xref: /linux/arch/s390/kernel/setup.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
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 #define KMSG_COMPONENT "setup"
18 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
19 
20 #include <linux/errno.h>
21 #include <linux/module.h>
22 #include <linux/sched.h>
23 #include <linux/kernel.h>
24 #include <linux/mm.h>
25 #include <linux/stddef.h>
26 #include <linux/unistd.h>
27 #include <linux/ptrace.h>
28 #include <linux/slab.h>
29 #include <linux/user.h>
30 #include <linux/tty.h>
31 #include <linux/ioport.h>
32 #include <linux/delay.h>
33 #include <linux/init.h>
34 #include <linux/initrd.h>
35 #include <linux/bootmem.h>
36 #include <linux/root_dev.h>
37 #include <linux/console.h>
38 #include <linux/kernel_stat.h>
39 #include <linux/device.h>
40 #include <linux/notifier.h>
41 #include <linux/pfn.h>
42 #include <linux/ctype.h>
43 #include <linux/reboot.h>
44 #include <linux/topology.h>
45 #include <linux/ftrace.h>
46 
47 #include <asm/ipl.h>
48 #include <asm/uaccess.h>
49 #include <asm/system.h>
50 #include <asm/smp.h>
51 #include <asm/mmu_context.h>
52 #include <asm/cpcmd.h>
53 #include <asm/lowcore.h>
54 #include <asm/irq.h>
55 #include <asm/page.h>
56 #include <asm/ptrace.h>
57 #include <asm/sections.h>
58 #include <asm/ebcdic.h>
59 #include <asm/compat.h>
60 #include <asm/kvm_virtio.h>
61 
62 long psw_kernel_bits	= (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
63 			   PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
64 long psw_user_bits	= (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
65 			   PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
66 			   PSW_MASK_PSTATE | PSW_DEFAULT_KEY);
67 
68 /*
69  * User copy operations.
70  */
71 struct uaccess_ops uaccess;
72 EXPORT_SYMBOL(uaccess);
73 
74 /*
75  * Machine setup..
76  */
77 unsigned int console_mode = 0;
78 EXPORT_SYMBOL(console_mode);
79 
80 unsigned int console_devno = -1;
81 EXPORT_SYMBOL(console_devno);
82 
83 unsigned int console_irq = -1;
84 EXPORT_SYMBOL(console_irq);
85 
86 unsigned long elf_hwcap = 0;
87 char elf_platform[ELF_PLATFORM_SIZE];
88 
89 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
90 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
91 
92 int __initdata memory_end_set;
93 unsigned long __initdata memory_end;
94 
95 /* An array with a pointer to the lowcore of every CPU. */
96 struct _lowcore *lowcore_ptr[NR_CPUS];
97 EXPORT_SYMBOL(lowcore_ptr);
98 
99 /*
100  * This is set up by the setup-routine at boot-time
101  * for S390 need to find out, what we have to setup
102  * using address 0x10400 ...
103  */
104 
105 #include <asm/setup.h>
106 
107 static struct resource code_resource = {
108 	.name  = "Kernel code",
109 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
110 };
111 
112 static struct resource data_resource = {
113 	.name = "Kernel data",
114 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
115 };
116 
117 /*
118  * cpu_init() initializes state that is per-CPU.
119  */
120 void __cpuinit cpu_init(void)
121 {
122         /*
123          * Store processor id in lowcore (used e.g. in timer_interrupt)
124          */
125 	get_cpu_id(&S390_lowcore.cpu_id);
126 
127         /*
128          * Force FPU initialization:
129          */
130         clear_thread_flag(TIF_USEDFPU);
131         clear_used_math();
132 
133 	atomic_inc(&init_mm.mm_count);
134 	current->active_mm = &init_mm;
135 	BUG_ON(current->mm);
136         enter_lazy_tlb(&init_mm, current);
137 }
138 
139 /*
140  * condev= and conmode= setup parameter.
141  */
142 
143 static int __init condev_setup(char *str)
144 {
145 	int vdev;
146 
147 	vdev = simple_strtoul(str, &str, 0);
148 	if (vdev >= 0 && vdev < 65536) {
149 		console_devno = vdev;
150 		console_irq = -1;
151 	}
152 	return 1;
153 }
154 
155 __setup("condev=", condev_setup);
156 
157 static int __init conmode_setup(char *str)
158 {
159 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
160 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
161                 SET_CONSOLE_SCLP;
162 #endif
163 #if defined(CONFIG_TN3215_CONSOLE)
164 	if (strncmp(str, "3215", 5) == 0)
165 		SET_CONSOLE_3215;
166 #endif
167 #if defined(CONFIG_TN3270_CONSOLE)
168 	if (strncmp(str, "3270", 5) == 0)
169 		SET_CONSOLE_3270;
170 #endif
171         return 1;
172 }
173 
174 __setup("conmode=", conmode_setup);
175 
176 static void __init conmode_default(void)
177 {
178 	char query_buffer[1024];
179 	char *ptr;
180 
181         if (MACHINE_IS_VM) {
182 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
183 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
184 		ptr = strstr(query_buffer, "SUBCHANNEL =");
185 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
186 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
187 		ptr = strstr(query_buffer, "CONMODE");
188 		/*
189 		 * Set the conmode to 3215 so that the device recognition
190 		 * will set the cu_type of the console to 3215. If the
191 		 * conmode is 3270 and we don't set it back then both
192 		 * 3215 and the 3270 driver will try to access the console
193 		 * device (3215 as console and 3270 as normal tty).
194 		 */
195 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
196 		if (ptr == NULL) {
197 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
198 			SET_CONSOLE_SCLP;
199 #endif
200 			return;
201 		}
202 		if (strncmp(ptr + 8, "3270", 4) == 0) {
203 #if defined(CONFIG_TN3270_CONSOLE)
204 			SET_CONSOLE_3270;
205 #elif defined(CONFIG_TN3215_CONSOLE)
206 			SET_CONSOLE_3215;
207 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
208 			SET_CONSOLE_SCLP;
209 #endif
210 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
211 #if defined(CONFIG_TN3215_CONSOLE)
212 			SET_CONSOLE_3215;
213 #elif defined(CONFIG_TN3270_CONSOLE)
214 			SET_CONSOLE_3270;
215 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
216 			SET_CONSOLE_SCLP;
217 #endif
218 		}
219 	} else {
220 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
221 		SET_CONSOLE_SCLP;
222 #endif
223 	}
224 }
225 
226 #ifdef CONFIG_ZFCPDUMP
227 static void __init setup_zfcpdump(unsigned int console_devno)
228 {
229 	static char str[41];
230 
231 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
232 		return;
233 	if (console_devno != -1)
234 		sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
235 			ipl_info.data.fcp.dev_id.devno, console_devno);
236 	else
237 		sprintf(str, " cio_ignore=all,!0.0.%04x",
238 			ipl_info.data.fcp.dev_id.devno);
239 	strcat(boot_command_line, str);
240 	console_loglevel = 2;
241 }
242 #else
243 static inline void setup_zfcpdump(unsigned int console_devno) {}
244 #endif /* CONFIG_ZFCPDUMP */
245 
246  /*
247  * Reboot, halt and power_off stubs. They just call _machine_restart,
248  * _machine_halt or _machine_power_off.
249  */
250 
251 void machine_restart(char *command)
252 {
253 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
254 		/*
255 		 * Only unblank the console if we are called in enabled
256 		 * context or a bust_spinlocks cleared the way for us.
257 		 */
258 		console_unblank();
259 	_machine_restart(command);
260 }
261 
262 void machine_halt(void)
263 {
264 	if (!in_interrupt() || oops_in_progress)
265 		/*
266 		 * Only unblank the console if we are called in enabled
267 		 * context or a bust_spinlocks cleared the way for us.
268 		 */
269 		console_unblank();
270 	_machine_halt();
271 }
272 
273 void machine_power_off(void)
274 {
275 	if (!in_interrupt() || oops_in_progress)
276 		/*
277 		 * Only unblank the console if we are called in enabled
278 		 * context or a bust_spinlocks cleared the way for us.
279 		 */
280 		console_unblank();
281 	_machine_power_off();
282 }
283 
284 /*
285  * Dummy power off function.
286  */
287 void (*pm_power_off)(void) = machine_power_off;
288 
289 static int __init early_parse_mem(char *p)
290 {
291 	memory_end = memparse(p, &p);
292 	memory_end_set = 1;
293 	return 0;
294 }
295 early_param("mem", early_parse_mem);
296 
297 #ifdef CONFIG_S390_SWITCH_AMODE
298 unsigned int switch_amode = 0;
299 EXPORT_SYMBOL_GPL(switch_amode);
300 
301 static int set_amode_and_uaccess(unsigned long user_amode,
302 				 unsigned long user32_amode)
303 {
304 	psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
305 			PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
306 			PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
307 #ifdef CONFIG_COMPAT
308 	psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
309 			  PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
310 			  PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
311 	psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
312 			  PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
313 			  PSW32_MASK_PSTATE;
314 #endif
315 	psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
316 			  PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
317 
318 	if (MACHINE_HAS_MVCOS) {
319 		memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
320 		return 1;
321 	} else {
322 		memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
323 		return 0;
324 	}
325 }
326 
327 /*
328  * Switch kernel/user addressing modes?
329  */
330 static int __init early_parse_switch_amode(char *p)
331 {
332 	switch_amode = 1;
333 	return 0;
334 }
335 early_param("switch_amode", early_parse_switch_amode);
336 
337 #else /* CONFIG_S390_SWITCH_AMODE */
338 static inline int set_amode_and_uaccess(unsigned long user_amode,
339 					unsigned long user32_amode)
340 {
341 	return 0;
342 }
343 #endif /* CONFIG_S390_SWITCH_AMODE */
344 
345 #ifdef CONFIG_S390_EXEC_PROTECT
346 unsigned int s390_noexec = 0;
347 EXPORT_SYMBOL_GPL(s390_noexec);
348 
349 /*
350  * Enable execute protection?
351  */
352 static int __init early_parse_noexec(char *p)
353 {
354 	if (!strncmp(p, "off", 3))
355 		return 0;
356 	switch_amode = 1;
357 	s390_noexec = 1;
358 	return 0;
359 }
360 early_param("noexec", early_parse_noexec);
361 #endif /* CONFIG_S390_EXEC_PROTECT */
362 
363 static void setup_addressing_mode(void)
364 {
365 	if (s390_noexec) {
366 		if (set_amode_and_uaccess(PSW_ASC_SECONDARY,
367 					  PSW32_ASC_SECONDARY))
368 			pr_info("Execute protection active, "
369 				"mvcos available\n");
370 		else
371 			pr_info("Execute protection active, "
372 				"mvcos not available\n");
373 	} else if (switch_amode) {
374 		if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
375 			pr_info("Address spaces switched, "
376 				"mvcos available\n");
377 		else
378 			pr_info("Address spaces switched, "
379 				"mvcos not available\n");
380 	}
381 #ifdef CONFIG_TRACE_IRQFLAGS
382 	sysc_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
383 	io_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
384 #endif
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 	if (switch_amode)
404 		lc->restart_psw.mask |= PSW_ASC_HOME;
405 	lc->external_new_psw.mask = psw_kernel_bits;
406 	lc->external_new_psw.addr =
407 		PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
408 	lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
409 	lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
410 	lc->program_new_psw.mask = psw_kernel_bits;
411 	lc->program_new_psw.addr =
412 		PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
413 	lc->mcck_new_psw.mask =
414 		psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
415 	lc->mcck_new_psw.addr =
416 		PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
417 	lc->io_new_psw.mask = psw_kernel_bits;
418 	lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
419 	lc->clock_comparator = -1ULL;
420 	lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
421 	lc->async_stack = (unsigned long)
422 		__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
423 	lc->panic_stack = (unsigned long)
424 		__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
425 	lc->current_task = (unsigned long) init_thread_union.thread_info.task;
426 	lc->thread_info = (unsigned long) &init_thread_union;
427 	lc->machine_flags = S390_lowcore.machine_flags;
428 #ifndef CONFIG_64BIT
429 	if (MACHINE_HAS_IEEE) {
430 		lc->extended_save_area_addr = (__u32)
431 			__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
432 		/* enable extended save area */
433 		__ctl_set_bit(14, 29);
434 	}
435 #else
436 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
437 #endif
438 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
439 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
440 	lc->exit_timer = S390_lowcore.exit_timer;
441 	lc->user_timer = S390_lowcore.user_timer;
442 	lc->system_timer = S390_lowcore.system_timer;
443 	lc->steal_timer = S390_lowcore.steal_timer;
444 	lc->last_update_timer = S390_lowcore.last_update_timer;
445 	lc->last_update_clock = S390_lowcore.last_update_clock;
446 	lc->ftrace_func = S390_lowcore.ftrace_func;
447 	set_prefix((u32)(unsigned long) lc);
448 	lowcore_ptr[0] = lc;
449 }
450 
451 static void __init
452 setup_resources(void)
453 {
454 	struct resource *res, *sub_res;
455 	int i;
456 
457 	code_resource.start = (unsigned long) &_text;
458 	code_resource.end = (unsigned long) &_etext - 1;
459 	data_resource.start = (unsigned long) &_etext;
460 	data_resource.end = (unsigned long) &_edata - 1;
461 
462 	for (i = 0; i < MEMORY_CHUNKS; i++) {
463 		if (!memory_chunk[i].size)
464 			continue;
465 		res = alloc_bootmem_low(sizeof(struct resource));
466 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
467 		switch (memory_chunk[i].type) {
468 		case CHUNK_READ_WRITE:
469 			res->name = "System RAM";
470 			break;
471 		case CHUNK_READ_ONLY:
472 			res->name = "System ROM";
473 			res->flags |= IORESOURCE_READONLY;
474 			break;
475 		default:
476 			res->name = "reserved";
477 		}
478 		res->start = memory_chunk[i].addr;
479 		res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
480 		request_resource(&iomem_resource, res);
481 
482 		if (code_resource.start >= res->start  &&
483 			code_resource.start <= res->end &&
484 			code_resource.end > res->end) {
485 			sub_res = alloc_bootmem_low(sizeof(struct resource));
486 			memcpy(sub_res, &code_resource,
487 				sizeof(struct resource));
488 			sub_res->end = res->end;
489 			code_resource.start = res->end + 1;
490 			request_resource(res, sub_res);
491 		}
492 
493 		if (code_resource.start >= res->start &&
494 			code_resource.start <= res->end &&
495 			code_resource.end <= res->end)
496 			request_resource(res, &code_resource);
497 
498 		if (data_resource.start >= res->start &&
499 			data_resource.start <= res->end &&
500 			data_resource.end > res->end) {
501 			sub_res = alloc_bootmem_low(sizeof(struct resource));
502 			memcpy(sub_res, &data_resource,
503 				sizeof(struct resource));
504 			sub_res->end = res->end;
505 			data_resource.start = res->end + 1;
506 			request_resource(res, sub_res);
507 		}
508 
509 		if (data_resource.start >= res->start &&
510 			data_resource.start <= res->end &&
511 			data_resource.end <= res->end)
512 			request_resource(res, &data_resource);
513 	}
514 }
515 
516 unsigned long real_memory_size;
517 EXPORT_SYMBOL_GPL(real_memory_size);
518 
519 static void __init setup_memory_end(void)
520 {
521 	unsigned long memory_size;
522 	unsigned long max_mem;
523 	int i;
524 
525 #ifdef CONFIG_ZFCPDUMP
526 	if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
527 		memory_end = ZFCPDUMP_HSA_SIZE;
528 		memory_end_set = 1;
529 	}
530 #endif
531 	memory_size = 0;
532 	memory_end &= PAGE_MASK;
533 
534 	max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
535 	memory_end = min(max_mem, memory_end);
536 
537 	/*
538 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
539 	 * extra checks that HOLES_IN_ZONE would require.
540 	 */
541 	for (i = 0; i < MEMORY_CHUNKS; i++) {
542 		unsigned long start, end;
543 		struct mem_chunk *chunk;
544 		unsigned long align;
545 
546 		chunk = &memory_chunk[i];
547 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
548 		start = (chunk->addr + align - 1) & ~(align - 1);
549 		end = (chunk->addr + chunk->size) & ~(align - 1);
550 		if (start >= end)
551 			memset(chunk, 0, sizeof(*chunk));
552 		else {
553 			chunk->addr = start;
554 			chunk->size = end - start;
555 		}
556 	}
557 
558 	for (i = 0; i < MEMORY_CHUNKS; i++) {
559 		struct mem_chunk *chunk = &memory_chunk[i];
560 
561 		real_memory_size = max(real_memory_size,
562 				       chunk->addr + chunk->size);
563 		if (chunk->addr >= max_mem) {
564 			memset(chunk, 0, sizeof(*chunk));
565 			continue;
566 		}
567 		if (chunk->addr + chunk->size > max_mem)
568 			chunk->size = max_mem - chunk->addr;
569 		memory_size = max(memory_size, chunk->addr + chunk->size);
570 	}
571 	if (!memory_end)
572 		memory_end = memory_size;
573 }
574 
575 static void __init
576 setup_memory(void)
577 {
578         unsigned long bootmap_size;
579 	unsigned long start_pfn, end_pfn;
580 	int i;
581 
582 	/*
583 	 * partially used pages are not usable - thus
584 	 * we are rounding upwards:
585 	 */
586 	start_pfn = PFN_UP(__pa(&_end));
587 	end_pfn = max_pfn = PFN_DOWN(memory_end);
588 
589 #ifdef CONFIG_BLK_DEV_INITRD
590 	/*
591 	 * Move the initrd in case the bitmap of the bootmem allocater
592 	 * would overwrite it.
593 	 */
594 
595 	if (INITRD_START && INITRD_SIZE) {
596 		unsigned long bmap_size;
597 		unsigned long start;
598 
599 		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
600 		bmap_size = PFN_PHYS(bmap_size);
601 
602 		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
603 			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
604 
605 			if (start + INITRD_SIZE > memory_end) {
606 				pr_err("initrd extends beyond end of "
607 				       "memory (0x%08lx > 0x%08lx) "
608 				       "disabling initrd\n",
609 				       start + INITRD_SIZE, memory_end);
610 				INITRD_START = INITRD_SIZE = 0;
611 			} else {
612 				pr_info("Moving initrd (0x%08lx -> "
613 					"0x%08lx, size: %ld)\n",
614 					INITRD_START, start, INITRD_SIZE);
615 				memmove((void *) start, (void *) INITRD_START,
616 					INITRD_SIZE);
617 				INITRD_START = start;
618 			}
619 		}
620 	}
621 #endif
622 
623 	/*
624 	 * Initialize the boot-time allocator
625 	 */
626 	bootmap_size = init_bootmem(start_pfn, end_pfn);
627 
628 	/*
629 	 * Register RAM areas with the bootmem allocator.
630 	 */
631 
632 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
633 		unsigned long start_chunk, end_chunk, pfn;
634 
635 		if (memory_chunk[i].type != CHUNK_READ_WRITE)
636 			continue;
637 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
638 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
639 		end_chunk = min(end_chunk, end_pfn);
640 		if (start_chunk >= end_chunk)
641 			continue;
642 		add_active_range(0, start_chunk, end_chunk);
643 		pfn = max(start_chunk, start_pfn);
644 		for (; pfn < end_chunk; pfn++)
645 			page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
646 	}
647 
648 	psw_set_key(PAGE_DEFAULT_KEY);
649 
650 	free_bootmem_with_active_regions(0, max_pfn);
651 
652 	/*
653 	 * Reserve memory used for lowcore/command line/kernel image.
654 	 */
655 	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
656 	reserve_bootmem((unsigned long)_stext,
657 			PFN_PHYS(start_pfn) - (unsigned long)_stext,
658 			BOOTMEM_DEFAULT);
659 	/*
660 	 * Reserve the bootmem bitmap itself as well. We do this in two
661 	 * steps (first step was init_bootmem()) because this catches
662 	 * the (very unlikely) case of us accidentally initializing the
663 	 * bootmem allocator with an invalid RAM area.
664 	 */
665 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
666 			BOOTMEM_DEFAULT);
667 
668 #ifdef CONFIG_BLK_DEV_INITRD
669 	if (INITRD_START && INITRD_SIZE) {
670 		if (INITRD_START + INITRD_SIZE <= memory_end) {
671 			reserve_bootmem(INITRD_START, INITRD_SIZE,
672 					BOOTMEM_DEFAULT);
673 			initrd_start = INITRD_START;
674 			initrd_end = initrd_start + INITRD_SIZE;
675 		} else {
676 			pr_err("initrd extends beyond end of "
677 			       "memory (0x%08lx > 0x%08lx) "
678 			       "disabling initrd\n",
679 			       initrd_start + INITRD_SIZE, memory_end);
680 			initrd_start = initrd_end = 0;
681 		}
682 	}
683 #endif
684 }
685 
686 /*
687  * Setup hardware capabilities.
688  */
689 static void __init setup_hwcaps(void)
690 {
691 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
692 	unsigned long long facility_list_extended;
693 	unsigned int facility_list;
694 	int i;
695 
696 	facility_list = stfl();
697 	/*
698 	 * The store facility list bits numbers as found in the principles
699 	 * of operation are numbered with bit 1UL<<31 as number 0 to
700 	 * bit 1UL<<0 as number 31.
701 	 *   Bit 0: instructions named N3, "backported" to esa-mode
702 	 *   Bit 2: z/Architecture mode is active
703 	 *   Bit 7: the store-facility-list-extended facility is installed
704 	 *   Bit 17: the message-security assist is installed
705 	 *   Bit 19: the long-displacement facility is installed
706 	 *   Bit 21: the extended-immediate facility is installed
707 	 *   Bit 22: extended-translation facility 3 is installed
708 	 *   Bit 30: extended-translation facility 3 enhancement facility
709 	 * These get translated to:
710 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
711 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
712 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
713 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
714 	 */
715 	for (i = 0; i < 6; i++)
716 		if (facility_list & (1UL << (31 - stfl_bits[i])))
717 			elf_hwcap |= 1UL << i;
718 
719 	if ((facility_list & (1UL << (31 - 22)))
720 	    && (facility_list & (1UL << (31 - 30))))
721 		elf_hwcap |= 1UL << 8;
722 
723 	/*
724 	 * Check for additional facilities with store-facility-list-extended.
725 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
726 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
727 	 * as stored by stfl, bits 32-xxx contain additional facilities.
728 	 * How many facility words are stored depends on the number of
729 	 * doublewords passed to the instruction. The additional facilites
730 	 * are:
731 	 *   Bit 42: decimal floating point facility is installed
732 	 *   Bit 44: perform floating point operation facility is installed
733 	 * translated to:
734 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
735 	 */
736 	if ((elf_hwcap & (1UL << 2)) &&
737 	    __stfle(&facility_list_extended, 1) > 0) {
738 		if ((facility_list_extended & (1ULL << (63 - 42)))
739 		    && (facility_list_extended & (1ULL << (63 - 44))))
740 			elf_hwcap |= 1UL << 6;
741 	}
742 
743 	if (MACHINE_HAS_HPAGE)
744 		elf_hwcap |= 1UL << 7;
745 
746 	switch (S390_lowcore.cpu_id.machine) {
747 	case 0x9672:
748 #if !defined(CONFIG_64BIT)
749 	default:	/* Use "g5" as default for 31 bit kernels. */
750 #endif
751 		strcpy(elf_platform, "g5");
752 		break;
753 	case 0x2064:
754 	case 0x2066:
755 #if defined(CONFIG_64BIT)
756 	default:	/* Use "z900" as default for 64 bit kernels. */
757 #endif
758 		strcpy(elf_platform, "z900");
759 		break;
760 	case 0x2084:
761 	case 0x2086:
762 		strcpy(elf_platform, "z990");
763 		break;
764 	case 0x2094:
765 	case 0x2096:
766 		strcpy(elf_platform, "z9-109");
767 		break;
768 	case 0x2097:
769 	case 0x2098:
770 		strcpy(elf_platform, "z10");
771 		break;
772 	}
773 }
774 
775 /*
776  * Setup function called from init/main.c just after the banner
777  * was printed.
778  */
779 
780 void __init
781 setup_arch(char **cmdline_p)
782 {
783 	/* set up preferred console */
784 	add_preferred_console("ttyS", 0, NULL);
785 
786         /*
787          * print what head.S has found out about the machine
788          */
789 #ifndef CONFIG_64BIT
790 	if (MACHINE_IS_VM)
791 		pr_info("Linux is running as a z/VM "
792 			"guest operating system in 31-bit mode\n");
793 	else
794 		pr_info("Linux is running natively in 31-bit mode\n");
795 	if (MACHINE_HAS_IEEE)
796 		pr_info("The hardware system has IEEE compatible "
797 			"floating point units\n");
798 	else
799 		pr_info("The hardware system has no IEEE compatible "
800 			"floating point units\n");
801 #else /* CONFIG_64BIT */
802 	if (MACHINE_IS_VM)
803 		pr_info("Linux is running as a z/VM "
804 			"guest operating system in 64-bit mode\n");
805 	else if (MACHINE_IS_KVM) {
806 		pr_info("Linux is running under KVM in 64-bit mode\n");
807 		add_preferred_console("hvc", 0, NULL);
808 		s390_virtio_console_init();
809 	} else
810 		pr_info("Linux is running natively in 64-bit mode\n");
811 #endif /* CONFIG_64BIT */
812 
813 	/* Have one command line that is parsed and saved in /proc/cmdline */
814 	/* boot_command_line has been already set up in early.c */
815 	*cmdline_p = boot_command_line;
816 
817         ROOT_DEV = Root_RAM0;
818 
819 	init_mm.start_code = PAGE_OFFSET;
820 	init_mm.end_code = (unsigned long) &_etext;
821 	init_mm.end_data = (unsigned long) &_edata;
822 	init_mm.brk = (unsigned long) &_end;
823 
824 	if (MACHINE_HAS_MVCOS)
825 		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
826 	else
827 		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
828 
829 	parse_early_param();
830 
831 	setup_ipl();
832 	setup_memory_end();
833 	setup_addressing_mode();
834 	setup_memory();
835 	setup_resources();
836 	setup_lowcore();
837 
838         cpu_init();
839 	__cpu_logical_map[0] = stap();
840 	s390_init_cpu_topology();
841 
842 	/*
843 	 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
844 	 */
845 	setup_hwcaps();
846 
847 	/*
848 	 * Create kernel page tables and switch to virtual addressing.
849 	 */
850         paging_init();
851 
852         /* Setup default console */
853 	conmode_default();
854 
855 	/* Setup zfcpdump support */
856 	setup_zfcpdump(console_devno);
857 }
858