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  * Initialize storage key for kernel pages
  38  */
  39 static noinline __init void init_kernel_storage_key(void)
  40 {
  41 #if PAGE_DEFAULT_KEY
  42         unsigned long end_pfn, init_pfn;
  43
  44         end_pfn = PFN_UP(__pa(_end));
  45
  46         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  47                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  48                                      PAGE_DEFAULT_KEY, 0);
  49 #endif
  50 }
  51
  52 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  53
  54 static noinline __init void detect_machine_type(void)
  55 {
  56         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  57
  58         /* Check current-configuration-level */
  59         if (stsi(NULL, 0, 0, 0) <= 2) {
  60                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
  61                 return;
  62         }
  63         /* Get virtual-machine cpu information. */
  64         if (stsi(vmms, 3, 2, 2) || !vmms->count)
  65                 return;
  66
  67         /* Detect known hypervisors */
  68         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
  69                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
  70         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
  71                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
  72 }
  73
  74 /* Remove leading, trailing and double whitespace. */
  75 static inline void strim_all(char *str)
  76 {
  77         char *s;
  78
  79         s = strim(str);
  80         if (s != str)
  81                 memmove(str, s, strlen(s));
  82         while (*str) {
  83                 if (!isspace(*str++))
  84                         continue;
  85                 if (isspace(*str)) {
  86                         s = skip_spaces(str);
  87                         memmove(str, s, strlen(s) + 1);
  88                 }
  89         }
  90 }
  91
  92 static noinline __init void setup_arch_string(void)
  93 {
  94         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
  95         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
  96         char mstr[80], hvstr[17];
  97
  98         if (stsi(mach, 1, 1, 1))
  99                 return;
 100         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 101         EBCASC(mach->type, sizeof(mach->type));
 102         EBCASC(mach->model, sizeof(mach->model));
 103         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 104         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 105                 mach->manufacturer, mach->type,
 106                 mach->model, mach->model_capacity);
 107         strim_all(mstr);
 108         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 109                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 110                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 111                 strim_all(hvstr);
 112         } else {
 113                 sprintf(hvstr, "%s",
 114                         MACHINE_IS_LPAR ? "LPAR" :
 115                         MACHINE_IS_VM ? "z/VM" :
 116                         MACHINE_IS_KVM ? "KVM" : "unknown");
 117         }
 118         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 119 }
 120
 121 static __init void setup_topology(void)
 122 {
 123         int max_mnest;
 124
 125         if (!test_facility(11))
 126                 return;
 127         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 128         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 129                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 130                         break;
 131         }
 132         topology_max_mnest = max_mnest;
 133 }
 134
 135 static void early_pgm_check_handler(void)
 136 {
 137         const struct exception_table_entry *fixup;
 138         unsigned long cr0, cr0_new;
 139         unsigned long addr;
 140
 141         addr = S390_lowcore.program_old_psw.addr;
 142         fixup = search_exception_tables(addr);
 143         if (!fixup)
 144                 disabled_wait(0);
 145         /* Disable low address protection before storing into lowcore. */
 146         __ctl_store(cr0, 0, 0);
 147         cr0_new = cr0 & ~(1UL << 28);
 148         __ctl_load(cr0_new, 0, 0);
 149         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 150         __ctl_load(cr0, 0, 0);
 151 }
 152
 153 static noinline __init void setup_lowcore_early(void)
 154 {
 155         psw_t psw;
 156
 157         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 158         if (IS_ENABLED(CONFIG_KASAN))
 159                 psw.mask |= PSW_MASK_DAT;
 160         psw.addr = (unsigned long) s390_base_ext_handler;
 161         S390_lowcore.external_new_psw = psw;
 162         psw.addr = (unsigned long) s390_base_pgm_handler;
 163         S390_lowcore.program_new_psw = psw;
 164         s390_base_pgm_handler_fn = early_pgm_check_handler;
 165         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 166 }
 167
 168 static noinline __init void setup_facility_list(void)
 169 {
 170         stfle(S390_lowcore.stfle_fac_list,
 171               ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 172         memcpy(S390_lowcore.alt_stfle_fac_list,
 173                S390_lowcore.stfle_fac_list,
 174                sizeof(S390_lowcore.alt_stfle_fac_list));
 175         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 176                 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
 177 }
 178
 179 static __init void detect_diag9c(void)
 180 {
 181         unsigned int cpu_address;
 182         int rc;
 183
 184         cpu_address = stap();
 185         diag_stat_inc(DIAG_STAT_X09C);
 186         asm volatile(
 187                 "       diag    %2,0,0x9c\n"
 188                 "0:     la      %0,0\n"
 189                 "1:\n"
 190                 EX_TABLE(0b,1b)
 191                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 192         if (!rc)
 193                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 194 }
 195
 196 static __init void detect_diag44(void)
 197 {
 198         int rc;
 199
 200         diag_stat_inc(DIAG_STAT_X044);
 201         asm volatile(
 202                 "       diag    0,0,0x44\n"
 203                 "0:     la      %0,0\n"
 204                 "1:\n"
 205                 EX_TABLE(0b,1b)
 206                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 207         if (!rc)
 208                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 209 }
 210
 211 static __init void detect_machine_facilities(void)
 212 {
 213         if (test_facility(8)) {
 214                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 215                 __ctl_set_bit(0, 23);
 216         }
 217         if (test_facility(78))
 218                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 219         if (test_facility(3))
 220                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 221         if (test_facility(50) && test_facility(73)) {
 222                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 223                 __ctl_set_bit(0, 55);
 224         }
 225         if (test_facility(51))
 226                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 227         if (test_facility(129)) {
 228                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 229                 __ctl_set_bit(0, 17);
 230         }
 231         if (test_facility(130)) {
 232                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 233                 __ctl_set_bit(0, 20);
 234         }
 235         if (test_facility(133))
 236                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 237         if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
 238                 /* Enabled signed clock comparator comparisons */
 239                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 240                 clock_comparator_max = -1ULL >> 1;
 241                 __ctl_set_bit(0, 53);
 242         }
 243 }
 244
 245 static inline void save_vector_registers(void)
 246 {
 247 #ifdef CONFIG_CRASH_DUMP
 248         if (test_facility(129))
 249                 save_vx_regs(boot_cpu_vector_save_area);
 250 #endif
 251 }
 252
 253 static int __init disable_vector_extension(char *str)
 254 {
 255         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 256         __ctl_clear_bit(0, 17);
 257         return 0;
 258 }
 259 early_param("novx", disable_vector_extension);
 260
 261 static int __init noexec_setup(char *str)
 262 {
 263         bool enabled;
 264         int rc;
 265
 266         rc = kstrtobool(str, &enabled);
 267         if (!rc && !enabled) {
 268                 /* Disable no-execute support */
 269                 S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
 270                 __ctl_clear_bit(0, 20);
 271         }
 272         return rc;
 273 }
 274 early_param("noexec", noexec_setup);
 275
 276 static int __init cad_setup(char *str)
 277 {
 278         bool enabled;
 279         int rc;
 280
 281         rc = kstrtobool(str, &enabled);
 282         if (!rc && enabled && test_facility(128))
 283                 /* Enable problem state CAD. */
 284                 __ctl_set_bit(2, 3);
 285         return rc;
 286 }
 287 early_param("cad", cad_setup);
 288
 289 /* Set up boot command line */
 290 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
 291 {
 292         char *parm, *delim;
 293         size_t rc, len;
 294
 295         len = strlen(boot_command_line);
 296
 297         delim = boot_command_line + len;        /* '\0' character position */
 298         parm  = boot_command_line + len + 1;    /* append right after '\0' */
 299
 300         rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
 301         if (rc) {
 302                 if (*parm == '=')
 303                         memmove(boot_command_line, parm + 1, rc);
 304                 else
 305                         *delim = ' ';           /* replace '\0' with space */
 306         }
 307 }
 308
 309 static inline int has_ebcdic_char(const char *str)
 310 {
 311         int i;
 312
 313         for (i = 0; str[i]; i++)
 314                 if (str[i] & 0x80)
 315                         return 1;
 316         return 0;
 317 }
 318
 319 static void __init setup_boot_command_line(void)
 320 {
 321         COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
 322         /* convert arch command line to ascii if necessary */
 323         if (has_ebcdic_char(COMMAND_LINE))
 324                 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
 325         /* copy arch command line */
 326         strlcpy(boot_command_line, strstrip(COMMAND_LINE),
 327                 ARCH_COMMAND_LINE_SIZE);
 328
 329         /* append IPL PARM data to the boot command line */
 330         if (MACHINE_IS_VM)
 331                 append_to_cmdline(append_ipl_vmparm);
 332
 333         append_to_cmdline(append_ipl_scpdata);
 334 }
 335
 336 static void __init check_image_bootable(void)
 337 {
 338         if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
 339                 return;
 340
 341         sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
 342         sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
 343         sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
 344         disabled_wait(0xbadb007);
 345 }
 346
 347 void __init startup_init(void)
 348 {
 349         check_image_bootable();
 350         time_early_init();
 351         init_kernel_storage_key();
 352         lockdep_off();
 353         setup_lowcore_early();
 354         setup_facility_list();
 355         detect_machine_type();
 356         setup_arch_string();
 357         ipl_store_parameters();
 358         setup_boot_command_line();
 359         detect_diag9c();
 360         detect_diag44();
 361         detect_machine_facilities();
 362         save_vector_registers();
 363         setup_topology();
 364         sclp_early_detect();
 365         lockdep_on();
 366 }