[MIPS] Avoid dupliate D-cache flush on R400C / R4400 SC and MC variants.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 0138cb2..df04a31 100644 (file)
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -381,17 +381,21 @@ static inline void local_r4k_flush_cache_mm(void * args)
        if (!cpu_context(smp_processor_id(), mm))
                return;
 
-       r4k_blast_dcache();
-
        /*
         * Kludge alert.  For obscure reasons R4000SC and R4400SC go nuts if we
         * only flush the primary caches but R10000 and R12000 behave sane ...
+        * R4000SC and R4400SC indexed S-cache ops also invalidate primary
+        * caches, so we can bail out early.
         */
        if (current_cpu_data.cputype == CPU_R4000SC ||
            current_cpu_data.cputype == CPU_R4000MC ||
            current_cpu_data.cputype == CPU_R4400SC ||
-           current_cpu_data.cputype == CPU_R4400MC)
+           current_cpu_data.cputype == CPU_R4400MC) {
                r4k_blast_scache();
+               return;
+       }
+
+       r4k_blast_dcache();
 }
 
 static void r4k_flush_cache_mm(struct mm_struct *mm)