drivers/staging/android/fiq_debugger/fiq_debugger.c

   1 /*
   2  * drivers/staging/android/fiq_debugger.c
   3  *
   4  * Serial Debugger Interface accessed through an FIQ interrupt.
   5  *
   6  * Copyright (C) 2008 Google, Inc.
   7  *
   8  * This software is licensed under the terms of the GNU General Public
   9  * License version 2, as published by the Free Software Foundation, and
  10  * may be copied, distributed, and modified under those terms.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <stdarg.h>
  19 #include <linux/module.h>
  20 #include <linux/io.h>
  21 #include <linux/console.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/clk.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/kernel_stat.h>
  26 #include <linux/kmsg_dump.h>
  27 #include <linux/irq.h>
  28 #include <linux/delay.h>
  29 #include <linux/reboot.h>
  30 #include <linux/sched.h>
  31 #include <linux/slab.h>
  32 #include <linux/smp.h>
  33 #include <linux/timer.h>
  34 #include <linux/tty.h>
  35 #include <linux/tty_flip.h>
  36 #include <linux/wakelock.h>
  37
  38 #ifdef CONFIG_FIQ_GLUE
  39 #include <asm/fiq_glue.h>
  40 #endif
  41
  42 #ifdef CONFIG_FIQ_DEBUGGER_UART_OVERLAY
  43 #include <linux/of.h>
  44 #endif
  45
  46 #include <linux/uaccess.h>
  47
  48 #include "fiq_debugger.h"
  49 #include "fiq_debugger_priv.h"
  50 #include "fiq_debugger_ringbuf.h"
  51
  52 #define DEBUG_MAX 64
  53 #define MAX_UNHANDLED_FIQ_COUNT 1000000
  54
  55 #define MAX_FIQ_DEBUGGER_PORTS 4
  56
  57 struct fiq_debugger_state {
  58 #ifdef CONFIG_FIQ_GLUE
  59         struct fiq_glue_handler handler;
  60 #endif
  61         struct fiq_debugger_output output;
  62
  63         int fiq;
  64         int uart_irq;
  65         int signal_irq;
  66         int wakeup_irq;
  67         bool wakeup_irq_no_set_wake;
  68         struct clk *clk;
  69         struct fiq_debugger_pdata *pdata;
  70         struct platform_device *pdev;
  71
  72         char debug_cmd[DEBUG_MAX];
  73         int debug_busy;
  74         int debug_abort;
  75
  76         char debug_buf[DEBUG_MAX];
  77         int debug_count;
  78
  79         bool no_sleep;
  80         bool debug_enable;
  81         bool ignore_next_wakeup_irq;
  82         struct timer_list sleep_timer;
  83         spinlock_t sleep_timer_lock;
  84         bool uart_enabled;
  85         struct wake_lock debugger_wake_lock;
  86         bool console_enable;
  87         int current_cpu;
  88         atomic_t unhandled_fiq_count;
  89         bool in_fiq;
  90
  91         struct work_struct work;
  92         spinlock_t work_lock;
  93         char work_cmd[DEBUG_MAX];
  94
  95 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
  96         spinlock_t console_lock;
  97         struct console console;
  98         struct tty_port tty_port;
  99         struct fiq_debugger_ringbuf *tty_rbuf;
 100         bool syslog_dumping;
 101 #endif
 102
 103         unsigned int last_irqs[NR_IRQS];
 104         unsigned int last_local_timer_irqs[NR_CPUS];
 105 };
 106
 107 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 108 struct tty_driver *fiq_tty_driver;
 109 #endif
 110
 111 #ifdef CONFIG_FIQ_DEBUGGER_NO_SLEEP
 112 static bool initial_no_sleep = true;
 113 #else
 114 static bool initial_no_sleep;
 115 #endif
 116
 117 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE
 118 static bool initial_debug_enable = true;
 119 static bool initial_console_enable = true;
 120 #else
 121 static bool initial_debug_enable;
 122 static bool initial_console_enable;
 123 #endif
 124
 125 static bool fiq_kgdb_enable;
 126 static bool fiq_debugger_disable;
 127
 128 module_param_named(no_sleep, initial_no_sleep, bool, 0644);
 129 module_param_named(debug_enable, initial_debug_enable, bool, 0644);
 130 module_param_named(console_enable, initial_console_enable, bool, 0644);
 131 module_param_named(kgdb_enable, fiq_kgdb_enable, bool, 0644);
 132 module_param_named(disable, fiq_debugger_disable, bool, 0644);
 133
 134 #ifdef CONFIG_FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON
 135 static inline
 136 void fiq_debugger_enable_wakeup_irq(struct fiq_debugger_state *state) {}
 137 static inline
 138 void fiq_debugger_disable_wakeup_irq(struct fiq_debugger_state *state) {}
 139 #else
 140 static inline
 141 void fiq_debugger_enable_wakeup_irq(struct fiq_debugger_state *state)
 142 {
 143         if (state->wakeup_irq < 0)
 144                 return;
 145         enable_irq(state->wakeup_irq);
 146         if (!state->wakeup_irq_no_set_wake)
 147                 enable_irq_wake(state->wakeup_irq);
 148 }
 149 static inline
 150 void fiq_debugger_disable_wakeup_irq(struct fiq_debugger_state *state)
 151 {
 152         if (state->wakeup_irq < 0)
 153                 return;
 154         disable_irq_nosync(state->wakeup_irq);
 155         if (!state->wakeup_irq_no_set_wake)
 156                 disable_irq_wake(state->wakeup_irq);
 157 }
 158 #endif
 159
 160 static inline bool fiq_debugger_have_fiq(struct fiq_debugger_state *state)
 161 {
 162         return (state->fiq >= 0);
 163 }
 164
 165 #ifdef CONFIG_FIQ_GLUE
 166 static void fiq_debugger_force_irq(struct fiq_debugger_state *state)
 167 {
 168         unsigned int irq = state->signal_irq;
 169
 170         if (WARN_ON(!fiq_debugger_have_fiq(state)))
 171                 return;
 172         if (state->pdata->force_irq) {
 173                 state->pdata->force_irq(state->pdev, irq);
 174         } else {
 175                 struct irq_chip *chip = irq_get_chip(irq);
 176                 if (chip && chip->irq_retrigger)
 177                         chip->irq_retrigger(irq_get_irq_data(irq));
 178         }
 179 }
 180 #endif
 181
 182 static void fiq_debugger_uart_enable(struct fiq_debugger_state *state)
 183 {
 184         if (state->clk)
 185                 clk_enable(state->clk);
 186         if (state->pdata->uart_enable)
 187                 state->pdata->uart_enable(state->pdev);
 188 }
 189
 190 static void fiq_debugger_uart_disable(struct fiq_debugger_state *state)
 191 {
 192         if (state->pdata->uart_disable)
 193                 state->pdata->uart_disable(state->pdev);
 194         if (state->clk)
 195                 clk_disable(state->clk);
 196 }
 197
 198 static void fiq_debugger_uart_flush(struct fiq_debugger_state *state)
 199 {
 200         if (state->pdata->uart_flush)
 201                 state->pdata->uart_flush(state->pdev);
 202 }
 203
 204 static void fiq_debugger_putc(struct fiq_debugger_state *state, char c)
 205 {
 206         state->pdata->uart_putc(state->pdev, c);
 207 }
 208
 209 static void fiq_debugger_puts(struct fiq_debugger_state *state, char *s)
 210 {
 211         unsigned c;
 212         while ((c = *s++)) {
 213                 if (c == '\n')
 214                         fiq_debugger_putc(state, '\r');
 215                 fiq_debugger_putc(state, c);
 216         }
 217 }
 218
 219 static void fiq_debugger_prompt(struct fiq_debugger_state *state)
 220 {
 221         fiq_debugger_puts(state, "debug> ");
 222 }
 223
 224 static void fiq_debugger_dump_kernel_log(struct fiq_debugger_state *state)
 225 {
 226         char buf[512];
 227         size_t len;
 228         struct kmsg_dumper dumper = { .active = true };
 229
 230
 231         kmsg_dump_rewind_nolock(&dumper);
 232         while (kmsg_dump_get_line_nolock(&dumper, true, buf,
 233                                          sizeof(buf) - 1, &len)) {
 234                 buf[len] = 0;
 235                 fiq_debugger_puts(state, buf);
 236         }
 237 }
 238
 239 static void fiq_debugger_printf(struct fiq_debugger_output *output,
 240                                const char *fmt, ...)
 241 {
 242         struct fiq_debugger_state *state;
 243         char buf[256];
 244         va_list ap;
 245
 246         state = container_of(output, struct fiq_debugger_state, output);
 247         va_start(ap, fmt);
 248         vsnprintf(buf, sizeof(buf), fmt, ap);
 249         va_end(ap);
 250
 251         fiq_debugger_puts(state, buf);
 252 }
 253
 254 /* Safe outside fiq context */
 255 static int fiq_debugger_printf_nfiq(void *cookie, const char *fmt, ...)
 256 {
 257         struct fiq_debugger_state *state = cookie;
 258         char buf[256];
 259         va_list ap;
 260         unsigned long irq_flags;
 261
 262         va_start(ap, fmt);
 263         vsnprintf(buf, 128, fmt, ap);
 264         va_end(ap);
 265
 266         local_irq_save(irq_flags);
 267         fiq_debugger_puts(state, buf);
 268         fiq_debugger_uart_flush(state);
 269         local_irq_restore(irq_flags);
 270         return state->debug_abort;
 271 }
 272
 273 static void fiq_debugger_dump_irqs(struct fiq_debugger_state *state)
 274 {
 275         int n;
 276         struct irq_desc *desc;
 277
 278         fiq_debugger_printf(&state->output,
 279                         "irqnr       total  since-last   status  name\n");
 280         for_each_irq_desc(n, desc) {
 281                 struct irqaction *act = desc->action;
 282                 if (!act && !kstat_irqs(n))
 283                         continue;
 284                 fiq_debugger_printf(&state->output, "%5d: %10u %11u %8x  %s\n", n,
 285                         kstat_irqs(n),
 286                         kstat_irqs(n) - state->last_irqs[n],
 287                         desc->status_use_accessors,
 288                         (act && act->name) ? act->name : "???");
 289                 state->last_irqs[n] = kstat_irqs(n);
 290         }
 291 }
 292
 293 static void fiq_debugger_do_ps(struct fiq_debugger_state *state)
 294 {
 295         struct task_struct *g;
 296         struct task_struct *p;
 297         unsigned task_state;
 298         static const char stat_nam[] = "RSDTtZX";
 299
 300         fiq_debugger_printf(&state->output, "pid   ppid  prio task            pc\n");
 301         read_lock(&tasklist_lock);
 302         do_each_thread(g, p) {
 303                 task_state = p->state ? __ffs(p->state) + 1 : 0;
 304                 fiq_debugger_printf(&state->output,
 305                              "%5d %5d %4d ", p->pid, p->parent->pid, p->prio);
 306                 fiq_debugger_printf(&state->output, "%-13.13s %c", p->comm,
 307                              task_state >= sizeof(stat_nam) ? '?' : stat_nam[task_state]);
 308                 if (task_state == TASK_RUNNING)
 309                         fiq_debugger_printf(&state->output, " running\n");
 310                 else
 311                         fiq_debugger_printf(&state->output, " %08lx\n",
 312                                         thread_saved_pc(p));
 313         } while_each_thread(g, p);
 314         read_unlock(&tasklist_lock);
 315 }
 316
 317 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 318 static void fiq_debugger_begin_syslog_dump(struct fiq_debugger_state *state)
 319 {
 320         state->syslog_dumping = true;
 321 }
 322
 323 static void fiq_debugger_end_syslog_dump(struct fiq_debugger_state *state)
 324 {
 325         state->syslog_dumping = false;
 326 }
 327 #else
 328 extern int do_syslog(int type, char __user *bug, int count);
 329 static void fiq_debugger_begin_syslog_dump(struct fiq_debugger_state *state)
 330 {
 331         do_syslog(5 /* clear */, NULL, 0);
 332 }
 333
 334 static void fiq_debugger_end_syslog_dump(struct fiq_debugger_state *state)
 335 {
 336         fiq_debugger_dump_kernel_log(state);
 337 }
 338 #endif
 339
 340 static void fiq_debugger_do_sysrq(struct fiq_debugger_state *state, char rq)
 341 {
 342         if ((rq == 'g' || rq == 'G') && !fiq_kgdb_enable) {
 343                 fiq_debugger_printf(&state->output, "sysrq-g blocked\n");
 344                 return;
 345         }
 346         fiq_debugger_begin_syslog_dump(state);
 347         handle_sysrq(rq);
 348         fiq_debugger_end_syslog_dump(state);
 349 }
 350
 351 #ifdef CONFIG_KGDB
 352 static void fiq_debugger_do_kgdb(struct fiq_debugger_state *state)
 353 {
 354         if (!fiq_kgdb_enable) {
 355                 fiq_debugger_printf(&state->output, "kgdb through fiq debugger not enabled\n");
 356                 return;
 357         }
 358
 359         fiq_debugger_printf(&state->output, "enabling console and triggering kgdb\n");
 360         state->console_enable = true;
 361         handle_sysrq('g');
 362 }
 363 #endif
 364
 365 static void fiq_debugger_schedule_work(struct fiq_debugger_state *state,
 366                 char *cmd)
 367 {
 368         unsigned long flags;
 369
 370         spin_lock_irqsave(&state->work_lock, flags);
 371         if (state->work_cmd[0] != '\0') {
 372                 fiq_debugger_printf(&state->output, "work command processor busy\n");
 373                 spin_unlock_irqrestore(&state->work_lock, flags);
 374                 return;
 375         }
 376
 377         strlcpy(state->work_cmd, cmd, sizeof(state->work_cmd));
 378         spin_unlock_irqrestore(&state->work_lock, flags);
 379
 380         schedule_work(&state->work);
 381 }
 382
 383 static void fiq_debugger_work(struct work_struct *work)
 384 {
 385         struct fiq_debugger_state *state;
 386         char work_cmd[DEBUG_MAX];
 387         char *cmd;
 388         unsigned long flags;
 389
 390         state = container_of(work, struct fiq_debugger_state, work);
 391
 392         spin_lock_irqsave(&state->work_lock, flags);
 393
 394         strlcpy(work_cmd, state->work_cmd, sizeof(work_cmd));
 395         state->work_cmd[0] = '\0';
 396
 397         spin_unlock_irqrestore(&state->work_lock, flags);
 398
 399         cmd = work_cmd;
 400         if (!strncmp(cmd, "reboot", 6)) {
 401                 cmd += 6;
 402                 while (*cmd == ' ')
 403                         cmd++;
 404                 if (cmd != '\0')
 405                         kernel_restart(cmd);
 406                 else
 407                         kernel_restart(NULL);
 408         } else {
 409                 fiq_debugger_printf(&state->output, "unknown work command '%s'\n",
 410                                 work_cmd);
 411         }
 412 }
 413
 414 /* This function CANNOT be called in FIQ context */
 415 static void fiq_debugger_irq_exec(struct fiq_debugger_state *state, char *cmd)
 416 {
 417         if (!strcmp(cmd, "ps"))
 418                 fiq_debugger_do_ps(state);
 419         if (!strcmp(cmd, "sysrq"))
 420                 fiq_debugger_do_sysrq(state, 'h');
 421         if (!strncmp(cmd, "sysrq ", 6))
 422                 fiq_debugger_do_sysrq(state, cmd[6]);
 423 #ifdef CONFIG_KGDB
 424         if (!strcmp(cmd, "kgdb"))
 425                 fiq_debugger_do_kgdb(state);
 426 #endif
 427         if (!strncmp(cmd, "reboot", 6))
 428                 fiq_debugger_schedule_work(state, cmd);
 429 }
 430
 431 static void fiq_debugger_help(struct fiq_debugger_state *state)
 432 {
 433         fiq_debugger_printf(&state->output,
 434                                 "FIQ Debugger commands:\n"
 435                                 " pc            PC status\n"
 436                                 " regs          Register dump\n"
 437                                 " allregs       Extended Register dump\n"
 438                                 " bt            Stack trace\n"
 439                                 " reboot [<c>]  Reboot with command <c>\n"
 440                                 " reset [<c>]   Hard reset with command <c>\n"
 441                                 " irqs          Interupt status\n"
 442                                 " kmsg          Kernel log\n"
 443                                 " version       Kernel version\n");
 444         fiq_debugger_printf(&state->output,
 445                                 " sleep         Allow sleep while in FIQ\n"
 446                                 " nosleep       Disable sleep while in FIQ\n"
 447                                 " console       Switch terminal to console\n"
 448                                 " cpu           Current CPU\n"
 449                                 " cpu <number>  Switch to CPU<number>\n");
 450         fiq_debugger_printf(&state->output,
 451                                 " ps            Process list\n"
 452                                 " sysrq         sysrq options\n"
 453                                 " sysrq <param> Execute sysrq with <param>\n");
 454 #ifdef CONFIG_KGDB
 455         fiq_debugger_printf(&state->output,
 456                                 " kgdb          Enter kernel debugger\n");
 457 #endif
 458 }
 459
 460 static void fiq_debugger_take_affinity(void *info)
 461 {
 462         struct fiq_debugger_state *state = info;
 463         struct cpumask cpumask;
 464
 465         cpumask_clear(&cpumask);
 466         cpumask_set_cpu(get_cpu(), &cpumask);
 467
 468         irq_set_affinity(state->uart_irq, &cpumask);
 469 }
 470
 471 static void fiq_debugger_switch_cpu(struct fiq_debugger_state *state, int cpu)
 472 {
 473         if (!fiq_debugger_have_fiq(state))
 474                 smp_call_function_single(cpu, fiq_debugger_take_affinity, state,
 475                                 false);
 476         state->current_cpu = cpu;
 477 }
 478
 479 static bool fiq_debugger_fiq_exec(struct fiq_debugger_state *state,
 480                         const char *cmd, const struct pt_regs *regs,
 481                         void *svc_sp)
 482 {
 483         bool signal_helper = false;
 484
 485         if (!strcmp(cmd, "help") || !strcmp(cmd, "?")) {
 486                 fiq_debugger_help(state);
 487         } else if (!strcmp(cmd, "pc")) {
 488                 fiq_debugger_dump_pc(&state->output, regs);
 489         } else if (!strcmp(cmd, "regs")) {
 490                 fiq_debugger_dump_regs(&state->output, regs);
 491         } else if (!strcmp(cmd, "allregs")) {
 492                 fiq_debugger_dump_allregs(&state->output, regs);
 493         } else if (!strcmp(cmd, "bt")) {
 494                 fiq_debugger_dump_stacktrace(&state->output, regs, 100, svc_sp);
 495         } else if (!strncmp(cmd, "reset", 5)) {
 496                 cmd += 5;
 497                 while (*cmd == ' ')
 498                         cmd++;
 499                 if (*cmd) {
 500                         char tmp_cmd[32];
 501                         strlcpy(tmp_cmd, cmd, sizeof(tmp_cmd));
 502                         machine_restart(tmp_cmd);
 503                 } else {
 504                         machine_restart(NULL);
 505                 }
 506         } else if (!strcmp(cmd, "irqs")) {
 507                 fiq_debugger_dump_irqs(state);
 508         } else if (!strcmp(cmd, "kmsg")) {
 509                 fiq_debugger_dump_kernel_log(state);
 510         } else if (!strcmp(cmd, "version")) {
 511                 fiq_debugger_printf(&state->output, "%s\n", linux_banner);
 512         } else if (!strcmp(cmd, "sleep")) {
 513                 state->no_sleep = false;
 514                 fiq_debugger_printf(&state->output, "enabling sleep\n");
 515         } else if (!strcmp(cmd, "nosleep")) {
 516                 state->no_sleep = true;
 517                 fiq_debugger_printf(&state->output, "disabling sleep\n");
 518         } else if (!strcmp(cmd, "console")) {
 519                 fiq_debugger_printf(&state->output, "console mode\n");
 520                 fiq_debugger_uart_flush(state);
 521                 state->console_enable = true;
 522         } else if (!strcmp(cmd, "cpu")) {
 523                 fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
 524         } else if (!strncmp(cmd, "cpu ", 4)) {
 525                 unsigned long cpu = 0;
 526                 if (kstrtoul(cmd + 4, 10, &cpu) == 0)
 527                         fiq_debugger_switch_cpu(state, cpu);
 528                 else
 529                         fiq_debugger_printf(&state->output, "invalid cpu\n");
 530                 fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
 531         } else {
 532                 if (state->debug_busy) {
 533                         fiq_debugger_printf(&state->output,
 534                                 "command processor busy. trying to abort.\n");
 535                         state->debug_abort = -1;
 536                 } else {
 537                         strcpy(state->debug_cmd, cmd);
 538                         state->debug_busy = 1;
 539                 }
 540
 541                 return true;
 542         }
 543         if (!state->console_enable)
 544                 fiq_debugger_prompt(state);
 545
 546         return signal_helper;
 547 }
 548
 549 static void fiq_debugger_sleep_timer_expired(unsigned long data)
 550 {
 551         struct fiq_debugger_state *state = (struct fiq_debugger_state *)data;
 552         unsigned long flags;
 553
 554         spin_lock_irqsave(&state->sleep_timer_lock, flags);
 555         if (state->uart_enabled && !state->no_sleep) {
 556                 if (state->debug_enable && !state->console_enable) {
 557                         state->debug_enable = false;
 558                         fiq_debugger_printf_nfiq(state,
 559                                         "suspending fiq debugger\n");
 560                 }
 561                 state->ignore_next_wakeup_irq = true;
 562                 fiq_debugger_uart_disable(state);
 563                 state->uart_enabled = false;
 564                 fiq_debugger_enable_wakeup_irq(state);
 565         }
 566         wake_unlock(&state->debugger_wake_lock);
 567         spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 568 }
 569
 570 static void fiq_debugger_handle_wakeup(struct fiq_debugger_state *state)
 571 {
 572         unsigned long flags;
 573
 574         spin_lock_irqsave(&state->sleep_timer_lock, flags);
 575         if (state->wakeup_irq >= 0 && state->ignore_next_wakeup_irq) {
 576                 state->ignore_next_wakeup_irq = false;
 577         } else if (!state->uart_enabled) {
 578                 wake_lock(&state->debugger_wake_lock);
 579                 fiq_debugger_uart_enable(state);
 580                 state->uart_enabled = true;
 581                 fiq_debugger_disable_wakeup_irq(state);
 582                 mod_timer(&state->sleep_timer, jiffies + HZ / 2);
 583         }
 584         spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 585 }
 586
 587 static irqreturn_t fiq_debugger_wakeup_irq_handler(int irq, void *dev)
 588 {
 589         struct fiq_debugger_state *state = dev;
 590
 591         if (!state->no_sleep)
 592                 fiq_debugger_puts(state, "WAKEUP\n");
 593         fiq_debugger_handle_wakeup(state);
 594
 595         return IRQ_HANDLED;
 596 }
 597
 598 static
 599 void fiq_debugger_handle_console_irq_context(struct fiq_debugger_state *state)
 600 {
 601 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
 602         if (state->tty_port.ops) {
 603                 int i;
 604                 int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
 605                 for (i = 0; i < count; i++) {
 606                         int c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
 607                         tty_insert_flip_char(&state->tty_port, c, TTY_NORMAL);
 608                         if (!fiq_debugger_ringbuf_consume(state->tty_rbuf, 1))
 609                                 pr_warn("fiq tty failed to consume byte\n");
 610                 }
 611                 tty_flip_buffer_push(&state->tty_port);
 612         }
 613 #endif
 614 }
 615
 616 static void fiq_debugger_handle_irq_context(struct fiq_debugger_state *state)
 617 {
 618         if (!state->no_sleep) {
 619                 unsigned long flags;
 620
 621                 spin_lock_irqsave(&state->sleep_timer_lock, flags);
 622                 wake_lock(&state->debugger_wake_lock);
 623                 mod_timer(&state->sleep_timer, jiffies + HZ * 5);
 624                 spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 625         }
 626         fiq_debugger_handle_console_irq_context(state);
 627         if (state->debug_busy) {
 628                 fiq_debugger_irq_exec(state, state->debug_cmd);
 629                 if (!state->console_enable)
 630                         fiq_debugger_prompt(state);
 631                 state->debug_busy = 0;
 632         }
 633 }
 634
 635 static int fiq_debugger_getc(struct fiq_debugger_state *state)
 636 {
 637         return state->pdata->uart_getc(state->pdev);
 638 }
 639
 640 static bool fiq_debugger_handle_uart_interrupt(struct fiq_debugger_state *state,
 641                         int this_cpu, const struct pt_regs *regs, void *svc_sp)
 642 {
 643         int c;
 644         static int last_c;
 645         int count = 0;
 646         bool signal_helper = false;
 647
 648         if (this_cpu != state->current_cpu) {
 649                 if (state->in_fiq)
 650                         return false;
 651
 652                 if (atomic_inc_return(&state->unhandled_fiq_count) !=
 653                                         MAX_UNHANDLED_FIQ_COUNT)
 654                         return false;
 655
 656                 fiq_debugger_printf(&state->output,
 657                         "fiq_debugger: cpu %d not responding, "
 658                         "reverting to cpu %d\n", state->current_cpu,
 659                         this_cpu);
 660
 661                 atomic_set(&state->unhandled_fiq_count, 0);
 662                 fiq_debugger_switch_cpu(state, this_cpu);
 663                 return false;
 664         }
 665
 666         state->in_fiq = true;
 667
 668         while ((c = fiq_debugger_getc(state)) != FIQ_DEBUGGER_NO_CHAR) {
 669                 count++;
 670                 if (!state->debug_enable) {
 671                         if ((c == 13) || (c == 10)) {
 672                                 state->debug_enable = true;
 673                                 state->debug_count = 0;
 674                                 fiq_debugger_prompt(state);
 675                         }
 676                 } else if (c == FIQ_DEBUGGER_BREAK) {
 677                         state->console_enable = false;
 678                         fiq_debugger_puts(state, "fiq debugger mode\n");
 679                         state->debug_count = 0;
 680                         fiq_debugger_prompt(state);
 681 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 682                 } else if (state->console_enable && state->tty_rbuf) {
 683                         fiq_debugger_ringbuf_push(state->tty_rbuf, c);
 684                         signal_helper = true;
 685 #endif
 686                 } else if ((c >= ' ') && (c < 127)) {
 687                         if (state->debug_count < (DEBUG_MAX - 1)) {
 688                                 state->debug_buf[state->debug_count++] = c;
 689                                 fiq_debugger_putc(state, c);
 690                         }
 691                 } else if ((c == 8) || (c == 127)) {
 692                         if (state->debug_count > 0) {
 693                                 state->debug_count--;
 694                                 fiq_debugger_putc(state, 8);
 695                                 fiq_debugger_putc(state, ' ');
 696                                 fiq_debugger_putc(state, 8);
 697                         }
 698                 } else if ((c == 13) || (c == 10)) {
 699                         if (c == '\r' || (c == '\n' && last_c != '\r')) {
 700                                 fiq_debugger_putc(state, '\r');
 701                                 fiq_debugger_putc(state, '\n');
 702                         }
 703                         if (state->debug_count) {
 704                                 state->debug_buf[state->debug_count] = 0;
 705                                 state->debug_count = 0;
 706                                 signal_helper |=
 707                                         fiq_debugger_fiq_exec(state,
 708                                                         state->debug_buf,
 709                                                         regs, svc_sp);
 710                         } else {
 711                                 fiq_debugger_prompt(state);
 712                         }
 713                 }
 714                 last_c = c;
 715         }
 716         if (!state->console_enable)
 717                 fiq_debugger_uart_flush(state);
 718         if (state->pdata->fiq_ack)
 719                 state->pdata->fiq_ack(state->pdev, state->fiq);
 720
 721         /* poke sleep timer if necessary */
 722         if (state->debug_enable && !state->no_sleep)
 723                 signal_helper = true;
 724
 725         atomic_set(&state->unhandled_fiq_count, 0);
 726         state->in_fiq = false;
 727
 728         return signal_helper;
 729 }
 730
 731 #ifdef CONFIG_FIQ_GLUE
 732 static void fiq_debugger_fiq(struct fiq_glue_handler *h,
 733                 const struct pt_regs *regs, void *svc_sp)
 734 {
 735         struct fiq_debugger_state *state =
 736                 container_of(h, struct fiq_debugger_state, handler);
 737         unsigned int this_cpu = THREAD_INFO(svc_sp)->cpu;
 738         bool need_irq;
 739
 740         need_irq = fiq_debugger_handle_uart_interrupt(state, this_cpu, regs,
 741                         svc_sp);
 742         if (need_irq)
 743                 fiq_debugger_force_irq(state);
 744 }
 745 #endif
 746
 747 /*
 748  * When not using FIQs, we only use this single interrupt as an entry point.
 749  * This just effectively takes over the UART interrupt and does all the work
 750  * in this context.
 751  */
 752 static irqreturn_t fiq_debugger_uart_irq(int irq, void *dev)
 753 {
 754         struct fiq_debugger_state *state = dev;
 755         bool not_done;
 756
 757         fiq_debugger_handle_wakeup(state);
 758
 759         /* handle the debugger irq in regular context */
 760         not_done = fiq_debugger_handle_uart_interrupt(state, smp_processor_id(),
 761                                               get_irq_regs(),
 762                                               current_thread_info());
 763         if (not_done)
 764                 fiq_debugger_handle_irq_context(state);
 765
 766         return IRQ_HANDLED;
 767 }
 768
 769 /*
 770  * If FIQs are used, not everything can happen in fiq context.
 771  * FIQ handler does what it can and then signals this interrupt to finish the
 772  * job in irq context.
 773  */
 774 static irqreturn_t fiq_debugger_signal_irq(int irq, void *dev)
 775 {
 776         struct fiq_debugger_state *state = dev;
 777
 778         if (state->pdata->force_irq_ack)
 779                 state->pdata->force_irq_ack(state->pdev, state->signal_irq);
 780
 781         fiq_debugger_handle_irq_context(state);
 782
 783         return IRQ_HANDLED;
 784 }
 785
 786 #ifdef CONFIG_FIQ_GLUE
 787 static void fiq_debugger_resume(struct fiq_glue_handler *h)
 788 {
 789         struct fiq_debugger_state *state =
 790                 container_of(h, struct fiq_debugger_state, handler);
 791         if (state->pdata->uart_resume)
 792                 state->pdata->uart_resume(state->pdev);
 793 }
 794 #endif
 795
 796 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
 797 struct tty_driver *fiq_debugger_console_device(struct console *co, int *index)
 798 {
 799         *index = co->index;
 800         return fiq_tty_driver;
 801 }
 802
 803 static void fiq_debugger_console_write(struct console *co,
 804                                 const char *s, unsigned int count)
 805 {
 806         struct fiq_debugger_state *state;
 807         unsigned long flags;
 808
 809         state = container_of(co, struct fiq_debugger_state, console);
 810
 811         if (!state->console_enable && !state->syslog_dumping)
 812                 return;
 813
 814         fiq_debugger_uart_enable(state);
 815         spin_lock_irqsave(&state->console_lock, flags);
 816         while (count--) {
 817                 if (*s == '\n')
 818                         fiq_debugger_putc(state, '\r');
 819                 fiq_debugger_putc(state, *s++);
 820         }
 821         fiq_debugger_uart_flush(state);
 822         spin_unlock_irqrestore(&state->console_lock, flags);
 823         fiq_debugger_uart_disable(state);
 824 }
 825
 826 static struct console fiq_debugger_console = {
 827         .name = "ttyFIQ",
 828         .device = fiq_debugger_console_device,
 829         .write = fiq_debugger_console_write,
 830         .flags = CON_PRINTBUFFER | CON_ANYTIME | CON_ENABLED,
 831 };
 832
 833 int fiq_tty_open(struct tty_struct *tty, struct file *filp)
 834 {
 835         int line = tty->index;
 836         struct fiq_debugger_state **states = tty->driver->driver_state;
 837         struct fiq_debugger_state *state = states[line];
 838
 839         return tty_port_open(&state->tty_port, tty, filp);
 840 }
 841
 842 void fiq_tty_close(struct tty_struct *tty, struct file *filp)
 843 {
 844         tty_port_close(tty->port, tty, filp);
 845 }
 846
 847 int  fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
 848 {
 849         int i;
 850         int line = tty->index;
 851         struct fiq_debugger_state **states = tty->driver->driver_state;
 852         struct fiq_debugger_state *state = states[line];
 853
 854         if (!state->console_enable)
 855                 return count;
 856
 857         fiq_debugger_uart_enable(state);
 858         spin_lock_irq(&state->console_lock);
 859         for (i = 0; i < count; i++)
 860                 fiq_debugger_putc(state, *buf++);
 861         spin_unlock_irq(&state->console_lock);
 862         fiq_debugger_uart_disable(state);
 863
 864         return count;
 865 }
 866
 867 int  fiq_tty_write_room(struct tty_struct *tty)
 868 {
 869         return 16;
 870 }
 871
 872 #ifdef CONFIG_CONSOLE_POLL
 873 static int fiq_tty_poll_init(struct tty_driver *driver, int line, char *options)
 874 {
 875         return 0;
 876 }
 877
 878 static int fiq_tty_poll_get_char(struct tty_driver *driver, int line)
 879 {
 880         struct fiq_debugger_state **states = driver->driver_state;
 881         struct fiq_debugger_state *state = states[line];
 882         int c = NO_POLL_CHAR;
 883
 884         fiq_debugger_uart_enable(state);
 885         if (fiq_debugger_have_fiq(state)) {
 886                 int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
 887                 if (count > 0) {
 888                         c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
 889                         fiq_debugger_ringbuf_consume(state->tty_rbuf, 1);
 890                 }
 891         } else {
 892                 c = fiq_debugger_getc(state);
 893                 if (c == FIQ_DEBUGGER_NO_CHAR)
 894                         c = NO_POLL_CHAR;
 895         }
 896         fiq_debugger_uart_disable(state);
 897
 898         return c;
 899 }
 900
 901 static void fiq_tty_poll_put_char(struct tty_driver *driver, int line, char ch)
 902 {
 903         struct fiq_debugger_state **states = driver->driver_state;
 904         struct fiq_debugger_state *state = states[line];
 905         fiq_debugger_uart_enable(state);
 906         fiq_debugger_putc(state, ch);
 907         fiq_debugger_uart_disable(state);
 908 }
 909 #endif
 910
 911 static const struct tty_port_operations fiq_tty_port_ops;
 912
 913 static const struct tty_operations fiq_tty_driver_ops = {
 914         .write = fiq_tty_write,
 915         .write_room = fiq_tty_write_room,
 916         .open = fiq_tty_open,
 917         .close = fiq_tty_close,
 918 #ifdef CONFIG_CONSOLE_POLL
 919         .poll_init = fiq_tty_poll_init,
 920         .poll_get_char = fiq_tty_poll_get_char,
 921         .poll_put_char = fiq_tty_poll_put_char,
 922 #endif
 923 };
 924
 925 static int fiq_debugger_tty_init(void)
 926 {
 927         int ret;
 928         struct fiq_debugger_state **states = NULL;
 929
 930         states = kzalloc(sizeof(*states) * MAX_FIQ_DEBUGGER_PORTS, GFP_KERNEL);
 931         if (!states) {
 932                 pr_err("Failed to allocate fiq debugger state structres\n");
 933                 return -ENOMEM;
 934         }
 935
 936         fiq_tty_driver = alloc_tty_driver(MAX_FIQ_DEBUGGER_PORTS);
 937         if (!fiq_tty_driver) {
 938                 pr_err("Failed to allocate fiq debugger tty\n");
 939                 ret = -ENOMEM;
 940                 goto err_free_state;
 941         }
 942
 943         fiq_tty_driver->owner           = THIS_MODULE;
 944         fiq_tty_driver->driver_name     = "fiq-debugger";
 945         fiq_tty_driver->name            = "ttyFIQ";
 946         fiq_tty_driver->type            = TTY_DRIVER_TYPE_SERIAL;
 947         fiq_tty_driver->subtype         = SERIAL_TYPE_NORMAL;
 948         fiq_tty_driver->init_termios    = tty_std_termios;
 949         fiq_tty_driver->flags           = TTY_DRIVER_REAL_RAW |
 950                                           TTY_DRIVER_DYNAMIC_DEV;
 951         fiq_tty_driver->driver_state    = states;
 952
 953         fiq_tty_driver->init_termios.c_cflag =
 954                                         B115200 | CS8 | CREAD | HUPCL | CLOCAL;
 955         fiq_tty_driver->init_termios.c_ispeed = 115200;
 956         fiq_tty_driver->init_termios.c_ospeed = 115200;
 957
 958         tty_set_operations(fiq_tty_driver, &fiq_tty_driver_ops);
 959
 960         ret = tty_register_driver(fiq_tty_driver);
 961         if (ret) {
 962                 pr_err("Failed to register fiq tty: %d\n", ret);
 963                 goto err_free_tty;
 964         }
 965
 966         pr_info("Registered FIQ tty driver\n");
 967         return 0;
 968
 969 err_free_tty:
 970         put_tty_driver(fiq_tty_driver);
 971         fiq_tty_driver = NULL;
 972 err_free_state:
 973         kfree(states);
 974         return ret;
 975 }
 976
 977 static int fiq_debugger_tty_init_one(struct fiq_debugger_state *state)
 978 {
 979         int ret;
 980         struct device *tty_dev;
 981         struct fiq_debugger_state **states = fiq_tty_driver->driver_state;
 982
 983         states[state->pdev->id] = state;
 984
 985         state->tty_rbuf = fiq_debugger_ringbuf_alloc(1024);
 986         if (!state->tty_rbuf) {
 987                 pr_err("Failed to allocate fiq debugger ringbuf\n");
 988                 ret = -ENOMEM;
 989                 goto err;
 990         }
 991
 992         tty_port_init(&state->tty_port);
 993         state->tty_port.ops = &fiq_tty_port_ops;
 994
 995         tty_dev = tty_port_register_device(&state->tty_port, fiq_tty_driver,
 996                                            state->pdev->id, &state->pdev->dev);
 997         if (IS_ERR(tty_dev)) {
 998                 pr_err("Failed to register fiq debugger tty device\n");
 999                 ret = PTR_ERR(tty_dev);
1000                 goto err;
1001         }
1002
1003         device_set_wakeup_capable(tty_dev, 1);
1004
1005         pr_info("Registered fiq debugger ttyFIQ%d\n", state->pdev->id);
1006
1007         return 0;
1008
1009 err:
1010         fiq_debugger_ringbuf_free(state->tty_rbuf);
1011         state->tty_rbuf = NULL;
1012         return ret;
1013 }
1014 #endif
1015
1016 static int fiq_debugger_dev_suspend(struct device *dev)
1017 {
1018         struct platform_device *pdev = to_platform_device(dev);
1019         struct fiq_debugger_state *state = platform_get_drvdata(pdev);
1020
1021         if (state->pdata->uart_dev_suspend)
1022                 return state->pdata->uart_dev_suspend(pdev);
1023         return 0;
1024 }
1025
1026 static int fiq_debugger_dev_resume(struct device *dev)
1027 {
1028         struct platform_device *pdev = to_platform_device(dev);
1029         struct fiq_debugger_state *state = platform_get_drvdata(pdev);
1030
1031         if (state->pdata->uart_dev_resume)
1032                 return state->pdata->uart_dev_resume(pdev);
1033         return 0;
1034 }
1035
1036 static int fiq_debugger_probe(struct platform_device *pdev)
1037 {
1038         int ret;
1039         struct fiq_debugger_pdata *pdata = dev_get_platdata(&pdev->dev);
1040         struct fiq_debugger_state *state;
1041         int fiq;
1042         int uart_irq;
1043
1044         if (pdev->id >= MAX_FIQ_DEBUGGER_PORTS)
1045                 return -EINVAL;
1046
1047         if (!pdata->uart_getc || !pdata->uart_putc)
1048                 return -EINVAL;
1049         if ((pdata->uart_enable && !pdata->uart_disable) ||
1050             (!pdata->uart_enable && pdata->uart_disable))
1051                 return -EINVAL;
1052
1053         fiq = platform_get_irq_byname(pdev, "fiq");
1054         uart_irq = platform_get_irq_byname(pdev, "uart_irq");
1055
1056         /* uart_irq mode and fiq mode are mutually exclusive, but one of them
1057          * is required */
1058         if ((uart_irq < 0 && fiq < 0) || (uart_irq >= 0 && fiq >= 0))
1059                 return -EINVAL;
1060         if (fiq >= 0 && !pdata->fiq_enable)
1061                 return -EINVAL;
1062
1063         state = kzalloc(sizeof(*state), GFP_KERNEL);
1064         state->output.printf = fiq_debugger_printf;
1065         setup_timer(&state->sleep_timer, fiq_debugger_sleep_timer_expired,
1066                     (unsigned long)state);
1067         state->pdata = pdata;
1068         state->pdev = pdev;
1069         state->no_sleep = initial_no_sleep;
1070         state->debug_enable = initial_debug_enable;
1071         state->console_enable = initial_console_enable;
1072
1073         state->fiq = fiq;
1074         state->uart_irq = uart_irq;
1075         state->signal_irq = platform_get_irq_byname(pdev, "signal");
1076         state->wakeup_irq = platform_get_irq_byname(pdev, "wakeup");
1077
1078         INIT_WORK(&state->work, fiq_debugger_work);
1079         spin_lock_init(&state->work_lock);
1080
1081         platform_set_drvdata(pdev, state);
1082
1083         spin_lock_init(&state->sleep_timer_lock);
1084
1085         if (state->wakeup_irq < 0 && fiq_debugger_have_fiq(state))
1086                 state->no_sleep = true;
1087         state->ignore_next_wakeup_irq = !state->no_sleep;
1088
1089         wake_lock_init(&state->debugger_wake_lock,
1090                         WAKE_LOCK_SUSPEND, "serial-debug");
1091
1092         state->clk = clk_get(&pdev->dev, NULL);
1093         if (IS_ERR(state->clk))
1094                 state->clk = NULL;
1095
1096         /* do not call pdata->uart_enable here since uart_init may still
1097          * need to do some initialization before uart_enable can work.
1098          * So, only try to manage the clock during init.
1099          */
1100         if (state->clk)
1101                 clk_enable(state->clk);
1102
1103         if (pdata->uart_init) {
1104                 ret = pdata->uart_init(pdev);
1105                 if (ret)
1106                         goto err_uart_init;
1107         }
1108
1109         fiq_debugger_printf_nfiq(state,
1110                                 "<hit enter %sto activate fiq debugger>\n",
1111                                 state->no_sleep ? "" : "twice ");
1112
1113 #ifdef CONFIG_FIQ_GLUE
1114         if (fiq_debugger_have_fiq(state)) {
1115                 state->handler.fiq = fiq_debugger_fiq;
1116                 state->handler.resume = fiq_debugger_resume;
1117                 ret = fiq_glue_register_handler(&state->handler);
1118                 if (ret) {
1119                         pr_err("%s: could not install fiq handler\n", __func__);
1120                         goto err_register_irq;
1121                 }
1122
1123                 pdata->fiq_enable(pdev, state->fiq, 1);
1124         } else
1125 #endif
1126         {
1127                 ret = request_irq(state->uart_irq, fiq_debugger_uart_irq,
1128                                   IRQF_NO_SUSPEND, "debug", state);
1129                 if (ret) {
1130                         pr_err("%s: could not install irq handler\n", __func__);
1131                         goto err_register_irq;
1132                 }
1133
1134                 /* for irq-only mode, we want this irq to wake us up, if it
1135                  * can.
1136                  */
1137                 enable_irq_wake(state->uart_irq);
1138         }
1139
1140         if (state->clk)
1141                 clk_disable(state->clk);
1142
1143         if (state->signal_irq >= 0) {
1144                 ret = request_irq(state->signal_irq, fiq_debugger_signal_irq,
1145                           IRQF_TRIGGER_RISING, "debug-signal", state);
1146                 if (ret)
1147                         pr_err("serial_debugger: could not install signal_irq");
1148         }
1149
1150         if (state->wakeup_irq >= 0) {
1151                 ret = request_irq(state->wakeup_irq,
1152                                   fiq_debugger_wakeup_irq_handler,
1153                                   IRQF_TRIGGER_FALLING,
1154                                   "debug-wakeup", state);
1155                 if (ret) {
1156                         pr_err("serial_debugger: "
1157                                 "could not install wakeup irq\n");
1158                         state->wakeup_irq = -1;
1159                 } else {
1160                         ret = enable_irq_wake(state->wakeup_irq);
1161                         if (ret) {
1162                                 pr_err("serial_debugger: "
1163                                         "could not enable wakeup\n");
1164                                 state->wakeup_irq_no_set_wake = true;
1165                         }
1166                 }
1167         }
1168         if (state->no_sleep)
1169                 fiq_debugger_handle_wakeup(state);
1170
1171 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
1172         spin_lock_init(&state->console_lock);
1173         state->console = fiq_debugger_console;
1174         state->console.index = pdev->id;
1175         if (!console_set_on_cmdline)
1176                 add_preferred_console(state->console.name,
1177                         state->console.index, NULL);
1178         register_console(&state->console);
1179         fiq_debugger_tty_init_one(state);
1180 #endif
1181         return 0;
1182
1183 err_register_irq:
1184         if (pdata->uart_free)
1185                 pdata->uart_free(pdev);
1186 err_uart_init:
1187         if (state->clk)
1188                 clk_disable(state->clk);
1189         if (state->clk)
1190                 clk_put(state->clk);
1191         wake_lock_destroy(&state->debugger_wake_lock);
1192         platform_set_drvdata(pdev, NULL);
1193         kfree(state);
1194         return ret;
1195 }
1196
1197 static const struct dev_pm_ops fiq_debugger_dev_pm_ops = {
1198         .suspend        = fiq_debugger_dev_suspend,
1199         .resume         = fiq_debugger_dev_resume,
1200 };
1201
1202 static struct platform_driver fiq_debugger_driver = {
1203         .probe  = fiq_debugger_probe,
1204         .driver = {
1205                 .name   = "fiq_debugger",
1206                 .pm     = &fiq_debugger_dev_pm_ops,
1207         },
1208 };
1209
1210 #if defined(CONFIG_FIQ_DEBUGGER_UART_OVERLAY)
1211 int fiq_debugger_uart_overlay(void)
1212 {
1213         struct device_node *onp = of_find_node_by_path("/uart_overlay@0");
1214         int ret;
1215
1216         if (!onp) {
1217                 pr_err("serial_debugger: uart overlay not found\n");
1218                 return -ENODEV;
1219         }
1220
1221         ret = of_overlay_create(onp);
1222         if (ret < 0) {
1223                 pr_err("serial_debugger: fail to create overlay: %d\n", ret);
1224                 of_node_put(onp);
1225                 return ret;
1226         }
1227
1228         pr_info("serial_debugger: uart overlay applied\n");
1229         return 0;
1230 }
1231 #endif
1232
1233 static int __init fiq_debugger_init(void)
1234 {
1235         if (fiq_debugger_disable) {
1236                 pr_err("serial_debugger: disabled\n");
1237                 return -ENODEV;
1238         }
1239 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
1240         fiq_debugger_tty_init();
1241 #endif
1242 #if defined(CONFIG_FIQ_DEBUGGER_UART_OVERLAY)
1243         fiq_debugger_uart_overlay();
1244 #endif
1245         return platform_driver_register(&fiq_debugger_driver);
1246 }
1247
1248 postcore_initcall(fiq_debugger_init);