]> git.sur5r.net Git - openocd/blob - src/target/armv8_dpm.c
tcl/target/stm32f0x: Allow overriding the Flash bank size
[openocd] / src / target / armv8_dpm.c
1 /*
2  * Copyright (C) 2009 by David Brownell
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  */
15
16 #ifdef HAVE_CONFIG_H
17 #include "config.h"
18 #endif
19
20 #include "arm.h"
21 #include "armv8.h"
22 #include "armv8_dpm.h"
23 #include <jtag/jtag.h>
24 #include "register.h"
25 #include "breakpoints.h"
26 #include "target_type.h"
27 #include "armv8_opcodes.h"
28
29 #include "helper/time_support.h"
30
31 /* T32 ITR format */
32 #define T32_FMTITR(instr) (((instr & 0x0000FFFF) << 16) | ((instr & 0xFFFF0000) >> 16))
33
34 /**
35  * @file
36  * Implements various ARM DPM operations using architectural debug registers.
37  * These routines layer over core-specific communication methods to cope with
38  * implementation differences between cores like ARM1136 and Cortex-A8.
39  *
40  * The "Debug Programmers' Model" (DPM) for ARMv6 and ARMv7 is defined by
41  * Part C (Debug Architecture) of the ARM Architecture Reference Manual,
42  * ARMv7-A and ARMv7-R edition (ARM DDI 0406B).  In OpenOCD, DPM operations
43  * are abstracted through internal programming interfaces to share code and
44  * to minimize needless differences in debug behavior between cores.
45  */
46
47 /**
48  * Get core state from EDSCR, without necessity to retrieve CPSR
49  */
50 enum arm_state armv8_dpm_get_core_state(struct arm_dpm *dpm)
51 {
52         int el = (dpm->dscr >> 8) & 0x3;
53         int rw = (dpm->dscr >> 10) & 0xF;
54
55         dpm->last_el = el;
56
57         /* In Debug state, each bit gives the current Execution state of each EL */
58         if ((rw >> el) & 0b1)
59                 return ARM_STATE_AARCH64;
60
61         return ARM_STATE_ARM;
62 }
63
64 /*----------------------------------------------------------------------*/
65
66 static int dpmv8_write_dcc(struct armv8_common *armv8, uint32_t data)
67 {
68         return mem_ap_write_u32(armv8->debug_ap,
69                                 armv8->debug_base + CPUV8_DBG_DTRRX, data);
70 }
71
72 static int dpmv8_write_dcc_64(struct armv8_common *armv8, uint64_t data)
73 {
74         int ret;
75         ret = mem_ap_write_u32(armv8->debug_ap,
76                                armv8->debug_base + CPUV8_DBG_DTRRX, data);
77         if (ret == ERROR_OK)
78                 ret = mem_ap_write_u32(armv8->debug_ap,
79                                 armv8->debug_base + CPUV8_DBG_DTRTX, data >> 32);
80         return ret;
81 }
82
83 static int dpmv8_read_dcc(struct armv8_common *armv8, uint32_t *data,
84         uint32_t *dscr_p)
85 {
86         uint32_t dscr = DSCR_ITE;
87         int retval;
88
89         if (dscr_p)
90                 dscr = *dscr_p;
91
92         /* Wait for DTRRXfull */
93         long long then = timeval_ms();
94         while ((dscr & DSCR_DTR_TX_FULL) == 0) {
95                 retval = mem_ap_read_atomic_u32(armv8->debug_ap,
96                                 armv8->debug_base + CPUV8_DBG_DSCR,
97                                 &dscr);
98                 if (retval != ERROR_OK)
99                         return retval;
100                 if (timeval_ms() > then + 1000) {
101                         LOG_ERROR("Timeout waiting for read dcc");
102                         return ERROR_FAIL;
103                 }
104         }
105
106         retval = mem_ap_read_atomic_u32(armv8->debug_ap,
107                                             armv8->debug_base + CPUV8_DBG_DTRTX,
108                                             data);
109         if (retval != ERROR_OK)
110                 return retval;
111
112         if (dscr_p)
113                 *dscr_p = dscr;
114
115         return retval;
116 }
117
118 static int dpmv8_read_dcc_64(struct armv8_common *armv8, uint64_t *data,
119         uint32_t *dscr_p)
120 {
121         uint32_t dscr = DSCR_ITE;
122         uint32_t higher;
123         int retval;
124
125         if (dscr_p)
126                 dscr = *dscr_p;
127
128         /* Wait for DTRRXfull */
129         long long then = timeval_ms();
130         while ((dscr & DSCR_DTR_TX_FULL) == 0) {
131                 retval = mem_ap_read_atomic_u32(armv8->debug_ap,
132                                 armv8->debug_base + CPUV8_DBG_DSCR,
133                                 &dscr);
134                 if (retval != ERROR_OK)
135                         return retval;
136                 if (timeval_ms() > then + 1000) {
137                         LOG_ERROR("Timeout waiting for DTR_TX_FULL, dscr = 0x%08" PRIx32, dscr);
138                         return ERROR_FAIL;
139                 }
140         }
141
142         retval = mem_ap_read_atomic_u32(armv8->debug_ap,
143                                             armv8->debug_base + CPUV8_DBG_DTRTX,
144                                             (uint32_t *)data);
145         if (retval != ERROR_OK)
146                 return retval;
147
148         retval = mem_ap_read_atomic_u32(armv8->debug_ap,
149                                             armv8->debug_base + CPUV8_DBG_DTRRX,
150                                             &higher);
151         if (retval != ERROR_OK)
152                 return retval;
153
154         *data = *(uint32_t *)data | (uint64_t)higher << 32;
155
156         if (dscr_p)
157                 *dscr_p = dscr;
158
159         return retval;
160 }
161
162 static int dpmv8_dpm_prepare(struct arm_dpm *dpm)
163 {
164         struct armv8_common *armv8 = dpm->arm->arch_info;
165         uint32_t dscr;
166         int retval;
167
168         /* set up invariant:  ITE is set after ever DPM operation */
169         long long then = timeval_ms();
170         for (;; ) {
171                 retval = mem_ap_read_atomic_u32(armv8->debug_ap,
172                                 armv8->debug_base + CPUV8_DBG_DSCR,
173                                 &dscr);
174                 if (retval != ERROR_OK)
175                         return retval;
176                 if ((dscr & DSCR_ITE) != 0)
177                         break;
178                 if (timeval_ms() > then + 1000) {
179                         LOG_ERROR("Timeout waiting for dpm prepare");
180                         return ERROR_FAIL;
181                 }
182         }
183
184         /* update the stored copy of dscr */
185         dpm->dscr = dscr;
186
187         /* this "should never happen" ... */
188         if (dscr & DSCR_DTR_RX_FULL) {
189                 LOG_ERROR("DSCR_DTR_RX_FULL, dscr 0x%08" PRIx32, dscr);
190                 /* Clear DCCRX */
191                 retval = mem_ap_read_u32(armv8->debug_ap,
192                         armv8->debug_base + CPUV8_DBG_DTRRX, &dscr);
193                 if (retval != ERROR_OK)
194                         return retval;
195         }
196
197         return retval;
198 }
199
200 static int dpmv8_dpm_finish(struct arm_dpm *dpm)
201 {
202         /* REVISIT what could be done here? */
203         return ERROR_OK;
204 }
205
206 static int dpmv8_exec_opcode(struct arm_dpm *dpm,
207         uint32_t opcode, uint32_t *p_dscr)
208 {
209         struct armv8_common *armv8 = dpm->arm->arch_info;
210         uint32_t dscr = dpm->dscr;
211         int retval;
212
213         if (p_dscr)
214                 dscr = *p_dscr;
215
216         /* Wait for InstrCompl bit to be set */
217         long long then = timeval_ms();
218         while ((dscr & DSCR_ITE) == 0) {
219                 retval = mem_ap_read_atomic_u32(armv8->debug_ap,
220                                 armv8->debug_base + CPUV8_DBG_DSCR, &dscr);
221                 if (retval != ERROR_OK) {
222                         LOG_ERROR("Could not read DSCR register, opcode = 0x%08" PRIx32, opcode);
223                         return retval;
224                 }
225                 if (timeval_ms() > then + 1000) {
226                         LOG_ERROR("Timeout waiting for aarch64_exec_opcode");
227                         return ERROR_FAIL;
228                 }
229         }
230
231         if (armv8_dpm_get_core_state(dpm) != ARM_STATE_AARCH64)
232                 opcode = T32_FMTITR(opcode);
233
234         retval = mem_ap_write_u32(armv8->debug_ap,
235                         armv8->debug_base + CPUV8_DBG_ITR, opcode);
236         if (retval != ERROR_OK)
237                 return retval;
238
239         then = timeval_ms();
240         do {
241                 retval = mem_ap_read_atomic_u32(armv8->debug_ap,
242                                 armv8->debug_base + CPUV8_DBG_DSCR, &dscr);
243                 if (retval != ERROR_OK) {
244                         LOG_ERROR("Could not read DSCR register");
245                         return retval;
246                 }
247                 if (timeval_ms() > then + 1000) {
248                         LOG_ERROR("Timeout waiting for aarch64_exec_opcode");
249                         return ERROR_FAIL;
250                 }
251         } while ((dscr & DSCR_ITE) == 0);       /* Wait for InstrCompl bit to be set */
252
253         /* update dscr and el after each command execution */
254         dpm->dscr = dscr;
255         if (dpm->last_el != ((dscr >> 8) & 3))
256                 LOG_DEBUG("EL %i -> %i", dpm->last_el, (dscr >> 8) & 3);
257         dpm->last_el = (dscr >> 8) & 3;
258
259         if (dscr & DSCR_ERR) {
260                 LOG_ERROR("Opcode 0x%08"PRIx32", DSCR.ERR=1, DSCR.EL=%i", opcode, dpm->last_el);
261                 armv8_dpm_handle_exception(dpm, true);
262                 retval = ERROR_FAIL;
263         }
264
265         if (p_dscr)
266                 *p_dscr = dscr;
267
268         return retval;
269 }
270
271 static int dpmv8_instr_execute(struct arm_dpm *dpm, uint32_t opcode)
272 {
273         return dpmv8_exec_opcode(dpm, opcode, NULL);
274 }
275
276 static int dpmv8_instr_write_data_dcc(struct arm_dpm *dpm,
277         uint32_t opcode, uint32_t data)
278 {
279         struct armv8_common *armv8 = dpm->arm->arch_info;
280         int retval;
281
282         retval = dpmv8_write_dcc(armv8, data);
283         if (retval != ERROR_OK)
284                 return retval;
285
286         return dpmv8_exec_opcode(dpm, opcode, 0);
287 }
288
289 static int dpmv8_instr_write_data_dcc_64(struct arm_dpm *dpm,
290         uint32_t opcode, uint64_t data)
291 {
292         struct armv8_common *armv8 = dpm->arm->arch_info;
293         int retval;
294
295         retval = dpmv8_write_dcc_64(armv8, data);
296         if (retval != ERROR_OK)
297                 return retval;
298
299         return dpmv8_exec_opcode(dpm, opcode, 0);
300 }
301
302 static int dpmv8_instr_write_data_r0(struct arm_dpm *dpm,
303         uint32_t opcode, uint32_t data)
304 {
305         struct armv8_common *armv8 = dpm->arm->arch_info;
306         uint32_t dscr = DSCR_ITE;
307         int retval;
308
309         retval = dpmv8_write_dcc(armv8, data);
310         if (retval != ERROR_OK)
311                 return retval;
312
313         retval = dpmv8_exec_opcode(dpm, armv8_opcode(armv8, READ_REG_DTRRX), &dscr);
314         if (retval != ERROR_OK)
315                 return retval;
316
317         /* then the opcode, taking data from R0 */
318         return dpmv8_exec_opcode(dpm, opcode, &dscr);
319 }
320
321 static int dpmv8_instr_write_data_r0_64(struct arm_dpm *dpm,
322         uint32_t opcode, uint64_t data)
323 {
324         struct armv8_common *armv8 = dpm->arm->arch_info;
325         int retval;
326
327         if (dpm->arm->core_state != ARM_STATE_AARCH64)
328                 return dpmv8_instr_write_data_r0(dpm, opcode, data);
329
330         /* transfer data from DCC to R0 */
331         retval = dpmv8_write_dcc_64(armv8, data);
332         if (retval == ERROR_OK)
333                 retval = dpmv8_exec_opcode(dpm, ARMV8_MRS(SYSTEM_DBG_DBGDTR_EL0, 0), &dpm->dscr);
334
335         /* then the opcode, taking data from R0 */
336         if (retval == ERROR_OK)
337                 retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
338
339         return retval;
340 }
341
342 static int dpmv8_instr_cpsr_sync(struct arm_dpm *dpm)
343 {
344         int retval;
345         struct armv8_common *armv8 = dpm->arm->arch_info;
346
347         /* "Prefetch flush" after modifying execution status in CPSR */
348         retval = dpmv8_exec_opcode(dpm, armv8_opcode(armv8, ARMV8_OPC_DSB_SY), &dpm->dscr);
349         if (retval == ERROR_OK)
350                 dpmv8_exec_opcode(dpm, armv8_opcode(armv8, ARMV8_OPC_ISB_SY), &dpm->dscr);
351         return retval;
352 }
353
354 static int dpmv8_instr_read_data_dcc(struct arm_dpm *dpm,
355         uint32_t opcode, uint32_t *data)
356 {
357         struct armv8_common *armv8 = dpm->arm->arch_info;
358         int retval;
359
360         /* the opcode, writing data to DCC */
361         retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
362         if (retval != ERROR_OK)
363                 return retval;
364
365         return dpmv8_read_dcc(armv8, data, &dpm->dscr);
366 }
367
368 static int dpmv8_instr_read_data_dcc_64(struct arm_dpm *dpm,
369         uint32_t opcode, uint64_t *data)
370 {
371         struct armv8_common *armv8 = dpm->arm->arch_info;
372         int retval;
373
374         /* the opcode, writing data to DCC */
375         retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
376         if (retval != ERROR_OK)
377                 return retval;
378
379         return dpmv8_read_dcc_64(armv8, data, &dpm->dscr);
380 }
381
382 static int dpmv8_instr_read_data_r0(struct arm_dpm *dpm,
383         uint32_t opcode, uint32_t *data)
384 {
385         struct armv8_common *armv8 = dpm->arm->arch_info;
386         int retval;
387
388         /* the opcode, writing data to R0 */
389         retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
390         if (retval != ERROR_OK)
391                 return retval;
392
393         /* write R0 to DCC */
394         retval = dpmv8_exec_opcode(dpm, armv8_opcode(armv8, WRITE_REG_DTRTX), &dpm->dscr);
395         if (retval != ERROR_OK)
396                 return retval;
397
398         return dpmv8_read_dcc(armv8, data, &dpm->dscr);
399 }
400
401 static int dpmv8_instr_read_data_r0_64(struct arm_dpm *dpm,
402         uint32_t opcode, uint64_t *data)
403 {
404         struct armv8_common *armv8 = dpm->arm->arch_info;
405         int retval;
406
407         if (dpm->arm->core_state != ARM_STATE_AARCH64) {
408                 uint32_t tmp;
409                 retval = dpmv8_instr_read_data_r0(dpm, opcode, &tmp);
410                 if (retval == ERROR_OK)
411                         *data = tmp;
412                 return retval;
413         }
414
415         /* the opcode, writing data to R0 */
416         retval = dpmv8_exec_opcode(dpm, opcode, &dpm->dscr);
417         if (retval != ERROR_OK)
418                 return retval;
419
420         /* write R0 to DCC */
421         retval = dpmv8_exec_opcode(dpm, ARMV8_MSR_GP(SYSTEM_DBG_DBGDTR_EL0, 0), &dpm->dscr);
422         if (retval != ERROR_OK)
423                 return retval;
424
425         return dpmv8_read_dcc_64(armv8, data, &dpm->dscr);
426 }
427
428 #if 0
429 static int dpmv8_bpwp_enable(struct arm_dpm *dpm, unsigned index_t,
430         target_addr_t addr, uint32_t control)
431 {
432         struct armv8_common *armv8 = dpm->arm->arch_info;
433         uint32_t vr = armv8->debug_base;
434         uint32_t cr = armv8->debug_base;
435         int retval;
436
437         switch (index_t) {
438                 case 0 ... 15:  /* breakpoints */
439                         vr += CPUV8_DBG_BVR_BASE;
440                         cr += CPUV8_DBG_BCR_BASE;
441                         break;
442                 case 16 ... 31: /* watchpoints */
443                         vr += CPUV8_DBG_WVR_BASE;
444                         cr += CPUV8_DBG_WCR_BASE;
445                         index_t -= 16;
446                         break;
447                 default:
448                         return ERROR_FAIL;
449         }
450         vr += 16 * index_t;
451         cr += 16 * index_t;
452
453         LOG_DEBUG("A8: bpwp enable, vr %08x cr %08x",
454                 (unsigned) vr, (unsigned) cr);
455
456         retval = mem_ap_write_atomic_u32(armv8->debug_ap, vr, addr);
457         if (retval != ERROR_OK)
458                 return retval;
459         return mem_ap_write_atomic_u32(armv8->debug_ap, cr, control);
460 }
461 #endif
462
463 static int dpmv8_bpwp_disable(struct arm_dpm *dpm, unsigned index_t)
464 {
465         struct armv8_common *armv8 = dpm->arm->arch_info;
466         uint32_t cr;
467
468         switch (index_t) {
469                 case 0 ... 15:
470                         cr = armv8->debug_base + CPUV8_DBG_BCR_BASE;
471                         break;
472                 case 16 ... 31:
473                         cr = armv8->debug_base + CPUV8_DBG_WCR_BASE;
474                         index_t -= 16;
475                         break;
476                 default:
477                         return ERROR_FAIL;
478         }
479         cr += 16 * index_t;
480
481         LOG_DEBUG("A: bpwp disable, cr %08x", (unsigned) cr);
482
483         /* clear control register */
484         return mem_ap_write_atomic_u32(armv8->debug_ap, cr, 0);
485 }
486
487 /*
488  * Coprocessor support
489  */
490
491 /* Read coprocessor */
492 static int dpmv8_mrc(struct target *target, int cpnum,
493         uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
494         uint32_t *value)
495 {
496         struct arm *arm = target_to_arm(target);
497         struct arm_dpm *dpm = arm->dpm;
498         int retval;
499
500         retval = dpm->prepare(dpm);
501         if (retval != ERROR_OK)
502                 return retval;
503
504         LOG_DEBUG("MRC p%d, %d, r0, c%d, c%d, %d", cpnum,
505                 (int) op1, (int) CRn,
506                 (int) CRm, (int) op2);
507
508         /* read coprocessor register into R0; return via DCC */
509         retval = dpm->instr_read_data_r0(dpm,
510                         ARMV4_5_MRC(cpnum, op1, 0, CRn, CRm, op2),
511                         value);
512
513         /* (void) */ dpm->finish(dpm);
514         return retval;
515 }
516
517 static int dpmv8_mcr(struct target *target, int cpnum,
518         uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
519         uint32_t value)
520 {
521         struct arm *arm = target_to_arm(target);
522         struct arm_dpm *dpm = arm->dpm;
523         int retval;
524
525         retval = dpm->prepare(dpm);
526         if (retval != ERROR_OK)
527                 return retval;
528
529         LOG_DEBUG("MCR p%d, %d, r0, c%d, c%d, %d", cpnum,
530                 (int) op1, (int) CRn,
531                 (int) CRm, (int) op2);
532
533         /* read DCC into r0; then write coprocessor register from R0 */
534         retval = dpm->instr_write_data_r0(dpm,
535                         ARMV4_5_MCR(cpnum, op1, 0, CRn, CRm, op2),
536                         value);
537
538         /* (void) */ dpm->finish(dpm);
539         return retval;
540 }
541
542 /*----------------------------------------------------------------------*/
543
544 /*
545  * Register access utilities
546  */
547
548 int armv8_dpm_modeswitch(struct arm_dpm *dpm, enum arm_mode mode)
549 {
550         struct armv8_common *armv8 = (struct armv8_common *)dpm->arm->arch_info;
551         int retval = ERROR_OK;
552         unsigned int target_el;
553         enum arm_state core_state;
554         uint32_t cpsr;
555
556         /* restore previous mode */
557         if (mode == ARM_MODE_ANY) {
558                 cpsr = buf_get_u32(dpm->arm->cpsr->value, 0, 32);
559
560                 LOG_DEBUG("restoring mode, cpsr = 0x%08"PRIx32, cpsr);
561
562         } else {
563                 LOG_DEBUG("setting mode 0x%"PRIx32, mode);
564                 cpsr = mode;
565         }
566
567         switch (cpsr & 0x1f) {
568         /* aarch32 modes */
569         case ARM_MODE_USR:
570                 target_el = 0;
571                 break;
572         case ARM_MODE_SVC:
573         case ARM_MODE_ABT:
574         case ARM_MODE_IRQ:
575         case ARM_MODE_FIQ:
576                 target_el = 1;
577                 break;
578         /*
579          * TODO: handle ARM_MODE_HYP
580          * case ARM_MODE_HYP:
581          *      target_el = 2;
582          *      break;
583          */
584         case ARM_MODE_MON:
585                 target_el = 3;
586                 break;
587         /* aarch64 modes */
588         default:
589                 target_el = (cpsr >> 2) & 3;
590         }
591
592         if (target_el > SYSTEM_CUREL_EL3) {
593                 LOG_ERROR("%s: Invalid target exception level %i", __func__, target_el);
594                 return ERROR_FAIL;
595         }
596
597         LOG_DEBUG("target_el = %i, last_el = %i", target_el, dpm->last_el);
598         if (target_el > dpm->last_el) {
599                 retval = dpm->instr_execute(dpm,
600                                 armv8_opcode(armv8, ARMV8_OPC_DCPS) | target_el);
601
602                 /* DCPS clobbers registers just like an exception taken */
603                 armv8_dpm_handle_exception(dpm, false);
604         } else {
605                 core_state = armv8_dpm_get_core_state(dpm);
606                 if (core_state != ARM_STATE_AARCH64) {
607                         /* cannot do DRPS/ERET when already in EL0 */
608                         if (dpm->last_el != 0) {
609                                 /* load SPSR with the desired mode and execute DRPS */
610                                 LOG_DEBUG("SPSR = 0x%08"PRIx32, cpsr);
611                                 retval = dpm->instr_write_data_r0(dpm,
612                                                 ARMV8_MSR_GP_xPSR_T1(1, 0, 15), cpsr);
613                                 if (retval == ERROR_OK)
614                                         retval = dpm->instr_execute(dpm, armv8_opcode(armv8, ARMV8_OPC_DRPS));
615                         }
616                 } else {
617                         /*
618                          * need to execute multiple DRPS instructions until target_el
619                          * is reached
620                          */
621                         while (retval == ERROR_OK && dpm->last_el != target_el) {
622                                 unsigned int cur_el = dpm->last_el;
623                                 retval = dpm->instr_execute(dpm, armv8_opcode(armv8, ARMV8_OPC_DRPS));
624                                 if (cur_el == dpm->last_el) {
625                                         LOG_INFO("Cannot reach EL %i, SPSR corrupted?", target_el);
626                                         break;
627                                 }
628                         }
629                 }
630
631                 /* On executing DRPS, DSPSR and DLR become UNKNOWN, mark them as dirty */
632                 dpm->arm->cpsr->dirty = true;
633                 dpm->arm->pc->dirty = true;
634
635                 /*
636                  * re-evaluate the core state, we might be in Aarch32 state now
637                  * we rely on dpm->dscr being up-to-date
638                  */
639                 core_state = armv8_dpm_get_core_state(dpm);
640                 armv8_select_opcodes(armv8, core_state == ARM_STATE_AARCH64);
641                 armv8_select_reg_access(armv8, core_state == ARM_STATE_AARCH64);
642         }
643
644         return retval;
645 }
646
647 /*
648  * Common register read, relies on armv8_select_reg_access() having been called.
649  */
650 static int dpmv8_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
651 {
652         struct armv8_common *armv8 = dpm->arm->arch_info;
653         int retval = ERROR_FAIL;
654
655         if (r->size <= 64) {
656                 uint64_t value_64;
657                 retval = armv8->read_reg_u64(armv8, regnum, &value_64);
658
659                 if (retval == ERROR_OK) {
660                         r->valid = true;
661                         r->dirty = false;
662                         buf_set_u64(r->value, 0, r->size, value_64);
663                         if (r->size == 64)
664                                 LOG_DEBUG("READ: %s, %16.8llx", r->name, (unsigned long long) value_64);
665                         else
666                                 LOG_DEBUG("READ: %s, %8.8x", r->name, (unsigned int) value_64);
667                 }
668         } else if (r->size <= 128) {
669                 uint64_t lvalue = 0, hvalue = 0;
670                 retval = armv8->read_reg_u128(armv8, regnum, &lvalue, &hvalue);
671
672                 if (retval == ERROR_OK) {
673                         r->valid = true;
674                         r->dirty = false;
675
676                         buf_set_u64(r->value, 0, 64, lvalue);
677                         buf_set_u64(r->value + 8, 0, r->size - 64, hvalue);
678
679                         LOG_DEBUG("READ: %s, lvalue=%16.8llx", r->name, (unsigned long long) lvalue);
680                         LOG_DEBUG("READ: %s, hvalue=%16.8llx", r->name, (unsigned long long) hvalue);
681                 }
682         }
683         return retval;
684 }
685
686 /*
687  * Common register write, relies on armv8_select_reg_access() having been called.
688  */
689 static int dpmv8_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
690 {
691         struct armv8_common *armv8 = dpm->arm->arch_info;
692         int retval = ERROR_FAIL;
693
694         if (r->size <= 64) {
695                 uint64_t value_64;
696
697                 value_64 = buf_get_u64(r->value, 0, r->size);
698                 retval = armv8->write_reg_u64(armv8, regnum, value_64);
699
700                 if (retval == ERROR_OK) {
701                         r->dirty = false;
702                         if (r->size == 64)
703                                 LOG_DEBUG("WRITE: %s, %16.8llx", r->name, (unsigned long long)value_64);
704                         else
705                                 LOG_DEBUG("WRITE: %s, %8.8x", r->name, (unsigned int)value_64);
706                 }
707         } else if (r->size <= 128) {
708                 uint64_t lvalue, hvalue;
709
710                 lvalue = buf_get_u64(r->value, 0, 64);
711                 hvalue = buf_get_u64(r->value + 8, 0, r->size - 64);
712                 retval = armv8->write_reg_u128(armv8, regnum, lvalue, hvalue);
713
714                 if (retval == ERROR_OK) {
715                         r->dirty = false;
716
717                         LOG_DEBUG("WRITE: %s, lvalue=%16.8llx", r->name, (unsigned long long) lvalue);
718                         LOG_DEBUG("WRITE: %s, hvalue=%16.8llx", r->name, (unsigned long long) hvalue);
719                 }
720         }
721
722         return retval;
723 }
724
725 /**
726  * Read basic registers of the the current context:  R0 to R15, and CPSR;
727  * sets the core mode (such as USR or IRQ) and state (such as ARM or Thumb).
728  * In normal operation this is called on entry to halting debug state,
729  * possibly after some other operations supporting restore of debug state
730  * or making sure the CPU is fully idle (drain write buffer, etc).
731  */
732 int armv8_dpm_read_current_registers(struct arm_dpm *dpm)
733 {
734         struct arm *arm = dpm->arm;
735         struct armv8_common *armv8 = (struct armv8_common *)arm->arch_info;
736         struct reg_cache *cache;
737         struct reg *r;
738         uint32_t cpsr;
739         int retval;
740
741         retval = dpm->prepare(dpm);
742         if (retval != ERROR_OK)
743                 return retval;
744
745         cache = arm->core_cache;
746
747         /* read R0 first (it's used for scratch), then CPSR */
748         r = cache->reg_list + ARMV8_R0;
749         if (!r->valid) {
750                 retval = dpmv8_read_reg(dpm, r, ARMV8_R0);
751                 if (retval != ERROR_OK)
752                         goto fail;
753         }
754         r->dirty = true;
755
756         /* read R1, too, it will be clobbered during memory access */
757         r = cache->reg_list + ARMV8_R1;
758         if (!r->valid) {
759                 retval = dpmv8_read_reg(dpm, r, ARMV8_R1);
760                 if (retval != ERROR_OK)
761                         goto fail;
762         }
763
764         /* read cpsr to r0 and get it back */
765         retval = dpm->instr_read_data_r0(dpm,
766                         armv8_opcode(armv8, READ_REG_DSPSR), &cpsr);
767         if (retval != ERROR_OK)
768                 goto fail;
769
770         /* update core mode and state */
771         armv8_set_cpsr(arm, cpsr);
772
773         for (unsigned int i = ARMV8_PC; i < cache->num_regs ; i++) {
774                 struct arm_reg *arm_reg;
775
776                 r = armv8_reg_current(arm, i);
777                 if (r->valid)
778                         continue;
779
780                 /* Skip reading FP-SIMD registers */
781                 if (r->number >= ARMV8_V0 && r->number <= ARMV8_FPCR)
782                         continue;
783
784                 /*
785                  * Only read registers that are available from the
786                  * current EL (or core mode).
787                  */
788                 arm_reg = r->arch_info;
789                 if (arm_reg->mode != ARM_MODE_ANY &&
790                                 dpm->last_el != armv8_curel_from_core_mode(arm_reg->mode))
791                         continue;
792
793                 retval = dpmv8_read_reg(dpm, r, i);
794                 if (retval != ERROR_OK)
795                         goto fail;
796
797         }
798
799 fail:
800         dpm->finish(dpm);
801         return retval;
802 }
803
804 /* Avoid needless I/O ... leave breakpoints and watchpoints alone
805  * unless they're removed, or need updating because of single-stepping
806  * or running debugger code.
807  */
808 static int dpmv8_maybe_update_bpwp(struct arm_dpm *dpm, bool bpwp,
809         struct dpm_bpwp *xp, int *set_p)
810 {
811         int retval = ERROR_OK;
812         bool disable;
813
814         if (!set_p) {
815                 if (!xp->dirty)
816                         goto done;
817                 xp->dirty = false;
818                 /* removed or startup; we must disable it */
819                 disable = true;
820         } else if (bpwp) {
821                 if (!xp->dirty)
822                         goto done;
823                 /* disabled, but we must set it */
824                 xp->dirty = disable = false;
825                 *set_p = true;
826         } else {
827                 if (!*set_p)
828                         goto done;
829                 /* set, but we must temporarily disable it */
830                 xp->dirty = disable = true;
831                 *set_p = false;
832         }
833
834         if (disable)
835                 retval = dpm->bpwp_disable(dpm, xp->number);
836         else
837                 retval = dpm->bpwp_enable(dpm, xp->number,
838                                 xp->address, xp->control);
839
840         if (retval != ERROR_OK)
841                 LOG_ERROR("%s: can't %s HW %spoint %d",
842                         disable ? "disable" : "enable",
843                         target_name(dpm->arm->target),
844                         (xp->number < 16) ? "break" : "watch",
845                         xp->number & 0xf);
846 done:
847         return retval;
848 }
849
850 static int dpmv8_add_breakpoint(struct target *target, struct breakpoint *bp);
851
852 /**
853  * Writes all modified core registers for all processor modes.  In normal
854  * operation this is called on exit from halting debug state.
855  *
856  * @param dpm: represents the processor
857  * @param bpwp: true ensures breakpoints and watchpoints are set,
858  *      false ensures they are cleared
859  */
860 int armv8_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp)
861 {
862         struct arm *arm = dpm->arm;
863         struct reg_cache *cache = arm->core_cache;
864         int retval;
865
866         retval = dpm->prepare(dpm);
867         if (retval != ERROR_OK)
868                 goto done;
869
870         /* If we're managing hardware breakpoints for this core, enable
871          * or disable them as requested.
872          *
873          * REVISIT We don't yet manage them for ANY cores.  Eventually
874          * we should be able to assume we handle them; but until then,
875          * cope with the hand-crafted breakpoint code.
876          */
877         if (arm->target->type->add_breakpoint == dpmv8_add_breakpoint) {
878                 for (unsigned i = 0; i < dpm->nbp; i++) {
879                         struct dpm_bp *dbp = dpm->dbp + i;
880                         struct breakpoint *bp = dbp->bp;
881
882                         retval = dpmv8_maybe_update_bpwp(dpm, bpwp, &dbp->bpwp,
883                                         bp ? &bp->set : NULL);
884                         if (retval != ERROR_OK)
885                                 goto done;
886                 }
887         }
888
889         /* enable/disable watchpoints */
890         for (unsigned i = 0; i < dpm->nwp; i++) {
891                 struct dpm_wp *dwp = dpm->dwp + i;
892                 struct watchpoint *wp = dwp->wp;
893
894                 retval = dpmv8_maybe_update_bpwp(dpm, bpwp, &dwp->bpwp,
895                                 wp ? &wp->set : NULL);
896                 if (retval != ERROR_OK)
897                         goto done;
898         }
899
900         /* NOTE:  writes to breakpoint and watchpoint registers might
901          * be queued, and need (efficient/batched) flushing later.
902          */
903
904         /* Restore original core mode and state */
905         retval = armv8_dpm_modeswitch(dpm, ARM_MODE_ANY);
906         if (retval != ERROR_OK)
907                 goto done;
908
909         /* check everything except our scratch register R0 */
910         for (unsigned i = 1; i < cache->num_regs; i++) {
911                 struct arm_reg *r;
912
913                 /* skip PC and CPSR */
914                 if (i == ARMV8_PC || i == ARMV8_xPSR)
915                         continue;
916                 /* skip invalid */
917                 if (!cache->reg_list[i].valid)
918                         continue;
919                 /* skip non-dirty */
920                 if (!cache->reg_list[i].dirty)
921                         continue;
922
923                 /* skip all registers not on the current EL */
924                 r = cache->reg_list[i].arch_info;
925                 if (r->mode != ARM_MODE_ANY &&
926                                 dpm->last_el != armv8_curel_from_core_mode(r->mode))
927                         continue;
928
929                 retval = dpmv8_write_reg(dpm, &cache->reg_list[i], i);
930                 if (retval != ERROR_OK)
931                         break;
932         }
933
934         /* flush CPSR and PC */
935         if (retval == ERROR_OK)
936                 retval = dpmv8_write_reg(dpm, &cache->reg_list[ARMV8_xPSR], ARMV8_xPSR);
937         if (retval == ERROR_OK)
938                 retval = dpmv8_write_reg(dpm, &cache->reg_list[ARMV8_PC], ARMV8_PC);
939         /* flush R0 -- it's *very* dirty by now */
940         if (retval == ERROR_OK)
941                 retval = dpmv8_write_reg(dpm, &cache->reg_list[0], 0);
942         if (retval == ERROR_OK)
943                 dpm->instr_cpsr_sync(dpm);
944 done:
945         dpm->finish(dpm);
946         return retval;
947 }
948
949 /*
950  * Standard ARM register accessors ... there are three methods
951  * in "struct arm", to support individual read/write and bulk read
952  * of registers.
953  */
954
955 static int armv8_dpm_read_core_reg(struct target *target, struct reg *r,
956         int regnum, enum arm_mode mode)
957 {
958         struct arm *arm = target_to_arm(target);
959         struct arm_dpm *dpm = target_to_arm(target)->dpm;
960         int retval;
961         int max = arm->core_cache->num_regs;
962
963         if (regnum < 0 || regnum >= max)
964                 return ERROR_COMMAND_SYNTAX_ERROR;
965
966         /*
967          * REVISIT what happens if we try to read SPSR in a core mode
968          * which has no such register?
969          */
970         retval = dpm->prepare(dpm);
971         if (retval != ERROR_OK)
972                 return retval;
973
974         retval = dpmv8_read_reg(dpm, r, regnum);
975         if (retval != ERROR_OK)
976                 goto fail;
977
978 fail:
979         /* (void) */ dpm->finish(dpm);
980         return retval;
981 }
982
983 static int armv8_dpm_write_core_reg(struct target *target, struct reg *r,
984         int regnum, enum arm_mode mode, uint8_t *value)
985 {
986         struct arm *arm = target_to_arm(target);
987         struct arm_dpm *dpm = target_to_arm(target)->dpm;
988         int retval;
989         int max = arm->core_cache->num_regs;
990
991         if (regnum < 0 || regnum > max)
992                 return ERROR_COMMAND_SYNTAX_ERROR;
993
994         /* REVISIT what happens if we try to write SPSR in a core mode
995          * which has no such register?
996          */
997
998         retval = dpm->prepare(dpm);
999         if (retval != ERROR_OK)
1000                 return retval;
1001
1002         retval = dpmv8_write_reg(dpm, r, regnum);
1003
1004         /* always clean up, regardless of error */
1005         dpm->finish(dpm);
1006
1007         return retval;
1008 }
1009
1010 static int armv8_dpm_full_context(struct target *target)
1011 {
1012         struct arm *arm = target_to_arm(target);
1013         struct arm_dpm *dpm = arm->dpm;
1014         struct reg_cache *cache = arm->core_cache;
1015         int retval;
1016         bool did_read;
1017
1018         retval = dpm->prepare(dpm);
1019         if (retval != ERROR_OK)
1020                 goto done;
1021
1022         do {
1023                 enum arm_mode mode = ARM_MODE_ANY;
1024
1025                 did_read = false;
1026
1027                 /* We "know" arm_dpm_read_current_registers() was called so
1028                  * the unmapped registers (R0..R7, PC, AND CPSR) and some
1029                  * view of R8..R14 are current.  We also "know" oddities of
1030                  * register mapping: special cases for R8..R12 and SPSR.
1031                  *
1032                  * Pick some mode with unread registers and read them all.
1033                  * Repeat until done.
1034                  */
1035                 for (unsigned i = 0; i < cache->num_regs; i++) {
1036                         struct arm_reg *r;
1037
1038                         if (cache->reg_list[i].valid)
1039                                 continue;
1040                         r = cache->reg_list[i].arch_info;
1041
1042                         /* may need to pick a mode and set CPSR */
1043                         if (!did_read) {
1044                                 did_read = true;
1045                                 mode = r->mode;
1046
1047                                 /* For regular (ARM_MODE_ANY) R8..R12
1048                                  * in case we've entered debug state
1049                                  * in FIQ mode we need to patch mode.
1050                                  */
1051                                 if (mode != ARM_MODE_ANY)
1052                                         retval = armv8_dpm_modeswitch(dpm, mode);
1053                                 else
1054                                         retval = armv8_dpm_modeswitch(dpm, ARM_MODE_USR);
1055
1056                                 if (retval != ERROR_OK)
1057                                         goto done;
1058                         }
1059                         if (r->mode != mode)
1060                                 continue;
1061
1062                         /* CPSR was read, so "R16" must mean SPSR */
1063                         retval = dpmv8_read_reg(dpm,
1064                                         &cache->reg_list[i],
1065                                         (r->num == 16) ? 17 : r->num);
1066                         if (retval != ERROR_OK)
1067                                 goto done;
1068                 }
1069
1070         } while (did_read);
1071
1072         retval = armv8_dpm_modeswitch(dpm, ARM_MODE_ANY);
1073         /* (void) */ dpm->finish(dpm);
1074 done:
1075         return retval;
1076 }
1077
1078
1079 /*----------------------------------------------------------------------*/
1080
1081 /*
1082  * Breakpoint and Watchpoint support.
1083  *
1084  * Hardware {break,watch}points are usually left active, to minimize
1085  * debug entry/exit costs.  When they are set or cleared, it's done in
1086  * batches.  Also, DPM-conformant hardware can update debug registers
1087  * regardless of whether the CPU is running or halted ... though that
1088  * fact isn't currently leveraged.
1089  */
1090
1091 static int dpmv8_bpwp_setup(struct arm_dpm *dpm, struct dpm_bpwp *xp,
1092         uint32_t addr, uint32_t length)
1093 {
1094         uint32_t control;
1095
1096         control = (1 << 0)      /* enable */
1097                 | (3 << 1);     /* both user and privileged access */
1098
1099         /* Match 1, 2, or all 4 byte addresses in this word.
1100          *
1101          * FIXME:  v7 hardware allows lengths up to 2 GB for BP and WP.
1102          * Support larger length, when addr is suitably aligned.  In
1103          * particular, allow watchpoints on 8 byte "double" values.
1104          *
1105          * REVISIT allow watchpoints on unaligned 2-bit values; and on
1106          * v7 hardware, unaligned 4-byte ones too.
1107          */
1108         switch (length) {
1109                 case 1:
1110                         control |= (1 << (addr & 3)) << 5;
1111                         break;
1112                 case 2:
1113                         /* require 2-byte alignment */
1114                         if (!(addr & 1)) {
1115                                 control |= (3 << (addr & 2)) << 5;
1116                                 break;
1117                         }
1118                 /* FALL THROUGH */
1119                 case 4:
1120                         /* require 4-byte alignment */
1121                         if (!(addr & 3)) {
1122                                 control |= 0xf << 5;
1123                                 break;
1124                         }
1125                 /* FALL THROUGH */
1126                 default:
1127                         LOG_ERROR("unsupported {break,watch}point length/alignment");
1128                         return ERROR_COMMAND_SYNTAX_ERROR;
1129         }
1130
1131         /* other shared control bits:
1132          * bits 15:14 == 0 ... both secure and nonsecure states (v6.1+ only)
1133          * bit 20 == 0 ... not linked to a context ID
1134          * bit 28:24 == 0 ... not ignoring N LSBs (v7 only)
1135          */
1136
1137         xp->address = addr & ~3;
1138         xp->control = control;
1139         xp->dirty = true;
1140
1141         LOG_DEBUG("BPWP: addr %8.8" PRIx32 ", control %" PRIx32 ", number %d",
1142                 xp->address, control, xp->number);
1143
1144         /* hardware is updated in write_dirty_registers() */
1145         return ERROR_OK;
1146 }
1147
1148 static int dpmv8_add_breakpoint(struct target *target, struct breakpoint *bp)
1149 {
1150         struct arm *arm = target_to_arm(target);
1151         struct arm_dpm *dpm = arm->dpm;
1152         int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
1153
1154         if (bp->length < 2)
1155                 return ERROR_COMMAND_SYNTAX_ERROR;
1156         if (!dpm->bpwp_enable)
1157                 return retval;
1158
1159         /* FIXME we need a generic solution for software breakpoints. */
1160         if (bp->type == BKPT_SOFT)
1161                 LOG_DEBUG("using HW bkpt, not SW...");
1162
1163         for (unsigned i = 0; i < dpm->nbp; i++) {
1164                 if (!dpm->dbp[i].bp) {
1165                         retval = dpmv8_bpwp_setup(dpm, &dpm->dbp[i].bpwp,
1166                                         bp->address, bp->length);
1167                         if (retval == ERROR_OK)
1168                                 dpm->dbp[i].bp = bp;
1169                         break;
1170                 }
1171         }
1172
1173         return retval;
1174 }
1175
1176 static int dpmv8_remove_breakpoint(struct target *target, struct breakpoint *bp)
1177 {
1178         struct arm *arm = target_to_arm(target);
1179         struct arm_dpm *dpm = arm->dpm;
1180         int retval = ERROR_COMMAND_SYNTAX_ERROR;
1181
1182         for (unsigned i = 0; i < dpm->nbp; i++) {
1183                 if (dpm->dbp[i].bp == bp) {
1184                         dpm->dbp[i].bp = NULL;
1185                         dpm->dbp[i].bpwp.dirty = true;
1186
1187                         /* hardware is updated in write_dirty_registers() */
1188                         retval = ERROR_OK;
1189                         break;
1190                 }
1191         }
1192
1193         return retval;
1194 }
1195
1196 static int dpmv8_watchpoint_setup(struct arm_dpm *dpm, unsigned index_t,
1197         struct watchpoint *wp)
1198 {
1199         int retval;
1200         struct dpm_wp *dwp = dpm->dwp + index_t;
1201         uint32_t control;
1202
1203         /* this hardware doesn't support data value matching or masking */
1204         if (wp->value || wp->mask != ~(uint32_t)0) {
1205                 LOG_DEBUG("watchpoint values and masking not supported");
1206                 return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
1207         }
1208
1209         retval = dpmv8_bpwp_setup(dpm, &dwp->bpwp, wp->address, wp->length);
1210         if (retval != ERROR_OK)
1211                 return retval;
1212
1213         control = dwp->bpwp.control;
1214         switch (wp->rw) {
1215                 case WPT_READ:
1216                         control |= 1 << 3;
1217                         break;
1218                 case WPT_WRITE:
1219                         control |= 2 << 3;
1220                         break;
1221                 case WPT_ACCESS:
1222                         control |= 3 << 3;
1223                         break;
1224         }
1225         dwp->bpwp.control = control;
1226
1227         dpm->dwp[index_t].wp = wp;
1228
1229         return retval;
1230 }
1231
1232 static int dpmv8_add_watchpoint(struct target *target, struct watchpoint *wp)
1233 {
1234         struct arm *arm = target_to_arm(target);
1235         struct arm_dpm *dpm = arm->dpm;
1236         int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
1237
1238         if (dpm->bpwp_enable) {
1239                 for (unsigned i = 0; i < dpm->nwp; i++) {
1240                         if (!dpm->dwp[i].wp) {
1241                                 retval = dpmv8_watchpoint_setup(dpm, i, wp);
1242                                 break;
1243                         }
1244                 }
1245         }
1246
1247         return retval;
1248 }
1249
1250 static int dpmv8_remove_watchpoint(struct target *target, struct watchpoint *wp)
1251 {
1252         struct arm *arm = target_to_arm(target);
1253         struct arm_dpm *dpm = arm->dpm;
1254         int retval = ERROR_COMMAND_SYNTAX_ERROR;
1255
1256         for (unsigned i = 0; i < dpm->nwp; i++) {
1257                 if (dpm->dwp[i].wp == wp) {
1258                         dpm->dwp[i].wp = NULL;
1259                         dpm->dwp[i].bpwp.dirty = true;
1260
1261                         /* hardware is updated in write_dirty_registers() */
1262                         retval = ERROR_OK;
1263                         break;
1264                 }
1265         }
1266
1267         return retval;
1268 }
1269
1270 void armv8_dpm_report_wfar(struct arm_dpm *dpm, uint64_t addr)
1271 {
1272         switch (dpm->arm->core_state) {
1273                 case ARM_STATE_ARM:
1274                 case ARM_STATE_AARCH64:
1275                         addr -= 8;
1276                         break;
1277                 case ARM_STATE_THUMB:
1278                 case ARM_STATE_THUMB_EE:
1279                         addr -= 4;
1280                         break;
1281                 case ARM_STATE_JAZELLE:
1282                         /* ?? */
1283                         break;
1284                 default:
1285                         LOG_DEBUG("Unknown core_state");
1286                         break;
1287         }
1288         dpm->wp_pc = addr;
1289 }
1290
1291 /*
1292  * Handle exceptions taken in debug state. This happens mostly for memory
1293  * accesses that violated a MMU policy. Taking an exception while in debug
1294  * state clobbers certain state registers on the target exception level.
1295  * Just mark those registers dirty so that they get restored on resume.
1296  * This works both for Aarch32 and Aarch64 states.
1297  *
1298  * This function must not perform any actions that trigger another exception
1299  * or a recursion will happen.
1300  */
1301 void armv8_dpm_handle_exception(struct arm_dpm *dpm, bool do_restore)
1302 {
1303         struct armv8_common *armv8 = dpm->arm->arch_info;
1304         struct reg_cache *cache = dpm->arm->core_cache;
1305         enum arm_state core_state;
1306         uint64_t dlr;
1307         uint32_t dspsr;
1308         unsigned int el;
1309
1310         static const int clobbered_regs_by_el[3][5] = {
1311                 { ARMV8_PC, ARMV8_xPSR, ARMV8_ELR_EL1, ARMV8_ESR_EL1, ARMV8_SPSR_EL1 },
1312                 { ARMV8_PC, ARMV8_xPSR, ARMV8_ELR_EL2, ARMV8_ESR_EL2, ARMV8_SPSR_EL2 },
1313                 { ARMV8_PC, ARMV8_xPSR, ARMV8_ELR_EL3, ARMV8_ESR_EL3, ARMV8_SPSR_EL3 },
1314         };
1315
1316         el = (dpm->dscr >> 8) & 3;
1317
1318         /* safety check, must not happen since EL0 cannot be a target for an exception */
1319         if (el < SYSTEM_CUREL_EL1 || el > SYSTEM_CUREL_EL3) {
1320                 LOG_ERROR("%s: EL %i is invalid, DSCR corrupted?", __func__, el);
1321                 return;
1322         }
1323
1324         /* Clear sticky error */
1325         mem_ap_write_u32(armv8->debug_ap,
1326                 armv8->debug_base + CPUV8_DBG_DRCR, DRCR_CSE);
1327
1328         armv8->read_reg_u64(armv8, ARMV8_xPSR, &dlr);
1329         dspsr = dlr;
1330         armv8->read_reg_u64(armv8, ARMV8_PC, &dlr);
1331
1332         LOG_DEBUG("Exception taken to EL %i, DLR=0x%016"PRIx64" DSPSR=0x%08"PRIx32,
1333                         el, dlr, dspsr);
1334
1335         /* mark all clobbered registers as dirty */
1336         for (int i = 0; i < 5; i++)
1337                 cache->reg_list[clobbered_regs_by_el[el-1][i]].dirty = true;
1338
1339         /*
1340          * re-evaluate the core state, we might be in Aarch64 state now
1341          * we rely on dpm->dscr being up-to-date
1342          */
1343         core_state = armv8_dpm_get_core_state(dpm);
1344         armv8_select_opcodes(armv8, core_state == ARM_STATE_AARCH64);
1345         armv8_select_reg_access(armv8, core_state == ARM_STATE_AARCH64);
1346
1347         if (do_restore)
1348                 armv8_dpm_modeswitch(dpm, ARM_MODE_ANY);
1349 }
1350
1351 /*----------------------------------------------------------------------*/
1352
1353 /*
1354  * Other debug and support utilities
1355  */
1356
1357 void armv8_dpm_report_dscr(struct arm_dpm *dpm, uint32_t dscr)
1358 {
1359         struct target *target = dpm->arm->target;
1360
1361         dpm->dscr = dscr;
1362         dpm->last_el = (dscr >> 8) & 3;
1363
1364         /* Examine debug reason */
1365         switch (DSCR_ENTRY(dscr)) {
1366                 /* FALL THROUGH -- assume a v6 core in abort mode */
1367                 case DSCRV8_ENTRY_EXT_DEBUG:    /* EDBGRQ */
1368                         target->debug_reason = DBG_REASON_DBGRQ;
1369                         break;
1370                 case DSCRV8_ENTRY_HALT_STEP_EXECLU:     /* HALT step */
1371                 case DSCRV8_ENTRY_HALT_STEP_NORMAL: /* Halt step*/
1372                 case DSCRV8_ENTRY_HALT_STEP:
1373                         target->debug_reason = DBG_REASON_SINGLESTEP;
1374                         break;
1375                 case DSCRV8_ENTRY_HLT:  /* HLT instruction (software breakpoint) */
1376                 case DSCRV8_ENTRY_BKPT: /* SW BKPT (?) */
1377                 case DSCRV8_ENTRY_RESET_CATCH:  /* Reset catch */
1378                 case DSCRV8_ENTRY_OS_UNLOCK:  /*OS unlock catch*/
1379                 case DSCRV8_ENTRY_EXCEPTION_CATCH:  /*exception catch*/
1380                 case DSCRV8_ENTRY_SW_ACCESS_DBG: /*SW access dbg register*/
1381                         target->debug_reason = DBG_REASON_BREAKPOINT;
1382                         break;
1383                 case DSCRV8_ENTRY_WATCHPOINT:   /* asynch watchpoint */
1384                         target->debug_reason = DBG_REASON_WATCHPOINT;
1385                         break;
1386                 default:
1387                         target->debug_reason = DBG_REASON_UNDEFINED;
1388                         break;
1389         }
1390
1391 }
1392
1393 /*----------------------------------------------------------------------*/
1394
1395 /*
1396  * Setup and management support.
1397  */
1398
1399 /**
1400  * Hooks up this DPM to its associated target; call only once.
1401  * Initially this only covers the register cache.
1402  *
1403  * Oh, and watchpoints.  Yeah.
1404  */
1405 int armv8_dpm_setup(struct arm_dpm *dpm)
1406 {
1407         struct arm *arm = dpm->arm;
1408         struct target *target = arm->target;
1409         struct reg_cache *cache;
1410         arm->dpm = dpm;
1411
1412         /* register access setup */
1413         arm->full_context = armv8_dpm_full_context;
1414         arm->read_core_reg = armv8_dpm_read_core_reg;
1415         arm->write_core_reg = armv8_dpm_write_core_reg;
1416
1417         if (arm->core_cache == NULL) {
1418                 cache = armv8_build_reg_cache(target);
1419                 if (!cache)
1420                         return ERROR_FAIL;
1421         }
1422
1423         /* coprocessor access setup */
1424         arm->mrc = dpmv8_mrc;
1425         arm->mcr = dpmv8_mcr;
1426
1427         dpm->prepare = dpmv8_dpm_prepare;
1428         dpm->finish = dpmv8_dpm_finish;
1429
1430         dpm->instr_execute = dpmv8_instr_execute;
1431         dpm->instr_write_data_dcc = dpmv8_instr_write_data_dcc;
1432         dpm->instr_write_data_dcc_64 = dpmv8_instr_write_data_dcc_64;
1433         dpm->instr_write_data_r0 = dpmv8_instr_write_data_r0;
1434         dpm->instr_write_data_r0_64 = dpmv8_instr_write_data_r0_64;
1435         dpm->instr_cpsr_sync = dpmv8_instr_cpsr_sync;
1436
1437         dpm->instr_read_data_dcc = dpmv8_instr_read_data_dcc;
1438         dpm->instr_read_data_dcc_64 = dpmv8_instr_read_data_dcc_64;
1439         dpm->instr_read_data_r0 = dpmv8_instr_read_data_r0;
1440         dpm->instr_read_data_r0_64 = dpmv8_instr_read_data_r0_64;
1441
1442         dpm->arm_reg_current = armv8_reg_current;
1443
1444 /*      dpm->bpwp_enable = dpmv8_bpwp_enable; */
1445         dpm->bpwp_disable = dpmv8_bpwp_disable;
1446
1447         /* breakpoint setup -- optional until it works everywhere */
1448         if (!target->type->add_breakpoint) {
1449                 target->type->add_breakpoint = dpmv8_add_breakpoint;
1450                 target->type->remove_breakpoint = dpmv8_remove_breakpoint;
1451         }
1452
1453         /* watchpoint setup */
1454         target->type->add_watchpoint = dpmv8_add_watchpoint;
1455         target->type->remove_watchpoint = dpmv8_remove_watchpoint;
1456
1457         /* FIXME add vector catch support */
1458
1459         dpm->nbp = 1 + ((dpm->didr >> 12) & 0xf);
1460         dpm->dbp = calloc(dpm->nbp, sizeof *dpm->dbp);
1461
1462         dpm->nwp = 1 + ((dpm->didr >> 20) & 0xf);
1463         dpm->dwp = calloc(dpm->nwp, sizeof *dpm->dwp);
1464
1465         if (!dpm->dbp || !dpm->dwp) {
1466                 free(dpm->dbp);
1467                 free(dpm->dwp);
1468                 return ERROR_FAIL;
1469         }
1470
1471         LOG_INFO("%s: hardware has %d breakpoints, %d watchpoints",
1472                 target_name(target), dpm->nbp, dpm->nwp);
1473
1474         /* REVISIT ... and some of those breakpoints could match
1475          * execution context IDs...
1476          */
1477
1478         return ERROR_OK;
1479 }
1480
1481 /**
1482  * Reinitializes DPM state at the beginning of a new debug session
1483  * or after a reset which may have affected the debug module.
1484  */
1485 int armv8_dpm_initialize(struct arm_dpm *dpm)
1486 {
1487         /* Disable all breakpoints and watchpoints at startup. */
1488         if (dpm->bpwp_disable) {
1489                 unsigned i;
1490
1491                 for (i = 0; i < dpm->nbp; i++) {
1492                         dpm->dbp[i].bpwp.number = i;
1493                         (void) dpm->bpwp_disable(dpm, i);
1494                 }
1495                 for (i = 0; i < dpm->nwp; i++) {
1496                         dpm->dwp[i].bpwp.number = 16 + i;
1497                         (void) dpm->bpwp_disable(dpm, 16 + i);
1498                 }
1499         } else
1500                 LOG_WARNING("%s: can't disable breakpoints and watchpoints",
1501                         target_name(dpm->arm->target));
1502
1503         return ERROR_OK;
1504 }