xref: /openbmc/linux/arch/s390/kernel/setup.c (revision a09d2831)
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 void __init set_preferred_console(void)
158 {
159 	if (MACHINE_IS_KVM)
160 		add_preferred_console("hvc", 0, NULL);
161 	else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
162 		add_preferred_console("ttyS", 0, NULL);
163 	else if (CONSOLE_IS_3270)
164 		add_preferred_console("tty3270", 0, NULL);
165 }
166 
167 static int __init conmode_setup(char *str)
168 {
169 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
170 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
171                 SET_CONSOLE_SCLP;
172 #endif
173 #if defined(CONFIG_TN3215_CONSOLE)
174 	if (strncmp(str, "3215", 5) == 0)
175 		SET_CONSOLE_3215;
176 #endif
177 #if defined(CONFIG_TN3270_CONSOLE)
178 	if (strncmp(str, "3270", 5) == 0)
179 		SET_CONSOLE_3270;
180 #endif
181 	set_preferred_console();
182         return 1;
183 }
184 
185 __setup("conmode=", conmode_setup);
186 
187 static void __init conmode_default(void)
188 {
189 	char query_buffer[1024];
190 	char *ptr;
191 
192         if (MACHINE_IS_VM) {
193 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
194 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
195 		ptr = strstr(query_buffer, "SUBCHANNEL =");
196 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
197 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
198 		ptr = strstr(query_buffer, "CONMODE");
199 		/*
200 		 * Set the conmode to 3215 so that the device recognition
201 		 * will set the cu_type of the console to 3215. If the
202 		 * conmode is 3270 and we don't set it back then both
203 		 * 3215 and the 3270 driver will try to access the console
204 		 * device (3215 as console and 3270 as normal tty).
205 		 */
206 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
207 		if (ptr == NULL) {
208 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
209 			SET_CONSOLE_SCLP;
210 #endif
211 			return;
212 		}
213 		if (strncmp(ptr + 8, "3270", 4) == 0) {
214 #if defined(CONFIG_TN3270_CONSOLE)
215 			SET_CONSOLE_3270;
216 #elif defined(CONFIG_TN3215_CONSOLE)
217 			SET_CONSOLE_3215;
218 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
219 			SET_CONSOLE_SCLP;
220 #endif
221 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
222 #if defined(CONFIG_TN3215_CONSOLE)
223 			SET_CONSOLE_3215;
224 #elif defined(CONFIG_TN3270_CONSOLE)
225 			SET_CONSOLE_3270;
226 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
227 			SET_CONSOLE_SCLP;
228 #endif
229 		}
230 	} else {
231 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
232 		SET_CONSOLE_SCLP;
233 #endif
234 	}
235 }
236 
237 #ifdef CONFIG_ZFCPDUMP
238 static void __init setup_zfcpdump(unsigned int console_devno)
239 {
240 	static char str[41];
241 
242 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
243 		return;
244 	if (console_devno != -1)
245 		sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
246 			ipl_info.data.fcp.dev_id.devno, console_devno);
247 	else
248 		sprintf(str, " cio_ignore=all,!0.0.%04x",
249 			ipl_info.data.fcp.dev_id.devno);
250 	strcat(boot_command_line, str);
251 	console_loglevel = 2;
252 }
253 #else
254 static inline void setup_zfcpdump(unsigned int console_devno) {}
255 #endif /* CONFIG_ZFCPDUMP */
256 
257  /*
258  * Reboot, halt and power_off stubs. They just call _machine_restart,
259  * _machine_halt or _machine_power_off.
260  */
261 
262 void machine_restart(char *command)
263 {
264 	if ((!in_interrupt() && !in_atomic()) || 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_restart(command);
271 }
272 
273 void machine_halt(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_halt();
282 }
283 
284 void machine_power_off(void)
285 {
286 	if (!in_interrupt() || oops_in_progress)
287 		/*
288 		 * Only unblank the console if we are called in enabled
289 		 * context or a bust_spinlocks cleared the way for us.
290 		 */
291 		console_unblank();
292 	_machine_power_off();
293 }
294 
295 /*
296  * Dummy power off function.
297  */
298 void (*pm_power_off)(void) = machine_power_off;
299 
300 static int __init early_parse_mem(char *p)
301 {
302 	memory_end = memparse(p, &p);
303 	memory_end_set = 1;
304 	return 0;
305 }
306 early_param("mem", early_parse_mem);
307 
308 unsigned int user_mode = HOME_SPACE_MODE;
309 EXPORT_SYMBOL_GPL(user_mode);
310 
311 static int set_amode_and_uaccess(unsigned long user_amode,
312 				 unsigned long user32_amode)
313 {
314 	psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
315 			PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
316 			PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
317 #ifdef CONFIG_COMPAT
318 	psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
319 			  PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
320 			  PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
321 	psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
322 			  PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
323 			  PSW32_MASK_PSTATE;
324 #endif
325 	psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
326 			  PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
327 
328 	if (MACHINE_HAS_MVCOS) {
329 		memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
330 		return 1;
331 	} else {
332 		memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
333 		return 0;
334 	}
335 }
336 
337 /*
338  * Switch kernel/user addressing modes?
339  */
340 static int __init early_parse_switch_amode(char *p)
341 {
342 	if (user_mode != SECONDARY_SPACE_MODE)
343 		user_mode = PRIMARY_SPACE_MODE;
344 	return 0;
345 }
346 early_param("switch_amode", early_parse_switch_amode);
347 
348 static int __init early_parse_user_mode(char *p)
349 {
350 	if (p && strcmp(p, "primary") == 0)
351 		user_mode = PRIMARY_SPACE_MODE;
352 #ifdef CONFIG_S390_EXEC_PROTECT
353 	else if (p && strcmp(p, "secondary") == 0)
354 		user_mode = SECONDARY_SPACE_MODE;
355 #endif
356 	else if (!p || strcmp(p, "home") == 0)
357 		user_mode = HOME_SPACE_MODE;
358 	else
359 		return 1;
360 	return 0;
361 }
362 early_param("user_mode", early_parse_user_mode);
363 
364 #ifdef CONFIG_S390_EXEC_PROTECT
365 /*
366  * Enable execute protection?
367  */
368 static int __init early_parse_noexec(char *p)
369 {
370 	if (!strncmp(p, "off", 3))
371 		return 0;
372 	user_mode = SECONDARY_SPACE_MODE;
373 	return 0;
374 }
375 early_param("noexec", early_parse_noexec);
376 #endif /* CONFIG_S390_EXEC_PROTECT */
377 
378 static void setup_addressing_mode(void)
379 {
380 	if (user_mode == SECONDARY_SPACE_MODE) {
381 		if (set_amode_and_uaccess(PSW_ASC_SECONDARY,
382 					  PSW32_ASC_SECONDARY))
383 			pr_info("Execute protection active, "
384 				"mvcos available\n");
385 		else
386 			pr_info("Execute protection active, "
387 				"mvcos not available\n");
388 	} else if (user_mode == PRIMARY_SPACE_MODE) {
389 		if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
390 			pr_info("Address spaces switched, "
391 				"mvcos available\n");
392 		else
393 			pr_info("Address spaces switched, "
394 				"mvcos not available\n");
395 	}
396 #ifdef CONFIG_TRACE_IRQFLAGS
397 	sysc_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
398 	io_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
399 #endif
400 }
401 
402 static void __init
403 setup_lowcore(void)
404 {
405 	struct _lowcore *lc;
406 	int lc_pages;
407 
408 	/*
409 	 * Setup lowcore for boot cpu
410 	 */
411 	lc_pages = sizeof(void *) == 8 ? 2 : 1;
412 	lc = (struct _lowcore *)
413 		__alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
414 	memset(lc, 0, lc_pages * PAGE_SIZE);
415 	lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
416 	lc->restart_psw.addr =
417 		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
418 	if (user_mode != HOME_SPACE_MODE)
419 		lc->restart_psw.mask |= PSW_ASC_HOME;
420 	lc->external_new_psw.mask = psw_kernel_bits;
421 	lc->external_new_psw.addr =
422 		PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
423 	lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
424 	lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
425 	lc->program_new_psw.mask = psw_kernel_bits;
426 	lc->program_new_psw.addr =
427 		PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
428 	lc->mcck_new_psw.mask =
429 		psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
430 	lc->mcck_new_psw.addr =
431 		PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
432 	lc->io_new_psw.mask = psw_kernel_bits;
433 	lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
434 	lc->clock_comparator = -1ULL;
435 	lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
436 	lc->async_stack = (unsigned long)
437 		__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
438 	lc->panic_stack = (unsigned long)
439 		__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
440 	lc->current_task = (unsigned long) init_thread_union.thread_info.task;
441 	lc->thread_info = (unsigned long) &init_thread_union;
442 	lc->machine_flags = S390_lowcore.machine_flags;
443 #ifndef CONFIG_64BIT
444 	if (MACHINE_HAS_IEEE) {
445 		lc->extended_save_area_addr = (__u32)
446 			__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
447 		/* enable extended save area */
448 		__ctl_set_bit(14, 29);
449 	}
450 #else
451 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
452 #endif
453 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
454 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
455 	lc->exit_timer = S390_lowcore.exit_timer;
456 	lc->user_timer = S390_lowcore.user_timer;
457 	lc->system_timer = S390_lowcore.system_timer;
458 	lc->steal_timer = S390_lowcore.steal_timer;
459 	lc->last_update_timer = S390_lowcore.last_update_timer;
460 	lc->last_update_clock = S390_lowcore.last_update_clock;
461 	lc->ftrace_func = S390_lowcore.ftrace_func;
462 	set_prefix((u32)(unsigned long) lc);
463 	lowcore_ptr[0] = lc;
464 }
465 
466 static void __init
467 setup_resources(void)
468 {
469 	struct resource *res, *sub_res;
470 	int i;
471 
472 	code_resource.start = (unsigned long) &_text;
473 	code_resource.end = (unsigned long) &_etext - 1;
474 	data_resource.start = (unsigned long) &_etext;
475 	data_resource.end = (unsigned long) &_edata - 1;
476 
477 	for (i = 0; i < MEMORY_CHUNKS; i++) {
478 		if (!memory_chunk[i].size)
479 			continue;
480 		res = alloc_bootmem_low(sizeof(struct resource));
481 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
482 		switch (memory_chunk[i].type) {
483 		case CHUNK_READ_WRITE:
484 			res->name = "System RAM";
485 			break;
486 		case CHUNK_READ_ONLY:
487 			res->name = "System ROM";
488 			res->flags |= IORESOURCE_READONLY;
489 			break;
490 		default:
491 			res->name = "reserved";
492 		}
493 		res->start = memory_chunk[i].addr;
494 		res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
495 		request_resource(&iomem_resource, res);
496 
497 		if (code_resource.start >= res->start  &&
498 			code_resource.start <= res->end &&
499 			code_resource.end > res->end) {
500 			sub_res = alloc_bootmem_low(sizeof(struct resource));
501 			memcpy(sub_res, &code_resource,
502 				sizeof(struct resource));
503 			sub_res->end = res->end;
504 			code_resource.start = res->end + 1;
505 			request_resource(res, sub_res);
506 		}
507 
508 		if (code_resource.start >= res->start &&
509 			code_resource.start <= res->end &&
510 			code_resource.end <= res->end)
511 			request_resource(res, &code_resource);
512 
513 		if (data_resource.start >= res->start &&
514 			data_resource.start <= res->end &&
515 			data_resource.end > res->end) {
516 			sub_res = alloc_bootmem_low(sizeof(struct resource));
517 			memcpy(sub_res, &data_resource,
518 				sizeof(struct resource));
519 			sub_res->end = res->end;
520 			data_resource.start = res->end + 1;
521 			request_resource(res, sub_res);
522 		}
523 
524 		if (data_resource.start >= res->start &&
525 			data_resource.start <= res->end &&
526 			data_resource.end <= res->end)
527 			request_resource(res, &data_resource);
528 	}
529 }
530 
531 unsigned long real_memory_size;
532 EXPORT_SYMBOL_GPL(real_memory_size);
533 
534 static void __init setup_memory_end(void)
535 {
536 	unsigned long memory_size;
537 	unsigned long max_mem;
538 	int i;
539 
540 #ifdef CONFIG_ZFCPDUMP
541 	if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
542 		memory_end = ZFCPDUMP_HSA_SIZE;
543 		memory_end_set = 1;
544 	}
545 #endif
546 	memory_size = 0;
547 	memory_end &= PAGE_MASK;
548 
549 	max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
550 	memory_end = min(max_mem, memory_end);
551 
552 	/*
553 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
554 	 * extra checks that HOLES_IN_ZONE would require.
555 	 */
556 	for (i = 0; i < MEMORY_CHUNKS; i++) {
557 		unsigned long start, end;
558 		struct mem_chunk *chunk;
559 		unsigned long align;
560 
561 		chunk = &memory_chunk[i];
562 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
563 		start = (chunk->addr + align - 1) & ~(align - 1);
564 		end = (chunk->addr + chunk->size) & ~(align - 1);
565 		if (start >= end)
566 			memset(chunk, 0, sizeof(*chunk));
567 		else {
568 			chunk->addr = start;
569 			chunk->size = end - start;
570 		}
571 	}
572 
573 	for (i = 0; i < MEMORY_CHUNKS; i++) {
574 		struct mem_chunk *chunk = &memory_chunk[i];
575 
576 		real_memory_size = max(real_memory_size,
577 				       chunk->addr + chunk->size);
578 		if (chunk->addr >= max_mem) {
579 			memset(chunk, 0, sizeof(*chunk));
580 			continue;
581 		}
582 		if (chunk->addr + chunk->size > max_mem)
583 			chunk->size = max_mem - chunk->addr;
584 		memory_size = max(memory_size, chunk->addr + chunk->size);
585 	}
586 	if (!memory_end)
587 		memory_end = memory_size;
588 }
589 
590 static void __init
591 setup_memory(void)
592 {
593         unsigned long bootmap_size;
594 	unsigned long start_pfn, end_pfn;
595 	int i;
596 
597 	/*
598 	 * partially used pages are not usable - thus
599 	 * we are rounding upwards:
600 	 */
601 	start_pfn = PFN_UP(__pa(&_end));
602 	end_pfn = max_pfn = PFN_DOWN(memory_end);
603 
604 #ifdef CONFIG_BLK_DEV_INITRD
605 	/*
606 	 * Move the initrd in case the bitmap of the bootmem allocater
607 	 * would overwrite it.
608 	 */
609 
610 	if (INITRD_START && INITRD_SIZE) {
611 		unsigned long bmap_size;
612 		unsigned long start;
613 
614 		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
615 		bmap_size = PFN_PHYS(bmap_size);
616 
617 		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
618 			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
619 
620 			if (start + INITRD_SIZE > memory_end) {
621 				pr_err("initrd extends beyond end of "
622 				       "memory (0x%08lx > 0x%08lx) "
623 				       "disabling initrd\n",
624 				       start + INITRD_SIZE, memory_end);
625 				INITRD_START = INITRD_SIZE = 0;
626 			} else {
627 				pr_info("Moving initrd (0x%08lx -> "
628 					"0x%08lx, size: %ld)\n",
629 					INITRD_START, start, INITRD_SIZE);
630 				memmove((void *) start, (void *) INITRD_START,
631 					INITRD_SIZE);
632 				INITRD_START = start;
633 			}
634 		}
635 	}
636 #endif
637 
638 	/*
639 	 * Initialize the boot-time allocator
640 	 */
641 	bootmap_size = init_bootmem(start_pfn, end_pfn);
642 
643 	/*
644 	 * Register RAM areas with the bootmem allocator.
645 	 */
646 
647 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
648 		unsigned long start_chunk, end_chunk, pfn;
649 
650 		if (memory_chunk[i].type != CHUNK_READ_WRITE)
651 			continue;
652 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
653 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
654 		end_chunk = min(end_chunk, end_pfn);
655 		if (start_chunk >= end_chunk)
656 			continue;
657 		add_active_range(0, start_chunk, end_chunk);
658 		pfn = max(start_chunk, start_pfn);
659 		for (; pfn < end_chunk; pfn++)
660 			page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
661 	}
662 
663 	psw_set_key(PAGE_DEFAULT_KEY);
664 
665 	free_bootmem_with_active_regions(0, max_pfn);
666 
667 	/*
668 	 * Reserve memory used for lowcore/command line/kernel image.
669 	 */
670 	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
671 	reserve_bootmem((unsigned long)_stext,
672 			PFN_PHYS(start_pfn) - (unsigned long)_stext,
673 			BOOTMEM_DEFAULT);
674 	/*
675 	 * Reserve the bootmem bitmap itself as well. We do this in two
676 	 * steps (first step was init_bootmem()) because this catches
677 	 * the (very unlikely) case of us accidentally initializing the
678 	 * bootmem allocator with an invalid RAM area.
679 	 */
680 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
681 			BOOTMEM_DEFAULT);
682 
683 #ifdef CONFIG_BLK_DEV_INITRD
684 	if (INITRD_START && INITRD_SIZE) {
685 		if (INITRD_START + INITRD_SIZE <= memory_end) {
686 			reserve_bootmem(INITRD_START, INITRD_SIZE,
687 					BOOTMEM_DEFAULT);
688 			initrd_start = INITRD_START;
689 			initrd_end = initrd_start + INITRD_SIZE;
690 		} else {
691 			pr_err("initrd extends beyond end of "
692 			       "memory (0x%08lx > 0x%08lx) "
693 			       "disabling initrd\n",
694 			       initrd_start + INITRD_SIZE, memory_end);
695 			initrd_start = initrd_end = 0;
696 		}
697 	}
698 #endif
699 }
700 
701 /*
702  * Setup hardware capabilities.
703  */
704 static void __init setup_hwcaps(void)
705 {
706 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
707 	unsigned long long facility_list_extended;
708 	unsigned int facility_list;
709 	int i;
710 
711 	facility_list = stfl();
712 	/*
713 	 * The store facility list bits numbers as found in the principles
714 	 * of operation are numbered with bit 1UL<<31 as number 0 to
715 	 * bit 1UL<<0 as number 31.
716 	 *   Bit 0: instructions named N3, "backported" to esa-mode
717 	 *   Bit 2: z/Architecture mode is active
718 	 *   Bit 7: the store-facility-list-extended facility is installed
719 	 *   Bit 17: the message-security assist is installed
720 	 *   Bit 19: the long-displacement facility is installed
721 	 *   Bit 21: the extended-immediate facility is installed
722 	 *   Bit 22: extended-translation facility 3 is installed
723 	 *   Bit 30: extended-translation facility 3 enhancement facility
724 	 * These get translated to:
725 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
726 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
727 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
728 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
729 	 */
730 	for (i = 0; i < 6; i++)
731 		if (facility_list & (1UL << (31 - stfl_bits[i])))
732 			elf_hwcap |= 1UL << i;
733 
734 	if ((facility_list & (1UL << (31 - 22)))
735 	    && (facility_list & (1UL << (31 - 30))))
736 		elf_hwcap |= HWCAP_S390_ETF3EH;
737 
738 	/*
739 	 * Check for additional facilities with store-facility-list-extended.
740 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
741 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
742 	 * as stored by stfl, bits 32-xxx contain additional facilities.
743 	 * How many facility words are stored depends on the number of
744 	 * doublewords passed to the instruction. The additional facilites
745 	 * are:
746 	 *   Bit 42: decimal floating point facility is installed
747 	 *   Bit 44: perform floating point operation facility is installed
748 	 * translated to:
749 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
750 	 */
751 	if ((elf_hwcap & (1UL << 2)) &&
752 	    __stfle(&facility_list_extended, 1) > 0) {
753 		if ((facility_list_extended & (1ULL << (63 - 42)))
754 		    && (facility_list_extended & (1ULL << (63 - 44))))
755 			elf_hwcap |= HWCAP_S390_DFP;
756 	}
757 
758 	/*
759 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
760 	 */
761 	if (MACHINE_HAS_HPAGE)
762 		elf_hwcap |= HWCAP_S390_HPAGE;
763 
764 	/*
765 	 * 64-bit register support for 31-bit processes
766 	 * HWCAP_S390_HIGH_GPRS is bit 9.
767 	 */
768 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
769 
770 	switch (S390_lowcore.cpu_id.machine) {
771 	case 0x9672:
772 #if !defined(CONFIG_64BIT)
773 	default:	/* Use "g5" as default for 31 bit kernels. */
774 #endif
775 		strcpy(elf_platform, "g5");
776 		break;
777 	case 0x2064:
778 	case 0x2066:
779 #if defined(CONFIG_64BIT)
780 	default:	/* Use "z900" as default for 64 bit kernels. */
781 #endif
782 		strcpy(elf_platform, "z900");
783 		break;
784 	case 0x2084:
785 	case 0x2086:
786 		strcpy(elf_platform, "z990");
787 		break;
788 	case 0x2094:
789 	case 0x2096:
790 		strcpy(elf_platform, "z9-109");
791 		break;
792 	case 0x2097:
793 	case 0x2098:
794 		strcpy(elf_platform, "z10");
795 		break;
796 	}
797 }
798 
799 /*
800  * Setup function called from init/main.c just after the banner
801  * was printed.
802  */
803 
804 void __init
805 setup_arch(char **cmdline_p)
806 {
807         /*
808          * print what head.S has found out about the machine
809          */
810 #ifndef CONFIG_64BIT
811 	if (MACHINE_IS_VM)
812 		pr_info("Linux is running as a z/VM "
813 			"guest operating system in 31-bit mode\n");
814 	else
815 		pr_info("Linux is running natively in 31-bit mode\n");
816 	if (MACHINE_HAS_IEEE)
817 		pr_info("The hardware system has IEEE compatible "
818 			"floating point units\n");
819 	else
820 		pr_info("The hardware system has no IEEE compatible "
821 			"floating point units\n");
822 #else /* CONFIG_64BIT */
823 	if (MACHINE_IS_VM)
824 		pr_info("Linux is running as a z/VM "
825 			"guest operating system in 64-bit mode\n");
826 	else if (MACHINE_IS_KVM)
827 		pr_info("Linux is running under KVM in 64-bit mode\n");
828 	else
829 		pr_info("Linux is running natively in 64-bit mode\n");
830 #endif /* CONFIG_64BIT */
831 
832 	/* Have one command line that is parsed and saved in /proc/cmdline */
833 	/* boot_command_line has been already set up in early.c */
834 	*cmdline_p = boot_command_line;
835 
836         ROOT_DEV = Root_RAM0;
837 
838 	init_mm.start_code = PAGE_OFFSET;
839 	init_mm.end_code = (unsigned long) &_etext;
840 	init_mm.end_data = (unsigned long) &_edata;
841 	init_mm.brk = (unsigned long) &_end;
842 
843 	if (MACHINE_HAS_MVCOS)
844 		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
845 	else
846 		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
847 
848 	parse_early_param();
849 
850 	setup_ipl();
851 	setup_memory_end();
852 	setup_addressing_mode();
853 	setup_memory();
854 	setup_resources();
855 	setup_lowcore();
856 
857         cpu_init();
858 	__cpu_logical_map[0] = stap();
859 	s390_init_cpu_topology();
860 
861 	/*
862 	 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
863 	 */
864 	setup_hwcaps();
865 
866 	/*
867 	 * Create kernel page tables and switch to virtual addressing.
868 	 */
869         paging_init();
870 
871         /* Setup default console */
872 	conmode_default();
873 	set_preferred_console();
874 
875 	/* Setup zfcpdump support */
876 	setup_zfcpdump(console_devno);
877 }
878