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/cc_platform.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.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 static struct mm_struct *efi_prev_mm;
  58
  59 /*
  60  * We need our own copy of the higher levels of the page tables
  61  * because we want to avoid inserting EFI region mappings (EFI_VA_END
  62  * to EFI_VA_START) into the standard kernel page tables. Everything
  63  * else can be shared, see efi_sync_low_kernel_mappings().
  64  *
  65  * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
  66  * allocation.
  67  */
  68 int __init efi_alloc_page_tables(void)
  69 {
  70         pgd_t *pgd, *efi_pgd;
  71         p4d_t *p4d;
  72         pud_t *pud;
  73         gfp_t gfp_mask;
  74
  75         gfp_mask = GFP_KERNEL | __GFP_ZERO;
  76         efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
  77         if (!efi_pgd)
  78                 goto fail;
  79
  80         pgd = efi_pgd + pgd_index(EFI_VA_END);
  81         p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
  82         if (!p4d)
  83                 goto free_pgd;
  84
  85         pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
  86         if (!pud)
  87                 goto free_p4d;
  88
  89         efi_mm.pgd = efi_pgd;
  90         mm_init_cpumask(&efi_mm);
  91         init_new_context(NULL, &efi_mm);
  92
  93         return 0;
  94
  95 free_p4d:
  96         if (pgtable_l5_enabled())
  97                 free_page((unsigned long)pgd_page_vaddr(*pgd));
  98 free_pgd:
  99         free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
 100 fail:
 101         return -ENOMEM;
 102 }
 103
 104 /*
 105  * Add low kernel mappings for passing arguments to EFI functions.
 106  */
 107 void efi_sync_low_kernel_mappings(void)
 108 {
 109         unsigned num_entries;
 110         pgd_t *pgd_k, *pgd_efi;
 111         p4d_t *p4d_k, *p4d_efi;
 112         pud_t *pud_k, *pud_efi;
 113         pgd_t *efi_pgd = efi_mm.pgd;
 114
 115         pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
 116         pgd_k = pgd_offset_k(PAGE_OFFSET);
 117
 118         num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
 119         memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
 120
 121         pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
 122         pgd_k = pgd_offset_k(EFI_VA_END);
 123         p4d_efi = p4d_offset(pgd_efi, 0);
 124         p4d_k = p4d_offset(pgd_k, 0);
 125
 126         num_entries = p4d_index(EFI_VA_END);
 127         memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
 128
 129         /*
 130          * We share all the PUD entries apart from those that map the
 131          * EFI regions. Copy around them.
 132          */
 133         BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
 134         BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
 135
 136         p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
 137         p4d_k = p4d_offset(pgd_k, EFI_VA_END);
 138         pud_efi = pud_offset(p4d_efi, 0);
 139         pud_k = pud_offset(p4d_k, 0);
 140
 141         num_entries = pud_index(EFI_VA_END);
 142         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 143
 144         pud_efi = pud_offset(p4d_efi, EFI_VA_START);
 145         pud_k = pud_offset(p4d_k, EFI_VA_START);
 146
 147         num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
 148         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 149 }
 150
 151 /*
 152  * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 153  */
 154 static inline phys_addr_t
 155 virt_to_phys_or_null_size(void *va, unsigned long size)
 156 {
 157         phys_addr_t pa;
 158
 159         if (!va)
 160                 return 0;
 161
 162         if (virt_addr_valid(va))
 163                 return virt_to_phys(va);
 164
 165         pa = slow_virt_to_phys(va);
 166
 167         /* check if the object crosses a page boundary */
 168         if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
 169                 return 0;
 170
 171         return pa;
 172 }
 173
 174 #define virt_to_phys_or_null(addr)                              \
 175         virt_to_phys_or_null_size((addr), sizeof(*(addr)))
 176
 177 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 178 {
 179         extern const u8 __efi64_thunk_ret_tramp[];
 180         unsigned long pfn, text, pf, rodata, tramp;
 181         struct page *page;
 182         unsigned npages;
 183         pgd_t *pgd = efi_mm.pgd;
 184
 185         /*
 186          * It can happen that the physical address of new_memmap lands in memory
 187          * which is not mapped in the EFI page table. Therefore we need to go
 188          * and ident-map those pages containing the map before calling
 189          * phys_efi_set_virtual_address_map().
 190          */
 191         pfn = pa_memmap >> PAGE_SHIFT;
 192         pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
 193         if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
 194                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 195                 return 1;
 196         }
 197
 198         /*
 199          * Certain firmware versions are way too sentimental and still believe
 200          * they are exclusive and unquestionable owners of the first physical page,
 201          * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
 202          * (but then write-access it later during SetVirtualAddressMap()).
 203          *
 204          * Create a 1:1 mapping for this page, to avoid triple faults during early
 205          * boot with such firmware. We are free to hand this page to the BIOS,
 206          * as trim_bios_range() will reserve the first page and isolate it away
 207          * from memory allocators anyway.
 208          */
 209         if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
 210                 pr_err("Failed to create 1:1 mapping for the first page!\n");
 211                 return 1;
 212         }
 213
 214         /*
 215          * When SEV-ES is active, the GHCB as set by the kernel will be used
 216          * by firmware. Create a 1:1 unencrypted mapping for each GHCB.
 217          */
 218         if (sev_es_efi_map_ghcbs(pgd)) {
 219                 pr_err("Failed to create 1:1 mapping for the GHCBs!\n");
 220                 return 1;
 221         }
 222
 223         /*
 224          * When making calls to the firmware everything needs to be 1:1
 225          * mapped and addressable with 32-bit pointers. Map the kernel
 226          * text and allocate a new stack because we can't rely on the
 227          * stack pointer being < 4GB.
 228          */
 229         if (!efi_is_mixed())
 230                 return 0;
 231
 232         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 233         if (!page) {
 234                 pr_err("Unable to allocate EFI runtime stack < 4GB\n");
 235                 return 1;
 236         }
 237
 238         efi_mixed_mode_stack_pa = page_to_phys(page + 1); /* stack grows down */
 239
 240         npages = (_etext - _text) >> PAGE_SHIFT;
 241         text = __pa(_text);
 242
 243         if (kernel_unmap_pages_in_pgd(pgd, text, npages)) {
 244                 pr_err("Failed to unmap kernel text 1:1 mapping\n");
 245                 return 1;
 246         }
 247
 248         npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
 249         rodata = __pa(__start_rodata);
 250         pfn = rodata >> PAGE_SHIFT;
 251
 252         pf = _PAGE_NX | _PAGE_ENC;
 253         if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
 254                 pr_err("Failed to map kernel rodata 1:1\n");
 255                 return 1;
 256         }
 257
 258         tramp = __pa(__efi64_thunk_ret_tramp);
 259         pfn = tramp >> PAGE_SHIFT;
 260
 261         pf = _PAGE_ENC;
 262         if (kernel_map_pages_in_pgd(pgd, pfn, tramp, 1, pf)) {
 263                 pr_err("Failed to map mixed mode return trampoline\n");
 264                 return 1;
 265         }
 266
 267         return 0;
 268 }
 269
 270 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 271 {
 272         unsigned long flags = _PAGE_RW;
 273         unsigned long pfn;
 274         pgd_t *pgd = efi_mm.pgd;
 275
 276         /*
 277          * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
 278          * executable images in memory that consist of both R-X and
 279          * RW- sections, so we cannot apply read-only or non-exec
 280          * permissions just yet. However, modern EFI systems provide
 281          * a memory attributes table that describes those sections
 282          * with the appropriate restricted permissions, which are
 283          * applied in efi_runtime_update_mappings() below. All other
 284          * regions can be mapped non-executable at this point, with
 285          * the exception of boot services code regions, but those will
 286          * be unmapped again entirely in efi_free_boot_services().
 287          */
 288         if (md->type != EFI_BOOT_SERVICES_CODE &&
 289             md->type != EFI_RUNTIME_SERVICES_CODE)
 290                 flags |= _PAGE_NX;
 291
 292         if (!(md->attribute & EFI_MEMORY_WB))
 293                 flags |= _PAGE_PCD;
 294
 295         if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) &&
 296             md->type != EFI_MEMORY_MAPPED_IO)
 297                 flags |= _PAGE_ENC;
 298
 299         pfn = md->phys_addr >> PAGE_SHIFT;
 300         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 301                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 302                            md->phys_addr, va);
 303 }
 304
 305 void __init efi_map_region(efi_memory_desc_t *md)
 306 {
 307         unsigned long size = md->num_pages << PAGE_SHIFT;
 308         u64 pa = md->phys_addr;
 309
 310         /*
 311          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 312          * firmware which doesn't update all internal pointers after switching
 313          * to virtual mode and would otherwise crap on us.
 314          */
 315         __map_region(md, md->phys_addr);
 316
 317         /*
 318          * Enforce the 1:1 mapping as the default virtual address when
 319          * booting in EFI mixed mode, because even though we may be
 320          * running a 64-bit kernel, the firmware may only be 32-bit.
 321          */
 322         if (efi_is_mixed()) {
 323                 md->virt_addr = md->phys_addr;
 324                 return;
 325         }
 326
 327         efi_va -= size;
 328
 329         /* Is PA 2M-aligned? */
 330         if (!(pa & (PMD_SIZE - 1))) {
 331                 efi_va &= PMD_MASK;
 332         } else {
 333                 u64 pa_offset = pa & (PMD_SIZE - 1);
 334                 u64 prev_va = efi_va;
 335
 336                 /* get us the same offset within this 2M page */
 337                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 338
 339                 if (efi_va > prev_va)
 340                         efi_va -= PMD_SIZE;
 341         }
 342
 343         if (efi_va < EFI_VA_END) {
 344                 pr_warn(FW_WARN "VA address range overflow!\n");
 345                 return;
 346         }
 347
 348         /* Do the VA map */
 349         __map_region(md, efi_va);
 350         md->virt_addr = efi_va;
 351 }
 352
 353 /*
 354  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 355  * md->virt_addr is the original virtual address which had been mapped in kexec
 356  * 1st kernel.
 357  */
 358 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 359 {
 360         __map_region(md, md->phys_addr);
 361         __map_region(md, md->virt_addr);
 362 }
 363
 364 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 365 {
 366         efi_setup = phys_addr + sizeof(struct setup_data);
 367 }
 368
 369 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 370 {
 371         unsigned long pfn;
 372         pgd_t *pgd = efi_mm.pgd;
 373         int err1, err2;
 374
 375         /* Update the 1:1 mapping */
 376         pfn = md->phys_addr >> PAGE_SHIFT;
 377         err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
 378         if (err1) {
 379                 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
 380                            md->phys_addr, md->virt_addr);
 381         }
 382
 383         err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
 384         if (err2) {
 385                 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
 386                            md->phys_addr, md->virt_addr);
 387         }
 388
 389         return err1 || err2;
 390 }
 391
 392 bool efi_disable_ibt_for_runtime __ro_after_init = true;
 393
 394 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md,
 395                                       bool has_ibt)
 396 {
 397         unsigned long pf = 0;
 398
 399         efi_disable_ibt_for_runtime |= !has_ibt;
 400
 401         if (md->attribute & EFI_MEMORY_XP)
 402                 pf |= _PAGE_NX;
 403
 404         if (!(md->attribute & EFI_MEMORY_RO))
 405                 pf |= _PAGE_RW;
 406
 407         if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 408                 pf |= _PAGE_ENC;
 409
 410         return efi_update_mappings(md, pf);
 411 }
 412
 413 void __init efi_runtime_update_mappings(void)
 414 {
 415         efi_memory_desc_t *md;
 416
 417         /*
 418          * Use the EFI Memory Attribute Table for mapping permissions if it
 419          * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
 420          */
 421         if (efi_enabled(EFI_MEM_ATTR)) {
 422                 efi_disable_ibt_for_runtime = false;
 423                 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
 424                 return;
 425         }
 426
 427         /*
 428          * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
 429          * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
 430          * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
 431          * published by the firmware. Even if we find a buggy implementation of
 432          * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
 433          * EFI_PROPERTIES_TABLE, because of the same reason.
 434          */
 435
 436         if (!efi_enabled(EFI_NX_PE_DATA))
 437                 return;
 438
 439         for_each_efi_memory_desc(md) {
 440                 unsigned long pf = 0;
 441
 442                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 443                         continue;
 444
 445                 if (!(md->attribute & EFI_MEMORY_WB))
 446                         pf |= _PAGE_PCD;
 447
 448                 if ((md->attribute & EFI_MEMORY_XP) ||
 449                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 450                         pf |= _PAGE_NX;
 451
 452                 if (!(md->attribute & EFI_MEMORY_RO) &&
 453                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 454                         pf |= _PAGE_RW;
 455
 456                 if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 457                         pf |= _PAGE_ENC;
 458
 459                 efi_update_mappings(md, pf);
 460         }
 461 }
 462
 463 void __init efi_dump_pagetable(void)
 464 {
 465 #ifdef CONFIG_EFI_PGT_DUMP
 466         ptdump_walk_pgd_level(NULL, &efi_mm);
 467 #endif
 468 }
 469
 470 /*
 471  * Makes the calling thread switch to/from efi_mm context. Can be used
 472  * in a kernel thread and user context. Preemption needs to remain disabled
 473  * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
 474  * can not change under us.
 475  * It should be ensured that there are no concurrent calls to this function.
 476  */
 477 static void efi_enter_mm(void)
 478 {
 479         efi_prev_mm = current->active_mm;
 480         current->active_mm = &efi_mm;
 481         switch_mm(efi_prev_mm, &efi_mm, NULL);
 482 }
 483
 484 static void efi_leave_mm(void)
 485 {
 486         current->active_mm = efi_prev_mm;
 487         switch_mm(&efi_mm, efi_prev_mm, NULL);
 488 }
 489
 490 void arch_efi_call_virt_setup(void)
 491 {
 492         efi_sync_low_kernel_mappings();
 493         efi_fpu_begin();
 494         firmware_restrict_branch_speculation_start();
 495         efi_enter_mm();
 496 }
 497
 498 void arch_efi_call_virt_teardown(void)
 499 {
 500         efi_leave_mm();
 501         firmware_restrict_branch_speculation_end();
 502         efi_fpu_end();
 503 }
 504
 505 static DEFINE_SPINLOCK(efi_runtime_lock);
 506
 507 /*
 508  * DS and ES contain user values.  We need to save them.
 509  * The 32-bit EFI code needs a valid DS, ES, and SS.  There's no
 510  * need to save the old SS: __KERNEL_DS is always acceptable.
 511  */
 512 #define __efi_thunk(func, ...)                                          \
 513 ({                                                                      \
 514         unsigned short __ds, __es;                                      \
 515         efi_status_t ____s;                                             \
 516                                                                         \
 517         savesegment(ds, __ds);                                          \
 518         savesegment(es, __es);                                          \
 519                                                                         \
 520         loadsegment(ss, __KERNEL_DS);                                   \
 521         loadsegment(ds, __KERNEL_DS);                                   \
 522         loadsegment(es, __KERNEL_DS);                                   \
 523                                                                         \
 524         ____s = efi64_thunk(efi.runtime->mixed_mode.func, __VA_ARGS__); \
 525                                                                         \
 526         loadsegment(ds, __ds);                                          \
 527         loadsegment(es, __es);                                          \
 528                                                                         \
 529         ____s ^= (____s & BIT(31)) | (____s & BIT_ULL(31)) << 32;       \
 530         ____s;                                                          \
 531 })
 532
 533 /*
 534  * Switch to the EFI page tables early so that we can access the 1:1
 535  * runtime services mappings which are not mapped in any other page
 536  * tables.
 537  *
 538  * Also, disable interrupts because the IDT points to 64-bit handlers,
 539  * which aren't going to function correctly when we switch to 32-bit.
 540  */
 541 #define efi_thunk(func...)                                              \
 542 ({                                                                      \
 543         efi_status_t __s;                                               \
 544                                                                         \
 545         arch_efi_call_virt_setup();                                     \
 546                                                                         \
 547         __s = __efi_thunk(func);                                        \
 548                                                                         \
 549         arch_efi_call_virt_teardown();                                  \
 550                                                                         \
 551         __s;                                                            \
 552 })
 553
 554 static efi_status_t __init __no_sanitize_address
 555 efi_thunk_set_virtual_address_map(unsigned long memory_map_size,
 556                                   unsigned long descriptor_size,
 557                                   u32 descriptor_version,
 558                                   efi_memory_desc_t *virtual_map)
 559 {
 560         efi_status_t status;
 561         unsigned long flags;
 562
 563         efi_sync_low_kernel_mappings();
 564         local_irq_save(flags);
 565
 566         efi_enter_mm();
 567
 568         status = __efi_thunk(set_virtual_address_map, memory_map_size,
 569                              descriptor_size, descriptor_version, virtual_map);
 570
 571         efi_leave_mm();
 572         local_irq_restore(flags);
 573
 574         return status;
 575 }
 576
 577 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 578 {
 579         return EFI_UNSUPPORTED;
 580 }
 581
 582 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 583 {
 584         return EFI_UNSUPPORTED;
 585 }
 586
 587 static efi_status_t
 588 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 589                           efi_time_t *tm)
 590 {
 591         return EFI_UNSUPPORTED;
 592 }
 593
 594 static efi_status_t
 595 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 596 {
 597         return EFI_UNSUPPORTED;
 598 }
 599
 600 static unsigned long efi_name_size(efi_char16_t *name)
 601 {
 602         return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
 603 }
 604
 605 static efi_status_t
 606 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 607                        u32 *attr, unsigned long *data_size, void *data)
 608 {
 609         u8 buf[24] __aligned(8);
 610         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 611         efi_status_t status;
 612         u32 phys_name, phys_vendor, phys_attr;
 613         u32 phys_data_size, phys_data;
 614         unsigned long flags;
 615
 616         spin_lock_irqsave(&efi_runtime_lock, flags);
 617
 618         *vnd = *vendor;
 619
 620         phys_data_size = virt_to_phys_or_null(data_size);
 621         phys_vendor = virt_to_phys_or_null(vnd);
 622         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 623         phys_attr = virt_to_phys_or_null(attr);
 624         phys_data = virt_to_phys_or_null_size(data, *data_size);
 625
 626         if (!phys_name || (data && !phys_data))
 627                 status = EFI_INVALID_PARAMETER;
 628         else
 629                 status = efi_thunk(get_variable, phys_name, phys_vendor,
 630                                    phys_attr, phys_data_size, phys_data);
 631
 632         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 633
 634         return status;
 635 }
 636
 637 static efi_status_t
 638 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 639                        u32 attr, unsigned long data_size, void *data)
 640 {
 641         u8 buf[24] __aligned(8);
 642         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 643         u32 phys_name, phys_vendor, phys_data;
 644         efi_status_t status;
 645         unsigned long flags;
 646
 647         spin_lock_irqsave(&efi_runtime_lock, flags);
 648
 649         *vnd = *vendor;
 650
 651         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 652         phys_vendor = virt_to_phys_or_null(vnd);
 653         phys_data = virt_to_phys_or_null_size(data, data_size);
 654
 655         if (!phys_name || (data && !phys_data))
 656                 status = EFI_INVALID_PARAMETER;
 657         else
 658                 status = efi_thunk(set_variable, phys_name, phys_vendor,
 659                                    attr, data_size, phys_data);
 660
 661         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 662
 663         return status;
 664 }
 665
 666 static efi_status_t
 667 efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
 668                                    u32 attr, unsigned long data_size,
 669                                    void *data)
 670 {
 671         u8 buf[24] __aligned(8);
 672         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 673         u32 phys_name, phys_vendor, phys_data;
 674         efi_status_t status;
 675         unsigned long flags;
 676
 677         if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
 678                 return EFI_NOT_READY;
 679
 680         *vnd = *vendor;
 681
 682         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 683         phys_vendor = virt_to_phys_or_null(vnd);
 684         phys_data = virt_to_phys_or_null_size(data, data_size);
 685
 686         if (!phys_name || (data && !phys_data))
 687                 status = EFI_INVALID_PARAMETER;
 688         else
 689                 status = efi_thunk(set_variable, phys_name, phys_vendor,
 690                                    attr, data_size, phys_data);
 691
 692         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 693
 694         return status;
 695 }
 696
 697 static efi_status_t
 698 efi_thunk_get_next_variable(unsigned long *name_size,
 699                             efi_char16_t *name,
 700                             efi_guid_t *vendor)
 701 {
 702         u8 buf[24] __aligned(8);
 703         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 704         efi_status_t status;
 705         u32 phys_name_size, phys_name, phys_vendor;
 706         unsigned long flags;
 707
 708         spin_lock_irqsave(&efi_runtime_lock, flags);
 709
 710         *vnd = *vendor;
 711
 712         phys_name_size = virt_to_phys_or_null(name_size);
 713         phys_vendor = virt_to_phys_or_null(vnd);
 714         phys_name = virt_to_phys_or_null_size(name, *name_size);
 715
 716         if (!phys_name)
 717                 status = EFI_INVALID_PARAMETER;
 718         else
 719                 status = efi_thunk(get_next_variable, phys_name_size,
 720                                    phys_name, phys_vendor);
 721
 722         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 723
 724         *vendor = *vnd;
 725         return status;
 726 }
 727
 728 static efi_status_t
 729 efi_thunk_get_next_high_mono_count(u32 *count)
 730 {
 731         return EFI_UNSUPPORTED;
 732 }
 733
 734 static void
 735 efi_thunk_reset_system(int reset_type, efi_status_t status,
 736                        unsigned long data_size, efi_char16_t *data)
 737 {
 738         u32 phys_data;
 739         unsigned long flags;
 740
 741         spin_lock_irqsave(&efi_runtime_lock, flags);
 742
 743         phys_data = virt_to_phys_or_null_size(data, data_size);
 744
 745         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
 746
 747         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 748 }
 749
 750 static efi_status_t
 751 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
 752                          unsigned long count, unsigned long sg_list)
 753 {
 754         /*
 755          * To properly support this function we would need to repackage
 756          * 'capsules' because the firmware doesn't understand 64-bit
 757          * pointers.
 758          */
 759         return EFI_UNSUPPORTED;
 760 }
 761
 762 static efi_status_t
 763 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 764                               u64 *remaining_space,
 765                               u64 *max_variable_size)
 766 {
 767         efi_status_t status;
 768         u32 phys_storage, phys_remaining, phys_max;
 769         unsigned long flags;
 770
 771         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 772                 return EFI_UNSUPPORTED;
 773
 774         spin_lock_irqsave(&efi_runtime_lock, flags);
 775
 776         phys_storage = virt_to_phys_or_null(storage_space);
 777         phys_remaining = virt_to_phys_or_null(remaining_space);
 778         phys_max = virt_to_phys_or_null(max_variable_size);
 779
 780         status = efi_thunk(query_variable_info, attr, phys_storage,
 781                            phys_remaining, phys_max);
 782
 783         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 784
 785         return status;
 786 }
 787
 788 static efi_status_t
 789 efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
 790                                           u64 *remaining_space,
 791                                           u64 *max_variable_size)
 792 {
 793         efi_status_t status;
 794         u32 phys_storage, phys_remaining, phys_max;
 795         unsigned long flags;
 796
 797         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 798                 return EFI_UNSUPPORTED;
 799
 800         if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
 801                 return EFI_NOT_READY;
 802
 803         phys_storage = virt_to_phys_or_null(storage_space);
 804         phys_remaining = virt_to_phys_or_null(remaining_space);
 805         phys_max = virt_to_phys_or_null(max_variable_size);
 806
 807         status = efi_thunk(query_variable_info, attr, phys_storage,
 808                            phys_remaining, phys_max);
 809
 810         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 811
 812         return status;
 813 }
 814
 815 static efi_status_t
 816 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
 817                              unsigned long count, u64 *max_size,
 818                              int *reset_type)
 819 {
 820         /*
 821          * To properly support this function we would need to repackage
 822          * 'capsules' because the firmware doesn't understand 64-bit
 823          * pointers.
 824          */
 825         return EFI_UNSUPPORTED;
 826 }
 827
 828 void __init efi_thunk_runtime_setup(void)
 829 {
 830         if (!IS_ENABLED(CONFIG_EFI_MIXED))
 831                 return;
 832
 833         efi.get_time = efi_thunk_get_time;
 834         efi.set_time = efi_thunk_set_time;
 835         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
 836         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
 837         efi.get_variable = efi_thunk_get_variable;
 838         efi.get_next_variable = efi_thunk_get_next_variable;
 839         efi.set_variable = efi_thunk_set_variable;
 840         efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
 841         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
 842         efi.reset_system = efi_thunk_reset_system;
 843         efi.query_variable_info = efi_thunk_query_variable_info;
 844         efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
 845         efi.update_capsule = efi_thunk_update_capsule;
 846         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
 847 }
 848
 849 efi_status_t __init __no_sanitize_address
 850 efi_set_virtual_address_map(unsigned long memory_map_size,
 851                             unsigned long descriptor_size,
 852                             u32 descriptor_version,
 853                             efi_memory_desc_t *virtual_map,
 854                             unsigned long systab_phys)
 855 {
 856         const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
 857         efi_status_t status;
 858         unsigned long flags;
 859
 860         if (efi_is_mixed())
 861                 return efi_thunk_set_virtual_address_map(memory_map_size,
 862                                                          descriptor_size,
 863                                                          descriptor_version,
 864                                                          virtual_map);
 865         efi_enter_mm();
 866
 867         efi_fpu_begin();
 868
 869         /* Disable interrupts around EFI calls: */
 870         local_irq_save(flags);
 871         status = arch_efi_call_virt(efi.runtime, set_virtual_address_map,
 872                                     memory_map_size, descriptor_size,
 873                                     descriptor_version, virtual_map);
 874         local_irq_restore(flags);
 875
 876         efi_fpu_end();
 877
 878         /* grab the virtually remapped EFI runtime services table pointer */
 879         efi.runtime = READ_ONCE(systab->runtime);
 880
 881         efi_leave_mm();
 882
 883         return status;
 884 }