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 }
  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
  86 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
  87
  88 static noinline __init void create_kernel_nss(void)
  89 {
  90         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
  91 #ifdef CONFIG_BLK_DEV_INITRD
  92         unsigned int sinitrd_pfn, einitrd_pfn;
  93 #endif
  94         int response;
  95         size_t len;
  96         char *savesys_ptr;
  97         char defsys_cmd[DEFSYS_CMD_SIZE];
  98         char savesys_cmd[SAVESYS_CMD_SIZE];
  99
 100         /* Do nothing if we are not running under VM */
 101         if (!MACHINE_IS_VM)
 102                 return;
 103
 104         /* Convert COMMAND_LINE to upper case */
 105         for (i = 0; i < strlen(boot_command_line); i++)
 106                 upper_command_line[i] = toupper(boot_command_line[i]);
 107
 108         savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 109
 110         if (!savesys_ptr)
 111                 return;
 112
 113         savesys_ptr += 8;    /* Point to the beginning of the NSS name */
 114         for (i = 0; i < NSS_NAME_SIZE; i++) {
 115                 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
 116                         break;
 117                 kernel_nss_name[i] = savesys_ptr[i];
 118         }
 119
 120         stext_pfn = PFN_DOWN(__pa(&_stext));
 121         eshared_pfn = PFN_DOWN(__pa(&_eshared));
 122         end_pfn = PFN_UP(__pa(&_end));
 123         min_size = end_pfn << 2;
 124
 125         sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 126                 kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
 127                 eshared_pfn, end_pfn);
 128
 129 #ifdef CONFIG_BLK_DEV_INITRD
 130         if (INITRD_START && INITRD_SIZE) {
 131                 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
 132                 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
 133                 min_size = einitrd_pfn << 2;
 134                 sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
 135                 sinitrd_pfn, einitrd_pfn);
 136         }
 137 #endif
 138
 139         sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
 140                 defsys_cmd, min_size);
 141         sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
 142                 kernel_nss_name, kernel_nss_name);
 143
 144         __cpcmd(defsys_cmd, NULL, 0, &response);
 145
 146         if (response != 0) {
 147                 pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
 148                         response);
 149                 kernel_nss_name[0] = '\0';
 150                 return;
 151         }
 152
 153         len = strlen(savesys_cmd);
 154         ASCEBC(savesys_cmd, len);
 155         response = savesys_ipl_nss(savesys_cmd, len);
 156
 157         /* On success: response is equal to the command size,
 158          *             max SAVESYS_CMD_SIZE
 159          * On error: response contains the numeric portion of cp error message.
 160          *           for SAVESYS it will be >= 263
 161          *           for missing privilege class, it will be 1
 162          */
 163         if (response > SAVESYS_CMD_SIZE || response == 1) {
 164                 pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
 165                         response);
 166                 kernel_nss_name[0] = '\0';
 167                 return;
 168         }
 169
 170         /* re-setup boot command line with new ipl vm parms */
 171         ipl_update_parameters();
 172         setup_boot_command_line();
 173
 174         ipl_flags = IPL_NSS_VALID;
 175 }
 176
 177 #else /* CONFIG_SHARED_KERNEL */
 178
 179 static inline void create_kernel_nss(void) { }
 180
 181 #endif /* CONFIG_SHARED_KERNEL */
 182
 183 /*
 184  * Clear bss memory
 185  */
 186 static noinline __init void clear_bss_section(void)
 187 {
 188         memset(__bss_start, 0, __bss_stop - __bss_start);
 189 }
 190
 191 /*
 192  * Initialize storage key for kernel pages
 193  */
 194 static noinline __init void init_kernel_storage_key(void)
 195 {
 196         unsigned long end_pfn, init_pfn;
 197
 198         end_pfn = PFN_UP(__pa(&_end));
 199
 200         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 201                 page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
 202 }
 203
 204 static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
 205
 206 static noinline __init void detect_machine_type(void)
 207 {
 208         /* No VM information? Looks like LPAR */
 209         if (stsi(&vmms, 3, 2, 2) == -ENOSYS)
 210                 return;
 211         if (!vmms.count)
 212                 return;
 213
 214         /* Running under KVM? If not we assume z/VM */
 215         if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
 216                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 217         else
 218                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 219 }
 220
 221 static __init void early_pgm_check_handler(void)
 222 {
 223         unsigned long addr;
 224         const struct exception_table_entry *fixup;
 225
 226         addr = S390_lowcore.program_old_psw.addr;
 227         fixup = search_exception_tables(addr & PSW_ADDR_INSN);
 228         if (!fixup)
 229                 disabled_wait(0);
 230         S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 231 }
 232
 233 static noinline __init void setup_lowcore_early(void)
 234 {
 235         psw_t psw;
 236
 237         psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
 238         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
 239         S390_lowcore.external_new_psw = psw;
 240         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 241         S390_lowcore.program_new_psw = psw;
 242         s390_base_pgm_handler_fn = early_pgm_check_handler;
 243 }
 244
 245 static noinline __init void setup_hpage(void)
 246 {
 247 #ifndef CONFIG_DEBUG_PAGEALLOC
 248         unsigned int facilities;
 249
 250         facilities = stfl();
 251         if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
 252                 return;
 253         S390_lowcore.machine_flags |= MACHINE_FLAG_HPAGE;
 254         __ctl_set_bit(0, 23);
 255 #endif
 256 }
 257
 258 static __init void detect_mvpg(void)
 259 {
 260 #ifndef CONFIG_64BIT
 261         int rc;
 262
 263         asm volatile(
 264                 "       la      0,0\n"
 265                 "       mvpg    %2,%2\n"
 266                 "0:     la      %0,0\n"
 267                 "1:\n"
 268                 EX_TABLE(0b,1b)
 269                 : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
 270         if (!rc)
 271                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
 272 #endif
 273 }
 274
 275 static __init void detect_ieee(void)
 276 {
 277 #ifndef CONFIG_64BIT
 278         int rc, tmp;
 279
 280         asm volatile(
 281                 "       efpc    %1,0\n"
 282                 "0:     la      %0,0\n"
 283                 "1:\n"
 284                 EX_TABLE(0b,1b)
 285                 : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
 286         if (!rc)
 287                 S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
 288 #endif
 289 }
 290
 291 static __init void detect_csp(void)
 292 {
 293 #ifndef CONFIG_64BIT
 294         int rc;
 295
 296         asm volatile(
 297                 "       la      0,0\n"
 298                 "       la      1,0\n"
 299                 "       la      2,4\n"
 300                 "       csp     0,2\n"
 301                 "0:     la      %0,0\n"
 302                 "1:\n"
 303                 EX_TABLE(0b,1b)
 304                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
 305         if (!rc)
 306                 S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
 307 #endif
 308 }
 309
 310 static __init void detect_diag9c(void)
 311 {
 312         unsigned int cpu_address;
 313         int rc;
 314
 315         cpu_address = stap();
 316         asm volatile(
 317                 "       diag    %2,0,0x9c\n"
 318                 "0:     la      %0,0\n"
 319                 "1:\n"
 320                 EX_TABLE(0b,1b)
 321                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 322         if (!rc)
 323                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 324 }
 325
 326 static __init void detect_diag44(void)
 327 {
 328 #ifdef CONFIG_64BIT
 329         int rc;
 330
 331         asm volatile(
 332                 "       diag    0,0,0x44\n"
 333                 "0:     la      %0,0\n"
 334                 "1:\n"
 335                 EX_TABLE(0b,1b)
 336                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 337         if (!rc)
 338                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 339 #endif
 340 }
 341
 342 static __init void detect_machine_facilities(void)
 343 {
 344 #ifdef CONFIG_64BIT
 345         unsigned int facilities;
 346
 347         facilities = stfl();
 348         if (facilities & (1 << 28))
 349                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 350         if (facilities & (1 << 23))
 351                 S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
 352         if (facilities & (1 << 4))
 353                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
 354 #endif
 355 }
 356
 357 static __init void rescue_initrd(void)
 358 {
 359 #ifdef CONFIG_BLK_DEV_INITRD
 360         /*
 361          * Move the initrd right behind the bss section in case it starts
 362          * within the bss section. So we don't overwrite it when the bss
 363          * section gets cleared.
 364          */
 365         if (!INITRD_START || !INITRD_SIZE)
 366                 return;
 367         if (INITRD_START >= (unsigned long) __bss_stop)
 368                 return;
 369         memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE);
 370         INITRD_START = (unsigned long) __bss_stop;
 371 #endif
 372 }
 373
 374 /* Set up boot command line */
 375 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 376 {
 377         char *parm, *delim;
 378         size_t rc, len;
 379
 380         len = strlen(boot_command_line);
 381
 382         delim = boot_command_line + len;        /* '\0' character position */
 383         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 384
 385         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 386         if (rc) {
 387                 if (*parm == '=')
 388                         memmove(boot_command_line, parm + 1, rc);
 389                 else
 390                         *delim = ' ';           /* replace '\0' with space */
 391         }
 392 }
 393
 394 static void __init setup_boot_command_line(void)
 395 {
 396         /* copy arch command line */
 397         strlcpy(boot_command_line, COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 398
 399         /* append IPL PARM data to the boot command line */
 400         if (MACHINE_IS_VM)
 401                 append_to_cmdline(append_ipl_vmparm);
 402
 403         append_to_cmdline(append_ipl_scpdata);
 404 }
 405
 406
 407 /*
 408  * Save ipl parameters, clear bss memory, initialize storage keys
 409  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 410  */
 411 void __init startup_init(void)
 412 {
 413         reset_tod_clock();
 414         ipl_save_parameters();
 415         rescue_initrd();
 416         clear_bss_section();
 417         init_kernel_storage_key();
 418         lockdep_init();
 419         lockdep_off();
 420         sort_main_extable();
 421         setup_lowcore_early();
 422         detect_machine_type();
 423         ipl_update_parameters();
 424         setup_boot_command_line();
 425         create_kernel_nss();
 426         detect_mvpg();
 427         detect_ieee();
 428         detect_csp();
 429         detect_diag9c();
 430         detect_diag44();
 431         detect_machine_facilities();
 432         setup_hpage();
 433         sclp_facilities_detect();
 434         detect_memory_layout(memory_chunk);
 435 #ifdef CONFIG_DYNAMIC_FTRACE
 436         S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
 437 #endif
 438         lockdep_on();
 439 }