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 unsigned long machine_flags;
  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_clock(&time) == 0)
  50                 return;
  51         /* TOD clock not running. Set the clock to Unix Epoch. */
  52         if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
  53                 disabled_wait(0);
  54
  55         sched_clock_base_cc = TOD_UNIX_EPOCH;
  56 }
  57
  58 #ifdef CONFIG_SHARED_KERNEL
  59 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
  60
  61 asm(
  62         "       .section .init.text,\"ax\",@progbits\n"
  63         "       .align  4\n"
  64         "       .type   savesys_ipl_nss, @function\n"
  65         "savesys_ipl_nss:\n"
  66 #ifdef CONFIG_64BIT
  67         "       stmg    6,15,48(15)\n"
  68         "       lgr     14,3\n"
  69         "       sam31\n"
  70         "       diag    2,14,0x8\n"
  71         "       sam64\n"
  72         "       lgr     2,14\n"
  73         "       lmg     6,15,48(15)\n"
  74 #else
  75         "       stm     6,15,24(15)\n"
  76         "       lr      14,3\n"
  77         "       diag    2,14,0x8\n"
  78         "       lr      2,14\n"
  79         "       lm      6,15,24(15)\n"
  80 #endif
  81         "       br      14\n"
  82         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\n");
  83
  84 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
  85
  86 static noinline __init void create_kernel_nss(void)
  87 {
  88         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
  89 #ifdef CONFIG_BLK_DEV_INITRD
  90         unsigned int sinitrd_pfn, einitrd_pfn;
  91 #endif
  92         int response;
  93         size_t len;
  94         char *savesys_ptr;
  95         char defsys_cmd[DEFSYS_CMD_SIZE];
  96         char savesys_cmd[SAVESYS_CMD_SIZE];
  97
  98         /* Do nothing if we are not running under VM */
  99         if (!MACHINE_IS_VM)
 100                 return;
 101
 102         /* Convert COMMAND_LINE to upper case */
 103         for (i = 0; i < strlen(boot_command_line); i++)
 104                 upper_command_line[i] = toupper(boot_command_line[i]);
 105
 106         savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 107
 108         if (!savesys_ptr)
 109                 return;
 110
 111         savesys_ptr += 8;    /* Point to the beginning of the NSS name */
 112         for (i = 0; i < NSS_NAME_SIZE; i++) {
 113                 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
 114                         break;
 115                 kernel_nss_name[i] = savesys_ptr[i];
 116         }
 117
 118         stext_pfn = PFN_DOWN(__pa(&_stext));
 119         eshared_pfn = PFN_DOWN(__pa(&_eshared));
 120         end_pfn = PFN_UP(__pa(&_end));
 121         min_size = end_pfn << 2;
 122
 123         sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 124                 kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
 125                 eshared_pfn, end_pfn);
 126
 127 #ifdef CONFIG_BLK_DEV_INITRD
 128         if (INITRD_START && INITRD_SIZE) {
 129                 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
 130                 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
 131                 min_size = einitrd_pfn << 2;
 132                 sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
 133                 sinitrd_pfn, einitrd_pfn);
 134         }
 135 #endif
 136
 137         sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
 138                 defsys_cmd, min_size);
 139         sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
 140                 kernel_nss_name, kernel_nss_name);
 141
 142         __cpcmd(defsys_cmd, NULL, 0, &response);
 143
 144         if (response != 0) {
 145                 kernel_nss_name[0] = '\0';
 146                 return;
 147         }
 148
 149         len = strlen(savesys_cmd);
 150         ASCEBC(savesys_cmd, len);
 151         response = savesys_ipl_nss(savesys_cmd, len);
 152
 153         /* On success: response is equal to the command size,
 154          *             max SAVESYS_CMD_SIZE
 155          * On error: response contains the numeric portion of cp error message.
 156          *           for SAVESYS it will be >= 263
 157          */
 158         if (response > SAVESYS_CMD_SIZE) {
 159                 kernel_nss_name[0] = '\0';
 160                 return;
 161         }
 162
 163         /* re-setup boot command line with new ipl vm parms */
 164         ipl_update_parameters();
 165         setup_boot_command_line();
 166
 167         ipl_flags = IPL_NSS_VALID;
 168 }
 169
 170 #else /* CONFIG_SHARED_KERNEL */
 171
 172 static inline void create_kernel_nss(void) { }
 173
 174 #endif /* CONFIG_SHARED_KERNEL */
 175
 176 /*
 177  * Clear bss memory
 178  */
 179 static noinline __init void clear_bss_section(void)
 180 {
 181         memset(__bss_start, 0, __bss_stop - __bss_start);
 182 }
 183
 184 /*
 185  * Initialize storage key for kernel pages
 186  */
 187 static noinline __init void init_kernel_storage_key(void)
 188 {
 189         unsigned long end_pfn, init_pfn;
 190
 191         end_pfn = PFN_UP(__pa(&_end));
 192
 193         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 194                 page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
 195 }
 196
 197 static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
 198
 199 static noinline __init void detect_machine_type(void)
 200 {
 201         /* No VM information? Looks like LPAR */
 202         if (stsi(&vmms, 3, 2, 2) == -ENOSYS)
 203                 return;
 204         if (!vmms.count)
 205                 return;
 206
 207         /* Running under KVM? If not we assume z/VM */
 208         if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
 209                 machine_flags |= MACHINE_FLAG_KVM;
 210         else
 211                 machine_flags |= MACHINE_FLAG_VM;
 212
 213         /* Store machine flags for setting up lowcore early */
 214         S390_lowcore.machine_flags = machine_flags;
 215 }
 216
 217 static __init void early_pgm_check_handler(void)
 218 {
 219         unsigned long addr;
 220         const struct exception_table_entry *fixup;
 221
 222         addr = S390_lowcore.program_old_psw.addr;
 223         fixup = search_exception_tables(addr & PSW_ADDR_INSN);
 224         if (!fixup)
 225                 disabled_wait(0);
 226         S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 227 }
 228
 229 static noinline __init void setup_lowcore_early(void)
 230 {
 231         psw_t psw;
 232
 233         psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
 234         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
 235         S390_lowcore.external_new_psw = psw;
 236         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 237         S390_lowcore.program_new_psw = psw;
 238         s390_base_pgm_handler_fn = early_pgm_check_handler;
 239 }
 240
 241 static noinline __init void setup_hpage(void)
 242 {
 243 #ifndef CONFIG_DEBUG_PAGEALLOC
 244         unsigned int facilities;
 245
 246         facilities = stfl();
 247         if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
 248                 return;
 249         machine_flags |= MACHINE_FLAG_HPAGE;
 250         __ctl_set_bit(0, 23);
 251 #endif
 252 }
 253
 254 static __init void detect_mvpg(void)
 255 {
 256 #ifndef CONFIG_64BIT
 257         int rc;
 258
 259         asm volatile(
 260                 "       la      0,0\n"
 261                 "       mvpg    %2,%2\n"
 262                 "0:     la      %0,0\n"
 263                 "1:\n"
 264                 EX_TABLE(0b,1b)
 265                 : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
 266         if (!rc)
 267                 machine_flags |= MACHINE_FLAG_MVPG;
 268 #endif
 269 }
 270
 271 static __init void detect_ieee(void)
 272 {
 273 #ifndef CONFIG_64BIT
 274         int rc, tmp;
 275
 276         asm volatile(
 277                 "       efpc    %1,0\n"
 278                 "0:     la      %0,0\n"
 279                 "1:\n"
 280                 EX_TABLE(0b,1b)
 281                 : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
 282         if (!rc)
 283                 machine_flags |= MACHINE_FLAG_IEEE;
 284 #endif
 285 }
 286
 287 static __init void detect_csp(void)
 288 {
 289 #ifndef CONFIG_64BIT
 290         int rc;
 291
 292         asm volatile(
 293                 "       la      0,0\n"
 294                 "       la      1,0\n"
 295                 "       la      2,4\n"
 296                 "       csp     0,2\n"
 297                 "0:     la      %0,0\n"
 298                 "1:\n"
 299                 EX_TABLE(0b,1b)
 300                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
 301         if (!rc)
 302                 machine_flags |= MACHINE_FLAG_CSP;
 303 #endif
 304 }
 305
 306 static __init void detect_diag9c(void)
 307 {
 308         unsigned int cpu_address;
 309         int rc;
 310
 311         cpu_address = stap();
 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                 machine_flags |= MACHINE_FLAG_DIAG9C;
 320 }
 321
 322 static __init void detect_diag44(void)
 323 {
 324 #ifdef CONFIG_64BIT
 325         int rc;
 326
 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                 machine_flags |= MACHINE_FLAG_DIAG44;
 335 #endif
 336 }
 337
 338 static __init void detect_machine_facilities(void)
 339 {
 340 #ifdef CONFIG_64BIT
 341         unsigned int facilities;
 342
 343         facilities = stfl();
 344         if (facilities & (1 << 28))
 345                 machine_flags |= MACHINE_FLAG_IDTE;
 346         if (facilities & (1 << 23))
 347                 machine_flags |= MACHINE_FLAG_PFMF;
 348         if (facilities & (1 << 4))
 349                 machine_flags |= MACHINE_FLAG_MVCOS;
 350 #endif
 351 }
 352
 353 static __init void rescue_initrd(void)
 354 {
 355 #ifdef CONFIG_BLK_DEV_INITRD
 356         /*
 357          * Move the initrd right behind the bss section in case it starts
 358          * within the bss section. So we don't overwrite it when the bss
 359          * section gets cleared.
 360          */
 361         if (!INITRD_START || !INITRD_SIZE)
 362                 return;
 363         if (INITRD_START >= (unsigned long) __bss_stop)
 364                 return;
 365         memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE);
 366         INITRD_START = (unsigned long) __bss_stop;
 367 #endif
 368 }
 369
 370 /* Set up boot command line */
 371 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 372 {
 373         char *parm, *delim;
 374         size_t rc, len;
 375
 376         len = strlen(boot_command_line);
 377
 378         delim = boot_command_line + len;        /* '\0' character position */
 379         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 380
 381         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 382         if (rc) {
 383                 if (*parm == '=')
 384                         memmove(boot_command_line, parm + 1, rc);
 385                 else
 386                         *delim = ' ';           /* replace '\0' with space */
 387         }
 388 }
 389
 390 static void __init setup_boot_command_line(void)
 391 {
 392         /* copy arch command line */
 393         strlcpy(boot_command_line, COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 394
 395         /* append IPL PARM data to the boot command line */
 396         if (MACHINE_IS_VM)
 397                 append_to_cmdline(append_ipl_vmparm);
 398
 399         append_to_cmdline(append_ipl_scpdata);
 400 }
 401
 402
 403 /*
 404  * Save ipl parameters, clear bss memory, initialize storage keys
 405  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 406  */
 407 void __init startup_init(void)
 408 {
 409         reset_tod_clock();
 410         ipl_save_parameters();
 411         rescue_initrd();
 412         clear_bss_section();
 413         init_kernel_storage_key();
 414         lockdep_init();
 415         lockdep_off();
 416         sort_main_extable();
 417         setup_lowcore_early();
 418         detect_machine_type();
 419         ipl_update_parameters();
 420         setup_boot_command_line();
 421         create_kernel_nss();
 422         detect_mvpg();
 423         detect_ieee();
 424         detect_csp();
 425         detect_diag9c();
 426         detect_diag44();
 427         detect_machine_facilities();
 428         setup_hpage();
 429         sclp_facilities_detect();
 430         detect_memory_layout(memory_chunk);
 431         S390_lowcore.machine_flags = machine_flags;
 432 #ifdef CONFIG_DYNAMIC_FTRACE
 433         S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
 434 #endif
 435         lockdep_on();
 436 }