xref: /linux/arch/s390/kernel/setup.c (revision 9ffc93f203c18a70623f21950f1dd473c9ec48cd)
1 /*
2  *  arch/s390/kernel/setup.c
3  *
4  *  S390 version
5  *    Copyright (C) IBM Corp. 1999,2012
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/memblock.h>
25 #include <linux/mm.h>
26 #include <linux/stddef.h>
27 #include <linux/unistd.h>
28 #include <linux/ptrace.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 #include <linux/kexec.h>
47 #include <linux/crash_dump.h>
48 #include <linux/memory.h>
49 #include <linux/compat.h>
50 
51 #include <asm/ipl.h>
52 #include <asm/uaccess.h>
53 #include <asm/smp.h>
54 #include <asm/mmu_context.h>
55 #include <asm/cpcmd.h>
56 #include <asm/lowcore.h>
57 #include <asm/irq.h>
58 #include <asm/page.h>
59 #include <asm/ptrace.h>
60 #include <asm/sections.h>
61 #include <asm/ebcdic.h>
62 #include <asm/kvm_virtio.h>
63 #include <asm/diag.h>
64 #include <asm/os_info.h>
65 #include "entry.h"
66 
67 long psw_kernel_bits	= PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_PRIMARY |
68 			  PSW_MASK_EA | PSW_MASK_BA;
69 long psw_user_bits	= PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT |
70 			  PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_MCHECK |
71 			  PSW_MASK_PSTATE | PSW_ASC_HOME;
72 
73 /*
74  * User copy operations.
75  */
76 struct uaccess_ops uaccess;
77 EXPORT_SYMBOL(uaccess);
78 
79 /*
80  * Machine setup..
81  */
82 unsigned int console_mode = 0;
83 EXPORT_SYMBOL(console_mode);
84 
85 unsigned int console_devno = -1;
86 EXPORT_SYMBOL(console_devno);
87 
88 unsigned int console_irq = -1;
89 EXPORT_SYMBOL(console_irq);
90 
91 unsigned long elf_hwcap = 0;
92 char elf_platform[ELF_PLATFORM_SIZE];
93 
94 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
95 
96 int __initdata memory_end_set;
97 unsigned long __initdata memory_end;
98 
99 unsigned long VMALLOC_START;
100 EXPORT_SYMBOL(VMALLOC_START);
101 
102 unsigned long VMALLOC_END;
103 EXPORT_SYMBOL(VMALLOC_END);
104 
105 struct page *vmemmap;
106 EXPORT_SYMBOL(vmemmap);
107 
108 /* An array with a pointer to the lowcore of every CPU. */
109 struct _lowcore *lowcore_ptr[NR_CPUS];
110 EXPORT_SYMBOL(lowcore_ptr);
111 
112 /*
113  * This is set up by the setup-routine at boot-time
114  * for S390 need to find out, what we have to setup
115  * using address 0x10400 ...
116  */
117 
118 #include <asm/setup.h>
119 
120 /*
121  * condev= and conmode= setup parameter.
122  */
123 
124 static int __init condev_setup(char *str)
125 {
126 	int vdev;
127 
128 	vdev = simple_strtoul(str, &str, 0);
129 	if (vdev >= 0 && vdev < 65536) {
130 		console_devno = vdev;
131 		console_irq = -1;
132 	}
133 	return 1;
134 }
135 
136 __setup("condev=", condev_setup);
137 
138 static void __init set_preferred_console(void)
139 {
140 	if (MACHINE_IS_KVM)
141 		add_preferred_console("hvc", 0, NULL);
142 	else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
143 		add_preferred_console("ttyS", 0, NULL);
144 	else if (CONSOLE_IS_3270)
145 		add_preferred_console("tty3270", 0, NULL);
146 }
147 
148 static int __init conmode_setup(char *str)
149 {
150 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
151 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
152                 SET_CONSOLE_SCLP;
153 #endif
154 #if defined(CONFIG_TN3215_CONSOLE)
155 	if (strncmp(str, "3215", 5) == 0)
156 		SET_CONSOLE_3215;
157 #endif
158 #if defined(CONFIG_TN3270_CONSOLE)
159 	if (strncmp(str, "3270", 5) == 0)
160 		SET_CONSOLE_3270;
161 #endif
162 	set_preferred_console();
163         return 1;
164 }
165 
166 __setup("conmode=", conmode_setup);
167 
168 static void __init conmode_default(void)
169 {
170 	char query_buffer[1024];
171 	char *ptr;
172 
173         if (MACHINE_IS_VM) {
174 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
175 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
176 		ptr = strstr(query_buffer, "SUBCHANNEL =");
177 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
178 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
179 		ptr = strstr(query_buffer, "CONMODE");
180 		/*
181 		 * Set the conmode to 3215 so that the device recognition
182 		 * will set the cu_type of the console to 3215. If the
183 		 * conmode is 3270 and we don't set it back then both
184 		 * 3215 and the 3270 driver will try to access the console
185 		 * device (3215 as console and 3270 as normal tty).
186 		 */
187 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
188 		if (ptr == NULL) {
189 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
190 			SET_CONSOLE_SCLP;
191 #endif
192 			return;
193 		}
194 		if (strncmp(ptr + 8, "3270", 4) == 0) {
195 #if defined(CONFIG_TN3270_CONSOLE)
196 			SET_CONSOLE_3270;
197 #elif defined(CONFIG_TN3215_CONSOLE)
198 			SET_CONSOLE_3215;
199 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
200 			SET_CONSOLE_SCLP;
201 #endif
202 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
203 #if defined(CONFIG_TN3215_CONSOLE)
204 			SET_CONSOLE_3215;
205 #elif defined(CONFIG_TN3270_CONSOLE)
206 			SET_CONSOLE_3270;
207 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
208 			SET_CONSOLE_SCLP;
209 #endif
210 		}
211 	} else {
212 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
213 		SET_CONSOLE_SCLP;
214 #endif
215 	}
216 }
217 
218 #ifdef CONFIG_ZFCPDUMP
219 static void __init setup_zfcpdump(unsigned int console_devno)
220 {
221 	static char str[41];
222 
223 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
224 		return;
225 	if (OLDMEM_BASE)
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 static int __init parse_vmalloc(char *arg)
292 {
293 	if (!arg)
294 		return -EINVAL;
295 	VMALLOC_END = (memparse(arg, &arg) + PAGE_SIZE - 1) & PAGE_MASK;
296 	return 0;
297 }
298 early_param("vmalloc", parse_vmalloc);
299 
300 unsigned int user_mode = HOME_SPACE_MODE;
301 EXPORT_SYMBOL_GPL(user_mode);
302 
303 static int set_amode_primary(void)
304 {
305 	psw_kernel_bits = (psw_kernel_bits & ~PSW_MASK_ASC) | PSW_ASC_HOME;
306 	psw_user_bits = (psw_user_bits & ~PSW_MASK_ASC) | PSW_ASC_PRIMARY;
307 #ifdef CONFIG_COMPAT
308 	psw32_user_bits =
309 		(psw32_user_bits & ~PSW32_MASK_ASC) | PSW32_ASC_PRIMARY;
310 #endif
311 
312 	if (MACHINE_HAS_MVCOS) {
313 		memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
314 		return 1;
315 	} else {
316 		memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
317 		return 0;
318 	}
319 }
320 
321 /*
322  * Switch kernel/user addressing modes?
323  */
324 static int __init early_parse_switch_amode(char *p)
325 {
326 	user_mode = PRIMARY_SPACE_MODE;
327 	return 0;
328 }
329 early_param("switch_amode", early_parse_switch_amode);
330 
331 static int __init early_parse_user_mode(char *p)
332 {
333 	if (p && strcmp(p, "primary") == 0)
334 		user_mode = PRIMARY_SPACE_MODE;
335 	else if (!p || strcmp(p, "home") == 0)
336 		user_mode = HOME_SPACE_MODE;
337 	else
338 		return 1;
339 	return 0;
340 }
341 early_param("user_mode", early_parse_user_mode);
342 
343 static void setup_addressing_mode(void)
344 {
345 	if (user_mode == PRIMARY_SPACE_MODE) {
346 		if (set_amode_primary())
347 			pr_info("Address spaces switched, "
348 				"mvcos available\n");
349 		else
350 			pr_info("Address spaces switched, "
351 				"mvcos not available\n");
352 	}
353 }
354 
355 void *restart_stack __attribute__((__section__(".data")));
356 
357 static void __init setup_lowcore(void)
358 {
359 	struct _lowcore *lc;
360 
361 	/*
362 	 * Setup lowcore for boot cpu
363 	 */
364 	BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
365 	lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
366 	lc->restart_psw.mask = psw_kernel_bits;
367 	lc->restart_psw.addr =
368 		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
369 	lc->external_new_psw.mask = psw_kernel_bits |
370 		PSW_MASK_DAT | PSW_MASK_MCHECK;
371 	lc->external_new_psw.addr =
372 		PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
373 	lc->svc_new_psw.mask = psw_kernel_bits |
374 		PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
375 	lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
376 	lc->program_new_psw.mask = psw_kernel_bits |
377 		PSW_MASK_DAT | PSW_MASK_MCHECK;
378 	lc->program_new_psw.addr =
379 		PSW_ADDR_AMODE | (unsigned long) pgm_check_handler;
380 	lc->mcck_new_psw.mask = psw_kernel_bits;
381 	lc->mcck_new_psw.addr =
382 		PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
383 	lc->io_new_psw.mask = psw_kernel_bits |
384 		PSW_MASK_DAT | PSW_MASK_MCHECK;
385 	lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
386 	lc->clock_comparator = -1ULL;
387 	lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
388 	lc->async_stack = (unsigned long)
389 		__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
390 	lc->panic_stack = (unsigned long)
391 		__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
392 	lc->current_task = (unsigned long) init_thread_union.thread_info.task;
393 	lc->thread_info = (unsigned long) &init_thread_union;
394 	lc->machine_flags = S390_lowcore.machine_flags;
395 	lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
396 	memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
397 	       MAX_FACILITY_BIT/8);
398 #ifndef CONFIG_64BIT
399 	if (MACHINE_HAS_IEEE) {
400 		lc->extended_save_area_addr = (__u32)
401 			__alloc_bootmem_low(PAGE_SIZE, PAGE_SIZE, 0);
402 		/* enable extended save area */
403 		__ctl_set_bit(14, 29);
404 	}
405 #else
406 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
407 #endif
408 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
409 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
410 	lc->exit_timer = S390_lowcore.exit_timer;
411 	lc->user_timer = S390_lowcore.user_timer;
412 	lc->system_timer = S390_lowcore.system_timer;
413 	lc->steal_timer = S390_lowcore.steal_timer;
414 	lc->last_update_timer = S390_lowcore.last_update_timer;
415 	lc->last_update_clock = S390_lowcore.last_update_clock;
416 	lc->ftrace_func = S390_lowcore.ftrace_func;
417 
418 	restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0);
419 	restart_stack += ASYNC_SIZE;
420 
421 	/*
422 	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
423 	 * restart data to the absolute zero lowcore. This is necesary if
424 	 * PSW restart is done on an offline CPU that has lowcore zero.
425 	 */
426 	lc->restart_stack = (unsigned long) restart_stack;
427 	lc->restart_fn = (unsigned long) do_restart;
428 	lc->restart_data = 0;
429 	lc->restart_source = -1UL;
430 	memcpy(&S390_lowcore.restart_stack, &lc->restart_stack,
431 	       4*sizeof(unsigned long));
432 	copy_to_absolute_zero(&S390_lowcore.restart_psw,
433 			      &lc->restart_psw, sizeof(psw_t));
434 
435 	set_prefix((u32)(unsigned long) lc);
436 	lowcore_ptr[0] = lc;
437 }
438 
439 static struct resource code_resource = {
440 	.name  = "Kernel code",
441 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
442 };
443 
444 static struct resource data_resource = {
445 	.name = "Kernel data",
446 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
447 };
448 
449 static struct resource bss_resource = {
450 	.name = "Kernel bss",
451 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
452 };
453 
454 static struct resource __initdata *standard_resources[] = {
455 	&code_resource,
456 	&data_resource,
457 	&bss_resource,
458 };
459 
460 static void __init setup_resources(void)
461 {
462 	struct resource *res, *std_res, *sub_res;
463 	int i, j;
464 
465 	code_resource.start = (unsigned long) &_text;
466 	code_resource.end = (unsigned long) &_etext - 1;
467 	data_resource.start = (unsigned long) &_etext;
468 	data_resource.end = (unsigned long) &_edata - 1;
469 	bss_resource.start = (unsigned long) &__bss_start;
470 	bss_resource.end = (unsigned long) &__bss_stop - 1;
471 
472 	for (i = 0; i < MEMORY_CHUNKS; i++) {
473 		if (!memory_chunk[i].size)
474 			continue;
475 		if (memory_chunk[i].type == CHUNK_OLDMEM ||
476 		    memory_chunk[i].type == CHUNK_CRASHK)
477 			continue;
478 		res = alloc_bootmem_low(sizeof(*res));
479 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
480 		switch (memory_chunk[i].type) {
481 		case CHUNK_READ_WRITE:
482 		case CHUNK_CRASHK:
483 			res->name = "System RAM";
484 			break;
485 		case CHUNK_READ_ONLY:
486 			res->name = "System ROM";
487 			res->flags |= IORESOURCE_READONLY;
488 			break;
489 		default:
490 			res->name = "reserved";
491 		}
492 		res->start = memory_chunk[i].addr;
493 		res->end = res->start + memory_chunk[i].size - 1;
494 		request_resource(&iomem_resource, res);
495 
496 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
497 			std_res = standard_resources[j];
498 			if (std_res->start < res->start ||
499 			    std_res->start > res->end)
500 				continue;
501 			if (std_res->end > res->end) {
502 				sub_res = alloc_bootmem_low(sizeof(*sub_res));
503 				*sub_res = *std_res;
504 				sub_res->end = res->end;
505 				std_res->start = res->end + 1;
506 				request_resource(res, sub_res);
507 			} else {
508 				request_resource(res, std_res);
509 			}
510 		}
511 	}
512 }
513 
514 unsigned long real_memory_size;
515 EXPORT_SYMBOL_GPL(real_memory_size);
516 
517 static void __init setup_memory_end(void)
518 {
519 	unsigned long vmax, vmalloc_size, tmp;
520 	int i;
521 
522 
523 #ifdef CONFIG_ZFCPDUMP
524 	if (ipl_info.type == IPL_TYPE_FCP_DUMP && !OLDMEM_BASE) {
525 		memory_end = ZFCPDUMP_HSA_SIZE;
526 		memory_end_set = 1;
527 	}
528 #endif
529 	real_memory_size = 0;
530 	memory_end &= PAGE_MASK;
531 
532 	/*
533 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
534 	 * extra checks that HOLES_IN_ZONE would require.
535 	 */
536 	for (i = 0; i < MEMORY_CHUNKS; i++) {
537 		unsigned long start, end;
538 		struct mem_chunk *chunk;
539 		unsigned long align;
540 
541 		chunk = &memory_chunk[i];
542 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
543 		start = (chunk->addr + align - 1) & ~(align - 1);
544 		end = (chunk->addr + chunk->size) & ~(align - 1);
545 		if (start >= end)
546 			memset(chunk, 0, sizeof(*chunk));
547 		else {
548 			chunk->addr = start;
549 			chunk->size = end - start;
550 		}
551 		real_memory_size = max(real_memory_size,
552 				       chunk->addr + chunk->size);
553 	}
554 
555 	/* Choose kernel address space layout: 2, 3, or 4 levels. */
556 #ifdef CONFIG_64BIT
557 	vmalloc_size = VMALLOC_END ?: 128UL << 30;
558 	tmp = (memory_end ?: real_memory_size) / PAGE_SIZE;
559 	tmp = tmp * (sizeof(struct page) + PAGE_SIZE) + vmalloc_size;
560 	if (tmp <= (1UL << 42))
561 		vmax = 1UL << 42;	/* 3-level kernel page table */
562 	else
563 		vmax = 1UL << 53;	/* 4-level kernel page table */
564 #else
565 	vmalloc_size = VMALLOC_END ?: 96UL << 20;
566 	vmax = 1UL << 31;		/* 2-level kernel page table */
567 #endif
568 	/* vmalloc area is at the end of the kernel address space. */
569 	VMALLOC_END = vmax;
570 	VMALLOC_START = vmax - vmalloc_size;
571 
572 	/* Split remaining virtual space between 1:1 mapping & vmemmap array */
573 	tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
574 	tmp = VMALLOC_START - tmp * sizeof(struct page);
575 	tmp &= ~((vmax >> 11) - 1);	/* align to page table level */
576 	tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
577 	vmemmap = (struct page *) tmp;
578 
579 	/* Take care that memory_end is set and <= vmemmap */
580 	memory_end = min(memory_end ?: real_memory_size, tmp);
581 
582 	/* Fixup memory chunk array to fit into 0..memory_end */
583 	for (i = 0; i < MEMORY_CHUNKS; i++) {
584 		struct mem_chunk *chunk = &memory_chunk[i];
585 
586 		if (chunk->addr >= memory_end) {
587 			memset(chunk, 0, sizeof(*chunk));
588 			continue;
589 		}
590 		if (chunk->addr + chunk->size > memory_end)
591 			chunk->size = memory_end - chunk->addr;
592 	}
593 }
594 
595 static void __init setup_vmcoreinfo(void)
596 {
597 #ifdef CONFIG_KEXEC
598 	unsigned long ptr = paddr_vmcoreinfo_note();
599 
600 	copy_to_absolute_zero(&S390_lowcore.vmcore_info, &ptr, sizeof(ptr));
601 #endif
602 }
603 
604 #ifdef CONFIG_CRASH_DUMP
605 
606 /*
607  * Find suitable location for crashkernel memory
608  */
609 static unsigned long __init find_crash_base(unsigned long crash_size,
610 					    char **msg)
611 {
612 	unsigned long crash_base;
613 	struct mem_chunk *chunk;
614 	int i;
615 
616 	if (memory_chunk[0].size < crash_size) {
617 		*msg = "first memory chunk must be at least crashkernel size";
618 		return 0;
619 	}
620 	if (OLDMEM_BASE && crash_size == OLDMEM_SIZE)
621 		return OLDMEM_BASE;
622 
623 	for (i = MEMORY_CHUNKS - 1; i >= 0; i--) {
624 		chunk = &memory_chunk[i];
625 		if (chunk->size == 0)
626 			continue;
627 		if (chunk->type != CHUNK_READ_WRITE)
628 			continue;
629 		if (chunk->size < crash_size)
630 			continue;
631 		crash_base = (chunk->addr + chunk->size) - crash_size;
632 		if (crash_base < crash_size)
633 			continue;
634 		if (crash_base < ZFCPDUMP_HSA_SIZE_MAX)
635 			continue;
636 		if (crash_base < (unsigned long) INITRD_START + INITRD_SIZE)
637 			continue;
638 		return crash_base;
639 	}
640 	*msg = "no suitable area found";
641 	return 0;
642 }
643 
644 /*
645  * Check if crash_base and crash_size is valid
646  */
647 static int __init verify_crash_base(unsigned long crash_base,
648 				    unsigned long crash_size,
649 				    char **msg)
650 {
651 	struct mem_chunk *chunk;
652 	int i;
653 
654 	/*
655 	 * Because we do the swap to zero, we must have at least 'crash_size'
656 	 * bytes free space before crash_base
657 	 */
658 	if (crash_size > crash_base) {
659 		*msg = "crashkernel offset must be greater than size";
660 		return -EINVAL;
661 	}
662 
663 	/* First memory chunk must be at least crash_size */
664 	if (memory_chunk[0].size < crash_size) {
665 		*msg = "first memory chunk must be at least crashkernel size";
666 		return -EINVAL;
667 	}
668 	/* Check if we fit into the respective memory chunk */
669 	for (i = 0; i < MEMORY_CHUNKS; i++) {
670 		chunk = &memory_chunk[i];
671 		if (chunk->size == 0)
672 			continue;
673 		if (crash_base < chunk->addr)
674 			continue;
675 		if (crash_base >= chunk->addr + chunk->size)
676 			continue;
677 		/* we have found the memory chunk */
678 		if (crash_base + crash_size > chunk->addr + chunk->size) {
679 			*msg = "selected memory chunk is too small for "
680 				"crashkernel memory";
681 			return -EINVAL;
682 		}
683 		return 0;
684 	}
685 	*msg = "invalid memory range specified";
686 	return -EINVAL;
687 }
688 
689 /*
690  * Reserve kdump memory by creating a memory hole in the mem_chunk array
691  */
692 static void __init reserve_kdump_bootmem(unsigned long addr, unsigned long size,
693 					 int type)
694 {
695 	create_mem_hole(memory_chunk, addr, size, type);
696 }
697 
698 /*
699  * When kdump is enabled, we have to ensure that no memory from
700  * the area [0 - crashkernel memory size] and
701  * [crashk_res.start - crashk_res.end] is set offline.
702  */
703 static int kdump_mem_notifier(struct notifier_block *nb,
704 			      unsigned long action, void *data)
705 {
706 	struct memory_notify *arg = data;
707 
708 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
709 		return NOTIFY_BAD;
710 	if (arg->start_pfn > PFN_DOWN(crashk_res.end))
711 		return NOTIFY_OK;
712 	if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
713 		return NOTIFY_OK;
714 	return NOTIFY_BAD;
715 }
716 
717 static struct notifier_block kdump_mem_nb = {
718 	.notifier_call = kdump_mem_notifier,
719 };
720 
721 #endif
722 
723 /*
724  * Make sure that oldmem, where the dump is stored, is protected
725  */
726 static void reserve_oldmem(void)
727 {
728 #ifdef CONFIG_CRASH_DUMP
729 	if (!OLDMEM_BASE)
730 		return;
731 
732 	reserve_kdump_bootmem(OLDMEM_BASE, OLDMEM_SIZE, CHUNK_OLDMEM);
733 	reserve_kdump_bootmem(OLDMEM_SIZE, memory_end - OLDMEM_SIZE,
734 			      CHUNK_OLDMEM);
735 	if (OLDMEM_BASE + OLDMEM_SIZE == real_memory_size)
736 		saved_max_pfn = PFN_DOWN(OLDMEM_BASE) - 1;
737 	else
738 		saved_max_pfn = PFN_DOWN(real_memory_size) - 1;
739 #endif
740 }
741 
742 /*
743  * Reserve memory for kdump kernel to be loaded with kexec
744  */
745 static void __init reserve_crashkernel(void)
746 {
747 #ifdef CONFIG_CRASH_DUMP
748 	unsigned long long crash_base, crash_size;
749 	char *msg = NULL;
750 	int rc;
751 
752 	rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
753 			       &crash_base);
754 	if (rc || crash_size == 0)
755 		return;
756 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
757 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
758 	if (register_memory_notifier(&kdump_mem_nb))
759 		return;
760 	if (!crash_base)
761 		crash_base = find_crash_base(crash_size, &msg);
762 	if (!crash_base) {
763 		pr_info("crashkernel reservation failed: %s\n", msg);
764 		unregister_memory_notifier(&kdump_mem_nb);
765 		return;
766 	}
767 	if (verify_crash_base(crash_base, crash_size, &msg)) {
768 		pr_info("crashkernel reservation failed: %s\n", msg);
769 		unregister_memory_notifier(&kdump_mem_nb);
770 		return;
771 	}
772 	if (!OLDMEM_BASE && MACHINE_IS_VM)
773 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
774 	crashk_res.start = crash_base;
775 	crashk_res.end = crash_base + crash_size - 1;
776 	insert_resource(&iomem_resource, &crashk_res);
777 	reserve_kdump_bootmem(crash_base, crash_size, CHUNK_CRASHK);
778 	pr_info("Reserving %lluMB of memory at %lluMB "
779 		"for crashkernel (System RAM: %luMB)\n",
780 		crash_size >> 20, crash_base >> 20, memory_end >> 20);
781 	os_info_crashkernel_add(crash_base, crash_size);
782 #endif
783 }
784 
785 static void __init setup_memory(void)
786 {
787         unsigned long bootmap_size;
788 	unsigned long start_pfn, end_pfn;
789 	int i;
790 
791 	/*
792 	 * partially used pages are not usable - thus
793 	 * we are rounding upwards:
794 	 */
795 	start_pfn = PFN_UP(__pa(&_end));
796 	end_pfn = max_pfn = PFN_DOWN(memory_end);
797 
798 #ifdef CONFIG_BLK_DEV_INITRD
799 	/*
800 	 * Move the initrd in case the bitmap of the bootmem allocater
801 	 * would overwrite it.
802 	 */
803 
804 	if (INITRD_START && INITRD_SIZE) {
805 		unsigned long bmap_size;
806 		unsigned long start;
807 
808 		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
809 		bmap_size = PFN_PHYS(bmap_size);
810 
811 		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
812 			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
813 
814 #ifdef CONFIG_CRASH_DUMP
815 			if (OLDMEM_BASE) {
816 				/* Move initrd behind kdump oldmem */
817 				if (start + INITRD_SIZE > OLDMEM_BASE &&
818 				    start < OLDMEM_BASE + OLDMEM_SIZE)
819 					start = OLDMEM_BASE + OLDMEM_SIZE;
820 			}
821 #endif
822 			if (start + INITRD_SIZE > memory_end) {
823 				pr_err("initrd extends beyond end of "
824 				       "memory (0x%08lx > 0x%08lx) "
825 				       "disabling initrd\n",
826 				       start + INITRD_SIZE, memory_end);
827 				INITRD_START = INITRD_SIZE = 0;
828 			} else {
829 				pr_info("Moving initrd (0x%08lx -> "
830 					"0x%08lx, size: %ld)\n",
831 					INITRD_START, start, INITRD_SIZE);
832 				memmove((void *) start, (void *) INITRD_START,
833 					INITRD_SIZE);
834 				INITRD_START = start;
835 			}
836 		}
837 	}
838 #endif
839 
840 	/*
841 	 * Initialize the boot-time allocator
842 	 */
843 	bootmap_size = init_bootmem(start_pfn, end_pfn);
844 
845 	/*
846 	 * Register RAM areas with the bootmem allocator.
847 	 */
848 
849 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
850 		unsigned long start_chunk, end_chunk, pfn;
851 
852 		if (memory_chunk[i].type != CHUNK_READ_WRITE &&
853 		    memory_chunk[i].type != CHUNK_CRASHK)
854 			continue;
855 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
856 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
857 		end_chunk = min(end_chunk, end_pfn);
858 		if (start_chunk >= end_chunk)
859 			continue;
860 		memblock_add_node(PFN_PHYS(start_chunk),
861 				  PFN_PHYS(end_chunk - start_chunk), 0);
862 		pfn = max(start_chunk, start_pfn);
863 		for (; pfn < end_chunk; pfn++)
864 			page_set_storage_key(PFN_PHYS(pfn),
865 					     PAGE_DEFAULT_KEY, 0);
866 	}
867 
868 	psw_set_key(PAGE_DEFAULT_KEY);
869 
870 	free_bootmem_with_active_regions(0, max_pfn);
871 
872 	/*
873 	 * Reserve memory used for lowcore/command line/kernel image.
874 	 */
875 	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
876 	reserve_bootmem((unsigned long)_stext,
877 			PFN_PHYS(start_pfn) - (unsigned long)_stext,
878 			BOOTMEM_DEFAULT);
879 	/*
880 	 * Reserve the bootmem bitmap itself as well. We do this in two
881 	 * steps (first step was init_bootmem()) because this catches
882 	 * the (very unlikely) case of us accidentally initializing the
883 	 * bootmem allocator with an invalid RAM area.
884 	 */
885 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
886 			BOOTMEM_DEFAULT);
887 
888 #ifdef CONFIG_CRASH_DUMP
889 	if (crashk_res.start)
890 		reserve_bootmem(crashk_res.start,
891 				crashk_res.end - crashk_res.start + 1,
892 				BOOTMEM_DEFAULT);
893 	if (is_kdump_kernel())
894 		reserve_bootmem(elfcorehdr_addr - OLDMEM_BASE,
895 				PAGE_ALIGN(elfcorehdr_size), BOOTMEM_DEFAULT);
896 #endif
897 #ifdef CONFIG_BLK_DEV_INITRD
898 	if (INITRD_START && INITRD_SIZE) {
899 		if (INITRD_START + INITRD_SIZE <= memory_end) {
900 			reserve_bootmem(INITRD_START, INITRD_SIZE,
901 					BOOTMEM_DEFAULT);
902 			initrd_start = INITRD_START;
903 			initrd_end = initrd_start + INITRD_SIZE;
904 		} else {
905 			pr_err("initrd extends beyond end of "
906 			       "memory (0x%08lx > 0x%08lx) "
907 			       "disabling initrd\n",
908 			       initrd_start + INITRD_SIZE, memory_end);
909 			initrd_start = initrd_end = 0;
910 		}
911 	}
912 #endif
913 }
914 
915 /*
916  * Setup hardware capabilities.
917  */
918 static void __init setup_hwcaps(void)
919 {
920 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
921 	struct cpuid cpu_id;
922 	int i;
923 
924 	/*
925 	 * The store facility list bits numbers as found in the principles
926 	 * of operation are numbered with bit 1UL<<31 as number 0 to
927 	 * bit 1UL<<0 as number 31.
928 	 *   Bit 0: instructions named N3, "backported" to esa-mode
929 	 *   Bit 2: z/Architecture mode is active
930 	 *   Bit 7: the store-facility-list-extended facility is installed
931 	 *   Bit 17: the message-security assist is installed
932 	 *   Bit 19: the long-displacement facility is installed
933 	 *   Bit 21: the extended-immediate facility is installed
934 	 *   Bit 22: extended-translation facility 3 is installed
935 	 *   Bit 30: extended-translation facility 3 enhancement facility
936 	 * These get translated to:
937 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
938 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
939 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
940 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
941 	 */
942 	for (i = 0; i < 6; i++)
943 		if (test_facility(stfl_bits[i]))
944 			elf_hwcap |= 1UL << i;
945 
946 	if (test_facility(22) && test_facility(30))
947 		elf_hwcap |= HWCAP_S390_ETF3EH;
948 
949 	/*
950 	 * Check for additional facilities with store-facility-list-extended.
951 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
952 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
953 	 * as stored by stfl, bits 32-xxx contain additional facilities.
954 	 * How many facility words are stored depends on the number of
955 	 * doublewords passed to the instruction. The additional facilities
956 	 * are:
957 	 *   Bit 42: decimal floating point facility is installed
958 	 *   Bit 44: perform floating point operation facility is installed
959 	 * translated to:
960 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
961 	 */
962 	if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
963 		elf_hwcap |= HWCAP_S390_DFP;
964 
965 	/*
966 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
967 	 */
968 	if (MACHINE_HAS_HPAGE)
969 		elf_hwcap |= HWCAP_S390_HPAGE;
970 
971 	/*
972 	 * 64-bit register support for 31-bit processes
973 	 * HWCAP_S390_HIGH_GPRS is bit 9.
974 	 */
975 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
976 
977 	get_cpu_id(&cpu_id);
978 	switch (cpu_id.machine) {
979 	case 0x9672:
980 #if !defined(CONFIG_64BIT)
981 	default:	/* Use "g5" as default for 31 bit kernels. */
982 #endif
983 		strcpy(elf_platform, "g5");
984 		break;
985 	case 0x2064:
986 	case 0x2066:
987 #if defined(CONFIG_64BIT)
988 	default:	/* Use "z900" as default for 64 bit kernels. */
989 #endif
990 		strcpy(elf_platform, "z900");
991 		break;
992 	case 0x2084:
993 	case 0x2086:
994 		strcpy(elf_platform, "z990");
995 		break;
996 	case 0x2094:
997 	case 0x2096:
998 		strcpy(elf_platform, "z9-109");
999 		break;
1000 	case 0x2097:
1001 	case 0x2098:
1002 		strcpy(elf_platform, "z10");
1003 		break;
1004 	case 0x2817:
1005 	case 0x2818:
1006 		strcpy(elf_platform, "z196");
1007 		break;
1008 	}
1009 }
1010 
1011 /*
1012  * Setup function called from init/main.c just after the banner
1013  * was printed.
1014  */
1015 
1016 void __init setup_arch(char **cmdline_p)
1017 {
1018         /*
1019          * print what head.S has found out about the machine
1020          */
1021 #ifndef CONFIG_64BIT
1022 	if (MACHINE_IS_VM)
1023 		pr_info("Linux is running as a z/VM "
1024 			"guest operating system in 31-bit mode\n");
1025 	else if (MACHINE_IS_LPAR)
1026 		pr_info("Linux is running natively in 31-bit mode\n");
1027 	if (MACHINE_HAS_IEEE)
1028 		pr_info("The hardware system has IEEE compatible "
1029 			"floating point units\n");
1030 	else
1031 		pr_info("The hardware system has no IEEE compatible "
1032 			"floating point units\n");
1033 #else /* CONFIG_64BIT */
1034 	if (MACHINE_IS_VM)
1035 		pr_info("Linux is running as a z/VM "
1036 			"guest operating system in 64-bit mode\n");
1037 	else if (MACHINE_IS_KVM)
1038 		pr_info("Linux is running under KVM in 64-bit mode\n");
1039 	else if (MACHINE_IS_LPAR)
1040 		pr_info("Linux is running natively in 64-bit mode\n");
1041 #endif /* CONFIG_64BIT */
1042 
1043 	/* Have one command line that is parsed and saved in /proc/cmdline */
1044 	/* boot_command_line has been already set up in early.c */
1045 	*cmdline_p = boot_command_line;
1046 
1047         ROOT_DEV = Root_RAM0;
1048 
1049 	init_mm.start_code = PAGE_OFFSET;
1050 	init_mm.end_code = (unsigned long) &_etext;
1051 	init_mm.end_data = (unsigned long) &_edata;
1052 	init_mm.brk = (unsigned long) &_end;
1053 
1054 	if (MACHINE_HAS_MVCOS)
1055 		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
1056 	else
1057 		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
1058 
1059 	parse_early_param();
1060 
1061 	os_info_init();
1062 	setup_ipl();
1063 	setup_memory_end();
1064 	setup_addressing_mode();
1065 	reserve_oldmem();
1066 	reserve_crashkernel();
1067 	setup_memory();
1068 	setup_resources();
1069 	setup_vmcoreinfo();
1070 	setup_lowcore();
1071 
1072         cpu_init();
1073 	s390_init_cpu_topology();
1074 
1075 	/*
1076 	 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
1077 	 */
1078 	setup_hwcaps();
1079 
1080 	/*
1081 	 * Create kernel page tables and switch to virtual addressing.
1082 	 */
1083         paging_init();
1084 
1085         /* Setup default console */
1086 	conmode_default();
1087 	set_preferred_console();
1088 
1089 	/* Setup zfcpdump support */
1090 	setup_zfcpdump(console_devno);
1091 }
1092