xref: /openbmc/qemu/target/hexagon/cpu.c (revision 646746a1)
1 /*
2  *  Copyright(c) 2019-2023 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 #include "tcg/tcg.h"
27 #include "exec/gdbstub.h"
28 
29 static void hexagon_v66_cpu_init(Object *obj) { }
30 static void hexagon_v67_cpu_init(Object *obj) { }
31 static void hexagon_v68_cpu_init(Object *obj) { }
32 static void hexagon_v69_cpu_init(Object *obj) { }
33 static void hexagon_v71_cpu_init(Object *obj) { }
34 static void hexagon_v73_cpu_init(Object *obj) { }
35 
36 static ObjectClass *hexagon_cpu_class_by_name(const char *cpu_model)
37 {
38     ObjectClass *oc;
39     char *typename;
40     char **cpuname;
41 
42     cpuname = g_strsplit(cpu_model, ",", 1);
43     typename = g_strdup_printf(HEXAGON_CPU_TYPE_NAME("%s"), cpuname[0]);
44     oc = object_class_by_name(typename);
45     g_strfreev(cpuname);
46     g_free(typename);
47 
48     return oc;
49 }
50 
51 static Property hexagon_cpu_properties[] = {
52     DEFINE_PROP_BOOL("lldb-compat", HexagonCPU, lldb_compat, false),
53     DEFINE_PROP_UNSIGNED("lldb-stack-adjust", HexagonCPU, lldb_stack_adjust, 0,
54                          qdev_prop_uint32, target_ulong),
55     DEFINE_PROP_BOOL("short-circuit", HexagonCPU, short_circuit, true),
56     DEFINE_PROP_END_OF_LIST()
57 };
58 
59 const char * const hexagon_regnames[TOTAL_PER_THREAD_REGS] = {
60    "r0", "r1",  "r2",  "r3",  "r4",   "r5",  "r6",  "r7",
61    "r8", "r9",  "r10", "r11", "r12",  "r13", "r14", "r15",
62   "r16", "r17", "r18", "r19", "r20",  "r21", "r22", "r23",
63   "r24", "r25", "r26", "r27", "r28",  "r29", "r30", "r31",
64   "sa0", "lc0", "sa1", "lc1", "p3_0", "c5",  "m0",  "m1",
65   "usr", "pc",  "ugp", "gp",  "cs0",  "cs1", "c14", "c15",
66   "c16", "c17", "c18", "c19", "pkt_cnt",  "insn_cnt", "hvx_cnt", "c23",
67   "c24", "c25", "c26", "c27", "c28",  "c29", "c30", "c31",
68 };
69 
70 /*
71  * One of the main debugging techniques is to use "-d cpu" and compare against
72  * LLDB output when single stepping.  However, the target and qemu put the
73  * stacks at different locations.  This is used to compensate so the diff is
74  * cleaner.
75  */
76 static target_ulong adjust_stack_ptrs(CPUHexagonState *env, target_ulong addr)
77 {
78     HexagonCPU *cpu = env_archcpu(env);
79     target_ulong stack_adjust = cpu->lldb_stack_adjust;
80     target_ulong stack_start = env->stack_start;
81     target_ulong stack_size = 0x10000;
82 
83     if (stack_adjust == 0) {
84         return addr;
85     }
86 
87     if (stack_start + 0x1000 >= addr && addr >= (stack_start - stack_size)) {
88         return addr - stack_adjust;
89     }
90     return addr;
91 }
92 
93 /* HEX_REG_P3_0_ALIASED (aka C4) is an alias for the predicate registers */
94 static target_ulong read_p3_0(CPUHexagonState *env)
95 {
96     int32_t control_reg = 0;
97     int i;
98     for (i = NUM_PREGS - 1; i >= 0; i--) {
99         control_reg <<= 8;
100         control_reg |= env->pred[i] & 0xff;
101     }
102     return control_reg;
103 }
104 
105 static void print_reg(FILE *f, CPUHexagonState *env, int regnum)
106 {
107     target_ulong value;
108 
109     if (regnum == HEX_REG_P3_0_ALIASED) {
110         value = read_p3_0(env);
111     } else {
112         value = regnum < 32 ? adjust_stack_ptrs(env, env->gpr[regnum])
113                             : env->gpr[regnum];
114     }
115 
116     qemu_fprintf(f, "  %s = 0x" TARGET_FMT_lx "\n",
117                  hexagon_regnames[regnum], value);
118 }
119 
120 static void print_vreg(FILE *f, CPUHexagonState *env, int regnum,
121                        bool skip_if_zero)
122 {
123     if (skip_if_zero) {
124         bool nonzero_found = false;
125         for (int i = 0; i < MAX_VEC_SIZE_BYTES; i++) {
126             if (env->VRegs[regnum].ub[i] != 0) {
127                 nonzero_found = true;
128                 break;
129             }
130         }
131         if (!nonzero_found) {
132             return;
133         }
134     }
135 
136     qemu_fprintf(f, "  v%d = ( ", regnum);
137     qemu_fprintf(f, "0x%02x", env->VRegs[regnum].ub[MAX_VEC_SIZE_BYTES - 1]);
138     for (int i = MAX_VEC_SIZE_BYTES - 2; i >= 0; i--) {
139         qemu_fprintf(f, ", 0x%02x", env->VRegs[regnum].ub[i]);
140     }
141     qemu_fprintf(f, " )\n");
142 }
143 
144 void hexagon_debug_vreg(CPUHexagonState *env, int regnum)
145 {
146     print_vreg(stdout, env, regnum, false);
147 }
148 
149 static void print_qreg(FILE *f, CPUHexagonState *env, int regnum,
150                        bool skip_if_zero)
151 {
152     if (skip_if_zero) {
153         bool nonzero_found = false;
154         for (int i = 0; i < MAX_VEC_SIZE_BYTES / 8; i++) {
155             if (env->QRegs[regnum].ub[i] != 0) {
156                 nonzero_found = true;
157                 break;
158             }
159         }
160         if (!nonzero_found) {
161             return;
162         }
163     }
164 
165     qemu_fprintf(f, "  q%d = ( ", regnum);
166     qemu_fprintf(f, "0x%02x",
167                  env->QRegs[regnum].ub[MAX_VEC_SIZE_BYTES / 8 - 1]);
168     for (int i = MAX_VEC_SIZE_BYTES / 8 - 2; i >= 0; i--) {
169         qemu_fprintf(f, ", 0x%02x", env->QRegs[regnum].ub[i]);
170     }
171     qemu_fprintf(f, " )\n");
172 }
173 
174 void hexagon_debug_qreg(CPUHexagonState *env, int regnum)
175 {
176     print_qreg(stdout, env, regnum, false);
177 }
178 
179 static void hexagon_dump(CPUHexagonState *env, FILE *f, int flags)
180 {
181     HexagonCPU *cpu = env_archcpu(env);
182 
183     if (cpu->lldb_compat) {
184         /*
185          * When comparing with LLDB, it doesn't step through single-cycle
186          * hardware loops the same way.  So, we just skip them here
187          */
188         if (env->gpr[HEX_REG_PC] == env->last_pc_dumped) {
189             return;
190         }
191         env->last_pc_dumped = env->gpr[HEX_REG_PC];
192     }
193 
194     qemu_fprintf(f, "General Purpose Registers = {\n");
195     for (int i = 0; i < 32; i++) {
196         print_reg(f, env, i);
197     }
198     print_reg(f, env, HEX_REG_SA0);
199     print_reg(f, env, HEX_REG_LC0);
200     print_reg(f, env, HEX_REG_SA1);
201     print_reg(f, env, HEX_REG_LC1);
202     print_reg(f, env, HEX_REG_M0);
203     print_reg(f, env, HEX_REG_M1);
204     print_reg(f, env, HEX_REG_USR);
205     print_reg(f, env, HEX_REG_P3_0_ALIASED);
206     print_reg(f, env, HEX_REG_GP);
207     print_reg(f, env, HEX_REG_UGP);
208     print_reg(f, env, HEX_REG_PC);
209 #ifdef CONFIG_USER_ONLY
210     /*
211      * Not modelled in user mode, print junk to minimize the diff's
212      * with LLDB output
213      */
214     qemu_fprintf(f, "  cause = 0x000000db\n");
215     qemu_fprintf(f, "  badva = 0x00000000\n");
216     qemu_fprintf(f, "  cs0 = 0x00000000\n");
217     qemu_fprintf(f, "  cs1 = 0x00000000\n");
218 #else
219     print_reg(f, env, HEX_REG_CAUSE);
220     print_reg(f, env, HEX_REG_BADVA);
221     print_reg(f, env, HEX_REG_CS0);
222     print_reg(f, env, HEX_REG_CS1);
223 #endif
224     qemu_fprintf(f, "}\n");
225 
226     if (flags & CPU_DUMP_FPU) {
227         qemu_fprintf(f, "Vector Registers = {\n");
228         for (int i = 0; i < NUM_VREGS; i++) {
229             print_vreg(f, env, i, true);
230         }
231         for (int i = 0; i < NUM_QREGS; i++) {
232             print_qreg(f, env, i, true);
233         }
234         qemu_fprintf(f, "}\n");
235     }
236 }
237 
238 static void hexagon_dump_state(CPUState *cs, FILE *f, int flags)
239 {
240     hexagon_dump(cpu_env(cs), f, flags);
241 }
242 
243 void hexagon_debug(CPUHexagonState *env)
244 {
245     hexagon_dump(env, stdout, CPU_DUMP_FPU);
246 }
247 
248 static void hexagon_cpu_set_pc(CPUState *cs, vaddr value)
249 {
250     cpu_env(cs)->gpr[HEX_REG_PC] = value;
251 }
252 
253 static vaddr hexagon_cpu_get_pc(CPUState *cs)
254 {
255     return cpu_env(cs)->gpr[HEX_REG_PC];
256 }
257 
258 static void hexagon_cpu_synchronize_from_tb(CPUState *cs,
259                                             const TranslationBlock *tb)
260 {
261     tcg_debug_assert(!tcg_cflags_has(cs, CF_PCREL));
262     cpu_env(cs)->gpr[HEX_REG_PC] = tb->pc;
263 }
264 
265 static bool hexagon_cpu_has_work(CPUState *cs)
266 {
267     return true;
268 }
269 
270 static void hexagon_restore_state_to_opc(CPUState *cs,
271                                          const TranslationBlock *tb,
272                                          const uint64_t *data)
273 {
274     cpu_env(cs)->gpr[HEX_REG_PC] = data[0];
275 }
276 
277 static void hexagon_cpu_reset_hold(Object *obj, ResetType type)
278 {
279     CPUState *cs = CPU(obj);
280     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(obj);
281     CPUHexagonState *env = cpu_env(cs);
282 
283     if (mcc->parent_phases.hold) {
284         mcc->parent_phases.hold(obj, type);
285     }
286 
287     set_default_nan_mode(1, &env->fp_status);
288     set_float_detect_tininess(float_tininess_before_rounding, &env->fp_status);
289 }
290 
291 static void hexagon_cpu_disas_set_info(CPUState *s, disassemble_info *info)
292 {
293     info->print_insn = print_insn_hexagon;
294 }
295 
296 static void hexagon_cpu_realize(DeviceState *dev, Error **errp)
297 {
298     CPUState *cs = CPU(dev);
299     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(dev);
300     Error *local_err = NULL;
301 
302     cpu_exec_realizefn(cs, &local_err);
303     if (local_err != NULL) {
304         error_propagate(errp, local_err);
305         return;
306     }
307 
308     gdb_register_coprocessor(cs, hexagon_hvx_gdb_read_register,
309                              hexagon_hvx_gdb_write_register,
310                              gdb_find_static_feature("hexagon-hvx.xml"), 0);
311 
312     qemu_init_vcpu(cs);
313     cpu_reset(cs);
314 
315     mcc->parent_realize(dev, errp);
316 }
317 
318 static void hexagon_cpu_init(Object *obj)
319 {
320 }
321 
322 #include "hw/core/tcg-cpu-ops.h"
323 
324 static const TCGCPUOps hexagon_tcg_ops = {
325     .initialize = hexagon_translate_init,
326     .synchronize_from_tb = hexagon_cpu_synchronize_from_tb,
327     .restore_state_to_opc = hexagon_restore_state_to_opc,
328 };
329 
330 static void hexagon_cpu_class_init(ObjectClass *c, void *data)
331 {
332     HexagonCPUClass *mcc = HEXAGON_CPU_CLASS(c);
333     CPUClass *cc = CPU_CLASS(c);
334     DeviceClass *dc = DEVICE_CLASS(c);
335     ResettableClass *rc = RESETTABLE_CLASS(c);
336 
337     device_class_set_parent_realize(dc, hexagon_cpu_realize,
338                                     &mcc->parent_realize);
339 
340     device_class_set_props(dc, hexagon_cpu_properties);
341     resettable_class_set_parent_phases(rc, NULL, hexagon_cpu_reset_hold, NULL,
342                                        &mcc->parent_phases);
343 
344     cc->class_by_name = hexagon_cpu_class_by_name;
345     cc->has_work = hexagon_cpu_has_work;
346     cc->dump_state = hexagon_dump_state;
347     cc->set_pc = hexagon_cpu_set_pc;
348     cc->get_pc = hexagon_cpu_get_pc;
349     cc->gdb_read_register = hexagon_gdb_read_register;
350     cc->gdb_write_register = hexagon_gdb_write_register;
351     cc->gdb_stop_before_watchpoint = true;
352     cc->gdb_core_xml_file = "hexagon-core.xml";
353     cc->disas_set_info = hexagon_cpu_disas_set_info;
354     cc->tcg_ops = &hexagon_tcg_ops;
355 }
356 
357 #define DEFINE_CPU(type_name, initfn)      \
358     {                                      \
359         .name = type_name,                 \
360         .parent = TYPE_HEXAGON_CPU,        \
361         .instance_init = initfn            \
362     }
363 
364 static const TypeInfo hexagon_cpu_type_infos[] = {
365     {
366         .name = TYPE_HEXAGON_CPU,
367         .parent = TYPE_CPU,
368         .instance_size = sizeof(HexagonCPU),
369         .instance_align = __alignof(HexagonCPU),
370         .instance_init = hexagon_cpu_init,
371         .abstract = true,
372         .class_size = sizeof(HexagonCPUClass),
373         .class_init = hexagon_cpu_class_init,
374     },
375     DEFINE_CPU(TYPE_HEXAGON_CPU_V66,              hexagon_v66_cpu_init),
376     DEFINE_CPU(TYPE_HEXAGON_CPU_V67,              hexagon_v67_cpu_init),
377     DEFINE_CPU(TYPE_HEXAGON_CPU_V68,              hexagon_v68_cpu_init),
378     DEFINE_CPU(TYPE_HEXAGON_CPU_V69,              hexagon_v69_cpu_init),
379     DEFINE_CPU(TYPE_HEXAGON_CPU_V71,              hexagon_v71_cpu_init),
380     DEFINE_CPU(TYPE_HEXAGON_CPU_V73,              hexagon_v73_cpu_init),
381 };
382 
383 DEFINE_TYPES(hexagon_cpu_type_infos)
384