arch/s390/kernel/early.c

   1 /*
   2  *    Copyright IBM Corp. 2007, 2009
   3  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
   4  *               Heiko Carstens <heiko.carstens@de.ibm.com>
   5  */
   6
   7 #define KMSG_COMPONENT "setup"
   8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   9
  10 #include <linux/compiler.h>
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/ctype.h>
  15 #include <linux/lockdep.h>
  16 #include <linux/module.h>
  17 #include <linux/pfn.h>
  18 #include <linux/uaccess.h>
  19 #include <linux/kernel.h>
  20 #include <asm/diag.h>
  21 #include <asm/ebcdic.h>
  22 #include <asm/ipl.h>
  23 #include <asm/lowcore.h>
  24 #include <asm/processor.h>
  25 #include <asm/sections.h>
  26 #include <asm/setup.h>
  27 #include <asm/sysinfo.h>
  28 #include <asm/cpcmd.h>
  29 #include <asm/sclp.h>
  30 #include <asm/facility.h>
  31 #include "entry.h"
  32
  33 /*
  34  * Create a Kernel NSS if the SAVESYS= parameter is defined
  35  */
  36 #define DEFSYS_CMD_SIZE         128
  37 #define SAVESYS_CMD_SIZE        32
  38
  39 char kernel_nss_name[NSS_NAME_SIZE + 1];
  40
  41 static void __init setup_boot_command_line(void);
  42
  43 /*
  44  * Get the TOD clock running.
  45  */
  46 static void __init reset_tod_clock(void)
  47 {
  48         u64 time;
  49
  50         if (store_tod_clock(&time) == 0)
  51                 return;
  52         /* TOD clock not running. Set the clock to Unix Epoch. */
  53         if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
  54                 disabled_wait(0);
  55
  56         sched_clock_base_cc = TOD_UNIX_EPOCH;
  57         S390_lowcore.last_update_clock = sched_clock_base_cc;
  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         "       stmg    6,15,48(15)\n"
  69         "       lgr     14,3\n"
  70         "       sam31\n"
  71         "       diag    2,14,0x8\n"
  72         "       sam64\n"
  73         "       lgr     2,14\n"
  74         "       lmg     6,15,48(15)\n"
  75         "       br      14\n"
  76         "       .size   savesys_ipl_nss, .-savesys_ipl_nss\n"
  77         "       .previous\n");
  78
  79 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
  80
  81 static noinline __init void create_kernel_nss(void)
  82 {
  83         unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
  84 #ifdef CONFIG_BLK_DEV_INITRD
  85         unsigned int sinitrd_pfn, einitrd_pfn;
  86 #endif
  87         int response;
  88         int hlen;
  89         size_t len;
  90         char *savesys_ptr;
  91         char defsys_cmd[DEFSYS_CMD_SIZE];
  92         char savesys_cmd[SAVESYS_CMD_SIZE];
  93
  94         /* Do nothing if we are not running under VM */
  95         if (!MACHINE_IS_VM)
  96                 return;
  97
  98         /* Convert COMMAND_LINE to upper case */
  99         for (i = 0; i < strlen(boot_command_line); i++)
 100                 upper_command_line[i] = toupper(boot_command_line[i]);
 101
 102         savesys_ptr = strstr(upper_command_line, "SAVESYS=");
 103
 104         if (!savesys_ptr)
 105                 return;
 106
 107         savesys_ptr += 8;    /* Point to the beginning of the NSS name */
 108         for (i = 0; i < NSS_NAME_SIZE; i++) {
 109                 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
 110                         break;
 111                 kernel_nss_name[i] = savesys_ptr[i];
 112         }
 113
 114         stext_pfn = PFN_DOWN(__pa(&_stext));
 115         eshared_pfn = PFN_DOWN(__pa(&_eshared));
 116         end_pfn = PFN_UP(__pa(&_end));
 117         min_size = end_pfn << 2;
 118
 119         hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
 120                         "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
 121                         kernel_nss_name, stext_pfn - 1, stext_pfn,
 122                         eshared_pfn - 1, eshared_pfn, end_pfn);
 123
 124 #ifdef CONFIG_BLK_DEV_INITRD
 125         if (INITRD_START && INITRD_SIZE) {
 126                 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
 127                 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
 128                 min_size = einitrd_pfn << 2;
 129                 hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 130                                  " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
 131         }
 132 #endif
 133
 134         snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
 135                  " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
 136         defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
 137         snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
 138                  kernel_nss_name, kernel_nss_name);
 139         savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
 140
 141         __cpcmd(defsys_cmd, NULL, 0, &response);
 142
 143         if (response != 0) {
 144                 pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
 145                         response);
 146                 kernel_nss_name[0] = '\0';
 147                 return;
 148         }
 149
 150         len = strlen(savesys_cmd);
 151         ASCEBC(savesys_cmd, len);
 152         response = savesys_ipl_nss(savesys_cmd, len);
 153
 154         /* On success: response is equal to the command size,
 155          *             max SAVESYS_CMD_SIZE
 156          * On error: response contains the numeric portion of cp error message.
 157          *           for SAVESYS it will be >= 263
 158          *           for missing privilege class, it will be 1
 159          */
 160         if (response > SAVESYS_CMD_SIZE || response == 1) {
 161                 pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
 162                         response);
 163                 kernel_nss_name[0] = '\0';
 164                 return;
 165         }
 166
 167         /* re-initialize cputime accounting. */
 168         sched_clock_base_cc = get_tod_clock();
 169         S390_lowcore.last_update_clock = sched_clock_base_cc;
 170         S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
 171         S390_lowcore.user_timer = 0;
 172         S390_lowcore.system_timer = 0;
 173         asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
 174
 175         /* re-setup boot command line with new ipl vm parms */
 176         ipl_update_parameters();
 177         setup_boot_command_line();
 178
 179         ipl_flags = IPL_NSS_VALID;
 180 }
 181
 182 #else /* CONFIG_SHARED_KERNEL */
 183
 184 static inline void create_kernel_nss(void) { }
 185
 186 #endif /* CONFIG_SHARED_KERNEL */
 187
 188 /*
 189  * Clear bss memory
 190  */
 191 static noinline __init void clear_bss_section(void)
 192 {
 193         memset(__bss_start, 0, __bss_stop - __bss_start);
 194 }
 195
 196 /*
 197  * Initialize storage key for kernel pages
 198  */
 199 static noinline __init void init_kernel_storage_key(void)
 200 {
 201 #if PAGE_DEFAULT_KEY
 202         unsigned long end_pfn, init_pfn;
 203
 204         end_pfn = PFN_UP(__pa(&_end));
 205
 206         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
 207                 page_set_storage_key(init_pfn << PAGE_SHIFT,
 208                                      PAGE_DEFAULT_KEY, 0);
 209 #endif
 210 }
 211
 212 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 213
 214 static noinline __init void detect_machine_type(void)
 215 {
 216         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
 217
 218         /* Check current-configuration-level */
 219         if (stsi(NULL, 0, 0, 0) <= 2) {
 220                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 221                 return;
 222         }
 223         /* Get virtual-machine cpu information. */
 224         if (stsi(vmms, 3, 2, 2) || !vmms->count)
 225                 return;
 226
 227         /* Detect known hypervisors */
 228         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 229                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 230         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
 231                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 232 }
 233
 234 static __init void setup_topology(void)
 235 {
 236         int max_mnest;
 237
 238         if (!test_facility(11))
 239                 return;
 240         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 241         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 242                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 243                         break;
 244         }
 245         topology_max_mnest = max_mnest;
 246 }
 247
 248 static void early_pgm_check_handler(void)
 249 {
 250         const struct exception_table_entry *fixup;
 251         unsigned long cr0, cr0_new;
 252         unsigned long addr;
 253
 254         addr = S390_lowcore.program_old_psw.addr;
 255         fixup = search_exception_tables(addr & PSW_ADDR_INSN);
 256         if (!fixup)
 257                 disabled_wait(0);
 258         /* Disable low address protection before storing into lowcore. */
 259         __ctl_store(cr0, 0, 0);
 260         cr0_new = cr0 & ~(1UL << 28);
 261         __ctl_load(cr0_new, 0, 0);
 262         S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
 263         __ctl_load(cr0, 0, 0);
 264 }
 265
 266 static noinline __init void setup_lowcore_early(void)
 267 {
 268         psw_t psw;
 269
 270         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 271         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
 272         S390_lowcore.external_new_psw = psw;
 273         psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 274         S390_lowcore.program_new_psw = psw;
 275         s390_base_pgm_handler_fn = early_pgm_check_handler;
 276 }
 277
 278 static noinline __init void setup_facility_list(void)
 279 {
 280         stfle(S390_lowcore.stfle_fac_list,
 281               ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 282         memcpy(S390_lowcore.alt_stfle_fac_list,
 283                S390_lowcore.stfle_fac_list,
 284                sizeof(S390_lowcore.alt_stfle_fac_list));
 285         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 286                 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
 287 }
 288
 289 static __init void detect_diag9c(void)
 290 {
 291         unsigned int cpu_address;
 292         int rc;
 293
 294         cpu_address = stap();
 295         diag_stat_inc(DIAG_STAT_X09C);
 296         asm volatile(
 297                 "       diag    %2,0,0x9c\n"
 298                 "0:     la      %0,0\n"
 299                 "1:\n"
 300                 EX_TABLE(0b,1b)
 301                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 302         if (!rc)
 303                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 304 }
 305
 306 static __init void detect_diag44(void)
 307 {
 308         int rc;
 309
 310         diag_stat_inc(DIAG_STAT_X044);
 311         asm volatile(
 312                 "       diag    0,0,0x44\n"
 313                 "0:     la      %0,0\n"
 314                 "1:\n"
 315                 EX_TABLE(0b,1b)
 316                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 317         if (!rc)
 318                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 319 }
 320
 321 static __init void detect_machine_facilities(void)
 322 {
 323         if (test_facility(8)) {
 324                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 325                 __ctl_set_bit(0, 23);
 326         }
 327         if (test_facility(78))
 328                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 329         if (test_facility(3))
 330                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 331         if (test_facility(40))
 332                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
 333         if (test_facility(50) && test_facility(73)) {
 334                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 335                 __ctl_set_bit(0, 55);
 336         }
 337         if (test_facility(51))
 338                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 339         if (test_facility(129)) {
 340                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 341                 __ctl_set_bit(0, 17);
 342         }
 343 }
 344
 345 static int __init disable_vector_extension(char *str)
 346 {
 347         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 348         __ctl_clear_bit(0, 17);
 349         return 1;
 350 }
 351 early_param("novx", disable_vector_extension);
 352
 353 static int __init cad_setup(char *str)
 354 {
 355         int val;
 356
 357         get_option(&str, &val);
 358         if (val && test_facility(128))
 359                 S390_lowcore.machine_flags |= MACHINE_FLAG_CAD;
 360         return 0;
 361 }
 362 early_param("cad", cad_setup);
 363
 364 static int __init cad_init(void)
 365 {
 366         if (MACHINE_HAS_CAD)
 367                 /* Enable problem state CAD. */
 368                 __ctl_set_bit(2, 3);
 369         return 0;
 370 }
 371 early_initcall(cad_init);
 372
 373 static __init void rescue_initrd(void)
 374 {
 375 #ifdef CONFIG_BLK_DEV_INITRD
 376         unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
 377         /*
 378          * Just like in case of IPL from VM reader we make sure there is a
 379          * gap of 4MB between end of kernel and start of initrd.
 380          * That way we can also be sure that saving an NSS will succeed,
 381          * which however only requires different segments.
 382          */
 383         if (!INITRD_START || !INITRD_SIZE)
 384                 return;
 385         if (INITRD_START >= min_initrd_addr)
 386                 return;
 387         memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
 388         INITRD_START = min_initrd_addr;
 389 #endif
 390 }
 391
 392 /* Set up boot command line */
 393 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 394 {
 395         char *parm, *delim;
 396         size_t rc, len;
 397
 398         len = strlen(boot_command_line);
 399
 400         delim = boot_command_line + len;        /* '\0' character position */
 401         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 402
 403         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 404         if (rc) {
 405                 if (*parm == '=')
 406                         memmove(boot_command_line, parm + 1, rc);
 407                 else
 408                         *delim = ' ';           /* replace '\0' with space */
 409         }
 410 }
 411
 412 static inline int has_ebcdic_char(const char *str)
 413 {
 414         int i;
 415
 416         for (i = 0; str[i]; i++)
 417                 if (str[i] & 0x80)
 418                         return 1;
 419         return 0;
 420 }
 421
 422 static void __init setup_boot_command_line(void)
 423 {
 424         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
 425         /* convert arch command line to ascii if necessary */
 426         if (has_ebcdic_char(COMMAND_LINE))
 427                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 428         /* copy arch command line */
 429         strlcpy(boot_command_line, strstrip(COMMAND_LINE),
 430                 ARCH_COMMAND_LINE_SIZE);
 431
 432         /* append IPL PARM data to the boot command line */
 433         if (MACHINE_IS_VM)
 434                 append_to_cmdline(append_ipl_vmparm);
 435
 436         append_to_cmdline(append_ipl_scpdata);
 437 }
 438
 439 /*
 440  * Save ipl parameters, clear bss memory, initialize storage keys
 441  * and create a kernel NSS at startup if the SAVESYS= parm is defined
 442  */
 443 void __init startup_init(void)
 444 {
 445         reset_tod_clock();
 446         ipl_save_parameters();
 447         rescue_initrd();
 448         clear_bss_section();
 449         init_kernel_storage_key();
 450         lockdep_init();
 451         lockdep_off();
 452         setup_lowcore_early();
 453         setup_facility_list();
 454         detect_machine_type();
 455         ipl_update_parameters();
 456         setup_boot_command_line();
 457         create_kernel_nss();
 458         detect_diag9c();
 459         detect_diag44();
 460         detect_machine_facilities();
 461         setup_topology();
 462         sclp_early_detect();
 463         lockdep_on();
 464 }