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/ftrace.h>
  16 #include <linux/lockdep.h>
  17 #include <linux/module.h>
  18 #include <linux/pfn.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/kernel.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 #ifdef CONFIG_64BIT
  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 #else
  77         "       stm     6,15,24(15)\n"
  78         "       lr      14,3\n"
  79         "       diag    2,14,0x8\n"
  80         "       lr      2,14\n"
  81         "       lm      6,15,24(15)\n"
  82 #endif
  83         "       br      14\n"
  84         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\n"
  85         "       .previous\n");
  86
  87 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
  88
  89 static noinline __init void create_kernel_nss(void)
  90 {
  91         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
  92 #ifdef CONFIG_BLK_DEV_INITRD
  93         unsigned int sinitrd_pfn, einitrd_pfn;
  94 #endif
  95         int response;
  96         int hlen;
  97         size_t len;
  98         char *savesys_ptr;
  99         char defsys_cmd[DEFSYS_CMD_SIZE];
 100         char savesys_cmd[SAVESYS_CMD_SIZE];
 101
 102         /* Do nothing if we are not running under VM */
 103         if (!MACHINE_IS_VM)
 104                 return;
 105
 106         /* Convert COMMAND_LINE to upper case */
 107         for (i = 0; i < strlen(boot_command_line); i++)
 108                 upper_command_line[i] = toupper(boot_command_line[i]);
 109
 110         savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 111
 112         if (!savesys_ptr)
 113                 return;
 114
 115         savesys_ptr += 8;    /* Point to the beginning of the NSS name */
 116         for (i = 0; i < NSS_NAME_SIZE; i++) {
 117                 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
 118                         break;
 119                 kernel_nss_name[i] = savesys_ptr[i];
 120         }
 121
 122         stext_pfn = PFN_DOWN(__pa(&_stext));
 123         eshared_pfn = PFN_DOWN(__pa(&_eshared));
 124         end_pfn = PFN_UP(__pa(&_end));
 125         min_size = end_pfn << 2;
 126
 127         hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
 128                         "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 129                         kernel_nss_name, stext_pfn - 1, stext_pfn,
 130                         eshared_pfn - 1, eshared_pfn, end_pfn);
 131
 132 #ifdef CONFIG_BLK_DEV_INITRD
 133         if (INITRD_START && INITRD_SIZE) {
 134                 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
 135                 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
 136                 min_size = einitrd_pfn << 2;
 137                 hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 138                                  " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
 139         }
 140 #endif
 141
 142         snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 143                  " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
 144         defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
 145         snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
 146                  kernel_nss_name, kernel_nss_name);
 147         savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
 148
 149         __cpcmd(defsys_cmd, NULL, 0, &response);
 150
 151         if (response != 0) {
 152                 pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
 153                         response);
 154                 kernel_nss_name[0] = '\0';
 155                 return;
 156         }
 157
 158         len = strlen(savesys_cmd);
 159         ASCEBC(savesys_cmd, len);
 160         response = savesys_ipl_nss(savesys_cmd, len);
 161
 162         /* On success: response is equal to the command size,
 163          *             max SAVESYS_CMD_SIZE
 164          * On error: response contains the numeric portion of cp error message.
 165          *           for SAVESYS it will be >= 263
 166          *           for missing privilege class, it will be 1
 167          */
 168         if (response > SAVESYS_CMD_SIZE || response == 1) {
 169                 pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
 170                         response);
 171                 kernel_nss_name[0] = '\0';
 172                 return;
 173         }
 174
 175         /* re-initialize cputime accounting. */
 176         sched_clock_base_cc = get_tod_clock();
 177         S390_lowcore.last_update_clock = sched_clock_base_cc;
 178         S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
 179         S390_lowcore.user_timer = 0;
 180         S390_lowcore.system_timer = 0;
 181         asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
 182
 183         /* re-setup boot command line with new ipl vm parms */
 184         ipl_update_parameters();
 185         setup_boot_command_line();
 186
 187         ipl_flags = IPL_NSS_VALID;
 188 }
 189
 190 #else /* CONFIG_SHARED_KERNEL */
 191
 192 static inline void create_kernel_nss(void) { }
 193
 194 #endif /* CONFIG_SHARED_KERNEL */
 195
 196 /*
 197  * Clear bss memory
 198  */
 199 static noinline __init void clear_bss_section(void)
 200 {
 201         memset(__bss_start, 0, __bss_stop - __bss_start);
 202 }
 203
 204 /*
 205  * Initialize storage key for kernel pages
 206  */
 207 static noinline __init void init_kernel_storage_key(void)
 208 {
 209 #if PAGE_DEFAULT_KEY
 210         unsigned long end_pfn, init_pfn;
 211
 212         end_pfn = PFN_UP(__pa(&_end));
 213
 214         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 215                 page_set_storage_key(init_pfn << PAGE_SHIFT,
 216                                      PAGE_DEFAULT_KEY, 0);
 217 #endif
 218 }
 219
 220 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 221
 222 static noinline __init void detect_machine_type(void)
 223 {
 224         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
 225
 226         /* Check current-configuration-level */
 227         if (stsi(NULL, 0, 0, 0) <= 2) {
 228                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 229                 return;
 230         }
 231         /* Get virtual-machine cpu information. */
 232         if (stsi(vmms, 3, 2, 2) || !vmms->count)
 233                 return;
 234
 235         /* Running under KVM? If not we assume z/VM */
 236         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 237                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 238         else
 239                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 240 }
 241
 242 static __init void setup_topology(void)
 243 {
 244 #ifdef CONFIG_64BIT
 245         int max_mnest;
 246
 247         if (!test_facility(11))
 248                 return;
 249         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 250         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 251                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 252                         break;
 253         }
 254         topology_max_mnest = max_mnest;
 255 #endif
 256 }
 257
 258 static void early_pgm_check_handler(void)
 259 {
 260         const struct exception_table_entry *fixup;
 261         unsigned long cr0, cr0_new;
 262         unsigned long addr;
 263
 264         addr = S390_lowcore.program_old_psw.addr;
 265         fixup = search_exception_tables(addr & PSW_ADDR_INSN);
 266         if (!fixup)
 267                 disabled_wait(0);
 268         /* Disable low address protection before storing into lowcore. */
 269         __ctl_store(cr0, 0, 0);
 270         cr0_new = cr0 & ~(1UL << 28);
 271         __ctl_load(cr0_new, 0, 0);
 272         S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
 273         __ctl_load(cr0, 0, 0);
 274 }
 275
 276 static noinline __init void setup_lowcore_early(void)
 277 {
 278         psw_t psw;
 279
 280         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 281         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
 282         S390_lowcore.external_new_psw = psw;
 283         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 284         S390_lowcore.program_new_psw = psw;
 285         s390_base_pgm_handler_fn = early_pgm_check_handler;
 286 }
 287
 288 static noinline __init void setup_facility_list(void)
 289 {
 290         stfle(S390_lowcore.stfle_fac_list,
 291               ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 292 }
 293
 294 static __init void detect_mvpg(void)
 295 {
 296 #ifndef CONFIG_64BIT
 297         int rc;
 298
 299         asm volatile(
 300                 "       la      0,0\n"
 301                 "       mvpg    %2,%2\n"
 302                 "0:     la      %0,0\n"
 303                 "1:\n"
 304                 EX_TABLE(0b,1b)
 305                 : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
 306         if (!rc)
 307                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
 308 #endif
 309 }
 310
 311 static __init void detect_ieee(void)
 312 {
 313 #ifndef CONFIG_64BIT
 314         int rc, tmp;
 315
 316         asm volatile(
 317                 "       efpc    %1,0\n"
 318                 "0:     la      %0,0\n"
 319                 "1:\n"
 320                 EX_TABLE(0b,1b)
 321                 : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
 322         if (!rc)
 323                 S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
 324 #endif
 325 }
 326
 327 static __init void detect_csp(void)
 328 {
 329 #ifndef CONFIG_64BIT
 330         int rc;
 331
 332         asm volatile(
 333                 "       la      0,0\n"
 334                 "       la      1,0\n"
 335                 "       la      2,4\n"
 336                 "       csp     0,2\n"
 337                 "0:     la      %0,0\n"
 338                 "1:\n"
 339                 EX_TABLE(0b,1b)
 340                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
 341         if (!rc)
 342                 S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
 343 #endif
 344 }
 345
 346 static __init void detect_diag9c(void)
 347 {
 348         unsigned int cpu_address;
 349         int rc;
 350
 351         cpu_address = stap();
 352         asm volatile(
 353                 "       diag    %2,0,0x9c\n"
 354                 "0:     la      %0,0\n"
 355                 "1:\n"
 356                 EX_TABLE(0b,1b)
 357                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 358         if (!rc)
 359                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 360 }
 361
 362 static __init void detect_diag44(void)
 363 {
 364 #ifdef CONFIG_64BIT
 365         int rc;
 366
 367         asm volatile(
 368                 "       diag    0,0,0x44\n"
 369                 "0:     la      %0,0\n"
 370                 "1:\n"
 371                 EX_TABLE(0b,1b)
 372                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 373         if (!rc)
 374                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 375 #endif
 376 }
 377
 378 static __init void detect_machine_facilities(void)
 379 {
 380 #ifdef CONFIG_64BIT
 381         if (test_facility(8)) {
 382                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 383                 __ctl_set_bit(0, 23);
 384         }
 385         if (test_facility(78))
 386                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 387         if (test_facility(3))
 388                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 389         if (test_facility(40))
 390                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
 391         if (test_facility(50) && test_facility(73))
 392                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 393         if (test_facility(66))
 394                 S390_lowcore.machine_flags |= MACHINE_FLAG_RRBM;
 395         if (test_facility(51))
 396                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 397 #endif
 398 }
 399
 400 static __init void rescue_initrd(void)
 401 {
 402 #ifdef CONFIG_BLK_DEV_INITRD
 403         unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
 404         /*
 405          * Just like in case of IPL from VM reader we make sure there is a
 406          * gap of 4MB between end of kernel and start of initrd.
 407          * That way we can also be sure that saving an NSS will succeed,
 408          * which however only requires different segments.
 409          */
 410         if (!INITRD_START || !INITRD_SIZE)
 411                 return;
 412         if (INITRD_START >= min_initrd_addr)
 413                 return;
 414         memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
 415         INITRD_START = min_initrd_addr;
 416 #endif
 417 }
 418
 419 /* Set up boot command line */
 420 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 421 {
 422         char *parm, *delim;
 423         size_t rc, len;
 424
 425         len = strlen(boot_command_line);
 426
 427         delim = boot_command_line + len;        /* '\0' character position */
 428         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 429
 430         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 431         if (rc) {
 432                 if (*parm == '=')
 433                         memmove(boot_command_line, parm + 1, rc);
 434                 else
 435                         *delim = ' ';           /* replace '\0' with space */
 436         }
 437 }
 438
 439 static inline int has_ebcdic_char(const char *str)
 440 {
 441         int i;
 442
 443         for (i = 0; str[i]; i++)
 444                 if (str[i] & 0x80)
 445                         return 1;
 446         return 0;
 447 }
 448
 449 static void __init setup_boot_command_line(void)
 450 {
 451         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
 452         /* convert arch command line to ascii if necessary */
 453         if (has_ebcdic_char(COMMAND_LINE))
 454                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 455         /* copy arch command line */
 456         strlcpy(boot_command_line, strstrip(COMMAND_LINE),
 457                 ARCH_COMMAND_LINE_SIZE);
 458
 459         /* append IPL PARM data to the boot command line */
 460         if (MACHINE_IS_VM)
 461                 append_to_cmdline(append_ipl_vmparm);
 462
 463         append_to_cmdline(append_ipl_scpdata);
 464 }
 465
 466 /*
 467  * Save ipl parameters, clear bss memory, initialize storage keys
 468  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 469  */
 470 void __init startup_init(void)
 471 {
 472         reset_tod_clock();
 473         ipl_save_parameters();
 474         rescue_initrd();
 475         clear_bss_section();
 476         init_kernel_storage_key();
 477         lockdep_init();
 478         lockdep_off();
 479         setup_lowcore_early();
 480         setup_facility_list();
 481         detect_machine_type();
 482         ipl_update_parameters();
 483         setup_boot_command_line();
 484         create_kernel_nss();
 485         detect_mvpg();
 486         detect_ieee();
 487         detect_csp();
 488         detect_diag9c();
 489         detect_diag44();
 490         detect_machine_facilities();
 491         setup_topology();
 492         sclp_early_detect();
 493 #ifdef CONFIG_DYNAMIC_FTRACE
 494         S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
 495 #endif
 496         lockdep_on();
 497 }