diff options
Diffstat (limited to 'arch/mips/kernel/traps.c')
| -rw-r--r-- | arch/mips/kernel/traps.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index dc6eaf4d93ea..88f04f0d2d21 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -1349,19 +1349,18 @@ asmlinkage void do_cpu(struct pt_regs *regs) 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. + * The COP3 opcode space and consequently the CP0.Status.CU3 + * bit and the CP0.Cause.CE=3 encoding have been removed as + * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs + * up the space has been reused for COP1X instructions, that + * are enabled by the CP0.Status.CU1 bit and consequently + * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable + * exceptions. Some FPU-less processors that implement one + * of these ISAs however use this code erroneously for COP1X + * instructions. Therefore we redirect this trap to the FP + * emulator too. */ - if (raw_cpu_has_fpu) { + if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) { force_sig(SIGILL, current); break; } |