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)