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 <asm/boot_data.h>
  33 #include "entry.h"
  34
  35 static void __init reset_tod_clock(void)
  36 {
  37         u64 time;
  38
  39         if (store_tod_clock(&time) == 0)
  40                 return;
  41         /* TOD clock not running. Set the clock to Unix Epoch. */
  42         if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
  43                 disabled_wait();
  44
  45         memset(tod_clock_base, 0, 16);
  46         *(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
  47         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
  48 }
  49
  50 /*
  51  * Initialize storage key for kernel pages
  52  */
  53 static noinline __init void init_kernel_storage_key(void)
  54 {
  55 #if PAGE_DEFAULT_KEY
  56         unsigned long end_pfn, init_pfn;
  57
  58         end_pfn = PFN_UP(__pa(_end));
  59
  60         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  61                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  62                                      PAGE_DEFAULT_KEY, 0);
  63 #endif
  64 }
  65
  66 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  67
  68 static noinline __init void detect_machine_type(void)
  69 {
  70         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  71
  72         /* Check current-configuration-level */
  73         if (stsi(NULL, 0, 0, 0) <= 2) {
  74                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
  75                 return;
  76         }
  77         /* Get virtual-machine cpu information. */
  78         if (stsi(vmms, 3, 2, 2) || !vmms->count)
  79                 return;
  80
  81         /* Detect known hypervisors */
  82         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
  83                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
  84         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
  85                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
  86 }
  87
  88 /* Remove leading, trailing and double whitespace. */
  89 static inline void strim_all(char *str)
  90 {
  91         char *s;
  92
  93         s = strim(str);
  94         if (s != str)
  95                 memmove(str, s, strlen(s));
  96         while (*str) {
  97                 if (!isspace(*str++))
  98                         continue;
  99                 if (isspace(*str)) {
 100                         s = skip_spaces(str);
 101                         memmove(str, s, strlen(s) + 1);
 102                 }
 103         }
 104 }
 105
 106 static noinline __init void setup_arch_string(void)
 107 {
 108         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 109         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 110         char mstr[80], hvstr[17];
 111
 112         if (stsi(mach, 1, 1, 1))
 113                 return;
 114         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 115         EBCASC(mach->type, sizeof(mach->type));
 116         EBCASC(mach->model, sizeof(mach->model));
 117         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 118         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 119                 mach->manufacturer, mach->type,
 120                 mach->model, mach->model_capacity);
 121         strim_all(mstr);
 122         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 123                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 124                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 125                 strim_all(hvstr);
 126         } else {
 127                 sprintf(hvstr, "%s",
 128                         MACHINE_IS_LPAR ? "LPAR" :
 129                         MACHINE_IS_VM ? "z/VM" :
 130                         MACHINE_IS_KVM ? "KVM" : "unknown");
 131         }
 132         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 133 }
 134
 135 static __init void setup_topology(void)
 136 {
 137         int max_mnest;
 138
 139         if (!test_facility(11))
 140                 return;
 141         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 142         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 143                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 144                         break;
 145         }
 146         topology_max_mnest = max_mnest;
 147 }
 148
 149 static void early_pgm_check_handler(void)
 150 {
 151         const struct exception_table_entry *fixup;
 152         unsigned long cr0, cr0_new;
 153         unsigned long addr;
 154
 155         addr = S390_lowcore.program_old_psw.addr;
 156         fixup = s390_search_extables(addr);
 157         if (!fixup)
 158                 disabled_wait();
 159         /* Disable low address protection before storing into lowcore. */
 160         __ctl_store(cr0, 0, 0);
 161         cr0_new = cr0 & ~(1UL << 28);
 162         __ctl_load(cr0_new, 0, 0);
 163         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 164         __ctl_load(cr0, 0, 0);
 165 }
 166
 167 static noinline __init void setup_lowcore_early(void)
 168 {
 169         psw_t psw;
 170
 171         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 172         if (IS_ENABLED(CONFIG_KASAN))
 173                 psw.mask |= PSW_MASK_DAT;
 174         psw.addr = (unsigned long) s390_base_ext_handler;
 175         S390_lowcore.external_new_psw = psw;
 176         psw.addr = (unsigned long) s390_base_pgm_handler;
 177         S390_lowcore.program_new_psw = psw;
 178         s390_base_pgm_handler_fn = early_pgm_check_handler;
 179         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 180 }
 181
 182 static noinline __init void setup_facility_list(void)
 183 {
 184         memcpy(S390_lowcore.alt_stfle_fac_list,
 185                S390_lowcore.stfle_fac_list,
 186                sizeof(S390_lowcore.alt_stfle_fac_list));
 187         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 188                 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
 189 }
 190
 191 static __init void detect_diag9c(void)
 192 {
 193         unsigned int cpu_address;
 194         int rc;
 195
 196         cpu_address = stap();
 197         diag_stat_inc(DIAG_STAT_X09C);
 198         asm volatile(
 199                 "       diag    %2,0,0x9c\n"
 200                 "0:     la      %0,0\n"
 201                 "1:\n"
 202                 EX_TABLE(0b,1b)
 203                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 204         if (!rc)
 205                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 206 }
 207
 208 static __init void detect_diag44(void)
 209 {
 210         int rc;
 211
 212         diag_stat_inc(DIAG_STAT_X044);
 213         asm volatile(
 214                 "       diag    0,0,0x44\n"
 215                 "0:     la      %0,0\n"
 216                 "1:\n"
 217                 EX_TABLE(0b,1b)
 218                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 219         if (!rc)
 220                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 221 }
 222
 223 static __init void detect_machine_facilities(void)
 224 {
 225         if (test_facility(8)) {
 226                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 227                 __ctl_set_bit(0, 23);
 228         }
 229         if (test_facility(78))
 230                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 231         if (test_facility(3))
 232                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 233         if (test_facility(50) && test_facility(73)) {
 234                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 235                 __ctl_set_bit(0, 55);
 236         }
 237         if (test_facility(51))
 238                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 239         if (test_facility(129)) {
 240                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 241                 __ctl_set_bit(0, 17);
 242         }
 243         if (test_facility(130)) {
 244                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 245                 __ctl_set_bit(0, 20);
 246         }
 247         if (test_facility(133))
 248                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 249         if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
 250                 /* Enabled signed clock comparator comparisons */
 251                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 252                 clock_comparator_max = -1ULL >> 1;
 253                 __ctl_set_bit(0, 53);
 254         }
 255         if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
 256                 S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
 257                 /* the control bit is set during PCI initialization */
 258         }
 259 }
 260
 261 static inline void save_vector_registers(void)
 262 {
 263 #ifdef CONFIG_CRASH_DUMP
 264         if (test_facility(129))
 265                 save_vx_regs(boot_cpu_vector_save_area);
 266 #endif
 267 }
 268
 269 static int __init disable_vector_extension(char *str)
 270 {
 271         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 272         __ctl_clear_bit(0, 17);
 273         return 0;
 274 }
 275 early_param("novx", disable_vector_extension);
 276
 277 static int __init noexec_setup(char *str)
 278 {
 279         bool enabled;
 280         int rc;
 281
 282         rc = kstrtobool(str, &enabled);
 283         if (!rc && !enabled) {
 284                 /* Disable no-execute support */
 285                 S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
 286                 __ctl_clear_bit(0, 20);
 287         }
 288         return rc;
 289 }
 290 early_param("noexec", noexec_setup);
 291
 292 static int __init cad_setup(char *str)
 293 {
 294         bool enabled;
 295         int rc;
 296
 297         rc = kstrtobool(str, &enabled);
 298         if (!rc && enabled && test_facility(128))
 299                 /* Enable problem state CAD. */
 300                 __ctl_set_bit(2, 3);
 301         return rc;
 302 }
 303 early_param("cad", cad_setup);
 304
 305 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 306 static void __init setup_boot_command_line(void)
 307 {
 308         /* copy arch command line */
 309         strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
 310 }
 311
 312 static void __init check_image_bootable(void)
 313 {
 314         if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
 315                 return;
 316
 317         sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
 318         sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
 319         sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
 320         disabled_wait();
 321 }
 322
 323 void __init startup_init(void)
 324 {
 325         reset_tod_clock();
 326         check_image_bootable();
 327         time_early_init();
 328         init_kernel_storage_key();
 329         lockdep_off();
 330         setup_lowcore_early();
 331         setup_facility_list();
 332         detect_machine_type();
 333         setup_arch_string();
 334         setup_boot_command_line();
 335         detect_diag9c();
 336         detect_diag44();
 337         detect_machine_facilities();
 338         save_vector_registers();
 339         setup_topology();
 340         sclp_early_detect();
 341         lockdep_on();
 342 }