xref: /openbmc/linux/arch/s390/kernel/setup.c (revision 44c2cd80)
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 
446 	set_prefix((u32)(unsigned long) lc);
447 	lowcore_ptr[0] = lc;
448 }
449 
450 static void __init setup_lowcore_dat_on(void)
451 {
452 	__ctl_clear_bit(0, 28);
453 	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
454 	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
455 	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
456 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
457 	__ctl_set_bit(0, 28);
458 }
459 
460 static struct resource code_resource = {
461 	.name  = "Kernel code",
462 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
463 };
464 
465 static struct resource data_resource = {
466 	.name = "Kernel data",
467 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
468 };
469 
470 static struct resource bss_resource = {
471 	.name = "Kernel bss",
472 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
473 };
474 
475 static struct resource __initdata *standard_resources[] = {
476 	&code_resource,
477 	&data_resource,
478 	&bss_resource,
479 };
480 
481 static void __init setup_resources(void)
482 {
483 	struct resource *res, *std_res, *sub_res;
484 	phys_addr_t start, end;
485 	int j;
486 	u64 i;
487 
488 	code_resource.start = (unsigned long) _text;
489 	code_resource.end = (unsigned long) _etext - 1;
490 	data_resource.start = (unsigned long) _etext;
491 	data_resource.end = (unsigned long) _edata - 1;
492 	bss_resource.start = (unsigned long) __bss_start;
493 	bss_resource.end = (unsigned long) __bss_stop - 1;
494 
495 	for_each_mem_range(i, &start, &end) {
496 		res = memblock_alloc(sizeof(*res), 8);
497 		if (!res)
498 			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
499 			      __func__, sizeof(*res), 8);
500 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
501 
502 		res->name = "System RAM";
503 		res->start = start;
504 		/*
505 		 * In memblock, end points to the first byte after the
506 		 * range while in resourses, end points to the last byte in
507 		 * the range.
508 		 */
509 		res->end = end - 1;
510 		request_resource(&iomem_resource, res);
511 
512 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
513 			std_res = standard_resources[j];
514 			if (std_res->start < res->start ||
515 			    std_res->start > res->end)
516 				continue;
517 			if (std_res->end > res->end) {
518 				sub_res = memblock_alloc(sizeof(*sub_res), 8);
519 				if (!sub_res)
520 					panic("%s: Failed to allocate %zu bytes align=0x%x\n",
521 					      __func__, sizeof(*sub_res), 8);
522 				*sub_res = *std_res;
523 				sub_res->end = res->end;
524 				std_res->start = res->end + 1;
525 				request_resource(res, sub_res);
526 			} else {
527 				request_resource(res, std_res);
528 			}
529 		}
530 	}
531 #ifdef CONFIG_CRASH_DUMP
532 	/*
533 	 * Re-add removed crash kernel memory as reserved memory. This makes
534 	 * sure it will be mapped with the identity mapping and struct pages
535 	 * will be created, so it can be resized later on.
536 	 * However add it later since the crash kernel resource should not be
537 	 * part of the System RAM resource.
538 	 */
539 	if (crashk_res.end) {
540 		memblock_add_node(crashk_res.start, resource_size(&crashk_res), 0);
541 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
542 		insert_resource(&iomem_resource, &crashk_res);
543 	}
544 #endif
545 }
546 
547 static void __init setup_memory_end(void)
548 {
549 	memblock_remove(ident_map_size, ULONG_MAX);
550 	max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
551 	pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
552 }
553 
554 #ifdef CONFIG_CRASH_DUMP
555 
556 /*
557  * When kdump is enabled, we have to ensure that no memory from the area
558  * [0 - crashkernel memory size] is set offline - it will be exchanged with
559  * the crashkernel memory region when kdump is triggered. The crashkernel
560  * memory region can never get offlined (pages are unmovable).
561  */
562 static int kdump_mem_notifier(struct notifier_block *nb,
563 			      unsigned long action, void *data)
564 {
565 	struct memory_notify *arg = data;
566 
567 	if (action != MEM_GOING_OFFLINE)
568 		return NOTIFY_OK;
569 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
570 		return NOTIFY_BAD;
571 	return NOTIFY_OK;
572 }
573 
574 static struct notifier_block kdump_mem_nb = {
575 	.notifier_call = kdump_mem_notifier,
576 };
577 
578 #endif
579 
580 /*
581  * Make sure that the area above identity mapping is protected
582  */
583 static void __init reserve_above_ident_map(void)
584 {
585 	memblock_reserve(ident_map_size, ULONG_MAX);
586 }
587 
588 /*
589  * Reserve memory for kdump kernel to be loaded with kexec
590  */
591 static void __init reserve_crashkernel(void)
592 {
593 #ifdef CONFIG_CRASH_DUMP
594 	unsigned long long crash_base, crash_size;
595 	phys_addr_t low, high;
596 	int rc;
597 
598 	rc = parse_crashkernel(boot_command_line, ident_map_size, &crash_size,
599 			       &crash_base);
600 
601 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
602 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
603 	if (rc || crash_size == 0)
604 		return;
605 
606 	if (memblock.memory.regions[0].size < crash_size) {
607 		pr_info("crashkernel reservation failed: %s\n",
608 			"first memory chunk must be at least crashkernel size");
609 		return;
610 	}
611 
612 	low = crash_base ?: OLDMEM_BASE;
613 	high = low + crash_size;
614 	if (low >= OLDMEM_BASE && high <= OLDMEM_BASE + OLDMEM_SIZE) {
615 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
616 		crash_base = low;
617 	} else {
618 		/* Find suitable area in free memory */
619 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
620 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
621 
622 		if (crash_base && crash_base < low) {
623 			pr_info("crashkernel reservation failed: %s\n",
624 				"crash_base too low");
625 			return;
626 		}
627 		low = crash_base ?: low;
628 		crash_base = memblock_find_in_range(low, high, crash_size,
629 						    KEXEC_CRASH_MEM_ALIGN);
630 	}
631 
632 	if (!crash_base) {
633 		pr_info("crashkernel reservation failed: %s\n",
634 			"no suitable area found");
635 		return;
636 	}
637 
638 	if (register_memory_notifier(&kdump_mem_nb))
639 		return;
640 
641 	if (!OLDMEM_BASE && MACHINE_IS_VM)
642 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
643 	crashk_res.start = crash_base;
644 	crashk_res.end = crash_base + crash_size - 1;
645 	memblock_remove(crash_base, crash_size);
646 	pr_info("Reserving %lluMB of memory at %lluMB "
647 		"for crashkernel (System RAM: %luMB)\n",
648 		crash_size >> 20, crash_base >> 20,
649 		(unsigned long)memblock.memory.total_size >> 20);
650 	os_info_crashkernel_add(crash_base, crash_size);
651 #endif
652 }
653 
654 /*
655  * Reserve the initrd from being used by memblock
656  */
657 static void __init reserve_initrd(void)
658 {
659 #ifdef CONFIG_BLK_DEV_INITRD
660 	if (!INITRD_START || !INITRD_SIZE)
661 		return;
662 	initrd_start = INITRD_START;
663 	initrd_end = initrd_start + INITRD_SIZE;
664 	memblock_reserve(INITRD_START, INITRD_SIZE);
665 #endif
666 }
667 
668 /*
669  * Reserve the memory area used to pass the certificate lists
670  */
671 static void __init reserve_certificate_list(void)
672 {
673 	if (ipl_cert_list_addr)
674 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
675 }
676 
677 static void __init reserve_mem_detect_info(void)
678 {
679 	unsigned long start, size;
680 
681 	get_mem_detect_reserved(&start, &size);
682 	if (size)
683 		memblock_reserve(start, size);
684 }
685 
686 static void __init free_mem_detect_info(void)
687 {
688 	unsigned long start, size;
689 
690 	get_mem_detect_reserved(&start, &size);
691 	if (size)
692 		memblock_free(start, size);
693 }
694 
695 static const char * __init get_mem_info_source(void)
696 {
697 	switch (mem_detect.info_source) {
698 	case MEM_DETECT_SCLP_STOR_INFO:
699 		return "sclp storage info";
700 	case MEM_DETECT_DIAG260:
701 		return "diag260";
702 	case MEM_DETECT_SCLP_READ_INFO:
703 		return "sclp read info";
704 	case MEM_DETECT_BIN_SEARCH:
705 		return "binary search";
706 	}
707 	return "none";
708 }
709 
710 static void __init memblock_add_mem_detect_info(void)
711 {
712 	unsigned long start, end;
713 	int i;
714 
715 	pr_debug("physmem info source: %s (%hhd)\n",
716 		 get_mem_info_source(), mem_detect.info_source);
717 	/* keep memblock lists close to the kernel */
718 	memblock_set_bottom_up(true);
719 	for_each_mem_detect_block(i, &start, &end) {
720 		memblock_add(start, end - start);
721 		memblock_physmem_add(start, end - start);
722 	}
723 	memblock_set_bottom_up(false);
724 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
725 	memblock_dump_all();
726 }
727 
728 /*
729  * Check for initrd being in usable memory
730  */
731 static void __init check_initrd(void)
732 {
733 #ifdef CONFIG_BLK_DEV_INITRD
734 	if (INITRD_START && INITRD_SIZE &&
735 	    !memblock_is_region_memory(INITRD_START, INITRD_SIZE)) {
736 		pr_err("The initial RAM disk does not fit into the memory\n");
737 		memblock_free(INITRD_START, INITRD_SIZE);
738 		initrd_start = initrd_end = 0;
739 	}
740 #endif
741 }
742 
743 /*
744  * Reserve memory used for lowcore/command line/kernel image.
745  */
746 static void __init reserve_kernel(void)
747 {
748 	unsigned long start_pfn = PFN_UP(__pa(_end));
749 
750 	memblock_reserve(0, HEAD_END);
751 	memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
752 			 - (unsigned long)_stext);
753 	memblock_reserve(__sdma, __edma - __sdma);
754 }
755 
756 static void __init setup_memory(void)
757 {
758 	phys_addr_t start, end;
759 	u64 i;
760 
761 	/*
762 	 * Init storage key for present memory
763 	 */
764 	for_each_mem_range(i, &start, &end)
765 		storage_key_init_range(start, end);
766 
767 	psw_set_key(PAGE_DEFAULT_KEY);
768 
769 	/* Only cosmetics */
770 	memblock_enforce_memory_limit(memblock_end_of_DRAM());
771 }
772 
773 /*
774  * Setup hardware capabilities.
775  */
776 static int __init setup_hwcaps(void)
777 {
778 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
779 	struct cpuid cpu_id;
780 	int i;
781 
782 	/*
783 	 * The store facility list bits numbers as found in the principles
784 	 * of operation are numbered with bit 1UL<<31 as number 0 to
785 	 * bit 1UL<<0 as number 31.
786 	 *   Bit 0: instructions named N3, "backported" to esa-mode
787 	 *   Bit 2: z/Architecture mode is active
788 	 *   Bit 7: the store-facility-list-extended facility is installed
789 	 *   Bit 17: the message-security assist is installed
790 	 *   Bit 19: the long-displacement facility is installed
791 	 *   Bit 21: the extended-immediate facility is installed
792 	 *   Bit 22: extended-translation facility 3 is installed
793 	 *   Bit 30: extended-translation facility 3 enhancement facility
794 	 * These get translated to:
795 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
796 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
797 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
798 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
799 	 */
800 	for (i = 0; i < 6; i++)
801 		if (test_facility(stfl_bits[i]))
802 			elf_hwcap |= 1UL << i;
803 
804 	if (test_facility(22) && test_facility(30))
805 		elf_hwcap |= HWCAP_S390_ETF3EH;
806 
807 	/*
808 	 * Check for additional facilities with store-facility-list-extended.
809 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
810 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
811 	 * as stored by stfl, bits 32-xxx contain additional facilities.
812 	 * How many facility words are stored depends on the number of
813 	 * doublewords passed to the instruction. The additional facilities
814 	 * are:
815 	 *   Bit 42: decimal floating point facility is installed
816 	 *   Bit 44: perform floating point operation facility is installed
817 	 * translated to:
818 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
819 	 */
820 	if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
821 		elf_hwcap |= HWCAP_S390_DFP;
822 
823 	/*
824 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
825 	 */
826 	if (MACHINE_HAS_EDAT1)
827 		elf_hwcap |= HWCAP_S390_HPAGE;
828 
829 	/*
830 	 * 64-bit register support for 31-bit processes
831 	 * HWCAP_S390_HIGH_GPRS is bit 9.
832 	 */
833 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
834 
835 	/*
836 	 * Transactional execution support HWCAP_S390_TE is bit 10.
837 	 */
838 	if (MACHINE_HAS_TE)
839 		elf_hwcap |= HWCAP_S390_TE;
840 
841 	/*
842 	 * Vector extension HWCAP_S390_VXRS is bit 11. The Vector extension
843 	 * can be disabled with the "novx" parameter. Use MACHINE_HAS_VX
844 	 * instead of facility bit 129.
845 	 */
846 	if (MACHINE_HAS_VX) {
847 		elf_hwcap |= HWCAP_S390_VXRS;
848 		if (test_facility(134))
849 			elf_hwcap |= HWCAP_S390_VXRS_BCD;
850 		if (test_facility(135))
851 			elf_hwcap |= HWCAP_S390_VXRS_EXT;
852 		if (test_facility(148))
853 			elf_hwcap |= HWCAP_S390_VXRS_EXT2;
854 		if (test_facility(152))
855 			elf_hwcap |= HWCAP_S390_VXRS_PDE;
856 	}
857 	if (test_facility(150))
858 		elf_hwcap |= HWCAP_S390_SORT;
859 	if (test_facility(151))
860 		elf_hwcap |= HWCAP_S390_DFLT;
861 
862 	/*
863 	 * Guarded storage support HWCAP_S390_GS is bit 12.
864 	 */
865 	if (MACHINE_HAS_GS)
866 		elf_hwcap |= HWCAP_S390_GS;
867 
868 	get_cpu_id(&cpu_id);
869 	add_device_randomness(&cpu_id, sizeof(cpu_id));
870 	switch (cpu_id.machine) {
871 	case 0x2064:
872 	case 0x2066:
873 	default:	/* Use "z900" as default for 64 bit kernels. */
874 		strcpy(elf_platform, "z900");
875 		break;
876 	case 0x2084:
877 	case 0x2086:
878 		strcpy(elf_platform, "z990");
879 		break;
880 	case 0x2094:
881 	case 0x2096:
882 		strcpy(elf_platform, "z9-109");
883 		break;
884 	case 0x2097:
885 	case 0x2098:
886 		strcpy(elf_platform, "z10");
887 		break;
888 	case 0x2817:
889 	case 0x2818:
890 		strcpy(elf_platform, "z196");
891 		break;
892 	case 0x2827:
893 	case 0x2828:
894 		strcpy(elf_platform, "zEC12");
895 		break;
896 	case 0x2964:
897 	case 0x2965:
898 		strcpy(elf_platform, "z13");
899 		break;
900 	case 0x3906:
901 	case 0x3907:
902 		strcpy(elf_platform, "z14");
903 		break;
904 	case 0x8561:
905 	case 0x8562:
906 		strcpy(elf_platform, "z15");
907 		break;
908 	}
909 
910 	/*
911 	 * Virtualization support HWCAP_INT_SIE is bit 0.
912 	 */
913 	if (sclp.has_sief2)
914 		int_hwcap |= HWCAP_INT_SIE;
915 
916 	return 0;
917 }
918 arch_initcall(setup_hwcaps);
919 
920 /*
921  * Add system information as device randomness
922  */
923 static void __init setup_randomness(void)
924 {
925 	struct sysinfo_3_2_2 *vmms;
926 
927 	vmms = (struct sysinfo_3_2_2 *) memblock_phys_alloc(PAGE_SIZE,
928 							    PAGE_SIZE);
929 	if (!vmms)
930 		panic("Failed to allocate memory for sysinfo structure\n");
931 
932 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
933 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
934 	memblock_free((unsigned long) vmms, PAGE_SIZE);
935 }
936 
937 /*
938  * Find the correct size for the task_struct. This depends on
939  * the size of the struct fpu at the end of the thread_struct
940  * which is embedded in the task_struct.
941  */
942 static void __init setup_task_size(void)
943 {
944 	int task_size = sizeof(struct task_struct);
945 
946 	if (!MACHINE_HAS_VX) {
947 		task_size -= sizeof(__vector128) * __NUM_VXRS;
948 		task_size += sizeof(freg_t) * __NUM_FPRS;
949 	}
950 	arch_task_struct_size = task_size;
951 }
952 
953 /*
954  * Issue diagnose 318 to set the control program name and
955  * version codes.
956  */
957 static void __init setup_control_program_code(void)
958 {
959 	union diag318_info diag318_info = {
960 		.cpnc = CPNC_LINUX,
961 		.cpvc = 0,
962 	};
963 
964 	if (!sclp.has_diag318)
965 		return;
966 
967 	diag_stat_inc(DIAG_STAT_X318);
968 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
969 }
970 
971 /*
972  * Print the component list from the IPL report
973  */
974 static void __init log_component_list(void)
975 {
976 	struct ipl_rb_component_entry *ptr, *end;
977 	char *str;
978 
979 	if (!early_ipl_comp_list_addr)
980 		return;
981 	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
982 		pr_info("Linux is running with Secure-IPL enabled\n");
983 	else
984 		pr_info("Linux is running with Secure-IPL disabled\n");
985 	ptr = (void *) early_ipl_comp_list_addr;
986 	end = (void *) ptr + early_ipl_comp_list_size;
987 	pr_info("The IPL report contains the following components:\n");
988 	while (ptr < end) {
989 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
990 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
991 				str = "signed, verified";
992 			else
993 				str = "signed, verification failed";
994 		} else {
995 			str = "not signed";
996 		}
997 		pr_info("%016llx - %016llx (%s)\n",
998 			ptr->addr, ptr->addr + ptr->len, str);
999 		ptr++;
1000 	}
1001 }
1002 
1003 /*
1004  * Setup function called from init/main.c just after the banner
1005  * was printed.
1006  */
1007 
1008 void __init setup_arch(char **cmdline_p)
1009 {
1010         /*
1011          * print what head.S has found out about the machine
1012          */
1013 	if (MACHINE_IS_VM)
1014 		pr_info("Linux is running as a z/VM "
1015 			"guest operating system in 64-bit mode\n");
1016 	else if (MACHINE_IS_KVM)
1017 		pr_info("Linux is running under KVM in 64-bit mode\n");
1018 	else if (MACHINE_IS_LPAR)
1019 		pr_info("Linux is running natively in 64-bit mode\n");
1020 	else
1021 		pr_info("Linux is running as a guest in 64-bit mode\n");
1022 
1023 	log_component_list();
1024 
1025 	/* Have one command line that is parsed and saved in /proc/cmdline */
1026 	/* boot_command_line has been already set up in early.c */
1027 	*cmdline_p = boot_command_line;
1028 
1029         ROOT_DEV = Root_RAM0;
1030 
1031 	init_mm.start_code = (unsigned long) _text;
1032 	init_mm.end_code = (unsigned long) _etext;
1033 	init_mm.end_data = (unsigned long) _edata;
1034 	init_mm.brk = (unsigned long) _end;
1035 
1036 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
1037 		nospec_auto_detect();
1038 
1039 	jump_label_init();
1040 	parse_early_param();
1041 #ifdef CONFIG_CRASH_DUMP
1042 	/* Deactivate elfcorehdr= kernel parameter */
1043 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
1044 #endif
1045 
1046 	os_info_init();
1047 	setup_ipl();
1048 	setup_task_size();
1049 	setup_control_program_code();
1050 
1051 	/* Do some memory reservations *before* memory is added to memblock */
1052 	reserve_above_ident_map();
1053 	reserve_kernel();
1054 	reserve_initrd();
1055 	reserve_certificate_list();
1056 	reserve_mem_detect_info();
1057 	memblock_allow_resize();
1058 
1059 	/* Get information about *all* installed memory */
1060 	memblock_add_mem_detect_info();
1061 
1062 	free_mem_detect_info();
1063 
1064 	setup_uv();
1065 	setup_memory_end();
1066 	setup_memory();
1067 	dma_contiguous_reserve(ident_map_size);
1068 	vmcp_cma_reserve();
1069 	if (MACHINE_HAS_EDAT2)
1070 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1071 
1072 	check_initrd();
1073 	reserve_crashkernel();
1074 #ifdef CONFIG_CRASH_DUMP
1075 	/*
1076 	 * Be aware that smp_save_dump_cpus() triggers a system reset.
1077 	 * Therefore CPU and device initialization should be done afterwards.
1078 	 */
1079 	smp_save_dump_cpus();
1080 #endif
1081 
1082 	setup_resources();
1083 	setup_lowcore_dat_off();
1084 	smp_fill_possible_mask();
1085 	cpu_detect_mhz_feature();
1086         cpu_init();
1087 	numa_setup();
1088 	smp_detect_cpus();
1089 	topology_init_early();
1090 
1091 	/*
1092 	 * Create kernel page tables and switch to virtual addressing.
1093 	 */
1094         paging_init();
1095 
1096 	/*
1097 	 * After paging_init created the kernel page table, the new PSWs
1098 	 * in lowcore can now run with DAT enabled.
1099 	 */
1100 	setup_lowcore_dat_on();
1101 
1102         /* Setup default console */
1103 	conmode_default();
1104 	set_preferred_console();
1105 
1106 	apply_alternative_instructions();
1107 	if (IS_ENABLED(CONFIG_EXPOLINE))
1108 		nospec_init_branches();
1109 
1110 	/* Setup zfcp/nvme dump support */
1111 	setup_zfcpdump();
1112 
1113 	/* Add system specific data to the random pool */
1114 	setup_randomness();
1115 }
1116