arch/s390/kernel/setup.c

   1 /*
   2  *  S390 version
   3  *    Copyright IBM Corp. 1999, 2012
   4  *    Author(s): Hartmut Penner (hp@de.ibm.com),
   5  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   6  *
   7  *  Derived from "arch/i386/kernel/setup.c"
   8  *    Copyright (C) 1995, Linus Torvalds
   9  */
  10
  11 /*
  12  * This file handles the architecture-dependent parts of initialization
  13  */
  14
  15 #define KMSG_COMPONENT "setup"
  16 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  17
  18 #include <linux/errno.h>
  19 #include <linux/export.h>
  20 #include <linux/sched.h>
  21 #include <linux/kernel.h>
  22 #include <linux/memblock.h>
  23 #include <linux/mm.h>
  24 #include <linux/stddef.h>
  25 #include <linux/unistd.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/random.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/kexec.h>
  45 #include <linux/crash_dump.h>
  46 #include <linux/memory.h>
  47 #include <linux/compat.h>
  48
  49 #include <asm/ipl.h>
  50 #include <asm/facility.h>
  51 #include <asm/smp.h>
  52 #include <asm/mmu_context.h>
  53 #include <asm/cpcmd.h>
  54 #include <asm/lowcore.h>
  55 #include <asm/irq.h>
  56 #include <asm/page.h>
  57 #include <asm/ptrace.h>
  58 #include <asm/sections.h>
  59 #include <asm/ebcdic.h>
  60 #include <asm/kvm_virtio.h>
  61 #include <asm/diag.h>
  62 #include <asm/os_info.h>
  63 #include <asm/sclp.h>
  64 #include <asm/sysinfo.h>
  65 #include <asm/numa.h>
  66 #include "entry.h"
  67
  68 /*
  69  * Machine setup..
  70  */
  71 unsigned int console_mode = 0;
  72 EXPORT_SYMBOL(console_mode);
  73
  74 unsigned int console_devno = -1;
  75 EXPORT_SYMBOL(console_devno);
  76
  77 unsigned int console_irq = -1;
  78 EXPORT_SYMBOL(console_irq);
  79
  80 unsigned long elf_hwcap __read_mostly = 0;
  81 char elf_platform[ELF_PLATFORM_SIZE];
  82
  83 int __initdata memory_end_set;
  84 unsigned long __initdata memory_end;
  85 unsigned long __initdata max_physmem_end;
  86
  87 unsigned long VMALLOC_START;
  88 EXPORT_SYMBOL(VMALLOC_START);
  89
  90 unsigned long VMALLOC_END;
  91 EXPORT_SYMBOL(VMALLOC_END);
  92
  93 struct page *vmemmap;
  94 EXPORT_SYMBOL(vmemmap);
  95
  96 unsigned long MODULES_VADDR;
  97 unsigned long MODULES_END;
  98
  99 /* An array with a pointer to the lowcore of every CPU. */
 100 struct _lowcore *lowcore_ptr[NR_CPUS];
 101 EXPORT_SYMBOL(lowcore_ptr);
 102
 103 /*
 104  * This is set up by the setup-routine at boot-time
 105  * for S390 need to find out, what we have to setup
 106  * using address 0x10400 ...
 107  */
 108
 109 #include <asm/setup.h>
 110
 111 /*
 112  * condev= and conmode= setup parameter.
 113  */
 114
 115 static int __init condev_setup(char *str)
 116 {
 117         int vdev;
 118
 119         vdev = simple_strtoul(str, &str, 0);
 120         if (vdev >= 0 && vdev < 65536) {
 121                 console_devno = vdev;
 122                 console_irq = -1;
 123         }
 124         return 1;
 125 }
 126
 127 __setup("condev=", condev_setup);
 128
 129 static void __init set_preferred_console(void)
 130 {
 131         if (MACHINE_IS_KVM) {
 132                 if (sclp.has_vt220)
 133                         add_preferred_console("ttyS", 1, NULL);
 134                 else if (sclp.has_linemode)
 135                         add_preferred_console("ttyS", 0, NULL);
 136                 else
 137                         add_preferred_console("hvc", 0, NULL);
 138         } else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
 139                 add_preferred_console("ttyS", 0, NULL);
 140         else if (CONSOLE_IS_3270)
 141                 add_preferred_console("tty3270", 0, NULL);
 142 }
 143
 144 static int __init conmode_setup(char *str)
 145 {
 146 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 147         if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
 148                 SET_CONSOLE_SCLP;
 149 #endif
 150 #if defined(CONFIG_TN3215_CONSOLE)
 151         if (strncmp(str, "3215", 5) == 0)
 152                 SET_CONSOLE_3215;
 153 #endif
 154 #if defined(CONFIG_TN3270_CONSOLE)
 155         if (strncmp(str, "3270", 5) == 0)
 156                 SET_CONSOLE_3270;
 157 #endif
 158         set_preferred_console();
 159         return 1;
 160 }
 161
 162 __setup("conmode=", conmode_setup);
 163
 164 static void __init conmode_default(void)
 165 {
 166         char query_buffer[1024];
 167         char *ptr;
 168
 169         if (MACHINE_IS_VM) {
 170                 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
 171                 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
 172                 ptr = strstr(query_buffer, "SUBCHANNEL =");
 173                 console_irq = simple_strtoul(ptr + 13, NULL, 16);
 174                 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
 175                 ptr = strstr(query_buffer, "CONMODE");
 176                 /*
 177                  * Set the conmode to 3215 so that the device recognition
 178                  * will set the cu_type of the console to 3215. If the
 179                  * conmode is 3270 and we don't set it back then both
 180                  * 3215 and the 3270 driver will try to access the console
 181                  * device (3215 as console and 3270 as normal tty).
 182                  */
 183                 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
 184                 if (ptr == NULL) {
 185 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 186                         SET_CONSOLE_SCLP;
 187 #endif
 188                         return;
 189                 }
 190                 if (strncmp(ptr + 8, "3270", 4) == 0) {
 191 #if defined(CONFIG_TN3270_CONSOLE)
 192                         SET_CONSOLE_3270;
 193 #elif defined(CONFIG_TN3215_CONSOLE)
 194                         SET_CONSOLE_3215;
 195 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 196                         SET_CONSOLE_SCLP;
 197 #endif
 198                 } else if (strncmp(ptr + 8, "3215", 4) == 0) {
 199 #if defined(CONFIG_TN3215_CONSOLE)
 200                         SET_CONSOLE_3215;
 201 #elif defined(CONFIG_TN3270_CONSOLE)
 202                         SET_CONSOLE_3270;
 203 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 204                         SET_CONSOLE_SCLP;
 205 #endif
 206                 }
 207         } else {
 208 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 209                 SET_CONSOLE_SCLP;
 210 #endif
 211         }
 212 }
 213
 214 #ifdef CONFIG_CRASH_DUMP
 215 static void __init setup_zfcpdump(void)
 216 {
 217         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 218                 return;
 219         if (OLDMEM_BASE)
 220                 return;
 221         strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
 222         console_loglevel = 2;
 223 }
 224 #else
 225 static inline void setup_zfcpdump(void) {}
 226 #endif /* CONFIG_CRASH_DUMP */
 227
 228  /*
 229  * Reboot, halt and power_off stubs. They just call _machine_restart,
 230  * _machine_halt or _machine_power_off.
 231  */
 232
 233 void machine_restart(char *command)
 234 {
 235         if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
 236                 /*
 237                  * Only unblank the console if we are called in enabled
 238                  * context or a bust_spinlocks cleared the way for us.
 239                  */
 240                 console_unblank();
 241         _machine_restart(command);
 242 }
 243
 244 void machine_halt(void)
 245 {
 246         if (!in_interrupt() || oops_in_progress)
 247                 /*
 248                  * Only unblank the console if we are called in enabled
 249                  * context or a bust_spinlocks cleared the way for us.
 250                  */
 251                 console_unblank();
 252         _machine_halt();
 253 }
 254
 255 void machine_power_off(void)
 256 {
 257         if (!in_interrupt() || oops_in_progress)
 258                 /*
 259                  * Only unblank the console if we are called in enabled
 260                  * context or a bust_spinlocks cleared the way for us.
 261                  */
 262                 console_unblank();
 263         _machine_power_off();
 264 }
 265
 266 /*
 267  * Dummy power off function.
 268  */
 269 void (*pm_power_off)(void) = machine_power_off;
 270 EXPORT_SYMBOL_GPL(pm_power_off);
 271
 272 static int __init early_parse_mem(char *p)
 273 {
 274         memory_end = memparse(p, &p);
 275         memory_end &= PAGE_MASK;
 276         memory_end_set = 1;
 277         return 0;
 278 }
 279 early_param("mem", early_parse_mem);
 280
 281 static int __init parse_vmalloc(char *arg)
 282 {
 283         if (!arg)
 284                 return -EINVAL;
 285         VMALLOC_END = (memparse(arg, &arg) + PAGE_SIZE - 1) & PAGE_MASK;
 286         return 0;
 287 }
 288 early_param("vmalloc", parse_vmalloc);
 289
 290 void *restart_stack __attribute__((__section__(".data")));
 291
 292 static void __init setup_lowcore(void)
 293 {
 294         struct _lowcore *lc;
 295
 296         /*
 297          * Setup lowcore for boot cpu
 298          */
 299         BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
 300         lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
 301         lc->restart_psw.mask = PSW_KERNEL_BITS;
 302         lc->restart_psw.addr =
 303                 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
 304         lc->external_new_psw.mask = PSW_KERNEL_BITS |
 305                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 306         lc->external_new_psw.addr =
 307                 PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
 308         lc->svc_new_psw.mask = PSW_KERNEL_BITS |
 309                 PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 310         lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
 311         lc->program_new_psw.mask = PSW_KERNEL_BITS |
 312                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 313         lc->program_new_psw.addr =
 314                 PSW_ADDR_AMODE | (unsigned long) pgm_check_handler;
 315         lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
 316         lc->mcck_new_psw.addr =
 317                 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
 318         lc->io_new_psw.mask = PSW_KERNEL_BITS |
 319                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 320         lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
 321         lc->clock_comparator = -1ULL;
 322         lc->kernel_stack = ((unsigned long) &init_thread_union)
 323                 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 324         lc->async_stack = (unsigned long)
 325                 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0)
 326                 + ASYNC_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 327         lc->panic_stack = (unsigned long)
 328                 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0)
 329                 + PAGE_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 330         lc->current_task = (unsigned long) init_thread_union.thread_info.task;
 331         lc->thread_info = (unsigned long) &init_thread_union;
 332         lc->machine_flags = S390_lowcore.machine_flags;
 333         lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
 334         memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
 335                MAX_FACILITY_BIT/8);
 336         if (MACHINE_HAS_VX)
 337                 lc->vector_save_area_addr =
 338                         (unsigned long) &lc->vector_save_area;
 339         lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
 340         lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
 341         lc->async_enter_timer = S390_lowcore.async_enter_timer;
 342         lc->exit_timer = S390_lowcore.exit_timer;
 343         lc->user_timer = S390_lowcore.user_timer;
 344         lc->system_timer = S390_lowcore.system_timer;
 345         lc->steal_timer = S390_lowcore.steal_timer;
 346         lc->last_update_timer = S390_lowcore.last_update_timer;
 347         lc->last_update_clock = S390_lowcore.last_update_clock;
 348
 349         restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0);
 350         restart_stack += ASYNC_SIZE;
 351
 352         /*
 353          * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
 354          * restart data to the absolute zero lowcore. This is necessary if
 355          * PSW restart is done on an offline CPU that has lowcore zero.
 356          */
 357         lc->restart_stack = (unsigned long) restart_stack;
 358         lc->restart_fn = (unsigned long) do_restart;
 359         lc->restart_data = 0;
 360         lc->restart_source = -1UL;
 361
 362         /* Setup absolute zero lowcore */
 363         mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
 364         mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
 365         mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
 366         mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
 367         mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
 368
 369 #ifdef CONFIG_SMP
 370         lc->spinlock_lockval = arch_spin_lockval(0);
 371 #endif
 372
 373         set_prefix((u32)(unsigned long) lc);
 374         lowcore_ptr[0] = lc;
 375 }
 376
 377 static struct resource code_resource = {
 378         .name  = "Kernel code",
 379         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
 380 };
 381
 382 static struct resource data_resource = {
 383         .name = "Kernel data",
 384         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
 385 };
 386
 387 static struct resource bss_resource = {
 388         .name = "Kernel bss",
 389         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
 390 };
 391
 392 static struct resource __initdata *standard_resources[] = {
 393         &code_resource,
 394         &data_resource,
 395         &bss_resource,
 396 };
 397
 398 static void __init setup_resources(void)
 399 {
 400         struct resource *res, *std_res, *sub_res;
 401         struct memblock_region *reg;
 402         int j;
 403
 404         code_resource.start = (unsigned long) &_text;
 405         code_resource.end = (unsigned long) &_etext - 1;
 406         data_resource.start = (unsigned long) &_etext;
 407         data_resource.end = (unsigned long) &_edata - 1;
 408         bss_resource.start = (unsigned long) &__bss_start;
 409         bss_resource.end = (unsigned long) &__bss_stop - 1;
 410
 411         for_each_memblock(memory, reg) {
 412                 res = alloc_bootmem_low(sizeof(*res));
 413                 res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
 414
 415                 res->name = "System RAM";
 416                 res->start = reg->base;
 417                 res->end = reg->base + reg->size - 1;
 418                 request_resource(&iomem_resource, res);
 419
 420                 for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
 421                         std_res = standard_resources[j];
 422                         if (std_res->start < res->start ||
 423                             std_res->start > res->end)
 424                                 continue;
 425                         if (std_res->end > res->end) {
 426                                 sub_res = alloc_bootmem_low(sizeof(*sub_res));
 427                                 *sub_res = *std_res;
 428                                 sub_res->end = res->end;
 429                                 std_res->start = res->end + 1;
 430                                 request_resource(res, sub_res);
 431                         } else {
 432                                 request_resource(res, std_res);
 433                         }
 434                 }
 435         }
 436 }
 437
 438 static void __init setup_memory_end(void)
 439 {
 440         unsigned long vmax, vmalloc_size, tmp;
 441
 442         /* Choose kernel address space layout: 2, 3, or 4 levels. */
 443         vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN;
 444         tmp = (memory_end ?: max_physmem_end) / PAGE_SIZE;
 445         tmp = tmp * (sizeof(struct page) + PAGE_SIZE);
 446         if (tmp + vmalloc_size + MODULES_LEN <= (1UL << 42))
 447                 vmax = 1UL << 42;       /* 3-level kernel page table */
 448         else
 449                 vmax = 1UL << 53;       /* 4-level kernel page table */
 450         /* module area is at the end of the kernel address space. */
 451         MODULES_END = vmax;
 452         MODULES_VADDR = MODULES_END - MODULES_LEN;
 453         VMALLOC_END = MODULES_VADDR;
 454         VMALLOC_START = vmax - vmalloc_size;
 455
 456         /* Split remaining virtual space between 1:1 mapping & vmemmap array */
 457         tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
 458         /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
 459         tmp = SECTION_ALIGN_UP(tmp);
 460         tmp = VMALLOC_START - tmp * sizeof(struct page);
 461         tmp &= ~((vmax >> 11) - 1);     /* align to page table level */
 462         tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
 463         vmemmap = (struct page *) tmp;
 464
 465         /* Take care that memory_end is set and <= vmemmap */
 466         memory_end = min(memory_end ?: max_physmem_end, tmp);
 467         max_pfn = max_low_pfn = PFN_DOWN(memory_end);
 468         memblock_remove(memory_end, ULONG_MAX);
 469
 470         pr_notice("Max memory size: %luMB\n", memory_end >> 20);
 471 }
 472
 473 static void __init setup_vmcoreinfo(void)
 474 {
 475         mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
 476 }
 477
 478 #ifdef CONFIG_CRASH_DUMP
 479
 480 /*
 481  * When kdump is enabled, we have to ensure that no memory from
 482  * the area [0 - crashkernel memory size] and
 483  * [crashk_res.start - crashk_res.end] is set offline.
 484  */
 485 static int kdump_mem_notifier(struct notifier_block *nb,
 486                               unsigned long action, void *data)
 487 {
 488         struct memory_notify *arg = data;
 489
 490         if (action != MEM_GOING_OFFLINE)
 491                 return NOTIFY_OK;
 492         if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
 493                 return NOTIFY_BAD;
 494         if (arg->start_pfn > PFN_DOWN(crashk_res.end))
 495                 return NOTIFY_OK;
 496         if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
 497                 return NOTIFY_OK;
 498         return NOTIFY_BAD;
 499 }
 500
 501 static struct notifier_block kdump_mem_nb = {
 502         .notifier_call = kdump_mem_notifier,
 503 };
 504
 505 #endif
 506
 507 /*
 508  * Make sure that the area behind memory_end is protected
 509  */
 510 static void reserve_memory_end(void)
 511 {
 512 #ifdef CONFIG_CRASH_DUMP
 513         if (ipl_info.type == IPL_TYPE_FCP_DUMP &&
 514             !OLDMEM_BASE && sclp.hsa_size) {
 515                 memory_end = sclp.hsa_size;
 516                 memory_end &= PAGE_MASK;
 517                 memory_end_set = 1;
 518         }
 519 #endif
 520         if (!memory_end_set)
 521                 return;
 522         memblock_reserve(memory_end, ULONG_MAX);
 523 }
 524
 525 /*
 526  * Make sure that oldmem, where the dump is stored, is protected
 527  */
 528 static void reserve_oldmem(void)
 529 {
 530 #ifdef CONFIG_CRASH_DUMP
 531         if (OLDMEM_BASE)
 532                 /* Forget all memory above the running kdump system */
 533                 memblock_reserve(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
 534 #endif
 535 }
 536
 537 /*
 538  * Make sure that oldmem, where the dump is stored, is protected
 539  */
 540 static void remove_oldmem(void)
 541 {
 542 #ifdef CONFIG_CRASH_DUMP
 543         if (OLDMEM_BASE)
 544                 /* Forget all memory above the running kdump system */
 545                 memblock_remove(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
 546 #endif
 547 }
 548
 549 /*
 550  * Reserve memory for kdump kernel to be loaded with kexec
 551  */
 552 static void __init reserve_crashkernel(void)
 553 {
 554 #ifdef CONFIG_CRASH_DUMP
 555         unsigned long long crash_base, crash_size;
 556         phys_addr_t low, high;
 557         int rc;
 558
 559         rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
 560                                &crash_base);
 561
 562         crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
 563         crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
 564         if (rc || crash_size == 0)
 565                 return;
 566
 567         if (memblock.memory.regions[0].size < crash_size) {
 568                 pr_info("crashkernel reservation failed: %s\n",
 569                         "first memory chunk must be at least crashkernel size");
 570                 return;
 571         }
 572
 573         low = crash_base ?: OLDMEM_BASE;
 574         high = low + crash_size;
 575         if (low >= OLDMEM_BASE && high <= OLDMEM_BASE + OLDMEM_SIZE) {
 576                 /* The crashkernel fits into OLDMEM, reuse OLDMEM */
 577                 crash_base = low;
 578         } else {
 579                 /* Find suitable area in free memory */
 580                 low = max_t(unsigned long, crash_size, sclp.hsa_size);
 581                 high = crash_base ? crash_base + crash_size : ULONG_MAX;
 582
 583                 if (crash_base && crash_base < low) {
 584                         pr_info("crashkernel reservation failed: %s\n",
 585                                 "crash_base too low");
 586                         return;
 587                 }
 588                 low = crash_base ?: low;
 589                 crash_base = memblock_find_in_range(low, high, crash_size,
 590                                                     KEXEC_CRASH_MEM_ALIGN);
 591         }
 592
 593         if (!crash_base) {
 594                 pr_info("crashkernel reservation failed: %s\n",
 595                         "no suitable area found");
 596                 return;
 597         }
 598
 599         if (register_memory_notifier(&kdump_mem_nb))
 600                 return;
 601
 602         if (!OLDMEM_BASE && MACHINE_IS_VM)
 603                 diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
 604         crashk_res.start = crash_base;
 605         crashk_res.end = crash_base + crash_size - 1;
 606         insert_resource(&iomem_resource, &crashk_res);
 607         memblock_remove(crash_base, crash_size);
 608         pr_info("Reserving %lluMB of memory at %lluMB "
 609                 "for crashkernel (System RAM: %luMB)\n",
 610                 crash_size >> 20, crash_base >> 20,
 611                 (unsigned long)memblock.memory.total_size >> 20);
 612         os_info_crashkernel_add(crash_base, crash_size);
 613 #endif
 614 }
 615
 616 /*
 617  * Reserve the initrd from being used by memblock
 618  */
 619 static void __init reserve_initrd(void)
 620 {
 621 #ifdef CONFIG_BLK_DEV_INITRD
 622         initrd_start = INITRD_START;
 623         initrd_end = initrd_start + INITRD_SIZE;
 624         memblock_reserve(INITRD_START, INITRD_SIZE);
 625 #endif
 626 }
 627
 628 /*
 629  * Check for initrd being in usable memory
 630  */
 631 static void __init check_initrd(void)
 632 {
 633 #ifdef CONFIG_BLK_DEV_INITRD
 634         if (INITRD_START && INITRD_SIZE &&
 635             !memblock_is_region_memory(INITRD_START, INITRD_SIZE)) {
 636                 pr_err("initrd does not fit memory.\n");
 637                 memblock_free(INITRD_START, INITRD_SIZE);
 638                 initrd_start = initrd_end = 0;
 639         }
 640 #endif
 641 }
 642
 643 /*
 644  * Reserve memory used for lowcore/command line/kernel image.
 645  */
 646 static void __init reserve_kernel(void)
 647 {
 648         unsigned long start_pfn = PFN_UP(__pa(&_end));
 649
 650 #ifdef CONFIG_DMA_API_DEBUG
 651         /*
 652          * DMA_API_DEBUG code stumbles over addresses from the
 653          * range [_ehead, _stext]. Mark the memory as reserved
 654          * so it is not used for CONFIG_DMA_API_DEBUG=y.
 655          */
 656         memblock_reserve(0, PFN_PHYS(start_pfn));
 657 #else
 658         memblock_reserve(0, (unsigned long)_ehead);
 659         memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
 660                          - (unsigned long)_stext);
 661 #endif
 662 }
 663
 664 static void __init reserve_elfcorehdr(void)
 665 {
 666 #ifdef CONFIG_CRASH_DUMP
 667         if (is_kdump_kernel())
 668                 memblock_reserve(elfcorehdr_addr - OLDMEM_BASE,
 669                                  PAGE_ALIGN(elfcorehdr_size));
 670 #endif
 671 }
 672
 673 static void __init setup_memory(void)
 674 {
 675         struct memblock_region *reg;
 676
 677         /*
 678          * Init storage key for present memory
 679          */
 680         for_each_memblock(memory, reg) {
 681                 storage_key_init_range(reg->base, reg->base + reg->size);
 682         }
 683         psw_set_key(PAGE_DEFAULT_KEY);
 684
 685         /* Only cosmetics */
 686         memblock_enforce_memory_limit(memblock_end_of_DRAM());
 687 }
 688
 689 /*
 690  * Setup hardware capabilities.
 691  */
 692 static int __init setup_hwcaps(void)
 693 {
 694         static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
 695         struct cpuid cpu_id;
 696         int i;
 697
 698         /*
 699          * The store facility list bits numbers as found in the principles
 700          * of operation are numbered with bit 1UL<<31 as number 0 to
 701          * bit 1UL<<0 as number 31.
 702          *   Bit 0: instructions named N3, "backported" to esa-mode
 703          *   Bit 2: z/Architecture mode is active
 704          *   Bit 7: the store-facility-list-extended facility is installed
 705          *   Bit 17: the message-security assist is installed
 706          *   Bit 19: the long-displacement facility is installed
 707          *   Bit 21: the extended-immediate facility is installed
 708          *   Bit 22: extended-translation facility 3 is installed
 709          *   Bit 30: extended-translation facility 3 enhancement facility
 710          * These get translated to:
 711          *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
 712          *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
 713          *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
 714          *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
 715          */
 716         for (i = 0; i < 6; i++)
 717                 if (test_facility(stfl_bits[i]))
 718                         elf_hwcap |= 1UL << i;
 719
 720         if (test_facility(22) && test_facility(30))
 721                 elf_hwcap |= HWCAP_S390_ETF3EH;
 722
 723         /*
 724          * Check for additional facilities with store-facility-list-extended.
 725          * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
 726          * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
 727          * as stored by stfl, bits 32-xxx contain additional facilities.
 728          * How many facility words are stored depends on the number of
 729          * doublewords passed to the instruction. The additional facilities
 730          * are:
 731          *   Bit 42: decimal floating point facility is installed
 732          *   Bit 44: perform floating point operation facility is installed
 733          * translated to:
 734          *   HWCAP_S390_DFP bit 6 (42 && 44).
 735          */
 736         if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
 737                 elf_hwcap |= HWCAP_S390_DFP;
 738
 739         /*
 740          * Huge page support HWCAP_S390_HPAGE is bit 7.
 741          */
 742         if (MACHINE_HAS_HPAGE)
 743                 elf_hwcap |= HWCAP_S390_HPAGE;
 744
 745         /*
 746          * 64-bit register support for 31-bit processes
 747          * HWCAP_S390_HIGH_GPRS is bit 9.
 748          */
 749         elf_hwcap |= HWCAP_S390_HIGH_GPRS;
 750
 751         /*
 752          * Transactional execution support HWCAP_S390_TE is bit 10.
 753          */
 754         if (test_facility(50) && test_facility(73))
 755                 elf_hwcap |= HWCAP_S390_TE;
 756
 757         /*
 758          * Vector extension HWCAP_S390_VXRS is bit 11. The Vector extension
 759          * can be disabled with the "novx" parameter. Use MACHINE_HAS_VX
 760          * instead of facility bit 129.
 761          */
 762         if (MACHINE_HAS_VX)
 763                 elf_hwcap |= HWCAP_S390_VXRS;
 764         get_cpu_id(&cpu_id);
 765         add_device_randomness(&cpu_id, sizeof(cpu_id));
 766         switch (cpu_id.machine) {
 767         case 0x2064:
 768         case 0x2066:
 769         default:        /* Use "z900" as default for 64 bit kernels. */
 770                 strcpy(elf_platform, "z900");
 771                 break;
 772         case 0x2084:
 773         case 0x2086:
 774                 strcpy(elf_platform, "z990");
 775                 break;
 776         case 0x2094:
 777         case 0x2096:
 778                 strcpy(elf_platform, "z9-109");
 779                 break;
 780         case 0x2097:
 781         case 0x2098:
 782                 strcpy(elf_platform, "z10");
 783                 break;
 784         case 0x2817:
 785         case 0x2818:
 786                 strcpy(elf_platform, "z196");
 787                 break;
 788         case 0x2827:
 789         case 0x2828:
 790                 strcpy(elf_platform, "zEC12");
 791                 break;
 792         case 0x2964:
 793                 strcpy(elf_platform, "z13");
 794                 break;
 795         }
 796         return 0;
 797 }
 798 arch_initcall(setup_hwcaps);
 799
 800 /*
 801  * Add system information as device randomness
 802  */
 803 static void __init setup_randomness(void)
 804 {
 805         struct sysinfo_3_2_2 *vmms;
 806
 807         vmms = (struct sysinfo_3_2_2 *) alloc_page(GFP_KERNEL);
 808         if (vmms && stsi(vmms, 3, 2, 2) == 0 && vmms->count)
 809                 add_device_randomness(&vmms, vmms->count);
 810         free_page((unsigned long) vmms);
 811 }
 812
 813 /*
 814  * Setup function called from init/main.c just after the banner
 815  * was printed.
 816  */
 817
 818 void __init setup_arch(char **cmdline_p)
 819 {
 820         /*
 821          * print what head.S has found out about the machine
 822          */
 823         if (MACHINE_IS_VM)
 824                 pr_info("Linux is running as a z/VM "
 825                         "guest operating system in 64-bit mode\n");
 826         else if (MACHINE_IS_KVM)
 827                 pr_info("Linux is running under KVM in 64-bit mode\n");
 828         else if (MACHINE_IS_LPAR)
 829                 pr_info("Linux is running natively in 64-bit mode\n");
 830
 831         /* Have one command line that is parsed and saved in /proc/cmdline */
 832         /* boot_command_line has been already set up in early.c */
 833         *cmdline_p = boot_command_line;
 834
 835         ROOT_DEV = Root_RAM0;
 836
 837         /* Is init_mm really needed? */
 838         init_mm.start_code = PAGE_OFFSET;
 839         init_mm.end_code = (unsigned long) &_etext;
 840         init_mm.end_data = (unsigned long) &_edata;
 841         init_mm.brk = (unsigned long) &_end;
 842
 843         parse_early_param();
 844         os_info_init();
 845         setup_ipl();
 846
 847         /* Do some memory reservations *before* memory is added to memblock */
 848         reserve_memory_end();
 849         reserve_oldmem();
 850         reserve_kernel();
 851         reserve_initrd();
 852         reserve_elfcorehdr();
 853         memblock_allow_resize();
 854
 855         /* Get information about *all* installed memory */
 856         detect_memory_memblock();
 857
 858         remove_oldmem();
 859
 860         /*
 861          * Make sure all chunks are MAX_ORDER aligned so we don't need the
 862          * extra checks that HOLES_IN_ZONE would require.
 863          *
 864          * Is this still required?
 865          */
 866         memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));
 867
 868         setup_memory_end();
 869         setup_memory();
 870
 871         check_initrd();
 872         reserve_crashkernel();
 873         /*
 874          * Be aware that smp_save_dump_cpus() triggers a system reset.
 875          * Therefore CPU and device initialization should be done afterwards.
 876          */
 877         smp_save_dump_cpus();
 878
 879         setup_resources();
 880         setup_vmcoreinfo();
 881         setup_lowcore();
 882         smp_fill_possible_mask();
 883         cpu_init();
 884         numa_setup();
 885
 886         /*
 887          * Create kernel page tables and switch to virtual addressing.
 888          */
 889         paging_init();
 890
 891         /* Setup default console */
 892         conmode_default();
 893         set_preferred_console();
 894
 895         /* Setup zfcpdump support */
 896         setup_zfcpdump();
 897
 898         /* Add system specific data to the random pool */
 899         setup_randomness();
 900 }