1 files changed, 18 insertions, 3 deletions

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index da0c29422cf2..cf7ac5483f53 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1025,6 +1025,24 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 
                 return;
 
+        case 3:
+                /*
+                 * Old (MIPS I and MIPS II) processors will set this code
+                 * for COP1X opcode instructions that replaced the original
+                 * COP3 space.  We don't limit COP1 space instructions in
+                 * the emulator according to the CPU ISA, so we want to
+                 * treat COP1X instructions consistently regardless of which
+                 * code the CPU chose.  Therefore we redirect this trap to
+                 * the FP emulator too.
+                 *
+                 * Then some newer FPU-less processors use this code
+                 * erroneously too, so they are covered by this choice
+                 * as well.
+                 */
+                if (raw_cpu_has_fpu)
+                        break;
+                /* Fall through.  */
+
         case 1:
                 if (used_math())        /* Using the FPU again.  */
                         own_fpu(1);
@@ -1048,9 +1066,6 @@ asmlinkage void do_cpu(struct pt_regs *regs)
         case 2:
                 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
                 return;
-
-        case 3:
-                break;
         }
 
         force_sig(SIGILL, current);