1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  S390 version
4  *    Copyright IBM Corp. 1999, 2012
5  *    Author(s): Hartmut Penner (hp@de.ibm.com),
6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
7  *
8  *  Derived from "arch/i386/kernel/setup.c"
9  *    Copyright (C) 1995, Linus Torvalds
10  */
11 
12 /*
13  * This file handles the architecture-dependent parts of initialization
14  */
15 
16 #define KMSG_COMPONENT "setup"
17 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
18 
19 #include <linux/errno.h>
20 #include <linux/export.h>
21 #include <linux/sched.h>
22 #include <linux/sched/task.h>
23 #include <linux/cpu.h>
24 #include <linux/kernel.h>
25 #include <linux/memblock.h>
26 #include <linux/mm.h>
27 #include <linux/stddef.h>
28 #include <linux/unistd.h>
29 #include <linux/ptrace.h>
30 #include <linux/random.h>
31 #include <linux/user.h>
32 #include <linux/tty.h>
33 #include <linux/ioport.h>
34 #include <linux/delay.h>
35 #include <linux/init.h>
36 #include <linux/initrd.h>
37 #include <linux/root_dev.h>
38 #include <linux/console.h>
39 #include <linux/kernel_stat.h>
40 #include <linux/dma-map-ops.h>
41 #include <linux/device.h>
42 #include <linux/notifier.h>
43 #include <linux/pfn.h>
44 #include <linux/ctype.h>
45 #include <linux/reboot.h>
46 #include <linux/topology.h>
47 #include <linux/kexec.h>
48 #include <linux/crash_dump.h>
49 #include <linux/memory.h>
50 #include <linux/compat.h>
51 #include <linux/start_kernel.h>
52 #include <linux/hugetlb.h>
53 #include <linux/kmemleak.h>
54 
55 #include <asm/archrandom.h>
56 #include <asm/boot_data.h>
57 #include <asm/machine.h>
58 #include <asm/ipl.h>
59 #include <asm/facility.h>
60 #include <asm/smp.h>
61 #include <asm/mmu_context.h>
62 #include <asm/cpcmd.h>
63 #include <asm/abs_lowcore.h>
64 #include <asm/nmi.h>
65 #include <asm/irq.h>
66 #include <asm/page.h>
67 #include <asm/ptrace.h>
68 #include <asm/sections.h>
69 #include <asm/ebcdic.h>
70 #include <asm/diag.h>
71 #include <asm/os_info.h>
72 #include <asm/sclp.h>
73 #include <asm/stacktrace.h>
74 #include <asm/sysinfo.h>
75 #include <asm/numa.h>
76 #include <asm/alternative.h>
77 #include <asm/nospec-branch.h>
78 #include <asm/physmem_info.h>
79 #include <asm/maccess.h>
80 #include <asm/uv.h>
81 #include <asm/asm-offsets.h>
82 #include "entry.h"
83 
84 /*
85  * Machine setup..
86  */
87 unsigned int console_mode = 0;
88 EXPORT_SYMBOL(console_mode);
89 
90 unsigned int console_devno = -1;
91 EXPORT_SYMBOL(console_devno);
92 
93 unsigned int console_irq = -1;
94 EXPORT_SYMBOL(console_irq);
95 
96 /*
97  * Some code and data needs to stay below 2 GB, even when the kernel would be
98  * relocated above 2 GB, because it has to use 31 bit addresses.
99  * Such code and data is part of the .amode31 section.
100  */
101 char __amode31_ref *__samode31 = _samode31;
102 char __amode31_ref *__eamode31 = _eamode31;
103 char __amode31_ref *__stext_amode31 = _stext_amode31;
104 char __amode31_ref *__etext_amode31 = _etext_amode31;
105 struct exception_table_entry __amode31_ref *__start_amode31_ex_table = _start_amode31_ex_table;
106 struct exception_table_entry __amode31_ref *__stop_amode31_ex_table = _stop_amode31_ex_table;
107 
108 /*
109  * Control registers CR2, CR5 and CR15 are initialized with addresses
110  * of tables that must be placed below 2G which is handled by the AMODE31
111  * sections.
112  * Because the AMODE31 sections are relocated below 2G at startup,
113  * the content of control registers CR2, CR5 and CR15 must be updated
114  * with new addresses after the relocation. The initial initialization of
115  * control registers occurs in head64.S and then gets updated again after AMODE31
116  * relocation. We must access the relevant AMODE31 tables indirectly via
117  * pointers placed in the .amode31.refs linker section. Those pointers get
118  * updated automatically during AMODE31 relocation and always contain a valid
119  * address within AMODE31 sections.
120  */
121 
122 static __amode31_data u32 __ctl_duct_amode31[16] __aligned(64);
123 
124 static __amode31_data u64 __ctl_aste_amode31[8] __aligned(64) = {
125 	[1] = 0xffffffffffffffff
126 };
127 
128 static __amode31_data u32 __ctl_duald_amode31[32] __aligned(128) = {
129 	0x80000000, 0, 0, 0,
130 	0x80000000, 0, 0, 0,
131 	0x80000000, 0, 0, 0,
132 	0x80000000, 0, 0, 0,
133 	0x80000000, 0, 0, 0,
134 	0x80000000, 0, 0, 0,
135 	0x80000000, 0, 0, 0,
136 	0x80000000, 0, 0, 0
137 };
138 
139 static __amode31_data u32 __ctl_linkage_stack_amode31[8] __aligned(64) = {
140 	0, 0, 0x89000000, 0,
141 	0, 0, 0x8a000000, 0
142 };
143 
144 static u64 __amode31_ref *__ctl_aste = __ctl_aste_amode31;
145 static u32 __amode31_ref *__ctl_duald = __ctl_duald_amode31;
146 static u32 __amode31_ref *__ctl_linkage_stack = __ctl_linkage_stack_amode31;
147 static u32 __amode31_ref *__ctl_duct = __ctl_duct_amode31;
148 
149 unsigned long __bootdata_preserved(max_mappable);
150 struct physmem_info __bootdata(physmem_info);
151 
152 struct vm_layout __bootdata_preserved(vm_layout);
153 EXPORT_SYMBOL(vm_layout);
154 int __bootdata_preserved(__kaslr_enabled);
155 unsigned int __bootdata_preserved(zlib_dfltcc_support);
156 EXPORT_SYMBOL(zlib_dfltcc_support);
157 u64 __bootdata_preserved(stfle_fac_list[16]);
158 EXPORT_SYMBOL(stfle_fac_list);
159 struct oldmem_data __bootdata_preserved(oldmem_data);
160 
161 char __bootdata(boot_rb)[PAGE_SIZE * 2];
162 bool __bootdata(boot_earlyprintk);
163 size_t __bootdata(boot_rb_off);
164 char __bootdata(bootdebug_filter)[128];
165 bool __bootdata(bootdebug);
166 
167 unsigned long __bootdata_preserved(VMALLOC_START);
168 EXPORT_SYMBOL(VMALLOC_START);
169 
170 unsigned long __bootdata_preserved(VMALLOC_END);
171 EXPORT_SYMBOL(VMALLOC_END);
172 
173 struct page *__bootdata_preserved(vmemmap);
174 EXPORT_SYMBOL(vmemmap);
175 unsigned long __bootdata_preserved(vmemmap_size);
176 
177 unsigned long __bootdata_preserved(MODULES_VADDR);
178 unsigned long __bootdata_preserved(MODULES_END);
179 
180 /* An array with a pointer to the lowcore of every CPU. */
181 struct lowcore *lowcore_ptr[NR_CPUS];
182 EXPORT_SYMBOL(lowcore_ptr);
183 
184 /*
185  * The Write Back bit position in the physaddr is given by the SLPC PCI.
186  * Leaving the mask zero always uses write through which is safe
187  */
188 unsigned long mio_wb_bit_mask __ro_after_init;
189 
190 /*
191  * This is set up by the setup-routine at boot-time
192  * for S390 need to find out, what we have to setup
193  * using address 0x10400 ...
194  */
195 
196 #include <asm/setup.h>
197 
198 /*
199  * condev= and conmode= setup parameter.
200  */
201 
202 static int __init condev_setup(char *str)
203 {
204 	int vdev;
205 
206 	vdev = simple_strtoul(str, &str, 0);
207 	if (vdev >= 0 && vdev < 65536) {
208 		console_devno = vdev;
209 		console_irq = -1;
210 	}
211 	return 1;
212 }
213 
214 __setup("condev=", condev_setup);
215 
216 static void __init set_preferred_console(void)
217 {
218 	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
219 		add_preferred_console("ttyS", 0, NULL);
220 	else if (CONSOLE_IS_3270)
221 		add_preferred_console("tty3270", 0, NULL);
222 	else if (CONSOLE_IS_VT220)
223 		add_preferred_console("ttysclp", 0, NULL);
224 	else if (CONSOLE_IS_HVC)
225 		add_preferred_console("hvc", 0, NULL);
226 }
227 
228 static int __init conmode_setup(char *str)
229 {
230 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
231 	if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
232                 SET_CONSOLE_SCLP;
233 #endif
234 #if defined(CONFIG_TN3215_CONSOLE)
235 	if (!strcmp(str, "3215"))
236 		SET_CONSOLE_3215;
237 #endif
238 #if defined(CONFIG_TN3270_CONSOLE)
239 	if (!strcmp(str, "3270"))
240 		SET_CONSOLE_3270;
241 #endif
242 	set_preferred_console();
243         return 1;
244 }
245 
246 __setup("conmode=", conmode_setup);
247 
248 static void __init conmode_default(void)
249 {
250 	char query_buffer[1024];
251 	char *ptr;
252 
253 	if (machine_is_vm()) {
254 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
255 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
256 		ptr = strstr(query_buffer, "SUBCHANNEL =");
257 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
258 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
259 		ptr = strstr(query_buffer, "CONMODE");
260 		/*
261 		 * Set the conmode to 3215 so that the device recognition
262 		 * will set the cu_type of the console to 3215. If the
263 		 * conmode is 3270 and we don't set it back then both
264 		 * 3215 and the 3270 driver will try to access the console
265 		 * device (3215 as console and 3270 as normal tty).
266 		 */
267 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
268 		if (ptr == NULL) {
269 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
270 			SET_CONSOLE_SCLP;
271 #endif
272 			return;
273 		}
274 		if (str_has_prefix(ptr + 8, "3270")) {
275 #if defined(CONFIG_TN3270_CONSOLE)
276 			SET_CONSOLE_3270;
277 #elif defined(CONFIG_TN3215_CONSOLE)
278 			SET_CONSOLE_3215;
279 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
280 			SET_CONSOLE_SCLP;
281 #endif
282 		} else if (str_has_prefix(ptr + 8, "3215")) {
283 #if defined(CONFIG_TN3215_CONSOLE)
284 			SET_CONSOLE_3215;
285 #elif defined(CONFIG_TN3270_CONSOLE)
286 			SET_CONSOLE_3270;
287 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
288 			SET_CONSOLE_SCLP;
289 #endif
290 		}
291 	} else if (machine_is_kvm()) {
292 		if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
293 			SET_CONSOLE_VT220;
294 		else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
295 			SET_CONSOLE_SCLP;
296 		else
297 			SET_CONSOLE_HVC;
298 	} else {
299 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
300 		SET_CONSOLE_SCLP;
301 #endif
302 	}
303 }
304 
305 #ifdef CONFIG_CRASH_DUMP
306 static void __init setup_zfcpdump(void)
307 {
308 	if (!is_ipl_type_dump())
309 		return;
310 	if (oldmem_data.start)
311 		return;
312 	strlcat(boot_command_line, " cio_ignore=all,!ipldev,!condev", COMMAND_LINE_SIZE);
313 	console_loglevel = 2;
314 }
315 #else
316 static inline void setup_zfcpdump(void) {}
317 #endif /* CONFIG_CRASH_DUMP */
318 
319  /*
320  * Reboot, halt and power_off stubs. They just call _machine_restart,
321  * _machine_halt or _machine_power_off.
322  */
323 
324 void machine_restart(char *command)
325 {
326 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
327 		/*
328 		 * Only unblank the console if we are called in enabled
329 		 * context or a bust_spinlocks cleared the way for us.
330 		 */
331 		console_unblank();
332 	_machine_restart(command);
333 }
334 
335 void machine_halt(void)
336 {
337 	if (!in_interrupt() || oops_in_progress)
338 		/*
339 		 * Only unblank the console if we are called in enabled
340 		 * context or a bust_spinlocks cleared the way for us.
341 		 */
342 		console_unblank();
343 	_machine_halt();
344 }
345 
346 void machine_power_off(void)
347 {
348 	if (!in_interrupt() || oops_in_progress)
349 		/*
350 		 * Only unblank the console if we are called in enabled
351 		 * context or a bust_spinlocks cleared the way for us.
352 		 */
353 		console_unblank();
354 	_machine_power_off();
355 }
356 
357 /*
358  * Dummy power off function.
359  */
360 void (*pm_power_off)(void) = machine_power_off;
361 EXPORT_SYMBOL_GPL(pm_power_off);
362 
363 void *restart_stack;
364 
365 unsigned long stack_alloc(void)
366 {
367 	void *stack;
368 
369 	stack = __vmalloc_node(THREAD_SIZE, THREAD_SIZE, THREADINFO_GFP,
370 			       NUMA_NO_NODE, __builtin_return_address(0));
371 	kmemleak_not_leak(stack);
372 	return (unsigned long)stack;
373 }
374 
375 void stack_free(unsigned long stack)
376 {
377 	vfree((void *)stack);
378 }
379 
380 static unsigned long __init stack_alloc_early(void)
381 {
382 	unsigned long stack;
383 
384 	stack = (unsigned long)memblock_alloc_or_panic(THREAD_SIZE, THREAD_SIZE);
385 	return stack;
386 }
387 
388 static void __init setup_lowcore(void)
389 {
390 	struct lowcore *lc, *abs_lc;
391 
392 	/*
393 	 * Setup lowcore for boot cpu
394 	 */
395 	BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
396 	lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
397 	if (!lc)
398 		panic("%s: Failed to allocate %zu bytes align=%zx\n",
399 		      __func__, sizeof(*lc), sizeof(*lc));
400 
401 	lc->pcpu = (unsigned long)per_cpu_ptr(&pcpu_devices, 0);
402 	lc->restart_psw.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT;
403 	lc->restart_psw.addr = __pa(restart_int_handler);
404 	lc->external_new_psw.mask = PSW_KERNEL_BITS;
405 	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
406 	lc->svc_new_psw.mask = PSW_KERNEL_BITS;
407 	lc->svc_new_psw.addr = (unsigned long) system_call;
408 	lc->program_new_psw.mask = PSW_KERNEL_BITS;
409 	lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
410 	lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
411 	lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
412 	lc->io_new_psw.mask = PSW_KERNEL_BITS;
413 	lc->io_new_psw.addr = (unsigned long) io_int_handler;
414 	lc->clock_comparator = clock_comparator_max;
415 	lc->current_task = (unsigned long)&init_task;
416 	lc->lpp = LPP_MAGIC;
417 	lc->preempt_count = get_lowcore()->preempt_count;
418 	nmi_alloc_mcesa_early(&lc->mcesad);
419 	lc->sys_enter_timer = get_lowcore()->sys_enter_timer;
420 	lc->exit_timer = get_lowcore()->exit_timer;
421 	lc->user_timer = get_lowcore()->user_timer;
422 	lc->system_timer = get_lowcore()->system_timer;
423 	lc->steal_timer = get_lowcore()->steal_timer;
424 	lc->last_update_timer = get_lowcore()->last_update_timer;
425 	lc->last_update_clock = get_lowcore()->last_update_clock;
426 	/*
427 	 * Allocate the global restart stack which is the same for
428 	 * all CPUs in case *one* of them does a PSW restart.
429 	 */
430 	restart_stack = (void *)(stack_alloc_early() + STACK_INIT_OFFSET);
431 	lc->mcck_stack = stack_alloc_early() + STACK_INIT_OFFSET;
432 	lc->async_stack = stack_alloc_early() + STACK_INIT_OFFSET;
433 	lc->nodat_stack = stack_alloc_early() + STACK_INIT_OFFSET;
434 	lc->kernel_stack = get_lowcore()->kernel_stack;
435 	/*
436 	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
437 	 * restart data to the absolute zero lowcore. This is necessary if
438 	 * PSW restart is done on an offline CPU that has lowcore zero.
439 	 */
440 	lc->restart_stack = (unsigned long) restart_stack;
441 	lc->restart_fn = (unsigned long) do_restart;
442 	lc->restart_data = 0;
443 	lc->restart_source = -1U;
444 	lc->spinlock_lockval = arch_spin_lockval(0);
445 	lc->spinlock_index = 0;
446 	arch_spin_lock_setup(0);
447 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
448 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
449 	lc->preempt_count = PREEMPT_DISABLED;
450 	lc->kernel_asce = get_lowcore()->kernel_asce;
451 	lc->user_asce = get_lowcore()->user_asce;
452 
453 	system_ctlreg_init_save_area(lc);
454 	abs_lc = get_abs_lowcore();
455 	abs_lc->restart_stack = lc->restart_stack;
456 	abs_lc->restart_fn = lc->restart_fn;
457 	abs_lc->restart_data = lc->restart_data;
458 	abs_lc->restart_source = lc->restart_source;
459 	abs_lc->restart_psw = lc->restart_psw;
460 	abs_lc->restart_flags = RESTART_FLAG_CTLREGS;
461 	abs_lc->program_new_psw = lc->program_new_psw;
462 	abs_lc->mcesad = lc->mcesad;
463 	put_abs_lowcore(abs_lc);
464 
465 	set_prefix(__pa(lc));
466 	lowcore_ptr[0] = lc;
467 	if (abs_lowcore_map(0, lowcore_ptr[0], false))
468 		panic("Couldn't setup absolute lowcore");
469 }
470 
471 static struct resource code_resource = {
472 	.name  = "Kernel code",
473 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
474 };
475 
476 static struct resource data_resource = {
477 	.name = "Kernel data",
478 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
479 };
480 
481 static struct resource bss_resource = {
482 	.name = "Kernel bss",
483 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
484 };
485 
486 static struct resource __initdata *standard_resources[] = {
487 	&code_resource,
488 	&data_resource,
489 	&bss_resource,
490 };
491 
492 static void __init setup_resources(void)
493 {
494 	struct resource *res, *std_res, *sub_res;
495 	phys_addr_t start, end;
496 	int j;
497 	u64 i;
498 
499 	code_resource.start = __pa_symbol(_text);
500 	code_resource.end = __pa_symbol(_etext) - 1;
501 	data_resource.start = __pa_symbol(_etext);
502 	data_resource.end = __pa_symbol(_edata) - 1;
503 	bss_resource.start = __pa_symbol(__bss_start);
504 	bss_resource.end = __pa_symbol(__bss_stop) - 1;
505 
506 	for_each_mem_range(i, &start, &end) {
507 		res = memblock_alloc_or_panic(sizeof(*res), 8);
508 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
509 
510 		res->name = "System RAM";
511 		res->start = start;
512 		/*
513 		 * In memblock, end points to the first byte after the
514 		 * range while in resources, end points to the last byte in
515 		 * the range.
516 		 */
517 		res->end = end - 1;
518 		request_resource(&iomem_resource, res);
519 
520 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
521 			std_res = standard_resources[j];
522 			if (std_res->start < res->start ||
523 			    std_res->start > res->end)
524 				continue;
525 			if (std_res->end > res->end) {
526 				sub_res = memblock_alloc_or_panic(sizeof(*sub_res), 8);
527 				*sub_res = *std_res;
528 				sub_res->end = res->end;
529 				std_res->start = res->end + 1;
530 				request_resource(res, sub_res);
531 			} else {
532 				request_resource(res, std_res);
533 			}
534 		}
535 	}
536 #ifdef CONFIG_CRASH_DUMP
537 	/*
538 	 * Re-add removed crash kernel memory as reserved memory. This makes
539 	 * sure it will be mapped with the identity mapping and struct pages
540 	 * will be created, so it can be resized later on.
541 	 * However add it later since the crash kernel resource should not be
542 	 * part of the System RAM resource.
543 	 */
544 	if (crashk_res.end) {
545 		memblock_add_node(crashk_res.start, resource_size(&crashk_res),
546 				  0, MEMBLOCK_NONE);
547 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
548 		insert_resource(&iomem_resource, &crashk_res);
549 	}
550 #endif
551 }
552 
553 static void __init setup_memory_end(void)
554 {
555 	max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
556 	pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
557 }
558 
559 #ifdef CONFIG_CRASH_DUMP
560 
561 /*
562  * When kdump is enabled, we have to ensure that no memory from the area
563  * [0 - crashkernel memory size] is set offline - it will be exchanged with
564  * the crashkernel memory region when kdump is triggered. The crashkernel
565  * memory region can never get offlined (pages are unmovable).
566  */
567 static int kdump_mem_notifier(struct notifier_block *nb,
568 			      unsigned long action, void *data)
569 {
570 	struct memory_notify *arg = data;
571 
572 	if (action != MEM_GOING_OFFLINE)
573 		return NOTIFY_OK;
574 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
575 		return NOTIFY_BAD;
576 	return NOTIFY_OK;
577 }
578 
579 static struct notifier_block kdump_mem_nb = {
580 	.notifier_call = kdump_mem_notifier,
581 };
582 
583 #endif
584 
585 /*
586  * Reserve page tables created by decompressor
587  */
588 static void __init reserve_pgtables(void)
589 {
590 	unsigned long start, end;
591 	struct reserved_range *range;
592 
593 	for_each_physmem_reserved_type_range(RR_VMEM, range, &start, &end)
594 		memblock_reserve(start, end - start);
595 }
596 
597 /*
598  * Reserve memory for kdump kernel to be loaded with kexec
599  */
600 static void __init reserve_crashkernel(void)
601 {
602 #ifdef CONFIG_CRASH_DUMP
603 	unsigned long long crash_base, crash_size;
604 	phys_addr_t low, high;
605 	int rc;
606 
607 	rc = parse_crashkernel(boot_command_line, ident_map_size,
608 			       &crash_size, &crash_base, NULL, NULL);
609 
610 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
611 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
612 	if (rc || crash_size == 0)
613 		return;
614 
615 	if (memblock.memory.regions[0].size < crash_size) {
616 		pr_info("crashkernel reservation failed: %s\n",
617 			"first memory chunk must be at least crashkernel size");
618 		return;
619 	}
620 
621 	low = crash_base ?: oldmem_data.start;
622 	high = low + crash_size;
623 	if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
624 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
625 		crash_base = low;
626 	} else {
627 		/* Find suitable area in free memory */
628 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
629 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
630 
631 		if (crash_base && crash_base < low) {
632 			pr_info("crashkernel reservation failed: %s\n",
633 				"crash_base too low");
634 			return;
635 		}
636 		low = crash_base ?: low;
637 		crash_base = memblock_phys_alloc_range(crash_size,
638 						       KEXEC_CRASH_MEM_ALIGN,
639 						       low, high);
640 	}
641 
642 	if (!crash_base) {
643 		pr_info("crashkernel reservation failed: %s\n",
644 			"no suitable area found");
645 		return;
646 	}
647 
648 	if (register_memory_notifier(&kdump_mem_nb)) {
649 		memblock_phys_free(crash_base, crash_size);
650 		return;
651 	}
652 
653 	if (!oldmem_data.start && machine_is_vm())
654 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
655 	crashk_res.start = crash_base;
656 	crashk_res.end = crash_base + crash_size - 1;
657 	memblock_remove(crash_base, crash_size);
658 	pr_info("Reserving %lluMB of memory at %lluMB "
659 		"for crashkernel (System RAM: %luMB)\n",
660 		crash_size >> 20, crash_base >> 20,
661 		(unsigned long)memblock.memory.total_size >> 20);
662 	os_info_crashkernel_add(crash_base, crash_size);
663 #endif
664 }
665 
666 /*
667  * Reserve the initrd from being used by memblock
668  */
669 static void __init reserve_initrd(void)
670 {
671 	unsigned long addr, size;
672 
673 	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD) || !get_physmem_reserved(RR_INITRD, &addr, &size))
674 		return;
675 	initrd_start = (unsigned long)__va(addr);
676 	initrd_end = initrd_start + size;
677 	memblock_reserve(addr, size);
678 }
679 
680 /*
681  * Reserve the memory area used to pass the certificate lists
682  */
683 static void __init reserve_certificate_list(void)
684 {
685 	if (ipl_cert_list_addr)
686 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
687 }
688 
689 static void __init reserve_physmem_info(void)
690 {
691 	unsigned long addr, size;
692 
693 	if (get_physmem_reserved(RR_MEM_DETECT_EXT, &addr, &size))
694 		memblock_reserve(addr, size);
695 }
696 
697 static void __init free_physmem_info(void)
698 {
699 	unsigned long addr, size;
700 
701 	if (get_physmem_reserved(RR_MEM_DETECT_EXT, &addr, &size))
702 		memblock_phys_free(addr, size);
703 }
704 
705 static void __init memblock_add_physmem_info(void)
706 {
707 	unsigned long start, end;
708 	int i;
709 
710 	pr_debug("physmem info source: %s (%hhd)\n",
711 		 get_physmem_info_source(), physmem_info.info_source);
712 	/* keep memblock lists close to the kernel */
713 	memblock_set_bottom_up(true);
714 	for_each_physmem_usable_range(i, &start, &end)
715 		memblock_add(start, end - start);
716 	for_each_physmem_online_range(i, &start, &end)
717 		memblock_physmem_add(start, end - start);
718 	memblock_set_bottom_up(false);
719 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
720 }
721 
722 /*
723  * Reserve memory used for lowcore.
724  */
725 static void __init reserve_lowcore(void)
726 {
727 	void *lowcore_start = get_lowcore();
728 	void *lowcore_end = lowcore_start + sizeof(struct lowcore);
729 	void *start, *end;
730 
731 	if (absolute_pointer(__identity_base) < lowcore_end) {
732 		start = max(lowcore_start, (void *)__identity_base);
733 		end = min(lowcore_end, (void *)(__identity_base + ident_map_size));
734 		memblock_reserve(__pa(start), __pa(end));
735 	}
736 }
737 
738 /*
739  * Reserve memory used for absolute lowcore/command line/kernel image.
740  */
741 static void __init reserve_kernel(void)
742 {
743 	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
744 	memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
745 	memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
746 	memblock_reserve(physmem_info.reserved[RR_AMODE31].start, __eamode31 - __samode31);
747 	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
748 	memblock_reserve(__pa(_stext), _end - _stext);
749 }
750 
751 static void __init setup_memory(void)
752 {
753 	phys_addr_t start, end;
754 	u64 i;
755 
756 	/*
757 	 * Init storage key for present memory
758 	 */
759 	for_each_mem_range(i, &start, &end)
760 		storage_key_init_range(start, end);
761 
762 	psw_set_key(PAGE_DEFAULT_KEY);
763 }
764 
765 static void __init relocate_amode31_section(void)
766 {
767 	unsigned long amode31_size = __eamode31 - __samode31;
768 	long amode31_offset, *ptr;
769 
770 	amode31_offset = AMODE31_START - (unsigned long)__samode31;
771 	pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
772 
773 	/* Move original AMODE31 section to the new one */
774 	memmove((void *)physmem_info.reserved[RR_AMODE31].start, __samode31, amode31_size);
775 	/* Zero out the old AMODE31 section to catch invalid accesses within it */
776 	memset(__samode31, 0, amode31_size);
777 
778 	/* Update all AMODE31 region references */
779 	for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
780 		*ptr += amode31_offset;
781 }
782 
783 /* This must be called after AMODE31 relocation */
784 static void __init setup_cr(void)
785 {
786 	union ctlreg2 cr2;
787 	union ctlreg5 cr5;
788 	union ctlreg15 cr15;
789 
790 	__ctl_duct[1] = (unsigned long)__ctl_aste;
791 	__ctl_duct[2] = (unsigned long)__ctl_aste;
792 	__ctl_duct[4] = (unsigned long)__ctl_duald;
793 
794 	/* Update control registers CR2, CR5 and CR15 */
795 	local_ctl_store(2, &cr2.reg);
796 	local_ctl_store(5, &cr5.reg);
797 	local_ctl_store(15, &cr15.reg);
798 	cr2.ducto = (unsigned long)__ctl_duct >> 6;
799 	cr5.pasteo = (unsigned long)__ctl_duct >> 6;
800 	cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
801 	system_ctl_load(2, &cr2.reg);
802 	system_ctl_load(5, &cr5.reg);
803 	system_ctl_load(15, &cr15.reg);
804 }
805 
806 /*
807  * Add system information as device randomness
808  */
809 static void __init setup_randomness(void)
810 {
811 	struct sysinfo_3_2_2 *vmms;
812 
813 	vmms = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
814 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
815 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
816 	memblock_free(vmms, PAGE_SIZE);
817 
818 	if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG))
819 		static_branch_enable(&s390_arch_random_available);
820 }
821 
822 /*
823  * Issue diagnose 318 to set the control program name and
824  * version codes.
825  */
826 static void __init setup_control_program_code(void)
827 {
828 	union diag318_info diag318_info = {
829 		.cpnc = CPNC_LINUX,
830 		.cpvc = 0,
831 	};
832 
833 	if (!sclp.has_diag318)
834 		return;
835 
836 	diag_stat_inc(DIAG_STAT_X318);
837 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
838 }
839 
840 /*
841  * Print the component list from the IPL report
842  */
843 static void __init log_component_list(void)
844 {
845 	struct ipl_rb_component_entry *ptr, *end;
846 	char *str;
847 
848 	if (!early_ipl_comp_list_addr)
849 		return;
850 	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
851 		pr_info("Linux is running with Secure-IPL enabled\n");
852 	else
853 		pr_info("Linux is running with Secure-IPL disabled\n");
854 	ptr = __va(early_ipl_comp_list_addr);
855 	end = (void *) ptr + early_ipl_comp_list_size;
856 	pr_info("The IPL report contains the following components:\n");
857 	while (ptr < end) {
858 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
859 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
860 				str = "signed, verified";
861 			else
862 				str = "signed, verification failed";
863 		} else {
864 			str = "not signed";
865 		}
866 		pr_info("%016llx - %016llx (%s)\n",
867 			ptr->addr, ptr->addr + ptr->len, str);
868 		ptr++;
869 	}
870 }
871 
872 /*
873  * Print avoiding interpretation of % in buf and taking bootdebug option
874  * into consideration.
875  */
876 static void __init print_rb_entry(const char *buf)
877 {
878 	char fmt[] = KERN_SOH "0boot: %s";
879 	int level = printk_get_level(buf);
880 
881 	buf = skip_timestamp(printk_skip_level(buf));
882 	if (level == KERN_DEBUG[1] && (!bootdebug || !bootdebug_filter_match(buf)))
883 		return;
884 
885 	fmt[1] = level;
886 	printk(fmt, buf);
887 }
888 
889 /*
890  * Setup function called from init/main.c just after the banner
891  * was printed.
892  */
893 
894 void __init setup_arch(char **cmdline_p)
895 {
896         /*
897          * print what head.S has found out about the machine
898          */
899 	if (machine_is_vm())
900 		pr_info("Linux is running as a z/VM "
901 			"guest operating system in 64-bit mode\n");
902 	else if (machine_is_kvm())
903 		pr_info("Linux is running under KVM in 64-bit mode\n");
904 	else if (machine_is_lpar())
905 		pr_info("Linux is running natively in 64-bit mode\n");
906 	else
907 		pr_info("Linux is running as a guest in 64-bit mode\n");
908 	/* Print decompressor messages if not already printed */
909 	if (!boot_earlyprintk)
910 		boot_rb_foreach(print_rb_entry);
911 
912 	if (machine_has_relocated_lowcore())
913 		pr_info("Lowcore relocated to 0x%px\n", get_lowcore());
914 
915 	log_component_list();
916 
917 	/* Have one command line that is parsed and saved in /proc/cmdline */
918 	/* boot_command_line has been already set up in early.c */
919 	*cmdline_p = boot_command_line;
920 
921         ROOT_DEV = Root_RAM0;
922 
923 	setup_initial_init_mm(_text, _etext, _edata, _end);
924 
925 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
926 		nospec_auto_detect();
927 
928 	jump_label_init();
929 	parse_early_param();
930 #ifdef CONFIG_CRASH_DUMP
931 	/* Deactivate elfcorehdr= kernel parameter */
932 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
933 #endif
934 
935 	os_info_init();
936 	setup_ipl();
937 	setup_control_program_code();
938 
939 	/* Do some memory reservations *before* memory is added to memblock */
940 	reserve_pgtables();
941 	reserve_lowcore();
942 	reserve_kernel();
943 	reserve_initrd();
944 	reserve_certificate_list();
945 	reserve_physmem_info();
946 	memblock_set_current_limit(ident_map_size);
947 	memblock_allow_resize();
948 
949 	/* Get information about *all* installed memory */
950 	memblock_add_physmem_info();
951 
952 	free_physmem_info();
953 	setup_memory_end();
954 	memblock_dump_all();
955 	setup_memory();
956 
957 	relocate_amode31_section();
958 	setup_cr();
959 	setup_uv();
960 	dma_contiguous_reserve(ident_map_size);
961 	vmcp_cma_reserve();
962 	if (cpu_has_edat2())
963 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
964 
965 	reserve_crashkernel();
966 #ifdef CONFIG_CRASH_DUMP
967 	/*
968 	 * Be aware that smp_save_dump_secondary_cpus() triggers a system reset.
969 	 * Therefore CPU and device initialization should be done afterwards.
970 	 */
971 	smp_save_dump_secondary_cpus();
972 #endif
973 
974 	setup_resources();
975 	setup_lowcore();
976 	smp_fill_possible_mask();
977 	cpu_detect_mhz_feature();
978         cpu_init();
979 	numa_setup();
980 	smp_detect_cpus();
981 	topology_init_early();
982 	setup_protection_map();
983 	/*
984 	 * Create kernel page tables.
985 	 */
986         paging_init();
987 
988 	/*
989 	 * After paging_init created the kernel page table, the new PSWs
990 	 * in lowcore can now run with DAT enabled.
991 	 */
992 #ifdef CONFIG_CRASH_DUMP
993 	smp_save_dump_ipl_cpu();
994 #endif
995 
996         /* Setup default console */
997 	conmode_default();
998 	set_preferred_console();
999 
1000 	apply_alternative_instructions();
1001 	if (IS_ENABLED(CONFIG_EXPOLINE))
1002 		nospec_init_branches();
1003 
1004 	/* Setup zfcp/nvme dump support */
1005 	setup_zfcpdump();
1006 
1007 	/* Add system specific data to the random pool */
1008 	setup_randomness();
1009 }
1010 
1011 void __init arch_cpu_finalize_init(void)
1012 {
1013 	sclp_init();
1014 }
1015