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