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 #include <asm/uasm.h>
23 
24 #define RS_MASK		0x1f
25 #define RS_SH		21
26 #define RT_MASK		0x1f
27 #define RT_SH		16
28 #define SCIMM_MASK	0xfffff
29 #define SCIMM_SH	6
30 
31 /* This macro sets the non-variable bits of an instruction. */
32 #define M(a, b, c, d, e, f)					\
33 	((a) << OP_SH						\
34 	 | (b) << RS_SH						\
35 	 | (c) << RT_SH						\
36 	 | (d) << RD_SH						\
37 	 | (e) << RE_SH						\
38 	 | (f) << FUNC_SH)
39 
40 /* This macro sets the non-variable bits of an R6 instruction. */
41 #define M6(a, b, c, d, e)					\
42 	((a) << OP_SH						\
43 	 | (b) << RS_SH						\
44 	 | (c) << RT_SH						\
45 	 | (d) << SIMM9_SH					\
46 	 | (e) << FUNC_SH)
47 
48 #include "uasm.c"
49 
50 static const struct insn insn_table[insn_invalid] = {
51 	[insn_addiu]	= {M(addiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
52 	[insn_addu]	= {M(spec_op, 0, 0, 0, 0, addu_op), RS | RT | RD},
53 	[insn_and]	= {M(spec_op, 0, 0, 0, 0, and_op), RS | RT | RD},
54 	[insn_andi]	= {M(andi_op, 0, 0, 0, 0, 0), RS | RT | UIMM},
55 	[insn_bbit0]	= {M(lwc2_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
56 	[insn_bbit1]	= {M(swc2_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
57 	[insn_beq]	= {M(beq_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
58 	[insn_beql]	= {M(beql_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
59 	[insn_bgez]	= {M(bcond_op, 0, bgez_op, 0, 0, 0), RS | BIMM},
60 	[insn_bgezl]	= {M(bcond_op, 0, bgezl_op, 0, 0, 0), RS | BIMM},
61 	[insn_bgtz]	= {M(bgtz_op, 0, 0, 0, 0, 0), RS | BIMM},
62 	[insn_blez]	= {M(blez_op, 0, 0, 0, 0, 0), RS | BIMM},
63 	[insn_bltz]	= {M(bcond_op, 0, bltz_op, 0, 0, 0), RS | BIMM},
64 	[insn_bltzl]	= {M(bcond_op, 0, bltzl_op, 0, 0, 0), RS | BIMM},
65 	[insn_bne]	= {M(bne_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
66 	[insn_break]	= {M(spec_op, 0, 0, 0, 0, break_op), SCIMM},
67 #ifndef CONFIG_CPU_MIPSR6
68 	[insn_cache]	= {M(cache_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
69 #else
70 	[insn_cache]	= {M6(spec3_op, 0, 0, 0, cache6_op),  RS | RT | SIMM9},
71 #endif
72 	[insn_cfc1]	= {M(cop1_op, cfc_op, 0, 0, 0, 0), RT | RD},
73 	[insn_cfcmsa]	= {M(msa_op, 0, msa_cfc_op, 0, 0, msa_elm_op), RD | RE},
74 	[insn_ctc1]	= {M(cop1_op, ctc_op, 0, 0, 0, 0), RT | RD},
75 	[insn_ctcmsa]	= {M(msa_op, 0, msa_ctc_op, 0, 0, msa_elm_op), RD | RE},
76 	[insn_daddiu]	= {M(daddiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
77 	[insn_daddu]	= {M(spec_op, 0, 0, 0, 0, daddu_op), RS | RT | RD},
78 	[insn_ddivu]	= {M(spec_op, 0, 0, 0, 0, ddivu_op), RS | RT},
79 	[insn_ddivu_r6]	= {M(spec_op, 0, 0, 0, ddivu_ddivu6_op, ddivu_op),
80 				RS | RT | RD},
81 	[insn_di]	= {M(cop0_op, mfmc0_op, 0, 12, 0, 0), RT},
82 	[insn_dins]	= {M(spec3_op, 0, 0, 0, 0, dins_op), RS | RT | RD | RE},
83 	[insn_dinsm]	= {M(spec3_op, 0, 0, 0, 0, dinsm_op), RS | RT | RD | RE},
84 	[insn_dinsu]	= {M(spec3_op, 0, 0, 0, 0, dinsu_op), RS | RT | RD | RE},
85 	[insn_divu]	= {M(spec_op, 0, 0, 0, 0, divu_op), RS | RT},
86 	[insn_divu_r6]	= {M(spec_op, 0, 0, 0, divu_divu6_op, divu_op),
87 				RS | RT | RD},
88 	[insn_dmfc0]	= {M(cop0_op, dmfc_op, 0, 0, 0, 0), RT | RD | SET},
89 	[insn_dmodu]	= {M(spec_op, 0, 0, 0, ddivu_dmodu_op, ddivu_op),
90 				RS | RT | RD},
91 	[insn_dmtc0]	= {M(cop0_op, dmtc_op, 0, 0, 0, 0), RT | RD | SET},
92 	[insn_dmultu]	= {M(spec_op, 0, 0, 0, 0, dmultu_op), RS | RT},
93 	[insn_dmulu]	= {M(spec_op, 0, 0, 0, dmultu_dmulu_op, dmultu_op),
94 				RS | RT | RD},
95 	[insn_drotr]	= {M(spec_op, 1, 0, 0, 0, dsrl_op), RT | RD | RE},
96 	[insn_drotr32]	= {M(spec_op, 1, 0, 0, 0, dsrl32_op), RT | RD | RE},
97 	[insn_dsbh]	= {M(spec3_op, 0, 0, 0, dsbh_op, dbshfl_op), RT | RD},
98 	[insn_dshd]	= {M(spec3_op, 0, 0, 0, dshd_op, dbshfl_op), RT | RD},
99 	[insn_dsll]	= {M(spec_op, 0, 0, 0, 0, dsll_op), RT | RD | RE},
100 	[insn_dsll32]	= {M(spec_op, 0, 0, 0, 0, dsll32_op), RT | RD | RE},
101 	[insn_dsllv]	= {M(spec_op, 0, 0, 0, 0, dsllv_op),  RS | RT | RD},
102 	[insn_dsra]	= {M(spec_op, 0, 0, 0, 0, dsra_op), RT | RD | RE},
103 	[insn_dsra32]	= {M(spec_op, 0, 0, 0, 0, dsra32_op), RT | RD | RE},
104 	[insn_dsrav]	= {M(spec_op, 0, 0, 0, 0, dsrav_op),  RS | RT | RD},
105 	[insn_dsrl]	= {M(spec_op, 0, 0, 0, 0, dsrl_op), RT | RD | RE},
106 	[insn_dsrl32]	= {M(spec_op, 0, 0, 0, 0, dsrl32_op), RT | RD | RE},
107 	[insn_dsrlv]	= {M(spec_op, 0, 0, 0, 0, dsrlv_op),  RS | RT | RD},
108 	[insn_dsubu]	= {M(spec_op, 0, 0, 0, 0, dsubu_op), RS | RT | RD},
109 	[insn_eret]	= {M(cop0_op, cop_op, 0, 0, 0, eret_op),  0},
110 	[insn_ext]	= {M(spec3_op, 0, 0, 0, 0, ext_op), RS | RT | RD | RE},
111 	[insn_ins]	= {M(spec3_op, 0, 0, 0, 0, ins_op), RS | RT | RD | RE},
112 	[insn_j]	= {M(j_op, 0, 0, 0, 0, 0),  JIMM},
113 	[insn_jal]	= {M(jal_op, 0, 0, 0, 0, 0),	JIMM},
114 	[insn_jalr]	= {M(spec_op, 0, 0, 0, 0, jalr_op), RS | RD},
115 #ifndef CONFIG_CPU_MIPSR6
116 	[insn_jr]	= {M(spec_op, 0, 0, 0, 0, jr_op),  RS},
117 #else
118 	[insn_jr]	= {M(spec_op, 0, 0, 0, 0, jalr_op),  RS},
119 #endif
120 	[insn_lb]	= {M(lb_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
121 	[insn_lbu]	= {M(lbu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
122 	[insn_ld]	= {M(ld_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
123 	[insn_lddir]	= {M(lwc2_op, 0, 0, 0, lddir_op, mult_op), RS | RT | RD},
124 	[insn_ldpte]	= {M(lwc2_op, 0, 0, 0, ldpte_op, mult_op), RS | RD},
125 	[insn_ldx]	= {M(spec3_op, 0, 0, 0, ldx_op, lx_op), RS | RT | RD},
126 	[insn_lh]	= {M(lh_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
127 	[insn_lhu]	= {M(lhu_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
128 #ifndef CONFIG_CPU_MIPSR6
129 	[insn_ll]	= {M(ll_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
130 	[insn_lld]	= {M(lld_op, 0, 0, 0, 0, 0),	RS | RT | SIMM},
131 #else
132 	[insn_ll]	= {M6(spec3_op, 0, 0, 0, ll6_op),  RS | RT | SIMM9},
133 	[insn_lld]	= {M6(spec3_op, 0, 0, 0, lld6_op),  RS | RT | SIMM9},
134 #endif
135 	[insn_lui]	= {M(lui_op, 0, 0, 0, 0, 0),	RT | SIMM},
136 	[insn_lw]	= {M(lw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
137 	[insn_lwu]	= {M(lwu_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
138 	[insn_lwx]	= {M(spec3_op, 0, 0, 0, lwx_op, lx_op), RS | RT | RD},
139 	[insn_mfc0]	= {M(cop0_op, mfc_op, 0, 0, 0, 0),  RT | RD | SET},
140 	[insn_mfhc0]	= {M(cop0_op, mfhc0_op, 0, 0, 0, 0),  RT | RD | SET},
141 	[insn_mfhi]	= {M(spec_op, 0, 0, 0, 0, mfhi_op), RD},
142 	[insn_mflo]	= {M(spec_op, 0, 0, 0, 0, mflo_op), RD},
143 	[insn_modu]	= {M(spec_op, 0, 0, 0, divu_modu_op, divu_op),
144 				RS | RT | RD},
145 	[insn_movn]	= {M(spec_op, 0, 0, 0, 0, movn_op), RS | RT | RD},
146 	[insn_movz]	= {M(spec_op, 0, 0, 0, 0, movz_op), RS | RT | RD},
147 	[insn_mtc0]	= {M(cop0_op, mtc_op, 0, 0, 0, 0),  RT | RD | SET},
148 	[insn_mthc0]	= {M(cop0_op, mthc0_op, 0, 0, 0, 0),  RT | RD | SET},
149 	[insn_mthi]	= {M(spec_op, 0, 0, 0, 0, mthi_op), RS},
150 	[insn_mtlo]	= {M(spec_op, 0, 0, 0, 0, mtlo_op), RS},
151 	[insn_mulu]	= {M(spec_op, 0, 0, 0, multu_mulu_op, multu_op),
152 				RS | RT | RD},
153 	[insn_muhu]	= {M(spec_op, 0, 0, 0, multu_muhu_op, multu_op),
154 				RS | RT | RD},
155 #ifndef CONFIG_CPU_MIPSR6
156 	[insn_mul]	= {M(spec2_op, 0, 0, 0, 0, mul_op), RS | RT | RD},
157 #else
158 	[insn_mul]	= {M(spec_op, 0, 0, 0, mult_mul_op, mult_op), RS | RT | RD},
159 #endif
160 	[insn_multu]	= {M(spec_op, 0, 0, 0, 0, multu_op), RS | RT},
161 	[insn_nor]	= {M(spec_op, 0, 0, 0, 0, nor_op),  RS | RT | RD},
162 	[insn_or]	= {M(spec_op, 0, 0, 0, 0, or_op),  RS | RT | RD},
163 	[insn_ori]	= {M(ori_op, 0, 0, 0, 0, 0),	RS | RT | UIMM},
164 #ifndef CONFIG_CPU_MIPSR6
165 	[insn_pref]	= {M(pref_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
166 #else
167 	[insn_pref]	= {M6(spec3_op, 0, 0, 0, pref6_op),  RS | RT | SIMM9},
168 #endif
169 	[insn_rfe]	= {M(cop0_op, cop_op, 0, 0, 0, rfe_op),  0},
170 	[insn_rotr]	= {M(spec_op, 1, 0, 0, 0, srl_op),  RT | RD | RE},
171 	[insn_sb]	= {M(sb_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
172 #ifndef CONFIG_CPU_MIPSR6
173 	[insn_sc]	= {M(sc_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
174 	[insn_scd]	= {M(scd_op, 0, 0, 0, 0, 0),	RS | RT | SIMM},
175 #else
176 	[insn_sc]	= {M6(spec3_op, 0, 0, 0, sc6_op),  RS | RT | SIMM9},
177 	[insn_scd]	= {M6(spec3_op, 0, 0, 0, scd6_op),  RS | RT | SIMM9},
178 #endif
179 	[insn_sd]	= {M(sd_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
180 	[insn_seleqz]	= {M(spec_op, 0, 0, 0, 0, seleqz_op), RS | RT | RD},
181 	[insn_selnez]	= {M(spec_op, 0, 0, 0, 0, selnez_op), RS | RT | RD},
182 	[insn_sh]	= {M(sh_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
183 	[insn_sll]	= {M(spec_op, 0, 0, 0, 0, sll_op),  RT | RD | RE},
184 	[insn_sllv]	= {M(spec_op, 0, 0, 0, 0, sllv_op),  RS | RT | RD},
185 	[insn_slt]	= {M(spec_op, 0, 0, 0, 0, slt_op),  RS | RT | RD},
186 	[insn_slti]	= {M(slti_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
187 	[insn_sltiu]	= {M(sltiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
188 	[insn_sltu]	= {M(spec_op, 0, 0, 0, 0, sltu_op), RS | RT | RD},
189 	[insn_sra]	= {M(spec_op, 0, 0, 0, 0, sra_op),  RT | RD | RE},
190 	[insn_srav]	= {M(spec_op, 0, 0, 0, 0, srav_op), RS | RT | RD},
191 	[insn_srl]	= {M(spec_op, 0, 0, 0, 0, srl_op),  RT | RD | RE},
192 	[insn_srlv]	= {M(spec_op, 0, 0, 0, 0, srlv_op),  RS | RT | RD},
193 	[insn_subu]	= {M(spec_op, 0, 0, 0, 0, subu_op),	RS | RT | RD},
194 	[insn_sw]	= {M(sw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM},
195 	[insn_sync]	= {M(spec_op, 0, 0, 0, 0, sync_op), RE},
196 	[insn_syscall]	= {M(spec_op, 0, 0, 0, 0, syscall_op), SCIMM},
197 	[insn_tlbp]	= {M(cop0_op, cop_op, 0, 0, 0, tlbp_op),  0},
198 	[insn_tlbr]	= {M(cop0_op, cop_op, 0, 0, 0, tlbr_op),  0},
199 	[insn_tlbwi]	= {M(cop0_op, cop_op, 0, 0, 0, tlbwi_op),  0},
200 	[insn_tlbwr]	= {M(cop0_op, cop_op, 0, 0, 0, tlbwr_op),  0},
201 	[insn_wait]	= {M(cop0_op, cop_op, 0, 0, 0, wait_op), SCIMM},
202 	[insn_wsbh]	= {M(spec3_op, 0, 0, 0, wsbh_op, bshfl_op), RT | RD},
203 	[insn_xor]	= {M(spec_op, 0, 0, 0, 0, xor_op),  RS | RT | RD},
204 	[insn_xori]	= {M(xori_op, 0, 0, 0, 0, 0),  RS | RT | UIMM},
205 	[insn_yield]	= {M(spec3_op, 0, 0, 0, 0, yield_op), RS | RD},
206 };
207 
208 #undef M
209 
build_bimm(s32 arg)210 static inline u32 build_bimm(s32 arg)
211 {
212 	WARN(arg > 0x1ffff || arg < -0x20000,
213 	     KERN_WARNING "Micro-assembler field overflow\n");
214 
215 	WARN(arg & 0x3, KERN_WARNING "Invalid micro-assembler branch target\n");
216 
217 	return ((arg < 0) ? (1 << 15) : 0) | ((arg >> 2) & 0x7fff);
218 }
219 
build_jimm(u32 arg)220 static inline u32 build_jimm(u32 arg)
221 {
222 	WARN(arg & ~(JIMM_MASK << 2),
223 	     KERN_WARNING "Micro-assembler field overflow\n");
224 
225 	return (arg >> 2) & JIMM_MASK;
226 }
227 
228 /*
229  * The order of opcode arguments is implicitly left to right,
230  * starting with RS and ending with FUNC or IMM.
231  */
build_insn(u32 ** buf,enum opcode opc,...)232 static void build_insn(u32 **buf, enum opcode opc, ...)
233 {
234 	const struct insn *ip;
235 	va_list ap;
236 	u32 op;
237 
238 	if (opc < 0 || opc >= insn_invalid ||
239 	    (opc == insn_daddiu && r4k_daddiu_bug()) ||
240 	    (insn_table[opc].match == 0 && insn_table[opc].fields == 0))
241 		panic("Unsupported Micro-assembler instruction %d", opc);
242 
243 	ip = &insn_table[opc];
244 
245 	op = ip->match;
246 	va_start(ap, opc);
247 	if (ip->fields & RS)
248 		op |= build_rs(va_arg(ap, u32));
249 	if (ip->fields & RT)
250 		op |= build_rt(va_arg(ap, u32));
251 	if (ip->fields & RD)
252 		op |= build_rd(va_arg(ap, u32));
253 	if (ip->fields & RE)
254 		op |= build_re(va_arg(ap, u32));
255 	if (ip->fields & SIMM)
256 		op |= build_simm(va_arg(ap, s32));
257 	if (ip->fields & UIMM)
258 		op |= build_uimm(va_arg(ap, u32));
259 	if (ip->fields & BIMM)
260 		op |= build_bimm(va_arg(ap, s32));
261 	if (ip->fields & JIMM)
262 		op |= build_jimm(va_arg(ap, u32));
263 	if (ip->fields & FUNC)
264 		op |= build_func(va_arg(ap, u32));
265 	if (ip->fields & SET)
266 		op |= build_set(va_arg(ap, u32));
267 	if (ip->fields & SCIMM)
268 		op |= build_scimm(va_arg(ap, u32));
269 	if (ip->fields & SIMM9)
270 		op |= build_scimm9(va_arg(ap, u32));
271 	va_end(ap);
272 
273 	**buf = op;
274 	(*buf)++;
275 }
276 
277 static inline void
__resolve_relocs(struct uasm_reloc * rel,struct uasm_label * lab)278 __resolve_relocs(struct uasm_reloc *rel, struct uasm_label *lab)
279 {
280 	long laddr = (long)lab->addr;
281 	long raddr = (long)rel->addr;
282 
283 	switch (rel->type) {
284 	case R_MIPS_PC16:
285 		*rel->addr |= build_bimm(laddr - (raddr + 4));
286 		break;
287 
288 	default:
289 		panic("Unsupported Micro-assembler relocation %d",
290 		      rel->type);
291 	}
292 }
293