arch/arm/common/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  * Copyright (C) 2010-2015 NVIDIA Corporation.  All rights reserved.
   8  *
   9  * This software is licensed under the terms of the GNU General Public
  10  * License version 2, as published by the Free Software Foundation, and
  11  * may be copied, distributed, and modified under those terms.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include <stdarg.h>
  20 #include <linux/module.h>
  21 #include <linux/io.h>
  22 #include <linux/console.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/clk.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/kernel_stat.h>
  27 #include <linux/kmsg_dump.h>
  28 #include <linux/irq.h>
  29 #include <linux/delay.h>
  30 #include <linux/reboot.h>
  31 #include <linux/sched.h>
  32 #include <linux/slab.h>
  33 #include <linux/smp.h>
  34 #include <linux/timer.h>
  35 #include <linux/tty.h>
  36 #include <linux/tty_flip.h>
  37 #include <linux/wakelock.h>
  38
  39 #ifdef CONFIG_FIQ_GLUE
  40 #include <asm/fiq_glue.h>
  41 #endif
  42
  43 #include <linux/uaccess.h>
  44
  45 #include "fiq_debugger.h"
  46 #include "fiq_debugger_priv.h"
  47 #include "fiq_debugger_ringbuf.h"
  48
  49 #define DEBUG_MAX 64
  50 #define MAX_UNHANDLED_FIQ_COUNT 1000000
  51
  52 #define MAX_FIQ_DEBUGGER_PORTS 4
  53 struct fiq_debugger_state {
  54 #ifdef CONFIG_FIQ_GLUE
  55         struct fiq_glue_handler handler;
  56 #endif
  57         struct fiq_debugger_output output;
  58
  59         int fiq;
  60         int uart_irq;
  61         int signal_irq;
  62         int wakeup_irq;
  63         bool wakeup_irq_no_set_wake;
  64         struct clk *clk;
  65         struct fiq_debugger_pdata *pdata;
  66         struct platform_device *pdev;
  67
  68         char debug_cmd[DEBUG_MAX];
  69         int debug_busy;
  70         int debug_abort;
  71
  72         char debug_buf[DEBUG_MAX];
  73         int debug_count;
  74
  75         bool no_sleep;
  76         bool debug_enable;
  77         bool ignore_next_wakeup_irq;
  78         struct timer_list sleep_timer;
  79         spinlock_t sleep_timer_lock;
  80         bool uart_enabled;
  81         struct wake_lock debugger_wake_lock;
  82         bool console_enable;
  83         int current_cpu;
  84         atomic_t unhandled_fiq_count;
  85         bool in_fiq;
  86
  87         struct work_struct work;
  88         spinlock_t work_lock;
  89         char work_cmd[DEBUG_MAX];
  90
  91 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
  92         spinlock_t console_lock;
  93         struct console console;
  94         struct tty_port tty_port;
  95         struct fiq_debugger_ringbuf *tty_rbuf;
  96         bool syslog_dumping;
  97 #endif
  98
  99         struct console *ram_console;
 100         unsigned int last_irqs[NR_IRQS];
 101         unsigned int last_local_timer_irqs[NR_CPUS];
 102 };
 103
 104 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 105 struct tty_driver *fiq_tty_driver;
 106 #endif
 107
 108 #ifdef CONFIG_FIQ_DEBUGGER_NO_SLEEP
 109 static bool initial_no_sleep = true;
 110 #else
 111 static bool initial_no_sleep;
 112 #endif
 113
 114 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE
 115 static bool initial_debug_enable = true;
 116 static bool initial_console_enable = true;
 117 #else
 118 static bool initial_debug_enable;
 119 static bool initial_console_enable;
 120 #endif
 121
 122 static bool fiq_kgdb_enable;
 123
 124 module_param_named(no_sleep, initial_no_sleep, bool, 0644);
 125 module_param_named(debug_enable, initial_debug_enable, bool, 0644);
 126 module_param_named(console_enable, initial_console_enable, bool, 0644);
 127 module_param_named(kgdb_enable, fiq_kgdb_enable, bool, 0644);
 128
 129 #ifdef CONFIG_FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON
 130 static inline
 131 void fiq_debugger_enable_wakeup_irq(struct fiq_debugger_state *state) {}
 132 static inline
 133 void fiq_debugger_disable_wakeup_irq(struct fiq_debugger_state *state) {}
 134 #else
 135 static inline
 136 void fiq_debugger_enable_wakeup_irq(struct fiq_debugger_state *state)
 137 {
 138         if (state->wakeup_irq < 0)
 139                 return;
 140         enable_irq(state->wakeup_irq);
 141         if (!state->wakeup_irq_no_set_wake)
 142                 enable_irq_wake(state->wakeup_irq);
 143 }
 144 static inline
 145 void fiq_debugger_disable_wakeup_irq(struct fiq_debugger_state *state)
 146 {
 147         if (state->wakeup_irq < 0)
 148                 return;
 149         disable_irq_nosync(state->wakeup_irq);
 150         if (!state->wakeup_irq_no_set_wake)
 151                 disable_irq_wake(state->wakeup_irq);
 152 }
 153 #endif
 154
 155 static inline bool fiq_debugger_have_fiq(struct fiq_debugger_state *state)
 156 {
 157         return (state->fiq >= 0);
 158 }
 159
 160 #ifdef CONFIG_FIQ_GLUE
 161 static void fiq_debugger_force_irq(struct fiq_debugger_state *state)
 162 {
 163         unsigned int irq = state->signal_irq;
 164
 165         if (WARN_ON(!fiq_debugger_have_fiq(state)))
 166                 return;
 167         if (state->pdata->force_irq) {
 168                 state->pdata->force_irq(state->pdev, irq);
 169         } else {
 170                 struct irq_chip *chip = irq_get_chip(irq);
 171                 if (chip && chip->irq_retrigger)
 172                         chip->irq_retrigger(irq_get_irq_data(irq));
 173         }
 174 }
 175 #endif
 176
 177 static void fiq_debugger_uart_enable(struct fiq_debugger_state *state)
 178 {
 179         if (state->clk)
 180                 clk_enable(state->clk);
 181         if (state->pdata->uart_enable)
 182                 state->pdata->uart_enable(state->pdev);
 183 }
 184
 185 static void fiq_debugger_uart_disable(struct fiq_debugger_state *state)
 186 {
 187         if (state->pdata->uart_disable)
 188                 state->pdata->uart_disable(state->pdev);
 189         if (state->clk)
 190                 clk_disable(state->clk);
 191 }
 192
 193 static void fiq_debugger_uart_flush(struct fiq_debugger_state *state)
 194 {
 195         if (state->pdata->uart_flush)
 196                 state->pdata->uart_flush(state->pdev);
 197 }
 198
 199 static void fiq_debugger_putc(struct fiq_debugger_state *state, char c)
 200 {
 201         state->pdata->uart_putc(state->pdev, c);
 202 }
 203
 204 static void fiq_debugger_puts(struct fiq_debugger_state *state, char *s)
 205 {
 206         unsigned c;
 207         while ((c = *s++)) {
 208                 if (c == '\n')
 209                         fiq_debugger_putc(state, '\r');
 210                 fiq_debugger_putc(state, c);
 211         }
 212 }
 213
 214 static void fiq_debugger_prompt(struct fiq_debugger_state *state)
 215 {
 216         fiq_debugger_puts(state, "debug> ");
 217 }
 218
 219 static void fiq_debugger_dump_kernel_log(struct fiq_debugger_state *state)
 220 {
 221         char buf[512];
 222         size_t len;
 223         struct kmsg_dumper dumper = { .active = true };
 224
 225
 226         kmsg_dump_rewind_nolock(&dumper);
 227         while (kmsg_dump_get_line_nolock(&dumper, true, buf,
 228                                          sizeof(buf) - 1, &len)) {
 229                 buf[len] = 0;
 230                 fiq_debugger_puts(state, buf);
 231         }
 232 }
 233
 234 static void fiq_debugger_printf(struct fiq_debugger_output *output,
 235                                const char *fmt, ...)
 236 {
 237         struct fiq_debugger_state *state;
 238         char buf[256];
 239         va_list ap;
 240         int n;
 241         state = container_of(output, struct fiq_debugger_state, output);
 242         va_start(ap, fmt);
 243         n = vsnprintf(buf, sizeof(buf), fmt, ap);
 244         if (NULL != state->ram_console)
 245                 state->ram_console->write(state->ram_console, buf, n);
 246         va_end(ap);
 247
 248         fiq_debugger_puts(state, buf);
 249 }
 250
 251 /* Safe outside fiq context */
 252 static int fiq_debugger_printf_nfiq(void *cookie, const char *fmt, ...)
 253 {
 254         struct fiq_debugger_state *state = cookie;
 255         char buf[256];
 256         va_list ap;
 257         unsigned long irq_flags;
 258
 259         va_start(ap, fmt);
 260         vsnprintf(buf, 128, fmt, ap);
 261         va_end(ap);
 262
 263         local_irq_save(irq_flags);
 264         fiq_debugger_puts(state, buf);
 265         fiq_debugger_uart_flush(state);
 266         local_irq_restore(irq_flags);
 267         return state->debug_abort;
 268 }
 269
 270 static void fiq_debugger_dump_irqs(struct fiq_debugger_state *state)
 271 {
 272         int n;
 273         struct irq_desc *desc;
 274
 275         fiq_debugger_printf(&state->output,
 276                         "irqnr       total  since-last   status  name\n");
 277         for_each_irq_desc(n, desc) {
 278                 struct irqaction *act = desc->action;
 279                 if (!act && !kstat_irqs(n))
 280                         continue;
 281                 fiq_debugger_printf(&state->output, "%5d: %10u %11u %8x  %s\n", n,
 282                         kstat_irqs(n),
 283                         kstat_irqs(n) - state->last_irqs[n],
 284                         desc->status_use_accessors,
 285                         (act && act->name) ? act->name : "???");
 286                 state->last_irqs[n] = kstat_irqs(n);
 287         }
 288 }
 289
 290 static void fiq_debugger_do_ps(struct fiq_debugger_state *state)
 291 {
 292         struct task_struct *g;
 293         struct task_struct *p;
 294         unsigned task_state;
 295         static const char stat_nam[] = "RSDTtZX";
 296
 297         fiq_debugger_printf(&state->output, "pid   ppid  prio task            pc\n");
 298         read_lock(&tasklist_lock);
 299         do_each_thread(g, p) {
 300                 task_state = p->state ? __ffs(p->state) + 1 : 0;
 301                 fiq_debugger_printf(&state->output,
 302                              "%5d %5d %4d ", p->pid, p->parent->pid, p->prio);
 303                 fiq_debugger_printf(&state->output, "%-13.13s %c", p->comm,
 304                              task_state >= sizeof(stat_nam) ? '?' : stat_nam[task_state]);
 305                 if (task_state == TASK_RUNNING)
 306                         fiq_debugger_printf(&state->output, " running\n");
 307                 else
 308                         fiq_debugger_printf(&state->output, " %08lx\n",
 309                                         thread_saved_pc(p));
 310         } while_each_thread(g, p);
 311         read_unlock(&tasklist_lock);
 312 }
 313
 314 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 315 static void fiq_debugger_begin_syslog_dump(struct fiq_debugger_state *state)
 316 {
 317         state->syslog_dumping = true;
 318 }
 319
 320 static void fiq_debugger_end_syslog_dump(struct fiq_debugger_state *state)
 321 {
 322         state->syslog_dumping = false;
 323 }
 324 #else
 325 extern int do_syslog(int type, char __user *bug, int count);
 326 static void fiq_debugger_begin_syslog_dump(struct fiq_debugger_state *state)
 327 {
 328         do_syslog(5 /* clear */, NULL, 0);
 329 }
 330
 331 static void fiq_debugger_end_syslog_dump(struct fiq_debugger_state *state)
 332 {
 333         fiq_debugger_dump_kernel_log(state);
 334 }
 335 #endif
 336
 337 static void fiq_debugger_do_sysrq(struct fiq_debugger_state *state, char rq)
 338 {
 339         if ((rq == 'g' || rq == 'G') && !fiq_kgdb_enable) {
 340                 fiq_debugger_printf(&state->output, "sysrq-g blocked\n");
 341                 return;
 342         }
 343         fiq_debugger_begin_syslog_dump(state);
 344         handle_sysrq(rq);
 345         fiq_debugger_end_syslog_dump(state);
 346 }
 347
 348 #ifdef CONFIG_KGDB
 349 static void fiq_debugger_do_kgdb(struct fiq_debugger_state *state)
 350 {
 351         if (!fiq_kgdb_enable) {
 352                 fiq_debugger_printf(&state->output, "kgdb through fiq debugger not enabled\n");
 353                 return;
 354         }
 355
 356         fiq_debugger_printf(&state->output, "enabling console and triggering kgdb\n");
 357         state->console_enable = true;
 358         handle_sysrq('g');
 359 }
 360 #endif
 361
 362 static void fiq_debugger_schedule_work(struct fiq_debugger_state *state,
 363                 char *cmd)
 364 {
 365         unsigned long flags;
 366
 367         spin_lock_irqsave(&state->work_lock, flags);
 368         if (state->work_cmd[0] != '\0') {
 369                 fiq_debugger_printf(&state->output, "work command processor busy\n");
 370                 spin_unlock_irqrestore(&state->work_lock, flags);
 371                 return;
 372         }
 373
 374         strlcpy(state->work_cmd, cmd, sizeof(state->work_cmd));
 375         spin_unlock_irqrestore(&state->work_lock, flags);
 376
 377         schedule_work(&state->work);
 378 }
 379
 380 static void fiq_debugger_work(struct work_struct *work)
 381 {
 382         struct fiq_debugger_state *state;
 383         char work_cmd[DEBUG_MAX];
 384         char *cmd;
 385         unsigned long flags;
 386
 387         state = container_of(work, struct fiq_debugger_state, work);
 388
 389         spin_lock_irqsave(&state->work_lock, flags);
 390
 391         strlcpy(work_cmd, state->work_cmd, sizeof(work_cmd));
 392         state->work_cmd[0] = '\0';
 393
 394         spin_unlock_irqrestore(&state->work_lock, flags);
 395
 396         cmd = work_cmd;
 397         if (!strncmp(cmd, "reboot", 6)) {
 398                 cmd += 6;
 399                 while (*cmd == ' ')
 400                         cmd++;
 401                 if (cmd != '\0')
 402                         kernel_restart(cmd);
 403                 else
 404                         kernel_restart(NULL);
 405         } else {
 406                 fiq_debugger_printf(&state->output, "unknown work command '%s'\n",
 407                                 work_cmd);
 408         }
 409 }
 410
 411 /* This function CANNOT be called in FIQ context */
 412 static void fiq_debugger_irq_exec(struct fiq_debugger_state *state, char *cmd)
 413 {
 414         if (!strcmp(cmd, "ps"))
 415                 fiq_debugger_do_ps(state);
 416         if (!strcmp(cmd, "sysrq"))
 417                 fiq_debugger_do_sysrq(state, 'h');
 418         if (!strncmp(cmd, "sysrq ", 6))
 419                 fiq_debugger_do_sysrq(state, cmd[6]);
 420 #ifdef CONFIG_KGDB
 421         if (!strcmp(cmd, "kgdb"))
 422                 fiq_debugger_do_kgdb(state);
 423 #endif
 424         if (!strncmp(cmd, "reboot", 6))
 425                 fiq_debugger_schedule_work(state, cmd);
 426 }
 427
 428 static void fiq_debugger_help(struct fiq_debugger_state *state)
 429 {
 430         fiq_debugger_printf(&state->output,
 431                                 "FIQ Debugger commands:\n"
 432                                 " pc            PC status\n"
 433                                 " regs          Register dump\n"
 434                                 " allregs       Extended Register dump\n"
 435                                 " bt            Stack trace\n"
 436                                 " reboot [<c>]  Reboot with command <c>\n"
 437                                 " reset [<c>]   Hard reset with command <c>\n"
 438                                 " irqs          Interupt status\n"
 439                                 " kmsg          Kernel log\n"
 440                                 " version       Kernel version\n");
 441         fiq_debugger_printf(&state->output,
 442                                 " sleep         Allow sleep while in FIQ\n"
 443                                 " nosleep       Disable sleep while in FIQ\n"
 444                                 " console       Switch terminal to console\n"
 445                                 " cpu           Current CPU\n"
 446                                 " cpu <number>  Switch to CPU<number>\n");
 447         fiq_debugger_printf(&state->output,
 448                                 " ps            Process list\n"
 449                                 " sysrq         sysrq options\n"
 450                                 " sysrq <param> Execute sysrq with <param>\n");
 451 #ifdef CONFIG_KGDB
 452         fiq_debugger_printf(&state->output,
 453                                 " kgdb          Enter kernel debugger\n");
 454 #endif
 455 }
 456
 457 static void fiq_debugger_take_affinity(void *info)
 458 {
 459         struct fiq_debugger_state *state = info;
 460         struct cpumask cpumask;
 461
 462         cpumask_clear(&cpumask);
 463         cpumask_set_cpu(get_cpu(), &cpumask);
 464
 465         irq_set_affinity(state->uart_irq, &cpumask);
 466 }
 467
 468 static void fiq_debugger_switch_cpu(struct fiq_debugger_state *state, int cpu)
 469 {
 470         if (!fiq_debugger_have_fiq(state))
 471                 smp_call_function_single(cpu, fiq_debugger_take_affinity, state,
 472                                 false);
 473         state->current_cpu = cpu;
 474 }
 475
 476 static bool fiq_debugger_fiq_exec(struct fiq_debugger_state *state,
 477                         const char *cmd, const struct pt_regs *regs,
 478                         void *svc_sp)
 479 {
 480         bool signal_helper = false;
 481
 482         fiq_debugger_dump_allregs(&state->output, regs);
 483
 484         if (!strcmp(cmd, "help") || !strcmp(cmd, "?")) {
 485                 fiq_debugger_help(state);
 486         } else if (!strcmp(cmd, "pc")) {
 487                 fiq_debugger_dump_pc(&state->output, regs);
 488         } else if (!strcmp(cmd, "regs")) {
 489                 fiq_debugger_dump_regs(&state->output, regs);
 490         } else if (!strcmp(cmd, "allregs")) {
 491                 fiq_debugger_dump_allregs(&state->output, regs);
 492         } else if (!strcmp(cmd, "bt")) {
 493                 fiq_debugger_dump_stacktrace(&state->output, regs, 100, svc_sp);
 494         } else if (!strncmp(cmd, "reset", 5)) {
 495                 cmd += 5;
 496                 while (*cmd == ' ')
 497                         cmd++;
 498                 if (*cmd) {
 499                         char tmp_cmd[32];
 500                         strlcpy(tmp_cmd, cmd, sizeof(tmp_cmd));
 501                         machine_restart(tmp_cmd);
 502                 } else {
 503                         machine_restart(NULL);
 504                 }
 505         } else if (!strcmp(cmd, "irqs")) {
 506                 fiq_debugger_dump_irqs(state);
 507         } else if (!strcmp(cmd, "kmsg")) {
 508                 fiq_debugger_dump_kernel_log(state);
 509         } else if (!strcmp(cmd, "version")) {
 510                 fiq_debugger_printf(&state->output, "%s\n", linux_banner);
 511         } else if (!strcmp(cmd, "sleep")) {
 512                 state->no_sleep = false;
 513                 fiq_debugger_printf(&state->output, "enabling sleep\n");
 514         } else if (!strcmp(cmd, "nosleep")) {
 515                 state->no_sleep = true;
 516                 fiq_debugger_printf(&state->output, "disabling sleep\n");
 517         } else if (!strcmp(cmd, "console")) {
 518                 fiq_debugger_printf(&state->output, "console mode\n");
 519                 fiq_debugger_uart_flush(state);
 520                 state->console_enable = true;
 521         } else if (!strcmp(cmd, "cpu")) {
 522                 fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
 523         } else if (!strncmp(cmd, "cpu ", 4)) {
 524                 unsigned long cpu = 0;
 525                 if (strict_strtoul(cmd + 4, 10, &cpu) == 0)
 526                         fiq_debugger_switch_cpu(state, cpu);
 527                 else
 528                         fiq_debugger_printf(&state->output, "invalid cpu\n");
 529                 fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
 530         } else {
 531                 if (state->debug_busy) {
 532                         fiq_debugger_printf(&state->output,
 533                                 "command processor busy. trying to abort.\n");
 534                         state->debug_abort = -1;
 535                 } else {
 536                         strcpy(state->debug_cmd, cmd);
 537                         state->debug_busy = 1;
 538                 }
 539
 540                 return true;
 541         }
 542         if (!state->console_enable)
 543                 fiq_debugger_prompt(state);
 544
 545         return signal_helper;
 546 }
 547
 548 static void fiq_debugger_sleep_timer_expired(unsigned long data)
 549 {
 550         struct fiq_debugger_state *state = (struct fiq_debugger_state *)data;
 551         unsigned long flags;
 552
 553         spin_lock_irqsave(&state->sleep_timer_lock, flags);
 554         if (state->uart_enabled && !state->no_sleep) {
 555                 if (state->debug_enable && !state->console_enable) {
 556                         state->debug_enable = false;
 557                         fiq_debugger_printf_nfiq(state,
 558                                         "suspending fiq debugger\n");
 559                 }
 560                 state->ignore_next_wakeup_irq = true;
 561                 fiq_debugger_uart_disable(state);
 562                 state->uart_enabled = false;
 563                 fiq_debugger_enable_wakeup_irq(state);
 564         }
 565         wake_unlock(&state->debugger_wake_lock);
 566         spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 567 }
 568
 569 static void fiq_debugger_handle_wakeup(struct fiq_debugger_state *state)
 570 {
 571         unsigned long flags;
 572
 573         spin_lock_irqsave(&state->sleep_timer_lock, flags);
 574         if (state->wakeup_irq >= 0 && state->ignore_next_wakeup_irq) {
 575                 state->ignore_next_wakeup_irq = false;
 576         } else if (!state->uart_enabled) {
 577                 wake_lock(&state->debugger_wake_lock);
 578                 fiq_debugger_uart_enable(state);
 579                 state->uart_enabled = true;
 580                 fiq_debugger_disable_wakeup_irq(state);
 581                 mod_timer(&state->sleep_timer, jiffies + HZ / 2);
 582         }
 583         spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 584 }
 585
 586 static irqreturn_t fiq_debugger_wakeup_irq_handler(int irq, void *dev)
 587 {
 588         struct fiq_debugger_state *state = dev;
 589
 590         if (!state->no_sleep)
 591                 fiq_debugger_puts(state, "WAKEUP\n");
 592         fiq_debugger_handle_wakeup(state);
 593
 594         return IRQ_HANDLED;
 595 }
 596
 597 static
 598 void fiq_debugger_handle_console_irq_context(struct fiq_debugger_state *state)
 599 {
 600 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
 601         if (state->tty_port.ops) {
 602                 int i;
 603                 int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
 604                 for (i = 0; i < count; i++) {
 605                         int c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
 606                         tty_insert_flip_char(&state->tty_port, c, TTY_NORMAL);
 607                         if (!fiq_debugger_ringbuf_consume(state->tty_rbuf, 1))
 608                                 pr_warn("fiq tty failed to consume byte\n");
 609                 }
 610                 tty_flip_buffer_push(&state->tty_port);
 611         }
 612 #endif
 613 }
 614
 615 static void fiq_debugger_handle_irq_context(struct fiq_debugger_state *state)
 616 {
 617         if (!state->no_sleep) {
 618                 unsigned long flags;
 619
 620                 spin_lock_irqsave(&state->sleep_timer_lock, flags);
 621                 wake_lock(&state->debugger_wake_lock);
 622                 mod_timer(&state->sleep_timer, jiffies + HZ * 5);
 623                 spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
 624         }
 625         fiq_debugger_handle_console_irq_context(state);
 626         if (state->debug_busy) {
 627                 fiq_debugger_irq_exec(state, state->debug_cmd);
 628                 if (!state->console_enable)
 629                         fiq_debugger_prompt(state);
 630                 state->debug_busy = 0;
 631         }
 632 }
 633
 634 static int fiq_debugger_getc(struct fiq_debugger_state *state)
 635 {
 636         return state->pdata->uart_getc(state->pdev);
 637 }
 638
 639 static bool fiq_debugger_handle_uart_interrupt(struct fiq_debugger_state *state,
 640                         int this_cpu, const struct pt_regs *regs, void *svc_sp)
 641 {
 642         int c;
 643         static int last_c;
 644         int count = 0;
 645         bool signal_helper = false;
 646
 647         if (this_cpu != state->current_cpu) {
 648                 if (state->in_fiq)
 649                         return false;
 650
 651                 if (atomic_inc_return(&state->unhandled_fiq_count) !=
 652                                         MAX_UNHANDLED_FIQ_COUNT)
 653                         return false;
 654
 655                 fiq_debugger_printf(&state->output,
 656                         "fiq_debugger: cpu %d not responding, "
 657                         "reverting to cpu %d\n", state->current_cpu,
 658                         this_cpu);
 659
 660                 atomic_set(&state->unhandled_fiq_count, 0);
 661                 fiq_debugger_switch_cpu(state, this_cpu);
 662                 return false;
 663         }
 664
 665         state->in_fiq = true;
 666
 667         while ((c = fiq_debugger_getc(state)) != FIQ_DEBUGGER_NO_CHAR) {
 668                 count++;
 669                 if (!state->debug_enable) {
 670                         if ((c == 13) || (c == 10)) {
 671                                 state->debug_enable = true;
 672                                 state->debug_count = 0;
 673                                 fiq_debugger_prompt(state);
 674                         }
 675                 } else if (c == FIQ_DEBUGGER_BREAK) {
 676                         state->console_enable = false;
 677                         fiq_debugger_puts(state, "fiq debugger mode\n");
 678                         state->debug_count = 0;
 679                         fiq_debugger_prompt(state);
 680 #ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
 681                 } else if (state->console_enable && state->tty_rbuf) {
 682                         fiq_debugger_ringbuf_push(state->tty_rbuf, c);
 683                         signal_helper = true;
 684 #endif
 685                 } else if ((c >= ' ') && (c < 127)) {
 686                         if (state->debug_count < (DEBUG_MAX - 1)) {
 687                                 state->debug_buf[state->debug_count++] = c;
 688                                 fiq_debugger_putc(state, c);
 689                         }
 690                 } else if ((c == 8) || (c == 127)) {
 691                         if (state->debug_count > 0) {
 692                                 state->debug_count--;
 693                                 fiq_debugger_putc(state, 8);
 694                                 fiq_debugger_putc(state, ' ');
 695                                 fiq_debugger_putc(state, 8);
 696                         }
 697                 } else if ((c == 13) || (c == 10)) {
 698                         if (c == '\r' || (c == '\n' && last_c != '\r')) {
 699                                 fiq_debugger_putc(state, '\r');
 700                                 fiq_debugger_putc(state, '\n');
 701                         }
 702                         if (state->debug_count) {
 703                                 state->debug_buf[state->debug_count] = 0;
 704                                 state->debug_count = 0;
 705                                 signal_helper |=
 706                                         fiq_debugger_fiq_exec(state,
 707                                                         state->debug_buf,
 708                                                         regs, svc_sp);
 709                         } else {
 710                                 fiq_debugger_prompt(state);
 711                         }
 712                 }
 713                 last_c = c;
 714         }
 715         if (!state->console_enable)
 716                 fiq_debugger_uart_flush(state);
 717         if (state->pdata->fiq_ack)
 718                 state->pdata->fiq_ack(state->pdev, state->fiq);
 719
 720         fiq_debugger_dump_allregs(&state->output, regs);
 721         fiq_debugger_dump_pc(&state->output, regs);
 722         fiq_debugger_dump_stacktrace(&state->output, regs, 100, svc_sp);
 723         /* poke sleep timer if necessary */
 724         if (state->debug_enable && !state->no_sleep)
 725                 signal_helper = true;
 726
 727         atomic_set(&state->unhandled_fiq_count, 0);
 728         state->in_fiq = false;
 729
 730         return signal_helper;
 731 }
 732
 733 #ifdef CONFIG_FIQ_GLUE
 734 static void fiq_debugger_fiq(struct fiq_glue_handler *h,
 735                 const struct pt_regs *regs, void *svc_sp)
 736 {
 737         struct fiq_debugger_state *state =
 738                 container_of(h, struct fiq_debugger_state, handler);
 739
 740         unsigned int this_cpu = THREAD_INFO(svc_sp)->cpu;
 741         bool need_irq;
 742
 743         need_irq = fiq_debugger_handle_uart_interrupt(state, this_cpu, regs,
 744                         svc_sp);
 745         if (need_irq)
 746                 fiq_debugger_force_irq(state);
 747 }
 748 #endif
 749
 750 /*
 751  * When not using FIQs, we only use this single interrupt as an entry point.
 752  * This just effectively takes over the UART interrupt and does all the work
 753  * in this context.
 754  */
 755 static irqreturn_t fiq_debugger_uart_irq(int irq, void *dev)
 756 {
 757         struct fiq_debugger_state *state = dev;
 758         bool not_done;
 759
 760         fiq_debugger_handle_wakeup(state);
 761
 762         /* handle the debugger irq in regular context */
 763         not_done = fiq_debugger_handle_uart_interrupt(state, smp_processor_id(),
 764                                               get_irq_regs(),
 765                                               current_thread_info());
 766         if (not_done)
 767                 fiq_debugger_handle_irq_context(state);
 768
 769         return IRQ_HANDLED;
 770 }
 771
 772 /*
 773  * If FIQs are used, not everything can happen in fiq context.
 774  * FIQ handler does what it can and then signals this interrupt to finish the
 775  * job in irq context.
 776  */
 777 static irqreturn_t fiq_debugger_signal_irq(int irq, void *dev)
 778 {
 779         struct fiq_debugger_state *state = dev;
 780
 781         if (state->pdata->force_irq_ack)
 782                 state->pdata->force_irq_ack(state->pdev, state->signal_irq);
 783
 784         fiq_debugger_handle_irq_context(state);
 785
 786         return IRQ_HANDLED;
 787 }
 788
 789 #ifdef CONFIG_FIQ_GLUE
 790 static void fiq_debugger_resume(struct fiq_glue_handler *h)
 791 {
 792         struct fiq_debugger_state *state =
 793                 container_of(h, struct fiq_debugger_state, handler);
 794         if (state->pdata->uart_resume)
 795                 state->pdata->uart_resume(state->pdev);
 796 }
 797 #endif
 798
 799 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
 800 struct tty_driver *fiq_debugger_console_device(struct console *co, int *index)
 801 {
 802         *index = co->index;
 803         return fiq_tty_driver;
 804 }
 805
 806 static void fiq_debugger_console_write(struct console *co,
 807                                 const char *s, unsigned int count)
 808 {
 809         struct fiq_debugger_state *state;
 810         unsigned long flags;
 811
 812         state = container_of(co, struct fiq_debugger_state, console);
 813
 814         if (!state->console_enable && !state->syslog_dumping)
 815                 return;
 816
 817         fiq_debugger_uart_enable(state);
 818         spin_lock_irqsave(&state->console_lock, flags);
 819         while (count--) {
 820                 if (*s == '\n')
 821                         fiq_debugger_putc(state, '\r');
 822                 fiq_debugger_putc(state, *s++);
 823         }
 824         fiq_debugger_uart_flush(state);
 825         spin_unlock_irqrestore(&state->console_lock, flags);
 826         fiq_debugger_uart_disable(state);
 827 }
 828
 829 static struct console fiq_debugger_console = {
 830         .name = "ttyFIQ",
 831         .device = fiq_debugger_console_device,
 832         .write = fiq_debugger_console_write,
 833         .flags = CON_PRINTBUFFER | CON_ANYTIME | CON_ENABLED,
 834 };
 835
 836 int fiq_tty_open(struct tty_struct *tty, struct file *filp)
 837 {
 838         int line = tty->index;
 839         struct fiq_debugger_state **states = tty->driver->driver_state;
 840         struct fiq_debugger_state *state = states[line];
 841
 842         return tty_port_open(&state->tty_port, tty, filp);
 843 }
 844
 845 void fiq_tty_close(struct tty_struct *tty, struct file *filp)
 846 {
 847         tty_port_close(tty->port, tty, filp);
 848 }
 849
 850 int  fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
 851 {
 852         int i;
 853         int line = tty->index;
 854         struct fiq_debugger_state **states = tty->driver->driver_state;
 855         struct fiq_debugger_state *state = states[line];
 856
 857         if (!state->console_enable)
 858                 return count;
 859
 860         fiq_debugger_uart_enable(state);
 861         spin_lock_irq(&state->console_lock);
 862         for (i = 0; i < count; i++)
 863                 fiq_debugger_putc(state, *buf++);
 864         spin_unlock_irq(&state->console_lock);
 865         fiq_debugger_uart_disable(state);
 866
 867         return count;
 868 }
 869
 870 int  fiq_tty_write_room(struct tty_struct *tty)
 871 {
 872         return 16;
 873 }
 874
 875 #ifdef CONFIG_CONSOLE_POLL
 876 static int fiq_tty_poll_init(struct tty_driver *driver, int line, char *options)
 877 {
 878         return 0;
 879 }
 880
 881 static int fiq_tty_poll_get_char(struct tty_driver *driver, int line)
 882 {
 883         struct fiq_debugger_state **states = driver->driver_state;
 884         struct fiq_debugger_state *state = states[line];
 885         int c = NO_POLL_CHAR;
 886
 887         fiq_debugger_uart_enable(state);
 888         if (fiq_debugger_have_fiq(state)) {
 889                 int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
 890                 if (count > 0) {
 891                         c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
 892                         fiq_debugger_ringbuf_consume(state->tty_rbuf, 1);
 893                 }
 894         } else {
 895                 c = fiq_debugger_getc(state);
 896                 if (c == FIQ_DEBUGGER_NO_CHAR)
 897                         c = NO_POLL_CHAR;
 898         }
 899         fiq_debugger_uart_disable(state);
 900
 901         return c;
 902 }
 903
 904 static void fiq_tty_poll_put_char(struct tty_driver *driver, int line, char ch)
 905 {
 906         struct fiq_debugger_state **states = driver->driver_state;
 907         struct fiq_debugger_state *state = states[line];
 908         fiq_debugger_uart_enable(state);
 909         fiq_debugger_putc(state, ch);
 910         fiq_debugger_uart_disable(state);
 911 }
 912 #endif
 913
 914 static const struct tty_port_operations fiq_tty_port_ops;
 915
 916 static const struct tty_operations fiq_tty_driver_ops = {
 917         .write = fiq_tty_write,
 918         .write_room = fiq_tty_write_room,
 919         .open = fiq_tty_open,
 920         .close = fiq_tty_close,
 921 #ifdef CONFIG_CONSOLE_POLL
 922         .poll_init = fiq_tty_poll_init,
 923         .poll_get_char = fiq_tty_poll_get_char,
 924         .poll_put_char = fiq_tty_poll_put_char,
 925 #endif
 926 };
 927
 928 static int fiq_debugger_tty_init(void)
 929 {
 930         int ret;
 931         struct fiq_debugger_state **states = NULL;
 932
 933         states = kzalloc(sizeof(*states) * MAX_FIQ_DEBUGGER_PORTS, GFP_KERNEL);
 934         if (!states) {
 935                 pr_err("Failed to allocate fiq debugger state structres\n");
 936                 return -ENOMEM;
 937         }
 938
 939         fiq_tty_driver = alloc_tty_driver(MAX_FIQ_DEBUGGER_PORTS);
 940         if (!fiq_tty_driver) {
 941                 pr_err("Failed to allocate fiq debugger tty\n");
 942                 ret = -ENOMEM;
 943                 goto err_free_state;
 944         }
 945
 946         fiq_tty_driver->owner           = THIS_MODULE;
 947         fiq_tty_driver->driver_name     = "fiq-debugger";
 948         fiq_tty_driver->name            = "ttyFIQ";
 949         fiq_tty_driver->type            = TTY_DRIVER_TYPE_SERIAL;
 950         fiq_tty_driver->subtype         = SERIAL_TYPE_NORMAL;
 951         fiq_tty_driver->init_termios    = tty_std_termios;
 952         fiq_tty_driver->flags           = TTY_DRIVER_REAL_RAW |
 953                                           TTY_DRIVER_DYNAMIC_DEV;
 954         fiq_tty_driver->driver_state    = states;
 955
 956         fiq_tty_driver->init_termios.c_cflag =
 957                                         B115200 | CS8 | CREAD | HUPCL | CLOCAL;
 958         fiq_tty_driver->init_termios.c_ispeed = 115200;
 959         fiq_tty_driver->init_termios.c_ospeed = 115200;
 960
 961         tty_set_operations(fiq_tty_driver, &fiq_tty_driver_ops);
 962
 963         ret = tty_register_driver(fiq_tty_driver);
 964         if (ret) {
 965                 pr_err("Failed to register fiq tty: %d\n", ret);
 966                 goto err_free_tty;
 967         }
 968
 969         pr_info("Registered FIQ tty driver\n");
 970         return 0;
 971
 972 err_free_tty:
 973         put_tty_driver(fiq_tty_driver);
 974         fiq_tty_driver = NULL;
 975 err_free_state:
 976         kfree(states);
 977         return ret;
 978 }
 979
 980 static int fiq_debugger_tty_init_one(struct fiq_debugger_state *state)
 981 {
 982         int ret;
 983         struct device *tty_dev;
 984         struct fiq_debugger_state **states = fiq_tty_driver->driver_state;
 985
 986         states[state->pdev->id] = state;
 987
 988         state->tty_rbuf = fiq_debugger_ringbuf_alloc(1024);
 989         if (!state->tty_rbuf) {
 990                 pr_err("Failed to allocate fiq debugger ringbuf\n");
 991                 ret = -ENOMEM;
 992                 goto err;
 993         }
 994
 995         tty_port_init(&state->tty_port);
 996         state->tty_port.ops = &fiq_tty_port_ops;
 997
 998         tty_dev = tty_port_register_device(&state->tty_port, fiq_tty_driver,
 999                                            state->pdev->id, &state->pdev->dev);
1000         if (IS_ERR(tty_dev)) {
1001                 pr_err("Failed to register fiq debugger tty device\n");
1002                 ret = PTR_ERR(tty_dev);
1003                 goto err;
1004         }
1005
1006         device_set_wakeup_capable(tty_dev, 1);
1007
1008         pr_info("Registered fiq debugger ttyFIQ%d\n", state->pdev->id);
1009
1010         return 0;
1011
1012 err:
1013         fiq_debugger_ringbuf_free(state->tty_rbuf);
1014         state->tty_rbuf = NULL;
1015         return ret;
1016 }
1017 #endif
1018
1019 static int fiq_debugger_dev_suspend(struct device *dev)
1020 {
1021         struct platform_device *pdev = to_platform_device(dev);
1022         struct fiq_debugger_state *state = platform_get_drvdata(pdev);
1023
1024         if (state->pdata->uart_dev_suspend)
1025                 return state->pdata->uart_dev_suspend(pdev);
1026         return 0;
1027 }
1028
1029 static int fiq_debugger_dev_resume(struct device *dev)
1030 {
1031         struct platform_device *pdev = to_platform_device(dev);
1032         struct fiq_debugger_state *state = platform_get_drvdata(pdev);
1033
1034         if (state->pdata->uart_dev_resume)
1035                 return state->pdata->uart_dev_resume(pdev);
1036         return 0;
1037 }
1038
1039 static int fiq_debugger_probe(struct platform_device *pdev)
1040 {
1041         int ret;
1042         struct fiq_debugger_pdata *pdata = dev_get_platdata(&pdev->dev);
1043         struct fiq_debugger_state *state;
1044         int fiq;
1045         int uart_irq;
1046         struct console *console;
1047         if (pdev->id >= MAX_FIQ_DEBUGGER_PORTS)
1048                 return -EINVAL;
1049
1050         if (!pdata->uart_getc || !pdata->uart_putc)
1051                 return -EINVAL;
1052         if ((pdata->uart_enable && !pdata->uart_disable) ||
1053             (!pdata->uart_enable && pdata->uart_disable))
1054                 return -EINVAL;
1055
1056         fiq = platform_get_irq_byname(pdev, "fiq");
1057         uart_irq = platform_get_irq_byname(pdev, "uart_irq");
1058
1059         /* uart_irq mode and fiq mode are mutually exclusive, but one of them
1060          * is required */
1061         if ((uart_irq < 0 && fiq < 0) || (uart_irq >= 0 && fiq >= 0))
1062                 return -EINVAL;
1063         if (fiq >= 0 && !pdata->fiq_enable)
1064                 return -EINVAL;
1065
1066         state = kzalloc(sizeof(*state), GFP_KERNEL);
1067         state->output.printf = fiq_debugger_printf;
1068         setup_timer(&state->sleep_timer, fiq_debugger_sleep_timer_expired,
1069                     (unsigned long)state);
1070         state->pdata = pdata;
1071         state->pdev = pdev;
1072         state->no_sleep = initial_no_sleep;
1073         state->debug_enable = initial_debug_enable;
1074         state->console_enable = initial_console_enable;
1075
1076         state->fiq = fiq;
1077         state->uart_irq = uart_irq;
1078         state->signal_irq = platform_get_irq_byname(pdev, "signal");
1079         state->wakeup_irq = platform_get_irq_byname(pdev, "wakeup");
1080
1081         INIT_WORK(&state->work, fiq_debugger_work);
1082         spin_lock_init(&state->work_lock);
1083
1084         platform_set_drvdata(pdev, state);
1085
1086         spin_lock_init(&state->sleep_timer_lock);
1087
1088         if (state->wakeup_irq < 0 && fiq_debugger_have_fiq(state))
1089                 state->no_sleep = true;
1090         state->ignore_next_wakeup_irq = !state->no_sleep;
1091
1092         wake_lock_init(&state->debugger_wake_lock,
1093                         WAKE_LOCK_SUSPEND, "serial-debug");
1094
1095         state->clk = clk_get(&pdev->dev, NULL);
1096         if (IS_ERR(state->clk))
1097                 state->clk = NULL;
1098
1099         /* do not call pdata->uart_enable here since uart_init may still
1100          * need to do some initialization before uart_enable can work.
1101          * So, only try to manage the clock during init.
1102          */
1103         if (state->clk)
1104                 clk_enable(state->clk);
1105
1106         if (pdata->uart_init) {
1107                 ret = pdata->uart_init(pdev);
1108                 if (ret)
1109                         goto err_uart_init;
1110         }
1111
1112         fiq_debugger_printf_nfiq(state,
1113                                 "<hit enter %sto activate fiq debugger>\n",
1114                                 state->no_sleep ? "" : "twice ");
1115
1116 #ifdef CONFIG_FIQ_GLUE
1117         if (fiq_debugger_have_fiq(state)) {
1118                 state->handler.fiq = fiq_debugger_fiq;
1119                 state->handler.resume = fiq_debugger_resume;
1120                 ret = fiq_glue_register_handler(&state->handler);
1121                 if (ret) {
1122                         pr_err("%s: could not install fiq handler\n", __func__);
1123                         goto err_register_irq;
1124                 }
1125
1126                 pdata->fiq_enable(pdev, state->fiq, 1);
1127         } else
1128 #endif
1129         {
1130                 ret = request_irq(state->uart_irq, fiq_debugger_uart_irq,
1131                                   IRQF_NO_SUSPEND, "debug", state);
1132                 if (ret) {
1133                         pr_err("%s: could not install irq handler\n", __func__);
1134                         goto err_register_irq;
1135                 }
1136
1137                 /* for irq-only mode, we want this irq to wake us up, if it
1138                  * can.
1139                  */
1140                 enable_irq_wake(state->uart_irq);
1141         }
1142
1143         if (state->clk)
1144                 clk_disable(state->clk);
1145
1146         if (state->signal_irq >= 0) {
1147                 ret = request_irq(state->signal_irq, fiq_debugger_signal_irq,
1148                           IRQF_TRIGGER_RISING, "debug-signal", state);
1149                 if (ret)
1150                         pr_err("serial_debugger: could not install signal_irq");
1151         }
1152
1153         if (state->wakeup_irq >= 0) {
1154                 ret = request_irq(state->wakeup_irq,
1155                                   fiq_debugger_wakeup_irq_handler,
1156                                   IRQF_TRIGGER_FALLING | IRQF_DISABLED,
1157                                   "debug-wakeup", state);
1158                 if (ret) {
1159                         pr_err("serial_debugger: "
1160                                 "could not install wakeup irq\n");
1161                         state->wakeup_irq = -1;
1162                 } else {
1163                         ret = enable_irq_wake(state->wakeup_irq);
1164                         if (ret) {
1165                                 pr_err("serial_debugger: "
1166                                         "could not enable wakeup\n");
1167                                 state->wakeup_irq_no_set_wake = true;
1168                         }
1169                 }
1170         }
1171         if (state->no_sleep)
1172                 fiq_debugger_handle_wakeup(state);
1173
1174 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
1175         spin_lock_init(&state->console_lock);
1176         state->console = fiq_debugger_console;
1177         state->console.index = pdev->id;
1178         if (!console_set_on_cmdline)
1179                 add_preferred_console(state->console.name,
1180                         state->console.index, NULL);
1181         register_console(&state->console);
1182         fiq_debugger_tty_init_one(state);
1183 #endif
1184         for_each_console(console)
1185                 if (0 == strcmp(console->name, "pstore")) {
1186                         state->ram_console = console;
1187                         break;
1188                 }
1189
1190         return 0;
1191
1192 err_register_irq:
1193         if (pdata->uart_free)
1194                 pdata->uart_free(pdev);
1195 err_uart_init:
1196         if (state->clk)
1197                 clk_disable(state->clk);
1198         if (state->clk)
1199                 clk_put(state->clk);
1200         wake_lock_destroy(&state->debugger_wake_lock);
1201         platform_set_drvdata(pdev, NULL);
1202         kfree(state);
1203         return ret;
1204 }
1205
1206 static const struct dev_pm_ops fiq_debugger_dev_pm_ops = {
1207         .suspend        = fiq_debugger_dev_suspend,
1208         .resume         = fiq_debugger_dev_resume,
1209 };
1210
1211 static struct platform_driver fiq_debugger_driver = {
1212         .probe  = fiq_debugger_probe,
1213         .driver = {
1214                 .name   = "fiq_debugger",
1215                 .pm     = &fiq_debugger_dev_pm_ops,
1216         },
1217 };
1218
1219 static int __init fiq_debugger_init(void)
1220 {
1221 #if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
1222         fiq_debugger_tty_init();
1223 #endif
1224         return platform_driver_register(&fiq_debugger_driver);
1225 }
1226
1227 postcore_initcall(fiq_debugger_init);