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
  54 #include <asm/boot_data.h>
  55 #include <asm/ipl.h>
  56 #include <asm/facility.h>
  57 #include <asm/smp.h>
  58 #include <asm/mmu_context.h>
  59 #include <asm/cpcmd.h>
  60 #include <asm/lowcore.h>
  61 #include <asm/nmi.h>
  62 #include <asm/irq.h>
  63 #include <asm/page.h>
  64 #include <asm/ptrace.h>
  65 #include <asm/sections.h>
  66 #include <asm/ebcdic.h>
  67 #include <asm/diag.h>
  68 #include <asm/os_info.h>
  69 #include <asm/sclp.h>
  70 #include <asm/stacktrace.h>
  71 #include <asm/sysinfo.h>
  72 #include <asm/numa.h>
  73 #include <asm/alternative.h>
  74 #include <asm/nospec-branch.h>
  75 #include <asm/mem_detect.h>
  76 #include <asm/uv.h>
  77 #include <asm/asm-offsets.h>
  78 #include "entry.h"
  79
  80 /*
  81  * Machine setup..
  82  */
  83 unsigned int console_mode = 0;
  84 EXPORT_SYMBOL(console_mode);
  85
  86 unsigned int console_devno = -1;
  87 EXPORT_SYMBOL(console_devno);
  88
  89 unsigned int console_irq = -1;
  90 EXPORT_SYMBOL(console_irq);
  91
  92 /*
  93  * Some code and data needs to stay below 2 GB, even when the kernel would be
  94  * relocated above 2 GB, because it has to use 31 bit addresses.
  95  * Such code and data is part of the .amode31 section.
  96  */
  97 unsigned long __amode31_ref __samode31 = __pa(&_samode31);
  98 unsigned long __amode31_ref __eamode31 = __pa(&_eamode31);
  99 unsigned long __amode31_ref __stext_amode31 = __pa(&_stext_amode31);
 100 unsigned long __amode31_ref __etext_amode31 = __pa(&_etext_amode31);
 101 struct exception_table_entry __amode31_ref *__start_amode31_ex_table = _start_amode31_ex_table;
 102 struct exception_table_entry __amode31_ref *__stop_amode31_ex_table = _stop_amode31_ex_table;
 103
 104 /*
 105  * Control registers CR2, CR5 and CR15 are initialized with addresses
 106  * of tables that must be placed below 2G which is handled by the AMODE31
 107  * sections.
 108  * Because the AMODE31 sections are relocated below 2G at startup,
 109  * the content of control registers CR2, CR5 and CR15 must be updated
 110  * with new addresses after the relocation. The initial initialization of
 111  * control registers occurs in head64.S and then gets updated again after AMODE31
 112  * relocation. We must access the relevant AMODE31 tables indirectly via
 113  * pointers placed in the .amode31.refs linker section. Those pointers get
 114  * updated automatically during AMODE31 relocation and always contain a valid
 115  * address within AMODE31 sections.
 116  */
 117
 118 static __amode31_data u32 __ctl_duct_amode31[16] __aligned(64);
 119
 120 static __amode31_data u64 __ctl_aste_amode31[8] __aligned(64) = {
 121         [1] = 0xffffffffffffffff
 122 };
 123
 124 static __amode31_data u32 __ctl_duald_amode31[32] __aligned(128) = {
 125         0x80000000, 0, 0, 0,
 126         0x80000000, 0, 0, 0,
 127         0x80000000, 0, 0, 0,
 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 };
 134
 135 static __amode31_data u32 __ctl_linkage_stack_amode31[8] __aligned(64) = {
 136         0, 0, 0x89000000, 0,
 137         0, 0, 0x8a000000, 0
 138 };
 139
 140 static u64 __amode31_ref *__ctl_aste = __ctl_aste_amode31;
 141 static u32 __amode31_ref *__ctl_duald = __ctl_duald_amode31;
 142 static u32 __amode31_ref *__ctl_linkage_stack = __ctl_linkage_stack_amode31;
 143 static u32 __amode31_ref *__ctl_duct = __ctl_duct_amode31;
 144
 145 int __bootdata(noexec_disabled);
 146 unsigned long __bootdata(ident_map_size);
 147 struct mem_detect_info __bootdata(mem_detect);
 148 struct initrd_data __bootdata(initrd_data);
 149
 150 unsigned long __bootdata_preserved(__kaslr_offset);
 151 unsigned int __bootdata_preserved(zlib_dfltcc_support);
 152 EXPORT_SYMBOL(zlib_dfltcc_support);
 153 u64 __bootdata_preserved(stfle_fac_list[16]);
 154 EXPORT_SYMBOL(stfle_fac_list);
 155 u64 __bootdata_preserved(alt_stfle_fac_list[16]);
 156 struct oldmem_data __bootdata_preserved(oldmem_data);
 157
 158 unsigned long VMALLOC_START;
 159 EXPORT_SYMBOL(VMALLOC_START);
 160
 161 unsigned long VMALLOC_END;
 162 EXPORT_SYMBOL(VMALLOC_END);
 163
 164 struct page *vmemmap;
 165 EXPORT_SYMBOL(vmemmap);
 166 unsigned long vmemmap_size;
 167
 168 unsigned long MODULES_VADDR;
 169 unsigned long MODULES_END;
 170
 171 /* An array with a pointer to the lowcore of every CPU. */
 172 struct lowcore *lowcore_ptr[NR_CPUS];
 173 EXPORT_SYMBOL(lowcore_ptr);
 174
 175 /*
 176  * The Write Back bit position in the physaddr is given by the SLPC PCI.
 177  * Leaving the mask zero always uses write through which is safe
 178  */
 179 unsigned long mio_wb_bit_mask __ro_after_init;
 180
 181 /*
 182  * This is set up by the setup-routine at boot-time
 183  * for S390 need to find out, what we have to setup
 184  * using address 0x10400 ...
 185  */
 186
 187 #include <asm/setup.h>
 188
 189 /*
 190  * condev= and conmode= setup parameter.
 191  */
 192
 193 static int __init condev_setup(char *str)
 194 {
 195         int vdev;
 196
 197         vdev = simple_strtoul(str, &str, 0);
 198         if (vdev >= 0 && vdev < 65536) {
 199                 console_devno = vdev;
 200                 console_irq = -1;
 201         }
 202         return 1;
 203 }
 204
 205 __setup("condev=", condev_setup);
 206
 207 static void __init set_preferred_console(void)
 208 {
 209         if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
 210                 add_preferred_console("ttyS", 0, NULL);
 211         else if (CONSOLE_IS_3270)
 212                 add_preferred_console("tty3270", 0, NULL);
 213         else if (CONSOLE_IS_VT220)
 214                 add_preferred_console("ttysclp", 0, NULL);
 215         else if (CONSOLE_IS_HVC)
 216                 add_preferred_console("hvc", 0, NULL);
 217 }
 218
 219 static int __init conmode_setup(char *str)
 220 {
 221 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 222         if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
 223                 SET_CONSOLE_SCLP;
 224 #endif
 225 #if defined(CONFIG_TN3215_CONSOLE)
 226         if (!strcmp(str, "3215"))
 227                 SET_CONSOLE_3215;
 228 #endif
 229 #if defined(CONFIG_TN3270_CONSOLE)
 230         if (!strcmp(str, "3270"))
 231                 SET_CONSOLE_3270;
 232 #endif
 233         set_preferred_console();
 234         return 1;
 235 }
 236
 237 __setup("conmode=", conmode_setup);
 238
 239 static void __init conmode_default(void)
 240 {
 241         char query_buffer[1024];
 242         char *ptr;
 243
 244         if (MACHINE_IS_VM) {
 245                 cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
 246                 console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
 247                 ptr = strstr(query_buffer, "SUBCHANNEL =");
 248                 console_irq = simple_strtoul(ptr + 13, NULL, 16);
 249                 cpcmd("QUERY TERM", query_buffer, 1024, NULL);
 250                 ptr = strstr(query_buffer, "CONMODE");
 251                 /*
 252                  * Set the conmode to 3215 so that the device recognition
 253                  * will set the cu_type of the console to 3215. If the
 254                  * conmode is 3270 and we don't set it back then both
 255                  * 3215 and the 3270 driver will try to access the console
 256                  * device (3215 as console and 3270 as normal tty).
 257                  */
 258                 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
 259                 if (ptr == NULL) {
 260 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 261                         SET_CONSOLE_SCLP;
 262 #endif
 263                         return;
 264                 }
 265                 if (str_has_prefix(ptr + 8, "3270")) {
 266 #if defined(CONFIG_TN3270_CONSOLE)
 267                         SET_CONSOLE_3270;
 268 #elif defined(CONFIG_TN3215_CONSOLE)
 269                         SET_CONSOLE_3215;
 270 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 271                         SET_CONSOLE_SCLP;
 272 #endif
 273                 } else if (str_has_prefix(ptr + 8, "3215")) {
 274 #if defined(CONFIG_TN3215_CONSOLE)
 275                         SET_CONSOLE_3215;
 276 #elif defined(CONFIG_TN3270_CONSOLE)
 277                         SET_CONSOLE_3270;
 278 #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 279                         SET_CONSOLE_SCLP;
 280 #endif
 281                 }
 282         } else if (MACHINE_IS_KVM) {
 283                 if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
 284                         SET_CONSOLE_VT220;
 285                 else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
 286                         SET_CONSOLE_SCLP;
 287                 else
 288                         SET_CONSOLE_HVC;
 289         } else {
 290 #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
 291                 SET_CONSOLE_SCLP;
 292 #endif
 293         }
 294 }
 295
 296 #ifdef CONFIG_CRASH_DUMP
 297 static void __init setup_zfcpdump(void)
 298 {
 299         if (!is_ipl_type_dump())
 300                 return;
 301         if (oldmem_data.start)
 302                 return;
 303         strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
 304         console_loglevel = 2;
 305 }
 306 #else
 307 static inline void setup_zfcpdump(void) {}
 308 #endif /* CONFIG_CRASH_DUMP */
 309
 310  /*
 311  * Reboot, halt and power_off stubs. They just call _machine_restart,
 312  * _machine_halt or _machine_power_off.
 313  */
 314
 315 void machine_restart(char *command)
 316 {
 317         if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
 318                 /*
 319                  * Only unblank the console if we are called in enabled
 320                  * context or a bust_spinlocks cleared the way for us.
 321                  */
 322                 console_unblank();
 323         _machine_restart(command);
 324 }
 325
 326 void machine_halt(void)
 327 {
 328         if (!in_interrupt() || oops_in_progress)
 329                 /*
 330                  * Only unblank the console if we are called in enabled
 331                  * context or a bust_spinlocks cleared the way for us.
 332                  */
 333                 console_unblank();
 334         _machine_halt();
 335 }
 336
 337 void machine_power_off(void)
 338 {
 339         if (!in_interrupt() || oops_in_progress)
 340                 /*
 341                  * Only unblank the console if we are called in enabled
 342                  * context or a bust_spinlocks cleared the way for us.
 343                  */
 344                 console_unblank();
 345         _machine_power_off();
 346 }
 347
 348 /*
 349  * Dummy power off function.
 350  */
 351 void (*pm_power_off)(void) = machine_power_off;
 352 EXPORT_SYMBOL_GPL(pm_power_off);
 353
 354 void *restart_stack;
 355
 356 unsigned long stack_alloc(void)
 357 {
 358 #ifdef CONFIG_VMAP_STACK
 359         return (unsigned long)__vmalloc_node(THREAD_SIZE, THREAD_SIZE,
 360                         THREADINFO_GFP, NUMA_NO_NODE,
 361                         __builtin_return_address(0));
 362 #else
 363         return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 364 #endif
 365 }
 366
 367 void stack_free(unsigned long stack)
 368 {
 369 #ifdef CONFIG_VMAP_STACK
 370         vfree((void *) stack);
 371 #else
 372         free_pages(stack, THREAD_SIZE_ORDER);
 373 #endif
 374 }
 375
 376 int __init arch_early_irq_init(void)
 377 {
 378         unsigned long stack;
 379
 380         stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 381         if (!stack)
 382                 panic("Couldn't allocate async stack");
 383         S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
 384         return 0;
 385 }
 386
 387 void __init arch_call_rest_init(void)
 388 {
 389         unsigned long stack;
 390
 391         stack = stack_alloc();
 392         if (!stack)
 393                 panic("Couldn't allocate kernel stack");
 394         current->stack = (void *) stack;
 395 #ifdef CONFIG_VMAP_STACK
 396         current->stack_vm_area = (void *) stack;
 397 #endif
 398         set_task_stack_end_magic(current);
 399         stack += STACK_INIT_OFFSET;
 400         S390_lowcore.kernel_stack = stack;
 401         call_on_stack_noreturn(rest_init, stack);
 402 }
 403
 404 static void __init setup_lowcore_dat_off(void)
 405 {
 406         unsigned long int_psw_mask = PSW_KERNEL_BITS;
 407         unsigned long mcck_stack;
 408         struct lowcore *lc;
 409
 410         if (IS_ENABLED(CONFIG_KASAN))
 411                 int_psw_mask |= PSW_MASK_DAT;
 412
 413         /*
 414          * Setup lowcore for boot cpu
 415          */
 416         BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
 417         lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
 418         if (!lc)
 419                 panic("%s: Failed to allocate %zu bytes align=%zx\n",
 420                       __func__, sizeof(*lc), sizeof(*lc));
 421
 422         lc->restart_psw.mask = PSW_KERNEL_BITS;
 423         lc->restart_psw.addr = (unsigned long) restart_int_handler;
 424         lc->external_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
 425         lc->external_new_psw.addr = (unsigned long) ext_int_handler;
 426         lc->svc_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
 427         lc->svc_new_psw.addr = (unsigned long) system_call;
 428         lc->program_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
 429         lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
 430         lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
 431         lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
 432         lc->io_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
 433         lc->io_new_psw.addr = (unsigned long) io_int_handler;
 434         lc->clock_comparator = clock_comparator_max;
 435         lc->nodat_stack = ((unsigned long) &init_thread_union)
 436                 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 437         lc->current_task = (unsigned long)&init_task;
 438         lc->lpp = LPP_MAGIC;
 439         lc->machine_flags = S390_lowcore.machine_flags;
 440         lc->preempt_count = S390_lowcore.preempt_count;
 441         nmi_alloc_boot_cpu(lc);
 442         lc->sys_enter_timer = S390_lowcore.sys_enter_timer;
 443         lc->exit_timer = S390_lowcore.exit_timer;
 444         lc->user_timer = S390_lowcore.user_timer;
 445         lc->system_timer = S390_lowcore.system_timer;
 446         lc->steal_timer = S390_lowcore.steal_timer;
 447         lc->last_update_timer = S390_lowcore.last_update_timer;
 448         lc->last_update_clock = S390_lowcore.last_update_clock;
 449
 450         /*
 451          * Allocate the global restart stack which is the same for
 452          * all CPUs in cast *one* of them does a PSW restart.
 453          */
 454         restart_stack = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
 455         if (!restart_stack)
 456                 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 457                       __func__, THREAD_SIZE, THREAD_SIZE);
 458         restart_stack += STACK_INIT_OFFSET;
 459
 460         /*
 461          * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
 462          * restart data to the absolute zero lowcore. This is necessary if
 463          * PSW restart is done on an offline CPU that has lowcore zero.
 464          */
 465         lc->restart_stack = (unsigned long) restart_stack;
 466         lc->restart_fn = (unsigned long) do_restart;
 467         lc->restart_data = 0;
 468         lc->restart_source = -1U;
 469
 470         mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
 471         if (!mcck_stack)
 472                 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 473                       __func__, THREAD_SIZE, THREAD_SIZE);
 474         lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
 475
 476         /* Setup absolute zero lowcore */
 477         mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
 478         mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
 479         mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
 480         mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
 481         mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
 482
 483         lc->spinlock_lockval = arch_spin_lockval(0);
 484         lc->spinlock_index = 0;
 485         arch_spin_lock_setup(0);
 486         lc->br_r1_trampoline = 0x07f1;  /* br %r1 */
 487         lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
 488         lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
 489         lc->preempt_count = PREEMPT_DISABLED;
 490
 491         set_prefix((u32)(unsigned long) lc);
 492         lowcore_ptr[0] = lc;
 493 }
 494
 495 static void __init setup_lowcore_dat_on(void)
 496 {
 497         struct lowcore *lc = lowcore_ptr[0];
 498
 499         __ctl_clear_bit(0, 28);
 500         S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
 501         S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
 502         S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
 503         S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
 504         __ctl_store(S390_lowcore.cregs_save_area, 0, 15);
 505         __ctl_set_bit(0, 28);
 506         mem_assign_absolute(S390_lowcore.restart_flags, RESTART_FLAG_CTLREGS);
 507         mem_assign_absolute(S390_lowcore.program_new_psw, lc->program_new_psw);
 508         memcpy_absolute(&S390_lowcore.cregs_save_area, lc->cregs_save_area,
 509                         sizeof(S390_lowcore.cregs_save_area));
 510 }
 511
 512 static struct resource code_resource = {
 513         .name  = "Kernel code",
 514         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 515 };
 516
 517 static struct resource data_resource = {
 518         .name = "Kernel data",
 519         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 520 };
 521
 522 static struct resource bss_resource = {
 523         .name = "Kernel bss",
 524         .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
 525 };
 526
 527 static struct resource __initdata *standard_resources[] = {
 528         &code_resource,
 529         &data_resource,
 530         &bss_resource,
 531 };
 532
 533 static void __init setup_resources(void)
 534 {
 535         struct resource *res, *std_res, *sub_res;
 536         phys_addr_t start, end;
 537         int j;
 538         u64 i;
 539
 540         code_resource.start = (unsigned long) _text;
 541         code_resource.end = (unsigned long) _etext - 1;
 542         data_resource.start = (unsigned long) _etext;
 543         data_resource.end = (unsigned long) _edata - 1;
 544         bss_resource.start = (unsigned long) __bss_start;
 545         bss_resource.end = (unsigned long) __bss_stop - 1;
 546
 547         for_each_mem_range(i, &start, &end) {
 548                 res = memblock_alloc(sizeof(*res), 8);
 549                 if (!res)
 550                         panic("%s: Failed to allocate %zu bytes align=0x%x\n",
 551                               __func__, sizeof(*res), 8);
 552                 res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
 553
 554                 res->name = "System RAM";
 555                 res->start = start;
 556                 /*
 557                  * In memblock, end points to the first byte after the
 558                  * range while in resourses, end points to the last byte in
 559                  * the range.
 560                  */
 561                 res->end = end - 1;
 562                 request_resource(&iomem_resource, res);
 563
 564                 for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
 565                         std_res = standard_resources[j];
 566                         if (std_res->start < res->start ||
 567                             std_res->start > res->end)
 568                                 continue;
 569                         if (std_res->end > res->end) {
 570                                 sub_res = memblock_alloc(sizeof(*sub_res), 8);
 571                                 if (!sub_res)
 572                                         panic("%s: Failed to allocate %zu bytes align=0x%x\n",
 573                                               __func__, sizeof(*sub_res), 8);
 574                                 *sub_res = *std_res;
 575                                 sub_res->end = res->end;
 576                                 std_res->start = res->end + 1;
 577                                 request_resource(res, sub_res);
 578                         } else {
 579                                 request_resource(res, std_res);
 580                         }
 581                 }
 582         }
 583 #ifdef CONFIG_CRASH_DUMP
 584         /*
 585          * Re-add removed crash kernel memory as reserved memory. This makes
 586          * sure it will be mapped with the identity mapping and struct pages
 587          * will be created, so it can be resized later on.
 588          * However add it later since the crash kernel resource should not be
 589          * part of the System RAM resource.
 590          */
 591         if (crashk_res.end) {
 592                 memblock_add_node(crashk_res.start, resource_size(&crashk_res), 0);
 593                 memblock_reserve(crashk_res.start, resource_size(&crashk_res));
 594                 insert_resource(&iomem_resource, &crashk_res);
 595         }
 596 #endif
 597 }
 598
 599 static void __init setup_memory_end(void)
 600 {
 601         memblock_remove(ident_map_size, ULONG_MAX);
 602         max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
 603         pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
 604 }
 605
 606 #ifdef CONFIG_CRASH_DUMP
 607
 608 /*
 609  * When kdump is enabled, we have to ensure that no memory from the area
 610  * [0 - crashkernel memory size] is set offline - it will be exchanged with
 611  * the crashkernel memory region when kdump is triggered. The crashkernel
 612  * memory region can never get offlined (pages are unmovable).
 613  */
 614 static int kdump_mem_notifier(struct notifier_block *nb,
 615                               unsigned long action, void *data)
 616 {
 617         struct memory_notify *arg = data;
 618
 619         if (action != MEM_GOING_OFFLINE)
 620                 return NOTIFY_OK;
 621         if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
 622                 return NOTIFY_BAD;
 623         return NOTIFY_OK;
 624 }
 625
 626 static struct notifier_block kdump_mem_nb = {
 627         .notifier_call = kdump_mem_notifier,
 628 };
 629
 630 #endif
 631
 632 /*
 633  * Make sure that the area above identity mapping is protected
 634  */
 635 static void __init reserve_above_ident_map(void)
 636 {
 637         memblock_reserve(ident_map_size, ULONG_MAX);
 638 }
 639
 640 /*
 641  * Reserve memory for kdump kernel to be loaded with kexec
 642  */
 643 static void __init reserve_crashkernel(void)
 644 {
 645 #ifdef CONFIG_CRASH_DUMP
 646         unsigned long long crash_base, crash_size;
 647         phys_addr_t low, high;
 648         int rc;
 649
 650         rc = parse_crashkernel(boot_command_line, ident_map_size, &crash_size,
 651                                &crash_base);
 652
 653         crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
 654         crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
 655         if (rc || crash_size == 0)
 656                 return;
 657
 658         if (memblock.memory.regions[0].size < crash_size) {
 659                 pr_info("crashkernel reservation failed: %s\n",
 660                         "first memory chunk must be at least crashkernel size");
 661                 return;
 662         }
 663
 664         low = crash_base ?: oldmem_data.start;
 665         high = low + crash_size;
 666         if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
 667                 /* The crashkernel fits into OLDMEM, reuse OLDMEM */
 668                 crash_base = low;
 669         } else {
 670                 /* Find suitable area in free memory */
 671                 low = max_t(unsigned long, crash_size, sclp.hsa_size);
 672                 high = crash_base ? crash_base + crash_size : ULONG_MAX;
 673
 674                 if (crash_base && crash_base < low) {
 675                         pr_info("crashkernel reservation failed: %s\n",
 676                                 "crash_base too low");
 677                         return;
 678                 }
 679                 low = crash_base ?: low;
 680                 crash_base = memblock_find_in_range(low, high, crash_size,
 681                                                     KEXEC_CRASH_MEM_ALIGN);
 682         }
 683
 684         if (!crash_base) {
 685                 pr_info("crashkernel reservation failed: %s\n",
 686                         "no suitable area found");
 687                 return;
 688         }
 689
 690         if (register_memory_notifier(&kdump_mem_nb))
 691                 return;
 692
 693         if (!oldmem_data.start && MACHINE_IS_VM)
 694                 diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
 695         crashk_res.start = crash_base;
 696         crashk_res.end = crash_base + crash_size - 1;
 697         memblock_remove(crash_base, crash_size);
 698         pr_info("Reserving %lluMB of memory at %lluMB "
 699                 "for crashkernel (System RAM: %luMB)\n",
 700                 crash_size >> 20, crash_base >> 20,
 701                 (unsigned long)memblock.memory.total_size >> 20);
 702         os_info_crashkernel_add(crash_base, crash_size);
 703 #endif
 704 }
 705
 706 /*
 707  * Reserve the initrd from being used by memblock
 708  */
 709 static void __init reserve_initrd(void)
 710 {
 711 #ifdef CONFIG_BLK_DEV_INITRD
 712         if (!initrd_data.start || !initrd_data.size)
 713                 return;
 714         initrd_start = initrd_data.start;
 715         initrd_end = initrd_start + initrd_data.size;
 716         memblock_reserve(initrd_data.start, initrd_data.size);
 717 #endif
 718 }
 719
 720 /*
 721  * Reserve the memory area used to pass the certificate lists
 722  */
 723 static void __init reserve_certificate_list(void)
 724 {
 725         if (ipl_cert_list_addr)
 726                 memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
 727 }
 728
 729 static void __init reserve_mem_detect_info(void)
 730 {
 731         unsigned long start, size;
 732
 733         get_mem_detect_reserved(&start, &size);
 734         if (size)
 735                 memblock_reserve(start, size);
 736 }
 737
 738 static void __init free_mem_detect_info(void)
 739 {
 740         unsigned long start, size;
 741
 742         get_mem_detect_reserved(&start, &size);
 743         if (size)
 744                 memblock_free(start, size);
 745 }
 746
 747 static const char * __init get_mem_info_source(void)
 748 {
 749         switch (mem_detect.info_source) {
 750         case MEM_DETECT_SCLP_STOR_INFO:
 751                 return "sclp storage info";
 752         case MEM_DETECT_DIAG260:
 753                 return "diag260";
 754         case MEM_DETECT_SCLP_READ_INFO:
 755                 return "sclp read info";
 756         case MEM_DETECT_BIN_SEARCH:
 757                 return "binary search";
 758         }
 759         return "none";
 760 }
 761
 762 static void __init memblock_add_mem_detect_info(void)
 763 {
 764         unsigned long start, end;
 765         int i;
 766
 767         pr_debug("physmem info source: %s (%hhd)\n",
 768                  get_mem_info_source(), mem_detect.info_source);
 769         /* keep memblock lists close to the kernel */
 770         memblock_set_bottom_up(true);
 771         for_each_mem_detect_block(i, &start, &end) {
 772                 memblock_add(start, end - start);
 773                 memblock_physmem_add(start, end - start);
 774         }
 775         memblock_set_bottom_up(false);
 776         memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
 777         memblock_dump_all();
 778 }
 779
 780 /*
 781  * Check for initrd being in usable memory
 782  */
 783 static void __init check_initrd(void)
 784 {
 785 #ifdef CONFIG_BLK_DEV_INITRD
 786         if (initrd_data.start && initrd_data.size &&
 787             !memblock_is_region_memory(initrd_data.start, initrd_data.size)) {
 788                 pr_err("The initial RAM disk does not fit into the memory\n");
 789                 memblock_free(initrd_data.start, initrd_data.size);
 790                 initrd_start = initrd_end = 0;
 791         }
 792 #endif
 793 }
 794
 795 /*
 796  * Reserve memory used for lowcore/command line/kernel image.
 797  */
 798 static void __init reserve_kernel(void)
 799 {
 800         unsigned long start_pfn = PFN_UP(__pa(_end));
 801
 802         memblock_reserve(0, STARTUP_NORMAL_OFFSET);
 803         memblock_reserve((unsigned long)sclp_early_sccb, EXT_SCCB_READ_SCP);
 804         memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
 805                          - (unsigned long)_stext);
 806 }
 807
 808 static void __init setup_memory(void)
 809 {
 810         phys_addr_t start, end;
 811         u64 i;
 812
 813         /*
 814          * Init storage key for present memory
 815          */
 816         for_each_mem_range(i, &start, &end)
 817                 storage_key_init_range(start, end);
 818
 819         psw_set_key(PAGE_DEFAULT_KEY);
 820
 821         /* Only cosmetics */
 822         memblock_enforce_memory_limit(memblock_end_of_DRAM());
 823 }
 824
 825 static void __init relocate_amode31_section(void)
 826 {
 827         unsigned long amode31_addr, amode31_size;
 828         long amode31_offset;
 829         long *ptr;
 830
 831         /* Allocate a new AMODE31 capable memory region */
 832         amode31_size = __eamode31 - __samode31;
 833         pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
 834         amode31_addr = (unsigned long)memblock_alloc_low(amode31_size, PAGE_SIZE);
 835         if (!amode31_addr)
 836                 panic("Failed to allocate memory for AMODE31 section\n");
 837         amode31_offset = amode31_addr - __samode31;
 838
 839         /* Move original AMODE31 section to the new one */
 840         memmove((void *)amode31_addr, (void *)__samode31, amode31_size);
 841         /* Zero out the old AMODE31 section to catch invalid accesses within it */
 842         memset((void *)__samode31, 0, amode31_size);
 843
 844         /* Update all AMODE31 region references */
 845         for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
 846                 *ptr += amode31_offset;
 847 }
 848
 849 /* This must be called after AMODE31 relocation */
 850 static void __init setup_cr(void)
 851 {
 852         union ctlreg2 cr2;
 853         union ctlreg5 cr5;
 854         union ctlreg15 cr15;
 855
 856         __ctl_duct[1] = (unsigned long)__ctl_aste;
 857         __ctl_duct[2] = (unsigned long)__ctl_aste;
 858         __ctl_duct[4] = (unsigned long)__ctl_duald;
 859
 860         /* Update control registers CR2, CR5 and CR15 */
 861         __ctl_store(cr2.val, 2, 2);
 862         __ctl_store(cr5.val, 5, 5);
 863         __ctl_store(cr15.val, 15, 15);
 864         cr2.ducto = (unsigned long)__ctl_duct >> 6;
 865         cr5.pasteo = (unsigned long)__ctl_duct >> 6;
 866         cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
 867         __ctl_load(cr2.val, 2, 2);
 868         __ctl_load(cr5.val, 5, 5);
 869         __ctl_load(cr15.val, 15, 15);
 870 }
 871
 872 /*
 873  * Add system information as device randomness
 874  */
 875 static void __init setup_randomness(void)
 876 {
 877         struct sysinfo_3_2_2 *vmms;
 878
 879         vmms = (struct sysinfo_3_2_2 *) memblock_phys_alloc(PAGE_SIZE,
 880                                                             PAGE_SIZE);
 881         if (!vmms)
 882                 panic("Failed to allocate memory for sysinfo structure\n");
 883
 884         if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
 885                 add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
 886         memblock_free((unsigned long) vmms, PAGE_SIZE);
 887 }
 888
 889 /*
 890  * Find the correct size for the task_struct. This depends on
 891  * the size of the struct fpu at the end of the thread_struct
 892  * which is embedded in the task_struct.
 893  */
 894 static void __init setup_task_size(void)
 895 {
 896         int task_size = sizeof(struct task_struct);
 897
 898         if (!MACHINE_HAS_VX) {
 899                 task_size -= sizeof(__vector128) * __NUM_VXRS;
 900                 task_size += sizeof(freg_t) * __NUM_FPRS;
 901         }
 902         arch_task_struct_size = task_size;
 903 }
 904
 905 /*
 906  * Issue diagnose 318 to set the control program name and
 907  * version codes.
 908  */
 909 static void __init setup_control_program_code(void)
 910 {
 911         union diag318_info diag318_info = {
 912                 .cpnc = CPNC_LINUX,
 913                 .cpvc = 0,
 914         };
 915
 916         if (!sclp.has_diag318)
 917                 return;
 918
 919         diag_stat_inc(DIAG_STAT_X318);
 920         asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
 921 }
 922
 923 /*
 924  * Print the component list from the IPL report
 925  */
 926 static void __init log_component_list(void)
 927 {
 928         struct ipl_rb_component_entry *ptr, *end;
 929         char *str;
 930
 931         if (!early_ipl_comp_list_addr)
 932                 return;
 933         if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
 934                 pr_info("Linux is running with Secure-IPL enabled\n");
 935         else
 936                 pr_info("Linux is running with Secure-IPL disabled\n");
 937         ptr = (void *) early_ipl_comp_list_addr;
 938         end = (void *) ptr + early_ipl_comp_list_size;
 939         pr_info("The IPL report contains the following components:\n");
 940         while (ptr < end) {
 941                 if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
 942                         if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
 943                                 str = "signed, verified";
 944                         else
 945                                 str = "signed, verification failed";
 946                 } else {
 947                         str = "not signed";
 948                 }
 949                 pr_info("%016llx - %016llx (%s)\n",
 950                         ptr->addr, ptr->addr + ptr->len, str);
 951                 ptr++;
 952         }
 953 }
 954
 955 /*
 956  * Setup function called from init/main.c just after the banner
 957  * was printed.
 958  */
 959
 960 void __init setup_arch(char **cmdline_p)
 961 {
 962         /*
 963          * print what head.S has found out about the machine
 964          */
 965         if (MACHINE_IS_VM)
 966                 pr_info("Linux is running as a z/VM "
 967                         "guest operating system in 64-bit mode\n");
 968         else if (MACHINE_IS_KVM)
 969                 pr_info("Linux is running under KVM in 64-bit mode\n");
 970         else if (MACHINE_IS_LPAR)
 971                 pr_info("Linux is running natively in 64-bit mode\n");
 972         else
 973                 pr_info("Linux is running as a guest in 64-bit mode\n");
 974
 975         log_component_list();
 976
 977         /* Have one command line that is parsed and saved in /proc/cmdline */
 978         /* boot_command_line has been already set up in early.c */
 979         *cmdline_p = boot_command_line;
 980
 981         ROOT_DEV = Root_RAM0;
 982
 983         setup_initial_init_mm(_text, _etext, _edata, _end);
 984
 985         if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
 986                 nospec_auto_detect();
 987
 988         jump_label_init();
 989         parse_early_param();
 990 #ifdef CONFIG_CRASH_DUMP
 991         /* Deactivate elfcorehdr= kernel parameter */
 992         elfcorehdr_addr = ELFCORE_ADDR_MAX;
 993 #endif
 994
 995         os_info_init();
 996         setup_ipl();
 997         setup_task_size();
 998         setup_control_program_code();
 999
1000         /* Do some memory reservations *before* memory is added to memblock */
1001         reserve_above_ident_map();
1002         reserve_kernel();
1003         reserve_initrd();
1004         reserve_certificate_list();
1005         reserve_mem_detect_info();
1006         memblock_allow_resize();
1007
1008         /* Get information about *all* installed memory */
1009         memblock_add_mem_detect_info();
1010
1011         free_mem_detect_info();
1012
1013         relocate_amode31_section();
1014         setup_cr();
1015
1016         setup_uv();
1017         setup_memory_end();
1018         setup_memory();
1019         dma_contiguous_reserve(ident_map_size);
1020         vmcp_cma_reserve();
1021         if (MACHINE_HAS_EDAT2)
1022                 hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1023
1024         check_initrd();
1025         reserve_crashkernel();
1026 #ifdef CONFIG_CRASH_DUMP
1027         /*
1028          * Be aware that smp_save_dump_cpus() triggers a system reset.
1029          * Therefore CPU and device initialization should be done afterwards.
1030          */
1031         smp_save_dump_cpus();
1032 #endif
1033
1034         setup_resources();
1035         setup_lowcore_dat_off();
1036         smp_fill_possible_mask();
1037         cpu_detect_mhz_feature();
1038         cpu_init();
1039         numa_setup();
1040         smp_detect_cpus();
1041         topology_init_early();
1042
1043         /*
1044          * Create kernel page tables and switch to virtual addressing.
1045          */
1046         paging_init();
1047
1048         /*
1049          * After paging_init created the kernel page table, the new PSWs
1050          * in lowcore can now run with DAT enabled.
1051          */
1052         setup_lowcore_dat_on();
1053
1054         /* Setup default console */
1055         conmode_default();
1056         set_preferred_console();
1057
1058         apply_alternative_instructions();
1059         if (IS_ENABLED(CONFIG_EXPOLINE))
1060                 nospec_init_branches();
1061
1062         /* Setup zfcp/nvme dump support */
1063         setup_zfcpdump();
1064
1065         /* Add system specific data to the random pool */
1066         setup_randomness();
1067 }