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                 pgd_offset_k(pgd * PGDIR_SIZE)->pgd &= ~_PAGE_NX;
 139         }
 140
 141 out:
 142         __flush_tlb_all();
 143
 144         return save_pgd;
 145 }
 146
 147 void __init efi_call_phys_epilog(pgd_t *save_pgd)
 148 {
 149         /*
 150          * After the lock is released, the original page table is restored.
 151          */
 152         int pgd_idx, i;
 153         int nr_pgds;
 154         pgd_t *pgd;
 155         p4d_t *p4d;
 156         pud_t *pud;
 157
 158         if (!efi_enabled(EFI_OLD_MEMMAP)) {
 159                 write_cr3((unsigned long)save_pgd);
 160                 __flush_tlb_all();
 161                 return;
 162         }
 163
 164         nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
 165
 166         for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) {
 167                 pgd = pgd_offset_k(pgd_idx * PGDIR_SIZE);
 168                 set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
 169
 170                 if (!(pgd_val(*pgd) & _PAGE_PRESENT))
 171                         continue;
 172
 173                 for (i = 0; i < PTRS_PER_P4D; i++) {
 174                         p4d = p4d_offset(pgd,
 175                                          pgd_idx * PGDIR_SIZE + i * P4D_SIZE);
 176
 177                         if (!(p4d_val(*p4d) & _PAGE_PRESENT))
 178                                 continue;
 179
 180                         pud = (pud_t *)p4d_page_vaddr(*p4d);
 181                         pud_free(&init_mm, pud);
 182                 }
 183
 184                 p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 185                 p4d_free(&init_mm, p4d);
 186         }
 187
 188         kfree(save_pgd);
 189
 190         __flush_tlb_all();
 191         early_code_mapping_set_exec(0);
 192 }
 193
 194 static pgd_t *efi_pgd;
 195
 196 /*
 197  * We need our own copy of the higher levels of the page tables
 198  * because we want to avoid inserting EFI region mappings (EFI_VA_END
 199  * to EFI_VA_START) into the standard kernel page tables. Everything
 200  * else can be shared, see efi_sync_low_kernel_mappings().
 201  *
 202  * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
 203  * allocation.
 204  */
 205 int __init efi_alloc_page_tables(void)
 206 {
 207         pgd_t *pgd;
 208         p4d_t *p4d;
 209         pud_t *pud;
 210         gfp_t gfp_mask;
 211
 212         if (efi_enabled(EFI_OLD_MEMMAP))
 213                 return 0;
 214
 215         gfp_mask = GFP_KERNEL | __GFP_ZERO;
 216         efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
 217         if (!efi_pgd)
 218                 return -ENOMEM;
 219
 220         pgd = efi_pgd + pgd_index(EFI_VA_END);
 221         p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
 222         if (!p4d) {
 223                 free_page((unsigned long)efi_pgd);
 224                 return -ENOMEM;
 225         }
 226
 227         pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
 228         if (!pud) {
 229                 if (CONFIG_PGTABLE_LEVELS > 4)
 230                         free_page((unsigned long) pgd_page_vaddr(*pgd));
 231                 free_page((unsigned long)efi_pgd);
 232                 return -ENOMEM;
 233         }
 234
 235         return 0;
 236 }
 237
 238 /*
 239  * Add low kernel mappings for passing arguments to EFI functions.
 240  */
 241 void efi_sync_low_kernel_mappings(void)
 242 {
 243         unsigned num_entries;
 244         pgd_t *pgd_k, *pgd_efi;
 245         p4d_t *p4d_k, *p4d_efi;
 246         pud_t *pud_k, *pud_efi;
 247
 248         if (efi_enabled(EFI_OLD_MEMMAP))
 249                 return;
 250
 251         /*
 252          * We can share all PGD entries apart from the one entry that
 253          * covers the EFI runtime mapping space.
 254          *
 255          * Make sure the EFI runtime region mappings are guaranteed to
 256          * only span a single PGD entry and that the entry also maps
 257          * other important kernel regions.
 258          */
 259         BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
 260         BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
 261                         (EFI_VA_END & PGDIR_MASK));
 262
 263         pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
 264         pgd_k = pgd_offset_k(PAGE_OFFSET);
 265
 266         num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
 267         memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
 268
 269         /*
 270          * As with PGDs, we share all P4D entries apart from the one entry
 271          * that covers the EFI runtime mapping space.
 272          */
 273         BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));
 274         BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));
 275
 276         pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
 277         pgd_k = pgd_offset_k(EFI_VA_END);
 278         p4d_efi = p4d_offset(pgd_efi, 0);
 279         p4d_k = p4d_offset(pgd_k, 0);
 280
 281         num_entries = p4d_index(EFI_VA_END);
 282         memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
 283
 284         /*
 285          * We share all the PUD entries apart from those that map the
 286          * EFI regions. Copy around them.
 287          */
 288         BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
 289         BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
 290
 291         p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
 292         p4d_k = p4d_offset(pgd_k, EFI_VA_END);
 293         pud_efi = pud_offset(p4d_efi, 0);
 294         pud_k = pud_offset(p4d_k, 0);
 295
 296         num_entries = pud_index(EFI_VA_END);
 297         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 298
 299         pud_efi = pud_offset(p4d_efi, EFI_VA_START);
 300         pud_k = pud_offset(p4d_k, EFI_VA_START);
 301
 302         num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
 303         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 304 }
 305
 306 /*
 307  * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 308  */
 309 static inline phys_addr_t
 310 virt_to_phys_or_null_size(void *va, unsigned long size)
 311 {
 312         bool bad_size;
 313
 314         if (!va)
 315                 return 0;
 316
 317         if (virt_addr_valid(va))
 318                 return virt_to_phys(va);
 319
 320         /*
 321          * A fully aligned variable on the stack is guaranteed not to
 322          * cross a page bounary. Try to catch strings on the stack by
 323          * checking that 'size' is a power of two.
 324          */
 325         bad_size = size > PAGE_SIZE || !is_power_of_2(size);
 326
 327         WARN_ON(!IS_ALIGNED((unsigned long)va, size) || bad_size);
 328
 329         return slow_virt_to_phys(va);
 330 }
 331
 332 #define virt_to_phys_or_null(addr)                              \
 333         virt_to_phys_or_null_size((addr), sizeof(*(addr)))
 334
 335 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 336 {
 337         unsigned long pfn, text, pf;
 338         struct page *page;
 339         unsigned npages;
 340         pgd_t *pgd;
 341
 342         if (efi_enabled(EFI_OLD_MEMMAP))
 343                 return 0;
 344
 345         /*
 346          * Since the PGD is encrypted, set the encryption mask so that when
 347          * this value is loaded into cr3 the PGD will be decrypted during
 348          * the pagetable walk.
 349          */
 350         efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd);
 351         pgd = efi_pgd;
 352
 353         /*
 354          * It can happen that the physical address of new_memmap lands in memory
 355          * which is not mapped in the EFI page table. Therefore we need to go
 356          * and ident-map those pages containing the map before calling
 357          * phys_efi_set_virtual_address_map().
 358          */
 359         pfn = pa_memmap >> PAGE_SHIFT;
 360         pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
 361         if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
 362                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 363                 return 1;
 364         }
 365
 366         efi_scratch.use_pgd = true;
 367
 368         /*
 369          * Certain firmware versions are way too sentimential and still believe
 370          * they are exclusive and unquestionable owners of the first physical page,
 371          * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
 372          * (but then write-access it later during SetVirtualAddressMap()).
 373          *
 374          * Create a 1:1 mapping for this page, to avoid triple faults during early
 375          * boot with such firmware. We are free to hand this page to the BIOS,
 376          * as trim_bios_range() will reserve the first page and isolate it away
 377          * from memory allocators anyway.
 378          */
 379         pf = _PAGE_RW;
 380         if (sev_active())
 381                 pf |= _PAGE_ENC;
 382
 383         if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
 384                 pr_err("Failed to create 1:1 mapping for the first page!\n");
 385                 return 1;
 386         }
 387
 388         /*
 389          * When making calls to the firmware everything needs to be 1:1
 390          * mapped and addressable with 32-bit pointers. Map the kernel
 391          * text and allocate a new stack because we can't rely on the
 392          * stack pointer being < 4GB.
 393          */
 394         if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
 395                 return 0;
 396
 397         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 398         if (!page)
 399                 panic("Unable to allocate EFI runtime stack < 4GB\n");
 400
 401         efi_scratch.phys_stack = virt_to_phys(page_address(page));
 402         efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
 403
 404         npages = (_etext - _text) >> PAGE_SHIFT;
 405         text = __pa(_text);
 406         pfn = text >> PAGE_SHIFT;
 407
 408         pf = _PAGE_RW | _PAGE_ENC;
 409         if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
 410                 pr_err("Failed to map kernel text 1:1\n");
 411                 return 1;
 412         }
 413
 414         return 0;
 415 }
 416
 417 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 418 {
 419         unsigned long flags = _PAGE_RW;
 420         unsigned long pfn;
 421         pgd_t *pgd = efi_pgd;
 422
 423         if (!(md->attribute & EFI_MEMORY_WB))
 424                 flags |= _PAGE_PCD;
 425
 426         if (sev_active())
 427                 flags |= _PAGE_ENC;
 428
 429         pfn = md->phys_addr >> PAGE_SHIFT;
 430         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 431                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 432                            md->phys_addr, va);
 433 }
 434
 435 void __init efi_map_region(efi_memory_desc_t *md)
 436 {
 437         unsigned long size = md->num_pages << PAGE_SHIFT;
 438         u64 pa = md->phys_addr;
 439
 440         if (efi_enabled(EFI_OLD_MEMMAP))
 441                 return old_map_region(md);
 442
 443         /*
 444          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 445          * firmware which doesn't update all internal pointers after switching
 446          * to virtual mode and would otherwise crap on us.
 447          */
 448         __map_region(md, md->phys_addr);
 449
 450         /*
 451          * Enforce the 1:1 mapping as the default virtual address when
 452          * booting in EFI mixed mode, because even though we may be
 453          * running a 64-bit kernel, the firmware may only be 32-bit.
 454          */
 455         if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
 456                 md->virt_addr = md->phys_addr;
 457                 return;
 458         }
 459
 460         efi_va -= size;
 461
 462         /* Is PA 2M-aligned? */
 463         if (!(pa & (PMD_SIZE - 1))) {
 464                 efi_va &= PMD_MASK;
 465         } else {
 466                 u64 pa_offset = pa & (PMD_SIZE - 1);
 467                 u64 prev_va = efi_va;
 468
 469                 /* get us the same offset within this 2M page */
 470                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 471
 472                 if (efi_va > prev_va)
 473                         efi_va -= PMD_SIZE;
 474         }
 475
 476         if (efi_va < EFI_VA_END) {
 477                 pr_warn(FW_WARN "VA address range overflow!\n");
 478                 return;
 479         }
 480
 481         /* Do the VA map */
 482         __map_region(md, efi_va);
 483         md->virt_addr = efi_va;
 484 }
 485
 486 /*
 487  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 488  * md->virt_addr is the original virtual address which had been mapped in kexec
 489  * 1st kernel.
 490  */
 491 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 492 {
 493         __map_region(md, md->phys_addr);
 494         __map_region(md, md->virt_addr);
 495 }
 496
 497 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
 498                                  u32 type, u64 attribute)
 499 {
 500         unsigned long last_map_pfn;
 501
 502         if (type == EFI_MEMORY_MAPPED_IO)
 503                 return ioremap(phys_addr, size);
 504
 505         last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
 506         if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
 507                 unsigned long top = last_map_pfn << PAGE_SHIFT;
 508                 efi_ioremap(top, size - (top - phys_addr), type, attribute);
 509         }
 510
 511         if (!(attribute & EFI_MEMORY_WB))
 512                 efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
 513
 514         return (void __iomem *)__va(phys_addr);
 515 }
 516
 517 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 518 {
 519         efi_setup = phys_addr + sizeof(struct setup_data);
 520 }
 521
 522 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 523 {
 524         unsigned long pfn;
 525         pgd_t *pgd = efi_pgd;
 526         int err1, err2;
 527
 528         /* Update the 1:1 mapping */
 529         pfn = md->phys_addr >> PAGE_SHIFT;
 530         err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
 531         if (err1) {
 532                 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
 533                            md->phys_addr, md->virt_addr);
 534         }
 535
 536         err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
 537         if (err2) {
 538                 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
 539                            md->phys_addr, md->virt_addr);
 540         }
 541
 542         return err1 || err2;
 543 }
 544
 545 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
 546 {
 547         unsigned long pf = 0;
 548
 549         if (md->attribute & EFI_MEMORY_XP)
 550                 pf |= _PAGE_NX;
 551
 552         if (!(md->attribute & EFI_MEMORY_RO))
 553                 pf |= _PAGE_RW;
 554
 555         if (sev_active())
 556                 pf |= _PAGE_ENC;
 557
 558         return efi_update_mappings(md, pf);
 559 }
 560
 561 void __init efi_runtime_update_mappings(void)
 562 {
 563         efi_memory_desc_t *md;
 564
 565         if (efi_enabled(EFI_OLD_MEMMAP)) {
 566                 if (__supported_pte_mask & _PAGE_NX)
 567                         runtime_code_page_mkexec();
 568                 return;
 569         }
 570
 571         /*
 572          * Use the EFI Memory Attribute Table for mapping permissions if it
 573          * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
 574          */
 575         if (efi_enabled(EFI_MEM_ATTR)) {
 576                 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
 577                 return;
 578         }
 579
 580         /*
 581          * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
 582          * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
 583          * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
 584          * published by the firmware. Even if we find a buggy implementation of
 585          * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
 586          * EFI_PROPERTIES_TABLE, because of the same reason.
 587          */
 588
 589         if (!efi_enabled(EFI_NX_PE_DATA))
 590                 return;
 591
 592         for_each_efi_memory_desc(md) {
 593                 unsigned long pf = 0;
 594
 595                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 596                         continue;
 597
 598                 if (!(md->attribute & EFI_MEMORY_WB))
 599                         pf |= _PAGE_PCD;
 600
 601                 if ((md->attribute & EFI_MEMORY_XP) ||
 602                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 603                         pf |= _PAGE_NX;
 604
 605                 if (!(md->attribute & EFI_MEMORY_RO) &&
 606                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 607                         pf |= _PAGE_RW;
 608
 609                 if (sev_active())
 610                         pf |= _PAGE_ENC;
 611
 612                 efi_update_mappings(md, pf);
 613         }
 614 }
 615
 616 void __init efi_dump_pagetable(void)
 617 {
 618 #ifdef CONFIG_EFI_PGT_DUMP
 619         if (efi_enabled(EFI_OLD_MEMMAP))
 620                 ptdump_walk_pgd_level(NULL, swapper_pg_dir);
 621         else
 622                 ptdump_walk_pgd_level(NULL, efi_pgd);
 623 #endif
 624 }
 625
 626 #ifdef CONFIG_EFI_MIXED
 627 extern efi_status_t efi64_thunk(u32, ...);
 628
 629 #define runtime_service32(func)                                          \
 630 ({                                                                       \
 631         u32 table = (u32)(unsigned long)efi.systab;                      \
 632         u32 *rt, *___f;                                                  \
 633                                                                          \
 634         rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime));  \
 635         ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
 636         *___f;                                                           \
 637 })
 638
 639 /*
 640  * Switch to the EFI page tables early so that we can access the 1:1
 641  * runtime services mappings which are not mapped in any other page
 642  * tables. This function must be called before runtime_service32().
 643  *
 644  * Also, disable interrupts because the IDT points to 64-bit handlers,
 645  * which aren't going to function correctly when we switch to 32-bit.
 646  */
 647 #define efi_thunk(f, ...)                                               \
 648 ({                                                                      \
 649         efi_status_t __s;                                               \
 650         unsigned long __flags;                                          \
 651         u32 __func;                                                     \
 652                                                                         \
 653         local_irq_save(__flags);                                        \
 654         arch_efi_call_virt_setup();                                     \
 655                                                                         \
 656         __func = runtime_service32(f);                                  \
 657         __s = efi64_thunk(__func, __VA_ARGS__);                         \
 658                                                                         \
 659         arch_efi_call_virt_teardown();                                  \
 660         local_irq_restore(__flags);                                     \
 661                                                                         \
 662         __s;                                                            \
 663 })
 664
 665 efi_status_t efi_thunk_set_virtual_address_map(
 666         void *phys_set_virtual_address_map,
 667         unsigned long memory_map_size,
 668         unsigned long descriptor_size,
 669         u32 descriptor_version,
 670         efi_memory_desc_t *virtual_map)
 671 {
 672         efi_status_t status;
 673         unsigned long flags;
 674         u32 func;
 675
 676         efi_sync_low_kernel_mappings();
 677         local_irq_save(flags);
 678
 679         efi_scratch.prev_cr3 = __read_cr3();
 680         write_cr3((unsigned long)efi_scratch.efi_pgt);
 681         __flush_tlb_all();
 682
 683         func = (u32)(unsigned long)phys_set_virtual_address_map;
 684         status = efi64_thunk(func, memory_map_size, descriptor_size,
 685                              descriptor_version, virtual_map);
 686
 687         write_cr3(efi_scratch.prev_cr3);
 688         __flush_tlb_all();
 689         local_irq_restore(flags);
 690
 691         return status;
 692 }
 693
 694 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 695 {
 696         efi_status_t status;
 697         u32 phys_tm, phys_tc;
 698
 699         spin_lock(&rtc_lock);
 700
 701         phys_tm = virt_to_phys_or_null(tm);
 702         phys_tc = virt_to_phys_or_null(tc);
 703
 704         status = efi_thunk(get_time, phys_tm, phys_tc);
 705
 706         spin_unlock(&rtc_lock);
 707
 708         return status;
 709 }
 710
 711 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 712 {
 713         efi_status_t status;
 714         u32 phys_tm;
 715
 716         spin_lock(&rtc_lock);
 717
 718         phys_tm = virt_to_phys_or_null(tm);
 719
 720         status = efi_thunk(set_time, phys_tm);
 721
 722         spin_unlock(&rtc_lock);
 723
 724         return status;
 725 }
 726
 727 static efi_status_t
 728 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 729                           efi_time_t *tm)
 730 {
 731         efi_status_t status;
 732         u32 phys_enabled, phys_pending, phys_tm;
 733
 734         spin_lock(&rtc_lock);
 735
 736         phys_enabled = virt_to_phys_or_null(enabled);
 737         phys_pending = virt_to_phys_or_null(pending);
 738         phys_tm = virt_to_phys_or_null(tm);
 739
 740         status = efi_thunk(get_wakeup_time, phys_enabled,
 741                              phys_pending, phys_tm);
 742
 743         spin_unlock(&rtc_lock);
 744
 745         return status;
 746 }
 747
 748 static efi_status_t
 749 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 750 {
 751         efi_status_t status;
 752         u32 phys_tm;
 753
 754         spin_lock(&rtc_lock);
 755
 756         phys_tm = virt_to_phys_or_null(tm);
 757
 758         status = efi_thunk(set_wakeup_time, enabled, phys_tm);
 759
 760         spin_unlock(&rtc_lock);
 761
 762         return status;
 763 }
 764
 765 static unsigned long efi_name_size(efi_char16_t *name)
 766 {
 767         return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
 768 }
 769
 770 static efi_status_t
 771 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 772                        u32 *attr, unsigned long *data_size, void *data)
 773 {
 774         efi_status_t status;
 775         u32 phys_name, phys_vendor, phys_attr;
 776         u32 phys_data_size, phys_data;
 777
 778         phys_data_size = virt_to_phys_or_null(data_size);
 779         phys_vendor = virt_to_phys_or_null(vendor);
 780         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 781         phys_attr = virt_to_phys_or_null(attr);
 782         phys_data = virt_to_phys_or_null_size(data, *data_size);
 783
 784         status = efi_thunk(get_variable, phys_name, phys_vendor,
 785                            phys_attr, phys_data_size, phys_data);
 786
 787         return status;
 788 }
 789
 790 static efi_status_t
 791 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 792                        u32 attr, unsigned long data_size, void *data)
 793 {
 794         u32 phys_name, phys_vendor, phys_data;
 795         efi_status_t status;
 796
 797         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 798         phys_vendor = virt_to_phys_or_null(vendor);
 799         phys_data = virt_to_phys_or_null_size(data, data_size);
 800
 801         /* If data_size is > sizeof(u32) we've got problems */
 802         status = efi_thunk(set_variable, phys_name, phys_vendor,
 803                            attr, data_size, phys_data);
 804
 805         return status;
 806 }
 807
 808 static efi_status_t
 809 efi_thunk_get_next_variable(unsigned long *name_size,
 810                             efi_char16_t *name,
 811                             efi_guid_t *vendor)
 812 {
 813         efi_status_t status;
 814         u32 phys_name_size, phys_name, phys_vendor;
 815
 816         phys_name_size = virt_to_phys_or_null(name_size);
 817         phys_vendor = virt_to_phys_or_null(vendor);
 818         phys_name = virt_to_phys_or_null_size(name, *name_size);
 819
 820         status = efi_thunk(get_next_variable, phys_name_size,
 821                            phys_name, phys_vendor);
 822
 823         return status;
 824 }
 825
 826 static efi_status_t
 827 efi_thunk_get_next_high_mono_count(u32 *count)
 828 {
 829         efi_status_t status;
 830         u32 phys_count;
 831
 832         phys_count = virt_to_phys_or_null(count);
 833         status = efi_thunk(get_next_high_mono_count, phys_count);
 834
 835         return status;
 836 }
 837
 838 static void
 839 efi_thunk_reset_system(int reset_type, efi_status_t status,
 840                        unsigned long data_size, efi_char16_t *data)
 841 {
 842         u32 phys_data;
 843
 844         phys_data = virt_to_phys_or_null_size(data, data_size);
 845
 846         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
 847 }
 848
 849 static efi_status_t
 850 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
 851                          unsigned long count, unsigned long sg_list)
 852 {
 853         /*
 854          * To properly support this function we would need to repackage
 855          * 'capsules' because the firmware doesn't understand 64-bit
 856          * pointers.
 857          */
 858         return EFI_UNSUPPORTED;
 859 }
 860
 861 static efi_status_t
 862 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 863                               u64 *remaining_space,
 864                               u64 *max_variable_size)
 865 {
 866         efi_status_t status;
 867         u32 phys_storage, phys_remaining, phys_max;
 868
 869         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 870                 return EFI_UNSUPPORTED;
 871
 872         phys_storage = virt_to_phys_or_null(storage_space);
 873         phys_remaining = virt_to_phys_or_null(remaining_space);
 874         phys_max = virt_to_phys_or_null(max_variable_size);
 875
 876         status = efi_thunk(query_variable_info, attr, phys_storage,
 877                            phys_remaining, phys_max);
 878
 879         return status;
 880 }
 881
 882 static efi_status_t
 883 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
 884                              unsigned long count, u64 *max_size,
 885                              int *reset_type)
 886 {
 887         /*
 888          * To properly support this function we would need to repackage
 889          * 'capsules' because the firmware doesn't understand 64-bit
 890          * pointers.
 891          */
 892         return EFI_UNSUPPORTED;
 893 }
 894
 895 void efi_thunk_runtime_setup(void)
 896 {
 897         efi.get_time = efi_thunk_get_time;
 898         efi.set_time = efi_thunk_set_time;
 899         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
 900         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
 901         efi.get_variable = efi_thunk_get_variable;
 902         efi.get_next_variable = efi_thunk_get_next_variable;
 903         efi.set_variable = efi_thunk_set_variable;
 904         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
 905         efi.reset_system = efi_thunk_reset_system;
 906         efi.query_variable_info = efi_thunk_query_variable_info;
 907         efi.update_capsule = efi_thunk_update_capsule;
 908         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
 909 }
 910 #endif /* CONFIG_EFI_MIXED */