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/pci_insn.h>
  34 #include "entry.h"
  35
  36 /*
  37  * Initialize storage key for kernel pages
  38  */
  39 static noinline __init void init_kernel_storage_key(void)
  40 {
  41 #if PAGE_DEFAULT_KEY
  42         unsigned long end_pfn, init_pfn;
  43
  44         end_pfn = PFN_UP(__pa(_end));
  45
  46         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  47                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  48                                      PAGE_DEFAULT_KEY, 0);
  49 #endif
  50 }
  51
  52 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  53
  54 static noinline __init void detect_machine_type(void)
  55 {
  56         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  57
  58         /* Check current-configuration-level */
  59         if (stsi(NULL, 0, 0, 0) <= 2) {
  60                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
  61                 return;
  62         }
  63         /* Get virtual-machine cpu information. */
  64         if (stsi(vmms, 3, 2, 2) || !vmms->count)
  65                 return;
  66
  67         /* Detect known hypervisors */
  68         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
  69                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
  70         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
  71                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
  72 }
  73
  74 /* Remove leading, trailing and double whitespace. */
  75 static inline void strim_all(char *str)
  76 {
  77         char *s;
  78
  79         s = strim(str);
  80         if (s != str)
  81                 memmove(str, s, strlen(s));
  82         while (*str) {
  83                 if (!isspace(*str++))
  84                         continue;
  85                 if (isspace(*str)) {
  86                         s = skip_spaces(str);
  87                         memmove(str, s, strlen(s) + 1);
  88                 }
  89         }
  90 }
  91
  92 static noinline __init void setup_arch_string(void)
  93 {
  94         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
  95         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
  96         char mstr[80], hvstr[17];
  97
  98         if (stsi(mach, 1, 1, 1))
  99                 return;
 100         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 101         EBCASC(mach->type, sizeof(mach->type));
 102         EBCASC(mach->model, sizeof(mach->model));
 103         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 104         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 105                 mach->manufacturer, mach->type,
 106                 mach->model, mach->model_capacity);
 107         strim_all(mstr);
 108         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 109                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 110                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 111                 strim_all(hvstr);
 112         } else {
 113                 sprintf(hvstr, "%s",
 114                         MACHINE_IS_LPAR ? "LPAR" :
 115                         MACHINE_IS_VM ? "z/VM" :
 116                         MACHINE_IS_KVM ? "KVM" : "unknown");
 117         }
 118         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 119 }
 120
 121 static __init void setup_topology(void)
 122 {
 123         int max_mnest;
 124
 125         if (!test_facility(11))
 126                 return;
 127         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 128         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 129                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 130                         break;
 131         }
 132         topology_max_mnest = max_mnest;
 133 }
 134
 135 static void early_pgm_check_handler(void)
 136 {
 137         const struct exception_table_entry *fixup;
 138         unsigned long cr0, cr0_new;
 139         unsigned long addr;
 140
 141         addr = S390_lowcore.program_old_psw.addr;
 142         fixup = s390_search_extables(addr);
 143         if (!fixup)
 144                 disabled_wait();
 145         /* Disable low address protection before storing into lowcore. */
 146         __ctl_store(cr0, 0, 0);
 147         cr0_new = cr0 & ~(1UL << 28);
 148         __ctl_load(cr0_new, 0, 0);
 149         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 150         __ctl_load(cr0, 0, 0);
 151 }
 152
 153 static noinline __init void setup_lowcore_early(void)
 154 {
 155         psw_t psw;
 156
 157         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 158         psw.addr = (unsigned long) s390_base_ext_handler;
 159         S390_lowcore.external_new_psw = psw;
 160         psw.addr = (unsigned long) s390_base_pgm_handler;
 161         S390_lowcore.program_new_psw = psw;
 162         s390_base_pgm_handler_fn = early_pgm_check_handler;
 163         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 164 }
 165
 166 static noinline __init void setup_facility_list(void)
 167 {
 168         memcpy(S390_lowcore.alt_stfle_fac_list,
 169                S390_lowcore.stfle_fac_list,
 170                sizeof(S390_lowcore.alt_stfle_fac_list));
 171         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 172                 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
 173 }
 174
 175 static __init void detect_diag9c(void)
 176 {
 177         unsigned int cpu_address;
 178         int rc;
 179
 180         cpu_address = stap();
 181         diag_stat_inc(DIAG_STAT_X09C);
 182         asm volatile(
 183                 "       diag    %2,0,0x9c\n"
 184                 "0:     la      %0,0\n"
 185                 "1:\n"
 186                 EX_TABLE(0b,1b)
 187                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
 188         if (!rc)
 189                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
 190 }
 191
 192 static __init void detect_diag44(void)
 193 {
 194         int rc;
 195
 196         diag_stat_inc(DIAG_STAT_X044);
 197         asm volatile(
 198                 "       diag    0,0,0x44\n"
 199                 "0:     la      %0,0\n"
 200                 "1:\n"
 201                 EX_TABLE(0b,1b)
 202                 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
 203         if (!rc)
 204                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
 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)) {
 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         enable_mio_ctl();
 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();
 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         setup_boot_command_line();
 315         detect_diag9c();
 316         detect_diag44();
 317         detect_machine_facilities();
 318         save_vector_registers();
 319         setup_topology();
 320         sclp_early_detect();
 321         lockdep_on();
 322 }