xref: /linux/arch/s390/kernel/setup.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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(max_physmem_end);
103 struct mem_detect_info __bootdata(mem_detect);
104 
105 struct exception_table_entry *__bootdata_preserved(__start_dma_ex_table);
106 struct exception_table_entry *__bootdata_preserved(__stop_dma_ex_table);
107 unsigned long __bootdata_preserved(__swsusp_reset_dma);
108 unsigned long __bootdata_preserved(__stext_dma);
109 unsigned long __bootdata_preserved(__etext_dma);
110 unsigned long __bootdata_preserved(__sdma);
111 unsigned long __bootdata_preserved(__edma);
112 unsigned long __bootdata_preserved(__kaslr_offset);
113 
114 unsigned long VMALLOC_START;
115 EXPORT_SYMBOL(VMALLOC_START);
116 
117 unsigned long VMALLOC_END;
118 EXPORT_SYMBOL(VMALLOC_END);
119 
120 struct page *vmemmap;
121 EXPORT_SYMBOL(vmemmap);
122 
123 unsigned long MODULES_VADDR;
124 unsigned long MODULES_END;
125 
126 /* An array with a pointer to the lowcore of every CPU. */
127 struct lowcore *lowcore_ptr[NR_CPUS];
128 EXPORT_SYMBOL(lowcore_ptr);
129 
130 /*
131  * This is set up by the setup-routine at boot-time
132  * for S390 need to find out, what we have to setup
133  * using address 0x10400 ...
134  */
135 
136 #include <asm/setup.h>
137 
138 /*
139  * condev= and conmode= setup parameter.
140  */
141 
142 static int __init condev_setup(char *str)
143 {
144 	int vdev;
145 
146 	vdev = simple_strtoul(str, &str, 0);
147 	if (vdev >= 0 && vdev < 65536) {
148 		console_devno = vdev;
149 		console_irq = -1;
150 	}
151 	return 1;
152 }
153 
154 __setup("condev=", condev_setup);
155 
156 static void __init set_preferred_console(void)
157 {
158 	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
159 		add_preferred_console("ttyS", 0, NULL);
160 	else if (CONSOLE_IS_3270)
161 		add_preferred_console("tty3270", 0, NULL);
162 	else if (CONSOLE_IS_VT220)
163 		add_preferred_console("ttyS", 1, NULL);
164 	else if (CONSOLE_IS_HVC)
165 		add_preferred_console("hvc", 0, NULL);
166 }
167 
168 static int __init conmode_setup(char *str)
169 {
170 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
171 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
172                 SET_CONSOLE_SCLP;
173 #endif
174 #if defined(CONFIG_TN3215_CONSOLE)
175 	if (strncmp(str, "3215", 5) == 0)
176 		SET_CONSOLE_3215;
177 #endif
178 #if defined(CONFIG_TN3270_CONSOLE)
179 	if (strncmp(str, "3270", 5) == 0)
180 		SET_CONSOLE_3270;
181 #endif
182 	set_preferred_console();
183         return 1;
184 }
185 
186 __setup("conmode=", conmode_setup);
187 
188 static void __init conmode_default(void)
189 {
190 	char query_buffer[1024];
191 	char *ptr;
192 
193         if (MACHINE_IS_VM) {
194 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
195 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
196 		ptr = strstr(query_buffer, "SUBCHANNEL =");
197 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
198 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
199 		ptr = strstr(query_buffer, "CONMODE");
200 		/*
201 		 * Set the conmode to 3215 so that the device recognition
202 		 * will set the cu_type of the console to 3215. If the
203 		 * conmode is 3270 and we don't set it back then both
204 		 * 3215 and the 3270 driver will try to access the console
205 		 * device (3215 as console and 3270 as normal tty).
206 		 */
207 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
208 		if (ptr == NULL) {
209 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
210 			SET_CONSOLE_SCLP;
211 #endif
212 			return;
213 		}
214 		if (strncmp(ptr + 8, "3270", 4) == 0) {
215 #if defined(CONFIG_TN3270_CONSOLE)
216 			SET_CONSOLE_3270;
217 #elif defined(CONFIG_TN3215_CONSOLE)
218 			SET_CONSOLE_3215;
219 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
220 			SET_CONSOLE_SCLP;
221 #endif
222 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
223 #if defined(CONFIG_TN3215_CONSOLE)
224 			SET_CONSOLE_3215;
225 #elif defined(CONFIG_TN3270_CONSOLE)
226 			SET_CONSOLE_3270;
227 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
228 			SET_CONSOLE_SCLP;
229 #endif
230 		}
231 	} else if (MACHINE_IS_KVM) {
232 		if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
233 			SET_CONSOLE_VT220;
234 		else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
235 			SET_CONSOLE_SCLP;
236 		else
237 			SET_CONSOLE_HVC;
238 	} else {
239 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
240 		SET_CONSOLE_SCLP;
241 #endif
242 	}
243 	if (IS_ENABLED(CONFIG_VT) && IS_ENABLED(CONFIG_DUMMY_CONSOLE))
244 		conswitchp = &dummy_con;
245 }
246 
247 #ifdef CONFIG_CRASH_DUMP
248 static void __init setup_zfcpdump(void)
249 {
250 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
251 		return;
252 	if (OLDMEM_BASE)
253 		return;
254 	strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
255 	console_loglevel = 2;
256 }
257 #else
258 static inline void setup_zfcpdump(void) {}
259 #endif /* CONFIG_CRASH_DUMP */
260 
261  /*
262  * Reboot, halt and power_off stubs. They just call _machine_restart,
263  * _machine_halt or _machine_power_off.
264  */
265 
266 void machine_restart(char *command)
267 {
268 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
269 		/*
270 		 * Only unblank the console if we are called in enabled
271 		 * context or a bust_spinlocks cleared the way for us.
272 		 */
273 		console_unblank();
274 	_machine_restart(command);
275 }
276 
277 void machine_halt(void)
278 {
279 	if (!in_interrupt() || oops_in_progress)
280 		/*
281 		 * Only unblank the console if we are called in enabled
282 		 * context or a bust_spinlocks cleared the way for us.
283 		 */
284 		console_unblank();
285 	_machine_halt();
286 }
287 
288 void machine_power_off(void)
289 {
290 	if (!in_interrupt() || oops_in_progress)
291 		/*
292 		 * Only unblank the console if we are called in enabled
293 		 * context or a bust_spinlocks cleared the way for us.
294 		 */
295 		console_unblank();
296 	_machine_power_off();
297 }
298 
299 /*
300  * Dummy power off function.
301  */
302 void (*pm_power_off)(void) = machine_power_off;
303 EXPORT_SYMBOL_GPL(pm_power_off);
304 
305 static int __init parse_vmalloc(char *arg)
306 {
307 	if (!arg)
308 		return -EINVAL;
309 	VMALLOC_END = (memparse(arg, &arg) + PAGE_SIZE - 1) & PAGE_MASK;
310 	return 0;
311 }
312 early_param("vmalloc", parse_vmalloc);
313 
314 void *restart_stack __section(.data);
315 
316 unsigned long stack_alloc(void)
317 {
318 #ifdef CONFIG_VMAP_STACK
319 	return (unsigned long)
320 		__vmalloc_node_range(THREAD_SIZE, THREAD_SIZE,
321 				     VMALLOC_START, VMALLOC_END,
322 				     THREADINFO_GFP,
323 				     PAGE_KERNEL, 0, NUMA_NO_NODE,
324 				     __builtin_return_address(0));
325 #else
326 	return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
327 #endif
328 }
329 
330 void stack_free(unsigned long stack)
331 {
332 #ifdef CONFIG_VMAP_STACK
333 	vfree((void *) stack);
334 #else
335 	free_pages(stack, THREAD_SIZE_ORDER);
336 #endif
337 }
338 
339 int __init arch_early_irq_init(void)
340 {
341 	unsigned long stack;
342 
343 	stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
344 	if (!stack)
345 		panic("Couldn't allocate async stack");
346 	S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
347 	return 0;
348 }
349 
350 static int __init async_stack_realloc(void)
351 {
352 	unsigned long old, new;
353 
354 	old = S390_lowcore.async_stack - STACK_INIT_OFFSET;
355 	new = stack_alloc();
356 	if (!new)
357 		panic("Couldn't allocate async stack");
358 	S390_lowcore.async_stack = new + STACK_INIT_OFFSET;
359 	free_pages(old, THREAD_SIZE_ORDER);
360 	return 0;
361 }
362 early_initcall(async_stack_realloc);
363 
364 void __init arch_call_rest_init(void)
365 {
366 	struct stack_frame *frame;
367 	unsigned long stack;
368 
369 	stack = stack_alloc();
370 	if (!stack)
371 		panic("Couldn't allocate kernel stack");
372 	current->stack = (void *) stack;
373 #ifdef CONFIG_VMAP_STACK
374 	current->stack_vm_area = (void *) stack;
375 #endif
376 	set_task_stack_end_magic(current);
377 	stack += STACK_INIT_OFFSET;
378 	S390_lowcore.kernel_stack = stack;
379 	frame = (struct stack_frame *) stack;
380 	memset(frame, 0, sizeof(*frame));
381 	/* Branch to rest_init on the new stack, never returns */
382 	asm volatile(
383 		"	la	15,0(%[_frame])\n"
384 		"	jg	rest_init\n"
385 		: : [_frame] "a" (frame));
386 }
387 
388 static void __init setup_lowcore_dat_off(void)
389 {
390 	struct lowcore *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->restart_psw.mask = PSW_KERNEL_BITS;
402 	lc->restart_psw.addr = (unsigned long) restart_int_handler;
403 	lc->external_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
404 	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
405 	lc->svc_new_psw.mask = PSW_KERNEL_BITS |
406 		PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
407 	lc->svc_new_psw.addr = (unsigned long) system_call;
408 	lc->program_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
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 | PSW_MASK_MCHECK;
413 	lc->io_new_psw.addr = (unsigned long) io_int_handler;
414 	lc->clock_comparator = clock_comparator_max;
415 	lc->nodat_stack = ((unsigned long) &init_thread_union)
416 		+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
417 	lc->current_task = (unsigned long)&init_task;
418 	lc->lpp = LPP_MAGIC;
419 	lc->machine_flags = S390_lowcore.machine_flags;
420 	lc->preempt_count = S390_lowcore.preempt_count;
421 	lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
422 	memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
423 	       sizeof(lc->stfle_fac_list));
424 	memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list,
425 	       sizeof(lc->alt_stfle_fac_list));
426 	nmi_alloc_boot_cpu(lc);
427 	vdso_alloc_boot_cpu(lc);
428 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
429 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
430 	lc->exit_timer = S390_lowcore.exit_timer;
431 	lc->user_timer = S390_lowcore.user_timer;
432 	lc->system_timer = S390_lowcore.system_timer;
433 	lc->steal_timer = S390_lowcore.steal_timer;
434 	lc->last_update_timer = S390_lowcore.last_update_timer;
435 	lc->last_update_clock = S390_lowcore.last_update_clock;
436 
437 	/*
438 	 * Allocate the global restart stack which is the same for
439 	 * all CPUs in cast *one* of them does a PSW restart.
440 	 */
441 	restart_stack = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
442 	if (!restart_stack)
443 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
444 		      __func__, THREAD_SIZE, THREAD_SIZE);
445 	restart_stack += STACK_INIT_OFFSET;
446 
447 	/*
448 	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
449 	 * restart data to the absolute zero lowcore. This is necessary if
450 	 * PSW restart is done on an offline CPU that has lowcore zero.
451 	 */
452 	lc->restart_stack = (unsigned long) restart_stack;
453 	lc->restart_fn = (unsigned long) do_restart;
454 	lc->restart_data = 0;
455 	lc->restart_source = -1UL;
456 
457 	/* Setup absolute zero lowcore */
458 	mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
459 	mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
460 	mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
461 	mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
462 	mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
463 
464 #ifdef CONFIG_SMP
465 	lc->spinlock_lockval = arch_spin_lockval(0);
466 	lc->spinlock_index = 0;
467 	arch_spin_lock_setup(0);
468 #endif
469 	lc->br_r1_trampoline = 0x07f1;	/* br %r1 */
470 
471 	set_prefix((u32)(unsigned long) lc);
472 	lowcore_ptr[0] = lc;
473 }
474 
475 static void __init setup_lowcore_dat_on(void)
476 {
477 	__ctl_clear_bit(0, 28);
478 	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
479 	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
480 	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
481 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
482 	__ctl_set_bit(0, 28);
483 }
484 
485 static struct resource code_resource = {
486 	.name  = "Kernel code",
487 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
488 };
489 
490 static struct resource data_resource = {
491 	.name = "Kernel data",
492 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
493 };
494 
495 static struct resource bss_resource = {
496 	.name = "Kernel bss",
497 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
498 };
499 
500 static struct resource __initdata *standard_resources[] = {
501 	&code_resource,
502 	&data_resource,
503 	&bss_resource,
504 };
505 
506 static void __init setup_resources(void)
507 {
508 	struct resource *res, *std_res, *sub_res;
509 	struct memblock_region *reg;
510 	int j;
511 
512 	code_resource.start = (unsigned long) _text;
513 	code_resource.end = (unsigned long) _etext - 1;
514 	data_resource.start = (unsigned long) _etext;
515 	data_resource.end = (unsigned long) _edata - 1;
516 	bss_resource.start = (unsigned long) __bss_start;
517 	bss_resource.end = (unsigned long) __bss_stop - 1;
518 
519 	for_each_memblock(memory, reg) {
520 		res = memblock_alloc(sizeof(*res), 8);
521 		if (!res)
522 			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
523 			      __func__, sizeof(*res), 8);
524 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
525 
526 		res->name = "System RAM";
527 		res->start = reg->base;
528 		res->end = reg->base + reg->size - 1;
529 		request_resource(&iomem_resource, res);
530 
531 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
532 			std_res = standard_resources[j];
533 			if (std_res->start < res->start ||
534 			    std_res->start > res->end)
535 				continue;
536 			if (std_res->end > res->end) {
537 				sub_res = memblock_alloc(sizeof(*sub_res), 8);
538 				if (!sub_res)
539 					panic("%s: Failed to allocate %zu bytes align=0x%x\n",
540 					      __func__, sizeof(*sub_res), 8);
541 				*sub_res = *std_res;
542 				sub_res->end = res->end;
543 				std_res->start = res->end + 1;
544 				request_resource(res, sub_res);
545 			} else {
546 				request_resource(res, std_res);
547 			}
548 		}
549 	}
550 #ifdef CONFIG_CRASH_DUMP
551 	/*
552 	 * Re-add removed crash kernel memory as reserved memory. This makes
553 	 * sure it will be mapped with the identity mapping and struct pages
554 	 * will be created, so it can be resized later on.
555 	 * However add it later since the crash kernel resource should not be
556 	 * part of the System RAM resource.
557 	 */
558 	if (crashk_res.end) {
559 		memblock_add_node(crashk_res.start, resource_size(&crashk_res), 0);
560 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
561 		insert_resource(&iomem_resource, &crashk_res);
562 	}
563 #endif
564 }
565 
566 static void __init setup_memory_end(void)
567 {
568 	unsigned long vmax, vmalloc_size, tmp;
569 
570 	/* Choose kernel address space layout: 3 or 4 levels. */
571 	vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN;
572 	if (IS_ENABLED(CONFIG_KASAN)) {
573 		vmax = IS_ENABLED(CONFIG_KASAN_S390_4_LEVEL_PAGING)
574 			   ? _REGION1_SIZE
575 			   : _REGION2_SIZE;
576 	} else {
577 		tmp = (memory_end ?: max_physmem_end) / PAGE_SIZE;
578 		tmp = tmp * (sizeof(struct page) + PAGE_SIZE);
579 		if (tmp + vmalloc_size + MODULES_LEN <= _REGION2_SIZE)
580 			vmax = _REGION2_SIZE; /* 3-level kernel page table */
581 		else
582 			vmax = _REGION1_SIZE; /* 4-level kernel page table */
583 	}
584 
585 	/* module area is at the end of the kernel address space. */
586 	MODULES_END = vmax;
587 	MODULES_VADDR = MODULES_END - MODULES_LEN;
588 	VMALLOC_END = MODULES_VADDR;
589 	VMALLOC_START = VMALLOC_END - vmalloc_size;
590 
591 	/* Split remaining virtual space between 1:1 mapping & vmemmap array */
592 	tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
593 	/* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
594 	tmp = SECTION_ALIGN_UP(tmp);
595 	tmp = VMALLOC_START - tmp * sizeof(struct page);
596 	tmp &= ~((vmax >> 11) - 1);	/* align to page table level */
597 	tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
598 	vmemmap = (struct page *) tmp;
599 
600 	/* Take care that memory_end is set and <= vmemmap */
601 	memory_end = min(memory_end ?: max_physmem_end, (unsigned long)vmemmap);
602 #ifdef CONFIG_KASAN
603 	/* fit in kasan shadow memory region between 1:1 and vmemmap */
604 	memory_end = min(memory_end, KASAN_SHADOW_START);
605 	vmemmap = max(vmemmap, (struct page *)KASAN_SHADOW_END);
606 #endif
607 	max_pfn = max_low_pfn = PFN_DOWN(memory_end);
608 	memblock_remove(memory_end, ULONG_MAX);
609 
610 	pr_notice("The maximum memory size is %luMB\n", memory_end >> 20);
611 }
612 
613 #ifdef CONFIG_CRASH_DUMP
614 
615 /*
616  * When kdump is enabled, we have to ensure that no memory from
617  * the area [0 - crashkernel memory size] and
618  * [crashk_res.start - crashk_res.end] is set offline.
619  */
620 static int kdump_mem_notifier(struct notifier_block *nb,
621 			      unsigned long action, void *data)
622 {
623 	struct memory_notify *arg = data;
624 
625 	if (action != MEM_GOING_OFFLINE)
626 		return NOTIFY_OK;
627 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
628 		return NOTIFY_BAD;
629 	if (arg->start_pfn > PFN_DOWN(crashk_res.end))
630 		return NOTIFY_OK;
631 	if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
632 		return NOTIFY_OK;
633 	return NOTIFY_BAD;
634 }
635 
636 static struct notifier_block kdump_mem_nb = {
637 	.notifier_call = kdump_mem_notifier,
638 };
639 
640 #endif
641 
642 /*
643  * Make sure that the area behind memory_end is protected
644  */
645 static void reserve_memory_end(void)
646 {
647 	if (memory_end_set)
648 		memblock_reserve(memory_end, ULONG_MAX);
649 }
650 
651 /*
652  * Make sure that oldmem, where the dump is stored, is protected
653  */
654 static void reserve_oldmem(void)
655 {
656 #ifdef CONFIG_CRASH_DUMP
657 	if (OLDMEM_BASE)
658 		/* Forget all memory above the running kdump system */
659 		memblock_reserve(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
660 #endif
661 }
662 
663 /*
664  * Make sure that oldmem, where the dump is stored, is protected
665  */
666 static void remove_oldmem(void)
667 {
668 #ifdef CONFIG_CRASH_DUMP
669 	if (OLDMEM_BASE)
670 		/* Forget all memory above the running kdump system */
671 		memblock_remove(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
672 #endif
673 }
674 
675 /*
676  * Reserve memory for kdump kernel to be loaded with kexec
677  */
678 static void __init reserve_crashkernel(void)
679 {
680 #ifdef CONFIG_CRASH_DUMP
681 	unsigned long long crash_base, crash_size;
682 	phys_addr_t low, high;
683 	int rc;
684 
685 	rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
686 			       &crash_base);
687 
688 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
689 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
690 	if (rc || crash_size == 0)
691 		return;
692 
693 	if (memblock.memory.regions[0].size < crash_size) {
694 		pr_info("crashkernel reservation failed: %s\n",
695 			"first memory chunk must be at least crashkernel size");
696 		return;
697 	}
698 
699 	low = crash_base ?: OLDMEM_BASE;
700 	high = low + crash_size;
701 	if (low >= OLDMEM_BASE && high <= OLDMEM_BASE + OLDMEM_SIZE) {
702 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
703 		crash_base = low;
704 	} else {
705 		/* Find suitable area in free memory */
706 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
707 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
708 
709 		if (crash_base && crash_base < low) {
710 			pr_info("crashkernel reservation failed: %s\n",
711 				"crash_base too low");
712 			return;
713 		}
714 		low = crash_base ?: low;
715 		crash_base = memblock_find_in_range(low, high, crash_size,
716 						    KEXEC_CRASH_MEM_ALIGN);
717 	}
718 
719 	if (!crash_base) {
720 		pr_info("crashkernel reservation failed: %s\n",
721 			"no suitable area found");
722 		return;
723 	}
724 
725 	if (register_memory_notifier(&kdump_mem_nb))
726 		return;
727 
728 	if (!OLDMEM_BASE && MACHINE_IS_VM)
729 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
730 	crashk_res.start = crash_base;
731 	crashk_res.end = crash_base + crash_size - 1;
732 	memblock_remove(crash_base, crash_size);
733 	pr_info("Reserving %lluMB of memory at %lluMB "
734 		"for crashkernel (System RAM: %luMB)\n",
735 		crash_size >> 20, crash_base >> 20,
736 		(unsigned long)memblock.memory.total_size >> 20);
737 	os_info_crashkernel_add(crash_base, crash_size);
738 #endif
739 }
740 
741 /*
742  * Reserve the initrd from being used by memblock
743  */
744 static void __init reserve_initrd(void)
745 {
746 #ifdef CONFIG_BLK_DEV_INITRD
747 	if (!INITRD_START || !INITRD_SIZE)
748 		return;
749 	initrd_start = INITRD_START;
750 	initrd_end = initrd_start + INITRD_SIZE;
751 	memblock_reserve(INITRD_START, INITRD_SIZE);
752 #endif
753 }
754 
755 /*
756  * Reserve the memory area used to pass the certificate lists
757  */
758 static void __init reserve_certificate_list(void)
759 {
760 	if (ipl_cert_list_addr)
761 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
762 }
763 
764 static void __init reserve_mem_detect_info(void)
765 {
766 	unsigned long start, size;
767 
768 	get_mem_detect_reserved(&start, &size);
769 	if (size)
770 		memblock_reserve(start, size);
771 }
772 
773 static void __init free_mem_detect_info(void)
774 {
775 	unsigned long start, size;
776 
777 	get_mem_detect_reserved(&start, &size);
778 	if (size)
779 		memblock_free(start, size);
780 }
781 
782 static void __init memblock_physmem_add(phys_addr_t start, phys_addr_t size)
783 {
784 	memblock_dbg("memblock_physmem_add: [%#016llx-%#016llx]\n",
785 		     start, start + size - 1);
786 	memblock_add_range(&memblock.memory, start, size, 0, 0);
787 	memblock_add_range(&memblock.physmem, start, size, 0, 0);
788 }
789 
790 static const char * __init get_mem_info_source(void)
791 {
792 	switch (mem_detect.info_source) {
793 	case MEM_DETECT_SCLP_STOR_INFO:
794 		return "sclp storage info";
795 	case MEM_DETECT_DIAG260:
796 		return "diag260";
797 	case MEM_DETECT_SCLP_READ_INFO:
798 		return "sclp read info";
799 	case MEM_DETECT_BIN_SEARCH:
800 		return "binary search";
801 	}
802 	return "none";
803 }
804 
805 static void __init memblock_add_mem_detect_info(void)
806 {
807 	unsigned long start, end;
808 	int i;
809 
810 	memblock_dbg("physmem info source: %s (%hhd)\n",
811 		     get_mem_info_source(), mem_detect.info_source);
812 	/* keep memblock lists close to the kernel */
813 	memblock_set_bottom_up(true);
814 	for_each_mem_detect_block(i, &start, &end)
815 		memblock_physmem_add(start, end - start);
816 	memblock_set_bottom_up(false);
817 	memblock_dump_all();
818 }
819 
820 /*
821  * Check for initrd being in usable memory
822  */
823 static void __init check_initrd(void)
824 {
825 #ifdef CONFIG_BLK_DEV_INITRD
826 	if (INITRD_START && INITRD_SIZE &&
827 	    !memblock_is_region_memory(INITRD_START, INITRD_SIZE)) {
828 		pr_err("The initial RAM disk does not fit into the memory\n");
829 		memblock_free(INITRD_START, INITRD_SIZE);
830 		initrd_start = initrd_end = 0;
831 	}
832 #endif
833 }
834 
835 /*
836  * Reserve memory used for lowcore/command line/kernel image.
837  */
838 static void __init reserve_kernel(void)
839 {
840 	unsigned long start_pfn = PFN_UP(__pa(_end));
841 
842 	memblock_reserve(0, HEAD_END);
843 	memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
844 			 - (unsigned long)_stext);
845 	memblock_reserve(__sdma, __edma - __sdma);
846 }
847 
848 static void __init setup_memory(void)
849 {
850 	struct memblock_region *reg;
851 
852 	/*
853 	 * Init storage key for present memory
854 	 */
855 	for_each_memblock(memory, reg) {
856 		storage_key_init_range(reg->base, reg->base + reg->size);
857 	}
858 	psw_set_key(PAGE_DEFAULT_KEY);
859 
860 	/* Only cosmetics */
861 	memblock_enforce_memory_limit(memblock_end_of_DRAM());
862 }
863 
864 /*
865  * Setup hardware capabilities.
866  */
867 static int __init setup_hwcaps(void)
868 {
869 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
870 	struct cpuid cpu_id;
871 	int i;
872 
873 	/*
874 	 * The store facility list bits numbers as found in the principles
875 	 * of operation are numbered with bit 1UL<<31 as number 0 to
876 	 * bit 1UL<<0 as number 31.
877 	 *   Bit 0: instructions named N3, "backported" to esa-mode
878 	 *   Bit 2: z/Architecture mode is active
879 	 *   Bit 7: the store-facility-list-extended facility is installed
880 	 *   Bit 17: the message-security assist is installed
881 	 *   Bit 19: the long-displacement facility is installed
882 	 *   Bit 21: the extended-immediate facility is installed
883 	 *   Bit 22: extended-translation facility 3 is installed
884 	 *   Bit 30: extended-translation facility 3 enhancement facility
885 	 * These get translated to:
886 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
887 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
888 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
889 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
890 	 */
891 	for (i = 0; i < 6; i++)
892 		if (test_facility(stfl_bits[i]))
893 			elf_hwcap |= 1UL << i;
894 
895 	if (test_facility(22) && test_facility(30))
896 		elf_hwcap |= HWCAP_S390_ETF3EH;
897 
898 	/*
899 	 * Check for additional facilities with store-facility-list-extended.
900 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
901 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
902 	 * as stored by stfl, bits 32-xxx contain additional facilities.
903 	 * How many facility words are stored depends on the number of
904 	 * doublewords passed to the instruction. The additional facilities
905 	 * are:
906 	 *   Bit 42: decimal floating point facility is installed
907 	 *   Bit 44: perform floating point operation facility is installed
908 	 * translated to:
909 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
910 	 */
911 	if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
912 		elf_hwcap |= HWCAP_S390_DFP;
913 
914 	/*
915 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
916 	 */
917 	if (MACHINE_HAS_EDAT1)
918 		elf_hwcap |= HWCAP_S390_HPAGE;
919 
920 	/*
921 	 * 64-bit register support for 31-bit processes
922 	 * HWCAP_S390_HIGH_GPRS is bit 9.
923 	 */
924 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
925 
926 	/*
927 	 * Transactional execution support HWCAP_S390_TE is bit 10.
928 	 */
929 	if (MACHINE_HAS_TE)
930 		elf_hwcap |= HWCAP_S390_TE;
931 
932 	/*
933 	 * Vector extension HWCAP_S390_VXRS is bit 11. The Vector extension
934 	 * can be disabled with the "novx" parameter. Use MACHINE_HAS_VX
935 	 * instead of facility bit 129.
936 	 */
937 	if (MACHINE_HAS_VX) {
938 		elf_hwcap |= HWCAP_S390_VXRS;
939 		if (test_facility(134))
940 			elf_hwcap |= HWCAP_S390_VXRS_EXT;
941 		if (test_facility(135))
942 			elf_hwcap |= HWCAP_S390_VXRS_BCD;
943 		if (test_facility(148))
944 			elf_hwcap |= HWCAP_S390_VXRS_EXT2;
945 		if (test_facility(152))
946 			elf_hwcap |= HWCAP_S390_VXRS_PDE;
947 	}
948 	if (test_facility(150))
949 		elf_hwcap |= HWCAP_S390_SORT;
950 	if (test_facility(151))
951 		elf_hwcap |= HWCAP_S390_DFLT;
952 
953 	/*
954 	 * Guarded storage support HWCAP_S390_GS is bit 12.
955 	 */
956 	if (MACHINE_HAS_GS)
957 		elf_hwcap |= HWCAP_S390_GS;
958 
959 	get_cpu_id(&cpu_id);
960 	add_device_randomness(&cpu_id, sizeof(cpu_id));
961 	switch (cpu_id.machine) {
962 	case 0x2064:
963 	case 0x2066:
964 	default:	/* Use "z900" as default for 64 bit kernels. */
965 		strcpy(elf_platform, "z900");
966 		break;
967 	case 0x2084:
968 	case 0x2086:
969 		strcpy(elf_platform, "z990");
970 		break;
971 	case 0x2094:
972 	case 0x2096:
973 		strcpy(elf_platform, "z9-109");
974 		break;
975 	case 0x2097:
976 	case 0x2098:
977 		strcpy(elf_platform, "z10");
978 		break;
979 	case 0x2817:
980 	case 0x2818:
981 		strcpy(elf_platform, "z196");
982 		break;
983 	case 0x2827:
984 	case 0x2828:
985 		strcpy(elf_platform, "zEC12");
986 		break;
987 	case 0x2964:
988 	case 0x2965:
989 		strcpy(elf_platform, "z13");
990 		break;
991 	case 0x3906:
992 	case 0x3907:
993 		strcpy(elf_platform, "z14");
994 		break;
995 	}
996 
997 	/*
998 	 * Virtualization support HWCAP_INT_SIE is bit 0.
999 	 */
1000 	if (sclp.has_sief2)
1001 		int_hwcap |= HWCAP_INT_SIE;
1002 
1003 	return 0;
1004 }
1005 arch_initcall(setup_hwcaps);
1006 
1007 /*
1008  * Add system information as device randomness
1009  */
1010 static void __init setup_randomness(void)
1011 {
1012 	struct sysinfo_3_2_2 *vmms;
1013 
1014 	vmms = (struct sysinfo_3_2_2 *) memblock_phys_alloc(PAGE_SIZE,
1015 							    PAGE_SIZE);
1016 	if (!vmms)
1017 		panic("Failed to allocate memory for sysinfo structure\n");
1018 
1019 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
1020 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
1021 	memblock_free((unsigned long) vmms, PAGE_SIZE);
1022 }
1023 
1024 /*
1025  * Find the correct size for the task_struct. This depends on
1026  * the size of the struct fpu at the end of the thread_struct
1027  * which is embedded in the task_struct.
1028  */
1029 static void __init setup_task_size(void)
1030 {
1031 	int task_size = sizeof(struct task_struct);
1032 
1033 	if (!MACHINE_HAS_VX) {
1034 		task_size -= sizeof(__vector128) * __NUM_VXRS;
1035 		task_size += sizeof(freg_t) * __NUM_FPRS;
1036 	}
1037 	arch_task_struct_size = task_size;
1038 }
1039 
1040 /*
1041  * Issue diagnose 318 to set the control program name and
1042  * version codes.
1043  */
1044 static void __init setup_control_program_code(void)
1045 {
1046 	union diag318_info diag318_info = {
1047 		.cpnc = CPNC_LINUX,
1048 		.cpvc_linux = 0,
1049 		.cpvc_distro = {0},
1050 	};
1051 
1052 	if (!sclp.has_diag318)
1053 		return;
1054 
1055 	diag_stat_inc(DIAG_STAT_X318);
1056 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
1057 }
1058 
1059 /*
1060  * Print the component list from the IPL report
1061  */
1062 static void __init log_component_list(void)
1063 {
1064 	struct ipl_rb_component_entry *ptr, *end;
1065 	char *str;
1066 
1067 	if (!early_ipl_comp_list_addr)
1068 		return;
1069 	if (ipl_block.hdr.flags & IPL_PL_FLAG_IPLSR)
1070 		pr_info("Linux is running with Secure-IPL enabled\n");
1071 	else
1072 		pr_info("Linux is running with Secure-IPL disabled\n");
1073 	ptr = (void *) early_ipl_comp_list_addr;
1074 	end = (void *) ptr + early_ipl_comp_list_size;
1075 	pr_info("The IPL report contains the following components:\n");
1076 	while (ptr < end) {
1077 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
1078 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
1079 				str = "signed, verified";
1080 			else
1081 				str = "signed, verification failed";
1082 		} else {
1083 			str = "not signed";
1084 		}
1085 		pr_info("%016llx - %016llx (%s)\n",
1086 			ptr->addr, ptr->addr + ptr->len, str);
1087 		ptr++;
1088 	}
1089 }
1090 
1091 /*
1092  * Setup function called from init/main.c just after the banner
1093  * was printed.
1094  */
1095 
1096 void __init setup_arch(char **cmdline_p)
1097 {
1098         /*
1099          * print what head.S has found out about the machine
1100          */
1101 	if (MACHINE_IS_VM)
1102 		pr_info("Linux is running as a z/VM "
1103 			"guest operating system in 64-bit mode\n");
1104 	else if (MACHINE_IS_KVM)
1105 		pr_info("Linux is running under KVM in 64-bit mode\n");
1106 	else if (MACHINE_IS_LPAR)
1107 		pr_info("Linux is running natively in 64-bit mode\n");
1108 	else
1109 		pr_info("Linux is running as a guest in 64-bit mode\n");
1110 
1111 	log_component_list();
1112 
1113 	/* Have one command line that is parsed and saved in /proc/cmdline */
1114 	/* boot_command_line has been already set up in early.c */
1115 	*cmdline_p = boot_command_line;
1116 
1117         ROOT_DEV = Root_RAM0;
1118 
1119 	/* Is init_mm really needed? */
1120 	init_mm.start_code = PAGE_OFFSET;
1121 	init_mm.end_code = (unsigned long) _etext;
1122 	init_mm.end_data = (unsigned long) _edata;
1123 	init_mm.brk = (unsigned long) _end;
1124 
1125 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
1126 		nospec_auto_detect();
1127 
1128 	parse_early_param();
1129 #ifdef CONFIG_CRASH_DUMP
1130 	/* Deactivate elfcorehdr= kernel parameter */
1131 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
1132 #endif
1133 
1134 	os_info_init();
1135 	setup_ipl();
1136 	setup_task_size();
1137 	setup_control_program_code();
1138 
1139 	/* Do some memory reservations *before* memory is added to memblock */
1140 	reserve_memory_end();
1141 	reserve_oldmem();
1142 	reserve_kernel();
1143 	reserve_initrd();
1144 	reserve_certificate_list();
1145 	reserve_mem_detect_info();
1146 	memblock_allow_resize();
1147 
1148 	/* Get information about *all* installed memory */
1149 	memblock_add_mem_detect_info();
1150 
1151 	free_mem_detect_info();
1152 	remove_oldmem();
1153 
1154 	/*
1155 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
1156 	 * extra checks that HOLES_IN_ZONE would require.
1157 	 *
1158 	 * Is this still required?
1159 	 */
1160 	memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));
1161 
1162 	setup_memory_end();
1163 	setup_memory();
1164 	dma_contiguous_reserve(memory_end);
1165 	vmcp_cma_reserve();
1166 
1167 	check_initrd();
1168 	reserve_crashkernel();
1169 #ifdef CONFIG_CRASH_DUMP
1170 	/*
1171 	 * Be aware that smp_save_dump_cpus() triggers a system reset.
1172 	 * Therefore CPU and device initialization should be done afterwards.
1173 	 */
1174 	smp_save_dump_cpus();
1175 #endif
1176 
1177 	setup_resources();
1178 	setup_lowcore_dat_off();
1179 	smp_fill_possible_mask();
1180 	cpu_detect_mhz_feature();
1181         cpu_init();
1182 	numa_setup();
1183 	smp_detect_cpus();
1184 	topology_init_early();
1185 
1186 	/*
1187 	 * Create kernel page tables and switch to virtual addressing.
1188 	 */
1189         paging_init();
1190 
1191 	/*
1192 	 * After paging_init created the kernel page table, the new PSWs
1193 	 * in lowcore can now run with DAT enabled.
1194 	 */
1195 	setup_lowcore_dat_on();
1196 
1197         /* Setup default console */
1198 	conmode_default();
1199 	set_preferred_console();
1200 
1201 	apply_alternative_instructions();
1202 	if (IS_ENABLED(CONFIG_EXPOLINE))
1203 		nospec_init_branches();
1204 
1205 	/* Setup zfcpdump support */
1206 	setup_zfcpdump();
1207 
1208 	/* Add system specific data to the random pool */
1209 	setup_randomness();
1210 }
1211