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/memblock.h>
  27 #include <linux/ioport.h>
  28 #include <linux/mc146818rtc.h>
  29 #include <linux/efi.h>
  30 #include <linux/export.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 #include <linux/sched/task.h>
  38
  39 #include <asm/setup.h>
  40 #include <asm/page.h>
  41 #include <asm/e820/api.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 #include <asm/sev-es.h>
  51
  52 /*
  53  * We allocate runtime services regions top-down, starting from -4G, i.e.
  54  * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
  55  */
  56 static u64 efi_va = EFI_VA_START;
  57
  58 struct efi_scratch efi_scratch;
  59
  60 EXPORT_SYMBOL_GPL(efi_mm);
  61
  62 /*
  63  * We need our own copy of the higher levels of the page tables
  64  * because we want to avoid inserting EFI region mappings (EFI_VA_END
  65  * to EFI_VA_START) into the standard kernel page tables. Everything
  66  * else can be shared, see efi_sync_low_kernel_mappings().
  67  *
  68  * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
  69  * allocation.
  70  */
  71 int __init efi_alloc_page_tables(void)
  72 {
  73         pgd_t *pgd, *efi_pgd;
  74         p4d_t *p4d;
  75         pud_t *pud;
  76         gfp_t gfp_mask;
  77
  78         gfp_mask = GFP_KERNEL | __GFP_ZERO;
  79         efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
  80         if (!efi_pgd)
  81                 goto fail;
  82
  83         pgd = efi_pgd + pgd_index(EFI_VA_END);
  84         p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
  85         if (!p4d)
  86                 goto free_pgd;
  87
  88         pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
  89         if (!pud)
  90                 goto free_p4d;
  91
  92         efi_mm.pgd = efi_pgd;
  93         mm_init_cpumask(&efi_mm);
  94         init_new_context(NULL, &efi_mm);
  95
  96         return 0;
  97
  98 free_p4d:
  99         if (pgtable_l5_enabled())
 100                 free_page((unsigned long)pgd_page_vaddr(*pgd));
 101 free_pgd:
 102         free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
 103 fail:
 104         return -ENOMEM;
 105 }
 106
 107 /*
 108  * Add low kernel mappings for passing arguments to EFI functions.
 109  */
 110 void efi_sync_low_kernel_mappings(void)
 111 {
 112         unsigned num_entries;
 113         pgd_t *pgd_k, *pgd_efi;
 114         p4d_t *p4d_k, *p4d_efi;
 115         pud_t *pud_k, *pud_efi;
 116         pgd_t *efi_pgd = efi_mm.pgd;
 117
 118         /*
 119          * We can share all PGD entries apart from the one entry that
 120          * covers the EFI runtime mapping space.
 121          *
 122          * Make sure the EFI runtime region mappings are guaranteed to
 123          * only span a single PGD entry and that the entry also maps
 124          * other important kernel regions.
 125          */
 126         MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
 127         MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
 128                         (EFI_VA_END & PGDIR_MASK));
 129
 130         pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
 131         pgd_k = pgd_offset_k(PAGE_OFFSET);
 132
 133         num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
 134         memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
 135
 136         /*
 137          * As with PGDs, we share all P4D entries apart from the one entry
 138          * that covers the EFI runtime mapping space.
 139          */
 140         BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));
 141         BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));
 142
 143         pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
 144         pgd_k = pgd_offset_k(EFI_VA_END);
 145         p4d_efi = p4d_offset(pgd_efi, 0);
 146         p4d_k = p4d_offset(pgd_k, 0);
 147
 148         num_entries = p4d_index(EFI_VA_END);
 149         memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
 150
 151         /*
 152          * We share all the PUD entries apart from those that map the
 153          * EFI regions. Copy around them.
 154          */
 155         BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
 156         BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
 157
 158         p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
 159         p4d_k = p4d_offset(pgd_k, EFI_VA_END);
 160         pud_efi = pud_offset(p4d_efi, 0);
 161         pud_k = pud_offset(p4d_k, 0);
 162
 163         num_entries = pud_index(EFI_VA_END);
 164         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 165
 166         pud_efi = pud_offset(p4d_efi, EFI_VA_START);
 167         pud_k = pud_offset(p4d_k, EFI_VA_START);
 168
 169         num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
 170         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 171 }
 172
 173 /*
 174  * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 175  */
 176 static inline phys_addr_t
 177 virt_to_phys_or_null_size(void *va, unsigned long size)
 178 {
 179         phys_addr_t pa;
 180
 181         if (!va)
 182                 return 0;
 183
 184         if (virt_addr_valid(va))
 185                 return virt_to_phys(va);
 186
 187         pa = slow_virt_to_phys(va);
 188
 189         /* check if the object crosses a page boundary */
 190         if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
 191                 return 0;
 192
 193         return pa;
 194 }
 195
 196 #define virt_to_phys_or_null(addr)                              \
 197         virt_to_phys_or_null_size((addr), sizeof(*(addr)))
 198
 199 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 200 {
 201         unsigned long pfn, text, pf, rodata;
 202         struct page *page;
 203         unsigned npages;
 204         pgd_t *pgd = efi_mm.pgd;
 205
 206         /*
 207          * It can happen that the physical address of new_memmap lands in memory
 208          * which is not mapped in the EFI page table. Therefore we need to go
 209          * and ident-map those pages containing the map before calling
 210          * phys_efi_set_virtual_address_map().
 211          */
 212         pfn = pa_memmap >> PAGE_SHIFT;
 213         pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
 214         if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
 215                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 216                 return 1;
 217         }
 218
 219         /*
 220          * Certain firmware versions are way too sentimential and still believe
 221          * they are exclusive and unquestionable owners of the first physical page,
 222          * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
 223          * (but then write-access it later during SetVirtualAddressMap()).
 224          *
 225          * Create a 1:1 mapping for this page, to avoid triple faults during early
 226          * boot with such firmware. We are free to hand this page to the BIOS,
 227          * as trim_bios_range() will reserve the first page and isolate it away
 228          * from memory allocators anyway.
 229          */
 230         if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
 231                 pr_err("Failed to create 1:1 mapping for the first page!\n");
 232                 return 1;
 233         }
 234
 235         /*
 236          * When SEV-ES is active, the GHCB as set by the kernel will be used
 237          * by firmware. Create a 1:1 unencrypted mapping for each GHCB.
 238          */
 239         if (sev_es_efi_map_ghcbs(pgd)) {
 240                 pr_err("Failed to create 1:1 mapping for the GHCBs!\n");
 241                 return 1;
 242         }
 243
 244         /*
 245          * When making calls to the firmware everything needs to be 1:1
 246          * mapped and addressable with 32-bit pointers. Map the kernel
 247          * text and allocate a new stack because we can't rely on the
 248          * stack pointer being < 4GB.
 249          */
 250         if (!efi_is_mixed())
 251                 return 0;
 252
 253         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 254         if (!page) {
 255                 pr_err("Unable to allocate EFI runtime stack < 4GB\n");
 256                 return 1;
 257         }
 258
 259         efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */
 260
 261         npages = (_etext - _text) >> PAGE_SHIFT;
 262         text = __pa(_text);
 263         pfn = text >> PAGE_SHIFT;
 264
 265         pf = _PAGE_ENC;
 266         if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
 267                 pr_err("Failed to map kernel text 1:1\n");
 268                 return 1;
 269         }
 270
 271         npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
 272         rodata = __pa(__start_rodata);
 273         pfn = rodata >> PAGE_SHIFT;
 274
 275         pf = _PAGE_NX | _PAGE_ENC;
 276         if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
 277                 pr_err("Failed to map kernel rodata 1:1\n");
 278                 return 1;
 279         }
 280
 281         return 0;
 282 }
 283
 284 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 285 {
 286         unsigned long flags = _PAGE_RW;
 287         unsigned long pfn;
 288         pgd_t *pgd = efi_mm.pgd;
 289
 290         /*
 291          * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
 292          * executable images in memory that consist of both R-X and
 293          * RW- sections, so we cannot apply read-only or non-exec
 294          * permissions just yet. However, modern EFI systems provide
 295          * a memory attributes table that describes those sections
 296          * with the appropriate restricted permissions, which are
 297          * applied in efi_runtime_update_mappings() below. All other
 298          * regions can be mapped non-executable at this point, with
 299          * the exception of boot services code regions, but those will
 300          * be unmapped again entirely in efi_free_boot_services().
 301          */
 302         if (md->type != EFI_BOOT_SERVICES_CODE &&
 303             md->type != EFI_RUNTIME_SERVICES_CODE)
 304                 flags |= _PAGE_NX;
 305
 306         if (!(md->attribute & EFI_MEMORY_WB))
 307                 flags |= _PAGE_PCD;
 308
 309         if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
 310                 flags |= _PAGE_ENC;
 311
 312         pfn = md->phys_addr >> PAGE_SHIFT;
 313         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 314                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 315                            md->phys_addr, va);
 316 }
 317
 318 void __init efi_map_region(efi_memory_desc_t *md)
 319 {
 320         unsigned long size = md->num_pages << PAGE_SHIFT;
 321         u64 pa = md->phys_addr;
 322
 323         /*
 324          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 325          * firmware which doesn't update all internal pointers after switching
 326          * to virtual mode and would otherwise crap on us.
 327          */
 328         __map_region(md, md->phys_addr);
 329
 330         /*
 331          * Enforce the 1:1 mapping as the default virtual address when
 332          * booting in EFI mixed mode, because even though we may be
 333          * running a 64-bit kernel, the firmware may only be 32-bit.
 334          */
 335         if (efi_is_mixed()) {
 336                 md->virt_addr = md->phys_addr;
 337                 return;
 338         }
 339
 340         efi_va -= size;
 341
 342         /* Is PA 2M-aligned? */
 343         if (!(pa & (PMD_SIZE - 1))) {
 344                 efi_va &= PMD_MASK;
 345         } else {
 346                 u64 pa_offset = pa & (PMD_SIZE - 1);
 347                 u64 prev_va = efi_va;
 348
 349                 /* get us the same offset within this 2M page */
 350                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 351
 352                 if (efi_va > prev_va)
 353                         efi_va -= PMD_SIZE;
 354         }
 355
 356         if (efi_va < EFI_VA_END) {
 357                 pr_warn(FW_WARN "VA address range overflow!\n");
 358                 return;
 359         }
 360
 361         /* Do the VA map */
 362         __map_region(md, efi_va);
 363         md->virt_addr = efi_va;
 364 }
 365
 366 /*
 367  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 368  * md->virt_addr is the original virtual address which had been mapped in kexec
 369  * 1st kernel.
 370  */
 371 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 372 {
 373         __map_region(md, md->phys_addr);
 374         __map_region(md, md->virt_addr);
 375 }
 376
 377 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 378 {
 379         efi_setup = phys_addr + sizeof(struct setup_data);
 380 }
 381
 382 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 383 {
 384         unsigned long pfn;
 385         pgd_t *pgd = efi_mm.pgd;
 386         int err1, err2;
 387
 388         /* Update the 1:1 mapping */
 389         pfn = md->phys_addr >> PAGE_SHIFT;
 390         err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
 391         if (err1) {
 392                 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
 393                            md->phys_addr, md->virt_addr);
 394         }
 395
 396         err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
 397         if (err2) {
 398                 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
 399                            md->phys_addr, md->virt_addr);
 400         }
 401
 402         return err1 || err2;
 403 }
 404
 405 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
 406 {
 407         unsigned long pf = 0;
 408
 409         if (md->attribute & EFI_MEMORY_XP)
 410                 pf |= _PAGE_NX;
 411
 412         if (!(md->attribute & EFI_MEMORY_RO))
 413                 pf |= _PAGE_RW;
 414
 415         if (sev_active())
 416                 pf |= _PAGE_ENC;
 417
 418         return efi_update_mappings(md, pf);
 419 }
 420
 421 void __init efi_runtime_update_mappings(void)
 422 {
 423         efi_memory_desc_t *md;
 424
 425         /*
 426          * Use the EFI Memory Attribute Table for mapping permissions if it
 427          * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
 428          */
 429         if (efi_enabled(EFI_MEM_ATTR)) {
 430                 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
 431                 return;
 432         }
 433
 434         /*
 435          * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
 436          * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
 437          * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
 438          * published by the firmware. Even if we find a buggy implementation of
 439          * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
 440          * EFI_PROPERTIES_TABLE, because of the same reason.
 441          */
 442
 443         if (!efi_enabled(EFI_NX_PE_DATA))
 444                 return;
 445
 446         for_each_efi_memory_desc(md) {
 447                 unsigned long pf = 0;
 448
 449                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 450                         continue;
 451
 452                 if (!(md->attribute & EFI_MEMORY_WB))
 453                         pf |= _PAGE_PCD;
 454
 455                 if ((md->attribute & EFI_MEMORY_XP) ||
 456                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 457                         pf |= _PAGE_NX;
 458
 459                 if (!(md->attribute & EFI_MEMORY_RO) &&
 460                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 461                         pf |= _PAGE_RW;
 462
 463                 if (sev_active())
 464                         pf |= _PAGE_ENC;
 465
 466                 efi_update_mappings(md, pf);
 467         }
 468 }
 469
 470 void __init efi_dump_pagetable(void)
 471 {
 472 #ifdef CONFIG_EFI_PGT_DUMP
 473         ptdump_walk_pgd_level(NULL, &efi_mm);
 474 #endif
 475 }
 476
 477 /*
 478  * Makes the calling thread switch to/from efi_mm context. Can be used
 479  * in a kernel thread and user context. Preemption needs to remain disabled
 480  * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
 481  * can not change under us.
 482  * It should be ensured that there are no concurent calls to this function.
 483  */
 484 void efi_switch_mm(struct mm_struct *mm)
 485 {
 486         efi_scratch.prev_mm = current->active_mm;
 487         current->active_mm = mm;
 488         switch_mm(efi_scratch.prev_mm, mm, NULL);
 489 }
 490
 491 static DEFINE_SPINLOCK(efi_runtime_lock);
 492
 493 /*
 494  * DS and ES contain user values.  We need to save them.
 495  * The 32-bit EFI code needs a valid DS, ES, and SS.  There's no
 496  * need to save the old SS: __KERNEL_DS is always acceptable.
 497  */
 498 #define __efi_thunk(func, ...)                                          \
 499 ({                                                                      \
 500         unsigned short __ds, __es;                                      \
 501         efi_status_t ____s;                                             \
 502                                                                         \
 503         savesegment(ds, __ds);                                          \
 504         savesegment(es, __es);                                          \
 505                                                                         \
 506         loadsegment(ss, __KERNEL_DS);                                   \
 507         loadsegment(ds, __KERNEL_DS);                                   \
 508         loadsegment(es, __KERNEL_DS);                                   \
 509                                                                         \
 510         ____s = efi64_thunk(efi.runtime->mixed_mode.func, __VA_ARGS__); \
 511                                                                         \
 512         loadsegment(ds, __ds);                                          \
 513         loadsegment(es, __es);                                          \
 514                                                                         \
 515         ____s ^= (____s & BIT(31)) | (____s & BIT_ULL(31)) << 32;       \
 516         ____s;                                                          \
 517 })
 518
 519 /*
 520  * Switch to the EFI page tables early so that we can access the 1:1
 521  * runtime services mappings which are not mapped in any other page
 522  * tables.
 523  *
 524  * Also, disable interrupts because the IDT points to 64-bit handlers,
 525  * which aren't going to function correctly when we switch to 32-bit.
 526  */
 527 #define efi_thunk(func...)                                              \
 528 ({                                                                      \
 529         efi_status_t __s;                                               \
 530                                                                         \
 531         arch_efi_call_virt_setup();                                     \
 532                                                                         \
 533         __s = __efi_thunk(func);                                        \
 534                                                                         \
 535         arch_efi_call_virt_teardown();                                  \
 536                                                                         \
 537         __s;                                                            \
 538 })
 539
 540 static efi_status_t __init __no_sanitize_address
 541 efi_thunk_set_virtual_address_map(unsigned long memory_map_size,
 542                                   unsigned long descriptor_size,
 543                                   u32 descriptor_version,
 544                                   efi_memory_desc_t *virtual_map)
 545 {
 546         efi_status_t status;
 547         unsigned long flags;
 548
 549         efi_sync_low_kernel_mappings();
 550         local_irq_save(flags);
 551
 552         efi_switch_mm(&efi_mm);
 553
 554         status = __efi_thunk(set_virtual_address_map, memory_map_size,
 555                              descriptor_size, descriptor_version, virtual_map);
 556
 557         efi_switch_mm(efi_scratch.prev_mm);
 558         local_irq_restore(flags);
 559
 560         return status;
 561 }
 562
 563 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 564 {
 565         return EFI_UNSUPPORTED;
 566 }
 567
 568 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 569 {
 570         return EFI_UNSUPPORTED;
 571 }
 572
 573 static efi_status_t
 574 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 575                           efi_time_t *tm)
 576 {
 577         return EFI_UNSUPPORTED;
 578 }
 579
 580 static efi_status_t
 581 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 582 {
 583         return EFI_UNSUPPORTED;
 584 }
 585
 586 static unsigned long efi_name_size(efi_char16_t *name)
 587 {
 588         return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
 589 }
 590
 591 static efi_status_t
 592 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 593                        u32 *attr, unsigned long *data_size, void *data)
 594 {
 595         u8 buf[24] __aligned(8);
 596         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 597         efi_status_t status;
 598         u32 phys_name, phys_vendor, phys_attr;
 599         u32 phys_data_size, phys_data;
 600         unsigned long flags;
 601
 602         spin_lock_irqsave(&efi_runtime_lock, flags);
 603
 604         *vnd = *vendor;
 605
 606         phys_data_size = virt_to_phys_or_null(data_size);
 607         phys_vendor = virt_to_phys_or_null(vnd);
 608         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 609         phys_attr = virt_to_phys_or_null(attr);
 610         phys_data = virt_to_phys_or_null_size(data, *data_size);
 611
 612         if (!phys_name || (data && !phys_data))
 613                 status = EFI_INVALID_PARAMETER;
 614         else
 615                 status = efi_thunk(get_variable, phys_name, phys_vendor,
 616                                    phys_attr, phys_data_size, phys_data);
 617
 618         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 619
 620         return status;
 621 }
 622
 623 static efi_status_t
 624 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 625                        u32 attr, unsigned long data_size, void *data)
 626 {
 627         u8 buf[24] __aligned(8);
 628         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 629         u32 phys_name, phys_vendor, phys_data;
 630         efi_status_t status;
 631         unsigned long flags;
 632
 633         spin_lock_irqsave(&efi_runtime_lock, flags);
 634
 635         *vnd = *vendor;
 636
 637         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 638         phys_vendor = virt_to_phys_or_null(vnd);
 639         phys_data = virt_to_phys_or_null_size(data, data_size);
 640
 641         if (!phys_name || (data && !phys_data))
 642                 status = EFI_INVALID_PARAMETER;
 643         else
 644                 status = efi_thunk(set_variable, phys_name, phys_vendor,
 645                                    attr, data_size, phys_data);
 646
 647         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 648
 649         return status;
 650 }
 651
 652 static efi_status_t
 653 efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
 654                                    u32 attr, unsigned long data_size,
 655                                    void *data)
 656 {
 657         u8 buf[24] __aligned(8);
 658         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 659         u32 phys_name, phys_vendor, phys_data;
 660         efi_status_t status;
 661         unsigned long flags;
 662
 663         if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
 664                 return EFI_NOT_READY;
 665
 666         *vnd = *vendor;
 667
 668         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 669         phys_vendor = virt_to_phys_or_null(vnd);
 670         phys_data = virt_to_phys_or_null_size(data, data_size);
 671
 672         if (!phys_name || (data && !phys_data))
 673                 status = EFI_INVALID_PARAMETER;
 674         else
 675                 status = efi_thunk(set_variable, phys_name, phys_vendor,
 676                                    attr, data_size, phys_data);
 677
 678         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 679
 680         return status;
 681 }
 682
 683 static efi_status_t
 684 efi_thunk_get_next_variable(unsigned long *name_size,
 685                             efi_char16_t *name,
 686                             efi_guid_t *vendor)
 687 {
 688         u8 buf[24] __aligned(8);
 689         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 690         efi_status_t status;
 691         u32 phys_name_size, phys_name, phys_vendor;
 692         unsigned long flags;
 693
 694         spin_lock_irqsave(&efi_runtime_lock, flags);
 695
 696         *vnd = *vendor;
 697
 698         phys_name_size = virt_to_phys_or_null(name_size);
 699         phys_vendor = virt_to_phys_or_null(vnd);
 700         phys_name = virt_to_phys_or_null_size(name, *name_size);
 701
 702         if (!phys_name)
 703                 status = EFI_INVALID_PARAMETER;
 704         else
 705                 status = efi_thunk(get_next_variable, phys_name_size,
 706                                    phys_name, phys_vendor);
 707
 708         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 709
 710         *vendor = *vnd;
 711         return status;
 712 }
 713
 714 static efi_status_t
 715 efi_thunk_get_next_high_mono_count(u32 *count)
 716 {
 717         return EFI_UNSUPPORTED;
 718 }
 719
 720 static void
 721 efi_thunk_reset_system(int reset_type, efi_status_t status,
 722                        unsigned long data_size, efi_char16_t *data)
 723 {
 724         u32 phys_data;
 725         unsigned long flags;
 726
 727         spin_lock_irqsave(&efi_runtime_lock, flags);
 728
 729         phys_data = virt_to_phys_or_null_size(data, data_size);
 730
 731         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
 732
 733         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 734 }
 735
 736 static efi_status_t
 737 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
 738                          unsigned long count, unsigned long sg_list)
 739 {
 740         /*
 741          * To properly support this function we would need to repackage
 742          * 'capsules' because the firmware doesn't understand 64-bit
 743          * pointers.
 744          */
 745         return EFI_UNSUPPORTED;
 746 }
 747
 748 static efi_status_t
 749 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 750                               u64 *remaining_space,
 751                               u64 *max_variable_size)
 752 {
 753         efi_status_t status;
 754         u32 phys_storage, phys_remaining, phys_max;
 755         unsigned long flags;
 756
 757         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 758                 return EFI_UNSUPPORTED;
 759
 760         spin_lock_irqsave(&efi_runtime_lock, flags);
 761
 762         phys_storage = virt_to_phys_or_null(storage_space);
 763         phys_remaining = virt_to_phys_or_null(remaining_space);
 764         phys_max = virt_to_phys_or_null(max_variable_size);
 765
 766         status = efi_thunk(query_variable_info, attr, phys_storage,
 767                            phys_remaining, phys_max);
 768
 769         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 770
 771         return status;
 772 }
 773
 774 static efi_status_t
 775 efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
 776                                           u64 *remaining_space,
 777                                           u64 *max_variable_size)
 778 {
 779         efi_status_t status;
 780         u32 phys_storage, phys_remaining, phys_max;
 781         unsigned long flags;
 782
 783         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 784                 return EFI_UNSUPPORTED;
 785
 786         if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
 787                 return EFI_NOT_READY;
 788
 789         phys_storage = virt_to_phys_or_null(storage_space);
 790         phys_remaining = virt_to_phys_or_null(remaining_space);
 791         phys_max = virt_to_phys_or_null(max_variable_size);
 792
 793         status = efi_thunk(query_variable_info, attr, phys_storage,
 794                            phys_remaining, phys_max);
 795
 796         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 797
 798         return status;
 799 }
 800
 801 static efi_status_t
 802 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
 803                              unsigned long count, u64 *max_size,
 804                              int *reset_type)
 805 {
 806         /*
 807          * To properly support this function we would need to repackage
 808          * 'capsules' because the firmware doesn't understand 64-bit
 809          * pointers.
 810          */
 811         return EFI_UNSUPPORTED;
 812 }
 813
 814 void __init efi_thunk_runtime_setup(void)
 815 {
 816         if (!IS_ENABLED(CONFIG_EFI_MIXED))
 817                 return;
 818
 819         efi.get_time = efi_thunk_get_time;
 820         efi.set_time = efi_thunk_set_time;
 821         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
 822         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
 823         efi.get_variable = efi_thunk_get_variable;
 824         efi.get_next_variable = efi_thunk_get_next_variable;
 825         efi.set_variable = efi_thunk_set_variable;
 826         efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
 827         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
 828         efi.reset_system = efi_thunk_reset_system;
 829         efi.query_variable_info = efi_thunk_query_variable_info;
 830         efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
 831         efi.update_capsule = efi_thunk_update_capsule;
 832         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
 833 }
 834
 835 efi_status_t __init __no_sanitize_address
 836 efi_set_virtual_address_map(unsigned long memory_map_size,
 837                             unsigned long descriptor_size,
 838                             u32 descriptor_version,
 839                             efi_memory_desc_t *virtual_map,
 840                             unsigned long systab_phys)
 841 {
 842         const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
 843         efi_status_t status;
 844         unsigned long flags;
 845
 846         if (efi_is_mixed())
 847                 return efi_thunk_set_virtual_address_map(memory_map_size,
 848                                                          descriptor_size,
 849                                                          descriptor_version,
 850                                                          virtual_map);
 851         efi_switch_mm(&efi_mm);
 852
 853         kernel_fpu_begin();
 854
 855         /* Disable interrupts around EFI calls: */
 856         local_irq_save(flags);
 857         status = efi_call(efi.runtime->set_virtual_address_map,
 858                           memory_map_size, descriptor_size,
 859                           descriptor_version, virtual_map);
 860         local_irq_restore(flags);
 861
 862         kernel_fpu_end();
 863
 864         /* grab the virtually remapped EFI runtime services table pointer */
 865         efi.runtime = READ_ONCE(systab->runtime);
 866
 867         efi_switch_mm(efi_scratch.prev_mm);
 868
 869         return status;
 870 }