arch/s390/kernel/setup.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  S390 version
   4  *    Copyright IBM Corp. 1999, 2012
   5  *    Author(s): Hartmut Penner (hp@de.ibm.com),
   6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  *
   8  *  Derived from "arch/i386/kernel/setup.c"
   9  *    Copyright (C) 1995, Linus Torvalds
  10  */
  11
  12 /*
  13  * This file handles the architecture-dependent parts of initialization
  14  */
  15
  16 #define KMSG_COMPONENT "setup"
  17 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  18
  19 #include <linux/errno.h>
  20 #include <linux/export.h>
  21 #include <linux/sched.h>
  22 #include <linux/sched/task.h>
  23 #include <linux/cpu.h>
  24 #include <linux/kernel.h>
  25 #include <linux/memblock.h>
  26 #include <linux/mm.h>
  27 #include <linux/stddef.h>
  28 #include <linux/unistd.h>
  29 #include <linux/ptrace.h>
  30 #include <linux/random.h>
  31 #include <linux/user.h>
  32 #include <linux/tty.h>
  33 #include <linux/ioport.h>
  34 #include <linux/delay.h>
  35 #include <linux/init.h>
  36 #include <linux/initrd.h>
  37 #include <linux/bootmem.h>
  38 #include <linux/root_dev.h>
  39 #include <linux/console.h>
  40 #include <linux/kernel_stat.h>
  41 #include <linux/dma-contiguous.h>
  42 #include <linux/device.h>
  43 #include <linux/notifier.h>
  44 #include <linux/pfn.h>
  45 #include <linux/ctype.h>
  46 #include <linux/reboot.h>
  47 #include <linux/topology.h>
  48 #include <linux/kexec.h>
  49 #include <linux/crash_dump.h>
  50 #include <linux/memory.h>
  51 #include <linux/compat.h>
  52
  53 #include <asm/ipl.h>
  54 #include <asm/facility.h>
  55 #include <asm/smp.h>
  56 #include <asm/mmu_context.h>
  57 #include <asm/cpcmd.h>
  58 #include <asm/lowcore.h>
  59 #include <asm/nmi.h>
  60 #include <asm/irq.h>
  61 #include <asm/page.h>
  62 #include <asm/ptrace.h>
  63 #include <asm/sections.h>
  64 #include <asm/ebcdic.h>
  65 #include <asm/diag.h>
  66 #include <asm/os_info.h>
  67 #include <asm/sclp.h>
  68 #include <asm/sysinfo.h>
  69 #include <asm/numa.h>
  70 #include <asm/alternative.h>
  71 #include "entry.h"
  72
  73 /*
  74  * Machine setup..
  75  */
  76 unsigned int console_mode = 0;
  77 EXPORT_SYMBOL(console_mode);
  78
  79 unsigned int console_devno = -1;
  80 EXPORT_SYMBOL(console_devno);
  81
  82 unsigned int console_irq = -1;
  83 EXPORT_SYMBOL(console_irq);
  84
  85 unsigned long elf_hwcap __read_mostly = 0;
  86 char elf_platform[ELF_PLATFORM_SIZE];
  87
  88 unsigned long int_hwcap = 0;
  89
  90 int __initdata memory_end_set;
  91 unsigned long __initdata memory_end;
  92 unsigned long __initdata max_physmem_end;
  93
  94 unsigned long VMALLOC_START;
  95 EXPORT_SYMBOL(VMALLOC_START);
  96
  97 unsigned long VMALLOC_END;
  98 EXPORT_SYMBOL(VMALLOC_END);
  99
 100 struct page *vmemmap;
 101 EXPORT_SYMBOL(vmemmap);
 102
 103 unsigned long MODULES_VADDR;
 104 unsigned long MODULES_END;
 105
 106 /* An array with a pointer to the lowcore of every CPU. */
 107 struct lowcore *lowcore_ptr[NR_CPUS];
 108 EXPORT_SYMBOL(lowcore_ptr);
 109
 110 /*
 111  * This is set up by the setup-routine at boot-time
 112  * for S390 need to find out, what we have to setup
 113  * using address 0x10400 ...
 114  */
 115
 116 #include <asm/setup.h>
 117
 118 /*
 119  * condev= and conmode= setup parameter.
 120  */
 121
 122 static int __init condev_setup(char *str)
 123 {
 124         int vdev;
 125
 126         vdev = simple_strtoul(str, &str, 0);
 127         if (vdev >= 0 && vdev < 65536) {
 128                 console_devno = vdev;
 129                 console_irq = -1;
 130         }
 131         return 1;
 132 }
 133
 134 __setup("condev=", condev_setup);
 135
 136 static void __init set_preferred_console(void)
 137 {
 138         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         else if (CONSOLE_IS_VT220)
 143                 add_preferred_console("ttyS", 1, NULL);
 144         else if (CONSOLE_IS_HVC)
 145                 add_preferred_console("hvc", 0, NULL);
 146 }
 147
 148 static int __init conmode_setup(char *str)
 149 {
 150 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 151         if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
 152                 SET_CONSOLE_SCLP;
 153 #endif
 154 #if defined(CONFIG_TN3215_CONSOLE)
 155         if (strncmp(str, "3215", 5) == 0)
 156                 SET_CONSOLE_3215;
 157 #endif
 158 #if defined(CONFIG_TN3270_CONSOLE)
 159         if (strncmp(str, "3270", 5) == 0)
 160                 SET_CONSOLE_3270;
 161 #endif
 162         set_preferred_console();
 163         return 1;
 164 }
 165
 166 __setup("conmode=", conmode_setup);
 167
 168 static void __init conmode_default(void)
 169 {
 170         char query_buffer[1024];
 171         char *ptr;
 172
 173         if (MACHINE_IS_VM) {
 174                 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
 175                 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
 176                 ptr = strstr(query_buffer, "SUBCHANNEL =");
 177                 console_irq = simple_strtoul(ptr + 13, NULL, 16);
 178                 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
 179                 ptr = strstr(query_buffer, "CONMODE");
 180                 /*
 181                  * Set the conmode to 3215 so that the device recognition
 182                  * will set the cu_type of the console to 3215. If the
 183                  * conmode is 3270 and we don't set it back then both
 184                  * 3215 and the 3270 driver will try to access the console
 185                  * device (3215 as console and 3270 as normal tty).
 186                  */
 187                 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
 188                 if (ptr == NULL) {
 189 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 190                         SET_CONSOLE_SCLP;
 191 #endif
 192                         return;
 193                 }
 194                 if (strncmp(ptr + 8, "3270", 4) == 0) {
 195 #if defined(CONFIG_TN3270_CONSOLE)
 196                         SET_CONSOLE_3270;
 197 #elif defined(CONFIG_TN3215_CONSOLE)
 198                         SET_CONSOLE_3215;
 199 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 200                         SET_CONSOLE_SCLP;
 201 #endif
 202                 } else if (strncmp(ptr + 8, "3215", 4) == 0) {
 203 #if defined(CONFIG_TN3215_CONSOLE)
 204                         SET_CONSOLE_3215;
 205 #elif defined(CONFIG_TN3270_CONSOLE)
 206                         SET_CONSOLE_3270;
 207 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 208                         SET_CONSOLE_SCLP;
 209 #endif
 210                 }
 211         } else if (MACHINE_IS_KVM) {
 212                 if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
 213                         SET_CONSOLE_VT220;
 214                 else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
 215                         SET_CONSOLE_SCLP;
 216                 else
 217                         SET_CONSOLE_HVC;
 218         } else {
 219 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 220                 SET_CONSOLE_SCLP;
 221 #endif
 222         }
 223 }
 224
 225 #ifdef CONFIG_CRASH_DUMP
 226 static void __init setup_zfcpdump(void)
 227 {
 228         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 229                 return;
 230         if (OLDMEM_BASE)
 231                 return;
 232         strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
 233         console_loglevel = 2;
 234 }
 235 #else
 236 static inline void setup_zfcpdump(void) {}
 237 #endif /* CONFIG_CRASH_DUMP */
 238
 239  /*
 240  * Reboot, halt and power_off stubs. They just call _machine_restart,
 241  * _machine_halt or _machine_power_off.
 242  */
 243
 244 void machine_restart(char *command)
 245 {
 246         if ((!in_interrupt() && !in_atomic()) || 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_restart(command);
 253 }
 254
 255 void machine_halt(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_halt();
 264 }
 265
 266 void machine_power_off(void)
 267 {
 268         if (!in_interrupt() || oops_in_progress)
 269                 /*
 270                  * Only unblank the console if we are called in enabled
 271                  * context or a bust_spinlocks cleared the way for us.
 272                  */
 273                 console_unblank();
 274         _machine_power_off();
 275 }
 276
 277 /*
 278  * Dummy power off function.
 279  */
 280 void (*pm_power_off)(void) = machine_power_off;
 281 EXPORT_SYMBOL_GPL(pm_power_off);
 282
 283 static int __init early_parse_mem(char *p)
 284 {
 285         memory_end = memparse(p, &p);
 286         memory_end &= PAGE_MASK;
 287         memory_end_set = 1;
 288         return 0;
 289 }
 290 early_param("mem", early_parse_mem);
 291
 292 static int __init parse_vmalloc(char *arg)
 293 {
 294         if (!arg)
 295                 return -EINVAL;
 296         VMALLOC_END = (memparse(arg, &arg) + PAGE_SIZE - 1) & PAGE_MASK;
 297         return 0;
 298 }
 299 early_param("vmalloc", parse_vmalloc);
 300
 301 void *restart_stack __section(.data);
 302
 303 static void __init setup_lowcore(void)
 304 {
 305         struct lowcore *lc;
 306
 307         /*
 308          * Setup lowcore for boot cpu
 309          */
 310         BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
 311         lc = memblock_virt_alloc_low(sizeof(*lc), sizeof(*lc));
 312         lc->restart_psw.mask = PSW_KERNEL_BITS;
 313         lc->restart_psw.addr = (unsigned long) restart_int_handler;
 314         lc->external_new_psw.mask = PSW_KERNEL_BITS |
 315                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 316         lc->external_new_psw.addr = (unsigned long) ext_int_handler;
 317         lc->svc_new_psw.mask = PSW_KERNEL_BITS |
 318                 PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 319         lc->svc_new_psw.addr = (unsigned long) system_call;
 320         lc->program_new_psw.mask = PSW_KERNEL_BITS |
 321                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 322         lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
 323         lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
 324         lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
 325         lc->io_new_psw.mask = PSW_KERNEL_BITS |
 326                 PSW_MASK_DAT | PSW_MASK_MCHECK;
 327         lc->io_new_psw.addr = (unsigned long) io_int_handler;
 328         lc->clock_comparator = clock_comparator_max;
 329         lc->kernel_stack = ((unsigned long) &init_thread_union)
 330                 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 331         lc->async_stack = (unsigned long)
 332                 memblock_virt_alloc(ASYNC_SIZE, ASYNC_SIZE)
 333                 + ASYNC_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 334         lc->panic_stack = (unsigned long)
 335                 memblock_virt_alloc(PAGE_SIZE, PAGE_SIZE)
 336                 + PAGE_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 337         lc->current_task = (unsigned long)&init_task;
 338         lc->lpp = LPP_MAGIC;
 339         lc->machine_flags = S390_lowcore.machine_flags;
 340         lc->preempt_count = S390_lowcore.preempt_count;
 341         lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
 342         memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
 343                MAX_FACILITY_BIT/8);
 344         nmi_alloc_boot_cpu(lc);
 345         vdso_alloc_boot_cpu(lc);
 346         lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
 347         lc->async_enter_timer = S390_lowcore.async_enter_timer;
 348         lc->exit_timer = S390_lowcore.exit_timer;
 349         lc->user_timer = S390_lowcore.user_timer;
 350         lc->system_timer = S390_lowcore.system_timer;
 351         lc->steal_timer = S390_lowcore.steal_timer;
 352         lc->last_update_timer = S390_lowcore.last_update_timer;
 353         lc->last_update_clock = S390_lowcore.last_update_clock;
 354
 355         restart_stack = memblock_virt_alloc(ASYNC_SIZE, ASYNC_SIZE);
 356         restart_stack += ASYNC_SIZE;
 357
 358         /*
 359          * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
 360          * restart data to the absolute zero lowcore. This is necessary if
 361          * PSW restart is done on an offline CPU that has lowcore zero.
 362          */
 363         lc->restart_stack = (unsigned long) restart_stack;
 364         lc->restart_fn = (unsigned long) do_restart;
 365         lc->restart_data = 0;
 366         lc->restart_source = -1UL;
 367
 368         /* Setup absolute zero lowcore */
 369         mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
 370         mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
 371         mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
 372         mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
 373         mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
 374
 375 #ifdef CONFIG_SMP
 376         lc->spinlock_lockval = arch_spin_lockval(0);
 377         lc->spinlock_index = 0;
 378         arch_spin_lock_setup(0);
 379 #endif
 380
 381         set_prefix((u32)(unsigned long) lc);
 382         lowcore_ptr[0] = lc;
 383 }
 384
 385 static struct resource code_resource = {
 386         .name  = "Kernel code",
 387         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 388 };
 389
 390 static struct resource data_resource = {
 391         .name = "Kernel data",
 392         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 393 };
 394
 395 static struct resource bss_resource = {
 396         .name = "Kernel bss",
 397         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 398 };
 399
 400 static struct resource __initdata *standard_resources[] = {
 401         &code_resource,
 402         &data_resource,
 403         &bss_resource,
 404 };
 405
 406 static void __init setup_resources(void)
 407 {
 408         struct resource *res, *std_res, *sub_res;
 409         struct memblock_region *reg;
 410         int j;
 411
 412         code_resource.start = (unsigned long) &_text;
 413         code_resource.end = (unsigned long) &_etext - 1;
 414         data_resource.start = (unsigned long) &_etext;
 415         data_resource.end = (unsigned long) &_edata - 1;
 416         bss_resource.start = (unsigned long) &__bss_start;
 417         bss_resource.end = (unsigned long) &__bss_stop - 1;
 418
 419         for_each_memblock(memory, reg) {
 420                 res = memblock_virt_alloc(sizeof(*res), 8);
 421                 res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
 422
 423                 res->name = "System RAM";
 424                 res->start = reg->base;
 425                 res->end = reg->base + reg->size - 1;
 426                 request_resource(&iomem_resource, res);
 427
 428                 for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
 429                         std_res = standard_resources[j];
 430                         if (std_res->start < res->start ||
 431                             std_res->start > res->end)
 432                                 continue;
 433                         if (std_res->end > res->end) {
 434                                 sub_res = memblock_virt_alloc(sizeof(*sub_res), 8);
 435                                 *sub_res = *std_res;
 436                                 sub_res->end = res->end;
 437                                 std_res->start = res->end + 1;
 438                                 request_resource(res, sub_res);
 439                         } else {
 440                                 request_resource(res, std_res);
 441                         }
 442                 }
 443         }
 444 #ifdef CONFIG_CRASH_DUMP
 445         /*
 446          * Re-add removed crash kernel memory as reserved memory. This makes
 447          * sure it will be mapped with the identity mapping and struct pages
 448          * will be created, so it can be resized later on.
 449          * However add it later since the crash kernel resource should not be
 450          * part of the System RAM resource.
 451          */
 452         if (crashk_res.end) {
 453                 memblock_add_node(crashk_res.start, resource_size(&crashk_res), 0);
 454                 memblock_reserve(crashk_res.start, resource_size(&crashk_res));
 455                 insert_resource(&iomem_resource, &crashk_res);
 456         }
 457 #endif
 458 }
 459
 460 static void __init setup_memory_end(void)
 461 {
 462         unsigned long vmax, vmalloc_size, tmp;
 463
 464         /* Choose kernel address space layout: 2, 3, or 4 levels. */
 465         vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN;
 466         tmp = (memory_end ?: max_physmem_end) / PAGE_SIZE;
 467         tmp = tmp * (sizeof(struct page) + PAGE_SIZE);
 468         if (tmp + vmalloc_size + MODULES_LEN <= _REGION2_SIZE)
 469                 vmax = _REGION2_SIZE; /* 3-level kernel page table */
 470         else
 471                 vmax = _REGION1_SIZE; /* 4-level kernel page table */
 472         /* module area is at the end of the kernel address space. */
 473         MODULES_END = vmax;
 474         MODULES_VADDR = MODULES_END - MODULES_LEN;
 475         VMALLOC_END = MODULES_VADDR;
 476         VMALLOC_START = vmax - vmalloc_size;
 477
 478         /* Split remaining virtual space between 1:1 mapping & vmemmap array */
 479         tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
 480         /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
 481         tmp = SECTION_ALIGN_UP(tmp);
 482         tmp = VMALLOC_START - tmp * sizeof(struct page);
 483         tmp &= ~((vmax >> 11) - 1);     /* align to page table level */
 484         tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
 485         vmemmap = (struct page *) tmp;
 486
 487         /* Take care that memory_end is set and <= vmemmap */
 488         memory_end = min(memory_end ?: max_physmem_end, tmp);
 489         max_pfn = max_low_pfn = PFN_DOWN(memory_end);
 490         memblock_remove(memory_end, ULONG_MAX);
 491
 492         pr_notice("The maximum memory size is %luMB\n", memory_end >> 20);
 493 }
 494
 495 #ifdef CONFIG_CRASH_DUMP
 496
 497 /*
 498  * When kdump is enabled, we have to ensure that no memory from
 499  * the area [0 - crashkernel memory size] and
 500  * [crashk_res.start - crashk_res.end] is set offline.
 501  */
 502 static int kdump_mem_notifier(struct notifier_block *nb,
 503                               unsigned long action, void *data)
 504 {
 505         struct memory_notify *arg = data;
 506
 507         if (action != MEM_GOING_OFFLINE)
 508                 return NOTIFY_OK;
 509         if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
 510                 return NOTIFY_BAD;
 511         if (arg->start_pfn > PFN_DOWN(crashk_res.end))
 512                 return NOTIFY_OK;
 513         if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
 514                 return NOTIFY_OK;
 515         return NOTIFY_BAD;
 516 }
 517
 518 static struct notifier_block kdump_mem_nb = {
 519         .notifier_call = kdump_mem_notifier,
 520 };
 521
 522 #endif
 523
 524 /*
 525  * Make sure that the area behind memory_end is protected
 526  */
 527 static void reserve_memory_end(void)
 528 {
 529 #ifdef CONFIG_CRASH_DUMP
 530         if (ipl_info.type == IPL_TYPE_FCP_DUMP &&
 531             !OLDMEM_BASE && sclp.hsa_size) {
 532                 memory_end = sclp.hsa_size;
 533                 memory_end &= PAGE_MASK;
 534                 memory_end_set = 1;
 535         }
 536 #endif
 537         if (!memory_end_set)
 538                 return;
 539         memblock_reserve(memory_end, ULONG_MAX);
 540 }
 541
 542 /*
 543  * Make sure that oldmem, where the dump is stored, is protected
 544  */
 545 static void reserve_oldmem(void)
 546 {
 547 #ifdef CONFIG_CRASH_DUMP
 548         if (OLDMEM_BASE)
 549                 /* Forget all memory above the running kdump system */
 550                 memblock_reserve(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
 551 #endif
 552 }
 553
 554 /*
 555  * Make sure that oldmem, where the dump is stored, is protected
 556  */
 557 static void remove_oldmem(void)
 558 {
 559 #ifdef CONFIG_CRASH_DUMP
 560         if (OLDMEM_BASE)
 561                 /* Forget all memory above the running kdump system */
 562                 memblock_remove(OLDMEM_SIZE, (phys_addr_t)ULONG_MAX);
 563 #endif
 564 }
 565
 566 /*
 567  * Reserve memory for kdump kernel to be loaded with kexec
 568  */
 569 static void __init reserve_crashkernel(void)
 570 {
 571 #ifdef CONFIG_CRASH_DUMP
 572         unsigned long long crash_base, crash_size;
 573         phys_addr_t low, high;
 574         int rc;
 575
 576         rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
 577                                &crash_base);
 578
 579         crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
 580         crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
 581         if (rc || crash_size == 0)
 582                 return;
 583
 584         if (memblock.memory.regions[0].size < crash_size) {
 585                 pr_info("crashkernel reservation failed: %s\n",
 586                         "first memory chunk must be at least crashkernel size");
 587                 return;
 588         }
 589
 590         low = crash_base ?: OLDMEM_BASE;
 591         high = low + crash_size;
 592         if (low >= OLDMEM_BASE && high <= OLDMEM_BASE + OLDMEM_SIZE) {
 593                 /* The crashkernel fits into OLDMEM, reuse OLDMEM */
 594                 crash_base = low;
 595         } else {
 596                 /* Find suitable area in free memory */
 597                 low = max_t(unsigned long, crash_size, sclp.hsa_size);
 598                 high = crash_base ? crash_base + crash_size : ULONG_MAX;
 599
 600                 if (crash_base && crash_base < low) {
 601                         pr_info("crashkernel reservation failed: %s\n",
 602                                 "crash_base too low");
 603                         return;
 604                 }
 605                 low = crash_base ?: low;
 606                 crash_base = memblock_find_in_range(low, high, crash_size,
 607                                                     KEXEC_CRASH_MEM_ALIGN);
 608         }
 609
 610         if (!crash_base) {
 611                 pr_info("crashkernel reservation failed: %s\n",
 612                         "no suitable area found");
 613                 return;
 614         }
 615
 616         if (register_memory_notifier(&kdump_mem_nb))
 617                 return;
 618
 619         if (!OLDMEM_BASE && MACHINE_IS_VM)
 620                 diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
 621         crashk_res.start = crash_base;
 622         crashk_res.end = crash_base + crash_size - 1;
 623         memblock_remove(crash_base, crash_size);
 624         pr_info("Reserving %lluMB of memory at %lluMB "
 625                 "for crashkernel (System RAM: %luMB)\n",
 626                 crash_size >> 20, crash_base >> 20,
 627                 (unsigned long)memblock.memory.total_size >> 20);
 628         os_info_crashkernel_add(crash_base, crash_size);
 629 #endif
 630 }
 631
 632 /*
 633  * Reserve the initrd from being used by memblock
 634  */
 635 static void __init reserve_initrd(void)
 636 {
 637 #ifdef CONFIG_BLK_DEV_INITRD
 638         if (!INITRD_START || !INITRD_SIZE)
 639                 return;
 640         initrd_start = INITRD_START;
 641         initrd_end = initrd_start + INITRD_SIZE;
 642         memblock_reserve(INITRD_START, INITRD_SIZE);
 643 #endif
 644 }
 645
 646 /*
 647  * Check for initrd being in usable memory
 648  */
 649 static void __init check_initrd(void)
 650 {
 651 #ifdef CONFIG_BLK_DEV_INITRD
 652         if (INITRD_START && INITRD_SIZE &&
 653             !memblock_is_region_memory(INITRD_START, INITRD_SIZE)) {
 654                 pr_err("The initial RAM disk does not fit into the memory\n");
 655                 memblock_free(INITRD_START, INITRD_SIZE);
 656                 initrd_start = initrd_end = 0;
 657         }
 658 #endif
 659 }
 660
 661 /*
 662  * Reserve memory used for lowcore/command line/kernel image.
 663  */
 664 static void __init reserve_kernel(void)
 665 {
 666         unsigned long start_pfn = PFN_UP(__pa(&_end));
 667
 668 #ifdef CONFIG_DMA_API_DEBUG
 669         /*
 670          * DMA_API_DEBUG code stumbles over addresses from the
 671          * range [_ehead, _stext]. Mark the memory as reserved
 672          * so it is not used for CONFIG_DMA_API_DEBUG=y.
 673          */
 674         memblock_reserve(0, PFN_PHYS(start_pfn));
 675 #else
 676         memblock_reserve(0, (unsigned long)_ehead);
 677         memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
 678                          - (unsigned long)_stext);
 679 #endif
 680 }
 681
 682 static void __init setup_memory(void)
 683 {
 684         struct memblock_region *reg;
 685
 686         /*
 687          * Init storage key for present memory
 688          */
 689         for_each_memblock(memory, reg) {
 690                 storage_key_init_range(reg->base, reg->base + reg->size);
 691         }
 692         psw_set_key(PAGE_DEFAULT_KEY);
 693
 694         /* Only cosmetics */
 695         memblock_enforce_memory_limit(memblock_end_of_DRAM());
 696 }
 697
 698 /*
 699  * Setup hardware capabilities.
 700  */
 701 static int __init setup_hwcaps(void)
 702 {
 703         static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
 704         struct cpuid cpu_id;
 705         int i;
 706
 707         /*
 708          * The store facility list bits numbers as found in the principles
 709          * of operation are numbered with bit 1UL<<31 as number 0 to
 710          * bit 1UL<<0 as number 31.
 711          *   Bit 0: instructions named N3, "backported" to esa-mode
 712          *   Bit 2: z/Architecture mode is active
 713          *   Bit 7: the store-facility-list-extended facility is installed
 714          *   Bit 17: the message-security assist is installed
 715          *   Bit 19: the long-displacement facility is installed
 716          *   Bit 21: the extended-immediate facility is installed
 717          *   Bit 22: extended-translation facility 3 is installed
 718          *   Bit 30: extended-translation facility 3 enhancement facility
 719          * These get translated to:
 720          *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
 721          *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
 722          *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
 723          *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
 724          */
 725         for (i = 0; i < 6; i++)
 726                 if (test_facility(stfl_bits[i]))
 727                         elf_hwcap |= 1UL << i;
 728
 729         if (test_facility(22) && test_facility(30))
 730                 elf_hwcap |= HWCAP_S390_ETF3EH;
 731
 732         /*
 733          * Check for additional facilities with store-facility-list-extended.
 734          * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
 735          * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
 736          * as stored by stfl, bits 32-xxx contain additional facilities.
 737          * How many facility words are stored depends on the number of
 738          * doublewords passed to the instruction. The additional facilities
 739          * are:
 740          *   Bit 42: decimal floating point facility is installed
 741          *   Bit 44: perform floating point operation facility is installed
 742          * translated to:
 743          *   HWCAP_S390_DFP bit 6 (42 && 44).
 744          */
 745         if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
 746                 elf_hwcap |= HWCAP_S390_DFP;
 747
 748         /*
 749          * Huge page support HWCAP_S390_HPAGE is bit 7.
 750          */
 751         if (MACHINE_HAS_EDAT1)
 752                 elf_hwcap |= HWCAP_S390_HPAGE;
 753
 754         /*
 755          * 64-bit register support for 31-bit processes
 756          * HWCAP_S390_HIGH_GPRS is bit 9.
 757          */
 758         elf_hwcap |= HWCAP_S390_HIGH_GPRS;
 759
 760         /*
 761          * Transactional execution support HWCAP_S390_TE is bit 10.
 762          */
 763         if (MACHINE_HAS_TE)
 764                 elf_hwcap |= HWCAP_S390_TE;
 765
 766         /*
 767          * Vector extension HWCAP_S390_VXRS is bit 11. The Vector extension
 768          * can be disabled with the "novx" parameter. Use MACHINE_HAS_VX
 769          * instead of facility bit 129.
 770          */
 771         if (MACHINE_HAS_VX) {
 772                 elf_hwcap |= HWCAP_S390_VXRS;
 773                 if (test_facility(134))
 774                         elf_hwcap |= HWCAP_S390_VXRS_EXT;
 775                 if (test_facility(135))
 776                         elf_hwcap |= HWCAP_S390_VXRS_BCD;
 777         }
 778
 779         /*
 780          * Guarded storage support HWCAP_S390_GS is bit 12.
 781          */
 782         if (MACHINE_HAS_GS)
 783                 elf_hwcap |= HWCAP_S390_GS;
 784
 785         get_cpu_id(&cpu_id);
 786         add_device_randomness(&cpu_id, sizeof(cpu_id));
 787         switch (cpu_id.machine) {
 788         case 0x2064:
 789         case 0x2066:
 790         default:        /* Use "z900" as default for 64 bit kernels. */
 791                 strcpy(elf_platform, "z900");
 792                 break;
 793         case 0x2084:
 794         case 0x2086:
 795                 strcpy(elf_platform, "z990");
 796                 break;
 797         case 0x2094:
 798         case 0x2096:
 799                 strcpy(elf_platform, "z9-109");
 800                 break;
 801         case 0x2097:
 802         case 0x2098:
 803                 strcpy(elf_platform, "z10");
 804                 break;
 805         case 0x2817:
 806         case 0x2818:
 807                 strcpy(elf_platform, "z196");
 808                 break;
 809         case 0x2827:
 810         case 0x2828:
 811                 strcpy(elf_platform, "zEC12");
 812                 break;
 813         case 0x2964:
 814         case 0x2965:
 815                 strcpy(elf_platform, "z13");
 816                 break;
 817         case 0x3906:
 818                 strcpy(elf_platform, "z14");
 819                 break;
 820         }
 821
 822         /*
 823          * Virtualization support HWCAP_INT_SIE is bit 0.
 824          */
 825         if (sclp.has_sief2)
 826                 int_hwcap |= HWCAP_INT_SIE;
 827
 828         return 0;
 829 }
 830 arch_initcall(setup_hwcaps);
 831
 832 /*
 833  * Add system information as device randomness
 834  */
 835 static void __init setup_randomness(void)
 836 {
 837         struct sysinfo_3_2_2 *vmms;
 838
 839         vmms = (struct sysinfo_3_2_2 *) memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 840         if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
 841                 add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
 842         memblock_free((unsigned long) vmms, PAGE_SIZE);
 843 }
 844
 845 /*
 846  * Find the correct size for the task_struct. This depends on
 847  * the size of the struct fpu at the end of the thread_struct
 848  * which is embedded in the task_struct.
 849  */
 850 static void __init setup_task_size(void)
 851 {
 852         int task_size = sizeof(struct task_struct);
 853
 854         if (!MACHINE_HAS_VX) {
 855                 task_size -= sizeof(__vector128) * __NUM_VXRS;
 856                 task_size += sizeof(freg_t) * __NUM_FPRS;
 857         }
 858         arch_task_struct_size = task_size;
 859 }
 860
 861 /*
 862  * Setup function called from init/main.c just after the banner
 863  * was printed.
 864  */
 865
 866 void __init setup_arch(char **cmdline_p)
 867 {
 868         /*
 869          * print what head.S has found out about the machine
 870          */
 871         if (MACHINE_IS_VM)
 872                 pr_info("Linux is running as a z/VM "
 873                         "guest operating system in 64-bit mode\n");
 874         else if (MACHINE_IS_KVM)
 875                 pr_info("Linux is running under KVM in 64-bit mode\n");
 876         else if (MACHINE_IS_LPAR)
 877                 pr_info("Linux is running natively in 64-bit mode\n");
 878
 879         /* Have one command line that is parsed and saved in /proc/cmdline */
 880         /* boot_command_line has been already set up in early.c */
 881         *cmdline_p = boot_command_line;
 882
 883         ROOT_DEV = Root_RAM0;
 884
 885         /* Is init_mm really needed? */
 886         init_mm.start_code = PAGE_OFFSET;
 887         init_mm.end_code = (unsigned long) &_etext;
 888         init_mm.end_data = (unsigned long) &_edata;
 889         init_mm.brk = (unsigned long) &_end;
 890
 891         parse_early_param();
 892 #ifdef CONFIG_CRASH_DUMP
 893         /* Deactivate elfcorehdr= kernel parameter */
 894         elfcorehdr_addr = ELFCORE_ADDR_MAX;
 895 #endif
 896
 897         os_info_init();
 898         setup_ipl();
 899         setup_task_size();
 900
 901         /* Do some memory reservations *before* memory is added to memblock */
 902         reserve_memory_end();
 903         reserve_oldmem();
 904         reserve_kernel();
 905         reserve_initrd();
 906         memblock_allow_resize();
 907
 908         /* Get information about *all* installed memory */
 909         detect_memory_memblock();
 910
 911         remove_oldmem();
 912
 913         /*
 914          * Make sure all chunks are MAX_ORDER aligned so we don't need the
 915          * extra checks that HOLES_IN_ZONE would require.
 916          *
 917          * Is this still required?
 918          */
 919         memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));
 920
 921         setup_memory_end();
 922         setup_memory();
 923         dma_contiguous_reserve(memory_end);
 924         vmcp_cma_reserve();
 925
 926         check_initrd();
 927         reserve_crashkernel();
 928 #ifdef CONFIG_CRASH_DUMP
 929         /*
 930          * Be aware that smp_save_dump_cpus() triggers a system reset.
 931          * Therefore CPU and device initialization should be done afterwards.
 932          */
 933         smp_save_dump_cpus();
 934 #endif
 935
 936         setup_resources();
 937         setup_lowcore();
 938         smp_fill_possible_mask();
 939         cpu_detect_mhz_feature();
 940         cpu_init();
 941         numa_setup();
 942         smp_detect_cpus();
 943         topology_init_early();
 944
 945         /*
 946          * Create kernel page tables and switch to virtual addressing.
 947          */
 948         paging_init();
 949
 950         /* Setup default console */
 951         conmode_default();
 952         set_preferred_console();
 953
 954         apply_alternative_instructions();
 955
 956         /* Setup zfcpdump support */
 957         setup_zfcpdump();
 958
 959         /* Add system specific data to the random pool */
 960         setup_randomness();
 961 }