arch/x86/platform/efi/efi_64.c

   1 /*
   2  * x86_64 specific EFI support functions
   3  * Based on Extensible Firmware Interface Specification version 1.0
   4  *
   5  * Copyright (C) 2005-2008 Intel Co.
   6  *      Fenghua Yu <fenghua.yu@intel.com>
   7  *      Bibo Mao <bibo.mao@intel.com>
   8  *      Chandramouli Narayanan <mouli@linux.intel.com>
   9  *      Huang Ying <ying.huang@intel.com>
  10  *
  11  * Code to convert EFI to E820 map has been implemented in elilo bootloader
  12  * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
  13  * is setup appropriately for EFI runtime code.
  14  * - mouli 06/14/2007.
  15  *
  16  */
  17
  18 #define pr_fmt(fmt) "efi: " fmt
  19
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/mm.h>
  23 #include <linux/types.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/ioport.h>
  27 #include <linux/init.h>
  28 #include <linux/mc146818rtc.h>
  29 #include <linux/efi.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/io.h>
  32 #include <linux/reboot.h>
  33 #include <linux/slab.h>
  34 #include <linux/ucs2_string.h>
  35
  36 #include <asm/setup.h>
  37 #include <asm/page.h>
  38 #include <asm/e820.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/tlbflush.h>
  41 #include <asm/proto.h>
  42 #include <asm/efi.h>
  43 #include <asm/cacheflush.h>
  44 #include <asm/fixmap.h>
  45 #include <asm/realmode.h>
  46 #include <asm/time.h>
  47 #include <asm/pgalloc.h>
  48
  49 /*
  50  * We allocate runtime services regions bottom-up, starting from -4G, i.e.
  51  * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
  52  */
  53 static u64 efi_va = EFI_VA_START;
  54
  55 struct efi_scratch efi_scratch;
  56
  57 static void __init early_code_mapping_set_exec(int executable)
  58 {
  59         efi_memory_desc_t *md;
  60
  61         if (!(__supported_pte_mask & _PAGE_NX))
  62                 return;
  63
  64         /* Make EFI service code area executable */
  65         for_each_efi_memory_desc(md) {
  66                 if (md->type == EFI_RUNTIME_SERVICES_CODE ||
  67                     md->type == EFI_BOOT_SERVICES_CODE)
  68                         efi_set_executable(md, executable);
  69         }
  70 }
  71
  72 pgd_t * __init efi_call_phys_prolog(void)
  73 {
  74         unsigned long vaddress;
  75         pgd_t *save_pgd;
  76
  77         int pgd;
  78         int n_pgds;
  79
  80         if (!efi_enabled(EFI_OLD_MEMMAP)) {
  81                 save_pgd = (pgd_t *)read_cr3();
  82                 write_cr3((unsigned long)efi_scratch.efi_pgt);
  83                 goto out;
  84         }
  85
  86         early_code_mapping_set_exec(1);
  87
  88         n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
  89         save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL);
  90
  91         for (pgd = 0; pgd < n_pgds; pgd++) {
  92                 save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE);
  93                 vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
  94                 set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
  95         }
  96 out:
  97         __flush_tlb_all();
  98
  99         return save_pgd;
 100 }
 101
 102 void __init efi_call_phys_epilog(pgd_t *save_pgd)
 103 {
 104         /*
 105          * After the lock is released, the original page table is restored.
 106          */
 107         int pgd_idx;
 108         int nr_pgds;
 109
 110         if (!efi_enabled(EFI_OLD_MEMMAP)) {
 111                 write_cr3((unsigned long)save_pgd);
 112                 __flush_tlb_all();
 113                 return;
 114         }
 115
 116         nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
 117
 118         for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++)
 119                 set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
 120
 121         kfree(save_pgd);
 122
 123         __flush_tlb_all();
 124         early_code_mapping_set_exec(0);
 125 }
 126
 127 static pgd_t *efi_pgd;
 128
 129 /*
 130  * We need our own copy of the higher levels of the page tables
 131  * because we want to avoid inserting EFI region mappings (EFI_VA_END
 132  * to EFI_VA_START) into the standard kernel page tables. Everything
 133  * else can be shared, see efi_sync_low_kernel_mappings().
 134  */
 135 int __init efi_alloc_page_tables(void)
 136 {
 137         pgd_t *pgd;
 138         pud_t *pud;
 139         gfp_t gfp_mask;
 140
 141         if (efi_enabled(EFI_OLD_MEMMAP))
 142                 return 0;
 143
 144         gfp_mask = GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO;
 145         efi_pgd = (pgd_t *)__get_free_page(gfp_mask);
 146         if (!efi_pgd)
 147                 return -ENOMEM;
 148
 149         pgd = efi_pgd + pgd_index(EFI_VA_END);
 150
 151         pud = pud_alloc_one(NULL, 0);
 152         if (!pud) {
 153                 free_page((unsigned long)efi_pgd);
 154                 return -ENOMEM;
 155         }
 156
 157         pgd_populate(NULL, pgd, pud);
 158
 159         return 0;
 160 }
 161
 162 /*
 163  * Add low kernel mappings for passing arguments to EFI functions.
 164  */
 165 void efi_sync_low_kernel_mappings(void)
 166 {
 167         unsigned num_entries;
 168         pgd_t *pgd_k, *pgd_efi;
 169         pud_t *pud_k, *pud_efi;
 170
 171         if (efi_enabled(EFI_OLD_MEMMAP))
 172                 return;
 173
 174         /*
 175          * We can share all PGD entries apart from the one entry that
 176          * covers the EFI runtime mapping space.
 177          *
 178          * Make sure the EFI runtime region mappings are guaranteed to
 179          * only span a single PGD entry and that the entry also maps
 180          * other important kernel regions.
 181          */
 182         BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
 183         BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
 184                         (EFI_VA_END & PGDIR_MASK));
 185
 186         pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
 187         pgd_k = pgd_offset_k(PAGE_OFFSET);
 188
 189         num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
 190         memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
 191
 192         /*
 193          * We share all the PUD entries apart from those that map the
 194          * EFI regions. Copy around them.
 195          */
 196         BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
 197         BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
 198
 199         pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
 200         pud_efi = pud_offset(pgd_efi, 0);
 201
 202         pgd_k = pgd_offset_k(EFI_VA_END);
 203         pud_k = pud_offset(pgd_k, 0);
 204
 205         num_entries = pud_index(EFI_VA_END);
 206         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 207
 208         pud_efi = pud_offset(pgd_efi, EFI_VA_START);
 209         pud_k = pud_offset(pgd_k, EFI_VA_START);
 210
 211         num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
 212         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 213 }
 214
 215 /*
 216  * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 217  */
 218 static inline phys_addr_t
 219 virt_to_phys_or_null_size(void *va, unsigned long size)
 220 {
 221         bool bad_size;
 222
 223         if (!va)
 224                 return 0;
 225
 226         if (virt_addr_valid(va))
 227                 return virt_to_phys(va);
 228
 229         /*
 230          * A fully aligned variable on the stack is guaranteed not to
 231          * cross a page bounary. Try to catch strings on the stack by
 232          * checking that 'size' is a power of two.
 233          */
 234         bad_size = size > PAGE_SIZE || !is_power_of_2(size);
 235
 236         WARN_ON(!IS_ALIGNED((unsigned long)va, size) || bad_size);
 237
 238         return slow_virt_to_phys(va);
 239 }
 240
 241 #define virt_to_phys_or_null(addr)                              \
 242         virt_to_phys_or_null_size((addr), sizeof(*(addr)))
 243
 244 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 245 {
 246         unsigned long pfn, text;
 247         struct page *page;
 248         unsigned npages;
 249         pgd_t *pgd;
 250
 251         if (efi_enabled(EFI_OLD_MEMMAP))
 252                 return 0;
 253
 254         efi_scratch.efi_pgt = (pgd_t *)__pa(efi_pgd);
 255         pgd = efi_pgd;
 256
 257         /*
 258          * It can happen that the physical address of new_memmap lands in memory
 259          * which is not mapped in the EFI page table. Therefore we need to go
 260          * and ident-map those pages containing the map before calling
 261          * phys_efi_set_virtual_address_map().
 262          */
 263         pfn = pa_memmap >> PAGE_SHIFT;
 264         if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, _PAGE_NX | _PAGE_RW)) {
 265                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 266                 return 1;
 267         }
 268
 269         efi_scratch.use_pgd = true;
 270
 271         /*
 272          * When making calls to the firmware everything needs to be 1:1
 273          * mapped and addressable with 32-bit pointers. Map the kernel
 274          * text and allocate a new stack because we can't rely on the
 275          * stack pointer being < 4GB.
 276          */
 277         if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
 278                 return 0;
 279
 280         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 281         if (!page)
 282                 panic("Unable to allocate EFI runtime stack < 4GB\n");
 283
 284         efi_scratch.phys_stack = virt_to_phys(page_address(page));
 285         efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
 286
 287         npages = (_etext - _text) >> PAGE_SHIFT;
 288         text = __pa(_text);
 289         pfn = text >> PAGE_SHIFT;
 290
 291         if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, _PAGE_RW)) {
 292                 pr_err("Failed to map kernel text 1:1\n");
 293                 return 1;
 294         }
 295
 296         return 0;
 297 }
 298
 299 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 300 {
 301         unsigned long flags = _PAGE_RW;
 302         unsigned long pfn;
 303         pgd_t *pgd = efi_pgd;
 304
 305         if (!(md->attribute & EFI_MEMORY_WB))
 306                 flags |= _PAGE_PCD;
 307
 308         pfn = md->phys_addr >> PAGE_SHIFT;
 309         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 310                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 311                            md->phys_addr, va);
 312 }
 313
 314 void __init efi_map_region(efi_memory_desc_t *md)
 315 {
 316         unsigned long size = md->num_pages << PAGE_SHIFT;
 317         u64 pa = md->phys_addr;
 318
 319         if (efi_enabled(EFI_OLD_MEMMAP))
 320                 return old_map_region(md);
 321
 322         /*
 323          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 324          * firmware which doesn't update all internal pointers after switching
 325          * to virtual mode and would otherwise crap on us.
 326          */
 327         __map_region(md, md->phys_addr);
 328
 329         /*
 330          * Enforce the 1:1 mapping as the default virtual address when
 331          * booting in EFI mixed mode, because even though we may be
 332          * running a 64-bit kernel, the firmware may only be 32-bit.
 333          */
 334         if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
 335                 md->virt_addr = md->phys_addr;
 336                 return;
 337         }
 338
 339         efi_va -= size;
 340
 341         /* Is PA 2M-aligned? */
 342         if (!(pa & (PMD_SIZE - 1))) {
 343                 efi_va &= PMD_MASK;
 344         } else {
 345                 u64 pa_offset = pa & (PMD_SIZE - 1);
 346                 u64 prev_va = efi_va;
 347
 348                 /* get us the same offset within this 2M page */
 349                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 350
 351                 if (efi_va > prev_va)
 352                         efi_va -= PMD_SIZE;
 353         }
 354
 355         if (efi_va < EFI_VA_END) {
 356                 pr_warn(FW_WARN "VA address range overflow!\n");
 357                 return;
 358         }
 359
 360         /* Do the VA map */
 361         __map_region(md, efi_va);
 362         md->virt_addr = efi_va;
 363 }
 364
 365 /*
 366  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 367  * md->virt_addr is the original virtual address which had been mapped in kexec
 368  * 1st kernel.
 369  */
 370 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 371 {
 372         __map_region(md, md->phys_addr);
 373         __map_region(md, md->virt_addr);
 374 }
 375
 376 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
 377                                  u32 type, u64 attribute)
 378 {
 379         unsigned long last_map_pfn;
 380
 381         if (type == EFI_MEMORY_MAPPED_IO)
 382                 return ioremap(phys_addr, size);
 383
 384         last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
 385         if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
 386                 unsigned long top = last_map_pfn << PAGE_SHIFT;
 387                 efi_ioremap(top, size - (top - phys_addr), type, attribute);
 388         }
 389
 390         if (!(attribute & EFI_MEMORY_WB))
 391                 efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
 392
 393         return (void __iomem *)__va(phys_addr);
 394 }
 395
 396 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 397 {
 398         efi_setup = phys_addr + sizeof(struct setup_data);
 399 }
 400
 401 void __init efi_runtime_update_mappings(void)
 402 {
 403         unsigned long pfn;
 404         pgd_t *pgd = efi_pgd;
 405         efi_memory_desc_t *md;
 406
 407         if (efi_enabled(EFI_OLD_MEMMAP)) {
 408                 if (__supported_pte_mask & _PAGE_NX)
 409                         runtime_code_page_mkexec();
 410                 return;
 411         }
 412
 413         if (!efi_enabled(EFI_NX_PE_DATA))
 414                 return;
 415
 416         for_each_efi_memory_desc(md) {
 417                 unsigned long pf = 0;
 418
 419                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 420                         continue;
 421
 422                 if (!(md->attribute & EFI_MEMORY_WB))
 423                         pf |= _PAGE_PCD;
 424
 425                 if ((md->attribute & EFI_MEMORY_XP) ||
 426                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 427                         pf |= _PAGE_NX;
 428
 429                 if (!(md->attribute & EFI_MEMORY_RO) &&
 430                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 431                         pf |= _PAGE_RW;
 432
 433                 /* Update the 1:1 mapping */
 434                 pfn = md->phys_addr >> PAGE_SHIFT;
 435                 if (kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf))
 436                         pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 437                                    md->phys_addr, md->virt_addr);
 438
 439                 if (kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf))
 440                         pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 441                                    md->phys_addr, md->virt_addr);
 442         }
 443 }
 444
 445 void __init efi_dump_pagetable(void)
 446 {
 447 #ifdef CONFIG_EFI_PGT_DUMP
 448         ptdump_walk_pgd_level(NULL, efi_pgd);
 449 #endif
 450 }
 451
 452 #ifdef CONFIG_EFI_MIXED
 453 extern efi_status_t efi64_thunk(u32, ...);
 454
 455 #define runtime_service32(func)                                          \
 456 ({                                                                       \
 457         u32 table = (u32)(unsigned long)efi.systab;                      \
 458         u32 *rt, *___f;                                                  \
 459                                                                          \
 460         rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime));  \
 461         ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
 462         *___f;                                                           \
 463 })
 464
 465 /*
 466  * Switch to the EFI page tables early so that we can access the 1:1
 467  * runtime services mappings which are not mapped in any other page
 468  * tables. This function must be called before runtime_service32().
 469  *
 470  * Also, disable interrupts because the IDT points to 64-bit handlers,
 471  * which aren't going to function correctly when we switch to 32-bit.
 472  */
 473 #define efi_thunk(f, ...)                                               \
 474 ({                                                                      \
 475         efi_status_t __s;                                               \
 476         unsigned long __flags;                                          \
 477         u32 __func;                                                     \
 478                                                                         \
 479         local_irq_save(__flags);                                        \
 480         arch_efi_call_virt_setup();                                     \
 481                                                                         \
 482         __func = runtime_service32(f);                                  \
 483         __s = efi64_thunk(__func, __VA_ARGS__);                         \
 484                                                                         \
 485         arch_efi_call_virt_teardown();                                  \
 486         local_irq_restore(__flags);                                     \
 487                                                                         \
 488         __s;                                                            \
 489 })
 490
 491 efi_status_t efi_thunk_set_virtual_address_map(
 492         void *phys_set_virtual_address_map,
 493         unsigned long memory_map_size,
 494         unsigned long descriptor_size,
 495         u32 descriptor_version,
 496         efi_memory_desc_t *virtual_map)
 497 {
 498         efi_status_t status;
 499         unsigned long flags;
 500         u32 func;
 501
 502         efi_sync_low_kernel_mappings();
 503         local_irq_save(flags);
 504
 505         efi_scratch.prev_cr3 = read_cr3();
 506         write_cr3((unsigned long)efi_scratch.efi_pgt);
 507         __flush_tlb_all();
 508
 509         func = (u32)(unsigned long)phys_set_virtual_address_map;
 510         status = efi64_thunk(func, memory_map_size, descriptor_size,
 511                              descriptor_version, virtual_map);
 512
 513         write_cr3(efi_scratch.prev_cr3);
 514         __flush_tlb_all();
 515         local_irq_restore(flags);
 516
 517         return status;
 518 }
 519
 520 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 521 {
 522         efi_status_t status;
 523         u32 phys_tm, phys_tc;
 524
 525         spin_lock(&rtc_lock);
 526
 527         phys_tm = virt_to_phys_or_null(tm);
 528         phys_tc = virt_to_phys_or_null(tc);
 529
 530         status = efi_thunk(get_time, phys_tm, phys_tc);
 531
 532         spin_unlock(&rtc_lock);
 533
 534         return status;
 535 }
 536
 537 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 538 {
 539         efi_status_t status;
 540         u32 phys_tm;
 541
 542         spin_lock(&rtc_lock);
 543
 544         phys_tm = virt_to_phys_or_null(tm);
 545
 546         status = efi_thunk(set_time, phys_tm);
 547
 548         spin_unlock(&rtc_lock);
 549
 550         return status;
 551 }
 552
 553 static efi_status_t
 554 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 555                           efi_time_t *tm)
 556 {
 557         efi_status_t status;
 558         u32 phys_enabled, phys_pending, phys_tm;
 559
 560         spin_lock(&rtc_lock);
 561
 562         phys_enabled = virt_to_phys_or_null(enabled);
 563         phys_pending = virt_to_phys_or_null(pending);
 564         phys_tm = virt_to_phys_or_null(tm);
 565
 566         status = efi_thunk(get_wakeup_time, phys_enabled,
 567                              phys_pending, phys_tm);
 568
 569         spin_unlock(&rtc_lock);
 570
 571         return status;
 572 }
 573
 574 static efi_status_t
 575 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 576 {
 577         efi_status_t status;
 578         u32 phys_tm;
 579
 580         spin_lock(&rtc_lock);
 581
 582         phys_tm = virt_to_phys_or_null(tm);
 583
 584         status = efi_thunk(set_wakeup_time, enabled, phys_tm);
 585
 586         spin_unlock(&rtc_lock);
 587
 588         return status;
 589 }
 590
 591 static unsigned long efi_name_size(efi_char16_t *name)
 592 {
 593         return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
 594 }
 595
 596 static efi_status_t
 597 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 598                        u32 *attr, unsigned long *data_size, void *data)
 599 {
 600         efi_status_t status;
 601         u32 phys_name, phys_vendor, phys_attr;
 602         u32 phys_data_size, phys_data;
 603
 604         phys_data_size = virt_to_phys_or_null(data_size);
 605         phys_vendor = virt_to_phys_or_null(vendor);
 606         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 607         phys_attr = virt_to_phys_or_null(attr);
 608         phys_data = virt_to_phys_or_null_size(data, *data_size);
 609
 610         status = efi_thunk(get_variable, phys_name, phys_vendor,
 611                            phys_attr, phys_data_size, phys_data);
 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         u32 phys_name, phys_vendor, phys_data;
 621         efi_status_t status;
 622
 623         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 624         phys_vendor = virt_to_phys_or_null(vendor);
 625         phys_data = virt_to_phys_or_null_size(data, data_size);
 626
 627         /* If data_size is > sizeof(u32) we've got problems */
 628         status = efi_thunk(set_variable, phys_name, phys_vendor,
 629                            attr, data_size, phys_data);
 630
 631         return status;
 632 }
 633
 634 static efi_status_t
 635 efi_thunk_get_next_variable(unsigned long *name_size,
 636                             efi_char16_t *name,
 637                             efi_guid_t *vendor)
 638 {
 639         efi_status_t status;
 640         u32 phys_name_size, phys_name, phys_vendor;
 641
 642         phys_name_size = virt_to_phys_or_null(name_size);
 643         phys_vendor = virt_to_phys_or_null(vendor);
 644         phys_name = virt_to_phys_or_null_size(name, *name_size);
 645
 646         status = efi_thunk(get_next_variable, phys_name_size,
 647                            phys_name, phys_vendor);
 648
 649         return status;
 650 }
 651
 652 static efi_status_t
 653 efi_thunk_get_next_high_mono_count(u32 *count)
 654 {
 655         efi_status_t status;
 656         u32 phys_count;
 657
 658         phys_count = virt_to_phys_or_null(count);
 659         status = efi_thunk(get_next_high_mono_count, phys_count);
 660
 661         return status;
 662 }
 663
 664 static void
 665 efi_thunk_reset_system(int reset_type, efi_status_t status,
 666                        unsigned long data_size, efi_char16_t *data)
 667 {
 668         u32 phys_data;
 669
 670         phys_data = virt_to_phys_or_null_size(data, data_size);
 671
 672         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
 673 }
 674
 675 static efi_status_t
 676 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
 677                          unsigned long count, unsigned long sg_list)
 678 {
 679         /*
 680          * To properly support this function we would need to repackage
 681          * 'capsules' because the firmware doesn't understand 64-bit
 682          * pointers.
 683          */
 684         return EFI_UNSUPPORTED;
 685 }
 686
 687 static efi_status_t
 688 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 689                               u64 *remaining_space,
 690                               u64 *max_variable_size)
 691 {
 692         efi_status_t status;
 693         u32 phys_storage, phys_remaining, phys_max;
 694
 695         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 696                 return EFI_UNSUPPORTED;
 697
 698         phys_storage = virt_to_phys_or_null(storage_space);
 699         phys_remaining = virt_to_phys_or_null(remaining_space);
 700         phys_max = virt_to_phys_or_null(max_variable_size);
 701
 702         status = efi_thunk(query_variable_info, attr, phys_storage,
 703                            phys_remaining, phys_max);
 704
 705         return status;
 706 }
 707
 708 static efi_status_t
 709 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
 710                              unsigned long count, u64 *max_size,
 711                              int *reset_type)
 712 {
 713         /*
 714          * To properly support this function we would need to repackage
 715          * 'capsules' because the firmware doesn't understand 64-bit
 716          * pointers.
 717          */
 718         return EFI_UNSUPPORTED;
 719 }
 720
 721 void efi_thunk_runtime_setup(void)
 722 {
 723         efi.get_time = efi_thunk_get_time;
 724         efi.set_time = efi_thunk_set_time;
 725         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
 726         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
 727         efi.get_variable = efi_thunk_get_variable;
 728         efi.get_next_variable = efi_thunk_get_next_variable;
 729         efi.set_variable = efi_thunk_set_variable;
 730         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
 731         efi.reset_system = efi_thunk_reset_system;
 732         efi.query_variable_info = efi_thunk_query_variable_info;
 733         efi.update_capsule = efi_thunk_update_capsule;
 734         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
 735 }
 736 #endif /* CONFIG_EFI_MIXED */