xref: /openbmc/linux/arch/s390/kernel/setup.c (revision 615c36f5)
1 /*
2  *  arch/s390/kernel/setup.c
3  *
4  *  S390 version
5  *    Copyright (C) IBM Corp. 1999,2010
6  *    Author(s): Hartmut Penner (hp@de.ibm.com),
7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
8  *
9  *  Derived from "arch/i386/kernel/setup.c"
10  *    Copyright (C) 1995, Linus Torvalds
11  */
12 
13 /*
14  * This file handles the architecture-dependent parts of initialization
15  */
16 
17 #define KMSG_COMPONENT "setup"
18 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
19 
20 #include <linux/errno.h>
21 #include <linux/module.h>
22 #include <linux/sched.h>
23 #include <linux/kernel.h>
24 #include <linux/mm.h>
25 #include <linux/stddef.h>
26 #include <linux/unistd.h>
27 #include <linux/ptrace.h>
28 #include <linux/user.h>
29 #include <linux/tty.h>
30 #include <linux/ioport.h>
31 #include <linux/delay.h>
32 #include <linux/init.h>
33 #include <linux/initrd.h>
34 #include <linux/bootmem.h>
35 #include <linux/root_dev.h>
36 #include <linux/console.h>
37 #include <linux/kernel_stat.h>
38 #include <linux/device.h>
39 #include <linux/notifier.h>
40 #include <linux/pfn.h>
41 #include <linux/ctype.h>
42 #include <linux/reboot.h>
43 #include <linux/topology.h>
44 #include <linux/ftrace.h>
45 #include <linux/kexec.h>
46 #include <linux/crash_dump.h>
47 #include <linux/memory.h>
48 
49 #include <asm/ipl.h>
50 #include <asm/uaccess.h>
51 #include <asm/system.h>
52 #include <asm/smp.h>
53 #include <asm/mmu_context.h>
54 #include <asm/cpcmd.h>
55 #include <asm/lowcore.h>
56 #include <asm/irq.h>
57 #include <asm/page.h>
58 #include <asm/ptrace.h>
59 #include <asm/sections.h>
60 #include <asm/ebcdic.h>
61 #include <asm/compat.h>
62 #include <asm/kvm_virtio.h>
63 #include <asm/diag.h>
64 
65 long psw_kernel_bits	= PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_PRIMARY |
66 			  PSW_MASK_EA | PSW_MASK_BA;
67 long psw_user_bits	= PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT |
68 			  PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_MCHECK |
69 			  PSW_MASK_PSTATE | PSW_ASC_HOME;
70 
71 /*
72  * User copy operations.
73  */
74 struct uaccess_ops uaccess;
75 EXPORT_SYMBOL(uaccess);
76 
77 /*
78  * Machine setup..
79  */
80 unsigned int console_mode = 0;
81 EXPORT_SYMBOL(console_mode);
82 
83 unsigned int console_devno = -1;
84 EXPORT_SYMBOL(console_devno);
85 
86 unsigned int console_irq = -1;
87 EXPORT_SYMBOL(console_irq);
88 
89 unsigned long elf_hwcap = 0;
90 char elf_platform[ELF_PLATFORM_SIZE];
91 
92 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
93 
94 int __initdata memory_end_set;
95 unsigned long __initdata memory_end;
96 
97 /* An array with a pointer to the lowcore of every CPU. */
98 struct _lowcore *lowcore_ptr[NR_CPUS];
99 EXPORT_SYMBOL(lowcore_ptr);
100 
101 /*
102  * This is set up by the setup-routine at boot-time
103  * for S390 need to find out, what we have to setup
104  * using address 0x10400 ...
105  */
106 
107 #include <asm/setup.h>
108 
109 /*
110  * condev= and conmode= setup parameter.
111  */
112 
113 static int __init condev_setup(char *str)
114 {
115 	int vdev;
116 
117 	vdev = simple_strtoul(str, &str, 0);
118 	if (vdev >= 0 && vdev < 65536) {
119 		console_devno = vdev;
120 		console_irq = -1;
121 	}
122 	return 1;
123 }
124 
125 __setup("condev=", condev_setup);
126 
127 static void __init set_preferred_console(void)
128 {
129 	if (MACHINE_IS_KVM)
130 		add_preferred_console("hvc", 0, NULL);
131 	else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
132 		add_preferred_console("ttyS", 0, NULL);
133 	else if (CONSOLE_IS_3270)
134 		add_preferred_console("tty3270", 0, NULL);
135 }
136 
137 static int __init conmode_setup(char *str)
138 {
139 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
140 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
141                 SET_CONSOLE_SCLP;
142 #endif
143 #if defined(CONFIG_TN3215_CONSOLE)
144 	if (strncmp(str, "3215", 5) == 0)
145 		SET_CONSOLE_3215;
146 #endif
147 #if defined(CONFIG_TN3270_CONSOLE)
148 	if (strncmp(str, "3270", 5) == 0)
149 		SET_CONSOLE_3270;
150 #endif
151 	set_preferred_console();
152         return 1;
153 }
154 
155 __setup("conmode=", conmode_setup);
156 
157 static void __init conmode_default(void)
158 {
159 	char query_buffer[1024];
160 	char *ptr;
161 
162         if (MACHINE_IS_VM) {
163 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
164 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
165 		ptr = strstr(query_buffer, "SUBCHANNEL =");
166 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
167 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
168 		ptr = strstr(query_buffer, "CONMODE");
169 		/*
170 		 * Set the conmode to 3215 so that the device recognition
171 		 * will set the cu_type of the console to 3215. If the
172 		 * conmode is 3270 and we don't set it back then both
173 		 * 3215 and the 3270 driver will try to access the console
174 		 * device (3215 as console and 3270 as normal tty).
175 		 */
176 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
177 		if (ptr == NULL) {
178 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
179 			SET_CONSOLE_SCLP;
180 #endif
181 			return;
182 		}
183 		if (strncmp(ptr + 8, "3270", 4) == 0) {
184 #if defined(CONFIG_TN3270_CONSOLE)
185 			SET_CONSOLE_3270;
186 #elif defined(CONFIG_TN3215_CONSOLE)
187 			SET_CONSOLE_3215;
188 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
189 			SET_CONSOLE_SCLP;
190 #endif
191 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
192 #if defined(CONFIG_TN3215_CONSOLE)
193 			SET_CONSOLE_3215;
194 #elif defined(CONFIG_TN3270_CONSOLE)
195 			SET_CONSOLE_3270;
196 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
197 			SET_CONSOLE_SCLP;
198 #endif
199 		}
200 	} else {
201 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
202 		SET_CONSOLE_SCLP;
203 #endif
204 	}
205 }
206 
207 #ifdef CONFIG_ZFCPDUMP
208 static void __init setup_zfcpdump(unsigned int console_devno)
209 {
210 	static char str[41];
211 
212 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
213 		return;
214 	if (console_devno != -1)
215 		sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
216 			ipl_info.data.fcp.dev_id.devno, console_devno);
217 	else
218 		sprintf(str, " cio_ignore=all,!0.0.%04x",
219 			ipl_info.data.fcp.dev_id.devno);
220 	strcat(boot_command_line, str);
221 	console_loglevel = 2;
222 }
223 #else
224 static inline void setup_zfcpdump(unsigned int console_devno) {}
225 #endif /* CONFIG_ZFCPDUMP */
226 
227  /*
228  * Reboot, halt and power_off stubs. They just call _machine_restart,
229  * _machine_halt or _machine_power_off.
230  */
231 
232 void machine_restart(char *command)
233 {
234 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
235 		/*
236 		 * Only unblank the console if we are called in enabled
237 		 * context or a bust_spinlocks cleared the way for us.
238 		 */
239 		console_unblank();
240 	_machine_restart(command);
241 }
242 
243 void machine_halt(void)
244 {
245 	if (!in_interrupt() || oops_in_progress)
246 		/*
247 		 * Only unblank the console if we are called in enabled
248 		 * context or a bust_spinlocks cleared the way for us.
249 		 */
250 		console_unblank();
251 	_machine_halt();
252 }
253 
254 void machine_power_off(void)
255 {
256 	if (!in_interrupt() || oops_in_progress)
257 		/*
258 		 * Only unblank the console if we are called in enabled
259 		 * context or a bust_spinlocks cleared the way for us.
260 		 */
261 		console_unblank();
262 	_machine_power_off();
263 }
264 
265 /*
266  * Dummy power off function.
267  */
268 void (*pm_power_off)(void) = machine_power_off;
269 
270 static int __init early_parse_mem(char *p)
271 {
272 	memory_end = memparse(p, &p);
273 	memory_end_set = 1;
274 	return 0;
275 }
276 early_param("mem", early_parse_mem);
277 
278 unsigned int user_mode = HOME_SPACE_MODE;
279 EXPORT_SYMBOL_GPL(user_mode);
280 
281 static int set_amode_primary(void)
282 {
283 	psw_kernel_bits = (psw_kernel_bits & ~PSW_MASK_ASC) | PSW_ASC_HOME;
284 	psw_user_bits = (psw_user_bits & ~PSW_MASK_ASC) | PSW_ASC_PRIMARY;
285 #ifdef CONFIG_COMPAT
286 	psw32_user_bits =
287 		(psw32_user_bits & ~PSW32_MASK_ASC) | PSW32_ASC_PRIMARY;
288 #endif
289 
290 	if (MACHINE_HAS_MVCOS) {
291 		memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
292 		return 1;
293 	} else {
294 		memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
295 		return 0;
296 	}
297 }
298 
299 /*
300  * Switch kernel/user addressing modes?
301  */
302 static int __init early_parse_switch_amode(char *p)
303 {
304 	user_mode = PRIMARY_SPACE_MODE;
305 	return 0;
306 }
307 early_param("switch_amode", early_parse_switch_amode);
308 
309 static int __init early_parse_user_mode(char *p)
310 {
311 	if (p && strcmp(p, "primary") == 0)
312 		user_mode = PRIMARY_SPACE_MODE;
313 	else if (!p || strcmp(p, "home") == 0)
314 		user_mode = HOME_SPACE_MODE;
315 	else
316 		return 1;
317 	return 0;
318 }
319 early_param("user_mode", early_parse_user_mode);
320 
321 static void setup_addressing_mode(void)
322 {
323 	if (user_mode == PRIMARY_SPACE_MODE) {
324 		if (set_amode_primary())
325 			pr_info("Address spaces switched, "
326 				"mvcos available\n");
327 		else
328 			pr_info("Address spaces switched, "
329 				"mvcos not available\n");
330 	}
331 }
332 
333 static void __init
334 setup_lowcore(void)
335 {
336 	struct _lowcore *lc;
337 
338 	/*
339 	 * Setup lowcore for boot cpu
340 	 */
341 	BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
342 	lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
343 	lc->restart_psw.mask = psw_kernel_bits;
344 	lc->restart_psw.addr =
345 		PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
346 	lc->external_new_psw.mask = psw_kernel_bits |
347 		PSW_MASK_DAT | PSW_MASK_MCHECK;
348 	lc->external_new_psw.addr =
349 		PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
350 	lc->svc_new_psw.mask = psw_kernel_bits |
351 		PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
352 	lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
353 	lc->program_new_psw.mask = psw_kernel_bits |
354 		PSW_MASK_DAT | PSW_MASK_MCHECK;
355 	lc->program_new_psw.addr =
356 		PSW_ADDR_AMODE | (unsigned long) pgm_check_handler;
357 	lc->mcck_new_psw.mask = psw_kernel_bits;
358 	lc->mcck_new_psw.addr =
359 		PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
360 	lc->io_new_psw.mask = psw_kernel_bits |
361 		PSW_MASK_DAT | PSW_MASK_MCHECK;
362 	lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
363 	lc->clock_comparator = -1ULL;
364 	lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
365 	lc->async_stack = (unsigned long)
366 		__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
367 	lc->panic_stack = (unsigned long)
368 		__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
369 	lc->current_task = (unsigned long) init_thread_union.thread_info.task;
370 	lc->thread_info = (unsigned long) &init_thread_union;
371 	lc->machine_flags = S390_lowcore.machine_flags;
372 	lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
373 	memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
374 	       MAX_FACILITY_BIT/8);
375 #ifndef CONFIG_64BIT
376 	if (MACHINE_HAS_IEEE) {
377 		lc->extended_save_area_addr = (__u32)
378 			__alloc_bootmem_low(PAGE_SIZE, PAGE_SIZE, 0);
379 		/* enable extended save area */
380 		__ctl_set_bit(14, 29);
381 	}
382 #else
383 	lc->cmf_hpp = -1ULL;
384 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
385 #endif
386 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
387 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
388 	lc->exit_timer = S390_lowcore.exit_timer;
389 	lc->user_timer = S390_lowcore.user_timer;
390 	lc->system_timer = S390_lowcore.system_timer;
391 	lc->steal_timer = S390_lowcore.steal_timer;
392 	lc->last_update_timer = S390_lowcore.last_update_timer;
393 	lc->last_update_clock = S390_lowcore.last_update_clock;
394 	lc->ftrace_func = S390_lowcore.ftrace_func;
395 	set_prefix((u32)(unsigned long) lc);
396 	lowcore_ptr[0] = lc;
397 }
398 
399 static struct resource code_resource = {
400 	.name  = "Kernel code",
401 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
402 };
403 
404 static struct resource data_resource = {
405 	.name = "Kernel data",
406 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
407 };
408 
409 static struct resource bss_resource = {
410 	.name = "Kernel bss",
411 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
412 };
413 
414 static struct resource __initdata *standard_resources[] = {
415 	&code_resource,
416 	&data_resource,
417 	&bss_resource,
418 };
419 
420 static void __init setup_resources(void)
421 {
422 	struct resource *res, *std_res, *sub_res;
423 	int i, j;
424 
425 	code_resource.start = (unsigned long) &_text;
426 	code_resource.end = (unsigned long) &_etext - 1;
427 	data_resource.start = (unsigned long) &_etext;
428 	data_resource.end = (unsigned long) &_edata - 1;
429 	bss_resource.start = (unsigned long) &__bss_start;
430 	bss_resource.end = (unsigned long) &__bss_stop - 1;
431 
432 	for (i = 0; i < MEMORY_CHUNKS; i++) {
433 		if (!memory_chunk[i].size)
434 			continue;
435 		if (memory_chunk[i].type == CHUNK_OLDMEM ||
436 		    memory_chunk[i].type == CHUNK_CRASHK)
437 			continue;
438 		res = alloc_bootmem_low(sizeof(*res));
439 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
440 		switch (memory_chunk[i].type) {
441 		case CHUNK_READ_WRITE:
442 		case CHUNK_CRASHK:
443 			res->name = "System RAM";
444 			break;
445 		case CHUNK_READ_ONLY:
446 			res->name = "System ROM";
447 			res->flags |= IORESOURCE_READONLY;
448 			break;
449 		default:
450 			res->name = "reserved";
451 		}
452 		res->start = memory_chunk[i].addr;
453 		res->end = res->start + memory_chunk[i].size - 1;
454 		request_resource(&iomem_resource, res);
455 
456 		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
457 			std_res = standard_resources[j];
458 			if (std_res->start < res->start ||
459 			    std_res->start > res->end)
460 				continue;
461 			if (std_res->end > res->end) {
462 				sub_res = alloc_bootmem_low(sizeof(*sub_res));
463 				*sub_res = *std_res;
464 				sub_res->end = res->end;
465 				std_res->start = res->end + 1;
466 				request_resource(res, sub_res);
467 			} else {
468 				request_resource(res, std_res);
469 			}
470 		}
471 	}
472 }
473 
474 unsigned long real_memory_size;
475 EXPORT_SYMBOL_GPL(real_memory_size);
476 
477 static void __init setup_memory_end(void)
478 {
479 	unsigned long memory_size;
480 	unsigned long max_mem;
481 	int i;
482 
483 
484 #ifdef CONFIG_ZFCPDUMP
485 	if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
486 		memory_end = ZFCPDUMP_HSA_SIZE;
487 		memory_end_set = 1;
488 	}
489 #endif
490 	memory_size = 0;
491 	memory_end &= PAGE_MASK;
492 
493 	max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
494 	memory_end = min(max_mem, memory_end);
495 
496 	/*
497 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
498 	 * extra checks that HOLES_IN_ZONE would require.
499 	 */
500 	for (i = 0; i < MEMORY_CHUNKS; i++) {
501 		unsigned long start, end;
502 		struct mem_chunk *chunk;
503 		unsigned long align;
504 
505 		chunk = &memory_chunk[i];
506 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
507 		start = (chunk->addr + align - 1) & ~(align - 1);
508 		end = (chunk->addr + chunk->size) & ~(align - 1);
509 		if (start >= end)
510 			memset(chunk, 0, sizeof(*chunk));
511 		else {
512 			chunk->addr = start;
513 			chunk->size = end - start;
514 		}
515 	}
516 
517 	for (i = 0; i < MEMORY_CHUNKS; i++) {
518 		struct mem_chunk *chunk = &memory_chunk[i];
519 
520 		real_memory_size = max(real_memory_size,
521 				       chunk->addr + chunk->size);
522 		if (chunk->addr >= max_mem) {
523 			memset(chunk, 0, sizeof(*chunk));
524 			continue;
525 		}
526 		if (chunk->addr + chunk->size > max_mem)
527 			chunk->size = max_mem - chunk->addr;
528 		memory_size = max(memory_size, chunk->addr + chunk->size);
529 	}
530 	if (!memory_end)
531 		memory_end = memory_size;
532 }
533 
534 void *restart_stack __attribute__((__section__(".data")));
535 
536 /*
537  * Setup new PSW and allocate stack for PSW restart interrupt
538  */
539 static void __init setup_restart_psw(void)
540 {
541 	psw_t psw;
542 
543 	restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0);
544 	restart_stack += ASYNC_SIZE;
545 
546 	/*
547 	 * Setup restart PSW for absolute zero lowcore. This is necesary
548 	 * if PSW restart is done on an offline CPU that has lowcore zero
549 	 */
550 	psw.mask = PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
551 	psw.addr = PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
552 	copy_to_absolute_zero(&S390_lowcore.restart_psw, &psw, sizeof(psw));
553 }
554 
555 static void __init setup_vmcoreinfo(void)
556 {
557 #ifdef CONFIG_KEXEC
558 	unsigned long ptr = paddr_vmcoreinfo_note();
559 
560 	copy_to_absolute_zero(&S390_lowcore.vmcore_info, &ptr, sizeof(ptr));
561 #endif
562 }
563 
564 #ifdef CONFIG_CRASH_DUMP
565 
566 /*
567  * Find suitable location for crashkernel memory
568  */
569 static unsigned long __init find_crash_base(unsigned long crash_size,
570 					    char **msg)
571 {
572 	unsigned long crash_base;
573 	struct mem_chunk *chunk;
574 	int i;
575 
576 	if (memory_chunk[0].size < crash_size) {
577 		*msg = "first memory chunk must be at least crashkernel size";
578 		return 0;
579 	}
580 	if (is_kdump_kernel() && (crash_size == OLDMEM_SIZE))
581 		return OLDMEM_BASE;
582 
583 	for (i = MEMORY_CHUNKS - 1; i >= 0; i--) {
584 		chunk = &memory_chunk[i];
585 		if (chunk->size == 0)
586 			continue;
587 		if (chunk->type != CHUNK_READ_WRITE)
588 			continue;
589 		if (chunk->size < crash_size)
590 			continue;
591 		crash_base = (chunk->addr + chunk->size) - crash_size;
592 		if (crash_base < crash_size)
593 			continue;
594 		if (crash_base < ZFCPDUMP_HSA_SIZE_MAX)
595 			continue;
596 		if (crash_base < (unsigned long) INITRD_START + INITRD_SIZE)
597 			continue;
598 		return crash_base;
599 	}
600 	*msg = "no suitable area found";
601 	return 0;
602 }
603 
604 /*
605  * Check if crash_base and crash_size is valid
606  */
607 static int __init verify_crash_base(unsigned long crash_base,
608 				    unsigned long crash_size,
609 				    char **msg)
610 {
611 	struct mem_chunk *chunk;
612 	int i;
613 
614 	/*
615 	 * Because we do the swap to zero, we must have at least 'crash_size'
616 	 * bytes free space before crash_base
617 	 */
618 	if (crash_size > crash_base) {
619 		*msg = "crashkernel offset must be greater than size";
620 		return -EINVAL;
621 	}
622 
623 	/* First memory chunk must be at least crash_size */
624 	if (memory_chunk[0].size < crash_size) {
625 		*msg = "first memory chunk must be at least crashkernel size";
626 		return -EINVAL;
627 	}
628 	/* Check if we fit into the respective memory chunk */
629 	for (i = 0; i < MEMORY_CHUNKS; i++) {
630 		chunk = &memory_chunk[i];
631 		if (chunk->size == 0)
632 			continue;
633 		if (crash_base < chunk->addr)
634 			continue;
635 		if (crash_base >= chunk->addr + chunk->size)
636 			continue;
637 		/* we have found the memory chunk */
638 		if (crash_base + crash_size > chunk->addr + chunk->size) {
639 			*msg = "selected memory chunk is too small for "
640 				"crashkernel memory";
641 			return -EINVAL;
642 		}
643 		return 0;
644 	}
645 	*msg = "invalid memory range specified";
646 	return -EINVAL;
647 }
648 
649 /*
650  * Reserve kdump memory by creating a memory hole in the mem_chunk array
651  */
652 static void __init reserve_kdump_bootmem(unsigned long addr, unsigned long size,
653 					 int type)
654 {
655 
656 	create_mem_hole(memory_chunk, addr, size, type);
657 }
658 
659 /*
660  * When kdump is enabled, we have to ensure that no memory from
661  * the area [0 - crashkernel memory size] and
662  * [crashk_res.start - crashk_res.end] is set offline.
663  */
664 static int kdump_mem_notifier(struct notifier_block *nb,
665 			      unsigned long action, void *data)
666 {
667 	struct memory_notify *arg = data;
668 
669 	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
670 		return NOTIFY_BAD;
671 	if (arg->start_pfn > PFN_DOWN(crashk_res.end))
672 		return NOTIFY_OK;
673 	if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
674 		return NOTIFY_OK;
675 	return NOTIFY_BAD;
676 }
677 
678 static struct notifier_block kdump_mem_nb = {
679 	.notifier_call = kdump_mem_notifier,
680 };
681 
682 #endif
683 
684 /*
685  * Make sure that oldmem, where the dump is stored, is protected
686  */
687 static void reserve_oldmem(void)
688 {
689 #ifdef CONFIG_CRASH_DUMP
690 	if (!OLDMEM_BASE)
691 		return;
692 
693 	reserve_kdump_bootmem(OLDMEM_BASE, OLDMEM_SIZE, CHUNK_OLDMEM);
694 	reserve_kdump_bootmem(OLDMEM_SIZE, memory_end - OLDMEM_SIZE,
695 			      CHUNK_OLDMEM);
696 	if (OLDMEM_BASE + OLDMEM_SIZE == real_memory_size)
697 		saved_max_pfn = PFN_DOWN(OLDMEM_BASE) - 1;
698 	else
699 		saved_max_pfn = PFN_DOWN(real_memory_size) - 1;
700 #endif
701 }
702 
703 /*
704  * Reserve memory for kdump kernel to be loaded with kexec
705  */
706 static void __init reserve_crashkernel(void)
707 {
708 #ifdef CONFIG_CRASH_DUMP
709 	unsigned long long crash_base, crash_size;
710 	char *msg;
711 	int rc;
712 
713 	rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
714 			       &crash_base);
715 	if (rc || crash_size == 0)
716 		return;
717 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
718 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
719 	if (register_memory_notifier(&kdump_mem_nb))
720 		return;
721 	if (!crash_base)
722 		crash_base = find_crash_base(crash_size, &msg);
723 	if (!crash_base) {
724 		pr_info("crashkernel reservation failed: %s\n", msg);
725 		unregister_memory_notifier(&kdump_mem_nb);
726 		return;
727 	}
728 	if (verify_crash_base(crash_base, crash_size, &msg)) {
729 		pr_info("crashkernel reservation failed: %s\n", msg);
730 		unregister_memory_notifier(&kdump_mem_nb);
731 		return;
732 	}
733 	if (!OLDMEM_BASE && MACHINE_IS_VM)
734 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
735 	crashk_res.start = crash_base;
736 	crashk_res.end = crash_base + crash_size - 1;
737 	insert_resource(&iomem_resource, &crashk_res);
738 	reserve_kdump_bootmem(crash_base, crash_size, CHUNK_CRASHK);
739 	pr_info("Reserving %lluMB of memory at %lluMB "
740 		"for crashkernel (System RAM: %luMB)\n",
741 		crash_size >> 20, crash_base >> 20, memory_end >> 20);
742 #endif
743 }
744 
745 static void __init
746 setup_memory(void)
747 {
748         unsigned long bootmap_size;
749 	unsigned long start_pfn, end_pfn;
750 	int i;
751 
752 	/*
753 	 * partially used pages are not usable - thus
754 	 * we are rounding upwards:
755 	 */
756 	start_pfn = PFN_UP(__pa(&_end));
757 	end_pfn = max_pfn = PFN_DOWN(memory_end);
758 
759 #ifdef CONFIG_BLK_DEV_INITRD
760 	/*
761 	 * Move the initrd in case the bitmap of the bootmem allocater
762 	 * would overwrite it.
763 	 */
764 
765 	if (INITRD_START && INITRD_SIZE) {
766 		unsigned long bmap_size;
767 		unsigned long start;
768 
769 		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
770 		bmap_size = PFN_PHYS(bmap_size);
771 
772 		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
773 			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
774 
775 #ifdef CONFIG_CRASH_DUMP
776 			if (OLDMEM_BASE) {
777 				/* Move initrd behind kdump oldmem */
778 				if (start + INITRD_SIZE > OLDMEM_BASE &&
779 				    start < OLDMEM_BASE + OLDMEM_SIZE)
780 					start = OLDMEM_BASE + OLDMEM_SIZE;
781 			}
782 #endif
783 			if (start + INITRD_SIZE > memory_end) {
784 				pr_err("initrd extends beyond end of "
785 				       "memory (0x%08lx > 0x%08lx) "
786 				       "disabling initrd\n",
787 				       start + INITRD_SIZE, memory_end);
788 				INITRD_START = INITRD_SIZE = 0;
789 			} else {
790 				pr_info("Moving initrd (0x%08lx -> "
791 					"0x%08lx, size: %ld)\n",
792 					INITRD_START, start, INITRD_SIZE);
793 				memmove((void *) start, (void *) INITRD_START,
794 					INITRD_SIZE);
795 				INITRD_START = start;
796 			}
797 		}
798 	}
799 #endif
800 
801 	/*
802 	 * Initialize the boot-time allocator
803 	 */
804 	bootmap_size = init_bootmem(start_pfn, end_pfn);
805 
806 	/*
807 	 * Register RAM areas with the bootmem allocator.
808 	 */
809 
810 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
811 		unsigned long start_chunk, end_chunk, pfn;
812 
813 		if (memory_chunk[i].type != CHUNK_READ_WRITE &&
814 		    memory_chunk[i].type != CHUNK_CRASHK)
815 			continue;
816 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
817 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
818 		end_chunk = min(end_chunk, end_pfn);
819 		if (start_chunk >= end_chunk)
820 			continue;
821 		add_active_range(0, start_chunk, end_chunk);
822 		pfn = max(start_chunk, start_pfn);
823 		for (; pfn < end_chunk; pfn++)
824 			page_set_storage_key(PFN_PHYS(pfn),
825 					     PAGE_DEFAULT_KEY, 0);
826 	}
827 
828 	psw_set_key(PAGE_DEFAULT_KEY);
829 
830 	free_bootmem_with_active_regions(0, max_pfn);
831 
832 	/*
833 	 * Reserve memory used for lowcore/command line/kernel image.
834 	 */
835 	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
836 	reserve_bootmem((unsigned long)_stext,
837 			PFN_PHYS(start_pfn) - (unsigned long)_stext,
838 			BOOTMEM_DEFAULT);
839 	/*
840 	 * Reserve the bootmem bitmap itself as well. We do this in two
841 	 * steps (first step was init_bootmem()) because this catches
842 	 * the (very unlikely) case of us accidentally initializing the
843 	 * bootmem allocator with an invalid RAM area.
844 	 */
845 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
846 			BOOTMEM_DEFAULT);
847 
848 #ifdef CONFIG_CRASH_DUMP
849 	if (crashk_res.start)
850 		reserve_bootmem(crashk_res.start,
851 				crashk_res.end - crashk_res.start + 1,
852 				BOOTMEM_DEFAULT);
853 	if (is_kdump_kernel())
854 		reserve_bootmem(elfcorehdr_addr - OLDMEM_BASE,
855 				PAGE_ALIGN(elfcorehdr_size), BOOTMEM_DEFAULT);
856 #endif
857 #ifdef CONFIG_BLK_DEV_INITRD
858 	if (INITRD_START && INITRD_SIZE) {
859 		if (INITRD_START + INITRD_SIZE <= memory_end) {
860 			reserve_bootmem(INITRD_START, INITRD_SIZE,
861 					BOOTMEM_DEFAULT);
862 			initrd_start = INITRD_START;
863 			initrd_end = initrd_start + INITRD_SIZE;
864 		} else {
865 			pr_err("initrd extends beyond end of "
866 			       "memory (0x%08lx > 0x%08lx) "
867 			       "disabling initrd\n",
868 			       initrd_start + INITRD_SIZE, memory_end);
869 			initrd_start = initrd_end = 0;
870 		}
871 	}
872 #endif
873 }
874 
875 /*
876  * Setup hardware capabilities.
877  */
878 static void __init setup_hwcaps(void)
879 {
880 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
881 	struct cpuid cpu_id;
882 	int i;
883 
884 	/*
885 	 * The store facility list bits numbers as found in the principles
886 	 * of operation are numbered with bit 1UL<<31 as number 0 to
887 	 * bit 1UL<<0 as number 31.
888 	 *   Bit 0: instructions named N3, "backported" to esa-mode
889 	 *   Bit 2: z/Architecture mode is active
890 	 *   Bit 7: the store-facility-list-extended facility is installed
891 	 *   Bit 17: the message-security assist is installed
892 	 *   Bit 19: the long-displacement facility is installed
893 	 *   Bit 21: the extended-immediate facility is installed
894 	 *   Bit 22: extended-translation facility 3 is installed
895 	 *   Bit 30: extended-translation facility 3 enhancement facility
896 	 * These get translated to:
897 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
898 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
899 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
900 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
901 	 */
902 	for (i = 0; i < 6; i++)
903 		if (test_facility(stfl_bits[i]))
904 			elf_hwcap |= 1UL << i;
905 
906 	if (test_facility(22) && test_facility(30))
907 		elf_hwcap |= HWCAP_S390_ETF3EH;
908 
909 	/*
910 	 * Check for additional facilities with store-facility-list-extended.
911 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
912 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
913 	 * as stored by stfl, bits 32-xxx contain additional facilities.
914 	 * How many facility words are stored depends on the number of
915 	 * doublewords passed to the instruction. The additional facilities
916 	 * are:
917 	 *   Bit 42: decimal floating point facility is installed
918 	 *   Bit 44: perform floating point operation facility is installed
919 	 * translated to:
920 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
921 	 */
922 	if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
923 		elf_hwcap |= HWCAP_S390_DFP;
924 
925 	/*
926 	 * Huge page support HWCAP_S390_HPAGE is bit 7.
927 	 */
928 	if (MACHINE_HAS_HPAGE)
929 		elf_hwcap |= HWCAP_S390_HPAGE;
930 
931 	/*
932 	 * 64-bit register support for 31-bit processes
933 	 * HWCAP_S390_HIGH_GPRS is bit 9.
934 	 */
935 	elf_hwcap |= HWCAP_S390_HIGH_GPRS;
936 
937 	get_cpu_id(&cpu_id);
938 	switch (cpu_id.machine) {
939 	case 0x9672:
940 #if !defined(CONFIG_64BIT)
941 	default:	/* Use "g5" as default for 31 bit kernels. */
942 #endif
943 		strcpy(elf_platform, "g5");
944 		break;
945 	case 0x2064:
946 	case 0x2066:
947 #if defined(CONFIG_64BIT)
948 	default:	/* Use "z900" as default for 64 bit kernels. */
949 #endif
950 		strcpy(elf_platform, "z900");
951 		break;
952 	case 0x2084:
953 	case 0x2086:
954 		strcpy(elf_platform, "z990");
955 		break;
956 	case 0x2094:
957 	case 0x2096:
958 		strcpy(elf_platform, "z9-109");
959 		break;
960 	case 0x2097:
961 	case 0x2098:
962 		strcpy(elf_platform, "z10");
963 		break;
964 	case 0x2817:
965 	case 0x2818:
966 		strcpy(elf_platform, "z196");
967 		break;
968 	}
969 }
970 
971 /*
972  * Setup function called from init/main.c just after the banner
973  * was printed.
974  */
975 
976 void __init
977 setup_arch(char **cmdline_p)
978 {
979         /*
980          * print what head.S has found out about the machine
981          */
982 #ifndef CONFIG_64BIT
983 	if (MACHINE_IS_VM)
984 		pr_info("Linux is running as a z/VM "
985 			"guest operating system in 31-bit mode\n");
986 	else if (MACHINE_IS_LPAR)
987 		pr_info("Linux is running natively in 31-bit mode\n");
988 	if (MACHINE_HAS_IEEE)
989 		pr_info("The hardware system has IEEE compatible "
990 			"floating point units\n");
991 	else
992 		pr_info("The hardware system has no IEEE compatible "
993 			"floating point units\n");
994 #else /* CONFIG_64BIT */
995 	if (MACHINE_IS_VM)
996 		pr_info("Linux is running as a z/VM "
997 			"guest operating system in 64-bit mode\n");
998 	else if (MACHINE_IS_KVM)
999 		pr_info("Linux is running under KVM in 64-bit mode\n");
1000 	else if (MACHINE_IS_LPAR)
1001 		pr_info("Linux is running natively in 64-bit mode\n");
1002 #endif /* CONFIG_64BIT */
1003 
1004 	/* Have one command line that is parsed and saved in /proc/cmdline */
1005 	/* boot_command_line has been already set up in early.c */
1006 	*cmdline_p = boot_command_line;
1007 
1008         ROOT_DEV = Root_RAM0;
1009 
1010 	init_mm.start_code = PAGE_OFFSET;
1011 	init_mm.end_code = (unsigned long) &_etext;
1012 	init_mm.end_data = (unsigned long) &_edata;
1013 	init_mm.brk = (unsigned long) &_end;
1014 
1015 	if (MACHINE_HAS_MVCOS)
1016 		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
1017 	else
1018 		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
1019 
1020 	parse_early_param();
1021 
1022 	setup_ipl();
1023 	setup_memory_end();
1024 	setup_addressing_mode();
1025 	reserve_oldmem();
1026 	reserve_crashkernel();
1027 	setup_memory();
1028 	setup_resources();
1029 	setup_vmcoreinfo();
1030 	setup_restart_psw();
1031 	setup_lowcore();
1032 
1033         cpu_init();
1034 	s390_init_cpu_topology();
1035 
1036 	/*
1037 	 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
1038 	 */
1039 	setup_hwcaps();
1040 
1041 	/*
1042 	 * Create kernel page tables and switch to virtual addressing.
1043 	 */
1044         paging_init();
1045 
1046         /* Setup default console */
1047 	conmode_default();
1048 	set_preferred_console();
1049 
1050 	/* Setup zfcpdump support */
1051 	setup_zfcpdump(console_devno);
1052 }
1053