arch/sh/kernel/setup.c

   1 /*
   2  * arch/sh/kernel/setup.c
   3  *
   4  * This file handles the architecture-dependent parts of initialization
   5  *
   6  *  Copyright (C) 1999  Niibe Yutaka
   7  *  Copyright (C) 2002 - 2007 Paul Mundt
   8  */
   9 #include <linux/screen_info.h>
  10 #include <linux/ioport.h>
  11 #include <linux/init.h>
  12 #include <linux/initrd.h>
  13 #include <linux/bootmem.h>
  14 #include <linux/console.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/root_dev.h>
  17 #include <linux/utsname.h>
  18 #include <linux/nodemask.h>
  19 #include <linux/cpu.h>
  20 #include <linux/pfn.h>
  21 #include <linux/fs.h>
  22 #include <linux/mm.h>
  23 #include <linux/kexec.h>
  24 #include <linux/module.h>
  25 #include <linux/smp.h>
  26 #include <linux/err.h>
  27 #include <linux/debugfs.h>
  28 #include <linux/crash_dump.h>
  29 #include <linux/mmzone.h>
  30 #include <linux/clk.h>
  31 #include <linux/delay.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/lmb.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/io.h>
  36 #include <asm/page.h>
  37 #include <asm/elf.h>
  38 #include <asm/sections.h>
  39 #include <asm/irq.h>
  40 #include <asm/setup.h>
  41 #include <asm/clock.h>
  42 #include <asm/mmu_context.h>
  43
  44 /*
  45  * Initialize loops_per_jiffy as 10000000 (1000MIPS).
  46  * This value will be used at the very early stage of serial setup.
  47  * The bigger value means no problem.
  48  */
  49 struct sh_cpuinfo cpu_data[NR_CPUS] __read_mostly = {
  50         [0] = {
  51                 .type                   = CPU_SH_NONE,
  52                 .loops_per_jiffy        = 10000000,
  53         },
  54 };
  55 EXPORT_SYMBOL(cpu_data);
  56
  57 /*
  58  * The machine vector. First entry in .machvec.init, or clobbered by
  59  * sh_mv= on the command line, prior to .machvec.init teardown.
  60  */
  61 struct sh_machine_vector sh_mv = { .mv_name = "generic", };
  62 EXPORT_SYMBOL(sh_mv);
  63
  64 #ifdef CONFIG_VT
  65 struct screen_info screen_info;
  66 #endif
  67
  68 extern int root_mountflags;
  69
  70 #define RAMDISK_IMAGE_START_MASK        0x07FF
  71 #define RAMDISK_PROMPT_FLAG             0x8000
  72 #define RAMDISK_LOAD_FLAG               0x4000
  73
  74 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0, };
  75
  76 static struct resource code_resource = {
  77         .name = "Kernel code",
  78         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
  79 };
  80
  81 static struct resource data_resource = {
  82         .name = "Kernel data",
  83         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
  84 };
  85
  86 static struct resource bss_resource = {
  87         .name   = "Kernel bss",
  88         .flags  = IORESOURCE_BUSY | IORESOURCE_MEM,
  89 };
  90
  91 unsigned long memory_start;
  92 EXPORT_SYMBOL(memory_start);
  93 unsigned long memory_end = 0;
  94 EXPORT_SYMBOL(memory_end);
  95
  96 static struct resource mem_resources[MAX_NUMNODES];
  97
  98 int l1i_cache_shape, l1d_cache_shape, l2_cache_shape;
  99
 100 static int __init early_parse_mem(char *p)
 101 {
 102         unsigned long size;
 103
 104         memory_start = (unsigned long)__va(__MEMORY_START);
 105         size = memparse(p, &p);
 106
 107         if (size > __MEMORY_SIZE) {
 108                 printk(KERN_ERR
 109                         "Using mem= to increase the size of kernel memory "
 110                         "is not allowed.\n"
 111                         "  Recompile the kernel with the correct value for "
 112                         "CONFIG_MEMORY_SIZE.\n");
 113                 return 0;
 114         }
 115
 116         memory_end = memory_start + size;
 117
 118         return 0;
 119 }
 120 early_param("mem", early_parse_mem);
 121
 122 /*
 123  * Register fully available low RAM pages with the bootmem allocator.
 124  */
 125 static void __init register_bootmem_low_pages(void)
 126 {
 127         unsigned long curr_pfn, last_pfn, pages;
 128
 129         /*
 130          * We are rounding up the start address of usable memory:
 131          */
 132         curr_pfn = PFN_UP(__MEMORY_START);
 133
 134         /*
 135          * ... and at the end of the usable range downwards:
 136          */
 137         last_pfn = PFN_DOWN(__pa(memory_end));
 138
 139         if (last_pfn > max_low_pfn)
 140                 last_pfn = max_low_pfn;
 141
 142         pages = last_pfn - curr_pfn;
 143         free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(pages));
 144 }
 145
 146 #ifdef CONFIG_KEXEC
 147 static void __init reserve_crashkernel(void)
 148 {
 149         unsigned long long free_mem;
 150         unsigned long long crash_size, crash_base;
 151         void *vp;
 152         int ret;
 153
 154         free_mem = ((unsigned long long)max_low_pfn - min_low_pfn) << PAGE_SHIFT;
 155
 156         ret = parse_crashkernel(boot_command_line, free_mem,
 157                         &crash_size, &crash_base);
 158         if (ret == 0 && crash_size) {
 159                 if (crash_base <= 0) {
 160                         vp = alloc_bootmem_nopanic(crash_size);
 161                         if (!vp) {
 162                                 printk(KERN_INFO "crashkernel allocation "
 163                                        "failed\n");
 164                                 return;
 165                         }
 166                         crash_base = __pa(vp);
 167                 } else if (reserve_bootmem(crash_base, crash_size,
 168                                         BOOTMEM_EXCLUSIVE) < 0) {
 169                         printk(KERN_INFO "crashkernel reservation failed - "
 170                                         "memory is in use\n");
 171                         return;
 172                 }
 173
 174                 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 175                                 "for crashkernel (System RAM: %ldMB)\n",
 176                                 (unsigned long)(crash_size >> 20),
 177                                 (unsigned long)(crash_base >> 20),
 178                                 (unsigned long)(free_mem >> 20));
 179                 crashk_res.start = crash_base;
 180                 crashk_res.end   = crash_base + crash_size - 1;
 181                 insert_resource(&iomem_resource, &crashk_res);
 182         }
 183 }
 184 #else
 185 static inline void __init reserve_crashkernel(void)
 186 {}
 187 #endif
 188
 189 void __cpuinit calibrate_delay(void)
 190 {
 191         struct clk *clk = clk_get(NULL, "cpu_clk");
 192
 193         if (IS_ERR(clk))
 194                 panic("Need a sane CPU clock definition!");
 195
 196         loops_per_jiffy = (clk_get_rate(clk) >> 1) / HZ;
 197
 198         printk(KERN_INFO "Calibrating delay loop (skipped)... "
 199                          "%lu.%02lu BogoMIPS PRESET (lpj=%lu)\n",
 200                          loops_per_jiffy/(500000/HZ),
 201                          (loops_per_jiffy/(5000/HZ)) % 100,
 202                          loops_per_jiffy);
 203 }
 204
 205 void __init __add_active_range(unsigned int nid, unsigned long start_pfn,
 206                                                 unsigned long end_pfn)
 207 {
 208         struct resource *res = &mem_resources[nid];
 209
 210         WARN_ON(res->name); /* max one active range per node for now */
 211
 212         res->name = "System RAM";
 213         res->start = start_pfn << PAGE_SHIFT;
 214         res->end = (end_pfn << PAGE_SHIFT) - 1;
 215         res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 216         if (request_resource(&iomem_resource, res)) {
 217                 pr_err("unable to request memory_resource 0x%lx 0x%lx\n",
 218                        start_pfn, end_pfn);
 219                 return;
 220         }
 221
 222         /*
 223          *  We don't know which RAM region contains kernel data,
 224          *  so we try it repeatedly and let the resource manager
 225          *  test it.
 226          */
 227         request_resource(res, &code_resource);
 228         request_resource(res, &data_resource);
 229         request_resource(res, &bss_resource);
 230
 231         add_active_range(nid, start_pfn, end_pfn);
 232 }
 233
 234 void __init setup_bootmem_allocator(unsigned long free_pfn)
 235 {
 236         unsigned long bootmap_size;
 237         unsigned long bootmap_pages, bootmem_paddr;
 238         u64 total_pages = (lmb_end_of_DRAM() - __MEMORY_START) >> PAGE_SHIFT;
 239         int i;
 240
 241         bootmap_pages = bootmem_bootmap_pages(total_pages);
 242
 243         bootmem_paddr = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 244
 245         /*
 246          * Find a proper area for the bootmem bitmap. After this
 247          * bootstrap step all allocations (until the page allocator
 248          * is intact) must be done via bootmem_alloc().
 249          */
 250         bootmap_size = init_bootmem_node(NODE_DATA(0),
 251                                          bootmem_paddr >> PAGE_SHIFT,
 252                                          min_low_pfn, max_low_pfn);
 253
 254         /* Add active regions with valid PFNs. */
 255         for (i = 0; i < lmb.memory.cnt; i++) {
 256                 unsigned long start_pfn, end_pfn;
 257                 start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
 258                 end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
 259                 __add_active_range(0, start_pfn, end_pfn);
 260         }
 261
 262         /*
 263          * Add all physical memory to the bootmem map and mark each
 264          * area as present.
 265          */
 266         register_bootmem_low_pages();
 267
 268         /* Reserve the sections we're already using. */
 269         for (i = 0; i < lmb.reserved.cnt; i++)
 270                 reserve_bootmem(lmb.reserved.region[i].base,
 271                                 lmb_size_bytes(&lmb.reserved, i),
 272                                 BOOTMEM_DEFAULT);
 273
 274         node_set_online(0);
 275
 276         sparse_memory_present_with_active_regions(0);
 277
 278 #ifdef CONFIG_BLK_DEV_INITRD
 279         ROOT_DEV = Root_RAM0;
 280
 281         if (LOADER_TYPE && INITRD_START) {
 282                 unsigned long initrd_start_phys = INITRD_START + __MEMORY_START;
 283
 284                 if (initrd_start_phys + INITRD_SIZE <= PFN_PHYS(max_low_pfn)) {
 285                         reserve_bootmem(initrd_start_phys, INITRD_SIZE,
 286                                         BOOTMEM_DEFAULT);
 287                         initrd_start = (unsigned long)__va(initrd_start_phys);
 288                         initrd_end = initrd_start + INITRD_SIZE;
 289                 } else {
 290                         printk("initrd extends beyond end of memory "
 291                                "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
 292                                initrd_start_phys + INITRD_SIZE,
 293                                (unsigned long)PFN_PHYS(max_low_pfn));
 294                         initrd_start = 0;
 295                 }
 296         }
 297 #endif
 298
 299         reserve_crashkernel();
 300 }
 301
 302 #ifndef CONFIG_NEED_MULTIPLE_NODES
 303 static void __init setup_memory(void)
 304 {
 305         unsigned long start_pfn;
 306         u64 base = min_low_pfn << PAGE_SHIFT;
 307         u64 size = (max_low_pfn << PAGE_SHIFT) - base;
 308
 309         /*
 310          * Partially used pages are not usable - thus
 311          * we are rounding upwards:
 312          */
 313         start_pfn = PFN_UP(__pa(_end));
 314
 315         lmb_add(base, size);
 316
 317         /*
 318          * Reserve the kernel text and
 319          * Reserve the bootmem bitmap. We do this in two steps (first step
 320          * was init_bootmem()), because this catches the (definitely buggy)
 321          * case of us accidentally initializing the bootmem allocator with
 322          * an invalid RAM area.
 323          */
 324         lmb_reserve(__MEMORY_START + CONFIG_ZERO_PAGE_OFFSET,
 325                     (PFN_PHYS(start_pfn) + PAGE_SIZE - 1) -
 326                     (__MEMORY_START + CONFIG_ZERO_PAGE_OFFSET));
 327
 328         /*
 329          * Reserve physical pages below CONFIG_ZERO_PAGE_OFFSET.
 330          */
 331         if (CONFIG_ZERO_PAGE_OFFSET != 0)
 332                 lmb_reserve(__MEMORY_START, CONFIG_ZERO_PAGE_OFFSET);
 333
 334         lmb_analyze();
 335         lmb_dump_all();
 336
 337         setup_bootmem_allocator(start_pfn);
 338 }
 339 #else
 340 extern void __init setup_memory(void);
 341 #endif
 342
 343 /*
 344  * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
 345  * is_kdump_kernel() to determine if we are booting after a panic. Hence
 346  * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
 347  */
 348 #ifdef CONFIG_CRASH_DUMP
 349 /* elfcorehdr= specifies the location of elf core header
 350  * stored by the crashed kernel.
 351  */
 352 static int __init parse_elfcorehdr(char *arg)
 353 {
 354         if (!arg)
 355                 return -EINVAL;
 356         elfcorehdr_addr = memparse(arg, &arg);
 357         return 0;
 358 }
 359 early_param("elfcorehdr", parse_elfcorehdr);
 360 #endif
 361
 362 void __init __attribute__ ((weak)) plat_early_device_setup(void)
 363 {
 364 }
 365
 366 void __init setup_arch(char **cmdline_p)
 367 {
 368         enable_mmu();
 369
 370         ROOT_DEV = old_decode_dev(ORIG_ROOT_DEV);
 371
 372         printk(KERN_NOTICE "Boot params:\n"
 373                            "... MOUNT_ROOT_RDONLY - %08lx\n"
 374                            "... RAMDISK_FLAGS     - %08lx\n"
 375                            "... ORIG_ROOT_DEV     - %08lx\n"
 376                            "... LOADER_TYPE       - %08lx\n"
 377                            "... INITRD_START      - %08lx\n"
 378                            "... INITRD_SIZE       - %08lx\n",
 379                            MOUNT_ROOT_RDONLY, RAMDISK_FLAGS,
 380                            ORIG_ROOT_DEV, LOADER_TYPE,
 381                            INITRD_START, INITRD_SIZE);
 382
 383 #ifdef CONFIG_BLK_DEV_RAM
 384         rd_image_start = RAMDISK_FLAGS & RAMDISK_IMAGE_START_MASK;
 385         rd_prompt = ((RAMDISK_FLAGS & RAMDISK_PROMPT_FLAG) != 0);
 386         rd_doload = ((RAMDISK_FLAGS & RAMDISK_LOAD_FLAG) != 0);
 387 #endif
 388
 389         if (!MOUNT_ROOT_RDONLY)
 390                 root_mountflags &= ~MS_RDONLY;
 391         init_mm.start_code = (unsigned long) _text;
 392         init_mm.end_code = (unsigned long) _etext;
 393         init_mm.end_data = (unsigned long) _edata;
 394         init_mm.brk = (unsigned long) _end;
 395
 396         code_resource.start = virt_to_phys(_text);
 397         code_resource.end = virt_to_phys(_etext)-1;
 398         data_resource.start = virt_to_phys(_etext);
 399         data_resource.end = virt_to_phys(_edata)-1;
 400         bss_resource.start = virt_to_phys(__bss_start);
 401         bss_resource.end = virt_to_phys(_ebss)-1;
 402
 403         memory_start = (unsigned long)__va(__MEMORY_START);
 404         if (!memory_end)
 405                 memory_end = memory_start + __MEMORY_SIZE;
 406
 407 #ifdef CONFIG_CMDLINE_BOOL
 408         strlcpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
 409 #else
 410         strlcpy(command_line, COMMAND_LINE, sizeof(command_line));
 411 #endif
 412
 413         /* Save unparsed command line copy for /proc/cmdline */
 414         memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 415         *cmdline_p = command_line;
 416
 417         parse_early_param();
 418
 419         plat_early_device_setup();
 420
 421         sh_mv_setup();
 422
 423         /*
 424          * Find the highest page frame number we have available
 425          */
 426         max_pfn = PFN_DOWN(__pa(memory_end));
 427
 428         /*
 429          * Determine low and high memory ranges:
 430          */
 431         max_low_pfn = max_pfn;
 432         min_low_pfn = __MEMORY_START >> PAGE_SHIFT;
 433
 434         nodes_clear(node_online_map);
 435
 436         /* Setup bootmem with available RAM */
 437         lmb_init();
 438         setup_memory();
 439         sparse_init();
 440
 441 #ifdef CONFIG_DUMMY_CONSOLE
 442         conswitchp = &dummy_con;
 443 #endif
 444
 445         /* Perform the machine specific initialisation */
 446         if (likely(sh_mv.mv_setup))
 447                 sh_mv.mv_setup(cmdline_p);
 448
 449         paging_init();
 450
 451 #ifdef CONFIG_SMP
 452         plat_smp_setup();
 453 #endif
 454 }
 455
 456 /* processor boot mode configuration */
 457 int generic_mode_pins(void)
 458 {
 459         pr_warning("generic_mode_pins(): missing mode pin configuration\n");
 460         return 0;
 461 }
 462
 463 int test_mode_pin(int pin)
 464 {
 465         return sh_mv.mv_mode_pins() & pin;
 466 }
 467
 468 static const char *cpu_name[] = {
 469         [CPU_SH7201]    = "SH7201",
 470         [CPU_SH7203]    = "SH7203",     [CPU_SH7263]    = "SH7263",
 471         [CPU_SH7206]    = "SH7206",     [CPU_SH7619]    = "SH7619",
 472         [CPU_SH7705]    = "SH7705",     [CPU_SH7706]    = "SH7706",
 473         [CPU_SH7707]    = "SH7707",     [CPU_SH7708]    = "SH7708",
 474         [CPU_SH7709]    = "SH7709",     [CPU_SH7710]    = "SH7710",
 475         [CPU_SH7712]    = "SH7712",     [CPU_SH7720]    = "SH7720",
 476         [CPU_SH7721]    = "SH7721",     [CPU_SH7729]    = "SH7729",
 477         [CPU_SH7750]    = "SH7750",     [CPU_SH7750S]   = "SH7750S",
 478         [CPU_SH7750R]   = "SH7750R",    [CPU_SH7751]    = "SH7751",
 479         [CPU_SH7751R]   = "SH7751R",    [CPU_SH7760]    = "SH7760",
 480         [CPU_SH4_202]   = "SH4-202",    [CPU_SH4_501]   = "SH4-501",
 481         [CPU_SH7763]    = "SH7763",     [CPU_SH7770]    = "SH7770",
 482         [CPU_SH7780]    = "SH7780",     [CPU_SH7781]    = "SH7781",
 483         [CPU_SH7343]    = "SH7343",     [CPU_SH7785]    = "SH7785",
 484         [CPU_SH7786]    = "SH7786",
 485         [CPU_SH7722]    = "SH7722",     [CPU_SHX3]      = "SH-X3",
 486         [CPU_SH5_101]   = "SH5-101",    [CPU_SH5_103]   = "SH5-103",
 487         [CPU_MXG]       = "MX-G",       [CPU_SH7723]    = "SH7723",
 488         [CPU_SH7366]    = "SH7366",     [CPU_SH7724]    = "SH7724",
 489         [CPU_SH_NONE]   = "Unknown"
 490 };
 491
 492 const char *get_cpu_subtype(struct sh_cpuinfo *c)
 493 {
 494         return cpu_name[c->type];
 495 }
 496 EXPORT_SYMBOL(get_cpu_subtype);
 497
 498 #ifdef CONFIG_PROC_FS
 499 /* Symbolic CPU flags, keep in sync with asm/cpu-features.h */
 500 static const char *cpu_flags[] = {
 501         "none", "fpu", "p2flush", "mmuassoc", "dsp", "perfctr",
 502         "ptea", "llsc", "l2", "op32", "pteaex", NULL
 503 };
 504
 505 static void show_cpuflags(struct seq_file *m, struct sh_cpuinfo *c)
 506 {
 507         unsigned long i;
 508
 509         seq_printf(m, "cpu flags\t:");
 510
 511         if (!c->flags) {
 512                 seq_printf(m, " %s\n", cpu_flags[0]);
 513                 return;
 514         }
 515
 516         for (i = 0; cpu_flags[i]; i++)
 517                 if ((c->flags & (1 << i)))
 518                         seq_printf(m, " %s", cpu_flags[i+1]);
 519
 520         seq_printf(m, "\n");
 521 }
 522
 523 static void show_cacheinfo(struct seq_file *m, const char *type,
 524                            struct cache_info info)
 525 {
 526         unsigned int cache_size;
 527
 528         cache_size = info.ways * info.sets * info.linesz;
 529
 530         seq_printf(m, "%s size\t: %2dKiB (%d-way)\n",
 531                    type, cache_size >> 10, info.ways);
 532 }
 533
 534 /*
 535  *      Get CPU information for use by the procfs.
 536  */
 537 static int show_cpuinfo(struct seq_file *m, void *v)
 538 {
 539         struct sh_cpuinfo *c = v;
 540         unsigned int cpu = c - cpu_data;
 541
 542         if (!cpu_online(cpu))
 543                 return 0;
 544
 545         if (cpu == 0)
 546                 seq_printf(m, "machine\t\t: %s\n", get_system_type());
 547
 548         seq_printf(m, "processor\t: %d\n", cpu);
 549         seq_printf(m, "cpu family\t: %s\n", init_utsname()->machine);
 550         seq_printf(m, "cpu type\t: %s\n", get_cpu_subtype(c));
 551         if (c->cut_major == -1)
 552                 seq_printf(m, "cut\t\t: unknown\n");
 553         else if (c->cut_minor == -1)
 554                 seq_printf(m, "cut\t\t: %d.x\n", c->cut_major);
 555         else
 556                 seq_printf(m, "cut\t\t: %d.%d\n", c->cut_major, c->cut_minor);
 557
 558         show_cpuflags(m, c);
 559
 560         seq_printf(m, "cache type\t: ");
 561
 562         /*
 563          * Check for what type of cache we have, we support both the
 564          * unified cache on the SH-2 and SH-3, as well as the harvard
 565          * style cache on the SH-4.
 566          */
 567         if (c->icache.flags & SH_CACHE_COMBINED) {
 568                 seq_printf(m, "unified\n");
 569                 show_cacheinfo(m, "cache", c->icache);
 570         } else {
 571                 seq_printf(m, "split (harvard)\n");
 572                 show_cacheinfo(m, "icache", c->icache);
 573                 show_cacheinfo(m, "dcache", c->dcache);
 574         }
 575
 576         /* Optional secondary cache */
 577         if (c->flags & CPU_HAS_L2_CACHE)
 578                 show_cacheinfo(m, "scache", c->scache);
 579
 580         seq_printf(m, "bogomips\t: %lu.%02lu\n",
 581                      c->loops_per_jiffy/(500000/HZ),
 582                      (c->loops_per_jiffy/(5000/HZ)) % 100);
 583
 584         return 0;
 585 }
 586
 587 static void *c_start(struct seq_file *m, loff_t *pos)
 588 {
 589         return *pos < NR_CPUS ? cpu_data + *pos : NULL;
 590 }
 591 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 592 {
 593         ++*pos;
 594         return c_start(m, pos);
 595 }
 596 static void c_stop(struct seq_file *m, void *v)
 597 {
 598 }
 599 const struct seq_operations cpuinfo_op = {
 600         .start  = c_start,
 601         .next   = c_next,
 602         .stop   = c_stop,
 603         .show   = show_cpuinfo,
 604 };
 605 #endif /* CONFIG_PROC_FS */
 606
 607 struct dentry *sh_debugfs_root;
 608
 609 static int __init sh_debugfs_init(void)
 610 {
 611         sh_debugfs_root = debugfs_create_dir("sh", NULL);
 612         if (!sh_debugfs_root)
 613                 return -ENOMEM;
 614         if (IS_ERR(sh_debugfs_root))
 615                 return PTR_ERR(sh_debugfs_root);
 616
 617         return 0;
 618 }
 619 arch_initcall(sh_debugfs_init);