xref: /openbmc/linux/arch/s390/kernel/setup.c (revision fe7498ef)
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_boot_cpu(lc);
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 	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
478 	if (!mcck_stack)
479 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
480 		      __func__, THREAD_SIZE, THREAD_SIZE);
481 	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
482 
483 	/* Setup absolute zero lowcore */
484 	mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
485 	mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
486 	mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
487 	mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
488 	mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
489 
490 	lc->spinlock_lockval = arch_spin_lockval(0);
491 	lc->spinlock_index = 0;
492 	arch_spin_lock_setup(0);
493 	lc->br_r1_trampoline = 0x07f1;	/* br %r1 */
494 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
495 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
496 	lc->preempt_count = PREEMPT_DISABLED;
497 
498 	set_prefix((u32)(unsigned long) lc);
499 	lowcore_ptr[0] = lc;
500 }
501 
502 static void __init setup_lowcore_dat_on(void)
503 {
504 	struct lowcore *lc = lowcore_ptr[0];
505 
506 	__ctl_clear_bit(0, 28);
507 	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
508 	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
509 	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
510 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
511 	__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
512 	__ctl_set_bit(0, 28);
513 	mem_assign_absolute(S390_lowcore.restart_flags, RESTART_FLAG_CTLREGS);
514 	mem_assign_absolute(S390_lowcore.program_new_psw, lc->program_new_psw);
515 	memcpy_absolute(&S390_lowcore.cregs_save_area, lc->cregs_save_area,
516 			sizeof(S390_lowcore.cregs_save_area));
517 }
518 
519 static struct resource code_resource = {
520 	.name  = "Kernel code",
521 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
522 };
523 
524 static struct resource data_resource = {
525 	.name = "Kernel data",
526 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
527 };
528 
529 static struct resource bss_resource = {
530 	.name = "Kernel bss",
531 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
532 };
533 
534 static struct resource __initdata *standard_resources[] = {
535 	&code_resource,
536 	&data_resource,
537 	&bss_resource,
538 };
539 
540 static void __init setup_resources(void)
541 {
542 	struct resource *res, *std_res, *sub_res;
543 	phys_addr_t start, end;
544 	int j;
545 	u64 i;
546 
547 	code_resource.start = (unsigned long) _text;
548 	code_resource.end = (unsigned long) _etext - 1;
549 	data_resource.start = (unsigned long) _etext;
550 	data_resource.end = (unsigned long) _edata - 1;
551 	bss_resource.start = (unsigned long) __bss_start;
552 	bss_resource.end = (unsigned long) __bss_stop - 1;
553 
554 	for_each_mem_range(i, &start, &end) {
555 		res = memblock_alloc(sizeof(*res), 8);
556 		if (!res)
557 			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
558 			      __func__, sizeof(*res), 8);
559 		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
560 
561 		res->name = "System RAM";
562 		res->start = start;
563 		/*
564 		 * In memblock, end points to the first byte after the
565 		 * range while in resourses, end points to the last byte in
566 		 * the range.
567 		 */
568 		res->end = end - 1;
569 		request_resource(&iomem_resource, res);
570 
571 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
572 			std_res = standard_resources[j];
573 			if (std_res->start < res->start ||
574 			    std_res->start > res->end)
575 				continue;
576 			if (std_res->end > res->end) {
577 				sub_res = memblock_alloc(sizeof(*sub_res), 8);
578 				if (!sub_res)
579 					panic("%s: Failed to allocate %zu bytes align=0x%x\n",
580 					      __func__, sizeof(*sub_res), 8);
581 				*sub_res = *std_res;
582 				sub_res->end = res->end;
583 				std_res->start = res->end + 1;
584 				request_resource(res, sub_res);
585 			} else {
586 				request_resource(res, std_res);
587 			}
588 		}
589 	}
590 #ifdef CONFIG_CRASH_DUMP
591 	/*
592 	 * Re-add removed crash kernel memory as reserved memory. This makes
593 	 * sure it will be mapped with the identity mapping and struct pages
594 	 * will be created, so it can be resized later on.
595 	 * However add it later since the crash kernel resource should not be
596 	 * part of the System RAM resource.
597 	 */
598 	if (crashk_res.end) {
599 		memblock_add_node(crashk_res.start, resource_size(&crashk_res),
600 				  0, MEMBLOCK_NONE);
601 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
602 		insert_resource(&iomem_resource, &crashk_res);
603 	}
604 #endif
605 }
606 
607 static void __init setup_memory_end(void)
608 {
609 	memblock_remove(ident_map_size, ULONG_MAX);
610 	max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
611 	pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
612 }
613 
614 #ifdef CONFIG_CRASH_DUMP
615 
616 /*
617  * When kdump is enabled, we have to ensure that no memory from the area
618  * [0 - crashkernel memory size] is set offline - it will be exchanged with
619  * the crashkernel memory region when kdump is triggered. The crashkernel
620  * memory region can never get offlined (pages are unmovable).
621  */
622 static int kdump_mem_notifier(struct notifier_block *nb,
623 			      unsigned long action, void *data)
624 {
625 	struct memory_notify *arg = data;
626 
627 	if (action != MEM_GOING_OFFLINE)
628 		return NOTIFY_OK;
629 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
630 		return NOTIFY_BAD;
631 	return NOTIFY_OK;
632 }
633 
634 static struct notifier_block kdump_mem_nb = {
635 	.notifier_call = kdump_mem_notifier,
636 };
637 
638 #endif
639 
640 /*
641  * Make sure that the area above identity mapping is protected
642  */
643 static void __init reserve_above_ident_map(void)
644 {
645 	memblock_reserve(ident_map_size, ULONG_MAX);
646 }
647 
648 /*
649  * Reserve memory for kdump kernel to be loaded with kexec
650  */
651 static void __init reserve_crashkernel(void)
652 {
653 #ifdef CONFIG_CRASH_DUMP
654 	unsigned long long crash_base, crash_size;
655 	phys_addr_t low, high;
656 	int rc;
657 
658 	rc = parse_crashkernel(boot_command_line, ident_map_size, &crash_size,
659 			       &crash_base);
660 
661 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
662 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
663 	if (rc || crash_size == 0)
664 		return;
665 
666 	if (memblock.memory.regions[0].size < crash_size) {
667 		pr_info("crashkernel reservation failed: %s\n",
668 			"first memory chunk must be at least crashkernel size");
669 		return;
670 	}
671 
672 	low = crash_base ?: oldmem_data.start;
673 	high = low + crash_size;
674 	if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
675 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
676 		crash_base = low;
677 	} else {
678 		/* Find suitable area in free memory */
679 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
680 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
681 
682 		if (crash_base && crash_base < low) {
683 			pr_info("crashkernel reservation failed: %s\n",
684 				"crash_base too low");
685 			return;
686 		}
687 		low = crash_base ?: low;
688 		crash_base = memblock_phys_alloc_range(crash_size,
689 						       KEXEC_CRASH_MEM_ALIGN,
690 						       low, high);
691 	}
692 
693 	if (!crash_base) {
694 		pr_info("crashkernel reservation failed: %s\n",
695 			"no suitable area found");
696 		return;
697 	}
698 
699 	if (register_memory_notifier(&kdump_mem_nb)) {
700 		memblock_phys_free(crash_base, crash_size);
701 		return;
702 	}
703 
704 	if (!oldmem_data.start && MACHINE_IS_VM)
705 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
706 	crashk_res.start = crash_base;
707 	crashk_res.end = crash_base + crash_size - 1;
708 	memblock_remove(crash_base, crash_size);
709 	pr_info("Reserving %lluMB of memory at %lluMB "
710 		"for crashkernel (System RAM: %luMB)\n",
711 		crash_size >> 20, crash_base >> 20,
712 		(unsigned long)memblock.memory.total_size >> 20);
713 	os_info_crashkernel_add(crash_base, crash_size);
714 #endif
715 }
716 
717 /*
718  * Reserve the initrd from being used by memblock
719  */
720 static void __init reserve_initrd(void)
721 {
722 #ifdef CONFIG_BLK_DEV_INITRD
723 	if (!initrd_data.start || !initrd_data.size)
724 		return;
725 	initrd_start = (unsigned long)__va(initrd_data.start);
726 	initrd_end = initrd_start + initrd_data.size;
727 	memblock_reserve(initrd_data.start, initrd_data.size);
728 #endif
729 }
730 
731 /*
732  * Reserve the memory area used to pass the certificate lists
733  */
734 static void __init reserve_certificate_list(void)
735 {
736 	if (ipl_cert_list_addr)
737 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
738 }
739 
740 static void __init reserve_mem_detect_info(void)
741 {
742 	unsigned long start, size;
743 
744 	get_mem_detect_reserved(&start, &size);
745 	if (size)
746 		memblock_reserve(start, size);
747 }
748 
749 static void __init free_mem_detect_info(void)
750 {
751 	unsigned long start, size;
752 
753 	get_mem_detect_reserved(&start, &size);
754 	if (size)
755 		memblock_phys_free(start, size);
756 }
757 
758 static const char * __init get_mem_info_source(void)
759 {
760 	switch (mem_detect.info_source) {
761 	case MEM_DETECT_SCLP_STOR_INFO:
762 		return "sclp storage info";
763 	case MEM_DETECT_DIAG260:
764 		return "diag260";
765 	case MEM_DETECT_SCLP_READ_INFO:
766 		return "sclp read info";
767 	case MEM_DETECT_BIN_SEARCH:
768 		return "binary search";
769 	}
770 	return "none";
771 }
772 
773 static void __init memblock_add_mem_detect_info(void)
774 {
775 	unsigned long start, end;
776 	int i;
777 
778 	pr_debug("physmem info source: %s (%hhd)\n",
779 		 get_mem_info_source(), mem_detect.info_source);
780 	/* keep memblock lists close to the kernel */
781 	memblock_set_bottom_up(true);
782 	for_each_mem_detect_block(i, &start, &end) {
783 		memblock_add(start, end - start);
784 		memblock_physmem_add(start, end - start);
785 	}
786 	memblock_set_bottom_up(false);
787 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
788 	memblock_dump_all();
789 }
790 
791 /*
792  * Check for initrd being in usable memory
793  */
794 static void __init check_initrd(void)
795 {
796 #ifdef CONFIG_BLK_DEV_INITRD
797 	if (initrd_data.start && initrd_data.size &&
798 	    !memblock_is_region_memory(initrd_data.start, initrd_data.size)) {
799 		pr_err("The initial RAM disk does not fit into the memory\n");
800 		memblock_phys_free(initrd_data.start, initrd_data.size);
801 		initrd_start = initrd_end = 0;
802 	}
803 #endif
804 }
805 
806 /*
807  * Reserve memory used for lowcore/command line/kernel image.
808  */
809 static void __init reserve_kernel(void)
810 {
811 	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
812 	memblock_reserve(__amode31_base, __eamode31 - __samode31);
813 	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
814 	memblock_reserve(__pa(_stext), _end - _stext);
815 }
816 
817 static void __init setup_memory(void)
818 {
819 	phys_addr_t start, end;
820 	u64 i;
821 
822 	/*
823 	 * Init storage key for present memory
824 	 */
825 	for_each_mem_range(i, &start, &end)
826 		storage_key_init_range(start, end);
827 
828 	psw_set_key(PAGE_DEFAULT_KEY);
829 
830 	/* Only cosmetics */
831 	memblock_enforce_memory_limit(memblock_end_of_DRAM());
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 
890 /*
891  * Find the correct size for the task_struct. This depends on
892  * the size of the struct fpu at the end of the thread_struct
893  * which is embedded in the task_struct.
894  */
895 static void __init setup_task_size(void)
896 {
897 	int task_size = sizeof(struct task_struct);
898 
899 	if (!MACHINE_HAS_VX) {
900 		task_size -= sizeof(__vector128) * __NUM_VXRS;
901 		task_size += sizeof(freg_t) * __NUM_FPRS;
902 	}
903 	arch_task_struct_size = task_size;
904 }
905 
906 /*
907  * Issue diagnose 318 to set the control program name and
908  * version codes.
909  */
910 static void __init setup_control_program_code(void)
911 {
912 	union diag318_info diag318_info = {
913 		.cpnc = CPNC_LINUX,
914 		.cpvc = 0,
915 	};
916 
917 	if (!sclp.has_diag318)
918 		return;
919 
920 	diag_stat_inc(DIAG_STAT_X318);
921 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
922 }
923 
924 /*
925  * Print the component list from the IPL report
926  */
927 static void __init log_component_list(void)
928 {
929 	struct ipl_rb_component_entry *ptr, *end;
930 	char *str;
931 
932 	if (!early_ipl_comp_list_addr)
933 		return;
934 	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
935 		pr_info("Linux is running with Secure-IPL enabled\n");
936 	else
937 		pr_info("Linux is running with Secure-IPL disabled\n");
938 	ptr = (void *) early_ipl_comp_list_addr;
939 	end = (void *) ptr + early_ipl_comp_list_size;
940 	pr_info("The IPL report contains the following components:\n");
941 	while (ptr < end) {
942 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
943 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
944 				str = "signed, verified";
945 			else
946 				str = "signed, verification failed";
947 		} else {
948 			str = "not signed";
949 		}
950 		pr_info("%016llx - %016llx (%s)\n",
951 			ptr->addr, ptr->addr + ptr->len, str);
952 		ptr++;
953 	}
954 }
955 
956 /*
957  * Setup function called from init/main.c just after the banner
958  * was printed.
959  */
960 
961 void __init setup_arch(char **cmdline_p)
962 {
963         /*
964          * print what head.S has found out about the machine
965          */
966 	if (MACHINE_IS_VM)
967 		pr_info("Linux is running as a z/VM "
968 			"guest operating system in 64-bit mode\n");
969 	else if (MACHINE_IS_KVM)
970 		pr_info("Linux is running under KVM in 64-bit mode\n");
971 	else if (MACHINE_IS_LPAR)
972 		pr_info("Linux is running natively in 64-bit mode\n");
973 	else
974 		pr_info("Linux is running as a guest in 64-bit mode\n");
975 
976 	log_component_list();
977 
978 	/* Have one command line that is parsed and saved in /proc/cmdline */
979 	/* boot_command_line has been already set up in early.c */
980 	*cmdline_p = boot_command_line;
981 
982         ROOT_DEV = Root_RAM0;
983 
984 	setup_initial_init_mm(_text, _etext, _edata, _end);
985 
986 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
987 		nospec_auto_detect();
988 
989 	jump_label_init();
990 	parse_early_param();
991 #ifdef CONFIG_CRASH_DUMP
992 	/* Deactivate elfcorehdr= kernel parameter */
993 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
994 #endif
995 
996 	os_info_init();
997 	setup_ipl();
998 	setup_task_size();
999 	setup_control_program_code();
1000 
1001 	/* Do some memory reservations *before* memory is added to memblock */
1002 	reserve_above_ident_map();
1003 	reserve_kernel();
1004 	reserve_initrd();
1005 	reserve_certificate_list();
1006 	reserve_mem_detect_info();
1007 	memblock_allow_resize();
1008 
1009 	/* Get information about *all* installed memory */
1010 	memblock_add_mem_detect_info();
1011 
1012 	free_mem_detect_info();
1013 
1014 	relocate_amode31_section();
1015 	setup_cr();
1016 
1017 	setup_uv();
1018 	setup_memory_end();
1019 	setup_memory();
1020 	dma_contiguous_reserve(ident_map_size);
1021 	vmcp_cma_reserve();
1022 	if (MACHINE_HAS_EDAT2)
1023 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1024 
1025 	check_initrd();
1026 	reserve_crashkernel();
1027 #ifdef CONFIG_CRASH_DUMP
1028 	/*
1029 	 * Be aware that smp_save_dump_cpus() triggers a system reset.
1030 	 * Therefore CPU and device initialization should be done afterwards.
1031 	 */
1032 	smp_save_dump_cpus();
1033 #endif
1034 
1035 	setup_resources();
1036 	setup_lowcore_dat_off();
1037 	smp_fill_possible_mask();
1038 	cpu_detect_mhz_feature();
1039         cpu_init();
1040 	numa_setup();
1041 	smp_detect_cpus();
1042 	topology_init_early();
1043 
1044 	if (test_facility(193))
1045 		static_branch_enable(&cpu_has_bear);
1046 
1047 	/*
1048 	 * Create kernel page tables and switch to virtual addressing.
1049 	 */
1050         paging_init();
1051 
1052 	/*
1053 	 * After paging_init created the kernel page table, the new PSWs
1054 	 * in lowcore can now run with DAT enabled.
1055 	 */
1056 	setup_lowcore_dat_on();
1057 
1058         /* Setup default console */
1059 	conmode_default();
1060 	set_preferred_console();
1061 
1062 	apply_alternative_instructions();
1063 	if (IS_ENABLED(CONFIG_EXPOLINE))
1064 		nospec_init_branches();
1065 
1066 	/* Setup zfcp/nvme dump support */
1067 	setup_zfcpdump();
1068 
1069 	/* Add system specific data to the random pool */
1070 	setup_randomness();
1071 }
1072