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         /* No VM information? Looks like LPAR */
 218         if (stsi(&vmms, 3, 2, 2) == -ENOSYS)
 219                 return;
 220         if (!vmms.count)
 221                 return;
 222
 223         /* Running under KVM? If not we assume z/VM */
 224         if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
 225                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 226         else
 227                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 228 }
 229
 230 static __init void early_pgm_check_handler(void)
 231 {
 232         unsigned long addr;
 233         const struct exception_table_entry *fixup;
 234
 235         addr = S390_lowcore.program_old_psw.addr;
 236         fixup = search_exception_tables(addr & PSW_ADDR_INSN);
 237         if (!fixup)
 238                 disabled_wait(0);
 239         S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 240 }
 241
 242 static noinline __init void setup_lowcore_early(void)
 243 {
 244         psw_t psw;
 245
 246         psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
 247         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
 248         S390_lowcore.external_new_psw = psw;
 249         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 250         S390_lowcore.program_new_psw = psw;
 251         s390_base_pgm_handler_fn = early_pgm_check_handler;
 252 }
 253
 254 static noinline __init void setup_hpage(void)
 255 {
 256 #ifndef CONFIG_DEBUG_PAGEALLOC
 257         unsigned int facilities;
 258
 259         facilities = stfl();
 260         if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
 261                 return;
 262         S390_lowcore.machine_flags |= MACHINE_FLAG_HPAGE;
 263         __ctl_set_bit(0, 23);
 264 #endif
 265 }
 266
 267 static __init void detect_mvpg(void)
 268 {
 269 #ifndef CONFIG_64BIT
 270         int rc;
 271
 272         asm volatile(
 273                 "       la      0,0\n"
 274                 "       mvpg    %2,%2\n"
 275                 "0:     la      %0,0\n"
 276                 "1:\n"
 277                 EX_TABLE(0b,1b)
 278                 : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
 279         if (!rc)
 280                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
 281 #endif
 282 }
 283
 284 static __init void detect_ieee(void)
 285 {
 286 #ifndef CONFIG_64BIT
 287         int rc, tmp;
 288
 289         asm volatile(
 290                 "       efpc    %1,0\n"
 291                 "0:     la      %0,0\n"
 292                 "1:\n"
 293                 EX_TABLE(0b,1b)
 294                 : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
 295         if (!rc)
 296                 S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
 297 #endif
 298 }
 299
 300 static __init void detect_csp(void)
 301 {
 302 #ifndef CONFIG_64BIT
 303         int rc;
 304
 305         asm volatile(
 306                 "       la      0,0\n"
 307                 "       la      1,0\n"
 308                 "       la      2,4\n"
 309                 "       csp     0,2\n"
 310                 "0:     la      %0,0\n"
 311                 "1:\n"
 312                 EX_TABLE(0b,1b)
 313                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
 314         if (!rc)
 315                 S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
 316 #endif
 317 }
 318
 319 static __init void detect_diag9c(void)
 320 {
 321         unsigned int cpu_address;
 322         int rc;
 323
 324         cpu_address = stap();
 325         asm volatile(
 326                 "       diag    %2,0,0x9c\n"
 327                 "0:     la      %0,0\n"
 328                 "1:\n"
 329                 EX_TABLE(0b,1b)
 330                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 331         if (!rc)
 332                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 333 }
 334
 335 static __init void detect_diag44(void)
 336 {
 337 #ifdef CONFIG_64BIT
 338         int rc;
 339
 340         asm volatile(
 341                 "       diag    0,0,0x44\n"
 342                 "0:     la      %0,0\n"
 343                 "1:\n"
 344                 EX_TABLE(0b,1b)
 345                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 346         if (!rc)
 347                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 348 #endif
 349 }
 350
 351 static __init void detect_machine_facilities(void)
 352 {
 353 #ifdef CONFIG_64BIT
 354         unsigned int facilities;
 355
 356         facilities = stfl();
 357         if (facilities & (1 << 28))
 358                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 359         if (facilities & (1 << 23))
 360                 S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
 361         if (facilities & (1 << 4))
 362                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
 363 #endif
 364 }
 365
 366 static __init void rescue_initrd(void)
 367 {
 368 #ifdef CONFIG_BLK_DEV_INITRD
 369         /*
 370          * Move the initrd right behind the bss section in case it starts
 371          * within the bss section. So we don't overwrite it when the bss
 372          * section gets cleared.
 373          */
 374         if (!INITRD_START || !INITRD_SIZE)
 375                 return;
 376         if (INITRD_START >= (unsigned long) __bss_stop)
 377                 return;
 378         memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE);
 379         INITRD_START = (unsigned long) __bss_stop;
 380 #endif
 381 }
 382
 383 /* Set up boot command line */
 384 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 385 {
 386         char *parm, *delim;
 387         size_t rc, len;
 388
 389         len = strlen(boot_command_line);
 390
 391         delim = boot_command_line + len;        /* '\0' character position */
 392         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 393
 394         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 395         if (rc) {
 396                 if (*parm == '=')
 397                         memmove(boot_command_line, parm + 1, rc);
 398                 else
 399                         *delim = ' ';           /* replace '\0' with space */
 400         }
 401 }
 402
 403 static void __init setup_boot_command_line(void)
 404 {
 405         /* copy arch command line */
 406         strlcpy(boot_command_line, COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 407
 408         /* append IPL PARM data to the boot command line */
 409         if (MACHINE_IS_VM)
 410                 append_to_cmdline(append_ipl_vmparm);
 411
 412         append_to_cmdline(append_ipl_scpdata);
 413 }
 414
 415
 416 /*
 417  * Save ipl parameters, clear bss memory, initialize storage keys
 418  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 419  */
 420 void __init startup_init(void)
 421 {
 422         reset_tod_clock();
 423         ipl_save_parameters();
 424         rescue_initrd();
 425         clear_bss_section();
 426         init_kernel_storage_key();
 427         lockdep_init();
 428         lockdep_off();
 429         sort_main_extable();
 430         setup_lowcore_early();
 431         detect_machine_type();
 432         ipl_update_parameters();
 433         setup_boot_command_line();
 434         create_kernel_nss();
 435         detect_mvpg();
 436         detect_ieee();
 437         detect_csp();
 438         detect_diag9c();
 439         detect_diag44();
 440         detect_machine_facilities();
 441         setup_hpage();
 442         sclp_facilities_detect();
 443         detect_memory_layout(memory_chunk);
 444 #ifdef CONFIG_DYNAMIC_FTRACE
 445         S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
 446 #endif
 447         lockdep_on();
 448 }