linux/drivers/remoteproc/remoteproc_debugfs.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Remote Processor Framework
   4 *
   5 * Copyright (C) 2011 Texas Instruments, Inc.
   6 * Copyright (C) 2011 Google, Inc.
   7 *
   8 * Ohad Ben-Cohen <ohad@wizery.com>
   9 * Mark Grosen <mgrosen@ti.com>
  10 * Brian Swetland <swetland@google.com>
  11 * Fernando Guzman Lugo <fernando.lugo@ti.com>
  12 * Suman Anna <s-anna@ti.com>
  13 * Robert Tivy <rtivy@ti.com>
  14 * Armando Uribe De Leon <x0095078@ti.com>
  15 */
  16
  17#define pr_fmt(fmt)    "%s: " fmt, __func__
  18
  19#include <linux/kernel.h>
  20#include <linux/debugfs.h>
  21#include <linux/remoteproc.h>
  22#include <linux/device.h>
  23#include <linux/uaccess.h>
  24
  25#include "remoteproc_internal.h"
  26
  27/* remoteproc debugfs parent dir */
  28static struct dentry *rproc_dbg;
  29
  30/*
  31 * A coredump-configuration-to-string lookup table, for exposing a
  32 * human readable configuration via debugfs. Always keep in sync with
  33 * enum rproc_coredump_mechanism
  34 */
  35static const char * const rproc_coredump_str[] = {
  36        [RPROC_COREDUMP_DISABLED]       = "disabled",
  37        [RPROC_COREDUMP_ENABLED]        = "enabled",
  38        [RPROC_COREDUMP_INLINE]         = "inline",
  39};
  40
  41/* Expose the current coredump configuration via debugfs */
  42static ssize_t rproc_coredump_read(struct file *filp, char __user *userbuf,
  43                                   size_t count, loff_t *ppos)
  44{
  45        struct rproc *rproc = filp->private_data;
  46        char buf[20];
  47        int len;
  48
  49        len = scnprintf(buf, sizeof(buf), "%s\n",
  50                        rproc_coredump_str[rproc->dump_conf]);
  51
  52        return simple_read_from_buffer(userbuf, count, ppos, buf, len);
  53}
  54
  55/*
  56 * By writing to the 'coredump' debugfs entry, we control the behavior of the
  57 * coredump mechanism dynamically. The default value of this entry is "disabled".
  58 *
  59 * The 'coredump' debugfs entry supports these commands:
  60 *
  61 * disabled:    By default coredump collection is disabled. Recovery will
  62 *              proceed without collecting any dump.
  63 *
  64 * enabled:     When the remoteproc crashes the entire coredump will be copied
  65 *              to a separate buffer and exposed to userspace.
  66 *
  67 * inline:      The coredump will not be copied to a separate buffer and the
  68 *              recovery process will have to wait until data is read by
  69 *              userspace. But this avoid usage of extra memory.
  70 */
  71static ssize_t rproc_coredump_write(struct file *filp,
  72                                    const char __user *user_buf, size_t count,
  73                                    loff_t *ppos)
  74{
  75        struct rproc *rproc = filp->private_data;
  76        int ret, err = 0;
  77        char buf[20];
  78
  79        if (count > sizeof(buf))
  80                return -EINVAL;
  81
  82        ret = copy_from_user(buf, user_buf, count);
  83        if (ret)
  84                return -EFAULT;
  85
  86        /* remove end of line */
  87        if (buf[count - 1] == '\n')
  88                buf[count - 1] = '\0';
  89
  90        if (rproc->state == RPROC_CRASHED) {
  91                dev_err(&rproc->dev, "can't change coredump configuration\n");
  92                err = -EBUSY;
  93                goto out;
  94        }
  95
  96        if (!strncmp(buf, "disabled", count)) {
  97                rproc->dump_conf = RPROC_COREDUMP_DISABLED;
  98        } else if (!strncmp(buf, "enabled", count)) {
  99                rproc->dump_conf = RPROC_COREDUMP_ENABLED;
 100        } else if (!strncmp(buf, "inline", count)) {
 101                rproc->dump_conf = RPROC_COREDUMP_INLINE;
 102        } else {
 103                dev_err(&rproc->dev, "Invalid coredump configuration\n");
 104                err = -EINVAL;
 105        }
 106out:
 107        return err ? err : count;
 108}
 109
 110static const struct file_operations rproc_coredump_fops = {
 111        .read = rproc_coredump_read,
 112        .write = rproc_coredump_write,
 113        .open = simple_open,
 114        .llseek = generic_file_llseek,
 115};
 116
 117/*
 118 * Some remote processors may support dumping trace logs into a shared
 119 * memory buffer. We expose this trace buffer using debugfs, so users
 120 * can easily tell what's going on remotely.
 121 *
 122 * We will most probably improve the rproc tracing facilities later on,
 123 * but this kind of lightweight and simple mechanism is always good to have,
 124 * as it provides very early tracing with little to no dependencies at all.
 125 */
 126static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
 127                                size_t count, loff_t *ppos)
 128{
 129        struct rproc_debug_trace *data = filp->private_data;
 130        struct rproc_mem_entry *trace = &data->trace_mem;
 131        void *va;
 132        char buf[100];
 133        int len;
 134
 135        va = rproc_da_to_va(data->rproc, trace->da, trace->len);
 136
 137        if (!va) {
 138                len = scnprintf(buf, sizeof(buf), "Trace %s not available\n",
 139                                trace->name);
 140                va = buf;
 141        } else {
 142                len = strnlen(va, trace->len);
 143        }
 144
 145        return simple_read_from_buffer(userbuf, count, ppos, va, len);
 146}
 147
 148static const struct file_operations trace_rproc_ops = {
 149        .read = rproc_trace_read,
 150        .open = simple_open,
 151        .llseek = generic_file_llseek,
 152};
 153
 154/* expose the name of the remote processor via debugfs */
 155static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
 156                               size_t count, loff_t *ppos)
 157{
 158        struct rproc *rproc = filp->private_data;
 159        /* need room for the name, a newline and a terminating null */
 160        char buf[100];
 161        int i;
 162
 163        i = scnprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
 164
 165        return simple_read_from_buffer(userbuf, count, ppos, buf, i);
 166}
 167
 168static const struct file_operations rproc_name_ops = {
 169        .read = rproc_name_read,
 170        .open = simple_open,
 171        .llseek = generic_file_llseek,
 172};
 173
 174/* expose recovery flag via debugfs */
 175static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf,
 176                                   size_t count, loff_t *ppos)
 177{
 178        struct rproc *rproc = filp->private_data;
 179        char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n";
 180
 181        return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
 182}
 183
 184/*
 185 * By writing to the 'recovery' debugfs entry, we control the behavior of the
 186 * recovery mechanism dynamically. The default value of this entry is "enabled".
 187 *
 188 * The 'recovery' debugfs entry supports these commands:
 189 *
 190 * enabled:     When enabled, the remote processor will be automatically
 191 *              recovered whenever it crashes. Moreover, if the remote
 192 *              processor crashes while recovery is disabled, it will
 193 *              be automatically recovered too as soon as recovery is enabled.
 194 *
 195 * disabled:    When disabled, a remote processor will remain in a crashed
 196 *              state if it crashes. This is useful for debugging purposes;
 197 *              without it, debugging a crash is substantially harder.
 198 *
 199 * recover:     This function will trigger an immediate recovery if the
 200 *              remote processor is in a crashed state, without changing
 201 *              or checking the recovery state (enabled/disabled).
 202 *              This is useful during debugging sessions, when one expects
 203 *              additional crashes to happen after enabling recovery. In this
 204 *              case, enabling recovery will make it hard to debug subsequent
 205 *              crashes, so it's recommended to keep recovery disabled, and
 206 *              instead use the "recover" command as needed.
 207 */
 208static ssize_t
 209rproc_recovery_write(struct file *filp, const char __user *user_buf,
 210                     size_t count, loff_t *ppos)
 211{
 212        struct rproc *rproc = filp->private_data;
 213        char buf[10];
 214        int ret;
 215
 216        if (count < 1 || count > sizeof(buf))
 217                return -EINVAL;
 218
 219        ret = copy_from_user(buf, user_buf, count);
 220        if (ret)
 221                return -EFAULT;
 222
 223        /* remove end of line */
 224        if (buf[count - 1] == '\n')
 225                buf[count - 1] = '\0';
 226
 227        if (!strncmp(buf, "enabled", count)) {
 228                /* change the flag and begin the recovery process if needed */
 229                rproc->recovery_disabled = false;
 230                rproc_trigger_recovery(rproc);
 231        } else if (!strncmp(buf, "disabled", count)) {
 232                rproc->recovery_disabled = true;
 233        } else if (!strncmp(buf, "recover", count)) {
 234                /* begin the recovery process without changing the flag */
 235                rproc_trigger_recovery(rproc);
 236        } else {
 237                return -EINVAL;
 238        }
 239
 240        return count;
 241}
 242
 243static const struct file_operations rproc_recovery_ops = {
 244        .read = rproc_recovery_read,
 245        .write = rproc_recovery_write,
 246        .open = simple_open,
 247        .llseek = generic_file_llseek,
 248};
 249
 250/* expose the crash trigger via debugfs */
 251static ssize_t
 252rproc_crash_write(struct file *filp, const char __user *user_buf,
 253                  size_t count, loff_t *ppos)
 254{
 255        struct rproc *rproc = filp->private_data;
 256        unsigned int type;
 257        int ret;
 258
 259        ret = kstrtouint_from_user(user_buf, count, 0, &type);
 260        if (ret < 0)
 261                return ret;
 262
 263        rproc_report_crash(rproc, type);
 264
 265        return count;
 266}
 267
 268static const struct file_operations rproc_crash_ops = {
 269        .write = rproc_crash_write,
 270        .open = simple_open,
 271        .llseek = generic_file_llseek,
 272};
 273
 274/* Expose resource table content via debugfs */
 275static int rproc_rsc_table_show(struct seq_file *seq, void *p)
 276{
 277        static const char * const types[] = {"carveout", "devmem", "trace", "vdev"};
 278        struct rproc *rproc = seq->private;
 279        struct resource_table *table = rproc->table_ptr;
 280        struct fw_rsc_carveout *c;
 281        struct fw_rsc_devmem *d;
 282        struct fw_rsc_trace *t;
 283        struct fw_rsc_vdev *v;
 284        int i, j;
 285
 286        if (!table) {
 287                seq_puts(seq, "No resource table found\n");
 288                return 0;
 289        }
 290
 291        for (i = 0; i < table->num; i++) {
 292                int offset = table->offset[i];
 293                struct fw_rsc_hdr *hdr = (void *)table + offset;
 294                void *rsc = (void *)hdr + sizeof(*hdr);
 295
 296                switch (hdr->type) {
 297                case RSC_CARVEOUT:
 298                        c = rsc;
 299                        seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
 300                        seq_printf(seq, "  Device Address 0x%x\n", c->da);
 301                        seq_printf(seq, "  Physical Address 0x%x\n", c->pa);
 302                        seq_printf(seq, "  Length 0x%x Bytes\n", c->len);
 303                        seq_printf(seq, "  Flags 0x%x\n", c->flags);
 304                        seq_printf(seq, "  Reserved (should be zero) [%d]\n", c->reserved);
 305                        seq_printf(seq, "  Name %s\n\n", c->name);
 306                        break;
 307                case RSC_DEVMEM:
 308                        d = rsc;
 309                        seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
 310                        seq_printf(seq, "  Device Address 0x%x\n", d->da);
 311                        seq_printf(seq, "  Physical Address 0x%x\n", d->pa);
 312                        seq_printf(seq, "  Length 0x%x Bytes\n", d->len);
 313                        seq_printf(seq, "  Flags 0x%x\n", d->flags);
 314                        seq_printf(seq, "  Reserved (should be zero) [%d]\n", d->reserved);
 315                        seq_printf(seq, "  Name %s\n\n", d->name);
 316                        break;
 317                case RSC_TRACE:
 318                        t = rsc;
 319                        seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
 320                        seq_printf(seq, "  Device Address 0x%x\n", t->da);
 321                        seq_printf(seq, "  Length 0x%x Bytes\n", t->len);
 322                        seq_printf(seq, "  Reserved (should be zero) [%d]\n", t->reserved);
 323                        seq_printf(seq, "  Name %s\n\n", t->name);
 324                        break;
 325                case RSC_VDEV:
 326                        v = rsc;
 327                        seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
 328
 329                        seq_printf(seq, "  ID %d\n", v->id);
 330                        seq_printf(seq, "  Notify ID %d\n", v->notifyid);
 331                        seq_printf(seq, "  Device features 0x%x\n", v->dfeatures);
 332                        seq_printf(seq, "  Guest features 0x%x\n", v->gfeatures);
 333                        seq_printf(seq, "  Config length 0x%x\n", v->config_len);
 334                        seq_printf(seq, "  Status 0x%x\n", v->status);
 335                        seq_printf(seq, "  Number of vrings %d\n", v->num_of_vrings);
 336                        seq_printf(seq, "  Reserved (should be zero) [%d][%d]\n\n",
 337                                   v->reserved[0], v->reserved[1]);
 338
 339                        for (j = 0; j < v->num_of_vrings; j++) {
 340                                seq_printf(seq, "  Vring %d\n", j);
 341                                seq_printf(seq, "    Device Address 0x%x\n", v->vring[j].da);
 342                                seq_printf(seq, "    Alignment %d\n", v->vring[j].align);
 343                                seq_printf(seq, "    Number of buffers %d\n", v->vring[j].num);
 344                                seq_printf(seq, "    Notify ID %d\n", v->vring[j].notifyid);
 345                                seq_printf(seq, "    Physical Address 0x%x\n\n",
 346                                           v->vring[j].pa);
 347                        }
 348                        break;
 349                default:
 350                        seq_printf(seq, "Unknown resource type found: %d [hdr: %pK]\n",
 351                                   hdr->type, hdr);
 352                        break;
 353                }
 354        }
 355
 356        return 0;
 357}
 358
 359DEFINE_SHOW_ATTRIBUTE(rproc_rsc_table);
 360
 361/* Expose carveout content via debugfs */
 362static int rproc_carveouts_show(struct seq_file *seq, void *p)
 363{
 364        struct rproc *rproc = seq->private;
 365        struct rproc_mem_entry *carveout;
 366
 367        list_for_each_entry(carveout, &rproc->carveouts, node) {
 368                seq_puts(seq, "Carveout memory entry:\n");
 369                seq_printf(seq, "\tName: %s\n", carveout->name);
 370                seq_printf(seq, "\tVirtual address: %pK\n", carveout->va);
 371                seq_printf(seq, "\tDMA address: %pad\n", &carveout->dma);
 372                seq_printf(seq, "\tDevice address: 0x%x\n", carveout->da);
 373                seq_printf(seq, "\tLength: 0x%zx Bytes\n\n", carveout->len);
 374        }
 375
 376        return 0;
 377}
 378
 379DEFINE_SHOW_ATTRIBUTE(rproc_carveouts);
 380
 381void rproc_remove_trace_file(struct dentry *tfile)
 382{
 383        debugfs_remove(tfile);
 384}
 385
 386struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
 387                                       struct rproc_debug_trace *trace)
 388{
 389        struct dentry *tfile;
 390
 391        tfile = debugfs_create_file(name, 0400, rproc->dbg_dir, trace,
 392                                    &trace_rproc_ops);
 393        if (!tfile) {
 394                dev_err(&rproc->dev, "failed to create debugfs trace entry\n");
 395                return NULL;
 396        }
 397
 398        return tfile;
 399}
 400
 401void rproc_delete_debug_dir(struct rproc *rproc)
 402{
 403        debugfs_remove_recursive(rproc->dbg_dir);
 404}
 405
 406void rproc_create_debug_dir(struct rproc *rproc)
 407{
 408        struct device *dev = &rproc->dev;
 409
 410        if (!rproc_dbg)
 411                return;
 412
 413        rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
 414        if (!rproc->dbg_dir)
 415                return;
 416
 417        debugfs_create_file("name", 0400, rproc->dbg_dir,
 418                            rproc, &rproc_name_ops);
 419        debugfs_create_file("recovery", 0600, rproc->dbg_dir,
 420                            rproc, &rproc_recovery_ops);
 421        debugfs_create_file("crash", 0200, rproc->dbg_dir,
 422                            rproc, &rproc_crash_ops);
 423        debugfs_create_file("resource_table", 0400, rproc->dbg_dir,
 424                            rproc, &rproc_rsc_table_fops);
 425        debugfs_create_file("carveout_memories", 0400, rproc->dbg_dir,
 426                            rproc, &rproc_carveouts_fops);
 427        debugfs_create_file("coredump", 0600, rproc->dbg_dir,
 428                            rproc, &rproc_coredump_fops);
 429}
 430
 431void __init rproc_init_debugfs(void)
 432{
 433        if (debugfs_initialized()) {
 434                rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
 435                if (!rproc_dbg)
 436                        pr_err("can't create debugfs dir\n");
 437        }
 438}
 439
 440void __exit rproc_exit_debugfs(void)
 441{
 442        debugfs_remove(rproc_dbg);
 443}
 444