MIPS: Compute branch returns for Cavium OCTEON specific branch instructions.

For Cavium OCTEON, compute the return epc value for OCTEON specific
branch instructions.

Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
index 6b5df8bfab85..0176ed015c89 100644
--- a/arch/mips/kernel/branch.c
+++ b/arch/mips/kernel/branch.c
@@ -205,6 +205,39 @@ int __compute_return_epc(struct pt_regs *regs)
                         break;
                 }
                 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)
+                        epc = epc + 4 + (insn.i_format.simmediate << 2);
+                else
+                        epc += 8;
+                regs->cp0_epc = epc;
+                break;
+        case ldc2_op: /* This is bbit032 on Octeon */
+                if ((regs->regs[insn.i_format.rs] &
+                    (1ull<<(insn.i_format.rt+32))) == 0)
+                        epc = epc + 4 + (insn.i_format.simmediate << 2);
+                else
+                        epc += 8;
+                regs->cp0_epc = epc;
+                break;
+        case swc2_op: /* This is bbit1 on Octeon */
+                if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
+                        epc = epc + 4 + (insn.i_format.simmediate << 2);
+                else
+                        epc += 8;
+                regs->cp0_epc = epc;
+                break;
+        case sdc2_op: /* This is bbit132 on Octeon */
+                if (regs->regs[insn.i_format.rs] &
+                    (1ull<<(insn.i_format.rt+32)))
+                        epc = epc + 4 + (insn.i_format.simmediate << 2);
+                else
+                        epc += 8;
+                regs->cp0_epc = epc;
+                break;
+#endif
         }
 
         return 0;