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          * Certain firmware versions are way too sentimential and still believe
 273          * they are exclusive and unquestionable owners of the first physical page,
 274          * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
 275          * (but then write-access it later during SetVirtualAddressMap()).
 276          *
 277          * Create a 1:1 mapping for this page, to avoid triple faults during early
 278          * boot with such firmware. We are free to hand this page to the BIOS,
 279          * as trim_bios_range() will reserve the first page and isolate it away
 280          * from memory allocators anyway.
 281          */
 282         if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, _PAGE_RW)) {
 283                 pr_err("Failed to create 1:1 mapping for the first page!\n");
 284                 return 1;
 285         }
 286
 287         /*
 288          * When making calls to the firmware everything needs to be 1:1
 289          * mapped and addressable with 32-bit pointers. Map the kernel
 290          * text and allocate a new stack because we can't rely on the
 291          * stack pointer being < 4GB.
 292          */
 293         if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
 294                 return 0;
 295
 296         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 297         if (!page)
 298                 panic("Unable to allocate EFI runtime stack < 4GB\n");
 299
 300         efi_scratch.phys_stack = virt_to_phys(page_address(page));
 301         efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
 302
 303         npages = (_etext - _text) >> PAGE_SHIFT;
 304         text = __pa(_text);
 305         pfn = text >> PAGE_SHIFT;
 306
 307         if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, _PAGE_RW)) {
 308                 pr_err("Failed to map kernel text 1:1\n");
 309                 return 1;
 310         }
 311
 312         return 0;
 313 }
 314
 315 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 316 {
 317         unsigned long flags = _PAGE_RW;
 318         unsigned long pfn;
 319         pgd_t *pgd = efi_pgd;
 320
 321         if (!(md->attribute & EFI_MEMORY_WB))
 322                 flags |= _PAGE_PCD;
 323
 324         pfn = md->phys_addr >> PAGE_SHIFT;
 325         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 326                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 327                            md->phys_addr, va);
 328 }
 329
 330 void __init efi_map_region(efi_memory_desc_t *md)
 331 {
 332         unsigned long size = md->num_pages << PAGE_SHIFT;
 333         u64 pa = md->phys_addr;
 334
 335         if (efi_enabled(EFI_OLD_MEMMAP))
 336                 return old_map_region(md);
 337
 338         /*
 339          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 340          * firmware which doesn't update all internal pointers after switching
 341          * to virtual mode and would otherwise crap on us.
 342          */
 343         __map_region(md, md->phys_addr);
 344
 345         /*
 346          * Enforce the 1:1 mapping as the default virtual address when
 347          * booting in EFI mixed mode, because even though we may be
 348          * running a 64-bit kernel, the firmware may only be 32-bit.
 349          */
 350         if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
 351                 md->virt_addr = md->phys_addr;
 352                 return;
 353         }
 354
 355         efi_va -= size;
 356
 357         /* Is PA 2M-aligned? */
 358         if (!(pa & (PMD_SIZE - 1))) {
 359                 efi_va &= PMD_MASK;
 360         } else {
 361                 u64 pa_offset = pa & (PMD_SIZE - 1);
 362                 u64 prev_va = efi_va;
 363
 364                 /* get us the same offset within this 2M page */
 365                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 366
 367                 if (efi_va > prev_va)
 368                         efi_va -= PMD_SIZE;
 369         }
 370
 371         if (efi_va < EFI_VA_END) {
 372                 pr_warn(FW_WARN "VA address range overflow!\n");
 373                 return;
 374         }
 375
 376         /* Do the VA map */
 377         __map_region(md, efi_va);
 378         md->virt_addr = efi_va;
 379 }
 380
 381 /*
 382  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 383  * md->virt_addr is the original virtual address which had been mapped in kexec
 384  * 1st kernel.
 385  */
 386 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 387 {
 388         __map_region(md, md->phys_addr);
 389         __map_region(md, md->virt_addr);
 390 }
 391
 392 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
 393                                  u32 type, u64 attribute)
 394 {
 395         unsigned long last_map_pfn;
 396
 397         if (type == EFI_MEMORY_MAPPED_IO)
 398                 return ioremap(phys_addr, size);
 399
 400         last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
 401         if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
 402                 unsigned long top = last_map_pfn << PAGE_SHIFT;
 403                 efi_ioremap(top, size - (top - phys_addr), type, attribute);
 404         }
 405
 406         if (!(attribute & EFI_MEMORY_WB))
 407                 efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
 408
 409         return (void __iomem *)__va(phys_addr);
 410 }
 411
 412 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 413 {
 414         efi_setup = phys_addr + sizeof(struct setup_data);
 415 }
 416
 417 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 418 {
 419         unsigned long pfn;
 420         pgd_t *pgd = efi_pgd;
 421         int err1, err2;
 422
 423         /* Update the 1:1 mapping */
 424         pfn = md->phys_addr >> PAGE_SHIFT;
 425         err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
 426         if (err1) {
 427                 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
 428                            md->phys_addr, md->virt_addr);
 429         }
 430
 431         err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
 432         if (err2) {
 433                 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
 434                            md->phys_addr, md->virt_addr);
 435         }
 436
 437         return err1 || err2;
 438 }
 439
 440 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
 441 {
 442         unsigned long pf = 0;
 443
 444         if (md->attribute & EFI_MEMORY_XP)
 445                 pf |= _PAGE_NX;
 446
 447         if (!(md->attribute & EFI_MEMORY_RO))
 448                 pf |= _PAGE_RW;
 449
 450         return efi_update_mappings(md, pf);
 451 }
 452
 453 void __init efi_runtime_update_mappings(void)
 454 {
 455         efi_memory_desc_t *md;
 456
 457         if (efi_enabled(EFI_OLD_MEMMAP)) {
 458                 if (__supported_pte_mask & _PAGE_NX)
 459                         runtime_code_page_mkexec();
 460                 return;
 461         }
 462
 463         /*
 464          * Use the EFI Memory Attribute Table for mapping permissions if it
 465          * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
 466          */
 467         if (efi_enabled(EFI_MEM_ATTR)) {
 468                 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
 469                 return;
 470         }
 471
 472         /*
 473          * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
 474          * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
 475          * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
 476          * published by the firmware. Even if we find a buggy implementation of
 477          * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
 478          * EFI_PROPERTIES_TABLE, because of the same reason.
 479          */
 480
 481         if (!efi_enabled(EFI_NX_PE_DATA))
 482                 return;
 483
 484         for_each_efi_memory_desc(md) {
 485                 unsigned long pf = 0;
 486
 487                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 488                         continue;
 489
 490                 if (!(md->attribute & EFI_MEMORY_WB))
 491                         pf |= _PAGE_PCD;
 492
 493                 if ((md->attribute & EFI_MEMORY_XP) ||
 494                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 495                         pf |= _PAGE_NX;
 496
 497                 if (!(md->attribute & EFI_MEMORY_RO) &&
 498                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 499                         pf |= _PAGE_RW;
 500
 501                 efi_update_mappings(md, pf);
 502         }
 503 }
 504
 505 void __init efi_dump_pagetable(void)
 506 {
 507 #ifdef CONFIG_EFI_PGT_DUMP
 508         ptdump_walk_pgd_level(NULL, efi_pgd);
 509 #endif
 510 }
 511
 512 #ifdef CONFIG_EFI_MIXED
 513 extern efi_status_t efi64_thunk(u32, ...);
 514
 515 #define runtime_service32(func)                                          \
 516 ({                                                                       \
 517         u32 table = (u32)(unsigned long)efi.systab;                      \
 518         u32 *rt, *___f;                                                  \
 519                                                                          \
 520         rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime));  \
 521         ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
 522         *___f;                                                           \
 523 })
 524
 525 /*
 526  * Switch to the EFI page tables early so that we can access the 1:1
 527  * runtime services mappings which are not mapped in any other page
 528  * tables. This function must be called before runtime_service32().
 529  *
 530  * Also, disable interrupts because the IDT points to 64-bit handlers,
 531  * which aren't going to function correctly when we switch to 32-bit.
 532  */
 533 #define efi_thunk(f, ...)                                               \
 534 ({                                                                      \
 535         efi_status_t __s;                                               \
 536         unsigned long __flags;                                          \
 537         u32 __func;                                                     \
 538                                                                         \
 539         local_irq_save(__flags);                                        \
 540         arch_efi_call_virt_setup();                                     \
 541                                                                         \
 542         __func = runtime_service32(f);                                  \
 543         __s = efi64_thunk(__func, __VA_ARGS__);                         \
 544                                                                         \
 545         arch_efi_call_virt_teardown();                                  \
 546         local_irq_restore(__flags);                                     \
 547                                                                         \
 548         __s;                                                            \
 549 })
 550
 551 efi_status_t efi_thunk_set_virtual_address_map(
 552         void *phys_set_virtual_address_map,
 553         unsigned long memory_map_size,
 554         unsigned long descriptor_size,
 555         u32 descriptor_version,
 556         efi_memory_desc_t *virtual_map)
 557 {
 558         efi_status_t status;
 559         unsigned long flags;
 560         u32 func;
 561
 562         efi_sync_low_kernel_mappings();
 563         local_irq_save(flags);
 564
 565         efi_scratch.prev_cr3 = read_cr3();
 566         write_cr3((unsigned long)efi_scratch.efi_pgt);
 567         __flush_tlb_all();
 568
 569         func = (u32)(unsigned long)phys_set_virtual_address_map;
 570         status = efi64_thunk(func, memory_map_size, descriptor_size,
 571                              descriptor_version, virtual_map);
 572
 573         write_cr3(efi_scratch.prev_cr3);
 574         __flush_tlb_all();
 575         local_irq_restore(flags);
 576
 577         return status;
 578 }
 579
 580 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 581 {
 582         efi_status_t status;
 583         u32 phys_tm, phys_tc;
 584
 585         spin_lock(&rtc_lock);
 586
 587         phys_tm = virt_to_phys_or_null(tm);
 588         phys_tc = virt_to_phys_or_null(tc);
 589
 590         status = efi_thunk(get_time, phys_tm, phys_tc);
 591
 592         spin_unlock(&rtc_lock);
 593
 594         return status;
 595 }
 596
 597 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 598 {
 599         efi_status_t status;
 600         u32 phys_tm;
 601
 602         spin_lock(&rtc_lock);
 603
 604         phys_tm = virt_to_phys_or_null(tm);
 605
 606         status = efi_thunk(set_time, phys_tm);
 607
 608         spin_unlock(&rtc_lock);
 609
 610         return status;
 611 }
 612
 613 static efi_status_t
 614 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 615                           efi_time_t *tm)
 616 {
 617         efi_status_t status;
 618         u32 phys_enabled, phys_pending, phys_tm;
 619
 620         spin_lock(&rtc_lock);
 621
 622         phys_enabled = virt_to_phys_or_null(enabled);
 623         phys_pending = virt_to_phys_or_null(pending);
 624         phys_tm = virt_to_phys_or_null(tm);
 625
 626         status = efi_thunk(get_wakeup_time, phys_enabled,
 627                              phys_pending, phys_tm);
 628
 629         spin_unlock(&rtc_lock);
 630
 631         return status;
 632 }
 633
 634 static efi_status_t
 635 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 636 {
 637         efi_status_t status;
 638         u32 phys_tm;
 639
 640         spin_lock(&rtc_lock);
 641
 642         phys_tm = virt_to_phys_or_null(tm);
 643
 644         status = efi_thunk(set_wakeup_time, enabled, phys_tm);
 645
 646         spin_unlock(&rtc_lock);
 647
 648         return status;
 649 }
 650
 651 static unsigned long efi_name_size(efi_char16_t *name)
 652 {
 653         return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
 654 }
 655
 656 static efi_status_t
 657 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 658                        u32 *attr, unsigned long *data_size, void *data)
 659 {
 660         efi_status_t status;
 661         u32 phys_name, phys_vendor, phys_attr;
 662         u32 phys_data_size, phys_data;
 663
 664         phys_data_size = virt_to_phys_or_null(data_size);
 665         phys_vendor = virt_to_phys_or_null(vendor);
 666         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 667         phys_attr = virt_to_phys_or_null(attr);
 668         phys_data = virt_to_phys_or_null_size(data, *data_size);
 669
 670         status = efi_thunk(get_variable, phys_name, phys_vendor,
 671                            phys_attr, phys_data_size, phys_data);
 672
 673         return status;
 674 }
 675
 676 static efi_status_t
 677 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 678                        u32 attr, unsigned long data_size, void *data)
 679 {
 680         u32 phys_name, phys_vendor, phys_data;
 681         efi_status_t status;
 682
 683         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 684         phys_vendor = virt_to_phys_or_null(vendor);
 685         phys_data = virt_to_phys_or_null_size(data, data_size);
 686
 687         /* If data_size is > sizeof(u32) we've got problems */
 688         status = efi_thunk(set_variable, phys_name, phys_vendor,
 689                            attr, data_size, phys_data);
 690
 691         return status;
 692 }
 693
 694 static efi_status_t
 695 efi_thunk_get_next_variable(unsigned long *name_size,
 696                             efi_char16_t *name,
 697                             efi_guid_t *vendor)
 698 {
 699         efi_status_t status;
 700         u32 phys_name_size, phys_name, phys_vendor;
 701
 702         phys_name_size = virt_to_phys_or_null(name_size);
 703         phys_vendor = virt_to_phys_or_null(vendor);
 704         phys_name = virt_to_phys_or_null_size(name, *name_size);
 705
 706         status = efi_thunk(get_next_variable, phys_name_size,
 707                            phys_name, phys_vendor);
 708
 709         return status;
 710 }
 711
 712 static efi_status_t
 713 efi_thunk_get_next_high_mono_count(u32 *count)
 714 {
 715         efi_status_t status;
 716         u32 phys_count;
 717
 718         phys_count = virt_to_phys_or_null(count);
 719         status = efi_thunk(get_next_high_mono_count, phys_count);
 720
 721         return status;
 722 }
 723
 724 static void
 725 efi_thunk_reset_system(int reset_type, efi_status_t status,
 726                        unsigned long data_size, efi_char16_t *data)
 727 {
 728         u32 phys_data;
 729
 730         phys_data = virt_to_phys_or_null_size(data, data_size);
 731
 732         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
 733 }
 734
 735 static efi_status_t
 736 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
 737                          unsigned long count, unsigned long sg_list)
 738 {
 739         /*
 740          * To properly support this function we would need to repackage
 741          * 'capsules' because the firmware doesn't understand 64-bit
 742          * pointers.
 743          */
 744         return EFI_UNSUPPORTED;
 745 }
 746
 747 static efi_status_t
 748 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 749                               u64 *remaining_space,
 750                               u64 *max_variable_size)
 751 {
 752         efi_status_t status;
 753         u32 phys_storage, phys_remaining, phys_max;
 754
 755         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 756                 return EFI_UNSUPPORTED;
 757
 758         phys_storage = virt_to_phys_or_null(storage_space);
 759         phys_remaining = virt_to_phys_or_null(remaining_space);
 760         phys_max = virt_to_phys_or_null(max_variable_size);
 761
 762         status = efi_thunk(query_variable_info, attr, phys_storage,
 763                            phys_remaining, phys_max);
 764
 765         return status;
 766 }
 767
 768 static efi_status_t
 769 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
 770                              unsigned long count, u64 *max_size,
 771                              int *reset_type)
 772 {
 773         /*
 774          * To properly support this function we would need to repackage
 775          * 'capsules' because the firmware doesn't understand 64-bit
 776          * pointers.
 777          */
 778         return EFI_UNSUPPORTED;
 779 }
 780
 781 void efi_thunk_runtime_setup(void)
 782 {
 783         efi.get_time = efi_thunk_get_time;
 784         efi.set_time = efi_thunk_set_time;
 785         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
 786         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
 787         efi.get_variable = efi_thunk_get_variable;
 788         efi.get_next_variable = efi_thunk_get_next_variable;
 789         efi.set_variable = efi_thunk_set_variable;
 790         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
 791         efi.reset_system = efi_thunk_reset_system;
 792         efi.query_variable_info = efi_thunk_query_variable_info;
 793         efi.update_capsule = efi_thunk_update_capsule;
 794         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
 795 }
 796 #endif /* CONFIG_EFI_MIXED */