xref: /openbmc/linux/arch/s390/kernel/setup.c (revision e69eae65523b457a3ac4262a66cfff57f2c924a9)
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 
91 int __initdata memory_end_set;
92 unsigned long __initdata memory_end;
93 
94 /* An array with a pointer to the lowcore of every CPU. */
95 struct _lowcore *lowcore_ptr[NR_CPUS];
96 EXPORT_SYMBOL(lowcore_ptr);
97 
98 /*
99  * This is set up by the setup-routine at boot-time
100  * for S390 need to find out, what we have to setup
101  * using address 0x10400 ...
102  */
103 
104 #include <asm/setup.h>
105 
106 static struct resource code_resource = {
107 	.name  = "Kernel code",
108 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
109 };
110 
111 static struct resource data_resource = {
112 	.name = "Kernel data",
113 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
114 };
115 
116 /*
117  * cpu_init() initializes state that is per-CPU.
118  */
119 void __cpuinit cpu_init(void)
120 {
121         /*
122          * Store processor id in lowcore (used e.g. in timer_interrupt)
123          */
124 	get_cpu_id(&S390_lowcore.cpu_id);
125 
126 	atomic_inc(&init_mm.mm_count);
127 	current->active_mm = &init_mm;
128 	BUG_ON(current->mm);
129         enter_lazy_tlb(&init_mm, current);
130 }
131 
132 /*
133  * condev= and conmode= setup parameter.
134  */
135 
136 static int __init condev_setup(char *str)
137 {
138 	int vdev;
139 
140 	vdev = simple_strtoul(str, &str, 0);
141 	if (vdev >= 0 && vdev < 65536) {
142 		console_devno = vdev;
143 		console_irq = -1;
144 	}
145 	return 1;
146 }
147 
148 __setup("condev=", condev_setup);
149 
150 static void __init set_preferred_console(void)
151 {
152 	if (MACHINE_IS_KVM)
153 		add_preferred_console("hvc", 0, NULL);
154 	else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
155 		add_preferred_console("ttyS", 0, NULL);
156 	else if (CONSOLE_IS_3270)
157 		add_preferred_console("tty3270", 0, NULL);
158 }
159 
160 static int __init conmode_setup(char *str)
161 {
162 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
163 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
164                 SET_CONSOLE_SCLP;
165 #endif
166 #if defined(CONFIG_TN3215_CONSOLE)
167 	if (strncmp(str, "3215", 5) == 0)
168 		SET_CONSOLE_3215;
169 #endif
170 #if defined(CONFIG_TN3270_CONSOLE)
171 	if (strncmp(str, "3270", 5) == 0)
172 		SET_CONSOLE_3270;
173 #endif
174 	set_preferred_console();
175         return 1;
176 }
177 
178 __setup("conmode=", conmode_setup);
179 
180 static void __init conmode_default(void)
181 {
182 	char query_buffer[1024];
183 	char *ptr;
184 
185         if (MACHINE_IS_VM) {
186 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
187 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
188 		ptr = strstr(query_buffer, "SUBCHANNEL =");
189 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
190 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
191 		ptr = strstr(query_buffer, "CONMODE");
192 		/*
193 		 * Set the conmode to 3215 so that the device recognition
194 		 * will set the cu_type of the console to 3215. If the
195 		 * conmode is 3270 and we don't set it back then both
196 		 * 3215 and the 3270 driver will try to access the console
197 		 * device (3215 as console and 3270 as normal tty).
198 		 */
199 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
200 		if (ptr == NULL) {
201 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
202 			SET_CONSOLE_SCLP;
203 #endif
204 			return;
205 		}
206 		if (strncmp(ptr + 8, "3270", 4) == 0) {
207 #if defined(CONFIG_TN3270_CONSOLE)
208 			SET_CONSOLE_3270;
209 #elif defined(CONFIG_TN3215_CONSOLE)
210 			SET_CONSOLE_3215;
211 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
212 			SET_CONSOLE_SCLP;
213 #endif
214 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
215 #if defined(CONFIG_TN3215_CONSOLE)
216 			SET_CONSOLE_3215;
217 #elif defined(CONFIG_TN3270_CONSOLE)
218 			SET_CONSOLE_3270;
219 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
220 			SET_CONSOLE_SCLP;
221 #endif
222 		}
223 	} else {
224 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
225 		SET_CONSOLE_SCLP;
226 #endif
227 	}
228 }
229 
230 #ifdef CONFIG_ZFCPDUMP
231 static void __init setup_zfcpdump(unsigned int console_devno)
232 {
233 	static char str[41];
234 
235 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
236 		return;
237 	if (console_devno != -1)
238 		sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
239 			ipl_info.data.fcp.dev_id.devno, console_devno);
240 	else
241 		sprintf(str, " cio_ignore=all,!0.0.%04x",
242 			ipl_info.data.fcp.dev_id.devno);
243 	strcat(boot_command_line, str);
244 	console_loglevel = 2;
245 }
246 #else
247 static inline void setup_zfcpdump(unsigned int console_devno) {}
248 #endif /* CONFIG_ZFCPDUMP */
249 
250  /*
251  * Reboot, halt and power_off stubs. They just call _machine_restart,
252  * _machine_halt or _machine_power_off.
253  */
254 
255 void machine_restart(char *command)
256 {
257 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
258 		/*
259 		 * Only unblank the console if we are called in enabled
260 		 * context or a bust_spinlocks cleared the way for us.
261 		 */
262 		console_unblank();
263 	_machine_restart(command);
264 }
265 
266 void machine_halt(void)
267 {
268 	if (!in_interrupt() || oops_in_progress)
269 		/*
270 		 * Only unblank the console if we are called in enabled
271 		 * context or a bust_spinlocks cleared the way for us.
272 		 */
273 		console_unblank();
274 	_machine_halt();
275 }
276 
277 void machine_power_off(void)
278 {
279 	if (!in_interrupt() || oops_in_progress)
280 		/*
281 		 * Only unblank the console if we are called in enabled
282 		 * context or a bust_spinlocks cleared the way for us.
283 		 */
284 		console_unblank();
285 	_machine_power_off();
286 }
287 
288 /*
289  * Dummy power off function.
290  */
291 void (*pm_power_off)(void) = machine_power_off;
292 
293 static int __init early_parse_mem(char *p)
294 {
295 	memory_end = memparse(p, &p);
296 	memory_end_set = 1;
297 	return 0;
298 }
299 early_param("mem", early_parse_mem);
300 
301 unsigned int user_mode = HOME_SPACE_MODE;
302 EXPORT_SYMBOL_GPL(user_mode);
303 
304 static int set_amode_and_uaccess(unsigned long user_amode,
305 				 unsigned long user32_amode)
306 {
307 	psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
308 			PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
309 			PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
310 #ifdef CONFIG_COMPAT
311 	psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
312 			  PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
313 			  PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
314 	psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
315 			  PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
316 			  PSW32_MASK_PSTATE;
317 #endif
318 	psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
319 			  PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
320 
321 	if (MACHINE_HAS_MVCOS) {
322 		memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
323 		return 1;
324 	} else {
325 		memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
326 		return 0;
327 	}
328 }
329 
330 /*
331  * Switch kernel/user addressing modes?
332  */
333 static int __init early_parse_switch_amode(char *p)
334 {
335 	if (user_mode != SECONDARY_SPACE_MODE)
336 		user_mode = PRIMARY_SPACE_MODE;
337 	return 0;
338 }
339 early_param("switch_amode", early_parse_switch_amode);
340 
341 static int __init early_parse_user_mode(char *p)
342 {
343 	if (p && strcmp(p, "primary") == 0)
344 		user_mode = PRIMARY_SPACE_MODE;
345 #ifdef CONFIG_S390_EXEC_PROTECT
346 	else if (p && strcmp(p, "secondary") == 0)
347 		user_mode = SECONDARY_SPACE_MODE;
348 #endif
349 	else if (!p || strcmp(p, "home") == 0)
350 		user_mode = HOME_SPACE_MODE;
351 	else
352 		return 1;
353 	return 0;
354 }
355 early_param("user_mode", early_parse_user_mode);
356 
357 #ifdef CONFIG_S390_EXEC_PROTECT
358 /*
359  * Enable execute protection?
360  */
361 static int __init early_parse_noexec(char *p)
362 {
363 	if (!strncmp(p, "off", 3))
364 		return 0;
365 	user_mode = SECONDARY_SPACE_MODE;
366 	return 0;
367 }
368 early_param("noexec", early_parse_noexec);
369 #endif /* CONFIG_S390_EXEC_PROTECT */
370 
371 static void setup_addressing_mode(void)
372 {
373 	if (user_mode == SECONDARY_SPACE_MODE) {
374 		if (set_amode_and_uaccess(PSW_ASC_SECONDARY,
375 					  PSW32_ASC_SECONDARY))
376 			pr_info("Execute protection active, "
377 				"mvcos available\n");
378 		else
379 			pr_info("Execute protection active, "
380 				"mvcos not available\n");
381 	} else if (user_mode == PRIMARY_SPACE_MODE) {
382 		if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
383 			pr_info("Address spaces switched, "
384 				"mvcos available\n");
385 		else
386 			pr_info("Address spaces switched, "
387 				"mvcos not available\n");
388 	}
389 #ifdef CONFIG_TRACE_IRQFLAGS
390 	sysc_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
391 	io_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
392 #endif
393 }
394 
395 static void __init
396 setup_lowcore(void)
397 {
398 	struct _lowcore *lc;
399 
400 	/*
401 	 * Setup lowcore for boot cpu
402 	 */
403 	BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
404 	lc = __alloc_bootmem(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
405 	lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
406 	lc->restart_psw.addr =
407 		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
408 	if (user_mode != HOME_SPACE_MODE)
409 		lc->restart_psw.mask |= PSW_ASC_HOME;
410 	lc->external_new_psw.mask = psw_kernel_bits;
411 	lc->external_new_psw.addr =
412 		PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
413 	lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
414 	lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
415 	lc->program_new_psw.mask = psw_kernel_bits;
416 	lc->program_new_psw.addr =
417 		PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
418 	lc->mcck_new_psw.mask =
419 		psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
420 	lc->mcck_new_psw.addr =
421 		PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
422 	lc->io_new_psw.mask = psw_kernel_bits;
423 	lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
424 	lc->clock_comparator = -1ULL;
425 	lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
426 	lc->async_stack = (unsigned long)
427 		__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
428 	lc->panic_stack = (unsigned long)
429 		__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
430 	lc->current_task = (unsigned long) init_thread_union.thread_info.task;
431 	lc->thread_info = (unsigned long) &init_thread_union;
432 	lc->machine_flags = S390_lowcore.machine_flags;
433 #ifndef CONFIG_64BIT
434 	if (MACHINE_HAS_IEEE) {
435 		lc->extended_save_area_addr = (__u32)
436 			__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
437 		/* enable extended save area */
438 		__ctl_set_bit(14, 29);
439 	}
440 #else
441 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
442 #endif
443 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
444 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
445 	lc->exit_timer = S390_lowcore.exit_timer;
446 	lc->user_timer = S390_lowcore.user_timer;
447 	lc->system_timer = S390_lowcore.system_timer;
448 	lc->steal_timer = S390_lowcore.steal_timer;
449 	lc->last_update_timer = S390_lowcore.last_update_timer;
450 	lc->last_update_clock = S390_lowcore.last_update_clock;
451 	lc->ftrace_func = S390_lowcore.ftrace_func;
452 	set_prefix((u32)(unsigned long) lc);
453 	lowcore_ptr[0] = lc;
454 }
455 
456 static void __init
457 setup_resources(void)
458 {
459 	struct resource *res, *sub_res;
460 	int i;
461 
462 	code_resource.start = (unsigned long) &_text;
463 	code_resource.end = (unsigned long) &_etext - 1;
464 	data_resource.start = (unsigned long) &_etext;
465 	data_resource.end = (unsigned long) &_edata - 1;
466 
467 	for (i = 0; i < MEMORY_CHUNKS; i++) {
468 		if (!memory_chunk[i].size)
469 			continue;
470 		res = alloc_bootmem_low(sizeof(struct resource));
471 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
472 		switch (memory_chunk[i].type) {
473 		case CHUNK_READ_WRITE:
474 			res->name = "System RAM";
475 			break;
476 		case CHUNK_READ_ONLY:
477 			res->name = "System ROM";
478 			res->flags |= IORESOURCE_READONLY;
479 			break;
480 		default:
481 			res->name = "reserved";
482 		}
483 		res->start = memory_chunk[i].addr;
484 		res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
485 		request_resource(&iomem_resource, res);
486 
487 		if (code_resource.start >= res->start  &&
488 			code_resource.start <= res->end &&
489 			code_resource.end > res->end) {
490 			sub_res = alloc_bootmem_low(sizeof(struct resource));
491 			memcpy(sub_res, &code_resource,
492 				sizeof(struct resource));
493 			sub_res->end = res->end;
494 			code_resource.start = res->end + 1;
495 			request_resource(res, sub_res);
496 		}
497 
498 		if (code_resource.start >= res->start &&
499 			code_resource.start <= res->end &&
500 			code_resource.end <= res->end)
501 			request_resource(res, &code_resource);
502 
503 		if (data_resource.start >= res->start &&
504 			data_resource.start <= res->end &&
505 			data_resource.end > res->end) {
506 			sub_res = alloc_bootmem_low(sizeof(struct resource));
507 			memcpy(sub_res, &data_resource,
508 				sizeof(struct resource));
509 			sub_res->end = res->end;
510 			data_resource.start = res->end + 1;
511 			request_resource(res, sub_res);
512 		}
513 
514 		if (data_resource.start >= res->start &&
515 			data_resource.start <= res->end &&
516 			data_resource.end <= res->end)
517 			request_resource(res, &data_resource);
518 	}
519 }
520 
521 unsigned long real_memory_size;
522 EXPORT_SYMBOL_GPL(real_memory_size);
523 
524 static void __init setup_memory_end(void)
525 {
526 	unsigned long memory_size;
527 	unsigned long max_mem;
528 	int i;
529 
530 #ifdef CONFIG_ZFCPDUMP
531 	if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
532 		memory_end = ZFCPDUMP_HSA_SIZE;
533 		memory_end_set = 1;
534 	}
535 #endif
536 	memory_size = 0;
537 	memory_end &= PAGE_MASK;
538 
539 	max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
540 	memory_end = min(max_mem, memory_end);
541 
542 	/*
543 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
544 	 * extra checks that HOLES_IN_ZONE would require.
545 	 */
546 	for (i = 0; i < MEMORY_CHUNKS; i++) {
547 		unsigned long start, end;
548 		struct mem_chunk *chunk;
549 		unsigned long align;
550 
551 		chunk = &memory_chunk[i];
552 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
553 		start = (chunk->addr + align - 1) & ~(align - 1);
554 		end = (chunk->addr + chunk->size) & ~(align - 1);
555 		if (start >= end)
556 			memset(chunk, 0, sizeof(*chunk));
557 		else {
558 			chunk->addr = start;
559 			chunk->size = end - start;
560 		}
561 	}
562 
563 	for (i = 0; i < MEMORY_CHUNKS; i++) {
564 		struct mem_chunk *chunk = &memory_chunk[i];
565 
566 		real_memory_size = max(real_memory_size,
567 				       chunk->addr + chunk->size);
568 		if (chunk->addr >= max_mem) {
569 			memset(chunk, 0, sizeof(*chunk));
570 			continue;
571 		}
572 		if (chunk->addr + chunk->size > max_mem)
573 			chunk->size = max_mem - chunk->addr;
574 		memory_size = max(memory_size, chunk->addr + chunk->size);
575 	}
576 	if (!memory_end)
577 		memory_end = memory_size;
578 }
579 
580 static void __init
581 setup_memory(void)
582 {
583         unsigned long bootmap_size;
584 	unsigned long start_pfn, end_pfn;
585 	int i;
586 
587 	/*
588 	 * partially used pages are not usable - thus
589 	 * we are rounding upwards:
590 	 */
591 	start_pfn = PFN_UP(__pa(&_end));
592 	end_pfn = max_pfn = PFN_DOWN(memory_end);
593 
594 #ifdef CONFIG_BLK_DEV_INITRD
595 	/*
596 	 * Move the initrd in case the bitmap of the bootmem allocater
597 	 * would overwrite it.
598 	 */
599 
600 	if (INITRD_START && INITRD_SIZE) {
601 		unsigned long bmap_size;
602 		unsigned long start;
603 
604 		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
605 		bmap_size = PFN_PHYS(bmap_size);
606 
607 		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
608 			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
609 
610 			if (start + INITRD_SIZE > memory_end) {
611 				pr_err("initrd extends beyond end of "
612 				       "memory (0x%08lx > 0x%08lx) "
613 				       "disabling initrd\n",
614 				       start + INITRD_SIZE, memory_end);
615 				INITRD_START = INITRD_SIZE = 0;
616 			} else {
617 				pr_info("Moving initrd (0x%08lx -> "
618 					"0x%08lx, size: %ld)\n",
619 					INITRD_START, start, INITRD_SIZE);
620 				memmove((void *) start, (void *) INITRD_START,
621 					INITRD_SIZE);
622 				INITRD_START = start;
623 			}
624 		}
625 	}
626 #endif
627 
628 	/*
629 	 * Initialize the boot-time allocator
630 	 */
631 	bootmap_size = init_bootmem(start_pfn, end_pfn);
632 
633 	/*
634 	 * Register RAM areas with the bootmem allocator.
635 	 */
636 
637 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
638 		unsigned long start_chunk, end_chunk, pfn;
639 
640 		if (memory_chunk[i].type != CHUNK_READ_WRITE)
641 			continue;
642 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
643 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
644 		end_chunk = min(end_chunk, end_pfn);
645 		if (start_chunk >= end_chunk)
646 			continue;
647 		add_active_range(0, start_chunk, end_chunk);
648 		pfn = max(start_chunk, start_pfn);
649 		for (; pfn < end_chunk; pfn++)
650 			page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
651 	}
652 
653 	psw_set_key(PAGE_DEFAULT_KEY);
654 
655 	free_bootmem_with_active_regions(0, max_pfn);
656 
657 	/*
658 	 * Reserve memory used for lowcore/command line/kernel image.
659 	 */
660 	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
661 	reserve_bootmem((unsigned long)_stext,
662 			PFN_PHYS(start_pfn) - (unsigned long)_stext,
663 			BOOTMEM_DEFAULT);
664 	/*
665 	 * Reserve the bootmem bitmap itself as well. We do this in two
666 	 * steps (first step was init_bootmem()) because this catches
667 	 * the (very unlikely) case of us accidentally initializing the
668 	 * bootmem allocator with an invalid RAM area.
669 	 */
670 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
671 			BOOTMEM_DEFAULT);
672 
673 #ifdef CONFIG_BLK_DEV_INITRD
674 	if (INITRD_START && INITRD_SIZE) {
675 		if (INITRD_START + INITRD_SIZE <= memory_end) {
676 			reserve_bootmem(INITRD_START, INITRD_SIZE,
677 					BOOTMEM_DEFAULT);
678 			initrd_start = INITRD_START;
679 			initrd_end = initrd_start + INITRD_SIZE;
680 		} else {
681 			pr_err("initrd extends beyond end of "
682 			       "memory (0x%08lx > 0x%08lx) "
683 			       "disabling initrd\n",
684 			       initrd_start + INITRD_SIZE, memory_end);
685 			initrd_start = initrd_end = 0;
686 		}
687 	}
688 #endif
689 }
690 
691 /*
692  * Setup hardware capabilities.
693  */
694 static void __init setup_hwcaps(void)
695 {
696 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
697 	unsigned long long facility_list_extended;
698 	unsigned int facility_list;
699 	int i;
700 
701 	facility_list = stfl();
702 	/*
703 	 * The store facility list bits numbers as found in the principles
704 	 * of operation are numbered with bit 1UL<<31 as number 0 to
705 	 * bit 1UL<<0 as number 31.
706 	 *   Bit 0: instructions named N3, "backported" to esa-mode
707 	 *   Bit 2: z/Architecture mode is active
708 	 *   Bit 7: the store-facility-list-extended facility is installed
709 	 *   Bit 17: the message-security assist is installed
710 	 *   Bit 19: the long-displacement facility is installed
711 	 *   Bit 21: the extended-immediate facility is installed
712 	 *   Bit 22: extended-translation facility 3 is installed
713 	 *   Bit 30: extended-translation facility 3 enhancement facility
714 	 * These get translated to:
715 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
716 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
717 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
718 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
719 	 */
720 	for (i = 0; i < 6; i++)
721 		if (facility_list & (1UL << (31 - stfl_bits[i])))
722 			elf_hwcap |= 1UL << i;
723 
724 	if ((facility_list & (1UL << (31 - 22)))
725 	    && (facility_list & (1UL << (31 - 30))))
726 		elf_hwcap |= HWCAP_S390_ETF3EH;
727 
728 	/*
729 	 * Check for additional facilities with store-facility-list-extended.
730 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
731 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
732 	 * as stored by stfl, bits 32-xxx contain additional facilities.
733 	 * How many facility words are stored depends on the number of
734 	 * doublewords passed to the instruction. The additional facilites
735 	 * are:
736 	 *   Bit 42: decimal floating point facility is installed
737 	 *   Bit 44: perform floating point operation facility is installed
738 	 * translated to:
739 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
740 	 */
741 	if ((elf_hwcap & (1UL << 2)) &&
742 	    __stfle(&facility_list_extended, 1) > 0) {
743 		if ((facility_list_extended & (1ULL << (63 - 42)))
744 		    && (facility_list_extended & (1ULL << (63 - 44))))
745 			elf_hwcap |= HWCAP_S390_DFP;
746 	}
747 
748 	/*
749 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
750 	 */
751 	if (MACHINE_HAS_HPAGE)
752 		elf_hwcap |= HWCAP_S390_HPAGE;
753 
754 	/*
755 	 * 64-bit register support for 31-bit processes
756 	 * HWCAP_S390_HIGH_GPRS is bit 9.
757 	 */
758 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
759 
760 	switch (S390_lowcore.cpu_id.machine) {
761 	case 0x9672:
762 #if !defined(CONFIG_64BIT)
763 	default:	/* Use "g5" as default for 31 bit kernels. */
764 #endif
765 		strcpy(elf_platform, "g5");
766 		break;
767 	case 0x2064:
768 	case 0x2066:
769 #if defined(CONFIG_64BIT)
770 	default:	/* Use "z900" as default for 64 bit kernels. */
771 #endif
772 		strcpy(elf_platform, "z900");
773 		break;
774 	case 0x2084:
775 	case 0x2086:
776 		strcpy(elf_platform, "z990");
777 		break;
778 	case 0x2094:
779 	case 0x2096:
780 		strcpy(elf_platform, "z9-109");
781 		break;
782 	case 0x2097:
783 	case 0x2098:
784 		strcpy(elf_platform, "z10");
785 		break;
786 	}
787 }
788 
789 /*
790  * Setup function called from init/main.c just after the banner
791  * was printed.
792  */
793 
794 void __init
795 setup_arch(char **cmdline_p)
796 {
797         /*
798          * print what head.S has found out about the machine
799          */
800 #ifndef CONFIG_64BIT
801 	if (MACHINE_IS_VM)
802 		pr_info("Linux is running as a z/VM "
803 			"guest operating system in 31-bit mode\n");
804 	else if (MACHINE_IS_LPAR)
805 		pr_info("Linux is running natively in 31-bit mode\n");
806 	if (MACHINE_HAS_IEEE)
807 		pr_info("The hardware system has IEEE compatible "
808 			"floating point units\n");
809 	else
810 		pr_info("The hardware system has no IEEE compatible "
811 			"floating point units\n");
812 #else /* CONFIG_64BIT */
813 	if (MACHINE_IS_VM)
814 		pr_info("Linux is running as a z/VM "
815 			"guest operating system in 64-bit mode\n");
816 	else if (MACHINE_IS_KVM)
817 		pr_info("Linux is running under KVM in 64-bit mode\n");
818 	else if (MACHINE_IS_LPAR)
819 		pr_info("Linux is running natively in 64-bit mode\n");
820 #endif /* CONFIG_64BIT */
821 
822 	/* Have one command line that is parsed and saved in /proc/cmdline */
823 	/* boot_command_line has been already set up in early.c */
824 	*cmdline_p = boot_command_line;
825 
826         ROOT_DEV = Root_RAM0;
827 
828 	init_mm.start_code = PAGE_OFFSET;
829 	init_mm.end_code = (unsigned long) &_etext;
830 	init_mm.end_data = (unsigned long) &_edata;
831 	init_mm.brk = (unsigned long) &_end;
832 
833 	if (MACHINE_HAS_MVCOS)
834 		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
835 	else
836 		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
837 
838 	parse_early_param();
839 
840 	setup_ipl();
841 	setup_memory_end();
842 	setup_addressing_mode();
843 	setup_memory();
844 	setup_resources();
845 	setup_lowcore();
846 
847         cpu_init();
848 	s390_init_cpu_topology();
849 
850 	/*
851 	 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
852 	 */
853 	setup_hwcaps();
854 
855 	/*
856 	 * Create kernel page tables and switch to virtual addressing.
857 	 */
858         paging_init();
859 
860         /* Setup default console */
861 	conmode_default();
862 	set_preferred_console();
863 
864 	/* Setup zfcpdump support */
865 	setup_zfcpdump(console_devno);
866 }
867