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 union tod_clock clk; 39 40 if (store_tod_clock_ext_cc(&clk) == 0) 41 return; 42 /* TOD clock not running. Set the clock to Unix Epoch. */ 43 if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk)) 44 disabled_wait(); 45 46 memset(&tod_clock_base, 0, sizeof(tod_clock_base)); 47 tod_clock_base.tod = 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.addr = (unsigned long)s390_base_pgm_handler; 173 psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA; 174 if (IS_ENABLED(CONFIG_KASAN)) 175 psw.mask |= PSW_MASK_DAT; 176 S390_lowcore.program_new_psw = psw; 177 s390_base_pgm_handler_fn = early_pgm_check_handler; 178 S390_lowcore.preempt_count = INIT_PREEMPT_COUNT; 179 } 180 181 static noinline __init void setup_facility_list(void) 182 { 183 memcpy(S390_lowcore.alt_stfle_fac_list, 184 S390_lowcore.stfle_fac_list, 185 sizeof(S390_lowcore.alt_stfle_fac_list)); 186 if (!IS_ENABLED(CONFIG_KERNEL_NOBP)) 187 __clear_facility(82, S390_lowcore.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 } 240 241 static 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 } 248 249 static 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 } 259 260 static inline void setup_access_registers(void) 261 { 262 unsigned int acrs[NUM_ACRS] = { 0 }; 263 264 restore_access_regs(acrs); 265 } 266 267 static 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 } 273 early_param("novx", disable_vector_extension); 274 275 char __bootdata(early_command_line)[COMMAND_LINE_SIZE]; 276 static 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 } 281 282 static void __init check_image_bootable(void) 283 { 284 if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING))) 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 } 292 293 void __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