xref: /openbmc/linux/arch/mips/mm/uasm-mips.c (revision 6c870213d6f3a25981c10728f46294a3bed1703f)
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_dmfc0, M(cop0_op, dmfc_op, 0, 0, 0, 0), RT | RD | SET},
71 	{ insn_dmtc0, M(cop0_op, dmtc_op, 0, 0, 0, 0), RT | RD | SET},
72 	{ insn_drotr32, M(spec_op, 1, 0, 0, 0, dsrl32_op), RT | RD | RE },
73 	{ insn_drotr, M(spec_op, 1, 0, 0, 0, dsrl_op), RT | RD | RE },
74 	{ insn_dsll32, M(spec_op, 0, 0, 0, 0, dsll32_op), RT | RD | RE },
75 	{ insn_dsll, M(spec_op, 0, 0, 0, 0, dsll_op), RT | RD | RE },
76 	{ insn_dsra, M(spec_op, 0, 0, 0, 0, dsra_op), RT | RD | RE },
77 	{ insn_dsrl32, M(spec_op, 0, 0, 0, 0, dsrl32_op), RT | RD | RE },
78 	{ insn_dsrl, M(spec_op, 0, 0, 0, 0, dsrl_op), RT | RD | RE },
79 	{ insn_dsubu, M(spec_op, 0, 0, 0, 0, dsubu_op), RS | RT | RD },
80 	{ insn_eret,  M(cop0_op, cop_op, 0, 0, 0, eret_op),  0 },
81 	{ insn_ext, M(spec3_op, 0, 0, 0, 0, ext_op), RS | RT | RD | RE },
82 	{ insn_ins, M(spec3_op, 0, 0, 0, 0, ins_op), RS | RT | RD | RE },
83 	{ insn_j,  M(j_op, 0, 0, 0, 0, 0),  JIMM },
84 	{ insn_jal,  M(jal_op, 0, 0, 0, 0, 0),	JIMM },
85 	{ insn_j,  M(j_op, 0, 0, 0, 0, 0),  JIMM },
86 	{ insn_jr,  M(spec_op, 0, 0, 0, 0, jr_op),  RS },
87 	{ insn_ld,  M(ld_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
88 	{ insn_ldx, M(spec3_op, 0, 0, 0, ldx_op, lx_op), RS | RT | RD },
89 	{ insn_lld,  M(lld_op, 0, 0, 0, 0, 0),	RS | RT | SIMM },
90 	{ insn_ll,  M(ll_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
91 	{ insn_lui,  M(lui_op, 0, 0, 0, 0, 0),	RT | SIMM },
92 	{ insn_lw,  M(lw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
93 	{ insn_lwx, M(spec3_op, 0, 0, 0, lwx_op, lx_op), RS | RT | RD },
94 	{ insn_mfc0,  M(cop0_op, mfc_op, 0, 0, 0, 0),  RT | RD | SET},
95 	{ insn_mtc0,  M(cop0_op, mtc_op, 0, 0, 0, 0),  RT | RD | SET},
96 	{ insn_ori,  M(ori_op, 0, 0, 0, 0, 0),	RS | RT | UIMM },
97 	{ insn_or,  M(spec_op, 0, 0, 0, 0, or_op),  RS | RT | RD },
98 	{ insn_pref,  M(pref_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
99 	{ insn_rfe,  M(cop0_op, cop_op, 0, 0, 0, rfe_op),  0 },
100 	{ insn_rotr,  M(spec_op, 1, 0, 0, 0, srl_op),  RT | RD | RE },
101 	{ insn_scd,  M(scd_op, 0, 0, 0, 0, 0),	RS | RT | SIMM },
102 	{ insn_sc,  M(sc_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
103 	{ insn_sd,  M(sd_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
104 	{ insn_sll,  M(spec_op, 0, 0, 0, 0, sll_op),  RT | RD | RE },
105 	{ insn_sra,  M(spec_op, 0, 0, 0, 0, sra_op),  RT | RD | RE },
106 	{ insn_srl,  M(spec_op, 0, 0, 0, 0, srl_op),  RT | RD | RE },
107 	{ insn_subu,  M(spec_op, 0, 0, 0, 0, subu_op),	RS | RT | RD },
108 	{ insn_sw,  M(sw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
109 	{ insn_syscall, M(spec_op, 0, 0, 0, 0, syscall_op), SCIMM},
110 	{ insn_tlbp,  M(cop0_op, cop_op, 0, 0, 0, tlbp_op),  0 },
111 	{ insn_tlbr,  M(cop0_op, cop_op, 0, 0, 0, tlbr_op),  0 },
112 	{ insn_tlbwi,  M(cop0_op, cop_op, 0, 0, 0, tlbwi_op),  0 },
113 	{ insn_tlbwr,  M(cop0_op, cop_op, 0, 0, 0, tlbwr_op),  0 },
114 	{ insn_xori,  M(xori_op, 0, 0, 0, 0, 0),  RS | RT | UIMM },
115 	{ insn_xor,  M(spec_op, 0, 0, 0, 0, xor_op),  RS | RT | RD },
116 	{ insn_invalid, 0, 0 }
117 };
118 
119 #undef M
120 
121 static inline u32 build_bimm(s32 arg)
122 {
123 	WARN(arg > 0x1ffff || arg < -0x20000,
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 >> 2) & 0x7fff);
129 }
130 
131 static inline u32 build_jimm(u32 arg)
132 {
133 	WARN(arg & ~(JIMM_MASK << 2),
134 	     KERN_WARNING "Micro-assembler field overflow\n");
135 
136 	return (arg >> 2) & 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  */
143 static 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[i].opcode != insn_invalid; i++)
151 		if (insn_table[i].opcode == opc) {
152 			ip = &insn_table[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 		op |= build_rs(va_arg(ap, u32));
163 	if (ip->fields & RT)
164 		op |= build_rt(va_arg(ap, u32));
165 	if (ip->fields & RD)
166 		op |= build_rd(va_arg(ap, u32));
167 	if (ip->fields & RE)
168 		op |= build_re(va_arg(ap, u32));
169 	if (ip->fields & SIMM)
170 		op |= build_simm(va_arg(ap, s32));
171 	if (ip->fields & UIMM)
172 		op |= build_uimm(va_arg(ap, u32));
173 	if (ip->fields & BIMM)
174 		op |= build_bimm(va_arg(ap, s32));
175 	if (ip->fields & JIMM)
176 		op |= build_jimm(va_arg(ap, u32));
177 	if (ip->fields & FUNC)
178 		op |= build_func(va_arg(ap, u32));
179 	if (ip->fields & SET)
180 		op |= build_set(va_arg(ap, u32));
181 	if (ip->fields & SCIMM)
182 		op |= build_scimm(va_arg(ap, u32));
183 	va_end(ap);
184 
185 	**buf = op;
186 	(*buf)++;
187 }
188 
189 static inline void
190 __resolve_relocs(struct uasm_reloc *rel, struct uasm_label *lab)
191 {
192 	long laddr = (long)lab->addr;
193 	long raddr = (long)rel->addr;
194 
195 	switch (rel->type) {
196 	case R_MIPS_PC16:
197 		*rel->addr |= build_bimm(laddr - (raddr + 4));
198 		break;
199 
200 	default:
201 		panic("Unsupported Micro-assembler relocation %d",
202 		      rel->type);
203 	}
204 }
205