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/pgtable.h>
  43 #include <asm/tlbflush.h>
  44 #include <asm/proto.h>
  45 #include <asm/efi.h>
  46 #include <asm/cacheflush.h>
  47 #include <asm/fixmap.h>
  48 #include <asm/realmode.h>
  49 #include <asm/time.h>
  50 #include <asm/pgalloc.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         if (efi_have_uv1_memmap())
  79                 return 0;
  80
  81         gfp_mask = GFP_KERNEL | __GFP_ZERO;
  82         efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
  83         if (!efi_pgd)
  84                 return -ENOMEM;
  85
  86         pgd = efi_pgd + pgd_index(EFI_VA_END);
  87         p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
  88         if (!p4d) {
  89                 free_page((unsigned long)efi_pgd);
  90                 return -ENOMEM;
  91         }
  92
  93         pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
  94         if (!pud) {
  95                 if (pgtable_l5_enabled())
  96                         free_page((unsigned long) pgd_page_vaddr(*pgd));
  97                 free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
  98                 return -ENOMEM;
  99         }
 100
 101         efi_mm.pgd = efi_pgd;
 102         mm_init_cpumask(&efi_mm);
 103         init_new_context(NULL, &efi_mm);
 104
 105         return 0;
 106 }
 107
 108 /*
 109  * Add low kernel mappings for passing arguments to EFI functions.
 110  */
 111 void efi_sync_low_kernel_mappings(void)
 112 {
 113         unsigned num_entries;
 114         pgd_t *pgd_k, *pgd_efi;
 115         p4d_t *p4d_k, *p4d_efi;
 116         pud_t *pud_k, *pud_efi;
 117         pgd_t *efi_pgd = efi_mm.pgd;
 118
 119         if (efi_have_uv1_memmap())
 120                 return;
 121
 122         /*
 123          * We can share all PGD entries apart from the one entry that
 124          * covers the EFI runtime mapping space.
 125          *
 126          * Make sure the EFI runtime region mappings are guaranteed to
 127          * only span a single PGD entry and that the entry also maps
 128          * other important kernel regions.
 129          */
 130         MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
 131         MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
 132                         (EFI_VA_END & PGDIR_MASK));
 133
 134         pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
 135         pgd_k = pgd_offset_k(PAGE_OFFSET);
 136
 137         num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
 138         memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
 139
 140         /*
 141          * As with PGDs, we share all P4D entries apart from the one entry
 142          * that covers the EFI runtime mapping space.
 143          */
 144         BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));
 145         BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));
 146
 147         pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
 148         pgd_k = pgd_offset_k(EFI_VA_END);
 149         p4d_efi = p4d_offset(pgd_efi, 0);
 150         p4d_k = p4d_offset(pgd_k, 0);
 151
 152         num_entries = p4d_index(EFI_VA_END);
 153         memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
 154
 155         /*
 156          * We share all the PUD entries apart from those that map the
 157          * EFI regions. Copy around them.
 158          */
 159         BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
 160         BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
 161
 162         p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
 163         p4d_k = p4d_offset(pgd_k, EFI_VA_END);
 164         pud_efi = pud_offset(p4d_efi, 0);
 165         pud_k = pud_offset(p4d_k, 0);
 166
 167         num_entries = pud_index(EFI_VA_END);
 168         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 169
 170         pud_efi = pud_offset(p4d_efi, EFI_VA_START);
 171         pud_k = pud_offset(p4d_k, EFI_VA_START);
 172
 173         num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
 174         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 175 }
 176
 177 /*
 178  * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 179  */
 180 static inline phys_addr_t
 181 virt_to_phys_or_null_size(void *va, unsigned long size)
 182 {
 183         phys_addr_t pa;
 184
 185         if (!va)
 186                 return 0;
 187
 188         if (virt_addr_valid(va))
 189                 return virt_to_phys(va);
 190
 191         pa = slow_virt_to_phys(va);
 192
 193         /* check if the object crosses a page boundary */
 194         if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
 195                 return 0;
 196
 197         return pa;
 198 }
 199
 200 #define virt_to_phys_or_null(addr)                              \
 201         virt_to_phys_or_null_size((addr), sizeof(*(addr)))
 202
 203 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 204 {
 205         unsigned long pfn, text, pf;
 206         struct page *page;
 207         unsigned npages;
 208         pgd_t *pgd = efi_mm.pgd;
 209
 210         if (efi_have_uv1_memmap())
 211                 return 0;
 212
 213         /*
 214          * It can happen that the physical address of new_memmap lands in memory
 215          * which is not mapped in the EFI page table. Therefore we need to go
 216          * and ident-map those pages containing the map before calling
 217          * phys_efi_set_virtual_address_map().
 218          */
 219         pfn = pa_memmap >> PAGE_SHIFT;
 220         pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
 221         if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
 222                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 223                 return 1;
 224         }
 225
 226         /*
 227          * Certain firmware versions are way too sentimential and still believe
 228          * they are exclusive and unquestionable owners of the first physical page,
 229          * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
 230          * (but then write-access it later during SetVirtualAddressMap()).
 231          *
 232          * Create a 1:1 mapping for this page, to avoid triple faults during early
 233          * boot with such firmware. We are free to hand this page to the BIOS,
 234          * as trim_bios_range() will reserve the first page and isolate it away
 235          * from memory allocators anyway.
 236          */
 237         if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
 238                 pr_err("Failed to create 1:1 mapping for the first page!\n");
 239                 return 1;
 240         }
 241
 242         /*
 243          * When making calls to the firmware everything needs to be 1:1
 244          * mapped and addressable with 32-bit pointers. Map the kernel
 245          * text and allocate a new stack because we can't rely on the
 246          * stack pointer being < 4GB.
 247          */
 248         if (!efi_is_mixed())
 249                 return 0;
 250
 251         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 252         if (!page) {
 253                 pr_err("Unable to allocate EFI runtime stack < 4GB\n");
 254                 return 1;
 255         }
 256
 257         efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */
 258
 259         npages = (__end_rodata_aligned - _text) >> PAGE_SHIFT;
 260         text = __pa(_text);
 261         pfn = text >> PAGE_SHIFT;
 262
 263         pf = _PAGE_ENC;
 264         if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
 265                 pr_err("Failed to map kernel text 1:1\n");
 266                 return 1;
 267         }
 268
 269         return 0;
 270 }
 271
 272 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 273 {
 274         unsigned long flags = _PAGE_RW;
 275         unsigned long pfn;
 276         pgd_t *pgd = efi_mm.pgd;
 277
 278         /*
 279          * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
 280          * executable images in memory that consist of both R-X and
 281          * RW- sections, so we cannot apply read-only or non-exec
 282          * permissions just yet. However, modern EFI systems provide
 283          * a memory attributes table that describes those sections
 284          * with the appropriate restricted permissions, which are
 285          * applied in efi_runtime_update_mappings() below. All other
 286          * regions can be mapped non-executable at this point, with
 287          * the exception of boot services code regions, but those will
 288          * be unmapped again entirely in efi_free_boot_services().
 289          */
 290         if (md->type != EFI_BOOT_SERVICES_CODE &&
 291             md->type != EFI_RUNTIME_SERVICES_CODE)
 292                 flags |= _PAGE_NX;
 293
 294         if (!(md->attribute & EFI_MEMORY_WB))
 295                 flags |= _PAGE_PCD;
 296
 297         if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
 298                 flags |= _PAGE_ENC;
 299
 300         pfn = md->phys_addr >> PAGE_SHIFT;
 301         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 302                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 303                            md->phys_addr, va);
 304 }
 305
 306 void __init efi_map_region(efi_memory_desc_t *md)
 307 {
 308         unsigned long size = md->num_pages << PAGE_SHIFT;
 309         u64 pa = md->phys_addr;
 310
 311         if (efi_have_uv1_memmap())
 312                 return old_map_region(md);
 313
 314         /*
 315          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 316          * firmware which doesn't update all internal pointers after switching
 317          * to virtual mode and would otherwise crap on us.
 318          */
 319         __map_region(md, md->phys_addr);
 320
 321         /*
 322          * Enforce the 1:1 mapping as the default virtual address when
 323          * booting in EFI mixed mode, because even though we may be
 324          * running a 64-bit kernel, the firmware may only be 32-bit.
 325          */
 326         if (efi_is_mixed()) {
 327                 md->virt_addr = md->phys_addr;
 328                 return;
 329         }
 330
 331         efi_va -= size;
 332
 333         /* Is PA 2M-aligned? */
 334         if (!(pa & (PMD_SIZE - 1))) {
 335                 efi_va &= PMD_MASK;
 336         } else {
 337                 u64 pa_offset = pa & (PMD_SIZE - 1);
 338                 u64 prev_va = efi_va;
 339
 340                 /* get us the same offset within this 2M page */
 341                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 342
 343                 if (efi_va > prev_va)
 344                         efi_va -= PMD_SIZE;
 345         }
 346
 347         if (efi_va < EFI_VA_END) {
 348                 pr_warn(FW_WARN "VA address range overflow!\n");
 349                 return;
 350         }
 351
 352         /* Do the VA map */
 353         __map_region(md, efi_va);
 354         md->virt_addr = efi_va;
 355 }
 356
 357 /*
 358  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 359  * md->virt_addr is the original virtual address which had been mapped in kexec
 360  * 1st kernel.
 361  */
 362 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 363 {
 364         __map_region(md, md->phys_addr);
 365         __map_region(md, md->virt_addr);
 366 }
 367
 368 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 369 {
 370         efi_setup = phys_addr + sizeof(struct setup_data);
 371 }
 372
 373 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 374 {
 375         unsigned long pfn;
 376         pgd_t *pgd = efi_mm.pgd;
 377         int err1, err2;
 378
 379         /* Update the 1:1 mapping */
 380         pfn = md->phys_addr >> PAGE_SHIFT;
 381         err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
 382         if (err1) {
 383                 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
 384                            md->phys_addr, md->virt_addr);
 385         }
 386
 387         err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
 388         if (err2) {
 389                 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
 390                            md->phys_addr, md->virt_addr);
 391         }
 392
 393         return err1 || err2;
 394 }
 395
 396 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
 397 {
 398         unsigned long pf = 0;
 399
 400         if (md->attribute & EFI_MEMORY_XP)
 401                 pf |= _PAGE_NX;
 402
 403         if (!(md->attribute & EFI_MEMORY_RO))
 404                 pf |= _PAGE_RW;
 405
 406         if (sev_active())
 407                 pf |= _PAGE_ENC;
 408
 409         return efi_update_mappings(md, pf);
 410 }
 411
 412 void __init efi_runtime_update_mappings(void)
 413 {
 414         efi_memory_desc_t *md;
 415
 416         if (efi_have_uv1_memmap()) {
 417                 if (__supported_pte_mask & _PAGE_NX)
 418                         runtime_code_page_mkexec();
 419                 return;
 420         }
 421
 422         /*
 423          * Use the EFI Memory Attribute Table for mapping permissions if it
 424          * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
 425          */
 426         if (efi_enabled(EFI_MEM_ATTR)) {
 427                 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
 428                 return;
 429         }
 430
 431         /*
 432          * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
 433          * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
 434          * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
 435          * published by the firmware. Even if we find a buggy implementation of
 436          * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
 437          * EFI_PROPERTIES_TABLE, because of the same reason.
 438          */
 439
 440         if (!efi_enabled(EFI_NX_PE_DATA))
 441                 return;
 442
 443         for_each_efi_memory_desc(md) {
 444                 unsigned long pf = 0;
 445
 446                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 447                         continue;
 448
 449                 if (!(md->attribute & EFI_MEMORY_WB))
 450                         pf |= _PAGE_PCD;
 451
 452                 if ((md->attribute & EFI_MEMORY_XP) ||
 453                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 454                         pf |= _PAGE_NX;
 455
 456                 if (!(md->attribute & EFI_MEMORY_RO) &&
 457                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 458                         pf |= _PAGE_RW;
 459
 460                 if (sev_active())
 461                         pf |= _PAGE_ENC;
 462
 463                 efi_update_mappings(md, pf);
 464         }
 465 }
 466
 467 void __init efi_dump_pagetable(void)
 468 {
 469 #ifdef CONFIG_EFI_PGT_DUMP
 470         if (efi_have_uv1_memmap())
 471                 ptdump_walk_pgd_level(NULL, &init_mm);
 472         else
 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 || !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 || !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         pgd_t *save_pgd = NULL;
 846
 847         if (efi_is_mixed())
 848                 return efi_thunk_set_virtual_address_map(memory_map_size,
 849                                                          descriptor_size,
 850                                                          descriptor_version,
 851                                                          virtual_map);
 852
 853         if (efi_have_uv1_memmap()) {
 854                 save_pgd = efi_uv1_memmap_phys_prolog();
 855                 if (!save_pgd)
 856                         return EFI_ABORTED;
 857         } else {
 858                 efi_switch_mm(&efi_mm);
 859         }
 860
 861         kernel_fpu_begin();
 862
 863         /* Disable interrupts around EFI calls: */
 864         local_irq_save(flags);
 865         status = efi_call(efi.runtime->set_virtual_address_map,
 866                           memory_map_size, descriptor_size,
 867                           descriptor_version, virtual_map);
 868         local_irq_restore(flags);
 869
 870         kernel_fpu_end();
 871
 872         /* grab the virtually remapped EFI runtime services table pointer */
 873         efi.runtime = READ_ONCE(systab->runtime);
 874
 875         if (save_pgd)
 876                 efi_uv1_memmap_phys_epilog(save_pgd);
 877         else
 878                 efi_switch_mm(efi_scratch.prev_mm);
 879
 880         return status;
 881 }