x86/platform/efi/efi_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * x86_64 specific EFI support functions
   4  * Based on Extensible Firmware Interface Specification version 1.0
   5  *
   6  * Copyright (C) 2005-2008 Intel Co.
   7  *      Fenghua Yu <fenghua.yu@intel.com>
   8  *      Bibo Mao <bibo.mao@intel.com>
   9  *      Chandramouli Narayanan <mouli@linux.intel.com>
  10  *      Huang Ying <ying.huang@intel.com>
  11  *
  12  * Code to convert EFI to E820 map has been implemented in elilo bootloader
  13  * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
  14  * is setup appropriately for EFI runtime code.
  15  * - mouli 06/14/2007.
  16  *
  17  */
  18
  19 #define pr_fmt(fmt) "efi: " fmt
  20
  21 #include <linux/kernel.h>
  22 #include <linux/init.h>
  23 #include <linux/mm.h>
  24 #include <linux/types.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/memblock.h>
  27 #include <linux/ioport.h>
  28 #include <linux/mc146818rtc.h>
  29 #include <linux/efi.h>
  30 #include <linux/export.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/io.h>
  33 #include <linux/reboot.h>
  34 #include <linux/slab.h>
  35 #include <linux/ucs2_string.h>
  36 #include <linux/cc_platform.h>
  37 #include <linux/sched/task.h>
  38
  39 #include <asm/setup.h>
  40 #include <asm/page.h>
  41 #include <asm/e820/api.h>
  42 #include <asm/tlbflush.h>
  43 #include <asm/proto.h>
  44 #include <asm/efi.h>
  45 #include <asm/cacheflush.h>
  46 #include <asm/fixmap.h>
  47 #include <asm/realmode.h>
  48 #include <asm/time.h>
  49 #include <asm/pgalloc.h>
  50 #include <asm/sev.h>
  51
  52 /*
  53  * We allocate runtime services regions top-down, starting from -4G, i.e.
  54  * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
  55  */
  56 static u64 efi_va = EFI_VA_START;
  57 static struct mm_struct *efi_prev_mm;
  58
  59 /*
  60  * We need our own copy of the higher levels of the page tables
  61  * because we want to avoid inserting EFI region mappings (EFI_VA_END
  62  * to EFI_VA_START) into the standard kernel page tables. Everything
  63  * else can be shared, see efi_sync_low_kernel_mappings().
  64  *
  65  * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
  66  * allocation.
  67  */
  68 int __init efi_alloc_page_tables(void)
  69 {
  70         pgd_t *pgd, *efi_pgd;
  71         p4d_t *p4d;
  72         pud_t *pud;
  73         gfp_t gfp_mask;
  74
  75         gfp_mask = GFP_KERNEL | __GFP_ZERO;
  76         efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
  77         if (!efi_pgd)
  78                 goto fail;
  79
  80         pgd = efi_pgd + pgd_index(EFI_VA_END);
  81         p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
  82         if (!p4d)
  83                 goto free_pgd;
  84
  85         pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
  86         if (!pud)
  87                 goto free_p4d;
  88
  89         efi_mm.pgd = efi_pgd;
  90         mm_init_cpumask(&efi_mm);
  91         init_new_context(NULL, &efi_mm);
  92
  93         return 0;
  94
  95 free_p4d:
  96         if (pgtable_l5_enabled())
  97                 free_page((unsigned long)pgd_page_vaddr(*pgd));
  98 free_pgd:
  99         free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
 100 fail:
 101         return -ENOMEM;
 102 }
 103
 104 /*
 105  * Add low kernel mappings for passing arguments to EFI functions.
 106  */
 107 void efi_sync_low_kernel_mappings(void)
 108 {
 109         unsigned num_entries;
 110         pgd_t *pgd_k, *pgd_efi;
 111         p4d_t *p4d_k, *p4d_efi;
 112         pud_t *pud_k, *pud_efi;
 113         pgd_t *efi_pgd = efi_mm.pgd;
 114
 115         pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
 116         pgd_k = pgd_offset_k(PAGE_OFFSET);
 117
 118         num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
 119         memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
 120
 121         pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
 122         pgd_k = pgd_offset_k(EFI_VA_END);
 123         p4d_efi = p4d_offset(pgd_efi, 0);
 124         p4d_k = p4d_offset(pgd_k, 0);
 125
 126         num_entries = p4d_index(EFI_VA_END);
 127         memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
 128
 129         /*
 130          * We share all the PUD entries apart from those that map the
 131          * EFI regions. Copy around them.
 132          */
 133         BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
 134         BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
 135
 136         p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
 137         p4d_k = p4d_offset(pgd_k, EFI_VA_END);
 138         pud_efi = pud_offset(p4d_efi, 0);
 139         pud_k = pud_offset(p4d_k, 0);
 140
 141         num_entries = pud_index(EFI_VA_END);
 142         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 143
 144         pud_efi = pud_offset(p4d_efi, EFI_VA_START);
 145         pud_k = pud_offset(p4d_k, EFI_VA_START);
 146
 147         num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
 148         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 149 }
 150
 151 /*
 152  * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 153  */
 154 static inline phys_addr_t
 155 virt_to_phys_or_null_size(void *va, unsigned long size)
 156 {
 157         phys_addr_t pa;
 158
 159         if (!va)
 160                 return 0;
 161
 162         if (virt_addr_valid(va))
 163                 return virt_to_phys(va);
 164
 165         pa = slow_virt_to_phys(va);
 166
 167         /* check if the object crosses a page boundary */
 168         if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
 169                 return 0;
 170
 171         return pa;
 172 }
 173
 174 #define virt_to_phys_or_null(addr)                              \
 175         virt_to_phys_or_null_size((addr), sizeof(*(addr)))
 176
 177 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 178 {
 179         extern const u8 __efi64_thunk_ret_tramp[];
 180         unsigned long pfn, text, pf, rodata, tramp;
 181         struct page *page;
 182         unsigned npages;
 183         pgd_t *pgd = efi_mm.pgd;
 184
 185         /*
 186          * It can happen that the physical address of new_memmap lands in memory
 187          * which is not mapped in the EFI page table. Therefore we need to go
 188          * and ident-map those pages containing the map before calling
 189          * phys_efi_set_virtual_address_map().
 190          */
 191         pfn = pa_memmap >> PAGE_SHIFT;
 192         pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
 193         if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
 194                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 195                 return 1;
 196         }
 197
 198         /*
 199          * Certain firmware versions are way too sentimental and still believe
 200          * they are exclusive and unquestionable owners of the first physical page,
 201          * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
 202          * (but then write-access it later during SetVirtualAddressMap()).
 203          *
 204          * Create a 1:1 mapping for this page, to avoid triple faults during early
 205          * boot with such firmware. We are free to hand this page to the BIOS,
 206          * as trim_bios_range() will reserve the first page and isolate it away
 207          * from memory allocators anyway.
 208          */
 209         if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
 210                 pr_err("Failed to create 1:1 mapping for the first page!\n");
 211                 return 1;
 212         }
 213
 214         /*
 215          * When SEV-ES is active, the GHCB as set by the kernel will be used
 216          * by firmware. Create a 1:1 unencrypted mapping for each GHCB.
 217          */
 218         if (sev_es_efi_map_ghcbs(pgd)) {
 219                 pr_err("Failed to create 1:1 mapping for the GHCBs!\n");
 220                 return 1;
 221         }
 222
 223         /*
 224          * When making calls to the firmware everything needs to be 1:1
 225          * mapped and addressable with 32-bit pointers. Map the kernel
 226          * text and allocate a new stack because we can't rely on the
 227          * stack pointer being < 4GB.
 228          */
 229         if (!efi_is_mixed())
 230                 return 0;
 231
 232         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 233         if (!page) {
 234                 pr_err("Unable to allocate EFI runtime stack < 4GB\n");
 235                 return 1;
 236         }
 237
 238         efi_mixed_mode_stack_pa = page_to_phys(page + 1); /* stack grows down */
 239
 240         npages = (_etext - _text) >> PAGE_SHIFT;
 241         text = __pa(_text);
 242
 243         if (kernel_unmap_pages_in_pgd(pgd, text, npages)) {
 244                 pr_err("Failed to unmap kernel text 1:1 mapping\n");
 245                 return 1;
 246         }
 247
 248         npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
 249         rodata = __pa(__start_rodata);
 250         pfn = rodata >> PAGE_SHIFT;
 251
 252         pf = _PAGE_NX | _PAGE_ENC;
 253         if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
 254                 pr_err("Failed to map kernel rodata 1:1\n");
 255                 return 1;
 256         }
 257
 258         tramp = __pa(__efi64_thunk_ret_tramp);
 259         pfn = tramp >> PAGE_SHIFT;
 260
 261         pf = _PAGE_ENC;
 262         if (kernel_map_pages_in_pgd(pgd, pfn, tramp, 1, pf)) {
 263                 pr_err("Failed to map mixed mode return trampoline\n");
 264                 return 1;
 265         }
 266
 267         return 0;
 268 }
 269
 270 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 271 {
 272         unsigned long flags = _PAGE_RW;
 273         unsigned long pfn;
 274         pgd_t *pgd = efi_mm.pgd;
 275
 276         /*
 277          * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
 278          * executable images in memory that consist of both R-X and
 279          * RW- sections, so we cannot apply read-only or non-exec
 280          * permissions just yet. However, modern EFI systems provide
 281          * a memory attributes table that describes those sections
 282          * with the appropriate restricted permissions, which are
 283          * applied in efi_runtime_update_mappings() below. All other
 284          * regions can be mapped non-executable at this point, with
 285          * the exception of boot services code regions, but those will
 286          * be unmapped again entirely in efi_free_boot_services().
 287          */
 288         if (md->type != EFI_BOOT_SERVICES_CODE &&
 289             md->type != EFI_RUNTIME_SERVICES_CODE)
 290                 flags |= _PAGE_NX;
 291
 292         if (!(md->attribute & EFI_MEMORY_WB))
 293                 flags |= _PAGE_PCD;
 294
 295         if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) &&
 296             md->type != EFI_MEMORY_MAPPED_IO)
 297                 flags |= _PAGE_ENC;
 298
 299         pfn = md->phys_addr >> PAGE_SHIFT;
 300         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 301                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 302                            md->phys_addr, va);
 303 }
 304
 305 void __init efi_map_region(efi_memory_desc_t *md)
 306 {
 307         unsigned long size = md->num_pages << PAGE_SHIFT;
 308         u64 pa = md->phys_addr;
 309
 310         /*
 311          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 312          * firmware which doesn't update all internal pointers after switching
 313          * to virtual mode and would otherwise crap on us.
 314          */
 315         __map_region(md, md->phys_addr);
 316
 317         /*
 318          * Enforce the 1:1 mapping as the default virtual address when
 319          * booting in EFI mixed mode, because even though we may be
 320          * running a 64-bit kernel, the firmware may only be 32-bit.
 321          */
 322         if (efi_is_mixed()) {
 323                 md->virt_addr = md->phys_addr;
 324                 return;
 325         }
 326
 327         efi_va -= size;
 328
 329         /* Is PA 2M-aligned? */
 330         if (!(pa & (PMD_SIZE - 1))) {
 331                 efi_va &= PMD_MASK;
 332         } else {
 333                 u64 pa_offset = pa & (PMD_SIZE - 1);
 334                 u64 prev_va = efi_va;
 335
 336                 /* get us the same offset within this 2M page */
 337                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 338
 339                 if (efi_va > prev_va)
 340                         efi_va -= PMD_SIZE;
 341         }
 342
 343         if (efi_va < EFI_VA_END) {
 344                 pr_warn(FW_WARN "VA address range overflow!\n");
 345                 return;
 346         }
 347
 348         /* Do the VA map */
 349         __map_region(md, efi_va);
 350         md->virt_addr = efi_va;
 351 }
 352
 353 /*
 354  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 355  * md->virt_addr is the original virtual address which had been mapped in kexec
 356  * 1st kernel.
 357  */
 358 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 359 {
 360         __map_region(md, md->phys_addr);
 361         __map_region(md, md->virt_addr);
 362 }
 363
 364 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 365 {
 366         efi_setup = phys_addr + sizeof(struct setup_data);
 367 }
 368
 369 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 370 {
 371         unsigned long pfn;
 372         pgd_t *pgd = efi_mm.pgd;
 373         int err1, err2;
 374
 375         /* Update the 1:1 mapping */
 376         pfn = md->phys_addr >> PAGE_SHIFT;
 377         err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
 378         if (err1) {
 379                 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
 380                            md->phys_addr, md->virt_addr);
 381         }
 382
 383         err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
 384         if (err2) {
 385                 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
 386                            md->phys_addr, md->virt_addr);
 387         }
 388
 389         return err1 || err2;
 390 }
 391
 392 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
 393 {
 394         unsigned long pf = 0;
 395
 396         if (md->attribute & EFI_MEMORY_XP)
 397                 pf |= _PAGE_NX;
 398
 399         if (!(md->attribute & EFI_MEMORY_RO))
 400                 pf |= _PAGE_RW;
 401
 402         if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 403                 pf |= _PAGE_ENC;
 404
 405         return efi_update_mappings(md, pf);
 406 }
 407
 408 void __init efi_runtime_update_mappings(void)
 409 {
 410         efi_memory_desc_t *md;
 411
 412         /*
 413          * Use the EFI Memory Attribute Table for mapping permissions if it
 414          * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
 415          */
 416         if (efi_enabled(EFI_MEM_ATTR)) {
 417                 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
 418                 return;
 419         }
 420
 421         /*
 422          * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
 423          * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
 424          * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
 425          * published by the firmware. Even if we find a buggy implementation of
 426          * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
 427          * EFI_PROPERTIES_TABLE, because of the same reason.
 428          */
 429
 430         if (!efi_enabled(EFI_NX_PE_DATA))
 431                 return;
 432
 433         for_each_efi_memory_desc(md) {
 434                 unsigned long pf = 0;
 435
 436                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 437                         continue;
 438
 439                 if (!(md->attribute & EFI_MEMORY_WB))
 440                         pf |= _PAGE_PCD;
 441
 442                 if ((md->attribute & EFI_MEMORY_XP) ||
 443                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 444                         pf |= _PAGE_NX;
 445
 446                 if (!(md->attribute & EFI_MEMORY_RO) &&
 447                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 448                         pf |= _PAGE_RW;
 449
 450                 if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 451                         pf |= _PAGE_ENC;
 452
 453                 efi_update_mappings(md, pf);
 454         }
 455 }
 456
 457 void __init efi_dump_pagetable(void)
 458 {
 459 #ifdef CONFIG_EFI_PGT_DUMP
 460         ptdump_walk_pgd_level(NULL, &efi_mm);
 461 #endif
 462 }
 463
 464 /*
 465  * Makes the calling thread switch to/from efi_mm context. Can be used
 466  * in a kernel thread and user context. Preemption needs to remain disabled
 467  * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
 468  * can not change under us.
 469  * It should be ensured that there are no concurrent calls to this function.
 470  */
 471 void efi_enter_mm(void)
 472 {
 473         efi_prev_mm = current->active_mm;
 474         current->active_mm = &efi_mm;
 475         switch_mm(efi_prev_mm, &efi_mm, NULL);
 476 }
 477
 478 void efi_leave_mm(void)
 479 {
 480         current->active_mm = efi_prev_mm;
 481         switch_mm(&efi_mm, efi_prev_mm, NULL);
 482 }
 483
 484 static DEFINE_SPINLOCK(efi_runtime_lock);
 485
 486 /*
 487  * DS and ES contain user values.  We need to save them.
 488  * The 32-bit EFI code needs a valid DS, ES, and SS.  There's no
 489  * need to save the old SS: __KERNEL_DS is always acceptable.
 490  */
 491 #define __efi_thunk(func, ...)                                          \
 492 ({                                                                      \
 493         unsigned short __ds, __es;                                      \
 494         efi_status_t ____s;                                             \
 495                                                                         \
 496         savesegment(ds, __ds);                                          \
 497         savesegment(es, __es);                                          \
 498                                                                         \
 499         loadsegment(ss, __KERNEL_DS);                                   \
 500         loadsegment(ds, __KERNEL_DS);                                   \
 501         loadsegment(es, __KERNEL_DS);                                   \
 502                                                                         \
 503         ____s = efi64_thunk(efi.runtime->mixed_mode.func, __VA_ARGS__); \
 504                                                                         \
 505         loadsegment(ds, __ds);                                          \
 506         loadsegment(es, __es);                                          \
 507                                                                         \
 508         ____s ^= (____s & BIT(31)) | (____s & BIT_ULL(31)) << 32;       \
 509         ____s;                                                          \
 510 })
 511
 512 /*
 513  * Switch to the EFI page tables early so that we can access the 1:1
 514  * runtime services mappings which are not mapped in any other page
 515  * tables.
 516  *
 517  * Also, disable interrupts because the IDT points to 64-bit handlers,
 518  * which aren't going to function correctly when we switch to 32-bit.
 519  */
 520 #define efi_thunk(func...)                                              \
 521 ({                                                                      \
 522         efi_status_t __s;                                               \
 523                                                                         \
 524         arch_efi_call_virt_setup();                                     \
 525                                                                         \
 526         __s = __efi_thunk(func);                                        \
 527                                                                         \
 528         arch_efi_call_virt_teardown();                                  \
 529                                                                         \
 530         __s;                                                            \
 531 })
 532
 533 static efi_status_t __init __no_sanitize_address
 534 efi_thunk_set_virtual_address_map(unsigned long memory_map_size,
 535                                   unsigned long descriptor_size,
 536                                   u32 descriptor_version,
 537                                   efi_memory_desc_t *virtual_map)
 538 {
 539         efi_status_t status;
 540         unsigned long flags;
 541
 542         efi_sync_low_kernel_mappings();
 543         local_irq_save(flags);
 544
 545         efi_enter_mm();
 546
 547         status = __efi_thunk(set_virtual_address_map, memory_map_size,
 548                              descriptor_size, descriptor_version, virtual_map);
 549
 550         efi_leave_mm();
 551         local_irq_restore(flags);
 552
 553         return status;
 554 }
 555
 556 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 557 {
 558         return EFI_UNSUPPORTED;
 559 }
 560
 561 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 562 {
 563         return EFI_UNSUPPORTED;
 564 }
 565
 566 static efi_status_t
 567 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 568                           efi_time_t *tm)
 569 {
 570         return EFI_UNSUPPORTED;
 571 }
 572
 573 static efi_status_t
 574 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 575 {
 576         return EFI_UNSUPPORTED;
 577 }
 578
 579 static unsigned long efi_name_size(efi_char16_t *name)
 580 {
 581         return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
 582 }
 583
 584 static efi_status_t
 585 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 586                        u32 *attr, unsigned long *data_size, void *data)
 587 {
 588         u8 buf[24] __aligned(8);
 589         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 590         efi_status_t status;
 591         u32 phys_name, phys_vendor, phys_attr;
 592         u32 phys_data_size, phys_data;
 593         unsigned long flags;
 594
 595         spin_lock_irqsave(&efi_runtime_lock, flags);
 596
 597         *vnd = *vendor;
 598
 599         phys_data_size = virt_to_phys_or_null(data_size);
 600         phys_vendor = virt_to_phys_or_null(vnd);
 601         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 602         phys_attr = virt_to_phys_or_null(attr);
 603         phys_data = virt_to_phys_or_null_size(data, *data_size);
 604
 605         if (!phys_name || (data && !phys_data))
 606                 status = EFI_INVALID_PARAMETER;
 607         else
 608                 status = efi_thunk(get_variable, phys_name, phys_vendor,
 609                                    phys_attr, phys_data_size, phys_data);
 610
 611         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 612
 613         return status;
 614 }
 615
 616 static efi_status_t
 617 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 618                        u32 attr, unsigned long data_size, void *data)
 619 {
 620         u8 buf[24] __aligned(8);
 621         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 622         u32 phys_name, phys_vendor, phys_data;
 623         efi_status_t status;
 624         unsigned long flags;
 625
 626         spin_lock_irqsave(&efi_runtime_lock, flags);
 627
 628         *vnd = *vendor;
 629
 630         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 631         phys_vendor = virt_to_phys_or_null(vnd);
 632         phys_data = virt_to_phys_or_null_size(data, data_size);
 633
 634         if (!phys_name || (data && !phys_data))
 635                 status = EFI_INVALID_PARAMETER;
 636         else
 637                 status = efi_thunk(set_variable, phys_name, phys_vendor,
 638                                    attr, data_size, phys_data);
 639
 640         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 641
 642         return status;
 643 }
 644
 645 static efi_status_t
 646 efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
 647                                    u32 attr, unsigned long data_size,
 648                                    void *data)
 649 {
 650         u8 buf[24] __aligned(8);
 651         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 652         u32 phys_name, phys_vendor, phys_data;
 653         efi_status_t status;
 654         unsigned long flags;
 655
 656         if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
 657                 return EFI_NOT_READY;
 658
 659         *vnd = *vendor;
 660
 661         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 662         phys_vendor = virt_to_phys_or_null(vnd);
 663         phys_data = virt_to_phys_or_null_size(data, data_size);
 664
 665         if (!phys_name || (data && !phys_data))
 666                 status = EFI_INVALID_PARAMETER;
 667         else
 668                 status = efi_thunk(set_variable, phys_name, phys_vendor,
 669                                    attr, data_size, phys_data);
 670
 671         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 672
 673         return status;
 674 }
 675
 676 static efi_status_t
 677 efi_thunk_get_next_variable(unsigned long *name_size,
 678                             efi_char16_t *name,
 679                             efi_guid_t *vendor)
 680 {
 681         u8 buf[24] __aligned(8);
 682         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 683         efi_status_t status;
 684         u32 phys_name_size, phys_name, phys_vendor;
 685         unsigned long flags;
 686
 687         spin_lock_irqsave(&efi_runtime_lock, flags);
 688
 689         *vnd = *vendor;
 690
 691         phys_name_size = virt_to_phys_or_null(name_size);
 692         phys_vendor = virt_to_phys_or_null(vnd);
 693         phys_name = virt_to_phys_or_null_size(name, *name_size);
 694
 695         if (!phys_name)
 696                 status = EFI_INVALID_PARAMETER;
 697         else
 698                 status = efi_thunk(get_next_variable, phys_name_size,
 699                                    phys_name, phys_vendor);
 700
 701         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 702
 703         *vendor = *vnd;
 704         return status;
 705 }
 706
 707 static efi_status_t
 708 efi_thunk_get_next_high_mono_count(u32 *count)
 709 {
 710         return EFI_UNSUPPORTED;
 711 }
 712
 713 static void
 714 efi_thunk_reset_system(int reset_type, efi_status_t status,
 715                        unsigned long data_size, efi_char16_t *data)
 716 {
 717         u32 phys_data;
 718         unsigned long flags;
 719
 720         spin_lock_irqsave(&efi_runtime_lock, flags);
 721
 722         phys_data = virt_to_phys_or_null_size(data, data_size);
 723
 724         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
 725
 726         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 727 }
 728
 729 static efi_status_t
 730 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
 731                          unsigned long count, unsigned long sg_list)
 732 {
 733         /*
 734          * To properly support this function we would need to repackage
 735          * 'capsules' because the firmware doesn't understand 64-bit
 736          * pointers.
 737          */
 738         return EFI_UNSUPPORTED;
 739 }
 740
 741 static efi_status_t
 742 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 743                               u64 *remaining_space,
 744                               u64 *max_variable_size)
 745 {
 746         efi_status_t status;
 747         u32 phys_storage, phys_remaining, phys_max;
 748         unsigned long flags;
 749
 750         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 751                 return EFI_UNSUPPORTED;
 752
 753         spin_lock_irqsave(&efi_runtime_lock, flags);
 754
 755         phys_storage = virt_to_phys_or_null(storage_space);
 756         phys_remaining = virt_to_phys_or_null(remaining_space);
 757         phys_max = virt_to_phys_or_null(max_variable_size);
 758
 759         status = efi_thunk(query_variable_info, attr, phys_storage,
 760                            phys_remaining, phys_max);
 761
 762         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 763
 764         return status;
 765 }
 766
 767 static efi_status_t
 768 efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
 769                                           u64 *remaining_space,
 770                                           u64 *max_variable_size)
 771 {
 772         efi_status_t status;
 773         u32 phys_storage, phys_remaining, phys_max;
 774         unsigned long flags;
 775
 776         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 777                 return EFI_UNSUPPORTED;
 778
 779         if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
 780                 return EFI_NOT_READY;
 781
 782         phys_storage = virt_to_phys_or_null(storage_space);
 783         phys_remaining = virt_to_phys_or_null(remaining_space);
 784         phys_max = virt_to_phys_or_null(max_variable_size);
 785
 786         status = efi_thunk(query_variable_info, attr, phys_storage,
 787                            phys_remaining, phys_max);
 788
 789         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 790
 791         return status;
 792 }
 793
 794 static efi_status_t
 795 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
 796                              unsigned long count, u64 *max_size,
 797                              int *reset_type)
 798 {
 799         /*
 800          * To properly support this function we would need to repackage
 801          * 'capsules' because the firmware doesn't understand 64-bit
 802          * pointers.
 803          */
 804         return EFI_UNSUPPORTED;
 805 }
 806
 807 void __init efi_thunk_runtime_setup(void)
 808 {
 809         if (!IS_ENABLED(CONFIG_EFI_MIXED))
 810                 return;
 811
 812         efi.get_time = efi_thunk_get_time;
 813         efi.set_time = efi_thunk_set_time;
 814         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
 815         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
 816         efi.get_variable = efi_thunk_get_variable;
 817         efi.get_next_variable = efi_thunk_get_next_variable;
 818         efi.set_variable = efi_thunk_set_variable;
 819         efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
 820         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
 821         efi.reset_system = efi_thunk_reset_system;
 822         efi.query_variable_info = efi_thunk_query_variable_info;
 823         efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
 824         efi.update_capsule = efi_thunk_update_capsule;
 825         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
 826 }
 827
 828 efi_status_t __init __no_sanitize_address
 829 efi_set_virtual_address_map(unsigned long memory_map_size,
 830                             unsigned long descriptor_size,
 831                             u32 descriptor_version,
 832                             efi_memory_desc_t *virtual_map,
 833                             unsigned long systab_phys)
 834 {
 835         const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
 836         efi_status_t status;
 837         unsigned long flags;
 838
 839         if (efi_is_mixed())
 840                 return efi_thunk_set_virtual_address_map(memory_map_size,
 841                                                          descriptor_size,
 842                                                          descriptor_version,
 843                                                          virtual_map);
 844         efi_enter_mm();
 845
 846         efi_fpu_begin();
 847
 848         /* Disable interrupts around EFI calls: */
 849         local_irq_save(flags);
 850         status = arch_efi_call_virt(efi.runtime, set_virtual_address_map,
 851                                     memory_map_size, descriptor_size,
 852                                     descriptor_version, virtual_map);
 853         local_irq_restore(flags);
 854
 855         efi_fpu_end();
 856
 857         /* grab the virtually remapped EFI runtime services table pointer */
 858         efi.runtime = READ_ONCE(systab->runtime);
 859
 860         efi_leave_mm();
 861
 862         return status;
 863 }