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