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 int __bootdata(is_full_image);
  37
  38 static void __init reset_tod_clock(void)
  39 {
  40         union tod_clock clk;
  41
  42         if (store_tod_clock_ext_cc(&clk) == 0)
  43                 return;
  44         /* TOD clock not running. Set the clock to Unix Epoch. */
  45         if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
  46                 disabled_wait();
  47
  48         memset(&tod_clock_base, 0, sizeof(tod_clock_base));
  49         tod_clock_base.tod = TOD_UNIX_EPOCH;
  50         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
  51 }
  52
  53 /*
  54  * Initialize storage key for kernel pages
  55  */
  56 static noinline __init void init_kernel_storage_key(void)
  57 {
  58 #if PAGE_DEFAULT_KEY
  59         unsigned long end_pfn, init_pfn;
  60
  61         end_pfn = PFN_UP(__pa(_end));
  62
  63         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
  64                 page_set_storage_key(init_pfn << PAGE_SHIFT,
  65                                      PAGE_DEFAULT_KEY, 0);
  66 #endif
  67 }
  68
  69 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  70
  71 static noinline __init void detect_machine_type(void)
  72 {
  73         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
  74
  75         /* Check current-configuration-level */
  76         if (stsi(NULL, 0, 0, 0) <= 2) {
  77                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
  78                 return;
  79         }
  80         /* Get virtual-machine cpu information. */
  81         if (stsi(vmms, 3, 2, 2) || !vmms->count)
  82                 return;
  83
  84         /* Detect known hypervisors */
  85         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
  86                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
  87         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
  88                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
  89 }
  90
  91 /* Remove leading, trailing and double whitespace. */
  92 static inline void strim_all(char *str)
  93 {
  94         char *s;
  95
  96         s = strim(str);
  97         if (s != str)
  98                 memmove(str, s, strlen(s));
  99         while (*str) {
 100                 if (!isspace(*str++))
 101                         continue;
 102                 if (isspace(*str)) {
 103                         s = skip_spaces(str);
 104                         memmove(str, s, strlen(s) + 1);
 105                 }
 106         }
 107 }
 108
 109 static noinline __init void setup_arch_string(void)
 110 {
 111         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
 112         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
 113         char mstr[80], hvstr[17];
 114
 115         if (stsi(mach, 1, 1, 1))
 116                 return;
 117         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
 118         EBCASC(mach->type, sizeof(mach->type));
 119         EBCASC(mach->model, sizeof(mach->model));
 120         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
 121         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
 122                 mach->manufacturer, mach->type,
 123                 mach->model, mach->model_capacity);
 124         strim_all(mstr);
 125         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
 126                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
 127                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
 128                 strim_all(hvstr);
 129         } else {
 130                 sprintf(hvstr, "%s",
 131                         MACHINE_IS_LPAR ? "LPAR" :
 132                         MACHINE_IS_VM ? "z/VM" :
 133                         MACHINE_IS_KVM ? "KVM" : "unknown");
 134         }
 135         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
 136 }
 137
 138 static __init void setup_topology(void)
 139 {
 140         int max_mnest;
 141
 142         if (!test_facility(11))
 143                 return;
 144         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 145         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
 146                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
 147                         break;
 148         }
 149         topology_max_mnest = max_mnest;
 150 }
 151
 152 static void early_pgm_check_handler(void)
 153 {
 154         const struct exception_table_entry *fixup;
 155         unsigned long cr0, cr0_new;
 156         unsigned long addr;
 157
 158         addr = S390_lowcore.program_old_psw.addr;
 159         fixup = s390_search_extables(addr);
 160         if (!fixup)
 161                 disabled_wait();
 162         /* Disable low address protection before storing into lowcore. */
 163         __ctl_store(cr0, 0, 0);
 164         cr0_new = cr0 & ~(1UL << 28);
 165         __ctl_load(cr0_new, 0, 0);
 166         S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
 167         __ctl_load(cr0, 0, 0);
 168 }
 169
 170 static noinline __init void setup_lowcore_early(void)
 171 {
 172         psw_t psw;
 173
 174         psw.addr = (unsigned long)s390_base_pgm_handler;
 175         psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
 176         if (IS_ENABLED(CONFIG_KASAN))
 177                 psw.mask |= PSW_MASK_DAT;
 178         S390_lowcore.program_new_psw = psw;
 179         s390_base_pgm_handler_fn = early_pgm_check_handler;
 180         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
 181 }
 182
 183 static noinline __init void setup_facility_list(void)
 184 {
 185         memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
 186         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
 187                 __clear_facility(82, 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.tod >> 63)) {
 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         if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
 240                 S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
 241                 /* the control bit is set during PCI initialization */
 242         }
 243 }
 244
 245 static inline void save_vector_registers(void)
 246 {
 247 #ifdef CONFIG_CRASH_DUMP
 248         if (test_facility(129))
 249                 save_vx_regs(boot_cpu_vector_save_area);
 250 #endif
 251 }
 252
 253 static inline void setup_control_registers(void)
 254 {
 255         unsigned long reg;
 256
 257         __ctl_store(reg, 0, 0);
 258         reg |= CR0_LOW_ADDRESS_PROTECTION;
 259         reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
 260         reg |= CR0_EXTERNAL_CALL_SUBMASK;
 261         __ctl_load(reg, 0, 0);
 262 }
 263
 264 static inline void setup_access_registers(void)
 265 {
 266         unsigned int acrs[NUM_ACRS] = { 0 };
 267
 268         restore_access_regs(acrs);
 269 }
 270
 271 static int __init disable_vector_extension(char *str)
 272 {
 273         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
 274         __ctl_clear_bit(0, 17);
 275         return 0;
 276 }
 277 early_param("novx", disable_vector_extension);
 278
 279 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 280 static void __init setup_boot_command_line(void)
 281 {
 282         /* copy arch command line */
 283         strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
 284 }
 285
 286 static void __init check_image_bootable(void)
 287 {
 288         if (is_full_image)
 289                 return;
 290
 291         sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
 292         sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
 293         sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
 294         disabled_wait();
 295 }
 296
 297 void __init startup_init(void)
 298 {
 299         reset_tod_clock();
 300         check_image_bootable();
 301         time_early_init();
 302         init_kernel_storage_key();
 303         lockdep_off();
 304         setup_lowcore_early();
 305         setup_facility_list();
 306         detect_machine_type();
 307         setup_arch_string();
 308         setup_boot_command_line();
 309         detect_diag9c();
 310         detect_machine_facilities();
 311         save_vector_registers();
 312         setup_topology();
 313         sclp_early_detect();
 314         setup_control_registers();
 315         setup_access_registers();
 316         lockdep_on();
 317 }