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 /*
  36  * Initialize storage key for kernel pages
  37  */
  38 static noinline __init void init_kernel_storage_key(void)
  39 {
  40 #if PAGE_DEFAULT_KEY
  41         unsigned long end_pfn, init_pfn;
  42
  43         end_pfn = PFN_UP(__pa(_end));
  44
  45         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  46                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  47                                      PAGE_DEFAULT_KEY, 0);
  48 #endif
  49 }
  50
  51 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  52
  53 static noinline __init void detect_machine_type(void)
  54 {
  55         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  56
  57         /* Check current-configuration-level */
  58         if (stsi(NULL, 0, 0, 0) <= 2) {
  59                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
  60                 return;
  61         }
  62         /* Get virtual-machine cpu information. */
  63         if (stsi(vmms, 3, 2, 2) || !vmms->count)
  64                 return;
  65
  66         /* Detect known hypervisors */
  67         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
  68                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
  69         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
  70                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
  71 }
  72
  73 /* Remove leading, trailing and double whitespace. */
  74 static inline void strim_all(char *str)
  75 {
  76         char *s;
  77
  78         s = strim(str);
  79         if (s != str)
  80                 memmove(str, s, strlen(s));
  81         while (*str) {
  82                 if (!isspace(*str++))
  83                         continue;
  84                 if (isspace(*str)) {
  85                         s = skip_spaces(str);
  86                         memmove(str, s, strlen(s) + 1);
  87                 }
  88         }
  89 }
  90
  91 static noinline __init void setup_arch_string(void)
  92 {
  93         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
  94         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
  95         char mstr[80], hvstr[17];
  96
  97         if (stsi(mach, 1, 1, 1))
  98                 return;
  99         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 100         EBCASC(mach->type, sizeof(mach->type));
 101         EBCASC(mach->model, sizeof(mach->model));
 102         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 103         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 104                 mach->manufacturer, mach->type,
 105                 mach->model, mach->model_capacity);
 106         strim_all(mstr);
 107         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 108                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 109                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 110                 strim_all(hvstr);
 111         } else {
 112                 sprintf(hvstr, "%s",
 113                         MACHINE_IS_LPAR ? "LPAR" :
 114                         MACHINE_IS_VM ? "z/VM" :
 115                         MACHINE_IS_KVM ? "KVM" : "unknown");
 116         }
 117         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 118 }
 119
 120 static __init void setup_topology(void)
 121 {
 122         int max_mnest;
 123
 124         if (!test_facility(11))
 125                 return;
 126         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 127         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 128                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 129                         break;
 130         }
 131         topology_max_mnest = max_mnest;
 132 }
 133
 134 static void early_pgm_check_handler(void)
 135 {
 136         const struct exception_table_entry *fixup;
 137         unsigned long cr0, cr0_new;
 138         unsigned long addr;
 139
 140         addr = S390_lowcore.program_old_psw.addr;
 141         fixup = search_exception_tables(addr);
 142         if (!fixup)
 143                 disabled_wait(0);
 144         /* Disable low address protection before storing into lowcore. */
 145         __ctl_store(cr0, 0, 0);
 146         cr0_new = cr0 & ~(1UL << 28);
 147         __ctl_load(cr0_new, 0, 0);
 148         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 149         __ctl_load(cr0, 0, 0);
 150 }
 151
 152 static noinline __init void setup_lowcore_early(void)
 153 {
 154         psw_t psw;
 155
 156         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 157         psw.addr = (unsigned long) s390_base_ext_handler;
 158         S390_lowcore.external_new_psw = psw;
 159         psw.addr = (unsigned long) s390_base_pgm_handler;
 160         S390_lowcore.program_new_psw = psw;
 161         s390_base_pgm_handler_fn = early_pgm_check_handler;
 162         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 163 }
 164
 165 static noinline __init void setup_facility_list(void)
 166 {
 167         stfle(S390_lowcore.stfle_fac_list,
 168               ARRAY_SIZE(S390_lowcore.stfle_fac_list));
 169         memcpy(S390_lowcore.alt_stfle_fac_list,
 170                S390_lowcore.stfle_fac_list,
 171                sizeof(S390_lowcore.alt_stfle_fac_list));
 172         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 173                 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
 174 }
 175
 176 static __init void detect_diag9c(void)
 177 {
 178         unsigned int cpu_address;
 179         int rc;
 180
 181         cpu_address = stap();
 182         diag_stat_inc(DIAG_STAT_X09C);
 183         asm volatile(
 184                 "       diag    %2,0,0x9c\n"
 185                 "0:     la      %0,0\n"
 186                 "1:\n"
 187                 EX_TABLE(0b,1b)
 188                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 189         if (!rc)
 190                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 191 }
 192
 193 static __init void detect_diag44(void)
 194 {
 195         int rc;
 196
 197         diag_stat_inc(DIAG_STAT_X044);
 198         asm volatile(
 199                 "       diag    0,0,0x44\n"
 200                 "0:     la      %0,0\n"
 201                 "1:\n"
 202                 EX_TABLE(0b,1b)
 203                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 204         if (!rc)
 205                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 206 }
 207
 208 static __init void detect_machine_facilities(void)
 209 {
 210         if (test_facility(8)) {
 211                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
 212                 __ctl_set_bit(0, 23);
 213         }
 214         if (test_facility(78))
 215                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
 216         if (test_facility(3))
 217                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 218         if (test_facility(50) && test_facility(73)) {
 219                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
 220                 __ctl_set_bit(0, 55);
 221         }
 222         if (test_facility(51))
 223                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
 224         if (test_facility(129)) {
 225                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
 226                 __ctl_set_bit(0, 17);
 227         }
 228         if (test_facility(130)) {
 229                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
 230                 __ctl_set_bit(0, 20);
 231         }
 232         if (test_facility(133))
 233                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
 234         if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
 235                 /* Enabled signed clock comparator comparisons */
 236                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
 237                 clock_comparator_max = -1ULL >> 1;
 238                 __ctl_set_bit(0, 53);
 239         }
 240 }
 241
 242 static inline void save_vector_registers(void)
 243 {
 244 #ifdef CONFIG_CRASH_DUMP
 245         if (test_facility(129))
 246                 save_vx_regs(boot_cpu_vector_save_area);
 247 #endif
 248 }
 249
 250 static int __init disable_vector_extension(char *str)
 251 {
 252         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 253         __ctl_clear_bit(0, 17);
 254         return 0;
 255 }
 256 early_param("novx", disable_vector_extension);
 257
 258 static int __init noexec_setup(char *str)
 259 {
 260         bool enabled;
 261         int rc;
 262
 263         rc = kstrtobool(str, &enabled);
 264         if (!rc && !enabled) {
 265                 /* Disable no-execute support */
 266                 S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
 267                 __ctl_clear_bit(0, 20);
 268         }
 269         return rc;
 270 }
 271 early_param("noexec", noexec_setup);
 272
 273 static int __init cad_setup(char *str)
 274 {
 275         bool enabled;
 276         int rc;
 277
 278         rc = kstrtobool(str, &enabled);
 279         if (!rc && enabled && test_facility(128))
 280                 /* Enable problem state CAD. */
 281                 __ctl_set_bit(2, 3);
 282         return rc;
 283 }
 284 early_param("cad", cad_setup);
 285
 286 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 287 static void __init setup_boot_command_line(void)
 288 {
 289         /* copy arch command line */
 290         strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
 291 }
 292
 293 static void __init check_image_bootable(void)
 294 {
 295         if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
 296                 return;
 297
 298         sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
 299         sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
 300         sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
 301         disabled_wait(0xbadb007);
 302 }
 303
 304 void __init startup_init(void)
 305 {
 306         check_image_bootable();
 307         time_early_init();
 308         init_kernel_storage_key();
 309         lockdep_off();
 310         setup_lowcore_early();
 311         setup_facility_list();
 312         detect_machine_type();
 313         setup_arch_string();
 314         ipl_store_parameters();
 315         setup_boot_command_line();
 316         detect_diag9c();
 317         detect_diag44();
 318         detect_machine_facilities();
 319         save_vector_registers();
 320         setup_topology();
 321         sclp_early_detect();
 322         lockdep_on();
 323 }