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.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA; 173 if (IS_ENABLED(CONFIG_KASAN)) 174 psw.mask |= PSW_MASK_DAT; 175 psw.addr = (unsigned long) s390_base_ext_handler; 176 S390_lowcore.external_new_psw = psw; 177 psw.addr = (unsigned long) s390_base_pgm_handler; 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(S390_lowcore.alt_stfle_fac_list, 186 S390_lowcore.stfle_fac_list, 187 sizeof(S390_lowcore.alt_stfle_fac_list)); 188 if (!IS_ENABLED(CONFIG_KERNEL_NOBP)) 189 __clear_facility(82, S390_lowcore.alt_stfle_fac_list); 190 } 191 192 static __init void detect_diag9c(void) 193 { 194 unsigned int cpu_address; 195 int rc; 196 197 cpu_address = stap(); 198 diag_stat_inc(DIAG_STAT_X09C); 199 asm volatile( 200 " diag %2,0,0x9c\n" 201 "0: la %0,0\n" 202 "1:\n" 203 EX_TABLE(0b,1b) 204 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc"); 205 if (!rc) 206 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C; 207 } 208 209 static __init void detect_machine_facilities(void) 210 { 211 if (test_facility(8)) { 212 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1; 213 __ctl_set_bit(0, 23); 214 } 215 if (test_facility(78)) 216 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2; 217 if (test_facility(3)) 218 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE; 219 if (test_facility(50) && test_facility(73)) { 220 S390_lowcore.machine_flags |= MACHINE_FLAG_TE; 221 __ctl_set_bit(0, 55); 222 } 223 if (test_facility(51)) 224 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC; 225 if (test_facility(129)) { 226 S390_lowcore.machine_flags |= MACHINE_FLAG_VX; 227 __ctl_set_bit(0, 17); 228 } 229 if (test_facility(130) && !noexec_disabled) { 230 S390_lowcore.machine_flags |= MACHINE_FLAG_NX; 231 __ctl_set_bit(0, 20); 232 } 233 if (test_facility(133)) 234 S390_lowcore.machine_flags |= MACHINE_FLAG_GS; 235 if (test_facility(139) && (tod_clock_base[1] & 0x80)) { 236 /* Enabled signed clock comparator comparisons */ 237 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC; 238 clock_comparator_max = -1ULL >> 1; 239 __ctl_set_bit(0, 53); 240 } 241 } 242 243 static inline void save_vector_registers(void) 244 { 245 #ifdef CONFIG_CRASH_DUMP 246 if (test_facility(129)) 247 save_vx_regs(boot_cpu_vector_save_area); 248 #endif 249 } 250 251 static inline void setup_control_registers(void) 252 { 253 unsigned long reg; 254 255 __ctl_store(reg, 0, 0); 256 reg |= CR0_LOW_ADDRESS_PROTECTION; 257 reg |= CR0_EMERGENCY_SIGNAL_SUBMASK; 258 reg |= CR0_EXTERNAL_CALL_SUBMASK; 259 __ctl_load(reg, 0, 0); 260 } 261 262 static inline void setup_access_registers(void) 263 { 264 unsigned int acrs[NUM_ACRS] = { 0 }; 265 266 restore_access_regs(acrs); 267 } 268 269 static int __init disable_vector_extension(char *str) 270 { 271 S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX; 272 __ctl_clear_bit(0, 17); 273 return 0; 274 } 275 early_param("novx", disable_vector_extension); 276 277 char __bootdata(early_command_line)[COMMAND_LINE_SIZE]; 278 static void __init setup_boot_command_line(void) 279 { 280 /* copy arch command line */ 281 strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE); 282 } 283 284 static void __init check_image_bootable(void) 285 { 286 if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING))) 287 return; 288 289 sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n"); 290 sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n"); 291 sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n"); 292 disabled_wait(); 293 } 294 295 void __init startup_init(void) 296 { 297 reset_tod_clock(); 298 check_image_bootable(); 299 time_early_init(); 300 init_kernel_storage_key(); 301 lockdep_off(); 302 setup_lowcore_early(); 303 setup_facility_list(); 304 detect_machine_type(); 305 setup_arch_string(); 306 setup_boot_command_line(); 307 detect_diag9c(); 308 detect_machine_facilities(); 309 save_vector_registers(); 310 setup_topology(); 311 sclp_early_detect(); 312 setup_control_registers(); 313 setup_access_registers(); 314 lockdep_on(); 315 } 316