xref: /openbmc/qemu/target/loongarch/gdbstub.c (revision 2e1cacfb)
1 /*
2  * LOONGARCH gdb server stub
3  *
4  * Copyright (c) 2021 Loongson Technology Corporation Limited
5  *
6  * SPDX-License-Identifier: LGPL-2.1+
7  */
8 
9 #include "qemu/osdep.h"
10 #include "cpu.h"
11 #include "internals.h"
12 #include "exec/gdbstub.h"
13 #include "gdbstub/helpers.h"
14 #include "vec.h"
15 
16 uint64_t read_fcc(CPULoongArchState *env)
17 {
18     uint64_t ret = 0;
19 
20     for (int i = 0; i < 8; ++i) {
21         ret |= (uint64_t)env->cf[i] << (i * 8);
22     }
23 
24     return ret;
25 }
26 
27 void write_fcc(CPULoongArchState *env, uint64_t val)
28 {
29     for (int i = 0; i < 8; ++i) {
30         env->cf[i] = (val >> (i * 8)) & 1;
31     }
32 }
33 
34 int loongarch_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
35 {
36     CPULoongArchState *env = cpu_env(cs);
37 
38     if (0 <= n && n <= 34) {
39         uint64_t val;
40 
41         if (n < 32) {
42             val = env->gpr[n];
43         } else if (n == 32) {
44             /* orig_a0 */
45             val = 0;
46         } else if (n == 33) {
47             val = env->pc;
48         } else /* if (n == 34) */ {
49             val = env->CSR_BADV;
50         }
51 
52         if (is_la64(env)) {
53             return gdb_get_reg64(mem_buf, val);
54         } else {
55             return gdb_get_reg32(mem_buf, val);
56         }
57     }
58 
59     return 0;
60 }
61 
62 int loongarch_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
63 {
64     CPULoongArchState *env = cpu_env(cs);
65     target_ulong tmp;
66     int read_length;
67     int length = 0;
68 
69     if (is_la64(env)) {
70         tmp = ldq_le_p(mem_buf);
71         read_length = 8;
72     } else {
73         tmp = ldl_le_p(mem_buf);
74         read_length = 4;
75     }
76 
77     if (0 <= n && n < 32) {
78         env->gpr[n] = tmp;
79         length = read_length;
80     } else if (n == 33) {
81         set_pc(env, tmp);
82         length = read_length;
83     }
84     return length;
85 }
86 
87 static int loongarch_gdb_get_fpu(CPUState *cs, GByteArray *mem_buf, int n)
88 {
89     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
90     CPULoongArchState *env = &cpu->env;
91 
92     if (0 <= n && n < 32) {
93         return gdb_get_reg64(mem_buf, env->fpr[n].vreg.D(0));
94     } else if (32 <= n && n < 40) {
95         return gdb_get_reg8(mem_buf, env->cf[n - 32]);
96     } else if (n == 40) {
97         return gdb_get_reg32(mem_buf, env->fcsr0);
98     }
99     return 0;
100 }
101 
102 static int loongarch_gdb_set_fpu(CPUState *cs, uint8_t *mem_buf, int n)
103 {
104     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
105     CPULoongArchState *env = &cpu->env;
106     int length = 0;
107 
108     if (0 <= n && n < 32) {
109         env->fpr[n].vreg.D(0) = ldq_le_p(mem_buf);
110         length = 8;
111     } else if (32 <= n && n < 40) {
112         env->cf[n - 32] = ldub_p(mem_buf);
113         length = 1;
114     } else if (n == 40) {
115         env->fcsr0 = ldl_le_p(mem_buf);
116         length = 4;
117     }
118     return length;
119 }
120 
121 #define VREG_NUM       32
122 #define REG64_LEN      64
123 
124 static int loongarch_gdb_get_vec(CPUState *cs, GByteArray *mem_buf, int n, int vl)
125 {
126     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
127     CPULoongArchState *env = &cpu->env;
128     int i, length = 0;
129 
130     if (0 <= n && n < VREG_NUM) {
131         for (i = 0; i < vl / REG64_LEN; i++) {
132             length += gdb_get_reg64(mem_buf, env->fpr[n].vreg.D(i));
133         }
134     }
135 
136     return length;
137 }
138 
139 static int loongarch_gdb_set_vec(CPUState *cs, uint8_t *mem_buf, int n, int vl)
140 {
141     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
142     CPULoongArchState *env = &cpu->env;
143     int i, length = 0;
144 
145     if (0 <= n && n < VREG_NUM) {
146         for (i = 0; i < vl / REG64_LEN; i++) {
147             env->fpr[n].vreg.D(i) = ldq_le_p(mem_buf + 8 * i);
148             length += 8;
149         }
150     }
151 
152     return length;
153 }
154 
155 static int loongarch_gdb_get_lsx(CPUState *cs, GByteArray *mem_buf, int n)
156 {
157     return loongarch_gdb_get_vec(cs, mem_buf, n, LSX_LEN);
158 }
159 
160 static int loongarch_gdb_set_lsx(CPUState *cs, uint8_t *mem_buf, int n)
161 {
162     return loongarch_gdb_set_vec(cs, mem_buf, n, LSX_LEN);
163 }
164 
165 static int loongarch_gdb_get_lasx(CPUState *cs, GByteArray *mem_buf, int n)
166 {
167     return loongarch_gdb_get_vec(cs, mem_buf, n, LASX_LEN);
168 }
169 
170 static int loongarch_gdb_set_lasx(CPUState *cs, uint8_t *mem_buf, int n)
171 {
172     return loongarch_gdb_set_vec(cs, mem_buf, n, LASX_LEN);
173 }
174 
175 void loongarch_cpu_register_gdb_regs_for_features(CPUState *cs)
176 {
177     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
178     CPULoongArchState *env = &cpu->env;
179 
180     if (FIELD_EX32(env->cpucfg[2], CPUCFG2, FP)) {
181         gdb_register_coprocessor(cs, loongarch_gdb_get_fpu, loongarch_gdb_set_fpu,
182                                  gdb_find_static_feature("loongarch-fpu.xml"), 0);
183     }
184 
185     if (FIELD_EX32(env->cpucfg[2], CPUCFG2, LSX)) {
186         gdb_register_coprocessor(cs, loongarch_gdb_get_lsx, loongarch_gdb_set_lsx,
187                                  gdb_find_static_feature("loongarch-lsx.xml"), 0);
188     }
189 
190     if (FIELD_EX32(env->cpucfg[2], CPUCFG2, LASX)) {
191         gdb_register_coprocessor(cs, loongarch_gdb_get_lasx, loongarch_gdb_set_lasx,
192                                  gdb_find_static_feature("loongarch-lasx.xml"), 0);
193     }
194 }
195