[S390] Remove data execution protection
[linux-3.10.git] / arch / s390 / kernel / setup.c
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
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
90 int __initdata memory_end_set;
91 unsigned long __initdata memory_end;
92
93 /* An array with a pointer to the lowcore of every CPU. */
94 struct _lowcore *lowcore_ptr[NR_CPUS];
95 EXPORT_SYMBOL(lowcore_ptr);
96
97 /*
98  * This is set up by the setup-routine at boot-time
99  * for S390 need to find out, what we have to setup
100  * using address 0x10400 ...
101  */
102
103 #include <asm/setup.h>
104
105 /*
106  * condev= and conmode= setup parameter.
107  */
108
109 static int __init condev_setup(char *str)
110 {
111         int vdev;
112
113         vdev = simple_strtoul(str, &str, 0);
114         if (vdev >= 0 && vdev < 65536) {
115                 console_devno = vdev;
116                 console_irq = -1;
117         }
118         return 1;
119 }
120
121 __setup("condev=", condev_setup);
122
123 static void __init set_preferred_console(void)
124 {
125         if (MACHINE_IS_KVM)
126                 add_preferred_console("hvc", 0, NULL);
127         else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
128                 add_preferred_console("ttyS", 0, NULL);
129         else if (CONSOLE_IS_3270)
130                 add_preferred_console("tty3270", 0, NULL);
131 }
132
133 static int __init conmode_setup(char *str)
134 {
135 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
136         if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
137                 SET_CONSOLE_SCLP;
138 #endif
139 #if defined(CONFIG_TN3215_CONSOLE)
140         if (strncmp(str, "3215", 5) == 0)
141                 SET_CONSOLE_3215;
142 #endif
143 #if defined(CONFIG_TN3270_CONSOLE)
144         if (strncmp(str, "3270", 5) == 0)
145                 SET_CONSOLE_3270;
146 #endif
147         set_preferred_console();
148         return 1;
149 }
150
151 __setup("conmode=", conmode_setup);
152
153 static void __init conmode_default(void)
154 {
155         char query_buffer[1024];
156         char *ptr;
157
158         if (MACHINE_IS_VM) {
159                 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
160                 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
161                 ptr = strstr(query_buffer, "SUBCHANNEL =");
162                 console_irq = simple_strtoul(ptr + 13, NULL, 16);
163                 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
164                 ptr = strstr(query_buffer, "CONMODE");
165                 /*
166                  * Set the conmode to 3215 so that the device recognition 
167                  * will set the cu_type of the console to 3215. If the
168                  * conmode is 3270 and we don't set it back then both
169                  * 3215 and the 3270 driver will try to access the console
170                  * device (3215 as console and 3270 as normal tty).
171                  */
172                 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
173                 if (ptr == NULL) {
174 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
175                         SET_CONSOLE_SCLP;
176 #endif
177                         return;
178                 }
179                 if (strncmp(ptr + 8, "3270", 4) == 0) {
180 #if defined(CONFIG_TN3270_CONSOLE)
181                         SET_CONSOLE_3270;
182 #elif defined(CONFIG_TN3215_CONSOLE)
183                         SET_CONSOLE_3215;
184 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
185                         SET_CONSOLE_SCLP;
186 #endif
187                 } else if (strncmp(ptr + 8, "3215", 4) == 0) {
188 #if defined(CONFIG_TN3215_CONSOLE)
189                         SET_CONSOLE_3215;
190 #elif defined(CONFIG_TN3270_CONSOLE)
191                         SET_CONSOLE_3270;
192 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
193                         SET_CONSOLE_SCLP;
194 #endif
195                 }
196         } else {
197 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
198                 SET_CONSOLE_SCLP;
199 #endif
200         }
201 }
202
203 #ifdef CONFIG_ZFCPDUMP
204 static void __init setup_zfcpdump(unsigned int console_devno)
205 {
206         static char str[41];
207
208         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
209                 return;
210         if (console_devno != -1)
211                 sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
212                         ipl_info.data.fcp.dev_id.devno, console_devno);
213         else
214                 sprintf(str, " cio_ignore=all,!0.0.%04x",
215                         ipl_info.data.fcp.dev_id.devno);
216         strcat(boot_command_line, str);
217         console_loglevel = 2;
218 }
219 #else
220 static inline void setup_zfcpdump(unsigned int console_devno) {}
221 #endif /* CONFIG_ZFCPDUMP */
222
223  /*
224  * Reboot, halt and power_off stubs. They just call _machine_restart,
225  * _machine_halt or _machine_power_off. 
226  */
227
228 void machine_restart(char *command)
229 {
230         if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
231                 /*
232                  * Only unblank the console if we are called in enabled
233                  * context or a bust_spinlocks cleared the way for us.
234                  */
235                 console_unblank();
236         _machine_restart(command);
237 }
238
239 void machine_halt(void)
240 {
241         if (!in_interrupt() || oops_in_progress)
242                 /*
243                  * Only unblank the console if we are called in enabled
244                  * context or a bust_spinlocks cleared the way for us.
245                  */
246                 console_unblank();
247         _machine_halt();
248 }
249
250 void machine_power_off(void)
251 {
252         if (!in_interrupt() || 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_power_off();
259 }
260
261 /*
262  * Dummy power off function.
263  */
264 void (*pm_power_off)(void) = machine_power_off;
265
266 static int __init early_parse_mem(char *p)
267 {
268         memory_end = memparse(p, &p);
269         memory_end_set = 1;
270         return 0;
271 }
272 early_param("mem", early_parse_mem);
273
274 unsigned int user_mode = HOME_SPACE_MODE;
275 EXPORT_SYMBOL_GPL(user_mode);
276
277 static int set_amode_and_uaccess(unsigned long user_amode,
278                                  unsigned long user32_amode)
279 {
280         psw_user_bits = PSW_BASE_BITS | PSW_MASK_DAT | user_amode |
281                         PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
282                         PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
283 #ifdef CONFIG_COMPAT
284         psw_user32_bits = PSW_BASE32_BITS | PSW_MASK_DAT | user_amode |
285                           PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
286                           PSW_MASK_PSTATE | PSW_DEFAULT_KEY;
287         psw32_user_bits = PSW32_BASE_BITS | PSW32_MASK_DAT | user32_amode |
288                           PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
289                           PSW32_MASK_PSTATE;
290 #endif
291         psw_kernel_bits = PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
292                           PSW_MASK_MCHECK | PSW_DEFAULT_KEY;
293
294         if (MACHINE_HAS_MVCOS) {
295                 memcpy(&uaccess, &uaccess_mvcos_switch, sizeof(uaccess));
296                 return 1;
297         } else {
298                 memcpy(&uaccess, &uaccess_pt, sizeof(uaccess));
299                 return 0;
300         }
301 }
302
303 /*
304  * Switch kernel/user addressing modes?
305  */
306 static int __init early_parse_switch_amode(char *p)
307 {
308         user_mode = PRIMARY_SPACE_MODE;
309         return 0;
310 }
311 early_param("switch_amode", early_parse_switch_amode);
312
313 static int __init early_parse_user_mode(char *p)
314 {
315         if (p && strcmp(p, "primary") == 0)
316                 user_mode = PRIMARY_SPACE_MODE;
317         else if (!p || strcmp(p, "home") == 0)
318                 user_mode = HOME_SPACE_MODE;
319         else
320                 return 1;
321         return 0;
322 }
323 early_param("user_mode", early_parse_user_mode);
324
325 static void setup_addressing_mode(void)
326 {
327         if (user_mode == PRIMARY_SPACE_MODE) {
328                 if (set_amode_and_uaccess(PSW_ASC_PRIMARY, PSW32_ASC_PRIMARY))
329                         pr_info("Address spaces switched, "
330                                 "mvcos available\n");
331                 else
332                         pr_info("Address spaces switched, "
333                                 "mvcos not available\n");
334         }
335 }
336
337 static void __init
338 setup_lowcore(void)
339 {
340         struct _lowcore *lc;
341
342         /*
343          * Setup lowcore for boot cpu
344          */
345         BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
346         lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
347         lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
348         lc->restart_psw.addr =
349                 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
350         if (user_mode != HOME_SPACE_MODE)
351                 lc->restart_psw.mask |= PSW_ASC_HOME;
352         lc->external_new_psw.mask = psw_kernel_bits;
353         lc->external_new_psw.addr =
354                 PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
355         lc->svc_new_psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
356         lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
357         lc->program_new_psw.mask = psw_kernel_bits;
358         lc->program_new_psw.addr =
359                 PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
360         lc->mcck_new_psw.mask =
361                 psw_kernel_bits & ~PSW_MASK_MCHECK & ~PSW_MASK_DAT;
362         lc->mcck_new_psw.addr =
363                 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
364         lc->io_new_psw.mask = psw_kernel_bits;
365         lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
366         lc->clock_comparator = -1ULL;
367         lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
368         lc->async_stack = (unsigned long)
369                 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
370         lc->panic_stack = (unsigned long)
371                 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
372         lc->current_task = (unsigned long) init_thread_union.thread_info.task;
373         lc->thread_info = (unsigned long) &init_thread_union;
374         lc->machine_flags = S390_lowcore.machine_flags;
375         lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
376         memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
377                MAX_FACILITY_BIT/8);
378 #ifndef CONFIG_64BIT
379         if (MACHINE_HAS_IEEE) {
380                 lc->extended_save_area_addr = (__u32)
381                         __alloc_bootmem_low(PAGE_SIZE, PAGE_SIZE, 0);
382                 /* enable extended save area */
383                 __ctl_set_bit(14, 29);
384         }
385 #else
386         lc->cmf_hpp = -1ULL;
387         lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
388 #endif
389         lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
390         lc->async_enter_timer = S390_lowcore.async_enter_timer;
391         lc->exit_timer = S390_lowcore.exit_timer;
392         lc->user_timer = S390_lowcore.user_timer;
393         lc->system_timer = S390_lowcore.system_timer;
394         lc->steal_timer = S390_lowcore.steal_timer;
395         lc->last_update_timer = S390_lowcore.last_update_timer;
396         lc->last_update_clock = S390_lowcore.last_update_clock;
397         lc->ftrace_func = S390_lowcore.ftrace_func;
398         set_prefix((u32)(unsigned long) lc);
399         lowcore_ptr[0] = lc;
400 }
401
402 static struct resource code_resource = {
403         .name  = "Kernel code",
404         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
405 };
406
407 static struct resource data_resource = {
408         .name = "Kernel data",
409         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
410 };
411
412 static struct resource bss_resource = {
413         .name = "Kernel bss",
414         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
415 };
416
417 static struct resource __initdata *standard_resources[] = {
418         &code_resource,
419         &data_resource,
420         &bss_resource,
421 };
422
423 static void __init setup_resources(void)
424 {
425         struct resource *res, *std_res, *sub_res;
426         int i, j;
427
428         code_resource.start = (unsigned long) &_text;
429         code_resource.end = (unsigned long) &_etext - 1;
430         data_resource.start = (unsigned long) &_etext;
431         data_resource.end = (unsigned long) &_edata - 1;
432         bss_resource.start = (unsigned long) &__bss_start;
433         bss_resource.end = (unsigned long) &__bss_stop - 1;
434
435         for (i = 0; i < MEMORY_CHUNKS; i++) {
436                 if (!memory_chunk[i].size)
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                         res->name = "System RAM";
443                         break;
444                 case CHUNK_READ_ONLY:
445                         res->name = "System ROM";
446                         res->flags |= IORESOURCE_READONLY;
447                         break;
448                 default:
449                         res->name = "reserved";
450                 }
451                 res->start = memory_chunk[i].addr;
452                 res->end = res->start + memory_chunk[i].size - 1;
453                 request_resource(&iomem_resource, res);
454
455                 for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
456                         std_res = standard_resources[j];
457                         if (std_res->start < res->start ||
458                             std_res->start > res->end)
459                                 continue;
460                         if (std_res->end > res->end) {
461                                 sub_res = alloc_bootmem_low(sizeof(*sub_res));
462                                 *sub_res = *std_res;
463                                 sub_res->end = res->end;
464                                 std_res->start = res->end + 1;
465                                 request_resource(res, sub_res);
466                         } else {
467                                 request_resource(res, std_res);
468                         }
469                 }
470         }
471 }
472
473 unsigned long real_memory_size;
474 EXPORT_SYMBOL_GPL(real_memory_size);
475
476 static void __init setup_memory_end(void)
477 {
478         unsigned long memory_size;
479         unsigned long max_mem;
480         int i;
481
482 #ifdef CONFIG_ZFCPDUMP
483         if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
484                 memory_end = ZFCPDUMP_HSA_SIZE;
485                 memory_end_set = 1;
486         }
487 #endif
488         memory_size = 0;
489         memory_end &= PAGE_MASK;
490
491         max_mem = memory_end ? min(VMEM_MAX_PHYS, memory_end) : VMEM_MAX_PHYS;
492         memory_end = min(max_mem, memory_end);
493
494         /*
495          * Make sure all chunks are MAX_ORDER aligned so we don't need the
496          * extra checks that HOLES_IN_ZONE would require.
497          */
498         for (i = 0; i < MEMORY_CHUNKS; i++) {
499                 unsigned long start, end;
500                 struct mem_chunk *chunk;
501                 unsigned long align;
502
503                 chunk = &memory_chunk[i];
504                 align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
505                 start = (chunk->addr + align - 1) & ~(align - 1);
506                 end = (chunk->addr + chunk->size) & ~(align - 1);
507                 if (start >= end)
508                         memset(chunk, 0, sizeof(*chunk));
509                 else {
510                         chunk->addr = start;
511                         chunk->size = end - start;
512                 }
513         }
514
515         for (i = 0; i < MEMORY_CHUNKS; i++) {
516                 struct mem_chunk *chunk = &memory_chunk[i];
517
518                 real_memory_size = max(real_memory_size,
519                                        chunk->addr + chunk->size);
520                 if (chunk->addr >= max_mem) {
521                         memset(chunk, 0, sizeof(*chunk));
522                         continue;
523                 }
524                 if (chunk->addr + chunk->size > max_mem)
525                         chunk->size = max_mem - chunk->addr;
526                 memory_size = max(memory_size, chunk->addr + chunk->size);
527         }
528         if (!memory_end)
529                 memory_end = memory_size;
530 }
531
532 static void __init
533 setup_memory(void)
534 {
535         unsigned long bootmap_size;
536         unsigned long start_pfn, end_pfn;
537         int i;
538
539         /*
540          * partially used pages are not usable - thus
541          * we are rounding upwards:
542          */
543         start_pfn = PFN_UP(__pa(&_end));
544         end_pfn = max_pfn = PFN_DOWN(memory_end);
545
546 #ifdef CONFIG_BLK_DEV_INITRD
547         /*
548          * Move the initrd in case the bitmap of the bootmem allocater
549          * would overwrite it.
550          */
551
552         if (INITRD_START && INITRD_SIZE) {
553                 unsigned long bmap_size;
554                 unsigned long start;
555
556                 bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
557                 bmap_size = PFN_PHYS(bmap_size);
558
559                 if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
560                         start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
561
562                         if (start + INITRD_SIZE > memory_end) {
563                                 pr_err("initrd extends beyond end of "
564                                        "memory (0x%08lx > 0x%08lx) "
565                                        "disabling initrd\n",
566                                        start + INITRD_SIZE, memory_end);
567                                 INITRD_START = INITRD_SIZE = 0;
568                         } else {
569                                 pr_info("Moving initrd (0x%08lx -> "
570                                         "0x%08lx, size: %ld)\n",
571                                         INITRD_START, start, INITRD_SIZE);
572                                 memmove((void *) start, (void *) INITRD_START,
573                                         INITRD_SIZE);
574                                 INITRD_START = start;
575                         }
576                 }
577         }
578 #endif
579
580         /*
581          * Initialize the boot-time allocator
582          */
583         bootmap_size = init_bootmem(start_pfn, end_pfn);
584
585         /*
586          * Register RAM areas with the bootmem allocator.
587          */
588
589         for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
590                 unsigned long start_chunk, end_chunk, pfn;
591
592                 if (memory_chunk[i].type != CHUNK_READ_WRITE)
593                         continue;
594                 start_chunk = PFN_DOWN(memory_chunk[i].addr);
595                 end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
596                 end_chunk = min(end_chunk, end_pfn);
597                 if (start_chunk >= end_chunk)
598                         continue;
599                 add_active_range(0, start_chunk, end_chunk);
600                 pfn = max(start_chunk, start_pfn);
601                 for (; pfn < end_chunk; pfn++)
602                         page_set_storage_key(PFN_PHYS(pfn),
603                                              PAGE_DEFAULT_KEY, 0);
604         }
605
606         psw_set_key(PAGE_DEFAULT_KEY);
607
608         free_bootmem_with_active_regions(0, max_pfn);
609
610         /*
611          * Reserve memory used for lowcore/command line/kernel image.
612          */
613         reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
614         reserve_bootmem((unsigned long)_stext,
615                         PFN_PHYS(start_pfn) - (unsigned long)_stext,
616                         BOOTMEM_DEFAULT);
617         /*
618          * Reserve the bootmem bitmap itself as well. We do this in two
619          * steps (first step was init_bootmem()) because this catches
620          * the (very unlikely) case of us accidentally initializing the
621          * bootmem allocator with an invalid RAM area.
622          */
623         reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
624                         BOOTMEM_DEFAULT);
625
626 #ifdef CONFIG_BLK_DEV_INITRD
627         if (INITRD_START && INITRD_SIZE) {
628                 if (INITRD_START + INITRD_SIZE <= memory_end) {
629                         reserve_bootmem(INITRD_START, INITRD_SIZE,
630                                         BOOTMEM_DEFAULT);
631                         initrd_start = INITRD_START;
632                         initrd_end = initrd_start + INITRD_SIZE;
633                 } else {
634                         pr_err("initrd extends beyond end of "
635                                "memory (0x%08lx > 0x%08lx) "
636                                "disabling initrd\n",
637                                initrd_start + INITRD_SIZE, memory_end);
638                         initrd_start = initrd_end = 0;
639                 }
640         }
641 #endif
642 }
643
644 /*
645  * Setup hardware capabilities.
646  */
647 static void __init setup_hwcaps(void)
648 {
649         static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
650         struct cpuid cpu_id;
651         int i;
652
653         /*
654          * The store facility list bits numbers as found in the principles
655          * of operation are numbered with bit 1UL<<31 as number 0 to
656          * bit 1UL<<0 as number 31.
657          *   Bit 0: instructions named N3, "backported" to esa-mode
658          *   Bit 2: z/Architecture mode is active
659          *   Bit 7: the store-facility-list-extended facility is installed
660          *   Bit 17: the message-security assist is installed
661          *   Bit 19: the long-displacement facility is installed
662          *   Bit 21: the extended-immediate facility is installed
663          *   Bit 22: extended-translation facility 3 is installed
664          *   Bit 30: extended-translation facility 3 enhancement facility
665          * These get translated to:
666          *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
667          *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
668          *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
669          *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
670          */
671         for (i = 0; i < 6; i++)
672                 if (test_facility(stfl_bits[i]))
673                         elf_hwcap |= 1UL << i;
674
675         if (test_facility(22) && test_facility(30))
676                 elf_hwcap |= HWCAP_S390_ETF3EH;
677
678         /*
679          * Check for additional facilities with store-facility-list-extended.
680          * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
681          * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
682          * as stored by stfl, bits 32-xxx contain additional facilities.
683          * How many facility words are stored depends on the number of
684          * doublewords passed to the instruction. The additional facilities
685          * are:
686          *   Bit 42: decimal floating point facility is installed
687          *   Bit 44: perform floating point operation facility is installed
688          * translated to:
689          *   HWCAP_S390_DFP bit 6 (42 && 44).
690          */
691         if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
692                 elf_hwcap |= HWCAP_S390_DFP;
693
694         /*
695          * Huge page support HWCAP_S390_HPAGE is bit 7.
696          */
697         if (MACHINE_HAS_HPAGE)
698                 elf_hwcap |= HWCAP_S390_HPAGE;
699
700         /*
701          * 64-bit register support for 31-bit processes
702          * HWCAP_S390_HIGH_GPRS is bit 9.
703          */
704         elf_hwcap |= HWCAP_S390_HIGH_GPRS;
705
706         get_cpu_id(&cpu_id);
707         switch (cpu_id.machine) {
708         case 0x9672:
709 #if !defined(CONFIG_64BIT)
710         default:        /* Use "g5" as default for 31 bit kernels. */
711 #endif
712                 strcpy(elf_platform, "g5");
713                 break;
714         case 0x2064:
715         case 0x2066:
716 #if defined(CONFIG_64BIT)
717         default:        /* Use "z900" as default for 64 bit kernels. */
718 #endif
719                 strcpy(elf_platform, "z900");
720                 break;
721         case 0x2084:
722         case 0x2086:
723                 strcpy(elf_platform, "z990");
724                 break;
725         case 0x2094:
726         case 0x2096:
727                 strcpy(elf_platform, "z9-109");
728                 break;
729         case 0x2097:
730         case 0x2098:
731                 strcpy(elf_platform, "z10");
732                 break;
733         case 0x2817:
734                 strcpy(elf_platform, "z196");
735                 break;
736         }
737 }
738
739 /*
740  * Setup function called from init/main.c just after the banner
741  * was printed.
742  */
743
744 void __init
745 setup_arch(char **cmdline_p)
746 {
747         /*
748          * print what head.S has found out about the machine
749          */
750 #ifndef CONFIG_64BIT
751         if (MACHINE_IS_VM)
752                 pr_info("Linux is running as a z/VM "
753                         "guest operating system in 31-bit mode\n");
754         else if (MACHINE_IS_LPAR)
755                 pr_info("Linux is running natively in 31-bit mode\n");
756         if (MACHINE_HAS_IEEE)
757                 pr_info("The hardware system has IEEE compatible "
758                         "floating point units\n");
759         else
760                 pr_info("The hardware system has no IEEE compatible "
761                         "floating point units\n");
762 #else /* CONFIG_64BIT */
763         if (MACHINE_IS_VM)
764                 pr_info("Linux is running as a z/VM "
765                         "guest operating system in 64-bit mode\n");
766         else if (MACHINE_IS_KVM)
767                 pr_info("Linux is running under KVM in 64-bit mode\n");
768         else if (MACHINE_IS_LPAR)
769                 pr_info("Linux is running natively in 64-bit mode\n");
770 #endif /* CONFIG_64BIT */
771
772         /* Have one command line that is parsed and saved in /proc/cmdline */
773         /* boot_command_line has been already set up in early.c */
774         *cmdline_p = boot_command_line;
775
776         ROOT_DEV = Root_RAM0;
777
778         init_mm.start_code = PAGE_OFFSET;
779         init_mm.end_code = (unsigned long) &_etext;
780         init_mm.end_data = (unsigned long) &_edata;
781         init_mm.brk = (unsigned long) &_end;
782
783         if (MACHINE_HAS_MVCOS)
784                 memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
785         else
786                 memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
787
788         parse_early_param();
789
790         setup_ipl();
791         setup_memory_end();
792         setup_addressing_mode();
793         setup_memory();
794         setup_resources();
795         setup_lowcore();
796
797         cpu_init();
798         s390_init_cpu_topology();
799
800         /*
801          * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
802          */
803         setup_hwcaps();
804
805         /*
806          * Create kernel page tables and switch to virtual addressing.
807          */
808         paging_init();
809
810         /* Setup default console */
811         conmode_default();
812         set_preferred_console();
813
814         /* Setup zfcpdump support */
815         setup_zfcpdump(console_devno);
816 }