path: root/arch/riscv/include/asm/insn.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2020 SiFive
 */

#ifndef _ASM_RISCV_INSN_H
#define _ASM_RISCV_INSN_H

#include <linux/bits.h>

#define RV_INSN_FUNCT3_MASK	GENMASK(14, 12)
#define RV_INSN_FUNCT3_OPOFF	12
#define RV_INSN_OPCODE_MASK	GENMASK(6, 0)
#define RV_INSN_OPCODE_OPOFF	0
#define RV_INSN_FUNCT12_OPOFF	20

#define RV_ENCODE_FUNCT3(f_)	(RVG_FUNCT3_##f_ << RV_INSN_FUNCT3_OPOFF)
#define RV_ENCODE_FUNCT12(f_)	(RVG_FUNCT12_##f_ << RV_INSN_FUNCT12_OPOFF)

/* The bit field of immediate value in I-type instruction */
#define RV_I_IMM_SIGN_OPOFF	31
#define RV_I_IMM_11_0_OPOFF	20
#define RV_I_IMM_SIGN_OFF	12
#define RV_I_IMM_11_0_OFF	0
#define RV_I_IMM_11_0_MASK	GENMASK(11, 0)

/* The bit field of immediate value in J-type instruction */
#define RV_J_IMM_SIGN_OPOFF	31
#define RV_J_IMM_10_1_OPOFF	21
#define RV_J_IMM_11_OPOFF	20
#define RV_J_IMM_19_12_OPOFF	12
#define RV_J_IMM_SIGN_OFF	20
#define RV_J_IMM_10_1_OFF	1
#define RV_J_IMM_11_OFF		11
#define RV_J_IMM_19_12_OFF	12
#define RV_J_IMM_10_1_MASK	GENMASK(9, 0)
#define RV_J_IMM_11_MASK	GENMASK(0, 0)
#define RV_J_IMM_19_12_MASK	GENMASK(7, 0)

/*
 * U-type IMMs contain the upper 20bits [31:20] of an immediate with
 * the rest filled in by zeros, so no shifting required. Similarly,
 * bit31 contains the signed state, so no sign extension necessary.
 */
#define RV_U_IMM_SIGN_OPOFF	31
#define RV_U_IMM_31_12_OPOFF	0
#define RV_U_IMM_31_12_MASK	GENMASK(31, 12)

/* The bit field of immediate value in B-type instruction */
#define RV_B_IMM_SIGN_OPOFF	31
#define RV_B_IMM_10_5_OPOFF	25
#define RV_B_IMM_4_1_OPOFF	8
#define RV_B_IMM_11_OPOFF	7
#define RV_B_IMM_SIGN_OFF	12
#define RV_B_IMM_10_5_OFF	5
#define RV_B_IMM_4_1_OFF	1
#define RV_B_IMM_11_OFF		11
#define RV_B_IMM_10_5_MASK	GENMASK(5, 0)
#define RV_B_IMM_4_1_MASK	GENMASK(3, 0)
#define RV_B_IMM_11_MASK	GENMASK(0, 0)

/* The register offset in RVG instruction */
#define RVG_RS1_OPOFF		15
#define RVG_RS2_OPOFF		20
#define RVG_RD_OPOFF		7
#define RVG_RD_MASK		GENMASK(4, 0)

/* The bit field of immediate value in RVC J instruction */
#define RVC_J_IMM_SIGN_OPOFF	12
#define RVC_J_IMM_4_OPOFF	11
#define RVC_J_IMM_9_8_OPOFF	9
#define RVC_J_IMM_10_OPOFF	8
#define RVC_J_IMM_6_OPOFF	7
#define RVC_J_IMM_7_OPOFF	6
#define RVC_J_IMM_3_1_OPOFF	3
#define RVC_J_IMM_5_OPOFF	2
#define RVC_J_IMM_SIGN_OFF	11
#define RVC_J_IMM_4_OFF		4
#define RVC_J_IMM_9_8_OFF	8
#define RVC_J_IMM_10_OFF	10
#define RVC_J_IMM_6_OFF		6
#define RVC_J_IMM_7_OFF		7
#define RVC_J_IMM_3_1_OFF	1
#define RVC_J_IMM_5_OFF		5
#define RVC_J_IMM_4_MASK	GENMASK(0, 0)
#define RVC_J_IMM_9_8_MASK	GENMASK(1, 0)
#define RVC_J_IMM_10_MASK	GENMASK(0, 0)
#define RVC_J_IMM_6_MASK	GENMASK(0, 0)
#define RVC_J_IMM_7_MASK	GENMASK(0, 0)
#define RVC_J_IMM_3_1_MASK	GENMASK(2, 0)
#define RVC_J_IMM_5_MASK	GENMASK(0, 0)

/* The bit field of immediate value in RVC B instruction */
#define RVC_B_IMM_SIGN_OPOFF	12
#define RVC_B_IMM_4_3_OPOFF	10
#define RVC_B_IMM_7_6_OPOFF	5
#define RVC_B_IMM_2_1_OPOFF	3
#define RVC_B_IMM_5_OPOFF	2
#define RVC_B_IMM_SIGN_OFF	8
#define RVC_B_IMM_4_3_OFF	3
#define RVC_B_IMM_7_6_OFF	6
#define RVC_B_IMM_2_1_OFF	1
#define RVC_B_IMM_5_OFF		5
#define RVC_B_IMM_4_3_MASK	GENMASK(1, 0)
#define RVC_B_IMM_7_6_MASK	GENMASK(1, 0)
#define RVC_B_IMM_2_1_MASK	GENMASK(1, 0)
#define RVC_B_IMM_5_MASK	GENMASK(0, 0)

#define RVC_INSN_FUNCT4_MASK	GENMASK(15, 12)
#define RVC_INSN_FUNCT4_OPOFF	12
#define RVC_INSN_FUNCT3_MASK	GENMASK(15, 13)
#define RVC_INSN_FUNCT3_OPOFF	13
#define RVC_INSN_J_RS2_MASK	GENMASK(6, 2)
#define RVC_INSN_OPCODE_MASK	GENMASK(1, 0)
#define RVC_ENCODE_FUNCT3(f_)	(RVC_FUNCT3_##f_ << RVC_INSN_FUNCT3_OPOFF)
#define RVC_ENCODE_FUNCT4(f_)	(RVC_FUNCT4_##f_ << RVC_INSN_FUNCT4_OPOFF)

/* The register offset in RVC op=C0 instruction */
#define RVC_C0_RS1_OPOFF	7
#define RVC_C0_RS2_OPOFF	2
#define RVC_C0_RD_OPOFF		2

/* The register offset in RVC op=C1 instruction */
#define RVC_C1_RS1_OPOFF	7
#define RVC_C1_RS2_OPOFF	2
#define RVC_C1_RD_OPOFF		7

/* The register offset in RVC op=C2 instruction */
#define RVC_C2_RS1_OPOFF	7
#define RVC_C2_RS2_OPOFF	2
#define RVC_C2_RD_OPOFF		7

/* parts of opcode for RVG*/
#define RVG_OPCODE_FENCE	0x0f
#define RVG_OPCODE_AUIPC	0x17
#define RVG_OPCODE_BRANCH	0x63
#define RVG_OPCODE_JALR		0x67
#define RVG_OPCODE_JAL		0x6f
#define RVG_OPCODE_SYSTEM	0x73

/* parts of opcode for RVC*/
#define RVC_OPCODE_C0		0x0
#define RVC_OPCODE_C1		0x1
#define RVC_OPCODE_C2		0x2

/* parts of funct3 code for I, M, A extension*/
#define RVG_FUNCT3_JALR		0x0
#define RVG_FUNCT3_BEQ		0x0
#define RVG_FUNCT3_BNE		0x1
#define RVG_FUNCT3_BLT		0x4
#define RVG_FUNCT3_BGE		0x5
#define RVG_FUNCT3_BLTU		0x6
#define RVG_FUNCT3_BGEU		0x7

/* parts of funct3 code for C extension*/
#define RVC_FUNCT3_C_BEQZ	0x6
#define RVC_FUNCT3_C_BNEZ	0x7
#define RVC_FUNCT3_C_J		0x5
#define RVC_FUNCT3_C_JAL	0x1
#define RVC_FUNCT4_C_JR		0x8
#define RVC_FUNCT4_C_JALR	0x9
#define RVC_FUNCT4_C_EBREAK	0x9

#define RVG_FUNCT12_EBREAK	0x1
#define RVG_FUNCT12_SRET	0x102

#define RVG_MATCH_AUIPC		(RVG_OPCODE_AUIPC)
#define RVG_MATCH_JALR		(RV_ENCODE_FUNCT3(JALR) | RVG_OPCODE_JALR)
#define RVG_MATCH_JAL		(RVG_OPCODE_JAL)
#define RVG_MATCH_FENCE		(RVG_OPCODE_FENCE)
#define RVG_MATCH_BEQ		(RV_ENCODE_FUNCT3(BEQ) | RVG_OPCODE_BRANCH)
#define RVG_MATCH_BNE		(RV_ENCODE_FUNCT3(BNE) | RVG_OPCODE_BRANCH)
#define RVG_MATCH_BLT		(RV_ENCODE_FUNCT3(BLT) | RVG_OPCODE_BRANCH)
#define RVG_MATCH_BGE		(RV_ENCODE_FUNCT3(BGE) | RVG_OPCODE_BRANCH)
#define RVG_MATCH_BLTU		(RV_ENCODE_FUNCT3(BLTU) | RVG_OPCODE_BRANCH)
#define RVG_MATCH_BGEU		(RV_ENCODE_FUNCT3(BGEU) | RVG_OPCODE_BRANCH)
#define RVG_MATCH_EBREAK	(RV_ENCODE_FUNCT12(EBREAK) | RVG_OPCODE_SYSTEM)
#define RVG_MATCH_SRET		(RV_ENCODE_FUNCT12(SRET) | RVG_OPCODE_SYSTEM)
#define RVC_MATCH_C_BEQZ	(RVC_ENCODE_FUNCT3(C_BEQZ) | RVC_OPCODE_C1)
#define RVC_MATCH_C_BNEZ	(RVC_ENCODE_FUNCT3(C_BNEZ) | RVC_OPCODE_C1)
#define RVC_MATCH_C_J		(RVC_ENCODE_FUNCT3(C_J) | RVC_OPCODE_C1)
#define RVC_MATCH_C_JAL		(RVC_ENCODE_FUNCT3(C_JAL) | RVC_OPCODE_C1)
#define RVC_MATCH_C_JR		(RVC_ENCODE_FUNCT4(C_JR) | RVC_OPCODE_C2)
#define RVC_MATCH_C_JALR	(RVC_ENCODE_FUNCT4(C_JALR) | RVC_OPCODE_C2)
#define RVC_MATCH_C_EBREAK	(RVC_ENCODE_FUNCT4(C_EBREAK) | RVC_OPCODE_C2)

#define RVG_MASK_AUIPC		(RV_INSN_OPCODE_MASK)
#define RVG_MASK_JALR		(RV_INSN_FUNCT3_MASK | RV_INSN_OPCODE_MASK)
#define RVG_MASK_JAL		(RV_INSN_OPCODE_MASK)
#define RVG_MASK_FENCE		(RV_INSN_OPCODE_MASK)
#define RVC_MASK_C_JALR		(RVC_INSN_FUNCT4_MASK | RVC_INSN_J_RS2_MASK | RVC_INSN_OPCODE_MASK)
#define RVC_MASK_C_JR		(RVC_INSN_FUNCT4_MASK | RVC_INSN_J_RS2_MASK | RVC_INSN_OPCODE_MASK)
#define RVC_MASK_C_JAL		(RVC_INSN_FUNCT3_MASK | RVC_INSN_OPCODE_MASK)
#define RVC_MASK_C_J		(RVC_INSN_FUNCT3_MASK | RVC_INSN_OPCODE_MASK)
#define RVG_MASK_BEQ		(RV_INSN_FUNCT3_MASK | RV_INSN_OPCODE_MASK)
#define RVG_MASK_BNE		(RV_INSN_FUNCT3_MASK | RV_INSN_OPCODE_MASK)
#define RVG_MASK_BLT		(RV_INSN_FUNCT3_MASK | RV_INSN_OPCODE_MASK)
#define RVG_MASK_BGE		(RV_INSN_FUNCT3_MASK | RV_INSN_OPCODE_MASK)
#define RVG_MASK_BLTU		(RV_INSN_FUNCT3_MASK | RV_INSN_OPCODE_MASK)
#define RVG_MASK_BGEU		(RV_INSN_FUNCT3_MASK | RV_INSN_OPCODE_MASK)
#define RVC_MASK_C_BEQZ		(RVC_INSN_FUNCT3_MASK | RVC_INSN_OPCODE_MASK)
#define RVC_MASK_C_BNEZ		(RVC_INSN_FUNCT3_MASK | RVC_INSN_OPCODE_MASK)
#define RVC_MASK_C_EBREAK	0xffff
#define RVG_MASK_EBREAK		0xffffffff
#define RVG_MASK_SRET		0xffffffff

#define __INSN_LENGTH_MASK	_UL(0x3)
#define __INSN_LENGTH_GE_32	_UL(0x3)
#define __INSN_OPCODE_MASK	_UL(0x7F)
#define __INSN_BRANCH_OPCODE	_UL(RVG_OPCODE_BRANCH)

#define __RISCV_INSN_FUNCS(name, mask, val)				\
static __always_inline bool riscv_insn_is_##name(u32 code)		\
{									\
	BUILD_BUG_ON(~(mask) & (val));					\
	return (code & (mask)) == (val);				\
}									\

#if __riscv_xlen == 32
/* C.JAL is an RV32C-only instruction */
__RISCV_INSN_FUNCS(c_jal, RVC_MASK_C_JAL, RVC_MATCH_C_JAL)
#else
#define riscv_insn_is_c_jal(opcode) 0
#endif
__RISCV_INSN_FUNCS(auipc, RVG_MASK_AUIPC, RVG_MATCH_AUIPC)
__RISCV_INSN_FUNCS(jalr, RVG_MASK_JALR, RVG_MATCH_JALR)
__RISCV_INSN_FUNCS(jal, RVG_MASK_JAL, RVG_MATCH_JAL)
__RISCV_INSN_FUNCS(c_jr, RVC_MASK_C_JR, RVC_MATCH_C_JR)
__RISCV_INSN_FUNCS(c_jalr, RVC_MASK_C_JALR, RVC_MATCH_C_JALR)
__RISCV_INSN_FUNCS(c_j, RVC_MASK_C_J, RVC_MATCH_C_J)
__RISCV_INSN_FUNCS(beq, RVG_MASK_BEQ, RVG_MATCH_BEQ)
__RISCV_INSN_FUNCS(bne, RVG_MASK_BNE, RVG_MATCH_BNE)
__RISCV_INSN_FUNCS(blt, RVG_MASK_BLT, RVG_MATCH_BLT)
__RISCV_INSN_FUNCS(bge, RVG_MASK_BGE, RVG_MATCH_BGE)
__RISCV_INSN_FUNCS(bltu, RVG_MASK_BLTU, RVG_MATCH_BLTU)
__RISCV_INSN_FUNCS(bgeu, RVG_MASK_BGEU, RVG_MATCH_BGEU)
__RISCV_INSN_FUNCS(c_beqz, RVC_MASK_C_BEQZ, RVC_MATCH_C_BEQZ)
__RISCV_INSN_FUNCS(c_bnez, RVC_MASK_C_BNEZ, RVC_MATCH_C_BNEZ)
__RISCV_INSN_FUNCS(c_ebreak, RVC_MASK_C_EBREAK, RVC_MATCH_C_EBREAK)
__RISCV_INSN_FUNCS(ebreak, RVG_MASK_EBREAK, RVG_MATCH_EBREAK)
__RISCV_INSN_FUNCS(sret, RVG_MASK_SRET, RVG_MATCH_SRET)
__RISCV_INSN_FUNCS(fence, RVG_MASK_FENCE, RVG_MATCH_FENCE);

/* special case to catch _any_ system instruction */
static __always_inline bool riscv_insn_is_system(u32 code)
{
	return (code & RV_INSN_OPCODE_MASK) == RVG_OPCODE_SYSTEM;
}

/* special case to catch _any_ branch instruction */
static __always_inline bool riscv_insn_is_branch(u32 code)
{
	return (code & RV_INSN_OPCODE_MASK) == RVG_OPCODE_BRANCH;
}

#define RV_IMM_SIGN(x) (-(((x) >> 31) & 1))
#define RVC_IMM_SIGN(x) (-(((x) >> 12) & 1))
#define RV_X(X, s, mask)  (((X) >> (s)) & (mask))
#define RVC_X(X, s, mask) RV_X(X, s, mask)

#define RV_EXTRACT_RD_REG(x) \
	({typeof(x) x_ = (x); \
	(RV_X(x_, RVG_RD_OPOFF, RVG_RD_MASK)); })

#define RV_EXTRACT_UTYPE_IMM(x) \
	({typeof(x) x_ = (x); \
	(RV_X(x_, RV_U_IMM_31_12_OPOFF, RV_U_IMM_31_12_MASK)); })

#define RV_EXTRACT_JTYPE_IMM(x) \
	({typeof(x) x_ = (x); \
	(RV_X(x_, RV_J_IMM_10_1_OPOFF, RV_J_IMM_10_1_MASK) << RV_J_IMM_10_1_OFF) | \
	(RV_X(x_, RV_J_IMM_11_OPOFF, RV_J_IMM_11_MASK) << RV_J_IMM_11_OFF) | \
	(RV_X(x_, RV_J_IMM_19_12_OPOFF, RV_J_IMM_19_12_MASK) << RV_J_IMM_19_12_OFF) | \
	(RV_IMM_SIGN(x_) << RV_J_IMM_SIGN_OFF); })

#define RV_EXTRACT_ITYPE_IMM(x) \
	({typeof(x) x_ = (x); \
	(RV_X(x_, RV_I_IMM_11_0_OPOFF, RV_I_IMM_11_0_MASK)) | \
	(RV_IMM_SIGN(x_) << RV_I_IMM_SIGN_OFF); })

#define RV_EXTRACT_BTYPE_IMM(x) \
	({typeof(x) x_ = (x); \
	(RV_X(x_, RV_B_IMM_4_1_OPOFF, RV_B_IMM_4_1_MASK) << RV_B_IMM_4_1_OFF) | \
	(RV_X(x_, RV_B_IMM_10_5_OPOFF, RV_B_IMM_10_5_MASK) << RV_B_IMM_10_5_OFF) | \
	(RV_X(x_, RV_B_IMM_11_OPOFF, RV_B_IMM_11_MASK) << RV_B_IMM_11_OFF) | \
	(RV_IMM_SIGN(x_) << RV_B_IMM_SIGN_OFF); })

#define RVC_EXTRACT_JTYPE_IMM(x) \
	({typeof(x) x_ = (x); \
	(RVC_X(x_, RVC_J_IMM_3_1_OPOFF, RVC_J_IMM_3_1_MASK) << RVC_J_IMM_3_1_OFF) | \
	(RVC_X(x_, RVC_J_IMM_4_OPOFF, RVC_J_IMM_4_MASK) << RVC_J_IMM_4_OFF) | \
	(RVC_X(x_, RVC_J_IMM_5_OPOFF, RVC_J_IMM_5_MASK) << RVC_J_IMM_5_OFF) | \
	(RVC_X(x_, RVC_J_IMM_6_OPOFF, RVC_J_IMM_6_MASK) << RVC_J_IMM_6_OFF) | \
	(RVC_X(x_, RVC_J_IMM_7_OPOFF, RVC_J_IMM_7_MASK) << RVC_J_IMM_7_OFF) | \
	(RVC_X(x_, RVC_J_IMM_9_8_OPOFF, RVC_J_IMM_9_8_MASK) << RVC_J_IMM_9_8_OFF) | \
	(RVC_X(x_, RVC_J_IMM_10_OPOFF, RVC_J_IMM_10_MASK) << RVC_J_IMM_10_OFF) | \
	(RVC_IMM_SIGN(x_) << RVC_J_IMM_SIGN_OFF); })

#define RVC_EXTRACT_BTYPE_IMM(x) \
	({typeof(x) x_ = (x); \
	(RVC_X(x_, RVC_B_IMM_2_1_OPOFF, RVC_B_IMM_2_1_MASK) << RVC_B_IMM_2_1_OFF) | \
	(RVC_X(x_, RVC_B_IMM_4_3_OPOFF, RVC_B_IMM_4_3_MASK) << RVC_B_IMM_4_3_OFF) | \
	(RVC_X(x_, RVC_B_IMM_5_OPOFF, RVC_B_IMM_5_MASK) << RVC_B_IMM_5_OFF) | \
	(RVC_X(x_, RVC_B_IMM_7_6_OPOFF, RVC_B_IMM_7_6_MASK) << RVC_B_IMM_7_6_OFF) | \
	(RVC_IMM_SIGN(x_) << RVC_B_IMM_SIGN_OFF); })

/*
 * Get the immediate from a J-type instruction.
 *
 * @insn: instruction to process
 * Return: immediate
 */
static inline s32 riscv_insn_extract_jtype_imm(u32 insn)
{
	return RV_EXTRACT_JTYPE_IMM(insn);
}

/*
 * Update a J-type instruction with an immediate value.
 *
 * @insn: pointer to the jtype instruction
 * @imm: the immediate to insert into the instruction
 */
static inline void riscv_insn_insert_jtype_imm(u32 *insn, s32 imm)
{
	/* drop the old IMMs, all jal IMM bits sit at 31:12 */
	*insn &= ~GENMASK(31, 12);
	*insn |= (RV_X(imm, RV_J_IMM_10_1_OFF, RV_J_IMM_10_1_MASK) << RV_J_IMM_10_1_OPOFF) |
		 (RV_X(imm, RV_J_IMM_11_OFF, RV_J_IMM_11_MASK) << RV_J_IMM_11_OPOFF) |
		 (RV_X(imm, RV_J_IMM_19_12_OFF, RV_J_IMM_19_12_MASK) << RV_J_IMM_19_12_OPOFF) |
		 (RV_X(imm, RV_J_IMM_SIGN_OFF, 1) << RV_J_IMM_SIGN_OPOFF);
}

/*
 * Put together one immediate from a U-type and I-type instruction pair.
 *
 * The U-type contains an upper immediate, meaning bits[31:12] with [11:0]
 * being zero, while the I-type contains a 12bit immediate.
 * Combined these can encode larger 32bit values and are used for example
 * in auipc + jalr pairs to allow larger jumps.
 *
 * @utype_insn: instruction containing the upper immediate
 * @itype_insn: instruction
 * Return: combined immediate
 */
static inline s32 riscv_insn_extract_utype_itype_imm(u32 utype_insn, u32 itype_insn)
{
	s32 imm;

	imm = RV_EXTRACT_UTYPE_IMM(utype_insn);
	imm += RV_EXTRACT_ITYPE_IMM(itype_insn);

	return imm;
}

/*
 * Update a set of two instructions (U-type + I-type) with an immediate value.
 *
 * Used for example in auipc+jalrs pairs the U-type instructions contains
 * a 20bit upper immediate representing bits[31:12], while the I-type
 * instruction contains a 12bit immediate representing bits[11:0].
 *
 * This also takes into account that both separate immediates are
 * considered as signed values, so if the I-type immediate becomes
 * negative (BIT(11) set) the U-type part gets adjusted.
 *
 * @utype_insn: pointer to the utype instruction of the pair
 * @itype_insn: pointer to the itype instruction of the pair
 * @imm: the immediate to insert into the two instructions
 */
static inline void riscv_insn_insert_utype_itype_imm(u32 *utype_insn, u32 *itype_insn, s32 imm)
{
	/* drop possible old IMM values */
	*utype_insn &= ~(RV_U_IMM_31_12_MASK);
	*itype_insn &= ~(RV_I_IMM_11_0_MASK << RV_I_IMM_11_0_OPOFF);

	/* add the adapted IMMs */
	*utype_insn |= (imm & RV_U_IMM_31_12_MASK) + ((imm & BIT(11)) << 1);
	*itype_insn |= ((imm & RV_I_IMM_11_0_MASK) << RV_I_IMM_11_0_OPOFF);
}
#endif /* _ASM_RISCV_INSN_H */