linux/arch/s390/kernel/early.c
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   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
  36int __bootdata(is_full_image);
  37
  38static 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 */
  56static 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
  69static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  70
  71static 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. */
  92static 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
 109static 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
 138static __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
 152static 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
 170static 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
 183static 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
 190static __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
 207static __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}
 240
 241static 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
 249static 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
 260static inline void setup_access_registers(void)
 261{
 262        unsigned int acrs[NUM_ACRS] = { 0 };
 263
 264        restore_access_regs(acrs);
 265}
 266
 267static 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}
 273early_param("novx", disable_vector_extension);
 274
 275char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 276static 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
 282static void __init check_image_bootable(void)
 283{
 284        if (is_full_image)
 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
 293void __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}
 314
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