nds32: Support FP emulation

The Andes FPU coprocessor does not support denormalized number handling.
According to the specification, FPU generates a denorm input exception
that requires the kernel to deal with this instrution operation when it
encounters denormalized operands. Hence an nds32 FPU ISA emulator in the
kernel is required to meet requirement.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Nickhu <nickhu@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

18 files changed, 737 insertions, 0 deletions

diff --git a/arch/nds32/math-emu/Makefile b/arch/nds32/math-emu/Makefile
new file mode 100644
index 000000000000..947fe0c3d52f
--- /dev/null
+++ b/arch/nds32/math-emu/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the Linux/nds32 kernel FPU emulation.
+#
+
+obj-y	:= fpuemu.o \
+	   fdivd.o fmuld.o fsubd.o faddd.o fs2d.o fsqrtd.o fcmpd.o fnegs.o \
+	   fdivs.o fmuls.o fsubs.o fadds.o fd2s.o fsqrts.o fcmps.o fnegd.o
diff --git a/arch/nds32/math-emu/faddd.c b/arch/nds32/math-emu/faddd.c
new file mode 100644
index 000000000000..f7fd4e3c3904
--- /dev/null
+++ b/arch/nds32/math-emu/faddd.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/double.h>
+void faddd(void *ft, void *fa, void *fb)
+{
+	FP_DECL_D(A);
+	FP_DECL_D(B);
+	FP_DECL_D(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_DP(A, fa);
+	FP_UNPACK_DP(B, fb);
+
+	FP_ADD_D(R, A, B);
+
+	FP_PACK_DP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+
+}
diff --git a/arch/nds32/math-emu/fadds.c b/arch/nds32/math-emu/fadds.c
new file mode 100644
index 000000000000..f5af6ca8cca5
--- /dev/null
+++ b/arch/nds32/math-emu/fadds.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+void fadds(void *ft, void *fa, void *fb)
+{
+	FP_DECL_S(A);
+	FP_DECL_S(B);
+	FP_DECL_S(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_SP(A, fa);
+	FP_UNPACK_SP(B, fb);
+
+	FP_ADD_S(R, A, B);
+
+	FP_PACK_SP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+
+}
diff --git a/arch/nds32/math-emu/fcmpd.c b/arch/nds32/math-emu/fcmpd.c
new file mode 100644
index 000000000000..0ea225abe880
--- /dev/null
+++ b/arch/nds32/math-emu/fcmpd.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/double.h>
+int fcmpd(void *ft, void *fa, void *fb, int cmpop)
+{
+	FP_DECL_D(A);
+	FP_DECL_D(B);
+	FP_DECL_EX;
+	long cmp;
+
+	FP_UNPACK_DP(A, fa);
+	FP_UNPACK_DP(B, fb);
+
+	FP_CMP_D(cmp, A, B, SF_CUN);
+	cmp += 2;
+	if (cmp == SF_CGT)
+		*(long *)ft = 0;
+	else
+		*(long *)ft = (cmp & cmpop) ? 1 : 0;
+
+	return 0;
+}
diff --git a/arch/nds32/math-emu/fcmps.c b/arch/nds32/math-emu/fcmps.c
new file mode 100644
index 000000000000..681480758213
--- /dev/null
+++ b/arch/nds32/math-emu/fcmps.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+int fcmps(void *ft, void *fa, void *fb, int cmpop)
+{
+	FP_DECL_S(A);
+	FP_DECL_S(B);
+	FP_DECL_EX;
+	long cmp;
+
+	FP_UNPACK_SP(A, fa);
+	FP_UNPACK_SP(B, fb);
+
+	FP_CMP_S(cmp, A, B, SF_CUN);
+	cmp += 2;
+	if (cmp == SF_CGT)
+		*(int *)ft = 0x0;
+	else
+		*(int *)ft = (cmp & cmpop) ? 0x1 : 0x0;
+
+	return 0;
+}
diff --git a/arch/nds32/math-emu/fd2s.c b/arch/nds32/math-emu/fd2s.c
new file mode 100644
index 000000000000..1328371e8170
--- /dev/null
+++ b/arch/nds32/math-emu/fd2s.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/double.h>
+#include <math-emu/single.h>
+#include <math-emu/soft-fp.h>
+void fd2s(void *ft, void *fa)
+{
+	FP_DECL_D(A);
+	FP_DECL_S(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_DP(A, fa);
+
+	FP_CONV(S, D, 1, 2, R, A);
+
+	FP_PACK_SP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fdivd.c b/arch/nds32/math-emu/fdivd.c
new file mode 100644
index 000000000000..458e7e98b08e
--- /dev/null
+++ b/arch/nds32/math-emu/fdivd.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+
+#include <linux/uaccess.h>
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/double.h>
+
+void fdivd(void *ft, void *fa, void *fb)
+{
+	FP_DECL_D(A);
+	FP_DECL_D(B);
+	FP_DECL_D(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_DP(A, fa);
+	FP_UNPACK_DP(B, fb);
+
+	if (B_c == FP_CLS_ZERO && A_c != FP_CLS_ZERO)
+		FP_SET_EXCEPTION(FP_EX_DIVZERO);
+
+	FP_DIV_D(R, A, B);
+
+	FP_PACK_DP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fdivs.c b/arch/nds32/math-emu/fdivs.c
new file mode 100644
index 000000000000..c7d202159ce2
--- /dev/null
+++ b/arch/nds32/math-emu/fdivs.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+void fdivs(void *ft, void *fa, void *fb)
+{
+	FP_DECL_S(A);
+	FP_DECL_S(B);
+	FP_DECL_S(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_SP(A, fa);
+	FP_UNPACK_SP(B, fb);
+
+	if (B_c == FP_CLS_ZERO && A_c != FP_CLS_ZERO)
+		FP_SET_EXCEPTION(FP_EX_DIVZERO);
+
+	FP_DIV_S(R, A, B);
+
+	FP_PACK_SP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fmuld.c b/arch/nds32/math-emu/fmuld.c
new file mode 100644
index 000000000000..f3c77a45ddc2
--- /dev/null
+++ b/arch/nds32/math-emu/fmuld.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/double.h>
+void fmuld(void *ft, void *fa, void *fb)
+{
+	FP_DECL_D(A);
+	FP_DECL_D(B);
+	FP_DECL_D(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_DP(A, fa);
+	FP_UNPACK_DP(B, fb);
+
+	FP_MUL_D(R, A, B);
+
+	FP_PACK_DP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fmuls.c b/arch/nds32/math-emu/fmuls.c
new file mode 100644
index 000000000000..cf150df938f9
--- /dev/null
+++ b/arch/nds32/math-emu/fmuls.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+void fmuls(void *ft, void *fa, void *fb)
+{
+	FP_DECL_S(A);
+	FP_DECL_S(B);
+	FP_DECL_S(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_SP(A, fa);
+	FP_UNPACK_SP(B, fb);
+
+	FP_MUL_S(R, A, B);
+
+	FP_PACK_SP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fnegd.c b/arch/nds32/math-emu/fnegd.c
new file mode 100644
index 000000000000..de7ea6a0873e
--- /dev/null
+++ b/arch/nds32/math-emu/fnegd.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/double.h>
+void fnegd(void *ft, void *fa)
+{
+	FP_DECL_D(A);
+	FP_DECL_D(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_DP(A, fa);
+
+	FP_NEG_D(R, A);
+
+	FP_PACK_DP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fnegs.c b/arch/nds32/math-emu/fnegs.c
new file mode 100644
index 000000000000..07270b326a77
--- /dev/null
+++ b/arch/nds32/math-emu/fnegs.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+void fnegs(void *ft, void *fa)
+{
+	FP_DECL_S(A);
+	FP_DECL_S(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_SP(A, fa);
+
+	FP_NEG_S(R, A);
+
+	FP_PACK_SP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fpuemu.c b/arch/nds32/math-emu/fpuemu.c
new file mode 100644
index 000000000000..2a01333d6e5f
--- /dev/null
+++ b/arch/nds32/math-emu/fpuemu.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+
+#include <asm/bitfield.h>
+#include <asm/uaccess.h>
+#include <asm/sfp-machine.h>
+#include <asm/fpuemu.h>
+#include <asm/nds32_fpu_inst.h>
+
+#define DPFROMREG(dp, x) (dp = (void *)((unsigned long *)fpu_reg + 2*x))
+#ifdef __NDS32_EL__
+#define SPFROMREG(sp, x)\
+	((sp) = (void *)((unsigned long *)fpu_reg + (x^1)))
+#else
+#define SPFROMREG(sp, x) ((sp) = (void *)((unsigned long *)fpu_reg + x))
+#endif
+
+#define DEF3OP(name, p, f1, f2) \
+void fpemu_##name##p(void *ft, void *fa, void *fb) \
+{ \
+	f1(fa, fa, fb); \
+	f2(ft, ft, fa); \
+}
+
+#define DEF3OPNEG(name, p, f1, f2, f3) \
+void fpemu_##name##p(void *ft, void *fa, void *fb) \
+{ \
+	f1(fa, fa, fb); \
+	f2(ft, ft, fa); \
+	f3(ft, ft); \
+}
+DEF3OP(fmadd, s, fmuls, fadds);
+DEF3OP(fmsub, s, fmuls, fsubs);
+DEF3OP(fmadd, d, fmuld, faddd);
+DEF3OP(fmsub, d, fmuld, fsubd);
+DEF3OPNEG(fnmadd, s, fmuls, fadds, fnegs);
+DEF3OPNEG(fnmsub, s, fmuls, fsubs, fnegs);
+DEF3OPNEG(fnmadd, d, fmuld, faddd, fnegd);
+DEF3OPNEG(fnmsub, d, fmuld, fsubd, fnegd);
+
+static const unsigned char cmptab[8] = {
+	SF_CEQ,
+	SF_CEQ,
+	SF_CLT,
+	SF_CLT,
+	SF_CLT | SF_CEQ,
+	SF_CLT | SF_CEQ,
+	SF_CUN,
+	SF_CUN
+};
+
+enum ARGTYPE {
+	S1S = 1,
+	S2S,
+	S1D,
+	CS,
+	D1D,
+	D2D,
+	D1S,
+	CD
+};
+union func_t {
+	void (*t)(void *ft, void *fa, void *fb);
+	void (*b)(void *ft, void *fa);
+};
+/*
+ * Emulate a single FPU arithmetic instruction.
+ */
+static int fpu_emu(struct fpu_struct *fpu_reg, unsigned long insn)
+{
+	int rfmt;		/* resulting format */
+	union func_t func;
+	int ftype = 0;
+
+	switch (rfmt = NDS32Insn_OPCODE_COP0(insn)) {
+	case fs1_op:{
+			switch (NDS32Insn_OPCODE_BIT69(insn)) {
+			case fadds_op:
+				func.t = fadds;
+				ftype = S2S;
+				break;
+			case fsubs_op:
+				func.t = fsubs;
+				ftype = S2S;
+				break;
+			case fmadds_op:
+				func.t = fpemu_fmadds;
+				ftype = S2S;
+				break;
+			case fmsubs_op:
+				func.t = fpemu_fmsubs;
+				ftype = S2S;
+				break;
+			case fnmadds_op:
+				func.t = fpemu_fnmadds;
+				ftype = S2S;
+				break;
+			case fnmsubs_op:
+				func.t = fpemu_fnmsubs;
+				ftype = S2S;
+				break;
+			case fmuls_op:
+				func.t = fmuls;
+				ftype = S2S;
+				break;
+			case fdivs_op:
+				func.t = fdivs;
+				ftype = S2S;
+				break;
+			case fs1_f2op_op:
+				switch (NDS32Insn_OPCODE_BIT1014(insn)) {
+				case fs2d_op:
+					func.b = fs2d;
+					ftype = S1D;
+					break;
+				case fsqrts_op:
+					func.b = fsqrts;
+					ftype = S1S;
+					break;
+				default:
+					return SIGILL;
+				}
+				break;
+			default:
+				return SIGILL;
+			}
+			break;
+		}
+	case fs2_op:
+		switch (NDS32Insn_OPCODE_BIT69(insn)) {
+		case fcmpeqs_op:
+		case fcmpeqs_e_op:
+		case fcmplts_op:
+		case fcmplts_e_op:
+		case fcmples_op:
+		case fcmples_e_op:
+		case fcmpuns_op:
+		case fcmpuns_e_op:
+			ftype = CS;
+			break;
+		default:
+			return SIGILL;
+		}
+		break;
+	case fd1_op:{
+			switch (NDS32Insn_OPCODE_BIT69(insn)) {
+			case faddd_op:
+				func.t = faddd;
+				ftype = D2D;
+				break;
+			case fsubd_op:
+				func.t = fsubd;
+				ftype = D2D;
+				break;
+			case fmaddd_op:
+				func.t = fpemu_fmaddd;
+				ftype = D2D;
+				break;
+			case fmsubd_op:
+				func.t = fpemu_fmsubd;
+				ftype = D2D;
+				break;
+			case fnmaddd_op:
+				func.t = fpemu_fnmaddd;
+				ftype = D2D;
+				break;
+			case fnmsubd_op:
+				func.t = fpemu_fnmsubd;
+				ftype = D2D;
+				break;
+			case fmuld_op:
+				func.t = fmuld;
+				ftype = D2D;
+				break;
+			case fdivd_op:
+				func.t = fdivd;
+				ftype = D2D;
+				break;
+			case fd1_f2op_op:
+				switch (NDS32Insn_OPCODE_BIT1014(insn)) {
+				case fd2s_op:
+					func.b = fd2s;
+					ftype = D1S;
+					break;
+				case fsqrtd_op:
+					func.b = fsqrtd;
+					ftype = D1D;
+					break;
+				default:
+					return SIGILL;
+				}
+				break;
+			default:
+				return SIGILL;
+
+			}
+			break;
+		}
+
+	case fd2_op:
+		switch (NDS32Insn_OPCODE_BIT69(insn)) {
+		case fcmpeqd_op:
+		case fcmpeqd_e_op:
+		case fcmpltd_op:
+		case fcmpltd_e_op:
+		case fcmpled_op:
+		case fcmpled_e_op:
+		case fcmpund_op:
+		case fcmpund_e_op:
+			ftype = CD;
+			break;
+		default:
+			return SIGILL;
+		}
+		break;
+
+	default:
+		return SIGILL;
+	}
+
+	switch (ftype) {
+	case S1S:{
+			void *ft, *fa;
+
+			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
+			SPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
+			func.b(ft, fa);
+			break;
+		}
+	case S2S:{
+			void *ft, *fa, *fb;
+
+			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
+			SPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
+			SPFROMREG(fb, NDS32Insn_OPCODE_Rb(insn));
+			func.t(ft, fa, fb);
+			break;
+		}
+	case S1D:{
+			void *ft, *fa;
+
+			DPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
+			SPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
+			func.b(ft, fa);
+			break;
+		}
+	case CS:{
+			unsigned int cmpop = NDS32Insn_OPCODE_BIT69(insn);
+			void *ft, *fa, *fb;
+
+			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
+			SPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
+			SPFROMREG(fb, NDS32Insn_OPCODE_Rb(insn));
+			if (cmpop < 0x8) {
+				cmpop = cmptab[cmpop];
+				fcmps(ft, fa, fb, cmpop);
+			} else
+				return SIGILL;
+			break;
+		}
+	case D1D:{
+			void *ft, *fa;
+
+			DPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
+			DPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
+			func.b(ft, fa);
+			break;
+		}
+	case D2D:{
+			void *ft, *fa, *fb;
+
+			DPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
+			DPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
+			DPFROMREG(fb, NDS32Insn_OPCODE_Rb(insn));
+			func.t(ft, fa, fb);
+			break;
+		}
+	case D1S:{
+			void *ft, *fa;
+
+			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
+			DPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
+			func.b(ft, fa);
+			break;
+		}
+	case CD:{
+			unsigned int cmpop = NDS32Insn_OPCODE_BIT69(insn);
+			void *ft, *fa, *fb;
+
+			SPFROMREG(ft, NDS32Insn_OPCODE_Rt(insn));
+			DPFROMREG(fa, NDS32Insn_OPCODE_Ra(insn));
+			DPFROMREG(fb, NDS32Insn_OPCODE_Rb(insn));
+			if (cmpop < 0x8) {
+				cmpop = cmptab[cmpop];
+				fcmpd(ft, fa, fb, cmpop);
+			} else
+				return SIGILL;
+			break;
+		}
+	default:
+		return SIGILL;
+	}
+
+	/*
+	 * If an exception is required, generate a tidy SIGFPE exception.
+	 */
+	if ((fpu_reg->fpcsr << 5) & fpu_reg->fpcsr & FPCSR_mskALLE)
+		return SIGFPE;
+	return 0;
+}
+
+
+int do_fpuemu(struct pt_regs *regs, struct fpu_struct *fpu)
+{
+	unsigned long insn = 0, addr = regs->ipc;
+	unsigned long emulpc, contpc;
+	unsigned char *pc = (void *)&insn;
+	char c;
+	int i = 0, ret;
+
+	for (i = 0; i < 4; i++) {
+		if (__get_user(c, (unsigned char *)addr++))
+			return SIGBUS;
+		*pc++ = c;
+	}
+
+	insn = be32_to_cpu(insn);
+
+	emulpc = regs->ipc;
+	contpc = regs->ipc + 4;
+
+	if (NDS32Insn_OPCODE(insn) != cop0_op)
+		return SIGILL;
+	switch (NDS32Insn_OPCODE_COP0(insn)) {
+	case fs1_op:
+	case fs2_op:
+	case fd1_op:
+	case fd2_op:
+		{
+			/* a real fpu computation instruction */
+			ret = fpu_emu(fpu, insn);
+			if (!ret)
+				regs->ipc = contpc;
+		}
+		break;
+
+	default:
+		return SIGILL;
+	}
+
+	return ret;
+}
diff --git a/arch/nds32/math-emu/fs2d.c b/arch/nds32/math-emu/fs2d.c
new file mode 100644
index 000000000000..0e8db9035631
--- /dev/null
+++ b/arch/nds32/math-emu/fs2d.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+
+#include <linux/uaccess.h>
+#include <asm/sfp-machine.h>
+#include <math-emu/double.h>
+#include <math-emu/single.h>
+#include <math-emu/soft-fp.h>
+
+void fs2d(void *ft, void *fa)
+{
+	FP_DECL_S(A);
+	FP_DECL_D(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_SP(A, fa);
+
+	FP_CONV(D, S, 2, 1, R, A);
+
+	FP_PACK_DP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fsqrtd.c b/arch/nds32/math-emu/fsqrtd.c
new file mode 100644
index 000000000000..c3a8dbd81d4e
--- /dev/null
+++ b/arch/nds32/math-emu/fsqrtd.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+
+#include <linux/uaccess.h>
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/double.h>
+void fsqrtd(void *ft, void *fa)
+{
+	FP_DECL_D(A);
+	FP_DECL_D(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_DP(A, fa);
+
+	FP_SQRT_D(R, A);
+
+	FP_PACK_DP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fsqrts.c b/arch/nds32/math-emu/fsqrts.c
new file mode 100644
index 000000000000..4c6f94b27328
--- /dev/null
+++ b/arch/nds32/math-emu/fsqrts.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+
+#include <linux/uaccess.h>
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+void fsqrts(void *ft, void *fa)
+{
+	FP_DECL_S(A);
+	FP_DECL_S(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_SP(A, fa);
+
+	FP_SQRT_S(R, A);
+
+	FP_PACK_SP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fsubd.c b/arch/nds32/math-emu/fsubd.c
new file mode 100644
index 000000000000..81b6a0d02a1f
--- /dev/null
+++ b/arch/nds32/math-emu/fsubd.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/double.h>
+void fsubd(void *ft, void *fa, void *fb)
+{
+
+	FP_DECL_D(A);
+	FP_DECL_D(B);
+	FP_DECL_D(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_DP(A, fa);
+	FP_UNPACK_DP(B, fb);
+
+	if (B_c != FP_CLS_NAN)
+		B_s ^= 1;
+
+	FP_ADD_D(R, A, B);
+
+	FP_PACK_DP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}
diff --git a/arch/nds32/math-emu/fsubs.c b/arch/nds32/math-emu/fsubs.c
new file mode 100644
index 000000000000..61ddd9708465
--- /dev/null
+++ b/arch/nds32/math-emu/fsubs.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <linux/uaccess.h>
+
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+void fsubs(void *ft, void *fa, void *fb)
+{
+
+	FP_DECL_S(A);
+	FP_DECL_S(B);
+	FP_DECL_S(R);
+	FP_DECL_EX;
+
+	FP_UNPACK_SP(A, fa);
+	FP_UNPACK_SP(B, fb);
+
+	if (B_c != FP_CLS_NAN)
+		B_s ^= 1;
+
+	FP_ADD_S(R, A, B);
+
+	FP_PACK_SP(ft, R);
+
+	__FPU_FPCSR |= FP_CUR_EXCEPTIONS;
+}