/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * A small micro-assembler. It is intentionally kept simple, does only
 * support a subset of instructions, and does not try to hide pipeline
 * effects like branch delay slots.
 *
 * Copyright (C) 2004, 2005, 2006, 2008	 Thiemo Seufer
 * Copyright (C) 2005, 2007  Maciej W. Rozycki
 * Copyright (C) 2006  Ralf Baechle (ralf@linux-mips.org)
 * Copyright (C) 2012, 2013  MIPS Technologies, Inc.  All rights reserved.
 */

enum fields {
	RS = 0x001,
	RT = 0x002,
	RD = 0x004,
	RE = 0x008,
	SIMM = 0x010,
	UIMM = 0x020,
	BIMM = 0x040,
	JIMM = 0x080,
	FUNC = 0x100,
	SET = 0x200,
	SCIMM = 0x400
};

#define OP_MASK		0x3f
#define OP_SH		26
#define RD_MASK		0x1f
#define RD_SH		11
#define RE_MASK		0x1f
#define RE_SH		6
#define IMM_MASK	0xffff
#define IMM_SH		0
#define JIMM_MASK	0x3ffffff
#define JIMM_SH		0
#define FUNC_MASK	0x3f
#define FUNC_SH		0
#define SET_MASK	0x7
#define SET_SH		0

enum opcode {
	insn_invalid,
	insn_addiu, insn_addu, insn_and, insn_andi, insn_bbit0, insn_bbit1,
	insn_beq, insn_beql, insn_bgez, insn_bgezl, insn_bltz, insn_bltzl,
	insn_bne, insn_cache, insn_daddiu, insn_daddu, insn_dins, insn_dinsm,
	insn_dmfc0, insn_dmtc0, insn_drotr, insn_drotr32, insn_dsll,
	insn_dsll32, insn_dsra, insn_dsrl, insn_dsrl32, insn_dsubu, insn_eret,
	insn_ext, insn_ins, insn_j, insn_jal, insn_jr, insn_ld, insn_ldx,
	insn_ll, insn_lld, insn_lui, insn_lw, insn_lwx, insn_mfc0, insn_mtc0,
	insn_or, insn_ori, insn_pref, insn_rfe, insn_rotr, insn_sc, insn_scd,
	insn_sd, insn_sll, insn_sra, insn_srl, insn_subu, insn_sw,
	insn_syscall, insn_tlbp, insn_tlbr, insn_tlbwi, insn_tlbwr, insn_xor,
	insn_xori,
};

struct insn {
	enum opcode opcode;
	u32 match;
	enum fields fields;
};

static inline u32 build_rs(u32 arg)
{
	WARN(arg & ~RS_MASK, KERN_WARNING "Micro-assembler field overflow\n");

	return (arg & RS_MASK) << RS_SH;
}

static inline u32 build_rt(u32 arg)
{
	WARN(arg & ~RT_MASK, KERN_WARNING "Micro-assembler field overflow\n");

	return (arg & RT_MASK) << RT_SH;
}

static inline u32 build_rd(u32 arg)
{
	WARN(arg & ~RD_MASK, KERN_WARNING "Micro-assembler field overflow\n");

	return (arg & RD_MASK) << RD_SH;
}

static inline u32 build_re(u32 arg)
{
	WARN(arg & ~RE_MASK, KERN_WARNING "Micro-assembler field overflow\n");

	return (arg & RE_MASK) << RE_SH;
}

static inline u32 build_simm(s32 arg)
{
	WARN(arg > 0x7fff || arg < -0x8000,
	     KERN_WARNING "Micro-assembler field overflow\n");

	return arg & 0xffff;
}

static inline u32 build_uimm(u32 arg)
{
	WARN(arg & ~IMM_MASK, KERN_WARNING "Micro-assembler field overflow\n");

	return arg & IMM_MASK;
}

static inline u32 build_scimm(u32 arg)
{
	WARN(arg & ~SCIMM_MASK,
	     KERN_WARNING "Micro-assembler field overflow\n");

	return (arg & SCIMM_MASK) << SCIMM_SH;
}

static inline u32 build_func(u32 arg)
{
	WARN(arg & ~FUNC_MASK, KERN_WARNING "Micro-assembler field overflow\n");

	return arg & FUNC_MASK;
}

static inline u32 build_set(u32 arg)
{
	WARN(arg & ~SET_MASK, KERN_WARNING "Micro-assembler field overflow\n");

	return arg & SET_MASK;
}

static void build_insn(u32 **buf, enum opcode opc, ...);

#define I_u1u2u3(op)					\
Ip_u1u2u3(op)						\
{							\
	build_insn(buf, insn##op, a, b, c);		\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u2u1u3(op)					\
Ip_u2u1u3(op)						\
{							\
	build_insn(buf, insn##op, b, a, c);		\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u3u1u2(op)					\
Ip_u3u1u2(op)						\
{							\
	build_insn(buf, insn##op, b, c, a);		\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u1u2s3(op)					\
Ip_u1u2s3(op)						\
{							\
	build_insn(buf, insn##op, a, b, c);		\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u2s3u1(op)					\
Ip_u2s3u1(op)						\
{							\
	build_insn(buf, insn##op, c, a, b);		\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u2u1s3(op)					\
Ip_u2u1s3(op)						\
{							\
	build_insn(buf, insn##op, b, a, c);		\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u2u1msbu3(op)					\
Ip_u2u1msbu3(op)					\
{							\
	build_insn(buf, insn##op, b, a, c+d-1, c);	\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u2u1msb32u3(op)				\
Ip_u2u1msbu3(op)					\
{							\
	build_insn(buf, insn##op, b, a, c+d-33, c);	\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u2u1msbdu3(op)				\
Ip_u2u1msbu3(op)					\
{							\
	build_insn(buf, insn##op, b, a, d-1, c);	\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u1u2(op)					\
Ip_u1u2(op)						\
{							\
	build_insn(buf, insn##op, a, b);		\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u1s2(op)					\
Ip_u1s2(op)						\
{							\
	build_insn(buf, insn##op, a, b);		\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_u1(op)					\
Ip_u1(op)						\
{							\
	build_insn(buf, insn##op, a);			\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

#define I_0(op)						\
Ip_0(op)						\
{							\
	build_insn(buf, insn##op);			\
}							\
UASM_EXPORT_SYMBOL(uasm_i##op);

I_u2u1s3(_addiu)
I_u3u1u2(_addu)
I_u2u1u3(_andi)
I_u3u1u2(_and)
I_u1u2s3(_beq)
I_u1u2s3(_beql)
I_u1s2(_bgez)
I_u1s2(_bgezl)
I_u1s2(_bltz)
I_u1s2(_bltzl)
I_u1u2s3(_bne)
I_u2s3u1(_cache)
I_u1u2u3(_dmfc0)
I_u1u2u3(_dmtc0)
I_u2u1s3(_daddiu)
I_u3u1u2(_daddu)
I_u2u1u3(_dsll)
I_u2u1u3(_dsll32)
I_u2u1u3(_dsra)
I_u2u1u3(_dsrl)
I_u2u1u3(_dsrl32)
I_u2u1u3(_drotr)
I_u2u1u3(_drotr32)
I_u3u1u2(_dsubu)
I_0(_eret)
I_u2u1msbdu3(_ext)
I_u2u1msbu3(_ins)
I_u1(_j)
I_u1(_jal)
I_u1(_jr)
I_u2s3u1(_ld)
I_u2s3u1(_ll)
I_u2s3u1(_lld)
I_u1s2(_lui)
I_u2s3u1(_lw)
I_u1u2u3(_mfc0)
I_u1u2u3(_mtc0)
I_u2u1u3(_ori)
I_u3u1u2(_or)
I_0(_rfe)
I_u2s3u1(_sc)
I_u2s3u1(_scd)
I_u2s3u1(_sd)
I_u2u1u3(_sll)
I_u2u1u3(_sra)
I_u2u1u3(_srl)
I_u2u1u3(_rotr)
I_u3u1u2(_subu)
I_u2s3u1(_sw)
I_0(_tlbp)
I_0(_tlbr)
I_0(_tlbwi)
I_0(_tlbwr)
I_u3u1u2(_xor)
I_u2u1u3(_xori)
I_u2u1msbu3(_dins);
I_u2u1msb32u3(_dinsm);
I_u1(_syscall);
I_u1u2s3(_bbit0);
I_u1u2s3(_bbit1);
I_u3u1u2(_lwx)
I_u3u1u2(_ldx)

#ifdef CONFIG_CPU_CAVIUM_OCTEON
#include <asm/octeon/octeon.h>
void ISAFUNC(uasm_i_pref)(u32 **buf, unsigned int a, signed int b,
			    unsigned int c)
{
	if (OCTEON_IS_MODEL(OCTEON_CN63XX_PASS1_X) && a <= 24 && a != 5)
		/*
		 * As per erratum Core-14449, replace prefetches 0-4,
		 * 6-24 with 'pref 28'.
		 */
		build_insn(buf, insn_pref, c, 28, b);
	else
		build_insn(buf, insn_pref, c, a, b);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_i_pref));
#else
I_u2s3u1(_pref)
#endif

/* Handle labels. */
void ISAFUNC(uasm_build_label)(struct uasm_label **lab, u32 *addr, int lid)
{
	(*lab)->addr = addr;
	(*lab)->lab = lid;
	(*lab)++;
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_build_label));

int ISAFUNC(uasm_in_compat_space_p)(long addr)
{
	/* Is this address in 32bit compat space? */
#ifdef CONFIG_64BIT
	return (((addr) & 0xffffffff00000000L) == 0xffffffff00000000L);
#else
	return 1;
#endif
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_in_compat_space_p));

static int uasm_rel_highest(long val)
{
#ifdef CONFIG_64BIT
	return ((((val + 0x800080008000L) >> 48) & 0xffff) ^ 0x8000) - 0x8000;
#else
	return 0;
#endif
}

static int uasm_rel_higher(long val)
{
#ifdef CONFIG_64BIT
	return ((((val + 0x80008000L) >> 32) & 0xffff) ^ 0x8000) - 0x8000;
#else
	return 0;
#endif
}

int ISAFUNC(uasm_rel_hi)(long val)
{
	return ((((val + 0x8000L) >> 16) & 0xffff) ^ 0x8000) - 0x8000;
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_rel_hi));

int ISAFUNC(uasm_rel_lo)(long val)
{
	return ((val & 0xffff) ^ 0x8000) - 0x8000;
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_rel_lo));

void ISAFUNC(UASM_i_LA_mostly)(u32 **buf, unsigned int rs, long addr)
{
	if (!ISAFUNC(uasm_in_compat_space_p)(addr)) {
		ISAFUNC(uasm_i_lui)(buf, rs, uasm_rel_highest(addr));
		if (uasm_rel_higher(addr))
			ISAFUNC(uasm_i_daddiu)(buf, rs, rs, uasm_rel_higher(addr));
		if (ISAFUNC(uasm_rel_hi(addr))) {
			ISAFUNC(uasm_i_dsll)(buf, rs, rs, 16);
			ISAFUNC(uasm_i_daddiu)(buf, rs, rs,
					ISAFUNC(uasm_rel_hi)(addr));
			ISAFUNC(uasm_i_dsll)(buf, rs, rs, 16);
		} else
			ISAFUNC(uasm_i_dsll32)(buf, rs, rs, 0);
	} else
		ISAFUNC(uasm_i_lui)(buf, rs, ISAFUNC(uasm_rel_hi(addr)));
}
UASM_EXPORT_SYMBOL(ISAFUNC(UASM_i_LA_mostly));

void ISAFUNC(UASM_i_LA)(u32 **buf, unsigned int rs, long addr)
{
	ISAFUNC(UASM_i_LA_mostly)(buf, rs, addr);
	if (ISAFUNC(uasm_rel_lo(addr))) {
		if (!ISAFUNC(uasm_in_compat_space_p)(addr))
			ISAFUNC(uasm_i_daddiu)(buf, rs, rs,
					ISAFUNC(uasm_rel_lo(addr)));
		else
			ISAFUNC(uasm_i_addiu)(buf, rs, rs,
					ISAFUNC(uasm_rel_lo(addr)));
	}
}
UASM_EXPORT_SYMBOL(ISAFUNC(UASM_i_LA));

/* Handle relocations. */
void ISAFUNC(uasm_r_mips_pc16)(struct uasm_reloc **rel, u32 *addr, int lid)
{
	(*rel)->addr = addr;
	(*rel)->type = R_MIPS_PC16;
	(*rel)->lab = lid;
	(*rel)++;
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_r_mips_pc16));

static inline void __resolve_relocs(struct uasm_reloc *rel,
				    struct uasm_label *lab);

void ISAFUNC(uasm_resolve_relocs)(struct uasm_reloc *rel,
				  struct uasm_label *lab)
{
	struct uasm_label *l;

	for (; rel->lab != UASM_LABEL_INVALID; rel++)
		for (l = lab; l->lab != UASM_LABEL_INVALID; l++)
			if (rel->lab == l->lab)
				__resolve_relocs(rel, l);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_resolve_relocs));

void ISAFUNC(uasm_move_relocs)(struct uasm_reloc *rel, u32 *first, u32 *end,
			       long off)
{
	for (; rel->lab != UASM_LABEL_INVALID; rel++)
		if (rel->addr >= first && rel->addr < end)
			rel->addr += off;
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_move_relocs));

void ISAFUNC(uasm_move_labels)(struct uasm_label *lab, u32 *first, u32 *end,
			       long off)
{
	for (; lab->lab != UASM_LABEL_INVALID; lab++)
		if (lab->addr >= first && lab->addr < end)
			lab->addr += off;
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_move_labels));

void ISAFUNC(uasm_copy_handler)(struct uasm_reloc *rel, struct uasm_label *lab,
				u32 *first, u32 *end, u32 *target)
{
	long off = (long)(target - first);

	memcpy(target, first, (end - first) * sizeof(u32));

	ISAFUNC(uasm_move_relocs(rel, first, end, off));
	ISAFUNC(uasm_move_labels(lab, first, end, off));
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_copy_handler));

int ISAFUNC(uasm_insn_has_bdelay)(struct uasm_reloc *rel, u32 *addr)
{
	for (; rel->lab != UASM_LABEL_INVALID; rel++) {
		if (rel->addr == addr
		    && (rel->type == R_MIPS_PC16
			|| rel->type == R_MIPS_26))
			return 1;
	}

	return 0;
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_insn_has_bdelay));

/* Convenience functions for labeled branches. */
void ISAFUNC(uasm_il_bltz)(u32 **p, struct uasm_reloc **r, unsigned int reg,
			   int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_bltz)(p, reg, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_bltz));

void ISAFUNC(uasm_il_b)(u32 **p, struct uasm_reloc **r, int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_b)(p, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_b));

void ISAFUNC(uasm_il_beqz)(u32 **p, struct uasm_reloc **r, unsigned int reg,
			   int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_beqz)(p, reg, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_beqz));

void ISAFUNC(uasm_il_beqzl)(u32 **p, struct uasm_reloc **r, unsigned int reg,
			    int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_beqzl)(p, reg, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_beqzl));

void ISAFUNC(uasm_il_bne)(u32 **p, struct uasm_reloc **r, unsigned int reg1,
			  unsigned int reg2, int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_bne)(p, reg1, reg2, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_bne));

void ISAFUNC(uasm_il_bnez)(u32 **p, struct uasm_reloc **r, unsigned int reg,
			   int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_bnez)(p, reg, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_bnez));

void ISAFUNC(uasm_il_bgezl)(u32 **p, struct uasm_reloc **r, unsigned int reg,
			    int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_bgezl)(p, reg, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_bgezl));

void ISAFUNC(uasm_il_bgez)(u32 **p, struct uasm_reloc **r, unsigned int reg,
			   int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_bgez)(p, reg, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_bgez));

void ISAFUNC(uasm_il_bbit0)(u32 **p, struct uasm_reloc **r, unsigned int reg,
			    unsigned int bit, int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_bbit0)(p, reg, bit, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_bbit0));

void ISAFUNC(uasm_il_bbit1)(u32 **p, struct uasm_reloc **r, unsigned int reg,
			    unsigned int bit, int lid)
{
	uasm_r_mips_pc16(r, *p, lid);
	ISAFUNC(uasm_i_bbit1)(p, reg, bit, 0);
}
UASM_EXPORT_SYMBOL(ISAFUNC(uasm_il_bbit1));