xref: /openbmc/linux/arch/s390/kernel/setup.c (revision 2dec9e09)
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/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/uv.h>
78 #include <asm/asm-offsets.h>
79 #include "entry.h"
80 
81 /*
82  * Machine setup..
83  */
84 unsigned int console_mode = 0;
85 EXPORT_SYMBOL(console_mode);
86 
87 unsigned int console_devno = -1;
88 EXPORT_SYMBOL(console_devno);
89 
90 unsigned int console_irq = -1;
91 EXPORT_SYMBOL(console_irq);
92 
93 /*
94  * Some code and data needs to stay below 2 GB, even when the kernel would be
95  * relocated above 2 GB, because it has to use 31 bit addresses.
96  * Such code and data is part of the .amode31 section.
97  */
98 unsigned long __amode31_ref __samode31 = (unsigned long)&_samode31;
99 unsigned long __amode31_ref __eamode31 = (unsigned long)&_eamode31;
100 unsigned long __amode31_ref __stext_amode31 = (unsigned long)&_stext_amode31;
101 unsigned long __amode31_ref __etext_amode31 = (unsigned long)&_etext_amode31;
102 struct exception_table_entry __amode31_ref *__start_amode31_ex_table = _start_amode31_ex_table;
103 struct exception_table_entry __amode31_ref *__stop_amode31_ex_table = _stop_amode31_ex_table;
104 
105 /*
106  * Control registers CR2, CR5 and CR15 are initialized with addresses
107  * of tables that must be placed below 2G which is handled by the AMODE31
108  * sections.
109  * Because the AMODE31 sections are relocated below 2G at startup,
110  * the content of control registers CR2, CR5 and CR15 must be updated
111  * with new addresses after the relocation. The initial initialization of
112  * control registers occurs in head64.S and then gets updated again after AMODE31
113  * relocation. We must access the relevant AMODE31 tables indirectly via
114  * pointers placed in the .amode31.refs linker section. Those pointers get
115  * updated automatically during AMODE31 relocation and always contain a valid
116  * address within AMODE31 sections.
117  */
118 
119 static __amode31_data u32 __ctl_duct_amode31[16] __aligned(64);
120 
121 static __amode31_data u64 __ctl_aste_amode31[8] __aligned(64) = {
122 	[1] = 0xffffffffffffffff
123 };
124 
125 static __amode31_data u32 __ctl_duald_amode31[32] __aligned(128) = {
126 	0x80000000, 0, 0, 0,
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 };
135 
136 static __amode31_data u32 __ctl_linkage_stack_amode31[8] __aligned(64) = {
137 	0, 0, 0x89000000, 0,
138 	0, 0, 0x8a000000, 0
139 };
140 
141 static u64 __amode31_ref *__ctl_aste = __ctl_aste_amode31;
142 static u32 __amode31_ref *__ctl_duald = __ctl_duald_amode31;
143 static u32 __amode31_ref *__ctl_linkage_stack = __ctl_linkage_stack_amode31;
144 static u32 __amode31_ref *__ctl_duct = __ctl_duct_amode31;
145 
146 int __bootdata(noexec_disabled);
147 unsigned long __bootdata(ident_map_size);
148 struct mem_detect_info __bootdata(mem_detect);
149 struct initrd_data __bootdata(initrd_data);
150 
151 unsigned long __bootdata_preserved(__kaslr_offset);
152 unsigned long __bootdata(__amode31_base);
153 unsigned int __bootdata_preserved(zlib_dfltcc_support);
154 EXPORT_SYMBOL(zlib_dfltcc_support);
155 u64 __bootdata_preserved(stfle_fac_list[16]);
156 EXPORT_SYMBOL(stfle_fac_list);
157 u64 __bootdata_preserved(alt_stfle_fac_list[16]);
158 struct oldmem_data __bootdata_preserved(oldmem_data);
159 
160 unsigned long VMALLOC_START;
161 EXPORT_SYMBOL(VMALLOC_START);
162 
163 unsigned long VMALLOC_END;
164 EXPORT_SYMBOL(VMALLOC_END);
165 
166 struct page *vmemmap;
167 EXPORT_SYMBOL(vmemmap);
168 unsigned long vmemmap_size;
169 
170 unsigned long MODULES_VADDR;
171 unsigned long MODULES_END;
172 
173 /* An array with a pointer to the lowcore of every CPU. */
174 struct lowcore *lowcore_ptr[NR_CPUS];
175 EXPORT_SYMBOL(lowcore_ptr);
176 
177 DEFINE_STATIC_KEY_FALSE(cpu_has_bear);
178 
179 /*
180  * The Write Back bit position in the physaddr is given by the SLPC PCI.
181  * Leaving the mask zero always uses write through which is safe
182  */
183 unsigned long mio_wb_bit_mask __ro_after_init;
184 
185 /*
186  * This is set up by the setup-routine at boot-time
187  * for S390 need to find out, what we have to setup
188  * using address 0x10400 ...
189  */
190 
191 #include <asm/setup.h>
192 
193 /*
194  * condev= and conmode= setup parameter.
195  */
196 
197 static int __init condev_setup(char *str)
198 {
199 	int vdev;
200 
201 	vdev = simple_strtoul(str, &str, 0);
202 	if (vdev >= 0 && vdev < 65536) {
203 		console_devno = vdev;
204 		console_irq = -1;
205 	}
206 	return 1;
207 }
208 
209 __setup("condev=", condev_setup);
210 
211 static void __init set_preferred_console(void)
212 {
213 	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
214 		add_preferred_console("ttyS", 0, NULL);
215 	else if (CONSOLE_IS_3270)
216 		add_preferred_console("tty3270", 0, NULL);
217 	else if (CONSOLE_IS_VT220)
218 		add_preferred_console("ttysclp", 0, NULL);
219 	else if (CONSOLE_IS_HVC)
220 		add_preferred_console("hvc", 0, NULL);
221 }
222 
223 static int __init conmode_setup(char *str)
224 {
225 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
226 	if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
227                 SET_CONSOLE_SCLP;
228 #endif
229 #if defined(CONFIG_TN3215_CONSOLE)
230 	if (!strcmp(str, "3215"))
231 		SET_CONSOLE_3215;
232 #endif
233 #if defined(CONFIG_TN3270_CONSOLE)
234 	if (!strcmp(str, "3270"))
235 		SET_CONSOLE_3270;
236 #endif
237 	set_preferred_console();
238         return 1;
239 }
240 
241 __setup("conmode=", conmode_setup);
242 
243 static void __init conmode_default(void)
244 {
245 	char query_buffer[1024];
246 	char *ptr;
247 
248         if (MACHINE_IS_VM) {
249 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
250 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
251 		ptr = strstr(query_buffer, "SUBCHANNEL =");
252 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
253 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
254 		ptr = strstr(query_buffer, "CONMODE");
255 		/*
256 		 * Set the conmode to 3215 so that the device recognition
257 		 * will set the cu_type of the console to 3215. If the
258 		 * conmode is 3270 and we don't set it back then both
259 		 * 3215 and the 3270 driver will try to access the console
260 		 * device (3215 as console and 3270 as normal tty).
261 		 */
262 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
263 		if (ptr == NULL) {
264 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
265 			SET_CONSOLE_SCLP;
266 #endif
267 			return;
268 		}
269 		if (str_has_prefix(ptr + 8, "3270")) {
270 #if defined(CONFIG_TN3270_CONSOLE)
271 			SET_CONSOLE_3270;
272 #elif defined(CONFIG_TN3215_CONSOLE)
273 			SET_CONSOLE_3215;
274 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
275 			SET_CONSOLE_SCLP;
276 #endif
277 		} else if (str_has_prefix(ptr + 8, "3215")) {
278 #if defined(CONFIG_TN3215_CONSOLE)
279 			SET_CONSOLE_3215;
280 #elif defined(CONFIG_TN3270_CONSOLE)
281 			SET_CONSOLE_3270;
282 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
283 			SET_CONSOLE_SCLP;
284 #endif
285 		}
286 	} else if (MACHINE_IS_KVM) {
287 		if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
288 			SET_CONSOLE_VT220;
289 		else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
290 			SET_CONSOLE_SCLP;
291 		else
292 			SET_CONSOLE_HVC;
293 	} else {
294 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
295 		SET_CONSOLE_SCLP;
296 #endif
297 	}
298 }
299 
300 #ifdef CONFIG_CRASH_DUMP
301 static void __init setup_zfcpdump(void)
302 {
303 	if (!is_ipl_type_dump())
304 		return;
305 	if (oldmem_data.start)
306 		return;
307 	strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
308 	console_loglevel = 2;
309 }
310 #else
311 static inline void setup_zfcpdump(void) {}
312 #endif /* CONFIG_CRASH_DUMP */
313 
314  /*
315  * Reboot, halt and power_off stubs. They just call _machine_restart,
316  * _machine_halt or _machine_power_off.
317  */
318 
319 void machine_restart(char *command)
320 {
321 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
322 		/*
323 		 * Only unblank the console if we are called in enabled
324 		 * context or a bust_spinlocks cleared the way for us.
325 		 */
326 		console_unblank();
327 	_machine_restart(command);
328 }
329 
330 void machine_halt(void)
331 {
332 	if (!in_interrupt() || oops_in_progress)
333 		/*
334 		 * Only unblank the console if we are called in enabled
335 		 * context or a bust_spinlocks cleared the way for us.
336 		 */
337 		console_unblank();
338 	_machine_halt();
339 }
340 
341 void machine_power_off(void)
342 {
343 	if (!in_interrupt() || oops_in_progress)
344 		/*
345 		 * Only unblank the console if we are called in enabled
346 		 * context or a bust_spinlocks cleared the way for us.
347 		 */
348 		console_unblank();
349 	_machine_power_off();
350 }
351 
352 /*
353  * Dummy power off function.
354  */
355 void (*pm_power_off)(void) = machine_power_off;
356 EXPORT_SYMBOL_GPL(pm_power_off);
357 
358 void *restart_stack;
359 
360 unsigned long stack_alloc(void)
361 {
362 #ifdef CONFIG_VMAP_STACK
363 	void *ret;
364 
365 	ret = __vmalloc_node(THREAD_SIZE, THREAD_SIZE, THREADINFO_GFP,
366 			     NUMA_NO_NODE, __builtin_return_address(0));
367 	kmemleak_not_leak(ret);
368 	return (unsigned long)ret;
369 #else
370 	return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
371 #endif
372 }
373 
374 void stack_free(unsigned long stack)
375 {
376 #ifdef CONFIG_VMAP_STACK
377 	vfree((void *) stack);
378 #else
379 	free_pages(stack, THREAD_SIZE_ORDER);
380 #endif
381 }
382 
383 int __init arch_early_irq_init(void)
384 {
385 	unsigned long stack;
386 
387 	stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
388 	if (!stack)
389 		panic("Couldn't allocate async stack");
390 	S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
391 	return 0;
392 }
393 
394 void __init arch_call_rest_init(void)
395 {
396 	unsigned long stack;
397 
398 	stack = stack_alloc();
399 	if (!stack)
400 		panic("Couldn't allocate kernel stack");
401 	current->stack = (void *) stack;
402 #ifdef CONFIG_VMAP_STACK
403 	current->stack_vm_area = (void *) stack;
404 #endif
405 	set_task_stack_end_magic(current);
406 	stack += STACK_INIT_OFFSET;
407 	S390_lowcore.kernel_stack = stack;
408 	call_on_stack_noreturn(rest_init, stack);
409 }
410 
411 static void __init setup_lowcore_dat_off(void)
412 {
413 	unsigned long int_psw_mask = PSW_KERNEL_BITS;
414 	unsigned long mcck_stack;
415 	struct lowcore *lc;
416 
417 	if (IS_ENABLED(CONFIG_KASAN))
418 		int_psw_mask |= PSW_MASK_DAT;
419 
420 	/*
421 	 * Setup lowcore for boot cpu
422 	 */
423 	BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
424 	lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
425 	if (!lc)
426 		panic("%s: Failed to allocate %zu bytes align=%zx\n",
427 		      __func__, sizeof(*lc), sizeof(*lc));
428 
429 	lc->restart_psw.mask = PSW_KERNEL_BITS;
430 	lc->restart_psw.addr = (unsigned long) restart_int_handler;
431 	lc->external_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
432 	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
433 	lc->svc_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
434 	lc->svc_new_psw.addr = (unsigned long) system_call;
435 	lc->program_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
436 	lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
437 	lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
438 	lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
439 	lc->io_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
440 	lc->io_new_psw.addr = (unsigned long) io_int_handler;
441 	lc->clock_comparator = clock_comparator_max;
442 	lc->nodat_stack = ((unsigned long) &init_thread_union)
443 		+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
444 	lc->current_task = (unsigned long)&init_task;
445 	lc->lpp = LPP_MAGIC;
446 	lc->machine_flags = S390_lowcore.machine_flags;
447 	lc->preempt_count = S390_lowcore.preempt_count;
448 	nmi_alloc_mcesa_early(&lc->mcesad);
449 	lc->sys_enter_timer = S390_lowcore.sys_enter_timer;
450 	lc->exit_timer = S390_lowcore.exit_timer;
451 	lc->user_timer = S390_lowcore.user_timer;
452 	lc->system_timer = S390_lowcore.system_timer;
453 	lc->steal_timer = S390_lowcore.steal_timer;
454 	lc->last_update_timer = S390_lowcore.last_update_timer;
455 	lc->last_update_clock = S390_lowcore.last_update_clock;
456 
457 	/*
458 	 * Allocate the global restart stack which is the same for
459 	 * all CPUs in cast *one* of them does a PSW restart.
460 	 */
461 	restart_stack = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
462 	if (!restart_stack)
463 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
464 		      __func__, THREAD_SIZE, THREAD_SIZE);
465 	restart_stack += STACK_INIT_OFFSET;
466 
467 	/*
468 	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
469 	 * restart data to the absolute zero lowcore. This is necessary if
470 	 * PSW restart is done on an offline CPU that has lowcore zero.
471 	 */
472 	lc->restart_stack = (unsigned long) restart_stack;
473 	lc->restart_fn = (unsigned long) do_restart;
474 	lc->restart_data = 0;
475 	lc->restart_source = -1U;
476 
477 	put_abs_lowcore(restart_stack, lc->restart_stack);
478 	put_abs_lowcore(restart_fn, lc->restart_fn);
479 	put_abs_lowcore(restart_data, lc->restart_data);
480 	put_abs_lowcore(restart_source, lc->restart_source);
481 	put_abs_lowcore(restart_psw, lc->restart_psw);
482 
483 	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
484 	if (!mcck_stack)
485 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
486 		      __func__, THREAD_SIZE, THREAD_SIZE);
487 	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
488 
489 	lc->spinlock_lockval = arch_spin_lockval(0);
490 	lc->spinlock_index = 0;
491 	arch_spin_lock_setup(0);
492 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
493 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
494 	lc->preempt_count = PREEMPT_DISABLED;
495 
496 	set_prefix(__pa(lc));
497 	lowcore_ptr[0] = lc;
498 }
499 
500 static void __init setup_lowcore_dat_on(void)
501 {
502 	struct lowcore *lc = lowcore_ptr[0];
503 	int cr;
504 
505 	__ctl_clear_bit(0, 28);
506 	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
507 	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
508 	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
509 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
510 	__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
511 	__ctl_set_bit(0, 28);
512 	put_abs_lowcore(restart_flags, RESTART_FLAG_CTLREGS);
513 	put_abs_lowcore(program_new_psw, lc->program_new_psw);
514 	for (cr = 0; cr < ARRAY_SIZE(lc->cregs_save_area); cr++)
515 		put_abs_lowcore(cregs_save_area[cr], lc->cregs_save_area[cr]);
516 }
517 
518 static struct resource code_resource = {
519 	.name  = "Kernel code",
520 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
521 };
522 
523 static struct resource data_resource = {
524 	.name = "Kernel data",
525 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
526 };
527 
528 static struct resource bss_resource = {
529 	.name = "Kernel bss",
530 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
531 };
532 
533 static struct resource __initdata *standard_resources[] = {
534 	&code_resource,
535 	&data_resource,
536 	&bss_resource,
537 };
538 
539 static void __init setup_resources(void)
540 {
541 	struct resource *res, *std_res, *sub_res;
542 	phys_addr_t start, end;
543 	int j;
544 	u64 i;
545 
546 	code_resource.start = (unsigned long) _text;
547 	code_resource.end = (unsigned long) _etext - 1;
548 	data_resource.start = (unsigned long) _etext;
549 	data_resource.end = (unsigned long) _edata - 1;
550 	bss_resource.start = (unsigned long) __bss_start;
551 	bss_resource.end = (unsigned long) __bss_stop - 1;
552 
553 	for_each_mem_range(i, &start, &end) {
554 		res = memblock_alloc(sizeof(*res), 8);
555 		if (!res)
556 			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
557 			      __func__, sizeof(*res), 8);
558 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
559 
560 		res->name = "System RAM";
561 		res->start = start;
562 		/*
563 		 * In memblock, end points to the first byte after the
564 		 * range while in resourses, end points to the last byte in
565 		 * the range.
566 		 */
567 		res->end = end - 1;
568 		request_resource(&iomem_resource, res);
569 
570 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
571 			std_res = standard_resources[j];
572 			if (std_res->start < res->start ||
573 			    std_res->start > res->end)
574 				continue;
575 			if (std_res->end > res->end) {
576 				sub_res = memblock_alloc(sizeof(*sub_res), 8);
577 				if (!sub_res)
578 					panic("%s: Failed to allocate %zu bytes align=0x%x\n",
579 					      __func__, sizeof(*sub_res), 8);
580 				*sub_res = *std_res;
581 				sub_res->end = res->end;
582 				std_res->start = res->end + 1;
583 				request_resource(res, sub_res);
584 			} else {
585 				request_resource(res, std_res);
586 			}
587 		}
588 	}
589 #ifdef CONFIG_CRASH_DUMP
590 	/*
591 	 * Re-add removed crash kernel memory as reserved memory. This makes
592 	 * sure it will be mapped with the identity mapping and struct pages
593 	 * will be created, so it can be resized later on.
594 	 * However add it later since the crash kernel resource should not be
595 	 * part of the System RAM resource.
596 	 */
597 	if (crashk_res.end) {
598 		memblock_add_node(crashk_res.start, resource_size(&crashk_res),
599 				  0, MEMBLOCK_NONE);
600 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
601 		insert_resource(&iomem_resource, &crashk_res);
602 	}
603 #endif
604 }
605 
606 static void __init setup_memory_end(void)
607 {
608 	memblock_remove(ident_map_size, PHYS_ADDR_MAX - ident_map_size);
609 	max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
610 	pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
611 }
612 
613 #ifdef CONFIG_CRASH_DUMP
614 
615 /*
616  * When kdump is enabled, we have to ensure that no memory from the area
617  * [0 - crashkernel memory size] is set offline - it will be exchanged with
618  * the crashkernel memory region when kdump is triggered. The crashkernel
619  * memory region can never get offlined (pages are unmovable).
620  */
621 static int kdump_mem_notifier(struct notifier_block *nb,
622 			      unsigned long action, void *data)
623 {
624 	struct memory_notify *arg = data;
625 
626 	if (action != MEM_GOING_OFFLINE)
627 		return NOTIFY_OK;
628 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
629 		return NOTIFY_BAD;
630 	return NOTIFY_OK;
631 }
632 
633 static struct notifier_block kdump_mem_nb = {
634 	.notifier_call = kdump_mem_notifier,
635 };
636 
637 #endif
638 
639 /*
640  * Reserve memory for kdump kernel to be loaded with kexec
641  */
642 static void __init reserve_crashkernel(void)
643 {
644 #ifdef CONFIG_CRASH_DUMP
645 	unsigned long long crash_base, crash_size;
646 	phys_addr_t low, high;
647 	int rc;
648 
649 	rc = parse_crashkernel(boot_command_line, ident_map_size, &crash_size,
650 			       &crash_base);
651 
652 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
653 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
654 	if (rc || crash_size == 0)
655 		return;
656 
657 	if (memblock.memory.regions[0].size < crash_size) {
658 		pr_info("crashkernel reservation failed: %s\n",
659 			"first memory chunk must be at least crashkernel size");
660 		return;
661 	}
662 
663 	low = crash_base ?: oldmem_data.start;
664 	high = low + crash_size;
665 	if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
666 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
667 		crash_base = low;
668 	} else {
669 		/* Find suitable area in free memory */
670 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
671 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
672 
673 		if (crash_base && crash_base < low) {
674 			pr_info("crashkernel reservation failed: %s\n",
675 				"crash_base too low");
676 			return;
677 		}
678 		low = crash_base ?: low;
679 		crash_base = memblock_phys_alloc_range(crash_size,
680 						       KEXEC_CRASH_MEM_ALIGN,
681 						       low, high);
682 	}
683 
684 	if (!crash_base) {
685 		pr_info("crashkernel reservation failed: %s\n",
686 			"no suitable area found");
687 		return;
688 	}
689 
690 	if (register_memory_notifier(&kdump_mem_nb)) {
691 		memblock_phys_free(crash_base, crash_size);
692 		return;
693 	}
694 
695 	if (!oldmem_data.start && MACHINE_IS_VM)
696 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
697 	crashk_res.start = crash_base;
698 	crashk_res.end = crash_base + crash_size - 1;
699 	memblock_remove(crash_base, crash_size);
700 	pr_info("Reserving %lluMB of memory at %lluMB "
701 		"for crashkernel (System RAM: %luMB)\n",
702 		crash_size >> 20, crash_base >> 20,
703 		(unsigned long)memblock.memory.total_size >> 20);
704 	os_info_crashkernel_add(crash_base, crash_size);
705 #endif
706 }
707 
708 /*
709  * Reserve the initrd from being used by memblock
710  */
711 static void __init reserve_initrd(void)
712 {
713 #ifdef CONFIG_BLK_DEV_INITRD
714 	if (!initrd_data.start || !initrd_data.size)
715 		return;
716 	initrd_start = (unsigned long)__va(initrd_data.start);
717 	initrd_end = initrd_start + initrd_data.size;
718 	memblock_reserve(initrd_data.start, initrd_data.size);
719 #endif
720 }
721 
722 /*
723  * Reserve the memory area used to pass the certificate lists
724  */
725 static void __init reserve_certificate_list(void)
726 {
727 	if (ipl_cert_list_addr)
728 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
729 }
730 
731 static void __init reserve_mem_detect_info(void)
732 {
733 	unsigned long start, size;
734 
735 	get_mem_detect_reserved(&start, &size);
736 	if (size)
737 		memblock_reserve(start, size);
738 }
739 
740 static void __init free_mem_detect_info(void)
741 {
742 	unsigned long start, size;
743 
744 	get_mem_detect_reserved(&start, &size);
745 	if (size)
746 		memblock_phys_free(start, size);
747 }
748 
749 static const char * __init get_mem_info_source(void)
750 {
751 	switch (mem_detect.info_source) {
752 	case MEM_DETECT_SCLP_STOR_INFO:
753 		return "sclp storage info";
754 	case MEM_DETECT_DIAG260:
755 		return "diag260";
756 	case MEM_DETECT_SCLP_READ_INFO:
757 		return "sclp read info";
758 	case MEM_DETECT_BIN_SEARCH:
759 		return "binary search";
760 	}
761 	return "none";
762 }
763 
764 static void __init memblock_add_mem_detect_info(void)
765 {
766 	unsigned long start, end;
767 	int i;
768 
769 	pr_debug("physmem info source: %s (%hhd)\n",
770 		 get_mem_info_source(), mem_detect.info_source);
771 	/* keep memblock lists close to the kernel */
772 	memblock_set_bottom_up(true);
773 	for_each_mem_detect_block(i, &start, &end) {
774 		memblock_add(start, end - start);
775 		memblock_physmem_add(start, end - start);
776 	}
777 	memblock_set_bottom_up(false);
778 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
779 }
780 
781 /*
782  * Check for initrd being in usable memory
783  */
784 static void __init check_initrd(void)
785 {
786 #ifdef CONFIG_BLK_DEV_INITRD
787 	if (initrd_data.start && initrd_data.size &&
788 	    !memblock_is_region_memory(initrd_data.start, initrd_data.size)) {
789 		pr_err("The initial RAM disk does not fit into the memory\n");
790 		memblock_phys_free(initrd_data.start, initrd_data.size);
791 		initrd_start = initrd_end = 0;
792 	}
793 #endif
794 }
795 
796 /*
797  * Reserve memory used for lowcore/command line/kernel image.
798  */
799 static void __init reserve_kernel(void)
800 {
801 	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
802 	memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
803 	memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
804 	memblock_reserve(__amode31_base, __eamode31 - __samode31);
805 	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
806 	memblock_reserve(__pa(_stext), _end - _stext);
807 }
808 
809 static void __init setup_memory(void)
810 {
811 	phys_addr_t start, end;
812 	u64 i;
813 
814 	/*
815 	 * Init storage key for present memory
816 	 */
817 	for_each_mem_range(i, &start, &end)
818 		storage_key_init_range(start, end);
819 
820 	psw_set_key(PAGE_DEFAULT_KEY);
821 }
822 
823 static void __init relocate_amode31_section(void)
824 {
825 	unsigned long amode31_size = __eamode31 - __samode31;
826 	long amode31_offset = __amode31_base - __samode31;
827 	long *ptr;
828 
829 	pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
830 
831 	/* Move original AMODE31 section to the new one */
832 	memmove((void *)__amode31_base, (void *)__samode31, amode31_size);
833 	/* Zero out the old AMODE31 section to catch invalid accesses within it */
834 	memset((void *)__samode31, 0, amode31_size);
835 
836 	/* Update all AMODE31 region references */
837 	for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
838 		*ptr += amode31_offset;
839 }
840 
841 /* This must be called after AMODE31 relocation */
842 static void __init setup_cr(void)
843 {
844 	union ctlreg2 cr2;
845 	union ctlreg5 cr5;
846 	union ctlreg15 cr15;
847 
848 	__ctl_duct[1] = (unsigned long)__ctl_aste;
849 	__ctl_duct[2] = (unsigned long)__ctl_aste;
850 	__ctl_duct[4] = (unsigned long)__ctl_duald;
851 
852 	/* Update control registers CR2, CR5 and CR15 */
853 	__ctl_store(cr2.val, 2, 2);
854 	__ctl_store(cr5.val, 5, 5);
855 	__ctl_store(cr15.val, 15, 15);
856 	cr2.ducto = (unsigned long)__ctl_duct >> 6;
857 	cr5.pasteo = (unsigned long)__ctl_duct >> 6;
858 	cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
859 	__ctl_load(cr2.val, 2, 2);
860 	__ctl_load(cr5.val, 5, 5);
861 	__ctl_load(cr15.val, 15, 15);
862 }
863 
864 /*
865  * Add system information as device randomness
866  */
867 static void __init setup_randomness(void)
868 {
869 	struct sysinfo_3_2_2 *vmms;
870 
871 	vmms = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
872 	if (!vmms)
873 		panic("Failed to allocate memory for sysinfo structure\n");
874 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
875 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
876 	memblock_free(vmms, PAGE_SIZE);
877 
878 	if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG))
879 		static_branch_enable(&s390_arch_random_available);
880 }
881 
882 /*
883  * Find the correct size for the task_struct. This depends on
884  * the size of the struct fpu at the end of the thread_struct
885  * which is embedded in the task_struct.
886  */
887 static void __init setup_task_size(void)
888 {
889 	int task_size = sizeof(struct task_struct);
890 
891 	if (!MACHINE_HAS_VX) {
892 		task_size -= sizeof(__vector128) * __NUM_VXRS;
893 		task_size += sizeof(freg_t) * __NUM_FPRS;
894 	}
895 	arch_task_struct_size = task_size;
896 }
897 
898 /*
899  * Issue diagnose 318 to set the control program name and
900  * version codes.
901  */
902 static void __init setup_control_program_code(void)
903 {
904 	union diag318_info diag318_info = {
905 		.cpnc = CPNC_LINUX,
906 		.cpvc = 0,
907 	};
908 
909 	if (!sclp.has_diag318)
910 		return;
911 
912 	diag_stat_inc(DIAG_STAT_X318);
913 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
914 }
915 
916 /*
917  * Print the component list from the IPL report
918  */
919 static void __init log_component_list(void)
920 {
921 	struct ipl_rb_component_entry *ptr, *end;
922 	char *str;
923 
924 	if (!early_ipl_comp_list_addr)
925 		return;
926 	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
927 		pr_info("Linux is running with Secure-IPL enabled\n");
928 	else
929 		pr_info("Linux is running with Secure-IPL disabled\n");
930 	ptr = (void *) early_ipl_comp_list_addr;
931 	end = (void *) ptr + early_ipl_comp_list_size;
932 	pr_info("The IPL report contains the following components:\n");
933 	while (ptr < end) {
934 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
935 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
936 				str = "signed, verified";
937 			else
938 				str = "signed, verification failed";
939 		} else {
940 			str = "not signed";
941 		}
942 		pr_info("%016llx - %016llx (%s)\n",
943 			ptr->addr, ptr->addr + ptr->len, str);
944 		ptr++;
945 	}
946 }
947 
948 /*
949  * Setup function called from init/main.c just after the banner
950  * was printed.
951  */
952 
953 void __init setup_arch(char **cmdline_p)
954 {
955         /*
956          * print what head.S has found out about the machine
957          */
958 	if (MACHINE_IS_VM)
959 		pr_info("Linux is running as a z/VM "
960 			"guest operating system in 64-bit mode\n");
961 	else if (MACHINE_IS_KVM)
962 		pr_info("Linux is running under KVM in 64-bit mode\n");
963 	else if (MACHINE_IS_LPAR)
964 		pr_info("Linux is running natively in 64-bit mode\n");
965 	else
966 		pr_info("Linux is running as a guest in 64-bit mode\n");
967 
968 	log_component_list();
969 
970 	/* Have one command line that is parsed and saved in /proc/cmdline */
971 	/* boot_command_line has been already set up in early.c */
972 	*cmdline_p = boot_command_line;
973 
974         ROOT_DEV = Root_RAM0;
975 
976 	setup_initial_init_mm(_text, _etext, _edata, _end);
977 
978 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
979 		nospec_auto_detect();
980 
981 	jump_label_init();
982 	parse_early_param();
983 #ifdef CONFIG_CRASH_DUMP
984 	/* Deactivate elfcorehdr= kernel parameter */
985 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
986 #endif
987 
988 	os_info_init();
989 	setup_ipl();
990 	setup_task_size();
991 	setup_control_program_code();
992 
993 	/* Do some memory reservations *before* memory is added to memblock */
994 	reserve_kernel();
995 	reserve_initrd();
996 	reserve_certificate_list();
997 	reserve_mem_detect_info();
998 	memblock_set_current_limit(ident_map_size);
999 	memblock_allow_resize();
1000 
1001 	/* Get information about *all* installed memory */
1002 	memblock_add_mem_detect_info();
1003 
1004 	free_mem_detect_info();
1005 	setup_memory_end();
1006 	memblock_dump_all();
1007 	setup_memory();
1008 
1009 	relocate_amode31_section();
1010 	setup_cr();
1011 	setup_uv();
1012 	dma_contiguous_reserve(ident_map_size);
1013 	vmcp_cma_reserve();
1014 	if (MACHINE_HAS_EDAT2)
1015 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1016 
1017 	check_initrd();
1018 	reserve_crashkernel();
1019 #ifdef CONFIG_CRASH_DUMP
1020 	/*
1021 	 * Be aware that smp_save_dump_cpus() triggers a system reset.
1022 	 * Therefore CPU and device initialization should be done afterwards.
1023 	 */
1024 	smp_save_dump_cpus();
1025 #endif
1026 
1027 	setup_resources();
1028 	setup_lowcore_dat_off();
1029 	smp_fill_possible_mask();
1030 	cpu_detect_mhz_feature();
1031         cpu_init();
1032 	numa_setup();
1033 	smp_detect_cpus();
1034 	topology_init_early();
1035 
1036 	if (test_facility(193))
1037 		static_branch_enable(&cpu_has_bear);
1038 
1039 	/*
1040 	 * Create kernel page tables and switch to virtual addressing.
1041 	 */
1042         paging_init();
1043 
1044 	/*
1045 	 * After paging_init created the kernel page table, the new PSWs
1046 	 * in lowcore can now run with DAT enabled.
1047 	 */
1048 	setup_lowcore_dat_on();
1049 
1050         /* Setup default console */
1051 	conmode_default();
1052 	set_preferred_console();
1053 
1054 	apply_alternative_instructions();
1055 	if (IS_ENABLED(CONFIG_EXPOLINE))
1056 		nospec_init_branches();
1057 
1058 	/* Setup zfcp/nvme dump support */
1059 	setup_zfcpdump();
1060 
1061 	/* Add system specific data to the random pool */
1062 	setup_randomness();
1063 }
1064