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