drivers/firmware/tegra/bpmp-debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
   4  */
   5 #include <linux/debugfs.h>
   6 #include <linux/dma-mapping.h>
   7 #include <linux/slab.h>
   8 #include <linux/uaccess.h>
   9
  10 #include <soc/tegra/bpmp.h>
  11 #include <soc/tegra/bpmp-abi.h>
  12
  13 static DEFINE_MUTEX(bpmp_debug_lock);
  14
  15 struct seqbuf {
  16         char *buf;
  17         size_t pos;
  18         size_t size;
  19 };
  20
  21 static void seqbuf_init(struct seqbuf *seqbuf, void *buf, size_t size)
  22 {
  23         seqbuf->buf = buf;
  24         seqbuf->size = size;
  25         seqbuf->pos = 0;
  26 }
  27
  28 static size_t seqbuf_avail(struct seqbuf *seqbuf)
  29 {
  30         return seqbuf->pos < seqbuf->size ? seqbuf->size - seqbuf->pos : 0;
  31 }
  32
  33 static size_t seqbuf_status(struct seqbuf *seqbuf)
  34 {
  35         return seqbuf->pos <= seqbuf->size ? 0 : -EOVERFLOW;
  36 }
  37
  38 static int seqbuf_eof(struct seqbuf *seqbuf)
  39 {
  40         return seqbuf->pos >= seqbuf->size;
  41 }
  42
  43 static int seqbuf_read(struct seqbuf *seqbuf, void *buf, size_t nbyte)
  44 {
  45         nbyte = min(nbyte, seqbuf_avail(seqbuf));
  46         memcpy(buf, seqbuf->buf + seqbuf->pos, nbyte);
  47         seqbuf->pos += nbyte;
  48         return seqbuf_status(seqbuf);
  49 }
  50
  51 static int seqbuf_read_u32(struct seqbuf *seqbuf, uint32_t *v)
  52 {
  53         int err;
  54
  55         err = seqbuf_read(seqbuf, v, 4);
  56         *v = le32_to_cpu(*v);
  57         return err;
  58 }
  59
  60 static int seqbuf_read_str(struct seqbuf *seqbuf, const char **str)
  61 {
  62         *str = seqbuf->buf + seqbuf->pos;
  63         seqbuf->pos += strnlen(*str, seqbuf_avail(seqbuf));
  64         seqbuf->pos++;
  65         return seqbuf_status(seqbuf);
  66 }
  67
  68 static void seqbuf_seek(struct seqbuf *seqbuf, ssize_t offset)
  69 {
  70         seqbuf->pos += offset;
  71 }
  72
  73 /* map filename in Linux debugfs to corresponding entry in BPMP */
  74 static const char *get_filename(struct tegra_bpmp *bpmp,
  75                                 const struct file *file, char *buf, int size)
  76 {
  77         const char *root_path, *filename = NULL;
  78         char *root_path_buf;
  79         size_t root_len;
  80         size_t root_path_buf_len = 512;
  81
  82         root_path_buf = kzalloc(root_path_buf_len, GFP_KERNEL);
  83         if (!root_path_buf)
  84                 goto out;
  85
  86         root_path = dentry_path(bpmp->debugfs_mirror, root_path_buf,
  87                                 root_path_buf_len);
  88         if (IS_ERR(root_path))
  89                 goto out;
  90
  91         root_len = strlen(root_path);
  92
  93         filename = dentry_path(file->f_path.dentry, buf, size);
  94         if (IS_ERR(filename)) {
  95                 filename = NULL;
  96                 goto out;
  97         }
  98
  99         if (strlen(filename) < root_len || strncmp(filename, root_path, root_len)) {
 100                 filename = NULL;
 101                 goto out;
 102         }
 103
 104         filename += root_len;
 105
 106 out:
 107         kfree(root_path_buf);
 108         return filename;
 109 }
 110
 111 static int mrq_debug_open(struct tegra_bpmp *bpmp, const char *name,
 112                           uint32_t *fd, uint32_t *len, bool write)
 113 {
 114         struct mrq_debug_request req = {
 115                 .cmd = cpu_to_le32(write ? CMD_DEBUG_OPEN_WO : CMD_DEBUG_OPEN_RO),
 116         };
 117         struct mrq_debug_response resp;
 118         struct tegra_bpmp_message msg = {
 119                 .mrq = MRQ_DEBUG,
 120                 .tx = {
 121                         .data = &req,
 122                         .size = sizeof(req),
 123                 },
 124                 .rx = {
 125                         .data = &resp,
 126                         .size = sizeof(resp),
 127                 },
 128         };
 129         ssize_t sz_name;
 130         int err = 0;
 131
 132         sz_name = strscpy(req.fop.name, name, sizeof(req.fop.name));
 133         if (sz_name < 0) {
 134                 pr_err("File name too large: %s\n", name);
 135                 return -EINVAL;
 136         }
 137
 138         err = tegra_bpmp_transfer(bpmp, &msg);
 139         if (err < 0)
 140                 return err;
 141         else if (msg.rx.ret < 0)
 142                 return -EINVAL;
 143
 144         *len = resp.fop.datalen;
 145         *fd = resp.fop.fd;
 146
 147         return 0;
 148 }
 149
 150 static int mrq_debug_close(struct tegra_bpmp *bpmp, uint32_t fd)
 151 {
 152         struct mrq_debug_request req = {
 153                 .cmd = cpu_to_le32(CMD_DEBUG_CLOSE),
 154                 .frd = {
 155                         .fd = fd,
 156                 },
 157         };
 158         struct mrq_debug_response resp;
 159         struct tegra_bpmp_message msg = {
 160                 .mrq = MRQ_DEBUG,
 161                 .tx = {
 162                         .data = &req,
 163                         .size = sizeof(req),
 164                 },
 165                 .rx = {
 166                         .data = &resp,
 167                         .size = sizeof(resp),
 168                 },
 169         };
 170         int err = 0;
 171
 172         err = tegra_bpmp_transfer(bpmp, &msg);
 173         if (err < 0)
 174                 return err;
 175         else if (msg.rx.ret < 0)
 176                 return -EINVAL;
 177
 178         return 0;
 179 }
 180
 181 static int mrq_debug_read(struct tegra_bpmp *bpmp, const char *name,
 182                           char *data, size_t sz_data, uint32_t *nbytes)
 183 {
 184         struct mrq_debug_request req = {
 185                 .cmd = cpu_to_le32(CMD_DEBUG_READ),
 186         };
 187         struct mrq_debug_response resp;
 188         struct tegra_bpmp_message msg = {
 189                 .mrq = MRQ_DEBUG,
 190                 .tx = {
 191                         .data = &req,
 192                         .size = sizeof(req),
 193                 },
 194                 .rx = {
 195                         .data = &resp,
 196                         .size = sizeof(resp),
 197                 },
 198         };
 199         uint32_t fd = 0, len = 0;
 200         int remaining, err;
 201
 202         mutex_lock(&bpmp_debug_lock);
 203         err = mrq_debug_open(bpmp, name, &fd, &len, 0);
 204         if (err)
 205                 goto out;
 206
 207         if (len > sz_data) {
 208                 err = -EFBIG;
 209                 goto close;
 210         }
 211
 212         req.frd.fd = fd;
 213         remaining = len;
 214
 215         while (remaining > 0) {
 216                 err = tegra_bpmp_transfer(bpmp, &msg);
 217                 if (err < 0) {
 218                         goto close;
 219                 } else if (msg.rx.ret < 0) {
 220                         err = -EINVAL;
 221                         goto close;
 222                 }
 223
 224                 if (resp.frd.readlen > remaining) {
 225                         pr_err("%s: read data length invalid\n", __func__);
 226                         err = -EINVAL;
 227                         goto close;
 228                 }
 229
 230                 memcpy(data, resp.frd.data, resp.frd.readlen);
 231                 data += resp.frd.readlen;
 232                 remaining -= resp.frd.readlen;
 233         }
 234
 235         *nbytes = len;
 236
 237 close:
 238         err = mrq_debug_close(bpmp, fd);
 239 out:
 240         mutex_unlock(&bpmp_debug_lock);
 241         return err;
 242 }
 243
 244 static int mrq_debug_write(struct tegra_bpmp *bpmp, const char *name,
 245                            uint8_t *data, size_t sz_data)
 246 {
 247         struct mrq_debug_request req = {
 248                 .cmd = cpu_to_le32(CMD_DEBUG_WRITE)
 249         };
 250         struct mrq_debug_response resp;
 251         struct tegra_bpmp_message msg = {
 252                 .mrq = MRQ_DEBUG,
 253                 .tx = {
 254                         .data = &req,
 255                         .size = sizeof(req),
 256                 },
 257                 .rx = {
 258                         .data = &resp,
 259                         .size = sizeof(resp),
 260                 },
 261         };
 262         uint32_t fd = 0, len = 0;
 263         size_t remaining;
 264         int err;
 265
 266         mutex_lock(&bpmp_debug_lock);
 267         err = mrq_debug_open(bpmp, name, &fd, &len, 1);
 268         if (err)
 269                 goto out;
 270
 271         if (sz_data > len) {
 272                 err = -EINVAL;
 273                 goto close;
 274         }
 275
 276         req.fwr.fd = fd;
 277         remaining = sz_data;
 278
 279         while (remaining > 0) {
 280                 len = min(remaining, sizeof(req.fwr.data));
 281                 memcpy(req.fwr.data, data, len);
 282                 req.fwr.datalen = len;
 283
 284                 err = tegra_bpmp_transfer(bpmp, &msg);
 285                 if (err < 0) {
 286                         goto close;
 287                 } else if (msg.rx.ret < 0) {
 288                         err = -EINVAL;
 289                         goto close;
 290                 }
 291
 292                 data += req.fwr.datalen;
 293                 remaining -= req.fwr.datalen;
 294         }
 295
 296 close:
 297         err = mrq_debug_close(bpmp, fd);
 298 out:
 299         mutex_unlock(&bpmp_debug_lock);
 300         return err;
 301 }
 302
 303 static int bpmp_debug_show(struct seq_file *m, void *p)
 304 {
 305         struct file *file = m->private;
 306         struct inode *inode = file_inode(file);
 307         struct tegra_bpmp *bpmp = inode->i_private;
 308         char fnamebuf[256];
 309         const char *filename;
 310         struct mrq_debug_request req = {
 311                 .cmd = cpu_to_le32(CMD_DEBUG_READ),
 312         };
 313         struct mrq_debug_response resp;
 314         struct tegra_bpmp_message msg = {
 315                 .mrq = MRQ_DEBUG,
 316                 .tx = {
 317                         .data = &req,
 318                         .size = sizeof(req),
 319                 },
 320                 .rx = {
 321                         .data = &resp,
 322                         .size = sizeof(resp),
 323                 },
 324         };
 325         uint32_t fd = 0, len = 0;
 326         int remaining, err;
 327
 328         filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
 329         if (!filename)
 330                 return -ENOENT;
 331
 332         mutex_lock(&bpmp_debug_lock);
 333         err = mrq_debug_open(bpmp, filename, &fd, &len, 0);
 334         if (err)
 335                 goto out;
 336
 337         req.frd.fd = fd;
 338         remaining = len;
 339
 340         while (remaining > 0) {
 341                 err = tegra_bpmp_transfer(bpmp, &msg);
 342                 if (err < 0) {
 343                         goto close;
 344                 } else if (msg.rx.ret < 0) {
 345                         err = -EINVAL;
 346                         goto close;
 347                 }
 348
 349                 if (resp.frd.readlen > remaining) {
 350                         pr_err("%s: read data length invalid\n", __func__);
 351                         err = -EINVAL;
 352                         goto close;
 353                 }
 354
 355                 seq_write(m, resp.frd.data, resp.frd.readlen);
 356                 remaining -= resp.frd.readlen;
 357         }
 358
 359 close:
 360         err = mrq_debug_close(bpmp, fd);
 361 out:
 362         mutex_unlock(&bpmp_debug_lock);
 363         return err;
 364 }
 365
 366 static ssize_t bpmp_debug_store(struct file *file, const char __user *buf,
 367                 size_t count, loff_t *f_pos)
 368 {
 369         struct inode *inode = file_inode(file);
 370         struct tegra_bpmp *bpmp = inode->i_private;
 371         char *databuf = NULL;
 372         char fnamebuf[256];
 373         const char *filename;
 374         ssize_t err;
 375
 376         filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
 377         if (!filename)
 378                 return -ENOENT;
 379
 380         databuf = memdup_user(buf, count);
 381         if (IS_ERR(databuf))
 382                 return PTR_ERR(databuf);
 383
 384         err = mrq_debug_write(bpmp, filename, databuf, count);
 385         kfree(databuf);
 386
 387         return err ?: count;
 388 }
 389
 390 static int bpmp_debug_open(struct inode *inode, struct file *file)
 391 {
 392         return single_open_size(file, bpmp_debug_show, file, SZ_256K);
 393 }
 394
 395 static const struct file_operations bpmp_debug_fops = {
 396         .open           = bpmp_debug_open,
 397         .read           = seq_read,
 398         .llseek         = seq_lseek,
 399         .write          = bpmp_debug_store,
 400         .release        = single_release,
 401 };
 402
 403 static int bpmp_populate_debugfs_inband(struct tegra_bpmp *bpmp,
 404                                         struct dentry *parent,
 405                                         char *ppath)
 406 {
 407         const size_t pathlen = SZ_256;
 408         const size_t bufsize = SZ_16K;
 409         uint32_t dsize, attrs = 0;
 410         struct dentry *dentry;
 411         struct seqbuf seqbuf;
 412         char *buf, *pathbuf;
 413         const char *name;
 414         int err = 0;
 415
 416         if (!bpmp || !parent || !ppath)
 417                 return -EINVAL;
 418
 419         buf = kmalloc(bufsize, GFP_KERNEL);
 420         if (!buf)
 421                 return -ENOMEM;
 422
 423         pathbuf = kzalloc(pathlen, GFP_KERNEL);
 424         if (!pathbuf) {
 425                 kfree(buf);
 426                 return -ENOMEM;
 427         }
 428
 429         err = mrq_debug_read(bpmp, ppath, buf, bufsize, &dsize);
 430         if (err)
 431                 goto out;
 432
 433         seqbuf_init(&seqbuf, buf, dsize);
 434
 435         while (!seqbuf_eof(&seqbuf)) {
 436                 err = seqbuf_read_u32(&seqbuf, &attrs);
 437                 if (err)
 438                         goto out;
 439
 440                 err = seqbuf_read_str(&seqbuf, &name);
 441                 if (err < 0)
 442                         goto out;
 443
 444                 if (attrs & DEBUGFS_S_ISDIR) {
 445                         size_t len;
 446
 447                         dentry = debugfs_create_dir(name, parent);
 448                         if (IS_ERR(dentry)) {
 449                                 err = PTR_ERR(dentry);
 450                                 goto out;
 451                         }
 452
 453                         len = snprintf(pathbuf, pathlen, "%s%s/", ppath, name);
 454                         if (len >= pathlen) {
 455                                 err = -EINVAL;
 456                                 goto out;
 457                         }
 458
 459                         err = bpmp_populate_debugfs_inband(bpmp, dentry,
 460                                                            pathbuf);
 461                         if (err < 0)
 462                                 goto out;
 463                 } else {
 464                         umode_t mode;
 465
 466                         mode = attrs & DEBUGFS_S_IRUSR ? 0400 : 0;
 467                         mode |= attrs & DEBUGFS_S_IWUSR ? 0200 : 0;
 468                         dentry = debugfs_create_file(name, mode, parent, bpmp,
 469                                                      &bpmp_debug_fops);
 470                         if (IS_ERR(dentry)) {
 471                                 err = -ENOMEM;
 472                                 goto out;
 473                         }
 474                 }
 475         }
 476
 477 out:
 478         kfree(pathbuf);
 479         kfree(buf);
 480
 481         return err;
 482 }
 483
 484 static int mrq_debugfs_read(struct tegra_bpmp *bpmp,
 485                             dma_addr_t name, size_t sz_name,
 486                             dma_addr_t data, size_t sz_data,
 487                             size_t *nbytes)
 488 {
 489         struct mrq_debugfs_request req = {
 490                 .cmd = cpu_to_le32(CMD_DEBUGFS_READ),
 491                 .fop = {
 492                         .fnameaddr = cpu_to_le32((uint32_t)name),
 493                         .fnamelen = cpu_to_le32((uint32_t)sz_name),
 494                         .dataaddr = cpu_to_le32((uint32_t)data),
 495                         .datalen = cpu_to_le32((uint32_t)sz_data),
 496                 },
 497         };
 498         struct mrq_debugfs_response resp;
 499         struct tegra_bpmp_message msg = {
 500                 .mrq = MRQ_DEBUGFS,
 501                 .tx = {
 502                         .data = &req,
 503                         .size = sizeof(req),
 504                 },
 505                 .rx = {
 506                         .data = &resp,
 507                         .size = sizeof(resp),
 508                 },
 509         };
 510         int err;
 511
 512         err = tegra_bpmp_transfer(bpmp, &msg);
 513         if (err < 0)
 514                 return err;
 515         else if (msg.rx.ret < 0)
 516                 return -EINVAL;
 517
 518         *nbytes = (size_t)resp.fop.nbytes;
 519
 520         return 0;
 521 }
 522
 523 static int mrq_debugfs_write(struct tegra_bpmp *bpmp,
 524                              dma_addr_t name, size_t sz_name,
 525                              dma_addr_t data, size_t sz_data)
 526 {
 527         const struct mrq_debugfs_request req = {
 528                 .cmd = cpu_to_le32(CMD_DEBUGFS_WRITE),
 529                 .fop = {
 530                         .fnameaddr = cpu_to_le32((uint32_t)name),
 531                         .fnamelen = cpu_to_le32((uint32_t)sz_name),
 532                         .dataaddr = cpu_to_le32((uint32_t)data),
 533                         .datalen = cpu_to_le32((uint32_t)sz_data),
 534                 },
 535         };
 536         struct tegra_bpmp_message msg = {
 537                 .mrq = MRQ_DEBUGFS,
 538                 .tx = {
 539                         .data = &req,
 540                         .size = sizeof(req),
 541                 },
 542         };
 543
 544         return tegra_bpmp_transfer(bpmp, &msg);
 545 }
 546
 547 static int mrq_debugfs_dumpdir(struct tegra_bpmp *bpmp, dma_addr_t addr,
 548                                size_t size, size_t *nbytes)
 549 {
 550         const struct mrq_debugfs_request req = {
 551                 .cmd = cpu_to_le32(CMD_DEBUGFS_DUMPDIR),
 552                 .dumpdir = {
 553                         .dataaddr = cpu_to_le32((uint32_t)addr),
 554                         .datalen = cpu_to_le32((uint32_t)size),
 555                 },
 556         };
 557         struct mrq_debugfs_response resp;
 558         struct tegra_bpmp_message msg = {
 559                 .mrq = MRQ_DEBUGFS,
 560                 .tx = {
 561                         .data = &req,
 562                         .size = sizeof(req),
 563                 },
 564                 .rx = {
 565                         .data = &resp,
 566                         .size = sizeof(resp),
 567                 },
 568         };
 569         int err;
 570
 571         err = tegra_bpmp_transfer(bpmp, &msg);
 572         if (err < 0)
 573                 return err;
 574         else if (msg.rx.ret < 0)
 575                 return -EINVAL;
 576
 577         *nbytes = (size_t)resp.dumpdir.nbytes;
 578
 579         return 0;
 580 }
 581
 582 static int debugfs_show(struct seq_file *m, void *p)
 583 {
 584         struct file *file = m->private;
 585         struct inode *inode = file_inode(file);
 586         struct tegra_bpmp *bpmp = inode->i_private;
 587         const size_t datasize = m->size;
 588         const size_t namesize = SZ_256;
 589         void *datavirt, *namevirt;
 590         dma_addr_t dataphys, namephys;
 591         char buf[256];
 592         const char *filename;
 593         size_t len, nbytes;
 594         int err;
 595
 596         filename = get_filename(bpmp, file, buf, sizeof(buf));
 597         if (!filename)
 598                 return -ENOENT;
 599
 600         namevirt = dma_alloc_coherent(bpmp->dev, namesize, &namephys,
 601                                       GFP_KERNEL | GFP_DMA32);
 602         if (!namevirt)
 603                 return -ENOMEM;
 604
 605         datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
 606                                       GFP_KERNEL | GFP_DMA32);
 607         if (!datavirt) {
 608                 err = -ENOMEM;
 609                 goto free_namebuf;
 610         }
 611
 612         len = strlen(filename);
 613         strncpy(namevirt, filename, namesize);
 614
 615         err = mrq_debugfs_read(bpmp, namephys, len, dataphys, datasize,
 616                                &nbytes);
 617
 618         if (!err)
 619                 seq_write(m, datavirt, nbytes);
 620
 621         dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
 622 free_namebuf:
 623         dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
 624
 625         return err;
 626 }
 627
 628 static int debugfs_open(struct inode *inode, struct file *file)
 629 {
 630         return single_open_size(file, debugfs_show, file, SZ_128K);
 631 }
 632
 633 static ssize_t debugfs_store(struct file *file, const char __user *buf,
 634                 size_t count, loff_t *f_pos)
 635 {
 636         struct inode *inode = file_inode(file);
 637         struct tegra_bpmp *bpmp = inode->i_private;
 638         const size_t datasize = count;
 639         const size_t namesize = SZ_256;
 640         void *datavirt, *namevirt;
 641         dma_addr_t dataphys, namephys;
 642         char fnamebuf[256];
 643         const char *filename;
 644         size_t len;
 645         int err;
 646
 647         filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
 648         if (!filename)
 649                 return -ENOENT;
 650
 651         namevirt = dma_alloc_coherent(bpmp->dev, namesize, &namephys,
 652                                       GFP_KERNEL | GFP_DMA32);
 653         if (!namevirt)
 654                 return -ENOMEM;
 655
 656         datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
 657                                       GFP_KERNEL | GFP_DMA32);
 658         if (!datavirt) {
 659                 err = -ENOMEM;
 660                 goto free_namebuf;
 661         }
 662
 663         len = strlen(filename);
 664         strncpy(namevirt, filename, namesize);
 665
 666         if (copy_from_user(datavirt, buf, count)) {
 667                 err = -EFAULT;
 668                 goto free_databuf;
 669         }
 670
 671         err = mrq_debugfs_write(bpmp, namephys, len, dataphys,
 672                                 count);
 673
 674 free_databuf:
 675         dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
 676 free_namebuf:
 677         dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
 678
 679         return err ?: count;
 680 }
 681
 682 static const struct file_operations debugfs_fops = {
 683         .open           = debugfs_open,
 684         .read           = seq_read,
 685         .llseek         = seq_lseek,
 686         .write          = debugfs_store,
 687         .release        = single_release,
 688 };
 689
 690 static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
 691                              struct dentry *parent, uint32_t depth)
 692 {
 693         int err;
 694         uint32_t d, t;
 695         const char *name;
 696         struct dentry *dentry;
 697
 698         while (!seqbuf_eof(seqbuf)) {
 699                 err = seqbuf_read_u32(seqbuf, &d);
 700                 if (err < 0)
 701                         return err;
 702
 703                 if (d < depth) {
 704                         seqbuf_seek(seqbuf, -4);
 705                         /* go up a level */
 706                         return 0;
 707                 } else if (d != depth) {
 708                         /* malformed data received from BPMP */
 709                         return -EIO;
 710                 }
 711
 712                 err = seqbuf_read_u32(seqbuf, &t);
 713                 if (err < 0)
 714                         return err;
 715                 err = seqbuf_read_str(seqbuf, &name);
 716                 if (err < 0)
 717                         return err;
 718
 719                 if (t & DEBUGFS_S_ISDIR) {
 720                         dentry = debugfs_create_dir(name, parent);
 721                         if (IS_ERR(dentry))
 722                                 return -ENOMEM;
 723                         err = bpmp_populate_dir(bpmp, seqbuf, dentry, depth+1);
 724                         if (err < 0)
 725                                 return err;
 726                 } else {
 727                         umode_t mode;
 728
 729                         mode = t & DEBUGFS_S_IRUSR ? S_IRUSR : 0;
 730                         mode |= t & DEBUGFS_S_IWUSR ? S_IWUSR : 0;
 731                         dentry = debugfs_create_file(name, mode,
 732                                                      parent, bpmp,
 733                                                      &debugfs_fops);
 734                         if (IS_ERR(dentry))
 735                                 return -ENOMEM;
 736                 }
 737         }
 738
 739         return 0;
 740 }
 741
 742 static int bpmp_populate_debugfs_shmem(struct tegra_bpmp *bpmp)
 743 {
 744         struct seqbuf seqbuf;
 745         const size_t sz = SZ_512K;
 746         dma_addr_t phys;
 747         size_t nbytes;
 748         void *virt;
 749         int err;
 750
 751         virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
 752                                   GFP_KERNEL | GFP_DMA32);
 753         if (!virt)
 754                 return -ENOMEM;
 755
 756         err = mrq_debugfs_dumpdir(bpmp, phys, sz, &nbytes);
 757         if (err < 0) {
 758                 goto free;
 759         } else if (nbytes > sz) {
 760                 err = -EINVAL;
 761                 goto free;
 762         }
 763
 764         seqbuf_init(&seqbuf, virt, nbytes);
 765         err = bpmp_populate_dir(bpmp, &seqbuf, bpmp->debugfs_mirror, 0);
 766 free:
 767         dma_free_coherent(bpmp->dev, sz, virt, phys);
 768
 769         return err;
 770 }
 771
 772 int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
 773 {
 774         struct dentry *root;
 775         bool inband;
 776         int err;
 777
 778         inband = tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUG);
 779
 780         if (!inband && !tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUGFS))
 781                 return 0;
 782
 783         root = debugfs_create_dir("bpmp", NULL);
 784         if (IS_ERR(root))
 785                 return -ENOMEM;
 786
 787         bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
 788         if (IS_ERR(bpmp->debugfs_mirror)) {
 789                 err = -ENOMEM;
 790                 goto out;
 791         }
 792
 793         if (inband)
 794                 err = bpmp_populate_debugfs_inband(bpmp, bpmp->debugfs_mirror,
 795                                                    "/");
 796         else
 797                 err = bpmp_populate_debugfs_shmem(bpmp);
 798
 799 out:
 800         if (err < 0)
 801                 debugfs_remove_recursive(root);
 802
 803         return err;
 804 }