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#include <linux/init.h>
  19
  20#include <asm/inst.h>
  21#include <asm/elf.h>
  22#include <asm/bugs.h>
  23#define UASM_ISA        _UASM_ISA_MICROMIPS
  24#include <asm/uasm.h>
  25
  26#define RS_MASK         0x1f
  27#define RS_SH           16
  28#define RT_MASK         0x1f
  29#define RT_SH           21
  30#define SCIMM_MASK      0x3ff
  31#define SCIMM_SH        16
  32
  33/* This macro sets the non-variable bits of an instruction. */
  34#define M(a, b, c, d, e, f)                                     \
  35        ((a) << OP_SH                                           \
  36         | (b) << RT_SH                                         \
  37         | (c) << RS_SH                                         \
  38         | (d) << RD_SH                                         \
  39         | (e) << RE_SH                                         \
  40         | (f) << FUNC_SH)
  41
  42/* Define these when we are not the ISA the kernel is being compiled with. */
  43#ifndef CONFIG_CPU_MICROMIPS
  44#define MM_uasm_i_b(buf, off) ISAOPC(_beq)(buf, 0, 0, off)
  45#define MM_uasm_i_beqz(buf, rs, off) ISAOPC(_beq)(buf, rs, 0, off)
  46#define MM_uasm_i_beqzl(buf, rs, off) ISAOPC(_beql)(buf, rs, 0, off)
  47#define MM_uasm_i_bnez(buf, rs, off) ISAOPC(_bne)(buf, rs, 0, off)
  48#endif
  49
  50#include "uasm.c"
  51
  52static struct insn insn_table_MM[] = {
  53        { insn_addu, M(mm_pool32a_op, 0, 0, 0, 0, mm_addu32_op), RT | RS | RD },
  54        { insn_addiu, M(mm_addiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
  55        { insn_and, M(mm_pool32a_op, 0, 0, 0, 0, mm_and_op), RT | RS | RD },
  56        { insn_andi, M(mm_andi32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
  57        { insn_beq, M(mm_beq32_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
  58        { insn_beql, 0, 0 },
  59        { insn_bgez, M(mm_pool32i_op, mm_bgez_op, 0, 0, 0, 0), RS | BIMM },
  60        { insn_bgezl, 0, 0 },
  61        { insn_bltz, M(mm_pool32i_op, mm_bltz_op, 0, 0, 0, 0), RS | BIMM },
  62        { insn_bltzl, 0, 0 },
  63        { insn_bne, M(mm_bne32_op, 0, 0, 0, 0, 0), RT | RS | BIMM },
  64        { insn_cache, M(mm_pool32b_op, 0, 0, mm_cache_func, 0, 0), RT | RS | SIMM },
  65        { insn_daddu, 0, 0 },
  66        { insn_daddiu, 0, 0 },
  67        { insn_dmfc0, 0, 0 },
  68        { insn_dmtc0, 0, 0 },
  69        { insn_dsll, 0, 0 },
  70        { insn_dsll32, 0, 0 },
  71        { insn_dsra, 0, 0 },
  72        { insn_dsrl, 0, 0 },
  73        { insn_dsrl32, 0, 0 },
  74        { insn_drotr, 0, 0 },
  75        { insn_drotr32, 0, 0 },
  76        { insn_dsubu, 0, 0 },
  77        { insn_eret, M(mm_pool32a_op, 0, 0, 0, mm_eret_op, mm_pool32axf_op), 0 },
  78        { insn_ins, M(mm_pool32a_op, 0, 0, 0, 0, mm_ins_op), RT | RS | RD | RE },
  79        { insn_ext, M(mm_pool32a_op, 0, 0, 0, 0, mm_ext_op), RT | RS | RD | RE },
  80        { insn_j, M(mm_j32_op, 0, 0, 0, 0, 0), JIMM },
  81        { insn_jal, M(mm_jal32_op, 0, 0, 0, 0, 0), JIMM },
  82        { insn_jr, M(mm_pool32a_op, 0, 0, 0, mm_jalr_op, mm_pool32axf_op), RS },
  83        { insn_ld, 0, 0 },
  84        { insn_ll, M(mm_pool32c_op, 0, 0, (mm_ll_func << 1), 0, 0), RS | RT | SIMM },
  85        { insn_lld, 0, 0 },
  86        { insn_lui, M(mm_pool32i_op, mm_lui_op, 0, 0, 0, 0), RS | SIMM },
  87        { insn_lw, M(mm_lw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
  88        { insn_mfc0, M(mm_pool32a_op, 0, 0, 0, mm_mfc0_op, mm_pool32axf_op), RT | RS | RD },
  89        { insn_mtc0, M(mm_pool32a_op, 0, 0, 0, mm_mtc0_op, mm_pool32axf_op), RT | RS | RD },
  90        { insn_or, M(mm_pool32a_op, 0, 0, 0, 0, mm_or32_op), RT | RS | RD },
  91        { insn_ori, M(mm_ori32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
  92        { insn_pref, M(mm_pool32c_op, 0, 0, (mm_pref_func << 1), 0, 0), RT | RS | SIMM },
  93        { insn_rfe, 0, 0 },
  94        { insn_sc, M(mm_pool32c_op, 0, 0, (mm_sc_func << 1), 0, 0), RT | RS | SIMM },
  95        { insn_scd, 0, 0 },
  96        { insn_sd, 0, 0 },
  97        { insn_sll, M(mm_pool32a_op, 0, 0, 0, 0, mm_sll32_op), RT | RS | RD },
  98        { insn_sra, M(mm_pool32a_op, 0, 0, 0, 0, mm_sra_op), RT | RS | RD },
  99        { insn_srl, M(mm_pool32a_op, 0, 0, 0, 0, mm_srl32_op), RT | RS | RD },
 100        { insn_rotr, M(mm_pool32a_op, 0, 0, 0, 0, mm_rotr_op), RT | RS | RD },
 101        { insn_subu, M(mm_pool32a_op, 0, 0, 0, 0, mm_subu32_op), RT | RS | RD },
 102        { insn_sw, M(mm_sw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
 103        { insn_tlbp, M(mm_pool32a_op, 0, 0, 0, mm_tlbp_op, mm_pool32axf_op), 0 },
 104        { insn_tlbr, M(mm_pool32a_op, 0, 0, 0, mm_tlbr_op, mm_pool32axf_op), 0 },
 105        { insn_tlbwi, M(mm_pool32a_op, 0, 0, 0, mm_tlbwi_op, mm_pool32axf_op), 0 },
 106        { insn_tlbwr, M(mm_pool32a_op, 0, 0, 0, mm_tlbwr_op, mm_pool32axf_op), 0 },
 107        { insn_xor, M(mm_pool32a_op, 0, 0, 0, 0, mm_xor32_op), RT | RS | RD },
 108        { insn_xori, M(mm_xori32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
 109        { insn_dins, 0, 0 },
 110        { insn_dinsm, 0, 0 },
 111        { insn_syscall, M(mm_pool32a_op, 0, 0, 0, mm_syscall_op, mm_pool32axf_op), SCIMM},
 112        { insn_bbit0, 0, 0 },
 113        { insn_bbit1, 0, 0 },
 114        { insn_lwx, 0, 0 },
 115        { insn_ldx, 0, 0 },
 116        { insn_invalid, 0, 0 }
 117};
 118
 119#undef M
 120
 121static inline u32 build_bimm(s32 arg)
 122{
 123        WARN(arg > 0xffff || arg < -0x10000,
 124             KERN_WARNING "Micro-assembler field overflow\n");
 125
 126        WARN(arg & 0x3, KERN_WARNING "Invalid micro-assembler branch target\n");
 127
 128        return ((arg < 0) ? (1 << 15) : 0) | ((arg >> 1) & 0x7fff);
 129}
 130
 131static inline u32 build_jimm(u32 arg)
 132{
 133
 134        WARN(arg & ~((JIMM_MASK << 2) | 1),
 135             KERN_WARNING "Micro-assembler field overflow\n");
 136
 137        return (arg >> 1) & JIMM_MASK;
 138}
 139
 140/*
 141 * The order of opcode arguments is implicitly left to right,
 142 * starting with RS and ending with FUNC or IMM.
 143 */
 144static void build_insn(u32 **buf, enum opcode opc, ...)
 145{
 146        struct insn *ip = NULL;
 147        unsigned int i;
 148        va_list ap;
 149        u32 op;
 150
 151        for (i = 0; insn_table_MM[i].opcode != insn_invalid; i++)
 152                if (insn_table_MM[i].opcode == opc) {
 153                        ip = &insn_table_MM[i];
 154                        break;
 155                }
 156
 157        if (!ip || (opc == insn_daddiu && r4k_daddiu_bug()))
 158                panic("Unsupported Micro-assembler instruction %d", opc);
 159
 160        op = ip->match;
 161        va_start(ap, opc);
 162        if (ip->fields & RS) {
 163                if (opc == insn_mfc0 || opc == insn_mtc0)
 164                        op |= build_rt(va_arg(ap, u32));
 165                else
 166                        op |= build_rs(va_arg(ap, u32));
 167        }
 168        if (ip->fields & RT) {
 169                if (opc == insn_mfc0 || opc == insn_mtc0)
 170                        op |= build_rs(va_arg(ap, u32));
 171                else
 172                        op |= build_rt(va_arg(ap, u32));
 173        }
 174        if (ip->fields & RD)
 175                op |= build_rd(va_arg(ap, u32));
 176        if (ip->fields & RE)
 177                op |= build_re(va_arg(ap, u32));
 178        if (ip->fields & SIMM)
 179                op |= build_simm(va_arg(ap, s32));
 180        if (ip->fields & UIMM)
 181                op |= build_uimm(va_arg(ap, u32));
 182        if (ip->fields & BIMM)
 183                op |= build_bimm(va_arg(ap, s32));
 184        if (ip->fields & JIMM)
 185                op |= build_jimm(va_arg(ap, u32));
 186        if (ip->fields & FUNC)
 187                op |= build_func(va_arg(ap, u32));
 188        if (ip->fields & SET)
 189                op |= build_set(va_arg(ap, u32));
 190        if (ip->fields & SCIMM)
 191                op |= build_scimm(va_arg(ap, u32));
 192        va_end(ap);
 193
 194#ifdef CONFIG_CPU_LITTLE_ENDIAN
 195        **buf = ((op & 0xffff) << 16) | (op >> 16);
 196#else
 197        **buf = op;
 198#endif
 199        (*buf)++;
 200}
 201
 202static inline void
 203__resolve_relocs(struct uasm_reloc *rel, struct uasm_label *lab)
 204{
 205        long laddr = (long)lab->addr;
 206        long raddr = (long)rel->addr;
 207
 208        switch (rel->type) {
 209        case R_MIPS_PC16:
 210#ifdef CONFIG_CPU_LITTLE_ENDIAN
 211                *rel->addr |= (build_bimm(laddr - (raddr + 4)) << 16);
 212#else
 213                *rel->addr |= build_bimm(laddr - (raddr + 4));
 214#endif
 215                break;
 216
 217        default:
 218                panic("Unsupported Micro-assembler relocation %d",
 219                      rel->type);
 220        }
 221}
 222