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