describe the FTLB, and only if it is
+                * present according to Config.MT.
                 */
-               if (cpu_has_mips_r6)
+               if (!cpu_has_mips_r6)
+                       mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
+               else if (cpu_has_ftlb)
                        mmuextdef = MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT;
                else
-                       mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF;
+                       mmuextdef = 0;
 
                switch (mmuextdef) {
                case MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT: