xref: /linux/arch/s390/kernel/setup.c (revision 13abf8130139c2ccd4962a7e5a8902be5e6cb5a7) 
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 #include <asm/page.h>
48 #include <asm/ptrace.h>
49 
50 /*
51  * Machine setup..
52  */
53 unsigned int console_mode = 0;
54 unsigned int console_devno = -1;
55 unsigned int console_irq = -1;
56 unsigned long memory_size = 0;
57 unsigned long machine_flags = 0;
58 struct {
59 	unsigned long addr, size, type;
60 } memory_chunk[MEMORY_CHUNKS] = { { 0 } };
61 #define CHUNK_READ_WRITE 0
62 #define CHUNK_READ_ONLY 1
63 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
64 unsigned long __initdata zholes_size[MAX_NR_ZONES];
65 static unsigned long __initdata memory_end;
66 
67 /*
68  * Setup options
69  */
70 extern int _text,_etext, _edata, _end;
71 
72 /*
73  * This is set up by the setup-routine at boot-time
74  * for S390 need to find out, what we have to setup
75  * using address 0x10400 ...
76  */
77 
78 #include <asm/setup.h>
79 
80 static char command_line[COMMAND_LINE_SIZE] = { 0, };
81 
82 static struct resource code_resource = {
83 	.name  = "Kernel code",
84 	.start = (unsigned long) &_text,
85 	.end = (unsigned long) &_etext - 1,
86 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
87 };
88 
89 static struct resource data_resource = {
90 	.name = "Kernel data",
91 	.start = (unsigned long) &_etext,
92 	.end = (unsigned long) &_edata - 1,
93 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
94 };
95 
96 /*
97  * cpu_init() initializes state that is per-CPU.
98  */
99 void __devinit cpu_init (void)
100 {
101         int addr = hard_smp_processor_id();
102 
103         /*
104          * Store processor id in lowcore (used e.g. in timer_interrupt)
105          */
106         asm volatile ("stidp %0": "=m" (S390_lowcore.cpu_data.cpu_id));
107         S390_lowcore.cpu_data.cpu_addr = addr;
108 
109         /*
110          * Force FPU initialization:
111          */
112         clear_thread_flag(TIF_USEDFPU);
113         clear_used_math();
114 
115 	atomic_inc(&init_mm.mm_count);
116 	current->active_mm = &init_mm;
117         if (current->mm)
118                 BUG();
119         enter_lazy_tlb(&init_mm, current);
120 }
121 
122 /*
123  * VM halt and poweroff setup routines
124  */
125 char vmhalt_cmd[128] = "";
126 char vmpoff_cmd[128] = "";
127 
128 static inline void strncpy_skip_quote(char *dst, char *src, int n)
129 {
130         int sx, dx;
131 
132         dx = 0;
133         for (sx = 0; src[sx] != 0; sx++) {
134                 if (src[sx] == '"') continue;
135                 dst[dx++] = src[sx];
136                 if (dx >= n) break;
137         }
138 }
139 
140 static int __init vmhalt_setup(char *str)
141 {
142         strncpy_skip_quote(vmhalt_cmd, str, 127);
143         vmhalt_cmd[127] = 0;
144         return 1;
145 }
146 
147 __setup("vmhalt=", vmhalt_setup);
148 
149 static int __init vmpoff_setup(char *str)
150 {
151         strncpy_skip_quote(vmpoff_cmd, str, 127);
152         vmpoff_cmd[127] = 0;
153         return 1;
154 }
155 
156 __setup("vmpoff=", vmpoff_setup);
157 
158 /*
159  * condev= and conmode= setup parameter.
160  */
161 
162 static int __init condev_setup(char *str)
163 {
164 	int vdev;
165 
166 	vdev = simple_strtoul(str, &str, 0);
167 	if (vdev >= 0 && vdev < 65536) {
168 		console_devno = vdev;
169 		console_irq = -1;
170 	}
171 	return 1;
172 }
173 
174 __setup("condev=", condev_setup);
175 
176 static int __init conmode_setup(char *str)
177 {
178 #if defined(CONFIG_SCLP_CONSOLE)
179 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
180                 SET_CONSOLE_SCLP;
181 #endif
182 #if defined(CONFIG_TN3215_CONSOLE)
183 	if (strncmp(str, "3215", 5) == 0)
184 		SET_CONSOLE_3215;
185 #endif
186 #if defined(CONFIG_TN3270_CONSOLE)
187 	if (strncmp(str, "3270", 5) == 0)
188 		SET_CONSOLE_3270;
189 #endif
190         return 1;
191 }
192 
193 __setup("conmode=", conmode_setup);
194 
195 static void __init conmode_default(void)
196 {
197 	char query_buffer[1024];
198 	char *ptr;
199 
200         if (MACHINE_IS_VM) {
201 		__cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
202 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
203 		ptr = strstr(query_buffer, "SUBCHANNEL =");
204 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
205 		__cpcmd("QUERY TERM", query_buffer, 1024, NULL);
206 		ptr = strstr(query_buffer, "CONMODE");
207 		/*
208 		 * Set the conmode to 3215 so that the device recognition
209 		 * will set the cu_type of the console to 3215. If the
210 		 * conmode is 3270 and we don't set it back then both
211 		 * 3215 and the 3270 driver will try to access the console
212 		 * device (3215 as console and 3270 as normal tty).
213 		 */
214 		__cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
215 		if (ptr == NULL) {
216 #if defined(CONFIG_SCLP_CONSOLE)
217 			SET_CONSOLE_SCLP;
218 #endif
219 			return;
220 		}
221 		if (strncmp(ptr + 8, "3270", 4) == 0) {
222 #if defined(CONFIG_TN3270_CONSOLE)
223 			SET_CONSOLE_3270;
224 #elif defined(CONFIG_TN3215_CONSOLE)
225 			SET_CONSOLE_3215;
226 #elif defined(CONFIG_SCLP_CONSOLE)
227 			SET_CONSOLE_SCLP;
228 #endif
229 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
230 #if defined(CONFIG_TN3215_CONSOLE)
231 			SET_CONSOLE_3215;
232 #elif defined(CONFIG_TN3270_CONSOLE)
233 			SET_CONSOLE_3270;
234 #elif defined(CONFIG_SCLP_CONSOLE)
235 			SET_CONSOLE_SCLP;
236 #endif
237 		}
238         } else if (MACHINE_IS_P390) {
239 #if defined(CONFIG_TN3215_CONSOLE)
240 		SET_CONSOLE_3215;
241 #elif defined(CONFIG_TN3270_CONSOLE)
242 		SET_CONSOLE_3270;
243 #endif
244 	} else {
245 #if defined(CONFIG_SCLP_CONSOLE)
246 		SET_CONSOLE_SCLP;
247 #endif
248 	}
249 }
250 
251 #ifdef CONFIG_SMP
252 extern void machine_restart_smp(char *);
253 extern void machine_halt_smp(void);
254 extern void machine_power_off_smp(void);
255 
256 void (*_machine_restart)(char *command) = machine_restart_smp;
257 void (*_machine_halt)(void) = machine_halt_smp;
258 void (*_machine_power_off)(void) = machine_power_off_smp;
259 #else
260 /*
261  * Reboot, halt and power_off routines for non SMP.
262  */
263 extern void reipl(unsigned long devno);
264 static void do_machine_restart_nonsmp(char * __unused)
265 {
266 	if (MACHINE_IS_VM)
267 		cpcmd ("IPL", NULL, 0);
268 	else
269 		reipl (0x10000 | S390_lowcore.ipl_device);
270 }
271 
272 static void do_machine_halt_nonsmp(void)
273 {
274         if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
275                 cpcmd(vmhalt_cmd, NULL, 0);
276         signal_processor(smp_processor_id(), sigp_stop_and_store_status);
277 }
278 
279 static void do_machine_power_off_nonsmp(void)
280 {
281         if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
282                 cpcmd(vmpoff_cmd, NULL, 0);
283         signal_processor(smp_processor_id(), sigp_stop_and_store_status);
284 }
285 
286 void (*_machine_restart)(char *command) = do_machine_restart_nonsmp;
287 void (*_machine_halt)(void) = do_machine_halt_nonsmp;
288 void (*_machine_power_off)(void) = do_machine_power_off_nonsmp;
289 #endif
290 
291  /*
292  * Reboot, halt and power_off stubs. They just call _machine_restart,
293  * _machine_halt or _machine_power_off.
294  */
295 
296 void machine_restart(char *command)
297 {
298 	console_unblank();
299 	_machine_restart(command);
300 }
301 
302 void machine_halt(void)
303 {
304 	console_unblank();
305 	_machine_halt();
306 }
307 
308 void machine_power_off(void)
309 {
310 	console_unblank();
311 	_machine_power_off();
312 }
313 
314 static void __init
315 add_memory_hole(unsigned long start, unsigned long end)
316 {
317 	unsigned long dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
318 
319 	if (end <= dma_pfn)
320 		zholes_size[ZONE_DMA] += end - start + 1;
321 	else if (start > dma_pfn)
322 		zholes_size[ZONE_NORMAL] += end - start + 1;
323 	else {
324 		zholes_size[ZONE_DMA] += dma_pfn - start + 1;
325 		zholes_size[ZONE_NORMAL] += end - dma_pfn;
326 	}
327 }
328 
329 static void __init
330 parse_cmdline_early(char **cmdline_p)
331 {
332 	char c = ' ', cn, *to = command_line, *from = COMMAND_LINE;
333 	unsigned long delay = 0;
334 
335 	/* Save unparsed command line copy for /proc/cmdline */
336 	memcpy(saved_command_line, COMMAND_LINE, COMMAND_LINE_SIZE);
337 	saved_command_line[COMMAND_LINE_SIZE-1] = '\0';
338 
339 	for (;;) {
340 		/*
341 		 * "mem=XXX[kKmM]" sets memsize
342 		 */
343 		if (c == ' ' && strncmp(from, "mem=", 4) == 0) {
344 			memory_end = simple_strtoul(from+4, &from, 0);
345 			if ( *from == 'K' || *from == 'k' ) {
346 				memory_end = memory_end << 10;
347 				from++;
348 			} else if ( *from == 'M' || *from == 'm' ) {
349 				memory_end = memory_end << 20;
350 				from++;
351 			}
352 		}
353 		/*
354 		 * "ipldelay=XXX[sm]" sets ipl delay in seconds or minutes
355 		 */
356 		if (c == ' ' && strncmp(from, "ipldelay=", 9) == 0) {
357 			delay = simple_strtoul(from+9, &from, 0);
358 			if (*from == 's' || *from == 'S') {
359 				delay = delay*1000000;
360 				from++;
361 			} else if (*from == 'm' || *from == 'M') {
362 				delay = delay*60*1000000;
363 				from++;
364 			}
365 			/* now wait for the requested amount of time */
366 			udelay(delay);
367 		}
368 		cn = *(from++);
369 		if (!cn)
370 			break;
371 		if (cn == '\n')
372 			cn = ' ';  /* replace newlines with space */
373 		if (cn == 0x0d)
374 			cn = ' ';  /* replace 0x0d with space */
375 		if (cn == ' ' && c == ' ')
376 			continue;  /* remove additional spaces */
377 		c = cn;
378 		if (to - command_line >= COMMAND_LINE_SIZE)
379 			break;
380 		*(to++) = c;
381 	}
382 	if (c == ' ' && to > command_line) to--;
383 	*to = '\0';
384 	*cmdline_p = command_line;
385 }
386 
387 static void __init
388 setup_lowcore(void)
389 {
390 	struct _lowcore *lc;
391 	int lc_pages;
392 
393 	/*
394 	 * Setup lowcore for boot cpu
395 	 */
396 	lc_pages = sizeof(void *) == 8 ? 2 : 1;
397 	lc = (struct _lowcore *)
398 		__alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
399 	memset(lc, 0, lc_pages * PAGE_SIZE);
400 	lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
401 	lc->restart_psw.addr =
402 		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
403 	lc->external_new_psw.mask = PSW_KERNEL_BITS;
404 	lc->external_new_psw.addr =
405 		PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
406 	lc->svc_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | PSW_MASK_EXT;
407 	lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
408 	lc->program_new_psw.mask = PSW_KERNEL_BITS;
409 	lc->program_new_psw.addr =
410 		PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
411 	lc->mcck_new_psw.mask =
412 		PSW_KERNEL_BITS & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
413 	lc->mcck_new_psw.addr =
414 		PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
415 	lc->io_new_psw.mask = PSW_KERNEL_BITS;
416 	lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
417 	lc->ipl_device = S390_lowcore.ipl_device;
418 	lc->jiffy_timer = -1LL;
419 	lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
420 	lc->async_stack = (unsigned long)
421 		__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
422 	lc->panic_stack = (unsigned long)
423 		__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
424 	lc->current_task = (unsigned long) init_thread_union.thread_info.task;
425 	lc->thread_info = (unsigned long) &init_thread_union;
426 #ifndef CONFIG_ARCH_S390X
427 	if (MACHINE_HAS_IEEE) {
428 		lc->extended_save_area_addr = (__u32)
429 			__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
430 		/* enable extended save area */
431 		ctl_set_bit(14, 29);
432 	}
433 #endif
434 	set_prefix((u32)(unsigned long) lc);
435 }
436 
437 static void __init
438 setup_resources(void)
439 {
440 	struct resource *res;
441 	int i;
442 
443 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
444 		res = alloc_bootmem_low(sizeof(struct resource));
445 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
446 		switch (memory_chunk[i].type) {
447 		case CHUNK_READ_WRITE:
448 			res->name = "System RAM";
449 			break;
450 		case CHUNK_READ_ONLY:
451 			res->name = "System ROM";
452 			res->flags |= IORESOURCE_READONLY;
453 			break;
454 		default:
455 			res->name = "reserved";
456 		}
457 		res->start = memory_chunk[i].addr;
458 		res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
459 		request_resource(&iomem_resource, res);
460 		request_resource(res, &code_resource);
461 		request_resource(res, &data_resource);
462 	}
463 }
464 
465 static void __init
466 setup_memory(void)
467 {
468         unsigned long bootmap_size;
469 	unsigned long start_pfn, end_pfn, init_pfn;
470 	unsigned long last_rw_end;
471 	int i;
472 
473 	/*
474 	 * partially used pages are not usable - thus
475 	 * we are rounding upwards:
476 	 */
477 	start_pfn = (__pa(&_end) + PAGE_SIZE - 1) >> PAGE_SHIFT;
478 	end_pfn = max_pfn = memory_end >> PAGE_SHIFT;
479 
480 	/* Initialize storage key for kernel pages */
481 	for (init_pfn = 0 ; init_pfn < start_pfn; init_pfn++)
482 		page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
483 
484 	/*
485 	 * Initialize the boot-time allocator (with low memory only):
486 	 */
487 	bootmap_size = init_bootmem(start_pfn, end_pfn);
488 
489 	/*
490 	 * Register RAM areas with the bootmem allocator.
491 	 */
492 	last_rw_end = start_pfn;
493 
494 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
495 		unsigned long start_chunk, end_chunk;
496 
497 		if (memory_chunk[i].type != CHUNK_READ_WRITE)
498 			continue;
499 		start_chunk = (memory_chunk[i].addr + PAGE_SIZE - 1);
500 		start_chunk >>= PAGE_SHIFT;
501 		end_chunk = (memory_chunk[i].addr + memory_chunk[i].size);
502 		end_chunk >>= PAGE_SHIFT;
503 		if (start_chunk < start_pfn)
504 			start_chunk = start_pfn;
505 		if (end_chunk > end_pfn)
506 			end_chunk = end_pfn;
507 		if (start_chunk < end_chunk) {
508 			/* Initialize storage key for RAM pages */
509 			for (init_pfn = start_chunk ; init_pfn < end_chunk;
510 			     init_pfn++)
511 				page_set_storage_key(init_pfn << PAGE_SHIFT,
512 						     PAGE_DEFAULT_KEY);
513 			free_bootmem(start_chunk << PAGE_SHIFT,
514 				     (end_chunk - start_chunk) << PAGE_SHIFT);
515 			if (last_rw_end < start_chunk)
516 				add_memory_hole(last_rw_end, start_chunk - 1);
517 			last_rw_end = end_chunk;
518 		}
519 	}
520 
521 	psw_set_key(PAGE_DEFAULT_KEY);
522 
523 	if (last_rw_end < end_pfn - 1)
524 		add_memory_hole(last_rw_end, end_pfn - 1);
525 
526 	/*
527 	 * Reserve the bootmem bitmap itself as well. We do this in two
528 	 * steps (first step was init_bootmem()) because this catches
529 	 * the (very unlikely) case of us accidentally initializing the
530 	 * bootmem allocator with an invalid RAM area.
531 	 */
532 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size);
533 
534 #ifdef CONFIG_BLK_DEV_INITRD
535 	if (INITRD_START) {
536 		if (INITRD_START + INITRD_SIZE <= memory_end) {
537 			reserve_bootmem(INITRD_START, INITRD_SIZE);
538 			initrd_start = INITRD_START;
539 			initrd_end = initrd_start + INITRD_SIZE;
540 		} else {
541 			printk("initrd extends beyond end of memory "
542 			       "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
543 			       initrd_start + INITRD_SIZE, memory_end);
544 			initrd_start = initrd_end = 0;
545 		}
546 	}
547 #endif
548 }
549 
550 /*
551  * Setup function called from init/main.c just after the banner
552  * was printed.
553  */
554 
555 void __init
556 setup_arch(char **cmdline_p)
557 {
558         /*
559          * print what head.S has found out about the machine
560          */
561 #ifndef CONFIG_ARCH_S390X
562 	printk((MACHINE_IS_VM) ?
563 	       "We are running under VM (31 bit mode)\n" :
564 	       "We are running native (31 bit mode)\n");
565 	printk((MACHINE_HAS_IEEE) ?
566 	       "This machine has an IEEE fpu\n" :
567 	       "This machine has no IEEE fpu\n");
568 #else /* CONFIG_ARCH_S390X */
569 	printk((MACHINE_IS_VM) ?
570 	       "We are running under VM (64 bit mode)\n" :
571 	       "We are running native (64 bit mode)\n");
572 #endif /* CONFIG_ARCH_S390X */
573 
574         ROOT_DEV = Root_RAM0;
575 #ifndef CONFIG_ARCH_S390X
576 	memory_end = memory_size & ~0x400000UL;  /* align memory end to 4MB */
577         /*
578          * We need some free virtual space to be able to do vmalloc.
579          * On a machine with 2GB memory we make sure that we have at
580          * least 128 MB free space for vmalloc.
581          */
582         if (memory_end > 1920*1024*1024)
583                 memory_end = 1920*1024*1024;
584 #else /* CONFIG_ARCH_S390X */
585 	memory_end = memory_size & ~0x200000UL;  /* detected in head.s */
586 #endif /* CONFIG_ARCH_S390X */
587 
588 	init_mm.start_code = PAGE_OFFSET;
589 	init_mm.end_code = (unsigned long) &_etext;
590 	init_mm.end_data = (unsigned long) &_edata;
591 	init_mm.brk = (unsigned long) &_end;
592 
593 	parse_cmdline_early(cmdline_p);
594 
595 	setup_memory();
596 	setup_resources();
597 	setup_lowcore();
598 
599         cpu_init();
600         __cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
601 
602 	/*
603 	 * Create kernel page tables and switch to virtual addressing.
604 	 */
605         paging_init();
606 
607         /* Setup default console */
608 	conmode_default();
609 }
610 
611 void print_cpu_info(struct cpuinfo_S390 *cpuinfo)
612 {
613    printk("cpu %d "
614 #ifdef CONFIG_SMP
615            "phys_idx=%d "
616 #endif
617            "vers=%02X ident=%06X machine=%04X unused=%04X\n",
618            cpuinfo->cpu_nr,
619 #ifdef CONFIG_SMP
620            cpuinfo->cpu_addr,
621 #endif
622            cpuinfo->cpu_id.version,
623            cpuinfo->cpu_id.ident,
624            cpuinfo->cpu_id.machine,
625            cpuinfo->cpu_id.unused);
626 }
627 
628 /*
629  * show_cpuinfo - Get information on one CPU for use by procfs.
630  */
631 
632 static int show_cpuinfo(struct seq_file *m, void *v)
633 {
634         struct cpuinfo_S390 *cpuinfo;
635 	unsigned long n = (unsigned long) v - 1;
636 
637 	if (!n) {
638 		seq_printf(m, "vendor_id       : IBM/S390\n"
639 			       "# processors    : %i\n"
640 			       "bogomips per cpu: %lu.%02lu\n",
641 			       num_online_cpus(), loops_per_jiffy/(500000/HZ),
642 			       (loops_per_jiffy/(5000/HZ))%100);
643 	}
644 	if (cpu_online(n)) {
645 #ifdef CONFIG_SMP
646 		if (smp_processor_id() == n)
647 			cpuinfo = &S390_lowcore.cpu_data;
648 		else
649 			cpuinfo = &lowcore_ptr[n]->cpu_data;
650 #else
651 		cpuinfo = &S390_lowcore.cpu_data;
652 #endif
653 		seq_printf(m, "processor %li: "
654 			       "version = %02X,  "
655 			       "identification = %06X,  "
656 			       "machine = %04X\n",
657 			       n, cpuinfo->cpu_id.version,
658 			       cpuinfo->cpu_id.ident,
659 			       cpuinfo->cpu_id.machine);
660 	}
661         return 0;
662 }
663 
664 static void *c_start(struct seq_file *m, loff_t *pos)
665 {
666 	return *pos < NR_CPUS ? (void *)((unsigned long) *pos + 1) : NULL;
667 }
668 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
669 {
670 	++*pos;
671 	return c_start(m, pos);
672 }
673 static void c_stop(struct seq_file *m, void *v)
674 {
675 }
676 struct seq_operations cpuinfo_op = {
677 	.start	= c_start,
678 	.next	= c_next,
679 	.stop	= c_stop,
680 	.show	= show_cpuinfo,
681 };
682 
683