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