arch/x86/platform/efi/efi_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * x86_64 specific EFI support functions
   4  * Based on Extensible Firmware Interface Specification version 1.0
   5  *
   6  * Copyright (C) 2005-2008 Intel Co.
   7  *      Fenghua Yu <fenghua.yu@intel.com>
   8  *      Bibo Mao <bibo.mao@intel.com>
   9  *      Chandramouli Narayanan <mouli@linux.intel.com>
  10  *      Huang Ying <ying.huang@intel.com>
  11  *
  12  * Code to convert EFI to E820 map has been implemented in elilo bootloader
  13  * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
  14  * is setup appropriately for EFI runtime code.
  15  * - mouli 06/14/2007.
  16  *
  17  */
  18
  19 #define pr_fmt(fmt) "efi: " fmt
  20
  21 #include <linux/kernel.h>
  22 #include <linux/init.h>
  23 #include <linux/mm.h>
  24 #include <linux/types.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/bootmem.h>
  27 #include <linux/ioport.h>
  28 #include <linux/init.h>
  29 #include <linux/mc146818rtc.h>
  30 #include <linux/efi.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/io.h>
  33 #include <linux/reboot.h>
  34 #include <linux/slab.h>
  35 #include <linux/ucs2_string.h>
  36 #include <linux/mem_encrypt.h>
  37
  38 #include <asm/setup.h>
  39 #include <asm/page.h>
  40 #include <asm/e820/api.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/tlbflush.h>
  43 #include <asm/proto.h>
  44 #include <asm/efi.h>
  45 #include <asm/cacheflush.h>
  46 #include <asm/fixmap.h>
  47 #include <asm/realmode.h>
  48 #include <asm/time.h>
  49 #include <asm/pgalloc.h>
  50
  51 /*
  52  * We allocate runtime services regions top-down, starting from -4G, i.e.
  53  * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
  54  */
  55 static u64 efi_va = EFI_VA_START;
  56
  57 struct efi_scratch efi_scratch;
  58
  59 static void __init early_code_mapping_set_exec(int executable)
  60 {
  61         efi_memory_desc_t *md;
  62
  63         if (!(__supported_pte_mask & _PAGE_NX))
  64                 return;
  65
  66         /* Make EFI service code area executable */
  67         for_each_efi_memory_desc(md) {
  68                 if (md->type == EFI_RUNTIME_SERVICES_CODE ||
  69                     md->type == EFI_BOOT_SERVICES_CODE)
  70                         efi_set_executable(md, executable);
  71         }
  72 }
  73
  74 pgd_t * __init efi_call_phys_prolog(void)
  75 {
  76         unsigned long vaddr, addr_pgd, addr_p4d, addr_pud;
  77         pgd_t *save_pgd, *pgd_k, *pgd_efi;
  78         p4d_t *p4d, *p4d_k, *p4d_efi;
  79         pud_t *pud;
  80
  81         int pgd;
  82         int n_pgds, i, j;
  83
  84         if (!efi_enabled(EFI_OLD_MEMMAP)) {
  85                 save_pgd = (pgd_t *)__read_cr3();
  86                 write_cr3((unsigned long)efi_scratch.efi_pgt);
  87                 goto out;
  88         }
  89
  90         early_code_mapping_set_exec(1);
  91
  92         n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
  93         save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL);
  94
  95         /*
  96          * Build 1:1 identity mapping for efi=old_map usage. Note that
  97          * PAGE_OFFSET is PGDIR_SIZE aligned when KASLR is disabled, while
  98          * it is PUD_SIZE ALIGNED with KASLR enabled. So for a given physical
  99          * address X, the pud_index(X) != pud_index(__va(X)), we can only copy
 100          * PUD entry of __va(X) to fill in pud entry of X to build 1:1 mapping.
 101          * This means here we can only reuse the PMD tables of the direct mapping.
 102          */
 103         for (pgd = 0; pgd < n_pgds; pgd++) {
 104                 addr_pgd = (unsigned long)(pgd * PGDIR_SIZE);
 105                 vaddr = (unsigned long)__va(pgd * PGDIR_SIZE);
 106                 pgd_efi = pgd_offset_k(addr_pgd);
 107                 save_pgd[pgd] = *pgd_efi;
 108
 109                 p4d = p4d_alloc(&init_mm, pgd_efi, addr_pgd);
 110                 if (!p4d) {
 111                         pr_err("Failed to allocate p4d table!\n");
 112                         goto out;
 113                 }
 114
 115                 for (i = 0; i < PTRS_PER_P4D; i++) {
 116                         addr_p4d = addr_pgd + i * P4D_SIZE;
 117                         p4d_efi = p4d + p4d_index(addr_p4d);
 118
 119                         pud = pud_alloc(&init_mm, p4d_efi, addr_p4d);
 120                         if (!pud) {
 121                                 pr_err("Failed to allocate pud table!\n");
 122                                 goto out;
 123                         }
 124
 125                         for (j = 0; j < PTRS_PER_PUD; j++) {
 126                                 addr_pud = addr_p4d + j * PUD_SIZE;
 127
 128                                 if (addr_pud > (max_pfn << PAGE_SHIFT))
 129                                         break;
 130
 131                                 vaddr = (unsigned long)__va(addr_pud);
 132
 133                                 pgd_k = pgd_offset_k(vaddr);
 134                                 p4d_k = p4d_offset(pgd_k, vaddr);
 135                                 pud[j] = *pud_offset(p4d_k, vaddr);
 136                         }
 137                 }
 138         }
 139 out:
 140         __flush_tlb_all();
 141
 142         return save_pgd;
 143 }
 144
 145 void __init efi_call_phys_epilog(pgd_t *save_pgd)
 146 {
 147         /*
 148          * After the lock is released, the original page table is restored.
 149          */
 150         int pgd_idx, i;
 151         int nr_pgds;
 152         pgd_t *pgd;
 153         p4d_t *p4d;
 154         pud_t *pud;
 155
 156         if (!efi_enabled(EFI_OLD_MEMMAP)) {
 157                 write_cr3((unsigned long)save_pgd);
 158                 __flush_tlb_all();
 159                 return;
 160         }
 161
 162         nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
 163
 164         for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) {
 165                 pgd = pgd_offset_k(pgd_idx * PGDIR_SIZE);
 166                 set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
 167
 168                 if (!(pgd_val(*pgd) & _PAGE_PRESENT))
 169                         continue;
 170
 171                 for (i = 0; i < PTRS_PER_P4D; i++) {
 172                         p4d = p4d_offset(pgd,
 173                                          pgd_idx * PGDIR_SIZE + i * P4D_SIZE);
 174
 175                         if (!(p4d_val(*p4d) & _PAGE_PRESENT))
 176                                 continue;
 177
 178                         pud = (pud_t *)p4d_page_vaddr(*p4d);
 179                         pud_free(&init_mm, pud);
 180                 }
 181
 182                 p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 183                 p4d_free(&init_mm, p4d);
 184         }
 185
 186         kfree(save_pgd);
 187
 188         __flush_tlb_all();
 189         early_code_mapping_set_exec(0);
 190 }
 191
 192 static pgd_t *efi_pgd;
 193
 194 /*
 195  * We need our own copy of the higher levels of the page tables
 196  * because we want to avoid inserting EFI region mappings (EFI_VA_END
 197  * to EFI_VA_START) into the standard kernel page tables. Everything
 198  * else can be shared, see efi_sync_low_kernel_mappings().
 199  *
 200  * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
 201  * allocation.
 202  */
 203 int __init efi_alloc_page_tables(void)
 204 {
 205         pgd_t *pgd;
 206         p4d_t *p4d;
 207         pud_t *pud;
 208         gfp_t gfp_mask;
 209
 210         if (efi_enabled(EFI_OLD_MEMMAP))
 211                 return 0;
 212
 213         gfp_mask = GFP_KERNEL | __GFP_ZERO;
 214         efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
 215         if (!efi_pgd)
 216                 return -ENOMEM;
 217
 218         pgd = efi_pgd + pgd_index(EFI_VA_END);
 219         p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
 220         if (!p4d) {
 221                 free_page((unsigned long)efi_pgd);
 222                 return -ENOMEM;
 223         }
 224
 225         pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
 226         if (!pud) {
 227                 if (CONFIG_PGTABLE_LEVELS > 4)
 228                         free_page((unsigned long) pgd_page_vaddr(*pgd));
 229                 free_page((unsigned long)efi_pgd);
 230                 return -ENOMEM;
 231         }
 232
 233         return 0;
 234 }
 235
 236 /*
 237  * Add low kernel mappings for passing arguments to EFI functions.
 238  */
 239 void efi_sync_low_kernel_mappings(void)
 240 {
 241         unsigned num_entries;
 242         pgd_t *pgd_k, *pgd_efi;
 243         p4d_t *p4d_k, *p4d_efi;
 244         pud_t *pud_k, *pud_efi;
 245
 246         if (efi_enabled(EFI_OLD_MEMMAP))
 247                 return;
 248
 249         /*
 250          * We can share all PGD entries apart from the one entry that
 251          * covers the EFI runtime mapping space.
 252          *
 253          * Make sure the EFI runtime region mappings are guaranteed to
 254          * only span a single PGD entry and that the entry also maps
 255          * other important kernel regions.
 256          */
 257         BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
 258         BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
 259                         (EFI_VA_END & PGDIR_MASK));
 260
 261         pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
 262         pgd_k = pgd_offset_k(PAGE_OFFSET);
 263
 264         num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
 265         memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
 266
 267         /*
 268          * As with PGDs, we share all P4D entries apart from the one entry
 269          * that covers the EFI runtime mapping space.
 270          */
 271         BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));
 272         BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));
 273
 274         pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
 275         pgd_k = pgd_offset_k(EFI_VA_END);
 276         p4d_efi = p4d_offset(pgd_efi, 0);
 277         p4d_k = p4d_offset(pgd_k, 0);
 278
 279         num_entries = p4d_index(EFI_VA_END);
 280         memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
 281
 282         /*
 283          * We share all the PUD entries apart from those that map the
 284          * EFI regions. Copy around them.
 285          */
 286         BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
 287         BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
 288
 289         p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
 290         p4d_k = p4d_offset(pgd_k, EFI_VA_END);
 291         pud_efi = pud_offset(p4d_efi, 0);
 292         pud_k = pud_offset(p4d_k, 0);
 293
 294         num_entries = pud_index(EFI_VA_END);
 295         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 296
 297         pud_efi = pud_offset(p4d_efi, EFI_VA_START);
 298         pud_k = pud_offset(p4d_k, EFI_VA_START);
 299
 300         num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
 301         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 302 }
 303
 304 /*
 305  * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 306  */
 307 static inline phys_addr_t
 308 virt_to_phys_or_null_size(void *va, unsigned long size)
 309 {
 310         bool bad_size;
 311
 312         if (!va)
 313                 return 0;
 314
 315         if (virt_addr_valid(va))
 316                 return virt_to_phys(va);
 317
 318         /*
 319          * A fully aligned variable on the stack is guaranteed not to
 320          * cross a page bounary. Try to catch strings on the stack by
 321          * checking that 'size' is a power of two.
 322          */
 323         bad_size = size > PAGE_SIZE || !is_power_of_2(size);
 324
 325         WARN_ON(!IS_ALIGNED((unsigned long)va, size) || bad_size);
 326
 327         return slow_virt_to_phys(va);
 328 }
 329
 330 #define virt_to_phys_or_null(addr)                              \
 331         virt_to_phys_or_null_size((addr), sizeof(*(addr)))
 332
 333 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 334 {
 335         unsigned long pfn, text, pf;
 336         struct page *page;
 337         unsigned npages;
 338         pgd_t *pgd;
 339
 340         if (efi_enabled(EFI_OLD_MEMMAP))
 341                 return 0;
 342
 343         /*
 344          * Since the PGD is encrypted, set the encryption mask so that when
 345          * this value is loaded into cr3 the PGD will be decrypted during
 346          * the pagetable walk.
 347          */
 348         efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd);
 349         pgd = efi_pgd;
 350
 351         /*
 352          * It can happen that the physical address of new_memmap lands in memory
 353          * which is not mapped in the EFI page table. Therefore we need to go
 354          * and ident-map those pages containing the map before calling
 355          * phys_efi_set_virtual_address_map().
 356          */
 357         pfn = pa_memmap >> PAGE_SHIFT;
 358         pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
 359         if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
 360                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 361                 return 1;
 362         }
 363
 364         efi_scratch.use_pgd = true;
 365
 366         /*
 367          * Certain firmware versions are way too sentimential and still believe
 368          * they are exclusive and unquestionable owners of the first physical page,
 369          * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
 370          * (but then write-access it later during SetVirtualAddressMap()).
 371          *
 372          * Create a 1:1 mapping for this page, to avoid triple faults during early
 373          * boot with such firmware. We are free to hand this page to the BIOS,
 374          * as trim_bios_range() will reserve the first page and isolate it away
 375          * from memory allocators anyway.
 376          */
 377         pf = _PAGE_RW;
 378         if (sev_active())
 379                 pf |= _PAGE_ENC;
 380
 381         if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
 382                 pr_err("Failed to create 1:1 mapping for the first page!\n");
 383                 return 1;
 384         }
 385
 386         /*
 387          * When making calls to the firmware everything needs to be 1:1
 388          * mapped and addressable with 32-bit pointers. Map the kernel
 389          * text and allocate a new stack because we can't rely on the
 390          * stack pointer being < 4GB.
 391          */
 392         if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
 393                 return 0;
 394
 395         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 396         if (!page)
 397                 panic("Unable to allocate EFI runtime stack < 4GB\n");
 398
 399         efi_scratch.phys_stack = virt_to_phys(page_address(page));
 400         efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
 401
 402         npages = (_etext - _text) >> PAGE_SHIFT;
 403         text = __pa(_text);
 404         pfn = text >> PAGE_SHIFT;
 405
 406         pf = _PAGE_RW | _PAGE_ENC;
 407         if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
 408                 pr_err("Failed to map kernel text 1:1\n");
 409                 return 1;
 410         }
 411
 412         return 0;
 413 }
 414
 415 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 416 {
 417         unsigned long flags = _PAGE_RW;
 418         unsigned long pfn;
 419         pgd_t *pgd = efi_pgd;
 420
 421         if (!(md->attribute & EFI_MEMORY_WB))
 422                 flags |= _PAGE_PCD;
 423
 424         if (sev_active())
 425                 flags |= _PAGE_ENC;
 426
 427         pfn = md->phys_addr >> PAGE_SHIFT;
 428         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 429                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 430                            md->phys_addr, va);
 431 }
 432
 433 void __init efi_map_region(efi_memory_desc_t *md)
 434 {
 435         unsigned long size = md->num_pages << PAGE_SHIFT;
 436         u64 pa = md->phys_addr;
 437
 438         if (efi_enabled(EFI_OLD_MEMMAP))
 439                 return old_map_region(md);
 440
 441         /*
 442          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 443          * firmware which doesn't update all internal pointers after switching
 444          * to virtual mode and would otherwise crap on us.
 445          */
 446         __map_region(md, md->phys_addr);
 447
 448         /*
 449          * Enforce the 1:1 mapping as the default virtual address when
 450          * booting in EFI mixed mode, because even though we may be
 451          * running a 64-bit kernel, the firmware may only be 32-bit.
 452          */
 453         if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
 454                 md->virt_addr = md->phys_addr;
 455                 return;
 456         }
 457
 458         efi_va -= size;
 459
 460         /* Is PA 2M-aligned? */
 461         if (!(pa & (PMD_SIZE - 1))) {
 462                 efi_va &= PMD_MASK;
 463         } else {
 464                 u64 pa_offset = pa & (PMD_SIZE - 1);
 465                 u64 prev_va = efi_va;
 466
 467                 /* get us the same offset within this 2M page */
 468                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 469
 470                 if (efi_va > prev_va)
 471                         efi_va -= PMD_SIZE;
 472         }
 473
 474         if (efi_va < EFI_VA_END) {
 475                 pr_warn(FW_WARN "VA address range overflow!\n");
 476                 return;
 477         }
 478
 479         /* Do the VA map */
 480         __map_region(md, efi_va);
 481         md->virt_addr = efi_va;
 482 }
 483
 484 /*
 485  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 486  * md->virt_addr is the original virtual address which had been mapped in kexec
 487  * 1st kernel.
 488  */
 489 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 490 {
 491         __map_region(md, md->phys_addr);
 492         __map_region(md, md->virt_addr);
 493 }
 494
 495 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
 496                                  u32 type, u64 attribute)
 497 {
 498         unsigned long last_map_pfn;
 499
 500         if (type == EFI_MEMORY_MAPPED_IO)
 501                 return ioremap(phys_addr, size);
 502
 503         last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
 504         if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
 505                 unsigned long top = last_map_pfn << PAGE_SHIFT;
 506                 efi_ioremap(top, size - (top - phys_addr), type, attribute);
 507         }
 508
 509         if (!(attribute & EFI_MEMORY_WB))
 510                 efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
 511
 512         return (void __iomem *)__va(phys_addr);
 513 }
 514
 515 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 516 {
 517         efi_setup = phys_addr + sizeof(struct setup_data);
 518 }
 519
 520 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 521 {
 522         unsigned long pfn;
 523         pgd_t *pgd = efi_pgd;
 524         int err1, err2;
 525
 526         /* Update the 1:1 mapping */
 527         pfn = md->phys_addr >> PAGE_SHIFT;
 528         err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
 529         if (err1) {
 530                 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
 531                            md->phys_addr, md->virt_addr);
 532         }
 533
 534         err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
 535         if (err2) {
 536                 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
 537                            md->phys_addr, md->virt_addr);
 538         }
 539
 540         return err1 || err2;
 541 }
 542
 543 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
 544 {
 545         unsigned long pf = 0;
 546
 547         if (md->attribute & EFI_MEMORY_XP)
 548                 pf |= _PAGE_NX;
 549
 550         if (!(md->attribute & EFI_MEMORY_RO))
 551                 pf |= _PAGE_RW;
 552
 553         if (sev_active())
 554                 pf |= _PAGE_ENC;
 555
 556         return efi_update_mappings(md, pf);
 557 }
 558
 559 void __init efi_runtime_update_mappings(void)
 560 {
 561         efi_memory_desc_t *md;
 562
 563         if (efi_enabled(EFI_OLD_MEMMAP)) {
 564                 if (__supported_pte_mask & _PAGE_NX)
 565                         runtime_code_page_mkexec();
 566                 return;
 567         }
 568
 569         /*
 570          * Use the EFI Memory Attribute Table for mapping permissions if it
 571          * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
 572          */
 573         if (efi_enabled(EFI_MEM_ATTR)) {
 574                 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
 575                 return;
 576         }
 577
 578         /*
 579          * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
 580          * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
 581          * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
 582          * published by the firmware. Even if we find a buggy implementation of
 583          * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
 584          * EFI_PROPERTIES_TABLE, because of the same reason.
 585          */
 586
 587         if (!efi_enabled(EFI_NX_PE_DATA))
 588                 return;
 589
 590         for_each_efi_memory_desc(md) {
 591                 unsigned long pf = 0;
 592
 593                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 594                         continue;
 595
 596                 if (!(md->attribute & EFI_MEMORY_WB))
 597                         pf |= _PAGE_PCD;
 598
 599                 if ((md->attribute & EFI_MEMORY_XP) ||
 600                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 601                         pf |= _PAGE_NX;
 602
 603                 if (!(md->attribute & EFI_MEMORY_RO) &&
 604                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 605                         pf |= _PAGE_RW;
 606
 607                 if (sev_active())
 608                         pf |= _PAGE_ENC;
 609
 610                 efi_update_mappings(md, pf);
 611         }
 612 }
 613
 614 void __init efi_dump_pagetable(void)
 615 {
 616 #ifdef CONFIG_EFI_PGT_DUMP
 617         if (efi_enabled(EFI_OLD_MEMMAP))
 618                 ptdump_walk_pgd_level(NULL, swapper_pg_dir);
 619         else
 620                 ptdump_walk_pgd_level(NULL, efi_pgd);
 621 #endif
 622 }
 623
 624 #ifdef CONFIG_EFI_MIXED
 625 extern efi_status_t efi64_thunk(u32, ...);
 626
 627 #define runtime_service32(func)                                          \
 628 ({                                                                       \
 629         u32 table = (u32)(unsigned long)efi.systab;                      \
 630         u32 *rt, *___f;                                                  \
 631                                                                          \
 632         rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime));  \
 633         ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
 634         *___f;                                                           \
 635 })
 636
 637 /*
 638  * Switch to the EFI page tables early so that we can access the 1:1
 639  * runtime services mappings which are not mapped in any other page
 640  * tables. This function must be called before runtime_service32().
 641  *
 642  * Also, disable interrupts because the IDT points to 64-bit handlers,
 643  * which aren't going to function correctly when we switch to 32-bit.
 644  */
 645 #define efi_thunk(f, ...)                                               \
 646 ({                                                                      \
 647         efi_status_t __s;                                               \
 648         unsigned long __flags;                                          \
 649         u32 __func;                                                     \
 650                                                                         \
 651         local_irq_save(__flags);                                        \
 652         arch_efi_call_virt_setup();                                     \
 653                                                                         \
 654         __func = runtime_service32(f);                                  \
 655         __s = efi64_thunk(__func, __VA_ARGS__);                         \
 656                                                                         \
 657         arch_efi_call_virt_teardown();                                  \
 658         local_irq_restore(__flags);                                     \
 659                                                                         \
 660         __s;                                                            \
 661 })
 662
 663 efi_status_t efi_thunk_set_virtual_address_map(
 664         void *phys_set_virtual_address_map,
 665         unsigned long memory_map_size,
 666         unsigned long descriptor_size,
 667         u32 descriptor_version,
 668         efi_memory_desc_t *virtual_map)
 669 {
 670         efi_status_t status;
 671         unsigned long flags;
 672         u32 func;
 673
 674         efi_sync_low_kernel_mappings();
 675         local_irq_save(flags);
 676
 677         efi_scratch.prev_cr3 = __read_cr3();
 678         write_cr3((unsigned long)efi_scratch.efi_pgt);
 679         __flush_tlb_all();
 680
 681         func = (u32)(unsigned long)phys_set_virtual_address_map;
 682         status = efi64_thunk(func, memory_map_size, descriptor_size,
 683                              descriptor_version, virtual_map);
 684
 685         write_cr3(efi_scratch.prev_cr3);
 686         __flush_tlb_all();
 687         local_irq_restore(flags);
 688
 689         return status;
 690 }
 691
 692 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 693 {
 694         efi_status_t status;
 695         u32 phys_tm, phys_tc;
 696
 697         spin_lock(&rtc_lock);
 698
 699         phys_tm = virt_to_phys_or_null(tm);
 700         phys_tc = virt_to_phys_or_null(tc);
 701
 702         status = efi_thunk(get_time, phys_tm, phys_tc);
 703
 704         spin_unlock(&rtc_lock);
 705
 706         return status;
 707 }
 708
 709 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 710 {
 711         efi_status_t status;
 712         u32 phys_tm;
 713
 714         spin_lock(&rtc_lock);
 715
 716         phys_tm = virt_to_phys_or_null(tm);
 717
 718         status = efi_thunk(set_time, phys_tm);
 719
 720         spin_unlock(&rtc_lock);
 721
 722         return status;
 723 }
 724
 725 static efi_status_t
 726 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 727                           efi_time_t *tm)
 728 {
 729         efi_status_t status;
 730         u32 phys_enabled, phys_pending, phys_tm;
 731
 732         spin_lock(&rtc_lock);
 733
 734         phys_enabled = virt_to_phys_or_null(enabled);
 735         phys_pending = virt_to_phys_or_null(pending);
 736         phys_tm = virt_to_phys_or_null(tm);
 737
 738         status = efi_thunk(get_wakeup_time, phys_enabled,
 739                              phys_pending, phys_tm);
 740
 741         spin_unlock(&rtc_lock);
 742
 743         return status;
 744 }
 745
 746 static efi_status_t
 747 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 748 {
 749         efi_status_t status;
 750         u32 phys_tm;
 751
 752         spin_lock(&rtc_lock);
 753
 754         phys_tm = virt_to_phys_or_null(tm);
 755
 756         status = efi_thunk(set_wakeup_time, enabled, phys_tm);
 757
 758         spin_unlock(&rtc_lock);
 759
 760         return status;
 761 }
 762
 763 static unsigned long efi_name_size(efi_char16_t *name)
 764 {
 765         return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
 766 }
 767
 768 static efi_status_t
 769 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 770                        u32 *attr, unsigned long *data_size, void *data)
 771 {
 772         efi_status_t status;
 773         u32 phys_name, phys_vendor, phys_attr;
 774         u32 phys_data_size, phys_data;
 775
 776         phys_data_size = virt_to_phys_or_null(data_size);
 777         phys_vendor = virt_to_phys_or_null(vendor);
 778         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 779         phys_attr = virt_to_phys_or_null(attr);
 780         phys_data = virt_to_phys_or_null_size(data, *data_size);
 781
 782         status = efi_thunk(get_variable, phys_name, phys_vendor,
 783                            phys_attr, phys_data_size, phys_data);
 784
 785         return status;
 786 }
 787
 788 static efi_status_t
 789 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 790                        u32 attr, unsigned long data_size, void *data)
 791 {
 792         u32 phys_name, phys_vendor, phys_data;
 793         efi_status_t status;
 794
 795         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 796         phys_vendor = virt_to_phys_or_null(vendor);
 797         phys_data = virt_to_phys_or_null_size(data, data_size);
 798
 799         /* If data_size is > sizeof(u32) we've got problems */
 800         status = efi_thunk(set_variable, phys_name, phys_vendor,
 801                            attr, data_size, phys_data);
 802
 803         return status;
 804 }
 805
 806 static efi_status_t
 807 efi_thunk_get_next_variable(unsigned long *name_size,
 808                             efi_char16_t *name,
 809                             efi_guid_t *vendor)
 810 {
 811         efi_status_t status;
 812         u32 phys_name_size, phys_name, phys_vendor;
 813
 814         phys_name_size = virt_to_phys_or_null(name_size);
 815         phys_vendor = virt_to_phys_or_null(vendor);
 816         phys_name = virt_to_phys_or_null_size(name, *name_size);
 817
 818         status = efi_thunk(get_next_variable, phys_name_size,
 819                            phys_name, phys_vendor);
 820
 821         return status;
 822 }
 823
 824 static efi_status_t
 825 efi_thunk_get_next_high_mono_count(u32 *count)
 826 {
 827         efi_status_t status;
 828         u32 phys_count;
 829
 830         phys_count = virt_to_phys_or_null(count);
 831         status = efi_thunk(get_next_high_mono_count, phys_count);
 832
 833         return status;
 834 }
 835
 836 static void
 837 efi_thunk_reset_system(int reset_type, efi_status_t status,
 838                        unsigned long data_size, efi_char16_t *data)
 839 {
 840         u32 phys_data;
 841
 842         phys_data = virt_to_phys_or_null_size(data, data_size);
 843
 844         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
 845 }
 846
 847 static efi_status_t
 848 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
 849                          unsigned long count, unsigned long sg_list)
 850 {
 851         /*
 852          * To properly support this function we would need to repackage
 853          * 'capsules' because the firmware doesn't understand 64-bit
 854          * pointers.
 855          */
 856         return EFI_UNSUPPORTED;
 857 }
 858
 859 static efi_status_t
 860 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 861                               u64 *remaining_space,
 862                               u64 *max_variable_size)
 863 {
 864         efi_status_t status;
 865         u32 phys_storage, phys_remaining, phys_max;
 866
 867         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 868                 return EFI_UNSUPPORTED;
 869
 870         phys_storage = virt_to_phys_or_null(storage_space);
 871         phys_remaining = virt_to_phys_or_null(remaining_space);
 872         phys_max = virt_to_phys_or_null(max_variable_size);
 873
 874         status = efi_thunk(query_variable_info, attr, phys_storage,
 875                            phys_remaining, phys_max);
 876
 877         return status;
 878 }
 879
 880 static efi_status_t
 881 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
 882                              unsigned long count, u64 *max_size,
 883                              int *reset_type)
 884 {
 885         /*
 886          * To properly support this function we would need to repackage
 887          * 'capsules' because the firmware doesn't understand 64-bit
 888          * pointers.
 889          */
 890         return EFI_UNSUPPORTED;
 891 }
 892
 893 void efi_thunk_runtime_setup(void)
 894 {
 895         efi.get_time = efi_thunk_get_time;
 896         efi.set_time = efi_thunk_set_time;
 897         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
 898         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
 899         efi.get_variable = efi_thunk_get_variable;
 900         efi.get_next_variable = efi_thunk_get_next_variable;
 901         efi.set_variable = efi_thunk_set_variable;
 902         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
 903         efi.reset_system = efi_thunk_reset_system;
 904         efi.query_variable_info = efi_thunk_query_variable_info;
 905         efi.update_capsule = efi_thunk_update_capsule;
 906         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
 907 }
 908 #endif /* CONFIG_EFI_MIXED */