xref: /openbmc/linux/arch/mips/mm/uasm-mips.c (revision a8a28aff)
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_CLASSIC
23 #include <asm/uasm.h>
24 
25 #define RS_MASK		0x1f
26 #define RS_SH		21
27 #define RT_MASK		0x1f
28 #define RT_SH		16
29 #define SCIMM_MASK	0xfffff
30 #define SCIMM_SH	6
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) << RS_SH						\
36 	 | (c) << RT_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 #ifdef CONFIG_CPU_MICROMIPS
43 #define CL_uasm_i_b(buf, off) ISAOPC(_beq)(buf, 0, 0, off)
44 #define CL_uasm_i_beqz(buf, rs, off) ISAOPC(_beq)(buf, rs, 0, off)
45 #define CL_uasm_i_beqzl(buf, rs, off) ISAOPC(_beql)(buf, rs, 0, off)
46 #define CL_uasm_i_bnez(buf, rs, off) ISAOPC(_bne)(buf, rs, 0, off)
47 #endif
48 
49 #include "uasm.c"
50 
51 static struct insn insn_table[] = {
52 	{ insn_addiu, M(addiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM },
53 	{ insn_addu, M(spec_op, 0, 0, 0, 0, addu_op), RS | RT | RD },
54 	{ insn_andi, M(andi_op, 0, 0, 0, 0, 0), RS | RT | UIMM },
55 	{ insn_and, M(spec_op, 0, 0, 0, 0, and_op), RS | RT | RD },
56 	{ insn_bbit0, M(lwc2_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
57 	{ insn_bbit1, M(swc2_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_beq, M(beq_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
60 	{ insn_bgezl, M(bcond_op, 0, bgezl_op, 0, 0, 0), RS | BIMM },
61 	{ insn_bgez, M(bcond_op, 0, bgez_op, 0, 0, 0), RS | BIMM },
62 	{ insn_bltzl, M(bcond_op, 0, bltzl_op, 0, 0, 0), RS | BIMM },
63 	{ insn_bltz, M(bcond_op, 0, bltz_op, 0, 0, 0), RS | BIMM },
64 	{ insn_bne, M(bne_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
65 	{ insn_cache,  M(cache_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
66 	{ insn_daddiu, M(daddiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM },
67 	{ insn_daddu, M(spec_op, 0, 0, 0, 0, daddu_op), RS | RT | RD },
68 	{ insn_dinsm, M(spec3_op, 0, 0, 0, 0, dinsm_op), RS | RT | RD | RE },
69 	{ insn_dins, M(spec3_op, 0, 0, 0, 0, dins_op), RS | RT | RD | RE },
70 	{ insn_divu, M(spec_op, 0, 0, 0, 0, divu_op), RS | RT },
71 	{ insn_dmfc0, M(cop0_op, dmfc_op, 0, 0, 0, 0), RT | RD | SET},
72 	{ insn_dmtc0, M(cop0_op, dmtc_op, 0, 0, 0, 0), RT | RD | SET},
73 	{ insn_drotr32, M(spec_op, 1, 0, 0, 0, dsrl32_op), RT | RD | RE },
74 	{ insn_drotr, M(spec_op, 1, 0, 0, 0, dsrl_op), RT | RD | RE },
75 	{ insn_dsll32, M(spec_op, 0, 0, 0, 0, dsll32_op), RT | RD | RE },
76 	{ insn_dsll, M(spec_op, 0, 0, 0, 0, dsll_op), RT | RD | RE },
77 	{ insn_dsra, M(spec_op, 0, 0, 0, 0, dsra_op), RT | RD | RE },
78 	{ insn_dsrl32, M(spec_op, 0, 0, 0, 0, dsrl32_op), RT | RD | RE },
79 	{ insn_dsrl, M(spec_op, 0, 0, 0, 0, dsrl_op), RT | RD | RE },
80 	{ insn_dsubu, M(spec_op, 0, 0, 0, 0, dsubu_op), RS | RT | RD },
81 	{ insn_eret,  M(cop0_op, cop_op, 0, 0, 0, eret_op),  0 },
82 	{ insn_ext, M(spec3_op, 0, 0, 0, 0, ext_op), RS | RT | RD | RE },
83 	{ insn_ins, M(spec3_op, 0, 0, 0, 0, ins_op), RS | RT | RD | RE },
84 	{ insn_j,  M(j_op, 0, 0, 0, 0, 0),  JIMM },
85 	{ insn_jal,  M(jal_op, 0, 0, 0, 0, 0),	JIMM },
86 	{ insn_jalr,  M(spec_op, 0, 0, 0, 0, jalr_op), RS | RD },
87 	{ insn_j,  M(j_op, 0, 0, 0, 0, 0),  JIMM },
88 	{ insn_jr,  M(spec_op, 0, 0, 0, 0, jr_op),  RS },
89 	{ insn_lb, M(lb_op, 0, 0, 0, 0, 0), RS | RT | SIMM },
90 	{ insn_ld,  M(ld_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
91 	{ insn_ldx, M(spec3_op, 0, 0, 0, ldx_op, lx_op), RS | RT | RD },
92 	{ insn_lh,  M(lh_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
93 	{ insn_lld,  M(lld_op, 0, 0, 0, 0, 0),	RS | RT | SIMM },
94 	{ insn_ll,  M(ll_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
95 	{ insn_lui,  M(lui_op, 0, 0, 0, 0, 0),	RT | SIMM },
96 	{ insn_lw,  M(lw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
97 	{ insn_lwx, M(spec3_op, 0, 0, 0, lwx_op, lx_op), RS | RT | RD },
98 	{ insn_mfc0,  M(cop0_op, mfc_op, 0, 0, 0, 0),  RT | RD | SET},
99 	{ insn_mfhi,  M(spec_op, 0, 0, 0, 0, mfhi_op), RD },
100 	{ insn_mflo,  M(spec_op, 0, 0, 0, 0, mflo_op), RD },
101 	{ insn_mtc0,  M(cop0_op, mtc_op, 0, 0, 0, 0),  RT | RD | SET},
102 	{ insn_mul, M(spec2_op, 0, 0, 0, 0, mul_op), RS | RT | RD},
103 	{ insn_ori,  M(ori_op, 0, 0, 0, 0, 0),	RS | RT | UIMM },
104 	{ insn_or,  M(spec_op, 0, 0, 0, 0, or_op),  RS | RT | RD },
105 	{ insn_pref,  M(pref_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
106 	{ insn_rfe,  M(cop0_op, cop_op, 0, 0, 0, rfe_op),  0 },
107 	{ insn_rotr,  M(spec_op, 1, 0, 0, 0, srl_op),  RT | RD | RE },
108 	{ insn_scd,  M(scd_op, 0, 0, 0, 0, 0),	RS | RT | SIMM },
109 	{ insn_sc,  M(sc_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
110 	{ insn_sd,  M(sd_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
111 	{ insn_sll,  M(spec_op, 0, 0, 0, 0, sll_op),  RT | RD | RE },
112 	{ insn_sllv,  M(spec_op, 0, 0, 0, 0, sllv_op),  RS | RT | RD },
113 	{ insn_slt,  M(spec_op, 0, 0, 0, 0, slt_op),  RS | RT | RD },
114 	{ insn_sltiu, M(sltiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM },
115 	{ insn_sltu, M(spec_op, 0, 0, 0, 0, sltu_op), RS | RT | RD },
116 	{ insn_sra,  M(spec_op, 0, 0, 0, 0, sra_op),  RT | RD | RE },
117 	{ insn_srl,  M(spec_op, 0, 0, 0, 0, srl_op),  RT | RD | RE },
118 	{ insn_srlv,  M(spec_op, 0, 0, 0, 0, srlv_op),  RS | RT | RD },
119 	{ insn_subu,  M(spec_op, 0, 0, 0, 0, subu_op),	RS | RT | RD },
120 	{ insn_sw,  M(sw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
121 	{ insn_sync, M(spec_op, 0, 0, 0, 0, sync_op), RE },
122 	{ insn_syscall, M(spec_op, 0, 0, 0, 0, syscall_op), SCIMM},
123 	{ insn_tlbp,  M(cop0_op, cop_op, 0, 0, 0, tlbp_op),  0 },
124 	{ insn_tlbr,  M(cop0_op, cop_op, 0, 0, 0, tlbr_op),  0 },
125 	{ insn_tlbwi,  M(cop0_op, cop_op, 0, 0, 0, tlbwi_op),  0 },
126 	{ insn_tlbwr,  M(cop0_op, cop_op, 0, 0, 0, tlbwr_op),  0 },
127 	{ insn_wait, M(cop0_op, cop_op, 0, 0, 0, wait_op), SCIMM },
128 	{ insn_wsbh, M(spec3_op, 0, 0, 0, wsbh_op, bshfl_op), RT | RD },
129 	{ insn_xori,  M(xori_op, 0, 0, 0, 0, 0),  RS | RT | UIMM },
130 	{ insn_xor,  M(spec_op, 0, 0, 0, 0, xor_op),  RS | RT | RD },
131 	{ insn_yield, M(spec3_op, 0, 0, 0, 0, yield_op), RS | RD },
132 	{ insn_invalid, 0, 0 }
133 };
134 
135 #undef M
136 
137 static inline u32 build_bimm(s32 arg)
138 {
139 	WARN(arg > 0x1ffff || arg < -0x20000,
140 	     KERN_WARNING "Micro-assembler field overflow\n");
141 
142 	WARN(arg & 0x3, KERN_WARNING "Invalid micro-assembler branch target\n");
143 
144 	return ((arg < 0) ? (1 << 15) : 0) | ((arg >> 2) & 0x7fff);
145 }
146 
147 static inline u32 build_jimm(u32 arg)
148 {
149 	WARN(arg & ~(JIMM_MASK << 2),
150 	     KERN_WARNING "Micro-assembler field overflow\n");
151 
152 	return (arg >> 2) & JIMM_MASK;
153 }
154 
155 /*
156  * The order of opcode arguments is implicitly left to right,
157  * starting with RS and ending with FUNC or IMM.
158  */
159 static void build_insn(u32 **buf, enum opcode opc, ...)
160 {
161 	struct insn *ip = NULL;
162 	unsigned int i;
163 	va_list ap;
164 	u32 op;
165 
166 	for (i = 0; insn_table[i].opcode != insn_invalid; i++)
167 		if (insn_table[i].opcode == opc) {
168 			ip = &insn_table[i];
169 			break;
170 		}
171 
172 	if (!ip || (opc == insn_daddiu && r4k_daddiu_bug()))
173 		panic("Unsupported Micro-assembler instruction %d", opc);
174 
175 	op = ip->match;
176 	va_start(ap, opc);
177 	if (ip->fields & RS)
178 		op |= build_rs(va_arg(ap, u32));
179 	if (ip->fields & RT)
180 		op |= build_rt(va_arg(ap, u32));
181 	if (ip->fields & RD)
182 		op |= build_rd(va_arg(ap, u32));
183 	if (ip->fields & RE)
184 		op |= build_re(va_arg(ap, u32));
185 	if (ip->fields & SIMM)
186 		op |= build_simm(va_arg(ap, s32));
187 	if (ip->fields & UIMM)
188 		op |= build_uimm(va_arg(ap, u32));
189 	if (ip->fields & BIMM)
190 		op |= build_bimm(va_arg(ap, s32));
191 	if (ip->fields & JIMM)
192 		op |= build_jimm(va_arg(ap, u32));
193 	if (ip->fields & FUNC)
194 		op |= build_func(va_arg(ap, u32));
195 	if (ip->fields & SET)
196 		op |= build_set(va_arg(ap, u32));
197 	if (ip->fields & SCIMM)
198 		op |= build_scimm(va_arg(ap, u32));
199 	va_end(ap);
200 
201 	**buf = op;
202 	(*buf)++;
203 }
204 
205 static inline void
206 __resolve_relocs(struct uasm_reloc *rel, struct uasm_label *lab)
207 {
208 	long laddr = (long)lab->addr;
209 	long raddr = (long)rel->addr;
210 
211 	switch (rel->type) {
212 	case R_MIPS_PC16:
213 		*rel->addr |= build_bimm(laddr - (raddr + 4));
214 		break;
215 
216 	default:
217 		panic("Unsupported Micro-assembler relocation %d",
218 		      rel->type);
219 	}
220 }
221