arch/s390/kernel/early.c

   1 /*
   2  *  arch/s390/kernel/early.c
   3  *
   4  *    Copyright IBM Corp. 2007, 2009
   5  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
   6  *               Heiko Carstens <heiko.carstens@de.ibm.com>
   7  */
   8
   9 #define KMSG_COMPONENT "setup"
  10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  11
  12 #include <linux/compiler.h>
  13 #include <linux/init.h>
  14 #include <linux/errno.h>
  15 #include <linux/string.h>
  16 #include <linux/ctype.h>
  17 #include <linux/ftrace.h>
  18 #include <linux/lockdep.h>
  19 #include <linux/module.h>
  20 #include <linux/pfn.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/kernel.h>
  23 #include <asm/ebcdic.h>
  24 #include <asm/ipl.h>
  25 #include <asm/lowcore.h>
  26 #include <asm/processor.h>
  27 #include <asm/sections.h>
  28 #include <asm/setup.h>
  29 #include <asm/sysinfo.h>
  30 #include <asm/cpcmd.h>
  31 #include <asm/sclp.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_clock(&time) == 0)
  52                 return;
  53         /* TOD clock not running. Set the clock to Unix Epoch. */
  54         if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
  55                 disabled_wait(0);
  56
  57         sched_clock_base_cc = TOD_UNIX_EPOCH;
  58         S390_lowcore.last_update_clock = sched_clock_base_cc;
  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 #ifdef CONFIG_64BIT
  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 #else
  78         "       stm     6,15,24(15)\n"
  79         "       lr      14,3\n"
  80         "       diag    2,14,0x8\n"
  81         "       lr      2,14\n"
  82         "       lm      6,15,24(15)\n"
  83 #endif
  84         "       br      14\n"
  85         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\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         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         sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 127                 kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
 128                 eshared_pfn, end_pfn);
 129
 130 #ifdef CONFIG_BLK_DEV_INITRD
 131         if (INITRD_START && INITRD_SIZE) {
 132                 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
 133                 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
 134                 min_size = einitrd_pfn << 2;
 135                 sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
 136                 sinitrd_pfn, einitrd_pfn);
 137         }
 138 #endif
 139
 140         sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
 141                 defsys_cmd, min_size);
 142         sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
 143                 kernel_nss_name, kernel_nss_name);
 144
 145         __cpcmd(defsys_cmd, NULL, 0, &response);
 146
 147         if (response != 0) {
 148                 pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
 149                         response);
 150                 kernel_nss_name[0] = '\0';
 151                 return;
 152         }
 153
 154         len = strlen(savesys_cmd);
 155         ASCEBC(savesys_cmd, len);
 156         response = savesys_ipl_nss(savesys_cmd, len);
 157
 158         /* On success: response is equal to the command size,
 159          *             max SAVESYS_CMD_SIZE
 160          * On error: response contains the numeric portion of cp error message.
 161          *           for SAVESYS it will be >= 263
 162          *           for missing privilege class, it will be 1
 163          */
 164         if (response > SAVESYS_CMD_SIZE || response == 1) {
 165                 pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
 166                         response);
 167                 kernel_nss_name[0] = '\0';
 168                 return;
 169         }
 170
 171         /* re-initialize cputime accounting. */
 172         sched_clock_base_cc = get_clock();
 173         S390_lowcore.last_update_clock = sched_clock_base_cc;
 174         S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
 175         S390_lowcore.user_timer = 0;
 176         S390_lowcore.system_timer = 0;
 177         asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
 178
 179         /* re-setup boot command line with new ipl vm parms */
 180         ipl_update_parameters();
 181         setup_boot_command_line();
 182
 183         ipl_flags = IPL_NSS_VALID;
 184 }
 185
 186 #else /* CONFIG_SHARED_KERNEL */
 187
 188 static inline void create_kernel_nss(void) { }
 189
 190 #endif /* CONFIG_SHARED_KERNEL */
 191
 192 /*
 193  * Clear bss memory
 194  */
 195 static noinline __init void clear_bss_section(void)
 196 {
 197         memset(__bss_start, 0, __bss_stop - __bss_start);
 198 }
 199
 200 /*
 201  * Initialize storage key for kernel pages
 202  */
 203 static noinline __init void init_kernel_storage_key(void)
 204 {
 205         unsigned long end_pfn, init_pfn;
 206
 207         end_pfn = PFN_UP(__pa(&_end));
 208
 209         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 210                 page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
 211 }
 212
 213 static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
 214
 215 static noinline __init void detect_machine_type(void)
 216 {
 217         /* Check current-configuration-level */
 218         if ((stsi(NULL, 0, 0, 0) >> 28) <= 2) {
 219                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 220                 return;
 221         }
 222         /* Get virtual-machine cpu information. */
 223         if (stsi(&vmms, 3, 2, 2) == -ENOSYS || !vmms.count)
 224                 return;
 225
 226         /* Running under KVM? If not we assume z/VM */
 227         if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
 228                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 229         else
 230                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 231 }
 232
 233 static __init void early_pgm_check_handler(void)
 234 {
 235         unsigned long addr;
 236         const struct exception_table_entry *fixup;
 237
 238         addr = S390_lowcore.program_old_psw.addr;
 239         fixup = search_exception_tables(addr & PSW_ADDR_INSN);
 240         if (!fixup)
 241                 disabled_wait(0);
 242         S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 243 }
 244
 245 static noinline __init void setup_lowcore_early(void)
 246 {
 247         psw_t psw;
 248
 249         psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
 250         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
 251         S390_lowcore.external_new_psw = psw;
 252         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 253         S390_lowcore.program_new_psw = psw;
 254         s390_base_pgm_handler_fn = early_pgm_check_handler;
 255 }
 256
 257 static noinline __init void setup_hpage(void)
 258 {
 259 #ifndef CONFIG_DEBUG_PAGEALLOC
 260         unsigned int facilities;
 261
 262         facilities = stfl();
 263         if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
 264                 return;
 265         S390_lowcore.machine_flags |= MACHINE_FLAG_HPAGE;
 266         __ctl_set_bit(0, 23);
 267 #endif
 268 }
 269
 270 static __init void detect_mvpg(void)
 271 {
 272 #ifndef CONFIG_64BIT
 273         int rc;
 274
 275         asm volatile(
 276                 "       la      0,0\n"
 277                 "       mvpg    %2,%2\n"
 278                 "0:     la      %0,0\n"
 279                 "1:\n"
 280                 EX_TABLE(0b,1b)
 281                 : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
 282         if (!rc)
 283                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
 284 #endif
 285 }
 286
 287 static __init void detect_ieee(void)
 288 {
 289 #ifndef CONFIG_64BIT
 290         int rc, tmp;
 291
 292         asm volatile(
 293                 "       efpc    %1,0\n"
 294                 "0:     la      %0,0\n"
 295                 "1:\n"
 296                 EX_TABLE(0b,1b)
 297                 : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
 298         if (!rc)
 299                 S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
 300 #endif
 301 }
 302
 303 static __init void detect_csp(void)
 304 {
 305 #ifndef CONFIG_64BIT
 306         int rc;
 307
 308         asm volatile(
 309                 "       la      0,0\n"
 310                 "       la      1,0\n"
 311                 "       la      2,4\n"
 312                 "       csp     0,2\n"
 313                 "0:     la      %0,0\n"
 314                 "1:\n"
 315                 EX_TABLE(0b,1b)
 316                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
 317         if (!rc)
 318                 S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
 319 #endif
 320 }
 321
 322 static __init void detect_diag9c(void)
 323 {
 324         unsigned int cpu_address;
 325         int rc;
 326
 327         cpu_address = stap();
 328         asm volatile(
 329                 "       diag    %2,0,0x9c\n"
 330                 "0:     la      %0,0\n"
 331                 "1:\n"
 332                 EX_TABLE(0b,1b)
 333                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 334         if (!rc)
 335                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 336 }
 337
 338 static __init void detect_diag44(void)
 339 {
 340 #ifdef CONFIG_64BIT
 341         int rc;
 342
 343         asm volatile(
 344                 "       diag    0,0,0x44\n"
 345                 "0:     la      %0,0\n"
 346                 "1:\n"
 347                 EX_TABLE(0b,1b)
 348                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 349         if (!rc)
 350                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 351 #endif
 352 }
 353
 354 static __init void detect_machine_facilities(void)
 355 {
 356 #ifdef CONFIG_64BIT
 357         unsigned int facilities;
 358
 359         facilities = stfl();
 360         if (facilities & (1 << 28))
 361                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 362         if (facilities & (1 << 23))
 363                 S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
 364         if (facilities & (1 << 4))
 365                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
 366 #endif
 367 }
 368
 369 static __init void rescue_initrd(void)
 370 {
 371 #ifdef CONFIG_BLK_DEV_INITRD
 372         /*
 373          * Move the initrd right behind the bss section in case it starts
 374          * within the bss section. So we don't overwrite it when the bss
 375          * section gets cleared.
 376          */
 377         if (!INITRD_START || !INITRD_SIZE)
 378                 return;
 379         if (INITRD_START >= (unsigned long) __bss_stop)
 380                 return;
 381         memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE);
 382         INITRD_START = (unsigned long) __bss_stop;
 383 #endif
 384 }
 385
 386 /* Set up boot command line */
 387 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 388 {
 389         char *parm, *delim;
 390         size_t rc, len;
 391
 392         len = strlen(boot_command_line);
 393
 394         delim = boot_command_line + len;        /* '\0' character position */
 395         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 396
 397         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 398         if (rc) {
 399                 if (*parm == '=')
 400                         memmove(boot_command_line, parm + 1, rc);
 401                 else
 402                         *delim = ' ';           /* replace '\0' with space */
 403         }
 404 }
 405
 406 static void __init setup_boot_command_line(void)
 407 {
 408         int i;
 409
 410         /* convert arch command line to ascii */
 411         for (i = 0; i < ARCH_COMMAND_LINE_SIZE; i++)
 412                 if (COMMAND_LINE[i] & 0x80)
 413                         break;
 414         if (i < ARCH_COMMAND_LINE_SIZE)
 415                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 416         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE-1] = 0;
 417
 418         /* copy arch command line */
 419         strlcpy(boot_command_line, strstrip(COMMAND_LINE),
 420                 ARCH_COMMAND_LINE_SIZE);
 421
 422         /* append IPL PARM data to the boot command line */
 423         if (MACHINE_IS_VM)
 424                 append_to_cmdline(append_ipl_vmparm);
 425
 426         append_to_cmdline(append_ipl_scpdata);
 427 }
 428
 429
 430 /*
 431  * Save ipl parameters, clear bss memory, initialize storage keys
 432  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 433  */
 434 void __init startup_init(void)
 435 {
 436         reset_tod_clock();
 437         ipl_save_parameters();
 438         rescue_initrd();
 439         clear_bss_section();
 440         init_kernel_storage_key();
 441         lockdep_init();
 442         lockdep_off();
 443         sort_main_extable();
 444         setup_lowcore_early();
 445         detect_machine_type();
 446         ipl_update_parameters();
 447         setup_boot_command_line();
 448         create_kernel_nss();
 449         detect_mvpg();
 450         detect_ieee();
 451         detect_csp();
 452         detect_diag9c();
 453         detect_diag44();
 454         detect_machine_facilities();
 455         setup_hpage();
 456         sclp_facilities_detect();
 457         detect_memory_layout(memory_chunk);
 458 #ifdef CONFIG_DYNAMIC_FTRACE
 459         S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
 460 #endif
 461         lockdep_on();
 462 }