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  */
   6
   7 #define KMSG_COMPONENT "setup"
   8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   9
  10 #include <linux/sched/debug.h>
  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/asm-extable.h>
  22 #include <linux/memblock.h>
  23 #include <asm/access-regs.h>
  24 #include <asm/diag.h>
  25 #include <asm/ebcdic.h>
  26 #include <asm/fpu.h>
  27 #include <asm/ipl.h>
  28 #include <asm/lowcore.h>
  29 #include <asm/processor.h>
  30 #include <asm/sections.h>
  31 #include <asm/setup.h>
  32 #include <asm/sysinfo.h>
  33 #include <asm/cpcmd.h>
  34 #include <asm/sclp.h>
  35 #include <asm/facility.h>
  36 #include <asm/boot_data.h>
  37 #include "entry.h"
  38
  39 #define decompressor_handled_param(param)                       \
  40 static int __init ignore_decompressor_param_##param(char *s)    \
  41 {                                                               \
  42         return 0;                                               \
  43 }                                                               \
  44 early_param(#param, ignore_decompressor_param_##param)
  45
  46 decompressor_handled_param(mem);
  47 decompressor_handled_param(vmalloc);
  48 decompressor_handled_param(dfltcc);
  49 decompressor_handled_param(facilities);
  50 decompressor_handled_param(nokaslr);
  51 decompressor_handled_param(cmma);
  52 decompressor_handled_param(relocate_lowcore);
  53 #if IS_ENABLED(CONFIG_KVM)
  54 decompressor_handled_param(prot_virt);
  55 #endif
  56
  57 static void __init kasan_early_init(void)
  58 {
  59 #ifdef CONFIG_KASAN
  60         init_task.kasan_depth = 0;
  61         sclp_early_printk("KernelAddressSanitizer initialized\n");
  62 #endif
  63 }
  64
  65 static void __init reset_tod_clock(void)
  66 {
  67         union tod_clock clk;
  68
  69         if (store_tod_clock_ext_cc(&clk) == 0)
  70                 return;
  71         /* TOD clock not running. Set the clock to Unix Epoch. */
  72         if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
  73                 disabled_wait();
  74
  75         memset(&tod_clock_base, 0, sizeof(tod_clock_base));
  76         tod_clock_base.tod = TOD_UNIX_EPOCH;
  77         get_lowcore()->last_update_clock = TOD_UNIX_EPOCH;
  78 }
  79
  80 /*
  81  * Initialize storage key for kernel pages
  82  */
  83 static noinline __init void init_kernel_storage_key(void)
  84 {
  85 #if PAGE_DEFAULT_KEY
  86         unsigned long end_pfn, init_pfn;
  87
  88         end_pfn = PFN_UP(__pa(_end));
  89
  90         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  91                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  92                                      PAGE_DEFAULT_KEY, 0);
  93 #endif
  94 }
  95
  96 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  97
  98 static noinline __init void detect_machine_type(void)
  99 {
 100         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
 101
 102         /* Check current-configuration-level */
 103         if (stsi(NULL, 0, 0, 0) <= 2) {
 104                 get_lowcore()->machine_flags |= MACHINE_FLAG_LPAR;
 105                 return;
 106         }
 107         /* Get virtual-machine cpu information. */
 108         if (stsi(vmms, 3, 2, 2) || !vmms->count)
 109                 return;
 110
 111         /* Detect known hypervisors */
 112         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 113                 get_lowcore()->machine_flags |= MACHINE_FLAG_KVM;
 114         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
 115                 get_lowcore()->machine_flags |= MACHINE_FLAG_VM;
 116 }
 117
 118 /* Remove leading, trailing and double whitespace. */
 119 static inline void strim_all(char *str)
 120 {
 121         char *s;
 122
 123         s = strim(str);
 124         if (s != str)
 125                 memmove(str, s, strlen(s));
 126         while (*str) {
 127                 if (!isspace(*str++))
 128                         continue;
 129                 if (isspace(*str)) {
 130                         s = skip_spaces(str);
 131                         memmove(str, s, strlen(s) + 1);
 132                 }
 133         }
 134 }
 135
 136 static noinline __init void setup_arch_string(void)
 137 {
 138         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 139         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 140         char mstr[80], hvstr[17];
 141
 142         if (stsi(mach, 1, 1, 1))
 143                 return;
 144         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 145         EBCASC(mach->type, sizeof(mach->type));
 146         EBCASC(mach->model, sizeof(mach->model));
 147         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 148         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 149                 mach->manufacturer, mach->type,
 150                 mach->model, mach->model_capacity);
 151         strim_all(mstr);
 152         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 153                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 154                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 155                 strim_all(hvstr);
 156         } else {
 157                 sprintf(hvstr, "%s",
 158                         MACHINE_IS_LPAR ? "LPAR" :
 159                         MACHINE_IS_VM ? "z/VM" :
 160                         MACHINE_IS_KVM ? "KVM" : "unknown");
 161         }
 162         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 163 }
 164
 165 static __init void setup_topology(void)
 166 {
 167         int max_mnest;
 168
 169         if (!test_facility(11))
 170                 return;
 171         get_lowcore()->machine_flags |= MACHINE_FLAG_TOPOLOGY;
 172         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 173                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 174                         break;
 175         }
 176         topology_max_mnest = max_mnest;
 177 }
 178
 179 void __init __do_early_pgm_check(struct pt_regs *regs)
 180 {
 181         struct lowcore *lc = get_lowcore();
 182         unsigned long ip;
 183
 184         regs->int_code = lc->pgm_int_code;
 185         regs->int_parm_long = lc->trans_exc_code;
 186         ip = __rewind_psw(regs->psw, regs->int_code >> 16);
 187
 188         /* Monitor Event? Might be a warning */
 189         if ((regs->int_code & PGM_INT_CODE_MASK) == 0x40) {
 190                 if (report_bug(ip, regs) == BUG_TRAP_TYPE_WARN)
 191                         return;
 192         }
 193         if (fixup_exception(regs))
 194                 return;
 195         /*
 196          * Unhandled exception - system cannot continue but try to get some
 197          * helpful messages to the console. Use early_printk() to print
 198          * some basic information in case it is too early for printk().
 199          */
 200         register_early_console();
 201         early_printk("PANIC: early exception %04x PSW: %016lx %016lx\n",
 202                      regs->int_code & 0xffff, regs->psw.mask, regs->psw.addr);
 203         show_regs(regs);
 204         disabled_wait();
 205 }
 206
 207 static noinline __init void setup_lowcore_early(void)
 208 {
 209         struct lowcore *lc = get_lowcore();
 210         psw_t psw;
 211
 212         psw.addr = (unsigned long)early_pgm_check_handler;
 213         psw.mask = PSW_KERNEL_BITS;
 214         lc->program_new_psw = psw;
 215         lc->preempt_count = INIT_PREEMPT_COUNT;
 216         lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
 217         lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
 218 }
 219
 220 static __init void detect_diag9c(void)
 221 {
 222         unsigned int cpu_address;
 223         int rc;
 224
 225         cpu_address = stap();
 226         diag_stat_inc(DIAG_STAT_X09C);
 227         asm volatile(
 228                 "       diag    %2,0,0x9c\n"
 229                 "0:     la      %0,0\n"
 230                 "1:\n"
 231                 EX_TABLE(0b,1b)
 232                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 233         if (!rc)
 234                 get_lowcore()->machine_flags |= MACHINE_FLAG_DIAG9C;
 235 }
 236
 237 static __init void detect_machine_facilities(void)
 238 {
 239         if (test_facility(8)) {
 240                 get_lowcore()->machine_flags |= MACHINE_FLAG_EDAT1;
 241                 system_ctl_set_bit(0, CR0_EDAT_BIT);
 242         }
 243         if (test_facility(78))
 244                 get_lowcore()->machine_flags |= MACHINE_FLAG_EDAT2;
 245         if (test_facility(3))
 246                 get_lowcore()->machine_flags |= MACHINE_FLAG_IDTE;
 247         if (test_facility(50) && test_facility(73)) {
 248                 get_lowcore()->machine_flags |= MACHINE_FLAG_TE;
 249                 system_ctl_set_bit(0, CR0_TRANSACTIONAL_EXECUTION_BIT);
 250         }
 251         if (test_facility(51))
 252                 get_lowcore()->machine_flags |= MACHINE_FLAG_TLB_LC;
 253         if (test_facility(129))
 254                 system_ctl_set_bit(0, CR0_VECTOR_BIT);
 255         if (test_facility(130))
 256                 get_lowcore()->machine_flags |= MACHINE_FLAG_NX;
 257         if (test_facility(133))
 258                 get_lowcore()->machine_flags |= MACHINE_FLAG_GS;
 259         if (test_facility(139) && (tod_clock_base.tod >> 63)) {
 260                 /* Enabled signed clock comparator comparisons */
 261                 get_lowcore()->machine_flags |= MACHINE_FLAG_SCC;
 262                 clock_comparator_max = -1ULL >> 1;
 263                 system_ctl_set_bit(0, CR0_CLOCK_COMPARATOR_SIGN_BIT);
 264         }
 265         if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
 266                 get_lowcore()->machine_flags |= MACHINE_FLAG_PCI_MIO;
 267                 /* the control bit is set during PCI initialization */
 268         }
 269         if (test_facility(194))
 270                 get_lowcore()->machine_flags |= MACHINE_FLAG_RDP;
 271         if (test_facility(85))
 272                 get_lowcore()->machine_flags |= MACHINE_FLAG_SEQ_INSN;
 273 }
 274
 275 static inline void save_vector_registers(void)
 276 {
 277 #ifdef CONFIG_CRASH_DUMP
 278         if (test_facility(129))
 279                 save_vx_regs(boot_cpu_vector_save_area);
 280 #endif
 281 }
 282
 283 static inline void setup_low_address_protection(void)
 284 {
 285         system_ctl_set_bit(0, CR0_LOW_ADDRESS_PROTECTION_BIT);
 286 }
 287
 288 static inline void setup_access_registers(void)
 289 {
 290         unsigned int acrs[NUM_ACRS] = { 0 };
 291
 292         restore_access_regs(acrs);
 293 }
 294
 295 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 296 static void __init setup_boot_command_line(void)
 297 {
 298         /* copy arch command line */
 299         strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
 300 }
 301
 302 static void __init sort_amode31_extable(void)
 303 {
 304         sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
 305 }
 306
 307 void __init startup_init(void)
 308 {
 309         kasan_early_init();
 310         reset_tod_clock();
 311         time_early_init();
 312         init_kernel_storage_key();
 313         lockdep_off();
 314         sort_amode31_extable();
 315         setup_lowcore_early();
 316         detect_machine_type();
 317         setup_arch_string();
 318         setup_boot_command_line();
 319         detect_diag9c();
 320         detect_machine_facilities();
 321         save_vector_registers();
 322         setup_topology();
 323         sclp_early_detect();
 324         setup_low_address_protection();
 325         setup_access_registers();
 326         lockdep_on();
 327 }