xref: /openbmc/qemu/target/hexagon/cpu.c (revision 4fa485a7)
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/qemu-print.h"
20 #include "cpu.h"
21 #include "internal.h"
22 #include "exec/exec-all.h"
23 #include "qapi/error.h"
24 #include "hw/qdev-properties.h"
25 #include "fpu/softfloat-helpers.h"
26 
27 static void hexagon_v67_cpu_init(Object *obj)
28 {
29 }
30 
31 static ObjectClass *hexagon_cpu_class_by_name(const char *cpu_model)
32 {
33     ObjectClass *oc;
34     char *typename;
35     char **cpuname;
36 
37     cpuname = g_strsplit(cpu_model, ",", 1);
38     typename = g_strdup_printf(HEXAGON_CPU_TYPE_NAME("%s"), cpuname[0]);
39     oc = object_class_by_name(typename);
40     g_strfreev(cpuname);
41     g_free(typename);
42     if (!oc || !object_class_dynamic_cast(oc, TYPE_HEXAGON_CPU) ||
43         object_class_is_abstract(oc)) {
44         return NULL;
45     }
46     return oc;
47 }
48 
49 static Property hexagon_lldb_compat_property =
50     DEFINE_PROP_BOOL("lldb-compat", HexagonCPU, lldb_compat, false);
51 static Property hexagon_lldb_stack_adjust_property =
52     DEFINE_PROP_UNSIGNED("lldb-stack-adjust", HexagonCPU, lldb_stack_adjust,
53                          0, qdev_prop_uint32, target_ulong);
54 
55 const char * const hexagon_regnames[TOTAL_PER_THREAD_REGS] = {
56    "r0", "r1",  "r2",  "r3",  "r4",   "r5",  "r6",  "r7",
57    "r8", "r9",  "r10", "r11", "r12",  "r13", "r14", "r15",
58   "r16", "r17", "r18", "r19", "r20",  "r21", "r22", "r23",
59   "r24", "r25", "r26", "r27", "r28",  "r29", "r30", "r31",
60   "sa0", "lc0", "sa1", "lc1", "p3_0", "c5",  "m0",  "m1",
61   "usr", "pc",  "ugp", "gp",  "cs0",  "cs1", "c14", "c15",
62   "c16", "c17", "c18", "c19", "pkt_cnt",  "insn_cnt", "hvx_cnt", "c23",
63   "c24", "c25", "c26", "c27", "c28",  "c29", "c30", "c31",
64 };
65 
66 /*
67  * One of the main debugging techniques is to use "-d cpu" and compare against
68  * LLDB output when single stepping.  However, the target and qemu put the
69  * stacks at different locations.  This is used to compensate so the diff is
70  * cleaner.
71  */
72 static target_ulong adjust_stack_ptrs(CPUHexagonState *env, target_ulong addr)
73 {
74     HexagonCPU *cpu = env_archcpu(env);
75     target_ulong stack_adjust = cpu->lldb_stack_adjust;
76     target_ulong stack_start = env->stack_start;
77     target_ulong stack_size = 0x10000;
78 
79     if (stack_adjust == 0) {
80         return addr;
81     }
82 
83     if (stack_start + 0x1000 >= addr && addr >= (stack_start - stack_size)) {
84         return addr - stack_adjust;
85     }
86     return addr;
87 }
88 
89 /* HEX_REG_P3_0 (aka C4) is an alias for the predicate registers */
90 static target_ulong read_p3_0(CPUHexagonState *env)
91 {
92     int32_t control_reg = 0;
93     int i;
94     for (i = NUM_PREGS - 1; i >= 0; i--) {
95         control_reg <<= 8;
96         control_reg |= env->pred[i] & 0xff;
97     }
98     return control_reg;
99 }
100 
101 static void print_reg(FILE *f, CPUHexagonState *env, int regnum)
102 {
103     target_ulong value;
104 
105     if (regnum == HEX_REG_P3_0) {
106         value = read_p3_0(env);
107     } else {
108         value = regnum < 32 ? adjust_stack_ptrs(env, env->gpr[regnum])
109                             : env->gpr[regnum];
110     }
111 
112     qemu_fprintf(f, "  %s = 0x" TARGET_FMT_lx "\n",
113                  hexagon_regnames[regnum], value);
114 }
115 
116 static void print_vreg(FILE *f, CPUHexagonState *env, int regnum,
117                        bool skip_if_zero)
118 {
119     if (skip_if_zero) {
120         bool nonzero_found = false;
121         for (int i = 0; i < MAX_VEC_SIZE_BYTES; i++) {
122             if (env->VRegs[regnum].ub[i] != 0) {
123                 nonzero_found = true;
124                 break;
125             }
126         }
127         if (!nonzero_found) {
128             return;
129         }
130     }
131 
132     qemu_fprintf(f, "  v%d = ( ", regnum);
133     qemu_fprintf(f, "0x%02x", env->VRegs[regnum].ub[MAX_VEC_SIZE_BYTES - 1]);
134     for (int i = MAX_VEC_SIZE_BYTES - 2; i >= 0; i--) {
135         qemu_fprintf(f, ", 0x%02x", env->VRegs[regnum].ub[i]);
136     }
137     qemu_fprintf(f, " )\n");
138 }
139 
140 void hexagon_debug_vreg(CPUHexagonState *env, int regnum)
141 {
142     print_vreg(stdout, env, regnum, false);
143 }
144 
145 static void print_qreg(FILE *f, CPUHexagonState *env, int regnum,
146                        bool skip_if_zero)
147 {
148     if (skip_if_zero) {
149         bool nonzero_found = false;
150         for (int i = 0; i < MAX_VEC_SIZE_BYTES / 8; i++) {
151             if (env->QRegs[regnum].ub[i] != 0) {
152                 nonzero_found = true;
153                 break;
154             }
155         }
156         if (!nonzero_found) {
157             return;
158         }
159     }
160 
161     qemu_fprintf(f, "  q%d = ( ", regnum);
162     qemu_fprintf(f, "0x%02x",
163                  env->QRegs[regnum].ub[MAX_VEC_SIZE_BYTES / 8 - 1]);
164     for (int i = MAX_VEC_SIZE_BYTES / 8 - 2; i >= 0; i--) {
165         qemu_fprintf(f, ", 0x%02x", env->QRegs[regnum].ub[i]);
166     }
167     qemu_fprintf(f, " )\n");
168 }
169 
170 void hexagon_debug_qreg(CPUHexagonState *env, int regnum)
171 {
172     print_qreg(stdout, env, regnum, false);
173 }
174 
175 static void hexagon_dump(CPUHexagonState *env, FILE *f, int flags)
176 {
177     HexagonCPU *cpu = env_archcpu(env);
178 
179     if (cpu->lldb_compat) {
180         /*
181          * When comparing with LLDB, it doesn't step through single-cycle
182          * hardware loops the same way.  So, we just skip them here
183          */
184         if (env->gpr[HEX_REG_PC] == env->last_pc_dumped) {
185             return;
186         }
187         env->last_pc_dumped = env->gpr[HEX_REG_PC];
188     }
189 
190     qemu_fprintf(f, "General Purpose Registers = {\n");
191     for (int i = 0; i < 32; i++) {
192         print_reg(f, env, i);
193     }
194     print_reg(f, env, HEX_REG_SA0);
195     print_reg(f, env, HEX_REG_LC0);
196     print_reg(f, env, HEX_REG_SA1);
197     print_reg(f, env, HEX_REG_LC1);
198     print_reg(f, env, HEX_REG_M0);
199     print_reg(f, env, HEX_REG_M1);
200     print_reg(f, env, HEX_REG_USR);
201     print_reg(f, env, HEX_REG_P3_0);
202     print_reg(f, env, HEX_REG_GP);
203     print_reg(f, env, HEX_REG_UGP);
204     print_reg(f, env, HEX_REG_PC);
205 #ifdef CONFIG_USER_ONLY
206     /*
207      * Not modelled in user mode, print junk to minimize the diff's
208      * with LLDB output
209      */
210     qemu_fprintf(f, "  cause = 0x000000db\n");
211     qemu_fprintf(f, "  badva = 0x00000000\n");
212     qemu_fprintf(f, "  cs0 = 0x00000000\n");
213     qemu_fprintf(f, "  cs1 = 0x00000000\n");
214 #else
215     print_reg(f, env, HEX_REG_CAUSE);
216     print_reg(f, env, HEX_REG_BADVA);
217     print_reg(f, env, HEX_REG_CS0);
218     print_reg(f, env, HEX_REG_CS1);
219 #endif
220     qemu_fprintf(f, "}\n");
221 
222     if (flags & CPU_DUMP_FPU) {
223         qemu_fprintf(f, "Vector Registers = {\n");
224         for (int i = 0; i < NUM_VREGS; i++) {
225             print_vreg(f, env, i, true);
226         }
227         for (int i = 0; i < NUM_QREGS; i++) {
228             print_qreg(f, env, i, true);
229         }
230         qemu_fprintf(f, "}\n");
231     }
232 }
233 
234 static void hexagon_dump_state(CPUState *cs, FILE *f, int flags)
235 {
236     HexagonCPU *cpu = HEXAGON_CPU(cs);
237     CPUHexagonState *env = &cpu->env;
238 
239     hexagon_dump(env, f, flags);
240 }
241 
242 void hexagon_debug(CPUHexagonState *env)
243 {
244     hexagon_dump(env, stdout, CPU_DUMP_FPU);
245 }
246 
247 static void hexagon_cpu_set_pc(CPUState *cs, vaddr value)
248 {
249     HexagonCPU *cpu = HEXAGON_CPU(cs);
250     CPUHexagonState *env = &cpu->env;
251     env->gpr[HEX_REG_PC] = value;
252 }
253 
254 static vaddr hexagon_cpu_get_pc(CPUState *cs)
255 {
256     HexagonCPU *cpu = HEXAGON_CPU(cs);
257     CPUHexagonState *env = &cpu->env;
258     return env->gpr[HEX_REG_PC];
259 }
260 
261 static void hexagon_cpu_synchronize_from_tb(CPUState *cs,
262                                             const TranslationBlock *tb)
263 {
264     HexagonCPU *cpu = HEXAGON_CPU(cs);
265     CPUHexagonState *env = &cpu->env;
266     env->gpr[HEX_REG_PC] = tb_pc(tb);
267 }
268 
269 static bool hexagon_cpu_has_work(CPUState *cs)
270 {
271     return true;
272 }
273 
274 static void hexagon_restore_state_to_opc(CPUState *cs,
275                                          const TranslationBlock *tb,
276                                          const uint64_t *data)
277 {
278     HexagonCPU *cpu = HEXAGON_CPU(cs);
279     CPUHexagonState *env = &cpu->env;
280 
281     env->gpr[HEX_REG_PC] = data[0];
282 }
283 
284 static void hexagon_cpu_reset_hold(Object *obj)
285 {
286     CPUState *cs = CPU(obj);
287     HexagonCPU *cpu = HEXAGON_CPU(cs);
288     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(cpu);
289     CPUHexagonState *env = &cpu->env;
290 
291     if (mcc->parent_phases.hold) {
292         mcc->parent_phases.hold(obj);
293     }
294 
295     set_default_nan_mode(1, &env->fp_status);
296     set_float_detect_tininess(float_tininess_before_rounding, &env->fp_status);
297 }
298 
299 static void hexagon_cpu_disas_set_info(CPUState *s, disassemble_info *info)
300 {
301     info->print_insn = print_insn_hexagon;
302 }
303 
304 static void hexagon_cpu_realize(DeviceState *dev, Error **errp)
305 {
306     CPUState *cs = CPU(dev);
307     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(dev);
308     Error *local_err = NULL;
309 
310     cpu_exec_realizefn(cs, &local_err);
311     if (local_err != NULL) {
312         error_propagate(errp, local_err);
313         return;
314     }
315 
316     qemu_init_vcpu(cs);
317     cpu_reset(cs);
318 
319     mcc->parent_realize(dev, errp);
320 }
321 
322 static void hexagon_cpu_init(Object *obj)
323 {
324     HexagonCPU *cpu = HEXAGON_CPU(obj);
325 
326     cpu_set_cpustate_pointers(cpu);
327     qdev_property_add_static(DEVICE(obj), &hexagon_lldb_compat_property);
328     qdev_property_add_static(DEVICE(obj), &hexagon_lldb_stack_adjust_property);
329 }
330 
331 #include "hw/core/tcg-cpu-ops.h"
332 
333 static const struct TCGCPUOps hexagon_tcg_ops = {
334     .initialize = hexagon_translate_init,
335     .synchronize_from_tb = hexagon_cpu_synchronize_from_tb,
336     .restore_state_to_opc = hexagon_restore_state_to_opc,
337 };
338 
339 static void hexagon_cpu_class_init(ObjectClass *c, void *data)
340 {
341     HexagonCPUClass *mcc = HEXAGON_CPU_CLASS(c);
342     CPUClass *cc = CPU_CLASS(c);
343     DeviceClass *dc = DEVICE_CLASS(c);
344     ResettableClass *rc = RESETTABLE_CLASS(c);
345 
346     device_class_set_parent_realize(dc, hexagon_cpu_realize,
347                                     &mcc->parent_realize);
348 
349     resettable_class_set_parent_phases(rc, NULL, hexagon_cpu_reset_hold, NULL,
350                                        &mcc->parent_phases);
351 
352     cc->class_by_name = hexagon_cpu_class_by_name;
353     cc->has_work = hexagon_cpu_has_work;
354     cc->dump_state = hexagon_dump_state;
355     cc->set_pc = hexagon_cpu_set_pc;
356     cc->get_pc = hexagon_cpu_get_pc;
357     cc->gdb_read_register = hexagon_gdb_read_register;
358     cc->gdb_write_register = hexagon_gdb_write_register;
359     cc->gdb_num_core_regs = TOTAL_PER_THREAD_REGS + NUM_VREGS + NUM_QREGS;
360     cc->gdb_stop_before_watchpoint = true;
361     cc->disas_set_info = hexagon_cpu_disas_set_info;
362     cc->tcg_ops = &hexagon_tcg_ops;
363 }
364 
365 #define DEFINE_CPU(type_name, initfn)      \
366     {                                      \
367         .name = type_name,                 \
368         .parent = TYPE_HEXAGON_CPU,        \
369         .instance_init = initfn            \
370     }
371 
372 static const TypeInfo hexagon_cpu_type_infos[] = {
373     {
374         .name = TYPE_HEXAGON_CPU,
375         .parent = TYPE_CPU,
376         .instance_size = sizeof(HexagonCPU),
377         .instance_init = hexagon_cpu_init,
378         .abstract = true,
379         .class_size = sizeof(HexagonCPUClass),
380         .class_init = hexagon_cpu_class_init,
381     },
382     DEFINE_CPU(TYPE_HEXAGON_CPU_V67,              hexagon_v67_cpu_init),
383 };
384 
385 DEFINE_TYPES(hexagon_cpu_type_infos)
386