MIPS: Handle OCTEON BBIT instructions in FPU emulator.

The branch emulation needs to handle the OCTEON BBIT instructions,
otherwise we get SIGILL instead of emulation.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5726/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index e773659ccf9f..46048d24328c 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -803,6 +803,32 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
                                 dec_insn.next_pc_inc;
                 return 1;
                 break;
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+        case lwc2_op: /* This is bbit0 on Octeon */
+                if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
+                        *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
+                else
+                        *contpc = regs->cp0_epc + 8;
+                return 1;
+        case ldc2_op: /* This is bbit032 on Octeon */
+                if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
+                        *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
+                else
+                        *contpc = regs->cp0_epc + 8;
+                return 1;
+        case swc2_op: /* This is bbit1 on Octeon */
+                if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
+                        *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
+                else
+                        *contpc = regs->cp0_epc + 8;
+                return 1;
+        case sdc2_op: /* This is bbit132 on Octeon */
+                if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
+                        *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
+                else
+                        *contpc = regs->cp0_epc + 8;
+                return 1;
+#endif
         case cop0_op:
         case cop1_op:
         case cop2_op: