xref: /openbmc/qemu/target/hexagon/cpu.c (revision ac1e8671)
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_v67_cpu_init(Object *obj) { }
30 static void hexagon_v68_cpu_init(Object *obj) { }
31 static void hexagon_v69_cpu_init(Object *obj) { }
32 static void hexagon_v71_cpu_init(Object *obj) { }
33 static void hexagon_v73_cpu_init(Object *obj) { }
34 
35 static ObjectClass *hexagon_cpu_class_by_name(const char *cpu_model)
36 {
37     ObjectClass *oc;
38     char *typename;
39     char **cpuname;
40 
41     cpuname = g_strsplit(cpu_model, ",", 1);
42     typename = g_strdup_printf(HEXAGON_CPU_TYPE_NAME("%s"), cpuname[0]);
43     oc = object_class_by_name(typename);
44     g_strfreev(cpuname);
45     g_free(typename);
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 static Property hexagon_short_circuit_property =
56     DEFINE_PROP_BOOL("short-circuit", HexagonCPU, short_circuit, true);
57 
58 const char * const hexagon_regnames[TOTAL_PER_THREAD_REGS] = {
59    "r0", "r1",  "r2",  "r3",  "r4",   "r5",  "r6",  "r7",
60    "r8", "r9",  "r10", "r11", "r12",  "r13", "r14", "r15",
61   "r16", "r17", "r18", "r19", "r20",  "r21", "r22", "r23",
62   "r24", "r25", "r26", "r27", "r28",  "r29", "r30", "r31",
63   "sa0", "lc0", "sa1", "lc1", "p3_0", "c5",  "m0",  "m1",
64   "usr", "pc",  "ugp", "gp",  "cs0",  "cs1", "c14", "c15",
65   "c16", "c17", "c18", "c19", "pkt_cnt",  "insn_cnt", "hvx_cnt", "c23",
66   "c24", "c25", "c26", "c27", "c28",  "c29", "c30", "c31",
67 };
68 
69 /*
70  * One of the main debugging techniques is to use "-d cpu" and compare against
71  * LLDB output when single stepping.  However, the target and qemu put the
72  * stacks at different locations.  This is used to compensate so the diff is
73  * cleaner.
74  */
75 static target_ulong adjust_stack_ptrs(CPUHexagonState *env, target_ulong addr)
76 {
77     HexagonCPU *cpu = env_archcpu(env);
78     target_ulong stack_adjust = cpu->lldb_stack_adjust;
79     target_ulong stack_start = env->stack_start;
80     target_ulong stack_size = 0x10000;
81 
82     if (stack_adjust == 0) {
83         return addr;
84     }
85 
86     if (stack_start + 0x1000 >= addr && addr >= (stack_start - stack_size)) {
87         return addr - stack_adjust;
88     }
89     return addr;
90 }
91 
92 /* HEX_REG_P3_0_ALIASED (aka C4) is an alias for the predicate registers */
93 static target_ulong read_p3_0(CPUHexagonState *env)
94 {
95     int32_t control_reg = 0;
96     int i;
97     for (i = NUM_PREGS - 1; i >= 0; i--) {
98         control_reg <<= 8;
99         control_reg |= env->pred[i] & 0xff;
100     }
101     return control_reg;
102 }
103 
104 static void print_reg(FILE *f, CPUHexagonState *env, int regnum)
105 {
106     target_ulong value;
107 
108     if (regnum == HEX_REG_P3_0_ALIASED) {
109         value = read_p3_0(env);
110     } else {
111         value = regnum < 32 ? adjust_stack_ptrs(env, env->gpr[regnum])
112                             : env->gpr[regnum];
113     }
114 
115     qemu_fprintf(f, "  %s = 0x" TARGET_FMT_lx "\n",
116                  hexagon_regnames[regnum], value);
117 }
118 
119 static void print_vreg(FILE *f, CPUHexagonState *env, int regnum,
120                        bool skip_if_zero)
121 {
122     if (skip_if_zero) {
123         bool nonzero_found = false;
124         for (int i = 0; i < MAX_VEC_SIZE_BYTES; i++) {
125             if (env->VRegs[regnum].ub[i] != 0) {
126                 nonzero_found = true;
127                 break;
128             }
129         }
130         if (!nonzero_found) {
131             return;
132         }
133     }
134 
135     qemu_fprintf(f, "  v%d = ( ", regnum);
136     qemu_fprintf(f, "0x%02x", env->VRegs[regnum].ub[MAX_VEC_SIZE_BYTES - 1]);
137     for (int i = MAX_VEC_SIZE_BYTES - 2; i >= 0; i--) {
138         qemu_fprintf(f, ", 0x%02x", env->VRegs[regnum].ub[i]);
139     }
140     qemu_fprintf(f, " )\n");
141 }
142 
143 void hexagon_debug_vreg(CPUHexagonState *env, int regnum)
144 {
145     print_vreg(stdout, env, regnum, false);
146 }
147 
148 static void print_qreg(FILE *f, CPUHexagonState *env, int regnum,
149                        bool skip_if_zero)
150 {
151     if (skip_if_zero) {
152         bool nonzero_found = false;
153         for (int i = 0; i < MAX_VEC_SIZE_BYTES / 8; i++) {
154             if (env->QRegs[regnum].ub[i] != 0) {
155                 nonzero_found = true;
156                 break;
157             }
158         }
159         if (!nonzero_found) {
160             return;
161         }
162     }
163 
164     qemu_fprintf(f, "  q%d = ( ", regnum);
165     qemu_fprintf(f, "0x%02x",
166                  env->QRegs[regnum].ub[MAX_VEC_SIZE_BYTES / 8 - 1]);
167     for (int i = MAX_VEC_SIZE_BYTES / 8 - 2; i >= 0; i--) {
168         qemu_fprintf(f, ", 0x%02x", env->QRegs[regnum].ub[i]);
169     }
170     qemu_fprintf(f, " )\n");
171 }
172 
173 void hexagon_debug_qreg(CPUHexagonState *env, int regnum)
174 {
175     print_qreg(stdout, env, regnum, false);
176 }
177 
178 static void hexagon_dump(CPUHexagonState *env, FILE *f, int flags)
179 {
180     HexagonCPU *cpu = env_archcpu(env);
181 
182     if (cpu->lldb_compat) {
183         /*
184          * When comparing with LLDB, it doesn't step through single-cycle
185          * hardware loops the same way.  So, we just skip them here
186          */
187         if (env->gpr[HEX_REG_PC] == env->last_pc_dumped) {
188             return;
189         }
190         env->last_pc_dumped = env->gpr[HEX_REG_PC];
191     }
192 
193     qemu_fprintf(f, "General Purpose Registers = {\n");
194     for (int i = 0; i < 32; i++) {
195         print_reg(f, env, i);
196     }
197     print_reg(f, env, HEX_REG_SA0);
198     print_reg(f, env, HEX_REG_LC0);
199     print_reg(f, env, HEX_REG_SA1);
200     print_reg(f, env, HEX_REG_LC1);
201     print_reg(f, env, HEX_REG_M0);
202     print_reg(f, env, HEX_REG_M1);
203     print_reg(f, env, HEX_REG_USR);
204     print_reg(f, env, HEX_REG_P3_0_ALIASED);
205     print_reg(f, env, HEX_REG_GP);
206     print_reg(f, env, HEX_REG_UGP);
207     print_reg(f, env, HEX_REG_PC);
208 #ifdef CONFIG_USER_ONLY
209     /*
210      * Not modelled in user mode, print junk to minimize the diff's
211      * with LLDB output
212      */
213     qemu_fprintf(f, "  cause = 0x000000db\n");
214     qemu_fprintf(f, "  badva = 0x00000000\n");
215     qemu_fprintf(f, "  cs0 = 0x00000000\n");
216     qemu_fprintf(f, "  cs1 = 0x00000000\n");
217 #else
218     print_reg(f, env, HEX_REG_CAUSE);
219     print_reg(f, env, HEX_REG_BADVA);
220     print_reg(f, env, HEX_REG_CS0);
221     print_reg(f, env, HEX_REG_CS1);
222 #endif
223     qemu_fprintf(f, "}\n");
224 
225     if (flags & CPU_DUMP_FPU) {
226         qemu_fprintf(f, "Vector Registers = {\n");
227         for (int i = 0; i < NUM_VREGS; i++) {
228             print_vreg(f, env, i, true);
229         }
230         for (int i = 0; i < NUM_QREGS; i++) {
231             print_qreg(f, env, i, true);
232         }
233         qemu_fprintf(f, "}\n");
234     }
235 }
236 
237 static void hexagon_dump_state(CPUState *cs, FILE *f, int flags)
238 {
239     HexagonCPU *cpu = HEXAGON_CPU(cs);
240     CPUHexagonState *env = &cpu->env;
241 
242     hexagon_dump(env, f, flags);
243 }
244 
245 void hexagon_debug(CPUHexagonState *env)
246 {
247     hexagon_dump(env, stdout, CPU_DUMP_FPU);
248 }
249 
250 static void hexagon_cpu_set_pc(CPUState *cs, vaddr value)
251 {
252     HexagonCPU *cpu = HEXAGON_CPU(cs);
253     CPUHexagonState *env = &cpu->env;
254     env->gpr[HEX_REG_PC] = value;
255 }
256 
257 static vaddr hexagon_cpu_get_pc(CPUState *cs)
258 {
259     HexagonCPU *cpu = HEXAGON_CPU(cs);
260     CPUHexagonState *env = &cpu->env;
261     return env->gpr[HEX_REG_PC];
262 }
263 
264 static void hexagon_cpu_synchronize_from_tb(CPUState *cs,
265                                             const TranslationBlock *tb)
266 {
267     HexagonCPU *cpu = HEXAGON_CPU(cs);
268     CPUHexagonState *env = &cpu->env;
269     tcg_debug_assert(!(cs->tcg_cflags & CF_PCREL));
270     env->gpr[HEX_REG_PC] = tb->pc;
271 }
272 
273 static bool hexagon_cpu_has_work(CPUState *cs)
274 {
275     return true;
276 }
277 
278 static void hexagon_restore_state_to_opc(CPUState *cs,
279                                          const TranslationBlock *tb,
280                                          const uint64_t *data)
281 {
282     HexagonCPU *cpu = HEXAGON_CPU(cs);
283     CPUHexagonState *env = &cpu->env;
284 
285     env->gpr[HEX_REG_PC] = data[0];
286 }
287 
288 static void hexagon_cpu_reset_hold(Object *obj)
289 {
290     CPUState *cs = CPU(obj);
291     HexagonCPU *cpu = HEXAGON_CPU(cs);
292     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(cpu);
293     CPUHexagonState *env = &cpu->env;
294 
295     if (mcc->parent_phases.hold) {
296         mcc->parent_phases.hold(obj);
297     }
298 
299     set_default_nan_mode(1, &env->fp_status);
300     set_float_detect_tininess(float_tininess_before_rounding, &env->fp_status);
301 }
302 
303 static void hexagon_cpu_disas_set_info(CPUState *s, disassemble_info *info)
304 {
305     info->print_insn = print_insn_hexagon;
306 }
307 
308 static void hexagon_cpu_realize(DeviceState *dev, Error **errp)
309 {
310     CPUState *cs = CPU(dev);
311     HexagonCPUClass *mcc = HEXAGON_CPU_GET_CLASS(dev);
312     Error *local_err = NULL;
313 
314     cpu_exec_realizefn(cs, &local_err);
315     if (local_err != NULL) {
316         error_propagate(errp, local_err);
317         return;
318     }
319 
320     gdb_register_coprocessor(cs, hexagon_hvx_gdb_read_register,
321                              hexagon_hvx_gdb_write_register,
322                              gdb_find_static_feature("hexagon-hvx.xml"), 0);
323 
324     qemu_init_vcpu(cs);
325     cpu_reset(cs);
326 
327     mcc->parent_realize(dev, errp);
328 }
329 
330 static void hexagon_cpu_init(Object *obj)
331 {
332     qdev_property_add_static(DEVICE(obj), &hexagon_lldb_compat_property);
333     qdev_property_add_static(DEVICE(obj), &hexagon_lldb_stack_adjust_property);
334     qdev_property_add_static(DEVICE(obj), &hexagon_short_circuit_property);
335 }
336 
337 #include "hw/core/tcg-cpu-ops.h"
338 
339 static const TCGCPUOps hexagon_tcg_ops = {
340     .initialize = hexagon_translate_init,
341     .synchronize_from_tb = hexagon_cpu_synchronize_from_tb,
342     .restore_state_to_opc = hexagon_restore_state_to_opc,
343 };
344 
345 static void hexagon_cpu_class_init(ObjectClass *c, void *data)
346 {
347     HexagonCPUClass *mcc = HEXAGON_CPU_CLASS(c);
348     CPUClass *cc = CPU_CLASS(c);
349     DeviceClass *dc = DEVICE_CLASS(c);
350     ResettableClass *rc = RESETTABLE_CLASS(c);
351 
352     device_class_set_parent_realize(dc, hexagon_cpu_realize,
353                                     &mcc->parent_realize);
354 
355     resettable_class_set_parent_phases(rc, NULL, hexagon_cpu_reset_hold, NULL,
356                                        &mcc->parent_phases);
357 
358     cc->class_by_name = hexagon_cpu_class_by_name;
359     cc->has_work = hexagon_cpu_has_work;
360     cc->dump_state = hexagon_dump_state;
361     cc->set_pc = hexagon_cpu_set_pc;
362     cc->get_pc = hexagon_cpu_get_pc;
363     cc->gdb_read_register = hexagon_gdb_read_register;
364     cc->gdb_write_register = hexagon_gdb_write_register;
365     cc->gdb_num_core_regs = TOTAL_PER_THREAD_REGS;
366     cc->gdb_stop_before_watchpoint = true;
367     cc->gdb_core_xml_file = "hexagon-core.xml";
368     cc->disas_set_info = hexagon_cpu_disas_set_info;
369     cc->tcg_ops = &hexagon_tcg_ops;
370 }
371 
372 #define DEFINE_CPU(type_name, initfn)      \
373     {                                      \
374         .name = type_name,                 \
375         .parent = TYPE_HEXAGON_CPU,        \
376         .instance_init = initfn            \
377     }
378 
379 static const TypeInfo hexagon_cpu_type_infos[] = {
380     {
381         .name = TYPE_HEXAGON_CPU,
382         .parent = TYPE_CPU,
383         .instance_size = sizeof(HexagonCPU),
384         .instance_align = __alignof(HexagonCPU),
385         .instance_init = hexagon_cpu_init,
386         .abstract = true,
387         .class_size = sizeof(HexagonCPUClass),
388         .class_init = hexagon_cpu_class_init,
389     },
390     DEFINE_CPU(TYPE_HEXAGON_CPU_V67,              hexagon_v67_cpu_init),
391     DEFINE_CPU(TYPE_HEXAGON_CPU_V68,              hexagon_v68_cpu_init),
392     DEFINE_CPU(TYPE_HEXAGON_CPU_V69,              hexagon_v69_cpu_init),
393     DEFINE_CPU(TYPE_HEXAGON_CPU_V71,              hexagon_v71_cpu_init),
394     DEFINE_CPU(TYPE_HEXAGON_CPU_V73,              hexagon_v73_cpu_init),
395 };
396 
397 DEFINE_TYPES(hexagon_cpu_type_infos)
398