xref: /openbmc/qemu/target/hexagon/cpu.c (revision 197a1372)
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 #include "tcg/tcg.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", "hvx_cnt", "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_ALIASED (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_ALIASED) {
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 print_vreg(FILE *f, CPUHexagonState *env, int regnum,
118                        bool skip_if_zero)
119 {
120     if (skip_if_zero) {
121         bool nonzero_found = false;
122         for (int i = 0; i < MAX_VEC_SIZE_BYTES; i++) {
123             if (env->VRegs[regnum].ub[i] != 0) {
124                 nonzero_found = true;
125                 break;
126             }
127         }
128         if (!nonzero_found) {
129             return;
130         }
131     }
132 
133     qemu_fprintf(f, "  v%d = ( ", regnum);
134     qemu_fprintf(f, "0x%02x", env->VRegs[regnum].ub[MAX_VEC_SIZE_BYTES - 1]);
135     for (int i = MAX_VEC_SIZE_BYTES - 2; i >= 0; i--) {
136         qemu_fprintf(f, ", 0x%02x", env->VRegs[regnum].ub[i]);
137     }
138     qemu_fprintf(f, " )\n");
139 }
140 
141 void hexagon_debug_vreg(CPUHexagonState *env, int regnum)
142 {
143     print_vreg(stdout, env, regnum, false);
144 }
145 
146 static void print_qreg(FILE *f, CPUHexagonState *env, int regnum,
147                        bool skip_if_zero)
148 {
149     if (skip_if_zero) {
150         bool nonzero_found = false;
151         for (int i = 0; i < MAX_VEC_SIZE_BYTES / 8; i++) {
152             if (env->QRegs[regnum].ub[i] != 0) {
153                 nonzero_found = true;
154                 break;
155             }
156         }
157         if (!nonzero_found) {
158             return;
159         }
160     }
161 
162     qemu_fprintf(f, "  q%d = ( ", regnum);
163     qemu_fprintf(f, "0x%02x",
164                  env->QRegs[regnum].ub[MAX_VEC_SIZE_BYTES / 8 - 1]);
165     for (int i = MAX_VEC_SIZE_BYTES / 8 - 2; i >= 0; i--) {
166         qemu_fprintf(f, ", 0x%02x", env->QRegs[regnum].ub[i]);
167     }
168     qemu_fprintf(f, " )\n");
169 }
170 
171 void hexagon_debug_qreg(CPUHexagonState *env, int regnum)
172 {
173     print_qreg(stdout, env, regnum, false);
174 }
175 
176 static void hexagon_dump(CPUHexagonState *env, FILE *f, int flags)
177 {
178     HexagonCPU *cpu = env_archcpu(env);
179 
180     if (cpu->lldb_compat) {
181         /*
182          * When comparing with LLDB, it doesn't step through single-cycle
183          * hardware loops the same way.  So, we just skip them here
184          */
185         if (env->gpr[HEX_REG_PC] == env->last_pc_dumped) {
186             return;
187         }
188         env->last_pc_dumped = env->gpr[HEX_REG_PC];
189     }
190 
191     qemu_fprintf(f, "General Purpose Registers = {\n");
192     for (int i = 0; i < 32; i++) {
193         print_reg(f, env, i);
194     }
195     print_reg(f, env, HEX_REG_SA0);
196     print_reg(f, env, HEX_REG_LC0);
197     print_reg(f, env, HEX_REG_SA1);
198     print_reg(f, env, HEX_REG_LC1);
199     print_reg(f, env, HEX_REG_M0);
200     print_reg(f, env, HEX_REG_M1);
201     print_reg(f, env, HEX_REG_USR);
202     print_reg(f, env, HEX_REG_P3_0_ALIASED);
203     print_reg(f, env, HEX_REG_GP);
204     print_reg(f, env, HEX_REG_UGP);
205     print_reg(f, env, HEX_REG_PC);
206 #ifdef CONFIG_USER_ONLY
207     /*
208      * Not modelled in user mode, print junk to minimize the diff's
209      * with LLDB output
210      */
211     qemu_fprintf(f, "  cause = 0x000000db\n");
212     qemu_fprintf(f, "  badva = 0x00000000\n");
213     qemu_fprintf(f, "  cs0 = 0x00000000\n");
214     qemu_fprintf(f, "  cs1 = 0x00000000\n");
215 #else
216     print_reg(f, env, HEX_REG_CAUSE);
217     print_reg(f, env, HEX_REG_BADVA);
218     print_reg(f, env, HEX_REG_CS0);
219     print_reg(f, env, HEX_REG_CS1);
220 #endif
221     qemu_fprintf(f, "}\n");
222 
223     if (flags & CPU_DUMP_FPU) {
224         qemu_fprintf(f, "Vector Registers = {\n");
225         for (int i = 0; i < NUM_VREGS; i++) {
226             print_vreg(f, env, i, true);
227         }
228         for (int i = 0; i < NUM_QREGS; i++) {
229             print_qreg(f, env, i, true);
230         }
231         qemu_fprintf(f, "}\n");
232     }
233 }
234 
235 static void hexagon_dump_state(CPUState *cs, FILE *f, int flags)
236 {
237     HexagonCPU *cpu = HEXAGON_CPU(cs);
238     CPUHexagonState *env = &cpu->env;
239 
240     hexagon_dump(env, 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     HexagonCPU *cpu = HEXAGON_CPU(cs);
251     CPUHexagonState *env = &cpu->env;
252     env->gpr[HEX_REG_PC] = value;
253 }
254 
255 static vaddr hexagon_cpu_get_pc(CPUState *cs)
256 {
257     HexagonCPU *cpu = HEXAGON_CPU(cs);
258     CPUHexagonState *env = &cpu->env;
259     return env->gpr[HEX_REG_PC];
260 }
261 
262 static void hexagon_cpu_synchronize_from_tb(CPUState *cs,
263                                             const TranslationBlock *tb)
264 {
265     HexagonCPU *cpu = HEXAGON_CPU(cs);
266     CPUHexagonState *env = &cpu->env;
267     tcg_debug_assert(!(cs->tcg_cflags & CF_PCREL));
268     env->gpr[HEX_REG_PC] = tb->pc;
269 }
270 
271 static bool hexagon_cpu_has_work(CPUState *cs)
272 {
273     return true;
274 }
275 
276 static void hexagon_restore_state_to_opc(CPUState *cs,
277                                          const TranslationBlock *tb,
278                                          const uint64_t *data)
279 {
280     HexagonCPU *cpu = HEXAGON_CPU(cs);
281     CPUHexagonState *env = &cpu->env;
282 
283     env->gpr[HEX_REG_PC] = data[0];
284 }
285 
286 static void hexagon_cpu_reset_hold(Object *obj)
287 {
288     CPUState *cs = CPU(obj);
289     HexagonCPU *cpu = HEXAGON_CPU(cs);
290     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(cpu);
291     CPUHexagonState *env = &cpu->env;
292 
293     if (mcc->parent_phases.hold) {
294         mcc->parent_phases.hold(obj);
295     }
296 
297     set_default_nan_mode(1, &env->fp_status);
298     set_float_detect_tininess(float_tininess_before_rounding, &env->fp_status);
299 }
300 
301 static void hexagon_cpu_disas_set_info(CPUState *s, disassemble_info *info)
302 {
303     info->print_insn = print_insn_hexagon;
304 }
305 
306 static void hexagon_cpu_realize(DeviceState *dev, Error **errp)
307 {
308     CPUState *cs = CPU(dev);
309     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(dev);
310     Error *local_err = NULL;
311 
312     cpu_exec_realizefn(cs, &local_err);
313     if (local_err != NULL) {
314         error_propagate(errp, local_err);
315         return;
316     }
317 
318     qemu_init_vcpu(cs);
319     cpu_reset(cs);
320 
321     mcc->parent_realize(dev, errp);
322 }
323 
324 static void hexagon_cpu_init(Object *obj)
325 {
326     HexagonCPU *cpu = HEXAGON_CPU(obj);
327 
328     cpu_set_cpustate_pointers(cpu);
329     qdev_property_add_static(DEVICE(obj), &hexagon_lldb_compat_property);
330     qdev_property_add_static(DEVICE(obj), &hexagon_lldb_stack_adjust_property);
331 }
332 
333 #include "hw/core/tcg-cpu-ops.h"
334 
335 static const struct TCGCPUOps hexagon_tcg_ops = {
336     .initialize = hexagon_translate_init,
337     .synchronize_from_tb = hexagon_cpu_synchronize_from_tb,
338     .restore_state_to_opc = hexagon_restore_state_to_opc,
339 };
340 
341 static void hexagon_cpu_class_init(ObjectClass *c, void *data)
342 {
343     HexagonCPUClass *mcc = HEXAGON_CPU_CLASS(c);
344     CPUClass *cc = CPU_CLASS(c);
345     DeviceClass *dc = DEVICE_CLASS(c);
346     ResettableClass *rc = RESETTABLE_CLASS(c);
347 
348     device_class_set_parent_realize(dc, hexagon_cpu_realize,
349                                     &mcc->parent_realize);
350 
351     resettable_class_set_parent_phases(rc, NULL, hexagon_cpu_reset_hold, NULL,
352                                        &mcc->parent_phases);
353 
354     cc->class_by_name = hexagon_cpu_class_by_name;
355     cc->has_work = hexagon_cpu_has_work;
356     cc->dump_state = hexagon_dump_state;
357     cc->set_pc = hexagon_cpu_set_pc;
358     cc->get_pc = hexagon_cpu_get_pc;
359     cc->gdb_read_register = hexagon_gdb_read_register;
360     cc->gdb_write_register = hexagon_gdb_write_register;
361     cc->gdb_num_core_regs = TOTAL_PER_THREAD_REGS + NUM_VREGS + NUM_QREGS;
362     cc->gdb_stop_before_watchpoint = true;
363     cc->disas_set_info = hexagon_cpu_disas_set_info;
364     cc->tcg_ops = &hexagon_tcg_ops;
365 }
366 
367 #define DEFINE_CPU(type_name, initfn)      \
368     {                                      \
369         .name = type_name,                 \
370         .parent = TYPE_HEXAGON_CPU,        \
371         .instance_init = initfn            \
372     }
373 
374 static const TypeInfo hexagon_cpu_type_infos[] = {
375     {
376         .name = TYPE_HEXAGON_CPU,
377         .parent = TYPE_CPU,
378         .instance_size = sizeof(HexagonCPU),
379         .instance_init = hexagon_cpu_init,
380         .abstract = true,
381         .class_size = sizeof(HexagonCPUClass),
382         .class_init = hexagon_cpu_class_init,
383     },
384     DEFINE_CPU(TYPE_HEXAGON_CPU_V67,              hexagon_v67_cpu_init),
385 };
386 
387 DEFINE_TYPES(hexagon_cpu_type_infos)
388