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/ftrace.h>
  45 #include <linux/kexec.h>
  46 #include <linux/crash_dump.h>
  47 #include <linux/memory.h>
  48 #include <linux/compat.h>
  49
  50 #include <asm/ipl.h>
  51 #include <asm/facility.h>
  52 #include <asm/smp.h>
  53 #include <asm/mmu_context.h>
  54 #include <asm/cpcmd.h>
  55 #include <asm/lowcore.h>
  56 #include <asm/irq.h>
  57 #include <asm/page.h>
  58 #include <asm/ptrace.h>
  59 #include <asm/sections.h>
  60 #include <asm/ebcdic.h>
  61 #include <asm/kvm_virtio.h>
  62 #include <asm/diag.h>
  63 #include <asm/os_info.h>
  64 #include <asm/sclp.h>
  65 #include <asm/sysinfo.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 = 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 #ifdef CONFIG_64BIT
  97 unsigned long MODULES_VADDR;
  98 unsigned long MODULES_END;
  99 #endif
 100
 101 /* An array with a pointer to the lowcore of every CPU. */
 102 struct _lowcore *lowcore_ptr[NR_CPUS];
 103 EXPORT_SYMBOL(lowcore_ptr);
 104
 105 /*
 106  * This is set up by the setup-routine at boot-time
 107  * for S390 need to find out, what we have to setup
 108  * using address 0x10400 ...
 109  */
 110
 111 #include <asm/setup.h>
 112
 113 /*
 114  * condev= and conmode= setup parameter.
 115  */
 116
 117 static int __init condev_setup(char *str)
 118 {
 119         int vdev;
 120
 121         vdev = simple_strtoul(str, &str, 0);
 122         if (vdev >= 0 && vdev < 65536) {
 123                 console_devno = vdev;
 124                 console_irq = -1;
 125         }
 126         return 1;
 127 }
 128
 129 __setup("condev=", condev_setup);
 130
 131 static void __init set_preferred_console(void)
 132 {
 133         if (MACHINE_IS_KVM) {
 134                 if (sclp_has_vt220())
 135                         add_preferred_console("ttyS", 1, NULL);
 136                 else if (sclp_has_linemode())
 137                         add_preferred_console("ttyS", 0, NULL);
 138                 else
 139                         add_preferred_console("hvc", 0, NULL);
 140         } else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
 141                 add_preferred_console("ttyS", 0, NULL);
 142         else if (CONSOLE_IS_3270)
 143                 add_preferred_console("tty3270", 0, NULL);
 144 }
 145
 146 static int __init conmode_setup(char *str)
 147 {
 148 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 149         if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
 150                 SET_CONSOLE_SCLP;
 151 #endif
 152 #if defined(CONFIG_TN3215_CONSOLE)
 153         if (strncmp(str, "3215", 5) == 0)
 154                 SET_CONSOLE_3215;
 155 #endif
 156 #if defined(CONFIG_TN3270_CONSOLE)
 157         if (strncmp(str, "3270", 5) == 0)
 158                 SET_CONSOLE_3270;
 159 #endif
 160         set_preferred_console();
 161         return 1;
 162 }
 163
 164 __setup("conmode=", conmode_setup);
 165
 166 static void __init conmode_default(void)
 167 {
 168         char query_buffer[1024];
 169         char *ptr;
 170
 171         if (MACHINE_IS_VM) {
 172                 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
 173                 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
 174                 ptr = strstr(query_buffer, "SUBCHANNEL =");
 175                 console_irq = simple_strtoul(ptr + 13, NULL, 16);
 176                 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
 177                 ptr = strstr(query_buffer, "CONMODE");
 178                 /*
 179                  * Set the conmode to 3215 so that the device recognition
 180                  * will set the cu_type of the console to 3215. If the
 181                  * conmode is 3270 and we don't set it back then both
 182                  * 3215 and the 3270 driver will try to access the console
 183                  * device (3215 as console and 3270 as normal tty).
 184                  */
 185                 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
 186                 if (ptr == NULL) {
 187 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 188                         SET_CONSOLE_SCLP;
 189 #endif
 190                         return;
 191                 }
 192                 if (strncmp(ptr + 8, "3270", 4) == 0) {
 193 #if defined(CONFIG_TN3270_CONSOLE)
 194                         SET_CONSOLE_3270;
 195 #elif defined(CONFIG_TN3215_CONSOLE)
 196                         SET_CONSOLE_3215;
 197 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 198                         SET_CONSOLE_SCLP;
 199 #endif
 200                 } else if (strncmp(ptr + 8, "3215", 4) == 0) {
 201 #if defined(CONFIG_TN3215_CONSOLE)
 202                         SET_CONSOLE_3215;
 203 #elif defined(CONFIG_TN3270_CONSOLE)
 204                         SET_CONSOLE_3270;
 205 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 206                         SET_CONSOLE_SCLP;
 207 #endif
 208                 }
 209         } else {
 210 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 211                 SET_CONSOLE_SCLP;
 212 #endif
 213         }
 214 }
 215
 216 #ifdef CONFIG_CRASH_DUMP
 217 static void __init setup_zfcpdump(void)
 218 {
 219         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 220                 return;
 221         if (OLDMEM_BASE)
 222                 return;
 223         strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
 224         console_loglevel = 2;
 225 }
 226 #else
 227 static inline void setup_zfcpdump(void) {}
 228 #endif /* CONFIG_CRASH_DUMP */
 229
 230  /*
 231  * Reboot, halt and power_off stubs. They just call _machine_restart,
 232  * _machine_halt or _machine_power_off.
 233  */
 234
 235 void machine_restart(char *command)
 236 {
 237         if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
 238                 /*
 239                  * Only unblank the console if we are called in enabled
 240                  * context or a bust_spinlocks cleared the way for us.
 241                  */
 242                 console_unblank();
 243         _machine_restart(command);
 244 }
 245
 246 void machine_halt(void)
 247 {
 248         if (!in_interrupt() || oops_in_progress)
 249                 /*
 250                  * Only unblank the console if we are called in enabled
 251                  * context or a bust_spinlocks cleared the way for us.
 252                  */
 253                 console_unblank();
 254         _machine_halt();
 255 }
 256
 257 void machine_power_off(void)
 258 {
 259         if (!in_interrupt() || oops_in_progress)
 260                 /*
 261                  * Only unblank the console if we are called in enabled
 262                  * context or a bust_spinlocks cleared the way for us.
 263                  */
 264                 console_unblank();
 265         _machine_power_off();
 266 }
 267
 268 /*
 269  * Dummy power off function.
 270  */
 271 void (*pm_power_off)(void) = machine_power_off;
 272 EXPORT_SYMBOL_GPL(pm_power_off);
 273
 274 static int __init early_parse_mem(char *p)
 275 {
 276         memory_end = memparse(p, &p);
 277         memory_end &= PAGE_MASK;
 278         memory_end_set = 1;
 279         return 0;
 280 }
 281 early_param("mem", early_parse_mem);
 282
 283 static int __init parse_vmalloc(char *arg)
 284 {
 285         if (!arg)
 286                 return -EINVAL;
 287         VMALLOC_END = (memparse(arg, &arg) + PAGE_SIZE - 1) & PAGE_MASK;
 288         return 0;
 289 }
 290 early_param("vmalloc", parse_vmalloc);
 291
 292 void *restart_stack __attribute__((__section__(".data")));
 293
 294 static void __init setup_lowcore(void)
 295 {
 296         struct _lowcore *lc;
 297
 298         /*
 299          * Setup lowcore for boot cpu
 300          */
 301         BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
 302         lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
 303         lc->restart_psw.mask = PSW_KERNEL_BITS;
 304         lc->restart_psw.addr =
 305                 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
 306         lc->external_new_psw.mask = PSW_KERNEL_BITS |
 307                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 308         lc->external_new_psw.addr =
 309                 PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
 310         lc->svc_new_psw.mask = PSW_KERNEL_BITS |
 311                 PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 312         lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
 313         lc->program_new_psw.mask = PSW_KERNEL_BITS |
 314                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 315         lc->program_new_psw.addr =
 316                 PSW_ADDR_AMODE | (unsigned long) pgm_check_handler;
 317         lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
 318         lc->mcck_new_psw.addr =
 319                 PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
 320         lc->io_new_psw.mask = PSW_KERNEL_BITS |
 321                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 322         lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
 323         lc->clock_comparator = -1ULL;
 324         lc->kernel_stack = ((unsigned long) &init_thread_union)
 325                 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 326         lc->async_stack = (unsigned long)
 327                 __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0)
 328                 + ASYNC_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 329         lc->panic_stack = (unsigned long)
 330                 __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0)
 331                 + PAGE_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 332         lc->current_task = (unsigned long) init_thread_union.thread_info.task;
 333         lc->thread_info = (unsigned long) &init_thread_union;
 334         lc->machine_flags = S390_lowcore.machine_flags;
 335         lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
 336         memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
 337                MAX_FACILITY_BIT/8);
 338 #ifndef CONFIG_64BIT
 339         if (MACHINE_HAS_IEEE) {
 340                 lc->extended_save_area_addr = (__u32)
 341                         __alloc_bootmem_low(PAGE_SIZE, PAGE_SIZE, 0);
 342                 /* enable extended save area */
 343                 __ctl_set_bit(14, 29);
 344         }
 345 #else
 346         if (MACHINE_HAS_VX)
 347                 lc->vector_save_area_addr =
 348                         (unsigned long) &lc->vector_save_area;
 349         lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
 350 #endif
 351         lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
 352         lc->async_enter_timer = S390_lowcore.async_enter_timer;
 353         lc->exit_timer = S390_lowcore.exit_timer;
 354         lc->user_timer = S390_lowcore.user_timer;
 355         lc->system_timer = S390_lowcore.system_timer;
 356         lc->steal_timer = S390_lowcore.steal_timer;
 357         lc->last_update_timer = S390_lowcore.last_update_timer;
 358         lc->last_update_clock = S390_lowcore.last_update_clock;
 359         lc->ftrace_func = S390_lowcore.ftrace_func;
 360
 361         restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0);
 362         restart_stack += ASYNC_SIZE;
 363
 364         /*
 365          * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
 366          * restart data to the absolute zero lowcore. This is necessary if
 367          * PSW restart is done on an offline CPU that has lowcore zero.
 368          */
 369         lc->restart_stack = (unsigned long) restart_stack;
 370         lc->restart_fn = (unsigned long) do_restart;
 371         lc->restart_data = 0;
 372         lc->restart_source = -1UL;
 373
 374         /* Setup absolute zero lowcore */
 375         mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
 376         mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
 377         mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
 378         mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
 379         mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
 380
 381 #ifdef CONFIG_SMP
 382         lc->spinlock_lockval = arch_spin_lockval(0);
 383 #endif
 384
 385         set_prefix((u32)(unsigned long) lc);
 386         lowcore_ptr[0] = lc;
 387 }
 388
 389 static struct resource code_resource = {
 390         .name  = "Kernel code",
 391         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
 392 };
 393
 394 static struct resource data_resource = {
 395         .name = "Kernel data",
 396         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
 397 };
 398
 399 static struct resource bss_resource = {
 400         .name = "Kernel bss",
 401         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
 402 };
 403
 404 static struct resource __initdata *standard_resources[] = {
 405         &code_resource,
 406         &data_resource,
 407         &bss_resource,
 408 };
 409
 410 static void __init setup_resources(void)
 411 {
 412         struct resource *res, *std_res, *sub_res;
 413         struct memblock_region *reg;
 414         int j;
 415
 416         code_resource.start = (unsigned long) &_text;
 417         code_resource.end = (unsigned long) &_etext - 1;
 418         data_resource.start = (unsigned long) &_etext;
 419         data_resource.end = (unsigned long) &_edata - 1;
 420         bss_resource.start = (unsigned long) &__bss_start;
 421         bss_resource.end = (unsigned long) &__bss_stop - 1;
 422
 423         for_each_memblock(memory, reg) {
 424                 res = alloc_bootmem_low(sizeof(*res));
 425                 res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
 426
 427                 res->name = "System RAM";
 428                 res->start = reg->base;
 429                 res->end = reg->base + reg->size - 1;
 430                 request_resource(&iomem_resource, res);
 431
 432                 for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
 433                         std_res = standard_resources[j];
 434                         if (std_res->start < res->start ||
 435                             std_res->start > res->end)
 436                                 continue;
 437                         if (std_res->end > res->end) {
 438                                 sub_res = alloc_bootmem_low(sizeof(*sub_res));
 439                                 *sub_res = *std_res;
 440                                 sub_res->end = res->end;
 441                                 std_res->start = res->end + 1;
 442                                 request_resource(res, sub_res);
 443                         } else {
 444                                 request_resource(res, std_res);
 445                         }
 446                 }
 447         }
 448 }
 449
 450 static void __init setup_memory_end(void)
 451 {
 452         unsigned long vmax, vmalloc_size, tmp;
 453
 454         /* Choose kernel address space layout: 2, 3, or 4 levels. */
 455 #ifdef CONFIG_64BIT
 456         vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN;
 457         tmp = (memory_end ?: max_physmem_end) / PAGE_SIZE;
 458         tmp = tmp * (sizeof(struct page) + PAGE_SIZE);
 459         if (tmp + vmalloc_size + MODULES_LEN <= (1UL << 42))
 460                 vmax = 1UL << 42;       /* 3-level kernel page table */
 461         else
 462                 vmax = 1UL << 53;       /* 4-level kernel page table */
 463         /* module area is at the end of the kernel address space. */
 464         MODULES_END = vmax;
 465         MODULES_VADDR = MODULES_END - MODULES_LEN;
 466         VMALLOC_END = MODULES_VADDR;
 467 #else
 468         vmalloc_size = VMALLOC_END ?: 96UL << 20;
 469         vmax = 1UL << 31;               /* 2-level kernel page table */
 470         /* vmalloc area is at the end of the kernel address space. */
 471         VMALLOC_END = vmax;
 472 #endif
 473         VMALLOC_START = vmax - vmalloc_size;
 474
 475         /* Split remaining virtual space between 1:1 mapping & vmemmap array */
 476         tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
 477         /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
 478         tmp = SECTION_ALIGN_UP(tmp);
 479         tmp = VMALLOC_START - tmp * sizeof(struct page);
 480         tmp &= ~((vmax >> 11) - 1);     /* align to page table level */
 481         tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
 482         vmemmap = (struct page *) tmp;
 483
 484         /* Take care that memory_end is set and <= vmemmap */
 485         memory_end = min(memory_end ?: max_physmem_end, tmp);
 486         max_pfn = max_low_pfn = PFN_DOWN(memory_end);
 487         memblock_remove(memory_end, ULONG_MAX);
 488
 489         pr_notice("Max memory size: %luMB\n", memory_end >> 20);
 490 }
 491
 492 static void __init setup_vmcoreinfo(void)
 493 {
 494         mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
 495 }
 496
 497 #ifdef CONFIG_CRASH_DUMP
 498
 499 /*
 500  * When kdump is enabled, we have to ensure that no memory from
 501  * the area [0 - crashkernel memory size] and
 502  * [crashk_res.start - crashk_res.end] is set offline.
 503  */
 504 static int kdump_mem_notifier(struct notifier_block *nb,
 505                               unsigned long action, void *data)
 506 {
 507         struct memory_notify *arg = data;
 508
 509         if (action != MEM_GOING_OFFLINE)
 510                 return NOTIFY_OK;
 511         if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
 512                 return NOTIFY_BAD;
 513         if (arg->start_pfn > PFN_DOWN(crashk_res.end))
 514                 return NOTIFY_OK;
 515         if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
 516                 return NOTIFY_OK;
 517         return NOTIFY_BAD;
 518 }
 519
 520 static struct notifier_block kdump_mem_nb = {
 521         .notifier_call = kdump_mem_notifier,
 522 };
 523
 524 #endif
 525
 526 /*
 527  * Make sure that the area behind memory_end is protected
 528  */
 529 static void reserve_memory_end(void)
 530 {
 531 #ifdef CONFIG_CRASH_DUMP
 532         if (ipl_info.type == IPL_TYPE_FCP_DUMP &&
 533             !OLDMEM_BASE && sclp_get_hsa_size()) {
 534                 memory_end = sclp_get_hsa_size();
 535                 memory_end &= PAGE_MASK;
 536                 memory_end_set = 1;
 537         }
 538 #endif
 539         if (!memory_end_set)
 540                 return;
 541         memblock_reserve(memory_end, ULONG_MAX);
 542 }
 543
 544 /*
 545  * Make sure that oldmem, where the dump is stored, is protected
 546  */
 547 static void reserve_oldmem(void)
 548 {
 549 #ifdef CONFIG_CRASH_DUMP
 550         if (OLDMEM_BASE)
 551                 /* Forget all memory above the running kdump system */
 552                 memblock_reserve(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
 553 #endif
 554 }
 555
 556 /*
 557  * Make sure that oldmem, where the dump is stored, is protected
 558  */
 559 static void remove_oldmem(void)
 560 {
 561 #ifdef CONFIG_CRASH_DUMP
 562         if (OLDMEM_BASE)
 563                 /* Forget all memory above the running kdump system */
 564                 memblock_remove(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
 565 #endif
 566 }
 567
 568 /*
 569  * Reserve memory for kdump kernel to be loaded with kexec
 570  */
 571 static void __init reserve_crashkernel(void)
 572 {
 573 #ifdef CONFIG_CRASH_DUMP
 574         unsigned long long crash_base, crash_size;
 575         phys_addr_t low, high;
 576         int rc;
 577
 578         rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
 579                                &crash_base);
 580
 581         crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
 582         crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
 583         if (rc || crash_size == 0)
 584                 return;
 585
 586         if (memblock.memory.regions[0].size < crash_size) {
 587                 pr_info("crashkernel reservation failed: %s\n",
 588                         "first memory chunk must be at least crashkernel size");
 589                 return;
 590         }
 591
 592         low = crash_base ?: OLDMEM_BASE;
 593         high = low + crash_size;
 594         if (low >= OLDMEM_BASE && high <= OLDMEM_BASE + OLDMEM_SIZE) {
 595                 /* The crashkernel fits into OLDMEM, reuse OLDMEM */
 596                 crash_base = low;
 597         } else {
 598                 /* Find suitable area in free memory */
 599                 low = max_t(unsigned long, crash_size, sclp_get_hsa_size());
 600                 high = crash_base ? crash_base + crash_size : ULONG_MAX;
 601
 602                 if (crash_base && crash_base < low) {
 603                         pr_info("crashkernel reservation failed: %s\n",
 604                                 "crash_base too low");
 605                         return;
 606                 }
 607                 low = crash_base ?: low;
 608                 crash_base = memblock_find_in_range(low, high, crash_size,
 609                                                     KEXEC_CRASH_MEM_ALIGN);
 610         }
 611
 612         if (!crash_base) {
 613                 pr_info("crashkernel reservation failed: %s\n",
 614                         "no suitable area found");
 615                 return;
 616         }
 617
 618         if (register_memory_notifier(&kdump_mem_nb))
 619                 return;
 620
 621         if (!OLDMEM_BASE && MACHINE_IS_VM)
 622                 diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
 623         crashk_res.start = crash_base;
 624         crashk_res.end = crash_base + crash_size - 1;
 625         insert_resource(&iomem_resource, &crashk_res);
 626         memblock_remove(crash_base, crash_size);
 627         pr_info("Reserving %lluMB of memory at %lluMB "
 628                 "for crashkernel (System RAM: %luMB)\n",
 629                 crash_size >> 20, crash_base >> 20,
 630                 (unsigned long)memblock.memory.total_size >> 20);
 631         os_info_crashkernel_add(crash_base, crash_size);
 632 #endif
 633 }
 634
 635 /*
 636  * Reserve the initrd from being used by memblock
 637  */
 638 static void __init reserve_initrd(void)
 639 {
 640 #ifdef CONFIG_BLK_DEV_INITRD
 641         initrd_start = INITRD_START;
 642         initrd_end = initrd_start + INITRD_SIZE;
 643         memblock_reserve(INITRD_START, INITRD_SIZE);
 644 #endif
 645 }
 646
 647 /*
 648  * Check for initrd being in usable memory
 649  */
 650 static void __init check_initrd(void)
 651 {
 652 #ifdef CONFIG_BLK_DEV_INITRD
 653         if (INITRD_START && INITRD_SIZE &&
 654             !memblock_is_region_memory(INITRD_START, INITRD_SIZE)) {
 655                 pr_err("initrd does not fit memory.\n");
 656                 memblock_free(INITRD_START, INITRD_SIZE);
 657                 initrd_start = initrd_end = 0;
 658         }
 659 #endif
 660 }
 661
 662 /*
 663  * Reserve all kernel text
 664  */
 665 static void __init reserve_kernel(void)
 666 {
 667         unsigned long start_pfn;
 668         start_pfn = PFN_UP(__pa(&_end));
 669
 670         /*
 671          * Reserve memory used for lowcore/command line/kernel image.
 672          */
 673         memblock_reserve(0, (unsigned long)_ehead);
 674         memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
 675                          - (unsigned long)_stext);
 676 }
 677
 678 static void __init reserve_elfcorehdr(void)
 679 {
 680 #ifdef CONFIG_CRASH_DUMP
 681         if (is_kdump_kernel())
 682                 memblock_reserve(elfcorehdr_addr - OLDMEM_BASE,
 683                                  PAGE_ALIGN(elfcorehdr_size));
 684 #endif
 685 }
 686
 687 static void __init setup_memory(void)
 688 {
 689         struct memblock_region *reg;
 690
 691         /*
 692          * Init storage key for present memory
 693          */
 694         for_each_memblock(memory, reg) {
 695                 storage_key_init_range(reg->base, reg->base + reg->size);
 696         }
 697         psw_set_key(PAGE_DEFAULT_KEY);
 698
 699         /* Only cosmetics */
 700         memblock_enforce_memory_limit(memblock_end_of_DRAM());
 701 }
 702
 703 /*
 704  * Setup hardware capabilities.
 705  */
 706 static void __init setup_hwcaps(void)
 707 {
 708         static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
 709         struct cpuid cpu_id;
 710         int i;
 711
 712         /*
 713          * The store facility list bits numbers as found in the principles
 714          * of operation are numbered with bit 1UL<<31 as number 0 to
 715          * bit 1UL<<0 as number 31.
 716          *   Bit 0: instructions named N3, "backported" to esa-mode
 717          *   Bit 2: z/Architecture mode is active
 718          *   Bit 7: the store-facility-list-extended facility is installed
 719          *   Bit 17: the message-security assist is installed
 720          *   Bit 19: the long-displacement facility is installed
 721          *   Bit 21: the extended-immediate facility is installed
 722          *   Bit 22: extended-translation facility 3 is installed
 723          *   Bit 30: extended-translation facility 3 enhancement facility
 724          * These get translated to:
 725          *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
 726          *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
 727          *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
 728          *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
 729          */
 730         for (i = 0; i < 6; i++)
 731                 if (test_facility(stfl_bits[i]))
 732                         elf_hwcap |= 1UL << i;
 733
 734         if (test_facility(22) && test_facility(30))
 735                 elf_hwcap |= HWCAP_S390_ETF3EH;
 736
 737         /*
 738          * Check for additional facilities with store-facility-list-extended.
 739          * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
 740          * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
 741          * as stored by stfl, bits 32-xxx contain additional facilities.
 742          * How many facility words are stored depends on the number of
 743          * doublewords passed to the instruction. The additional facilities
 744          * are:
 745          *   Bit 42: decimal floating point facility is installed
 746          *   Bit 44: perform floating point operation facility is installed
 747          * translated to:
 748          *   HWCAP_S390_DFP bit 6 (42 && 44).
 749          */
 750         if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
 751                 elf_hwcap |= HWCAP_S390_DFP;
 752
 753         /*
 754          * Huge page support HWCAP_S390_HPAGE is bit 7.
 755          */
 756         if (MACHINE_HAS_HPAGE)
 757                 elf_hwcap |= HWCAP_S390_HPAGE;
 758
 759 #if defined(CONFIG_64BIT)
 760         /*
 761          * 64-bit register support for 31-bit processes
 762          * HWCAP_S390_HIGH_GPRS is bit 9.
 763          */
 764         elf_hwcap |= HWCAP_S390_HIGH_GPRS;
 765
 766         /*
 767          * Transactional execution support HWCAP_S390_TE is bit 10.
 768          */
 769         if (test_facility(50) && test_facility(73))
 770                 elf_hwcap |= HWCAP_S390_TE;
 771
 772         /*
 773          * Vector extension HWCAP_S390_VXRS is bit 11.
 774          */
 775         if (test_facility(129))
 776                 elf_hwcap |= HWCAP_S390_VXRS;
 777 #endif
 778
 779         get_cpu_id(&cpu_id);
 780         add_device_randomness(&cpu_id, sizeof(cpu_id));
 781         switch (cpu_id.machine) {
 782         case 0x9672:
 783 #if !defined(CONFIG_64BIT)
 784         default:        /* Use "g5" as default for 31 bit kernels. */
 785 #endif
 786                 strcpy(elf_platform, "g5");
 787                 break;
 788         case 0x2064:
 789         case 0x2066:
 790 #if defined(CONFIG_64BIT)
 791         default:        /* Use "z900" as default for 64 bit kernels. */
 792 #endif
 793                 strcpy(elf_platform, "z900");
 794                 break;
 795         case 0x2084:
 796         case 0x2086:
 797                 strcpy(elf_platform, "z990");
 798                 break;
 799         case 0x2094:
 800         case 0x2096:
 801                 strcpy(elf_platform, "z9-109");
 802                 break;
 803         case 0x2097:
 804         case 0x2098:
 805                 strcpy(elf_platform, "z10");
 806                 break;
 807         case 0x2817:
 808         case 0x2818:
 809                 strcpy(elf_platform, "z196");
 810                 break;
 811         case 0x2827:
 812         case 0x2828:
 813                 strcpy(elf_platform, "zEC12");
 814                 break;
 815         }
 816 }
 817
 818 /*
 819  * Add system information as device randomness
 820  */
 821 static void __init setup_randomness(void)
 822 {
 823         struct sysinfo_3_2_2 *vmms;
 824
 825         vmms = (struct sysinfo_3_2_2 *) alloc_page(GFP_KERNEL);
 826         if (vmms && stsi(vmms, 3, 2, 2) == 0 && vmms->count)
 827                 add_device_randomness(&vmms, vmms->count);
 828         free_page((unsigned long) vmms);
 829 }
 830
 831 /*
 832  * Setup function called from init/main.c just after the banner
 833  * was printed.
 834  */
 835
 836 void __init setup_arch(char **cmdline_p)
 837 {
 838         /*
 839          * print what head.S has found out about the machine
 840          */
 841 #ifndef CONFIG_64BIT
 842         if (MACHINE_IS_VM)
 843                 pr_info("Linux is running as a z/VM "
 844                         "guest operating system in 31-bit mode\n");
 845         else if (MACHINE_IS_LPAR)
 846                 pr_info("Linux is running natively in 31-bit mode\n");
 847         if (MACHINE_HAS_IEEE)
 848                 pr_info("The hardware system has IEEE compatible "
 849                         "floating point units\n");
 850         else
 851                 pr_info("The hardware system has no IEEE compatible "
 852                         "floating point units\n");
 853 #else /* CONFIG_64BIT */
 854         if (MACHINE_IS_VM)
 855                 pr_info("Linux is running as a z/VM "
 856                         "guest operating system in 64-bit mode\n");
 857         else if (MACHINE_IS_KVM)
 858                 pr_info("Linux is running under KVM in 64-bit mode\n");
 859         else if (MACHINE_IS_LPAR)
 860                 pr_info("Linux is running natively in 64-bit mode\n");
 861 #endif /* CONFIG_64BIT */
 862
 863         /* Have one command line that is parsed and saved in /proc/cmdline */
 864         /* boot_command_line has been already set up in early.c */
 865         *cmdline_p = boot_command_line;
 866
 867         ROOT_DEV = Root_RAM0;
 868
 869         /* Is init_mm really needed? */
 870         init_mm.start_code = PAGE_OFFSET;
 871         init_mm.end_code = (unsigned long) &_etext;
 872         init_mm.end_data = (unsigned long) &_edata;
 873         init_mm.brk = (unsigned long) &_end;
 874
 875         parse_early_param();
 876         os_info_init();
 877         setup_ipl();
 878
 879         /* Do some memory reservations *before* memory is added to memblock */
 880         reserve_memory_end();
 881         reserve_oldmem();
 882         reserve_kernel();
 883         reserve_initrd();
 884         reserve_elfcorehdr();
 885         memblock_allow_resize();
 886
 887         /* Get information about *all* installed memory */
 888         detect_memory_memblock();
 889
 890         remove_oldmem();
 891
 892         /*
 893          * Make sure all chunks are MAX_ORDER aligned so we don't need the
 894          * extra checks that HOLES_IN_ZONE would require.
 895          *
 896          * Is this still required?
 897          */
 898         memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));
 899
 900         setup_memory_end();
 901         setup_memory();
 902
 903         check_initrd();
 904         reserve_crashkernel();
 905
 906         setup_resources();
 907         setup_vmcoreinfo();
 908         setup_lowcore();
 909         smp_fill_possible_mask();
 910         cpu_init();
 911         s390_init_cpu_topology();
 912
 913         /*
 914          * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
 915          */
 916         setup_hwcaps();
 917
 918         /*
 919          * Create kernel page tables and switch to virtual addressing.
 920          */
 921         paging_init();
 922
 923         /* Setup default console */
 924         conmode_default();
 925         set_preferred_console();
 926
 927         /* Setup zfcpdump support */
 928         setup_zfcpdump();
 929
 930         /* Add system specific data to the random pool */
 931         setup_randomness();
 932 }
 933
 934 #ifdef CONFIG_32BIT
 935 static int no_removal_warning __initdata;
 936
 937 static int __init parse_no_removal_warning(char *str)
 938 {
 939         no_removal_warning = 1;
 940         return 0;
 941 }
 942 __setup("no_removal_warning", parse_no_removal_warning);
 943
 944 static int __init removal_warning(void)
 945 {
 946         if (no_removal_warning)
 947                 return 0;
 948         printk(KERN_ALERT "\n\n");
 949         printk(KERN_CONT "Warning - you are using a 31 bit kernel!\n\n");
 950         printk(KERN_CONT "We plan to remove 31 bit kernel support from the kernel sources in March 2015.\n");
 951         printk(KERN_CONT "Currently we assume that nobody is using the 31 bit kernel on old 31 bit\n");
 952         printk(KERN_CONT "hardware anymore. If you think that the code should not be removed and also\n");
 953         printk(KERN_CONT "future versions of the Linux kernel should be able to run in 31 bit mode\n");
 954         printk(KERN_CONT "please let us know. Please write to:\n");
 955         printk(KERN_CONT "linux390@de.ibm.com (mail address) and/or\n");
 956         printk(KERN_CONT "linux-s390@vger.kernel.org (mailing list).\n\n");
 957         printk(KERN_CONT "Thank you!\n\n");
 958         printk(KERN_CONT "If this kernel runs on a 64 bit machine you may consider using a 64 bit kernel.\n");
 959         printk(KERN_CONT "This message can be disabled with the \"no_removal_warning\" kernel parameter.\n");
 960         schedule_timeout_uninterruptible(300 * HZ);
 961         return 0;
 962 }
 963 early_initcall(removal_warning);
 964 #endif