arch/s390/kernel/early.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Copyright IBM Corp. 2007, 2009
   4  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
   5  *               Heiko Carstens <heiko.carstens@de.ibm.com>
   6  */
   7
   8 #define KMSG_COMPONENT "setup"
   9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  10
  11 #include <linux/compiler.h>
  12 #include <linux/init.h>
  13 #include <linux/errno.h>
  14 #include <linux/string.h>
  15 #include <linux/ctype.h>
  16 #include <linux/lockdep.h>
  17 #include <linux/extable.h>
  18 #include <linux/pfn.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/kernel.h>
  21 #include <asm/diag.h>
  22 #include <asm/ebcdic.h>
  23 #include <asm/ipl.h>
  24 #include <asm/lowcore.h>
  25 #include <asm/processor.h>
  26 #include <asm/sections.h>
  27 #include <asm/setup.h>
  28 #include <asm/sysinfo.h>
  29 #include <asm/cpcmd.h>
  30 #include <asm/sclp.h>
  31 #include <asm/facility.h>
  32 #include "entry.h"
  33
  34 static void __init setup_boot_command_line(void);
  35
  36 /*
  37  * Get the TOD clock running.
  38  */
  39 static void __init reset_tod_clock(void)
  40 {
  41         u64 time;
  42
  43         if (store_tod_clock(&time) == 0)
  44                 return;
  45         /* TOD clock not running. Set the clock to Unix Epoch. */
  46         if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
  47                 disabled_wait(0);
  48
  49         memset(tod_clock_base, 0, 16);
  50         *(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
  51         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
  52 }
  53
  54 /*
  55  * Clear bss memory
  56  */
  57 static noinline __init void clear_bss_section(void)
  58 {
  59         memset(__bss_start, 0, __bss_stop - __bss_start);
  60 }
  61
  62 /*
  63  * Initialize storage key for kernel pages
  64  */
  65 static noinline __init void init_kernel_storage_key(void)
  66 {
  67 #if PAGE_DEFAULT_KEY
  68         unsigned long end_pfn, init_pfn;
  69
  70         end_pfn = PFN_UP(__pa(&_end));
  71
  72         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  73                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  74                                      PAGE_DEFAULT_KEY, 0);
  75 #endif
  76 }
  77
  78 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  79
  80 static noinline __init void detect_machine_type(void)
  81 {
  82         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  83
  84         /* Check current-configuration-level */
  85         if (stsi(NULL, 0, 0, 0) <= 2) {
  86                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
  87                 return;
  88         }
  89         /* Get virtual-machine cpu information. */
  90         if (stsi(vmms, 3, 2, 2) || !vmms->count)
  91                 return;
  92
  93         /* Running under KVM? If not we assume z/VM */
  94         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
  95                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
  96         else
  97                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
  98 }
  99
 100 /* Remove leading, trailing and double whitespace. */
 101 static inline void strim_all(char *str)
 102 {
 103         char *s;
 104
 105         s = strim(str);
 106         if (s != str)
 107                 memmove(str, s, strlen(s));
 108         while (*str) {
 109                 if (!isspace(*str++))
 110                         continue;
 111                 if (isspace(*str)) {
 112                         s = skip_spaces(str);
 113                         memmove(str, s, strlen(s) + 1);
 114                 }
 115         }
 116 }
 117
 118 static noinline __init void setup_arch_string(void)
 119 {
 120         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 121         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 122         char mstr[80], hvstr[17];
 123
 124         if (stsi(mach, 1, 1, 1))
 125                 return;
 126         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 127         EBCASC(mach->type, sizeof(mach->type));
 128         EBCASC(mach->model, sizeof(mach->model));
 129         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 130         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 131                 mach->manufacturer, mach->type,
 132                 mach->model, mach->model_capacity);
 133         strim_all(mstr);
 134         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 135                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 136                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 137                 strim_all(hvstr);
 138         } else {
 139                 sprintf(hvstr, "%s",
 140                         MACHINE_IS_LPAR ? "LPAR" :
 141                         MACHINE_IS_VM ? "z/VM" :
 142                         MACHINE_IS_KVM ? "KVM" : "unknown");
 143         }
 144         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 145 }
 146
 147 static __init void setup_topology(void)
 148 {
 149         int max_mnest;
 150
 151         if (!test_facility(11))
 152                 return;
 153         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 154         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 155                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 156                         break;
 157         }
 158         topology_max_mnest = max_mnest;
 159 }
 160
 161 static void early_pgm_check_handler(void)
 162 {
 163         const struct exception_table_entry *fixup;
 164         unsigned long cr0, cr0_new;
 165         unsigned long addr;
 166
 167         addr = S390_lowcore.program_old_psw.addr;
 168         fixup = search_exception_tables(addr);
 169         if (!fixup)
 170                 disabled_wait(0);
 171         /* Disable low address protection before storing into lowcore. */
 172         __ctl_store(cr0, 0, 0);
 173         cr0_new = cr0 & ~(1UL << 28);
 174         __ctl_load(cr0_new, 0, 0);
 175         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 176         __ctl_load(cr0, 0, 0);
 177 }
 178
 179 static noinline __init void setup_lowcore_early(void)
 180 {
 181         psw_t psw;
 182
 183         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 184         psw.addr = (unsigned long) s390_base_ext_handler;
 185         S390_lowcore.external_new_psw = psw;
 186         psw.addr = (unsigned long) s390_base_pgm_handler;
 187         S390_lowcore.program_new_psw = psw;
 188         s390_base_pgm_handler_fn = early_pgm_check_handler;
 189         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 190 }
 191
 192 static noinline __init void setup_facility_list(void)
 193 {
 194         stfle(S390_lowcore.stfle_fac_list,
 195               ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 196         memcpy(S390_lowcore.alt_stfle_fac_list,
 197                S390_lowcore.stfle_fac_list,
 198                sizeof(S390_lowcore.alt_stfle_fac_list));
 199         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 200                 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
 201 }
 202
 203 static __init void detect_diag9c(void)
 204 {
 205         unsigned int cpu_address;
 206         int rc;
 207
 208         cpu_address = stap();
 209         diag_stat_inc(DIAG_STAT_X09C);
 210         asm volatile(
 211                 "       diag    %2,0,0x9c\n"
 212                 "0:     la      %0,0\n"
 213                 "1:\n"
 214                 EX_TABLE(0b,1b)
 215                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 216         if (!rc)
 217                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 218 }
 219
 220 static __init void detect_diag44(void)
 221 {
 222         int rc;
 223
 224         diag_stat_inc(DIAG_STAT_X044);
 225         asm volatile(
 226                 "       diag    0,0,0x44\n"
 227                 "0:     la      %0,0\n"
 228                 "1:\n"
 229                 EX_TABLE(0b,1b)
 230                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 231         if (!rc)
 232                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 233 }
 234
 235 static __init void detect_machine_facilities(void)
 236 {
 237         if (test_facility(8)) {
 238                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 239                 __ctl_set_bit(0, 23);
 240         }
 241         if (test_facility(78))
 242                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 243         if (test_facility(3))
 244                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 245         if (test_facility(40))
 246                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
 247         if (test_facility(50) && test_facility(73)) {
 248                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 249                 __ctl_set_bit(0, 55);
 250         }
 251         if (test_facility(51))
 252                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 253         if (test_facility(129)) {
 254                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 255                 __ctl_set_bit(0, 17);
 256         }
 257         if (test_facility(130)) {
 258                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 259                 __ctl_set_bit(0, 20);
 260         }
 261         if (test_facility(133))
 262                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 263         if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
 264                 /* Enabled signed clock comparator comparisons */
 265                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 266                 clock_comparator_max = -1ULL >> 1;
 267                 __ctl_set_bit(0, 53);
 268         }
 269 }
 270
 271 static inline void save_vector_registers(void)
 272 {
 273 #ifdef CONFIG_CRASH_DUMP
 274         if (test_facility(129))
 275                 save_vx_regs(boot_cpu_vector_save_area);
 276 #endif
 277 }
 278
 279 static int __init disable_vector_extension(char *str)
 280 {
 281         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 282         __ctl_clear_bit(0, 17);
 283         return 0;
 284 }
 285 early_param("novx", disable_vector_extension);
 286
 287 static int __init noexec_setup(char *str)
 288 {
 289         bool enabled;
 290         int rc;
 291
 292         rc = kstrtobool(str, &enabled);
 293         if (!rc && !enabled) {
 294                 /* Disable no-execute support */
 295                 S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
 296                 __ctl_clear_bit(0, 20);
 297         }
 298         return rc;
 299 }
 300 early_param("noexec", noexec_setup);
 301
 302 static int __init cad_setup(char *str)
 303 {
 304         bool enabled;
 305         int rc;
 306
 307         rc = kstrtobool(str, &enabled);
 308         if (!rc && enabled && test_facility(128))
 309                 /* Enable problem state CAD. */
 310                 __ctl_set_bit(2, 3);
 311         return rc;
 312 }
 313 early_param("cad", cad_setup);
 314
 315 static __init void memmove_early(void *dst, const void *src, size_t n)
 316 {
 317         unsigned long addr;
 318         long incr;
 319         psw_t old;
 320
 321         if (!n)
 322                 return;
 323         incr = 1;
 324         if (dst > src) {
 325                 incr = -incr;
 326                 dst += n - 1;
 327                 src += n - 1;
 328         }
 329         old = S390_lowcore.program_new_psw;
 330         S390_lowcore.program_new_psw.mask = __extract_psw();
 331         asm volatile(
 332                 "       larl    %[addr],1f\n"
 333                 "       stg     %[addr],%[psw_pgm_addr]\n"
 334                 "0:     mvc     0(1,%[dst]),0(%[src])\n"
 335                 "       agr     %[dst],%[incr]\n"
 336                 "       agr     %[src],%[incr]\n"
 337                 "       brctg   %[n],0b\n"
 338                 "1:\n"
 339                 : [addr] "=&d" (addr),
 340                   [psw_pgm_addr] "=Q" (S390_lowcore.program_new_psw.addr),
 341                   [dst] "+&a" (dst), [src] "+&a" (src),  [n] "+d" (n)
 342                 : [incr] "d" (incr)
 343                 : "cc", "memory");
 344         S390_lowcore.program_new_psw = old;
 345 }
 346
 347 static __init noinline void ipl_save_parameters(void)
 348 {
 349         void *src, *dst;
 350
 351         src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
 352         dst = (void *) IPL_PARMBLOCK_ORIGIN;
 353         memmove_early(dst, src, PAGE_SIZE);
 354         S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
 355 }
 356
 357 static __init noinline void rescue_initrd(void)
 358 {
 359 #ifdef CONFIG_BLK_DEV_INITRD
 360         unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
 361         /*
 362          * Just like in case of IPL from VM reader we make sure there is a
 363          * gap of 4MB between end of kernel and start of initrd.
 364          * That way we can also be sure that saving an NSS will succeed,
 365          * which however only requires different segments.
 366          */
 367         if (!INITRD_START || !INITRD_SIZE)
 368                 return;
 369         if (INITRD_START >= min_initrd_addr)
 370                 return;
 371         memmove_early((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
 372         INITRD_START = min_initrd_addr;
 373 #endif
 374 }
 375
 376 /* Set up boot command line */
 377 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 378 {
 379         char *parm, *delim;
 380         size_t rc, len;
 381
 382         len = strlen(boot_command_line);
 383
 384         delim = boot_command_line + len;        /* '\0' character position */
 385         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 386
 387         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 388         if (rc) {
 389                 if (*parm == '=')
 390                         memmove(boot_command_line, parm + 1, rc);
 391                 else
 392                         *delim = ' ';           /* replace '\0' with space */
 393         }
 394 }
 395
 396 static inline int has_ebcdic_char(const char *str)
 397 {
 398         int i;
 399
 400         for (i = 0; str[i]; i++)
 401                 if (str[i] & 0x80)
 402                         return 1;
 403         return 0;
 404 }
 405
 406 static void __init setup_boot_command_line(void)
 407 {
 408         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
 409         /* convert arch command line to ascii if necessary */
 410         if (has_ebcdic_char(COMMAND_LINE))
 411                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 412         /* copy arch command line */
 413         strlcpy(boot_command_line, strstrip(COMMAND_LINE),
 414                 ARCH_COMMAND_LINE_SIZE);
 415
 416         /* append IPL PARM data to the boot command line */
 417         if (MACHINE_IS_VM)
 418                 append_to_cmdline(append_ipl_vmparm);
 419
 420         append_to_cmdline(append_ipl_scpdata);
 421 }
 422
 423 void __init startup_init(void)
 424 {
 425         reset_tod_clock();
 426         ipl_save_parameters();
 427         rescue_initrd();
 428         clear_bss_section();
 429         ipl_verify_parameters();
 430         time_early_init();
 431         init_kernel_storage_key();
 432         lockdep_off();
 433         setup_lowcore_early();
 434         setup_facility_list();
 435         detect_machine_type();
 436         setup_arch_string();
 437         ipl_update_parameters();
 438         setup_boot_command_line();
 439         detect_diag9c();
 440         detect_diag44();
 441         detect_machine_facilities();
 442         save_vector_registers();
 443         setup_topology();
 444         sclp_early_detect();
 445         lockdep_on();
 446 }