/*
 * 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.
 */

#include <linux/kernel.h>
#include <linux/types.h>

#include <asm/inst.h>
#include <asm/elf.h>
#include <asm/bugs.h>
#define UASM_ISA        _UASM_ISA_CLASSIC
#include <asm/uasm.h>

#define RS_MASK         0x1f
#define RS_SH           21
#define RT_MASK         0x1f
#define RT_SH           16
#define SCIMM_MASK      0xfffff
#define SCIMM_SH        6

/* This macro sets the non-variable bits of an instruction. */
#define M(a, b, c, d, e, f)                                     \
        ((a) << OP_SH                                           \
         | (b) << RS_SH                                         \
         | (c) << RT_SH                                         \
         | (d) << RD_SH                                         \
         | (e) << RE_SH                                         \
         | (f) << FUNC_SH)

/* This macro sets the non-variable bits of an R6 instruction. */
#define M6(a, b, c, d, e)                                       \
        ((a) << OP_SH                                           \
         | (b) << RS_SH                                         \
         | (c) << RT_SH                                         \
         | (d) << SIMM9_SH                                      \
         | (e) << FUNC_SH)

#include "uasm.c"

static const struct insn insn_table[insn_invalid] = {
        [insn_addiu]    = {M(addiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
        [insn_addu]     = {M(spec_op, 0, 0, 0, 0, addu_op), RS | RT | RD},
        [insn_and]      = {M(spec_op, 0, 0, 0, 0, and_op), RS | RT | RD},
        [insn_andi]     = {M(andi_op, 0, 0, 0, 0, 0), RS | RT | UIMM},
        [insn_bbit0]    = {M(lwc2_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
        [insn_bbit1]    = {M(swc2_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
        [insn_beq]      = {M(beq_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
        [insn_beql]     = {M(beql_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
        [insn_bgez]     = {M(bcond_op, 0, bgez_op, 0, 0, 0), RS | BIMM},
        [insn_bgezl]    = {M(bcond_op, 0, bgezl_op, 0, 0, 0), RS | BIMM},
        [insn_bgtz]     = {M(bgtz_op, 0, 0, 0, 0, 0), RS | BIMM},
        [insn_blez]     = {M(blez_op, 0, 0, 0, 0, 0), RS | BIMM},
        [insn_bltz]     = {M(bcond_op, 0, bltz_op, 0, 0, 0), RS | BIMM},
        [insn_bltzl]    = {M(bcond_op, 0, bltzl_op, 0, 0, 0), RS | BIMM},
        [insn_bne]      = {M(bne_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
        [insn_break]    = {M(spec_op, 0, 0, 0, 0, break_op), SCIMM},
#ifndef CONFIG_CPU_MIPSR6
        [insn_cache]    = {M(cache_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
#else
        [insn_cache]    = {M6(spec3_op, 0, 0, 0, cache6_op),  RS | RT | SIMM9},
#endif
        [insn_cfc1]     = {M(cop1_op, cfc_op, 0, 0, 0, 0), RT | RD},
        [insn_cfcmsa]   = {M(msa_op, 0, msa_cfc_op, 0, 0, msa_elm_op), RD | RE},
        [insn_ctc1]     = {M(cop1_op, ctc_op, 0, 0, 0, 0), RT | RD},
        [insn_ctcmsa]   = {M(msa_op, 0, msa_ctc_op, 0, 0, msa_elm_op), RD | RE},
        [insn_daddiu]   = {M(daddiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
        [insn_daddu]    = {M(spec_op, 0, 0, 0, 0, daddu_op), RS | RT | RD},
        [insn_ddivu]    = {M(spec_op, 0, 0, 0, 0, ddivu_op), RS | RT},
        [insn_di]       = {M(cop0_op, mfmc0_op, 0, 12, 0, 0), RT},
        [insn_dins]     = {M(spec3_op, 0, 0, 0, 0, dins_op), RS | RT | RD | RE},
        [insn_dinsm]    = {M(spec3_op, 0, 0, 0, 0, dinsm_op), RS | RT | RD | RE},
        [insn_dinsu]    = {M(spec3_op, 0, 0, 0, 0, dinsu_op), RS | RT | RD | RE},
        [insn_divu]     = {M(spec_op, 0, 0, 0, 0, divu_op), RS | RT},
        [insn_dmfc0]    = {M(cop0_op, dmfc_op, 0, 0, 0, 0), RT | RD | SET},
        [insn_dmtc0]    = {M(cop0_op, dmtc_op, 0, 0, 0, 0), RT | RD | SET},
        [insn_dmultu]   = {M(spec_op, 0, 0, 0, 0, dmultu_op), RS | RT},
        [insn_drotr]    = {M(spec_op, 1, 0, 0, 0, dsrl_op), RT | RD | RE},
        [insn_drotr32]  = {M(spec_op, 1, 0, 0, 0, dsrl32_op), RT | RD | RE},
        [insn_dsbh]     = {M(spec3_op, 0, 0, 0, dsbh_op, dbshfl_op), RT | RD},
        [insn_dshd]     = {M(spec3_op, 0, 0, 0, dshd_op, dbshfl_op), RT | RD},
        [insn_dsll]     = {M(spec_op, 0, 0, 0, 0, dsll_op), RT | RD | RE},
        [insn_dsll32]   = {M(spec_op, 0, 0, 0, 0, dsll32_op), RT | RD | RE},
        [insn_dsllv]    = {M(spec_op, 0, 0, 0, 0, dsllv_op),  RS | RT | RD},
        [insn_dsra]     = {M(spec_op, 0, 0, 0, 0, dsra_op), RT | RD | RE},
        [insn_dsra32]   = {M(spec_op, 0, 0, 0, 0, dsra32_op), RT | RD | RE},
        [insn_dsrav]    = {M(spec_op, 0, 0, 0, 0, dsrav_op),  RS | RT | RD},
        [insn_dsrl]     = {M(spec_op, 0, 0, 0, 0, dsrl_op), RT | RD | RE},
        [insn_dsrl32]   = {M(spec_op, 0, 0, 0, 0, dsrl32_op), RT | RD | RE},
        [insn_dsrlv]    = {M(spec_op, 0, 0, 0, 0, dsrlv_op),  RS | RT | RD},
        [insn_dsubu]    = {M(spec_op, 0, 0, 0, 0, dsubu_op), RS | RT | RD},
        [insn_eret]     = {M(cop0_op, cop_op, 0, 0, 0, eret_op),  0},
        [insn_ext]      = {M(spec3_op, 0, 0, 0, 0, ext_op), RS | RT | RD | RE},
        [insn_ins]      = {M(spec3_op, 0, 0, 0, 0, ins_op), RS | RT | RD | RE},
        [insn_j]        = {M(j_op, 0, 0, 0, 0, 0),  JIMM},
        [insn_jal]      = {M(jal_op, 0, 0, 0, 0, 0),    JIMM},
        [insn_jalr]     = {M(spec_op, 0, 0, 0, 0, jalr_op), RS | RD},
#ifndef CONFIG_CPU_MIPSR6
        [insn_jr]       = {M(spec_op, 0, 0, 0, 0, jr_op),  RS},
#else
        [insn_jr]       = {M(spec_op, 0, 0, 0, 0, jalr_op),  RS},
#endif
        [insn_lb]       = {M(lb_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
        [insn_lbu]      = {M(lbu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
        [insn_ld]       = {M(ld_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_lddir]    = {M(lwc2_op, 0, 0, 0, lddir_op, mult_op), RS | RT | RD},
        [insn_ldpte]    = {M(lwc2_op, 0, 0, 0, ldpte_op, mult_op), RS | RD},
        [insn_ldx]      = {M(spec3_op, 0, 0, 0, ldx_op, lx_op), RS | RT | RD},
        [insn_lh]       = {M(lh_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_lhu]      = {M(lhu_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
#ifndef CONFIG_CPU_MIPSR6
        [insn_ll]       = {M(ll_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_lld]      = {M(lld_op, 0, 0, 0, 0, 0),    RS | RT | SIMM},
#else
        [insn_ll]       = {M6(spec3_op, 0, 0, 0, ll6_op),  RS | RT | SIMM9},
        [insn_lld]      = {M6(spec3_op, 0, 0, 0, lld6_op),  RS | RT | SIMM9},
#endif
        [insn_lui]      = {M(lui_op, 0, 0, 0, 0, 0),    RT | SIMM},
        [insn_lw]       = {M(lw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_lwu]      = {M(lwu_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_lwx]      = {M(spec3_op, 0, 0, 0, lwx_op, lx_op), RS | RT | RD},
        [insn_mfc0]     = {M(cop0_op, mfc_op, 0, 0, 0, 0),  RT | RD | SET},
        [insn_mfhc0]    = {M(cop0_op, mfhc0_op, 0, 0, 0, 0),  RT | RD | SET},
        [insn_mfhi]     = {M(spec_op, 0, 0, 0, 0, mfhi_op), RD},
        [insn_mflo]     = {M(spec_op, 0, 0, 0, 0, mflo_op), RD},
        [insn_movn]     = {M(spec_op, 0, 0, 0, 0, movn_op), RS | RT | RD},
        [insn_movz]     = {M(spec_op, 0, 0, 0, 0, movz_op), RS | RT | RD},
        [insn_mtc0]     = {M(cop0_op, mtc_op, 0, 0, 0, 0),  RT | RD | SET},
        [insn_mthc0]    = {M(cop0_op, mthc0_op, 0, 0, 0, 0),  RT | RD | SET},
        [insn_mthi]     = {M(spec_op, 0, 0, 0, 0, mthi_op), RS},
        [insn_mtlo]     = {M(spec_op, 0, 0, 0, 0, mtlo_op), RS},
#ifndef CONFIG_CPU_MIPSR6
        [insn_mul]      = {M(spec2_op, 0, 0, 0, 0, mul_op), RS | RT | RD},
#else
        [insn_mul]      = {M(spec_op, 0, 0, 0, mult_mul_op, mult_op), RS | RT | RD},
#endif
        [insn_multu]    = {M(spec_op, 0, 0, 0, 0, multu_op), RS | RT},
        [insn_nor]      = {M(spec_op, 0, 0, 0, 0, nor_op),  RS | RT | RD},
        [insn_or]       = {M(spec_op, 0, 0, 0, 0, or_op),  RS | RT | RD},
        [insn_ori]      = {M(ori_op, 0, 0, 0, 0, 0),    RS | RT | UIMM},
#ifndef CONFIG_CPU_MIPSR6
        [insn_pref]     = {M(pref_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
#else
        [insn_pref]     = {M6(spec3_op, 0, 0, 0, pref6_op),  RS | RT | SIMM9},
#endif
        [insn_rfe]      = {M(cop0_op, cop_op, 0, 0, 0, rfe_op),  0},
        [insn_rotr]     = {M(spec_op, 1, 0, 0, 0, srl_op),  RT | RD | RE},
        [insn_sb]       = {M(sb_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
#ifndef CONFIG_CPU_MIPSR6
        [insn_sc]       = {M(sc_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_scd]      = {M(scd_op, 0, 0, 0, 0, 0),    RS | RT | SIMM},
#else
        [insn_sc]       = {M6(spec3_op, 0, 0, 0, sc6_op),  RS | RT | SIMM9},
        [insn_scd]      = {M6(spec3_op, 0, 0, 0, scd6_op),  RS | RT | SIMM9},
#endif
        [insn_sd]       = {M(sd_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_sh]       = {M(sh_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_sll]      = {M(spec_op, 0, 0, 0, 0, sll_op),  RT | RD | RE},
        [insn_sllv]     = {M(spec_op, 0, 0, 0, 0, sllv_op),  RS | RT | RD},
        [insn_slt]      = {M(spec_op, 0, 0, 0, 0, slt_op),  RS | RT | RD},
        [insn_slti]     = {M(slti_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
        [insn_sltiu]    = {M(sltiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
        [insn_sltu]     = {M(spec_op, 0, 0, 0, 0, sltu_op), RS | RT | RD},
        [insn_sra]      = {M(spec_op, 0, 0, 0, 0, sra_op),  RT | RD | RE},
        [insn_srl]      = {M(spec_op, 0, 0, 0, 0, srl_op),  RT | RD | RE},
        [insn_srlv]     = {M(spec_op, 0, 0, 0, 0, srlv_op),  RS | RT | RD},
        [insn_subu]     = {M(spec_op, 0, 0, 0, 0, subu_op),     RS | RT | RD},
        [insn_sw]       = {M(sw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
        [insn_sync]     = {M(spec_op, 0, 0, 0, 0, sync_op), RE},
        [insn_syscall]  = {M(spec_op, 0, 0, 0, 0, syscall_op), SCIMM},
        [insn_tlbp]     = {M(cop0_op, cop_op, 0, 0, 0, tlbp_op),  0},
        [insn_tlbr]     = {M(cop0_op, cop_op, 0, 0, 0, tlbr_op),  0},
        [insn_tlbwi]    = {M(cop0_op, cop_op, 0, 0, 0, tlbwi_op),  0},
        [insn_tlbwr]    = {M(cop0_op, cop_op, 0, 0, 0, tlbwr_op),  0},
        [insn_wait]     = {M(cop0_op, cop_op, 0, 0, 0, wait_op), SCIMM},
        [insn_wsbh]     = {M(spec3_op, 0, 0, 0, wsbh_op, bshfl_op), RT | RD},
        [insn_xor]      = {M(spec_op, 0, 0, 0, 0, xor_op),  RS | RT | RD},
        [insn_xori]     = {M(xori_op, 0, 0, 0, 0, 0),  RS | RT | UIMM},
        [insn_yield]    = {M(spec3_op, 0, 0, 0, 0, yield_op), RS | RD},
};

#undef M

static inline u32 build_bimm(s32 arg)
{
        WARN(arg > 0x1ffff || arg < -0x20000,
             KERN_WARNING "Micro-assembler field overflow\n");

        WARN(arg & 0x3, KERN_WARNING "Invalid micro-assembler branch target\n");

        return ((arg < 0) ? (1 << 15) : 0) | ((arg >> 2) & 0x7fff);
}

static inline u32 build_jimm(u32 arg)
{
        WARN(arg & ~(JIMM_MASK << 2),
             KERN_WARNING "Micro-assembler field overflow\n");

        return (arg >> 2) & JIMM_MASK;
}

/*
 * The order of opcode arguments is implicitly left to right,
 * starting with RS and ending with FUNC or IMM.
 */
static void build_insn(u32 **buf, enum opcode opc, ...)
{
        const struct insn *ip;
        va_list ap;
        u32 op;

        if (opc < 0 || opc >= insn_invalid ||
            (opc == insn_daddiu && r4k_daddiu_bug()) ||
            (insn_table[opc].match == 0 && insn_table[opc].fields == 0))
                panic("Unsupported Micro-assembler instruction %d", opc);

        ip = &insn_table[opc];

        op = ip->match;
        va_start(ap, opc);
        if (ip->fields & RS)
                op |= build_rs(va_arg(ap, u32));
        if (ip->fields & RT)
                op |= build_rt(va_arg(ap, u32));
        if (ip->fields & RD)
                op |= build_rd(va_arg(ap, u32));
        if (ip->fields & RE)
                op |= build_re(va_arg(ap, u32));
        if (ip->fields & SIMM)
                op |= build_simm(va_arg(ap, s32));
        if (ip->fields & UIMM)
                op |= build_uimm(va_arg(ap, u32));
        if (ip->fields & BIMM)
                op |= build_bimm(va_arg(ap, s32));
        if (ip->fields & JIMM)
                op |= build_jimm(va_arg(ap, u32));
        if (ip->fields & FUNC)
                op |= build_func(va_arg(ap, u32));
        if (ip->fields & SET)
                op |= build_set(va_arg(ap, u32));
        if (ip->fields & SCIMM)
                op |= build_scimm(va_arg(ap, u32));
        if (ip->fields & SIMM9)
                op |= build_scimm9(va_arg(ap, u32));
        va_end(ap);

        **buf = op;
        (*buf)++;
}

static inline void
__resolve_relocs(struct uasm_reloc *rel, struct uasm_label *lab)
{
        long laddr = (long)lab->addr;
        long raddr = (long)rel->addr;

        switch (rel->type) {
        case R_MIPS_PC16:
                *rel->addr |= build_bimm(laddr - (raddr + 4));
                break;

        default:
                panic("Unsupported Micro-assembler relocation %d",
                      rel->type);
        }
}