xref: /openbmc/linux/arch/s390/kernel/setup.c (revision 86db9f28)
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-contiguous.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 
53 #include <asm/boot_data.h>
54 #include <asm/ipl.h>
55 #include <asm/facility.h>
56 #include <asm/smp.h>
57 #include <asm/mmu_context.h>
58 #include <asm/cpcmd.h>
59 #include <asm/lowcore.h>
60 #include <asm/nmi.h>
61 #include <asm/irq.h>
62 #include <asm/page.h>
63 #include <asm/ptrace.h>
64 #include <asm/sections.h>
65 #include <asm/ebcdic.h>
66 #include <asm/diag.h>
67 #include <asm/os_info.h>
68 #include <asm/sclp.h>
69 #include <asm/stacktrace.h>
70 #include <asm/sysinfo.h>
71 #include <asm/numa.h>
72 #include <asm/alternative.h>
73 #include <asm/nospec-branch.h>
74 #include <asm/mem_detect.h>
75 #include <asm/uv.h>
76 #include "entry.h"
77 
78 /*
79  * Machine setup..
80  */
81 unsigned int console_mode = 0;
82 EXPORT_SYMBOL(console_mode);
83 
84 unsigned int console_devno = -1;
85 EXPORT_SYMBOL(console_devno);
86 
87 unsigned int console_irq = -1;
88 EXPORT_SYMBOL(console_irq);
89 
90 unsigned long elf_hwcap __read_mostly = 0;
91 char elf_platform[ELF_PLATFORM_SIZE];
92 
93 unsigned long int_hwcap = 0;
94 
95 #ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
96 int __bootdata_preserved(prot_virt_guest);
97 #endif
98 
99 int __bootdata(noexec_disabled);
100 int __bootdata(memory_end_set);
101 unsigned long __bootdata(memory_end);
102 unsigned long __bootdata(vmalloc_size);
103 unsigned long __bootdata(max_physmem_end);
104 struct mem_detect_info __bootdata(mem_detect);
105 
106 struct exception_table_entry *__bootdata_preserved(__start_dma_ex_table);
107 struct exception_table_entry *__bootdata_preserved(__stop_dma_ex_table);
108 unsigned long __bootdata_preserved(__swsusp_reset_dma);
109 unsigned long __bootdata_preserved(__stext_dma);
110 unsigned long __bootdata_preserved(__etext_dma);
111 unsigned long __bootdata_preserved(__sdma);
112 unsigned long __bootdata_preserved(__edma);
113 unsigned long __bootdata_preserved(__kaslr_offset);
114 
115 unsigned long VMALLOC_START;
116 EXPORT_SYMBOL(VMALLOC_START);
117 
118 unsigned long VMALLOC_END;
119 EXPORT_SYMBOL(VMALLOC_END);
120 
121 struct page *vmemmap;
122 EXPORT_SYMBOL(vmemmap);
123 
124 unsigned long MODULES_VADDR;
125 unsigned long MODULES_END;
126 
127 /* An array with a pointer to the lowcore of every CPU. */
128 struct lowcore *lowcore_ptr[NR_CPUS];
129 EXPORT_SYMBOL(lowcore_ptr);
130 
131 /*
132  * This is set up by the setup-routine at boot-time
133  * for S390 need to find out, what we have to setup
134  * using address 0x10400 ...
135  */
136 
137 #include <asm/setup.h>
138 
139 /*
140  * condev= and conmode= setup parameter.
141  */
142 
143 static int __init condev_setup(char *str)
144 {
145 	int vdev;
146 
147 	vdev = simple_strtoul(str, &str, 0);
148 	if (vdev >= 0 && vdev < 65536) {
149 		console_devno = vdev;
150 		console_irq = -1;
151 	}
152 	return 1;
153 }
154 
155 __setup("condev=", condev_setup);
156 
157 static void __init set_preferred_console(void)
158 {
159 	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
160 		add_preferred_console("ttyS", 0, NULL);
161 	else if (CONSOLE_IS_3270)
162 		add_preferred_console("tty3270", 0, NULL);
163 	else if (CONSOLE_IS_VT220)
164 		add_preferred_console("ttyS", 1, NULL);
165 	else if (CONSOLE_IS_HVC)
166 		add_preferred_console("hvc", 0, NULL);
167 }
168 
169 static int __init conmode_setup(char *str)
170 {
171 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
172 	if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
173                 SET_CONSOLE_SCLP;
174 #endif
175 #if defined(CONFIG_TN3215_CONSOLE)
176 	if (!strcmp(str, "3215"))
177 		SET_CONSOLE_3215;
178 #endif
179 #if defined(CONFIG_TN3270_CONSOLE)
180 	if (!strcmp(str, "3270"))
181 		SET_CONSOLE_3270;
182 #endif
183 	set_preferred_console();
184         return 1;
185 }
186 
187 __setup("conmode=", conmode_setup);
188 
189 static void __init conmode_default(void)
190 {
191 	char query_buffer[1024];
192 	char *ptr;
193 
194         if (MACHINE_IS_VM) {
195 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
196 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
197 		ptr = strstr(query_buffer, "SUBCHANNEL =");
198 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
199 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
200 		ptr = strstr(query_buffer, "CONMODE");
201 		/*
202 		 * Set the conmode to 3215 so that the device recognition
203 		 * will set the cu_type of the console to 3215. If the
204 		 * conmode is 3270 and we don't set it back then both
205 		 * 3215 and the 3270 driver will try to access the console
206 		 * device (3215 as console and 3270 as normal tty).
207 		 */
208 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
209 		if (ptr == NULL) {
210 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
211 			SET_CONSOLE_SCLP;
212 #endif
213 			return;
214 		}
215 		if (str_has_prefix(ptr + 8, "3270")) {
216 #if defined(CONFIG_TN3270_CONSOLE)
217 			SET_CONSOLE_3270;
218 #elif defined(CONFIG_TN3215_CONSOLE)
219 			SET_CONSOLE_3215;
220 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
221 			SET_CONSOLE_SCLP;
222 #endif
223 		} else if (str_has_prefix(ptr + 8, "3215")) {
224 #if defined(CONFIG_TN3215_CONSOLE)
225 			SET_CONSOLE_3215;
226 #elif defined(CONFIG_TN3270_CONSOLE)
227 			SET_CONSOLE_3270;
228 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
229 			SET_CONSOLE_SCLP;
230 #endif
231 		}
232 	} else if (MACHINE_IS_KVM) {
233 		if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
234 			SET_CONSOLE_VT220;
235 		else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
236 			SET_CONSOLE_SCLP;
237 		else
238 			SET_CONSOLE_HVC;
239 	} else {
240 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
241 		SET_CONSOLE_SCLP;
242 #endif
243 	}
244 	if (IS_ENABLED(CONFIG_VT) && IS_ENABLED(CONFIG_DUMMY_CONSOLE))
245 		conswitchp = &dummy_con;
246 }
247 
248 #ifdef CONFIG_CRASH_DUMP
249 static void __init setup_zfcpdump(void)
250 {
251 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
252 		return;
253 	if (OLDMEM_BASE)
254 		return;
255 	strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
256 	console_loglevel = 2;
257 }
258 #else
259 static inline void setup_zfcpdump(void) {}
260 #endif /* CONFIG_CRASH_DUMP */
261 
262  /*
263  * Reboot, halt and power_off stubs. They just call _machine_restart,
264  * _machine_halt or _machine_power_off.
265  */
266 
267 void machine_restart(char *command)
268 {
269 	if ((!in_interrupt() && !in_atomic()) || 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_restart(command);
276 }
277 
278 void machine_halt(void)
279 {
280 	if (!in_interrupt() || oops_in_progress)
281 		/*
282 		 * Only unblank the console if we are called in enabled
283 		 * context or a bust_spinlocks cleared the way for us.
284 		 */
285 		console_unblank();
286 	_machine_halt();
287 }
288 
289 void machine_power_off(void)
290 {
291 	if (!in_interrupt() || oops_in_progress)
292 		/*
293 		 * Only unblank the console if we are called in enabled
294 		 * context or a bust_spinlocks cleared the way for us.
295 		 */
296 		console_unblank();
297 	_machine_power_off();
298 }
299 
300 /*
301  * Dummy power off function.
302  */
303 void (*pm_power_off)(void) = machine_power_off;
304 EXPORT_SYMBOL_GPL(pm_power_off);
305 
306 void *restart_stack __section(.data);
307 
308 unsigned long stack_alloc(void)
309 {
310 #ifdef CONFIG_VMAP_STACK
311 	return (unsigned long)
312 		__vmalloc_node_range(THREAD_SIZE, THREAD_SIZE,
313 				     VMALLOC_START, VMALLOC_END,
314 				     THREADINFO_GFP,
315 				     PAGE_KERNEL, 0, NUMA_NO_NODE,
316 				     __builtin_return_address(0));
317 #else
318 	return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
319 #endif
320 }
321 
322 void stack_free(unsigned long stack)
323 {
324 #ifdef CONFIG_VMAP_STACK
325 	vfree((void *) stack);
326 #else
327 	free_pages(stack, THREAD_SIZE_ORDER);
328 #endif
329 }
330 
331 int __init arch_early_irq_init(void)
332 {
333 	unsigned long stack;
334 
335 	stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
336 	if (!stack)
337 		panic("Couldn't allocate async stack");
338 	S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
339 	return 0;
340 }
341 
342 static int __init async_stack_realloc(void)
343 {
344 	unsigned long old, new;
345 
346 	old = S390_lowcore.async_stack - STACK_INIT_OFFSET;
347 	new = stack_alloc();
348 	if (!new)
349 		panic("Couldn't allocate async stack");
350 	S390_lowcore.async_stack = new + STACK_INIT_OFFSET;
351 	free_pages(old, THREAD_SIZE_ORDER);
352 	return 0;
353 }
354 early_initcall(async_stack_realloc);
355 
356 void __init arch_call_rest_init(void)
357 {
358 	struct stack_frame *frame;
359 	unsigned long stack;
360 
361 	stack = stack_alloc();
362 	if (!stack)
363 		panic("Couldn't allocate kernel stack");
364 	current->stack = (void *) stack;
365 #ifdef CONFIG_VMAP_STACK
366 	current->stack_vm_area = (void *) stack;
367 #endif
368 	set_task_stack_end_magic(current);
369 	stack += STACK_INIT_OFFSET;
370 	S390_lowcore.kernel_stack = stack;
371 	frame = (struct stack_frame *) stack;
372 	memset(frame, 0, sizeof(*frame));
373 	/* Branch to rest_init on the new stack, never returns */
374 	asm volatile(
375 		"	la	15,0(%[_frame])\n"
376 		"	jg	rest_init\n"
377 		: : [_frame] "a" (frame));
378 }
379 
380 static void __init setup_lowcore_dat_off(void)
381 {
382 	struct lowcore *lc;
383 
384 	/*
385 	 * Setup lowcore for boot cpu
386 	 */
387 	BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
388 	lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
389 	if (!lc)
390 		panic("%s: Failed to allocate %zu bytes align=%zx\n",
391 		      __func__, sizeof(*lc), sizeof(*lc));
392 
393 	lc->restart_psw.mask = PSW_KERNEL_BITS;
394 	lc->restart_psw.addr = (unsigned long) restart_int_handler;
395 	lc->external_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
396 	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
397 	lc->svc_new_psw.mask = PSW_KERNEL_BITS |
398 		PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
399 	lc->svc_new_psw.addr = (unsigned long) system_call;
400 	lc->program_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
401 	lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
402 	lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
403 	lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
404 	lc->io_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
405 	lc->io_new_psw.addr = (unsigned long) io_int_handler;
406 	lc->clock_comparator = clock_comparator_max;
407 	lc->nodat_stack = ((unsigned long) &init_thread_union)
408 		+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
409 	lc->current_task = (unsigned long)&init_task;
410 	lc->lpp = LPP_MAGIC;
411 	lc->machine_flags = S390_lowcore.machine_flags;
412 	lc->preempt_count = S390_lowcore.preempt_count;
413 	lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
414 	memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
415 	       sizeof(lc->stfle_fac_list));
416 	memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list,
417 	       sizeof(lc->alt_stfle_fac_list));
418 	nmi_alloc_boot_cpu(lc);
419 	vdso_alloc_boot_cpu(lc);
420 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
421 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
422 	lc->exit_timer = S390_lowcore.exit_timer;
423 	lc->user_timer = S390_lowcore.user_timer;
424 	lc->system_timer = S390_lowcore.system_timer;
425 	lc->steal_timer = S390_lowcore.steal_timer;
426 	lc->last_update_timer = S390_lowcore.last_update_timer;
427 	lc->last_update_clock = S390_lowcore.last_update_clock;
428 
429 	/*
430 	 * Allocate the global restart stack which is the same for
431 	 * all CPUs in cast *one* of them does a PSW restart.
432 	 */
433 	restart_stack = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
434 	if (!restart_stack)
435 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
436 		      __func__, THREAD_SIZE, THREAD_SIZE);
437 	restart_stack += STACK_INIT_OFFSET;
438 
439 	/*
440 	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
441 	 * restart data to the absolute zero lowcore. This is necessary if
442 	 * PSW restart is done on an offline CPU that has lowcore zero.
443 	 */
444 	lc->restart_stack = (unsigned long) restart_stack;
445 	lc->restart_fn = (unsigned long) do_restart;
446 	lc->restart_data = 0;
447 	lc->restart_source = -1UL;
448 
449 	/* Setup absolute zero lowcore */
450 	mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
451 	mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
452 	mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
453 	mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
454 	mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
455 
456 	lc->spinlock_lockval = arch_spin_lockval(0);
457 	lc->spinlock_index = 0;
458 	arch_spin_lock_setup(0);
459 	lc->br_r1_trampoline = 0x07f1;	/* br %r1 */
460 
461 	set_prefix((u32)(unsigned long) lc);
462 	lowcore_ptr[0] = lc;
463 }
464 
465 static void __init setup_lowcore_dat_on(void)
466 {
467 	__ctl_clear_bit(0, 28);
468 	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
469 	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
470 	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
471 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
472 	__ctl_set_bit(0, 28);
473 }
474 
475 static struct resource code_resource = {
476 	.name  = "Kernel code",
477 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
478 };
479 
480 static struct resource data_resource = {
481 	.name = "Kernel data",
482 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
483 };
484 
485 static struct resource bss_resource = {
486 	.name = "Kernel bss",
487 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
488 };
489 
490 static struct resource __initdata *standard_resources[] = {
491 	&code_resource,
492 	&data_resource,
493 	&bss_resource,
494 };
495 
496 static void __init setup_resources(void)
497 {
498 	struct resource *res, *std_res, *sub_res;
499 	struct memblock_region *reg;
500 	int j;
501 
502 	code_resource.start = (unsigned long) _text;
503 	code_resource.end = (unsigned long) _etext - 1;
504 	data_resource.start = (unsigned long) _etext;
505 	data_resource.end = (unsigned long) _edata - 1;
506 	bss_resource.start = (unsigned long) __bss_start;
507 	bss_resource.end = (unsigned long) __bss_stop - 1;
508 
509 	for_each_memblock(memory, reg) {
510 		res = memblock_alloc(sizeof(*res), 8);
511 		if (!res)
512 			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
513 			      __func__, sizeof(*res), 8);
514 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
515 
516 		res->name = "System RAM";
517 		res->start = reg->base;
518 		res->end = reg->base + reg->size - 1;
519 		request_resource(&iomem_resource, res);
520 
521 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
522 			std_res = standard_resources[j];
523 			if (std_res->start < res->start ||
524 			    std_res->start > res->end)
525 				continue;
526 			if (std_res->end > res->end) {
527 				sub_res = memblock_alloc(sizeof(*sub_res), 8);
528 				if (!sub_res)
529 					panic("%s: Failed to allocate %zu bytes align=0x%x\n",
530 					      __func__, sizeof(*sub_res), 8);
531 				*sub_res = *std_res;
532 				sub_res->end = res->end;
533 				std_res->start = res->end + 1;
534 				request_resource(res, sub_res);
535 			} else {
536 				request_resource(res, std_res);
537 			}
538 		}
539 	}
540 #ifdef CONFIG_CRASH_DUMP
541 	/*
542 	 * Re-add removed crash kernel memory as reserved memory. This makes
543 	 * sure it will be mapped with the identity mapping and struct pages
544 	 * will be created, so it can be resized later on.
545 	 * However add it later since the crash kernel resource should not be
546 	 * part of the System RAM resource.
547 	 */
548 	if (crashk_res.end) {
549 		memblock_add_node(crashk_res.start, resource_size(&crashk_res), 0);
550 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
551 		insert_resource(&iomem_resource, &crashk_res);
552 	}
553 #endif
554 }
555 
556 static void __init setup_memory_end(void)
557 {
558 	unsigned long vmax, tmp;
559 
560 	/* Choose kernel address space layout: 3 or 4 levels. */
561 	if (IS_ENABLED(CONFIG_KASAN)) {
562 		vmax = IS_ENABLED(CONFIG_KASAN_S390_4_LEVEL_PAGING)
563 			   ? _REGION1_SIZE
564 			   : _REGION2_SIZE;
565 	} else {
566 		tmp = (memory_end ?: max_physmem_end) / PAGE_SIZE;
567 		tmp = tmp * (sizeof(struct page) + PAGE_SIZE);
568 		if (tmp + vmalloc_size + MODULES_LEN <= _REGION2_SIZE)
569 			vmax = _REGION2_SIZE; /* 3-level kernel page table */
570 		else
571 			vmax = _REGION1_SIZE; /* 4-level kernel page table */
572 	}
573 
574 	/* module area is at the end of the kernel address space. */
575 	MODULES_END = vmax;
576 	MODULES_VADDR = MODULES_END - MODULES_LEN;
577 	VMALLOC_END = MODULES_VADDR;
578 	VMALLOC_START = VMALLOC_END - vmalloc_size;
579 
580 	/* Split remaining virtual space between 1:1 mapping & vmemmap array */
581 	tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
582 	/* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
583 	tmp = SECTION_ALIGN_UP(tmp);
584 	tmp = VMALLOC_START - tmp * sizeof(struct page);
585 	tmp &= ~((vmax >> 11) - 1);	/* align to page table level */
586 	tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
587 	vmemmap = (struct page *) tmp;
588 
589 	/* Take care that memory_end is set and <= vmemmap */
590 	memory_end = min(memory_end ?: max_physmem_end, (unsigned long)vmemmap);
591 #ifdef CONFIG_KASAN
592 	/* fit in kasan shadow memory region between 1:1 and vmemmap */
593 	memory_end = min(memory_end, KASAN_SHADOW_START);
594 	vmemmap = max(vmemmap, (struct page *)KASAN_SHADOW_END);
595 #endif
596 	max_pfn = max_low_pfn = PFN_DOWN(memory_end);
597 	memblock_remove(memory_end, ULONG_MAX);
598 
599 	pr_notice("The maximum memory size is %luMB\n", memory_end >> 20);
600 }
601 
602 #ifdef CONFIG_CRASH_DUMP
603 
604 /*
605  * When kdump is enabled, we have to ensure that no memory from
606  * the area [0 - crashkernel memory size] and
607  * [crashk_res.start - crashk_res.end] is set offline.
608  */
609 static int kdump_mem_notifier(struct notifier_block *nb,
610 			      unsigned long action, void *data)
611 {
612 	struct memory_notify *arg = data;
613 
614 	if (action != MEM_GOING_OFFLINE)
615 		return NOTIFY_OK;
616 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
617 		return NOTIFY_BAD;
618 	if (arg->start_pfn > PFN_DOWN(crashk_res.end))
619 		return NOTIFY_OK;
620 	if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
621 		return NOTIFY_OK;
622 	return NOTIFY_BAD;
623 }
624 
625 static struct notifier_block kdump_mem_nb = {
626 	.notifier_call = kdump_mem_notifier,
627 };
628 
629 #endif
630 
631 /*
632  * Make sure that the area behind memory_end is protected
633  */
634 static void reserve_memory_end(void)
635 {
636 	if (memory_end_set)
637 		memblock_reserve(memory_end, ULONG_MAX);
638 }
639 
640 /*
641  * Make sure that oldmem, where the dump is stored, is protected
642  */
643 static void reserve_oldmem(void)
644 {
645 #ifdef CONFIG_CRASH_DUMP
646 	if (OLDMEM_BASE)
647 		/* Forget all memory above the running kdump system */
648 		memblock_reserve(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
649 #endif
650 }
651 
652 /*
653  * Make sure that oldmem, where the dump is stored, is protected
654  */
655 static void remove_oldmem(void)
656 {
657 #ifdef CONFIG_CRASH_DUMP
658 	if (OLDMEM_BASE)
659 		/* Forget all memory above the running kdump system */
660 		memblock_remove(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
661 #endif
662 }
663 
664 /*
665  * Reserve memory for kdump kernel to be loaded with kexec
666  */
667 static void __init reserve_crashkernel(void)
668 {
669 #ifdef CONFIG_CRASH_DUMP
670 	unsigned long long crash_base, crash_size;
671 	phys_addr_t low, high;
672 	int rc;
673 
674 	rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
675 			       &crash_base);
676 
677 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
678 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
679 	if (rc || crash_size == 0)
680 		return;
681 
682 	if (memblock.memory.regions[0].size < crash_size) {
683 		pr_info("crashkernel reservation failed: %s\n",
684 			"first memory chunk must be at least crashkernel size");
685 		return;
686 	}
687 
688 	low = crash_base ?: OLDMEM_BASE;
689 	high = low + crash_size;
690 	if (low >= OLDMEM_BASE && high <= OLDMEM_BASE + OLDMEM_SIZE) {
691 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
692 		crash_base = low;
693 	} else {
694 		/* Find suitable area in free memory */
695 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
696 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
697 
698 		if (crash_base && crash_base < low) {
699 			pr_info("crashkernel reservation failed: %s\n",
700 				"crash_base too low");
701 			return;
702 		}
703 		low = crash_base ?: low;
704 		crash_base = memblock_find_in_range(low, high, crash_size,
705 						    KEXEC_CRASH_MEM_ALIGN);
706 	}
707 
708 	if (!crash_base) {
709 		pr_info("crashkernel reservation failed: %s\n",
710 			"no suitable area found");
711 		return;
712 	}
713 
714 	if (register_memory_notifier(&kdump_mem_nb))
715 		return;
716 
717 	if (!OLDMEM_BASE && MACHINE_IS_VM)
718 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
719 	crashk_res.start = crash_base;
720 	crashk_res.end = crash_base + crash_size - 1;
721 	memblock_remove(crash_base, crash_size);
722 	pr_info("Reserving %lluMB of memory at %lluMB "
723 		"for crashkernel (System RAM: %luMB)\n",
724 		crash_size >> 20, crash_base >> 20,
725 		(unsigned long)memblock.memory.total_size >> 20);
726 	os_info_crashkernel_add(crash_base, crash_size);
727 #endif
728 }
729 
730 /*
731  * Reserve the initrd from being used by memblock
732  */
733 static void __init reserve_initrd(void)
734 {
735 #ifdef CONFIG_BLK_DEV_INITRD
736 	if (!INITRD_START || !INITRD_SIZE)
737 		return;
738 	initrd_start = INITRD_START;
739 	initrd_end = initrd_start + INITRD_SIZE;
740 	memblock_reserve(INITRD_START, INITRD_SIZE);
741 #endif
742 }
743 
744 /*
745  * Reserve the memory area used to pass the certificate lists
746  */
747 static void __init reserve_certificate_list(void)
748 {
749 	if (ipl_cert_list_addr)
750 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
751 }
752 
753 static void __init reserve_mem_detect_info(void)
754 {
755 	unsigned long start, size;
756 
757 	get_mem_detect_reserved(&start, &size);
758 	if (size)
759 		memblock_reserve(start, size);
760 }
761 
762 static void __init free_mem_detect_info(void)
763 {
764 	unsigned long start, size;
765 
766 	get_mem_detect_reserved(&start, &size);
767 	if (size)
768 		memblock_free(start, size);
769 }
770 
771 static void __init memblock_physmem_add(phys_addr_t start, phys_addr_t size)
772 {
773 	memblock_dbg("memblock_physmem_add: [%#016llx-%#016llx]\n",
774 		     start, start + size - 1);
775 	memblock_add_range(&memblock.memory, start, size, 0, 0);
776 	memblock_add_range(&memblock.physmem, start, size, 0, 0);
777 }
778 
779 static const char * __init get_mem_info_source(void)
780 {
781 	switch (mem_detect.info_source) {
782 	case MEM_DETECT_SCLP_STOR_INFO:
783 		return "sclp storage info";
784 	case MEM_DETECT_DIAG260:
785 		return "diag260";
786 	case MEM_DETECT_SCLP_READ_INFO:
787 		return "sclp read info";
788 	case MEM_DETECT_BIN_SEARCH:
789 		return "binary search";
790 	}
791 	return "none";
792 }
793 
794 static void __init memblock_add_mem_detect_info(void)
795 {
796 	unsigned long start, end;
797 	int i;
798 
799 	memblock_dbg("physmem info source: %s (%hhd)\n",
800 		     get_mem_info_source(), mem_detect.info_source);
801 	/* keep memblock lists close to the kernel */
802 	memblock_set_bottom_up(true);
803 	for_each_mem_detect_block(i, &start, &end)
804 		memblock_physmem_add(start, end - start);
805 	memblock_set_bottom_up(false);
806 	memblock_dump_all();
807 }
808 
809 /*
810  * Check for initrd being in usable memory
811  */
812 static void __init check_initrd(void)
813 {
814 #ifdef CONFIG_BLK_DEV_INITRD
815 	if (INITRD_START && INITRD_SIZE &&
816 	    !memblock_is_region_memory(INITRD_START, INITRD_SIZE)) {
817 		pr_err("The initial RAM disk does not fit into the memory\n");
818 		memblock_free(INITRD_START, INITRD_SIZE);
819 		initrd_start = initrd_end = 0;
820 	}
821 #endif
822 }
823 
824 /*
825  * Reserve memory used for lowcore/command line/kernel image.
826  */
827 static void __init reserve_kernel(void)
828 {
829 	unsigned long start_pfn = PFN_UP(__pa(_end));
830 
831 	memblock_reserve(0, HEAD_END);
832 	memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
833 			 - (unsigned long)_stext);
834 	memblock_reserve(__sdma, __edma - __sdma);
835 }
836 
837 static void __init setup_memory(void)
838 {
839 	struct memblock_region *reg;
840 
841 	/*
842 	 * Init storage key for present memory
843 	 */
844 	for_each_memblock(memory, reg) {
845 		storage_key_init_range(reg->base, reg->base + reg->size);
846 	}
847 	psw_set_key(PAGE_DEFAULT_KEY);
848 
849 	/* Only cosmetics */
850 	memblock_enforce_memory_limit(memblock_end_of_DRAM());
851 }
852 
853 /*
854  * Setup hardware capabilities.
855  */
856 static int __init setup_hwcaps(void)
857 {
858 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
859 	struct cpuid cpu_id;
860 	int i;
861 
862 	/*
863 	 * The store facility list bits numbers as found in the principles
864 	 * of operation are numbered with bit 1UL<<31 as number 0 to
865 	 * bit 1UL<<0 as number 31.
866 	 *   Bit 0: instructions named N3, "backported" to esa-mode
867 	 *   Bit 2: z/Architecture mode is active
868 	 *   Bit 7: the store-facility-list-extended facility is installed
869 	 *   Bit 17: the message-security assist is installed
870 	 *   Bit 19: the long-displacement facility is installed
871 	 *   Bit 21: the extended-immediate facility is installed
872 	 *   Bit 22: extended-translation facility 3 is installed
873 	 *   Bit 30: extended-translation facility 3 enhancement facility
874 	 * These get translated to:
875 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
876 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
877 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
878 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
879 	 */
880 	for (i = 0; i < 6; i++)
881 		if (test_facility(stfl_bits[i]))
882 			elf_hwcap |= 1UL << i;
883 
884 	if (test_facility(22) && test_facility(30))
885 		elf_hwcap |= HWCAP_S390_ETF3EH;
886 
887 	/*
888 	 * Check for additional facilities with store-facility-list-extended.
889 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
890 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
891 	 * as stored by stfl, bits 32-xxx contain additional facilities.
892 	 * How many facility words are stored depends on the number of
893 	 * doublewords passed to the instruction. The additional facilities
894 	 * are:
895 	 *   Bit 42: decimal floating point facility is installed
896 	 *   Bit 44: perform floating point operation facility is installed
897 	 * translated to:
898 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
899 	 */
900 	if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
901 		elf_hwcap |= HWCAP_S390_DFP;
902 
903 	/*
904 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
905 	 */
906 	if (MACHINE_HAS_EDAT1)
907 		elf_hwcap |= HWCAP_S390_HPAGE;
908 
909 	/*
910 	 * 64-bit register support for 31-bit processes
911 	 * HWCAP_S390_HIGH_GPRS is bit 9.
912 	 */
913 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
914 
915 	/*
916 	 * Transactional execution support HWCAP_S390_TE is bit 10.
917 	 */
918 	if (MACHINE_HAS_TE)
919 		elf_hwcap |= HWCAP_S390_TE;
920 
921 	/*
922 	 * Vector extension HWCAP_S390_VXRS is bit 11. The Vector extension
923 	 * can be disabled with the "novx" parameter. Use MACHINE_HAS_VX
924 	 * instead of facility bit 129.
925 	 */
926 	if (MACHINE_HAS_VX) {
927 		elf_hwcap |= HWCAP_S390_VXRS;
928 		if (test_facility(134))
929 			elf_hwcap |= HWCAP_S390_VXRS_EXT;
930 		if (test_facility(135))
931 			elf_hwcap |= HWCAP_S390_VXRS_BCD;
932 		if (test_facility(148))
933 			elf_hwcap |= HWCAP_S390_VXRS_EXT2;
934 		if (test_facility(152))
935 			elf_hwcap |= HWCAP_S390_VXRS_PDE;
936 	}
937 	if (test_facility(150))
938 		elf_hwcap |= HWCAP_S390_SORT;
939 	if (test_facility(151))
940 		elf_hwcap |= HWCAP_S390_DFLT;
941 
942 	/*
943 	 * Guarded storage support HWCAP_S390_GS is bit 12.
944 	 */
945 	if (MACHINE_HAS_GS)
946 		elf_hwcap |= HWCAP_S390_GS;
947 
948 	get_cpu_id(&cpu_id);
949 	add_device_randomness(&cpu_id, sizeof(cpu_id));
950 	switch (cpu_id.machine) {
951 	case 0x2064:
952 	case 0x2066:
953 	default:	/* Use "z900" as default for 64 bit kernels. */
954 		strcpy(elf_platform, "z900");
955 		break;
956 	case 0x2084:
957 	case 0x2086:
958 		strcpy(elf_platform, "z990");
959 		break;
960 	case 0x2094:
961 	case 0x2096:
962 		strcpy(elf_platform, "z9-109");
963 		break;
964 	case 0x2097:
965 	case 0x2098:
966 		strcpy(elf_platform, "z10");
967 		break;
968 	case 0x2817:
969 	case 0x2818:
970 		strcpy(elf_platform, "z196");
971 		break;
972 	case 0x2827:
973 	case 0x2828:
974 		strcpy(elf_platform, "zEC12");
975 		break;
976 	case 0x2964:
977 	case 0x2965:
978 		strcpy(elf_platform, "z13");
979 		break;
980 	case 0x3906:
981 	case 0x3907:
982 		strcpy(elf_platform, "z14");
983 		break;
984 	case 0x8561:
985 	case 0x8562:
986 		strcpy(elf_platform, "z15");
987 		break;
988 	}
989 
990 	/*
991 	 * Virtualization support HWCAP_INT_SIE is bit 0.
992 	 */
993 	if (sclp.has_sief2)
994 		int_hwcap |= HWCAP_INT_SIE;
995 
996 	return 0;
997 }
998 arch_initcall(setup_hwcaps);
999 
1000 /*
1001  * Add system information as device randomness
1002  */
1003 static void __init setup_randomness(void)
1004 {
1005 	struct sysinfo_3_2_2 *vmms;
1006 
1007 	vmms = (struct sysinfo_3_2_2 *) memblock_phys_alloc(PAGE_SIZE,
1008 							    PAGE_SIZE);
1009 	if (!vmms)
1010 		panic("Failed to allocate memory for sysinfo structure\n");
1011 
1012 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
1013 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
1014 	memblock_free((unsigned long) vmms, PAGE_SIZE);
1015 }
1016 
1017 /*
1018  * Find the correct size for the task_struct. This depends on
1019  * the size of the struct fpu at the end of the thread_struct
1020  * which is embedded in the task_struct.
1021  */
1022 static void __init setup_task_size(void)
1023 {
1024 	int task_size = sizeof(struct task_struct);
1025 
1026 	if (!MACHINE_HAS_VX) {
1027 		task_size -= sizeof(__vector128) * __NUM_VXRS;
1028 		task_size += sizeof(freg_t) * __NUM_FPRS;
1029 	}
1030 	arch_task_struct_size = task_size;
1031 }
1032 
1033 /*
1034  * Issue diagnose 318 to set the control program name and
1035  * version codes.
1036  */
1037 static void __init setup_control_program_code(void)
1038 {
1039 	union diag318_info diag318_info = {
1040 		.cpnc = CPNC_LINUX,
1041 		.cpvc_linux = 0,
1042 		.cpvc_distro = {0},
1043 	};
1044 
1045 	if (!sclp.has_diag318)
1046 		return;
1047 
1048 	diag_stat_inc(DIAG_STAT_X318);
1049 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
1050 }
1051 
1052 /*
1053  * Print the component list from the IPL report
1054  */
1055 static void __init log_component_list(void)
1056 {
1057 	struct ipl_rb_component_entry *ptr, *end;
1058 	char *str;
1059 
1060 	if (!early_ipl_comp_list_addr)
1061 		return;
1062 	if (ipl_block.hdr.flags & IPL_PL_FLAG_IPLSR)
1063 		pr_info("Linux is running with Secure-IPL enabled\n");
1064 	else
1065 		pr_info("Linux is running with Secure-IPL disabled\n");
1066 	ptr = (void *) early_ipl_comp_list_addr;
1067 	end = (void *) ptr + early_ipl_comp_list_size;
1068 	pr_info("The IPL report contains the following components:\n");
1069 	while (ptr < end) {
1070 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
1071 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
1072 				str = "signed, verified";
1073 			else
1074 				str = "signed, verification failed";
1075 		} else {
1076 			str = "not signed";
1077 		}
1078 		pr_info("%016llx - %016llx (%s)\n",
1079 			ptr->addr, ptr->addr + ptr->len, str);
1080 		ptr++;
1081 	}
1082 }
1083 
1084 /*
1085  * Setup function called from init/main.c just after the banner
1086  * was printed.
1087  */
1088 
1089 void __init setup_arch(char **cmdline_p)
1090 {
1091         /*
1092          * print what head.S has found out about the machine
1093          */
1094 	if (MACHINE_IS_VM)
1095 		pr_info("Linux is running as a z/VM "
1096 			"guest operating system in 64-bit mode\n");
1097 	else if (MACHINE_IS_KVM)
1098 		pr_info("Linux is running under KVM in 64-bit mode\n");
1099 	else if (MACHINE_IS_LPAR)
1100 		pr_info("Linux is running natively in 64-bit mode\n");
1101 	else
1102 		pr_info("Linux is running as a guest in 64-bit mode\n");
1103 
1104 	log_component_list();
1105 
1106 	/* Have one command line that is parsed and saved in /proc/cmdline */
1107 	/* boot_command_line has been already set up in early.c */
1108 	*cmdline_p = boot_command_line;
1109 
1110         ROOT_DEV = Root_RAM0;
1111 
1112 	init_mm.start_code = (unsigned long) _text;
1113 	init_mm.end_code = (unsigned long) _etext;
1114 	init_mm.end_data = (unsigned long) _edata;
1115 	init_mm.brk = (unsigned long) _end;
1116 
1117 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
1118 		nospec_auto_detect();
1119 
1120 	parse_early_param();
1121 #ifdef CONFIG_CRASH_DUMP
1122 	/* Deactivate elfcorehdr= kernel parameter */
1123 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
1124 #endif
1125 
1126 	os_info_init();
1127 	setup_ipl();
1128 	setup_task_size();
1129 	setup_control_program_code();
1130 
1131 	/* Do some memory reservations *before* memory is added to memblock */
1132 	reserve_memory_end();
1133 	reserve_oldmem();
1134 	reserve_kernel();
1135 	reserve_initrd();
1136 	reserve_certificate_list();
1137 	reserve_mem_detect_info();
1138 	memblock_allow_resize();
1139 
1140 	/* Get information about *all* installed memory */
1141 	memblock_add_mem_detect_info();
1142 
1143 	free_mem_detect_info();
1144 	remove_oldmem();
1145 
1146 	/*
1147 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
1148 	 * extra checks that HOLES_IN_ZONE would require.
1149 	 *
1150 	 * Is this still required?
1151 	 */
1152 	memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));
1153 
1154 	setup_memory_end();
1155 	setup_memory();
1156 	dma_contiguous_reserve(memory_end);
1157 	vmcp_cma_reserve();
1158 
1159 	check_initrd();
1160 	reserve_crashkernel();
1161 #ifdef CONFIG_CRASH_DUMP
1162 	/*
1163 	 * Be aware that smp_save_dump_cpus() triggers a system reset.
1164 	 * Therefore CPU and device initialization should be done afterwards.
1165 	 */
1166 	smp_save_dump_cpus();
1167 #endif
1168 
1169 	setup_resources();
1170 	setup_lowcore_dat_off();
1171 	smp_fill_possible_mask();
1172 	cpu_detect_mhz_feature();
1173         cpu_init();
1174 	numa_setup();
1175 	smp_detect_cpus();
1176 	topology_init_early();
1177 
1178 	/*
1179 	 * Create kernel page tables and switch to virtual addressing.
1180 	 */
1181         paging_init();
1182 
1183 	/*
1184 	 * After paging_init created the kernel page table, the new PSWs
1185 	 * in lowcore can now run with DAT enabled.
1186 	 */
1187 	setup_lowcore_dat_on();
1188 
1189         /* Setup default console */
1190 	conmode_default();
1191 	set_preferred_console();
1192 
1193 	apply_alternative_instructions();
1194 	if (IS_ENABLED(CONFIG_EXPOLINE))
1195 		nospec_init_branches();
1196 
1197 	/* Setup zfcpdump support */
1198 	setup_zfcpdump();
1199 
1200 	/* Add system specific data to the random pool */
1201 	setup_randomness();
1202 }
1203