xref: /openbmc/qemu/target/hexagon/cpu.c (revision 8c8a7ed5)
1 /*
2  *  Copyright(c) 2019-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
3  *
4  *  This program is free software; you can redistribute it and/or modify
5  *  it under the terms of the GNU General Public License as published by
6  *  the Free Software Foundation; either version 2 of the License, or
7  *  (at your option) any later version.
8  *
9  *  This program is distributed in the hope that it will be useful,
10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *  GNU General Public License for more details.
13  *
14  *  You should have received a copy of the GNU General Public License
15  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include "qemu/osdep.h"
19 #include "qemu/log.h"
20 #include "qemu/qemu-print.h"
21 #include "cpu.h"
22 #include "internal.h"
23 #include "exec/exec-all.h"
24 #include "qapi/error.h"
25 #include "hw/qdev-properties.h"
26 #include "fpu/softfloat-helpers.h"
27 
28 static void hexagon_v67_cpu_init(Object *obj)
29 {
30 }
31 
32 static ObjectClass *hexagon_cpu_class_by_name(const char *cpu_model)
33 {
34     ObjectClass *oc;
35     char *typename;
36     char **cpuname;
37 
38     cpuname = g_strsplit(cpu_model, ",", 1);
39     typename = g_strdup_printf(HEXAGON_CPU_TYPE_NAME("%s"), cpuname[0]);
40     oc = object_class_by_name(typename);
41     g_strfreev(cpuname);
42     g_free(typename);
43     if (!oc || !object_class_dynamic_cast(oc, TYPE_HEXAGON_CPU) ||
44         object_class_is_abstract(oc)) {
45         return NULL;
46     }
47     return oc;
48 }
49 
50 static Property hexagon_lldb_compat_property =
51     DEFINE_PROP_BOOL("lldb-compat", HexagonCPU, lldb_compat, false);
52 static Property hexagon_lldb_stack_adjust_property =
53     DEFINE_PROP_UNSIGNED("lldb-stack-adjust", HexagonCPU, lldb_stack_adjust,
54                          0, qdev_prop_uint32, target_ulong);
55 
56 const char * const hexagon_regnames[TOTAL_PER_THREAD_REGS] = {
57    "r0", "r1",  "r2",  "r3",  "r4",   "r5",  "r6",  "r7",
58    "r8", "r9",  "r10", "r11", "r12",  "r13", "r14", "r15",
59   "r16", "r17", "r18", "r19", "r20",  "r21", "r22", "r23",
60   "r24", "r25", "r26", "r27", "r28",  "r29", "r30", "r31",
61   "sa0", "lc0", "sa1", "lc1", "p3_0", "c5",  "m0",  "m1",
62   "usr", "pc",  "ugp", "gp",  "cs0",  "cs1", "c14", "c15",
63   "c16", "c17", "c18", "c19", "pkt_cnt",  "insn_cnt", "c22", "c23",
64   "c24", "c25", "c26", "c27", "c28",  "c29", "c30", "c31",
65 };
66 
67 /*
68  * One of the main debugging techniques is to use "-d cpu" and compare against
69  * LLDB output when single stepping.  However, the target and qemu put the
70  * stacks at different locations.  This is used to compensate so the diff is
71  * cleaner.
72  */
73 static target_ulong adjust_stack_ptrs(CPUHexagonState *env, target_ulong addr)
74 {
75     HexagonCPU *cpu = env_archcpu(env);
76     target_ulong stack_adjust = cpu->lldb_stack_adjust;
77     target_ulong stack_start = env->stack_start;
78     target_ulong stack_size = 0x10000;
79 
80     if (stack_adjust == 0) {
81         return addr;
82     }
83 
84     if (stack_start + 0x1000 >= addr && addr >= (stack_start - stack_size)) {
85         return addr - stack_adjust;
86     }
87     return addr;
88 }
89 
90 /* HEX_REG_P3_0 (aka C4) is an alias for the predicate registers */
91 static target_ulong read_p3_0(CPUHexagonState *env)
92 {
93     int32_t control_reg = 0;
94     int i;
95     for (i = NUM_PREGS - 1; i >= 0; i--) {
96         control_reg <<= 8;
97         control_reg |= env->pred[i] & 0xff;
98     }
99     return control_reg;
100 }
101 
102 static void print_reg(FILE *f, CPUHexagonState *env, int regnum)
103 {
104     target_ulong value;
105 
106     if (regnum == HEX_REG_P3_0) {
107         value = read_p3_0(env);
108     } else {
109         value = regnum < 32 ? adjust_stack_ptrs(env, env->gpr[regnum])
110                             : env->gpr[regnum];
111     }
112 
113     qemu_fprintf(f, "  %s = 0x" TARGET_FMT_lx "\n",
114                  hexagon_regnames[regnum], value);
115 }
116 
117 static void hexagon_dump(CPUHexagonState *env, FILE *f)
118 {
119     HexagonCPU *cpu = env_archcpu(env);
120 
121     if (cpu->lldb_compat) {
122         /*
123          * When comparing with LLDB, it doesn't step through single-cycle
124          * hardware loops the same way.  So, we just skip them here
125          */
126         if (env->gpr[HEX_REG_PC] == env->last_pc_dumped) {
127             return;
128         }
129         env->last_pc_dumped = env->gpr[HEX_REG_PC];
130     }
131 
132     qemu_fprintf(f, "General Purpose Registers = {\n");
133     for (int i = 0; i < 32; i++) {
134         print_reg(f, env, i);
135     }
136     print_reg(f, env, HEX_REG_SA0);
137     print_reg(f, env, HEX_REG_LC0);
138     print_reg(f, env, HEX_REG_SA1);
139     print_reg(f, env, HEX_REG_LC1);
140     print_reg(f, env, HEX_REG_M0);
141     print_reg(f, env, HEX_REG_M1);
142     print_reg(f, env, HEX_REG_USR);
143     print_reg(f, env, HEX_REG_P3_0);
144     print_reg(f, env, HEX_REG_GP);
145     print_reg(f, env, HEX_REG_UGP);
146     print_reg(f, env, HEX_REG_PC);
147 #ifdef CONFIG_USER_ONLY
148     /*
149      * Not modelled in user mode, print junk to minimize the diff's
150      * with LLDB output
151      */
152     qemu_fprintf(f, "  cause = 0x000000db\n");
153     qemu_fprintf(f, "  badva = 0x00000000\n");
154     qemu_fprintf(f, "  cs0 = 0x00000000\n");
155     qemu_fprintf(f, "  cs1 = 0x00000000\n");
156 #else
157     print_reg(f, env, HEX_REG_CAUSE);
158     print_reg(f, env, HEX_REG_BADVA);
159     print_reg(f, env, HEX_REG_CS0);
160     print_reg(f, env, HEX_REG_CS1);
161 #endif
162     qemu_fprintf(f, "}\n");
163 }
164 
165 static void hexagon_dump_state(CPUState *cs, FILE *f, int flags)
166 {
167     HexagonCPU *cpu = HEXAGON_CPU(cs);
168     CPUHexagonState *env = &cpu->env;
169 
170     hexagon_dump(env, f);
171 }
172 
173 void hexagon_debug(CPUHexagonState *env)
174 {
175     hexagon_dump(env, stdout);
176 }
177 
178 static void hexagon_cpu_set_pc(CPUState *cs, vaddr value)
179 {
180     HexagonCPU *cpu = HEXAGON_CPU(cs);
181     CPUHexagonState *env = &cpu->env;
182     env->gpr[HEX_REG_PC] = value;
183 }
184 
185 static void hexagon_cpu_synchronize_from_tb(CPUState *cs,
186                                             const TranslationBlock *tb)
187 {
188     HexagonCPU *cpu = HEXAGON_CPU(cs);
189     CPUHexagonState *env = &cpu->env;
190     env->gpr[HEX_REG_PC] = tb->pc;
191 }
192 
193 static bool hexagon_cpu_has_work(CPUState *cs)
194 {
195     return true;
196 }
197 
198 void restore_state_to_opc(CPUHexagonState *env, TranslationBlock *tb,
199                           target_ulong *data)
200 {
201     env->gpr[HEX_REG_PC] = data[0];
202 }
203 
204 static void hexagon_cpu_reset(DeviceState *dev)
205 {
206     CPUState *cs = CPU(dev);
207     HexagonCPU *cpu = HEXAGON_CPU(cs);
208     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(cpu);
209     CPUHexagonState *env = &cpu->env;
210 
211     mcc->parent_reset(dev);
212 
213     set_default_nan_mode(1, &env->fp_status);
214     set_float_detect_tininess(float_tininess_before_rounding, &env->fp_status);
215 }
216 
217 static void hexagon_cpu_disas_set_info(CPUState *s, disassemble_info *info)
218 {
219     info->print_insn = print_insn_hexagon;
220 }
221 
222 static void hexagon_cpu_realize(DeviceState *dev, Error **errp)
223 {
224     CPUState *cs = CPU(dev);
225     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(dev);
226     Error *local_err = NULL;
227 
228     cpu_exec_realizefn(cs, &local_err);
229     if (local_err != NULL) {
230         error_propagate(errp, local_err);
231         return;
232     }
233 
234     qemu_init_vcpu(cs);
235     cpu_reset(cs);
236 
237     mcc->parent_realize(dev, errp);
238 }
239 
240 static void hexagon_cpu_init(Object *obj)
241 {
242     HexagonCPU *cpu = HEXAGON_CPU(obj);
243 
244     cpu_set_cpustate_pointers(cpu);
245     qdev_property_add_static(DEVICE(obj), &hexagon_lldb_compat_property);
246     qdev_property_add_static(DEVICE(obj), &hexagon_lldb_stack_adjust_property);
247 }
248 
249 static bool hexagon_tlb_fill(CPUState *cs, vaddr address, int size,
250                              MMUAccessType access_type, int mmu_idx,
251                              bool probe, uintptr_t retaddr)
252 {
253 #ifdef CONFIG_USER_ONLY
254     switch (access_type) {
255     case MMU_INST_FETCH:
256         cs->exception_index = HEX_EXCP_FETCH_NO_UPAGE;
257         break;
258     case MMU_DATA_LOAD:
259         cs->exception_index = HEX_EXCP_PRIV_NO_UREAD;
260         break;
261     case MMU_DATA_STORE:
262         cs->exception_index = HEX_EXCP_PRIV_NO_UWRITE;
263         break;
264     }
265     cpu_loop_exit_restore(cs, retaddr);
266 #else
267 #error System mode not implemented for Hexagon
268 #endif
269 }
270 
271 #include "hw/core/tcg-cpu-ops.h"
272 
273 static struct TCGCPUOps hexagon_tcg_ops = {
274     .initialize = hexagon_translate_init,
275     .synchronize_from_tb = hexagon_cpu_synchronize_from_tb,
276     .tlb_fill = hexagon_tlb_fill,
277 };
278 
279 static void hexagon_cpu_class_init(ObjectClass *c, void *data)
280 {
281     HexagonCPUClass *mcc = HEXAGON_CPU_CLASS(c);
282     CPUClass *cc = CPU_CLASS(c);
283     DeviceClass *dc = DEVICE_CLASS(c);
284 
285     device_class_set_parent_realize(dc, hexagon_cpu_realize,
286                                     &mcc->parent_realize);
287 
288     device_class_set_parent_reset(dc, hexagon_cpu_reset, &mcc->parent_reset);
289 
290     cc->class_by_name = hexagon_cpu_class_by_name;
291     cc->has_work = hexagon_cpu_has_work;
292     cc->dump_state = hexagon_dump_state;
293     cc->set_pc = hexagon_cpu_set_pc;
294     cc->gdb_read_register = hexagon_gdb_read_register;
295     cc->gdb_write_register = hexagon_gdb_write_register;
296     cc->gdb_num_core_regs = TOTAL_PER_THREAD_REGS;
297     cc->gdb_stop_before_watchpoint = true;
298     cc->disas_set_info = hexagon_cpu_disas_set_info;
299     cc->tcg_ops = &hexagon_tcg_ops;
300 }
301 
302 #define DEFINE_CPU(type_name, initfn)      \
303     {                                      \
304         .name = type_name,                 \
305         .parent = TYPE_HEXAGON_CPU,        \
306         .instance_init = initfn            \
307     }
308 
309 static const TypeInfo hexagon_cpu_type_infos[] = {
310     {
311         .name = TYPE_HEXAGON_CPU,
312         .parent = TYPE_CPU,
313         .instance_size = sizeof(HexagonCPU),
314         .instance_init = hexagon_cpu_init,
315         .abstract = true,
316         .class_size = sizeof(HexagonCPUClass),
317         .class_init = hexagon_cpu_class_init,
318     },
319     DEFINE_CPU(TYPE_HEXAGON_CPU_V67,              hexagon_v67_cpu_init),
320 };
321 
322 DEFINE_TYPES(hexagon_cpu_type_infos)
323