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 #include <linux/compiler.h>
  10 #include <linux/init.h>
  11 #include <linux/errno.h>
  12 #include <linux/string.h>
  13 #include <linux/ctype.h>
  14 #include <linux/ftrace.h>
  15 #include <linux/lockdep.h>
  16 #include <linux/module.h>
  17 #include <linux/pfn.h>
  18 #include <linux/uaccess.h>
  19 #include <asm/ebcdic.h>
  20 #include <asm/ipl.h>
  21 #include <asm/lowcore.h>
  22 #include <asm/processor.h>
  23 #include <asm/sections.h>
  24 #include <asm/setup.h>
  25 #include <asm/sysinfo.h>
  26 #include <asm/cpcmd.h>
  27 #include <asm/sclp.h>
  28 #include "entry.h"
  29
  30 /*
  31  * Create a Kernel NSS if the SAVESYS= parameter is defined
  32  */
  33 #define DEFSYS_CMD_SIZE         128
  34 #define SAVESYS_CMD_SIZE        32
  35
  36 char kernel_nss_name[NSS_NAME_SIZE + 1];
  37
  38 static void __init setup_boot_command_line(void);
  39
  40 /*
  41  * Get the TOD clock running.
  42  */
  43 static void __init reset_tod_clock(void)
  44 {
  45         u64 time;
  46
  47         if (store_clock(&time) == 0)
  48                 return;
  49         /* TOD clock not running. Set the clock to Unix Epoch. */
  50         if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
  51                 disabled_wait(0);
  52
  53         sched_clock_base_cc = TOD_UNIX_EPOCH;
  54 }
  55
  56 #ifdef CONFIG_SHARED_KERNEL
  57 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
  58
  59 asm(
  60         "       .section .init.text,\"ax\",@progbits\n"
  61         "       .align  4\n"
  62         "       .type   savesys_ipl_nss, @function\n"
  63         "savesys_ipl_nss:\n"
  64 #ifdef CONFIG_64BIT
  65         "       stmg    6,15,48(15)\n"
  66         "       lgr     14,3\n"
  67         "       sam31\n"
  68         "       diag    2,14,0x8\n"
  69         "       sam64\n"
  70         "       lgr     2,14\n"
  71         "       lmg     6,15,48(15)\n"
  72 #else
  73         "       stm     6,15,24(15)\n"
  74         "       lr      14,3\n"
  75         "       diag    2,14,0x8\n"
  76         "       lr      2,14\n"
  77         "       lm      6,15,24(15)\n"
  78 #endif
  79         "       br      14\n"
  80         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\n");
  81
  82 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
  83
  84 static noinline __init void create_kernel_nss(void)
  85 {
  86         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
  87 #ifdef CONFIG_BLK_DEV_INITRD
  88         unsigned int sinitrd_pfn, einitrd_pfn;
  89 #endif
  90         int response;
  91         size_t len;
  92         char *savesys_ptr;
  93         char defsys_cmd[DEFSYS_CMD_SIZE];
  94         char savesys_cmd[SAVESYS_CMD_SIZE];
  95
  96         /* Do nothing if we are not running under VM */
  97         if (!MACHINE_IS_VM)
  98                 return;
  99
 100         /* Convert COMMAND_LINE to upper case */
 101         for (i = 0; i < strlen(boot_command_line); i++)
 102                 upper_command_line[i] = toupper(boot_command_line[i]);
 103
 104         savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 105
 106         if (!savesys_ptr)
 107                 return;
 108
 109         savesys_ptr += 8;    /* Point to the beginning of the NSS name */
 110         for (i = 0; i < NSS_NAME_SIZE; i++) {
 111                 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
 112                         break;
 113                 kernel_nss_name[i] = savesys_ptr[i];
 114         }
 115
 116         stext_pfn = PFN_DOWN(__pa(&_stext));
 117         eshared_pfn = PFN_DOWN(__pa(&_eshared));
 118         end_pfn = PFN_UP(__pa(&_end));
 119         min_size = end_pfn << 2;
 120
 121         sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 122                 kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
 123                 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                 sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
 131                 sinitrd_pfn, einitrd_pfn);
 132         }
 133 #endif
 134
 135         sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
 136                 defsys_cmd, min_size);
 137         sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
 138                 kernel_nss_name, kernel_nss_name);
 139
 140         __cpcmd(defsys_cmd, NULL, 0, &response);
 141
 142         if (response != 0) {
 143                 kernel_nss_name[0] = '\0';
 144                 return;
 145         }
 146
 147         len = strlen(savesys_cmd);
 148         ASCEBC(savesys_cmd, len);
 149         response = savesys_ipl_nss(savesys_cmd, len);
 150
 151         /* On success: response is equal to the command size,
 152          *             max SAVESYS_CMD_SIZE
 153          * On error: response contains the numeric portion of cp error message.
 154          *           for SAVESYS it will be >= 263
 155          */
 156         if (response > SAVESYS_CMD_SIZE) {
 157                 kernel_nss_name[0] = '\0';
 158                 return;
 159         }
 160
 161         /* re-setup boot command line with new ipl vm parms */
 162         ipl_update_parameters();
 163         setup_boot_command_line();
 164
 165         ipl_flags = IPL_NSS_VALID;
 166 }
 167
 168 #else /* CONFIG_SHARED_KERNEL */
 169
 170 static inline void create_kernel_nss(void) { }
 171
 172 #endif /* CONFIG_SHARED_KERNEL */
 173
 174 /*
 175  * Clear bss memory
 176  */
 177 static noinline __init void clear_bss_section(void)
 178 {
 179         memset(__bss_start, 0, __bss_stop - __bss_start);
 180 }
 181
 182 /*
 183  * Initialize storage key for kernel pages
 184  */
 185 static noinline __init void init_kernel_storage_key(void)
 186 {
 187         unsigned long end_pfn, init_pfn;
 188
 189         end_pfn = PFN_UP(__pa(&_end));
 190
 191         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 192                 page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
 193 }
 194
 195 static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
 196
 197 static noinline __init void detect_machine_type(void)
 198 {
 199         /* No VM information? Looks like LPAR */
 200         if (stsi(&vmms, 3, 2, 2) == -ENOSYS)
 201                 return;
 202         if (!vmms.count)
 203                 return;
 204
 205         /* Running under KVM? If not we assume z/VM */
 206         if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
 207                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 208         else
 209                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 210 }
 211
 212 static __init void early_pgm_check_handler(void)
 213 {
 214         unsigned long addr;
 215         const struct exception_table_entry *fixup;
 216
 217         addr = S390_lowcore.program_old_psw.addr;
 218         fixup = search_exception_tables(addr & PSW_ADDR_INSN);
 219         if (!fixup)
 220                 disabled_wait(0);
 221         S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 222 }
 223
 224 static noinline __init void setup_lowcore_early(void)
 225 {
 226         psw_t psw;
 227
 228         psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
 229         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
 230         S390_lowcore.external_new_psw = psw;
 231         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 232         S390_lowcore.program_new_psw = psw;
 233         s390_base_pgm_handler_fn = early_pgm_check_handler;
 234 }
 235
 236 static noinline __init void setup_hpage(void)
 237 {
 238 #ifndef CONFIG_DEBUG_PAGEALLOC
 239         unsigned int facilities;
 240
 241         facilities = stfl();
 242         if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
 243                 return;
 244         S390_lowcore.machine_flags |= MACHINE_FLAG_HPAGE;
 245         __ctl_set_bit(0, 23);
 246 #endif
 247 }
 248
 249 static __init void detect_mvpg(void)
 250 {
 251 #ifndef CONFIG_64BIT
 252         int rc;
 253
 254         asm volatile(
 255                 "       la      0,0\n"
 256                 "       mvpg    %2,%2\n"
 257                 "0:     la      %0,0\n"
 258                 "1:\n"
 259                 EX_TABLE(0b,1b)
 260                 : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
 261         if (!rc)
 262                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
 263 #endif
 264 }
 265
 266 static __init void detect_ieee(void)
 267 {
 268 #ifndef CONFIG_64BIT
 269         int rc, tmp;
 270
 271         asm volatile(
 272                 "       efpc    %1,0\n"
 273                 "0:     la      %0,0\n"
 274                 "1:\n"
 275                 EX_TABLE(0b,1b)
 276                 : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
 277         if (!rc)
 278                 S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
 279 #endif
 280 }
 281
 282 static __init void detect_csp(void)
 283 {
 284 #ifndef CONFIG_64BIT
 285         int rc;
 286
 287         asm volatile(
 288                 "       la      0,0\n"
 289                 "       la      1,0\n"
 290                 "       la      2,4\n"
 291                 "       csp     0,2\n"
 292                 "0:     la      %0,0\n"
 293                 "1:\n"
 294                 EX_TABLE(0b,1b)
 295                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
 296         if (!rc)
 297                 S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
 298 #endif
 299 }
 300
 301 static __init void detect_diag9c(void)
 302 {
 303         unsigned int cpu_address;
 304         int rc;
 305
 306         cpu_address = stap();
 307         asm volatile(
 308                 "       diag    %2,0,0x9c\n"
 309                 "0:     la      %0,0\n"
 310                 "1:\n"
 311                 EX_TABLE(0b,1b)
 312                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 313         if (!rc)
 314                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 315 }
 316
 317 static __init void detect_diag44(void)
 318 {
 319 #ifdef CONFIG_64BIT
 320         int rc;
 321
 322         asm volatile(
 323                 "       diag    0,0,0x44\n"
 324                 "0:     la      %0,0\n"
 325                 "1:\n"
 326                 EX_TABLE(0b,1b)
 327                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 328         if (!rc)
 329                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 330 #endif
 331 }
 332
 333 static __init void detect_machine_facilities(void)
 334 {
 335 #ifdef CONFIG_64BIT
 336         unsigned int facilities;
 337
 338         facilities = stfl();
 339         if (facilities & (1 << 28))
 340                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 341         if (facilities & (1 << 23))
 342                 S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
 343         if (facilities & (1 << 4))
 344                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
 345 #endif
 346 }
 347
 348 static __init void rescue_initrd(void)
 349 {
 350 #ifdef CONFIG_BLK_DEV_INITRD
 351         /*
 352          * Move the initrd right behind the bss section in case it starts
 353          * within the bss section. So we don't overwrite it when the bss
 354          * section gets cleared.
 355          */
 356         if (!INITRD_START || !INITRD_SIZE)
 357                 return;
 358         if (INITRD_START >= (unsigned long) __bss_stop)
 359                 return;
 360         memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE);
 361         INITRD_START = (unsigned long) __bss_stop;
 362 #endif
 363 }
 364
 365 /* Set up boot command line */
 366 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 367 {
 368         char *parm, *delim;
 369         size_t rc, len;
 370
 371         len = strlen(boot_command_line);
 372
 373         delim = boot_command_line + len;        /* '\0' character position */
 374         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 375
 376         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 377         if (rc) {
 378                 if (*parm == '=')
 379                         memmove(boot_command_line, parm + 1, rc);
 380                 else
 381                         *delim = ' ';           /* replace '\0' with space */
 382         }
 383 }
 384
 385 static void __init setup_boot_command_line(void)
 386 {
 387         /* copy arch command line */
 388         strlcpy(boot_command_line, COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 389
 390         /* append IPL PARM data to the boot command line */
 391         if (MACHINE_IS_VM)
 392                 append_to_cmdline(append_ipl_vmparm);
 393
 394         append_to_cmdline(append_ipl_scpdata);
 395 }
 396
 397
 398 /*
 399  * Save ipl parameters, clear bss memory, initialize storage keys
 400  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 401  */
 402 void __init startup_init(void)
 403 {
 404         reset_tod_clock();
 405         ipl_save_parameters();
 406         rescue_initrd();
 407         clear_bss_section();
 408         init_kernel_storage_key();
 409         lockdep_init();
 410         lockdep_off();
 411         sort_main_extable();
 412         setup_lowcore_early();
 413         detect_machine_type();
 414         ipl_update_parameters();
 415         setup_boot_command_line();
 416         create_kernel_nss();
 417         detect_mvpg();
 418         detect_ieee();
 419         detect_csp();
 420         detect_diag9c();
 421         detect_diag44();
 422         detect_machine_facilities();
 423         setup_hpage();
 424         sclp_facilities_detect();
 425         detect_memory_layout(memory_chunk);
 426 #ifdef CONFIG_DYNAMIC_FTRACE
 427         S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
 428 #endif
 429         lockdep_on();
 430 }