arch/s390/kernel/sysinfo.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright IBM Corp. 2001, 2009
   4  *  Author(s): Ulrich Weigand <Ulrich.Weigand@de.ibm.com>,
   5  *             Martin Schwidefsky <schwidefsky@de.ibm.com>,
   6  */
   7
   8 #include <linux/debugfs.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mm.h>
  11 #include <linux/proc_fs.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/init.h>
  14 #include <linux/delay.h>
  15 #include <linux/export.h>
  16 #include <linux/slab.h>
  17 #include <asm/asm-extable.h>
  18 #include <asm/ebcdic.h>
  19 #include <asm/debug.h>
  20 #include <asm/sysinfo.h>
  21 #include <asm/cpcmd.h>
  22 #include <asm/topology.h>
  23 #include <asm/fpu/api.h>
  24
  25 int topology_max_mnest;
  26
  27 static inline int __stsi(void *sysinfo, int fc, int sel1, int sel2, int *lvl)
  28 {
  29         int r0 = (fc << 28) | sel1;
  30         int rc = 0;
  31
  32         asm volatile(
  33                 "       lr      0,%[r0]\n"
  34                 "       lr      1,%[r1]\n"
  35                 "       stsi    0(%[sysinfo])\n"
  36                 "0:     jz      2f\n"
  37                 "1:     lhi     %[rc],%[retval]\n"
  38                 "2:     lr      %[r0],0\n"
  39                 EX_TABLE(0b, 1b)
  40                 : [r0] "+d" (r0), [rc] "+d" (rc)
  41                 : [r1] "d" (sel2),
  42                   [sysinfo] "a" (sysinfo),
  43                   [retval] "K" (-EOPNOTSUPP)
  44                 : "cc", "0", "1", "memory");
  45         *lvl = ((unsigned int) r0) >> 28;
  46         return rc;
  47 }
  48
  49 /*
  50  * stsi - store system information
  51  *
  52  * Returns the current configuration level if function code 0 was specified.
  53  * Otherwise returns 0 on success or a negative value on error.
  54  */
  55 int stsi(void *sysinfo, int fc, int sel1, int sel2)
  56 {
  57         int lvl, rc;
  58
  59         rc = __stsi(sysinfo, fc, sel1, sel2, &lvl);
  60         if (rc)
  61                 return rc;
  62         return fc ? 0 : lvl;
  63 }
  64 EXPORT_SYMBOL(stsi);
  65
  66 #ifdef CONFIG_PROC_FS
  67
  68 static bool convert_ext_name(unsigned char encoding, char *name, size_t len)
  69 {
  70         switch (encoding) {
  71         case 1: /* EBCDIC */
  72                 EBCASC(name, len);
  73                 break;
  74         case 2: /* UTF-8 */
  75                 break;
  76         default:
  77                 return false;
  78         }
  79         return true;
  80 }
  81
  82 static void stsi_1_1_1(struct seq_file *m, struct sysinfo_1_1_1 *info)
  83 {
  84         int i;
  85
  86         if (stsi(info, 1, 1, 1))
  87                 return;
  88         EBCASC(info->manufacturer, sizeof(info->manufacturer));
  89         EBCASC(info->type, sizeof(info->type));
  90         EBCASC(info->model, sizeof(info->model));
  91         EBCASC(info->sequence, sizeof(info->sequence));
  92         EBCASC(info->plant, sizeof(info->plant));
  93         EBCASC(info->model_capacity, sizeof(info->model_capacity));
  94         EBCASC(info->model_perm_cap, sizeof(info->model_perm_cap));
  95         EBCASC(info->model_temp_cap, sizeof(info->model_temp_cap));
  96         seq_printf(m, "Manufacturer:         %-16.16s\n", info->manufacturer);
  97         seq_printf(m, "Type:                 %-4.4s\n", info->type);
  98         if (info->lic)
  99                 seq_printf(m, "LIC Identifier:       %016lx\n", info->lic);
 100         /*
 101          * Sigh: the model field has been renamed with System z9
 102          * to model_capacity and a new model field has been added
 103          * after the plant field. To avoid confusing older programs
 104          * the "Model:" prints "model_capacity model" or just
 105          * "model_capacity" if the model string is empty .
 106          */
 107         seq_printf(m, "Model:                %-16.16s", info->model_capacity);
 108         if (info->model[0] != '\0')
 109                 seq_printf(m, " %-16.16s", info->model);
 110         seq_putc(m, '\n');
 111         seq_printf(m, "Sequence Code:        %-16.16s\n", info->sequence);
 112         seq_printf(m, "Plant:                %-4.4s\n", info->plant);
 113         seq_printf(m, "Model Capacity:       %-16.16s %08u\n",
 114                    info->model_capacity, info->model_cap_rating);
 115         if (info->model_perm_cap_rating)
 116                 seq_printf(m, "Model Perm. Capacity: %-16.16s %08u\n",
 117                            info->model_perm_cap,
 118                            info->model_perm_cap_rating);
 119         if (info->model_temp_cap_rating)
 120                 seq_printf(m, "Model Temp. Capacity: %-16.16s %08u\n",
 121                            info->model_temp_cap,
 122                            info->model_temp_cap_rating);
 123         if (info->ncr)
 124                 seq_printf(m, "Nominal Cap. Rating:  %08u\n", info->ncr);
 125         if (info->npr)
 126                 seq_printf(m, "Nominal Perm. Rating: %08u\n", info->npr);
 127         if (info->ntr)
 128                 seq_printf(m, "Nominal Temp. Rating: %08u\n", info->ntr);
 129         if (info->cai) {
 130                 seq_printf(m, "Capacity Adj. Ind.:   %d\n", info->cai);
 131                 seq_printf(m, "Capacity Ch. Reason:  %d\n", info->ccr);
 132                 seq_printf(m, "Capacity Transient:   %d\n", info->t);
 133         }
 134         if (info->p) {
 135                 for (i = 1; i <= ARRAY_SIZE(info->typepct); i++) {
 136                         seq_printf(m, "Type %d Percentage:    %d\n",
 137                                    i, info->typepct[i - 1]);
 138                 }
 139         }
 140 }
 141
 142 static void stsi_15_1_x(struct seq_file *m, struct sysinfo_15_1_x *info)
 143 {
 144         int i;
 145
 146         seq_putc(m, '\n');
 147         if (!MACHINE_HAS_TOPOLOGY)
 148                 return;
 149         if (stsi(info, 15, 1, topology_max_mnest))
 150                 return;
 151         seq_printf(m, "CPU Topology HW:     ");
 152         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
 153                 seq_printf(m, " %d", info->mag[i]);
 154         seq_putc(m, '\n');
 155 #ifdef CONFIG_SCHED_TOPOLOGY
 156         store_topology(info);
 157         seq_printf(m, "CPU Topology SW:     ");
 158         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
 159                 seq_printf(m, " %d", info->mag[i]);
 160         seq_putc(m, '\n');
 161 #endif
 162 }
 163
 164 static void stsi_1_2_2(struct seq_file *m, struct sysinfo_1_2_2 *info)
 165 {
 166         struct sysinfo_1_2_2_extension *ext;
 167         int i;
 168
 169         if (stsi(info, 1, 2, 2))
 170                 return;
 171         ext = (struct sysinfo_1_2_2_extension *)
 172                 ((unsigned long) info + info->acc_offset);
 173         seq_printf(m, "CPUs Total:           %d\n", info->cpus_total);
 174         seq_printf(m, "CPUs Configured:      %d\n", info->cpus_configured);
 175         seq_printf(m, "CPUs Standby:         %d\n", info->cpus_standby);
 176         seq_printf(m, "CPUs Reserved:        %d\n", info->cpus_reserved);
 177         if (info->mt_installed) {
 178                 seq_printf(m, "CPUs G-MTID:          %d\n", info->mt_gtid);
 179                 seq_printf(m, "CPUs S-MTID:          %d\n", info->mt_stid);
 180         }
 181         /*
 182          * Sigh 2. According to the specification the alternate
 183          * capability field is a 32 bit floating point number
 184          * if the higher order 8 bits are not zero. Printing
 185          * a floating point number in the kernel is a no-no,
 186          * always print the number as 32 bit unsigned integer.
 187          * The user-space needs to know about the strange
 188          * encoding of the alternate cpu capability.
 189          */
 190         seq_printf(m, "Capability:           %u", info->capability);
 191         if (info->format == 1)
 192                 seq_printf(m, " %u", ext->alt_capability);
 193         seq_putc(m, '\n');
 194         if (info->nominal_cap)
 195                 seq_printf(m, "Nominal Capability:   %d\n", info->nominal_cap);
 196         if (info->secondary_cap)
 197                 seq_printf(m, "Secondary Capability: %d\n", info->secondary_cap);
 198         for (i = 2; i <= info->cpus_total; i++) {
 199                 seq_printf(m, "Adjustment %02d-way:    %u",
 200                            i, info->adjustment[i-2]);
 201                 if (info->format == 1)
 202                         seq_printf(m, " %u", ext->alt_adjustment[i-2]);
 203                 seq_putc(m, '\n');
 204         }
 205 }
 206
 207 static void stsi_2_2_2(struct seq_file *m, struct sysinfo_2_2_2 *info)
 208 {
 209         if (stsi(info, 2, 2, 2))
 210                 return;
 211         EBCASC(info->name, sizeof(info->name));
 212         seq_putc(m, '\n');
 213         seq_printf(m, "LPAR Number:          %d\n", info->lpar_number);
 214         seq_printf(m, "LPAR Characteristics: ");
 215         if (info->characteristics & LPAR_CHAR_DEDICATED)
 216                 seq_printf(m, "Dedicated ");
 217         if (info->characteristics & LPAR_CHAR_SHARED)
 218                 seq_printf(m, "Shared ");
 219         if (info->characteristics & LPAR_CHAR_LIMITED)
 220                 seq_printf(m, "Limited ");
 221         seq_putc(m, '\n');
 222         seq_printf(m, "LPAR Name:            %-8.8s\n", info->name);
 223         seq_printf(m, "LPAR Adjustment:      %d\n", info->caf);
 224         seq_printf(m, "LPAR CPUs Total:      %d\n", info->cpus_total);
 225         seq_printf(m, "LPAR CPUs Configured: %d\n", info->cpus_configured);
 226         seq_printf(m, "LPAR CPUs Standby:    %d\n", info->cpus_standby);
 227         seq_printf(m, "LPAR CPUs Reserved:   %d\n", info->cpus_reserved);
 228         seq_printf(m, "LPAR CPUs Dedicated:  %d\n", info->cpus_dedicated);
 229         seq_printf(m, "LPAR CPUs Shared:     %d\n", info->cpus_shared);
 230         if (info->mt_installed) {
 231                 seq_printf(m, "LPAR CPUs G-MTID:     %d\n", info->mt_gtid);
 232                 seq_printf(m, "LPAR CPUs S-MTID:     %d\n", info->mt_stid);
 233                 seq_printf(m, "LPAR CPUs PS-MTID:    %d\n", info->mt_psmtid);
 234         }
 235         if (convert_ext_name(info->vsne, info->ext_name, sizeof(info->ext_name))) {
 236                 seq_printf(m, "LPAR Extended Name:   %-.256s\n", info->ext_name);
 237                 seq_printf(m, "LPAR UUID:            %pUb\n", &info->uuid);
 238         }
 239 }
 240
 241 static void print_ext_name(struct seq_file *m, int lvl,
 242                            struct sysinfo_3_2_2 *info)
 243 {
 244         size_t len = sizeof(info->ext_names[lvl]);
 245
 246         if (!convert_ext_name(info->vm[lvl].evmne, info->ext_names[lvl], len))
 247                 return;
 248         seq_printf(m, "VM%02d Extended Name:   %-.256s\n", lvl,
 249                    info->ext_names[lvl]);
 250 }
 251
 252 static void print_uuid(struct seq_file *m, int i, struct sysinfo_3_2_2 *info)
 253 {
 254         if (uuid_is_null(&info->vm[i].uuid))
 255                 return;
 256         seq_printf(m, "VM%02d UUID:            %pUb\n", i, &info->vm[i].uuid);
 257 }
 258
 259 static void stsi_3_2_2(struct seq_file *m, struct sysinfo_3_2_2 *info)
 260 {
 261         int i;
 262
 263         if (stsi(info, 3, 2, 2))
 264                 return;
 265         for (i = 0; i < info->count; i++) {
 266                 EBCASC(info->vm[i].name, sizeof(info->vm[i].name));
 267                 EBCASC(info->vm[i].cpi, sizeof(info->vm[i].cpi));
 268                 seq_putc(m, '\n');
 269                 seq_printf(m, "VM%02d Name:            %-8.8s\n", i, info->vm[i].name);
 270                 seq_printf(m, "VM%02d Control Program: %-16.16s\n", i, info->vm[i].cpi);
 271                 seq_printf(m, "VM%02d Adjustment:      %d\n", i, info->vm[i].caf);
 272                 seq_printf(m, "VM%02d CPUs Total:      %d\n", i, info->vm[i].cpus_total);
 273                 seq_printf(m, "VM%02d CPUs Configured: %d\n", i, info->vm[i].cpus_configured);
 274                 seq_printf(m, "VM%02d CPUs Standby:    %d\n", i, info->vm[i].cpus_standby);
 275                 seq_printf(m, "VM%02d CPUs Reserved:   %d\n", i, info->vm[i].cpus_reserved);
 276                 print_ext_name(m, i, info);
 277                 print_uuid(m, i, info);
 278         }
 279 }
 280
 281 static int sysinfo_show(struct seq_file *m, void *v)
 282 {
 283         void *info = (void *)get_zeroed_page(GFP_KERNEL);
 284         int level;
 285
 286         if (!info)
 287                 return 0;
 288         level = stsi(NULL, 0, 0, 0);
 289         if (level >= 1)
 290                 stsi_1_1_1(m, info);
 291         if (level >= 1)
 292                 stsi_15_1_x(m, info);
 293         if (level >= 1)
 294                 stsi_1_2_2(m, info);
 295         if (level >= 2)
 296                 stsi_2_2_2(m, info);
 297         if (level >= 3)
 298                 stsi_3_2_2(m, info);
 299         free_page((unsigned long)info);
 300         return 0;
 301 }
 302
 303 static int __init sysinfo_create_proc(void)
 304 {
 305         proc_create_single("sysinfo", 0444, NULL, sysinfo_show);
 306         return 0;
 307 }
 308 device_initcall(sysinfo_create_proc);
 309
 310 #endif /* CONFIG_PROC_FS */
 311
 312 /*
 313  * Service levels interface.
 314  */
 315
 316 static DECLARE_RWSEM(service_level_sem);
 317 static LIST_HEAD(service_level_list);
 318
 319 int register_service_level(struct service_level *slr)
 320 {
 321         struct service_level *ptr;
 322
 323         down_write(&service_level_sem);
 324         list_for_each_entry(ptr, &service_level_list, list)
 325                 if (ptr == slr) {
 326                         up_write(&service_level_sem);
 327                         return -EEXIST;
 328                 }
 329         list_add_tail(&slr->list, &service_level_list);
 330         up_write(&service_level_sem);
 331         return 0;
 332 }
 333 EXPORT_SYMBOL(register_service_level);
 334
 335 int unregister_service_level(struct service_level *slr)
 336 {
 337         struct service_level *ptr, *next;
 338         int rc = -ENOENT;
 339
 340         down_write(&service_level_sem);
 341         list_for_each_entry_safe(ptr, next, &service_level_list, list) {
 342                 if (ptr != slr)
 343                         continue;
 344                 list_del(&ptr->list);
 345                 rc = 0;
 346                 break;
 347         }
 348         up_write(&service_level_sem);
 349         return rc;
 350 }
 351 EXPORT_SYMBOL(unregister_service_level);
 352
 353 static void *service_level_start(struct seq_file *m, loff_t *pos)
 354 {
 355         down_read(&service_level_sem);
 356         return seq_list_start(&service_level_list, *pos);
 357 }
 358
 359 static void *service_level_next(struct seq_file *m, void *p, loff_t *pos)
 360 {
 361         return seq_list_next(p, &service_level_list, pos);
 362 }
 363
 364 static void service_level_stop(struct seq_file *m, void *p)
 365 {
 366         up_read(&service_level_sem);
 367 }
 368
 369 static int service_level_show(struct seq_file *m, void *p)
 370 {
 371         struct service_level *slr;
 372
 373         slr = list_entry(p, struct service_level, list);
 374         slr->seq_print(m, slr);
 375         return 0;
 376 }
 377
 378 static const struct seq_operations service_level_seq_ops = {
 379         .start          = service_level_start,
 380         .next           = service_level_next,
 381         .stop           = service_level_stop,
 382         .show           = service_level_show
 383 };
 384
 385 static void service_level_vm_print(struct seq_file *m,
 386                                    struct service_level *slr)
 387 {
 388         char *query_buffer, *str;
 389
 390         query_buffer = kmalloc(1024, GFP_KERNEL | GFP_DMA);
 391         if (!query_buffer)
 392                 return;
 393         cpcmd("QUERY CPLEVEL", query_buffer, 1024, NULL);
 394         str = strchr(query_buffer, '\n');
 395         if (str)
 396                 *str = 0;
 397         seq_printf(m, "VM: %s\n", query_buffer);
 398         kfree(query_buffer);
 399 }
 400
 401 static struct service_level service_level_vm = {
 402         .seq_print = service_level_vm_print
 403 };
 404
 405 static __init int create_proc_service_level(void)
 406 {
 407         proc_create_seq("service_levels", 0, NULL, &service_level_seq_ops);
 408         if (MACHINE_IS_VM)
 409                 register_service_level(&service_level_vm);
 410         return 0;
 411 }
 412 subsys_initcall(create_proc_service_level);
 413
 414 /*
 415  * CPU capability might have changed. Therefore recalculate loops_per_jiffy.
 416  */
 417 void s390_adjust_jiffies(void)
 418 {
 419         struct sysinfo_1_2_2 *info;
 420         unsigned long capability;
 421         struct kernel_fpu fpu;
 422
 423         info = (void *) get_zeroed_page(GFP_KERNEL);
 424         if (!info)
 425                 return;
 426
 427         if (stsi(info, 1, 2, 2) == 0) {
 428                 /*
 429                  * Major sigh. The cpu capability encoding is "special".
 430                  * If the first 9 bits of info->capability are 0 then it
 431                  * is a 32 bit unsigned integer in the range 0 .. 2^23.
 432                  * If the first 9 bits are != 0 then it is a 32 bit float.
 433                  * In addition a lower value indicates a proportionally
 434                  * higher cpu capacity. Bogomips are the other way round.
 435                  * To get to a halfway suitable number we divide 1e7
 436                  * by the cpu capability number. Yes, that means a floating
 437                  * point division ..
 438                  */
 439                 kernel_fpu_begin(&fpu, KERNEL_FPR);
 440                 asm volatile(
 441                         "       sfpc    %3\n"
 442                         "       l       %0,%1\n"
 443                         "       tmlh    %0,0xff80\n"
 444                         "       jnz     0f\n"
 445                         "       cefbr   %%f2,%0\n"
 446                         "       j       1f\n"
 447                         "0:     le      %%f2,%1\n"
 448                         "1:     cefbr   %%f0,%2\n"
 449                         "       debr    %%f0,%%f2\n"
 450                         "       cgebr   %0,5,%%f0\n"
 451                         : "=&d" (capability)
 452                         : "Q" (info->capability), "d" (10000000), "d" (0)
 453                         : "cc"
 454                         );
 455                 kernel_fpu_end(&fpu, KERNEL_FPR);
 456         } else
 457                 /*
 458                  * Really old machine without stsi block for basic
 459                  * cpu information. Report 42.0 bogomips.
 460                  */
 461                 capability = 42;
 462         loops_per_jiffy = capability * (500000/HZ);
 463         free_page((unsigned long) info);
 464 }
 465
 466 /*
 467  * calibrate the delay loop
 468  */
 469 void calibrate_delay(void)
 470 {
 471         s390_adjust_jiffies();
 472         /* Print the good old Bogomips line .. */
 473         printk(KERN_DEBUG "Calibrating delay loop (skipped)... "
 474                "%lu.%02lu BogoMIPS preset\n", loops_per_jiffy/(500000/HZ),
 475                (loops_per_jiffy/(5000/HZ)) % 100);
 476 }
 477
 478 #ifdef CONFIG_DEBUG_FS
 479
 480 #define STSI_FILE(fc, s1, s2)                                                  \
 481 static int stsi_open_##fc##_##s1##_##s2(struct inode *inode, struct file *file)\
 482 {                                                                              \
 483         file->private_data = (void *) get_zeroed_page(GFP_KERNEL);             \
 484         if (!file->private_data)                                               \
 485                 return -ENOMEM;                                                \
 486         if (stsi(file->private_data, fc, s1, s2)) {                            \
 487                 free_page((unsigned long)file->private_data);                  \
 488                 file->private_data = NULL;                                     \
 489                 return -EACCES;                                                \
 490         }                                                                      \
 491         return nonseekable_open(inode, file);                                  \
 492 }                                                                              \
 493                                                                                \
 494 static const struct file_operations stsi_##fc##_##s1##_##s2##_fs_ops = {       \
 495         .open           = stsi_open_##fc##_##s1##_##s2,                        \
 496         .release        = stsi_release,                                        \
 497         .read           = stsi_read,                                           \
 498         .llseek         = no_llseek,                                           \
 499 };
 500
 501 static int stsi_release(struct inode *inode, struct file *file)
 502 {
 503         free_page((unsigned long)file->private_data);
 504         return 0;
 505 }
 506
 507 static ssize_t stsi_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 508 {
 509         return simple_read_from_buffer(buf, size, ppos, file->private_data, PAGE_SIZE);
 510 }
 511
 512 STSI_FILE( 1, 1, 1);
 513 STSI_FILE( 1, 2, 1);
 514 STSI_FILE( 1, 2, 2);
 515 STSI_FILE( 2, 2, 1);
 516 STSI_FILE( 2, 2, 2);
 517 STSI_FILE( 3, 2, 2);
 518 STSI_FILE(15, 1, 2);
 519 STSI_FILE(15, 1, 3);
 520 STSI_FILE(15, 1, 4);
 521 STSI_FILE(15, 1, 5);
 522 STSI_FILE(15, 1, 6);
 523
 524 struct stsi_file {
 525         const struct file_operations *fops;
 526         char *name;
 527 };
 528
 529 static struct stsi_file stsi_file[] __initdata = {
 530         {.fops = &stsi_1_1_1_fs_ops,  .name =  "1_1_1"},
 531         {.fops = &stsi_1_2_1_fs_ops,  .name =  "1_2_1"},
 532         {.fops = &stsi_1_2_2_fs_ops,  .name =  "1_2_2"},
 533         {.fops = &stsi_2_2_1_fs_ops,  .name =  "2_2_1"},
 534         {.fops = &stsi_2_2_2_fs_ops,  .name =  "2_2_2"},
 535         {.fops = &stsi_3_2_2_fs_ops,  .name =  "3_2_2"},
 536         {.fops = &stsi_15_1_2_fs_ops, .name = "15_1_2"},
 537         {.fops = &stsi_15_1_3_fs_ops, .name = "15_1_3"},
 538         {.fops = &stsi_15_1_4_fs_ops, .name = "15_1_4"},
 539         {.fops = &stsi_15_1_5_fs_ops, .name = "15_1_5"},
 540         {.fops = &stsi_15_1_6_fs_ops, .name = "15_1_6"},
 541 };
 542
 543 static u8 stsi_0_0_0;
 544
 545 static __init int stsi_init_debugfs(void)
 546 {
 547         struct dentry *stsi_root;
 548         struct stsi_file *sf;
 549         int lvl, i;
 550
 551         stsi_root = debugfs_create_dir("stsi", arch_debugfs_dir);
 552         lvl = stsi(NULL, 0, 0, 0);
 553         if (lvl > 0)
 554                 stsi_0_0_0 = lvl;
 555         debugfs_create_u8("0_0_0", 0400, stsi_root, &stsi_0_0_0);
 556         for (i = 0; i < ARRAY_SIZE(stsi_file); i++) {
 557                 sf = &stsi_file[i];
 558                 debugfs_create_file(sf->name, 0400, stsi_root, NULL, sf->fops);
 559         }
 560         if (IS_ENABLED(CONFIG_SCHED_TOPOLOGY) && MACHINE_HAS_TOPOLOGY) {
 561                 char link_to[10];
 562
 563                 sprintf(link_to, "15_1_%d", topology_mnest_limit());
 564                 debugfs_create_symlink("topology", stsi_root, link_to);
 565         }
 566         return 0;
 567 }
 568 device_initcall(stsi_init_debugfs);
 569
 570 #endif /* CONFIG_DEBUG_FS */