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_phys_alloc_range(crash_size,
 681                                                        KEXEC_CRASH_MEM_ALIGN,
 682                                                        low, high);
 683         }
 684
 685         if (!crash_base) {
 686                 pr_info("crashkernel reservation failed: %s\n",
 687                         "no suitable area found");
 688                 return;
 689         }
 690
 691         if (register_memory_notifier(&kdump_mem_nb)) {
 692                 memblock_free(crash_base, crash_size);
 693                 return;
 694         }
 695
 696         if (!oldmem_data.start && MACHINE_IS_VM)
 697                 diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
 698         crashk_res.start = crash_base;
 699         crashk_res.end = crash_base + crash_size - 1;
 700         memblock_remove(crash_base, crash_size);
 701         pr_info("Reserving %lluMB of memory at %lluMB "
 702                 "for crashkernel (System RAM: %luMB)\n",
 703                 crash_size >> 20, crash_base >> 20,
 704                 (unsigned long)memblock.memory.total_size >> 20);
 705         os_info_crashkernel_add(crash_base, crash_size);
 706 #endif
 707 }
 708
 709 /*
 710  * Reserve the initrd from being used by memblock
 711  */
 712 static void __init reserve_initrd(void)
 713 {
 714 #ifdef CONFIG_BLK_DEV_INITRD
 715         if (!initrd_data.start || !initrd_data.size)
 716                 return;
 717         initrd_start = initrd_data.start;
 718         initrd_end = initrd_start + initrd_data.size;
 719         memblock_reserve(initrd_data.start, initrd_data.size);
 720 #endif
 721 }
 722
 723 /*
 724  * Reserve the memory area used to pass the certificate lists
 725  */
 726 static void __init reserve_certificate_list(void)
 727 {
 728         if (ipl_cert_list_addr)
 729                 memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
 730 }
 731
 732 static void __init reserve_mem_detect_info(void)
 733 {
 734         unsigned long start, size;
 735
 736         get_mem_detect_reserved(&start, &size);
 737         if (size)
 738                 memblock_reserve(start, size);
 739 }
 740
 741 static void __init free_mem_detect_info(void)
 742 {
 743         unsigned long start, size;
 744
 745         get_mem_detect_reserved(&start, &size);
 746         if (size)
 747                 memblock_free(start, size);
 748 }
 749
 750 static const char * __init get_mem_info_source(void)
 751 {
 752         switch (mem_detect.info_source) {
 753         case MEM_DETECT_SCLP_STOR_INFO:
 754                 return "sclp storage info";
 755         case MEM_DETECT_DIAG260:
 756                 return "diag260";
 757         case MEM_DETECT_SCLP_READ_INFO:
 758                 return "sclp read info";
 759         case MEM_DETECT_BIN_SEARCH:
 760                 return "binary search";
 761         }
 762         return "none";
 763 }
 764
 765 static void __init memblock_add_mem_detect_info(void)
 766 {
 767         unsigned long start, end;
 768         int i;
 769
 770         pr_debug("physmem info source: %s (%hhd)\n",
 771                  get_mem_info_source(), mem_detect.info_source);
 772         /* keep memblock lists close to the kernel */
 773         memblock_set_bottom_up(true);
 774         for_each_mem_detect_block(i, &start, &end) {
 775                 memblock_add(start, end - start);
 776                 memblock_physmem_add(start, end - start);
 777         }
 778         memblock_set_bottom_up(false);
 779         memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
 780         memblock_dump_all();
 781 }
 782
 783 /*
 784  * Check for initrd being in usable memory
 785  */
 786 static void __init check_initrd(void)
 787 {
 788 #ifdef CONFIG_BLK_DEV_INITRD
 789         if (initrd_data.start && initrd_data.size &&
 790             !memblock_is_region_memory(initrd_data.start, initrd_data.size)) {
 791                 pr_err("The initial RAM disk does not fit into the memory\n");
 792                 memblock_free(initrd_data.start, initrd_data.size);
 793                 initrd_start = initrd_end = 0;
 794         }
 795 #endif
 796 }
 797
 798 /*
 799  * Reserve memory used for lowcore/command line/kernel image.
 800  */
 801 static void __init reserve_kernel(void)
 802 {
 803         unsigned long start_pfn = PFN_UP(__pa(_end));
 804
 805         memblock_reserve(0, STARTUP_NORMAL_OFFSET);
 806         memblock_reserve((unsigned long)sclp_early_sccb, EXT_SCCB_READ_SCP);
 807         memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
 808                          - (unsigned long)_stext);
 809 }
 810
 811 static void __init setup_memory(void)
 812 {
 813         phys_addr_t start, end;
 814         u64 i;
 815
 816         /*
 817          * Init storage key for present memory
 818          */
 819         for_each_mem_range(i, &start, &end)
 820                 storage_key_init_range(start, end);
 821
 822         psw_set_key(PAGE_DEFAULT_KEY);
 823
 824         /* Only cosmetics */
 825         memblock_enforce_memory_limit(memblock_end_of_DRAM());
 826 }
 827
 828 static void __init relocate_amode31_section(void)
 829 {
 830         unsigned long amode31_addr, amode31_size;
 831         long amode31_offset;
 832         long *ptr;
 833
 834         /* Allocate a new AMODE31 capable memory region */
 835         amode31_size = __eamode31 - __samode31;
 836         pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
 837         amode31_addr = (unsigned long)memblock_alloc_low(amode31_size, PAGE_SIZE);
 838         if (!amode31_addr)
 839                 panic("Failed to allocate memory for AMODE31 section\n");
 840         amode31_offset = amode31_addr - __samode31;
 841
 842         /* Move original AMODE31 section to the new one */
 843         memmove((void *)amode31_addr, (void *)__samode31, amode31_size);
 844         /* Zero out the old AMODE31 section to catch invalid accesses within it */
 845         memset((void *)__samode31, 0, amode31_size);
 846
 847         /* Update all AMODE31 region references */
 848         for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
 849                 *ptr += amode31_offset;
 850 }
 851
 852 /* This must be called after AMODE31 relocation */
 853 static void __init setup_cr(void)
 854 {
 855         union ctlreg2 cr2;
 856         union ctlreg5 cr5;
 857         union ctlreg15 cr15;
 858
 859         __ctl_duct[1] = (unsigned long)__ctl_aste;
 860         __ctl_duct[2] = (unsigned long)__ctl_aste;
 861         __ctl_duct[4] = (unsigned long)__ctl_duald;
 862
 863         /* Update control registers CR2, CR5 and CR15 */
 864         __ctl_store(cr2.val, 2, 2);
 865         __ctl_store(cr5.val, 5, 5);
 866         __ctl_store(cr15.val, 15, 15);
 867         cr2.ducto = (unsigned long)__ctl_duct >> 6;
 868         cr5.pasteo = (unsigned long)__ctl_duct >> 6;
 869         cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
 870         __ctl_load(cr2.val, 2, 2);
 871         __ctl_load(cr5.val, 5, 5);
 872         __ctl_load(cr15.val, 15, 15);
 873 }
 874
 875 /*
 876  * Add system information as device randomness
 877  */
 878 static void __init setup_randomness(void)
 879 {
 880         struct sysinfo_3_2_2 *vmms;
 881
 882         vmms = (struct sysinfo_3_2_2 *) memblock_phys_alloc(PAGE_SIZE,
 883                                                             PAGE_SIZE);
 884         if (!vmms)
 885                 panic("Failed to allocate memory for sysinfo structure\n");
 886
 887         if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
 888                 add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
 889         memblock_free((unsigned long) vmms, PAGE_SIZE);
 890 }
 891
 892 /*
 893  * Find the correct size for the task_struct. This depends on
 894  * the size of the struct fpu at the end of the thread_struct
 895  * which is embedded in the task_struct.
 896  */
 897 static void __init setup_task_size(void)
 898 {
 899         int task_size = sizeof(struct task_struct);
 900
 901         if (!MACHINE_HAS_VX) {
 902                 task_size -= sizeof(__vector128) * __NUM_VXRS;
 903                 task_size += sizeof(freg_t) * __NUM_FPRS;
 904         }
 905         arch_task_struct_size = task_size;
 906 }
 907
 908 /*
 909  * Issue diagnose 318 to set the control program name and
 910  * version codes.
 911  */
 912 static void __init setup_control_program_code(void)
 913 {
 914         union diag318_info diag318_info = {
 915                 .cpnc = CPNC_LINUX,
 916                 .cpvc = 0,
 917         };
 918
 919         if (!sclp.has_diag318)
 920                 return;
 921
 922         diag_stat_inc(DIAG_STAT_X318);
 923         asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
 924 }
 925
 926 /*
 927  * Print the component list from the IPL report
 928  */
 929 static void __init log_component_list(void)
 930 {
 931         struct ipl_rb_component_entry *ptr, *end;
 932         char *str;
 933
 934         if (!early_ipl_comp_list_addr)
 935                 return;
 936         if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
 937                 pr_info("Linux is running with Secure-IPL enabled\n");
 938         else
 939                 pr_info("Linux is running with Secure-IPL disabled\n");
 940         ptr = (void *) early_ipl_comp_list_addr;
 941         end = (void *) ptr + early_ipl_comp_list_size;
 942         pr_info("The IPL report contains the following components:\n");
 943         while (ptr < end) {
 944                 if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
 945                         if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
 946                                 str = "signed, verified";
 947                         else
 948                                 str = "signed, verification failed";
 949                 } else {
 950                         str = "not signed";
 951                 }
 952                 pr_info("%016llx - %016llx (%s)\n",
 953                         ptr->addr, ptr->addr + ptr->len, str);
 954                 ptr++;
 955         }
 956 }
 957
 958 /*
 959  * Setup function called from init/main.c just after the banner
 960  * was printed.
 961  */
 962
 963 void __init setup_arch(char **cmdline_p)
 964 {
 965         /*
 966          * print what head.S has found out about the machine
 967          */
 968         if (MACHINE_IS_VM)
 969                 pr_info("Linux is running as a z/VM "
 970                         "guest operating system in 64-bit mode\n");
 971         else if (MACHINE_IS_KVM)
 972                 pr_info("Linux is running under KVM in 64-bit mode\n");
 973         else if (MACHINE_IS_LPAR)
 974                 pr_info("Linux is running natively in 64-bit mode\n");
 975         else
 976                 pr_info("Linux is running as a guest in 64-bit mode\n");
 977
 978         log_component_list();
 979
 980         /* Have one command line that is parsed and saved in /proc/cmdline */
 981         /* boot_command_line has been already set up in early.c */
 982         *cmdline_p = boot_command_line;
 983
 984         ROOT_DEV = Root_RAM0;
 985
 986         setup_initial_init_mm(_text, _etext, _edata, _end);
 987
 988         if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
 989                 nospec_auto_detect();
 990
 991         jump_label_init();
 992         parse_early_param();
 993 #ifdef CONFIG_CRASH_DUMP
 994         /* Deactivate elfcorehdr= kernel parameter */
 995         elfcorehdr_addr = ELFCORE_ADDR_MAX;
 996 #endif
 997
 998         os_info_init();
 999         setup_ipl();
1000         setup_task_size();
1001         setup_control_program_code();
1002
1003         /* Do some memory reservations *before* memory is added to memblock */
1004         reserve_above_ident_map();
1005         reserve_kernel();
1006         reserve_initrd();
1007         reserve_certificate_list();
1008         reserve_mem_detect_info();
1009         memblock_allow_resize();
1010
1011         /* Get information about *all* installed memory */
1012         memblock_add_mem_detect_info();
1013
1014         free_mem_detect_info();
1015
1016         relocate_amode31_section();
1017         setup_cr();
1018
1019         setup_uv();
1020         setup_memory_end();
1021         setup_memory();
1022         dma_contiguous_reserve(ident_map_size);
1023         vmcp_cma_reserve();
1024         if (MACHINE_HAS_EDAT2)
1025                 hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1026
1027         check_initrd();
1028         reserve_crashkernel();
1029 #ifdef CONFIG_CRASH_DUMP
1030         /*
1031          * Be aware that smp_save_dump_cpus() triggers a system reset.
1032          * Therefore CPU and device initialization should be done afterwards.
1033          */
1034         smp_save_dump_cpus();
1035 #endif
1036
1037         setup_resources();
1038         setup_lowcore_dat_off();
1039         smp_fill_possible_mask();
1040         cpu_detect_mhz_feature();
1041         cpu_init();
1042         numa_setup();
1043         smp_detect_cpus();
1044         topology_init_early();
1045
1046         /*
1047          * Create kernel page tables and switch to virtual addressing.
1048          */
1049         paging_init();
1050
1051         /*
1052          * After paging_init created the kernel page table, the new PSWs
1053          * in lowcore can now run with DAT enabled.
1054          */
1055         setup_lowcore_dat_on();
1056
1057         /* Setup default console */
1058         conmode_default();
1059         set_preferred_console();
1060
1061         apply_alternative_instructions();
1062         if (IS_ENABLED(CONFIG_EXPOLINE))
1063                 nospec_init_branches();
1064
1065         /* Setup zfcp/nvme dump support */
1066         setup_zfcpdump();
1067
1068         /* Add system specific data to the random pool */
1069         setup_randomness();
1070 }