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