xref: /linux/arch/s390/kernel/setup.c (revision 6b3d638ca897e099fa99bd6d02189d3176f80a47)
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/ipl.h>
58 #include <asm/facility.h>
59 #include <asm/smp.h>
60 #include <asm/mmu_context.h>
61 #include <asm/cpcmd.h>
62 #include <asm/abs_lowcore.h>
63 #include <asm/nmi.h>
64 #include <asm/irq.h>
65 #include <asm/page.h>
66 #include <asm/ptrace.h>
67 #include <asm/sections.h>
68 #include <asm/ebcdic.h>
69 #include <asm/diag.h>
70 #include <asm/os_info.h>
71 #include <asm/sclp.h>
72 #include <asm/stacktrace.h>
73 #include <asm/sysinfo.h>
74 #include <asm/numa.h>
75 #include <asm/alternative.h>
76 #include <asm/nospec-branch.h>
77 #include <asm/physmem_info.h>
78 #include <asm/maccess.h>
79 #include <asm/uv.h>
80 #include <asm/asm-offsets.h>
81 #include "entry.h"
82 
83 /*
84  * Machine setup..
85  */
86 unsigned int console_mode = 0;
87 EXPORT_SYMBOL(console_mode);
88 
89 unsigned int console_devno = -1;
90 EXPORT_SYMBOL(console_devno);
91 
92 unsigned int console_irq = -1;
93 EXPORT_SYMBOL(console_irq);
94 
95 /*
96  * Some code and data needs to stay below 2 GB, even when the kernel would be
97  * relocated above 2 GB, because it has to use 31 bit addresses.
98  * Such code and data is part of the .amode31 section.
99  */
100 char __amode31_ref *__samode31 = _samode31;
101 char __amode31_ref *__eamode31 = _eamode31;
102 char __amode31_ref *__stext_amode31 = _stext_amode31;
103 char __amode31_ref *__etext_amode31 = _etext_amode31;
104 struct exception_table_entry __amode31_ref *__start_amode31_ex_table = _start_amode31_ex_table;
105 struct exception_table_entry __amode31_ref *__stop_amode31_ex_table = _stop_amode31_ex_table;
106 
107 /*
108  * Control registers CR2, CR5 and CR15 are initialized with addresses
109  * of tables that must be placed below 2G which is handled by the AMODE31
110  * sections.
111  * Because the AMODE31 sections are relocated below 2G at startup,
112  * the content of control registers CR2, CR5 and CR15 must be updated
113  * with new addresses after the relocation. The initial initialization of
114  * control registers occurs in head64.S and then gets updated again after AMODE31
115  * relocation. We must access the relevant AMODE31 tables indirectly via
116  * pointers placed in the .amode31.refs linker section. Those pointers get
117  * updated automatically during AMODE31 relocation and always contain a valid
118  * address within AMODE31 sections.
119  */
120 
121 static __amode31_data u32 __ctl_duct_amode31[16] __aligned(64);
122 
123 static __amode31_data u64 __ctl_aste_amode31[8] __aligned(64) = {
124 	[1] = 0xffffffffffffffff
125 };
126 
127 static __amode31_data u32 __ctl_duald_amode31[32] __aligned(128) = {
128 	0x80000000, 0, 0, 0,
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 };
137 
138 static __amode31_data u32 __ctl_linkage_stack_amode31[8] __aligned(64) = {
139 	0, 0, 0x89000000, 0,
140 	0, 0, 0x8a000000, 0
141 };
142 
143 static u64 __amode31_ref *__ctl_aste = __ctl_aste_amode31;
144 static u32 __amode31_ref *__ctl_duald = __ctl_duald_amode31;
145 static u32 __amode31_ref *__ctl_linkage_stack = __ctl_linkage_stack_amode31;
146 static u32 __amode31_ref *__ctl_duct = __ctl_duct_amode31;
147 
148 unsigned long __bootdata_preserved(max_mappable);
149 struct physmem_info __bootdata(physmem_info);
150 
151 struct vm_layout __bootdata_preserved(vm_layout);
152 EXPORT_SYMBOL(vm_layout);
153 int __bootdata_preserved(__kaslr_enabled);
154 unsigned int __bootdata_preserved(zlib_dfltcc_support);
155 EXPORT_SYMBOL(zlib_dfltcc_support);
156 u64 __bootdata_preserved(stfle_fac_list[16]);
157 EXPORT_SYMBOL(stfle_fac_list);
158 struct oldmem_data __bootdata_preserved(oldmem_data);
159 
160 unsigned long __bootdata_preserved(VMALLOC_START);
161 EXPORT_SYMBOL(VMALLOC_START);
162 
163 unsigned long __bootdata_preserved(VMALLOC_END);
164 EXPORT_SYMBOL(VMALLOC_END);
165 
166 struct page *__bootdata_preserved(vmemmap);
167 EXPORT_SYMBOL(vmemmap);
168 unsigned long __bootdata_preserved(vmemmap_size);
169 
170 unsigned long __bootdata_preserved(MODULES_VADDR);
171 unsigned long __bootdata_preserved(MODULES_END);
172 
173 /* An array with a pointer to the lowcore of every CPU. */
174 struct lowcore *lowcore_ptr[NR_CPUS];
175 EXPORT_SYMBOL(lowcore_ptr);
176 
177 DEFINE_STATIC_KEY_FALSE(cpu_has_bear);
178 
179 /*
180  * The Write Back bit position in the physaddr is given by the SLPC PCI.
181  * Leaving the mask zero always uses write through which is safe
182  */
183 unsigned long mio_wb_bit_mask __ro_after_init;
184 
185 /*
186  * This is set up by the setup-routine at boot-time
187  * for S390 need to find out, what we have to setup
188  * using address 0x10400 ...
189  */
190 
191 #include <asm/setup.h>
192 
193 /*
194  * condev= and conmode= setup parameter.
195  */
196 
197 static int __init condev_setup(char *str)
198 {
199 	int vdev;
200 
201 	vdev = simple_strtoul(str, &str, 0);
202 	if (vdev >= 0 && vdev < 65536) {
203 		console_devno = vdev;
204 		console_irq = -1;
205 	}
206 	return 1;
207 }
208 
209 __setup("condev=", condev_setup);
210 
211 static void __init set_preferred_console(void)
212 {
213 	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
214 		add_preferred_console("ttyS", 0, NULL);
215 	else if (CONSOLE_IS_3270)
216 		add_preferred_console("tty3270", 0, NULL);
217 	else if (CONSOLE_IS_VT220)
218 		add_preferred_console("ttysclp", 0, NULL);
219 	else if (CONSOLE_IS_HVC)
220 		add_preferred_console("hvc", 0, NULL);
221 }
222 
223 static int __init conmode_setup(char *str)
224 {
225 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
226 	if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
227                 SET_CONSOLE_SCLP;
228 #endif
229 #if defined(CONFIG_TN3215_CONSOLE)
230 	if (!strcmp(str, "3215"))
231 		SET_CONSOLE_3215;
232 #endif
233 #if defined(CONFIG_TN3270_CONSOLE)
234 	if (!strcmp(str, "3270"))
235 		SET_CONSOLE_3270;
236 #endif
237 	set_preferred_console();
238         return 1;
239 }
240 
241 __setup("conmode=", conmode_setup);
242 
243 static void __init conmode_default(void)
244 {
245 	char query_buffer[1024];
246 	char *ptr;
247 
248         if (MACHINE_IS_VM) {
249 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
250 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
251 		ptr = strstr(query_buffer, "SUBCHANNEL =");
252 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
253 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
254 		ptr = strstr(query_buffer, "CONMODE");
255 		/*
256 		 * Set the conmode to 3215 so that the device recognition
257 		 * will set the cu_type of the console to 3215. If the
258 		 * conmode is 3270 and we don't set it back then both
259 		 * 3215 and the 3270 driver will try to access the console
260 		 * device (3215 as console and 3270 as normal tty).
261 		 */
262 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
263 		if (ptr == NULL) {
264 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
265 			SET_CONSOLE_SCLP;
266 #endif
267 			return;
268 		}
269 		if (str_has_prefix(ptr + 8, "3270")) {
270 #if defined(CONFIG_TN3270_CONSOLE)
271 			SET_CONSOLE_3270;
272 #elif defined(CONFIG_TN3215_CONSOLE)
273 			SET_CONSOLE_3215;
274 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
275 			SET_CONSOLE_SCLP;
276 #endif
277 		} else if (str_has_prefix(ptr + 8, "3215")) {
278 #if defined(CONFIG_TN3215_CONSOLE)
279 			SET_CONSOLE_3215;
280 #elif defined(CONFIG_TN3270_CONSOLE)
281 			SET_CONSOLE_3270;
282 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
283 			SET_CONSOLE_SCLP;
284 #endif
285 		}
286 	} else if (MACHINE_IS_KVM) {
287 		if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
288 			SET_CONSOLE_VT220;
289 		else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
290 			SET_CONSOLE_SCLP;
291 		else
292 			SET_CONSOLE_HVC;
293 	} else {
294 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
295 		SET_CONSOLE_SCLP;
296 #endif
297 	}
298 }
299 
300 #ifdef CONFIG_CRASH_DUMP
301 static void __init setup_zfcpdump(void)
302 {
303 	if (!is_ipl_type_dump())
304 		return;
305 	if (oldmem_data.start)
306 		return;
307 	strlcat(boot_command_line, " cio_ignore=all,!ipldev,!condev", COMMAND_LINE_SIZE);
308 	console_loglevel = 2;
309 }
310 #else
311 static inline void setup_zfcpdump(void) {}
312 #endif /* CONFIG_CRASH_DUMP */
313 
314  /*
315  * Reboot, halt and power_off stubs. They just call _machine_restart,
316  * _machine_halt or _machine_power_off.
317  */
318 
319 void machine_restart(char *command)
320 {
321 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
322 		/*
323 		 * Only unblank the console if we are called in enabled
324 		 * context or a bust_spinlocks cleared the way for us.
325 		 */
326 		console_unblank();
327 	_machine_restart(command);
328 }
329 
330 void machine_halt(void)
331 {
332 	if (!in_interrupt() || oops_in_progress)
333 		/*
334 		 * Only unblank the console if we are called in enabled
335 		 * context or a bust_spinlocks cleared the way for us.
336 		 */
337 		console_unblank();
338 	_machine_halt();
339 }
340 
341 void machine_power_off(void)
342 {
343 	if (!in_interrupt() || oops_in_progress)
344 		/*
345 		 * Only unblank the console if we are called in enabled
346 		 * context or a bust_spinlocks cleared the way for us.
347 		 */
348 		console_unblank();
349 	_machine_power_off();
350 }
351 
352 /*
353  * Dummy power off function.
354  */
355 void (*pm_power_off)(void) = machine_power_off;
356 EXPORT_SYMBOL_GPL(pm_power_off);
357 
358 void *restart_stack;
359 
360 unsigned long stack_alloc(void)
361 {
362 	void *stack;
363 
364 	stack = __vmalloc_node(THREAD_SIZE, THREAD_SIZE, THREADINFO_GFP,
365 			       NUMA_NO_NODE, __builtin_return_address(0));
366 	kmemleak_not_leak(stack);
367 	return (unsigned long)stack;
368 }
369 
370 void stack_free(unsigned long stack)
371 {
372 	vfree((void *)stack);
373 }
374 
375 static unsigned long __init stack_alloc_early(void)
376 {
377 	unsigned long stack;
378 
379 	stack = (unsigned long)memblock_alloc_or_panic(THREAD_SIZE, THREAD_SIZE);
380 	return stack;
381 }
382 
383 static void __init setup_lowcore(void)
384 {
385 	struct lowcore *lc, *abs_lc;
386 
387 	/*
388 	 * Setup lowcore for boot cpu
389 	 */
390 	BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
391 	lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
392 	if (!lc)
393 		panic("%s: Failed to allocate %zu bytes align=%zx\n",
394 		      __func__, sizeof(*lc), sizeof(*lc));
395 
396 	lc->pcpu = (unsigned long)per_cpu_ptr(&pcpu_devices, 0);
397 	lc->restart_psw.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT;
398 	lc->restart_psw.addr = __pa(restart_int_handler);
399 	lc->external_new_psw.mask = PSW_KERNEL_BITS;
400 	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
401 	lc->svc_new_psw.mask = PSW_KERNEL_BITS;
402 	lc->svc_new_psw.addr = (unsigned long) system_call;
403 	lc->program_new_psw.mask = PSW_KERNEL_BITS;
404 	lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
405 	lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
406 	lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
407 	lc->io_new_psw.mask = PSW_KERNEL_BITS;
408 	lc->io_new_psw.addr = (unsigned long) io_int_handler;
409 	lc->clock_comparator = clock_comparator_max;
410 	lc->current_task = (unsigned long)&init_task;
411 	lc->lpp = LPP_MAGIC;
412 	lc->machine_flags = get_lowcore()->machine_flags;
413 	lc->preempt_count = get_lowcore()->preempt_count;
414 	nmi_alloc_mcesa_early(&lc->mcesad);
415 	lc->sys_enter_timer = get_lowcore()->sys_enter_timer;
416 	lc->exit_timer = get_lowcore()->exit_timer;
417 	lc->user_timer = get_lowcore()->user_timer;
418 	lc->system_timer = get_lowcore()->system_timer;
419 	lc->steal_timer = get_lowcore()->steal_timer;
420 	lc->last_update_timer = get_lowcore()->last_update_timer;
421 	lc->last_update_clock = get_lowcore()->last_update_clock;
422 	/*
423 	 * Allocate the global restart stack which is the same for
424 	 * all CPUs in case *one* of them does a PSW restart.
425 	 */
426 	restart_stack = (void *)(stack_alloc_early() + STACK_INIT_OFFSET);
427 	lc->mcck_stack = stack_alloc_early() + STACK_INIT_OFFSET;
428 	lc->async_stack = stack_alloc_early() + STACK_INIT_OFFSET;
429 	lc->nodat_stack = stack_alloc_early() + STACK_INIT_OFFSET;
430 	lc->kernel_stack = get_lowcore()->kernel_stack;
431 	/*
432 	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
433 	 * restart data to the absolute zero lowcore. This is necessary if
434 	 * PSW restart is done on an offline CPU that has lowcore zero.
435 	 */
436 	lc->restart_stack = (unsigned long) restart_stack;
437 	lc->restart_fn = (unsigned long) do_restart;
438 	lc->restart_data = 0;
439 	lc->restart_source = -1U;
440 	lc->spinlock_lockval = arch_spin_lockval(0);
441 	lc->spinlock_index = 0;
442 	arch_spin_lock_setup(0);
443 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
444 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
445 	lc->preempt_count = PREEMPT_DISABLED;
446 	lc->kernel_asce = get_lowcore()->kernel_asce;
447 	lc->user_asce = get_lowcore()->user_asce;
448 
449 	system_ctlreg_init_save_area(lc);
450 	abs_lc = get_abs_lowcore();
451 	abs_lc->restart_stack = lc->restart_stack;
452 	abs_lc->restart_fn = lc->restart_fn;
453 	abs_lc->restart_data = lc->restart_data;
454 	abs_lc->restart_source = lc->restart_source;
455 	abs_lc->restart_psw = lc->restart_psw;
456 	abs_lc->restart_flags = RESTART_FLAG_CTLREGS;
457 	abs_lc->program_new_psw = lc->program_new_psw;
458 	abs_lc->mcesad = lc->mcesad;
459 	put_abs_lowcore(abs_lc);
460 
461 	set_prefix(__pa(lc));
462 	lowcore_ptr[0] = lc;
463 	if (abs_lowcore_map(0, lowcore_ptr[0], false))
464 		panic("Couldn't setup absolute lowcore");
465 }
466 
467 static struct resource code_resource = {
468 	.name  = "Kernel code",
469 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
470 };
471 
472 static struct resource data_resource = {
473 	.name = "Kernel data",
474 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
475 };
476 
477 static struct resource bss_resource = {
478 	.name = "Kernel bss",
479 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
480 };
481 
482 static struct resource __initdata *standard_resources[] = {
483 	&code_resource,
484 	&data_resource,
485 	&bss_resource,
486 };
487 
488 static void __init setup_resources(void)
489 {
490 	struct resource *res, *std_res, *sub_res;
491 	phys_addr_t start, end;
492 	int j;
493 	u64 i;
494 
495 	code_resource.start = __pa_symbol(_text);
496 	code_resource.end = __pa_symbol(_etext) - 1;
497 	data_resource.start = __pa_symbol(_etext);
498 	data_resource.end = __pa_symbol(_edata) - 1;
499 	bss_resource.start = __pa_symbol(__bss_start);
500 	bss_resource.end = __pa_symbol(__bss_stop) - 1;
501 
502 	for_each_mem_range(i, &start, &end) {
503 		res = memblock_alloc_or_panic(sizeof(*res), 8);
504 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
505 
506 		res->name = "System RAM";
507 		res->start = start;
508 		/*
509 		 * In memblock, end points to the first byte after the
510 		 * range while in resources, end points to the last byte in
511 		 * the range.
512 		 */
513 		res->end = end - 1;
514 		request_resource(&iomem_resource, res);
515 
516 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
517 			std_res = standard_resources[j];
518 			if (std_res->start < res->start ||
519 			    std_res->start > res->end)
520 				continue;
521 			if (std_res->end > res->end) {
522 				sub_res = memblock_alloc_or_panic(sizeof(*sub_res), 8);
523 				*sub_res = *std_res;
524 				sub_res->end = res->end;
525 				std_res->start = res->end + 1;
526 				request_resource(res, sub_res);
527 			} else {
528 				request_resource(res, std_res);
529 			}
530 		}
531 	}
532 #ifdef CONFIG_CRASH_DUMP
533 	/*
534 	 * Re-add removed crash kernel memory as reserved memory. This makes
535 	 * sure it will be mapped with the identity mapping and struct pages
536 	 * will be created, so it can be resized later on.
537 	 * However add it later since the crash kernel resource should not be
538 	 * part of the System RAM resource.
539 	 */
540 	if (crashk_res.end) {
541 		memblock_add_node(crashk_res.start, resource_size(&crashk_res),
542 				  0, MEMBLOCK_NONE);
543 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
544 		insert_resource(&iomem_resource, &crashk_res);
545 	}
546 #endif
547 }
548 
549 static void __init setup_memory_end(void)
550 {
551 	max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
552 	pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
553 }
554 
555 #ifdef CONFIG_CRASH_DUMP
556 
557 /*
558  * When kdump is enabled, we have to ensure that no memory from the area
559  * [0 - crashkernel memory size] is set offline - it will be exchanged with
560  * the crashkernel memory region when kdump is triggered. The crashkernel
561  * memory region can never get offlined (pages are unmovable).
562  */
563 static int kdump_mem_notifier(struct notifier_block *nb,
564 			      unsigned long action, void *data)
565 {
566 	struct memory_notify *arg = data;
567 
568 	if (action != MEM_GOING_OFFLINE)
569 		return NOTIFY_OK;
570 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
571 		return NOTIFY_BAD;
572 	return NOTIFY_OK;
573 }
574 
575 static struct notifier_block kdump_mem_nb = {
576 	.notifier_call = kdump_mem_notifier,
577 };
578 
579 #endif
580 
581 /*
582  * Reserve page tables created by decompressor
583  */
584 static void __init reserve_pgtables(void)
585 {
586 	unsigned long start, end;
587 	struct reserved_range *range;
588 
589 	for_each_physmem_reserved_type_range(RR_VMEM, range, &start, &end)
590 		memblock_reserve(start, end - start);
591 }
592 
593 /*
594  * Reserve memory for kdump kernel to be loaded with kexec
595  */
596 static void __init reserve_crashkernel(void)
597 {
598 #ifdef CONFIG_CRASH_DUMP
599 	unsigned long long crash_base, crash_size;
600 	phys_addr_t low, high;
601 	int rc;
602 
603 	rc = parse_crashkernel(boot_command_line, ident_map_size,
604 			       &crash_size, &crash_base, NULL, NULL);
605 
606 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
607 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
608 	if (rc || crash_size == 0)
609 		return;
610 
611 	if (memblock.memory.regions[0].size < crash_size) {
612 		pr_info("crashkernel reservation failed: %s\n",
613 			"first memory chunk must be at least crashkernel size");
614 		return;
615 	}
616 
617 	low = crash_base ?: oldmem_data.start;
618 	high = low + crash_size;
619 	if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
620 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
621 		crash_base = low;
622 	} else {
623 		/* Find suitable area in free memory */
624 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
625 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
626 
627 		if (crash_base && crash_base < low) {
628 			pr_info("crashkernel reservation failed: %s\n",
629 				"crash_base too low");
630 			return;
631 		}
632 		low = crash_base ?: low;
633 		crash_base = memblock_phys_alloc_range(crash_size,
634 						       KEXEC_CRASH_MEM_ALIGN,
635 						       low, high);
636 	}
637 
638 	if (!crash_base) {
639 		pr_info("crashkernel reservation failed: %s\n",
640 			"no suitable area found");
641 		return;
642 	}
643 
644 	if (register_memory_notifier(&kdump_mem_nb)) {
645 		memblock_phys_free(crash_base, crash_size);
646 		return;
647 	}
648 
649 	if (!oldmem_data.start && MACHINE_IS_VM)
650 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
651 	crashk_res.start = crash_base;
652 	crashk_res.end = crash_base + crash_size - 1;
653 	memblock_remove(crash_base, crash_size);
654 	pr_info("Reserving %lluMB of memory at %lluMB "
655 		"for crashkernel (System RAM: %luMB)\n",
656 		crash_size >> 20, crash_base >> 20,
657 		(unsigned long)memblock.memory.total_size >> 20);
658 	os_info_crashkernel_add(crash_base, crash_size);
659 #endif
660 }
661 
662 /*
663  * Reserve the initrd from being used by memblock
664  */
665 static void __init reserve_initrd(void)
666 {
667 	unsigned long addr, size;
668 
669 	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD) || !get_physmem_reserved(RR_INITRD, &addr, &size))
670 		return;
671 	initrd_start = (unsigned long)__va(addr);
672 	initrd_end = initrd_start + size;
673 	memblock_reserve(addr, size);
674 }
675 
676 /*
677  * Reserve the memory area used to pass the certificate lists
678  */
679 static void __init reserve_certificate_list(void)
680 {
681 	if (ipl_cert_list_addr)
682 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
683 }
684 
685 static void __init reserve_physmem_info(void)
686 {
687 	unsigned long addr, size;
688 
689 	if (get_physmem_reserved(RR_MEM_DETECT_EXTENDED, &addr, &size))
690 		memblock_reserve(addr, size);
691 }
692 
693 static void __init free_physmem_info(void)
694 {
695 	unsigned long addr, size;
696 
697 	if (get_physmem_reserved(RR_MEM_DETECT_EXTENDED, &addr, &size))
698 		memblock_phys_free(addr, size);
699 }
700 
701 static void __init memblock_add_physmem_info(void)
702 {
703 	unsigned long start, end;
704 	int i;
705 
706 	pr_debug("physmem info source: %s (%hhd)\n",
707 		 get_physmem_info_source(), physmem_info.info_source);
708 	/* keep memblock lists close to the kernel */
709 	memblock_set_bottom_up(true);
710 	for_each_physmem_usable_range(i, &start, &end)
711 		memblock_add(start, end - start);
712 	for_each_physmem_online_range(i, &start, &end)
713 		memblock_physmem_add(start, end - start);
714 	memblock_set_bottom_up(false);
715 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
716 }
717 
718 /*
719  * Reserve memory used for lowcore.
720  */
721 static void __init reserve_lowcore(void)
722 {
723 	void *lowcore_start = get_lowcore();
724 	void *lowcore_end = lowcore_start + sizeof(struct lowcore);
725 	void *start, *end;
726 
727 	if ((void *)__identity_base < lowcore_end) {
728 		start = max(lowcore_start, (void *)__identity_base);
729 		end = min(lowcore_end, (void *)(__identity_base + ident_map_size));
730 		memblock_reserve(__pa(start), __pa(end));
731 	}
732 }
733 
734 /*
735  * Reserve memory used for absolute lowcore/command line/kernel image.
736  */
737 static void __init reserve_kernel(void)
738 {
739 	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
740 	memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
741 	memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
742 	memblock_reserve(physmem_info.reserved[RR_AMODE31].start, __eamode31 - __samode31);
743 	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
744 	memblock_reserve(__pa(_stext), _end - _stext);
745 }
746 
747 static void __init setup_memory(void)
748 {
749 	phys_addr_t start, end;
750 	u64 i;
751 
752 	/*
753 	 * Init storage key for present memory
754 	 */
755 	for_each_mem_range(i, &start, &end)
756 		storage_key_init_range(start, end);
757 
758 	psw_set_key(PAGE_DEFAULT_KEY);
759 }
760 
761 static void __init relocate_amode31_section(void)
762 {
763 	unsigned long amode31_size = __eamode31 - __samode31;
764 	long amode31_offset, *ptr;
765 
766 	amode31_offset = AMODE31_START - (unsigned long)__samode31;
767 	pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
768 
769 	/* Move original AMODE31 section to the new one */
770 	memmove((void *)physmem_info.reserved[RR_AMODE31].start, __samode31, amode31_size);
771 	/* Zero out the old AMODE31 section to catch invalid accesses within it */
772 	memset(__samode31, 0, amode31_size);
773 
774 	/* Update all AMODE31 region references */
775 	for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
776 		*ptr += amode31_offset;
777 }
778 
779 /* This must be called after AMODE31 relocation */
780 static void __init setup_cr(void)
781 {
782 	union ctlreg2 cr2;
783 	union ctlreg5 cr5;
784 	union ctlreg15 cr15;
785 
786 	__ctl_duct[1] = (unsigned long)__ctl_aste;
787 	__ctl_duct[2] = (unsigned long)__ctl_aste;
788 	__ctl_duct[4] = (unsigned long)__ctl_duald;
789 
790 	/* Update control registers CR2, CR5 and CR15 */
791 	local_ctl_store(2, &cr2.reg);
792 	local_ctl_store(5, &cr5.reg);
793 	local_ctl_store(15, &cr15.reg);
794 	cr2.ducto = (unsigned long)__ctl_duct >> 6;
795 	cr5.pasteo = (unsigned long)__ctl_duct >> 6;
796 	cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
797 	system_ctl_load(2, &cr2.reg);
798 	system_ctl_load(5, &cr5.reg);
799 	system_ctl_load(15, &cr15.reg);
800 }
801 
802 /*
803  * Add system information as device randomness
804  */
805 static void __init setup_randomness(void)
806 {
807 	struct sysinfo_3_2_2 *vmms;
808 
809 	vmms = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
810 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
811 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
812 	memblock_free(vmms, PAGE_SIZE);
813 
814 	if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG))
815 		static_branch_enable(&s390_arch_random_available);
816 }
817 
818 /*
819  * Issue diagnose 318 to set the control program name and
820  * version codes.
821  */
822 static void __init setup_control_program_code(void)
823 {
824 	union diag318_info diag318_info = {
825 		.cpnc = CPNC_LINUX,
826 		.cpvc = 0,
827 	};
828 
829 	if (!sclp.has_diag318)
830 		return;
831 
832 	diag_stat_inc(DIAG_STAT_X318);
833 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
834 }
835 
836 /*
837  * Print the component list from the IPL report
838  */
839 static void __init log_component_list(void)
840 {
841 	struct ipl_rb_component_entry *ptr, *end;
842 	char *str;
843 
844 	if (!early_ipl_comp_list_addr)
845 		return;
846 	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
847 		pr_info("Linux is running with Secure-IPL enabled\n");
848 	else
849 		pr_info("Linux is running with Secure-IPL disabled\n");
850 	ptr = __va(early_ipl_comp_list_addr);
851 	end = (void *) ptr + early_ipl_comp_list_size;
852 	pr_info("The IPL report contains the following components:\n");
853 	while (ptr < end) {
854 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
855 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
856 				str = "signed, verified";
857 			else
858 				str = "signed, verification failed";
859 		} else {
860 			str = "not signed";
861 		}
862 		pr_info("%016llx - %016llx (%s)\n",
863 			ptr->addr, ptr->addr + ptr->len, str);
864 		ptr++;
865 	}
866 }
867 
868 /*
869  * Setup function called from init/main.c just after the banner
870  * was printed.
871  */
872 
873 void __init setup_arch(char **cmdline_p)
874 {
875         /*
876          * print what head.S has found out about the machine
877          */
878 	if (MACHINE_IS_VM)
879 		pr_info("Linux is running as a z/VM "
880 			"guest operating system in 64-bit mode\n");
881 	else if (MACHINE_IS_KVM)
882 		pr_info("Linux is running under KVM in 64-bit mode\n");
883 	else if (MACHINE_IS_LPAR)
884 		pr_info("Linux is running natively in 64-bit mode\n");
885 	else
886 		pr_info("Linux is running as a guest in 64-bit mode\n");
887 
888 	if (have_relocated_lowcore())
889 		pr_info("Lowcore relocated to 0x%px\n", get_lowcore());
890 
891 	log_component_list();
892 
893 	/* Have one command line that is parsed and saved in /proc/cmdline */
894 	/* boot_command_line has been already set up in early.c */
895 	*cmdline_p = boot_command_line;
896 
897         ROOT_DEV = Root_RAM0;
898 
899 	setup_initial_init_mm(_text, _etext, _edata, _end);
900 
901 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
902 		nospec_auto_detect();
903 
904 	jump_label_init();
905 	parse_early_param();
906 #ifdef CONFIG_CRASH_DUMP
907 	/* Deactivate elfcorehdr= kernel parameter */
908 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
909 #endif
910 
911 	os_info_init();
912 	setup_ipl();
913 	setup_control_program_code();
914 
915 	/* Do some memory reservations *before* memory is added to memblock */
916 	reserve_pgtables();
917 	reserve_lowcore();
918 	reserve_kernel();
919 	reserve_initrd();
920 	reserve_certificate_list();
921 	reserve_physmem_info();
922 	memblock_set_current_limit(ident_map_size);
923 	memblock_allow_resize();
924 
925 	/* Get information about *all* installed memory */
926 	memblock_add_physmem_info();
927 
928 	free_physmem_info();
929 	setup_memory_end();
930 	memblock_dump_all();
931 	setup_memory();
932 
933 	relocate_amode31_section();
934 	setup_cr();
935 	setup_uv();
936 	dma_contiguous_reserve(ident_map_size);
937 	vmcp_cma_reserve();
938 	if (MACHINE_HAS_EDAT2)
939 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
940 
941 	reserve_crashkernel();
942 #ifdef CONFIG_CRASH_DUMP
943 	/*
944 	 * Be aware that smp_save_dump_secondary_cpus() triggers a system reset.
945 	 * Therefore CPU and device initialization should be done afterwards.
946 	 */
947 	smp_save_dump_secondary_cpus();
948 #endif
949 
950 	setup_resources();
951 	setup_lowcore();
952 	smp_fill_possible_mask();
953 	cpu_detect_mhz_feature();
954         cpu_init();
955 	numa_setup();
956 	smp_detect_cpus();
957 	topology_init_early();
958 
959 	if (test_facility(193))
960 		static_branch_enable(&cpu_has_bear);
961 
962 	setup_protection_map();
963 	/*
964 	 * Create kernel page tables.
965 	 */
966         paging_init();
967 
968 	/*
969 	 * After paging_init created the kernel page table, the new PSWs
970 	 * in lowcore can now run with DAT enabled.
971 	 */
972 #ifdef CONFIG_CRASH_DUMP
973 	smp_save_dump_ipl_cpu();
974 #endif
975 
976         /* Setup default console */
977 	conmode_default();
978 	set_preferred_console();
979 
980 	apply_alternative_instructions();
981 	if (IS_ENABLED(CONFIG_EXPOLINE))
982 		nospec_init_branches();
983 
984 	/* Setup zfcp/nvme dump support */
985 	setup_zfcpdump();
986 
987 	/* Add system specific data to the random pool */
988 	setup_randomness();
989 }
990