xref: /openbmc/linux/arch/s390/kernel/setup.c (revision c0c45238)
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 	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 	put_abs_lowcore(restart_stack, lc->restart_stack);
485 	put_abs_lowcore(restart_fn, lc->restart_fn);
486 	put_abs_lowcore(restart_data, lc->restart_data);
487 	put_abs_lowcore(restart_source, lc->restart_source);
488 	put_abs_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->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
494 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
495 	lc->preempt_count = PREEMPT_DISABLED;
496 
497 	set_prefix((u32)(unsigned long) lc);
498 	lowcore_ptr[0] = lc;
499 }
500 
501 static void __init setup_lowcore_dat_on(void)
502 {
503 	struct lowcore *lc = lowcore_ptr[0];
504 	int cr;
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 	put_abs_lowcore(restart_flags, RESTART_FLAG_CTLREGS);
514 	put_abs_lowcore(program_new_psw, lc->program_new_psw);
515 	for (cr = 0; cr < ARRAY_SIZE(lc->cregs_save_area); cr++)
516 		put_abs_lowcore(cregs_save_area[cr], lc->cregs_save_area[cr]);
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, PHYS_ADDR_MAX - ident_map_size);
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  * Reserve memory for kdump kernel to be loaded with kexec
642  */
643 static void __init reserve_crashkernel(void)
644 {
645 #ifdef CONFIG_CRASH_DUMP
646 	unsigned long long crash_base, crash_size;
647 	phys_addr_t low, high;
648 	int rc;
649 
650 	rc = parse_crashkernel(boot_command_line, ident_map_size, &crash_size,
651 			       &crash_base);
652 
653 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
654 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
655 	if (rc || crash_size == 0)
656 		return;
657 
658 	if (memblock.memory.regions[0].size < crash_size) {
659 		pr_info("crashkernel reservation failed: %s\n",
660 			"first memory chunk must be at least crashkernel size");
661 		return;
662 	}
663 
664 	low = crash_base ?: oldmem_data.start;
665 	high = low + crash_size;
666 	if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
667 		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
668 		crash_base = low;
669 	} else {
670 		/* Find suitable area in free memory */
671 		low = max_t(unsigned long, crash_size, sclp.hsa_size);
672 		high = crash_base ? crash_base + crash_size : ULONG_MAX;
673 
674 		if (crash_base && crash_base < low) {
675 			pr_info("crashkernel reservation failed: %s\n",
676 				"crash_base too low");
677 			return;
678 		}
679 		low = crash_base ?: low;
680 		crash_base = memblock_phys_alloc_range(crash_size,
681 						       KEXEC_CRASH_MEM_ALIGN,
682 						       low, high);
683 	}
684 
685 	if (!crash_base) {
686 		pr_info("crashkernel reservation failed: %s\n",
687 			"no suitable area found");
688 		return;
689 	}
690 
691 	if (register_memory_notifier(&kdump_mem_nb)) {
692 		memblock_phys_free(crash_base, crash_size);
693 		return;
694 	}
695 
696 	if (!oldmem_data.start && MACHINE_IS_VM)
697 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
698 	crashk_res.start = crash_base;
699 	crashk_res.end = crash_base + crash_size - 1;
700 	memblock_remove(crash_base, crash_size);
701 	pr_info("Reserving %lluMB of memory at %lluMB "
702 		"for crashkernel (System RAM: %luMB)\n",
703 		crash_size >> 20, crash_base >> 20,
704 		(unsigned long)memblock.memory.total_size >> 20);
705 	os_info_crashkernel_add(crash_base, crash_size);
706 #endif
707 }
708 
709 /*
710  * Reserve the initrd from being used by memblock
711  */
712 static void __init reserve_initrd(void)
713 {
714 #ifdef CONFIG_BLK_DEV_INITRD
715 	if (!initrd_data.start || !initrd_data.size)
716 		return;
717 	initrd_start = (unsigned long)__va(initrd_data.start);
718 	initrd_end = initrd_start + initrd_data.size;
719 	memblock_reserve(initrd_data.start, initrd_data.size);
720 #endif
721 }
722 
723 /*
724  * Reserve the memory area used to pass the certificate lists
725  */
726 static void __init reserve_certificate_list(void)
727 {
728 	if (ipl_cert_list_addr)
729 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
730 }
731 
732 static void __init reserve_mem_detect_info(void)
733 {
734 	unsigned long start, size;
735 
736 	get_mem_detect_reserved(&start, &size);
737 	if (size)
738 		memblock_reserve(start, size);
739 }
740 
741 static void __init free_mem_detect_info(void)
742 {
743 	unsigned long start, size;
744 
745 	get_mem_detect_reserved(&start, &size);
746 	if (size)
747 		memblock_phys_free(start, size);
748 }
749 
750 static const char * __init get_mem_info_source(void)
751 {
752 	switch (mem_detect.info_source) {
753 	case MEM_DETECT_SCLP_STOR_INFO:
754 		return "sclp storage info";
755 	case MEM_DETECT_DIAG260:
756 		return "diag260";
757 	case MEM_DETECT_SCLP_READ_INFO:
758 		return "sclp read info";
759 	case MEM_DETECT_BIN_SEARCH:
760 		return "binary search";
761 	}
762 	return "none";
763 }
764 
765 static void __init memblock_add_mem_detect_info(void)
766 {
767 	unsigned long start, end;
768 	int i;
769 
770 	pr_debug("physmem info source: %s (%hhd)\n",
771 		 get_mem_info_source(), mem_detect.info_source);
772 	/* keep memblock lists close to the kernel */
773 	memblock_set_bottom_up(true);
774 	for_each_mem_detect_block(i, &start, &end) {
775 		memblock_add(start, end - start);
776 		memblock_physmem_add(start, end - start);
777 	}
778 	memblock_set_bottom_up(false);
779 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
780 }
781 
782 /*
783  * Check for initrd being in usable memory
784  */
785 static void __init check_initrd(void)
786 {
787 #ifdef CONFIG_BLK_DEV_INITRD
788 	if (initrd_data.start && initrd_data.size &&
789 	    !memblock_is_region_memory(initrd_data.start, initrd_data.size)) {
790 		pr_err("The initial RAM disk does not fit into the memory\n");
791 		memblock_phys_free(initrd_data.start, initrd_data.size);
792 		initrd_start = initrd_end = 0;
793 	}
794 #endif
795 }
796 
797 /*
798  * Reserve memory used for lowcore/command line/kernel image.
799  */
800 static void __init reserve_kernel(void)
801 {
802 	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
803 	memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
804 	memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
805 	memblock_reserve(__amode31_base, __eamode31 - __samode31);
806 	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
807 	memblock_reserve(__pa(_stext), _end - _stext);
808 }
809 
810 static void __init setup_memory(void)
811 {
812 	phys_addr_t start, end;
813 	u64 i;
814 
815 	/*
816 	 * Init storage key for present memory
817 	 */
818 	for_each_mem_range(i, &start, &end)
819 		storage_key_init_range(start, end);
820 
821 	psw_set_key(PAGE_DEFAULT_KEY);
822 }
823 
824 static void __init relocate_amode31_section(void)
825 {
826 	unsigned long amode31_size = __eamode31 - __samode31;
827 	long amode31_offset = __amode31_base - __samode31;
828 	long *ptr;
829 
830 	pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
831 
832 	/* Move original AMODE31 section to the new one */
833 	memmove((void *)__amode31_base, (void *)__samode31, amode31_size);
834 	/* Zero out the old AMODE31 section to catch invalid accesses within it */
835 	memset((void *)__samode31, 0, amode31_size);
836 
837 	/* Update all AMODE31 region references */
838 	for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
839 		*ptr += amode31_offset;
840 }
841 
842 /* This must be called after AMODE31 relocation */
843 static void __init setup_cr(void)
844 {
845 	union ctlreg2 cr2;
846 	union ctlreg5 cr5;
847 	union ctlreg15 cr15;
848 
849 	__ctl_duct[1] = (unsigned long)__ctl_aste;
850 	__ctl_duct[2] = (unsigned long)__ctl_aste;
851 	__ctl_duct[4] = (unsigned long)__ctl_duald;
852 
853 	/* Update control registers CR2, CR5 and CR15 */
854 	__ctl_store(cr2.val, 2, 2);
855 	__ctl_store(cr5.val, 5, 5);
856 	__ctl_store(cr15.val, 15, 15);
857 	cr2.ducto = (unsigned long)__ctl_duct >> 6;
858 	cr5.pasteo = (unsigned long)__ctl_duct >> 6;
859 	cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
860 	__ctl_load(cr2.val, 2, 2);
861 	__ctl_load(cr5.val, 5, 5);
862 	__ctl_load(cr15.val, 15, 15);
863 }
864 
865 /*
866  * Add system information as device randomness
867  */
868 static void __init setup_randomness(void)
869 {
870 	struct sysinfo_3_2_2 *vmms;
871 
872 	vmms = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
873 	if (!vmms)
874 		panic("Failed to allocate memory for sysinfo structure\n");
875 	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
876 		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
877 	memblock_free(vmms, PAGE_SIZE);
878 }
879 
880 /*
881  * Find the correct size for the task_struct. This depends on
882  * the size of the struct fpu at the end of the thread_struct
883  * which is embedded in the task_struct.
884  */
885 static void __init setup_task_size(void)
886 {
887 	int task_size = sizeof(struct task_struct);
888 
889 	if (!MACHINE_HAS_VX) {
890 		task_size -= sizeof(__vector128) * __NUM_VXRS;
891 		task_size += sizeof(freg_t) * __NUM_FPRS;
892 	}
893 	arch_task_struct_size = task_size;
894 }
895 
896 /*
897  * Issue diagnose 318 to set the control program name and
898  * version codes.
899  */
900 static void __init setup_control_program_code(void)
901 {
902 	union diag318_info diag318_info = {
903 		.cpnc = CPNC_LINUX,
904 		.cpvc = 0,
905 	};
906 
907 	if (!sclp.has_diag318)
908 		return;
909 
910 	diag_stat_inc(DIAG_STAT_X318);
911 	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
912 }
913 
914 /*
915  * Print the component list from the IPL report
916  */
917 static void __init log_component_list(void)
918 {
919 	struct ipl_rb_component_entry *ptr, *end;
920 	char *str;
921 
922 	if (!early_ipl_comp_list_addr)
923 		return;
924 	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
925 		pr_info("Linux is running with Secure-IPL enabled\n");
926 	else
927 		pr_info("Linux is running with Secure-IPL disabled\n");
928 	ptr = (void *) early_ipl_comp_list_addr;
929 	end = (void *) ptr + early_ipl_comp_list_size;
930 	pr_info("The IPL report contains the following components:\n");
931 	while (ptr < end) {
932 		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
933 			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
934 				str = "signed, verified";
935 			else
936 				str = "signed, verification failed";
937 		} else {
938 			str = "not signed";
939 		}
940 		pr_info("%016llx - %016llx (%s)\n",
941 			ptr->addr, ptr->addr + ptr->len, str);
942 		ptr++;
943 	}
944 }
945 
946 /*
947  * Setup function called from init/main.c just after the banner
948  * was printed.
949  */
950 
951 void __init setup_arch(char **cmdline_p)
952 {
953         /*
954          * print what head.S has found out about the machine
955          */
956 	if (MACHINE_IS_VM)
957 		pr_info("Linux is running as a z/VM "
958 			"guest operating system in 64-bit mode\n");
959 	else if (MACHINE_IS_KVM)
960 		pr_info("Linux is running under KVM in 64-bit mode\n");
961 	else if (MACHINE_IS_LPAR)
962 		pr_info("Linux is running natively in 64-bit mode\n");
963 	else
964 		pr_info("Linux is running as a guest in 64-bit mode\n");
965 
966 	log_component_list();
967 
968 	/* Have one command line that is parsed and saved in /proc/cmdline */
969 	/* boot_command_line has been already set up in early.c */
970 	*cmdline_p = boot_command_line;
971 
972         ROOT_DEV = Root_RAM0;
973 
974 	setup_initial_init_mm(_text, _etext, _edata, _end);
975 
976 	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
977 		nospec_auto_detect();
978 
979 	jump_label_init();
980 	parse_early_param();
981 #ifdef CONFIG_CRASH_DUMP
982 	/* Deactivate elfcorehdr= kernel parameter */
983 	elfcorehdr_addr = ELFCORE_ADDR_MAX;
984 #endif
985 
986 	os_info_init();
987 	setup_ipl();
988 	setup_task_size();
989 	setup_control_program_code();
990 
991 	/* Do some memory reservations *before* memory is added to memblock */
992 	reserve_kernel();
993 	reserve_initrd();
994 	reserve_certificate_list();
995 	reserve_mem_detect_info();
996 	memblock_set_current_limit(ident_map_size);
997 	memblock_allow_resize();
998 
999 	/* Get information about *all* installed memory */
1000 	memblock_add_mem_detect_info();
1001 
1002 	free_mem_detect_info();
1003 	setup_memory_end();
1004 	memblock_dump_all();
1005 	setup_memory();
1006 
1007 	relocate_amode31_section();
1008 	setup_cr();
1009 	setup_uv();
1010 	dma_contiguous_reserve(ident_map_size);
1011 	vmcp_cma_reserve();
1012 	if (MACHINE_HAS_EDAT2)
1013 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1014 
1015 	check_initrd();
1016 	reserve_crashkernel();
1017 #ifdef CONFIG_CRASH_DUMP
1018 	/*
1019 	 * Be aware that smp_save_dump_cpus() triggers a system reset.
1020 	 * Therefore CPU and device initialization should be done afterwards.
1021 	 */
1022 	smp_save_dump_cpus();
1023 #endif
1024 
1025 	setup_resources();
1026 	setup_lowcore_dat_off();
1027 	smp_fill_possible_mask();
1028 	cpu_detect_mhz_feature();
1029         cpu_init();
1030 	numa_setup();
1031 	smp_detect_cpus();
1032 	topology_init_early();
1033 
1034 	if (test_facility(193))
1035 		static_branch_enable(&cpu_has_bear);
1036 
1037 	/*
1038 	 * Create kernel page tables and switch to virtual addressing.
1039 	 */
1040         paging_init();
1041 
1042 	/*
1043 	 * After paging_init created the kernel page table, the new PSWs
1044 	 * in lowcore can now run with DAT enabled.
1045 	 */
1046 	setup_lowcore_dat_on();
1047 
1048         /* Setup default console */
1049 	conmode_default();
1050 	set_preferred_console();
1051 
1052 	apply_alternative_instructions();
1053 	if (IS_ENABLED(CONFIG_EXPOLINE))
1054 		nospec_init_branches();
1055 
1056 	/* Setup zfcp/nvme dump support */
1057 	setup_zfcpdump();
1058 
1059 	/* Add system specific data to the random pool */
1060 	setup_randomness();
1061 }
1062