1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * prepare to run common code 4 * 5 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE 6 */ 7 8 #define DISABLE_BRANCH_PROFILING 9 #include <linux/init.h> 10 #include <linux/linkage.h> 11 #include <linux/types.h> 12 #include <linux/kernel.h> 13 #include <linux/string.h> 14 #include <linux/percpu.h> 15 #include <linux/start_kernel.h> 16 #include <linux/io.h> 17 #include <linux/memblock.h> 18 #include <linux/mem_encrypt.h> 19 20 #include <asm/processor.h> 21 #include <asm/proto.h> 22 #include <asm/smp.h> 23 #include <asm/setup.h> 24 #include <asm/desc.h> 25 #include <asm/pgtable.h> 26 #include <asm/tlbflush.h> 27 #include <asm/sections.h> 28 #include <asm/kdebug.h> 29 #include <asm/e820/api.h> 30 #include <asm/bios_ebda.h> 31 #include <asm/bootparam_utils.h> 32 #include <asm/microcode.h> 33 #include <asm/kasan.h> 34 35 #ifdef CONFIG_X86_5LEVEL 36 #undef pgtable_l5_enabled 37 #define pgtable_l5_enabled __pgtable_l5_enabled 38 #endif 39 40 /* 41 * Manage page tables very early on. 42 */ 43 extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; 44 static unsigned int __initdata next_early_pgt; 45 pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); 46 47 #ifdef CONFIG_X86_5LEVEL 48 unsigned int __pgtable_l5_enabled __ro_after_init; 49 EXPORT_SYMBOL(__pgtable_l5_enabled); 50 unsigned int pgdir_shift __ro_after_init = 39; 51 EXPORT_SYMBOL(pgdir_shift); 52 unsigned int ptrs_per_p4d __ro_after_init = 1; 53 EXPORT_SYMBOL(ptrs_per_p4d); 54 #endif 55 56 #ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT 57 unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4; 58 EXPORT_SYMBOL(page_offset_base); 59 unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE_L4; 60 EXPORT_SYMBOL(vmalloc_base); 61 unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4; 62 EXPORT_SYMBOL(vmemmap_base); 63 #endif 64 65 #define __head __section(.head.text) 66 67 static void __head *fixup_pointer(void *ptr, unsigned long physaddr) 68 { 69 return ptr - (void *)_text + (void *)physaddr; 70 } 71 72 static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr) 73 { 74 return fixup_pointer(ptr, physaddr); 75 } 76 77 #ifdef CONFIG_X86_5LEVEL 78 static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr) 79 { 80 return fixup_pointer(ptr, physaddr); 81 } 82 83 static bool __head check_la57_support(unsigned long physaddr) 84 { 85 if (native_cpuid_eax(0) < 7) 86 return false; 87 88 if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31)))) 89 return false; 90 91 *fixup_int(&pgtable_l5_enabled, physaddr) = 1; 92 *fixup_int(&pgdir_shift, physaddr) = 48; 93 *fixup_int(&ptrs_per_p4d, physaddr) = 512; 94 *fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5; 95 *fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5; 96 *fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5; 97 98 return true; 99 } 100 #else 101 static bool __head check_la57_support(unsigned long physaddr) 102 { 103 return false; 104 } 105 #endif 106 107 unsigned long __head __startup_64(unsigned long physaddr, 108 struct boot_params *bp) 109 { 110 unsigned long load_delta, *p; 111 unsigned long pgtable_flags; 112 pgdval_t *pgd; 113 p4dval_t *p4d; 114 pudval_t *pud; 115 pmdval_t *pmd, pmd_entry; 116 bool la57; 117 int i; 118 unsigned int *next_pgt_ptr; 119 120 la57 = check_la57_support(physaddr); 121 122 /* Is the address too large? */ 123 if (physaddr >> MAX_PHYSMEM_BITS) 124 for (;;); 125 126 /* 127 * Compute the delta between the address I am compiled to run at 128 * and the address I am actually running at. 129 */ 130 load_delta = physaddr - (unsigned long)(_text - __START_KERNEL_map); 131 132 /* Is the address not 2M aligned? */ 133 if (load_delta & ~PMD_PAGE_MASK) 134 for (;;); 135 136 /* Activate Secure Memory Encryption (SME) if supported and enabled */ 137 sme_enable(bp); 138 139 /* Include the SME encryption mask in the fixup value */ 140 load_delta += sme_get_me_mask(); 141 142 /* Fixup the physical addresses in the page table */ 143 144 pgd = fixup_pointer(&early_top_pgt, physaddr); 145 p = pgd + pgd_index(__START_KERNEL_map); 146 if (la57) 147 *p = (unsigned long)level4_kernel_pgt; 148 else 149 *p = (unsigned long)level3_kernel_pgt; 150 *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta; 151 152 if (la57) { 153 p4d = fixup_pointer(&level4_kernel_pgt, physaddr); 154 p4d[511] += load_delta; 155 } 156 157 pud = fixup_pointer(&level3_kernel_pgt, physaddr); 158 pud[510] += load_delta; 159 pud[511] += load_delta; 160 161 pmd = fixup_pointer(level2_fixmap_pgt, physaddr); 162 pmd[506] += load_delta; 163 164 /* 165 * Set up the identity mapping for the switchover. These 166 * entries should *NOT* have the global bit set! This also 167 * creates a bunch of nonsense entries but that is fine -- 168 * it avoids problems around wraparound. 169 */ 170 171 next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr); 172 pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr); 173 pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr); 174 175 pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask(); 176 177 if (la57) { 178 p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr); 179 180 i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD; 181 pgd[i + 0] = (pgdval_t)p4d + pgtable_flags; 182 pgd[i + 1] = (pgdval_t)p4d + pgtable_flags; 183 184 i = (physaddr >> P4D_SHIFT) % PTRS_PER_P4D; 185 p4d[i + 0] = (pgdval_t)pud + pgtable_flags; 186 p4d[i + 1] = (pgdval_t)pud + pgtable_flags; 187 } else { 188 i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD; 189 pgd[i + 0] = (pgdval_t)pud + pgtable_flags; 190 pgd[i + 1] = (pgdval_t)pud + pgtable_flags; 191 } 192 193 i = (physaddr >> PUD_SHIFT) % PTRS_PER_PUD; 194 pud[i + 0] = (pudval_t)pmd + pgtable_flags; 195 pud[i + 1] = (pudval_t)pmd + pgtable_flags; 196 197 pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL; 198 pmd_entry += sme_get_me_mask(); 199 pmd_entry += physaddr; 200 201 for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) { 202 int idx = i + (physaddr >> PMD_SHIFT) % PTRS_PER_PMD; 203 pmd[idx] = pmd_entry + i * PMD_SIZE; 204 } 205 206 /* 207 * Fixup the kernel text+data virtual addresses. Note that 208 * we might write invalid pmds, when the kernel is relocated 209 * cleanup_highmap() fixes this up along with the mappings 210 * beyond _end. 211 */ 212 213 pmd = fixup_pointer(level2_kernel_pgt, physaddr); 214 for (i = 0; i < PTRS_PER_PMD; i++) { 215 if (pmd[i] & _PAGE_PRESENT) 216 pmd[i] += load_delta; 217 } 218 219 /* 220 * Fixup phys_base - remove the memory encryption mask to obtain 221 * the true physical address. 222 */ 223 *fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask(); 224 225 /* Encrypt the kernel and related (if SME is active) */ 226 sme_encrypt_kernel(bp); 227 228 /* 229 * Return the SME encryption mask (if SME is active) to be used as a 230 * modifier for the initial pgdir entry programmed into CR3. 231 */ 232 return sme_get_me_mask(); 233 } 234 235 unsigned long __startup_secondary_64(void) 236 { 237 /* 238 * Return the SME encryption mask (if SME is active) to be used as a 239 * modifier for the initial pgdir entry programmed into CR3. 240 */ 241 return sme_get_me_mask(); 242 } 243 244 /* Wipe all early page tables except for the kernel symbol map */ 245 static void __init reset_early_page_tables(void) 246 { 247 memset(early_top_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1)); 248 next_early_pgt = 0; 249 write_cr3(__sme_pa_nodebug(early_top_pgt)); 250 } 251 252 /* Create a new PMD entry */ 253 int __init __early_make_pgtable(unsigned long address, pmdval_t pmd) 254 { 255 unsigned long physaddr = address - __PAGE_OFFSET; 256 pgdval_t pgd, *pgd_p; 257 p4dval_t p4d, *p4d_p; 258 pudval_t pud, *pud_p; 259 pmdval_t *pmd_p; 260 261 /* Invalid address or early pgt is done ? */ 262 if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt)) 263 return -1; 264 265 again: 266 pgd_p = &early_top_pgt[pgd_index(address)].pgd; 267 pgd = *pgd_p; 268 269 /* 270 * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is 271 * critical -- __PAGE_OFFSET would point us back into the dynamic 272 * range and we might end up looping forever... 273 */ 274 if (!pgtable_l5_enabled) 275 p4d_p = pgd_p; 276 else if (pgd) 277 p4d_p = (p4dval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 278 else { 279 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 280 reset_early_page_tables(); 281 goto again; 282 } 283 284 p4d_p = (p4dval_t *)early_dynamic_pgts[next_early_pgt++]; 285 memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D); 286 *pgd_p = (pgdval_t)p4d_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 287 } 288 p4d_p += p4d_index(address); 289 p4d = *p4d_p; 290 291 if (p4d) 292 pud_p = (pudval_t *)((p4d & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 293 else { 294 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 295 reset_early_page_tables(); 296 goto again; 297 } 298 299 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++]; 300 memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD); 301 *p4d_p = (p4dval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 302 } 303 pud_p += pud_index(address); 304 pud = *pud_p; 305 306 if (pud) 307 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 308 else { 309 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 310 reset_early_page_tables(); 311 goto again; 312 } 313 314 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++]; 315 memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD); 316 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 317 } 318 pmd_p[pmd_index(address)] = pmd; 319 320 return 0; 321 } 322 323 int __init early_make_pgtable(unsigned long address) 324 { 325 unsigned long physaddr = address - __PAGE_OFFSET; 326 pmdval_t pmd; 327 328 pmd = (physaddr & PMD_MASK) + early_pmd_flags; 329 330 return __early_make_pgtable(address, pmd); 331 } 332 333 /* Don't add a printk in there. printk relies on the PDA which is not initialized 334 yet. */ 335 static void __init clear_bss(void) 336 { 337 memset(__bss_start, 0, 338 (unsigned long) __bss_stop - (unsigned long) __bss_start); 339 } 340 341 static unsigned long get_cmd_line_ptr(void) 342 { 343 unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr; 344 345 cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32; 346 347 return cmd_line_ptr; 348 } 349 350 static void __init copy_bootdata(char *real_mode_data) 351 { 352 char * command_line; 353 unsigned long cmd_line_ptr; 354 355 /* 356 * If SME is active, this will create decrypted mappings of the 357 * boot data in advance of the copy operations. 358 */ 359 sme_map_bootdata(real_mode_data); 360 361 memcpy(&boot_params, real_mode_data, sizeof boot_params); 362 sanitize_boot_params(&boot_params); 363 cmd_line_ptr = get_cmd_line_ptr(); 364 if (cmd_line_ptr) { 365 command_line = __va(cmd_line_ptr); 366 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); 367 } 368 369 /* 370 * The old boot data is no longer needed and won't be reserved, 371 * freeing up that memory for use by the system. If SME is active, 372 * we need to remove the mappings that were created so that the 373 * memory doesn't remain mapped as decrypted. 374 */ 375 sme_unmap_bootdata(real_mode_data); 376 } 377 378 asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) 379 { 380 /* 381 * Build-time sanity checks on the kernel image and module 382 * area mappings. (these are purely build-time and produce no code) 383 */ 384 BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map); 385 BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE); 386 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); 387 BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0); 388 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0); 389 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); 390 MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == 391 (__START_KERNEL & PGDIR_MASK))); 392 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END); 393 394 cr4_init_shadow(); 395 396 /* Kill off the identity-map trampoline */ 397 reset_early_page_tables(); 398 399 clear_bss(); 400 401 clear_page(init_top_pgt); 402 403 /* 404 * SME support may update early_pmd_flags to include the memory 405 * encryption mask, so it needs to be called before anything 406 * that may generate a page fault. 407 */ 408 sme_early_init(); 409 410 kasan_early_init(); 411 412 idt_setup_early_handler(); 413 414 copy_bootdata(__va(real_mode_data)); 415 416 /* 417 * Load microcode early on BSP. 418 */ 419 load_ucode_bsp(); 420 421 /* set init_top_pgt kernel high mapping*/ 422 init_top_pgt[511] = early_top_pgt[511]; 423 424 x86_64_start_reservations(real_mode_data); 425 } 426 427 void __init x86_64_start_reservations(char *real_mode_data) 428 { 429 /* version is always not zero if it is copied */ 430 if (!boot_params.hdr.version) 431 copy_bootdata(__va(real_mode_data)); 432 433 x86_early_init_platform_quirks(); 434 435 switch (boot_params.hdr.hardware_subarch) { 436 case X86_SUBARCH_INTEL_MID: 437 x86_intel_mid_early_setup(); 438 break; 439 default: 440 break; 441 } 442 443 start_kernel(); 444 } 445