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 <asm/switch_to.h>
  34 #include "entry.h"
  35
  36 static void __init reset_tod_clock(void)
  37 {
  38         u64 time;
  39
  40         if (store_tod_clock(&time) == 0)
  41                 return;
  42         /* TOD clock not running. Set the clock to Unix Epoch. */
  43         if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
  44                 disabled_wait();
  45
  46         memset(tod_clock_base, 0, 16);
  47         *(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
  48         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
  49 }
  50
  51 /*
  52  * Initialize storage key for kernel pages
  53  */
  54 static noinline __init void init_kernel_storage_key(void)
  55 {
  56 #if PAGE_DEFAULT_KEY
  57         unsigned long end_pfn, init_pfn;
  58
  59         end_pfn = PFN_UP(__pa(_end));
  60
  61         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  62                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  63                                      PAGE_DEFAULT_KEY, 0);
  64 #endif
  65 }
  66
  67 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  68
  69 static noinline __init void detect_machine_type(void)
  70 {
  71         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  72
  73         /* Check current-configuration-level */
  74         if (stsi(NULL, 0, 0, 0) <= 2) {
  75                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
  76                 return;
  77         }
  78         /* Get virtual-machine cpu information. */
  79         if (stsi(vmms, 3, 2, 2) || !vmms->count)
  80                 return;
  81
  82         /* Detect known hypervisors */
  83         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
  84                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
  85         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
  86                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
  87 }
  88
  89 /* Remove leading, trailing and double whitespace. */
  90 static inline void strim_all(char *str)
  91 {
  92         char *s;
  93
  94         s = strim(str);
  95         if (s != str)
  96                 memmove(str, s, strlen(s));
  97         while (*str) {
  98                 if (!isspace(*str++))
  99                         continue;
 100                 if (isspace(*str)) {
 101                         s = skip_spaces(str);
 102                         memmove(str, s, strlen(s) + 1);
 103                 }
 104         }
 105 }
 106
 107 static noinline __init void setup_arch_string(void)
 108 {
 109         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 110         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 111         char mstr[80], hvstr[17];
 112
 113         if (stsi(mach, 1, 1, 1))
 114                 return;
 115         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 116         EBCASC(mach->type, sizeof(mach->type));
 117         EBCASC(mach->model, sizeof(mach->model));
 118         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 119         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 120                 mach->manufacturer, mach->type,
 121                 mach->model, mach->model_capacity);
 122         strim_all(mstr);
 123         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 124                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 125                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 126                 strim_all(hvstr);
 127         } else {
 128                 sprintf(hvstr, "%s",
 129                         MACHINE_IS_LPAR ? "LPAR" :
 130                         MACHINE_IS_VM ? "z/VM" :
 131                         MACHINE_IS_KVM ? "KVM" : "unknown");
 132         }
 133         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 134 }
 135
 136 static __init void setup_topology(void)
 137 {
 138         int max_mnest;
 139
 140         if (!test_facility(11))
 141                 return;
 142         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 143         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 144                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 145                         break;
 146         }
 147         topology_max_mnest = max_mnest;
 148 }
 149
 150 static void early_pgm_check_handler(void)
 151 {
 152         const struct exception_table_entry *fixup;
 153         unsigned long cr0, cr0_new;
 154         unsigned long addr;
 155
 156         addr = S390_lowcore.program_old_psw.addr;
 157         fixup = s390_search_extables(addr);
 158         if (!fixup)
 159                 disabled_wait();
 160         /* Disable low address protection before storing into lowcore. */
 161         __ctl_store(cr0, 0, 0);
 162         cr0_new = cr0 & ~(1UL << 28);
 163         __ctl_load(cr0_new, 0, 0);
 164         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 165         __ctl_load(cr0, 0, 0);
 166 }
 167
 168 static noinline __init void setup_lowcore_early(void)
 169 {
 170         psw_t psw;
 171
 172         psw.addr = (unsigned long)s390_base_pgm_handler;
 173         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 174         if (IS_ENABLED(CONFIG_KASAN))
 175                 psw.mask |= PSW_MASK_DAT;
 176         S390_lowcore.program_new_psw = psw;
 177         s390_base_pgm_handler_fn = early_pgm_check_handler;
 178         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 179 }
 180
 181 static noinline __init void setup_facility_list(void)
 182 {
 183         memcpy(S390_lowcore.alt_stfle_fac_list,
 184                S390_lowcore.stfle_fac_list,
 185                sizeof(S390_lowcore.alt_stfle_fac_list));
 186         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 187                 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
 188 }
 189
 190 static __init void detect_diag9c(void)
 191 {
 192         unsigned int cpu_address;
 193         int rc;
 194
 195         cpu_address = stap();
 196         diag_stat_inc(DIAG_STAT_X09C);
 197         asm volatile(
 198                 "       diag    %2,0,0x9c\n"
 199                 "0:     la      %0,0\n"
 200                 "1:\n"
 201                 EX_TABLE(0b,1b)
 202                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 203         if (!rc)
 204                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 205 }
 206
 207 static __init void detect_machine_facilities(void)
 208 {
 209         if (test_facility(8)) {
 210                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 211                 __ctl_set_bit(0, 23);
 212         }
 213         if (test_facility(78))
 214                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 215         if (test_facility(3))
 216                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 217         if (test_facility(50) && test_facility(73)) {
 218                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 219                 __ctl_set_bit(0, 55);
 220         }
 221         if (test_facility(51))
 222                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 223         if (test_facility(129)) {
 224                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 225                 __ctl_set_bit(0, 17);
 226         }
 227         if (test_facility(130) && !noexec_disabled) {
 228                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 229                 __ctl_set_bit(0, 20);
 230         }
 231         if (test_facility(133))
 232                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 233         if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
 234                 /* Enabled signed clock comparator comparisons */
 235                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 236                 clock_comparator_max = -1ULL >> 1;
 237                 __ctl_set_bit(0, 53);
 238         }
 239 }
 240
 241 static inline void save_vector_registers(void)
 242 {
 243 #ifdef CONFIG_CRASH_DUMP
 244         if (test_facility(129))
 245                 save_vx_regs(boot_cpu_vector_save_area);
 246 #endif
 247 }
 248
 249 static inline void setup_control_registers(void)
 250 {
 251         unsigned long reg;
 252
 253         __ctl_store(reg, 0, 0);
 254         reg |= CR0_LOW_ADDRESS_PROTECTION;
 255         reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
 256         reg |= CR0_EXTERNAL_CALL_SUBMASK;
 257         __ctl_load(reg, 0, 0);
 258 }
 259
 260 static inline void setup_access_registers(void)
 261 {
 262         unsigned int acrs[NUM_ACRS] = { 0 };
 263
 264         restore_access_regs(acrs);
 265 }
 266
 267 static int __init disable_vector_extension(char *str)
 268 {
 269         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 270         __ctl_clear_bit(0, 17);
 271         return 0;
 272 }
 273 early_param("novx", disable_vector_extension);
 274
 275 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 276 static void __init setup_boot_command_line(void)
 277 {
 278         /* copy arch command line */
 279         strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
 280 }
 281
 282 static void __init check_image_bootable(void)
 283 {
 284         if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
 285                 return;
 286
 287         sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
 288         sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
 289         sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
 290         disabled_wait();
 291 }
 292
 293 void __init startup_init(void)
 294 {
 295         reset_tod_clock();
 296         check_image_bootable();
 297         time_early_init();
 298         init_kernel_storage_key();
 299         lockdep_off();
 300         setup_lowcore_early();
 301         setup_facility_list();
 302         detect_machine_type();
 303         setup_arch_string();
 304         setup_boot_command_line();
 305         detect_diag9c();
 306         detect_machine_facilities();
 307         save_vector_registers();
 308         setup_topology();
 309         sclp_early_detect();
 310         setup_control_registers();
 311         setup_access_registers();
 312         lockdep_on();
 313 }