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>
44 #include <asm/uaccess.h>
45 #include <asm/system.h>
47 #include <asm/mmu_context.h>
48 #include <asm/cpcmd.h>
49 #include <asm/lowcore.h>
52 #include <asm/ptrace.h>
53 #include <asm/sections.h>
54 #include <asm/ebcdic.h>
55 #include <asm/compat.h>
57 long psw_kernel_bits = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
58 PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
59 long psw_user_bits = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
60 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
61 PSW_MASK_PSTATE | PSW_DEFAULT_KEY);
64 * User copy operations.
66 struct uaccess_ops uaccess;
67 EXPORT_SYMBOL_GPL(uaccess);
72 unsigned int console_mode = 0;
73 unsigned int console_devno = -1;
74 unsigned int console_irq = -1;
75 unsigned long machine_flags = 0;
77 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
78 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
79 static unsigned long __initdata memory_end;
82 * This is set up by the setup-routine at boot-time
83 * for S390 need to find out, what we have to setup
84 * using address 0x10400 ...
87 #include <asm/setup.h>
89 static struct resource code_resource = {
90 .name = "Kernel code",
91 .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
94 static struct resource data_resource = {
95 .name = "Kernel data",
96 .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
100 * cpu_init() initializes state that is per-CPU.
102 void __devinit cpu_init (void)
104 int addr = hard_smp_processor_id();
107 * Store processor id in lowcore (used e.g. in timer_interrupt)
109 asm volatile("stidp %0": "=m" (S390_lowcore.cpu_data.cpu_id));
110 S390_lowcore.cpu_data.cpu_addr = addr;
113 * Force FPU initialization:
115 clear_thread_flag(TIF_USEDFPU);
118 atomic_inc(&init_mm.mm_count);
119 current->active_mm = &init_mm;
122 enter_lazy_tlb(&init_mm, current);
126 * VM halt and poweroff setup routines
128 char vmhalt_cmd[128] = "";
129 char vmpoff_cmd[128] = "";
130 static char vmpanic_cmd[128] = "";
132 static void strncpy_skip_quote(char *dst, char *src, int n)
137 for (sx = 0; src[sx] != 0; sx++) {
138 if (src[sx] == '"') continue;
144 static int __init vmhalt_setup(char *str)
146 strncpy_skip_quote(vmhalt_cmd, str, 127);
151 __setup("vmhalt=", vmhalt_setup);
153 static int __init vmpoff_setup(char *str)
155 strncpy_skip_quote(vmpoff_cmd, str, 127);
160 __setup("vmpoff=", vmpoff_setup);
162 static int vmpanic_notify(struct notifier_block *self, unsigned long event,
165 if (MACHINE_IS_VM && strlen(vmpanic_cmd) > 0)
166 cpcmd(vmpanic_cmd, NULL, 0, NULL);
171 #define PANIC_PRI_VMPANIC 0
173 static struct notifier_block vmpanic_nb = {
174 .notifier_call = vmpanic_notify,
175 .priority = PANIC_PRI_VMPANIC
178 static int __init vmpanic_setup(char *str)
180 static int register_done __initdata = 0;
182 strncpy_skip_quote(vmpanic_cmd, str, 127);
183 vmpanic_cmd[127] = 0;
184 if (!register_done) {
186 atomic_notifier_chain_register(&panic_notifier_list,
192 __setup("vmpanic=", vmpanic_setup);
195 * condev= and conmode= setup parameter.
198 static int __init condev_setup(char *str)
202 vdev = simple_strtoul(str, &str, 0);
203 if (vdev >= 0 && vdev < 65536) {
204 console_devno = vdev;
210 __setup("condev=", condev_setup);
212 static int __init conmode_setup(char *str)
214 #if defined(CONFIG_SCLP_CONSOLE)
215 if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
218 #if defined(CONFIG_TN3215_CONSOLE)
219 if (strncmp(str, "3215", 5) == 0)
222 #if defined(CONFIG_TN3270_CONSOLE)
223 if (strncmp(str, "3270", 5) == 0)
229 __setup("conmode=", conmode_setup);
231 static void __init conmode_default(void)
233 char query_buffer[1024];
237 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
238 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
239 ptr = strstr(query_buffer, "SUBCHANNEL =");
240 console_irq = simple_strtoul(ptr + 13, NULL, 16);
241 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
242 ptr = strstr(query_buffer, "CONMODE");
244 * Set the conmode to 3215 so that the device recognition
245 * will set the cu_type of the console to 3215. If the
246 * conmode is 3270 and we don't set it back then both
247 * 3215 and the 3270 driver will try to access the console
248 * device (3215 as console and 3270 as normal tty).
250 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
252 #if defined(CONFIG_SCLP_CONSOLE)
257 if (strncmp(ptr + 8, "3270", 4) == 0) {
258 #if defined(CONFIG_TN3270_CONSOLE)
260 #elif defined(CONFIG_TN3215_CONSOLE)
262 #elif defined(CONFIG_SCLP_CONSOLE)
265 } else if (strncmp(ptr + 8, "3215", 4) == 0) {
266 #if defined(CONFIG_TN3215_CONSOLE)
268 #elif defined(CONFIG_TN3270_CONSOLE)
270 #elif defined(CONFIG_SCLP_CONSOLE)
274 } else if (MACHINE_IS_P390) {
275 #if defined(CONFIG_TN3215_CONSOLE)
277 #elif defined(CONFIG_TN3270_CONSOLE)
281 #if defined(CONFIG_SCLP_CONSOLE)
288 void (*_machine_restart)(char *command) = machine_restart_smp;
289 void (*_machine_halt)(void) = machine_halt_smp;
290 void (*_machine_power_off)(void) = machine_power_off_smp;
293 * Reboot, halt and power_off routines for non SMP.
295 static void do_machine_restart_nonsmp(char * __unused)
300 static void do_machine_halt_nonsmp(void)
302 if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
303 __cpcmd(vmhalt_cmd, NULL, 0, NULL);
304 signal_processor(smp_processor_id(), sigp_stop_and_store_status);
307 static void do_machine_power_off_nonsmp(void)
309 if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
310 __cpcmd(vmpoff_cmd, NULL, 0, NULL);
311 signal_processor(smp_processor_id(), sigp_stop_and_store_status);
314 void (*_machine_restart)(char *command) = do_machine_restart_nonsmp;
315 void (*_machine_halt)(void) = do_machine_halt_nonsmp;
316 void (*_machine_power_off)(void) = do_machine_power_off_nonsmp;
320 * Reboot, halt and power_off stubs. They just call _machine_restart,
321 * _machine_halt or _machine_power_off.
324 void machine_restart(char *command)
326 if (!in_interrupt() || oops_in_progress)
328 * Only unblank the console if we are called in enabled
329 * context or a bust_spinlocks cleared the way for us.
332 _machine_restart(command);
335 void machine_halt(void)
337 if (!in_interrupt() || oops_in_progress)
339 * Only unblank the console if we are called in enabled
340 * context or a bust_spinlocks cleared the way for us.
346 void machine_power_off(void)
348 if (!in_interrupt() || oops_in_progress)
350 * Only unblank the console if we are called in enabled
351 * context or a bust_spinlocks cleared the way for us.
354 _machine_power_off();
358 * Dummy power off function.
360 void (*pm_power_off)(void) = machine_power_off;
362 static int __init early_parse_mem(char *p)
364 memory_end = memparse(p, &p);
367 early_param("mem", early_parse_mem);
370 * "ipldelay=XXX[sm]" sets ipl delay in seconds or minutes
372 static int __init early_parse_ipldelay(char *p)
374 unsigned long delay = 0;
376 delay = simple_strtoul(p, &p, 0);
385 delay *= 60 * 1000000;
388 /* now wait for the requested amount of time */
393 early_param("ipldelay", early_parse_ipldelay);
395 #ifdef CONFIG_S390_SWITCH_AMODE
396 unsigned int switch_amode = 0;
397 EXPORT_SYMBOL_GPL(switch_amode);
399 static void set_amode_and_uaccess(unsigned long user_amode,
400 unsigned long user32_amode)
402 psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
403 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
404 PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
406 psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
407 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
408 PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
409 psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
410 PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
413 psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
414 PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
416 if (MACHINE_HAS_MVCOS) {
417 printk("mvcos available.\n");
418 memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
420 printk("mvcos not available.\n");
421 memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
426 * Switch kernel/user addressing modes?
428 static int __init early_parse_switch_amode(char *p)
433 early_param("switch_amode", early_parse_switch_amode);
435 #else /* CONFIG_S390_SWITCH_AMODE */
436 static inline void set_amode_and_uaccess(unsigned long user_amode,
437 unsigned long user32_amode)
440 #endif /* CONFIG_S390_SWITCH_AMODE */
442 #ifdef CONFIG_S390_EXEC_PROTECT
443 unsigned int s390_noexec = 0;
444 EXPORT_SYMBOL_GPL(s390_noexec);
447 * Enable execute protection?
449 static int __init early_parse_noexec(char *p)
451 if (!strncmp(p, "off", 3))
457 early_param("noexec", early_parse_noexec);
458 #endif /* CONFIG_S390_EXEC_PROTECT */
460 static void setup_addressing_mode(void)
463 printk("S390 execute protection active, ");
464 set_amode_and_uaccess(PSW_ASC_SECONDARY, PSW32_ASC_SECONDARY);
468 printk("S390 address spaces switched, ");
469 set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY);
480 * Setup lowcore for boot cpu
482 lc_pages = sizeof(void *) == 8 ? 2 : 1;
483 lc = (struct _lowcore *)
484 __alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
485 memset(lc, 0, lc_pages * PAGE_SIZE);
486 lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
487 lc->restart_psw.addr =
488 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
490 lc->restart_psw.mask |= PSW_ASC_HOME;
491 lc->external_new_psw.mask = psw_kernel_bits;
492 lc->external_new_psw.addr =
493 PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
494 lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
495 lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
496 lc->program_new_psw.mask = psw_kernel_bits;
497 lc->program_new_psw.addr =
498 PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
499 lc->mcck_new_psw.mask =
500 psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
501 lc->mcck_new_psw.addr =
502 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
503 lc->io_new_psw.mask = psw_kernel_bits;
504 lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
505 lc->ipl_device = S390_lowcore.ipl_device;
506 lc->jiffy_timer = -1LL;
507 lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
508 lc->async_stack = (unsigned long)
509 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
510 lc->panic_stack = (unsigned long)
511 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
512 lc->current_task = (unsigned long) init_thread_union.thread_info.task;
513 lc->thread_info = (unsigned long) &init_thread_union;
515 if (MACHINE_HAS_IEEE) {
516 lc->extended_save_area_addr = (__u32)
517 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
518 /* enable extended save area */
519 __ctl_set_bit(14, 29);
522 set_prefix((u32)(unsigned long) lc);
526 setup_resources(void)
528 struct resource *res, *sub_res;
531 code_resource.start = (unsigned long) &_text;
532 code_resource.end = (unsigned long) &_etext - 1;
533 data_resource.start = (unsigned long) &_etext;
534 data_resource.end = (unsigned long) &_edata - 1;
536 for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
537 res = alloc_bootmem_low(sizeof(struct resource));
538 res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
539 switch (memory_chunk[i].type) {
540 case CHUNK_READ_WRITE:
541 res->name = "System RAM";
543 case CHUNK_READ_ONLY:
544 res->name = "System ROM";
545 res->flags |= IORESOURCE_READONLY;
548 res->name = "reserved";
550 res->start = memory_chunk[i].addr;
551 res->end = memory_chunk[i].addr + memory_chunk[i].size - 1;
552 request_resource(&iomem_resource, res);
554 if (code_resource.start >= res->start &&
555 code_resource.start <= res->end &&
556 code_resource.end > res->end) {
557 sub_res = alloc_bootmem_low(sizeof(struct resource));
558 memcpy(sub_res, &code_resource,
559 sizeof(struct resource));
560 sub_res->end = res->end;
561 code_resource.start = res->end + 1;
562 request_resource(res, sub_res);
565 if (code_resource.start >= res->start &&
566 code_resource.start <= res->end &&
567 code_resource.end <= res->end)
568 request_resource(res, &code_resource);
570 if (data_resource.start >= res->start &&
571 data_resource.start <= res->end &&
572 data_resource.end > res->end) {
573 sub_res = alloc_bootmem_low(sizeof(struct resource));
574 memcpy(sub_res, &data_resource,
575 sizeof(struct resource));
576 sub_res->end = res->end;
577 data_resource.start = res->end + 1;
578 request_resource(res, sub_res);
581 if (data_resource.start >= res->start &&
582 data_resource.start <= res->end &&
583 data_resource.end <= res->end)
584 request_resource(res, &data_resource);
588 static void __init setup_memory_end(void)
590 unsigned long real_size, memory_size;
591 unsigned long max_mem, max_phys;
594 memory_size = real_size = 0;
595 max_phys = VMALLOC_END_INIT - VMALLOC_MIN_SIZE;
596 memory_end &= PAGE_MASK;
598 max_mem = memory_end ? min(max_phys, memory_end) : max_phys;
600 for (i = 0; i < MEMORY_CHUNKS; i++) {
601 struct mem_chunk *chunk = &memory_chunk[i];
603 real_size = max(real_size, chunk->addr + chunk->size);
604 if (chunk->addr >= max_mem) {
605 memset(chunk, 0, sizeof(*chunk));
608 if (chunk->addr + chunk->size > max_mem)
609 chunk->size = max_mem - chunk->addr;
610 memory_size = max(memory_size, chunk->addr + chunk->size);
613 memory_end = memory_size;
619 unsigned long bootmap_size;
620 unsigned long start_pfn, end_pfn;
624 * partially used pages are not usable - thus
625 * we are rounding upwards:
627 start_pfn = PFN_UP(__pa(&_end));
628 end_pfn = max_pfn = PFN_DOWN(memory_end);
630 #ifdef CONFIG_BLK_DEV_INITRD
632 * Move the initrd in case the bitmap of the bootmem allocater
633 * would overwrite it.
636 if (INITRD_START && INITRD_SIZE) {
637 unsigned long bmap_size;
640 bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
641 bmap_size = PFN_PHYS(bmap_size);
643 if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
644 start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
646 if (start + INITRD_SIZE > memory_end) {
647 printk("initrd extends beyond end of memory "
648 "(0x%08lx > 0x%08lx)\n"
649 "disabling initrd\n",
650 start + INITRD_SIZE, memory_end);
651 INITRD_START = INITRD_SIZE = 0;
653 printk("Moving initrd (0x%08lx -> 0x%08lx, "
655 INITRD_START, start, INITRD_SIZE);
656 memmove((void *) start, (void *) INITRD_START,
658 INITRD_START = start;
665 * Initialize the boot-time allocator
667 bootmap_size = init_bootmem(start_pfn, end_pfn);
670 * Register RAM areas with the bootmem allocator.
673 for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
674 unsigned long start_chunk, end_chunk, pfn;
676 if (memory_chunk[i].type != CHUNK_READ_WRITE)
678 start_chunk = PFN_DOWN(memory_chunk[i].addr);
679 end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size) - 1;
680 end_chunk = min(end_chunk, end_pfn);
681 if (start_chunk >= end_chunk)
683 add_active_range(0, start_chunk, end_chunk);
684 pfn = max(start_chunk, start_pfn);
685 for (; pfn <= end_chunk; pfn++)
686 page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
689 psw_set_key(PAGE_DEFAULT_KEY);
691 free_bootmem_with_active_regions(0, max_pfn);
692 reserve_bootmem(0, PFN_PHYS(start_pfn));
695 * Reserve the bootmem bitmap itself as well. We do this in two
696 * steps (first step was init_bootmem()) because this catches
697 * the (very unlikely) case of us accidentally initializing the
698 * bootmem allocator with an invalid RAM area.
700 reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size);
702 #ifdef CONFIG_BLK_DEV_INITRD
703 if (INITRD_START && INITRD_SIZE) {
704 if (INITRD_START + INITRD_SIZE <= memory_end) {
705 reserve_bootmem(INITRD_START, INITRD_SIZE);
706 initrd_start = INITRD_START;
707 initrd_end = initrd_start + INITRD_SIZE;
709 printk("initrd extends beyond end of memory "
710 "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
711 initrd_start + INITRD_SIZE, memory_end);
712 initrd_start = initrd_end = 0;
719 * Setup function called from init/main.c just after the banner
724 setup_arch(char **cmdline_p)
727 * print what head.S has found out about the machine
730 printk((MACHINE_IS_VM) ?
731 "We are running under VM (31 bit mode)\n" :
732 "We are running native (31 bit mode)\n");
733 printk((MACHINE_HAS_IEEE) ?
734 "This machine has an IEEE fpu\n" :
735 "This machine has no IEEE fpu\n");
736 #else /* CONFIG_64BIT */
737 printk((MACHINE_IS_VM) ?
738 "We are running under VM (64 bit mode)\n" :
739 "We are running native (64 bit mode)\n");
740 #endif /* CONFIG_64BIT */
742 /* Save unparsed command line copy for /proc/cmdline */
743 strlcpy(saved_command_line, COMMAND_LINE, COMMAND_LINE_SIZE);
745 *cmdline_p = COMMAND_LINE;
746 *(*cmdline_p + COMMAND_LINE_SIZE - 1) = '\0';
748 ROOT_DEV = Root_RAM0;
750 init_mm.start_code = PAGE_OFFSET;
751 init_mm.end_code = (unsigned long) &_etext;
752 init_mm.end_data = (unsigned long) &_edata;
753 init_mm.brk = (unsigned long) &_end;
755 if (MACHINE_HAS_MVCOS)
756 memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
758 memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
763 setup_addressing_mode();
769 __cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
770 smp_setup_cpu_possible_map();
773 * Create kernel page tables and switch to virtual addressing.
777 /* Setup default console */
781 void print_cpu_info(struct cpuinfo_S390 *cpuinfo)
787 "vers=%02X ident=%06X machine=%04X unused=%04X\n",
792 cpuinfo->cpu_id.version,
793 cpuinfo->cpu_id.ident,
794 cpuinfo->cpu_id.machine,
795 cpuinfo->cpu_id.unused);
799 * show_cpuinfo - Get information on one CPU for use by procfs.
802 static int show_cpuinfo(struct seq_file *m, void *v)
804 struct cpuinfo_S390 *cpuinfo;
805 unsigned long n = (unsigned long) v - 1;
807 s390_adjust_jiffies();
810 seq_printf(m, "vendor_id : IBM/S390\n"
811 "# processors : %i\n"
812 "bogomips per cpu: %lu.%02lu\n",
813 num_online_cpus(), loops_per_jiffy/(500000/HZ),
814 (loops_per_jiffy/(5000/HZ))%100);
818 if (smp_processor_id() == n)
819 cpuinfo = &S390_lowcore.cpu_data;
821 cpuinfo = &lowcore_ptr[n]->cpu_data;
823 cpuinfo = &S390_lowcore.cpu_data;
825 seq_printf(m, "processor %li: "
827 "identification = %06X, "
829 n, cpuinfo->cpu_id.version,
830 cpuinfo->cpu_id.ident,
831 cpuinfo->cpu_id.machine);
837 static void *c_start(struct seq_file *m, loff_t *pos)
839 return *pos < NR_CPUS ? (void *)((unsigned long) *pos + 1) : NULL;
841 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
844 return c_start(m, pos);
846 static void c_stop(struct seq_file *m, void *v)
849 struct seq_operations cpuinfo_op = {
853 .show = show_cpuinfo,