Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

Pull MIPS fix from Ralf Baechle:
 "Just a single patch which fixes a special case in the MIPS FPU
  emulator which is always required, even on CPUs with FPU.  There is
  the rare special case that an FPU (or certain other instructions) in a
  branch delay slot is causing an exception and then the branch
  instruction will need to be emulated by the kernel before resuming
  execution.  This is working great except if the branch instruction is
  an Octeon BBIT instruction.

  The boring disclaimer - all MIPS defconfigs build tested and no
  regressions and runtime tested on Octeon, no known issues"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: Handle OCTEON BBIT instructions in FPU emulator.

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: