linux/arch/mips/mm/uasm-micromips.c
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   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * A small micro-assembler. It is intentionally kept simple, does only
   7 * support a subset of instructions, and does not try to hide pipeline
   8 * effects like branch delay slots.
   9 *
  10 * Copyright (C) 2004, 2005, 2006, 2008  Thiemo Seufer
  11 * Copyright (C) 2005, 2007  Maciej W. Rozycki
  12 * Copyright (C) 2006  Ralf Baechle (ralf@linux-mips.org)
  13 * Copyright (C) 2012, 2013   MIPS Technologies, Inc.  All rights reserved.
  14 */
  15
  16#include <linux/kernel.h>
  17#include <linux/types.h>
  18
  19#include <asm/inst.h>
  20#include <asm/elf.h>
  21#include <asm/bugs.h>
  22#define UASM_ISA        _UASM_ISA_MICROMIPS
  23#include <asm/uasm.h>
  24
  25#define RS_MASK         0x1f
  26#define RS_SH           16
  27#define RT_MASK         0x1f
  28#define RT_SH           21
  29#define SCIMM_MASK      0x3ff
  30#define SCIMM_SH        16
  31
  32/* This macro sets the non-variable bits of an instruction. */
  33#define M(a, b, c, d, e, f)                                     \
  34        ((a) << OP_SH                                           \
  35         | (b) << RT_SH                                         \
  36         | (c) << RS_SH                                         \
  37         | (d) << RD_SH                                         \
  38         | (e) << RE_SH                                         \
  39         | (f) << FUNC_SH)
  40
  41/* Define these when we are not the ISA the kernel is being compiled with. */
  42#ifndef CONFIG_CPU_MICROMIPS
  43#define MM_uasm_i_b(buf, off) ISAOPC(_beq)(buf, 0, 0, off)
  44#define MM_uasm_i_beqz(buf, rs, off) ISAOPC(_beq)(buf, rs, 0, off)
  45#define MM_uasm_i_beqzl(buf, rs, off) ISAOPC(_beql)(buf, rs, 0, off)
  46#define MM_uasm_i_bnez(buf, rs, off) ISAOPC(_bne)(buf, rs, 0, off)
  47#endif
  48
  49#include "uasm.c"
  50
  51static struct insn insn_table_MM[] = {
  52        { insn_addu, M(mm_pool32a_op, 0, 0, 0, 0, mm_addu32_op), RT | RS | RD },
  53        { insn_addiu, M(mm_addiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
  54        { insn_and, M(mm_pool32a_op, 0, 0, 0, 0, mm_and_op), RT | RS | RD },
  55        { insn_andi, M(mm_andi32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
  56        { insn_beq, M(mm_beq32_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
  57        { insn_beql, 0, 0 },
  58        { insn_bgez, M(mm_pool32i_op, mm_bgez_op, 0, 0, 0, 0), RS | BIMM },
  59        { insn_bgezl, 0, 0 },
  60        { insn_bltz, M(mm_pool32i_op, mm_bltz_op, 0, 0, 0, 0), RS | BIMM },
  61        { insn_bltzl, 0, 0 },
  62        { insn_bne, M(mm_bne32_op, 0, 0, 0, 0, 0), RT | RS | BIMM },
  63        { insn_cache, M(mm_pool32b_op, 0, 0, mm_cache_func, 0, 0), RT | RS | SIMM },
  64        { insn_daddu, 0, 0 },
  65        { insn_daddiu, 0, 0 },
  66        { insn_dmfc0, 0, 0 },
  67        { insn_dmtc0, 0, 0 },
  68        { insn_dsll, 0, 0 },
  69        { insn_dsll32, 0, 0 },
  70        { insn_dsra, 0, 0 },
  71        { insn_dsrl, 0, 0 },
  72        { insn_dsrl32, 0, 0 },
  73        { insn_drotr, 0, 0 },
  74        { insn_drotr32, 0, 0 },
  75        { insn_dsubu, 0, 0 },
  76        { insn_eret, M(mm_pool32a_op, 0, 0, 0, mm_eret_op, mm_pool32axf_op), 0 },
  77        { insn_ins, M(mm_pool32a_op, 0, 0, 0, 0, mm_ins_op), RT | RS | RD | RE },
  78        { insn_ext, M(mm_pool32a_op, 0, 0, 0, 0, mm_ext_op), RT | RS | RD | RE },
  79        { insn_j, M(mm_j32_op, 0, 0, 0, 0, 0), JIMM },
  80        { insn_jal, M(mm_jal32_op, 0, 0, 0, 0, 0), JIMM },
  81        { insn_jr, M(mm_pool32a_op, 0, 0, 0, mm_jalr_op, mm_pool32axf_op), RS },
  82        { insn_ld, 0, 0 },
  83        { insn_ll, M(mm_pool32c_op, 0, 0, (mm_ll_func << 1), 0, 0), RS | RT | SIMM },
  84        { insn_lld, 0, 0 },
  85        { insn_lui, M(mm_pool32i_op, mm_lui_op, 0, 0, 0, 0), RS | SIMM },
  86        { insn_lw, M(mm_lw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
  87        { insn_mfc0, M(mm_pool32a_op, 0, 0, 0, mm_mfc0_op, mm_pool32axf_op), RT | RS | RD },
  88        { insn_mtc0, M(mm_pool32a_op, 0, 0, 0, mm_mtc0_op, mm_pool32axf_op), RT | RS | RD },
  89        { insn_or, M(mm_pool32a_op, 0, 0, 0, 0, mm_or32_op), RT | RS | RD },
  90        { insn_ori, M(mm_ori32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
  91        { insn_pref, M(mm_pool32c_op, 0, 0, (mm_pref_func << 1), 0, 0), RT | RS | SIMM },
  92        { insn_rfe, 0, 0 },
  93        { insn_sc, M(mm_pool32c_op, 0, 0, (mm_sc_func << 1), 0, 0), RT | RS | SIMM },
  94        { insn_scd, 0, 0 },
  95        { insn_sd, 0, 0 },
  96        { insn_sll, M(mm_pool32a_op, 0, 0, 0, 0, mm_sll32_op), RT | RS | RD },
  97        { insn_sra, M(mm_pool32a_op, 0, 0, 0, 0, mm_sra_op), RT | RS | RD },
  98        { insn_srl, M(mm_pool32a_op, 0, 0, 0, 0, mm_srl32_op), RT | RS | RD },
  99        { insn_rotr, M(mm_pool32a_op, 0, 0, 0, 0, mm_rotr_op), RT | RS | RD },
 100        { insn_subu, M(mm_pool32a_op, 0, 0, 0, 0, mm_subu32_op), RT | RS | RD },
 101        { insn_sw, M(mm_sw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
 102        { insn_tlbp, M(mm_pool32a_op, 0, 0, 0, mm_tlbp_op, mm_pool32axf_op), 0 },
 103        { insn_tlbr, M(mm_pool32a_op, 0, 0, 0, mm_tlbr_op, mm_pool32axf_op), 0 },
 104        { insn_tlbwi, M(mm_pool32a_op, 0, 0, 0, mm_tlbwi_op, mm_pool32axf_op), 0 },
 105        { insn_tlbwr, M(mm_pool32a_op, 0, 0, 0, mm_tlbwr_op, mm_pool32axf_op), 0 },
 106        { insn_xor, M(mm_pool32a_op, 0, 0, 0, 0, mm_xor32_op), RT | RS | RD },
 107        { insn_xori, M(mm_xori32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
 108        { insn_dins, 0, 0 },
 109        { insn_dinsm, 0, 0 },
 110        { insn_syscall, M(mm_pool32a_op, 0, 0, 0, mm_syscall_op, mm_pool32axf_op), SCIMM},
 111        { insn_bbit0, 0, 0 },
 112        { insn_bbit1, 0, 0 },
 113        { insn_lwx, 0, 0 },
 114        { insn_ldx, 0, 0 },
 115        { insn_invalid, 0, 0 }
 116};
 117
 118#undef M
 119
 120static inline u32 build_bimm(s32 arg)
 121{
 122        WARN(arg > 0xffff || arg < -0x10000,
 123             KERN_WARNING "Micro-assembler field overflow\n");
 124
 125        WARN(arg & 0x3, KERN_WARNING "Invalid micro-assembler branch target\n");
 126
 127        return ((arg < 0) ? (1 << 15) : 0) | ((arg >> 1) & 0x7fff);
 128}
 129
 130static inline u32 build_jimm(u32 arg)
 131{
 132
 133        WARN(arg & ~((JIMM_MASK << 2) | 1),
 134             KERN_WARNING "Micro-assembler field overflow\n");
 135
 136        return (arg >> 1) & JIMM_MASK;
 137}
 138
 139/*
 140 * The order of opcode arguments is implicitly left to right,
 141 * starting with RS and ending with FUNC or IMM.
 142 */
 143static void build_insn(u32 **buf, enum opcode opc, ...)
 144{
 145        struct insn *ip = NULL;
 146        unsigned int i;
 147        va_list ap;
 148        u32 op;
 149
 150        for (i = 0; insn_table_MM[i].opcode != insn_invalid; i++)
 151                if (insn_table_MM[i].opcode == opc) {
 152                        ip = &insn_table_MM[i];
 153                        break;
 154                }
 155
 156        if (!ip || (opc == insn_daddiu && r4k_daddiu_bug()))
 157                panic("Unsupported Micro-assembler instruction %d", opc);
 158
 159        op = ip->match;
 160        va_start(ap, opc);
 161        if (ip->fields & RS) {
 162                if (opc == insn_mfc0 || opc == insn_mtc0)
 163                        op |= build_rt(va_arg(ap, u32));
 164                else
 165                        op |= build_rs(va_arg(ap, u32));
 166        }
 167        if (ip->fields & RT) {
 168                if (opc == insn_mfc0 || opc == insn_mtc0)
 169                        op |= build_rs(va_arg(ap, u32));
 170                else
 171                        op |= build_rt(va_arg(ap, u32));
 172        }
 173        if (ip->fields & RD)
 174                op |= build_rd(va_arg(ap, u32));
 175        if (ip->fields & RE)
 176                op |= build_re(va_arg(ap, u32));
 177        if (ip->fields & SIMM)
 178                op |= build_simm(va_arg(ap, s32));
 179        if (ip->fields & UIMM)
 180                op |= build_uimm(va_arg(ap, u32));
 181        if (ip->fields & BIMM)
 182                op |= build_bimm(va_arg(ap, s32));
 183        if (ip->fields & JIMM)
 184                op |= build_jimm(va_arg(ap, u32));
 185        if (ip->fields & FUNC)
 186                op |= build_func(va_arg(ap, u32));
 187        if (ip->fields & SET)
 188                op |= build_set(va_arg(ap, u32));
 189        if (ip->fields & SCIMM)
 190                op |= build_scimm(va_arg(ap, u32));
 191        va_end(ap);
 192
 193#ifdef CONFIG_CPU_LITTLE_ENDIAN
 194        **buf = ((op & 0xffff) << 16) | (op >> 16);
 195#else
 196        **buf = op;
 197#endif
 198        (*buf)++;
 199}
 200
 201static inline void
 202__resolve_relocs(struct uasm_reloc *rel, struct uasm_label *lab)
 203{
 204        long laddr = (long)lab->addr;
 205        long raddr = (long)rel->addr;
 206
 207        switch (rel->type) {
 208        case R_MIPS_PC16:
 209#ifdef CONFIG_CPU_LITTLE_ENDIAN
 210                *rel->addr |= (build_bimm(laddr - (raddr + 4)) << 16);
 211#else
 212                *rel->addr |= build_bimm(laddr - (raddr + 4));
 213#endif
 214                break;
 215
 216        default:
 217                panic("Unsupported Micro-assembler relocation %d",
 218                      rel->type);
 219        }
 220}
 221