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/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/extable.h>
  17 #include <linux/pfn.h>
  18 #include <linux/uaccess.h>
  19 #include <linux/kernel.h>
  20 #include <asm/asm-extable.h>
  21 #include <linux/memblock.h>
  22 #include <asm/diag.h>
  23 #include <asm/ebcdic.h>
  24 #include <asm/ipl.h>
  25 #include <asm/lowcore.h>
  26 #include <asm/processor.h>
  27 #include <asm/sections.h>
  28 #include <asm/setup.h>
  29 #include <asm/sysinfo.h>
  30 #include <asm/cpcmd.h>
  31 #include <asm/sclp.h>
  32 #include <asm/facility.h>
  33 #include <asm/boot_data.h>
  34 #include <asm/switch_to.h>
  35 #include "entry.h"
  36
  37 #define decompressor_handled_param(param)                       \
  38 static int __init ignore_decompressor_param_##param(char *s)    \
  39 {                                                               \
  40         return 0;                                               \
  41 }                                                               \
  42 early_param(#param, ignore_decompressor_param_##param)
  43
  44 decompressor_handled_param(mem);
  45 decompressor_handled_param(vmalloc);
  46 decompressor_handled_param(dfltcc);
  47 decompressor_handled_param(facilities);
  48 decompressor_handled_param(nokaslr);
  49 #if IS_ENABLED(CONFIG_KVM)
  50 decompressor_handled_param(prot_virt);
  51 #endif
  52
  53 static void __init kasan_early_init(void)
  54 {
  55 #ifdef CONFIG_KASAN
  56         init_task.kasan_depth = 0;
  57         sclp_early_printk("KernelAddressSanitizer initialized\n");
  58 #endif
  59 }
  60
  61 static void __init reset_tod_clock(void)
  62 {
  63         union tod_clock clk;
  64
  65         if (store_tod_clock_ext_cc(&clk) == 0)
  66                 return;
  67         /* TOD clock not running. Set the clock to Unix Epoch. */
  68         if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
  69                 disabled_wait();
  70
  71         memset(&tod_clock_base, 0, sizeof(tod_clock_base));
  72         tod_clock_base.tod = TOD_UNIX_EPOCH;
  73         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
  74 }
  75
  76 /*
  77  * Initialize storage key for kernel pages
  78  */
  79 static noinline __init void init_kernel_storage_key(void)
  80 {
  81 #if PAGE_DEFAULT_KEY
  82         unsigned long end_pfn, init_pfn;
  83
  84         end_pfn = PFN_UP(__pa(_end));
  85
  86         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  87                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  88                                      PAGE_DEFAULT_KEY, 0);
  89 #endif
  90 }
  91
  92 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  93
  94 static noinline __init void detect_machine_type(void)
  95 {
  96         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  97
  98         /* Check current-configuration-level */
  99         if (stsi(NULL, 0, 0, 0) <= 2) {
 100                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 101                 return;
 102         }
 103         /* Get virtual-machine cpu information. */
 104         if (stsi(vmms, 3, 2, 2) || !vmms->count)
 105                 return;
 106
 107         /* Detect known hypervisors */
 108         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 109                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 110         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
 111                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 112 }
 113
 114 /* Remove leading, trailing and double whitespace. */
 115 static inline void strim_all(char *str)
 116 {
 117         char *s;
 118
 119         s = strim(str);
 120         if (s != str)
 121                 memmove(str, s, strlen(s));
 122         while (*str) {
 123                 if (!isspace(*str++))
 124                         continue;
 125                 if (isspace(*str)) {
 126                         s = skip_spaces(str);
 127                         memmove(str, s, strlen(s) + 1);
 128                 }
 129         }
 130 }
 131
 132 static noinline __init void setup_arch_string(void)
 133 {
 134         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 135         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 136         char mstr[80], hvstr[17];
 137
 138         if (stsi(mach, 1, 1, 1))
 139                 return;
 140         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 141         EBCASC(mach->type, sizeof(mach->type));
 142         EBCASC(mach->model, sizeof(mach->model));
 143         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 144         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 145                 mach->manufacturer, mach->type,
 146                 mach->model, mach->model_capacity);
 147         strim_all(mstr);
 148         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 149                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 150                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 151                 strim_all(hvstr);
 152         } else {
 153                 sprintf(hvstr, "%s",
 154                         MACHINE_IS_LPAR ? "LPAR" :
 155                         MACHINE_IS_VM ? "z/VM" :
 156                         MACHINE_IS_KVM ? "KVM" : "unknown");
 157         }
 158         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 159 }
 160
 161 static __init void setup_topology(void)
 162 {
 163         int max_mnest;
 164
 165         if (!test_facility(11))
 166                 return;
 167         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 168         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 169                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 170                         break;
 171         }
 172         topology_max_mnest = max_mnest;
 173 }
 174
 175 void __do_early_pgm_check(struct pt_regs *regs)
 176 {
 177         if (!fixup_exception(regs))
 178                 disabled_wait();
 179 }
 180
 181 static noinline __init void setup_lowcore_early(void)
 182 {
 183         psw_t psw;
 184
 185         psw.addr = (unsigned long)early_pgm_check_handler;
 186         psw.mask = PSW_KERNEL_BITS;
 187         S390_lowcore.program_new_psw = psw;
 188         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 189 }
 190
 191 static noinline __init void setup_facility_list(void)
 192 {
 193         memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
 194         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 195                 __clear_facility(82, alt_stfle_fac_list);
 196 }
 197
 198 static __init void detect_diag9c(void)
 199 {
 200         unsigned int cpu_address;
 201         int rc;
 202
 203         cpu_address = stap();
 204         diag_stat_inc(DIAG_STAT_X09C);
 205         asm volatile(
 206                 "       diag    %2,0,0x9c\n"
 207                 "0:     la      %0,0\n"
 208                 "1:\n"
 209                 EX_TABLE(0b,1b)
 210                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 211         if (!rc)
 212                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 213 }
 214
 215 static __init void detect_machine_facilities(void)
 216 {
 217         if (test_facility(8)) {
 218                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 219                 __ctl_set_bit(0, 23);
 220         }
 221         if (test_facility(78))
 222                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 223         if (test_facility(3))
 224                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 225         if (test_facility(50) && test_facility(73)) {
 226                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 227                 __ctl_set_bit(0, 55);
 228         }
 229         if (test_facility(51))
 230                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 231         if (test_facility(129)) {
 232                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 233                 __ctl_set_bit(0, 17);
 234         }
 235         if (test_facility(130))
 236                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 237         if (test_facility(133))
 238                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 239         if (test_facility(139) && (tod_clock_base.tod >> 63)) {
 240                 /* Enabled signed clock comparator comparisons */
 241                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 242                 clock_comparator_max = -1ULL >> 1;
 243                 __ctl_set_bit(0, 53);
 244         }
 245         if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
 246                 S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
 247                 /* the control bit is set during PCI initialization */
 248         }
 249         if (test_facility(194))
 250                 S390_lowcore.machine_flags |= MACHINE_FLAG_RDP;
 251 }
 252
 253 static inline void save_vector_registers(void)
 254 {
 255 #ifdef CONFIG_CRASH_DUMP
 256         if (test_facility(129))
 257                 save_vx_regs(boot_cpu_vector_save_area);
 258 #endif
 259 }
 260
 261 static inline void setup_control_registers(void)
 262 {
 263         unsigned long reg;
 264
 265         __ctl_store(reg, 0, 0);
 266         reg |= CR0_LOW_ADDRESS_PROTECTION;
 267         reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
 268         reg |= CR0_EXTERNAL_CALL_SUBMASK;
 269         __ctl_load(reg, 0, 0);
 270 }
 271
 272 static inline void setup_access_registers(void)
 273 {
 274         unsigned int acrs[NUM_ACRS] = { 0 };
 275
 276         restore_access_regs(acrs);
 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 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 288 static void __init setup_boot_command_line(void)
 289 {
 290         /* copy arch command line */
 291         strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
 292 }
 293
 294 static void __init sort_amode31_extable(void)
 295 {
 296         sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
 297 }
 298
 299 void __init startup_init(void)
 300 {
 301         kasan_early_init();
 302         reset_tod_clock();
 303         time_early_init();
 304         init_kernel_storage_key();
 305         lockdep_off();
 306         sort_amode31_extable();
 307         setup_lowcore_early();
 308         setup_facility_list();
 309         detect_machine_type();
 310         setup_arch_string();
 311         setup_boot_command_line();
 312         detect_diag9c();
 313         detect_machine_facilities();
 314         save_vector_registers();
 315         setup_topology();
 316         sclp_early_detect();
 317         setup_control_registers();
 318         setup_access_registers();
 319         lockdep_on();
 320 }