xref: /linux/arch/s390/kernel/setup.c (revision 0c93ea4064a209cdc36de8a9a3003d43d08f46f7)
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 
46 #include <asm/ipl.h>
47 #include <asm/uaccess.h>
48 #include <asm/system.h>
49 #include <asm/smp.h>
50 #include <asm/mmu_context.h>
51 #include <asm/cpcmd.h>
52 #include <asm/lowcore.h>
53 #include <asm/irq.h>
54 #include <asm/page.h>
55 #include <asm/ptrace.h>
56 #include <asm/sections.h>
57 #include <asm/ebcdic.h>
58 #include <asm/compat.h>
59 #include <asm/kvm_virtio.h>
60 
61 long psw_kernel_bits	= (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
62 			   PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
63 long psw_user_bits	= (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
64 			   PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
65 			   PSW_MASK_PSTATE | PSW_DEFAULT_KEY);
66 
67 /*
68  * User copy operations.
69  */
70 struct uaccess_ops uaccess;
71 EXPORT_SYMBOL(uaccess);
72 
73 /*
74  * Machine setup..
75  */
76 unsigned int console_mode = 0;
77 unsigned int console_devno = -1;
78 unsigned int console_irq = -1;
79 unsigned long machine_flags;
80 unsigned long elf_hwcap = 0;
81 char elf_platform[ELF_PLATFORM_SIZE];
82 
83 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
84 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
85 
86 int __initdata memory_end_set;
87 unsigned long __initdata memory_end;
88 
89 /*
90  * This is set up by the setup-routine at boot-time
91  * for S390 need to find out, what we have to setup
92  * using address 0x10400 ...
93  */
94 
95 #include <asm/setup.h>
96 
97 static struct resource code_resource = {
98 	.name  = "Kernel code",
99 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
100 };
101 
102 static struct resource data_resource = {
103 	.name = "Kernel data",
104 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
105 };
106 
107 /*
108  * cpu_init() initializes state that is per-CPU.
109  */
110 void __cpuinit cpu_init(void)
111 {
112         int addr = hard_smp_processor_id();
113 
114         /*
115          * Store processor id in lowcore (used e.g. in timer_interrupt)
116          */
117 	get_cpu_id(&S390_lowcore.cpu_data.cpu_id);
118         S390_lowcore.cpu_data.cpu_addr = addr;
119 
120         /*
121          * Force FPU initialization:
122          */
123         clear_thread_flag(TIF_USEDFPU);
124         clear_used_math();
125 
126 	atomic_inc(&init_mm.mm_count);
127 	current->active_mm = &init_mm;
128         if (current->mm)
129                 BUG();
130         enter_lazy_tlb(&init_mm, current);
131 }
132 
133 /*
134  * condev= and conmode= setup parameter.
135  */
136 
137 static int __init condev_setup(char *str)
138 {
139 	int vdev;
140 
141 	vdev = simple_strtoul(str, &str, 0);
142 	if (vdev >= 0 && vdev < 65536) {
143 		console_devno = vdev;
144 		console_irq = -1;
145 	}
146 	return 1;
147 }
148 
149 __setup("condev=", condev_setup);
150 
151 static int __init conmode_setup(char *str)
152 {
153 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
154 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
155                 SET_CONSOLE_SCLP;
156 #endif
157 #if defined(CONFIG_TN3215_CONSOLE)
158 	if (strncmp(str, "3215", 5) == 0)
159 		SET_CONSOLE_3215;
160 #endif
161 #if defined(CONFIG_TN3270_CONSOLE)
162 	if (strncmp(str, "3270", 5) == 0)
163 		SET_CONSOLE_3270;
164 #endif
165         return 1;
166 }
167 
168 __setup("conmode=", conmode_setup);
169 
170 static void __init conmode_default(void)
171 {
172 	char query_buffer[1024];
173 	char *ptr;
174 
175         if (MACHINE_IS_VM) {
176 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
177 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
178 		ptr = strstr(query_buffer, "SUBCHANNEL =");
179 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
180 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
181 		ptr = strstr(query_buffer, "CONMODE");
182 		/*
183 		 * Set the conmode to 3215 so that the device recognition
184 		 * will set the cu_type of the console to 3215. If the
185 		 * conmode is 3270 and we don't set it back then both
186 		 * 3215 and the 3270 driver will try to access the console
187 		 * device (3215 as console and 3270 as normal tty).
188 		 */
189 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
190 		if (ptr == NULL) {
191 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
192 			SET_CONSOLE_SCLP;
193 #endif
194 			return;
195 		}
196 		if (strncmp(ptr + 8, "3270", 4) == 0) {
197 #if defined(CONFIG_TN3270_CONSOLE)
198 			SET_CONSOLE_3270;
199 #elif defined(CONFIG_TN3215_CONSOLE)
200 			SET_CONSOLE_3215;
201 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
202 			SET_CONSOLE_SCLP;
203 #endif
204 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
205 #if defined(CONFIG_TN3215_CONSOLE)
206 			SET_CONSOLE_3215;
207 #elif defined(CONFIG_TN3270_CONSOLE)
208 			SET_CONSOLE_3270;
209 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
210 			SET_CONSOLE_SCLP;
211 #endif
212 		}
213 	} else {
214 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
215 		SET_CONSOLE_SCLP;
216 #endif
217 	}
218 }
219 
220 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
221 static void __init setup_zfcpdump(unsigned int console_devno)
222 {
223 	static char str[41];
224 
225 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
226 		return;
227 	if (console_devno != -1)
228 		sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
229 			ipl_info.data.fcp.dev_id.devno, console_devno);
230 	else
231 		sprintf(str, " cio_ignore=all,!0.0.%04x",
232 			ipl_info.data.fcp.dev_id.devno);
233 	strcat(boot_command_line, str);
234 	console_loglevel = 2;
235 }
236 #else
237 static inline void setup_zfcpdump(unsigned int console_devno) {}
238 #endif /* CONFIG_ZFCPDUMP */
239 
240  /*
241  * Reboot, halt and power_off stubs. They just call _machine_restart,
242  * _machine_halt or _machine_power_off.
243  */
244 
245 void machine_restart(char *command)
246 {
247 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
248 		/*
249 		 * Only unblank the console if we are called in enabled
250 		 * context or a bust_spinlocks cleared the way for us.
251 		 */
252 		console_unblank();
253 	_machine_restart(command);
254 }
255 
256 void machine_halt(void)
257 {
258 	if (!in_interrupt() || oops_in_progress)
259 		/*
260 		 * Only unblank the console if we are called in enabled
261 		 * context or a bust_spinlocks cleared the way for us.
262 		 */
263 		console_unblank();
264 	_machine_halt();
265 }
266 
267 void machine_power_off(void)
268 {
269 	if (!in_interrupt() || oops_in_progress)
270 		/*
271 		 * Only unblank the console if we are called in enabled
272 		 * context or a bust_spinlocks cleared the way for us.
273 		 */
274 		console_unblank();
275 	_machine_power_off();
276 }
277 
278 /*
279  * Dummy power off function.
280  */
281 void (*pm_power_off)(void) = machine_power_off;
282 
283 static int __init early_parse_mem(char *p)
284 {
285 	memory_end = memparse(p, &p);
286 	memory_end_set = 1;
287 	return 0;
288 }
289 early_param("mem", early_parse_mem);
290 
291 #ifdef CONFIG_S390_SWITCH_AMODE
292 #ifdef CONFIG_PGSTE
293 unsigned int switch_amode = 1;
294 #else
295 unsigned int switch_amode = 0;
296 #endif
297 EXPORT_SYMBOL_GPL(switch_amode);
298 
299 static int set_amode_and_uaccess(unsigned long user_amode,
300 				 unsigned long user32_amode)
301 {
302 	psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
303 			PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
304 			PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
305 #ifdef CONFIG_COMPAT
306 	psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
307 			  PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
308 			  PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
309 	psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
310 			  PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
311 			  PSW32_MASK_PSTATE;
312 #endif
313 	psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
314 			  PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
315 
316 	if (MACHINE_HAS_MVCOS) {
317 		memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
318 		return 1;
319 	} else {
320 		memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
321 		return 0;
322 	}
323 }
324 
325 /*
326  * Switch kernel/user addressing modes?
327  */
328 static int __init early_parse_switch_amode(char *p)
329 {
330 	switch_amode = 1;
331 	return 0;
332 }
333 early_param("switch_amode", early_parse_switch_amode);
334 
335 #else /* CONFIG_S390_SWITCH_AMODE */
336 static inline int set_amode_and_uaccess(unsigned long user_amode,
337 					unsigned long user32_amode)
338 {
339 	return 0;
340 }
341 #endif /* CONFIG_S390_SWITCH_AMODE */
342 
343 #ifdef CONFIG_S390_EXEC_PROTECT
344 unsigned int s390_noexec = 0;
345 EXPORT_SYMBOL_GPL(s390_noexec);
346 
347 /*
348  * Enable execute protection?
349  */
350 static int __init early_parse_noexec(char *p)
351 {
352 	if (!strncmp(p, "off", 3))
353 		return 0;
354 	switch_amode = 1;
355 	s390_noexec = 1;
356 	return 0;
357 }
358 early_param("noexec", early_parse_noexec);
359 #endif /* CONFIG_S390_EXEC_PROTECT */
360 
361 static void setup_addressing_mode(void)
362 {
363 	if (s390_noexec) {
364 		if (set_amode_and_uaccess(PSW_ASC_SECONDARY,
365 					  PSW32_ASC_SECONDARY))
366 			pr_info("Execute protection active, "
367 				"mvcos available\n");
368 		else
369 			pr_info("Execute protection active, "
370 				"mvcos not available\n");
371 	} else if (switch_amode) {
372 		if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
373 			pr_info("Address spaces switched, "
374 				"mvcos available\n");
375 		else
376 			pr_info("Address spaces switched, "
377 				"mvcos not available\n");
378 	}
379 #ifdef CONFIG_TRACE_IRQFLAGS
380 	sysc_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
381 	io_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
382 #endif
383 }
384 
385 static void __init
386 setup_lowcore(void)
387 {
388 	struct _lowcore *lc;
389 	int lc_pages;
390 
391 	/*
392 	 * Setup lowcore for boot cpu
393 	 */
394 	lc_pages = sizeof(void *) == 8 ? 2 : 1;
395 	lc = (struct _lowcore *)
396 		__alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
397 	memset(lc, 0, lc_pages * PAGE_SIZE);
398 	lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
399 	lc->restart_psw.addr =
400 		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
401 	if (switch_amode)
402 		lc->restart_psw.mask |= PSW_ASC_HOME;
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->clock_comparator = -1ULL;
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_64BIT
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 #else
434 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
435 #endif
436 	set_prefix((u32)(unsigned long) lc);
437 }
438 
439 static void __init
440 setup_resources(void)
441 {
442 	struct resource *res, *sub_res;
443 	int i;
444 
445 	code_resource.start = (unsigned long) &_text;
446 	code_resource.end = (unsigned long) &_etext - 1;
447 	data_resource.start = (unsigned long) &_etext;
448 	data_resource.end = (unsigned long) &_edata - 1;
449 
450 	for (i = 0; i < MEMORY_CHUNKS; i++) {
451 		if (!memory_chunk[i].size)
452 			continue;
453 		res = alloc_bootmem_low(sizeof(struct resource));
454 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
455 		switch (memory_chunk[i].type) {
456 		case CHUNK_READ_WRITE:
457 			res->name = "System RAM";
458 			break;
459 		case CHUNK_READ_ONLY:
460 			res->name = "System ROM";
461 			res->flags |= IORESOURCE_READONLY;
462 			break;
463 		default:
464 			res->name = "reserved";
465 		}
466 		res->start = memory_chunk[i].addr;
467 		res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
468 		request_resource(&iomem_resource, res);
469 
470 		if (code_resource.start >= res->start  &&
471 			code_resource.start <= res->end &&
472 			code_resource.end > res->end) {
473 			sub_res = alloc_bootmem_low(sizeof(struct resource));
474 			memcpy(sub_res, &code_resource,
475 				sizeof(struct resource));
476 			sub_res->end = res->end;
477 			code_resource.start = res->end + 1;
478 			request_resource(res, sub_res);
479 		}
480 
481 		if (code_resource.start >= res->start &&
482 			code_resource.start <= res->end &&
483 			code_resource.end <= res->end)
484 			request_resource(res, &code_resource);
485 
486 		if (data_resource.start >= res->start &&
487 			data_resource.start <= res->end &&
488 			data_resource.end > res->end) {
489 			sub_res = alloc_bootmem_low(sizeof(struct resource));
490 			memcpy(sub_res, &data_resource,
491 				sizeof(struct resource));
492 			sub_res->end = res->end;
493 			data_resource.start = res->end + 1;
494 			request_resource(res, sub_res);
495 		}
496 
497 		if (data_resource.start >= res->start &&
498 			data_resource.start <= res->end &&
499 			data_resource.end <= res->end)
500 			request_resource(res, &data_resource);
501 	}
502 }
503 
504 unsigned long real_memory_size;
505 EXPORT_SYMBOL_GPL(real_memory_size);
506 
507 static void __init setup_memory_end(void)
508 {
509 	unsigned long memory_size;
510 	unsigned long max_mem;
511 	int i;
512 
513 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
514 	if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
515 		memory_end = ZFCPDUMP_HSA_SIZE;
516 		memory_end_set = 1;
517 	}
518 #endif
519 	memory_size = 0;
520 	memory_end &= PAGE_MASK;
521 
522 	max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
523 	memory_end = min(max_mem, memory_end);
524 
525 	/*
526 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
527 	 * extra checks that HOLES_IN_ZONE would require.
528 	 */
529 	for (i = 0; i < MEMORY_CHUNKS; i++) {
530 		unsigned long start, end;
531 		struct mem_chunk *chunk;
532 		unsigned long align;
533 
534 		chunk = &memory_chunk[i];
535 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
536 		start = (chunk->addr + align - 1) & ~(align - 1);
537 		end = (chunk->addr + chunk->size) & ~(align - 1);
538 		if (start >= end)
539 			memset(chunk, 0, sizeof(*chunk));
540 		else {
541 			chunk->addr = start;
542 			chunk->size = end - start;
543 		}
544 	}
545 
546 	for (i = 0; i < MEMORY_CHUNKS; i++) {
547 		struct mem_chunk *chunk = &memory_chunk[i];
548 
549 		real_memory_size = max(real_memory_size,
550 				       chunk->addr + chunk->size);
551 		if (chunk->addr >= max_mem) {
552 			memset(chunk, 0, sizeof(*chunk));
553 			continue;
554 		}
555 		if (chunk->addr + chunk->size > max_mem)
556 			chunk->size = max_mem - chunk->addr;
557 		memory_size = max(memory_size, chunk->addr + chunk->size);
558 	}
559 	if (!memory_end)
560 		memory_end = memory_size;
561 }
562 
563 static void __init
564 setup_memory(void)
565 {
566         unsigned long bootmap_size;
567 	unsigned long start_pfn, end_pfn;
568 	int i;
569 
570 	/*
571 	 * partially used pages are not usable - thus
572 	 * we are rounding upwards:
573 	 */
574 	start_pfn = PFN_UP(__pa(&_end));
575 	end_pfn = max_pfn = PFN_DOWN(memory_end);
576 
577 #ifdef CONFIG_BLK_DEV_INITRD
578 	/*
579 	 * Move the initrd in case the bitmap of the bootmem allocater
580 	 * would overwrite it.
581 	 */
582 
583 	if (INITRD_START && INITRD_SIZE) {
584 		unsigned long bmap_size;
585 		unsigned long start;
586 
587 		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
588 		bmap_size = PFN_PHYS(bmap_size);
589 
590 		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
591 			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
592 
593 			if (start + INITRD_SIZE > memory_end) {
594 				pr_err("initrd extends beyond end of "
595 				       "memory (0x%08lx > 0x%08lx) "
596 				       "disabling initrd\n",
597 				       start + INITRD_SIZE, memory_end);
598 				INITRD_START = INITRD_SIZE = 0;
599 			} else {
600 				pr_info("Moving initrd (0x%08lx -> "
601 					"0x%08lx, size: %ld)\n",
602 					INITRD_START, start, INITRD_SIZE);
603 				memmove((void *) start, (void *) INITRD_START,
604 					INITRD_SIZE);
605 				INITRD_START = start;
606 			}
607 		}
608 	}
609 #endif
610 
611 	/*
612 	 * Initialize the boot-time allocator
613 	 */
614 	bootmap_size = init_bootmem(start_pfn, end_pfn);
615 
616 	/*
617 	 * Register RAM areas with the bootmem allocator.
618 	 */
619 
620 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
621 		unsigned long start_chunk, end_chunk, pfn;
622 
623 		if (memory_chunk[i].type != CHUNK_READ_WRITE)
624 			continue;
625 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
626 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
627 		end_chunk = min(end_chunk, end_pfn);
628 		if (start_chunk >= end_chunk)
629 			continue;
630 		add_active_range(0, start_chunk, end_chunk);
631 		pfn = max(start_chunk, start_pfn);
632 		for (; pfn < end_chunk; pfn++)
633 			page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
634 	}
635 
636 	psw_set_key(PAGE_DEFAULT_KEY);
637 
638 	free_bootmem_with_active_regions(0, max_pfn);
639 
640 	/*
641 	 * Reserve memory used for lowcore/command line/kernel image.
642 	 */
643 	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
644 	reserve_bootmem((unsigned long)_stext,
645 			PFN_PHYS(start_pfn) - (unsigned long)_stext,
646 			BOOTMEM_DEFAULT);
647 	/*
648 	 * Reserve the bootmem bitmap itself as well. We do this in two
649 	 * steps (first step was init_bootmem()) because this catches
650 	 * the (very unlikely) case of us accidentally initializing the
651 	 * bootmem allocator with an invalid RAM area.
652 	 */
653 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
654 			BOOTMEM_DEFAULT);
655 
656 #ifdef CONFIG_BLK_DEV_INITRD
657 	if (INITRD_START && INITRD_SIZE) {
658 		if (INITRD_START + INITRD_SIZE <= memory_end) {
659 			reserve_bootmem(INITRD_START, INITRD_SIZE,
660 					BOOTMEM_DEFAULT);
661 			initrd_start = INITRD_START;
662 			initrd_end = initrd_start + INITRD_SIZE;
663 		} else {
664 			pr_err("initrd extends beyond end of "
665 			       "memory (0x%08lx > 0x%08lx) "
666 			       "disabling initrd\n",
667 			       initrd_start + INITRD_SIZE, memory_end);
668 			initrd_start = initrd_end = 0;
669 		}
670 	}
671 #endif
672 }
673 
674 /*
675  * Setup hardware capabilities.
676  */
677 static void __init setup_hwcaps(void)
678 {
679 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
680 	struct cpuinfo_S390 *cpuinfo = &S390_lowcore.cpu_data;
681 	unsigned long long facility_list_extended;
682 	unsigned int facility_list;
683 	int i;
684 
685 	facility_list = stfl();
686 	/*
687 	 * The store facility list bits numbers as found in the principles
688 	 * of operation are numbered with bit 1UL<<31 as number 0 to
689 	 * bit 1UL<<0 as number 31.
690 	 *   Bit 0: instructions named N3, "backported" to esa-mode
691 	 *   Bit 2: z/Architecture mode is active
692 	 *   Bit 7: the store-facility-list-extended facility is installed
693 	 *   Bit 17: the message-security assist is installed
694 	 *   Bit 19: the long-displacement facility is installed
695 	 *   Bit 21: the extended-immediate facility is installed
696 	 * These get translated to:
697 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
698 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
699 	 *   HWCAP_S390_LDISP bit 4, and HWCAP_S390_EIMM bit 5.
700 	 */
701 	for (i = 0; i < 6; i++)
702 		if (facility_list & (1UL << (31 - stfl_bits[i])))
703 			elf_hwcap |= 1UL << i;
704 
705 	/*
706 	 * Check for additional facilities with store-facility-list-extended.
707 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
708 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
709 	 * as stored by stfl, bits 32-xxx contain additional facilities.
710 	 * How many facility words are stored depends on the number of
711 	 * doublewords passed to the instruction. The additional facilites
712 	 * are:
713 	 *   Bit 43: decimal floating point facility is installed
714 	 * translated to:
715 	 *   HWCAP_S390_DFP bit 6.
716 	 */
717 	if ((elf_hwcap & (1UL << 2)) &&
718 	    __stfle(&facility_list_extended, 1) > 0) {
719 		if (facility_list_extended & (1ULL << (64 - 43)))
720 			elf_hwcap |= 1UL << 6;
721 	}
722 
723 	if (MACHINE_HAS_HPAGE)
724 		elf_hwcap |= 1UL << 7;
725 
726 	switch (cpuinfo->cpu_id.machine) {
727 	case 0x9672:
728 #if !defined(CONFIG_64BIT)
729 	default:	/* Use "g5" as default for 31 bit kernels. */
730 #endif
731 		strcpy(elf_platform, "g5");
732 		break;
733 	case 0x2064:
734 	case 0x2066:
735 #if defined(CONFIG_64BIT)
736 	default:	/* Use "z900" as default for 64 bit kernels. */
737 #endif
738 		strcpy(elf_platform, "z900");
739 		break;
740 	case 0x2084:
741 	case 0x2086:
742 		strcpy(elf_platform, "z990");
743 		break;
744 	case 0x2094:
745 	case 0x2096:
746 		strcpy(elf_platform, "z9-109");
747 		break;
748 	case 0x2097:
749 	case 0x2098:
750 		strcpy(elf_platform, "z10");
751 		break;
752 	}
753 }
754 
755 /*
756  * Setup function called from init/main.c just after the banner
757  * was printed.
758  */
759 
760 void __init
761 setup_arch(char **cmdline_p)
762 {
763 	/* set up preferred console */
764 	add_preferred_console("ttyS", 0, NULL);
765 
766         /*
767          * print what head.S has found out about the machine
768          */
769 #ifndef CONFIG_64BIT
770 	if (MACHINE_IS_VM)
771 		pr_info("Linux is running as a z/VM "
772 			"guest operating system in 31-bit mode\n");
773 	else
774 		pr_info("Linux is running natively in 31-bit mode\n");
775 	if (MACHINE_HAS_IEEE)
776 		pr_info("The hardware system has IEEE compatible "
777 			"floating point units\n");
778 	else
779 		pr_info("The hardware system has no IEEE compatible "
780 			"floating point units\n");
781 #else /* CONFIG_64BIT */
782 	if (MACHINE_IS_VM)
783 		pr_info("Linux is running as a z/VM "
784 			"guest operating system in 64-bit mode\n");
785 	else if (MACHINE_IS_KVM) {
786 		pr_info("Linux is running under KVM in 64-bit mode\n");
787 		add_preferred_console("hvc", 0, NULL);
788 		s390_virtio_console_init();
789 	} else
790 		pr_info("Linux is running natively in 64-bit mode\n");
791 #endif /* CONFIG_64BIT */
792 
793 	/* Have one command line that is parsed and saved in /proc/cmdline */
794 	/* boot_command_line has been already set up in early.c */
795 	*cmdline_p = boot_command_line;
796 
797         ROOT_DEV = Root_RAM0;
798 
799 	init_mm.start_code = PAGE_OFFSET;
800 	init_mm.end_code = (unsigned long) &_etext;
801 	init_mm.end_data = (unsigned long) &_edata;
802 	init_mm.brk = (unsigned long) &_end;
803 
804 	if (MACHINE_HAS_MVCOS)
805 		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
806 	else
807 		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
808 
809 	parse_early_param();
810 
811 	setup_ipl();
812 	setup_memory_end();
813 	setup_addressing_mode();
814 	setup_memory();
815 	setup_resources();
816 	setup_lowcore();
817 
818         cpu_init();
819         __cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
820 	s390_init_cpu_topology();
821 
822 	/*
823 	 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
824 	 */
825 	setup_hwcaps();
826 
827 	/*
828 	 * Create kernel page tables and switch to virtual addressing.
829 	 */
830         paging_init();
831 
832         /* Setup default console */
833 	conmode_default();
834 
835 	/* Setup zfcpdump support */
836 	setup_zfcpdump(console_devno);
837 }
838