xref: /openbmc/linux/arch/s390/kernel/setup.c (revision 4dc7ccf7)
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/user.h>
29 #include <linux/tty.h>
30 #include <linux/ioport.h>
31 #include <linux/delay.h>
32 #include <linux/init.h>
33 #include <linux/initrd.h>
34 #include <linux/bootmem.h>
35 #include <linux/root_dev.h>
36 #include <linux/console.h>
37 #include <linux/kernel_stat.h>
38 #include <linux/device.h>
39 #include <linux/notifier.h>
40 #include <linux/pfn.h>
41 #include <linux/ctype.h>
42 #include <linux/reboot.h>
43 #include <linux/topology.h>
44 #include <linux/ftrace.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 EXPORT_SYMBOL(console_mode);
78 
79 unsigned int console_devno = -1;
80 EXPORT_SYMBOL(console_devno);
81 
82 unsigned int console_irq = -1;
83 EXPORT_SYMBOL(console_irq);
84 
85 unsigned long elf_hwcap = 0;
86 char elf_platform[ELF_PLATFORM_SIZE];
87 
88 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
89 
90 int __initdata memory_end_set;
91 unsigned long __initdata memory_end;
92 
93 /* An array with a pointer to the lowcore of every CPU. */
94 struct _lowcore *lowcore_ptr[NR_CPUS];
95 EXPORT_SYMBOL(lowcore_ptr);
96 
97 /*
98  * This is set up by the setup-routine at boot-time
99  * for S390 need to find out, what we have to setup
100  * using address 0x10400 ...
101  */
102 
103 #include <asm/setup.h>
104 
105 static struct resource code_resource = {
106 	.name  = "Kernel code",
107 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
108 };
109 
110 static struct resource data_resource = {
111 	.name = "Kernel data",
112 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
113 };
114 
115 /*
116  * cpu_init() initializes state that is per-CPU.
117  */
118 void __cpuinit cpu_init(void)
119 {
120         /*
121          * Store processor id in lowcore (used e.g. in timer_interrupt)
122          */
123 	get_cpu_id(&S390_lowcore.cpu_id);
124 
125 	atomic_inc(&init_mm.mm_count);
126 	current->active_mm = &init_mm;
127 	BUG_ON(current->mm);
128         enter_lazy_tlb(&init_mm, current);
129 }
130 
131 /*
132  * condev= and conmode= setup parameter.
133  */
134 
135 static int __init condev_setup(char *str)
136 {
137 	int vdev;
138 
139 	vdev = simple_strtoul(str, &str, 0);
140 	if (vdev >= 0 && vdev < 65536) {
141 		console_devno = vdev;
142 		console_irq = -1;
143 	}
144 	return 1;
145 }
146 
147 __setup("condev=", condev_setup);
148 
149 static void __init set_preferred_console(void)
150 {
151 	if (MACHINE_IS_KVM)
152 		add_preferred_console("hvc", 0, NULL);
153 	else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
154 		add_preferred_console("ttyS", 0, NULL);
155 	else if (CONSOLE_IS_3270)
156 		add_preferred_console("tty3270", 0, NULL);
157 }
158 
159 static int __init conmode_setup(char *str)
160 {
161 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
162 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
163                 SET_CONSOLE_SCLP;
164 #endif
165 #if defined(CONFIG_TN3215_CONSOLE)
166 	if (strncmp(str, "3215", 5) == 0)
167 		SET_CONSOLE_3215;
168 #endif
169 #if defined(CONFIG_TN3270_CONSOLE)
170 	if (strncmp(str, "3270", 5) == 0)
171 		SET_CONSOLE_3270;
172 #endif
173 	set_preferred_console();
174         return 1;
175 }
176 
177 __setup("conmode=", conmode_setup);
178 
179 static void __init conmode_default(void)
180 {
181 	char query_buffer[1024];
182 	char *ptr;
183 
184         if (MACHINE_IS_VM) {
185 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
186 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
187 		ptr = strstr(query_buffer, "SUBCHANNEL =");
188 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
189 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
190 		ptr = strstr(query_buffer, "CONMODE");
191 		/*
192 		 * Set the conmode to 3215 so that the device recognition
193 		 * will set the cu_type of the console to 3215. If the
194 		 * conmode is 3270 and we don't set it back then both
195 		 * 3215 and the 3270 driver will try to access the console
196 		 * device (3215 as console and 3270 as normal tty).
197 		 */
198 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
199 		if (ptr == NULL) {
200 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
201 			SET_CONSOLE_SCLP;
202 #endif
203 			return;
204 		}
205 		if (strncmp(ptr + 8, "3270", 4) == 0) {
206 #if defined(CONFIG_TN3270_CONSOLE)
207 			SET_CONSOLE_3270;
208 #elif defined(CONFIG_TN3215_CONSOLE)
209 			SET_CONSOLE_3215;
210 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
211 			SET_CONSOLE_SCLP;
212 #endif
213 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
214 #if defined(CONFIG_TN3215_CONSOLE)
215 			SET_CONSOLE_3215;
216 #elif defined(CONFIG_TN3270_CONSOLE)
217 			SET_CONSOLE_3270;
218 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
219 			SET_CONSOLE_SCLP;
220 #endif
221 		}
222 	} else {
223 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
224 		SET_CONSOLE_SCLP;
225 #endif
226 	}
227 }
228 
229 #ifdef CONFIG_ZFCPDUMP
230 static void __init setup_zfcpdump(unsigned int console_devno)
231 {
232 	static char str[41];
233 
234 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
235 		return;
236 	if (console_devno != -1)
237 		sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
238 			ipl_info.data.fcp.dev_id.devno, console_devno);
239 	else
240 		sprintf(str, " cio_ignore=all,!0.0.%04x",
241 			ipl_info.data.fcp.dev_id.devno);
242 	strcat(boot_command_line, str);
243 	console_loglevel = 2;
244 }
245 #else
246 static inline void setup_zfcpdump(unsigned int console_devno) {}
247 #endif /* CONFIG_ZFCPDUMP */
248 
249  /*
250  * Reboot, halt and power_off stubs. They just call _machine_restart,
251  * _machine_halt or _machine_power_off.
252  */
253 
254 void machine_restart(char *command)
255 {
256 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
257 		/*
258 		 * Only unblank the console if we are called in enabled
259 		 * context or a bust_spinlocks cleared the way for us.
260 		 */
261 		console_unblank();
262 	_machine_restart(command);
263 }
264 
265 void machine_halt(void)
266 {
267 	if (!in_interrupt() || oops_in_progress)
268 		/*
269 		 * Only unblank the console if we are called in enabled
270 		 * context or a bust_spinlocks cleared the way for us.
271 		 */
272 		console_unblank();
273 	_machine_halt();
274 }
275 
276 void machine_power_off(void)
277 {
278 	if (!in_interrupt() || oops_in_progress)
279 		/*
280 		 * Only unblank the console if we are called in enabled
281 		 * context or a bust_spinlocks cleared the way for us.
282 		 */
283 		console_unblank();
284 	_machine_power_off();
285 }
286 
287 /*
288  * Dummy power off function.
289  */
290 void (*pm_power_off)(void) = machine_power_off;
291 
292 static int __init early_parse_mem(char *p)
293 {
294 	memory_end = memparse(p, &p);
295 	memory_end_set = 1;
296 	return 0;
297 }
298 early_param("mem", early_parse_mem);
299 
300 unsigned int user_mode = HOME_SPACE_MODE;
301 EXPORT_SYMBOL_GPL(user_mode);
302 
303 static int set_amode_and_uaccess(unsigned long user_amode,
304 				 unsigned long user32_amode)
305 {
306 	psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
307 			PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
308 			PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
309 #ifdef CONFIG_COMPAT
310 	psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
311 			  PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
312 			  PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
313 	psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
314 			  PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
315 			  PSW32_MASK_PSTATE;
316 #endif
317 	psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
318 			  PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
319 
320 	if (MACHINE_HAS_MVCOS) {
321 		memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
322 		return 1;
323 	} else {
324 		memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
325 		return 0;
326 	}
327 }
328 
329 /*
330  * Switch kernel/user addressing modes?
331  */
332 static int __init early_parse_switch_amode(char *p)
333 {
334 	if (user_mode != SECONDARY_SPACE_MODE)
335 		user_mode = PRIMARY_SPACE_MODE;
336 	return 0;
337 }
338 early_param("switch_amode", early_parse_switch_amode);
339 
340 static int __init early_parse_user_mode(char *p)
341 {
342 	if (p && strcmp(p, "primary") == 0)
343 		user_mode = PRIMARY_SPACE_MODE;
344 #ifdef CONFIG_S390_EXEC_PROTECT
345 	else if (p && strcmp(p, "secondary") == 0)
346 		user_mode = SECONDARY_SPACE_MODE;
347 #endif
348 	else if (!p || strcmp(p, "home") == 0)
349 		user_mode = HOME_SPACE_MODE;
350 	else
351 		return 1;
352 	return 0;
353 }
354 early_param("user_mode", early_parse_user_mode);
355 
356 #ifdef CONFIG_S390_EXEC_PROTECT
357 /*
358  * Enable execute protection?
359  */
360 static int __init early_parse_noexec(char *p)
361 {
362 	if (!strncmp(p, "off", 3))
363 		return 0;
364 	user_mode = SECONDARY_SPACE_MODE;
365 	return 0;
366 }
367 early_param("noexec", early_parse_noexec);
368 #endif /* CONFIG_S390_EXEC_PROTECT */
369 
370 static void setup_addressing_mode(void)
371 {
372 	if (user_mode == SECONDARY_SPACE_MODE) {
373 		if (set_amode_and_uaccess(PSW_ASC_SECONDARY,
374 					  PSW32_ASC_SECONDARY))
375 			pr_info("Execute protection active, "
376 				"mvcos available\n");
377 		else
378 			pr_info("Execute protection active, "
379 				"mvcos not available\n");
380 	} else if (user_mode == PRIMARY_SPACE_MODE) {
381 		if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
382 			pr_info("Address spaces switched, "
383 				"mvcos available\n");
384 		else
385 			pr_info("Address spaces switched, "
386 				"mvcos not available\n");
387 	}
388 #ifdef CONFIG_TRACE_IRQFLAGS
389 	sysc_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
390 	io_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
391 #endif
392 }
393 
394 static void __init
395 setup_lowcore(void)
396 {
397 	struct _lowcore *lc;
398 
399 	/*
400 	 * Setup lowcore for boot cpu
401 	 */
402 	BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
403 	lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
404 	lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
405 	lc->restart_psw.addr =
406 		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
407 	if (user_mode != HOME_SPACE_MODE)
408 		lc->restart_psw.mask |= PSW_ASC_HOME;
409 	lc->external_new_psw.mask = psw_kernel_bits;
410 	lc->external_new_psw.addr =
411 		PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
412 	lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
413 	lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
414 	lc->program_new_psw.mask = psw_kernel_bits;
415 	lc->program_new_psw.addr =
416 		PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
417 	lc->mcck_new_psw.mask =
418 		psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
419 	lc->mcck_new_psw.addr =
420 		PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
421 	lc->io_new_psw.mask = psw_kernel_bits;
422 	lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
423 	lc->clock_comparator = -1ULL;
424 	lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
425 	lc->async_stack = (unsigned long)
426 		__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
427 	lc->panic_stack = (unsigned long)
428 		__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
429 	lc->current_task = (unsigned long) init_thread_union.thread_info.task;
430 	lc->thread_info = (unsigned long) &init_thread_union;
431 	lc->machine_flags = S390_lowcore.machine_flags;
432 #ifndef CONFIG_64BIT
433 	if (MACHINE_HAS_IEEE) {
434 		lc->extended_save_area_addr = (__u32)
435 			__alloc_bootmem_low(PAGE_SIZE, PAGE_SIZE, 0);
436 		/* enable extended save area */
437 		__ctl_set_bit(14, 29);
438 	}
439 #else
440 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
441 #endif
442 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
443 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
444 	lc->exit_timer = S390_lowcore.exit_timer;
445 	lc->user_timer = S390_lowcore.user_timer;
446 	lc->system_timer = S390_lowcore.system_timer;
447 	lc->steal_timer = S390_lowcore.steal_timer;
448 	lc->last_update_timer = S390_lowcore.last_update_timer;
449 	lc->last_update_clock = S390_lowcore.last_update_clock;
450 	lc->ftrace_func = S390_lowcore.ftrace_func;
451 	set_prefix((u32)(unsigned long) lc);
452 	lowcore_ptr[0] = lc;
453 }
454 
455 static void __init
456 setup_resources(void)
457 {
458 	struct resource *res, *sub_res;
459 	int i;
460 
461 	code_resource.start = (unsigned long) &_text;
462 	code_resource.end = (unsigned long) &_etext - 1;
463 	data_resource.start = (unsigned long) &_etext;
464 	data_resource.end = (unsigned long) &_edata - 1;
465 
466 	for (i = 0; i < MEMORY_CHUNKS; i++) {
467 		if (!memory_chunk[i].size)
468 			continue;
469 		res = alloc_bootmem_low(sizeof(struct resource));
470 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
471 		switch (memory_chunk[i].type) {
472 		case CHUNK_READ_WRITE:
473 			res->name = "System RAM";
474 			break;
475 		case CHUNK_READ_ONLY:
476 			res->name = "System ROM";
477 			res->flags |= IORESOURCE_READONLY;
478 			break;
479 		default:
480 			res->name = "reserved";
481 		}
482 		res->start = memory_chunk[i].addr;
483 		res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
484 		request_resource(&iomem_resource, res);
485 
486 		if (code_resource.start >= res->start  &&
487 			code_resource.start <= res->end &&
488 			code_resource.end > res->end) {
489 			sub_res = alloc_bootmem_low(sizeof(struct resource));
490 			memcpy(sub_res, &code_resource,
491 				sizeof(struct resource));
492 			sub_res->end = res->end;
493 			code_resource.start = res->end + 1;
494 			request_resource(res, sub_res);
495 		}
496 
497 		if (code_resource.start >= res->start &&
498 			code_resource.start <= res->end &&
499 			code_resource.end <= res->end)
500 			request_resource(res, &code_resource);
501 
502 		if (data_resource.start >= res->start &&
503 			data_resource.start <= res->end &&
504 			data_resource.end > res->end) {
505 			sub_res = alloc_bootmem_low(sizeof(struct resource));
506 			memcpy(sub_res, &data_resource,
507 				sizeof(struct resource));
508 			sub_res->end = res->end;
509 			data_resource.start = res->end + 1;
510 			request_resource(res, sub_res);
511 		}
512 
513 		if (data_resource.start >= res->start &&
514 			data_resource.start <= res->end &&
515 			data_resource.end <= res->end)
516 			request_resource(res, &data_resource);
517 	}
518 }
519 
520 unsigned long real_memory_size;
521 EXPORT_SYMBOL_GPL(real_memory_size);
522 
523 static void __init setup_memory_end(void)
524 {
525 	unsigned long memory_size;
526 	unsigned long max_mem;
527 	int i;
528 
529 #ifdef CONFIG_ZFCPDUMP
530 	if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
531 		memory_end = ZFCPDUMP_HSA_SIZE;
532 		memory_end_set = 1;
533 	}
534 #endif
535 	memory_size = 0;
536 	memory_end &= PAGE_MASK;
537 
538 	max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
539 	memory_end = min(max_mem, memory_end);
540 
541 	/*
542 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
543 	 * extra checks that HOLES_IN_ZONE would require.
544 	 */
545 	for (i = 0; i < MEMORY_CHUNKS; i++) {
546 		unsigned long start, end;
547 		struct mem_chunk *chunk;
548 		unsigned long align;
549 
550 		chunk = &memory_chunk[i];
551 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
552 		start = (chunk->addr + align - 1) & ~(align - 1);
553 		end = (chunk->addr + chunk->size) & ~(align - 1);
554 		if (start >= end)
555 			memset(chunk, 0, sizeof(*chunk));
556 		else {
557 			chunk->addr = start;
558 			chunk->size = end - start;
559 		}
560 	}
561 
562 	for (i = 0; i < MEMORY_CHUNKS; i++) {
563 		struct mem_chunk *chunk = &memory_chunk[i];
564 
565 		real_memory_size = max(real_memory_size,
566 				       chunk->addr + chunk->size);
567 		if (chunk->addr >= max_mem) {
568 			memset(chunk, 0, sizeof(*chunk));
569 			continue;
570 		}
571 		if (chunk->addr + chunk->size > max_mem)
572 			chunk->size = max_mem - chunk->addr;
573 		memory_size = max(memory_size, chunk->addr + chunk->size);
574 	}
575 	if (!memory_end)
576 		memory_end = memory_size;
577 }
578 
579 static void __init
580 setup_memory(void)
581 {
582         unsigned long bootmap_size;
583 	unsigned long start_pfn, end_pfn;
584 	int i;
585 
586 	/*
587 	 * partially used pages are not usable - thus
588 	 * we are rounding upwards:
589 	 */
590 	start_pfn = PFN_UP(__pa(&_end));
591 	end_pfn = max_pfn = PFN_DOWN(memory_end);
592 
593 #ifdef CONFIG_BLK_DEV_INITRD
594 	/*
595 	 * Move the initrd in case the bitmap of the bootmem allocater
596 	 * would overwrite it.
597 	 */
598 
599 	if (INITRD_START && INITRD_SIZE) {
600 		unsigned long bmap_size;
601 		unsigned long start;
602 
603 		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
604 		bmap_size = PFN_PHYS(bmap_size);
605 
606 		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
607 			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
608 
609 			if (start + INITRD_SIZE > memory_end) {
610 				pr_err("initrd extends beyond end of "
611 				       "memory (0x%08lx > 0x%08lx) "
612 				       "disabling initrd\n",
613 				       start + INITRD_SIZE, memory_end);
614 				INITRD_START = INITRD_SIZE = 0;
615 			} else {
616 				pr_info("Moving initrd (0x%08lx -> "
617 					"0x%08lx, size: %ld)\n",
618 					INITRD_START, start, INITRD_SIZE);
619 				memmove((void *) start, (void *) INITRD_START,
620 					INITRD_SIZE);
621 				INITRD_START = start;
622 			}
623 		}
624 	}
625 #endif
626 
627 	/*
628 	 * Initialize the boot-time allocator
629 	 */
630 	bootmap_size = init_bootmem(start_pfn, end_pfn);
631 
632 	/*
633 	 * Register RAM areas with the bootmem allocator.
634 	 */
635 
636 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
637 		unsigned long start_chunk, end_chunk, pfn;
638 
639 		if (memory_chunk[i].type != CHUNK_READ_WRITE)
640 			continue;
641 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
642 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
643 		end_chunk = min(end_chunk, end_pfn);
644 		if (start_chunk >= end_chunk)
645 			continue;
646 		add_active_range(0, start_chunk, end_chunk);
647 		pfn = max(start_chunk, start_pfn);
648 		for (; pfn < end_chunk; pfn++)
649 			page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
650 	}
651 
652 	psw_set_key(PAGE_DEFAULT_KEY);
653 
654 	free_bootmem_with_active_regions(0, max_pfn);
655 
656 	/*
657 	 * Reserve memory used for lowcore/command line/kernel image.
658 	 */
659 	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
660 	reserve_bootmem((unsigned long)_stext,
661 			PFN_PHYS(start_pfn) - (unsigned long)_stext,
662 			BOOTMEM_DEFAULT);
663 	/*
664 	 * Reserve the bootmem bitmap itself as well. We do this in two
665 	 * steps (first step was init_bootmem()) because this catches
666 	 * the (very unlikely) case of us accidentally initializing the
667 	 * bootmem allocator with an invalid RAM area.
668 	 */
669 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
670 			BOOTMEM_DEFAULT);
671 
672 #ifdef CONFIG_BLK_DEV_INITRD
673 	if (INITRD_START && INITRD_SIZE) {
674 		if (INITRD_START + INITRD_SIZE <= memory_end) {
675 			reserve_bootmem(INITRD_START, INITRD_SIZE,
676 					BOOTMEM_DEFAULT);
677 			initrd_start = INITRD_START;
678 			initrd_end = initrd_start + INITRD_SIZE;
679 		} else {
680 			pr_err("initrd extends beyond end of "
681 			       "memory (0x%08lx > 0x%08lx) "
682 			       "disabling initrd\n",
683 			       initrd_start + INITRD_SIZE, memory_end);
684 			initrd_start = initrd_end = 0;
685 		}
686 	}
687 #endif
688 }
689 
690 /*
691  * Setup hardware capabilities.
692  */
693 static void __init setup_hwcaps(void)
694 {
695 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
696 	unsigned long long facility_list_extended;
697 	unsigned int facility_list;
698 	int i;
699 
700 	facility_list = stfl();
701 	/*
702 	 * The store facility list bits numbers as found in the principles
703 	 * of operation are numbered with bit 1UL<<31 as number 0 to
704 	 * bit 1UL<<0 as number 31.
705 	 *   Bit 0: instructions named N3, "backported" to esa-mode
706 	 *   Bit 2: z/Architecture mode is active
707 	 *   Bit 7: the store-facility-list-extended facility is installed
708 	 *   Bit 17: the message-security assist is installed
709 	 *   Bit 19: the long-displacement facility is installed
710 	 *   Bit 21: the extended-immediate facility is installed
711 	 *   Bit 22: extended-translation facility 3 is installed
712 	 *   Bit 30: extended-translation facility 3 enhancement facility
713 	 * These get translated to:
714 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
715 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
716 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
717 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
718 	 */
719 	for (i = 0; i < 6; i++)
720 		if (facility_list & (1UL << (31 - stfl_bits[i])))
721 			elf_hwcap |= 1UL << i;
722 
723 	if ((facility_list & (1UL << (31 - 22)))
724 	    && (facility_list & (1UL << (31 - 30))))
725 		elf_hwcap |= HWCAP_S390_ETF3EH;
726 
727 	/*
728 	 * Check for additional facilities with store-facility-list-extended.
729 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
730 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
731 	 * as stored by stfl, bits 32-xxx contain additional facilities.
732 	 * How many facility words are stored depends on the number of
733 	 * doublewords passed to the instruction. The additional facilites
734 	 * are:
735 	 *   Bit 42: decimal floating point facility is installed
736 	 *   Bit 44: perform floating point operation facility is installed
737 	 * translated to:
738 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
739 	 */
740 	if ((elf_hwcap & (1UL << 2)) &&
741 	    __stfle(&facility_list_extended, 1) > 0) {
742 		if ((facility_list_extended & (1ULL << (63 - 42)))
743 		    && (facility_list_extended & (1ULL << (63 - 44))))
744 			elf_hwcap |= HWCAP_S390_DFP;
745 	}
746 
747 	/*
748 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
749 	 */
750 	if (MACHINE_HAS_HPAGE)
751 		elf_hwcap |= HWCAP_S390_HPAGE;
752 
753 	/*
754 	 * 64-bit register support for 31-bit processes
755 	 * HWCAP_S390_HIGH_GPRS is bit 9.
756 	 */
757 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
758 
759 	switch (S390_lowcore.cpu_id.machine) {
760 	case 0x9672:
761 #if !defined(CONFIG_64BIT)
762 	default:	/* Use "g5" as default for 31 bit kernels. */
763 #endif
764 		strcpy(elf_platform, "g5");
765 		break;
766 	case 0x2064:
767 	case 0x2066:
768 #if defined(CONFIG_64BIT)
769 	default:	/* Use "z900" as default for 64 bit kernels. */
770 #endif
771 		strcpy(elf_platform, "z900");
772 		break;
773 	case 0x2084:
774 	case 0x2086:
775 		strcpy(elf_platform, "z990");
776 		break;
777 	case 0x2094:
778 	case 0x2096:
779 		strcpy(elf_platform, "z9-109");
780 		break;
781 	case 0x2097:
782 	case 0x2098:
783 		strcpy(elf_platform, "z10");
784 		break;
785 	}
786 }
787 
788 /*
789  * Setup function called from init/main.c just after the banner
790  * was printed.
791  */
792 
793 void __init
794 setup_arch(char **cmdline_p)
795 {
796         /*
797          * print what head.S has found out about the machine
798          */
799 #ifndef CONFIG_64BIT
800 	if (MACHINE_IS_VM)
801 		pr_info("Linux is running as a z/VM "
802 			"guest operating system in 31-bit mode\n");
803 	else if (MACHINE_IS_LPAR)
804 		pr_info("Linux is running natively in 31-bit mode\n");
805 	if (MACHINE_HAS_IEEE)
806 		pr_info("The hardware system has IEEE compatible "
807 			"floating point units\n");
808 	else
809 		pr_info("The hardware system has no IEEE compatible "
810 			"floating point units\n");
811 #else /* CONFIG_64BIT */
812 	if (MACHINE_IS_VM)
813 		pr_info("Linux is running as a z/VM "
814 			"guest operating system in 64-bit mode\n");
815 	else if (MACHINE_IS_KVM)
816 		pr_info("Linux is running under KVM in 64-bit mode\n");
817 	else if (MACHINE_IS_LPAR)
818 		pr_info("Linux is running natively in 64-bit mode\n");
819 #endif /* CONFIG_64BIT */
820 
821 	/* Have one command line that is parsed and saved in /proc/cmdline */
822 	/* boot_command_line has been already set up in early.c */
823 	*cmdline_p = boot_command_line;
824 
825         ROOT_DEV = Root_RAM0;
826 
827 	init_mm.start_code = PAGE_OFFSET;
828 	init_mm.end_code = (unsigned long) &_etext;
829 	init_mm.end_data = (unsigned long) &_edata;
830 	init_mm.brk = (unsigned long) &_end;
831 
832 	if (MACHINE_HAS_MVCOS)
833 		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
834 	else
835 		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
836 
837 	parse_early_param();
838 
839 	setup_ipl();
840 	setup_memory_end();
841 	setup_addressing_mode();
842 	setup_memory();
843 	setup_resources();
844 	setup_lowcore();
845 
846         cpu_init();
847 	s390_init_cpu_topology();
848 
849 	/*
850 	 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
851 	 */
852 	setup_hwcaps();
853 
854 	/*
855 	 * Create kernel page tables and switch to virtual addressing.
856 	 */
857         paging_init();
858 
859         /* Setup default console */
860 	conmode_default();
861 	set_preferred_console();
862 
863 	/* Setup zfcpdump support */
864 	setup_zfcpdump(console_devno);
865 }
866