xref: /openbmc/linux/arch/s390/kernel/setup.c (revision ac73d4bf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  S390 version
4  *    Copyright IBM Corp. 1999, 2012
5  *    Author(s): Hartmut Penner (hp@de.ibm.com),
6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
7  *
8  *  Derived from "arch/i386/kernel/setup.c"
9  *    Copyright (C) 1995, Linus Torvalds
10  */
11 
12 /*
13  * This file handles the architecture-dependent parts of initialization
14  */
15 
16 #define KMSG_COMPONENT "setup"
17 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
18 
19 #include <linux/errno.h>
20 #include <linux/export.h>
21 #include <linux/sched.h>
22 #include <linux/sched/task.h>
23 #include <linux/cpu.h>
24 #include <linux/kernel.h>
25 #include <linux/memblock.h>
26 #include <linux/mm.h>
27 #include <linux/stddef.h>
28 #include <linux/unistd.h>
29 #include <linux/ptrace.h>
30 #include <linux/random.h>
31 #include <linux/user.h>
32 #include <linux/tty.h>
33 #include <linux/ioport.h>
34 #include <linux/delay.h>
35 #include <linux/init.h>
36 #include <linux/initrd.h>
37 #include <linux/root_dev.h>
38 #include <linux/console.h>
39 #include <linux/kernel_stat.h>
40 #include <linux/dma-map-ops.h>
41 #include <linux/device.h>
42 #include <linux/notifier.h>
43 #include <linux/pfn.h>
44 #include <linux/ctype.h>
45 #include <linux/reboot.h>
46 #include <linux/topology.h>
47 #include <linux/kexec.h>
48 #include <linux/crash_dump.h>
49 #include <linux/memory.h>
50 #include <linux/compat.h>
51 #include <linux/start_kernel.h>
52 #include <linux/hugetlb.h>
53 #include <linux/kmemleak.h>
54 
55 #include <asm/boot_data.h>
56 #include <asm/ipl.h>
57 #include <asm/facility.h>
58 #include <asm/smp.h>
59 #include <asm/mmu_context.h>
60 #include <asm/cpcmd.h>
61 #include <asm/abs_lowcore.h>
62 #include <asm/nmi.h>
63 #include <asm/irq.h>
64 #include <asm/page.h>
65 #include <asm/ptrace.h>
66 #include <asm/sections.h>
67 #include <asm/ebcdic.h>
68 #include <asm/diag.h>
69 #include <asm/os_info.h>
70 #include <asm/sclp.h>
71 #include <asm/stacktrace.h>
72 #include <asm/sysinfo.h>
73 #include <asm/numa.h>
74 #include <asm/alternative.h>
75 #include <asm/nospec-branch.h>
76 #include <asm/mem_detect.h>
77 #include <asm/maccess.h>
78 #include <asm/uv.h>
79 #include <asm/asm-offsets.h>
80 #include "entry.h"
81 
82 /*
83  * Machine setup..
84  */
85 unsigned int console_mode = 0;
86 EXPORT_SYMBOL(console_mode);
87 
88 unsigned int console_devno = -1;
89 EXPORT_SYMBOL(console_devno);
90 
91 unsigned int console_irq = -1;
92 EXPORT_SYMBOL(console_irq);
93 
94 /*
95  * Some code and data needs to stay below 2 GB, even when the kernel would be
96  * relocated above 2 GB, because it has to use 31 bit addresses.
97  * Such code and data is part of the .amode31 section.
98  */
99 unsigned long __amode31_ref __samode31 = (unsigned long)&_samode31;
100 unsigned long __amode31_ref __eamode31 = (unsigned long)&_eamode31;
101 unsigned long __amode31_ref __stext_amode31 = (unsigned long)&_stext_amode31;
102 unsigned long __amode31_ref __etext_amode31 = (unsigned long)&_etext_amode31;
103 struct exception_table_entry __amode31_ref *__start_amode31_ex_table = _start_amode31_ex_table;
104 struct exception_table_entry __amode31_ref *__stop_amode31_ex_table = _stop_amode31_ex_table;
105 
106 /*
107  * Control registers CR2, CR5 and CR15 are initialized with addresses
108  * of tables that must be placed below 2G which is handled by the AMODE31
109  * sections.
110  * Because the AMODE31 sections are relocated below 2G at startup,
111  * the content of control registers CR2, CR5 and CR15 must be updated
112  * with new addresses after the relocation. The initial initialization of
113  * control registers occurs in head64.S and then gets updated again after AMODE31
114  * relocation. We must access the relevant AMODE31 tables indirectly via
115  * pointers placed in the .amode31.refs linker section. Those pointers get
116  * updated automatically during AMODE31 relocation and always contain a valid
117  * address within AMODE31 sections.
118  */
119 
120 static __amode31_data u32 __ctl_duct_amode31[16] __aligned(64);
121 
122 static __amode31_data u64 __ctl_aste_amode31[8] __aligned(64) = {
123 	[1] = 0xffffffffffffffff
124 };
125 
126 static __amode31_data u32 __ctl_duald_amode31[32] __aligned(128) = {
127 	0x80000000, 0, 0, 0,
128 	0x80000000, 0, 0, 0,
129 	0x80000000, 0, 0, 0,
130 	0x80000000, 0, 0, 0,
131 	0x80000000, 0, 0, 0,
132 	0x80000000, 0, 0, 0,
133 	0x80000000, 0, 0, 0,
134 	0x80000000, 0, 0, 0
135 };
136 
137 static __amode31_data u32 __ctl_linkage_stack_amode31[8] __aligned(64) = {
138 	0, 0, 0x89000000, 0,
139 	0, 0, 0x8a000000, 0
140 };
141 
142 static u64 __amode31_ref *__ctl_aste = __ctl_aste_amode31;
143 static u32 __amode31_ref *__ctl_duald = __ctl_duald_amode31;
144 static u32 __amode31_ref *__ctl_linkage_stack = __ctl_linkage_stack_amode31;
145 static u32 __amode31_ref *__ctl_duct = __ctl_duct_amode31;
146 
147 int __bootdata(noexec_disabled);
148 unsigned long __bootdata(ident_map_size);
149 struct mem_detect_info __bootdata(mem_detect);
150 struct initrd_data __bootdata(initrd_data);
151 
152 unsigned long __bootdata_preserved(__kaslr_offset);
153 unsigned long __bootdata(__amode31_base);
154 unsigned int __bootdata_preserved(zlib_dfltcc_support);
155 EXPORT_SYMBOL(zlib_dfltcc_support);
156 u64 __bootdata_preserved(stfle_fac_list[16]);
157 EXPORT_SYMBOL(stfle_fac_list);
158 u64 __bootdata_preserved(alt_stfle_fac_list[16]);
159 struct oldmem_data __bootdata_preserved(oldmem_data);
160 
161 unsigned long VMALLOC_START;
162 EXPORT_SYMBOL(VMALLOC_START);
163 
164 unsigned long VMALLOC_END;
165 EXPORT_SYMBOL(VMALLOC_END);
166 
167 struct page *vmemmap;
168 EXPORT_SYMBOL(vmemmap);
169 unsigned long vmemmap_size;
170 
171 unsigned long MODULES_VADDR;
172 unsigned long MODULES_END;
173 
174 /* An array with a pointer to the lowcore of every CPU. */
175 struct lowcore *lowcore_ptr[NR_CPUS];
176 EXPORT_SYMBOL(lowcore_ptr);
177 
178 DEFINE_STATIC_KEY_FALSE(cpu_has_bear);
179 
180 /*
181  * The Write Back bit position in the physaddr is given by the SLPC PCI.
182  * Leaving the mask zero always uses write through which is safe
183  */
184 unsigned long mio_wb_bit_mask __ro_after_init;
185 
186 /*
187  * This is set up by the setup-routine at boot-time
188  * for S390 need to find out, what we have to setup
189  * using address 0x10400 ...
190  */
191 
192 #include <asm/setup.h>
193 
194 /*
195  * condev= and conmode= setup parameter.
196  */
197 
198 static int __init condev_setup(char *str)
199 {
200 	int vdev;
201 
202 	vdev = simple_strtoul(str, &str, 0);
203 	if (vdev >= 0 && vdev < 65536) {
204 		console_devno = vdev;
205 		console_irq = -1;
206 	}
207 	return 1;
208 }
209 
210 __setup("condev=", condev_setup);
211 
212 static void __init set_preferred_console(void)
213 {
214 	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
215 		add_preferred_console("ttyS", 0, NULL);
216 	else if (CONSOLE_IS_3270)
217 		add_preferred_console("tty3270", 0, NULL);
218 	else if (CONSOLE_IS_VT220)
219 		add_preferred_console("ttysclp", 0, NULL);
220 	else if (CONSOLE_IS_HVC)
221 		add_preferred_console("hvc", 0, NULL);
222 }
223 
224 static int __init conmode_setup(char *str)
225 {
226 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
227 	if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
228                 SET_CONSOLE_SCLP;
229 #endif
230 #if defined(CONFIG_TN3215_CONSOLE)
231 	if (!strcmp(str, "3215"))
232 		SET_CONSOLE_3215;
233 #endif
234 #if defined(CONFIG_TN3270_CONSOLE)
235 	if (!strcmp(str, "3270"))
236 		SET_CONSOLE_3270;
237 #endif
238 	set_preferred_console();
239         return 1;
240 }
241 
242 __setup("conmode=", conmode_setup);
243 
244 static void __init conmode_default(void)
245 {
246 	char query_buffer[1024];
247 	char *ptr;
248 
249         if (MACHINE_IS_VM) {
250 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
251 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
252 		ptr = strstr(query_buffer, "SUBCHANNEL =");
253 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
254 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
255 		ptr = strstr(query_buffer, "CONMODE");
256 		/*
257 		 * Set the conmode to 3215 so that the device recognition
258 		 * will set the cu_type of the console to 3215. If the
259 		 * conmode is 3270 and we don't set it back then both
260 		 * 3215 and the 3270 driver will try to access the console
261 		 * device (3215 as console and 3270 as normal tty).
262 		 */
263 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
264 		if (ptr == NULL) {
265 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
266 			SET_CONSOLE_SCLP;
267 #endif
268 			return;
269 		}
270 		if (str_has_prefix(ptr + 8, "3270")) {
271 #if defined(CONFIG_TN3270_CONSOLE)
272 			SET_CONSOLE_3270;
273 #elif defined(CONFIG_TN3215_CONSOLE)
274 			SET_CONSOLE_3215;
275 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
276 			SET_CONSOLE_SCLP;
277 #endif
278 		} else if (str_has_prefix(ptr + 8, "3215")) {
279 #if defined(CONFIG_TN3215_CONSOLE)
280 			SET_CONSOLE_3215;
281 #elif defined(CONFIG_TN3270_CONSOLE)
282 			SET_CONSOLE_3270;
283 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
284 			SET_CONSOLE_SCLP;
285 #endif
286 		}
287 	} else if (MACHINE_IS_KVM) {
288 		if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
289 			SET_CONSOLE_VT220;
290 		else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
291 			SET_CONSOLE_SCLP;
292 		else
293 			SET_CONSOLE_HVC;
294 	} else {
295 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
296 		SET_CONSOLE_SCLP;
297 #endif
298 	}
299 }
300 
301 #ifdef CONFIG_CRASH_DUMP
302 static void __init setup_zfcpdump(void)
303 {
304 	if (!is_ipl_type_dump())
305 		return;
306 	if (oldmem_data.start)
307 		return;
308 	strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
309 	console_loglevel = 2;
310 }
311 #else
312 static inline void setup_zfcpdump(void) {}
313 #endif /* CONFIG_CRASH_DUMP */
314 
315  /*
316  * Reboot, halt and power_off stubs. They just call _machine_restart,
317  * _machine_halt or _machine_power_off.
318  */
319 
320 void machine_restart(char *command)
321 {
322 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
323 		/*
324 		 * Only unblank the console if we are called in enabled
325 		 * context or a bust_spinlocks cleared the way for us.
326 		 */
327 		console_unblank();
328 	_machine_restart(command);
329 }
330 
331 void machine_halt(void)
332 {
333 	if (!in_interrupt() || oops_in_progress)
334 		/*
335 		 * Only unblank the console if we are called in enabled
336 		 * context or a bust_spinlocks cleared the way for us.
337 		 */
338 		console_unblank();
339 	_machine_halt();
340 }
341 
342 void machine_power_off(void)
343 {
344 	if (!in_interrupt() || oops_in_progress)
345 		/*
346 		 * Only unblank the console if we are called in enabled
347 		 * context or a bust_spinlocks cleared the way for us.
348 		 */
349 		console_unblank();
350 	_machine_power_off();
351 }
352 
353 /*
354  * Dummy power off function.
355  */
356 void (*pm_power_off)(void) = machine_power_off;
357 EXPORT_SYMBOL_GPL(pm_power_off);
358 
359 void *restart_stack;
360 
361 unsigned long stack_alloc(void)
362 {
363 #ifdef CONFIG_VMAP_STACK
364 	void *ret;
365 
366 	ret = __vmalloc_node(THREAD_SIZE, THREAD_SIZE, THREADINFO_GFP,
367 			     NUMA_NO_NODE, __builtin_return_address(0));
368 	kmemleak_not_leak(ret);
369 	return (unsigned long)ret;
370 #else
371 	return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
372 #endif
373 }
374 
375 void stack_free(unsigned long stack)
376 {
377 #ifdef CONFIG_VMAP_STACK
378 	vfree((void *) stack);
379 #else
380 	free_pages(stack, THREAD_SIZE_ORDER);
381 #endif
382 }
383 
384 int __init arch_early_irq_init(void)
385 {
386 	unsigned long stack;
387 
388 	stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
389 	if (!stack)
390 		panic("Couldn't allocate async stack");
391 	S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
392 	return 0;
393 }
394 
395 void __init arch_call_rest_init(void)
396 {
397 	unsigned long stack;
398 
399 	smp_reinit_ipl_cpu();
400 	stack = stack_alloc();
401 	if (!stack)
402 		panic("Couldn't allocate kernel stack");
403 	current->stack = (void *) stack;
404 #ifdef CONFIG_VMAP_STACK
405 	current->stack_vm_area = (void *) stack;
406 #endif
407 	set_task_stack_end_magic(current);
408 	stack += STACK_INIT_OFFSET;
409 	S390_lowcore.kernel_stack = stack;
410 	call_on_stack_noreturn(rest_init, stack);
411 }
412 
413 static void __init setup_lowcore_dat_off(void)
414 {
415 	unsigned long int_psw_mask = PSW_KERNEL_BITS;
416 	struct lowcore *abs_lc, *lc;
417 	unsigned long mcck_stack;
418 	unsigned long flags;
419 
420 	if (IS_ENABLED(CONFIG_KASAN))
421 		int_psw_mask |= PSW_MASK_DAT;
422 
423 	/*
424 	 * Setup lowcore for boot cpu
425 	 */
426 	BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
427 	lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
428 	if (!lc)
429 		panic("%s: Failed to allocate %zu bytes align=%zx\n",
430 		      __func__, sizeof(*lc), sizeof(*lc));
431 
432 	lc->restart_psw.mask = PSW_KERNEL_BITS;
433 	lc->restart_psw.addr = (unsigned long) restart_int_handler;
434 	lc->external_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
435 	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
436 	lc->svc_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
437 	lc->svc_new_psw.addr = (unsigned long) system_call;
438 	lc->program_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
439 	lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
440 	lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
441 	lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
442 	lc->io_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
443 	lc->io_new_psw.addr = (unsigned long) io_int_handler;
444 	lc->clock_comparator = clock_comparator_max;
445 	lc->nodat_stack = ((unsigned long) &init_thread_union)
446 		+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
447 	lc->current_task = (unsigned long)&init_task;
448 	lc->lpp = LPP_MAGIC;
449 	lc->machine_flags = S390_lowcore.machine_flags;
450 	lc->preempt_count = S390_lowcore.preempt_count;
451 	nmi_alloc_mcesa_early(&lc->mcesad);
452 	lc->sys_enter_timer = S390_lowcore.sys_enter_timer;
453 	lc->exit_timer = S390_lowcore.exit_timer;
454 	lc->user_timer = S390_lowcore.user_timer;
455 	lc->system_timer = S390_lowcore.system_timer;
456 	lc->steal_timer = S390_lowcore.steal_timer;
457 	lc->last_update_timer = S390_lowcore.last_update_timer;
458 	lc->last_update_clock = S390_lowcore.last_update_clock;
459 
460 	/*
461 	 * Allocate the global restart stack which is the same for
462 	 * all CPUs in cast *one* of them does a PSW restart.
463 	 */
464 	restart_stack = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
465 	if (!restart_stack)
466 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
467 		      __func__, THREAD_SIZE, THREAD_SIZE);
468 	restart_stack += STACK_INIT_OFFSET;
469 
470 	/*
471 	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
472 	 * restart data to the absolute zero lowcore. This is necessary if
473 	 * PSW restart is done on an offline CPU that has lowcore zero.
474 	 */
475 	lc->restart_stack = (unsigned long) restart_stack;
476 	lc->restart_fn = (unsigned long) do_restart;
477 	lc->restart_data = 0;
478 	lc->restart_source = -1U;
479 
480 	abs_lc = get_abs_lowcore(&flags);
481 	abs_lc->restart_stack = lc->restart_stack;
482 	abs_lc->restart_fn = lc->restart_fn;
483 	abs_lc->restart_data = lc->restart_data;
484 	abs_lc->restart_source = lc->restart_source;
485 	abs_lc->restart_psw = lc->restart_psw;
486 	abs_lc->mcesad = lc->mcesad;
487 	put_abs_lowcore(abs_lc, flags);
488 
489 	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
490 	if (!mcck_stack)
491 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
492 		      __func__, THREAD_SIZE, THREAD_SIZE);
493 	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
494 
495 	lc->spinlock_lockval = arch_spin_lockval(0);
496 	lc->spinlock_index = 0;
497 	arch_spin_lock_setup(0);
498 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
499 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
500 	lc->preempt_count = PREEMPT_DISABLED;
501 
502 	set_prefix(__pa(lc));
503 	lowcore_ptr[0] = lc;
504 }
505 
506 static void __init setup_lowcore_dat_on(void)
507 {
508 	struct lowcore *abs_lc;
509 	unsigned long flags;
510 
511 	__ctl_clear_bit(0, 28);
512 	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
513 	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
514 	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
515 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
516 	__ctl_set_bit(0, 28);
517 	__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
518 	if (abs_lowcore_map(0, lowcore_ptr[0], true))
519 		panic("Couldn't setup absolute lowcore");
520 	abs_lowcore_mapped = true;
521 	abs_lc = get_abs_lowcore(&flags);
522 	abs_lc->restart_flags = RESTART_FLAG_CTLREGS;
523 	abs_lc->program_new_psw = S390_lowcore.program_new_psw;
524 	memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area,
525 	       sizeof(abs_lc->cregs_save_area));
526 	put_abs_lowcore(abs_lc, flags);
527 }
528 
529 static struct resource code_resource = {
530 	.name  = "Kernel code",
531 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
532 };
533 
534 static struct resource data_resource = {
535 	.name = "Kernel data",
536 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
537 };
538 
539 static struct resource bss_resource = {
540 	.name = "Kernel bss",
541 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
542 };
543 
544 static struct resource __initdata *standard_resources[] = {
545 	&code_resource,
546 	&data_resource,
547 	&bss_resource,
548 };
549 
550 static void __init setup_resources(void)
551 {
552 	struct resource *res, *std_res, *sub_res;
553 	phys_addr_t start, end;
554 	int j;
555 	u64 i;
556 
557 	code_resource.start = (unsigned long) _text;
558 	code_resource.end = (unsigned long) _etext - 1;
559 	data_resource.start = (unsigned long) _etext;
560 	data_resource.end = (unsigned long) _edata - 1;
561 	bss_resource.start = (unsigned long) __bss_start;
562 	bss_resource.end = (unsigned long) __bss_stop - 1;
563 
564 	for_each_mem_range(i, &start, &end) {
565 		res = memblock_alloc(sizeof(*res), 8);
566 		if (!res)
567 			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
568 			      __func__, sizeof(*res), 8);
569 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
570 
571 		res->name = "System RAM";
572 		res->start = start;
573 		/*
574 		 * In memblock, end points to the first byte after the
575 		 * range while in resourses, end points to the last byte in
576 		 * the range.
577 		 */
578 		res->end = end - 1;
579 		request_resource(&iomem_resource, res);
580 
581 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
582 			std_res = standard_resources[j];
583 			if (std_res->start < res->start ||
584 			    std_res->start > res->end)
585 				continue;
586 			if (std_res->end > res->end) {
587 				sub_res = memblock_alloc(sizeof(*sub_res), 8);
588 				if (!sub_res)
589 					panic("%s: Failed to allocate %zu bytes align=0x%x\n",
590 					      __func__, sizeof(*sub_res), 8);
591 				*sub_res = *std_res;
592 				sub_res->end = res->end;
593 				std_res->start = res->end + 1;
594 				request_resource(res, sub_res);
595 			} else {
596 				request_resource(res, std_res);
597 			}
598 		}
599 	}
600 #ifdef CONFIG_CRASH_DUMP
601 	/*
602 	 * Re-add removed crash kernel memory as reserved memory. This makes
603 	 * sure it will be mapped with the identity mapping and struct pages
604 	 * will be created, so it can be resized later on.
605 	 * However add it later since the crash kernel resource should not be
606 	 * part of the System RAM resource.
607 	 */
608 	if (crashk_res.end) {
609 		memblock_add_node(crashk_res.start, resource_size(&crashk_res),
610 				  0, MEMBLOCK_NONE);
611 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
612 		insert_resource(&iomem_resource, &crashk_res);
613 	}
614 #endif
615 }
616 
617 static void __init setup_memory_end(void)
618 {
619 	memblock_remove(ident_map_size, PHYS_ADDR_MAX - ident_map_size);
620 	max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
621 	pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
622 }
623 
624 #ifdef CONFIG_CRASH_DUMP
625 
626 /*
627  * When kdump is enabled, we have to ensure that no memory from the area
628  * [0 - crashkernel memory size] is set offline - it will be exchanged with
629  * the crashkernel memory region when kdump is triggered. The crashkernel
630  * memory region can never get offlined (pages are unmovable).
631  */
632 static int kdump_mem_notifier(struct notifier_block *nb,
633 			      unsigned long action, void *data)
634 {
635 	struct memory_notify *arg = data;
636 
637 	if (action != MEM_GOING_OFFLINE)
638 		return NOTIFY_OK;
639 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
640 		return NOTIFY_BAD;
641 	return NOTIFY_OK;
642 }
643 
644 static struct notifier_block kdump_mem_nb = {
645 	.notifier_call = kdump_mem_notifier,
646 };
647 
648 #endif
649 
650 /*
651  * Reserve memory for kdump kernel to be loaded with kexec
652  */
653 static void __init reserve_crashkernel(void)
654 {
655 #ifdef CONFIG_CRASH_DUMP
656 	unsigned long long crash_base, crash_size;
657 	phys_addr_t low, high;
658 	int rc;
659 
660 	rc = parse_crashkernel(boot_command_line, ident_map_size, &crash_size,
661 			       &crash_base);
662 
663 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
664 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
665 	if (rc || crash_size == 0)
666 		return;
667 
668 	if (memblock.memory.regions[0].size < crash_size) {
669 		pr_info("crashkernel reservation failed: %s\n",
670 			"first memory chunk must be at least crashkernel size");
671 		return;
672 	}
673 
674 	low = crash_base ?: oldmem_data.start;
675 	high = low + crash_size;
676 	if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
677 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
678 		crash_base = low;
679 	} else {
680 		/* Find suitable area in free memory */
681 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
682 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
683 
684 		if (crash_base && crash_base < low) {
685 			pr_info("crashkernel reservation failed: %s\n",
686 				"crash_base too low");
687 			return;
688 		}
689 		low = crash_base ?: low;
690 		crash_base = memblock_phys_alloc_range(crash_size,
691 						       KEXEC_CRASH_MEM_ALIGN,
692 						       low, high);
693 	}
694 
695 	if (!crash_base) {
696 		pr_info("crashkernel reservation failed: %s\n",
697 			"no suitable area found");
698 		return;
699 	}
700 
701 	if (register_memory_notifier(&kdump_mem_nb)) {
702 		memblock_phys_free(crash_base, crash_size);
703 		return;
704 	}
705 
706 	if (!oldmem_data.start && MACHINE_IS_VM)
707 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
708 	crashk_res.start = crash_base;
709 	crashk_res.end = crash_base + crash_size - 1;
710 	memblock_remove(crash_base, crash_size);
711 	pr_info("Reserving %lluMB of memory at %lluMB "
712 		"for crashkernel (System RAM: %luMB)\n",
713 		crash_size >> 20, crash_base >> 20,
714 		(unsigned long)memblock.memory.total_size >> 20);
715 	os_info_crashkernel_add(crash_base, crash_size);
716 #endif
717 }
718 
719 /*
720  * Reserve the initrd from being used by memblock
721  */
722 static void __init reserve_initrd(void)
723 {
724 #ifdef CONFIG_BLK_DEV_INITRD
725 	if (!initrd_data.start || !initrd_data.size)
726 		return;
727 	initrd_start = (unsigned long)__va(initrd_data.start);
728 	initrd_end = initrd_start + initrd_data.size;
729 	memblock_reserve(initrd_data.start, initrd_data.size);
730 #endif
731 }
732 
733 /*
734  * Reserve the memory area used to pass the certificate lists
735  */
736 static void __init reserve_certificate_list(void)
737 {
738 	if (ipl_cert_list_addr)
739 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
740 }
741 
742 static void __init reserve_mem_detect_info(void)
743 {
744 	unsigned long start, size;
745 
746 	get_mem_detect_reserved(&start, &size);
747 	if (size)
748 		memblock_reserve(start, size);
749 }
750 
751 static void __init free_mem_detect_info(void)
752 {
753 	unsigned long start, size;
754 
755 	get_mem_detect_reserved(&start, &size);
756 	if (size)
757 		memblock_phys_free(start, size);
758 }
759 
760 static const char * __init get_mem_info_source(void)
761 {
762 	switch (mem_detect.info_source) {
763 	case MEM_DETECT_SCLP_STOR_INFO:
764 		return "sclp storage info";
765 	case MEM_DETECT_DIAG260:
766 		return "diag260";
767 	case MEM_DETECT_SCLP_READ_INFO:
768 		return "sclp read info";
769 	case MEM_DETECT_BIN_SEARCH:
770 		return "binary search";
771 	}
772 	return "none";
773 }
774 
775 static void __init memblock_add_mem_detect_info(void)
776 {
777 	unsigned long start, end;
778 	int i;
779 
780 	pr_debug("physmem info source: %s (%hhd)\n",
781 		 get_mem_info_source(), mem_detect.info_source);
782 	/* keep memblock lists close to the kernel */
783 	memblock_set_bottom_up(true);
784 	for_each_mem_detect_block(i, &start, &end) {
785 		memblock_add(start, end - start);
786 		memblock_physmem_add(start, end - start);
787 	}
788 	memblock_set_bottom_up(false);
789 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
790 }
791 
792 /*
793  * Check for initrd being in usable memory
794  */
795 static void __init check_initrd(void)
796 {
797 #ifdef CONFIG_BLK_DEV_INITRD
798 	if (initrd_data.start && initrd_data.size &&
799 	    !memblock_is_region_memory(initrd_data.start, initrd_data.size)) {
800 		pr_err("The initial RAM disk does not fit into the memory\n");
801 		memblock_phys_free(initrd_data.start, initrd_data.size);
802 		initrd_start = initrd_end = 0;
803 	}
804 #endif
805 }
806 
807 /*
808  * Reserve memory used for lowcore/command line/kernel image.
809  */
810 static void __init reserve_kernel(void)
811 {
812 	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
813 	memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
814 	memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
815 	memblock_reserve(__amode31_base, __eamode31 - __samode31);
816 	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
817 	memblock_reserve(__pa(_stext), _end - _stext);
818 }
819 
820 static void __init setup_memory(void)
821 {
822 	phys_addr_t start, end;
823 	u64 i;
824 
825 	/*
826 	 * Init storage key for present memory
827 	 */
828 	for_each_mem_range(i, &start, &end)
829 		storage_key_init_range(start, end);
830 
831 	psw_set_key(PAGE_DEFAULT_KEY);
832 }
833 
834 static void __init relocate_amode31_section(void)
835 {
836 	unsigned long amode31_size = __eamode31 - __samode31;
837 	long amode31_offset = __amode31_base - __samode31;
838 	long *ptr;
839 
840 	pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
841 
842 	/* Move original AMODE31 section to the new one */
843 	memmove((void *)__amode31_base, (void *)__samode31, amode31_size);
844 	/* Zero out the old AMODE31 section to catch invalid accesses within it */
845 	memset((void *)__samode31, 0, amode31_size);
846 
847 	/* Update all AMODE31 region references */
848 	for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
849 		*ptr += amode31_offset;
850 }
851 
852 /* This must be called after AMODE31 relocation */
853 static void __init setup_cr(void)
854 {
855 	union ctlreg2 cr2;
856 	union ctlreg5 cr5;
857 	union ctlreg15 cr15;
858 
859 	__ctl_duct[1] = (unsigned long)__ctl_aste;
860 	__ctl_duct[2] = (unsigned long)__ctl_aste;
861 	__ctl_duct[4] = (unsigned long)__ctl_duald;
862 
863 	/* Update control registers CR2, CR5 and CR15 */
864 	__ctl_store(cr2.val, 2, 2);
865 	__ctl_store(cr5.val, 5, 5);
866 	__ctl_store(cr15.val, 15, 15);
867 	cr2.ducto = (unsigned long)__ctl_duct >> 6;
868 	cr5.pasteo = (unsigned long)__ctl_duct >> 6;
869 	cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
870 	__ctl_load(cr2.val, 2, 2);
871 	__ctl_load(cr5.val, 5, 5);
872 	__ctl_load(cr15.val, 15, 15);
873 }
874 
875 /*
876  * Add system information as device randomness
877  */
878 static void __init setup_randomness(void)
879 {
880 	struct sysinfo_3_2_2 *vmms;
881 
882 	vmms = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
883 	if (!vmms)
884 		panic("Failed to allocate memory for sysinfo structure\n");
885 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
886 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
887 	memblock_free(vmms, PAGE_SIZE);
888 
889 	if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG))
890 		static_branch_enable(&s390_arch_random_available);
891 }
892 
893 /*
894  * Find the correct size for the task_struct. This depends on
895  * the size of the struct fpu at the end of the thread_struct
896  * which is embedded in the task_struct.
897  */
898 static void __init setup_task_size(void)
899 {
900 	int task_size = sizeof(struct task_struct);
901 
902 	if (!MACHINE_HAS_VX) {
903 		task_size -= sizeof(__vector128) * __NUM_VXRS;
904 		task_size += sizeof(freg_t) * __NUM_FPRS;
905 	}
906 	arch_task_struct_size = task_size;
907 }
908 
909 /*
910  * Issue diagnose 318 to set the control program name and
911  * version codes.
912  */
913 static void __init setup_control_program_code(void)
914 {
915 	union diag318_info diag318_info = {
916 		.cpnc = CPNC_LINUX,
917 		.cpvc = 0,
918 	};
919 
920 	if (!sclp.has_diag318)
921 		return;
922 
923 	diag_stat_inc(DIAG_STAT_X318);
924 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
925 }
926 
927 /*
928  * Print the component list from the IPL report
929  */
930 static void __init log_component_list(void)
931 {
932 	struct ipl_rb_component_entry *ptr, *end;
933 	char *str;
934 
935 	if (!early_ipl_comp_list_addr)
936 		return;
937 	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
938 		pr_info("Linux is running with Secure-IPL enabled\n");
939 	else
940 		pr_info("Linux is running with Secure-IPL disabled\n");
941 	ptr = (void *) early_ipl_comp_list_addr;
942 	end = (void *) ptr + early_ipl_comp_list_size;
943 	pr_info("The IPL report contains the following components:\n");
944 	while (ptr < end) {
945 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
946 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
947 				str = "signed, verified";
948 			else
949 				str = "signed, verification failed";
950 		} else {
951 			str = "not signed";
952 		}
953 		pr_info("%016llx - %016llx (%s)\n",
954 			ptr->addr, ptr->addr + ptr->len, str);
955 		ptr++;
956 	}
957 }
958 
959 /*
960  * Setup function called from init/main.c just after the banner
961  * was printed.
962  */
963 
964 void __init setup_arch(char **cmdline_p)
965 {
966         /*
967          * print what head.S has found out about the machine
968          */
969 	if (MACHINE_IS_VM)
970 		pr_info("Linux is running as a z/VM "
971 			"guest operating system in 64-bit mode\n");
972 	else if (MACHINE_IS_KVM)
973 		pr_info("Linux is running under KVM in 64-bit mode\n");
974 	else if (MACHINE_IS_LPAR)
975 		pr_info("Linux is running natively in 64-bit mode\n");
976 	else
977 		pr_info("Linux is running as a guest in 64-bit mode\n");
978 
979 	log_component_list();
980 
981 	/* Have one command line that is parsed and saved in /proc/cmdline */
982 	/* boot_command_line has been already set up in early.c */
983 	*cmdline_p = boot_command_line;
984 
985         ROOT_DEV = Root_RAM0;
986 
987 	setup_initial_init_mm(_text, _etext, _edata, _end);
988 
989 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
990 		nospec_auto_detect();
991 
992 	jump_label_init();
993 	parse_early_param();
994 #ifdef CONFIG_CRASH_DUMP
995 	/* Deactivate elfcorehdr= kernel parameter */
996 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
997 #endif
998 
999 	os_info_init();
1000 	setup_ipl();
1001 	setup_task_size();
1002 	setup_control_program_code();
1003 
1004 	/* Do some memory reservations *before* memory is added to memblock */
1005 	reserve_kernel();
1006 	reserve_initrd();
1007 	reserve_certificate_list();
1008 	reserve_mem_detect_info();
1009 	memblock_set_current_limit(ident_map_size);
1010 	memblock_allow_resize();
1011 
1012 	/* Get information about *all* installed memory */
1013 	memblock_add_mem_detect_info();
1014 
1015 	free_mem_detect_info();
1016 	setup_memory_end();
1017 	memblock_dump_all();
1018 	setup_memory();
1019 
1020 	relocate_amode31_section();
1021 	setup_cr();
1022 	setup_uv();
1023 	dma_contiguous_reserve(ident_map_size);
1024 	vmcp_cma_reserve();
1025 	if (MACHINE_HAS_EDAT2)
1026 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1027 
1028 	check_initrd();
1029 	reserve_crashkernel();
1030 #ifdef CONFIG_CRASH_DUMP
1031 	/*
1032 	 * Be aware that smp_save_dump_secondary_cpus() triggers a system reset.
1033 	 * Therefore CPU and device initialization should be done afterwards.
1034 	 */
1035 	smp_save_dump_secondary_cpus();
1036 #endif
1037 
1038 	setup_resources();
1039 	setup_lowcore_dat_off();
1040 	smp_fill_possible_mask();
1041 	cpu_detect_mhz_feature();
1042         cpu_init();
1043 	numa_setup();
1044 	smp_detect_cpus();
1045 	topology_init_early();
1046 
1047 	if (test_facility(193))
1048 		static_branch_enable(&cpu_has_bear);
1049 
1050 	/*
1051 	 * Create kernel page tables and switch to virtual addressing.
1052 	 */
1053         paging_init();
1054 	memcpy_real_init();
1055 	/*
1056 	 * After paging_init created the kernel page table, the new PSWs
1057 	 * in lowcore can now run with DAT enabled.
1058 	 */
1059 	setup_lowcore_dat_on();
1060 #ifdef CONFIG_CRASH_DUMP
1061 	smp_save_dump_ipl_cpu();
1062 #endif
1063 
1064         /* Setup default console */
1065 	conmode_default();
1066 	set_preferred_console();
1067 
1068 	apply_alternative_instructions();
1069 	if (IS_ENABLED(CONFIG_EXPOLINE))
1070 		nospec_init_branches();
1071 
1072 	/* Setup zfcp/nvme dump support */
1073 	setup_zfcpdump();
1074 
1075 	/* Add system specific data to the random pool */
1076 	setup_randomness();
1077 }
1078