arch/s390/kernel/setup.c

   1 /*
   2  *  arch/s390/kernel/setup.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Hartmut Penner (hp@de.ibm.com),
   7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8  *
   9  *  Derived from "arch/i386/kernel/setup.c"
  10  *    Copyright (C) 1995, Linus Torvalds
  11  */
  12
  13 /*
  14  * This file handles the architecture-dependent parts of initialization
  15  */
  16
  17 #include <linux/errno.h>
  18 #include <linux/module.h>
  19 #include <linux/sched.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mm.h>
  22 #include <linux/stddef.h>
  23 #include <linux/unistd.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/slab.h>
  26 #include <linux/user.h>
  27 #include <linux/a.out.h>
  28 #include <linux/tty.h>
  29 #include <linux/ioport.h>
  30 #include <linux/delay.h>
  31 #include <linux/config.h>
  32 #include <linux/init.h>
  33 #include <linux/initrd.h>
  34 #include <linux/bootmem.h>
  35 #include <linux/root_dev.h>
  36 #include <linux/console.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/kernel_stat.h>
  39
  40 #include <asm/uaccess.h>
  41 #include <asm/system.h>
  42 #include <asm/smp.h>
  43 #include <asm/mmu_context.h>
  44 #include <asm/cpcmd.h>
  45 #include <asm/lowcore.h>
  46 #include <asm/irq.h>
  47
  48 /*
  49  * Machine setup..
  50  */
  51 unsigned int console_mode = 0;
  52 unsigned int console_device = -1;
  53 unsigned int console_irq = -1;
  54 unsigned long memory_size = 0;
  55 unsigned long machine_flags = 0;
  56 struct { unsigned long addr, size, type; } memory_chunk[16] = { { 0 } };
  57 #define CHUNK_READ_WRITE 0
  58 #define CHUNK_READ_ONLY 1
  59 int cpus_initialized = 0;
  60 static cpumask_t cpu_initialized;
  61 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
  62
  63 /*
  64  * Setup options
  65  */
  66 extern int _text,_etext, _edata, _end;
  67
  68 /*
  69  * This is set up by the setup-routine at boot-time
  70  * for S390 need to find out, what we have to setup
  71  * using address 0x10400 ...
  72  */
  73
  74 #include <asm/setup.h>
  75
  76 static char command_line[COMMAND_LINE_SIZE] = { 0, };
  77        char saved_command_line[COMMAND_LINE_SIZE];
  78
  79 static struct resource code_resource = { "Kernel code", 0x100000, 0 };
  80 static struct resource data_resource = { "Kernel data", 0, 0 };
  81
  82 /*
  83  * cpu_init() initializes state that is per-CPU.
  84  */
  85 void __devinit cpu_init (void)
  86 {
  87         int nr = smp_processor_id();
  88         int addr = hard_smp_processor_id();
  89
  90         if (cpu_test_and_set(nr,cpu_initialized)) {
  91                 printk("CPU#%d ALREADY INITIALIZED!!!!!!!!!\n", nr);
  92                 for (;;) local_irq_enable();
  93         }
  94         cpus_initialized++;
  95
  96         /*
  97          * Store processor id in lowcore (used e.g. in timer_interrupt)
  98          */
  99         asm volatile ("stidp %0": "=m" (S390_lowcore.cpu_data.cpu_id));
 100         S390_lowcore.cpu_data.cpu_addr = addr;
 101
 102         /*
 103          * Force FPU initialization:
 104          */
 105         clear_thread_flag(TIF_USEDFPU);
 106         current->used_math = 0;
 107
 108         /* Setup active_mm for idle_task  */
 109         atomic_inc(&init_mm.mm_count);
 110         current->active_mm = &init_mm;
 111         if (current->mm)
 112                 BUG();
 113         enter_lazy_tlb(&init_mm, current);
 114 }
 115
 116 /*
 117  * VM halt and poweroff setup routines
 118  */
 119 char vmhalt_cmd[128] = "";
 120 char vmpoff_cmd[128] = "";
 121
 122 static inline void strncpy_skip_quote(char *dst, char *src, int n)
 123 {
 124         int sx, dx;
 125
 126         dx = 0;
 127         for (sx = 0; src[sx] != 0; sx++) {
 128                 if (src[sx] == '"') continue;
 129                 dst[dx++] = src[sx];
 130                 if (dx >= n) break;
 131         }
 132 }
 133
 134 static int __init vmhalt_setup(char *str)
 135 {
 136         strncpy_skip_quote(vmhalt_cmd, str, 127);
 137         vmhalt_cmd[127] = 0;
 138         return 1;
 139 }
 140
 141 __setup("vmhalt=", vmhalt_setup);
 142
 143 static int __init vmpoff_setup(char *str)
 144 {
 145         strncpy_skip_quote(vmpoff_cmd, str, 127);
 146         vmpoff_cmd[127] = 0;
 147         return 1;
 148 }
 149
 150 __setup("vmpoff=", vmpoff_setup);
 151
 152 /*
 153  * condev= and conmode= setup parameter.
 154  */
 155
 156 static int __init condev_setup(char *str)
 157 {
 158         int vdev;
 159
 160         vdev = simple_strtoul(str, &str, 0);
 161         if (vdev >= 0 && vdev < 65536) {
 162                 console_device = vdev;
 163                 console_irq = -1;
 164         }
 165         return 1;
 166 }
 167
 168 __setup("condev=", condev_setup);
 169
 170 static int __init conmode_setup(char *str)
 171 {
 172 #if defined(CONFIG_SCLP_CONSOLE)
 173         if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
 174                 SET_CONSOLE_SCLP;
 175 #endif
 176 #if defined(CONFIG_TN3215_CONSOLE)
 177         if (strncmp(str, "3215", 5) == 0)
 178                 SET_CONSOLE_3215;
 179 #endif
 180 #if defined(CONFIG_TN3270_CONSOLE)
 181         if (strncmp(str, "3270", 5) == 0)
 182                 SET_CONSOLE_3270;
 183 #endif
 184         return 1;
 185 }
 186
 187 __setup("conmode=", conmode_setup);
 188
 189 static void __init conmode_default(void)
 190 {
 191         char query_buffer[1024];
 192         char *ptr;
 193
 194         if (MACHINE_IS_VM) {
 195                 cpcmd("QUERY CONSOLE", query_buffer, 1024);
 196                 console_device = simple_strtoul(query_buffer + 5, NULL, 16);
 197                 ptr = strstr(query_buffer, "SUBCHANNEL =");
 198                 console_irq = simple_strtoul(ptr + 13, NULL, 16);
 199                 cpcmd("QUERY TERM", query_buffer, 1024);
 200                 ptr = strstr(query_buffer, "CONMODE");
 201                 /*
 202                  * Set the conmode to 3215 so that the device recognition
 203                  * will set the cu_type of the console to 3215. If the
 204                  * conmode is 3270 and we don't set it back then both
 205                  * 3215 and the 3270 driver will try to access the console
 206                  * device (3215 as console and 3270 as normal tty).
 207                  */
 208                 cpcmd("TERM CONMODE 3215", NULL, 0);
 209                 if (ptr == NULL) {
 210 #if defined(CONFIG_SCLP_CONSOLE)
 211                         SET_CONSOLE_SCLP;
 212 #endif
 213                         return;
 214                 }
 215                 if (strncmp(ptr + 8, "3270", 4) == 0) {
 216 #if defined(CONFIG_TN3270_CONSOLE)
 217                         SET_CONSOLE_3270;
 218 #elif defined(CONFIG_TN3215_CONSOLE)
 219                         SET_CONSOLE_3215;
 220 #elif defined(CONFIG_SCLP_CONSOLE)
 221                         SET_CONSOLE_SCLP;
 222 #endif
 223                 } else if (strncmp(ptr + 8, "3215", 4) == 0) {
 224 #if defined(CONFIG_TN3215_CONSOLE)
 225                         SET_CONSOLE_3215;
 226 #elif defined(CONFIG_TN3270_CONSOLE)
 227                         SET_CONSOLE_3270;
 228 #elif defined(CONFIG_SCLP_CONSOLE)
 229                         SET_CONSOLE_SCLP;
 230 #endif
 231                 }
 232         } else if (MACHINE_IS_P390) {
 233 #if defined(CONFIG_TN3215_CONSOLE)
 234                 SET_CONSOLE_3215;
 235 #elif defined(CONFIG_TN3270_CONSOLE)
 236                 SET_CONSOLE_3270;
 237 #endif
 238         } else {
 239 #if defined(CONFIG_SCLP_CONSOLE)
 240                 SET_CONSOLE_SCLP;
 241 #endif
 242         }
 243 }
 244
 245 #ifdef CONFIG_SMP
 246 extern void machine_restart_smp(char *);
 247 extern void machine_halt_smp(void);
 248 extern void machine_power_off_smp(void);
 249
 250 void (*_machine_restart)(char *command) = machine_restart_smp;
 251 void (*_machine_halt)(void) = machine_halt_smp;
 252 void (*_machine_power_off)(void) = machine_power_off_smp;
 253 #else
 254 /*
 255  * Reboot, halt and power_off routines for non SMP.
 256  */
 257 extern void reipl(unsigned long devno);
 258 static void do_machine_restart_nonsmp(char * __unused)
 259 {
 260         if (MACHINE_IS_VM)
 261                 cpcmd ("IPL", NULL, 0);
 262         else
 263                 reipl (0x10000 | S390_lowcore.ipl_device);
 264 }
 265
 266 static void do_machine_halt_nonsmp(void)
 267 {
 268         if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
 269                 cpcmd(vmhalt_cmd, NULL, 0);
 270         signal_processor(smp_processor_id(), sigp_stop_and_store_status);
 271 }
 272
 273 static void do_machine_power_off_nonsmp(void)
 274 {
 275         if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
 276                 cpcmd(vmpoff_cmd, NULL, 0);
 277         signal_processor(smp_processor_id(), sigp_stop_and_store_status);
 278 }
 279
 280 void (*_machine_restart)(char *command) = do_machine_restart_nonsmp;
 281 void (*_machine_halt)(void) = do_machine_halt_nonsmp;
 282 void (*_machine_power_off)(void) = do_machine_power_off_nonsmp;
 283 #endif
 284
 285  /*
 286  * Reboot, halt and power_off stubs. They just call _machine_restart,
 287  * _machine_halt or _machine_power_off.
 288  */
 289
 290 void machine_restart(char *command)
 291 {
 292         console_unblank();
 293         _machine_restart(command);
 294 }
 295
 296 EXPORT_SYMBOL(machine_restart);
 297
 298 void machine_halt(void)
 299 {
 300         console_unblank();
 301         _machine_halt();
 302 }
 303
 304 EXPORT_SYMBOL(machine_halt);
 305
 306 void machine_power_off(void)
 307 {
 308         console_unblank();
 309         _machine_power_off();
 310 }
 311
 312 EXPORT_SYMBOL(machine_power_off);
 313
 314 /*
 315  * Setup function called from init/main.c just after the banner
 316  * was printed.
 317  */
 318 extern char _pstart, _pend, _stext;
 319
 320 void __init setup_arch(char **cmdline_p)
 321 {
 322         unsigned long bootmap_size;
 323         unsigned long memory_start, memory_end;
 324         char c = ' ', cn, *to = command_line, *from = COMMAND_LINE;
 325         struct resource *res;
 326         unsigned long start_pfn, end_pfn;
 327         static unsigned int smptrap=0;
 328         unsigned long delay = 0;
 329         struct _lowcore *lc;
 330         int i;
 331
 332         if (smptrap)
 333                 return;
 334         smptrap=1;
 335
 336         /*
 337          * print what head.S has found out about the machine
 338          */
 339 #ifndef CONFIG_ARCH_S390X
 340         printk((MACHINE_IS_VM) ?
 341                "We are running under VM (31 bit mode)\n" :
 342                "We are running native (31 bit mode)\n");
 343         printk((MACHINE_HAS_IEEE) ?
 344                "This machine has an IEEE fpu\n" :
 345                "This machine has no IEEE fpu\n");
 346 #else /* CONFIG_ARCH_S390X */
 347         printk((MACHINE_IS_VM) ?
 348                "We are running under VM (64 bit mode)\n" :
 349                "We are running native (64 bit mode)\n");
 350 #endif /* CONFIG_ARCH_S390X */
 351
 352         ROOT_DEV = Root_RAM0;
 353         memory_start = (unsigned long) &_end;    /* fixit if use $CODELO etc*/
 354 #ifndef CONFIG_ARCH_S390X
 355         memory_end = memory_size & ~0x400000UL;  /* align memory end to 4MB */
 356         /*
 357          * We need some free virtual space to be able to do vmalloc.
 358          * On a machine with 2GB memory we make sure that we have at
 359          * least 128 MB free space for vmalloc.
 360          */
 361         if (memory_end > 1920*1024*1024)
 362                 memory_end = 1920*1024*1024;
 363 #else /* CONFIG_ARCH_S390X */
 364         memory_end = memory_size & ~0x200000UL;  /* detected in head.s */
 365 #endif /* CONFIG_ARCH_S390X */
 366         init_mm.start_code = PAGE_OFFSET;
 367         init_mm.end_code = (unsigned long) &_etext;
 368         init_mm.end_data = (unsigned long) &_edata;
 369         init_mm.brk = (unsigned long) &_end;
 370
 371         code_resource.start = (unsigned long) &_text;
 372         code_resource.end = (unsigned long) &_etext - 1;
 373         data_resource.start = (unsigned long) &_etext;
 374         data_resource.end = (unsigned long) &_edata - 1;
 375
 376         /* Save unparsed command line copy for /proc/cmdline */
 377         memcpy(saved_command_line, COMMAND_LINE, COMMAND_LINE_SIZE);
 378         saved_command_line[COMMAND_LINE_SIZE-1] = '\0';
 379
 380         for (;;) {
 381                 /*
 382                  * "mem=XXX[kKmM]" sets memsize
 383                  */
 384                 if (c == ' ' && strncmp(from, "mem=", 4) == 0) {
 385                         memory_end = simple_strtoul(from+4, &from, 0);
 386                         if ( *from == 'K' || *from == 'k' ) {
 387                                 memory_end = memory_end << 10;
 388                                 from++;
 389                         } else if ( *from == 'M' || *from == 'm' ) {
 390                                 memory_end = memory_end << 20;
 391                                 from++;
 392                         }
 393                 }
 394                 /*
 395                  * "ipldelay=XXX[sm]" sets ipl delay in seconds or minutes
 396                  */
 397                 if (c == ' ' && strncmp(from, "ipldelay=", 9) == 0) {
 398                         delay = simple_strtoul(from+9, &from, 0);
 399                         if (*from == 's' || *from == 'S') {
 400                                 delay = delay*1000000;
 401                                 from++;
 402                         } else if (*from == 'm' || *from == 'M') {
 403                                 delay = delay*60*1000000;
 404                                 from++;
 405                         }
 406                         /* now wait for the requested amount of time */
 407                         udelay(delay);
 408                 }
 409                 cn = *(from++);
 410                 if (!cn)
 411                         break;
 412                 if (cn == '\n')
 413                         cn = ' ';  /* replace newlines with space */
 414                 if (cn == 0x0d)
 415                         cn = ' ';  /* replace 0x0d with space */
 416                 if (cn == ' ' && c == ' ')
 417                         continue;  /* remove additional spaces */
 418                 c = cn;
 419                 if (to - command_line >= COMMAND_LINE_SIZE)
 420                         break;
 421                 *(to++) = c;
 422         }
 423         if (c == ' ' && to > command_line) to--;
 424         *to = '\0';
 425         *cmdline_p = command_line;
 426
 427         /*
 428          * partially used pages are not usable - thus
 429          * we are rounding upwards:
 430          */
 431         start_pfn = (__pa(&_end) + PAGE_SIZE - 1) >> PAGE_SHIFT;
 432         end_pfn = max_pfn = memory_end >> PAGE_SHIFT;
 433
 434         /*
 435          * Initialize the boot-time allocator (with low memory only):
 436          */
 437         bootmap_size = init_bootmem(start_pfn, end_pfn);
 438
 439         /*
 440          * Register RAM areas with the bootmem allocator.
 441          */
 442         for (i = 0; i < 16 && memory_chunk[i].size > 0; i++) {
 443                 unsigned long start_chunk, end_chunk;
 444
 445                 if (memory_chunk[i].type != CHUNK_READ_WRITE)
 446                         continue;
 447                 start_chunk = (memory_chunk[i].addr + PAGE_SIZE - 1);
 448                 start_chunk >>= PAGE_SHIFT;
 449                 end_chunk = (memory_chunk[i].addr + memory_chunk[i].size);
 450                 end_chunk >>= PAGE_SHIFT;
 451                 if (start_chunk < start_pfn)
 452                         start_chunk = start_pfn;
 453                 if (end_chunk > end_pfn)
 454                         end_chunk = end_pfn;
 455                 if (start_chunk < end_chunk)
 456                         free_bootmem(start_chunk << PAGE_SHIFT,
 457                                      (end_chunk - start_chunk) << PAGE_SHIFT);
 458         }
 459
 460         /*
 461          * Reserve the bootmem bitmap itself as well. We do this in two
 462          * steps (first step was init_bootmem()) because this catches
 463          * the (very unlikely) case of us accidentally initializing the
 464          * bootmem allocator with an invalid RAM area.
 465          */
 466         reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size);
 467
 468 #ifdef CONFIG_BLK_DEV_INITRD
 469         if (INITRD_START) {
 470                 if (INITRD_START + INITRD_SIZE <= memory_end) {
 471                         reserve_bootmem(INITRD_START, INITRD_SIZE);
 472                         initrd_start = INITRD_START;
 473                         initrd_end = initrd_start + INITRD_SIZE;
 474                 } else {
 475                         printk("initrd extends beyond end of memory "
 476                                "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
 477                                initrd_start + INITRD_SIZE, memory_end);
 478                         initrd_start = initrd_end = 0;
 479                 }
 480         }
 481 #endif
 482
 483         /*
 484          * Setup lowcore for boot cpu
 485          */
 486 #ifndef CONFIG_ARCH_S390X
 487         lc = (struct _lowcore *) __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
 488         memset(lc, 0, PAGE_SIZE);
 489 #else /* CONFIG_ARCH_S390X */
 490         lc = (struct _lowcore *) __alloc_bootmem(2*PAGE_SIZE, 2*PAGE_SIZE, 0);
 491         memset(lc, 0, 2*PAGE_SIZE);
 492 #endif /* CONFIG_ARCH_S390X */
 493         lc->restart_psw.mask = PSW_BASE_BITS;
 494         lc->restart_psw.addr =
 495                 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
 496         lc->external_new_psw.mask = PSW_KERNEL_BITS;
 497         lc->external_new_psw.addr =
 498                 PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
 499         lc->svc_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | PSW_MASK_EXT;
 500         lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
 501         lc->program_new_psw.mask = PSW_KERNEL_BITS;
 502         lc->program_new_psw.addr =
 503                 PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
 504         lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
 505         lc->mcck_new_psw.addr =
 506                 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
 507         lc->io_new_psw.mask = PSW_KERNEL_BITS;
 508         lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
 509         lc->ipl_device = S390_lowcore.ipl_device;
 510         lc->jiffy_timer = -1LL;
 511         lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
 512         lc->async_stack = (unsigned long)
 513                 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
 514         lc->current_task = (unsigned long) init_thread_union.thread_info.task;
 515         lc->thread_info = (unsigned long) &init_thread_union;
 516 #ifdef CONFIG_ARCH_S390X
 517         if (MACHINE_HAS_DIAG44)
 518                 lc->diag44_opcode = 0x83000044;
 519         else
 520                 lc->diag44_opcode = 0x07000700;
 521 #endif /* CONFIG_ARCH_S390X */
 522         set_prefix((u32)(unsigned long) lc);
 523         cpu_init();
 524         __cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
 525
 526         /*
 527          * Create kernel page tables and switch to virtual addressing.
 528          */
 529         paging_init();
 530
 531         res = alloc_bootmem_low(sizeof(struct resource));
 532         res->start = 0;
 533         res->end = memory_end;
 534         res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 535         request_resource(&iomem_resource, res);
 536         request_resource(res, &code_resource);
 537         request_resource(res, &data_resource);
 538
 539         /* Setup default console */
 540         conmode_default();
 541 }
 542
 543 void print_cpu_info(struct cpuinfo_S390 *cpuinfo)
 544 {
 545    printk("cpu %d "
 546 #ifdef CONFIG_SMP
 547            "phys_idx=%d "
 548 #endif
 549            "vers=%02X ident=%06X machine=%04X unused=%04X\n",
 550            cpuinfo->cpu_nr,
 551 #ifdef CONFIG_SMP
 552            cpuinfo->cpu_addr,
 553 #endif
 554            cpuinfo->cpu_id.version,
 555            cpuinfo->cpu_id.ident,
 556            cpuinfo->cpu_id.machine,
 557            cpuinfo->cpu_id.unused);
 558 }
 559
 560 /*
 561  * show_cpuinfo - Get information on one CPU for use by procfs.
 562  */
 563
 564 static int show_cpuinfo(struct seq_file *m, void *v)
 565 {
 566         struct cpuinfo_S390 *cpuinfo;
 567         unsigned long n = (unsigned long) v - 1;
 568
 569         if (!n) {
 570                 seq_printf(m, "vendor_id       : IBM/S390\n"
 571                                "# processors    : %i\n"
 572                                "bogomips per cpu: %lu.%02lu\n",
 573                                num_online_cpus(), loops_per_jiffy/(500000/HZ),
 574                                (loops_per_jiffy/(5000/HZ))%100);
 575         }
 576         if (cpu_online(n)) {
 577 #ifdef CONFIG_SMP
 578                 if (smp_processor_id() == n)
 579                         cpuinfo = &S390_lowcore.cpu_data;
 580                 else
 581                         cpuinfo = &lowcore_ptr[n]->cpu_data;
 582 #else
 583                 cpuinfo = &S390_lowcore.cpu_data;
 584 #endif
 585                 seq_printf(m, "processor %li: "
 586                                "version = %02X,  "
 587                                "identification = %06X,  "
 588                                "machine = %04X\n",
 589                                n, cpuinfo->cpu_id.version,
 590                                cpuinfo->cpu_id.ident,
 591                                cpuinfo->cpu_id.machine);
 592         }
 593         return 0;
 594 }
 595
 596 static void *c_start(struct seq_file *m, loff_t *pos)
 597 {
 598         return *pos < NR_CPUS ? (void *)((unsigned long) *pos + 1) : NULL;
 599 }
 600 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 601 {
 602         ++*pos;
 603         return c_start(m, pos);
 604 }
 605 static void c_stop(struct seq_file *m, void *v)
 606 {
 607 }
 608 struct seq_operations cpuinfo_op = {
 609         .start  = c_start,
 610         .next   = c_next,
 611         .stop   = c_stop,
 612         .show   = show_cpuinfo,
 613 };
 614
 615 /*
 616  * show_interrupts is needed by /proc/interrupts.
 617  */
 618
 619 static const char *intrclass_names[] = {
 620         "EXT",
 621         "I/O",
 622 };
 623
 624 int show_interrupts(struct seq_file *p, void *v)
 625 {
 626         int i = *(loff_t *) v, j;
 627
 628         if (i == 0) {
 629                 seq_puts(p, "           ");
 630                 for (j=0; j<NR_CPUS; j++)
 631                         if (cpu_online(j))
 632                                 seq_printf(p, "CPU%d       ",j);
 633                 seq_putc(p, '\n');
 634         }
 635
 636         if (i < NR_IRQS) {
 637                 seq_printf(p, "%s: ", intrclass_names[i]);
 638 #ifndef CONFIG_SMP
 639                 seq_printf(p, "%10u ", kstat_irqs(i));
 640 #else
 641                 for (j = 0; j < NR_CPUS; j++)
 642                         if (cpu_online(j))
 643                                 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 644 #endif
 645                 seq_putc(p, '\n');
 646
 647         }
 648
 649         return 0;
 650 }