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/module.h>
  17 #include <linux/pfn.h>
  18 #include <linux/uaccess.h>
  19 #include <linux/kernel.h>
  20 #include <asm/ebcdic.h>
  21 #include <asm/ipl.h>
  22 #include <asm/lowcore.h>
  23 #include <asm/processor.h>
  24 #include <asm/sections.h>
  25 #include <asm/setup.h>
  26 #include <asm/sysinfo.h>
  27 #include <asm/cpcmd.h>
  28 #include <asm/sclp.h>
  29 #include <asm/facility.h>
  30 #include "entry.h"
  31
  32 /*
  33  * Create a Kernel NSS if the SAVESYS= parameter is defined
  34  */
  35 #define DEFSYS_CMD_SIZE         128
  36 #define SAVESYS_CMD_SIZE        32
  37
  38 char kernel_nss_name[NSS_NAME_SIZE + 1];
  39
  40 static void __init setup_boot_command_line(void);
  41
  42 /*
  43  * Get the TOD clock running.
  44  */
  45 static void __init reset_tod_clock(void)
  46 {
  47         u64 time;
  48
  49         if (store_tod_clock(&time) == 0)
  50                 return;
  51         /* TOD clock not running. Set the clock to Unix Epoch. */
  52         if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
  53                 disabled_wait(0);
  54
  55         sched_clock_base_cc = TOD_UNIX_EPOCH;
  56         S390_lowcore.last_update_clock = sched_clock_base_cc;
  57 }
  58
  59 #ifdef CONFIG_SHARED_KERNEL
  60 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
  61
  62 asm(
  63         "       .section .init.text,\"ax\",@progbits\n"
  64         "       .align  4\n"
  65         "       .type   savesys_ipl_nss, @function\n"
  66         "savesys_ipl_nss:\n"
  67 #ifdef CONFIG_64BIT
  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 #else
  76         "       stm     6,15,24(15)\n"
  77         "       lr      14,3\n"
  78         "       diag    2,14,0x8\n"
  79         "       lr      2,14\n"
  80         "       lm      6,15,24(15)\n"
  81 #endif
  82         "       br      14\n"
  83         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\n"
  84         "       .previous\n");
  85
  86 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
  87
  88 static noinline __init void create_kernel_nss(void)
  89 {
  90         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
  91 #ifdef CONFIG_BLK_DEV_INITRD
  92         unsigned int sinitrd_pfn, einitrd_pfn;
  93 #endif
  94         int response;
  95         int hlen;
  96         size_t len;
  97         char *savesys_ptr;
  98         char defsys_cmd[DEFSYS_CMD_SIZE];
  99         char savesys_cmd[SAVESYS_CMD_SIZE];
 100
 101         /* Do nothing if we are not running under VM */
 102         if (!MACHINE_IS_VM)
 103                 return;
 104
 105         /* Convert COMMAND_LINE to upper case */
 106         for (i = 0; i < strlen(boot_command_line); i++)
 107                 upper_command_line[i] = toupper(boot_command_line[i]);
 108
 109         savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 110
 111         if (!savesys_ptr)
 112                 return;
 113
 114         savesys_ptr += 8;    /* Point to the beginning of the NSS name */
 115         for (i = 0; i < NSS_NAME_SIZE; i++) {
 116                 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
 117                         break;
 118                 kernel_nss_name[i] = savesys_ptr[i];
 119         }
 120
 121         stext_pfn = PFN_DOWN(__pa(&_stext));
 122         eshared_pfn = PFN_DOWN(__pa(&_eshared));
 123         end_pfn = PFN_UP(__pa(&_end));
 124         min_size = end_pfn << 2;
 125
 126         hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
 127                         "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 128                         kernel_nss_name, stext_pfn - 1, stext_pfn,
 129                         eshared_pfn - 1, eshared_pfn, end_pfn);
 130
 131 #ifdef CONFIG_BLK_DEV_INITRD
 132         if (INITRD_START && INITRD_SIZE) {
 133                 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
 134                 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
 135                 min_size = einitrd_pfn << 2;
 136                 hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 137                                  " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
 138         }
 139 #endif
 140
 141         snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 142                  " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
 143         defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
 144         snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
 145                  kernel_nss_name, kernel_nss_name);
 146         savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
 147
 148         __cpcmd(defsys_cmd, NULL, 0, &response);
 149
 150         if (response != 0) {
 151                 pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
 152                         response);
 153                 kernel_nss_name[0] = '\0';
 154                 return;
 155         }
 156
 157         len = strlen(savesys_cmd);
 158         ASCEBC(savesys_cmd, len);
 159         response = savesys_ipl_nss(savesys_cmd, len);
 160
 161         /* On success: response is equal to the command size,
 162          *             max SAVESYS_CMD_SIZE
 163          * On error: response contains the numeric portion of cp error message.
 164          *           for SAVESYS it will be >= 263
 165          *           for missing privilege class, it will be 1
 166          */
 167         if (response > SAVESYS_CMD_SIZE || response == 1) {
 168                 pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
 169                         response);
 170                 kernel_nss_name[0] = '\0';
 171                 return;
 172         }
 173
 174         /* re-initialize cputime accounting. */
 175         sched_clock_base_cc = get_tod_clock();
 176         S390_lowcore.last_update_clock = sched_clock_base_cc;
 177         S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
 178         S390_lowcore.user_timer = 0;
 179         S390_lowcore.system_timer = 0;
 180         asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
 181
 182         /* re-setup boot command line with new ipl vm parms */
 183         ipl_update_parameters();
 184         setup_boot_command_line();
 185
 186         ipl_flags = IPL_NSS_VALID;
 187 }
 188
 189 #else /* CONFIG_SHARED_KERNEL */
 190
 191 static inline void create_kernel_nss(void) { }
 192
 193 #endif /* CONFIG_SHARED_KERNEL */
 194
 195 /*
 196  * Clear bss memory
 197  */
 198 static noinline __init void clear_bss_section(void)
 199 {
 200         memset(__bss_start, 0, __bss_stop - __bss_start);
 201 }
 202
 203 /*
 204  * Initialize storage key for kernel pages
 205  */
 206 static noinline __init void init_kernel_storage_key(void)
 207 {
 208 #if PAGE_DEFAULT_KEY
 209         unsigned long end_pfn, init_pfn;
 210
 211         end_pfn = PFN_UP(__pa(&_end));
 212
 213         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 214                 page_set_storage_key(init_pfn << PAGE_SHIFT,
 215                                      PAGE_DEFAULT_KEY, 0);
 216 #endif
 217 }
 218
 219 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 220
 221 static noinline __init void detect_machine_type(void)
 222 {
 223         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
 224
 225         /* Check current-configuration-level */
 226         if (stsi(NULL, 0, 0, 0) <= 2) {
 227                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 228                 return;
 229         }
 230         /* Get virtual-machine cpu information. */
 231         if (stsi(vmms, 3, 2, 2) || !vmms->count)
 232                 return;
 233
 234         /* Running under KVM? If not we assume z/VM */
 235         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 236                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 237         else
 238                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 239 }
 240
 241 static __init void setup_topology(void)
 242 {
 243 #ifdef CONFIG_64BIT
 244         int max_mnest;
 245
 246         if (!test_facility(11))
 247                 return;
 248         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 249         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 250                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 251                         break;
 252         }
 253         topology_max_mnest = max_mnest;
 254 #endif
 255 }
 256
 257 static void early_pgm_check_handler(void)
 258 {
 259         const struct exception_table_entry *fixup;
 260         unsigned long cr0, cr0_new;
 261         unsigned long addr;
 262
 263         addr = S390_lowcore.program_old_psw.addr;
 264         fixup = search_exception_tables(addr & PSW_ADDR_INSN);
 265         if (!fixup)
 266                 disabled_wait(0);
 267         /* Disable low address protection before storing into lowcore. */
 268         __ctl_store(cr0, 0, 0);
 269         cr0_new = cr0 & ~(1UL << 28);
 270         __ctl_load(cr0_new, 0, 0);
 271         S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
 272         __ctl_load(cr0, 0, 0);
 273 }
 274
 275 static noinline __init void setup_lowcore_early(void)
 276 {
 277         psw_t psw;
 278
 279         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 280         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
 281         S390_lowcore.external_new_psw = psw;
 282         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 283         S390_lowcore.program_new_psw = psw;
 284         s390_base_pgm_handler_fn = early_pgm_check_handler;
 285 }
 286
 287 static noinline __init void setup_facility_list(void)
 288 {
 289         stfle(S390_lowcore.stfle_fac_list,
 290               ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 291 }
 292
 293 static __init void detect_mvpg(void)
 294 {
 295 #ifndef CONFIG_64BIT
 296         int rc;
 297
 298         asm volatile(
 299                 "       la      0,0\n"
 300                 "       mvpg    %2,%2\n"
 301                 "0:     la      %0,0\n"
 302                 "1:\n"
 303                 EX_TABLE(0b,1b)
 304                 : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
 305         if (!rc)
 306                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
 307 #endif
 308 }
 309
 310 static __init void detect_ieee(void)
 311 {
 312 #ifndef CONFIG_64BIT
 313         int rc, tmp;
 314
 315         asm volatile(
 316                 "       efpc    %1,0\n"
 317                 "0:     la      %0,0\n"
 318                 "1:\n"
 319                 EX_TABLE(0b,1b)
 320                 : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
 321         if (!rc)
 322                 S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
 323 #endif
 324 }
 325
 326 static __init void detect_csp(void)
 327 {
 328 #ifndef CONFIG_64BIT
 329         int rc;
 330
 331         asm volatile(
 332                 "       la      0,0\n"
 333                 "       la      1,0\n"
 334                 "       la      2,4\n"
 335                 "       csp     0,2\n"
 336                 "0:     la      %0,0\n"
 337                 "1:\n"
 338                 EX_TABLE(0b,1b)
 339                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
 340         if (!rc)
 341                 S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
 342 #endif
 343 }
 344
 345 static __init void detect_diag9c(void)
 346 {
 347         unsigned int cpu_address;
 348         int rc;
 349
 350         cpu_address = stap();
 351         asm volatile(
 352                 "       diag    %2,0,0x9c\n"
 353                 "0:     la      %0,0\n"
 354                 "1:\n"
 355                 EX_TABLE(0b,1b)
 356                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 357         if (!rc)
 358                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 359 }
 360
 361 static __init void detect_diag44(void)
 362 {
 363 #ifdef CONFIG_64BIT
 364         int rc;
 365
 366         asm volatile(
 367                 "       diag    0,0,0x44\n"
 368                 "0:     la      %0,0\n"
 369                 "1:\n"
 370                 EX_TABLE(0b,1b)
 371                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 372         if (!rc)
 373                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 374 #endif
 375 }
 376
 377 static __init void detect_machine_facilities(void)
 378 {
 379 #ifdef CONFIG_64BIT
 380         if (test_facility(8)) {
 381                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 382                 __ctl_set_bit(0, 23);
 383         }
 384         if (test_facility(78))
 385                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 386         if (test_facility(3))
 387                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 388         if (test_facility(40))
 389                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
 390         if (test_facility(50) && test_facility(73))
 391                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 392         if (test_facility(51))
 393                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 394         if (test_facility(129))
 395                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 396 #endif
 397 }
 398
 399 static __init void rescue_initrd(void)
 400 {
 401 #ifdef CONFIG_BLK_DEV_INITRD
 402         unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
 403         /*
 404          * Just like in case of IPL from VM reader we make sure there is a
 405          * gap of 4MB between end of kernel and start of initrd.
 406          * That way we can also be sure that saving an NSS will succeed,
 407          * which however only requires different segments.
 408          */
 409         if (!INITRD_START || !INITRD_SIZE)
 410                 return;
 411         if (INITRD_START >= min_initrd_addr)
 412                 return;
 413         memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
 414         INITRD_START = min_initrd_addr;
 415 #endif
 416 }
 417
 418 /* Set up boot command line */
 419 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 420 {
 421         char *parm, *delim;
 422         size_t rc, len;
 423
 424         len = strlen(boot_command_line);
 425
 426         delim = boot_command_line + len;        /* '\0' character position */
 427         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 428
 429         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 430         if (rc) {
 431                 if (*parm == '=')
 432                         memmove(boot_command_line, parm + 1, rc);
 433                 else
 434                         *delim = ' ';           /* replace '\0' with space */
 435         }
 436 }
 437
 438 static inline int has_ebcdic_char(const char *str)
 439 {
 440         int i;
 441
 442         for (i = 0; str[i]; i++)
 443                 if (str[i] & 0x80)
 444                         return 1;
 445         return 0;
 446 }
 447
 448 static void __init setup_boot_command_line(void)
 449 {
 450         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
 451         /* convert arch command line to ascii if necessary */
 452         if (has_ebcdic_char(COMMAND_LINE))
 453                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 454         /* copy arch command line */
 455         strlcpy(boot_command_line, strstrip(COMMAND_LINE),
 456                 ARCH_COMMAND_LINE_SIZE);
 457
 458         /* append IPL PARM data to the boot command line */
 459         if (MACHINE_IS_VM)
 460                 append_to_cmdline(append_ipl_vmparm);
 461
 462         append_to_cmdline(append_ipl_scpdata);
 463 }
 464
 465 /*
 466  * Save ipl parameters, clear bss memory, initialize storage keys
 467  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 468  */
 469 void __init startup_init(void)
 470 {
 471         reset_tod_clock();
 472         ipl_save_parameters();
 473         rescue_initrd();
 474         clear_bss_section();
 475         init_kernel_storage_key();
 476         lockdep_init();
 477         lockdep_off();
 478         setup_lowcore_early();
 479         setup_facility_list();
 480         detect_machine_type();
 481         ipl_update_parameters();
 482         setup_boot_command_line();
 483         create_kernel_nss();
 484         detect_mvpg();
 485         detect_ieee();
 486         detect_csp();
 487         detect_diag9c();
 488         detect_diag44();
 489         detect_machine_facilities();
 490         setup_topology();
 491         sclp_early_detect();
 492         lockdep_on();
 493 }