arch/blackfin/kernel/kgdb.c

   1 /*
   2  * File:         arch/blackfin/kernel/kgdb.c
   3  * Based on:
   4  * Author:       Sonic Zhang
   5  *
   6  * Created:
   7  * Description:
   8  *
   9  * Rev:          $Id: kgdb_bfin_linux-2.6.x.patch 4934 2007-02-13 09:32:11Z sonicz $
  10  *
  11  * Modified:
  12  *               Copyright 2005-2006 Analog Devices Inc.
  13  *
  14  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  15  *
  16  * This program is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License as published by
  18  * the Free Software Foundation; either version 2 of the License, or
  19  * (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program; if not, see the file COPYING, or write
  28  * to the Free Software Foundation, Inc.,
  29  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  30  */
  31
  32 #include <linux/string.h>
  33 #include <linux/kernel.h>
  34 #include <linux/sched.h>
  35 #include <linux/smp.h>
  36 #include <linux/spinlock.h>
  37 #include <linux/delay.h>
  38 #include <linux/ptrace.h>               /* for linux pt_regs struct */
  39 #include <linux/kgdb.h>
  40 #include <linux/console.h>
  41 #include <linux/init.h>
  42 #include <linux/debugger.h>
  43 #include <linux/errno.h>
  44 #include <linux/irq.h>
  45 #include <asm/system.h>
  46 #include <asm/traps.h>
  47 #include <asm/blackfin.h>
  48
  49 /* Put the error code here just in case the user cares.  */
  50 int gdb_bf533errcode;
  51 /* Likewise, the vector number here (since GDB only gets the signal
  52    number through the usual means, and that's not very specific).  */
  53 int gdb_bf533vector = -1;
  54
  55 #if KGDB_MAX_NO_CPUS != 8
  56 #error change the definition of slavecpulocks
  57 #endif
  58
  59 void regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  60 {
  61         gdb_regs[BFIN_R0] = regs->r0;
  62         gdb_regs[BFIN_R1] = regs->r1;
  63         gdb_regs[BFIN_R2] = regs->r2;
  64         gdb_regs[BFIN_R3] = regs->r3;
  65         gdb_regs[BFIN_R4] = regs->r4;
  66         gdb_regs[BFIN_R5] = regs->r5;
  67         gdb_regs[BFIN_R6] = regs->r6;
  68         gdb_regs[BFIN_R7] = regs->r7;
  69         gdb_regs[BFIN_P0] = regs->p0;
  70         gdb_regs[BFIN_P1] = regs->p1;
  71         gdb_regs[BFIN_P2] = regs->p2;
  72         gdb_regs[BFIN_P3] = regs->p3;
  73         gdb_regs[BFIN_P4] = regs->p4;
  74         gdb_regs[BFIN_P5] = regs->p5;
  75         gdb_regs[BFIN_SP] = regs->reserved;
  76         gdb_regs[BFIN_FP] = regs->fp;
  77         gdb_regs[BFIN_I0] = regs->i0;
  78         gdb_regs[BFIN_I1] = regs->i1;
  79         gdb_regs[BFIN_I2] = regs->i2;
  80         gdb_regs[BFIN_I3] = regs->i3;
  81         gdb_regs[BFIN_M0] = regs->m0;
  82         gdb_regs[BFIN_M1] = regs->m1;
  83         gdb_regs[BFIN_M2] = regs->m2;
  84         gdb_regs[BFIN_M3] = regs->m3;
  85         gdb_regs[BFIN_B0] = regs->b0;
  86         gdb_regs[BFIN_B1] = regs->b1;
  87         gdb_regs[BFIN_B2] = regs->b2;
  88         gdb_regs[BFIN_B3] = regs->b3;
  89         gdb_regs[BFIN_L0] = regs->l0;
  90         gdb_regs[BFIN_L1] = regs->l1;
  91         gdb_regs[BFIN_L2] = regs->l2;
  92         gdb_regs[BFIN_L3] = regs->l3;
  93         gdb_regs[BFIN_A0_DOT_X] = regs->a0x;
  94         gdb_regs[BFIN_A0_DOT_W] = regs->a0w;
  95         gdb_regs[BFIN_A1_DOT_X] = regs->a1x;
  96         gdb_regs[BFIN_A1_DOT_W] = regs->a1w;
  97         gdb_regs[BFIN_ASTAT] = regs->astat;
  98         gdb_regs[BFIN_RETS] = regs->rets;
  99         gdb_regs[BFIN_LC0] = regs->lc0;
 100         gdb_regs[BFIN_LT0] = regs->lt0;
 101         gdb_regs[BFIN_LB0] = regs->lb0;
 102         gdb_regs[BFIN_LC1] = regs->lc1;
 103         gdb_regs[BFIN_LT1] = regs->lt1;
 104         gdb_regs[BFIN_LB1] = regs->lb1;
 105         gdb_regs[BFIN_CYCLES] = 0;
 106         gdb_regs[BFIN_CYCLES2] = 0;
 107         gdb_regs[BFIN_USP] = regs->usp;
 108         gdb_regs[BFIN_SEQSTAT] = regs->seqstat;
 109         gdb_regs[BFIN_SYSCFG] = regs->syscfg;
 110         gdb_regs[BFIN_RETI] = regs->pc;
 111         gdb_regs[BFIN_RETX] = regs->retx;
 112         gdb_regs[BFIN_RETN] = regs->retn;
 113         gdb_regs[BFIN_RETE] = regs->rete;
 114         gdb_regs[BFIN_PC] = regs->pc;
 115         gdb_regs[BFIN_CC] = 0;
 116         gdb_regs[BFIN_EXTRA1] = 0;
 117         gdb_regs[BFIN_EXTRA2] = 0;
 118         gdb_regs[BFIN_EXTRA3] = 0;
 119         gdb_regs[BFIN_IPEND] = regs->ipend;
 120 }
 121
 122 /*
 123  * Extracts ebp, esp and eip values understandable by gdb from the values
 124  * saved by switch_to.
 125  * thread.esp points to ebp. flags and ebp are pushed in switch_to hence esp
 126  * prior to entering switch_to is 8 greater then the value that is saved.
 127  * If switch_to changes, change following code appropriately.
 128  */
 129 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
 130 {
 131         gdb_regs[BFIN_SP] = p->thread.ksp;
 132         gdb_regs[BFIN_PC] = p->thread.pc;
 133         gdb_regs[BFIN_SEQSTAT] = p->thread.seqstat;
 134 }
 135
 136 void gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *regs)
 137 {
 138         regs->r0 = gdb_regs[BFIN_R0];
 139         regs->r1 = gdb_regs[BFIN_R1];
 140         regs->r2 = gdb_regs[BFIN_R2];
 141         regs->r3 = gdb_regs[BFIN_R3];
 142         regs->r4 = gdb_regs[BFIN_R4];
 143         regs->r5 = gdb_regs[BFIN_R5];
 144         regs->r6 = gdb_regs[BFIN_R6];
 145         regs->r7 = gdb_regs[BFIN_R7];
 146         regs->p0 = gdb_regs[BFIN_P0];
 147         regs->p1 = gdb_regs[BFIN_P1];
 148         regs->p2 = gdb_regs[BFIN_P2];
 149         regs->p3 = gdb_regs[BFIN_P3];
 150         regs->p4 = gdb_regs[BFIN_P4];
 151         regs->p5 = gdb_regs[BFIN_P5];
 152         regs->fp = gdb_regs[BFIN_FP];
 153         regs->i0 = gdb_regs[BFIN_I0];
 154         regs->i1 = gdb_regs[BFIN_I1];
 155         regs->i2 = gdb_regs[BFIN_I2];
 156         regs->i3 = gdb_regs[BFIN_I3];
 157         regs->m0 = gdb_regs[BFIN_M0];
 158         regs->m1 = gdb_regs[BFIN_M1];
 159         regs->m2 = gdb_regs[BFIN_M2];
 160         regs->m3 = gdb_regs[BFIN_M3];
 161         regs->b0 = gdb_regs[BFIN_B0];
 162         regs->b1 = gdb_regs[BFIN_B1];
 163         regs->b2 = gdb_regs[BFIN_B2];
 164         regs->b3 = gdb_regs[BFIN_B3];
 165         regs->l0 = gdb_regs[BFIN_L0];
 166         regs->l1 = gdb_regs[BFIN_L1];
 167         regs->l2 = gdb_regs[BFIN_L2];
 168         regs->l3 = gdb_regs[BFIN_L3];
 169         regs->a0x = gdb_regs[BFIN_A0_DOT_X];
 170         regs->a0w = gdb_regs[BFIN_A0_DOT_W];
 171         regs->a1x = gdb_regs[BFIN_A1_DOT_X];
 172         regs->a1w = gdb_regs[BFIN_A1_DOT_W];
 173         regs->rets = gdb_regs[BFIN_RETS];
 174         regs->lc0 = gdb_regs[BFIN_LC0];
 175         regs->lt0 = gdb_regs[BFIN_LT0];
 176         regs->lb0 = gdb_regs[BFIN_LB0];
 177         regs->lc1 = gdb_regs[BFIN_LC1];
 178         regs->lt1 = gdb_regs[BFIN_LT1];
 179         regs->lb1 = gdb_regs[BFIN_LB1];
 180         regs->usp = gdb_regs[BFIN_USP];
 181         regs->syscfg = gdb_regs[BFIN_SYSCFG];
 182         regs->retx = gdb_regs[BFIN_PC];
 183         regs->retn = gdb_regs[BFIN_RETN];
 184         regs->rete = gdb_regs[BFIN_RETE];
 185         regs->pc = gdb_regs[BFIN_PC];
 186
 187 #if 0                           /* can't change these */
 188         regs->astat = gdb_regs[BFIN_ASTAT];
 189         regs->seqstat = gdb_regs[BFIN_SEQSTAT];
 190         regs->ipend = gdb_regs[BFIN_IPEND];
 191 #endif
 192 }
 193
 194 struct hw_breakpoint {
 195         unsigned int occupied:1;
 196         unsigned int skip:1;
 197         unsigned int enabled:1;
 198         unsigned int type:1;
 199         unsigned int dataacc:2;
 200         unsigned short count;
 201         unsigned int addr;
 202 } breakinfo[HW_BREAKPOINT_NUM];
 203
 204 int kgdb_arch_init(void)
 205 {
 206         debugger_step = 0;
 207
 208         kgdb_remove_all_hw_break();
 209         return 0;
 210 }
 211
 212 int kgdb_set_hw_break(unsigned long addr)
 213 {
 214         int breakno;
 215         for (breakno = 0; breakno < HW_BREAKPOINT_NUM; breakno++)
 216                 if (!breakinfo[breakno].occupied) {
 217                         breakinfo[breakno].occupied = 1;
 218                         breakinfo[breakno].enabled = 1;
 219                         breakinfo[breakno].type = 1;
 220                         breakinfo[breakno].addr = addr;
 221                         return 0;
 222                 }
 223
 224         return -ENOSPC;
 225 }
 226
 227 int kgdb_remove_hw_break(unsigned long addr)
 228 {
 229         int breakno;
 230         for (breakno = 0; breakno < HW_BREAKPOINT_NUM; breakno++)
 231                 if (breakinfo[breakno].addr == addr)
 232                         memset(&(breakinfo[breakno]), 0, sizeof(struct hw_breakpoint));
 233
 234         return 0;
 235 }
 236
 237 void kgdb_remove_all_hw_break(void)
 238 {
 239         memset(breakinfo, 0, sizeof(struct hw_breakpoint)*8);
 240 }
 241
 242 /*
 243 void kgdb_show_info(void)
 244 {
 245         printk(KERN_DEBUG "hwd: wpia0=0x%x, wpiacnt0=%d, wpiactl=0x%x, wpstat=0x%x\n",
 246                 bfin_read_WPIA0(), bfin_read_WPIACNT0(),
 247                 bfin_read_WPIACTL(), bfin_read_WPSTAT());
 248 }
 249 */
 250
 251 void kgdb_correct_hw_break(void)
 252 {
 253         int breakno;
 254         int correctit;
 255         uint32_t wpdactl = bfin_read_WPDACTL();
 256
 257         correctit = 0;
 258         for (breakno = 0; breakno < HW_BREAKPOINT_NUM; breakno++) {
 259                 if (breakinfo[breakno].type == 1) {
 260                         switch (breakno) {
 261                         case 0:
 262                                 if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN0)) {
 263                                         correctit = 1;
 264                                         wpdactl &= ~(WPIREN01|EMUSW0);
 265                                         wpdactl |= WPIAEN0|WPICNTEN0;
 266                                         bfin_write_WPIA0(breakinfo[breakno].addr);
 267                                         bfin_write_WPIACNT0(breakinfo[breakno].skip);
 268                                 } else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN0)) {
 269                                         correctit = 1;
 270                                         wpdactl &= ~WPIAEN0;
 271                                 }
 272                                 break;
 273
 274                         case 1:
 275                                 if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN1)) {
 276                                         correctit = 1;
 277                                         wpdactl &= ~(WPIREN01|EMUSW1);
 278                                         wpdactl |= WPIAEN1|WPICNTEN1;
 279                                         bfin_write_WPIA1(breakinfo[breakno].addr);
 280                                         bfin_write_WPIACNT1(breakinfo[breakno].skip);
 281                                 } else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN1)) {
 282                                         correctit = 1;
 283                                         wpdactl &= ~WPIAEN1;
 284                                 }
 285                                 break;
 286
 287                         case 2:
 288                                 if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN2)) {
 289                                         correctit = 1;
 290                                         wpdactl &= ~(WPIREN23|EMUSW2);
 291                                         wpdactl |= WPIAEN2|WPICNTEN2;
 292                                         bfin_write_WPIA2(breakinfo[breakno].addr);
 293                                         bfin_write_WPIACNT2(breakinfo[breakno].skip);
 294                                 } else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN2)) {
 295                                         correctit = 1;
 296                                         wpdactl &= ~WPIAEN2;
 297                                 }
 298                                 break;
 299
 300                         case 3:
 301                                 if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN3)) {
 302                                         correctit = 1;
 303                                         wpdactl &= ~(WPIREN23|EMUSW3);
 304                                         wpdactl |= WPIAEN3|WPICNTEN3;
 305                                         bfin_write_WPIA3(breakinfo[breakno].addr);
 306                                         bfin_write_WPIACNT3(breakinfo[breakno].skip);
 307                                 } else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN3)) {
 308                                         correctit = 1;
 309                                         wpdactl &= ~WPIAEN3;
 310                                 }
 311                                 break;
 312                         case 4:
 313                                 if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN4)) {
 314                                         correctit = 1;
 315                                         wpdactl &= ~(WPIREN45|EMUSW4);
 316                                         wpdactl |= WPIAEN4|WPICNTEN4;
 317                                         bfin_write_WPIA4(breakinfo[breakno].addr);
 318                                         bfin_write_WPIACNT4(breakinfo[breakno].skip);
 319                                 } else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN4)) {
 320                                         correctit = 1;
 321                                         wpdactl &= ~WPIAEN4;
 322                                 }
 323                                 break;
 324                         case 5:
 325                                 if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN5)) {
 326                                         correctit = 1;
 327                                         wpdactl &= ~(WPIREN45|EMUSW5);
 328                                         wpdactl |= WPIAEN5|WPICNTEN5;
 329                                         bfin_write_WPIA5(breakinfo[breakno].addr);
 330                                         bfin_write_WPIACNT5(breakinfo[breakno].skip);
 331                                 } else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN5)) {
 332                                         correctit = 1;
 333                                         wpdactl &= ~WPIAEN5;
 334                                 }
 335                                 break;
 336                         }
 337                 }
 338         }
 339         if (correctit) {
 340                 wpdactl &= ~WPAND;
 341                 wpdactl |= WPPWR;
 342                 /*printk("correct_hw_break: wpdactl=0x%x\n", wpdactl);*/
 343                 bfin_write_WPDACTL(wpdactl);
 344                 CSYNC();
 345                 /*kgdb_show_info();*/
 346         }
 347 }
 348
 349 void kgdb_disable_hw_debug(struct pt_regs *regs)
 350 {
 351         /* Disable hardware debugging while we are in kgdb */
 352         bfin_write_WPIACTL(bfin_read_WPIACTL() & ~0x1);
 353         CSYNC();
 354 }
 355
 356 void kgdb_post_master_code(struct pt_regs *regs, int eVector, int err_code)
 357 {
 358         /* Master processor is completely in the debugger */
 359         gdb_bf533vector = eVector;
 360         gdb_bf533errcode = err_code;
 361 }
 362
 363 int kgdb_arch_handle_exception(int exceptionVector, int signo,
 364                                int err_code, char *remcom_in_buffer,
 365                                char *remcom_out_buffer,
 366                                struct pt_regs *linux_regs)
 367 {
 368         long addr;
 369         long breakno;
 370         char *ptr;
 371         int newPC;
 372         int wp_status;
 373         int i;
 374
 375         switch (remcom_in_buffer[0]) {
 376         case 'c':
 377         case 's':
 378                 if (kgdb_contthread && kgdb_contthread != current) {
 379                         strcpy(remcom_out_buffer, "E00");
 380                         break;
 381                 }
 382
 383                 kgdb_contthread = NULL;
 384
 385                 /* try to read optional parameter, pc unchanged if no parm */
 386                 ptr = &remcom_in_buffer[1];
 387                 if (kgdb_hex2long(&ptr, &addr)) {
 388                         linux_regs->retx = addr;
 389                 }
 390                 newPC = linux_regs->retx;
 391
 392                 /* clear the trace bit */
 393                 linux_regs->syscfg &= 0xfffffffe;
 394
 395                 /* set the trace bit if we're stepping */
 396                 if (remcom_in_buffer[0] == 's') {
 397                         linux_regs->syscfg |= 0x1;
 398                         debugger_step = linux_regs->ipend;
 399                         debugger_step >>= 6;
 400                         for (i = 10; i > 0; i--, debugger_step >>= 1)
 401                                 if (debugger_step & 1)
 402                                         break;
 403                         /* i indicate event priority of current stopped instruction
 404                          * user space instruction is 0, IVG15 is 1, IVTMR is 10.
 405                          * debugger_step > 0 means in single step mode
 406                          */
 407                         debugger_step = i + 1;
 408                 } else {
 409                         debugger_step = 0;
 410                 }
 411
 412                 wp_status = bfin_read_WPSTAT();
 413                 CSYNC();
 414
 415                 if (exceptionVector == VEC_WATCH) {
 416                         for (breakno = 0; breakno < 6; ++breakno) {
 417                                 if (wp_status & (1 << breakno)) {
 418                                         breakinfo->skip = 1;
 419                                         break;
 420                                 }
 421                         }
 422                 }
 423                 kgdb_correct_hw_break();
 424
 425                 bfin_write_WPSTAT(0);
 426
 427                 return 0;
 428         }                       /* switch */
 429         return -1;              /* this means that we do not want to exit from the handler */
 430 }
 431
 432 struct kgdb_arch arch_kgdb_ops = {
 433         .gdb_bpt_instr = {0xa1},
 434         .flags = KGDB_HW_BREAKPOINT,
 435 };