2 * arch/s390/kernel/setup.c
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)
9 * Derived from "arch/i386/kernel/setup.c"
10 * Copyright (C) 1995, Linus Torvalds
14 * This file handles the architecture-dependent parts of initialization
17 #include <linux/errno.h>
18 #include <linux/module.h>
19 #include <linux/sched.h>
20 #include <linux/kernel.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/init.h>
32 #include <linux/initrd.h>
33 #include <linux/bootmem.h>
34 #include <linux/root_dev.h>
35 #include <linux/console.h>
36 #include <linux/seq_file.h>
37 #include <linux/kernel_stat.h>
38 #include <linux/device.h>
39 #include <linux/notifier.h>
40 #include <linux/pfn.h>
41 #include <linux/ctype.h>
42 #include <linux/reboot.h>
45 #include <asm/uaccess.h>
46 #include <asm/system.h>
48 #include <asm/mmu_context.h>
49 #include <asm/cpcmd.h>
50 #include <asm/lowcore.h>
53 #include <asm/ptrace.h>
54 #include <asm/sections.h>
55 #include <asm/ebcdic.h>
56 #include <asm/compat.h>
58 long psw_kernel_bits = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
59 PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
60 long psw_user_bits = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
61 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
62 PSW_MASK_PSTATE | PSW_DEFAULT_KEY);
65 * User copy operations.
67 struct uaccess_ops uaccess;
68 EXPORT_SYMBOL_GPL(uaccess);
73 unsigned int console_mode = 0;
74 unsigned int console_devno = -1;
75 unsigned int console_irq = -1;
76 unsigned long machine_flags = 0;
78 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
79 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
80 static unsigned long __initdata memory_end;
83 * This is set up by the setup-routine at boot-time
84 * for S390 need to find out, what we have to setup
85 * using address 0x10400 ...
88 #include <asm/setup.h>
90 static struct resource code_resource = {
91 .name = "Kernel code",
92 .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
95 static struct resource data_resource = {
96 .name = "Kernel data",
97 .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
101 * cpu_init() initializes state that is per-CPU.
103 void __devinit cpu_init (void)
105 int addr = hard_smp_processor_id();
108 * Store processor id in lowcore (used e.g. in timer_interrupt)
110 get_cpu_id(&S390_lowcore.cpu_data.cpu_id);
111 S390_lowcore.cpu_data.cpu_addr = addr;
114 * Force FPU initialization:
116 clear_thread_flag(TIF_USEDFPU);
119 atomic_inc(&init_mm.mm_count);
120 current->active_mm = &init_mm;
123 enter_lazy_tlb(&init_mm, current);
127 * VM halt and poweroff setup routines
129 char vmhalt_cmd[128] = "";
130 char vmpoff_cmd[128] = "";
131 static char vmpanic_cmd[128] = "";
133 static void strncpy_skip_quote(char *dst, char *src, int n)
138 for (sx = 0; src[sx] != 0; sx++) {
139 if (src[sx] == '"') continue;
145 static int __init vmhalt_setup(char *str)
147 strncpy_skip_quote(vmhalt_cmd, str, 127);
152 __setup("vmhalt=", vmhalt_setup);
154 static int __init vmpoff_setup(char *str)
156 strncpy_skip_quote(vmpoff_cmd, str, 127);
161 __setup("vmpoff=", vmpoff_setup);
163 static int vmpanic_notify(struct notifier_block *self, unsigned long event,
166 if (MACHINE_IS_VM && strlen(vmpanic_cmd) > 0)
167 cpcmd(vmpanic_cmd, NULL, 0, NULL);
172 #define PANIC_PRI_VMPANIC 0
174 static struct notifier_block vmpanic_nb = {
175 .notifier_call = vmpanic_notify,
176 .priority = PANIC_PRI_VMPANIC
179 static int __init vmpanic_setup(char *str)
181 static int register_done __initdata = 0;
183 strncpy_skip_quote(vmpanic_cmd, str, 127);
184 vmpanic_cmd[127] = 0;
185 if (!register_done) {
187 atomic_notifier_chain_register(&panic_notifier_list,
193 __setup("vmpanic=", vmpanic_setup);
196 * condev= and conmode= setup parameter.
199 static int __init condev_setup(char *str)
203 vdev = simple_strtoul(str, &str, 0);
204 if (vdev >= 0 && vdev < 65536) {
205 console_devno = vdev;
211 __setup("condev=", condev_setup);
213 static int __init conmode_setup(char *str)
215 #if defined(CONFIG_SCLP_CONSOLE)
216 if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
219 #if defined(CONFIG_TN3215_CONSOLE)
220 if (strncmp(str, "3215", 5) == 0)
223 #if defined(CONFIG_TN3270_CONSOLE)
224 if (strncmp(str, "3270", 5) == 0)
230 __setup("conmode=", conmode_setup);
232 static void __init conmode_default(void)
234 char query_buffer[1024];
238 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
239 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
240 ptr = strstr(query_buffer, "SUBCHANNEL =");
241 console_irq = simple_strtoul(ptr + 13, NULL, 16);
242 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
243 ptr = strstr(query_buffer, "CONMODE");
245 * Set the conmode to 3215 so that the device recognition
246 * will set the cu_type of the console to 3215. If the
247 * conmode is 3270 and we don't set it back then both
248 * 3215 and the 3270 driver will try to access the console
249 * device (3215 as console and 3270 as normal tty).
251 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
253 #if defined(CONFIG_SCLP_CONSOLE)
258 if (strncmp(ptr + 8, "3270", 4) == 0) {
259 #if defined(CONFIG_TN3270_CONSOLE)
261 #elif defined(CONFIG_TN3215_CONSOLE)
263 #elif defined(CONFIG_SCLP_CONSOLE)
266 } else if (strncmp(ptr + 8, "3215", 4) == 0) {
267 #if defined(CONFIG_TN3215_CONSOLE)
269 #elif defined(CONFIG_TN3270_CONSOLE)
271 #elif defined(CONFIG_SCLP_CONSOLE)
275 } else if (MACHINE_IS_P390) {
276 #if defined(CONFIG_TN3215_CONSOLE)
278 #elif defined(CONFIG_TN3270_CONSOLE)
282 #if defined(CONFIG_SCLP_CONSOLE)
289 void (*_machine_restart)(char *command) = machine_restart_smp;
290 void (*_machine_halt)(void) = machine_halt_smp;
291 void (*_machine_power_off)(void) = machine_power_off_smp;
294 * Reboot, halt and power_off routines for non SMP.
296 static void do_machine_restart_nonsmp(char * __unused)
301 static void do_machine_halt_nonsmp(void)
303 if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
304 __cpcmd(vmhalt_cmd, NULL, 0, NULL);
305 signal_processor(smp_processor_id(), sigp_stop_and_store_status);
308 static void do_machine_power_off_nonsmp(void)
310 if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
311 __cpcmd(vmpoff_cmd, NULL, 0, NULL);
312 signal_processor(smp_processor_id(), sigp_stop_and_store_status);
315 void (*_machine_restart)(char *command) = do_machine_restart_nonsmp;
316 void (*_machine_halt)(void) = do_machine_halt_nonsmp;
317 void (*_machine_power_off)(void) = do_machine_power_off_nonsmp;
321 * Reboot, halt and power_off stubs. They just call _machine_restart,
322 * _machine_halt or _machine_power_off.
325 void machine_restart(char *command)
327 if (!in_interrupt() || oops_in_progress)
329 * Only unblank the console if we are called in enabled
330 * context or a bust_spinlocks cleared the way for us.
333 _machine_restart(command);
336 void machine_halt(void)
338 if (!in_interrupt() || oops_in_progress)
340 * Only unblank the console if we are called in enabled
341 * context or a bust_spinlocks cleared the way for us.
347 void machine_power_off(void)
349 if (!in_interrupt() || oops_in_progress)
351 * Only unblank the console if we are called in enabled
352 * context or a bust_spinlocks cleared the way for us.
355 _machine_power_off();
359 * Dummy power off function.
361 void (*pm_power_off)(void) = machine_power_off;
363 static int __init early_parse_mem(char *p)
365 memory_end = memparse(p, &p);
368 early_param("mem", early_parse_mem);
371 * "ipldelay=XXX[sm]" sets ipl delay in seconds or minutes
373 static int __init early_parse_ipldelay(char *p)
375 unsigned long delay = 0;
377 delay = simple_strtoul(p, &p, 0);
386 delay *= 60 * 1000000;
389 /* now wait for the requested amount of time */
394 early_param("ipldelay", early_parse_ipldelay);
396 #ifdef CONFIG_S390_SWITCH_AMODE
397 unsigned int switch_amode = 0;
398 EXPORT_SYMBOL_GPL(switch_amode);
400 static void set_amode_and_uaccess(unsigned long user_amode,
401 unsigned long user32_amode)
403 psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
404 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
405 PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
407 psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
408 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
409 PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
410 psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
411 PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
414 psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
415 PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
417 if (MACHINE_HAS_MVCOS) {
418 printk("mvcos available.\n");
419 memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
421 printk("mvcos not available.\n");
422 memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
427 * Switch kernel/user addressing modes?
429 static int __init early_parse_switch_amode(char *p)
434 early_param("switch_amode", early_parse_switch_amode);
436 #else /* CONFIG_S390_SWITCH_AMODE */
437 static inline void set_amode_and_uaccess(unsigned long user_amode,
438 unsigned long user32_amode)
441 #endif /* CONFIG_S390_SWITCH_AMODE */
443 #ifdef CONFIG_S390_EXEC_PROTECT
444 unsigned int s390_noexec = 0;
445 EXPORT_SYMBOL_GPL(s390_noexec);
448 * Enable execute protection?
450 static int __init early_parse_noexec(char *p)
452 if (!strncmp(p, "off", 3))
458 early_param("noexec", early_parse_noexec);
459 #endif /* CONFIG_S390_EXEC_PROTECT */
461 static void setup_addressing_mode(void)
464 printk("S390 execute protection active, ");
465 set_amode_and_uaccess(PSW_ASC_SECONDARY, PSW32_ASC_SECONDARY);
469 printk("S390 address spaces switched, ");
470 set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY);
481 * Setup lowcore for boot cpu
483 lc_pages = sizeof(void *) == 8 ? 2 : 1;
484 lc = (struct _lowcore *)
485 __alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
486 memset(lc, 0, lc_pages * PAGE_SIZE);
487 lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
488 lc->restart_psw.addr =
489 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
491 lc->restart_psw.mask |= PSW_ASC_HOME;
492 lc->external_new_psw.mask = psw_kernel_bits;
493 lc->external_new_psw.addr =
494 PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
495 lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
496 lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
497 lc->program_new_psw.mask = psw_kernel_bits;
498 lc->program_new_psw.addr =
499 PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
500 lc->mcck_new_psw.mask =
501 psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
502 lc->mcck_new_psw.addr =
503 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
504 lc->io_new_psw.mask = psw_kernel_bits;
505 lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
506 lc->ipl_device = S390_lowcore.ipl_device;
507 lc->jiffy_timer = -1LL;
508 lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
509 lc->async_stack = (unsigned long)
510 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
511 lc->panic_stack = (unsigned long)
512 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
513 lc->current_task = (unsigned long) init_thread_union.thread_info.task;
514 lc->thread_info = (unsigned long) &init_thread_union;
516 if (MACHINE_HAS_IEEE) {
517 lc->extended_save_area_addr = (__u32)
518 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
519 /* enable extended save area */
520 __ctl_set_bit(14, 29);
523 set_prefix((u32)(unsigned long) lc);
527 setup_resources(void)
529 struct resource *res, *sub_res;
532 code_resource.start = (unsigned long) &_text;
533 code_resource.end = (unsigned long) &_etext - 1;
534 data_resource.start = (unsigned long) &_etext;
535 data_resource.end = (unsigned long) &_edata - 1;
537 for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
538 res = alloc_bootmem_low(sizeof(struct resource));
539 res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
540 switch (memory_chunk[i].type) {
541 case CHUNK_READ_WRITE:
542 res->name = "System RAM";
544 case CHUNK_READ_ONLY:
545 res->name = "System ROM";
546 res->flags |= IORESOURCE_READONLY;
549 res->name = "reserved";
551 res->start = memory_chunk[i].addr;
552 res->end = memory_chunk[i].addr + memory_chunk[i].size - 1;
553 request_resource(&iomem_resource, res);
555 if (code_resource.start >= res->start &&
556 code_resource.start <= res->end &&
557 code_resource.end > res->end) {
558 sub_res = alloc_bootmem_low(sizeof(struct resource));
559 memcpy(sub_res, &code_resource,
560 sizeof(struct resource));
561 sub_res->end = res->end;
562 code_resource.start = res->end + 1;
563 request_resource(res, sub_res);
566 if (code_resource.start >= res->start &&
567 code_resource.start <= res->end &&
568 code_resource.end <= res->end)
569 request_resource(res, &code_resource);
571 if (data_resource.start >= res->start &&
572 data_resource.start <= res->end &&
573 data_resource.end > res->end) {
574 sub_res = alloc_bootmem_low(sizeof(struct resource));
575 memcpy(sub_res, &data_resource,
576 sizeof(struct resource));
577 sub_res->end = res->end;
578 data_resource.start = res->end + 1;
579 request_resource(res, sub_res);
582 if (data_resource.start >= res->start &&
583 data_resource.start <= res->end &&
584 data_resource.end <= res->end)
585 request_resource(res, &data_resource);
589 static void __init setup_memory_end(void)
591 unsigned long real_size, memory_size;
592 unsigned long max_mem, max_phys;
595 memory_size = real_size = 0;
596 max_phys = VMALLOC_END_INIT - VMALLOC_MIN_SIZE;
597 memory_end &= PAGE_MASK;
599 max_mem = memory_end ? min(max_phys, memory_end) : max_phys;
601 for (i = 0; i < MEMORY_CHUNKS; i++) {
602 struct mem_chunk *chunk = &memory_chunk[i];
604 real_size = max(real_size, chunk->addr + chunk->size);
605 if (chunk->addr >= max_mem) {
606 memset(chunk, 0, sizeof(*chunk));
609 if (chunk->addr + chunk->size > max_mem)
610 chunk->size = max_mem - chunk->addr;
611 memory_size = max(memory_size, chunk->addr + chunk->size);
614 memory_end = memory_size;
620 unsigned long bootmap_size;
621 unsigned long start_pfn, end_pfn;
625 * partially used pages are not usable - thus
626 * we are rounding upwards:
628 start_pfn = PFN_UP(__pa(&_end));
629 end_pfn = max_pfn = PFN_DOWN(memory_end);
631 #ifdef CONFIG_BLK_DEV_INITRD
633 * Move the initrd in case the bitmap of the bootmem allocater
634 * would overwrite it.
637 if (INITRD_START && INITRD_SIZE) {
638 unsigned long bmap_size;
641 bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
642 bmap_size = PFN_PHYS(bmap_size);
644 if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
645 start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
647 if (start + INITRD_SIZE > memory_end) {
648 printk("initrd extends beyond end of memory "
649 "(0x%08lx > 0x%08lx)\n"
650 "disabling initrd\n",
651 start + INITRD_SIZE, memory_end);
652 INITRD_START = INITRD_SIZE = 0;
654 printk("Moving initrd (0x%08lx -> 0x%08lx, "
656 INITRD_START, start, INITRD_SIZE);
657 memmove((void *) start, (void *) INITRD_START,
659 INITRD_START = start;
666 * Initialize the boot-time allocator
668 bootmap_size = init_bootmem(start_pfn, end_pfn);
671 * Register RAM areas with the bootmem allocator.
674 for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
675 unsigned long start_chunk, end_chunk, pfn;
677 if (memory_chunk[i].type != CHUNK_READ_WRITE)
679 start_chunk = PFN_DOWN(memory_chunk[i].addr);
680 end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size) - 1;
681 end_chunk = min(end_chunk, end_pfn);
682 if (start_chunk >= end_chunk)
684 add_active_range(0, start_chunk, end_chunk);
685 pfn = max(start_chunk, start_pfn);
686 for (; pfn <= end_chunk; pfn++)
687 page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
690 psw_set_key(PAGE_DEFAULT_KEY);
692 free_bootmem_with_active_regions(0, max_pfn);
693 reserve_bootmem(0, PFN_PHYS(start_pfn));
696 * Reserve the bootmem bitmap itself as well. We do this in two
697 * steps (first step was init_bootmem()) because this catches
698 * the (very unlikely) case of us accidentally initializing the
699 * bootmem allocator with an invalid RAM area.
701 reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size);
703 #ifdef CONFIG_BLK_DEV_INITRD
704 if (INITRD_START && INITRD_SIZE) {
705 if (INITRD_START + INITRD_SIZE <= memory_end) {
706 reserve_bootmem(INITRD_START, INITRD_SIZE);
707 initrd_start = INITRD_START;
708 initrd_end = initrd_start + INITRD_SIZE;
710 printk("initrd extends beyond end of memory "
711 "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
712 initrd_start + INITRD_SIZE, memory_end);
713 initrd_start = initrd_end = 0;
720 * Setup function called from init/main.c just after the banner
725 setup_arch(char **cmdline_p)
728 * print what head.S has found out about the machine
731 printk((MACHINE_IS_VM) ?
732 "We are running under VM (31 bit mode)\n" :
733 "We are running native (31 bit mode)\n");
734 printk((MACHINE_HAS_IEEE) ?
735 "This machine has an IEEE fpu\n" :
736 "This machine has no IEEE fpu\n");
737 #else /* CONFIG_64BIT */
738 printk((MACHINE_IS_VM) ?
739 "We are running under VM (64 bit mode)\n" :
740 "We are running native (64 bit mode)\n");
741 #endif /* CONFIG_64BIT */
743 /* Save unparsed command line copy for /proc/cmdline */
744 strlcpy(boot_command_line, COMMAND_LINE, COMMAND_LINE_SIZE);
746 *cmdline_p = COMMAND_LINE;
747 *(*cmdline_p + COMMAND_LINE_SIZE - 1) = '\0';
749 ROOT_DEV = Root_RAM0;
751 init_mm.start_code = PAGE_OFFSET;
752 init_mm.end_code = (unsigned long) &_etext;
753 init_mm.end_data = (unsigned long) &_edata;
754 init_mm.brk = (unsigned long) &_end;
756 if (MACHINE_HAS_MVCOS)
757 memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
759 memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
764 setup_addressing_mode();
770 __cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
771 smp_setup_cpu_possible_map();
774 * Create kernel page tables and switch to virtual addressing.
778 /* Setup default console */
782 void print_cpu_info(struct cpuinfo_S390 *cpuinfo)
788 "vers=%02X ident=%06X machine=%04X unused=%04X\n",
793 cpuinfo->cpu_id.version,
794 cpuinfo->cpu_id.ident,
795 cpuinfo->cpu_id.machine,
796 cpuinfo->cpu_id.unused);
800 * show_cpuinfo - Get information on one CPU for use by procfs.
803 static int show_cpuinfo(struct seq_file *m, void *v)
805 struct cpuinfo_S390 *cpuinfo;
806 unsigned long n = (unsigned long) v - 1;
808 s390_adjust_jiffies();
811 seq_printf(m, "vendor_id : IBM/S390\n"
812 "# processors : %i\n"
813 "bogomips per cpu: %lu.%02lu\n",
814 num_online_cpus(), loops_per_jiffy/(500000/HZ),
815 (loops_per_jiffy/(5000/HZ))%100);
819 if (smp_processor_id() == n)
820 cpuinfo = &S390_lowcore.cpu_data;
822 cpuinfo = &lowcore_ptr[n]->cpu_data;
824 cpuinfo = &S390_lowcore.cpu_data;
826 seq_printf(m, "processor %li: "
828 "identification = %06X, "
830 n, cpuinfo->cpu_id.version,
831 cpuinfo->cpu_id.ident,
832 cpuinfo->cpu_id.machine);
838 static void *c_start(struct seq_file *m, loff_t *pos)
840 return *pos < NR_CPUS ? (void *)((unsigned long) *pos + 1) : NULL;
842 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
845 return c_start(m, pos);
847 static void c_stop(struct seq_file *m, void *v)
850 struct seq_operations cpuinfo_op = {
854 .show = show_cpuinfo,