xref: /openbmc/linux/arch/s390/kernel/setup.c (revision 82ced6fd)
1 /*
2  *  arch/s390/kernel/setup.c
3  *
4  *  S390 version
5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
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/slab.h>
29 #include <linux/user.h>
30 #include <linux/tty.h>
31 #include <linux/ioport.h>
32 #include <linux/delay.h>
33 #include <linux/init.h>
34 #include <linux/initrd.h>
35 #include <linux/bootmem.h>
36 #include <linux/root_dev.h>
37 #include <linux/console.h>
38 #include <linux/kernel_stat.h>
39 #include <linux/device.h>
40 #include <linux/notifier.h>
41 #include <linux/pfn.h>
42 #include <linux/ctype.h>
43 #include <linux/reboot.h>
44 #include <linux/topology.h>
45 
46 #include <asm/ipl.h>
47 #include <asm/uaccess.h>
48 #include <asm/system.h>
49 #include <asm/smp.h>
50 #include <asm/mmu_context.h>
51 #include <asm/cpcmd.h>
52 #include <asm/lowcore.h>
53 #include <asm/irq.h>
54 #include <asm/page.h>
55 #include <asm/ptrace.h>
56 #include <asm/sections.h>
57 #include <asm/ebcdic.h>
58 #include <asm/compat.h>
59 #include <asm/kvm_virtio.h>
60 
61 long psw_kernel_bits	= (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
62 			   PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
63 long psw_user_bits	= (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
64 			   PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
65 			   PSW_MASK_PSTATE | PSW_DEFAULT_KEY);
66 
67 /*
68  * User copy operations.
69  */
70 struct uaccess_ops uaccess;
71 EXPORT_SYMBOL(uaccess);
72 
73 /*
74  * Machine setup..
75  */
76 unsigned int console_mode = 0;
77 EXPORT_SYMBOL(console_mode);
78 
79 unsigned int console_devno = -1;
80 EXPORT_SYMBOL(console_devno);
81 
82 unsigned int console_irq = -1;
83 EXPORT_SYMBOL(console_irq);
84 
85 unsigned long elf_hwcap = 0;
86 char elf_platform[ELF_PLATFORM_SIZE];
87 
88 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
89 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
90 
91 int __initdata memory_end_set;
92 unsigned long __initdata memory_end;
93 
94 /* An array with a pointer to the lowcore of every CPU. */
95 struct _lowcore *lowcore_ptr[NR_CPUS];
96 EXPORT_SYMBOL(lowcore_ptr);
97 
98 /*
99  * This is set up by the setup-routine at boot-time
100  * for S390 need to find out, what we have to setup
101  * using address 0x10400 ...
102  */
103 
104 #include <asm/setup.h>
105 
106 static struct resource code_resource = {
107 	.name  = "Kernel code",
108 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
109 };
110 
111 static struct resource data_resource = {
112 	.name = "Kernel data",
113 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
114 };
115 
116 /*
117  * cpu_init() initializes state that is per-CPU.
118  */
119 void __cpuinit cpu_init(void)
120 {
121         /*
122          * Store processor id in lowcore (used e.g. in timer_interrupt)
123          */
124 	get_cpu_id(&S390_lowcore.cpu_id);
125 
126         /*
127          * Force FPU initialization:
128          */
129         clear_thread_flag(TIF_USEDFPU);
130         clear_used_math();
131 
132 	atomic_inc(&init_mm.mm_count);
133 	current->active_mm = &init_mm;
134 	BUG_ON(current->mm);
135         enter_lazy_tlb(&init_mm, current);
136 }
137 
138 /*
139  * condev= and conmode= setup parameter.
140  */
141 
142 static int __init condev_setup(char *str)
143 {
144 	int vdev;
145 
146 	vdev = simple_strtoul(str, &str, 0);
147 	if (vdev >= 0 && vdev < 65536) {
148 		console_devno = vdev;
149 		console_irq = -1;
150 	}
151 	return 1;
152 }
153 
154 __setup("condev=", condev_setup);
155 
156 static int __init conmode_setup(char *str)
157 {
158 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
159 	if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
160                 SET_CONSOLE_SCLP;
161 #endif
162 #if defined(CONFIG_TN3215_CONSOLE)
163 	if (strncmp(str, "3215", 5) == 0)
164 		SET_CONSOLE_3215;
165 #endif
166 #if defined(CONFIG_TN3270_CONSOLE)
167 	if (strncmp(str, "3270", 5) == 0)
168 		SET_CONSOLE_3270;
169 #endif
170         return 1;
171 }
172 
173 __setup("conmode=", conmode_setup);
174 
175 static void __init conmode_default(void)
176 {
177 	char query_buffer[1024];
178 	char *ptr;
179 
180         if (MACHINE_IS_VM) {
181 		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
182 		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
183 		ptr = strstr(query_buffer, "SUBCHANNEL =");
184 		console_irq = simple_strtoul(ptr + 13, NULL, 16);
185 		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
186 		ptr = strstr(query_buffer, "CONMODE");
187 		/*
188 		 * Set the conmode to 3215 so that the device recognition
189 		 * will set the cu_type of the console to 3215. If the
190 		 * conmode is 3270 and we don't set it back then both
191 		 * 3215 and the 3270 driver will try to access the console
192 		 * device (3215 as console and 3270 as normal tty).
193 		 */
194 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
195 		if (ptr == NULL) {
196 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
197 			SET_CONSOLE_SCLP;
198 #endif
199 			return;
200 		}
201 		if (strncmp(ptr + 8, "3270", 4) == 0) {
202 #if defined(CONFIG_TN3270_CONSOLE)
203 			SET_CONSOLE_3270;
204 #elif defined(CONFIG_TN3215_CONSOLE)
205 			SET_CONSOLE_3215;
206 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
207 			SET_CONSOLE_SCLP;
208 #endif
209 		} else if (strncmp(ptr + 8, "3215", 4) == 0) {
210 #if defined(CONFIG_TN3215_CONSOLE)
211 			SET_CONSOLE_3215;
212 #elif defined(CONFIG_TN3270_CONSOLE)
213 			SET_CONSOLE_3270;
214 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
215 			SET_CONSOLE_SCLP;
216 #endif
217 		}
218 	} else {
219 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
220 		SET_CONSOLE_SCLP;
221 #endif
222 	}
223 }
224 
225 #ifdef CONFIG_ZFCPDUMP
226 static void __init setup_zfcpdump(unsigned int console_devno)
227 {
228 	static char str[41];
229 
230 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
231 		return;
232 	if (console_devno != -1)
233 		sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
234 			ipl_info.data.fcp.dev_id.devno, console_devno);
235 	else
236 		sprintf(str, " cio_ignore=all,!0.0.%04x",
237 			ipl_info.data.fcp.dev_id.devno);
238 	strcat(boot_command_line, str);
239 	console_loglevel = 2;
240 }
241 #else
242 static inline void setup_zfcpdump(unsigned int console_devno) {}
243 #endif /* CONFIG_ZFCPDUMP */
244 
245  /*
246  * Reboot, halt and power_off stubs. They just call _machine_restart,
247  * _machine_halt or _machine_power_off.
248  */
249 
250 void machine_restart(char *command)
251 {
252 	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
253 		/*
254 		 * Only unblank the console if we are called in enabled
255 		 * context or a bust_spinlocks cleared the way for us.
256 		 */
257 		console_unblank();
258 	_machine_restart(command);
259 }
260 
261 void machine_halt(void)
262 {
263 	if (!in_interrupt() || oops_in_progress)
264 		/*
265 		 * Only unblank the console if we are called in enabled
266 		 * context or a bust_spinlocks cleared the way for us.
267 		 */
268 		console_unblank();
269 	_machine_halt();
270 }
271 
272 void machine_power_off(void)
273 {
274 	if (!in_interrupt() || oops_in_progress)
275 		/*
276 		 * Only unblank the console if we are called in enabled
277 		 * context or a bust_spinlocks cleared the way for us.
278 		 */
279 		console_unblank();
280 	_machine_power_off();
281 }
282 
283 /*
284  * Dummy power off function.
285  */
286 void (*pm_power_off)(void) = machine_power_off;
287 
288 static int __init early_parse_mem(char *p)
289 {
290 	memory_end = memparse(p, &p);
291 	memory_end_set = 1;
292 	return 0;
293 }
294 early_param("mem", early_parse_mem);
295 
296 #ifdef CONFIG_S390_SWITCH_AMODE
297 unsigned int switch_amode = 0;
298 EXPORT_SYMBOL_GPL(switch_amode);
299 
300 static int set_amode_and_uaccess(unsigned long user_amode,
301 				 unsigned long user32_amode)
302 {
303 	psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
304 			PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
305 			PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
306 #ifdef CONFIG_COMPAT
307 	psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
308 			  PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
309 			  PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
310 	psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
311 			  PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
312 			  PSW32_MASK_PSTATE;
313 #endif
314 	psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
315 			  PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
316 
317 	if (MACHINE_HAS_MVCOS) {
318 		memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
319 		return 1;
320 	} else {
321 		memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
322 		return 0;
323 	}
324 }
325 
326 /*
327  * Switch kernel/user addressing modes?
328  */
329 static int __init early_parse_switch_amode(char *p)
330 {
331 	switch_amode = 1;
332 	return 0;
333 }
334 early_param("switch_amode", early_parse_switch_amode);
335 
336 #else /* CONFIG_S390_SWITCH_AMODE */
337 static inline int set_amode_and_uaccess(unsigned long user_amode,
338 					unsigned long user32_amode)
339 {
340 	return 0;
341 }
342 #endif /* CONFIG_S390_SWITCH_AMODE */
343 
344 #ifdef CONFIG_S390_EXEC_PROTECT
345 unsigned int s390_noexec = 0;
346 EXPORT_SYMBOL_GPL(s390_noexec);
347 
348 /*
349  * Enable execute protection?
350  */
351 static int __init early_parse_noexec(char *p)
352 {
353 	if (!strncmp(p, "off", 3))
354 		return 0;
355 	switch_amode = 1;
356 	s390_noexec = 1;
357 	return 0;
358 }
359 early_param("noexec", early_parse_noexec);
360 #endif /* CONFIG_S390_EXEC_PROTECT */
361 
362 static void setup_addressing_mode(void)
363 {
364 	if (s390_noexec) {
365 		if (set_amode_and_uaccess(PSW_ASC_SECONDARY,
366 					  PSW32_ASC_SECONDARY))
367 			pr_info("Execute protection active, "
368 				"mvcos available\n");
369 		else
370 			pr_info("Execute protection active, "
371 				"mvcos not available\n");
372 	} else if (switch_amode) {
373 		if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
374 			pr_info("Address spaces switched, "
375 				"mvcos available\n");
376 		else
377 			pr_info("Address spaces switched, "
378 				"mvcos not available\n");
379 	}
380 #ifdef CONFIG_TRACE_IRQFLAGS
381 	sysc_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
382 	io_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
383 #endif
384 }
385 
386 static void __init
387 setup_lowcore(void)
388 {
389 	struct _lowcore *lc;
390 	int lc_pages;
391 
392 	/*
393 	 * Setup lowcore for boot cpu
394 	 */
395 	lc_pages = sizeof(void *) == 8 ? 2 : 1;
396 	lc = (struct _lowcore *)
397 		__alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
398 	memset(lc, 0, lc_pages * PAGE_SIZE);
399 	lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
400 	lc->restart_psw.addr =
401 		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
402 	if (switch_amode)
403 		lc->restart_psw.mask |= PSW_ASC_HOME;
404 	lc->external_new_psw.mask = psw_kernel_bits;
405 	lc->external_new_psw.addr =
406 		PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
407 	lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
408 	lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
409 	lc->program_new_psw.mask = psw_kernel_bits;
410 	lc->program_new_psw.addr =
411 		PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
412 	lc->mcck_new_psw.mask =
413 		psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
414 	lc->mcck_new_psw.addr =
415 		PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
416 	lc->io_new_psw.mask = psw_kernel_bits;
417 	lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
418 	lc->clock_comparator = -1ULL;
419 	lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
420 	lc->async_stack = (unsigned long)
421 		__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
422 	lc->panic_stack = (unsigned long)
423 		__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
424 	lc->current_task = (unsigned long) init_thread_union.thread_info.task;
425 	lc->thread_info = (unsigned long) &init_thread_union;
426 	lc->machine_flags = S390_lowcore.machine_flags;
427 #ifndef CONFIG_64BIT
428 	if (MACHINE_HAS_IEEE) {
429 		lc->extended_save_area_addr = (__u32)
430 			__alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
431 		/* enable extended save area */
432 		__ctl_set_bit(14, 29);
433 	}
434 #else
435 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
436 #endif
437 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
438 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
439 	lc->exit_timer = S390_lowcore.exit_timer;
440 	lc->user_timer = S390_lowcore.user_timer;
441 	lc->system_timer = S390_lowcore.system_timer;
442 	lc->steal_timer = S390_lowcore.steal_timer;
443 	lc->last_update_timer = S390_lowcore.last_update_timer;
444 	lc->last_update_clock = S390_lowcore.last_update_clock;
445 	set_prefix((u32)(unsigned long) lc);
446 	lowcore_ptr[0] = lc;
447 }
448 
449 static void __init
450 setup_resources(void)
451 {
452 	struct resource *res, *sub_res;
453 	int i;
454 
455 	code_resource.start = (unsigned long) &_text;
456 	code_resource.end = (unsigned long) &_etext - 1;
457 	data_resource.start = (unsigned long) &_etext;
458 	data_resource.end = (unsigned long) &_edata - 1;
459 
460 	for (i = 0; i < MEMORY_CHUNKS; i++) {
461 		if (!memory_chunk[i].size)
462 			continue;
463 		res = alloc_bootmem_low(sizeof(struct resource));
464 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
465 		switch (memory_chunk[i].type) {
466 		case CHUNK_READ_WRITE:
467 			res->name = "System RAM";
468 			break;
469 		case CHUNK_READ_ONLY:
470 			res->name = "System ROM";
471 			res->flags |= IORESOURCE_READONLY;
472 			break;
473 		default:
474 			res->name = "reserved";
475 		}
476 		res->start = memory_chunk[i].addr;
477 		res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
478 		request_resource(&iomem_resource, res);
479 
480 		if (code_resource.start >= res->start  &&
481 			code_resource.start <= res->end &&
482 			code_resource.end > res->end) {
483 			sub_res = alloc_bootmem_low(sizeof(struct resource));
484 			memcpy(sub_res, &code_resource,
485 				sizeof(struct resource));
486 			sub_res->end = res->end;
487 			code_resource.start = res->end + 1;
488 			request_resource(res, sub_res);
489 		}
490 
491 		if (code_resource.start >= res->start &&
492 			code_resource.start <= res->end &&
493 			code_resource.end <= res->end)
494 			request_resource(res, &code_resource);
495 
496 		if (data_resource.start >= res->start &&
497 			data_resource.start <= res->end &&
498 			data_resource.end > res->end) {
499 			sub_res = alloc_bootmem_low(sizeof(struct resource));
500 			memcpy(sub_res, &data_resource,
501 				sizeof(struct resource));
502 			sub_res->end = res->end;
503 			data_resource.start = res->end + 1;
504 			request_resource(res, sub_res);
505 		}
506 
507 		if (data_resource.start >= res->start &&
508 			data_resource.start <= res->end &&
509 			data_resource.end <= res->end)
510 			request_resource(res, &data_resource);
511 	}
512 }
513 
514 unsigned long real_memory_size;
515 EXPORT_SYMBOL_GPL(real_memory_size);
516 
517 static void __init setup_memory_end(void)
518 {
519 	unsigned long memory_size;
520 	unsigned long max_mem;
521 	int i;
522 
523 #ifdef CONFIG_ZFCPDUMP
524 	if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
525 		memory_end = ZFCPDUMP_HSA_SIZE;
526 		memory_end_set = 1;
527 	}
528 #endif
529 	memory_size = 0;
530 	memory_end &= PAGE_MASK;
531 
532 	max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
533 	memory_end = min(max_mem, memory_end);
534 
535 	/*
536 	 * Make sure all chunks are MAX_ORDER aligned so we don't need the
537 	 * extra checks that HOLES_IN_ZONE would require.
538 	 */
539 	for (i = 0; i < MEMORY_CHUNKS; i++) {
540 		unsigned long start, end;
541 		struct mem_chunk *chunk;
542 		unsigned long align;
543 
544 		chunk = &memory_chunk[i];
545 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
546 		start = (chunk->addr + align - 1) & ~(align - 1);
547 		end = (chunk->addr + chunk->size) & ~(align - 1);
548 		if (start >= end)
549 			memset(chunk, 0, sizeof(*chunk));
550 		else {
551 			chunk->addr = start;
552 			chunk->size = end - start;
553 		}
554 	}
555 
556 	for (i = 0; i < MEMORY_CHUNKS; i++) {
557 		struct mem_chunk *chunk = &memory_chunk[i];
558 
559 		real_memory_size = max(real_memory_size,
560 				       chunk->addr + chunk->size);
561 		if (chunk->addr >= max_mem) {
562 			memset(chunk, 0, sizeof(*chunk));
563 			continue;
564 		}
565 		if (chunk->addr + chunk->size > max_mem)
566 			chunk->size = max_mem - chunk->addr;
567 		memory_size = max(memory_size, chunk->addr + chunk->size);
568 	}
569 	if (!memory_end)
570 		memory_end = memory_size;
571 }
572 
573 static void __init
574 setup_memory(void)
575 {
576         unsigned long bootmap_size;
577 	unsigned long start_pfn, end_pfn;
578 	int i;
579 
580 	/*
581 	 * partially used pages are not usable - thus
582 	 * we are rounding upwards:
583 	 */
584 	start_pfn = PFN_UP(__pa(&_end));
585 	end_pfn = max_pfn = PFN_DOWN(memory_end);
586 
587 #ifdef CONFIG_BLK_DEV_INITRD
588 	/*
589 	 * Move the initrd in case the bitmap of the bootmem allocater
590 	 * would overwrite it.
591 	 */
592 
593 	if (INITRD_START && INITRD_SIZE) {
594 		unsigned long bmap_size;
595 		unsigned long start;
596 
597 		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
598 		bmap_size = PFN_PHYS(bmap_size);
599 
600 		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
601 			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
602 
603 			if (start + INITRD_SIZE > memory_end) {
604 				pr_err("initrd extends beyond end of "
605 				       "memory (0x%08lx > 0x%08lx) "
606 				       "disabling initrd\n",
607 				       start + INITRD_SIZE, memory_end);
608 				INITRD_START = INITRD_SIZE = 0;
609 			} else {
610 				pr_info("Moving initrd (0x%08lx -> "
611 					"0x%08lx, size: %ld)\n",
612 					INITRD_START, start, INITRD_SIZE);
613 				memmove((void *) start, (void *) INITRD_START,
614 					INITRD_SIZE);
615 				INITRD_START = start;
616 			}
617 		}
618 	}
619 #endif
620 
621 	/*
622 	 * Initialize the boot-time allocator
623 	 */
624 	bootmap_size = init_bootmem(start_pfn, end_pfn);
625 
626 	/*
627 	 * Register RAM areas with the bootmem allocator.
628 	 */
629 
630 	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
631 		unsigned long start_chunk, end_chunk, pfn;
632 
633 		if (memory_chunk[i].type != CHUNK_READ_WRITE)
634 			continue;
635 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
636 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
637 		end_chunk = min(end_chunk, end_pfn);
638 		if (start_chunk >= end_chunk)
639 			continue;
640 		add_active_range(0, start_chunk, end_chunk);
641 		pfn = max(start_chunk, start_pfn);
642 		for (; pfn < end_chunk; pfn++)
643 			page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
644 	}
645 
646 	psw_set_key(PAGE_DEFAULT_KEY);
647 
648 	free_bootmem_with_active_regions(0, max_pfn);
649 
650 	/*
651 	 * Reserve memory used for lowcore/command line/kernel image.
652 	 */
653 	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
654 	reserve_bootmem((unsigned long)_stext,
655 			PFN_PHYS(start_pfn) - (unsigned long)_stext,
656 			BOOTMEM_DEFAULT);
657 	/*
658 	 * Reserve the bootmem bitmap itself as well. We do this in two
659 	 * steps (first step was init_bootmem()) because this catches
660 	 * the (very unlikely) case of us accidentally initializing the
661 	 * bootmem allocator with an invalid RAM area.
662 	 */
663 	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
664 			BOOTMEM_DEFAULT);
665 
666 #ifdef CONFIG_BLK_DEV_INITRD
667 	if (INITRD_START && INITRD_SIZE) {
668 		if (INITRD_START + INITRD_SIZE <= memory_end) {
669 			reserve_bootmem(INITRD_START, INITRD_SIZE,
670 					BOOTMEM_DEFAULT);
671 			initrd_start = INITRD_START;
672 			initrd_end = initrd_start + INITRD_SIZE;
673 		} else {
674 			pr_err("initrd extends beyond end of "
675 			       "memory (0x%08lx > 0x%08lx) "
676 			       "disabling initrd\n",
677 			       initrd_start + INITRD_SIZE, memory_end);
678 			initrd_start = initrd_end = 0;
679 		}
680 	}
681 #endif
682 }
683 
684 /*
685  * Setup hardware capabilities.
686  */
687 static void __init setup_hwcaps(void)
688 {
689 	static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
690 	unsigned long long facility_list_extended;
691 	unsigned int facility_list;
692 	int i;
693 
694 	facility_list = stfl();
695 	/*
696 	 * The store facility list bits numbers as found in the principles
697 	 * of operation are numbered with bit 1UL<<31 as number 0 to
698 	 * bit 1UL<<0 as number 31.
699 	 *   Bit 0: instructions named N3, "backported" to esa-mode
700 	 *   Bit 2: z/Architecture mode is active
701 	 *   Bit 7: the store-facility-list-extended facility is installed
702 	 *   Bit 17: the message-security assist is installed
703 	 *   Bit 19: the long-displacement facility is installed
704 	 *   Bit 21: the extended-immediate facility is installed
705 	 *   Bit 22: extended-translation facility 3 is installed
706 	 *   Bit 30: extended-translation facility 3 enhancement facility
707 	 * These get translated to:
708 	 *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
709 	 *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
710 	 *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
711 	 *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
712 	 */
713 	for (i = 0; i < 6; i++)
714 		if (facility_list & (1UL << (31 - stfl_bits[i])))
715 			elf_hwcap |= 1UL << i;
716 
717 	if ((facility_list & (1UL << (31 - 22)))
718 	    && (facility_list & (1UL << (31 - 30))))
719 		elf_hwcap |= 1UL << 8;
720 
721 	/*
722 	 * Check for additional facilities with store-facility-list-extended.
723 	 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
724 	 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
725 	 * as stored by stfl, bits 32-xxx contain additional facilities.
726 	 * How many facility words are stored depends on the number of
727 	 * doublewords passed to the instruction. The additional facilites
728 	 * are:
729 	 *   Bit 42: decimal floating point facility is installed
730 	 *   Bit 44: perform floating point operation facility is installed
731 	 * translated to:
732 	 *   HWCAP_S390_DFP bit 6 (42 && 44).
733 	 */
734 	if ((elf_hwcap & (1UL << 2)) &&
735 	    __stfle(&facility_list_extended, 1) > 0) {
736 		if ((facility_list_extended & (1ULL << (63 - 42)))
737 		    && (facility_list_extended & (1ULL << (63 - 44))))
738 			elf_hwcap |= 1UL << 6;
739 	}
740 
741 	if (MACHINE_HAS_HPAGE)
742 		elf_hwcap |= 1UL << 7;
743 
744 	switch (S390_lowcore.cpu_id.machine) {
745 	case 0x9672:
746 #if !defined(CONFIG_64BIT)
747 	default:	/* Use "g5" as default for 31 bit kernels. */
748 #endif
749 		strcpy(elf_platform, "g5");
750 		break;
751 	case 0x2064:
752 	case 0x2066:
753 #if defined(CONFIG_64BIT)
754 	default:	/* Use "z900" as default for 64 bit kernels. */
755 #endif
756 		strcpy(elf_platform, "z900");
757 		break;
758 	case 0x2084:
759 	case 0x2086:
760 		strcpy(elf_platform, "z990");
761 		break;
762 	case 0x2094:
763 	case 0x2096:
764 		strcpy(elf_platform, "z9-109");
765 		break;
766 	case 0x2097:
767 	case 0x2098:
768 		strcpy(elf_platform, "z10");
769 		break;
770 	}
771 }
772 
773 /*
774  * Setup function called from init/main.c just after the banner
775  * was printed.
776  */
777 
778 void __init
779 setup_arch(char **cmdline_p)
780 {
781 	/* set up preferred console */
782 	add_preferred_console("ttyS", 0, NULL);
783 
784         /*
785          * print what head.S has found out about the machine
786          */
787 #ifndef CONFIG_64BIT
788 	if (MACHINE_IS_VM)
789 		pr_info("Linux is running as a z/VM "
790 			"guest operating system in 31-bit mode\n");
791 	else
792 		pr_info("Linux is running natively in 31-bit mode\n");
793 	if (MACHINE_HAS_IEEE)
794 		pr_info("The hardware system has IEEE compatible "
795 			"floating point units\n");
796 	else
797 		pr_info("The hardware system has no IEEE compatible "
798 			"floating point units\n");
799 #else /* CONFIG_64BIT */
800 	if (MACHINE_IS_VM)
801 		pr_info("Linux is running as a z/VM "
802 			"guest operating system in 64-bit mode\n");
803 	else if (MACHINE_IS_KVM) {
804 		pr_info("Linux is running under KVM in 64-bit mode\n");
805 		add_preferred_console("hvc", 0, NULL);
806 		s390_virtio_console_init();
807 	} else
808 		pr_info("Linux is running natively in 64-bit mode\n");
809 #endif /* CONFIG_64BIT */
810 
811 	/* Have one command line that is parsed and saved in /proc/cmdline */
812 	/* boot_command_line has been already set up in early.c */
813 	*cmdline_p = boot_command_line;
814 
815         ROOT_DEV = Root_RAM0;
816 
817 	init_mm.start_code = PAGE_OFFSET;
818 	init_mm.end_code = (unsigned long) &_etext;
819 	init_mm.end_data = (unsigned long) &_edata;
820 	init_mm.brk = (unsigned long) &_end;
821 
822 	if (MACHINE_HAS_MVCOS)
823 		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
824 	else
825 		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
826 
827 	parse_early_param();
828 
829 	setup_ipl();
830 	setup_memory_end();
831 	setup_addressing_mode();
832 	setup_memory();
833 	setup_resources();
834 	setup_lowcore();
835 
836         cpu_init();
837 	__cpu_logical_map[0] = stap();
838 	s390_init_cpu_topology();
839 
840 	/*
841 	 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
842 	 */
843 	setup_hwcaps();
844 
845 	/*
846 	 * Create kernel page tables and switch to virtual addressing.
847 	 */
848         paging_init();
849 
850         /* Setup default console */
851 	conmode_default();
852 
853 	/* Setup zfcpdump support */
854 	setup_zfcpdump(console_devno);
855 }
856