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/root_dev.h>
  38 #include <linux/console.h>
  39 #include <linux/kernel_stat.h>
  40 #include <linux/dma-map-ops.h>
  41 #include <linux/device.h>
  42 #include <linux/notifier.h>
  43 #include <linux/pfn.h>
  44 #include <linux/ctype.h>
  45 #include <linux/reboot.h>
  46 #include <linux/topology.h>
  47 #include <linux/kexec.h>
  48 #include <linux/crash_dump.h>
  49 #include <linux/memory.h>
  50 #include <linux/compat.h>
  51 #include <linux/start_kernel.h>
  52 #include <linux/hugetlb.h>
  53 #include <linux/kmemleak.h>
  54
  55 #include <asm/archrandom.h>
  56 #include <asm/boot_data.h>
  57 #include <asm/ipl.h>
  58 #include <asm/facility.h>
  59 #include <asm/smp.h>
  60 #include <asm/mmu_context.h>
  61 #include <asm/cpcmd.h>
  62 #include <asm/abs_lowcore.h>
  63 #include <asm/nmi.h>
  64 #include <asm/irq.h>
  65 #include <asm/page.h>
  66 #include <asm/ptrace.h>
  67 #include <asm/sections.h>
  68 #include <asm/ebcdic.h>
  69 #include <asm/diag.h>
  70 #include <asm/os_info.h>
  71 #include <asm/sclp.h>
  72 #include <asm/stacktrace.h>
  73 #include <asm/sysinfo.h>
  74 #include <asm/numa.h>
  75 #include <asm/alternative.h>
  76 #include <asm/nospec-branch.h>
  77 #include <asm/physmem_info.h>
  78 #include <asm/maccess.h>
  79 #include <asm/uv.h>
  80 #include <asm/asm-offsets.h>
  81 #include "entry.h"
  82
  83 /*
  84  * Machine setup..
  85  */
  86 unsigned int console_mode = 0;
  87 EXPORT_SYMBOL(console_mode);
  88
  89 unsigned int console_devno = -1;
  90 EXPORT_SYMBOL(console_devno);
  91
  92 unsigned int console_irq = -1;
  93 EXPORT_SYMBOL(console_irq);
  94
  95 /*
  96  * Some code and data needs to stay below 2 GB, even when the kernel would be
  97  * relocated above 2 GB, because it has to use 31 bit addresses.
  98  * Such code and data is part of the .amode31 section.
  99  */
 100 char __amode31_ref *__samode31 = _samode31;
 101 char __amode31_ref *__eamode31 = _eamode31;
 102 char __amode31_ref *__stext_amode31 = _stext_amode31;
 103 char __amode31_ref *__etext_amode31 = _etext_amode31;
 104 struct exception_table_entry __amode31_ref *__start_amode31_ex_table = _start_amode31_ex_table;
 105 struct exception_table_entry __amode31_ref *__stop_amode31_ex_table = _stop_amode31_ex_table;
 106
 107 /*
 108  * Control registers CR2, CR5 and CR15 are initialized with addresses
 109  * of tables that must be placed below 2G which is handled by the AMODE31
 110  * sections.
 111  * Because the AMODE31 sections are relocated below 2G at startup,
 112  * the content of control registers CR2, CR5 and CR15 must be updated
 113  * with new addresses after the relocation. The initial initialization of
 114  * control registers occurs in head64.S and then gets updated again after AMODE31
 115  * relocation. We must access the relevant AMODE31 tables indirectly via
 116  * pointers placed in the .amode31.refs linker section. Those pointers get
 117  * updated automatically during AMODE31 relocation and always contain a valid
 118  * address within AMODE31 sections.
 119  */
 120
 121 static __amode31_data u32 __ctl_duct_amode31[16] __aligned(64);
 122
 123 static __amode31_data u64 __ctl_aste_amode31[8] __aligned(64) = {
 124         [1] = 0xffffffffffffffff
 125 };
 126
 127 static __amode31_data u32 __ctl_duald_amode31[32] __aligned(128) = {
 128         0x80000000, 0, 0, 0,
 129         0x80000000, 0, 0, 0,
 130         0x80000000, 0, 0, 0,
 131         0x80000000, 0, 0, 0,
 132         0x80000000, 0, 0, 0,
 133         0x80000000, 0, 0, 0,
 134         0x80000000, 0, 0, 0,
 135         0x80000000, 0, 0, 0
 136 };
 137
 138 static __amode31_data u32 __ctl_linkage_stack_amode31[8] __aligned(64) = {
 139         0, 0, 0x89000000, 0,
 140         0, 0, 0x8a000000, 0
 141 };
 142
 143 static u64 __amode31_ref *__ctl_aste = __ctl_aste_amode31;
 144 static u32 __amode31_ref *__ctl_duald = __ctl_duald_amode31;
 145 static u32 __amode31_ref *__ctl_linkage_stack = __ctl_linkage_stack_amode31;
 146 static u32 __amode31_ref *__ctl_duct = __ctl_duct_amode31;
 147
 148 unsigned long __bootdata_preserved(max_mappable);
 149 unsigned long __bootdata(ident_map_size);
 150 struct physmem_info __bootdata(physmem_info);
 151
 152 unsigned long __bootdata_preserved(__kaslr_offset);
 153 int __bootdata_preserved(__kaslr_enabled);
 154 unsigned int __bootdata_preserved(zlib_dfltcc_support);
 155 EXPORT_SYMBOL(zlib_dfltcc_support);
 156 u64 __bootdata_preserved(stfle_fac_list[16]);
 157 EXPORT_SYMBOL(stfle_fac_list);
 158 u64 __bootdata_preserved(alt_stfle_fac_list[16]);
 159 struct oldmem_data __bootdata_preserved(oldmem_data);
 160
 161 unsigned long VMALLOC_START;
 162 EXPORT_SYMBOL(VMALLOC_START);
 163
 164 unsigned long VMALLOC_END;
 165 EXPORT_SYMBOL(VMALLOC_END);
 166
 167 struct page *vmemmap;
 168 EXPORT_SYMBOL(vmemmap);
 169 unsigned long vmemmap_size;
 170
 171 unsigned long MODULES_VADDR;
 172 unsigned long MODULES_END;
 173
 174 /* An array with a pointer to the lowcore of every CPU. */
 175 struct lowcore *lowcore_ptr[NR_CPUS];
 176 EXPORT_SYMBOL(lowcore_ptr);
 177
 178 DEFINE_STATIC_KEY_FALSE(cpu_has_bear);
 179
 180 /*
 181  * The Write Back bit position in the physaddr is given by the SLPC PCI.
 182  * Leaving the mask zero always uses write through which is safe
 183  */
 184 unsigned long mio_wb_bit_mask __ro_after_init;
 185
 186 /*
 187  * This is set up by the setup-routine at boot-time
 188  * for S390 need to find out, what we have to setup
 189  * using address 0x10400 ...
 190  */
 191
 192 #include <asm/setup.h>
 193
 194 /*
 195  * condev= and conmode= setup parameter.
 196  */
 197
 198 static int __init condev_setup(char *str)
 199 {
 200         int vdev;
 201
 202         vdev = simple_strtoul(str, &str, 0);
 203         if (vdev >= 0 && vdev < 65536) {
 204                 console_devno = vdev;
 205                 console_irq = -1;
 206         }
 207         return 1;
 208 }
 209
 210 __setup("condev=", condev_setup);
 211
 212 static void __init set_preferred_console(void)
 213 {
 214         if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
 215                 add_preferred_console("ttyS", 0, NULL);
 216         else if (CONSOLE_IS_3270)
 217                 add_preferred_console("tty3270", 0, NULL);
 218         else if (CONSOLE_IS_VT220)
 219                 add_preferred_console("ttysclp", 0, NULL);
 220         else if (CONSOLE_IS_HVC)
 221                 add_preferred_console("hvc", 0, NULL);
 222 }
 223
 224 static int __init conmode_setup(char *str)
 225 {
 226 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 227         if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
 228                 SET_CONSOLE_SCLP;
 229 #endif
 230 #if defined(CONFIG_TN3215_CONSOLE)
 231         if (!strcmp(str, "3215"))
 232                 SET_CONSOLE_3215;
 233 #endif
 234 #if defined(CONFIG_TN3270_CONSOLE)
 235         if (!strcmp(str, "3270"))
 236                 SET_CONSOLE_3270;
 237 #endif
 238         set_preferred_console();
 239         return 1;
 240 }
 241
 242 __setup("conmode=", conmode_setup);
 243
 244 static void __init conmode_default(void)
 245 {
 246         char query_buffer[1024];
 247         char *ptr;
 248
 249         if (MACHINE_IS_VM) {
 250                 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
 251                 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
 252                 ptr = strstr(query_buffer, "SUBCHANNEL =");
 253                 console_irq = simple_strtoul(ptr + 13, NULL, 16);
 254                 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
 255                 ptr = strstr(query_buffer, "CONMODE");
 256                 /*
 257                  * Set the conmode to 3215 so that the device recognition
 258                  * will set the cu_type of the console to 3215. If the
 259                  * conmode is 3270 and we don't set it back then both
 260                  * 3215 and the 3270 driver will try to access the console
 261                  * device (3215 as console and 3270 as normal tty).
 262                  */
 263                 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
 264                 if (ptr == NULL) {
 265 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 266                         SET_CONSOLE_SCLP;
 267 #endif
 268                         return;
 269                 }
 270                 if (str_has_prefix(ptr + 8, "3270")) {
 271 #if defined(CONFIG_TN3270_CONSOLE)
 272                         SET_CONSOLE_3270;
 273 #elif defined(CONFIG_TN3215_CONSOLE)
 274                         SET_CONSOLE_3215;
 275 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 276                         SET_CONSOLE_SCLP;
 277 #endif
 278                 } else if (str_has_prefix(ptr + 8, "3215")) {
 279 #if defined(CONFIG_TN3215_CONSOLE)
 280                         SET_CONSOLE_3215;
 281 #elif defined(CONFIG_TN3270_CONSOLE)
 282                         SET_CONSOLE_3270;
 283 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 284                         SET_CONSOLE_SCLP;
 285 #endif
 286                 }
 287         } else if (MACHINE_IS_KVM) {
 288                 if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
 289                         SET_CONSOLE_VT220;
 290                 else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
 291                         SET_CONSOLE_SCLP;
 292                 else
 293                         SET_CONSOLE_HVC;
 294         } else {
 295 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 296                 SET_CONSOLE_SCLP;
 297 #endif
 298         }
 299 }
 300
 301 #ifdef CONFIG_CRASH_DUMP
 302 static void __init setup_zfcpdump(void)
 303 {
 304         if (!is_ipl_type_dump())
 305                 return;
 306         if (oldmem_data.start)
 307                 return;
 308         strlcat(boot_command_line, " cio_ignore=all,!ipldev,!condev", COMMAND_LINE_SIZE);
 309         console_loglevel = 2;
 310 }
 311 #else
 312 static inline void setup_zfcpdump(void) {}
 313 #endif /* CONFIG_CRASH_DUMP */
 314
 315  /*
 316  * Reboot, halt and power_off stubs. They just call _machine_restart,
 317  * _machine_halt or _machine_power_off.
 318  */
 319
 320 void machine_restart(char *command)
 321 {
 322         if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
 323                 /*
 324                  * Only unblank the console if we are called in enabled
 325                  * context or a bust_spinlocks cleared the way for us.
 326                  */
 327                 console_unblank();
 328         _machine_restart(command);
 329 }
 330
 331 void machine_halt(void)
 332 {
 333         if (!in_interrupt() || oops_in_progress)
 334                 /*
 335                  * Only unblank the console if we are called in enabled
 336                  * context or a bust_spinlocks cleared the way for us.
 337                  */
 338                 console_unblank();
 339         _machine_halt();
 340 }
 341
 342 void machine_power_off(void)
 343 {
 344         if (!in_interrupt() || oops_in_progress)
 345                 /*
 346                  * Only unblank the console if we are called in enabled
 347                  * context or a bust_spinlocks cleared the way for us.
 348                  */
 349                 console_unblank();
 350         _machine_power_off();
 351 }
 352
 353 /*
 354  * Dummy power off function.
 355  */
 356 void (*pm_power_off)(void) = machine_power_off;
 357 EXPORT_SYMBOL_GPL(pm_power_off);
 358
 359 void *restart_stack;
 360
 361 unsigned long stack_alloc(void)
 362 {
 363 #ifdef CONFIG_VMAP_STACK
 364         void *ret;
 365
 366         ret = __vmalloc_node(THREAD_SIZE, THREAD_SIZE, THREADINFO_GFP,
 367                              NUMA_NO_NODE, __builtin_return_address(0));
 368         kmemleak_not_leak(ret);
 369         return (unsigned long)ret;
 370 #else
 371         return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 372 #endif
 373 }
 374
 375 void stack_free(unsigned long stack)
 376 {
 377 #ifdef CONFIG_VMAP_STACK
 378         vfree((void *) stack);
 379 #else
 380         free_pages(stack, THREAD_SIZE_ORDER);
 381 #endif
 382 }
 383
 384 static unsigned long __init stack_alloc_early(void)
 385 {
 386         unsigned long stack;
 387
 388         stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
 389         if (!stack) {
 390                 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 391                       __func__, THREAD_SIZE, THREAD_SIZE);
 392         }
 393         return stack;
 394 }
 395
 396 static void __init setup_lowcore(void)
 397 {
 398         struct lowcore *lc, *abs_lc;
 399
 400         /*
 401          * Setup lowcore for boot cpu
 402          */
 403         BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
 404         lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
 405         if (!lc)
 406                 panic("%s: Failed to allocate %zu bytes align=%zx\n",
 407                       __func__, sizeof(*lc), sizeof(*lc));
 408
 409         lc->restart_psw.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT;
 410         lc->restart_psw.addr = __pa(restart_int_handler);
 411         lc->external_new_psw.mask = PSW_KERNEL_BITS;
 412         lc->external_new_psw.addr = (unsigned long) ext_int_handler;
 413         lc->svc_new_psw.mask = PSW_KERNEL_BITS;
 414         lc->svc_new_psw.addr = (unsigned long) system_call;
 415         lc->program_new_psw.mask = PSW_KERNEL_BITS;
 416         lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
 417         lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
 418         lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
 419         lc->io_new_psw.mask = PSW_KERNEL_BITS;
 420         lc->io_new_psw.addr = (unsigned long) io_int_handler;
 421         lc->clock_comparator = clock_comparator_max;
 422         lc->current_task = (unsigned long)&init_task;
 423         lc->lpp = LPP_MAGIC;
 424         lc->machine_flags = S390_lowcore.machine_flags;
 425         lc->preempt_count = S390_lowcore.preempt_count;
 426         nmi_alloc_mcesa_early(&lc->mcesad);
 427         lc->sys_enter_timer = S390_lowcore.sys_enter_timer;
 428         lc->exit_timer = S390_lowcore.exit_timer;
 429         lc->user_timer = S390_lowcore.user_timer;
 430         lc->system_timer = S390_lowcore.system_timer;
 431         lc->steal_timer = S390_lowcore.steal_timer;
 432         lc->last_update_timer = S390_lowcore.last_update_timer;
 433         lc->last_update_clock = S390_lowcore.last_update_clock;
 434         /*
 435          * Allocate the global restart stack which is the same for
 436          * all CPUs in case *one* of them does a PSW restart.
 437          */
 438         restart_stack = (void *)(stack_alloc_early() + STACK_INIT_OFFSET);
 439         lc->mcck_stack = stack_alloc_early() + STACK_INIT_OFFSET;
 440         lc->async_stack = stack_alloc_early() + STACK_INIT_OFFSET;
 441         lc->nodat_stack = stack_alloc_early() + STACK_INIT_OFFSET;
 442         lc->kernel_stack = S390_lowcore.kernel_stack;
 443         /*
 444          * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
 445          * restart data to the absolute zero lowcore. This is necessary if
 446          * PSW restart is done on an offline CPU that has lowcore zero.
 447          */
 448         lc->restart_stack = (unsigned long) restart_stack;
 449         lc->restart_fn = (unsigned long) do_restart;
 450         lc->restart_data = 0;
 451         lc->restart_source = -1U;
 452         lc->spinlock_lockval = arch_spin_lockval(0);
 453         lc->spinlock_index = 0;
 454         arch_spin_lock_setup(0);
 455         lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
 456         lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
 457         lc->preempt_count = PREEMPT_DISABLED;
 458         lc->kernel_asce = S390_lowcore.kernel_asce;
 459         lc->user_asce = S390_lowcore.user_asce;
 460
 461         system_ctlreg_init_save_area(lc);
 462         abs_lc = get_abs_lowcore();
 463         abs_lc->restart_stack = lc->restart_stack;
 464         abs_lc->restart_fn = lc->restart_fn;
 465         abs_lc->restart_data = lc->restart_data;
 466         abs_lc->restart_source = lc->restart_source;
 467         abs_lc->restart_psw = lc->restart_psw;
 468         abs_lc->restart_flags = RESTART_FLAG_CTLREGS;
 469         abs_lc->program_new_psw = lc->program_new_psw;
 470         abs_lc->mcesad = lc->mcesad;
 471         put_abs_lowcore(abs_lc);
 472
 473         set_prefix(__pa(lc));
 474         lowcore_ptr[0] = lc;
 475         if (abs_lowcore_map(0, lowcore_ptr[0], false))
 476                 panic("Couldn't setup absolute lowcore");
 477 }
 478
 479 static struct resource code_resource = {
 480         .name  = "Kernel code",
 481         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 482 };
 483
 484 static struct resource data_resource = {
 485         .name = "Kernel data",
 486         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 487 };
 488
 489 static struct resource bss_resource = {
 490         .name = "Kernel bss",
 491         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 492 };
 493
 494 static struct resource __initdata *standard_resources[] = {
 495         &code_resource,
 496         &data_resource,
 497         &bss_resource,
 498 };
 499
 500 static void __init setup_resources(void)
 501 {
 502         struct resource *res, *std_res, *sub_res;
 503         phys_addr_t start, end;
 504         int j;
 505         u64 i;
 506
 507         code_resource.start = (unsigned long) _text;
 508         code_resource.end = (unsigned long) _etext - 1;
 509         data_resource.start = (unsigned long) _etext;
 510         data_resource.end = (unsigned long) _edata - 1;
 511         bss_resource.start = (unsigned long) __bss_start;
 512         bss_resource.end = (unsigned long) __bss_stop - 1;
 513
 514         for_each_mem_range(i, &start, &end) {
 515                 res = memblock_alloc(sizeof(*res), 8);
 516                 if (!res)
 517                         panic("%s: Failed to allocate %zu bytes align=0x%x\n",
 518                               __func__, sizeof(*res), 8);
 519                 res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
 520
 521                 res->name = "System RAM";
 522                 res->start = start;
 523                 /*
 524                  * In memblock, end points to the first byte after the
 525                  * range while in resources, end points to the last byte in
 526                  * the range.
 527                  */
 528                 res->end = end - 1;
 529                 request_resource(&iomem_resource, res);
 530
 531                 for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
 532                         std_res = standard_resources[j];
 533                         if (std_res->start < res->start ||
 534                             std_res->start > res->end)
 535                                 continue;
 536                         if (std_res->end > res->end) {
 537                                 sub_res = memblock_alloc(sizeof(*sub_res), 8);
 538                                 if (!sub_res)
 539                                         panic("%s: Failed to allocate %zu bytes align=0x%x\n",
 540                                               __func__, sizeof(*sub_res), 8);
 541                                 *sub_res = *std_res;
 542                                 sub_res->end = res->end;
 543                                 std_res->start = res->end + 1;
 544                                 request_resource(res, sub_res);
 545                         } else {
 546                                 request_resource(res, std_res);
 547                         }
 548                 }
 549         }
 550 #ifdef CONFIG_CRASH_DUMP
 551         /*
 552          * Re-add removed crash kernel memory as reserved memory. This makes
 553          * sure it will be mapped with the identity mapping and struct pages
 554          * will be created, so it can be resized later on.
 555          * However add it later since the crash kernel resource should not be
 556          * part of the System RAM resource.
 557          */
 558         if (crashk_res.end) {
 559                 memblock_add_node(crashk_res.start, resource_size(&crashk_res),
 560                                   0, MEMBLOCK_NONE);
 561                 memblock_reserve(crashk_res.start, resource_size(&crashk_res));
 562                 insert_resource(&iomem_resource, &crashk_res);
 563         }
 564 #endif
 565 }
 566
 567 static void __init setup_memory_end(void)
 568 {
 569         max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
 570         pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
 571 }
 572
 573 #ifdef CONFIG_CRASH_DUMP
 574
 575 /*
 576  * When kdump is enabled, we have to ensure that no memory from the area
 577  * [0 - crashkernel memory size] is set offline - it will be exchanged with
 578  * the crashkernel memory region when kdump is triggered. The crashkernel
 579  * memory region can never get offlined (pages are unmovable).
 580  */
 581 static int kdump_mem_notifier(struct notifier_block *nb,
 582                               unsigned long action, void *data)
 583 {
 584         struct memory_notify *arg = data;
 585
 586         if (action != MEM_GOING_OFFLINE)
 587                 return NOTIFY_OK;
 588         if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
 589                 return NOTIFY_BAD;
 590         return NOTIFY_OK;
 591 }
 592
 593 static struct notifier_block kdump_mem_nb = {
 594         .notifier_call = kdump_mem_notifier,
 595 };
 596
 597 #endif
 598
 599 /*
 600  * Reserve page tables created by decompressor
 601  */
 602 static void __init reserve_pgtables(void)
 603 {
 604         unsigned long start, end;
 605         struct reserved_range *range;
 606
 607         for_each_physmem_reserved_type_range(RR_VMEM, range, &start, &end)
 608                 memblock_reserve(start, end - start);
 609 }
 610
 611 /*
 612  * Reserve memory for kdump kernel to be loaded with kexec
 613  */
 614 static void __init reserve_crashkernel(void)
 615 {
 616 #ifdef CONFIG_CRASH_DUMP
 617         unsigned long long crash_base, crash_size;
 618         phys_addr_t low, high;
 619         int rc;
 620
 621         rc = parse_crashkernel(boot_command_line, ident_map_size,
 622                                &crash_size, &crash_base, NULL, NULL);
 623
 624         crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
 625         crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
 626         if (rc || crash_size == 0)
 627                 return;
 628
 629         if (memblock.memory.regions[0].size < crash_size) {
 630                 pr_info("crashkernel reservation failed: %s\n",
 631                         "first memory chunk must be at least crashkernel size");
 632                 return;
 633         }
 634
 635         low = crash_base ?: oldmem_data.start;
 636         high = low + crash_size;
 637         if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
 638                 /* The crashkernel fits into OLDMEM, reuse OLDMEM */
 639                 crash_base = low;
 640         } else {
 641                 /* Find suitable area in free memory */
 642                 low = max_t(unsigned long, crash_size, sclp.hsa_size);
 643                 high = crash_base ? crash_base + crash_size : ULONG_MAX;
 644
 645                 if (crash_base && crash_base < low) {
 646                         pr_info("crashkernel reservation failed: %s\n",
 647                                 "crash_base too low");
 648                         return;
 649                 }
 650                 low = crash_base ?: low;
 651                 crash_base = memblock_phys_alloc_range(crash_size,
 652                                                        KEXEC_CRASH_MEM_ALIGN,
 653                                                        low, high);
 654         }
 655
 656         if (!crash_base) {
 657                 pr_info("crashkernel reservation failed: %s\n",
 658                         "no suitable area found");
 659                 return;
 660         }
 661
 662         if (register_memory_notifier(&kdump_mem_nb)) {
 663                 memblock_phys_free(crash_base, crash_size);
 664                 return;
 665         }
 666
 667         if (!oldmem_data.start && MACHINE_IS_VM)
 668                 diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
 669         crashk_res.start = crash_base;
 670         crashk_res.end = crash_base + crash_size - 1;
 671         memblock_remove(crash_base, crash_size);
 672         pr_info("Reserving %lluMB of memory at %lluMB "
 673                 "for crashkernel (System RAM: %luMB)\n",
 674                 crash_size >> 20, crash_base >> 20,
 675                 (unsigned long)memblock.memory.total_size >> 20);
 676         os_info_crashkernel_add(crash_base, crash_size);
 677 #endif
 678 }
 679
 680 /*
 681  * Reserve the initrd from being used by memblock
 682  */
 683 static void __init reserve_initrd(void)
 684 {
 685         unsigned long addr, size;
 686
 687         if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD) || !get_physmem_reserved(RR_INITRD, &addr, &size))
 688                 return;
 689         initrd_start = (unsigned long)__va(addr);
 690         initrd_end = initrd_start + size;
 691         memblock_reserve(addr, size);
 692 }
 693
 694 /*
 695  * Reserve the memory area used to pass the certificate lists
 696  */
 697 static void __init reserve_certificate_list(void)
 698 {
 699         if (ipl_cert_list_addr)
 700                 memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
 701 }
 702
 703 static void __init reserve_physmem_info(void)
 704 {
 705         unsigned long addr, size;
 706
 707         if (get_physmem_reserved(RR_MEM_DETECT_EXTENDED, &addr, &size))
 708                 memblock_reserve(addr, size);
 709 }
 710
 711 static void __init free_physmem_info(void)
 712 {
 713         unsigned long addr, size;
 714
 715         if (get_physmem_reserved(RR_MEM_DETECT_EXTENDED, &addr, &size))
 716                 memblock_phys_free(addr, size);
 717 }
 718
 719 static void __init memblock_add_physmem_info(void)
 720 {
 721         unsigned long start, end;
 722         int i;
 723
 724         pr_debug("physmem info source: %s (%hhd)\n",
 725                  get_physmem_info_source(), physmem_info.info_source);
 726         /* keep memblock lists close to the kernel */
 727         memblock_set_bottom_up(true);
 728         for_each_physmem_usable_range(i, &start, &end)
 729                 memblock_add(start, end - start);
 730         for_each_physmem_online_range(i, &start, &end)
 731                 memblock_physmem_add(start, end - start);
 732         memblock_set_bottom_up(false);
 733         memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
 734 }
 735
 736 /*
 737  * Reserve memory used for lowcore/command line/kernel image.
 738  */
 739 static void __init reserve_kernel(void)
 740 {
 741         memblock_reserve(0, STARTUP_NORMAL_OFFSET);
 742         memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
 743         memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
 744         memblock_reserve(physmem_info.reserved[RR_AMODE31].start, __eamode31 - __samode31);
 745         memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
 746         memblock_reserve(__pa(_stext), _end - _stext);
 747 }
 748
 749 static void __init setup_memory(void)
 750 {
 751         phys_addr_t start, end;
 752         u64 i;
 753
 754         /*
 755          * Init storage key for present memory
 756          */
 757         for_each_mem_range(i, &start, &end)
 758                 storage_key_init_range(start, end);
 759
 760         psw_set_key(PAGE_DEFAULT_KEY);
 761 }
 762
 763 static void __init relocate_amode31_section(void)
 764 {
 765         unsigned long amode31_size = __eamode31 - __samode31;
 766         long amode31_offset, *ptr;
 767
 768         amode31_offset = physmem_info.reserved[RR_AMODE31].start - (unsigned long)__samode31;
 769         pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
 770
 771         /* Move original AMODE31 section to the new one */
 772         memmove((void *)physmem_info.reserved[RR_AMODE31].start, __samode31, amode31_size);
 773         /* Zero out the old AMODE31 section to catch invalid accesses within it */
 774         memset(__samode31, 0, amode31_size);
 775
 776         /* Update all AMODE31 region references */
 777         for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
 778                 *ptr += amode31_offset;
 779 }
 780
 781 /* This must be called after AMODE31 relocation */
 782 static void __init setup_cr(void)
 783 {
 784         union ctlreg2 cr2;
 785         union ctlreg5 cr5;
 786         union ctlreg15 cr15;
 787
 788         __ctl_duct[1] = (unsigned long)__ctl_aste;
 789         __ctl_duct[2] = (unsigned long)__ctl_aste;
 790         __ctl_duct[4] = (unsigned long)__ctl_duald;
 791
 792         /* Update control registers CR2, CR5 and CR15 */
 793         local_ctl_store(2, &cr2.reg);
 794         local_ctl_store(5, &cr5.reg);
 795         local_ctl_store(15, &cr15.reg);
 796         cr2.ducto = (unsigned long)__ctl_duct >> 6;
 797         cr5.pasteo = (unsigned long)__ctl_duct >> 6;
 798         cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
 799         system_ctl_load(2, &cr2.reg);
 800         system_ctl_load(5, &cr5.reg);
 801         system_ctl_load(15, &cr15.reg);
 802 }
 803
 804 /*
 805  * Add system information as device randomness
 806  */
 807 static void __init setup_randomness(void)
 808 {
 809         struct sysinfo_3_2_2 *vmms;
 810
 811         vmms = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 812         if (!vmms)
 813                 panic("Failed to allocate memory for sysinfo structure\n");
 814         if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
 815                 add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
 816         memblock_free(vmms, PAGE_SIZE);
 817
 818         if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG))
 819                 static_branch_enable(&s390_arch_random_available);
 820 }
 821
 822 /*
 823  * Issue diagnose 318 to set the control program name and
 824  * version codes.
 825  */
 826 static void __init setup_control_program_code(void)
 827 {
 828         union diag318_info diag318_info = {
 829                 .cpnc = CPNC_LINUX,
 830                 .cpvc = 0,
 831         };
 832
 833         if (!sclp.has_diag318)
 834                 return;
 835
 836         diag_stat_inc(DIAG_STAT_X318);
 837         asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
 838 }
 839
 840 /*
 841  * Print the component list from the IPL report
 842  */
 843 static void __init log_component_list(void)
 844 {
 845         struct ipl_rb_component_entry *ptr, *end;
 846         char *str;
 847
 848         if (!early_ipl_comp_list_addr)
 849                 return;
 850         if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
 851                 pr_info("Linux is running with Secure-IPL enabled\n");
 852         else
 853                 pr_info("Linux is running with Secure-IPL disabled\n");
 854         ptr = __va(early_ipl_comp_list_addr);
 855         end = (void *) ptr + early_ipl_comp_list_size;
 856         pr_info("The IPL report contains the following components:\n");
 857         while (ptr < end) {
 858                 if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
 859                         if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
 860                                 str = "signed, verified";
 861                         else
 862                                 str = "signed, verification failed";
 863                 } else {
 864                         str = "not signed";
 865                 }
 866                 pr_info("%016llx - %016llx (%s)\n",
 867                         ptr->addr, ptr->addr + ptr->len, str);
 868                 ptr++;
 869         }
 870 }
 871
 872 /*
 873  * Setup function called from init/main.c just after the banner
 874  * was printed.
 875  */
 876
 877 void __init setup_arch(char **cmdline_p)
 878 {
 879         /*
 880          * print what head.S has found out about the machine
 881          */
 882         if (MACHINE_IS_VM)
 883                 pr_info("Linux is running as a z/VM "
 884                         "guest operating system in 64-bit mode\n");
 885         else if (MACHINE_IS_KVM)
 886                 pr_info("Linux is running under KVM in 64-bit mode\n");
 887         else if (MACHINE_IS_LPAR)
 888                 pr_info("Linux is running natively in 64-bit mode\n");
 889         else
 890                 pr_info("Linux is running as a guest in 64-bit mode\n");
 891
 892         log_component_list();
 893
 894         /* Have one command line that is parsed and saved in /proc/cmdline */
 895         /* boot_command_line has been already set up in early.c */
 896         *cmdline_p = boot_command_line;
 897
 898         ROOT_DEV = Root_RAM0;
 899
 900         setup_initial_init_mm(_text, _etext, _edata, _end);
 901
 902         if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
 903                 nospec_auto_detect();
 904
 905         jump_label_init();
 906         parse_early_param();
 907 #ifdef CONFIG_CRASH_DUMP
 908         /* Deactivate elfcorehdr= kernel parameter */
 909         elfcorehdr_addr = ELFCORE_ADDR_MAX;
 910 #endif
 911
 912         os_info_init();
 913         setup_ipl();
 914         setup_control_program_code();
 915
 916         /* Do some memory reservations *before* memory is added to memblock */
 917         reserve_pgtables();
 918         reserve_kernel();
 919         reserve_initrd();
 920         reserve_certificate_list();
 921         reserve_physmem_info();
 922         memblock_set_current_limit(ident_map_size);
 923         memblock_allow_resize();
 924
 925         /* Get information about *all* installed memory */
 926         memblock_add_physmem_info();
 927
 928         free_physmem_info();
 929         setup_memory_end();
 930         memblock_dump_all();
 931         setup_memory();
 932
 933         relocate_amode31_section();
 934         setup_cr();
 935         setup_uv();
 936         dma_contiguous_reserve(ident_map_size);
 937         vmcp_cma_reserve();
 938         if (MACHINE_HAS_EDAT2)
 939                 hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
 940
 941         reserve_crashkernel();
 942 #ifdef CONFIG_CRASH_DUMP
 943         /*
 944          * Be aware that smp_save_dump_secondary_cpus() triggers a system reset.
 945          * Therefore CPU and device initialization should be done afterwards.
 946          */
 947         smp_save_dump_secondary_cpus();
 948 #endif
 949
 950         setup_resources();
 951         setup_lowcore();
 952         smp_fill_possible_mask();
 953         cpu_detect_mhz_feature();
 954         cpu_init();
 955         numa_setup();
 956         smp_detect_cpus();
 957         topology_init_early();
 958
 959         if (test_facility(193))
 960                 static_branch_enable(&cpu_has_bear);
 961
 962         /*
 963          * Create kernel page tables.
 964          */
 965         paging_init();
 966
 967         /*
 968          * After paging_init created the kernel page table, the new PSWs
 969          * in lowcore can now run with DAT enabled.
 970          */
 971 #ifdef CONFIG_CRASH_DUMP
 972         smp_save_dump_ipl_cpu();
 973 #endif
 974
 975         /* Setup default console */
 976         conmode_default();
 977         set_preferred_console();
 978
 979         apply_alternative_instructions();
 980         if (IS_ENABLED(CONFIG_EXPOLINE))
 981                 nospec_init_branches();
 982
 983         /* Setup zfcp/nvme dump support */
 984         setup_zfcpdump();
 985
 986         /* Add system specific data to the random pool */
 987         setup_randomness();
 988 }