arch/s390/kernel/early.c

   1 /*
   2  *    Copyright IBM Corp. 2007, 2009
   3  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
   4  *               Heiko Carstens <heiko.carstens@de.ibm.com>
   5  */
   6
   7 #define KMSG_COMPONENT "setup"
   8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   9
  10 #include <linux/compiler.h>
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/ctype.h>
  15 #include <linux/lockdep.h>
  16 #include <linux/extable.h>
  17 #include <linux/pfn.h>
  18 #include <linux/uaccess.h>
  19 #include <linux/kernel.h>
  20 #include <asm/diag.h>
  21 #include <asm/ebcdic.h>
  22 #include <asm/ipl.h>
  23 #include <asm/lowcore.h>
  24 #include <asm/processor.h>
  25 #include <asm/sections.h>
  26 #include <asm/setup.h>
  27 #include <asm/sysinfo.h>
  28 #include <asm/cpcmd.h>
  29 #include <asm/sclp.h>
  30 #include <asm/facility.h>
  31 #include "entry.h"
  32
  33 /*
  34  * Create a Kernel NSS if the SAVESYS= parameter is defined
  35  */
  36 #define DEFSYS_CMD_SIZE         128
  37 #define SAVESYS_CMD_SIZE        32
  38
  39 char kernel_nss_name[NSS_NAME_SIZE + 1];
  40
  41 static void __init setup_boot_command_line(void);
  42
  43 /*
  44  * Get the TOD clock running.
  45  */
  46 static void __init reset_tod_clock(void)
  47 {
  48         u64 time;
  49
  50         if (store_tod_clock(&time) == 0)
  51                 return;
  52         /* TOD clock not running. Set the clock to Unix Epoch. */
  53         if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
  54                 disabled_wait(0);
  55
  56         memset(tod_clock_base, 0, 16);
  57         *(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
  58         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
  59 }
  60
  61 #ifdef CONFIG_SHARED_KERNEL
  62 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
  63
  64 asm(
  65         "       .section .init.text,\"ax\",@progbits\n"
  66         "       .align  4\n"
  67         "       .type   savesys_ipl_nss, @function\n"
  68         "savesys_ipl_nss:\n"
  69         "       stmg    6,15,48(15)\n"
  70         "       lgr     14,3\n"
  71         "       sam31\n"
  72         "       diag    2,14,0x8\n"
  73         "       sam64\n"
  74         "       lgr     2,14\n"
  75         "       lmg     6,15,48(15)\n"
  76         "       br      14\n"
  77         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\n"
  78         "       .previous\n");
  79
  80 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
  81
  82 static noinline __init void create_kernel_nss(void)
  83 {
  84         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
  85 #ifdef CONFIG_BLK_DEV_INITRD
  86         unsigned int sinitrd_pfn, einitrd_pfn;
  87 #endif
  88         int response;
  89         int hlen;
  90         size_t len;
  91         char *savesys_ptr;
  92         char defsys_cmd[DEFSYS_CMD_SIZE];
  93         char savesys_cmd[SAVESYS_CMD_SIZE];
  94
  95         /* Do nothing if we are not running under VM */
  96         if (!MACHINE_IS_VM)
  97                 return;
  98
  99         /* Convert COMMAND_LINE to upper case */
 100         for (i = 0; i < strlen(boot_command_line); i++)
 101                 upper_command_line[i] = toupper(boot_command_line[i]);
 102
 103         savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 104
 105         if (!savesys_ptr)
 106                 return;
 107
 108         savesys_ptr += 8;    /* Point to the beginning of the NSS name */
 109         for (i = 0; i < NSS_NAME_SIZE; i++) {
 110                 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
 111                         break;
 112                 kernel_nss_name[i] = savesys_ptr[i];
 113         }
 114
 115         stext_pfn = PFN_DOWN(__pa(&_stext));
 116         eshared_pfn = PFN_DOWN(__pa(&_eshared));
 117         end_pfn = PFN_UP(__pa(&_end));
 118         min_size = end_pfn << 2;
 119
 120         hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
 121                         "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 122                         kernel_nss_name, stext_pfn - 1, stext_pfn,
 123                         eshared_pfn - 1, eshared_pfn, end_pfn);
 124
 125 #ifdef CONFIG_BLK_DEV_INITRD
 126         if (INITRD_START && INITRD_SIZE) {
 127                 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
 128                 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
 129                 min_size = einitrd_pfn << 2;
 130                 hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 131                                  " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
 132         }
 133 #endif
 134
 135         snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 136                  " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
 137         defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
 138         snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
 139                  kernel_nss_name, kernel_nss_name);
 140         savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
 141
 142         __cpcmd(defsys_cmd, NULL, 0, &response);
 143
 144         if (response != 0) {
 145                 pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
 146                         response);
 147                 kernel_nss_name[0] = '\0';
 148                 return;
 149         }
 150
 151         len = strlen(savesys_cmd);
 152         ASCEBC(savesys_cmd, len);
 153         response = savesys_ipl_nss(savesys_cmd, len);
 154
 155         /* On success: response is equal to the command size,
 156          *             max SAVESYS_CMD_SIZE
 157          * On error: response contains the numeric portion of cp error message.
 158          *           for SAVESYS it will be >= 263
 159          *           for missing privilege class, it will be 1
 160          */
 161         if (response > SAVESYS_CMD_SIZE || response == 1) {
 162                 pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
 163                         response);
 164                 kernel_nss_name[0] = '\0';
 165                 return;
 166         }
 167
 168         /* re-initialize cputime accounting. */
 169         get_tod_clock_ext(tod_clock_base);
 170         S390_lowcore.last_update_clock = *(__u64 *) &tod_clock_base[1];
 171         S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
 172         S390_lowcore.user_timer = 0;
 173         S390_lowcore.system_timer = 0;
 174         asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
 175
 176         /* re-setup boot command line with new ipl vm parms */
 177         ipl_update_parameters();
 178         setup_boot_command_line();
 179
 180         ipl_flags = IPL_NSS_VALID;
 181 }
 182
 183 #else /* CONFIG_SHARED_KERNEL */
 184
 185 static inline void create_kernel_nss(void) { }
 186
 187 #endif /* CONFIG_SHARED_KERNEL */
 188
 189 /*
 190  * Clear bss memory
 191  */
 192 static noinline __init void clear_bss_section(void)
 193 {
 194         memset(__bss_start, 0, __bss_stop - __bss_start);
 195 }
 196
 197 /*
 198  * Initialize storage key for kernel pages
 199  */
 200 static noinline __init void init_kernel_storage_key(void)
 201 {
 202 #if PAGE_DEFAULT_KEY
 203         unsigned long end_pfn, init_pfn;
 204
 205         end_pfn = PFN_UP(__pa(&_end));
 206
 207         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 208                 page_set_storage_key(init_pfn << PAGE_SHIFT,
 209                                      PAGE_DEFAULT_KEY, 0);
 210 #endif
 211 }
 212
 213 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 214
 215 static noinline __init void detect_machine_type(void)
 216 {
 217         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
 218
 219         /* Check current-configuration-level */
 220         if (stsi(NULL, 0, 0, 0) <= 2) {
 221                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 222                 return;
 223         }
 224         /* Get virtual-machine cpu information. */
 225         if (stsi(vmms, 3, 2, 2) || !vmms->count)
 226                 return;
 227
 228         /* Running under KVM? If not we assume z/VM */
 229         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 230                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 231         else
 232                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 233 }
 234
 235 /* Remove leading, trailing and double whitespace. */
 236 static inline void strim_all(char *str)
 237 {
 238         char *s;
 239
 240         s = strim(str);
 241         if (s != str)
 242                 memmove(str, s, strlen(s));
 243         while (*str) {
 244                 if (!isspace(*str++))
 245                         continue;
 246                 if (isspace(*str)) {
 247                         s = skip_spaces(str);
 248                         memmove(str, s, strlen(s) + 1);
 249                 }
 250         }
 251 }
 252
 253 static noinline __init void setup_arch_string(void)
 254 {
 255         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 256         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 257         char mstr[80], hvstr[17];
 258
 259         if (stsi(mach, 1, 1, 1))
 260                 return;
 261         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 262         EBCASC(mach->type, sizeof(mach->type));
 263         EBCASC(mach->model, sizeof(mach->model));
 264         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 265         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 266                 mach->manufacturer, mach->type,
 267                 mach->model, mach->model_capacity);
 268         strim_all(mstr);
 269         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 270                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 271                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 272                 strim_all(hvstr);
 273         } else {
 274                 sprintf(hvstr, "%s",
 275                         MACHINE_IS_LPAR ? "LPAR" :
 276                         MACHINE_IS_VM ? "z/VM" :
 277                         MACHINE_IS_KVM ? "KVM" : "unknown");
 278         }
 279         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 280 }
 281
 282 static __init void setup_topology(void)
 283 {
 284         int max_mnest;
 285
 286         if (!test_facility(11))
 287                 return;
 288         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 289         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 290                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 291                         break;
 292         }
 293         topology_max_mnest = max_mnest;
 294 }
 295
 296 static void early_pgm_check_handler(void)
 297 {
 298         const struct exception_table_entry *fixup;
 299         unsigned long cr0, cr0_new;
 300         unsigned long addr;
 301
 302         addr = S390_lowcore.program_old_psw.addr;
 303         fixup = search_exception_tables(addr);
 304         if (!fixup)
 305                 disabled_wait(0);
 306         /* Disable low address protection before storing into lowcore. */
 307         __ctl_store(cr0, 0, 0);
 308         cr0_new = cr0 & ~(1UL << 28);
 309         __ctl_load(cr0_new, 0, 0);
 310         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 311         __ctl_load(cr0, 0, 0);
 312 }
 313
 314 static noinline __init void setup_lowcore_early(void)
 315 {
 316         psw_t psw;
 317
 318         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 319         psw.addr = (unsigned long) s390_base_ext_handler;
 320         S390_lowcore.external_new_psw = psw;
 321         psw.addr = (unsigned long) s390_base_pgm_handler;
 322         S390_lowcore.program_new_psw = psw;
 323         s390_base_pgm_handler_fn = early_pgm_check_handler;
 324         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 325 }
 326
 327 static noinline __init void setup_facility_list(void)
 328 {
 329         stfle(S390_lowcore.stfle_fac_list,
 330               ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 331 }
 332
 333 static __init void detect_diag9c(void)
 334 {
 335         unsigned int cpu_address;
 336         int rc;
 337
 338         cpu_address = stap();
 339         diag_stat_inc(DIAG_STAT_X09C);
 340         asm volatile(
 341                 "       diag    %2,0,0x9c\n"
 342                 "0:     la      %0,0\n"
 343                 "1:\n"
 344                 EX_TABLE(0b,1b)
 345                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 346         if (!rc)
 347                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 348 }
 349
 350 static __init void detect_diag44(void)
 351 {
 352         int rc;
 353
 354         diag_stat_inc(DIAG_STAT_X044);
 355         asm volatile(
 356                 "       diag    0,0,0x44\n"
 357                 "0:     la      %0,0\n"
 358                 "1:\n"
 359                 EX_TABLE(0b,1b)
 360                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 361         if (!rc)
 362                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 363 }
 364
 365 static __init void detect_machine_facilities(void)
 366 {
 367         if (test_facility(8)) {
 368                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 369                 __ctl_set_bit(0, 23);
 370         }
 371         if (test_facility(78))
 372                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 373         if (test_facility(3))
 374                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 375         if (test_facility(40))
 376                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
 377         if (test_facility(50) && test_facility(73))
 378                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 379         if (test_facility(51))
 380                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 381         if (test_facility(129)) {
 382                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 383                 __ctl_set_bit(0, 17);
 384         }
 385         if (test_facility(130)) {
 386                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 387                 __ctl_set_bit(0, 20);
 388         }
 389         if (test_facility(133))
 390                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 391         if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
 392                 /* Enabled signed clock comparator comparisons */
 393                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 394                 clock_comparator_max = -1ULL >> 1;
 395                 __ctl_set_bit(0, 53);
 396         }
 397 }
 398
 399 static inline void save_vector_registers(void)
 400 {
 401 #ifdef CONFIG_CRASH_DUMP
 402         if (test_facility(129))
 403                 save_vx_regs(boot_cpu_vector_save_area);
 404 #endif
 405 }
 406
 407 static int __init topology_setup(char *str)
 408 {
 409         bool enabled;
 410         int rc;
 411
 412         rc = kstrtobool(str, &enabled);
 413         if (!rc && !enabled)
 414                 S390_lowcore.machine_flags &= ~MACHINE_FLAG_TOPOLOGY;
 415         return rc;
 416 }
 417 early_param("topology", topology_setup);
 418
 419 static int __init disable_vector_extension(char *str)
 420 {
 421         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 422         __ctl_clear_bit(0, 17);
 423         return 0;
 424 }
 425 early_param("novx", disable_vector_extension);
 426
 427 static int __init noexec_setup(char *str)
 428 {
 429         bool enabled;
 430         int rc;
 431
 432         rc = kstrtobool(str, &enabled);
 433         if (!rc && !enabled) {
 434                 /* Disable no-execute support */
 435                 S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
 436                 __ctl_clear_bit(0, 20);
 437         }
 438         return rc;
 439 }
 440 early_param("noexec", noexec_setup);
 441
 442 static int __init cad_setup(char *str)
 443 {
 444         bool enabled;
 445         int rc;
 446
 447         rc = kstrtobool(str, &enabled);
 448         if (!rc && enabled && test_facility(128))
 449                 /* Enable problem state CAD. */
 450                 __ctl_set_bit(2, 3);
 451         return rc;
 452 }
 453 early_param("cad", cad_setup);
 454
 455 static __init void memmove_early(void *dst, const void *src, size_t n)
 456 {
 457         unsigned long addr;
 458         long incr;
 459         psw_t old;
 460
 461         if (!n)
 462                 return;
 463         incr = 1;
 464         if (dst > src) {
 465                 incr = -incr;
 466                 dst += n - 1;
 467                 src += n - 1;
 468         }
 469         old = S390_lowcore.program_new_psw;
 470         S390_lowcore.program_new_psw.mask = __extract_psw();
 471         asm volatile(
 472                 "       larl    %[addr],1f\n"
 473                 "       stg     %[addr],%[psw_pgm_addr]\n"
 474                 "0:     mvc     0(1,%[dst]),0(%[src])\n"
 475                 "       agr     %[dst],%[incr]\n"
 476                 "       agr     %[src],%[incr]\n"
 477                 "       brctg   %[n],0b\n"
 478                 "1:\n"
 479                 : [addr] "=&d" (addr),
 480                   [psw_pgm_addr] "=Q" (S390_lowcore.program_new_psw.addr),
 481                   [dst] "+&a" (dst), [src] "+&a" (src),  [n] "+d" (n)
 482                 : [incr] "d" (incr)
 483                 : "cc", "memory");
 484         S390_lowcore.program_new_psw = old;
 485 }
 486
 487 static __init noinline void ipl_save_parameters(void)
 488 {
 489         void *src, *dst;
 490
 491         src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
 492         dst = (void *) IPL_PARMBLOCK_ORIGIN;
 493         memmove_early(dst, src, PAGE_SIZE);
 494         S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
 495 }
 496
 497 static __init noinline void rescue_initrd(void)
 498 {
 499 #ifdef CONFIG_BLK_DEV_INITRD
 500         unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
 501         /*
 502          * Just like in case of IPL from VM reader we make sure there is a
 503          * gap of 4MB between end of kernel and start of initrd.
 504          * That way we can also be sure that saving an NSS will succeed,
 505          * which however only requires different segments.
 506          */
 507         if (!INITRD_START || !INITRD_SIZE)
 508                 return;
 509         if (INITRD_START >= min_initrd_addr)
 510                 return;
 511         memmove_early((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
 512         INITRD_START = min_initrd_addr;
 513 #endif
 514 }
 515
 516 /* Set up boot command line */
 517 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 518 {
 519         char *parm, *delim;
 520         size_t rc, len;
 521
 522         len = strlen(boot_command_line);
 523
 524         delim = boot_command_line + len;        /* '\0' character position */
 525         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 526
 527         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 528         if (rc) {
 529                 if (*parm == '=')
 530                         memmove(boot_command_line, parm + 1, rc);
 531                 else
 532                         *delim = ' ';           /* replace '\0' with space */
 533         }
 534 }
 535
 536 static inline int has_ebcdic_char(const char *str)
 537 {
 538         int i;
 539
 540         for (i = 0; str[i]; i++)
 541                 if (str[i] & 0x80)
 542                         return 1;
 543         return 0;
 544 }
 545
 546 static void __init setup_boot_command_line(void)
 547 {
 548         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
 549         /* convert arch command line to ascii if necessary */
 550         if (has_ebcdic_char(COMMAND_LINE))
 551                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 552         /* copy arch command line */
 553         strlcpy(boot_command_line, strstrip(COMMAND_LINE),
 554                 ARCH_COMMAND_LINE_SIZE);
 555
 556         /* append IPL PARM data to the boot command line */
 557         if (MACHINE_IS_VM)
 558                 append_to_cmdline(append_ipl_vmparm);
 559
 560         append_to_cmdline(append_ipl_scpdata);
 561 }
 562
 563 /*
 564  * Save ipl parameters, clear bss memory, initialize storage keys
 565  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 566  */
 567 void __init startup_init(void)
 568 {
 569         reset_tod_clock();
 570         ipl_save_parameters();
 571         rescue_initrd();
 572         clear_bss_section();
 573         ipl_verify_parameters();
 574         time_early_init();
 575         init_kernel_storage_key();
 576         lockdep_off();
 577         setup_lowcore_early();
 578         setup_facility_list();
 579         detect_machine_type();
 580         setup_arch_string();
 581         ipl_update_parameters();
 582         setup_boot_command_line();
 583         create_kernel_nss();
 584         detect_diag9c();
 585         detect_diag44();
 586         detect_machine_facilities();
 587         save_vector_registers();
 588         setup_topology();
 589         sclp_early_detect();
 590         lockdep_on();
 591 }