arch/s390/kernel/early.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Copyright IBM Corp. 2007, 2009
   4  *    Author(s): Hongjie Yang <[email protected]>,
   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(noexec);
  48 decompressor_handled_param(facilities);
  49 decompressor_handled_param(nokaslr);
  50 #if IS_ENABLED(CONFIG_KVM)
  51 decompressor_handled_param(prot_virt);
  52 #endif
  53
  54 static void __init kasan_early_init(void)
  55 {
  56 #ifdef CONFIG_KASAN
  57         init_task.kasan_depth = 0;
  58         sclp_early_printk("KernelAddressSanitizer initialized\n");
  59 #endif
  60 }
  61
  62 static void __init reset_tod_clock(void)
  63 {
  64         union tod_clock clk;
  65
  66         if (store_tod_clock_ext_cc(&clk) == 0)
  67                 return;
  68         /* TOD clock not running. Set the clock to Unix Epoch. */
  69         if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
  70                 disabled_wait();
  71
  72         memset(&tod_clock_base, 0, sizeof(tod_clock_base));
  73         tod_clock_base.tod = TOD_UNIX_EPOCH;
  74         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
  75 }
  76
  77 /*
  78  * Initialize storage key for kernel pages
  79  */
  80 static noinline __init void init_kernel_storage_key(void)
  81 {
  82 #if PAGE_DEFAULT_KEY
  83         unsigned long end_pfn, init_pfn;
  84
  85         end_pfn = PFN_UP(__pa(_end));
  86
  87         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  88                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  89                                      PAGE_DEFAULT_KEY, 0);
  90 #endif
  91 }
  92
  93 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  94
  95 static noinline __init void detect_machine_type(void)
  96 {
  97         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  98
  99         /* Check current-configuration-level */
 100         if (stsi(NULL, 0, 0, 0) <= 2) {
 101                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 102                 return;
 103         }
 104         /* Get virtual-machine cpu information. */
 105         if (stsi(vmms, 3, 2, 2) || !vmms->count)
 106                 return;
 107
 108         /* Detect known hypervisors */
 109         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 110                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 111         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
 112                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 113 }
 114
 115 /* Remove leading, trailing and double whitespace. */
 116 static inline void strim_all(char *str)
 117 {
 118         char *s;
 119
 120         s = strim(str);
 121         if (s != str)
 122                 memmove(str, s, strlen(s));
 123         while (*str) {
 124                 if (!isspace(*str++))
 125                         continue;
 126                 if (isspace(*str)) {
 127                         s = skip_spaces(str);
 128                         memmove(str, s, strlen(s) + 1);
 129                 }
 130         }
 131 }
 132
 133 static noinline __init void setup_arch_string(void)
 134 {
 135         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 136         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 137         char mstr[80], hvstr[17];
 138
 139         if (stsi(mach, 1, 1, 1))
 140                 return;
 141         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 142         EBCASC(mach->type, sizeof(mach->type));
 143         EBCASC(mach->model, sizeof(mach->model));
 144         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 145         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 146                 mach->manufacturer, mach->type,
 147                 mach->model, mach->model_capacity);
 148         strim_all(mstr);
 149         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 150                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 151                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 152                 strim_all(hvstr);
 153         } else {
 154                 sprintf(hvstr, "%s",
 155                         MACHINE_IS_LPAR ? "LPAR" :
 156                         MACHINE_IS_VM ? "z/VM" :
 157                         MACHINE_IS_KVM ? "KVM" : "unknown");
 158         }
 159         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 160 }
 161
 162 static __init void setup_topology(void)
 163 {
 164         int max_mnest;
 165
 166         if (!test_facility(11))
 167                 return;
 168         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 169         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 170                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 171                         break;
 172         }
 173         topology_max_mnest = max_mnest;
 174 }
 175
 176 void __do_early_pgm_check(struct pt_regs *regs)
 177 {
 178         if (!fixup_exception(regs))
 179                 disabled_wait();
 180 }
 181
 182 static noinline __init void setup_lowcore_early(void)
 183 {
 184         psw_t psw;
 185
 186         psw.addr = (unsigned long)early_pgm_check_handler;
 187         psw.mask = PSW_KERNEL_BITS;
 188         S390_lowcore.program_new_psw = psw;
 189         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 190 }
 191
 192 static noinline __init void setup_facility_list(void)
 193 {
 194         memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
 195         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 196                 __clear_facility(82, alt_stfle_fac_list);
 197 }
 198
 199 static __init void detect_diag9c(void)
 200 {
 201         unsigned int cpu_address;
 202         int rc;
 203
 204         cpu_address = stap();
 205         diag_stat_inc(DIAG_STAT_X09C);
 206         asm volatile(
 207                 "       diag    %2,0,0x9c\n"
 208                 "0:     la      %0,0\n"
 209                 "1:\n"
 210                 EX_TABLE(0b,1b)
 211                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 212         if (!rc)
 213                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 214 }
 215
 216 static __init void detect_machine_facilities(void)
 217 {
 218         if (test_facility(8)) {
 219                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 220                 __ctl_set_bit(0, 23);
 221         }
 222         if (test_facility(78))
 223                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 224         if (test_facility(3))
 225                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 226         if (test_facility(50) && test_facility(73)) {
 227                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 228                 __ctl_set_bit(0, 55);
 229         }
 230         if (test_facility(51))
 231                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 232         if (test_facility(129)) {
 233                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 234                 __ctl_set_bit(0, 17);
 235         }
 236         if (test_facility(130) && !noexec_disabled) {
 237                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 238                 __ctl_set_bit(0, 20);
 239         }
 240         if (test_facility(133))
 241                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 242         if (test_facility(139) && (tod_clock_base.tod >> 63)) {
 243                 /* Enabled signed clock comparator comparisons */
 244                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 245                 clock_comparator_max = -1ULL >> 1;
 246                 __ctl_set_bit(0, 53);
 247         }
 248         if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
 249                 S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
 250                 /* the control bit is set during PCI initialization */
 251         }
 252         if (test_facility(194))
 253                 S390_lowcore.machine_flags |= MACHINE_FLAG_RDP;
 254 }
 255
 256 static inline void save_vector_registers(void)
 257 {
 258 #ifdef CONFIG_CRASH_DUMP
 259         if (test_facility(129))
 260                 save_vx_regs(boot_cpu_vector_save_area);
 261 #endif
 262 }
 263
 264 static inline void setup_control_registers(void)
 265 {
 266         unsigned long reg;
 267
 268         __ctl_store(reg, 0, 0);
 269         reg |= CR0_LOW_ADDRESS_PROTECTION;
 270         reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
 271         reg |= CR0_EXTERNAL_CALL_SUBMASK;
 272         __ctl_load(reg, 0, 0);
 273 }
 274
 275 static inline void setup_access_registers(void)
 276 {
 277         unsigned int acrs[NUM_ACRS] = { 0 };
 278
 279         restore_access_regs(acrs);
 280 }
 281
 282 static int __init disable_vector_extension(char *str)
 283 {
 284         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 285         __ctl_clear_bit(0, 17);
 286         return 0;
 287 }
 288 early_param("novx", disable_vector_extension);
 289
 290 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 291 static void __init setup_boot_command_line(void)
 292 {
 293         /* copy arch command line */
 294         strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
 295 }
 296
 297 static void __init sort_amode31_extable(void)
 298 {
 299         sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
 300 }
 301
 302 void __init startup_init(void)
 303 {
 304         kasan_early_init();
 305         reset_tod_clock();
 306         time_early_init();
 307         init_kernel_storage_key();
 308         lockdep_off();
 309         sort_amode31_extable();
 310         setup_lowcore_early();
 311         setup_facility_list();
 312         detect_machine_type();
 313         setup_arch_string();
 314         setup_boot_command_line();
 315         detect_diag9c();
 316         detect_machine_facilities();
 317         save_vector_registers();
 318         setup_topology();
 319         sclp_early_detect();
 320         setup_control_registers();
 321         setup_access_registers();
 322         lockdep_on();
 323 }