xref: /openbmc/linux/arch/s390/kernel/setup.c (revision aa0dc6a7)
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 
54 #include <asm/boot_data.h>
55 #include <asm/ipl.h>
56 #include <asm/facility.h>
57 #include <asm/smp.h>
58 #include <asm/mmu_context.h>
59 #include <asm/cpcmd.h>
60 #include <asm/lowcore.h>
61 #include <asm/nmi.h>
62 #include <asm/irq.h>
63 #include <asm/page.h>
64 #include <asm/ptrace.h>
65 #include <asm/sections.h>
66 #include <asm/ebcdic.h>
67 #include <asm/diag.h>
68 #include <asm/os_info.h>
69 #include <asm/sclp.h>
70 #include <asm/stacktrace.h>
71 #include <asm/sysinfo.h>
72 #include <asm/numa.h>
73 #include <asm/alternative.h>
74 #include <asm/nospec-branch.h>
75 #include <asm/mem_detect.h>
76 #include <asm/uv.h>
77 #include <asm/asm-offsets.h>
78 #include "entry.h"
79 
80 /*
81  * Machine setup..
82  */
83 unsigned int console_mode = 0;
84 EXPORT_SYMBOL(console_mode);
85 
86 unsigned int console_devno = -1;
87 EXPORT_SYMBOL(console_devno);
88 
89 unsigned int console_irq = -1;
90 EXPORT_SYMBOL(console_irq);
91 
92 unsigned long elf_hwcap __read_mostly = 0;
93 char elf_platform[ELF_PLATFORM_SIZE];
94 
95 unsigned long int_hwcap = 0;
96 
97 int __bootdata(noexec_disabled);
98 unsigned long __bootdata(ident_map_size);
99 struct mem_detect_info __bootdata(mem_detect);
100 
101 struct exception_table_entry *__bootdata_preserved(__start_dma_ex_table);
102 struct exception_table_entry *__bootdata_preserved(__stop_dma_ex_table);
103 unsigned long __bootdata_preserved(__stext_dma);
104 unsigned long __bootdata_preserved(__etext_dma);
105 unsigned long __bootdata_preserved(__sdma);
106 unsigned long __bootdata_preserved(__edma);
107 unsigned long __bootdata_preserved(__kaslr_offset);
108 unsigned int __bootdata_preserved(zlib_dfltcc_support);
109 EXPORT_SYMBOL(zlib_dfltcc_support);
110 u64 __bootdata_preserved(stfle_fac_list[16]);
111 EXPORT_SYMBOL(stfle_fac_list);
112 u64 __bootdata_preserved(alt_stfle_fac_list[16]);
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 unsigned long vmemmap_size;
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  * The Write Back bit position in the physaddr is given by the SLPC PCI.
133  * Leaving the mask zero always uses write through which is safe
134  */
135 unsigned long mio_wb_bit_mask __ro_after_init;
136 
137 /*
138  * This is set up by the setup-routine at boot-time
139  * for S390 need to find out, what we have to setup
140  * using address 0x10400 ...
141  */
142 
143 #include <asm/setup.h>
144 
145 /*
146  * condev= and conmode= setup parameter.
147  */
148 
149 static int __init condev_setup(char *str)
150 {
151 	int vdev;
152 
153 	vdev = simple_strtoul(str, &str, 0);
154 	if (vdev >= 0 && vdev < 65536) {
155 		console_devno = vdev;
156 		console_irq = -1;
157 	}
158 	return 1;
159 }
160 
161 __setup("condev=", condev_setup);
162 
163 static void __init set_preferred_console(void)
164 {
165 	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
166 		add_preferred_console("ttyS", 0, NULL);
167 	else if (CONSOLE_IS_3270)
168 		add_preferred_console("tty3270", 0, NULL);
169 	else if (CONSOLE_IS_VT220)
170 		add_preferred_console("ttysclp", 0, NULL);
171 	else if (CONSOLE_IS_HVC)
172 		add_preferred_console("hvc", 0, NULL);
173 }
174 
175 static int __init conmode_setup(char *str)
176 {
177 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
178 	if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
179                 SET_CONSOLE_SCLP;
180 #endif
181 #if defined(CONFIG_TN3215_CONSOLE)
182 	if (!strcmp(str, "3215"))
183 		SET_CONSOLE_3215;
184 #endif
185 #if defined(CONFIG_TN3270_CONSOLE)
186 	if (!strcmp(str, "3270"))
187 		SET_CONSOLE_3270;
188 #endif
189 	set_preferred_console();
190         return 1;
191 }
192 
193 __setup("conmode=", conmode_setup);
194 
195 static void __init conmode_default(void)
196 {
197 	char query_buffer[1024];
198 	char *ptr;
199 
200         if (MACHINE_IS_VM) {
201 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
202 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
203 		ptr = strstr(query_buffer, "SUBCHANNEL =");
204 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
205 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
206 		ptr = strstr(query_buffer, "CONMODE");
207 		/*
208 		 * Set the conmode to 3215 so that the device recognition
209 		 * will set the cu_type of the console to 3215. If the
210 		 * conmode is 3270 and we don't set it back then both
211 		 * 3215 and the 3270 driver will try to access the console
212 		 * device (3215 as console and 3270 as normal tty).
213 		 */
214 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
215 		if (ptr == NULL) {
216 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
217 			SET_CONSOLE_SCLP;
218 #endif
219 			return;
220 		}
221 		if (str_has_prefix(ptr + 8, "3270")) {
222 #if defined(CONFIG_TN3270_CONSOLE)
223 			SET_CONSOLE_3270;
224 #elif defined(CONFIG_TN3215_CONSOLE)
225 			SET_CONSOLE_3215;
226 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
227 			SET_CONSOLE_SCLP;
228 #endif
229 		} else if (str_has_prefix(ptr + 8, "3215")) {
230 #if defined(CONFIG_TN3215_CONSOLE)
231 			SET_CONSOLE_3215;
232 #elif defined(CONFIG_TN3270_CONSOLE)
233 			SET_CONSOLE_3270;
234 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
235 			SET_CONSOLE_SCLP;
236 #endif
237 		}
238 	} else if (MACHINE_IS_KVM) {
239 		if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
240 			SET_CONSOLE_VT220;
241 		else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
242 			SET_CONSOLE_SCLP;
243 		else
244 			SET_CONSOLE_HVC;
245 	} else {
246 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
247 		SET_CONSOLE_SCLP;
248 #endif
249 	}
250 }
251 
252 #ifdef CONFIG_CRASH_DUMP
253 static void __init setup_zfcpdump(void)
254 {
255 	if (!is_ipl_type_dump())
256 		return;
257 	if (OLDMEM_BASE)
258 		return;
259 	strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
260 	console_loglevel = 2;
261 }
262 #else
263 static inline void setup_zfcpdump(void) {}
264 #endif /* CONFIG_CRASH_DUMP */
265 
266  /*
267  * Reboot, halt and power_off stubs. They just call _machine_restart,
268  * _machine_halt or _machine_power_off.
269  */
270 
271 void machine_restart(char *command)
272 {
273 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
274 		/*
275 		 * Only unblank the console if we are called in enabled
276 		 * context or a bust_spinlocks cleared the way for us.
277 		 */
278 		console_unblank();
279 	_machine_restart(command);
280 }
281 
282 void machine_halt(void)
283 {
284 	if (!in_interrupt() || oops_in_progress)
285 		/*
286 		 * Only unblank the console if we are called in enabled
287 		 * context or a bust_spinlocks cleared the way for us.
288 		 */
289 		console_unblank();
290 	_machine_halt();
291 }
292 
293 void machine_power_off(void)
294 {
295 	if (!in_interrupt() || oops_in_progress)
296 		/*
297 		 * Only unblank the console if we are called in enabled
298 		 * context or a bust_spinlocks cleared the way for us.
299 		 */
300 		console_unblank();
301 	_machine_power_off();
302 }
303 
304 /*
305  * Dummy power off function.
306  */
307 void (*pm_power_off)(void) = machine_power_off;
308 EXPORT_SYMBOL_GPL(pm_power_off);
309 
310 void *restart_stack;
311 
312 unsigned long stack_alloc(void)
313 {
314 #ifdef CONFIG_VMAP_STACK
315 	return (unsigned long)__vmalloc_node(THREAD_SIZE, THREAD_SIZE,
316 			THREADINFO_GFP, NUMA_NO_NODE,
317 			__builtin_return_address(0));
318 #else
319 	return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
320 #endif
321 }
322 
323 void stack_free(unsigned long stack)
324 {
325 #ifdef CONFIG_VMAP_STACK
326 	vfree((void *) stack);
327 #else
328 	free_pages(stack, THREAD_SIZE_ORDER);
329 #endif
330 }
331 
332 int __init arch_early_irq_init(void)
333 {
334 	unsigned long stack;
335 
336 	stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
337 	if (!stack)
338 		panic("Couldn't allocate async stack");
339 	S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
340 	return 0;
341 }
342 
343 void __init arch_call_rest_init(void)
344 {
345 	unsigned long stack;
346 
347 	stack = stack_alloc();
348 	if (!stack)
349 		panic("Couldn't allocate kernel stack");
350 	current->stack = (void *) stack;
351 #ifdef CONFIG_VMAP_STACK
352 	current->stack_vm_area = (void *) stack;
353 #endif
354 	set_task_stack_end_magic(current);
355 	stack += STACK_INIT_OFFSET;
356 	S390_lowcore.kernel_stack = stack;
357 	call_on_stack_noreturn(rest_init, stack);
358 }
359 
360 static void __init setup_lowcore_dat_off(void)
361 {
362 	unsigned long int_psw_mask = PSW_KERNEL_BITS;
363 	unsigned long mcck_stack;
364 	struct lowcore *lc;
365 
366 	if (IS_ENABLED(CONFIG_KASAN))
367 		int_psw_mask |= PSW_MASK_DAT;
368 
369 	/*
370 	 * Setup lowcore for boot cpu
371 	 */
372 	BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
373 	lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
374 	if (!lc)
375 		panic("%s: Failed to allocate %zu bytes align=%zx\n",
376 		      __func__, sizeof(*lc), sizeof(*lc));
377 
378 	lc->restart_psw.mask = PSW_KERNEL_BITS;
379 	lc->restart_psw.addr = (unsigned long) restart_int_handler;
380 	lc->external_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
381 	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
382 	lc->svc_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
383 	lc->svc_new_psw.addr = (unsigned long) system_call;
384 	lc->program_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
385 	lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
386 	lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
387 	lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
388 	lc->io_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
389 	lc->io_new_psw.addr = (unsigned long) io_int_handler;
390 	lc->clock_comparator = clock_comparator_max;
391 	lc->nodat_stack = ((unsigned long) &init_thread_union)
392 		+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
393 	lc->current_task = (unsigned long)&init_task;
394 	lc->lpp = LPP_MAGIC;
395 	lc->machine_flags = S390_lowcore.machine_flags;
396 	lc->preempt_count = S390_lowcore.preempt_count;
397 	nmi_alloc_boot_cpu(lc);
398 	lc->sys_enter_timer = S390_lowcore.sys_enter_timer;
399 	lc->exit_timer = S390_lowcore.exit_timer;
400 	lc->user_timer = S390_lowcore.user_timer;
401 	lc->system_timer = S390_lowcore.system_timer;
402 	lc->steal_timer = S390_lowcore.steal_timer;
403 	lc->last_update_timer = S390_lowcore.last_update_timer;
404 	lc->last_update_clock = S390_lowcore.last_update_clock;
405 
406 	/*
407 	 * Allocate the global restart stack which is the same for
408 	 * all CPUs in cast *one* of them does a PSW restart.
409 	 */
410 	restart_stack = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
411 	if (!restart_stack)
412 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
413 		      __func__, THREAD_SIZE, THREAD_SIZE);
414 	restart_stack += STACK_INIT_OFFSET;
415 
416 	/*
417 	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
418 	 * restart data to the absolute zero lowcore. This is necessary if
419 	 * PSW restart is done on an offline CPU that has lowcore zero.
420 	 */
421 	lc->restart_stack = (unsigned long) restart_stack;
422 	lc->restart_fn = (unsigned long) do_restart;
423 	lc->restart_data = 0;
424 	lc->restart_source = -1UL;
425 
426 	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
427 	if (!mcck_stack)
428 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
429 		      __func__, THREAD_SIZE, THREAD_SIZE);
430 	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
431 
432 	/* Setup absolute zero lowcore */
433 	mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
434 	mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
435 	mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
436 	mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
437 	mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
438 
439 	lc->spinlock_lockval = arch_spin_lockval(0);
440 	lc->spinlock_index = 0;
441 	arch_spin_lock_setup(0);
442 	lc->br_r1_trampoline = 0x07f1;	/* br %r1 */
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 
447 	set_prefix((u32)(unsigned long) lc);
448 	lowcore_ptr[0] = lc;
449 }
450 
451 static void __init setup_lowcore_dat_on(void)
452 {
453 	__ctl_clear_bit(0, 28);
454 	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
455 	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
456 	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
457 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
458 	__ctl_set_bit(0, 28);
459 }
460 
461 static struct resource code_resource = {
462 	.name  = "Kernel code",
463 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
464 };
465 
466 static struct resource data_resource = {
467 	.name = "Kernel data",
468 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
469 };
470 
471 static struct resource bss_resource = {
472 	.name = "Kernel bss",
473 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
474 };
475 
476 static struct resource __initdata *standard_resources[] = {
477 	&code_resource,
478 	&data_resource,
479 	&bss_resource,
480 };
481 
482 static void __init setup_resources(void)
483 {
484 	struct resource *res, *std_res, *sub_res;
485 	phys_addr_t start, end;
486 	int j;
487 	u64 i;
488 
489 	code_resource.start = (unsigned long) _text;
490 	code_resource.end = (unsigned long) _etext - 1;
491 	data_resource.start = (unsigned long) _etext;
492 	data_resource.end = (unsigned long) _edata - 1;
493 	bss_resource.start = (unsigned long) __bss_start;
494 	bss_resource.end = (unsigned long) __bss_stop - 1;
495 
496 	for_each_mem_range(i, &start, &end) {
497 		res = memblock_alloc(sizeof(*res), 8);
498 		if (!res)
499 			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
500 			      __func__, sizeof(*res), 8);
501 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
502 
503 		res->name = "System RAM";
504 		res->start = start;
505 		/*
506 		 * In memblock, end points to the first byte after the
507 		 * range while in resourses, end points to the last byte in
508 		 * the range.
509 		 */
510 		res->end = end - 1;
511 		request_resource(&iomem_resource, res);
512 
513 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
514 			std_res = standard_resources[j];
515 			if (std_res->start < res->start ||
516 			    std_res->start > res->end)
517 				continue;
518 			if (std_res->end > res->end) {
519 				sub_res = memblock_alloc(sizeof(*sub_res), 8);
520 				if (!sub_res)
521 					panic("%s: Failed to allocate %zu bytes align=0x%x\n",
522 					      __func__, 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), 0);
542 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
543 		insert_resource(&iomem_resource, &crashk_res);
544 	}
545 #endif
546 }
547 
548 static void __init setup_memory_end(void)
549 {
550 	memblock_remove(ident_map_size, ULONG_MAX);
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  * Make sure that the area above identity mapping is protected
583  */
584 static void __init reserve_above_ident_map(void)
585 {
586 	memblock_reserve(ident_map_size, ULONG_MAX);
587 }
588 
589 /*
590  * Reserve memory for kdump kernel to be loaded with kexec
591  */
592 static void __init reserve_crashkernel(void)
593 {
594 #ifdef CONFIG_CRASH_DUMP
595 	unsigned long long crash_base, crash_size;
596 	phys_addr_t low, high;
597 	int rc;
598 
599 	rc = parse_crashkernel(boot_command_line, ident_map_size, &crash_size,
600 			       &crash_base);
601 
602 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
603 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
604 	if (rc || crash_size == 0)
605 		return;
606 
607 	if (memblock.memory.regions[0].size < crash_size) {
608 		pr_info("crashkernel reservation failed: %s\n",
609 			"first memory chunk must be at least crashkernel size");
610 		return;
611 	}
612 
613 	low = crash_base ?: OLDMEM_BASE;
614 	high = low + crash_size;
615 	if (low >= OLDMEM_BASE && high <= OLDMEM_BASE + OLDMEM_SIZE) {
616 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
617 		crash_base = low;
618 	} else {
619 		/* Find suitable area in free memory */
620 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
621 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
622 
623 		if (crash_base && crash_base < low) {
624 			pr_info("crashkernel reservation failed: %s\n",
625 				"crash_base too low");
626 			return;
627 		}
628 		low = crash_base ?: low;
629 		crash_base = memblock_find_in_range(low, high, crash_size,
630 						    KEXEC_CRASH_MEM_ALIGN);
631 	}
632 
633 	if (!crash_base) {
634 		pr_info("crashkernel reservation failed: %s\n",
635 			"no suitable area found");
636 		return;
637 	}
638 
639 	if (register_memory_notifier(&kdump_mem_nb))
640 		return;
641 
642 	if (!OLDMEM_BASE && MACHINE_IS_VM)
643 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
644 	crashk_res.start = crash_base;
645 	crashk_res.end = crash_base + crash_size - 1;
646 	memblock_remove(crash_base, crash_size);
647 	pr_info("Reserving %lluMB of memory at %lluMB "
648 		"for crashkernel (System RAM: %luMB)\n",
649 		crash_size >> 20, crash_base >> 20,
650 		(unsigned long)memblock.memory.total_size >> 20);
651 	os_info_crashkernel_add(crash_base, crash_size);
652 #endif
653 }
654 
655 /*
656  * Reserve the initrd from being used by memblock
657  */
658 static void __init reserve_initrd(void)
659 {
660 #ifdef CONFIG_BLK_DEV_INITRD
661 	if (!INITRD_START || !INITRD_SIZE)
662 		return;
663 	initrd_start = INITRD_START;
664 	initrd_end = initrd_start + INITRD_SIZE;
665 	memblock_reserve(INITRD_START, INITRD_SIZE);
666 #endif
667 }
668 
669 /*
670  * Reserve the memory area used to pass the certificate lists
671  */
672 static void __init reserve_certificate_list(void)
673 {
674 	if (ipl_cert_list_addr)
675 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
676 }
677 
678 static void __init reserve_mem_detect_info(void)
679 {
680 	unsigned long start, size;
681 
682 	get_mem_detect_reserved(&start, &size);
683 	if (size)
684 		memblock_reserve(start, size);
685 }
686 
687 static void __init free_mem_detect_info(void)
688 {
689 	unsigned long start, size;
690 
691 	get_mem_detect_reserved(&start, &size);
692 	if (size)
693 		memblock_free(start, size);
694 }
695 
696 static const char * __init get_mem_info_source(void)
697 {
698 	switch (mem_detect.info_source) {
699 	case MEM_DETECT_SCLP_STOR_INFO:
700 		return "sclp storage info";
701 	case MEM_DETECT_DIAG260:
702 		return "diag260";
703 	case MEM_DETECT_SCLP_READ_INFO:
704 		return "sclp read info";
705 	case MEM_DETECT_BIN_SEARCH:
706 		return "binary search";
707 	}
708 	return "none";
709 }
710 
711 static void __init memblock_add_mem_detect_info(void)
712 {
713 	unsigned long start, end;
714 	int i;
715 
716 	pr_debug("physmem info source: %s (%hhd)\n",
717 		 get_mem_info_source(), mem_detect.info_source);
718 	/* keep memblock lists close to the kernel */
719 	memblock_set_bottom_up(true);
720 	for_each_mem_detect_block(i, &start, &end) {
721 		memblock_add(start, end - start);
722 		memblock_physmem_add(start, end - start);
723 	}
724 	memblock_set_bottom_up(false);
725 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
726 	memblock_dump_all();
727 }
728 
729 /*
730  * Check for initrd being in usable memory
731  */
732 static void __init check_initrd(void)
733 {
734 #ifdef CONFIG_BLK_DEV_INITRD
735 	if (INITRD_START && INITRD_SIZE &&
736 	    !memblock_is_region_memory(INITRD_START, INITRD_SIZE)) {
737 		pr_err("The initial RAM disk does not fit into the memory\n");
738 		memblock_free(INITRD_START, INITRD_SIZE);
739 		initrd_start = initrd_end = 0;
740 	}
741 #endif
742 }
743 
744 /*
745  * Reserve memory used for lowcore/command line/kernel image.
746  */
747 static void __init reserve_kernel(void)
748 {
749 	unsigned long start_pfn = PFN_UP(__pa(_end));
750 
751 	memblock_reserve(0, HEAD_END);
752 	memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
753 			 - (unsigned long)_stext);
754 	memblock_reserve(__sdma, __edma - __sdma);
755 }
756 
757 static void __init setup_memory(void)
758 {
759 	phys_addr_t start, end;
760 	u64 i;
761 
762 	/*
763 	 * Init storage key for present memory
764 	 */
765 	for_each_mem_range(i, &start, &end)
766 		storage_key_init_range(start, end);
767 
768 	psw_set_key(PAGE_DEFAULT_KEY);
769 
770 	/* Only cosmetics */
771 	memblock_enforce_memory_limit(memblock_end_of_DRAM());
772 }
773 
774 /*
775  * Setup hardware capabilities.
776  */
777 static int __init setup_hwcaps(void)
778 {
779 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
780 	struct cpuid cpu_id;
781 	int i;
782 
783 	/*
784 	 * The store facility list bits numbers as found in the principles
785 	 * of operation are numbered with bit 1UL<<31 as number 0 to
786 	 * bit 1UL<<0 as number 31.
787 	 *   Bit 0: instructions named N3, "backported" to esa-mode
788 	 *   Bit 2: z/Architecture mode is active
789 	 *   Bit 7: the store-facility-list-extended facility is installed
790 	 *   Bit 17: the message-security assist is installed
791 	 *   Bit 19: the long-displacement facility is installed
792 	 *   Bit 21: the extended-immediate facility is installed
793 	 *   Bit 22: extended-translation facility 3 is installed
794 	 *   Bit 30: extended-translation facility 3 enhancement facility
795 	 * These get translated to:
796 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
797 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
798 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
799 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
800 	 */
801 	for (i = 0; i < 6; i++)
802 		if (test_facility(stfl_bits[i]))
803 			elf_hwcap |= 1UL << i;
804 
805 	if (test_facility(22) && test_facility(30))
806 		elf_hwcap |= HWCAP_S390_ETF3EH;
807 
808 	/*
809 	 * Check for additional facilities with store-facility-list-extended.
810 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
811 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
812 	 * as stored by stfl, bits 32-xxx contain additional facilities.
813 	 * How many facility words are stored depends on the number of
814 	 * doublewords passed to the instruction. The additional facilities
815 	 * are:
816 	 *   Bit 42: decimal floating point facility is installed
817 	 *   Bit 44: perform floating point operation facility is installed
818 	 * translated to:
819 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
820 	 */
821 	if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
822 		elf_hwcap |= HWCAP_S390_DFP;
823 
824 	/*
825 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
826 	 */
827 	if (MACHINE_HAS_EDAT1)
828 		elf_hwcap |= HWCAP_S390_HPAGE;
829 
830 	/*
831 	 * 64-bit register support for 31-bit processes
832 	 * HWCAP_S390_HIGH_GPRS is bit 9.
833 	 */
834 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
835 
836 	/*
837 	 * Transactional execution support HWCAP_S390_TE is bit 10.
838 	 */
839 	if (MACHINE_HAS_TE)
840 		elf_hwcap |= HWCAP_S390_TE;
841 
842 	/*
843 	 * Vector extension HWCAP_S390_VXRS is bit 11. The Vector extension
844 	 * can be disabled with the "novx" parameter. Use MACHINE_HAS_VX
845 	 * instead of facility bit 129.
846 	 */
847 	if (MACHINE_HAS_VX) {
848 		elf_hwcap |= HWCAP_S390_VXRS;
849 		if (test_facility(134))
850 			elf_hwcap |= HWCAP_S390_VXRS_BCD;
851 		if (test_facility(135))
852 			elf_hwcap |= HWCAP_S390_VXRS_EXT;
853 		if (test_facility(148))
854 			elf_hwcap |= HWCAP_S390_VXRS_EXT2;
855 		if (test_facility(152))
856 			elf_hwcap |= HWCAP_S390_VXRS_PDE;
857 	}
858 	if (test_facility(150))
859 		elf_hwcap |= HWCAP_S390_SORT;
860 	if (test_facility(151))
861 		elf_hwcap |= HWCAP_S390_DFLT;
862 
863 	/*
864 	 * Guarded storage support HWCAP_S390_GS is bit 12.
865 	 */
866 	if (MACHINE_HAS_GS)
867 		elf_hwcap |= HWCAP_S390_GS;
868 
869 	get_cpu_id(&cpu_id);
870 	add_device_randomness(&cpu_id, sizeof(cpu_id));
871 	switch (cpu_id.machine) {
872 	case 0x2064:
873 	case 0x2066:
874 	default:	/* Use "z900" as default for 64 bit kernels. */
875 		strcpy(elf_platform, "z900");
876 		break;
877 	case 0x2084:
878 	case 0x2086:
879 		strcpy(elf_platform, "z990");
880 		break;
881 	case 0x2094:
882 	case 0x2096:
883 		strcpy(elf_platform, "z9-109");
884 		break;
885 	case 0x2097:
886 	case 0x2098:
887 		strcpy(elf_platform, "z10");
888 		break;
889 	case 0x2817:
890 	case 0x2818:
891 		strcpy(elf_platform, "z196");
892 		break;
893 	case 0x2827:
894 	case 0x2828:
895 		strcpy(elf_platform, "zEC12");
896 		break;
897 	case 0x2964:
898 	case 0x2965:
899 		strcpy(elf_platform, "z13");
900 		break;
901 	case 0x3906:
902 	case 0x3907:
903 		strcpy(elf_platform, "z14");
904 		break;
905 	case 0x8561:
906 	case 0x8562:
907 		strcpy(elf_platform, "z15");
908 		break;
909 	}
910 
911 	/*
912 	 * Virtualization support HWCAP_INT_SIE is bit 0.
913 	 */
914 	if (sclp.has_sief2)
915 		int_hwcap |= HWCAP_INT_SIE;
916 
917 	return 0;
918 }
919 arch_initcall(setup_hwcaps);
920 
921 /*
922  * Add system information as device randomness
923  */
924 static void __init setup_randomness(void)
925 {
926 	struct sysinfo_3_2_2 *vmms;
927 
928 	vmms = (struct sysinfo_3_2_2 *) memblock_phys_alloc(PAGE_SIZE,
929 							    PAGE_SIZE);
930 	if (!vmms)
931 		panic("Failed to allocate memory for sysinfo structure\n");
932 
933 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
934 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
935 	memblock_free((unsigned long) vmms, PAGE_SIZE);
936 }
937 
938 /*
939  * Find the correct size for the task_struct. This depends on
940  * the size of the struct fpu at the end of the thread_struct
941  * which is embedded in the task_struct.
942  */
943 static void __init setup_task_size(void)
944 {
945 	int task_size = sizeof(struct task_struct);
946 
947 	if (!MACHINE_HAS_VX) {
948 		task_size -= sizeof(__vector128) * __NUM_VXRS;
949 		task_size += sizeof(freg_t) * __NUM_FPRS;
950 	}
951 	arch_task_struct_size = task_size;
952 }
953 
954 /*
955  * Issue diagnose 318 to set the control program name and
956  * version codes.
957  */
958 static void __init setup_control_program_code(void)
959 {
960 	union diag318_info diag318_info = {
961 		.cpnc = CPNC_LINUX,
962 		.cpvc = 0,
963 	};
964 
965 	if (!sclp.has_diag318)
966 		return;
967 
968 	diag_stat_inc(DIAG_STAT_X318);
969 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
970 }
971 
972 /*
973  * Print the component list from the IPL report
974  */
975 static void __init log_component_list(void)
976 {
977 	struct ipl_rb_component_entry *ptr, *end;
978 	char *str;
979 
980 	if (!early_ipl_comp_list_addr)
981 		return;
982 	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
983 		pr_info("Linux is running with Secure-IPL enabled\n");
984 	else
985 		pr_info("Linux is running with Secure-IPL disabled\n");
986 	ptr = (void *) early_ipl_comp_list_addr;
987 	end = (void *) ptr + early_ipl_comp_list_size;
988 	pr_info("The IPL report contains the following components:\n");
989 	while (ptr < end) {
990 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
991 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
992 				str = "signed, verified";
993 			else
994 				str = "signed, verification failed";
995 		} else {
996 			str = "not signed";
997 		}
998 		pr_info("%016llx - %016llx (%s)\n",
999 			ptr->addr, ptr->addr + ptr->len, str);
1000 		ptr++;
1001 	}
1002 }
1003 
1004 /*
1005  * Setup function called from init/main.c just after the banner
1006  * was printed.
1007  */
1008 
1009 void __init setup_arch(char **cmdline_p)
1010 {
1011         /*
1012          * print what head.S has found out about the machine
1013          */
1014 	if (MACHINE_IS_VM)
1015 		pr_info("Linux is running as a z/VM "
1016 			"guest operating system in 64-bit mode\n");
1017 	else if (MACHINE_IS_KVM)
1018 		pr_info("Linux is running under KVM in 64-bit mode\n");
1019 	else if (MACHINE_IS_LPAR)
1020 		pr_info("Linux is running natively in 64-bit mode\n");
1021 	else
1022 		pr_info("Linux is running as a guest in 64-bit mode\n");
1023 
1024 	log_component_list();
1025 
1026 	/* Have one command line that is parsed and saved in /proc/cmdline */
1027 	/* boot_command_line has been already set up in early.c */
1028 	*cmdline_p = boot_command_line;
1029 
1030         ROOT_DEV = Root_RAM0;
1031 
1032 	setup_initial_init_mm(_text, _etext, _edata, _end);
1033 
1034 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
1035 		nospec_auto_detect();
1036 
1037 	jump_label_init();
1038 	parse_early_param();
1039 #ifdef CONFIG_CRASH_DUMP
1040 	/* Deactivate elfcorehdr= kernel parameter */
1041 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
1042 #endif
1043 
1044 	os_info_init();
1045 	setup_ipl();
1046 	setup_task_size();
1047 	setup_control_program_code();
1048 
1049 	/* Do some memory reservations *before* memory is added to memblock */
1050 	reserve_above_ident_map();
1051 	reserve_kernel();
1052 	reserve_initrd();
1053 	reserve_certificate_list();
1054 	reserve_mem_detect_info();
1055 	memblock_allow_resize();
1056 
1057 	/* Get information about *all* installed memory */
1058 	memblock_add_mem_detect_info();
1059 
1060 	free_mem_detect_info();
1061 
1062 	setup_uv();
1063 	setup_memory_end();
1064 	setup_memory();
1065 	dma_contiguous_reserve(ident_map_size);
1066 	vmcp_cma_reserve();
1067 	if (MACHINE_HAS_EDAT2)
1068 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1069 
1070 	check_initrd();
1071 	reserve_crashkernel();
1072 #ifdef CONFIG_CRASH_DUMP
1073 	/*
1074 	 * Be aware that smp_save_dump_cpus() triggers a system reset.
1075 	 * Therefore CPU and device initialization should be done afterwards.
1076 	 */
1077 	smp_save_dump_cpus();
1078 #endif
1079 
1080 	setup_resources();
1081 	setup_lowcore_dat_off();
1082 	smp_fill_possible_mask();
1083 	cpu_detect_mhz_feature();
1084         cpu_init();
1085 	numa_setup();
1086 	smp_detect_cpus();
1087 	topology_init_early();
1088 
1089 	/*
1090 	 * Create kernel page tables and switch to virtual addressing.
1091 	 */
1092         paging_init();
1093 
1094 	/*
1095 	 * After paging_init created the kernel page table, the new PSWs
1096 	 * in lowcore can now run with DAT enabled.
1097 	 */
1098 	setup_lowcore_dat_on();
1099 
1100         /* Setup default console */
1101 	conmode_default();
1102 	set_preferred_console();
1103 
1104 	apply_alternative_instructions();
1105 	if (IS_ENABLED(CONFIG_EXPOLINE))
1106 		nospec_init_branches();
1107 
1108 	/* Setup zfcp/nvme dump support */
1109 	setup_zfcpdump();
1110 
1111 	/* Add system specific data to the random pool */
1112 	setup_randomness();
1113 }
1114