arch/mips/mm/uasm-micromips.c

   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
  52 static 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
 121 static 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
 131 static 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  */
 144 static 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
 202 static 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 }