xref: /openbmc/linux/arch/mips/mm/uasm-micromips.c (revision 5104d265)
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 }
222