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/dma-contiguous.h>
  39 #include <linux/device.h>
  40 #include <linux/notifier.h>
  41 #include <linux/pfn.h>
  42 #include <linux/ctype.h>
  43 #include <linux/reboot.h>
  44 #include <linux/topology.h>
  45 #include <linux/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 <asm/numa.h>
  67 #include "entry.h"
  68
  69 /*
  70  * Machine setup..
  71  */
  72 unsigned int console_mode = 0;
  73 EXPORT_SYMBOL(console_mode);
  74
  75 unsigned int console_devno = -1;
  76 EXPORT_SYMBOL(console_devno);
  77
  78 unsigned int console_irq = -1;
  79 EXPORT_SYMBOL(console_irq);
  80
  81 unsigned long elf_hwcap __read_mostly = 0;
  82 char elf_platform[ELF_PLATFORM_SIZE];
  83
  84 unsigned long int_hwcap = 0;
  85
  86 int __initdata memory_end_set;
  87 unsigned long __initdata memory_end;
  88 unsigned long __initdata max_physmem_end;
  89
  90 unsigned long VMALLOC_START;
  91 EXPORT_SYMBOL(VMALLOC_START);
  92
  93 unsigned long VMALLOC_END;
  94 EXPORT_SYMBOL(VMALLOC_END);
  95
  96 struct page *vmemmap;
  97 EXPORT_SYMBOL(vmemmap);
  98
  99 unsigned long MODULES_VADDR;
 100 unsigned long MODULES_END;
 101
 102 /* An array with a pointer to the lowcore of every CPU. */
 103 struct lowcore *lowcore_ptr[NR_CPUS];
 104 EXPORT_SYMBOL(lowcore_ptr);
 105
 106 /*
 107  * This is set up by the setup-routine at boot-time
 108  * for S390 need to find out, what we have to setup
 109  * using address 0x10400 ...
 110  */
 111
 112 #include <asm/setup.h>
 113
 114 /*
 115  * condev= and conmode= setup parameter.
 116  */
 117
 118 static int __init condev_setup(char *str)
 119 {
 120         int vdev;
 121
 122         vdev = simple_strtoul(str, &str, 0);
 123         if (vdev >= 0 && vdev < 65536) {
 124                 console_devno = vdev;
 125                 console_irq = -1;
 126         }
 127         return 1;
 128 }
 129
 130 __setup("condev=", condev_setup);
 131
 132 static void __init set_preferred_console(void)
 133 {
 134         if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
 135                 add_preferred_console("ttyS", 0, NULL);
 136         else if (CONSOLE_IS_3270)
 137                 add_preferred_console("tty3270", 0, NULL);
 138         else if (CONSOLE_IS_VT220)
 139                 add_preferred_console("ttyS", 1, NULL);
 140         else if (CONSOLE_IS_HVC)
 141                 add_preferred_console("hvc", 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 if (MACHINE_IS_KVM) {
 208                 if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
 209                         SET_CONSOLE_VT220;
 210                 else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
 211                         SET_CONSOLE_SCLP;
 212                 else
 213                         SET_CONSOLE_HVC;
 214         } else {
 215 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 216                 SET_CONSOLE_SCLP;
 217 #endif
 218         }
 219 }
 220
 221 #ifdef CONFIG_CRASH_DUMP
 222 static void __init setup_zfcpdump(void)
 223 {
 224         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 225                 return;
 226         if (OLDMEM_BASE)
 227                 return;
 228         strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
 229         console_loglevel = 2;
 230 }
 231 #else
 232 static inline void setup_zfcpdump(void) {}
 233 #endif /* CONFIG_CRASH_DUMP */
 234
 235  /*
 236  * Reboot, halt and power_off stubs. They just call _machine_restart,
 237  * _machine_halt or _machine_power_off.
 238  */
 239
 240 void machine_restart(char *command)
 241 {
 242         if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
 243                 /*
 244                  * Only unblank the console if we are called in enabled
 245                  * context or a bust_spinlocks cleared the way for us.
 246                  */
 247                 console_unblank();
 248         _machine_restart(command);
 249 }
 250
 251 void machine_halt(void)
 252 {
 253         if (!in_interrupt() || oops_in_progress)
 254                 /*
 255                  * Only unblank the console if we are called in enabled
 256                  * context or a bust_spinlocks cleared the way for us.
 257                  */
 258                 console_unblank();
 259         _machine_halt();
 260 }
 261
 262 void machine_power_off(void)
 263 {
 264         if (!in_interrupt() || oops_in_progress)
 265                 /*
 266                  * Only unblank the console if we are called in enabled
 267                  * context or a bust_spinlocks cleared the way for us.
 268                  */
 269                 console_unblank();
 270         _machine_power_off();
 271 }
 272
 273 /*
 274  * Dummy power off function.
 275  */
 276 void (*pm_power_off)(void) = machine_power_off;
 277 EXPORT_SYMBOL_GPL(pm_power_off);
 278
 279 static int __init early_parse_mem(char *p)
 280 {
 281         memory_end = memparse(p, &p);
 282         memory_end &= PAGE_MASK;
 283         memory_end_set = 1;
 284         return 0;
 285 }
 286 early_param("mem", early_parse_mem);
 287
 288 static int __init parse_vmalloc(char *arg)
 289 {
 290         if (!arg)
 291                 return -EINVAL;
 292         VMALLOC_END = (memparse(arg, &arg) + PAGE_SIZE - 1) & PAGE_MASK;
 293         return 0;
 294 }
 295 early_param("vmalloc", parse_vmalloc);
 296
 297 void *restart_stack __section(.data);
 298
 299 static void __init setup_lowcore(void)
 300 {
 301         struct lowcore *lc;
 302
 303         /*
 304          * Setup lowcore for boot cpu
 305          */
 306         BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * 4096);
 307         lc = memblock_virt_alloc_low(sizeof(*lc), sizeof(*lc));
 308         lc->restart_psw.mask = PSW_KERNEL_BITS;
 309         lc->restart_psw.addr = (unsigned long) restart_int_handler;
 310         lc->external_new_psw.mask = PSW_KERNEL_BITS |
 311                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 312         lc->external_new_psw.addr = (unsigned long) ext_int_handler;
 313         lc->svc_new_psw.mask = PSW_KERNEL_BITS |
 314                 PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 315         lc->svc_new_psw.addr = (unsigned long) system_call;
 316         lc->program_new_psw.mask = PSW_KERNEL_BITS |
 317                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 318         lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
 319         lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
 320         lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
 321         lc->io_new_psw.mask = PSW_KERNEL_BITS |
 322                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 323         lc->io_new_psw.addr = (unsigned long) io_int_handler;
 324         lc->clock_comparator = -1ULL;
 325         lc->kernel_stack = ((unsigned long) &init_thread_union)
 326                 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 327         lc->async_stack = (unsigned long)
 328                 memblock_virt_alloc(ASYNC_SIZE, ASYNC_SIZE)
 329                 + ASYNC_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 330         lc->panic_stack = (unsigned long)
 331                 memblock_virt_alloc(PAGE_SIZE, PAGE_SIZE)
 332                 + PAGE_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 333         lc->current_task = (unsigned long)&init_task;
 334         lc->lpp = LPP_MAGIC;
 335         lc->machine_flags = S390_lowcore.machine_flags;
 336         lc->preempt_count = S390_lowcore.preempt_count;
 337         lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
 338         memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
 339                MAX_FACILITY_BIT/8);
 340         if (MACHINE_HAS_VX)
 341                 lc->vector_save_area_addr =
 342                         (unsigned long) &lc->vector_save_area;
 343         lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
 344         lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
 345         lc->async_enter_timer = S390_lowcore.async_enter_timer;
 346         lc->exit_timer = S390_lowcore.exit_timer;
 347         lc->user_timer = S390_lowcore.user_timer;
 348         lc->system_timer = S390_lowcore.system_timer;
 349         lc->steal_timer = S390_lowcore.steal_timer;
 350         lc->last_update_timer = S390_lowcore.last_update_timer;
 351         lc->last_update_clock = S390_lowcore.last_update_clock;
 352
 353         restart_stack = memblock_virt_alloc(ASYNC_SIZE, ASYNC_SIZE);
 354         restart_stack += ASYNC_SIZE;
 355
 356         /*
 357          * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
 358          * restart data to the absolute zero lowcore. This is necessary if
 359          * PSW restart is done on an offline CPU that has lowcore zero.
 360          */
 361         lc->restart_stack = (unsigned long) restart_stack;
 362         lc->restart_fn = (unsigned long) do_restart;
 363         lc->restart_data = 0;
 364         lc->restart_source = -1UL;
 365
 366         /* Setup absolute zero lowcore */
 367         mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
 368         mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
 369         mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
 370         mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
 371         mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
 372
 373 #ifdef CONFIG_SMP
 374         lc->spinlock_lockval = arch_spin_lockval(0);
 375 #endif
 376
 377         set_prefix((u32)(unsigned long) lc);
 378         lowcore_ptr[0] = lc;
 379 }
 380
 381 static struct resource code_resource = {
 382         .name  = "Kernel code",
 383         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 384 };
 385
 386 static struct resource data_resource = {
 387         .name = "Kernel data",
 388         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 389 };
 390
 391 static struct resource bss_resource = {
 392         .name = "Kernel bss",
 393         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 394 };
 395
 396 static struct resource __initdata *standard_resources[] = {
 397         &code_resource,
 398         &data_resource,
 399         &bss_resource,
 400 };
 401
 402 static void __init setup_resources(void)
 403 {
 404         struct resource *res, *std_res, *sub_res;
 405         struct memblock_region *reg;
 406         int j;
 407
 408         code_resource.start = (unsigned long) &_text;
 409         code_resource.end = (unsigned long) &_etext - 1;
 410         data_resource.start = (unsigned long) &_etext;
 411         data_resource.end = (unsigned long) &_edata - 1;
 412         bss_resource.start = (unsigned long) &__bss_start;
 413         bss_resource.end = (unsigned long) &__bss_stop - 1;
 414
 415         for_each_memblock(memory, reg) {
 416                 res = memblock_virt_alloc(sizeof(*res), 8);
 417                 res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
 418
 419                 res->name = "System RAM";
 420                 res->start = reg->base;
 421                 res->end = reg->base + reg->size - 1;
 422                 request_resource(&iomem_resource, res);
 423
 424                 for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
 425                         std_res = standard_resources[j];
 426                         if (std_res->start < res->start ||
 427                             std_res->start > res->end)
 428                                 continue;
 429                         if (std_res->end > res->end) {
 430                                 sub_res = memblock_virt_alloc(sizeof(*sub_res), 8);
 431                                 *sub_res = *std_res;
 432                                 sub_res->end = res->end;
 433                                 std_res->start = res->end + 1;
 434                                 request_resource(res, sub_res);
 435                         } else {
 436                                 request_resource(res, std_res);
 437                         }
 438                 }
 439         }
 440 #ifdef CONFIG_CRASH_DUMP
 441         /*
 442          * Re-add removed crash kernel memory as reserved memory. This makes
 443          * sure it will be mapped with the identity mapping and struct pages
 444          * will be created, so it can be resized later on.
 445          * However add it later since the crash kernel resource should not be
 446          * part of the System RAM resource.
 447          */
 448         if (crashk_res.end) {
 449                 memblock_add_node(crashk_res.start, resource_size(&crashk_res), 0);
 450                 memblock_reserve(crashk_res.start, resource_size(&crashk_res));
 451                 insert_resource(&iomem_resource, &crashk_res);
 452         }
 453 #endif
 454 }
 455
 456 static void __init setup_memory_end(void)
 457 {
 458         unsigned long vmax, vmalloc_size, tmp;
 459
 460         /* Choose kernel address space layout: 2, 3, or 4 levels. */
 461         vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN;
 462         tmp = (memory_end ?: max_physmem_end) / PAGE_SIZE;
 463         tmp = tmp * (sizeof(struct page) + PAGE_SIZE);
 464         if (tmp + vmalloc_size + MODULES_LEN <= (1UL << 42))
 465                 vmax = 1UL << 42;       /* 3-level kernel page table */
 466         else
 467                 vmax = 1UL << 53;       /* 4-level kernel page table */
 468         /* module area is at the end of the kernel address space. */
 469         MODULES_END = vmax;
 470         MODULES_VADDR = MODULES_END - MODULES_LEN;
 471         VMALLOC_END = MODULES_VADDR;
 472         VMALLOC_START = vmax - vmalloc_size;
 473
 474         /* Split remaining virtual space between 1:1 mapping & vmemmap array */
 475         tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
 476         /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
 477         tmp = SECTION_ALIGN_UP(tmp);
 478         tmp = VMALLOC_START - tmp * sizeof(struct page);
 479         tmp &= ~((vmax >> 11) - 1);     /* align to page table level */
 480         tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
 481         vmemmap = (struct page *) tmp;
 482
 483         /* Take care that memory_end is set and <= vmemmap */
 484         memory_end = min(memory_end ?: max_physmem_end, tmp);
 485         max_pfn = max_low_pfn = PFN_DOWN(memory_end);
 486         memblock_remove(memory_end, ULONG_MAX);
 487
 488         pr_notice("The maximum memory size is %luMB\n", memory_end >> 20);
 489 }
 490
 491 static void __init setup_vmcoreinfo(void)
 492 {
 493         mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
 494 }
 495
 496 #ifdef CONFIG_CRASH_DUMP
 497
 498 /*
 499  * When kdump is enabled, we have to ensure that no memory from
 500  * the area [0 - crashkernel memory size] and
 501  * [crashk_res.start - crashk_res.end] is set offline.
 502  */
 503 static int kdump_mem_notifier(struct notifier_block *nb,
 504                               unsigned long action, void *data)
 505 {
 506         struct memory_notify *arg = data;
 507
 508         if (action != MEM_GOING_OFFLINE)
 509                 return NOTIFY_OK;
 510         if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
 511                 return NOTIFY_BAD;
 512         if (arg->start_pfn > PFN_DOWN(crashk_res.end))
 513                 return NOTIFY_OK;
 514         if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
 515                 return NOTIFY_OK;
 516         return NOTIFY_BAD;
 517 }
 518
 519 static struct notifier_block kdump_mem_nb = {
 520         .notifier_call = kdump_mem_notifier,
 521 };
 522
 523 #endif
 524
 525 /*
 526  * Make sure that the area behind memory_end is protected
 527  */
 528 static void reserve_memory_end(void)
 529 {
 530 #ifdef CONFIG_CRASH_DUMP
 531         if (ipl_info.type == IPL_TYPE_FCP_DUMP &&
 532             !OLDMEM_BASE && sclp.hsa_size) {
 533                 memory_end = sclp.hsa_size;
 534                 memory_end &= PAGE_MASK;
 535                 memory_end_set = 1;
 536         }
 537 #endif
 538         if (!memory_end_set)
 539                 return;
 540         memblock_reserve(memory_end, ULONG_MAX);
 541 }
 542
 543 /*
 544  * Make sure that oldmem, where the dump is stored, is protected
 545  */
 546 static void reserve_oldmem(void)
 547 {
 548 #ifdef CONFIG_CRASH_DUMP
 549         if (OLDMEM_BASE)
 550                 /* Forget all memory above the running kdump system */
 551                 memblock_reserve(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
 552 #endif
 553 }
 554
 555 /*
 556  * Make sure that oldmem, where the dump is stored, is protected
 557  */
 558 static void remove_oldmem(void)
 559 {
 560 #ifdef CONFIG_CRASH_DUMP
 561         if (OLDMEM_BASE)
 562                 /* Forget all memory above the running kdump system */
 563                 memblock_remove(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
 564 #endif
 565 }
 566
 567 /*
 568  * Reserve memory for kdump kernel to be loaded with kexec
 569  */
 570 static void __init reserve_crashkernel(void)
 571 {
 572 #ifdef CONFIG_CRASH_DUMP
 573         unsigned long long crash_base, crash_size;
 574         phys_addr_t low, high;
 575         int rc;
 576
 577         rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
 578                                &crash_base);
 579
 580         crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
 581         crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
 582         if (rc || crash_size == 0)
 583                 return;
 584
 585         if (memblock.memory.regions[0].size < crash_size) {
 586                 pr_info("crashkernel reservation failed: %s\n",
 587                         "first memory chunk must be at least crashkernel size");
 588                 return;
 589         }
 590
 591         low = crash_base ?: OLDMEM_BASE;
 592         high = low + crash_size;
 593         if (low >= OLDMEM_BASE && high <= OLDMEM_BASE + OLDMEM_SIZE) {
 594                 /* The crashkernel fits into OLDMEM, reuse OLDMEM */
 595                 crash_base = low;
 596         } else {
 597                 /* Find suitable area in free memory */
 598                 low = max_t(unsigned long, crash_size, sclp.hsa_size);
 599                 high = crash_base ? crash_base + crash_size : ULONG_MAX;
 600
 601                 if (crash_base && crash_base < low) {
 602                         pr_info("crashkernel reservation failed: %s\n",
 603                                 "crash_base too low");
 604                         return;
 605                 }
 606                 low = crash_base ?: low;
 607                 crash_base = memblock_find_in_range(low, high, crash_size,
 608                                                     KEXEC_CRASH_MEM_ALIGN);
 609         }
 610
 611         if (!crash_base) {
 612                 pr_info("crashkernel reservation failed: %s\n",
 613                         "no suitable area found");
 614                 return;
 615         }
 616
 617         if (register_memory_notifier(&kdump_mem_nb))
 618                 return;
 619
 620         if (!OLDMEM_BASE && MACHINE_IS_VM)
 621                 diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
 622         crashk_res.start = crash_base;
 623         crashk_res.end = crash_base + crash_size - 1;
 624         memblock_remove(crash_base, crash_size);
 625         pr_info("Reserving %lluMB of memory at %lluMB "
 626                 "for crashkernel (System RAM: %luMB)\n",
 627                 crash_size >> 20, crash_base >> 20,
 628                 (unsigned long)memblock.memory.total_size >> 20);
 629         os_info_crashkernel_add(crash_base, crash_size);
 630 #endif
 631 }
 632
 633 /*
 634  * Reserve the initrd from being used by memblock
 635  */
 636 static void __init reserve_initrd(void)
 637 {
 638 #ifdef CONFIG_BLK_DEV_INITRD
 639         initrd_start = INITRD_START;
 640         initrd_end = initrd_start + INITRD_SIZE;
 641         memblock_reserve(INITRD_START, INITRD_SIZE);
 642 #endif
 643 }
 644
 645 /*
 646  * Check for initrd being in usable memory
 647  */
 648 static void __init check_initrd(void)
 649 {
 650 #ifdef CONFIG_BLK_DEV_INITRD
 651         if (INITRD_START && INITRD_SIZE &&
 652             !memblock_is_region_memory(INITRD_START, INITRD_SIZE)) {
 653                 pr_err("The initial RAM disk does not fit into the memory\n");
 654                 memblock_free(INITRD_START, INITRD_SIZE);
 655                 initrd_start = initrd_end = 0;
 656         }
 657 #endif
 658 }
 659
 660 /*
 661  * Reserve memory used for lowcore/command line/kernel image.
 662  */
 663 static void __init reserve_kernel(void)
 664 {
 665         unsigned long start_pfn = PFN_UP(__pa(&_end));
 666
 667 #ifdef CONFIG_DMA_API_DEBUG
 668         /*
 669          * DMA_API_DEBUG code stumbles over addresses from the
 670          * range [_ehead, _stext]. Mark the memory as reserved
 671          * so it is not used for CONFIG_DMA_API_DEBUG=y.
 672          */
 673         memblock_reserve(0, PFN_PHYS(start_pfn));
 674 #else
 675         memblock_reserve(0, (unsigned long)_ehead);
 676         memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
 677                          - (unsigned long)_stext);
 678 #endif
 679 }
 680
 681 static void __init setup_memory(void)
 682 {
 683         struct memblock_region *reg;
 684
 685         /*
 686          * Init storage key for present memory
 687          */
 688         for_each_memblock(memory, reg) {
 689                 storage_key_init_range(reg->base, reg->base + reg->size);
 690         }
 691         psw_set_key(PAGE_DEFAULT_KEY);
 692
 693         /* Only cosmetics */
 694         memblock_enforce_memory_limit(memblock_end_of_DRAM());
 695 }
 696
 697 /*
 698  * Setup hardware capabilities.
 699  */
 700 static int __init setup_hwcaps(void)
 701 {
 702         static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
 703         struct cpuid cpu_id;
 704         int i;
 705
 706         /*
 707          * The store facility list bits numbers as found in the principles
 708          * of operation are numbered with bit 1UL<<31 as number 0 to
 709          * bit 1UL<<0 as number 31.
 710          *   Bit 0: instructions named N3, "backported" to esa-mode
 711          *   Bit 2: z/Architecture mode is active
 712          *   Bit 7: the store-facility-list-extended facility is installed
 713          *   Bit 17: the message-security assist is installed
 714          *   Bit 19: the long-displacement facility is installed
 715          *   Bit 21: the extended-immediate facility is installed
 716          *   Bit 22: extended-translation facility 3 is installed
 717          *   Bit 30: extended-translation facility 3 enhancement facility
 718          * These get translated to:
 719          *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
 720          *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
 721          *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
 722          *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
 723          */
 724         for (i = 0; i < 6; i++)
 725                 if (test_facility(stfl_bits[i]))
 726                         elf_hwcap |= 1UL << i;
 727
 728         if (test_facility(22) && test_facility(30))
 729                 elf_hwcap |= HWCAP_S390_ETF3EH;
 730
 731         /*
 732          * Check for additional facilities with store-facility-list-extended.
 733          * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
 734          * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
 735          * as stored by stfl, bits 32-xxx contain additional facilities.
 736          * How many facility words are stored depends on the number of
 737          * doublewords passed to the instruction. The additional facilities
 738          * are:
 739          *   Bit 42: decimal floating point facility is installed
 740          *   Bit 44: perform floating point operation facility is installed
 741          * translated to:
 742          *   HWCAP_S390_DFP bit 6 (42 && 44).
 743          */
 744         if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
 745                 elf_hwcap |= HWCAP_S390_DFP;
 746
 747         /*
 748          * Huge page support HWCAP_S390_HPAGE is bit 7.
 749          */
 750         if (MACHINE_HAS_HPAGE)
 751                 elf_hwcap |= HWCAP_S390_HPAGE;
 752
 753         /*
 754          * 64-bit register support for 31-bit processes
 755          * HWCAP_S390_HIGH_GPRS is bit 9.
 756          */
 757         elf_hwcap |= HWCAP_S390_HIGH_GPRS;
 758
 759         /*
 760          * Transactional execution support HWCAP_S390_TE is bit 10.
 761          */
 762         if (test_facility(50) && test_facility(73))
 763                 elf_hwcap |= HWCAP_S390_TE;
 764
 765         /*
 766          * Vector extension HWCAP_S390_VXRS is bit 11. The Vector extension
 767          * can be disabled with the "novx" parameter. Use MACHINE_HAS_VX
 768          * instead of facility bit 129.
 769          */
 770         if (MACHINE_HAS_VX)
 771                 elf_hwcap |= HWCAP_S390_VXRS;
 772         get_cpu_id(&cpu_id);
 773         add_device_randomness(&cpu_id, sizeof(cpu_id));
 774         switch (cpu_id.machine) {
 775         case 0x2064:
 776         case 0x2066:
 777         default:        /* Use "z900" as default for 64 bit kernels. */
 778                 strcpy(elf_platform, "z900");
 779                 break;
 780         case 0x2084:
 781         case 0x2086:
 782                 strcpy(elf_platform, "z990");
 783                 break;
 784         case 0x2094:
 785         case 0x2096:
 786                 strcpy(elf_platform, "z9-109");
 787                 break;
 788         case 0x2097:
 789         case 0x2098:
 790                 strcpy(elf_platform, "z10");
 791                 break;
 792         case 0x2817:
 793         case 0x2818:
 794                 strcpy(elf_platform, "z196");
 795                 break;
 796         case 0x2827:
 797         case 0x2828:
 798                 strcpy(elf_platform, "zEC12");
 799                 break;
 800         case 0x2964:
 801         case 0x2965:
 802                 strcpy(elf_platform, "z13");
 803                 break;
 804         }
 805
 806         /*
 807          * Virtualization support HWCAP_INT_SIE is bit 0.
 808          */
 809         if (sclp.has_sief2)
 810                 int_hwcap |= HWCAP_INT_SIE;
 811
 812         return 0;
 813 }
 814 arch_initcall(setup_hwcaps);
 815
 816 /*
 817  * Add system information as device randomness
 818  */
 819 static void __init setup_randomness(void)
 820 {
 821         struct sysinfo_3_2_2 *vmms;
 822
 823         vmms = (struct sysinfo_3_2_2 *) alloc_page(GFP_KERNEL);
 824         if (vmms && stsi(vmms, 3, 2, 2) == 0 && vmms->count)
 825                 add_device_randomness(&vmms, vmms->count);
 826         free_page((unsigned long) vmms);
 827 }
 828
 829 /*
 830  * Find the correct size for the task_struct. This depends on
 831  * the size of the struct fpu at the end of the thread_struct
 832  * which is embedded in the task_struct.
 833  */
 834 static void __init setup_task_size(void)
 835 {
 836         int task_size = sizeof(struct task_struct);
 837
 838         if (!MACHINE_HAS_VX) {
 839                 task_size -= sizeof(__vector128) * __NUM_VXRS;
 840                 task_size += sizeof(freg_t) * __NUM_FPRS;
 841         }
 842         arch_task_struct_size = task_size;
 843 }
 844
 845 /*
 846  * Setup function called from init/main.c just after the banner
 847  * was printed.
 848  */
 849
 850 void __init setup_arch(char **cmdline_p)
 851 {
 852         /*
 853          * print what head.S has found out about the machine
 854          */
 855         if (MACHINE_IS_VM)
 856                 pr_info("Linux is running as a z/VM "
 857                         "guest operating system in 64-bit mode\n");
 858         else if (MACHINE_IS_KVM)
 859                 pr_info("Linux is running under KVM in 64-bit mode\n");
 860         else if (MACHINE_IS_LPAR)
 861                 pr_info("Linux is running natively in 64-bit mode\n");
 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 #ifdef CONFIG_CRASH_DUMP
 877         /* Deactivate elfcorehdr= kernel parameter */
 878         elfcorehdr_addr = ELFCORE_ADDR_MAX;
 879 #endif
 880
 881         os_info_init();
 882         setup_ipl();
 883         setup_task_size();
 884
 885         /* Do some memory reservations *before* memory is added to memblock */
 886         reserve_memory_end();
 887         reserve_oldmem();
 888         reserve_kernel();
 889         reserve_initrd();
 890         memblock_allow_resize();
 891
 892         /* Get information about *all* installed memory */
 893         detect_memory_memblock();
 894
 895         remove_oldmem();
 896
 897         /*
 898          * Make sure all chunks are MAX_ORDER aligned so we don't need the
 899          * extra checks that HOLES_IN_ZONE would require.
 900          *
 901          * Is this still required?
 902          */
 903         memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));
 904
 905         setup_memory_end();
 906         setup_memory();
 907         dma_contiguous_reserve(memory_end);
 908
 909         check_initrd();
 910         reserve_crashkernel();
 911 #ifdef CONFIG_CRASH_DUMP
 912         /*
 913          * Be aware that smp_save_dump_cpus() triggers a system reset.
 914          * Therefore CPU and device initialization should be done afterwards.
 915          */
 916         smp_save_dump_cpus();
 917 #endif
 918
 919         setup_resources();
 920         setup_vmcoreinfo();
 921         setup_lowcore();
 922         smp_fill_possible_mask();
 923         cpu_detect_mhz_feature();
 924         cpu_init();
 925         numa_setup();
 926         smp_detect_cpus();
 927         topology_init_early();
 928
 929         /*
 930          * Create kernel page tables and switch to virtual addressing.
 931          */
 932         paging_init();
 933
 934         /* Setup default console */
 935         conmode_default();
 936         set_preferred_console();
 937
 938         /* Setup zfcpdump support */
 939         setup_zfcpdump();
 940
 941         /* Add system specific data to the random pool */
 942         setup_randomness();
 943 }