arch/s390/kernel/early.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Copyright IBM Corp. 2007, 2009
   4  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
   5  *               Heiko Carstens <heiko.carstens@de.ibm.com>
   6  */
   7
   8 #define KMSG_COMPONENT "setup"
   9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  10
  11 #include <linux/compiler.h>
  12 #include <linux/init.h>
  13 #include <linux/errno.h>
  14 #include <linux/string.h>
  15 #include <linux/ctype.h>
  16 #include <linux/lockdep.h>
  17 #include <linux/extable.h>
  18 #include <linux/pfn.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/kernel.h>
  21 #include <asm/diag.h>
  22 #include <asm/ebcdic.h>
  23 #include <asm/ipl.h>
  24 #include <asm/lowcore.h>
  25 #include <asm/processor.h>
  26 #include <asm/sections.h>
  27 #include <asm/setup.h>
  28 #include <asm/sysinfo.h>
  29 #include <asm/cpcmd.h>
  30 #include <asm/sclp.h>
  31 #include <asm/facility.h>
  32 #include "entry.h"
  33
  34 /*
  35  * Create a Kernel NSS if the SAVESYS= parameter is defined
  36  */
  37 #define DEFSYS_CMD_SIZE         128
  38 #define SAVESYS_CMD_SIZE        32
  39
  40 char kernel_nss_name[NSS_NAME_SIZE + 1];
  41
  42 static void __init setup_boot_command_line(void);
  43
  44 /*
  45  * Get the TOD clock running.
  46  */
  47 static void __init reset_tod_clock(void)
  48 {
  49         u64 time;
  50
  51         if (store_tod_clock(&time) == 0)
  52                 return;
  53         /* TOD clock not running. Set the clock to Unix Epoch. */
  54         if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
  55                 disabled_wait(0);
  56
  57         memset(tod_clock_base, 0, 16);
  58         *(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
  59         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
  60 }
  61
  62 #ifdef CONFIG_SHARED_KERNEL
  63 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
  64
  65 asm(
  66         "       .section .init.text,\"ax\",@progbits\n"
  67         "       .align  4\n"
  68         "       .type   savesys_ipl_nss, @function\n"
  69         "savesys_ipl_nss:\n"
  70         "       stmg    6,15,48(15)\n"
  71         "       lgr     14,3\n"
  72         "       sam31\n"
  73         "       diag    2,14,0x8\n"
  74         "       sam64\n"
  75         "       lgr     2,14\n"
  76         "       lmg     6,15,48(15)\n"
  77         "       br      14\n"
  78         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\n"
  79         "       .previous\n");
  80
  81 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
  82
  83 static noinline __init void create_kernel_nss(void)
  84 {
  85         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
  86 #ifdef CONFIG_BLK_DEV_INITRD
  87         unsigned int sinitrd_pfn, einitrd_pfn;
  88 #endif
  89         int response;
  90         int hlen;
  91         size_t len;
  92         char *savesys_ptr;
  93         char defsys_cmd[DEFSYS_CMD_SIZE];
  94         char savesys_cmd[SAVESYS_CMD_SIZE];
  95
  96         /* Do nothing if we are not running under VM */
  97         if (!MACHINE_IS_VM)
  98                 return;
  99
 100         /* Convert COMMAND_LINE to upper case */
 101         for (i = 0; i < strlen(boot_command_line); i++)
 102                 upper_command_line[i] = toupper(boot_command_line[i]);
 103
 104         savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 105
 106         if (!savesys_ptr)
 107                 return;
 108
 109         savesys_ptr += 8;    /* Point to the beginning of the NSS name */
 110         for (i = 0; i < NSS_NAME_SIZE; i++) {
 111                 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
 112                         break;
 113                 kernel_nss_name[i] = savesys_ptr[i];
 114         }
 115
 116         stext_pfn = PFN_DOWN(__pa(&_stext));
 117         eshared_pfn = PFN_DOWN(__pa(&_eshared));
 118         end_pfn = PFN_UP(__pa(&_end));
 119         min_size = end_pfn << 2;
 120
 121         hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
 122                         "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 123                         kernel_nss_name, stext_pfn - 1, stext_pfn,
 124                         eshared_pfn - 1, eshared_pfn, end_pfn);
 125
 126 #ifdef CONFIG_BLK_DEV_INITRD
 127         if (INITRD_START && INITRD_SIZE) {
 128                 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
 129                 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
 130                 min_size = einitrd_pfn << 2;
 131                 hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 132                                  " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
 133         }
 134 #endif
 135
 136         snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 137                  " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
 138         defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
 139         snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
 140                  kernel_nss_name, kernel_nss_name);
 141         savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
 142
 143         __cpcmd(defsys_cmd, NULL, 0, &response);
 144
 145         if (response != 0) {
 146                 pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
 147                         response);
 148                 kernel_nss_name[0] = '\0';
 149                 return;
 150         }
 151
 152         len = strlen(savesys_cmd);
 153         ASCEBC(savesys_cmd, len);
 154         response = savesys_ipl_nss(savesys_cmd, len);
 155
 156         /* On success: response is equal to the command size,
 157          *             max SAVESYS_CMD_SIZE
 158          * On error: response contains the numeric portion of cp error message.
 159          *           for SAVESYS it will be >= 263
 160          *           for missing privilege class, it will be 1
 161          */
 162         if (response > SAVESYS_CMD_SIZE || response == 1) {
 163                 pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
 164                         response);
 165                 kernel_nss_name[0] = '\0';
 166                 return;
 167         }
 168
 169         /* re-initialize cputime accounting. */
 170         get_tod_clock_ext(tod_clock_base);
 171         S390_lowcore.last_update_clock = *(__u64 *) &tod_clock_base[1];
 172         S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
 173         S390_lowcore.user_timer = 0;
 174         S390_lowcore.system_timer = 0;
 175         asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
 176
 177         /* re-setup boot command line with new ipl vm parms */
 178         ipl_update_parameters();
 179         setup_boot_command_line();
 180
 181         ipl_flags = IPL_NSS_VALID;
 182 }
 183
 184 #else /* CONFIG_SHARED_KERNEL */
 185
 186 static inline void create_kernel_nss(void) { }
 187
 188 #endif /* CONFIG_SHARED_KERNEL */
 189
 190 /*
 191  * Clear bss memory
 192  */
 193 static noinline __init void clear_bss_section(void)
 194 {
 195         memset(__bss_start, 0, __bss_stop - __bss_start);
 196 }
 197
 198 /*
 199  * Initialize storage key for kernel pages
 200  */
 201 static noinline __init void init_kernel_storage_key(void)
 202 {
 203 #if PAGE_DEFAULT_KEY
 204         unsigned long end_pfn, init_pfn;
 205
 206         end_pfn = PFN_UP(__pa(&_end));
 207
 208         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 209                 page_set_storage_key(init_pfn << PAGE_SHIFT,
 210                                      PAGE_DEFAULT_KEY, 0);
 211 #endif
 212 }
 213
 214 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 215
 216 static noinline __init void detect_machine_type(void)
 217 {
 218         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
 219
 220         /* Check current-configuration-level */
 221         if (stsi(NULL, 0, 0, 0) <= 2) {
 222                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 223                 return;
 224         }
 225         /* Get virtual-machine cpu information. */
 226         if (stsi(vmms, 3, 2, 2) || !vmms->count)
 227                 return;
 228
 229         /* Detect known hypervisors */
 230         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 231                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 232         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
 233                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 234 }
 235
 236 /* Remove leading, trailing and double whitespace. */
 237 static inline void strim_all(char *str)
 238 {
 239         char *s;
 240
 241         s = strim(str);
 242         if (s != str)
 243                 memmove(str, s, strlen(s));
 244         while (*str) {
 245                 if (!isspace(*str++))
 246                         continue;
 247                 if (isspace(*str)) {
 248                         s = skip_spaces(str);
 249                         memmove(str, s, strlen(s) + 1);
 250                 }
 251         }
 252 }
 253
 254 static noinline __init void setup_arch_string(void)
 255 {
 256         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 257         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 258         char mstr[80], hvstr[17];
 259
 260         if (stsi(mach, 1, 1, 1))
 261                 return;
 262         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 263         EBCASC(mach->type, sizeof(mach->type));
 264         EBCASC(mach->model, sizeof(mach->model));
 265         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 266         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 267                 mach->manufacturer, mach->type,
 268                 mach->model, mach->model_capacity);
 269         strim_all(mstr);
 270         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 271                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 272                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 273                 strim_all(hvstr);
 274         } else {
 275                 sprintf(hvstr, "%s",
 276                         MACHINE_IS_LPAR ? "LPAR" :
 277                         MACHINE_IS_VM ? "z/VM" :
 278                         MACHINE_IS_KVM ? "KVM" : "unknown");
 279         }
 280         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 281 }
 282
 283 static __init void setup_topology(void)
 284 {
 285         int max_mnest;
 286
 287         if (!test_facility(11))
 288                 return;
 289         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 290         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 291                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 292                         break;
 293         }
 294         topology_max_mnest = max_mnest;
 295 }
 296
 297 static void early_pgm_check_handler(void)
 298 {
 299         const struct exception_table_entry *fixup;
 300         unsigned long cr0, cr0_new;
 301         unsigned long addr;
 302
 303         addr = S390_lowcore.program_old_psw.addr;
 304         fixup = search_exception_tables(addr);
 305         if (!fixup)
 306                 disabled_wait(0);
 307         /* Disable low address protection before storing into lowcore. */
 308         __ctl_store(cr0, 0, 0);
 309         cr0_new = cr0 & ~(1UL << 28);
 310         __ctl_load(cr0_new, 0, 0);
 311         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 312         __ctl_load(cr0, 0, 0);
 313 }
 314
 315 static noinline __init void setup_lowcore_early(void)
 316 {
 317         psw_t psw;
 318
 319         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 320         psw.addr = (unsigned long) s390_base_ext_handler;
 321         S390_lowcore.external_new_psw = psw;
 322         psw.addr = (unsigned long) s390_base_pgm_handler;
 323         S390_lowcore.program_new_psw = psw;
 324         s390_base_pgm_handler_fn = early_pgm_check_handler;
 325         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 326 }
 327
 328 static noinline __init void setup_facility_list(void)
 329 {
 330         stfle(S390_lowcore.stfle_fac_list,
 331               ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 332         memcpy(S390_lowcore.alt_stfle_fac_list,
 333                S390_lowcore.stfle_fac_list,
 334                sizeof(S390_lowcore.alt_stfle_fac_list));
 335         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 336                 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
 337 }
 338
 339 static __init void detect_diag9c(void)
 340 {
 341         unsigned int cpu_address;
 342         int rc;
 343
 344         cpu_address = stap();
 345         diag_stat_inc(DIAG_STAT_X09C);
 346         asm volatile(
 347                 "       diag    %2,0,0x9c\n"
 348                 "0:     la      %0,0\n"
 349                 "1:\n"
 350                 EX_TABLE(0b,1b)
 351                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 352         if (!rc)
 353                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 354 }
 355
 356 static __init void detect_diag44(void)
 357 {
 358         int rc;
 359
 360         diag_stat_inc(DIAG_STAT_X044);
 361         asm volatile(
 362                 "       diag    0,0,0x44\n"
 363                 "0:     la      %0,0\n"
 364                 "1:\n"
 365                 EX_TABLE(0b,1b)
 366                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 367         if (!rc)
 368                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 369 }
 370
 371 static __init void detect_machine_facilities(void)
 372 {
 373         if (test_facility(8)) {
 374                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 375                 __ctl_set_bit(0, 23);
 376         }
 377         if (test_facility(78))
 378                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 379         if (test_facility(3))
 380                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 381         if (test_facility(40))
 382                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
 383         if (test_facility(50) && test_facility(73)) {
 384                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 385                 __ctl_set_bit(0, 55);
 386         }
 387         if (test_facility(51))
 388                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 389         if (test_facility(129)) {
 390                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 391                 __ctl_set_bit(0, 17);
 392         }
 393         if (test_facility(130)) {
 394                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 395                 __ctl_set_bit(0, 20);
 396         }
 397         if (test_facility(133))
 398                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 399         if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
 400                 /* Enabled signed clock comparator comparisons */
 401                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 402                 clock_comparator_max = -1ULL >> 1;
 403                 __ctl_set_bit(0, 53);
 404         }
 405 }
 406
 407 static inline void save_vector_registers(void)
 408 {
 409 #ifdef CONFIG_CRASH_DUMP
 410         if (test_facility(129))
 411                 save_vx_regs(boot_cpu_vector_save_area);
 412 #endif
 413 }
 414
 415 static int __init disable_vector_extension(char *str)
 416 {
 417         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 418         __ctl_clear_bit(0, 17);
 419         return 0;
 420 }
 421 early_param("novx", disable_vector_extension);
 422
 423 static int __init noexec_setup(char *str)
 424 {
 425         bool enabled;
 426         int rc;
 427
 428         rc = kstrtobool(str, &enabled);
 429         if (!rc && !enabled) {
 430                 /* Disable no-execute support */
 431                 S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
 432                 __ctl_clear_bit(0, 20);
 433         }
 434         return rc;
 435 }
 436 early_param("noexec", noexec_setup);
 437
 438 static int __init cad_setup(char *str)
 439 {
 440         bool enabled;
 441         int rc;
 442
 443         rc = kstrtobool(str, &enabled);
 444         if (!rc && enabled && test_facility(128))
 445                 /* Enable problem state CAD. */
 446                 __ctl_set_bit(2, 3);
 447         return rc;
 448 }
 449 early_param("cad", cad_setup);
 450
 451 static __init void memmove_early(void *dst, const void *src, size_t n)
 452 {
 453         unsigned long addr;
 454         long incr;
 455         psw_t old;
 456
 457         if (!n)
 458                 return;
 459         incr = 1;
 460         if (dst > src) {
 461                 incr = -incr;
 462                 dst += n - 1;
 463                 src += n - 1;
 464         }
 465         old = S390_lowcore.program_new_psw;
 466         S390_lowcore.program_new_psw.mask = __extract_psw();
 467         asm volatile(
 468                 "       larl    %[addr],1f\n"
 469                 "       stg     %[addr],%[psw_pgm_addr]\n"
 470                 "0:     mvc     0(1,%[dst]),0(%[src])\n"
 471                 "       agr     %[dst],%[incr]\n"
 472                 "       agr     %[src],%[incr]\n"
 473                 "       brctg   %[n],0b\n"
 474                 "1:\n"
 475                 : [addr] "=&d" (addr),
 476                   [psw_pgm_addr] "=Q" (S390_lowcore.program_new_psw.addr),
 477                   [dst] "+&a" (dst), [src] "+&a" (src),  [n] "+d" (n)
 478                 : [incr] "d" (incr)
 479                 : "cc", "memory");
 480         S390_lowcore.program_new_psw = old;
 481 }
 482
 483 static __init noinline void ipl_save_parameters(void)
 484 {
 485         void *src, *dst;
 486
 487         src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
 488         dst = (void *) IPL_PARMBLOCK_ORIGIN;
 489         memmove_early(dst, src, PAGE_SIZE);
 490         S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
 491 }
 492
 493 static __init noinline void rescue_initrd(void)
 494 {
 495 #ifdef CONFIG_BLK_DEV_INITRD
 496         unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
 497         /*
 498          * Just like in case of IPL from VM reader we make sure there is a
 499          * gap of 4MB between end of kernel and start of initrd.
 500          * That way we can also be sure that saving an NSS will succeed,
 501          * which however only requires different segments.
 502          */
 503         if (!INITRD_START || !INITRD_SIZE)
 504                 return;
 505         if (INITRD_START >= min_initrd_addr)
 506                 return;
 507         memmove_early((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
 508         INITRD_START = min_initrd_addr;
 509 #endif
 510 }
 511
 512 /* Set up boot command line */
 513 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 514 {
 515         char *parm, *delim;
 516         size_t rc, len;
 517
 518         len = strlen(boot_command_line);
 519
 520         delim = boot_command_line + len;        /* '\0' character position */
 521         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 522
 523         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 524         if (rc) {
 525                 if (*parm == '=')
 526                         memmove(boot_command_line, parm + 1, rc);
 527                 else
 528                         *delim = ' ';           /* replace '\0' with space */
 529         }
 530 }
 531
 532 static inline int has_ebcdic_char(const char *str)
 533 {
 534         int i;
 535
 536         for (i = 0; str[i]; i++)
 537                 if (str[i] & 0x80)
 538                         return 1;
 539         return 0;
 540 }
 541
 542 static void __init setup_boot_command_line(void)
 543 {
 544         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
 545         /* convert arch command line to ascii if necessary */
 546         if (has_ebcdic_char(COMMAND_LINE))
 547                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 548         /* copy arch command line */
 549         strlcpy(boot_command_line, strstrip(COMMAND_LINE),
 550                 ARCH_COMMAND_LINE_SIZE);
 551
 552         /* append IPL PARM data to the boot command line */
 553         if (MACHINE_IS_VM)
 554                 append_to_cmdline(append_ipl_vmparm);
 555
 556         append_to_cmdline(append_ipl_scpdata);
 557 }
 558
 559 /*
 560  * Save ipl parameters, clear bss memory, initialize storage keys
 561  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 562  */
 563 void __init startup_init(void)
 564 {
 565         reset_tod_clock();
 566         ipl_save_parameters();
 567         rescue_initrd();
 568         clear_bss_section();
 569         ipl_verify_parameters();
 570         time_early_init();
 571         init_kernel_storage_key();
 572         lockdep_off();
 573         setup_lowcore_early();
 574         setup_facility_list();
 575         detect_machine_type();
 576         setup_arch_string();
 577         ipl_update_parameters();
 578         setup_boot_command_line();
 579         create_kernel_nss();
 580         detect_diag9c();
 581         detect_diag44();
 582         detect_machine_facilities();
 583         save_vector_registers();
 584         setup_topology();
 585         sclp_early_detect();
 586         lockdep_on();
 587 }