UPSTREAM: MIPS: Allow emulation for unaligned [LS]DXC1 instructions

If an address error exception occurs for a LDXC1 or SDXC1 instruction,
within the cop1x opcode space, allow it to be passed through to the FPU
emulator rather than resulting in a SIGILL. This causes LDXC1 & SDXC1 to
be handled in a manner consistent with the more common LDC1 & SDC1
instructions.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13143/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit e70ac023f9)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

arch/mips/kernel/unaligned.c

@@ -1191,6 +1191,7 @@ static void emulate_load_store_insn(struct pt_regs *regs,
 	case ldc1_op:
 	case swc1_op:
 	case sdc1_op:
+	case cop1x_op:
 		die_if_kernel("Unaligned FP access in kernel code", regs);
 		BUG_ON(!used_math());