Initial import

1 files changed, 2218 insertions, 0 deletions

diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
new file mode 100644
index 000000000..22b9b2cb9
--- /dev/null
+++ b/arch/mips/math-emu/cp1emu.c
@@ -0,0 +1,2218 @@
+/*
+ * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator
+ *
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ *
+ * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 2000  MIPS Technologies, Inc.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.
+ *
+ * A complete emulator for MIPS coprocessor 1 instructions.  This is
+ * required for #float(switch) or #float(trap), where it catches all
+ * COP1 instructions via the "CoProcessor Unusable" exception.
+ *
+ * More surprisingly it is also required for #float(ieee), to help out
+ * the hardware FPU at the boundaries of the IEEE-754 representation
+ * (denormalised values, infinities, underflow, etc).  It is made
+ * quite nasty because emulation of some non-COP1 instructions is
+ * required, e.g. in branch delay slots.
+ *
+ * Note if you know that you won't have an FPU, then you'll get much
+ * better performance by compiling with -msoft-float!
+ */
+#include <linux/sched.h>
+#include <linux/debugfs.h>
+#include <linux/kconfig.h>
+#include <linux/percpu-defs.h>
+#include <linux/perf_event.h>
+
+#include <asm/branch.h>
+#include <asm/inst.h>
+#include <asm/ptrace.h>
+#include <asm/signal.h>
+#include <asm/uaccess.h>
+
+#include <asm/cpu-info.h>
+#include <asm/processor.h>
+#include <asm/fpu_emulator.h>
+#include <asm/fpu.h>
+#include <asm/mips-r2-to-r6-emul.h>
+
+#include "ieee754.h"
+
+/* Function which emulates a floating point instruction. */
+
+static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
+	mips_instruction);
+
+static int fpux_emu(struct pt_regs *,
+	struct mips_fpu_struct *, mips_instruction, void *__user *);
+
+/* Control registers */
+
+#define FPCREG_RID	0	/* $0  = revision id */
+#define FPCREG_FCCR	25	/* $25 = fccr */
+#define FPCREG_FEXR	26	/* $26 = fexr */
+#define FPCREG_FENR	28	/* $28 = fenr */
+#define FPCREG_CSR	31	/* $31 = csr */
+
+/* convert condition code register number to csr bit */
+const unsigned int fpucondbit[8] = {
+	FPU_CSR_COND,
+	FPU_CSR_COND1,
+	FPU_CSR_COND2,
+	FPU_CSR_COND3,
+	FPU_CSR_COND4,
+	FPU_CSR_COND5,
+	FPU_CSR_COND6,
+	FPU_CSR_COND7
+};
+
+/* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
+static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
+static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
+static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
+static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
+
+/*
+ * This functions translates a 32-bit microMIPS instruction
+ * into a 32-bit MIPS32 instruction. Returns 0 on success
+ * and SIGILL otherwise.
+ */
+static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
+{
+	union mips_instruction insn = *insn_ptr;
+	union mips_instruction mips32_insn = insn;
+	int func, fmt, op;
+
+	switch (insn.mm_i_format.opcode) {
+	case mm_ldc132_op:
+		mips32_insn.mm_i_format.opcode = ldc1_op;
+		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
+		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
+		break;
+	case mm_lwc132_op:
+		mips32_insn.mm_i_format.opcode = lwc1_op;
+		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
+		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
+		break;
+	case mm_sdc132_op:
+		mips32_insn.mm_i_format.opcode = sdc1_op;
+		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
+		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
+		break;
+	case mm_swc132_op:
+		mips32_insn.mm_i_format.opcode = swc1_op;
+		mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
+		mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
+		break;
+	case mm_pool32i_op:
+		/* NOTE: offset is << by 1 if in microMIPS mode. */
+		if ((insn.mm_i_format.rt == mm_bc1f_op) ||
+		    (insn.mm_i_format.rt == mm_bc1t_op)) {
+			mips32_insn.fb_format.opcode = cop1_op;
+			mips32_insn.fb_format.bc = bc_op;
+			mips32_insn.fb_format.flag =
+				(insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
+		} else
+			return SIGILL;
+		break;
+	case mm_pool32f_op:
+		switch (insn.mm_fp0_format.func) {
+		case mm_32f_01_op:
+		case mm_32f_11_op:
+		case mm_32f_02_op:
+		case mm_32f_12_op:
+		case mm_32f_41_op:
+		case mm_32f_51_op:
+		case mm_32f_42_op:
+		case mm_32f_52_op:
+			op = insn.mm_fp0_format.func;
+			if (op == mm_32f_01_op)
+				func = madd_s_op;
+			else if (op == mm_32f_11_op)
+				func = madd_d_op;
+			else if (op == mm_32f_02_op)
+				func = nmadd_s_op;
+			else if (op == mm_32f_12_op)
+				func = nmadd_d_op;
+			else if (op == mm_32f_41_op)
+				func = msub_s_op;
+			else if (op == mm_32f_51_op)
+				func = msub_d_op;
+			else if (op == mm_32f_42_op)
+				func = nmsub_s_op;
+			else
+				func = nmsub_d_op;
+			mips32_insn.fp6_format.opcode = cop1x_op;
+			mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
+			mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
+			mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
+			mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
+			mips32_insn.fp6_format.func = func;
+			break;
+		case mm_32f_10_op:
+			func = -1;	/* Invalid */
+			op = insn.mm_fp5_format.op & 0x7;
+			if (op == mm_ldxc1_op)
+				func = ldxc1_op;
+			else if (op == mm_sdxc1_op)
+				func = sdxc1_op;
+			else if (op == mm_lwxc1_op)
+				func = lwxc1_op;
+			else if (op == mm_swxc1_op)
+				func = swxc1_op;
+
+			if (func != -1) {
+				mips32_insn.r_format.opcode = cop1x_op;
+				mips32_insn.r_format.rs =
+					insn.mm_fp5_format.base;
+				mips32_insn.r_format.rt =
+					insn.mm_fp5_format.index;
+				mips32_insn.r_format.rd = 0;
+				mips32_insn.r_format.re = insn.mm_fp5_format.fd;
+				mips32_insn.r_format.func = func;
+			} else
+				return SIGILL;
+			break;
+		case mm_32f_40_op:
+			op = -1;	/* Invalid */
+			if (insn.mm_fp2_format.op == mm_fmovt_op)
+				op = 1;
+			else if (insn.mm_fp2_format.op == mm_fmovf_op)
+				op = 0;
+			if (op != -1) {
+				mips32_insn.fp0_format.opcode = cop1_op;
+				mips32_insn.fp0_format.fmt =
+					sdps_format[insn.mm_fp2_format.fmt];
+				mips32_insn.fp0_format.ft =
+					(insn.mm_fp2_format.cc<<2) + op;
+				mips32_insn.fp0_format.fs =
+					insn.mm_fp2_format.fs;
+				mips32_insn.fp0_format.fd =
+					insn.mm_fp2_format.fd;
+				mips32_insn.fp0_format.func = fmovc_op;
+			} else
+				return SIGILL;
+			break;
+		case mm_32f_60_op:
+			func = -1;	/* Invalid */
+			if (insn.mm_fp0_format.op == mm_fadd_op)
+				func = fadd_op;
+			else if (insn.mm_fp0_format.op == mm_fsub_op)
+				func = fsub_op;
+			else if (insn.mm_fp0_format.op == mm_fmul_op)
+				func = fmul_op;
+			else if (insn.mm_fp0_format.op == mm_fdiv_op)
+				func = fdiv_op;
+			if (func != -1) {
+				mips32_insn.fp0_format.opcode = cop1_op;
+				mips32_insn.fp0_format.fmt =
+					sdps_format[insn.mm_fp0_format.fmt];
+				mips32_insn.fp0_format.ft =
+					insn.mm_fp0_format.ft;
+				mips32_insn.fp0_format.fs =
+					insn.mm_fp0_format.fs;
+				mips32_insn.fp0_format.fd =
+					insn.mm_fp0_format.fd;
+				mips32_insn.fp0_format.func = func;
+			} else
+				return SIGILL;
+			break;
+		case mm_32f_70_op:
+			func = -1;	/* Invalid */
+			if (insn.mm_fp0_format.op == mm_fmovn_op)
+				func = fmovn_op;
+			else if (insn.mm_fp0_format.op == mm_fmovz_op)
+				func = fmovz_op;
+			if (func != -1) {
+				mips32_insn.fp0_format.opcode = cop1_op;
+				mips32_insn.fp0_format.fmt =
+					sdps_format[insn.mm_fp0_format.fmt];
+				mips32_insn.fp0_format.ft =
+					insn.mm_fp0_format.ft;
+				mips32_insn.fp0_format.fs =
+					insn.mm_fp0_format.fs;
+				mips32_insn.fp0_format.fd =
+					insn.mm_fp0_format.fd;
+				mips32_insn.fp0_format.func = func;
+			} else
+				return SIGILL;
+			break;
+		case mm_32f_73_op:    /* POOL32FXF */
+			switch (insn.mm_fp1_format.op) {
+			case mm_movf0_op:
+			case mm_movf1_op:
+			case mm_movt0_op:
+			case mm_movt1_op:
+				if ((insn.mm_fp1_format.op & 0x7f) ==
+				    mm_movf0_op)
+					op = 0;
+				else
+					op = 1;
+				mips32_insn.r_format.opcode = spec_op;
+				mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
+				mips32_insn.r_format.rt =
+					(insn.mm_fp4_format.cc << 2) + op;
+				mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
+				mips32_insn.r_format.re = 0;
+				mips32_insn.r_format.func = movc_op;
+				break;
+			case mm_fcvtd0_op:
+			case mm_fcvtd1_op:
+			case mm_fcvts0_op:
+			case mm_fcvts1_op:
+				if ((insn.mm_fp1_format.op & 0x7f) ==
+				    mm_fcvtd0_op) {
+					func = fcvtd_op;
+					fmt = swl_format[insn.mm_fp3_format.fmt];
+				} else {
+					func = fcvts_op;
+					fmt = dwl_format[insn.mm_fp3_format.fmt];
+				}
+				mips32_insn.fp0_format.opcode = cop1_op;
+				mips32_insn.fp0_format.fmt = fmt;
+				mips32_insn.fp0_format.ft = 0;
+				mips32_insn.fp0_format.fs =
+					insn.mm_fp3_format.fs;
+				mips32_insn.fp0_format.fd =
+					insn.mm_fp3_format.rt;
+				mips32_insn.fp0_format.func = func;
+				break;
+			case mm_fmov0_op:
+			case mm_fmov1_op:
+			case mm_fabs0_op:
+			case mm_fabs1_op:
+			case mm_fneg0_op:
+			case mm_fneg1_op:
+				if ((insn.mm_fp1_format.op & 0x7f) ==
+				    mm_fmov0_op)
+					func = fmov_op;
+				else if ((insn.mm_fp1_format.op & 0x7f) ==
+					 mm_fabs0_op)
+					func = fabs_op;
+				else
+					func = fneg_op;
+				mips32_insn.fp0_format.opcode = cop1_op;
+				mips32_insn.fp0_format.fmt =
+					sdps_format[insn.mm_fp3_format.fmt];
+				mips32_insn.fp0_format.ft = 0;
+				mips32_insn.fp0_format.fs =
+					insn.mm_fp3_format.fs;
+				mips32_insn.fp0_format.fd =
+					insn.mm_fp3_format.rt;
+				mips32_insn.fp0_format.func = func;
+				break;
+			case mm_ffloorl_op:
+			case mm_ffloorw_op:
+			case mm_fceill_op:
+			case mm_fceilw_op:
+			case mm_ftruncl_op:
+			case mm_ftruncw_op:
+			case mm_froundl_op:
+			case mm_froundw_op:
+			case mm_fcvtl_op:
+			case mm_fcvtw_op:
+				if (insn.mm_fp1_format.op == mm_ffloorl_op)
+					func = ffloorl_op;
+				else if (insn.mm_fp1_format.op == mm_ffloorw_op)
+					func = ffloor_op;
+				else if (insn.mm_fp1_format.op == mm_fceill_op)
+					func = fceill_op;
+				else if (insn.mm_fp1_format.op == mm_fceilw_op)
+					func = fceil_op;
+				else if (insn.mm_fp1_format.op == mm_ftruncl_op)
+					func = ftruncl_op;
+				else if (insn.mm_fp1_format.op == mm_ftruncw_op)
+					func = ftrunc_op;
+				else if (insn.mm_fp1_format.op == mm_froundl_op)
+					func = froundl_op;
+				else if (insn.mm_fp1_format.op == mm_froundw_op)
+					func = fround_op;
+				else if (insn.mm_fp1_format.op == mm_fcvtl_op)
+					func = fcvtl_op;
+				else
+					func = fcvtw_op;
+				mips32_insn.fp0_format.opcode = cop1_op;
+				mips32_insn.fp0_format.fmt =
+					sd_format[insn.mm_fp1_format.fmt];
+				mips32_insn.fp0_format.ft = 0;
+				mips32_insn.fp0_format.fs =
+					insn.mm_fp1_format.fs;
+				mips32_insn.fp0_format.fd =
+					insn.mm_fp1_format.rt;
+				mips32_insn.fp0_format.func = func;
+				break;
+			case mm_frsqrt_op:
+			case mm_fsqrt_op:
+			case mm_frecip_op:
+				if (insn.mm_fp1_format.op == mm_frsqrt_op)
+					func = frsqrt_op;
+				else if (insn.mm_fp1_format.op == mm_fsqrt_op)
+					func = fsqrt_op;
+				else
+					func = frecip_op;
+				mips32_insn.fp0_format.opcode = cop1_op;
+				mips32_insn.fp0_format.fmt =
+					sdps_format[insn.mm_fp1_format.fmt];
+				mips32_insn.fp0_format.ft = 0;
+				mips32_insn.fp0_format.fs =
+					insn.mm_fp1_format.fs;
+				mips32_insn.fp0_format.fd =
+					insn.mm_fp1_format.rt;
+				mips32_insn.fp0_format.func = func;
+				break;
+			case mm_mfc1_op:
+			case mm_mtc1_op:
+			case mm_cfc1_op:
+			case mm_ctc1_op:
+			case mm_mfhc1_op:
+			case mm_mthc1_op:
+				if (insn.mm_fp1_format.op == mm_mfc1_op)
+					op = mfc_op;
+				else if (insn.mm_fp1_format.op == mm_mtc1_op)
+					op = mtc_op;
+				else if (insn.mm_fp1_format.op == mm_cfc1_op)
+					op = cfc_op;
+				else if (insn.mm_fp1_format.op == mm_ctc1_op)
+					op = ctc_op;
+				else if (insn.mm_fp1_format.op == mm_mfhc1_op)
+					op = mfhc_op;
+				else
+					op = mthc_op;
+				mips32_insn.fp1_format.opcode = cop1_op;
+				mips32_insn.fp1_format.op = op;
+				mips32_insn.fp1_format.rt =
+					insn.mm_fp1_format.rt;
+				mips32_insn.fp1_format.fs =
+					insn.mm_fp1_format.fs;
+				mips32_insn.fp1_format.fd = 0;
+				mips32_insn.fp1_format.func = 0;
+				break;
+			default:
+				return SIGILL;
+			}
+			break;
+		case mm_32f_74_op:	/* c.cond.fmt */
+			mips32_insn.fp0_format.opcode = cop1_op;
+			mips32_insn.fp0_format.fmt =
+				sdps_format[insn.mm_fp4_format.fmt];
+			mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
+			mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
+			mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
+			mips32_insn.fp0_format.func =
+				insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
+			break;
+		default:
+			return SIGILL;
+		}
+		break;
+	default:
+		return SIGILL;
+	}
+
+	*insn_ptr = mips32_insn;
+	return 0;
+}
+
+/*
+ * Redundant with logic already in kernel/branch.c,
+ * embedded in compute_return_epc.  At some point,
+ * a single subroutine should be used across both
+ * modules.
+ */
+static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
+			 unsigned long *contpc)
+{
+	union mips_instruction insn = (union mips_instruction)dec_insn.insn;
+	unsigned int fcr31;
+	unsigned int bit = 0;
+
+	switch (insn.i_format.opcode) {
+	case spec_op:
+		switch (insn.r_format.func) {
+		case jalr_op:
+			regs->regs[insn.r_format.rd] =
+				regs->cp0_epc + dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+			/* Fall through */
+		case jr_op:
+			/* For R6, JR already emulated in jalr_op */
+			if (NO_R6EMU && insn.r_format.opcode == jr_op)
+				break;
+			*contpc = regs->regs[insn.r_format.rs];
+			return 1;
+		}
+		break;
+	case bcond_op:
+		switch (insn.i_format.rt) {
+		case bltzal_op:
+		case bltzall_op:
+			if (NO_R6EMU && (insn.i_format.rs ||
+			    insn.i_format.rt == bltzall_op))
+				break;
+
+			regs->regs[31] = regs->cp0_epc +
+				dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+			/* Fall through */
+		case bltzl_op:
+			if (NO_R6EMU)
+				break;
+		case bltz_op:
+			if ((long)regs->regs[insn.i_format.rs] < 0)
+				*contpc = regs->cp0_epc +
+					dec_insn.pc_inc +
+					(insn.i_format.simmediate << 2);
+			else
+				*contpc = regs->cp0_epc +
+					dec_insn.pc_inc +
+					dec_insn.next_pc_inc;
+			return 1;
+		case bgezal_op:
+		case bgezall_op:
+			if (NO_R6EMU && (insn.i_format.rs ||
+			    insn.i_format.rt == bgezall_op))
+				break;
+
+			regs->regs[31] = regs->cp0_epc +
+				dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+			/* Fall through */
+		case bgezl_op:
+			if (NO_R6EMU)
+				break;
+		case bgez_op:
+			if ((long)regs->regs[insn.i_format.rs] >= 0)
+				*contpc = regs->cp0_epc +
+					dec_insn.pc_inc +
+					(insn.i_format.simmediate << 2);
+			else
+				*contpc = regs->cp0_epc +
+					dec_insn.pc_inc +
+					dec_insn.next_pc_inc;
+			return 1;
+		}
+		break;
+	case jalx_op:
+		set_isa16_mode(bit);
+	case jal_op:
+		regs->regs[31] = regs->cp0_epc +
+			dec_insn.pc_inc +
+			dec_insn.next_pc_inc;
+		/* Fall through */
+	case j_op:
+		*contpc = regs->cp0_epc + dec_insn.pc_inc;
+		*contpc >>= 28;
+		*contpc <<= 28;
+		*contpc |= (insn.j_format.target << 2);
+		/* Set microMIPS mode bit: XOR for jalx. */
+		*contpc ^= bit;
+		return 1;
+	case beql_op:
+		if (NO_R6EMU)
+			break;
+	case beq_op:
+		if (regs->regs[insn.i_format.rs] ==
+		    regs->regs[insn.i_format.rt])
+			*contpc = regs->cp0_epc +
+				dec_insn.pc_inc +
+				(insn.i_format.simmediate << 2);
+		else
+			*contpc = regs->cp0_epc +
+				dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+		return 1;
+	case bnel_op:
+		if (NO_R6EMU)
+			break;
+	case bne_op:
+		if (regs->regs[insn.i_format.rs] !=
+		    regs->regs[insn.i_format.rt])
+			*contpc = regs->cp0_epc +
+				dec_insn.pc_inc +
+				(insn.i_format.simmediate << 2);
+		else
+			*contpc = regs->cp0_epc +
+				dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+		return 1;
+	case blezl_op:
+		if (NO_R6EMU)
+			break;
+	case blez_op:
+
+		/*
+		 * Compact branches for R6 for the
+		 * blez and blezl opcodes.
+		 * BLEZ  | rs = 0 | rt != 0  == BLEZALC
+		 * BLEZ  | rs = rt != 0      == BGEZALC
+		 * BLEZ  | rs != 0 | rt != 0 == BGEUC
+		 * BLEZL | rs = 0 | rt != 0  == BLEZC
+		 * BLEZL | rs = rt != 0      == BGEZC
+		 * BLEZL | rs != 0 | rt != 0 == BGEC
+		 *
+		 * For real BLEZ{,L}, rt is always 0.
+		 */
+		if (cpu_has_mips_r6 && insn.i_format.rt) {
+			if ((insn.i_format.opcode == blez_op) &&
+			    ((!insn.i_format.rs && insn.i_format.rt) ||
+			     (insn.i_format.rs == insn.i_format.rt)))
+				regs->regs[31] = regs->cp0_epc +
+					dec_insn.pc_inc;
+			*contpc = regs->cp0_epc + dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+
+			return 1;
+		}
+		if ((long)regs->regs[insn.i_format.rs] <= 0)
+			*contpc = regs->cp0_epc +
+				dec_insn.pc_inc +
+				(insn.i_format.simmediate << 2);
+		else
+			*contpc = regs->cp0_epc +
+				dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+		return 1;
+	case bgtzl_op:
+		if (NO_R6EMU)
+			break;
+	case bgtz_op:
+		/*
+		 * Compact branches for R6 for the
+		 * bgtz and bgtzl opcodes.
+		 * BGTZ  | rs = 0 | rt != 0  == BGTZALC
+		 * BGTZ  | rs = rt != 0      == BLTZALC
+		 * BGTZ  | rs != 0 | rt != 0 == BLTUC
+		 * BGTZL | rs = 0 | rt != 0  == BGTZC
+		 * BGTZL | rs = rt != 0      == BLTZC
+		 * BGTZL | rs != 0 | rt != 0 == BLTC
+		 *
+		 * *ZALC varint for BGTZ &&& rt != 0
+		 * For real GTZ{,L}, rt is always 0.
+		 */
+		if (cpu_has_mips_r6 && insn.i_format.rt) {
+			if ((insn.i_format.opcode == blez_op) &&
+			    ((!insn.i_format.rs && insn.i_format.rt) ||
+			     (insn.i_format.rs == insn.i_format.rt)))
+				regs->regs[31] = regs->cp0_epc +
+					dec_insn.pc_inc;
+			*contpc = regs->cp0_epc + dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+
+			return 1;
+		}
+
+		if ((long)regs->regs[insn.i_format.rs] > 0)
+			*contpc = regs->cp0_epc +
+				dec_insn.pc_inc +
+				(insn.i_format.simmediate << 2);
+		else
+			*contpc = regs->cp0_epc +
+				dec_insn.pc_inc +
+				dec_insn.next_pc_inc;
+		return 1;
+	case cbcond0_op:
+	case cbcond1_op:
+		if (!cpu_has_mips_r6)
+			break;
+		if (insn.i_format.rt && !insn.i_format.rs)
+			regs->regs[31] = regs->cp0_epc + 4;
+		*contpc = regs->cp0_epc + dec_insn.pc_inc +
+			dec_insn.next_pc_inc;
+
+		return 1;
+#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;
+#else
+	case bc6_op:
+		/*
+		 * Only valid for MIPS R6 but we can still end up
+		 * here from a broken userland so just tell emulator
+		 * this is not a branch and let it break later on.
+		 */
+		if  (!cpu_has_mips_r6)
+			break;
+		*contpc = regs->cp0_epc + dec_insn.pc_inc +
+			dec_insn.next_pc_inc;
+
+		return 1;
+	case balc6_op:
+		if (!cpu_has_mips_r6)
+			break;
+		regs->regs[31] = regs->cp0_epc + 4;
+		*contpc = regs->cp0_epc + dec_insn.pc_inc +
+			dec_insn.next_pc_inc;
+
+		return 1;
+	case beqzcjic_op:
+		if (!cpu_has_mips_r6)
+			break;
+		*contpc = regs->cp0_epc + dec_insn.pc_inc +
+			dec_insn.next_pc_inc;
+
+		return 1;
+	case bnezcjialc_op:
+		if (!cpu_has_mips_r6)
+			break;
+		if (!insn.i_format.rs)
+			regs->regs[31] = regs->cp0_epc + 4;
+		*contpc = regs->cp0_epc + dec_insn.pc_inc +
+			dec_insn.next_pc_inc;
+
+		return 1;
+#endif
+	case cop0_op:
+	case cop1_op:
+		/* Need to check for R6 bc1nez and bc1eqz branches */
+		if (cpu_has_mips_r6 &&
+		    ((insn.i_format.rs == bc1eqz_op) ||
+		     (insn.i_format.rs == bc1nez_op))) {
+			bit = 0;
+			switch (insn.i_format.rs) {
+			case bc1eqz_op:
+				if (get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1)
+				    bit = 1;
+				break;
+			case bc1nez_op:
+				if (!(get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1))
+				    bit = 1;
+				break;
+			}
+			if (bit)
+				*contpc = regs->cp0_epc +
+					dec_insn.pc_inc +
+					(insn.i_format.simmediate << 2);
+			else
+				*contpc = regs->cp0_epc +
+					dec_insn.pc_inc +
+					dec_insn.next_pc_inc;
+
+			return 1;
+		}
+		/* R2/R6 compatible cop1 instruction. Fall through */
+	case cop2_op:
+	case cop1x_op:
+		if (insn.i_format.rs == bc_op) {
+			preempt_disable();
+			if (is_fpu_owner())
+			        fcr31 = read_32bit_cp1_register(CP1_STATUS);
+			else
+				fcr31 = current->thread.fpu.fcr31;
+			preempt_enable();
+
+			bit = (insn.i_format.rt >> 2);
+			bit += (bit != 0);
+			bit += 23;
+			switch (insn.i_format.rt & 3) {
+			case 0:	/* bc1f */
+			case 2:	/* bc1fl */
+				if (~fcr31 & (1 << bit))
+					*contpc = regs->cp0_epc +
+						dec_insn.pc_inc +
+						(insn.i_format.simmediate << 2);
+				else
+					*contpc = regs->cp0_epc +
+						dec_insn.pc_inc +
+						dec_insn.next_pc_inc;
+				return 1;
+			case 1:	/* bc1t */
+			case 3:	/* bc1tl */
+				if (fcr31 & (1 << bit))
+					*contpc = regs->cp0_epc +
+						dec_insn.pc_inc +
+						(insn.i_format.simmediate << 2);
+				else
+					*contpc = regs->cp0_epc +
+						dec_insn.pc_inc +
+						dec_insn.next_pc_inc;
+				return 1;
+			}
+		}
+		break;
+	}
+	return 0;
+}
+
+/*
+ * In the Linux kernel, we support selection of FPR format on the
+ * basis of the Status.FR bit.	If an FPU is not present, the FR bit
+ * is hardwired to zero, which would imply a 32-bit FPU even for
+ * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
+ * FPU emu is slow and bulky and optimizing this function offers fairly
+ * sizeable benefits so we try to be clever and make this function return
+ * a constant whenever possible, that is on 64-bit kernels without O32
+ * compatibility enabled and on 32-bit without 64-bit FPU support.
+ */
+static inline int cop1_64bit(struct pt_regs *xcp)
+{
+	if (config_enabled(CONFIG_64BIT) && !config_enabled(CONFIG_MIPS32_O32))
+		return 1;
+	else if (config_enabled(CONFIG_32BIT) &&
+		 !config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT))
+		return 0;
+
+	return !test_thread_flag(TIF_32BIT_FPREGS);
+}
+
+static inline bool hybrid_fprs(void)
+{
+	return test_thread_flag(TIF_HYBRID_FPREGS);
+}
+
+#define SIFROMREG(si, x)						\
+do {									\
+	if (cop1_64bit(xcp) && !hybrid_fprs())				\
+		(si) = (int)get_fpr32(&ctx->fpr[x], 0);			\
+	else								\
+		(si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1);	\
+} while (0)
+
+#define SITOREG(si, x)							\
+do {									\
+	if (cop1_64bit(xcp) && !hybrid_fprs()) {			\
+		unsigned i;						\
+		set_fpr32(&ctx->fpr[x], 0, si);				\
+		for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)	\
+			set_fpr32(&ctx->fpr[x], i, 0);			\
+	} else {							\
+		set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si);		\
+	}								\
+} while (0)
+
+#define SIFROMHREG(si, x)	((si) = (int)get_fpr32(&ctx->fpr[x], 1))
+
+#define SITOHREG(si, x)							\
+do {									\
+	unsigned i;							\
+	set_fpr32(&ctx->fpr[x], 1, si);					\
+	for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++)		\
+		set_fpr32(&ctx->fpr[x], i, 0);				\
+} while (0)
+
+#define DIFROMREG(di, x)						\
+	((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
+
+#define DITOREG(di, x)							\
+do {									\
+	unsigned fpr, i;						\
+	fpr = (x) & ~(cop1_64bit(xcp) == 0);				\
+	set_fpr64(&ctx->fpr[fpr], 0, di);				\
+	for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++)		\
+		set_fpr64(&ctx->fpr[fpr], i, 0);			\
+} while (0)
+
+#define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
+#define SPTOREG(sp, x)	SITOREG((sp).bits, x)
+#define DPFROMREG(dp, x)	DIFROMREG((dp).bits, x)
+#define DPTOREG(dp, x)	DITOREG((dp).bits, x)
+
+/*
+ * Emulate a CFC1 instruction.
+ */
+static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+			    mips_instruction ir)
+{
+	u32 fcr31 = ctx->fcr31;
+	u32 value = 0;
+
+	switch (MIPSInst_RD(ir)) {
+	case FPCREG_CSR:
+		value = fcr31;
+		pr_debug("%p gpr[%d]<-csr=%08x\n",
+			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+		break;
+
+	case FPCREG_FENR:
+		if (!cpu_has_mips_r)
+			break;
+		value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
+			MIPS_FENR_FS;
+		value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
+		pr_debug("%p gpr[%d]<-enr=%08x\n",
+			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+		break;
+
+	case FPCREG_FEXR:
+		if (!cpu_has_mips_r)
+			break;
+		value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
+		pr_debug("%p gpr[%d]<-exr=%08x\n",
+			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+		break;
+
+	case FPCREG_FCCR:
+		if (!cpu_has_mips_r)
+			break;
+		value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
+			MIPS_FCCR_COND0;
+		value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
+			 (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
+		pr_debug("%p gpr[%d]<-ccr=%08x\n",
+			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+		break;
+
+	case FPCREG_RID:
+		value = boot_cpu_data.fpu_id;
+		break;
+
+	default:
+		break;
+	}
+
+	if (MIPSInst_RT(ir))
+		xcp->regs[MIPSInst_RT(ir)] = value;
+}
+
+/*
+ * Emulate a CTC1 instruction.
+ */
+static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+			    mips_instruction ir)
+{
+	u32 fcr31 = ctx->fcr31;
+	u32 value;
+	u32 mask;
+
+	if (MIPSInst_RT(ir) == 0)
+		value = 0;
+	else
+		value = xcp->regs[MIPSInst_RT(ir)];
+
+	switch (MIPSInst_RD(ir)) {
+	case FPCREG_CSR:
+		pr_debug("%p gpr[%d]->csr=%08x\n",
+			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+
+		/* Preserve read-only bits.  */
+		mask = boot_cpu_data.fpu_msk31;
+		fcr31 = (value & ~mask) | (fcr31 & mask);
+		break;
+
+	case FPCREG_FENR:
+		if (!cpu_has_mips_r)
+			break;
+		pr_debug("%p gpr[%d]->enr=%08x\n",
+			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+		fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
+		fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
+			 FPU_CSR_FS;
+		fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
+		break;
+
+	case FPCREG_FEXR:
+		if (!cpu_has_mips_r)
+			break;
+		pr_debug("%p gpr[%d]->exr=%08x\n",
+			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+		fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
+		fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
+		break;
+
+	case FPCREG_FCCR:
+		if (!cpu_has_mips_r)
+			break;
+		pr_debug("%p gpr[%d]->ccr=%08x\n",
+			 (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+		fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
+		fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
+			 FPU_CSR_COND;
+		fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
+			 FPU_CSR_CONDX;
+		break;
+
+	default:
+		break;
+	}
+
+	ctx->fcr31 = fcr31;
+}
+
+/*
+ * Emulate the single floating point instruction pointed at by EPC.
+ * Two instructions if the instruction is in a branch delay slot.
+ */
+
+static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+		struct mm_decoded_insn dec_insn, void *__user *fault_addr)
+{
+	unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
+	unsigned int cond, cbit;
+	mips_instruction ir;
+	int likely, pc_inc;
+	u32 __user *wva;
+	u64 __user *dva;
+	u32 wval;
+	u64 dval;
+	int sig;
+
+	/*
+	 * These are giving gcc a gentle hint about what to expect in
+	 * dec_inst in order to do better optimization.
+	 */
+	if (!cpu_has_mmips && dec_insn.micro_mips_mode)
+		unreachable();
+
+	/* XXX NEC Vr54xx bug workaround */
+	if (delay_slot(xcp)) {
+		if (dec_insn.micro_mips_mode) {
+			if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
+				clear_delay_slot(xcp);
+		} else {
+			if (!isBranchInstr(xcp, dec_insn, &contpc))
+				clear_delay_slot(xcp);
+		}
+	}
+
+	if (delay_slot(xcp)) {
+		/*
+		 * The instruction to be emulated is in a branch delay slot
+		 * which means that we have to	emulate the branch instruction
+		 * BEFORE we do the cop1 instruction.
+		 *
+		 * This branch could be a COP1 branch, but in that case we
+		 * would have had a trap for that instruction, and would not
+		 * come through this route.
+		 *
+		 * Linux MIPS branch emulator operates on context, updating the
+		 * cp0_epc.
+		 */
+		ir = dec_insn.next_insn;  /* process delay slot instr */
+		pc_inc = dec_insn.next_pc_inc;
+	} else {
+		ir = dec_insn.insn;       /* process current instr */
+		pc_inc = dec_insn.pc_inc;
+	}
+
+	/*
+	 * Since microMIPS FPU instructios are a subset of MIPS32 FPU
+	 * instructions, we want to convert microMIPS FPU instructions
+	 * into MIPS32 instructions so that we could reuse all of the
+	 * FPU emulation code.
+	 *
+	 * NOTE: We cannot do this for branch instructions since they
+	 *       are not a subset. Example: Cannot emulate a 16-bit
+	 *       aligned target address with a MIPS32 instruction.
+	 */
+	if (dec_insn.micro_mips_mode) {
+		/*
+		 * If next instruction is a 16-bit instruction, then it
+		 * it cannot be a FPU instruction. This could happen
+		 * since we can be called for non-FPU instructions.
+		 */
+		if ((pc_inc == 2) ||
+			(microMIPS32_to_MIPS32((union mips_instruction *)&ir)
+			 == SIGILL))
+			return SIGILL;
+	}
+
+emul:
+	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
+	MIPS_FPU_EMU_INC_STATS(emulated);
+	switch (MIPSInst_OPCODE(ir)) {
+	case ldc1_op:
+		dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
+				     MIPSInst_SIMM(ir));
+		MIPS_FPU_EMU_INC_STATS(loads);
+
+		if (!access_ok(VERIFY_READ, dva, sizeof(u64))) {
+			MIPS_FPU_EMU_INC_STATS(errors);
+			*fault_addr = dva;
+			return SIGBUS;
+		}
+		if (__get_user(dval, dva)) {
+			MIPS_FPU_EMU_INC_STATS(errors);
+			*fault_addr = dva;
+			return SIGSEGV;
+		}
+		DITOREG(dval, MIPSInst_RT(ir));
+		break;
+
+	case sdc1_op:
+		dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
+				      MIPSInst_SIMM(ir));
+		MIPS_FPU_EMU_INC_STATS(stores);
+		DIFROMREG(dval, MIPSInst_RT(ir));
+		if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) {
+			MIPS_FPU_EMU_INC_STATS(errors);
+			*fault_addr = dva;
+			return SIGBUS;
+		}
+		if (__put_user(dval, dva)) {
+			MIPS_FPU_EMU_INC_STATS(errors);
+			*fault_addr = dva;
+			return SIGSEGV;
+		}
+		break;
+
+	case lwc1_op:
+		wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
+				      MIPSInst_SIMM(ir));
+		MIPS_FPU_EMU_INC_STATS(loads);
+		if (!access_ok(VERIFY_READ, wva, sizeof(u32))) {
+			MIPS_FPU_EMU_INC_STATS(errors);
+			*fault_addr = wva;
+			return SIGBUS;
+		}
+		if (__get_user(wval, wva)) {
+			MIPS_FPU_EMU_INC_STATS(errors);
+			*fault_addr = wva;
+			return SIGSEGV;
+		}
+		SITOREG(wval, MIPSInst_RT(ir));
+		break;
+
+	case swc1_op:
+		wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
+				      MIPSInst_SIMM(ir));
+		MIPS_FPU_EMU_INC_STATS(stores);
+		SIFROMREG(wval, MIPSInst_RT(ir));
+		if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) {
+			MIPS_FPU_EMU_INC_STATS(errors);
+			*fault_addr = wva;
+			return SIGBUS;
+		}
+		if (__put_user(wval, wva)) {
+			MIPS_FPU_EMU_INC_STATS(errors);
+			*fault_addr = wva;
+			return SIGSEGV;
+		}
+		break;
+
+	case cop1_op:
+		switch (MIPSInst_RS(ir)) {
+		case dmfc_op:
+			if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+				return SIGILL;
+
+			/* copregister fs -> gpr[rt] */
+			if (MIPSInst_RT(ir) != 0) {
+				DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
+					MIPSInst_RD(ir));
+			}
+			break;
+
+		case dmtc_op:
+			if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+				return SIGILL;
+
+			/* copregister fs <- rt */
+			DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
+			break;
+
+		case mfhc_op:
+			if (!cpu_has_mips_r2)
+				goto sigill;
+
+			/* copregister rd -> gpr[rt] */
+			if (MIPSInst_RT(ir) != 0) {
+				SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
+					MIPSInst_RD(ir));
+			}
+			break;
+
+		case mthc_op:
+			if (!cpu_has_mips_r2)
+				goto sigill;
+
+			/* copregister rd <- gpr[rt] */
+			SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
+			break;
+
+		case mfc_op:
+			/* copregister rd -> gpr[rt] */
+			if (MIPSInst_RT(ir) != 0) {
+				SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
+					MIPSInst_RD(ir));
+			}
+			break;
+
+		case mtc_op:
+			/* copregister rd <- rt */
+			SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
+			break;
+
+		case cfc_op:
+			/* cop control register rd -> gpr[rt] */
+			cop1_cfc(xcp, ctx, ir);
+			break;
+
+		case ctc_op:
+			/* copregister rd <- rt */
+			cop1_ctc(xcp, ctx, ir);
+			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
+				return SIGFPE;
+			}
+			break;
+
+		case bc_op:
+			if (delay_slot(xcp))
+				return SIGILL;
+
+			if (cpu_has_mips_4_5_r)
+				cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
+			else
+				cbit = FPU_CSR_COND;
+			cond = ctx->fcr31 & cbit;
+
+			likely = 0;
+			switch (MIPSInst_RT(ir) & 3) {
+			case bcfl_op:
+				if (cpu_has_mips_2_3_4_5_r)
+					likely = 1;
+				/* Fall through */
+			case bcf_op:
+				cond = !cond;
+				break;
+			case bctl_op:
+				if (cpu_has_mips_2_3_4_5_r)
+					likely = 1;
+				/* Fall through */
+			case bct_op:
+				break;
+			}
+
+			set_delay_slot(xcp);
+			if (cond) {
+				/*
+				 * Branch taken: emulate dslot instruction
+				 */
+				unsigned long bcpc;
+
+				/*
+				 * Remember EPC at the branch to point back
+				 * at so that any delay-slot instruction
+				 * signal is not silently ignored.
+				 */
+				bcpc = xcp->cp0_epc;
+				xcp->cp0_epc += dec_insn.pc_inc;
+
+				contpc = MIPSInst_SIMM(ir);
+				ir = dec_insn.next_insn;
+				if (dec_insn.micro_mips_mode) {
+					contpc = (xcp->cp0_epc + (contpc << 1));
+
+					/* If 16-bit instruction, not FPU. */
+					if ((dec_insn.next_pc_inc == 2) ||
+						(microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
+
+						/*
+						 * Since this instruction will
+						 * be put on the stack with
+						 * 32-bit words, get around
+						 * this problem by putting a
+						 * NOP16 as the second one.
+						 */
+						if (dec_insn.next_pc_inc == 2)
+							ir = (ir & (~0xffff)) | MM_NOP16;
+
+						/*
+						 * Single step the non-CP1
+						 * instruction in the dslot.
+						 */
+						sig = mips_dsemul(xcp, ir,
+								  contpc);
+						if (sig)
+							xcp->cp0_epc = bcpc;
+						/*
+						 * SIGILL forces out of
+						 * the emulation loop.
+						 */
+						return sig ? sig : SIGILL;
+					}
+				} else
+					contpc = (xcp->cp0_epc + (contpc << 2));
+
+				switch (MIPSInst_OPCODE(ir)) {
+				case lwc1_op:
+				case swc1_op:
+					goto emul;
+
+				case ldc1_op:
+				case sdc1_op:
+					if (cpu_has_mips_2_3_4_5_r)
+						goto emul;
+
+					goto bc_sigill;
+
+				case cop1_op:
+					goto emul;
+
+				case cop1x_op:
+					if (cpu_has_mips_4_5_64_r2_r6)
+						/* its one of ours */
+						goto emul;
+
+					goto bc_sigill;
+
+				case spec_op:
+					switch (MIPSInst_FUNC(ir)) {
+					case movc_op:
+						if (cpu_has_mips_4_5_r)
+							goto emul;
+
+						goto bc_sigill;
+					}
+					break;
+
+				bc_sigill:
+					xcp->cp0_epc = bcpc;
+					return SIGILL;
+				}
+
+				/*
+				 * Single step the non-cp1
+				 * instruction in the dslot
+				 */
+				sig = mips_dsemul(xcp, ir, contpc);
+				if (sig)
+					xcp->cp0_epc = bcpc;
+				/* SIGILL forces out of the emulation loop.  */
+				return sig ? sig : SIGILL;
+			} else if (likely) {	/* branch not taken */
+				/*
+				 * branch likely nullifies
+				 * dslot if not taken
+				 */
+				xcp->cp0_epc += dec_insn.pc_inc;
+				contpc += dec_insn.pc_inc;
+				/*
+				 * else continue & execute
+				 * dslot as normal insn
+				 */
+			}
+			break;
+
+		default:
+			if (!(MIPSInst_RS(ir) & 0x10))
+				return SIGILL;
+
+			/* a real fpu computation instruction */
+			if ((sig = fpu_emu(xcp, ctx, ir)))
+				return sig;
+		}
+		break;
+
+	case cop1x_op:
+		if (!cpu_has_mips_4_5_64_r2_r6)
+			return SIGILL;
+
+		sig = fpux_emu(xcp, ctx, ir, fault_addr);
+		if (sig)
+			return sig;
+		break;
+
+	case spec_op:
+		if (!cpu_has_mips_4_5_r)
+			return SIGILL;
+
+		if (MIPSInst_FUNC(ir) != movc_op)
+			return SIGILL;
+		cond = fpucondbit[MIPSInst_RT(ir) >> 2];
+		if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
+			xcp->regs[MIPSInst_RD(ir)] =
+				xcp->regs[MIPSInst_RS(ir)];
+		break;
+	default:
+sigill:
+		return SIGILL;
+	}
+
+	/* we did it !! */
+	xcp->cp0_epc = contpc;
+	clear_delay_slot(xcp);
+
+	return 0;
+}
+
+/*
+ * Conversion table from MIPS compare ops 48-63
+ * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
+ */
+static const unsigned char cmptab[8] = {
+	0,			/* cmp_0 (sig) cmp_sf */
+	IEEE754_CUN,		/* cmp_un (sig) cmp_ngle */
+	IEEE754_CEQ,		/* cmp_eq (sig) cmp_seq */
+	IEEE754_CEQ | IEEE754_CUN,	/* cmp_ueq (sig) cmp_ngl  */
+	IEEE754_CLT,		/* cmp_olt (sig) cmp_lt */
+	IEEE754_CLT | IEEE754_CUN,	/* cmp_ult (sig) cmp_nge */
+	IEEE754_CLT | IEEE754_CEQ,	/* cmp_ole (sig) cmp_le */
+	IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN,	/* cmp_ule (sig) cmp_ngt */
+};
+
+
+/*
+ * Additional MIPS4 instructions
+ */
+
+#define DEF3OP(name, p, f1, f2, f3)					\
+static union ieee754##p fpemu_##p##_##name(union ieee754##p r,		\
+	union ieee754##p s, union ieee754##p t)				\
+{									\
+	struct _ieee754_csr ieee754_csr_save;				\
+	s = f1(s, t);							\
+	ieee754_csr_save = ieee754_csr;					\
+	s = f2(s, r);							\
+	ieee754_csr_save.cx |= ieee754_csr.cx;				\
+	ieee754_csr_save.sx |= ieee754_csr.sx;				\
+	s = f3(s);							\
+	ieee754_csr.cx |= ieee754_csr_save.cx;				\
+	ieee754_csr.sx |= ieee754_csr_save.sx;				\
+	return s;							\
+}
+
+static union ieee754dp fpemu_dp_recip(union ieee754dp d)
+{
+	return ieee754dp_div(ieee754dp_one(0), d);
+}
+
+static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
+{
+	return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
+}
+
+static union ieee754sp fpemu_sp_recip(union ieee754sp s)
+{
+	return ieee754sp_div(ieee754sp_one(0), s);
+}
+
+static union ieee754sp fpemu_sp_rsqrt(union ieee754sp s)
+{
+	return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
+}
+
+DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
+DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
+DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
+DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
+DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
+DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
+DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
+DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
+
+static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+	mips_instruction ir, void *__user *fault_addr)
+{
+	unsigned rcsr = 0;	/* resulting csr */
+
+	MIPS_FPU_EMU_INC_STATS(cp1xops);
+
+	switch (MIPSInst_FMA_FFMT(ir)) {
+	case s_fmt:{		/* 0 */
+
+		union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
+		union ieee754sp fd, fr, fs, ft;
+		u32 __user *va;
+		u32 val;
+
+		switch (MIPSInst_FUNC(ir)) {
+		case lwxc1_op:
+			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
+				xcp->regs[MIPSInst_FT(ir)]);
+
+			MIPS_FPU_EMU_INC_STATS(loads);
+			if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				*fault_addr = va;
+				return SIGBUS;
+			}
+			if (__get_user(val, va)) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				*fault_addr = va;
+				return SIGSEGV;
+			}
+			SITOREG(val, MIPSInst_FD(ir));
+			break;
+
+		case swxc1_op:
+			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
+				xcp->regs[MIPSInst_FT(ir)]);
+
+			MIPS_FPU_EMU_INC_STATS(stores);
+
+			SIFROMREG(val, MIPSInst_FS(ir));
+			if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				*fault_addr = va;
+				return SIGBUS;
+			}
+			if (put_user(val, va)) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				*fault_addr = va;
+				return SIGSEGV;
+			}
+			break;
+
+		case madd_s_op:
+			handler = fpemu_sp_madd;
+			goto scoptop;
+		case msub_s_op:
+			handler = fpemu_sp_msub;
+			goto scoptop;
+		case nmadd_s_op:
+			handler = fpemu_sp_nmadd;
+			goto scoptop;
+		case nmsub_s_op:
+			handler = fpemu_sp_nmsub;
+			goto scoptop;
+
+		      scoptop:
+			SPFROMREG(fr, MIPSInst_FR(ir));
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			SPFROMREG(ft, MIPSInst_FT(ir));
+			fd = (*handler) (fr, fs, ft);
+			SPTOREG(fd, MIPSInst_FD(ir));
+
+		      copcsr:
+			if (ieee754_cxtest(IEEE754_INEXACT)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
+				rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
+			}
+			if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
+				rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
+			}
+			if (ieee754_cxtest(IEEE754_OVERFLOW)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
+				rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
+			}
+			if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
+				rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
+			}
+
+			ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
+			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
+				/*printk ("SIGFPE: FPU csr = %08x\n",
+				   ctx->fcr31); */
+				return SIGFPE;
+			}
+
+			break;
+
+		default:
+			return SIGILL;
+		}
+		break;
+	}
+
+	case d_fmt:{		/* 1 */
+		union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
+		union ieee754dp fd, fr, fs, ft;
+		u64 __user *va;
+		u64 val;
+
+		switch (MIPSInst_FUNC(ir)) {
+		case ldxc1_op:
+			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
+				xcp->regs[MIPSInst_FT(ir)]);
+
+			MIPS_FPU_EMU_INC_STATS(loads);
+			if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				*fault_addr = va;
+				return SIGBUS;
+			}
+			if (__get_user(val, va)) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				*fault_addr = va;
+				return SIGSEGV;
+			}
+			DITOREG(val, MIPSInst_FD(ir));
+			break;
+
+		case sdxc1_op:
+			va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
+				xcp->regs[MIPSInst_FT(ir)]);
+
+			MIPS_FPU_EMU_INC_STATS(stores);
+			DIFROMREG(val, MIPSInst_FS(ir));
+			if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				*fault_addr = va;
+				return SIGBUS;
+			}
+			if (__put_user(val, va)) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				*fault_addr = va;
+				return SIGSEGV;
+			}
+			break;
+
+		case madd_d_op:
+			handler = fpemu_dp_madd;
+			goto dcoptop;
+		case msub_d_op:
+			handler = fpemu_dp_msub;
+			goto dcoptop;
+		case nmadd_d_op:
+			handler = fpemu_dp_nmadd;
+			goto dcoptop;
+		case nmsub_d_op:
+			handler = fpemu_dp_nmsub;
+			goto dcoptop;
+
+		      dcoptop:
+			DPFROMREG(fr, MIPSInst_FR(ir));
+			DPFROMREG(fs, MIPSInst_FS(ir));
+			DPFROMREG(ft, MIPSInst_FT(ir));
+			fd = (*handler) (fr, fs, ft);
+			DPTOREG(fd, MIPSInst_FD(ir));
+			goto copcsr;
+
+		default:
+			return SIGILL;
+		}
+		break;
+	}
+
+	case 0x3:
+		if (MIPSInst_FUNC(ir) != pfetch_op)
+			return SIGILL;
+
+		/* ignore prefx operation */
+		break;
+
+	default:
+		return SIGILL;
+	}
+
+	return 0;
+}
+
+
+
+/*
+ * Emulate a single COP1 arithmetic instruction.
+ */
+static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+	mips_instruction ir)
+{
+	int rfmt;		/* resulting format */
+	unsigned rcsr = 0;	/* resulting csr */
+	unsigned int oldrm;
+	unsigned int cbit;
+	unsigned cond;
+	union {
+		union ieee754dp d;
+		union ieee754sp s;
+		int w;
+		s64 l;
+	} rv;			/* resulting value */
+	u64 bits;
+
+	MIPS_FPU_EMU_INC_STATS(cp1ops);
+	switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
+	case s_fmt: {		/* 0 */
+		union {
+			union ieee754sp(*b) (union ieee754sp, union ieee754sp);
+			union ieee754sp(*u) (union ieee754sp);
+		} handler;
+		union ieee754sp fs, ft;
+
+		switch (MIPSInst_FUNC(ir)) {
+			/* binary ops */
+		case fadd_op:
+			handler.b = ieee754sp_add;
+			goto scopbop;
+		case fsub_op:
+			handler.b = ieee754sp_sub;
+			goto scopbop;
+		case fmul_op:
+			handler.b = ieee754sp_mul;
+			goto scopbop;
+		case fdiv_op:
+			handler.b = ieee754sp_div;
+			goto scopbop;
+
+			/* unary  ops */
+		case fsqrt_op:
+			if (!cpu_has_mips_2_3_4_5_r)
+				return SIGILL;
+
+			handler.u = ieee754sp_sqrt;
+			goto scopuop;
+
+		/*
+		 * Note that on some MIPS IV implementations such as the
+		 * R5000 and R8000 the FSQRT and FRECIP instructions do not
+		 * achieve full IEEE-754 accuracy - however this emulator does.
+		 */
+		case frsqrt_op:
+			if (!cpu_has_mips_4_5_64_r2_r6)
+				return SIGILL;
+
+			handler.u = fpemu_sp_rsqrt;
+			goto scopuop;
+
+		case frecip_op:
+			if (!cpu_has_mips_4_5_64_r2_r6)
+				return SIGILL;
+
+			handler.u = fpemu_sp_recip;
+			goto scopuop;
+
+		case fmovc_op:
+			if (!cpu_has_mips_4_5_r)
+				return SIGILL;
+
+			cond = fpucondbit[MIPSInst_FT(ir) >> 2];
+			if (((ctx->fcr31 & cond) != 0) !=
+				((MIPSInst_FT(ir) & 1) != 0))
+				return 0;
+			SPFROMREG(rv.s, MIPSInst_FS(ir));
+			break;
+
+		case fmovz_op:
+			if (!cpu_has_mips_4_5_r)
+				return SIGILL;
+
+			if (xcp->regs[MIPSInst_FT(ir)] != 0)
+				return 0;
+			SPFROMREG(rv.s, MIPSInst_FS(ir));
+			break;
+
+		case fmovn_op:
+			if (!cpu_has_mips_4_5_r)
+				return SIGILL;
+
+			if (xcp->regs[MIPSInst_FT(ir)] == 0)
+				return 0;
+			SPFROMREG(rv.s, MIPSInst_FS(ir));
+			break;
+
+		case fabs_op:
+			handler.u = ieee754sp_abs;
+			goto scopuop;
+
+		case fneg_op:
+			handler.u = ieee754sp_neg;
+			goto scopuop;
+
+		case fmov_op:
+			/* an easy one */
+			SPFROMREG(rv.s, MIPSInst_FS(ir));
+			goto copcsr;
+
+			/* binary op on handler */
+scopbop:
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			SPFROMREG(ft, MIPSInst_FT(ir));
+
+			rv.s = (*handler.b) (fs, ft);
+			goto copcsr;
+scopuop:
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			rv.s = (*handler.u) (fs);
+			goto copcsr;
+copcsr:
+			if (ieee754_cxtest(IEEE754_INEXACT)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_inexact);
+				rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
+			}
+			if (ieee754_cxtest(IEEE754_UNDERFLOW)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_underflow);
+				rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
+			}
+			if (ieee754_cxtest(IEEE754_OVERFLOW)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_overflow);
+				rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
+			}
+			if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv);
+				rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
+			}
+			if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) {
+				MIPS_FPU_EMU_INC_STATS(ieee754_invalidop);
+				rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
+			}
+			break;
+
+			/* unary conv ops */
+		case fcvts_op:
+			return SIGILL;	/* not defined */
+
+		case fcvtd_op:
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			rv.d = ieee754dp_fsp(fs);
+			rfmt = d_fmt;
+			goto copcsr;
+
+		case fcvtw_op:
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			rv.w = ieee754sp_tint(fs);
+			rfmt = w_fmt;
+			goto copcsr;
+
+		case fround_op:
+		case ftrunc_op:
+		case fceil_op:
+		case ffloor_op:
+			if (!cpu_has_mips_2_3_4_5_r)
+				return SIGILL;
+
+			oldrm = ieee754_csr.rm;
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			ieee754_csr.rm = MIPSInst_FUNC(ir);
+			rv.w = ieee754sp_tint(fs);
+			ieee754_csr.rm = oldrm;
+			rfmt = w_fmt;
+			goto copcsr;
+
+		case fcvtl_op:
+			if (!cpu_has_mips_3_4_5_64_r2_r6)
+				return SIGILL;
+
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			rv.l = ieee754sp_tlong(fs);
+			rfmt = l_fmt;
+			goto copcsr;
+
+		case froundl_op:
+		case ftruncl_op:
+		case fceill_op:
+		case ffloorl_op:
+			if (!cpu_has_mips_3_4_5_64_r2_r6)
+				return SIGILL;
+
+			oldrm = ieee754_csr.rm;
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			ieee754_csr.rm = MIPSInst_FUNC(ir);
+			rv.l = ieee754sp_tlong(fs);
+			ieee754_csr.rm = oldrm;
+			rfmt = l_fmt;
+			goto copcsr;
+
+		default:
+			if (MIPSInst_FUNC(ir) >= fcmp_op) {
+				unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
+				union ieee754sp fs, ft;
+
+				SPFROMREG(fs, MIPSInst_FS(ir));
+				SPFROMREG(ft, MIPSInst_FT(ir));
+				rv.w = ieee754sp_cmp(fs, ft,
+					cmptab[cmpop & 0x7], cmpop & 0x8);
+				rfmt = -1;
+				if ((cmpop & 0x8) && ieee754_cxtest
+					(IEEE754_INVALID_OPERATION))
+					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
+				else
+					goto copcsr;
+
+			} else
+				return SIGILL;
+			break;
+		}
+		break;
+	}
+
+	case d_fmt: {
+		union ieee754dp fs, ft;
+		union {
+			union ieee754dp(*b) (union ieee754dp, union ieee754dp);
+			union ieee754dp(*u) (union ieee754dp);
+		} handler;
+
+		switch (MIPSInst_FUNC(ir)) {
+			/* binary ops */
+		case fadd_op:
+			handler.b = ieee754dp_add;
+			goto dcopbop;
+		case fsub_op:
+			handler.b = ieee754dp_sub;
+			goto dcopbop;
+		case fmul_op:
+			handler.b = ieee754dp_mul;
+			goto dcopbop;
+		case fdiv_op:
+			handler.b = ieee754dp_div;
+			goto dcopbop;
+
+			/* unary  ops */
+		case fsqrt_op:
+			if (!cpu_has_mips_2_3_4_5_r)
+				return SIGILL;
+
+			handler.u = ieee754dp_sqrt;
+			goto dcopuop;
+		/*
+		 * Note that on some MIPS IV implementations such as the
+		 * R5000 and R8000 the FSQRT and FRECIP instructions do not
+		 * achieve full IEEE-754 accuracy - however this emulator does.
+		 */
+		case frsqrt_op:
+			if (!cpu_has_mips_4_5_64_r2_r6)
+				return SIGILL;
+
+			handler.u = fpemu_dp_rsqrt;
+			goto dcopuop;
+		case frecip_op:
+			if (!cpu_has_mips_4_5_64_r2_r6)
+				return SIGILL;
+
+			handler.u = fpemu_dp_recip;
+			goto dcopuop;
+		case fmovc_op:
+			if (!cpu_has_mips_4_5_r)
+				return SIGILL;
+
+			cond = fpucondbit[MIPSInst_FT(ir) >> 2];
+			if (((ctx->fcr31 & cond) != 0) !=
+				((MIPSInst_FT(ir) & 1) != 0))
+				return 0;
+			DPFROMREG(rv.d, MIPSInst_FS(ir));
+			break;
+		case fmovz_op:
+			if (!cpu_has_mips_4_5_r)
+				return SIGILL;
+
+			if (xcp->regs[MIPSInst_FT(ir)] != 0)
+				return 0;
+			DPFROMREG(rv.d, MIPSInst_FS(ir));
+			break;
+		case fmovn_op:
+			if (!cpu_has_mips_4_5_r)
+				return SIGILL;
+
+			if (xcp->regs[MIPSInst_FT(ir)] == 0)
+				return 0;
+			DPFROMREG(rv.d, MIPSInst_FS(ir));
+			break;
+		case fabs_op:
+			handler.u = ieee754dp_abs;
+			goto dcopuop;
+
+		case fneg_op:
+			handler.u = ieee754dp_neg;
+			goto dcopuop;
+
+		case fmov_op:
+			/* an easy one */
+			DPFROMREG(rv.d, MIPSInst_FS(ir));
+			goto copcsr;
+
+			/* binary op on handler */
+dcopbop:
+			DPFROMREG(fs, MIPSInst_FS(ir));
+			DPFROMREG(ft, MIPSInst_FT(ir));
+
+			rv.d = (*handler.b) (fs, ft);
+			goto copcsr;
+dcopuop:
+			DPFROMREG(fs, MIPSInst_FS(ir));
+			rv.d = (*handler.u) (fs);
+			goto copcsr;
+
+		/*
+		 * unary conv ops
+		 */
+		case fcvts_op:
+			DPFROMREG(fs, MIPSInst_FS(ir));
+			rv.s = ieee754sp_fdp(fs);
+			rfmt = s_fmt;
+			goto copcsr;
+
+		case fcvtd_op:
+			return SIGILL;	/* not defined */
+
+		case fcvtw_op:
+			DPFROMREG(fs, MIPSInst_FS(ir));
+			rv.w = ieee754dp_tint(fs);	/* wrong */
+			rfmt = w_fmt;
+			goto copcsr;
+
+		case fround_op:
+		case ftrunc_op:
+		case fceil_op:
+		case ffloor_op:
+			if (!cpu_has_mips_2_3_4_5_r)
+				return SIGILL;
+
+			oldrm = ieee754_csr.rm;
+			DPFROMREG(fs, MIPSInst_FS(ir));
+			ieee754_csr.rm = MIPSInst_FUNC(ir);
+			rv.w = ieee754dp_tint(fs);
+			ieee754_csr.rm = oldrm;
+			rfmt = w_fmt;
+			goto copcsr;
+
+		case fcvtl_op:
+			if (!cpu_has_mips_3_4_5_64_r2_r6)
+				return SIGILL;
+
+			DPFROMREG(fs, MIPSInst_FS(ir));
+			rv.l = ieee754dp_tlong(fs);
+			rfmt = l_fmt;
+			goto copcsr;
+
+		case froundl_op:
+		case ftruncl_op:
+		case fceill_op:
+		case ffloorl_op:
+			if (!cpu_has_mips_3_4_5_64_r2_r6)
+				return SIGILL;
+
+			oldrm = ieee754_csr.rm;
+			DPFROMREG(fs, MIPSInst_FS(ir));
+			ieee754_csr.rm = MIPSInst_FUNC(ir);
+			rv.l = ieee754dp_tlong(fs);
+			ieee754_csr.rm = oldrm;
+			rfmt = l_fmt;
+			goto copcsr;
+
+		default:
+			if (MIPSInst_FUNC(ir) >= fcmp_op) {
+				unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
+				union ieee754dp fs, ft;
+
+				DPFROMREG(fs, MIPSInst_FS(ir));
+				DPFROMREG(ft, MIPSInst_FT(ir));
+				rv.w = ieee754dp_cmp(fs, ft,
+					cmptab[cmpop & 0x7], cmpop & 0x8);
+				rfmt = -1;
+				if ((cmpop & 0x8)
+					&&
+					ieee754_cxtest
+					(IEEE754_INVALID_OPERATION))
+					rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
+				else
+					goto copcsr;
+
+			}
+			else {
+				return SIGILL;
+			}
+			break;
+		}
+		break;
+
+	case w_fmt:
+		switch (MIPSInst_FUNC(ir)) {
+		case fcvts_op:
+			/* convert word to single precision real */
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			rv.s = ieee754sp_fint(fs.bits);
+			rfmt = s_fmt;
+			goto copcsr;
+		case fcvtd_op:
+			/* convert word to double precision real */
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			rv.d = ieee754dp_fint(fs.bits);
+			rfmt = d_fmt;
+			goto copcsr;
+		default:
+			return SIGILL;
+		}
+		break;
+	}
+
+	case l_fmt:
+
+		if (!cpu_has_mips_3_4_5_64_r2_r6)
+			return SIGILL;
+
+		DIFROMREG(bits, MIPSInst_FS(ir));
+
+		switch (MIPSInst_FUNC(ir)) {
+		case fcvts_op:
+			/* convert long to single precision real */
+			rv.s = ieee754sp_flong(bits);
+			rfmt = s_fmt;
+			goto copcsr;
+		case fcvtd_op:
+			/* convert long to double precision real */
+			rv.d = ieee754dp_flong(bits);
+			rfmt = d_fmt;
+			goto copcsr;
+		default:
+			return SIGILL;
+		}
+		break;
+
+	default:
+		return SIGILL;
+	}
+
+	/*
+	 * Update the fpu CSR register for this operation.
+	 * If an exception is required, generate a tidy SIGFPE exception,
+	 * without updating the result register.
+	 * Note: cause exception bits do not accumulate, they are rewritten
+	 * for each op; only the flag/sticky bits accumulate.
+	 */
+	ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
+	if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
+		/*printk ("SIGFPE: FPU csr = %08x\n",ctx->fcr31); */
+		return SIGFPE;
+	}
+
+	/*
+	 * Now we can safely write the result back to the register file.
+	 */
+	switch (rfmt) {
+	case -1:
+
+		if (cpu_has_mips_4_5_r)
+			cbit = fpucondbit[MIPSInst_FD(ir) >> 2];
+		else
+			cbit = FPU_CSR_COND;
+		if (rv.w)
+			ctx->fcr31 |= cbit;
+		else
+			ctx->fcr31 &= ~cbit;
+		break;
+
+	case d_fmt:
+		DPTOREG(rv.d, MIPSInst_FD(ir));
+		break;
+	case s_fmt:
+		SPTOREG(rv.s, MIPSInst_FD(ir));
+		break;
+	case w_fmt:
+		SITOREG(rv.w, MIPSInst_FD(ir));
+		break;
+	case l_fmt:
+		if (!cpu_has_mips_3_4_5_64_r2_r6)
+			return SIGILL;
+
+		DITOREG(rv.l, MIPSInst_FD(ir));
+		break;
+	default:
+		return SIGILL;
+	}
+
+	return 0;
+}
+
+int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+	int has_fpu, void *__user *fault_addr)
+{
+	unsigned long oldepc, prevepc;
+	struct mm_decoded_insn dec_insn;
+	u16 instr[4];
+	u16 *instr_ptr;
+	int sig = 0;
+
+	oldepc = xcp->cp0_epc;
+	do {
+		prevepc = xcp->cp0_epc;
+
+		if (get_isa16_mode(prevepc) && cpu_has_mmips) {
+			/*
+			 * Get next 2 microMIPS instructions and convert them
+			 * into 32-bit instructions.
+			 */
+			if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
+			    (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
+			    (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
+			    (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				return SIGBUS;
+			}
+			instr_ptr = instr;
+
+			/* Get first instruction. */
+			if (mm_insn_16bit(*instr_ptr)) {
+				/* Duplicate the half-word. */
+				dec_insn.insn = (*instr_ptr << 16) |
+					(*instr_ptr);
+				/* 16-bit instruction. */
+				dec_insn.pc_inc = 2;
+				instr_ptr += 1;
+			} else {
+				dec_insn.insn = (*instr_ptr << 16) |
+					*(instr_ptr+1);
+				/* 32-bit instruction. */
+				dec_insn.pc_inc = 4;
+				instr_ptr += 2;
+			}
+			/* Get second instruction. */
+			if (mm_insn_16bit(*instr_ptr)) {
+				/* Duplicate the half-word. */
+				dec_insn.next_insn = (*instr_ptr << 16) |
+					(*instr_ptr);
+				/* 16-bit instruction. */
+				dec_insn.next_pc_inc = 2;
+			} else {
+				dec_insn.next_insn = (*instr_ptr << 16) |
+					*(instr_ptr+1);
+				/* 32-bit instruction. */
+				dec_insn.next_pc_inc = 4;
+			}
+			dec_insn.micro_mips_mode = 1;
+		} else {
+			if ((get_user(dec_insn.insn,
+			    (mips_instruction __user *) xcp->cp0_epc)) ||
+			    (get_user(dec_insn.next_insn,
+			    (mips_instruction __user *)(xcp->cp0_epc+4)))) {
+				MIPS_FPU_EMU_INC_STATS(errors);
+				return SIGBUS;
+			}
+			dec_insn.pc_inc = 4;
+			dec_insn.next_pc_inc = 4;
+			dec_insn.micro_mips_mode = 0;
+		}
+
+		if ((dec_insn.insn == 0) ||
+		   ((dec_insn.pc_inc == 2) &&
+		   ((dec_insn.insn & 0xffff) == MM_NOP16)))
+			xcp->cp0_epc += dec_insn.pc_inc;	/* Skip NOPs */
+		else {
+			/*
+			 * The 'ieee754_csr' is an alias of ctx->fcr31.
+			 * No need to copy ctx->fcr31 to ieee754_csr.
+			 */
+			sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
+		}
+
+		if (has_fpu)
+			break;
+		if (sig)
+			break;
+
+		cond_resched();
+	} while (xcp->cp0_epc > prevepc);
+
+	/* SIGILL indicates a non-fpu instruction */
+	if (sig == SIGILL && xcp->cp0_epc != oldepc)
+		/* but if EPC has advanced, then ignore it */
+		sig = 0;
+
+	return sig;
+}