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, u32 *v)
  52 {
  53         return seqbuf_read(seqbuf, v, 4);
  54 }
  55
  56 static int seqbuf_read_str(struct seqbuf *seqbuf, const char **str)
  57 {
  58         *str = seqbuf->buf + seqbuf->pos;
  59         seqbuf->pos += strnlen(*str, seqbuf_avail(seqbuf));
  60         seqbuf->pos++;
  61         return seqbuf_status(seqbuf);
  62 }
  63
  64 static void seqbuf_seek(struct seqbuf *seqbuf, ssize_t offset)
  65 {
  66         seqbuf->pos += offset;
  67 }
  68
  69 /* map filename in Linux debugfs to corresponding entry in BPMP */
  70 static const char *get_filename(struct tegra_bpmp *bpmp,
  71                                 const struct file *file, char *buf, int size)
  72 {
  73         const char *root_path, *filename = NULL;
  74         char *root_path_buf;
  75         size_t root_len;
  76         size_t root_path_buf_len = 512;
  77
  78         root_path_buf = kzalloc(root_path_buf_len, GFP_KERNEL);
  79         if (!root_path_buf)
  80                 goto out;
  81
  82         root_path = dentry_path(bpmp->debugfs_mirror, root_path_buf,
  83                                 root_path_buf_len);
  84         if (IS_ERR(root_path))
  85                 goto out;
  86
  87         root_len = strlen(root_path);
  88
  89         filename = dentry_path(file->f_path.dentry, buf, size);
  90         if (IS_ERR(filename)) {
  91                 filename = NULL;
  92                 goto out;
  93         }
  94
  95         if (strlen(filename) < root_len || strncmp(filename, root_path, root_len)) {
  96                 filename = NULL;
  97                 goto out;
  98         }
  99
 100         filename += root_len;
 101
 102 out:
 103         kfree(root_path_buf);
 104         return filename;
 105 }
 106
 107 static int mrq_debug_open(struct tegra_bpmp *bpmp, const char *name,
 108                           u32 *fd, u32 *len, bool write)
 109 {
 110         struct mrq_debug_request req = {
 111                 .cmd = write ? CMD_DEBUG_OPEN_WO : CMD_DEBUG_OPEN_RO,
 112         };
 113         struct mrq_debug_response resp;
 114         struct tegra_bpmp_message msg = {
 115                 .mrq = MRQ_DEBUG,
 116                 .tx = {
 117                         .data = &req,
 118                         .size = sizeof(req),
 119                 },
 120                 .rx = {
 121                         .data = &resp,
 122                         .size = sizeof(resp),
 123                 },
 124         };
 125         ssize_t sz_name;
 126         int err = 0;
 127
 128         sz_name = strscpy(req.fop.name, name, sizeof(req.fop.name));
 129         if (sz_name < 0) {
 130                 pr_err("File name too large: %s\n", name);
 131                 return -EINVAL;
 132         }
 133
 134         err = tegra_bpmp_transfer(bpmp, &msg);
 135         if (err < 0)
 136                 return err;
 137         else if (msg.rx.ret < 0)
 138                 return -EINVAL;
 139
 140         *len = resp.fop.datalen;
 141         *fd = resp.fop.fd;
 142
 143         return 0;
 144 }
 145
 146 static int mrq_debug_close(struct tegra_bpmp *bpmp, u32 fd)
 147 {
 148         struct mrq_debug_request req = {
 149                 .cmd = CMD_DEBUG_CLOSE,
 150                 .frd = {
 151                         .fd = fd,
 152                 },
 153         };
 154         struct mrq_debug_response resp;
 155         struct tegra_bpmp_message msg = {
 156                 .mrq = MRQ_DEBUG,
 157                 .tx = {
 158                         .data = &req,
 159                         .size = sizeof(req),
 160                 },
 161                 .rx = {
 162                         .data = &resp,
 163                         .size = sizeof(resp),
 164                 },
 165         };
 166         int err = 0;
 167
 168         err = tegra_bpmp_transfer(bpmp, &msg);
 169         if (err < 0)
 170                 return err;
 171         else if (msg.rx.ret < 0)
 172                 return -EINVAL;
 173
 174         return 0;
 175 }
 176
 177 static int mrq_debug_read(struct tegra_bpmp *bpmp, const char *name,
 178                           char *data, size_t sz_data, u32 *nbytes)
 179 {
 180         struct mrq_debug_request req = {
 181                 .cmd = CMD_DEBUG_READ,
 182         };
 183         struct mrq_debug_response resp;
 184         struct tegra_bpmp_message msg = {
 185                 .mrq = MRQ_DEBUG,
 186                 .tx = {
 187                         .data = &req,
 188                         .size = sizeof(req),
 189                 },
 190                 .rx = {
 191                         .data = &resp,
 192                         .size = sizeof(resp),
 193                 },
 194         };
 195         u32 fd = 0, len = 0;
 196         int remaining, err, close_err;
 197
 198         mutex_lock(&bpmp_debug_lock);
 199         err = mrq_debug_open(bpmp, name, &fd, &len, 0);
 200         if (err)
 201                 goto out;
 202
 203         if (len > sz_data) {
 204                 err = -EFBIG;
 205                 goto close;
 206         }
 207
 208         req.frd.fd = fd;
 209         remaining = len;
 210
 211         while (remaining > 0) {
 212                 err = tegra_bpmp_transfer(bpmp, &msg);
 213                 if (err < 0) {
 214                         goto close;
 215                 } else if (msg.rx.ret < 0) {
 216                         err = -EINVAL;
 217                         goto close;
 218                 }
 219
 220                 if (resp.frd.readlen > remaining) {
 221                         pr_err("%s: read data length invalid\n", __func__);
 222                         err = -EINVAL;
 223                         goto close;
 224                 }
 225
 226                 memcpy(data, resp.frd.data, resp.frd.readlen);
 227                 data += resp.frd.readlen;
 228                 remaining -= resp.frd.readlen;
 229         }
 230
 231         *nbytes = len;
 232
 233 close:
 234         close_err = mrq_debug_close(bpmp, fd);
 235         if (!err)
 236                 err = close_err;
 237 out:
 238         mutex_unlock(&bpmp_debug_lock);
 239         return err;
 240 }
 241
 242 static int mrq_debug_write(struct tegra_bpmp *bpmp, const char *name,
 243                            uint8_t *data, size_t sz_data)
 244 {
 245         struct mrq_debug_request req = {
 246                 .cmd = CMD_DEBUG_WRITE
 247         };
 248         struct mrq_debug_response resp;
 249         struct tegra_bpmp_message msg = {
 250                 .mrq = MRQ_DEBUG,
 251                 .tx = {
 252                         .data = &req,
 253                         .size = sizeof(req),
 254                 },
 255                 .rx = {
 256                         .data = &resp,
 257                         .size = sizeof(resp),
 258                 },
 259         };
 260         u32 fd = 0, len = 0;
 261         size_t remaining;
 262         int err;
 263
 264         mutex_lock(&bpmp_debug_lock);
 265         err = mrq_debug_open(bpmp, name, &fd, &len, 1);
 266         if (err)
 267                 goto out;
 268
 269         if (sz_data > len) {
 270                 err = -EINVAL;
 271                 goto close;
 272         }
 273
 274         req.fwr.fd = fd;
 275         remaining = sz_data;
 276
 277         while (remaining > 0) {
 278                 len = min(remaining, sizeof(req.fwr.data));
 279                 memcpy(req.fwr.data, data, len);
 280                 req.fwr.datalen = len;
 281
 282                 err = tegra_bpmp_transfer(bpmp, &msg);
 283                 if (err < 0) {
 284                         goto close;
 285                 } else if (msg.rx.ret < 0) {
 286                         err = -EINVAL;
 287                         goto close;
 288                 }
 289
 290                 data += req.fwr.datalen;
 291                 remaining -= req.fwr.datalen;
 292         }
 293
 294 close:
 295         err = mrq_debug_close(bpmp, fd);
 296 out:
 297         mutex_unlock(&bpmp_debug_lock);
 298         return err;
 299 }
 300
 301 static int bpmp_debug_show(struct seq_file *m, void *p)
 302 {
 303         struct file *file = m->private;
 304         struct inode *inode = file_inode(file);
 305         struct tegra_bpmp *bpmp = inode->i_private;
 306         char fnamebuf[256];
 307         const char *filename;
 308         struct mrq_debug_request req = {
 309                 .cmd = CMD_DEBUG_READ,
 310         };
 311         struct mrq_debug_response resp;
 312         struct tegra_bpmp_message msg = {
 313                 .mrq = MRQ_DEBUG,
 314                 .tx = {
 315                         .data = &req,
 316                         .size = sizeof(req),
 317                 },
 318                 .rx = {
 319                         .data = &resp,
 320                         .size = sizeof(resp),
 321                 },
 322         };
 323         u32 fd = 0, len = 0;
 324         int remaining, err, close_err;
 325
 326         filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
 327         if (!filename)
 328                 return -ENOENT;
 329
 330         mutex_lock(&bpmp_debug_lock);
 331         err = mrq_debug_open(bpmp, filename, &fd, &len, 0);
 332         if (err)
 333                 goto out;
 334
 335         req.frd.fd = fd;
 336         remaining = len;
 337
 338         while (remaining > 0) {
 339                 err = tegra_bpmp_transfer(bpmp, &msg);
 340                 if (err < 0) {
 341                         goto close;
 342                 } else if (msg.rx.ret < 0) {
 343                         err = -EINVAL;
 344                         goto close;
 345                 }
 346
 347                 if (resp.frd.readlen > remaining) {
 348                         pr_err("%s: read data length invalid\n", __func__);
 349                         err = -EINVAL;
 350                         goto close;
 351                 }
 352
 353                 seq_write(m, resp.frd.data, resp.frd.readlen);
 354                 remaining -= resp.frd.readlen;
 355         }
 356
 357 close:
 358         close_err = mrq_debug_close(bpmp, fd);
 359         if (!err)
 360                 err = close_err;
 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         struct dentry *dentry;
 410         u32 dsize, attrs = 0;
 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 = CMD_DEBUGFS_READ,
 491                 .fop = {
 492                         .fnameaddr = (u32)name,
 493                         .fnamelen = (u32)sz_name,
 494                         .dataaddr = (u32)data,
 495                         .datalen = (u32)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 = CMD_DEBUGFS_WRITE,
 529                 .fop = {
 530                         .fnameaddr = (u32)name,
 531                         .fnamelen = (u32)sz_name,
 532                         .dataaddr = (u32)data,
 533                         .datalen = (u32)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 = CMD_DEBUGFS_DUMPDIR,
 552                 .dumpdir = {
 553                         .dataaddr = (u32)addr,
 554                         .datalen = (u32)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, u32 depth)
 692 {
 693         int err;
 694         u32 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 }