MIPS: math-emu: Emulate missing BC1{EQ,NE}Z instructions

commit c909ca71 upstream.

Commit c8a34581 ("MIPS: Emulate the BC1{EQ,NE}Z FPU instructions")
added support for emulating the new R6 BC1{EQ,NE}Z branches but it missed
the case where the instruction that caused the exception was not on a DS.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Fixes: c8a34581 ("MIPS: Emulate the BC1{EQ,NE}Z FPU instructions")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10738/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/mips/math-emu/cp1emu.c

@@ -1181,6 +1181,24 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 			}
 			break;
 
+		case bc1eqz_op:
+		case bc1nez_op:
+			if (!cpu_has_mips_r6 || delay_slot(xcp))
+				return SIGILL;
+
+			cond = likely = 0;
+			switch (MIPSInst_RS(ir)) {
+			case bc1eqz_op:
+				if (get_fpr32(&current->thread.fpu.fpr[MIPSInst_RT(ir)], 0) & 0x1)
+				    cond = 1;
+				break;
+			case bc1nez_op:
+				if (!(get_fpr32(&current->thread.fpu.fpr[MIPSInst_RT(ir)], 0) & 0x1))
+				    cond = 1;
+				break;
+			}
+			goto branch_common;
+
 		case bc_op:
 			if (delay_slot(xcp))
 				return SIGILL;
@@ -1207,7 +1225,7 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 			case bct_op:
 				break;
 			}
-
+branch_common:
 			set_delay_slot(xcp);
 			if (cond) {
 				/*