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