2 * arch/s390/kernel/setup.c
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)
9 * Derived from "arch/i386/kernel/setup.c"
10 * Copyright (C) 1995, Linus Torvalds
14 * This file handles the architecture-dependent parts of initialization
17 #define KMSG_COMPONENT "setup"
18 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
20 #include <linux/errno.h>
21 #include <linux/module.h>
22 #include <linux/sched.h>
23 #include <linux/kernel.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 #include <linux/ftrace.h>
48 #include <asm/uaccess.h>
49 #include <asm/system.h>
51 #include <asm/mmu_context.h>
52 #include <asm/cpcmd.h>
53 #include <asm/lowcore.h>
56 #include <asm/ptrace.h>
57 #include <asm/sections.h>
58 #include <asm/ebcdic.h>
59 #include <asm/compat.h>
60 #include <asm/kvm_virtio.h>
62 long psw_kernel_bits = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
63 PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
64 long psw_user_bits = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
65 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
66 PSW_MASK_PSTATE | PSW_DEFAULT_KEY);
69 * User copy operations.
71 struct uaccess_ops uaccess;
72 EXPORT_SYMBOL(uaccess);
77 unsigned int console_mode = 0;
78 EXPORT_SYMBOL(console_mode);
80 unsigned int console_devno = -1;
81 EXPORT_SYMBOL(console_devno);
83 unsigned int console_irq = -1;
84 EXPORT_SYMBOL(console_irq);
86 unsigned long elf_hwcap = 0;
87 char elf_platform[ELF_PLATFORM_SIZE];
89 struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
90 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
92 int __initdata memory_end_set;
93 unsigned long __initdata memory_end;
95 /* An array with a pointer to the lowcore of every CPU. */
96 struct _lowcore *lowcore_ptr[NR_CPUS];
97 EXPORT_SYMBOL(lowcore_ptr);
100 * This is set up by the setup-routine at boot-time
101 * for S390 need to find out, what we have to setup
102 * using address 0x10400 ...
105 #include <asm/setup.h>
107 static struct resource code_resource = {
108 .name = "Kernel code",
109 .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
112 static struct resource data_resource = {
113 .name = "Kernel data",
114 .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
118 * cpu_init() initializes state that is per-CPU.
120 void __cpuinit cpu_init(void)
123 * Store processor id in lowcore (used e.g. in timer_interrupt)
125 get_cpu_id(&S390_lowcore.cpu_id);
127 atomic_inc(&init_mm.mm_count);
128 current->active_mm = &init_mm;
130 enter_lazy_tlb(&init_mm, current);
134 * condev= and conmode= setup parameter.
137 static int __init condev_setup(char *str)
141 vdev = simple_strtoul(str, &str, 0);
142 if (vdev >= 0 && vdev < 65536) {
143 console_devno = vdev;
149 __setup("condev=", condev_setup);
151 static void __init set_preferred_console(void)
154 add_preferred_console("hvc", 0, NULL);
155 else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
156 add_preferred_console("ttyS", 0, NULL);
157 else if (CONSOLE_IS_3270)
158 add_preferred_console("tty3270", 0, NULL);
161 static int __init conmode_setup(char *str)
163 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
164 if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
167 #if defined(CONFIG_TN3215_CONSOLE)
168 if (strncmp(str, "3215", 5) == 0)
171 #if defined(CONFIG_TN3270_CONSOLE)
172 if (strncmp(str, "3270", 5) == 0)
175 set_preferred_console();
179 __setup("conmode=", conmode_setup);
181 static void __init conmode_default(void)
183 char query_buffer[1024];
187 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
188 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
189 ptr = strstr(query_buffer, "SUBCHANNEL =");
190 console_irq = simple_strtoul(ptr + 13, NULL, 16);
191 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
192 ptr = strstr(query_buffer, "CONMODE");
194 * Set the conmode to 3215 so that the device recognition
195 * will set the cu_type of the console to 3215. If the
196 * conmode is 3270 and we don't set it back then both
197 * 3215 and the 3270 driver will try to access the console
198 * device (3215 as console and 3270 as normal tty).
200 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
202 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
207 if (strncmp(ptr + 8, "3270", 4) == 0) {
208 #if defined(CONFIG_TN3270_CONSOLE)
210 #elif defined(CONFIG_TN3215_CONSOLE)
212 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
215 } else if (strncmp(ptr + 8, "3215", 4) == 0) {
216 #if defined(CONFIG_TN3215_CONSOLE)
218 #elif defined(CONFIG_TN3270_CONSOLE)
220 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
225 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
231 #ifdef CONFIG_ZFCPDUMP
232 static void __init setup_zfcpdump(unsigned int console_devno)
236 if (ipl_info.type != IPL_TYPE_FCP_DUMP)
238 if (console_devno != -1)
239 sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
240 ipl_info.data.fcp.dev_id.devno, console_devno);
242 sprintf(str, " cio_ignore=all,!0.0.%04x",
243 ipl_info.data.fcp.dev_id.devno);
244 strcat(boot_command_line, str);
245 console_loglevel = 2;
248 static inline void setup_zfcpdump(unsigned int console_devno) {}
249 #endif /* CONFIG_ZFCPDUMP */
252 * Reboot, halt and power_off stubs. They just call _machine_restart,
253 * _machine_halt or _machine_power_off.
256 void machine_restart(char *command)
258 if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
260 * Only unblank the console if we are called in enabled
261 * context or a bust_spinlocks cleared the way for us.
264 _machine_restart(command);
267 void machine_halt(void)
269 if (!in_interrupt() || oops_in_progress)
271 * Only unblank the console if we are called in enabled
272 * context or a bust_spinlocks cleared the way for us.
278 void machine_power_off(void)
280 if (!in_interrupt() || oops_in_progress)
282 * Only unblank the console if we are called in enabled
283 * context or a bust_spinlocks cleared the way for us.
286 _machine_power_off();
290 * Dummy power off function.
292 void (*pm_power_off)(void) = machine_power_off;
294 static int __init early_parse_mem(char *p)
296 memory_end = memparse(p, &p);
300 early_param("mem", early_parse_mem);
302 unsigned int user_mode = HOME_SPACE_MODE;
303 EXPORT_SYMBOL_GPL(user_mode);
305 static int set_amode_and_uaccess(unsigned long user_amode,
306 unsigned long user32_amode)
308 psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
309 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
310 PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
312 psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
313 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
314 PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
315 psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
316 PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
319 psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
320 PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
322 if (MACHINE_HAS_MVCOS) {
323 memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
326 memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
332 * Switch kernel/user addressing modes?
334 static int __init early_parse_switch_amode(char *p)
336 if (user_mode != SECONDARY_SPACE_MODE)
337 user_mode = PRIMARY_SPACE_MODE;
340 early_param("switch_amode", early_parse_switch_amode);
342 static int __init early_parse_user_mode(char *p)
344 if (p && strcmp(p, "primary") == 0)
345 user_mode = PRIMARY_SPACE_MODE;
346 #ifdef CONFIG_S390_EXEC_PROTECT
347 else if (p && strcmp(p, "secondary") == 0)
348 user_mode = SECONDARY_SPACE_MODE;
350 else if (!p || strcmp(p, "home") == 0)
351 user_mode = HOME_SPACE_MODE;
356 early_param("user_mode", early_parse_user_mode);
358 #ifdef CONFIG_S390_EXEC_PROTECT
360 * Enable execute protection?
362 static int __init early_parse_noexec(char *p)
364 if (!strncmp(p, "off", 3))
366 user_mode = SECONDARY_SPACE_MODE;
369 early_param("noexec", early_parse_noexec);
370 #endif /* CONFIG_S390_EXEC_PROTECT */
372 static void setup_addressing_mode(void)
374 if (user_mode == SECONDARY_SPACE_MODE) {
375 if (set_amode_and_uaccess(PSW_ASC_SECONDARY,
376 PSW32_ASC_SECONDARY))
377 pr_info("Execute protection active, "
378 "mvcos available\n");
380 pr_info("Execute protection active, "
381 "mvcos not available\n");
382 } else if (user_mode == PRIMARY_SPACE_MODE) {
383 if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
384 pr_info("Address spaces switched, "
385 "mvcos available\n");
387 pr_info("Address spaces switched, "
388 "mvcos not available\n");
390 #ifdef CONFIG_TRACE_IRQFLAGS
391 sysc_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
392 io_restore_trace_psw.mask = psw_kernel_bits & ~PSW_MASK_MCHECK;
403 * Setup lowcore for boot cpu
405 lc_pages = sizeof(void *) == 8 ? 2 : 1;
406 lc = (struct _lowcore *)
407 __alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
408 memset(lc, 0, lc_pages * PAGE_SIZE);
409 lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
410 lc->restart_psw.addr =
411 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
412 if (user_mode != HOME_SPACE_MODE)
413 lc->restart_psw.mask |= PSW_ASC_HOME;
414 lc->external_new_psw.mask = psw_kernel_bits;
415 lc->external_new_psw.addr =
416 PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
417 lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
418 lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
419 lc->program_new_psw.mask = psw_kernel_bits;
420 lc->program_new_psw.addr =
421 PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
422 lc->mcck_new_psw.mask =
423 psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
424 lc->mcck_new_psw.addr =
425 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
426 lc->io_new_psw.mask = psw_kernel_bits;
427 lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
428 lc->clock_comparator = -1ULL;
429 lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
430 lc->async_stack = (unsigned long)
431 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
432 lc->panic_stack = (unsigned long)
433 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
434 lc->current_task = (unsigned long) init_thread_union.thread_info.task;
435 lc->thread_info = (unsigned long) &init_thread_union;
436 lc->machine_flags = S390_lowcore.machine_flags;
438 if (MACHINE_HAS_IEEE) {
439 lc->extended_save_area_addr = (__u32)
440 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
441 /* enable extended save area */
442 __ctl_set_bit(14, 29);
445 lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
447 lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
448 lc->async_enter_timer = S390_lowcore.async_enter_timer;
449 lc->exit_timer = S390_lowcore.exit_timer;
450 lc->user_timer = S390_lowcore.user_timer;
451 lc->system_timer = S390_lowcore.system_timer;
452 lc->steal_timer = S390_lowcore.steal_timer;
453 lc->last_update_timer = S390_lowcore.last_update_timer;
454 lc->last_update_clock = S390_lowcore.last_update_clock;
455 lc->ftrace_func = S390_lowcore.ftrace_func;
456 set_prefix((u32)(unsigned long) lc);
461 setup_resources(void)
463 struct resource *res, *sub_res;
466 code_resource.start = (unsigned long) &_text;
467 code_resource.end = (unsigned long) &_etext - 1;
468 data_resource.start = (unsigned long) &_etext;
469 data_resource.end = (unsigned long) &_edata - 1;
471 for (i = 0; i < MEMORY_CHUNKS; i++) {
472 if (!memory_chunk[i].size)
474 res = alloc_bootmem_low(sizeof(struct resource));
475 res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
476 switch (memory_chunk[i].type) {
477 case CHUNK_READ_WRITE:
478 res->name = "System RAM";
480 case CHUNK_READ_ONLY:
481 res->name = "System ROM";
482 res->flags |= IORESOURCE_READONLY;
485 res->name = "reserved";
487 res->start = memory_chunk[i].addr;
488 res->end = memory_chunk[i].addr + memory_chunk[i].size - 1;
489 request_resource(&iomem_resource, res);
491 if (code_resource.start >= res->start &&
492 code_resource.start <= res->end &&
493 code_resource.end > res->end) {
494 sub_res = alloc_bootmem_low(sizeof(struct resource));
495 memcpy(sub_res, &code_resource,
496 sizeof(struct resource));
497 sub_res->end = res->end;
498 code_resource.start = res->end + 1;
499 request_resource(res, sub_res);
502 if (code_resource.start >= res->start &&
503 code_resource.start <= res->end &&
504 code_resource.end <= res->end)
505 request_resource(res, &code_resource);
507 if (data_resource.start >= res->start &&
508 data_resource.start <= res->end &&
509 data_resource.end > res->end) {
510 sub_res = alloc_bootmem_low(sizeof(struct resource));
511 memcpy(sub_res, &data_resource,
512 sizeof(struct resource));
513 sub_res->end = res->end;
514 data_resource.start = res->end + 1;
515 request_resource(res, sub_res);
518 if (data_resource.start >= res->start &&
519 data_resource.start <= res->end &&
520 data_resource.end <= res->end)
521 request_resource(res, &data_resource);
525 unsigned long real_memory_size;
526 EXPORT_SYMBOL_GPL(real_memory_size);
528 static void __init setup_memory_end(void)
530 unsigned long memory_size;
531 unsigned long max_mem;
534 #ifdef CONFIG_ZFCPDUMP
535 if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
536 memory_end = ZFCPDUMP_HSA_SIZE;
541 memory_end &= PAGE_MASK;
543 max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
544 memory_end = min(max_mem, memory_end);
547 * Make sure all chunks are MAX_ORDER aligned so we don't need the
548 * extra checks that HOLES_IN_ZONE would require.
550 for (i = 0; i < MEMORY_CHUNKS; i++) {
551 unsigned long start, end;
552 struct mem_chunk *chunk;
555 chunk = &memory_chunk[i];
556 align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
557 start = (chunk->addr + align - 1) & ~(align - 1);
558 end = (chunk->addr + chunk->size) & ~(align - 1);
560 memset(chunk, 0, sizeof(*chunk));
563 chunk->size = end - start;
567 for (i = 0; i < MEMORY_CHUNKS; i++) {
568 struct mem_chunk *chunk = &memory_chunk[i];
570 real_memory_size = max(real_memory_size,
571 chunk->addr + chunk->size);
572 if (chunk->addr >= max_mem) {
573 memset(chunk, 0, sizeof(*chunk));
576 if (chunk->addr + chunk->size > max_mem)
577 chunk->size = max_mem - chunk->addr;
578 memory_size = max(memory_size, chunk->addr + chunk->size);
581 memory_end = memory_size;
587 unsigned long bootmap_size;
588 unsigned long start_pfn, end_pfn;
592 * partially used pages are not usable - thus
593 * we are rounding upwards:
595 start_pfn = PFN_UP(__pa(&_end));
596 end_pfn = max_pfn = PFN_DOWN(memory_end);
598 #ifdef CONFIG_BLK_DEV_INITRD
600 * Move the initrd in case the bitmap of the bootmem allocater
601 * would overwrite it.
604 if (INITRD_START && INITRD_SIZE) {
605 unsigned long bmap_size;
608 bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
609 bmap_size = PFN_PHYS(bmap_size);
611 if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
612 start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
614 if (start + INITRD_SIZE > memory_end) {
615 pr_err("initrd extends beyond end of "
616 "memory (0x%08lx > 0x%08lx) "
617 "disabling initrd\n",
618 start + INITRD_SIZE, memory_end);
619 INITRD_START = INITRD_SIZE = 0;
621 pr_info("Moving initrd (0x%08lx -> "
622 "0x%08lx, size: %ld)\n",
623 INITRD_START, start, INITRD_SIZE);
624 memmove((void *) start, (void *) INITRD_START,
626 INITRD_START = start;
633 * Initialize the boot-time allocator
635 bootmap_size = init_bootmem(start_pfn, end_pfn);
638 * Register RAM areas with the bootmem allocator.
641 for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
642 unsigned long start_chunk, end_chunk, pfn;
644 if (memory_chunk[i].type != CHUNK_READ_WRITE)
646 start_chunk = PFN_DOWN(memory_chunk[i].addr);
647 end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
648 end_chunk = min(end_chunk, end_pfn);
649 if (start_chunk >= end_chunk)
651 add_active_range(0, start_chunk, end_chunk);
652 pfn = max(start_chunk, start_pfn);
653 for (; pfn < end_chunk; pfn++)
654 page_set_storage_key(PFN_PHYS(pfn), PAGE_DEFAULT_KEY);
657 psw_set_key(PAGE_DEFAULT_KEY);
659 free_bootmem_with_active_regions(0, max_pfn);
662 * Reserve memory used for lowcore/command line/kernel image.
664 reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
665 reserve_bootmem((unsigned long)_stext,
666 PFN_PHYS(start_pfn) - (unsigned long)_stext,
669 * Reserve the bootmem bitmap itself as well. We do this in two
670 * steps (first step was init_bootmem()) because this catches
671 * the (very unlikely) case of us accidentally initializing the
672 * bootmem allocator with an invalid RAM area.
674 reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
677 #ifdef CONFIG_BLK_DEV_INITRD
678 if (INITRD_START && INITRD_SIZE) {
679 if (INITRD_START + INITRD_SIZE <= memory_end) {
680 reserve_bootmem(INITRD_START, INITRD_SIZE,
682 initrd_start = INITRD_START;
683 initrd_end = initrd_start + INITRD_SIZE;
685 pr_err("initrd extends beyond end of "
686 "memory (0x%08lx > 0x%08lx) "
687 "disabling initrd\n",
688 initrd_start + INITRD_SIZE, memory_end);
689 initrd_start = initrd_end = 0;
696 * Setup hardware capabilities.
698 static void __init setup_hwcaps(void)
700 static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
701 unsigned long long facility_list_extended;
702 unsigned int facility_list;
705 facility_list = stfl();
707 * The store facility list bits numbers as found in the principles
708 * of operation are numbered with bit 1UL<<31 as number 0 to
709 * bit 1UL<<0 as number 31.
710 * Bit 0: instructions named N3, "backported" to esa-mode
711 * Bit 2: z/Architecture mode is active
712 * Bit 7: the store-facility-list-extended facility is installed
713 * Bit 17: the message-security assist is installed
714 * Bit 19: the long-displacement facility is installed
715 * Bit 21: the extended-immediate facility is installed
716 * Bit 22: extended-translation facility 3 is installed
717 * Bit 30: extended-translation facility 3 enhancement facility
718 * These get translated to:
719 * HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
720 * HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
721 * HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
722 * HWCAP_S390_ETF3EH bit 8 (22 && 30).
724 for (i = 0; i < 6; i++)
725 if (facility_list & (1UL << (31 - stfl_bits[i])))
726 elf_hwcap |= 1UL << i;
728 if ((facility_list & (1UL << (31 - 22)))
729 && (facility_list & (1UL << (31 - 30))))
730 elf_hwcap |= HWCAP_S390_ETF3EH;
733 * Check for additional facilities with store-facility-list-extended.
734 * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
735 * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
736 * as stored by stfl, bits 32-xxx contain additional facilities.
737 * How many facility words are stored depends on the number of
738 * doublewords passed to the instruction. The additional facilites
740 * Bit 42: decimal floating point facility is installed
741 * Bit 44: perform floating point operation facility is installed
743 * HWCAP_S390_DFP bit 6 (42 && 44).
745 if ((elf_hwcap & (1UL << 2)) &&
746 __stfle(&facility_list_extended, 1) > 0) {
747 if ((facility_list_extended & (1ULL << (63 - 42)))
748 && (facility_list_extended & (1ULL << (63 - 44))))
749 elf_hwcap |= HWCAP_S390_DFP;
753 * Huge page support HWCAP_S390_HPAGE is bit 7.
755 if (MACHINE_HAS_HPAGE)
756 elf_hwcap |= HWCAP_S390_HPAGE;
759 * 64-bit register support for 31-bit processes
760 * HWCAP_S390_HIGH_GPRS is bit 9.
762 elf_hwcap |= HWCAP_S390_HIGH_GPRS;
764 switch (S390_lowcore.cpu_id.machine) {
766 #if !defined(CONFIG_64BIT)
767 default: /* Use "g5" as default for 31 bit kernels. */
769 strcpy(elf_platform, "g5");
773 #if defined(CONFIG_64BIT)
774 default: /* Use "z900" as default for 64 bit kernels. */
776 strcpy(elf_platform, "z900");
780 strcpy(elf_platform, "z990");
784 strcpy(elf_platform, "z9-109");
788 strcpy(elf_platform, "z10");
794 * Setup function called from init/main.c just after the banner
799 setup_arch(char **cmdline_p)
802 * print what head.S has found out about the machine
806 pr_info("Linux is running as a z/VM "
807 "guest operating system in 31-bit mode\n");
809 pr_info("Linux is running natively in 31-bit mode\n");
810 if (MACHINE_HAS_IEEE)
811 pr_info("The hardware system has IEEE compatible "
812 "floating point units\n");
814 pr_info("The hardware system has no IEEE compatible "
815 "floating point units\n");
816 #else /* CONFIG_64BIT */
818 pr_info("Linux is running as a z/VM "
819 "guest operating system in 64-bit mode\n");
820 else if (MACHINE_IS_KVM)
821 pr_info("Linux is running under KVM in 64-bit mode\n");
823 pr_info("Linux is running natively in 64-bit mode\n");
824 #endif /* CONFIG_64BIT */
826 /* Have one command line that is parsed and saved in /proc/cmdline */
827 /* boot_command_line has been already set up in early.c */
828 *cmdline_p = boot_command_line;
830 ROOT_DEV = Root_RAM0;
832 init_mm.start_code = PAGE_OFFSET;
833 init_mm.end_code = (unsigned long) &_etext;
834 init_mm.end_data = (unsigned long) &_edata;
835 init_mm.brk = (unsigned long) &_end;
837 if (MACHINE_HAS_MVCOS)
838 memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
840 memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
846 setup_addressing_mode();
852 s390_init_cpu_topology();
855 * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
860 * Create kernel page tables and switch to virtual addressing.
864 /* Setup default console */
866 set_preferred_console();
868 /* Setup zfcpdump support */
869 setup_zfcpdump(console_devno);