arch/x86/platform/efi/efi

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This source file includes following definitions.
early_code_mapping_set_exec
efi_call_phys_prolog
efi_call_phys_epilog
efi_alloc_page_tables
efi_sync_low_kernel_mappings
virt_to_phys_or_null_size
efi_setup_page_tables
__map_region
efi_map_region
efi_map_region_fixed
efi_ioremap
parse_efi_setup
efi_update_mappings
efi_update_mem_attr
efi_runtime_update_mappings
efi_dump_pagetable
efi_switch_mm
efi_thunk_set_virtual_address_map
efi_thunk_get_time
efi_thunk_set_time
efi_thunk_get_wakeup_time
efi_thunk_set_wakeup_time
efi_name_size
efi_thunk_get_variable
efi_thunk_set_variable
efi_thunk_set_variable_nonblocking
efi_thunk_get_next_variable
efi_thunk_get_next_high_mono_count
efi_thunk_reset_system
efi_thunk_update_capsule
efi_thunk_query_variable_info
efi_thunk_query_variable_info_nonblocking
efi_thunk_query_capsule_caps
efi_thunk_runtime_setup
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * x86_64 specific EFI support functions
   4  * Based on Extensible Firmware Interface Specification version 1.0
   5  *
   6  * Copyright (C) 2005-2008 Intel Co.
   7  *      Fenghua Yu <fenghua.yu@intel.com>
   8  *      Bibo Mao <bibo.mao@intel.com>
   9  *      Chandramouli Narayanan <mouli@linux.intel.com>
  10  *      Huang Ying <ying.huang@intel.com>
  11  *
  12  * Code to convert EFI to E820 map has been implemented in elilo bootloader
  13  * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
  14  * is setup appropriately for EFI runtime code.
  15  * - mouli 06/14/2007.
  16  *
  17  */
  18 
  19 #define pr_fmt(fmt) "efi: " fmt
  20 
  21 #include <linux/kernel.h>
  22 #include <linux/init.h>
  23 #include <linux/mm.h>
  24 #include <linux/types.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/memblock.h>
  27 #include <linux/ioport.h>
  28 #include <linux/mc146818rtc.h>
  29 #include <linux/efi.h>
  30 #include <linux/export.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/io.h>
  33 #include <linux/reboot.h>
  34 #include <linux/slab.h>
  35 #include <linux/ucs2_string.h>
  36 #include <linux/mem_encrypt.h>
  37 #include <linux/sched/task.h>
  38 
  39 #include <asm/setup.h>
  40 #include <asm/page.h>
  41 #include <asm/e820/api.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/tlbflush.h>
  44 #include <asm/proto.h>
  45 #include <asm/efi.h>
  46 #include <asm/cacheflush.h>
  47 #include <asm/fixmap.h>
  48 #include <asm/realmode.h>
  49 #include <asm/time.h>
  50 #include <asm/pgalloc.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 
  58 struct efi_scratch efi_scratch;
  59 
  60 static void __init early_code_mapping_set_exec(int executable)
  61 {
  62         efi_memory_desc_t *md;
  63 
  64         if (!(__supported_pte_mask & _PAGE_NX))
  65                 return;
  66 
  67         /* Make EFI service code area executable */
  68         for_each_efi_memory_desc(md) {
  69                 if (md->type == EFI_RUNTIME_SERVICES_CODE ||
  70                     md->type == EFI_BOOT_SERVICES_CODE)
  71                         efi_set_executable(md, executable);
  72         }
  73 }
  74 
  75 pgd_t * __init efi_call_phys_prolog(void)
  76 {
  77         unsigned long vaddr, addr_pgd, addr_p4d, addr_pud;
  78         pgd_t *save_pgd, *pgd_k, *pgd_efi;
  79         p4d_t *p4d, *p4d_k, *p4d_efi;
  80         pud_t *pud;
  81 
  82         int pgd;
  83         int n_pgds, i, j;
  84 
  85         if (!efi_enabled(EFI_OLD_MEMMAP)) {
  86                 efi_switch_mm(&efi_mm);
  87                 return efi_mm.pgd;
  88         }
  89 
  90         early_code_mapping_set_exec(1);
  91 
  92         n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
  93         save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL);
  94         if (!save_pgd)
  95                 return NULL;
  96 
  97         /*
  98          * Build 1:1 identity mapping for efi=old_map usage. Note that
  99          * PAGE_OFFSET is PGDIR_SIZE aligned when KASLR is disabled, while
 100          * it is PUD_SIZE ALIGNED with KASLR enabled. So for a given physical
 101          * address X, the pud_index(X) != pud_index(__va(X)), we can only copy
 102          * PUD entry of __va(X) to fill in pud entry of X to build 1:1 mapping.
 103          * This means here we can only reuse the PMD tables of the direct mapping.
 104          */
 105         for (pgd = 0; pgd < n_pgds; pgd++) {
 106                 addr_pgd = (unsigned long)(pgd * PGDIR_SIZE);
 107                 vaddr = (unsigned long)__va(pgd * PGDIR_SIZE);
 108                 pgd_efi = pgd_offset_k(addr_pgd);
 109                 save_pgd[pgd] = *pgd_efi;
 110 
 111                 p4d = p4d_alloc(&init_mm, pgd_efi, addr_pgd);
 112                 if (!p4d) {
 113                         pr_err("Failed to allocate p4d table!\n");
 114                         goto out;
 115                 }
 116 
 117                 for (i = 0; i < PTRS_PER_P4D; i++) {
 118                         addr_p4d = addr_pgd + i * P4D_SIZE;
 119                         p4d_efi = p4d + p4d_index(addr_p4d);
 120 
 121                         pud = pud_alloc(&init_mm, p4d_efi, addr_p4d);
 122                         if (!pud) {
 123                                 pr_err("Failed to allocate pud table!\n");
 124                                 goto out;
 125                         }
 126 
 127                         for (j = 0; j < PTRS_PER_PUD; j++) {
 128                                 addr_pud = addr_p4d + j * PUD_SIZE;
 129 
 130                                 if (addr_pud > (max_pfn << PAGE_SHIFT))
 131                                         break;
 132 
 133                                 vaddr = (unsigned long)__va(addr_pud);
 134 
 135                                 pgd_k = pgd_offset_k(vaddr);
 136                                 p4d_k = p4d_offset(pgd_k, vaddr);
 137                                 pud[j] = *pud_offset(p4d_k, vaddr);
 138                         }
 139                 }
 140                 pgd_offset_k(pgd * PGDIR_SIZE)->pgd &= ~_PAGE_NX;
 141         }
 142 
 143         __flush_tlb_all();
 144         return save_pgd;
 145 out:
 146         efi_call_phys_epilog(save_pgd);
 147         return NULL;
 148 }
 149 
 150 void __init efi_call_phys_epilog(pgd_t *save_pgd)
 151 {
 152         /*
 153          * After the lock is released, the original page table is restored.
 154          */
 155         int pgd_idx, i;
 156         int nr_pgds;
 157         pgd_t *pgd;
 158         p4d_t *p4d;
 159         pud_t *pud;
 160 
 161         if (!efi_enabled(EFI_OLD_MEMMAP)) {
 162                 efi_switch_mm(efi_scratch.prev_mm);
 163                 return;
 164         }
 165 
 166         nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
 167 
 168         for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) {
 169                 pgd = pgd_offset_k(pgd_idx * PGDIR_SIZE);
 170                 set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
 171 
 172                 if (!pgd_present(*pgd))
 173                         continue;
 174 
 175                 for (i = 0; i < PTRS_PER_P4D; i++) {
 176                         p4d = p4d_offset(pgd,
 177                                          pgd_idx * PGDIR_SIZE + i * P4D_SIZE);
 178 
 179                         if (!p4d_present(*p4d))
 180                                 continue;
 181 
 182                         pud = (pud_t *)p4d_page_vaddr(*p4d);
 183                         pud_free(&init_mm, pud);
 184                 }
 185 
 186                 p4d = (p4d_t *)pgd_page_vaddr(*pgd);
 187                 p4d_free(&init_mm, p4d);
 188         }
 189 
 190         kfree(save_pgd);
 191 
 192         __flush_tlb_all();
 193         early_code_mapping_set_exec(0);
 194 }
 195 
 196 EXPORT_SYMBOL_GPL(efi_mm);
 197 
 198 /*
 199  * We need our own copy of the higher levels of the page tables
 200  * because we want to avoid inserting EFI region mappings (EFI_VA_END
 201  * to EFI_VA_START) into the standard kernel page tables. Everything
 202  * else can be shared, see efi_sync_low_kernel_mappings().
 203  *
 204  * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
 205  * allocation.
 206  */
 207 int __init efi_alloc_page_tables(void)
 208 {
 209         pgd_t *pgd, *efi_pgd;
 210         p4d_t *p4d;
 211         pud_t *pud;
 212         gfp_t gfp_mask;
 213 
 214         if (efi_enabled(EFI_OLD_MEMMAP))
 215                 return 0;
 216 
 217         gfp_mask = GFP_KERNEL | __GFP_ZERO;
 218         efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
 219         if (!efi_pgd)
 220                 return -ENOMEM;
 221 
 222         pgd = efi_pgd + pgd_index(EFI_VA_END);
 223         p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
 224         if (!p4d) {
 225                 free_page((unsigned long)efi_pgd);
 226                 return -ENOMEM;
 227         }
 228 
 229         pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
 230         if (!pud) {
 231                 if (pgtable_l5_enabled())
 232                         free_page((unsigned long) pgd_page_vaddr(*pgd));
 233                 free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
 234                 return -ENOMEM;
 235         }
 236 
 237         efi_mm.pgd = efi_pgd;
 238         mm_init_cpumask(&efi_mm);
 239         init_new_context(NULL, &efi_mm);
 240 
 241         return 0;
 242 }
 243 
 244 /*
 245  * Add low kernel mappings for passing arguments to EFI functions.
 246  */
 247 void efi_sync_low_kernel_mappings(void)
 248 {
 249         unsigned num_entries;
 250         pgd_t *pgd_k, *pgd_efi;
 251         p4d_t *p4d_k, *p4d_efi;
 252         pud_t *pud_k, *pud_efi;
 253         pgd_t *efi_pgd = efi_mm.pgd;
 254 
 255         if (efi_enabled(EFI_OLD_MEMMAP))
 256                 return;
 257 
 258         /*
 259          * We can share all PGD entries apart from the one entry that
 260          * covers the EFI runtime mapping space.
 261          *
 262          * Make sure the EFI runtime region mappings are guaranteed to
 263          * only span a single PGD entry and that the entry also maps
 264          * other important kernel regions.
 265          */
 266         MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
 267         MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
 268                         (EFI_VA_END & PGDIR_MASK));
 269 
 270         pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
 271         pgd_k = pgd_offset_k(PAGE_OFFSET);
 272 
 273         num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
 274         memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
 275 
 276         /*
 277          * As with PGDs, we share all P4D entries apart from the one entry
 278          * that covers the EFI runtime mapping space.
 279          */
 280         BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));
 281         BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));
 282 
 283         pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
 284         pgd_k = pgd_offset_k(EFI_VA_END);
 285         p4d_efi = p4d_offset(pgd_efi, 0);
 286         p4d_k = p4d_offset(pgd_k, 0);
 287 
 288         num_entries = p4d_index(EFI_VA_END);
 289         memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
 290 
 291         /*
 292          * We share all the PUD entries apart from those that map the
 293          * EFI regions. Copy around them.
 294          */
 295         BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
 296         BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
 297 
 298         p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
 299         p4d_k = p4d_offset(pgd_k, EFI_VA_END);
 300         pud_efi = pud_offset(p4d_efi, 0);
 301         pud_k = pud_offset(p4d_k, 0);
 302 
 303         num_entries = pud_index(EFI_VA_END);
 304         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 305 
 306         pud_efi = pud_offset(p4d_efi, EFI_VA_START);
 307         pud_k = pud_offset(p4d_k, EFI_VA_START);
 308 
 309         num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
 310         memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
 311 }
 312 
 313 /*
 314  * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 315  */
 316 static inline phys_addr_t
 317 virt_to_phys_or_null_size(void *va, unsigned long size)
 318 {
 319         phys_addr_t pa;
 320 
 321         if (!va)
 322                 return 0;
 323 
 324         if (virt_addr_valid(va))
 325                 return virt_to_phys(va);
 326 
 327         pa = slow_virt_to_phys(va);
 328 
 329         /* check if the object crosses a page boundary */
 330         if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
 331                 return 0;
 332 
 333         return pa;
 334 }
 335 
 336 #define virt_to_phys_or_null(addr)                              \
 337         virt_to_phys_or_null_size((addr), sizeof(*(addr)))
 338 
 339 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 340 {
 341         unsigned long pfn, text, pf;
 342         struct page *page;
 343         unsigned npages;
 344         pgd_t *pgd = efi_mm.pgd;
 345 
 346         if (efi_enabled(EFI_OLD_MEMMAP))
 347                 return 0;
 348 
 349         /*
 350          * It can happen that the physical address of new_memmap lands in memory
 351          * which is not mapped in the EFI page table. Therefore we need to go
 352          * and ident-map those pages containing the map before calling
 353          * phys_efi_set_virtual_address_map().
 354          */
 355         pfn = pa_memmap >> PAGE_SHIFT;
 356         pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
 357         if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
 358                 pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 359                 return 1;
 360         }
 361 
 362         /*
 363          * Certain firmware versions are way too sentimential and still believe
 364          * they are exclusive and unquestionable owners of the first physical page,
 365          * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
 366          * (but then write-access it later during SetVirtualAddressMap()).
 367          *
 368          * Create a 1:1 mapping for this page, to avoid triple faults during early
 369          * boot with such firmware. We are free to hand this page to the BIOS,
 370          * as trim_bios_range() will reserve the first page and isolate it away
 371          * from memory allocators anyway.
 372          */
 373         pf = _PAGE_RW;
 374         if (sev_active())
 375                 pf |= _PAGE_ENC;
 376 
 377         if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
 378                 pr_err("Failed to create 1:1 mapping for the first page!\n");
 379                 return 1;
 380         }
 381 
 382         /*
 383          * When making calls to the firmware everything needs to be 1:1
 384          * mapped and addressable with 32-bit pointers. Map the kernel
 385          * text and allocate a new stack because we can't rely on the
 386          * stack pointer being < 4GB.
 387          */
 388         if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
 389                 return 0;
 390 
 391         page = alloc_page(GFP_KERNEL|__GFP_DMA32);
 392         if (!page) {
 393                 pr_err("Unable to allocate EFI runtime stack < 4GB\n");
 394                 return 1;
 395         }
 396 
 397         efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */
 398 
 399         npages = (_etext - _text) >> PAGE_SHIFT;
 400         text = __pa(_text);
 401         pfn = text >> PAGE_SHIFT;
 402 
 403         pf = _PAGE_RW | _PAGE_ENC;
 404         if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
 405                 pr_err("Failed to map kernel text 1:1\n");
 406                 return 1;
 407         }
 408 
 409         return 0;
 410 }
 411 
 412 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 413 {
 414         unsigned long flags = _PAGE_RW;
 415         unsigned long pfn;
 416         pgd_t *pgd = efi_mm.pgd;
 417 
 418         if (!(md->attribute & EFI_MEMORY_WB))
 419                 flags |= _PAGE_PCD;
 420 
 421         if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
 422                 flags |= _PAGE_ENC;
 423 
 424         pfn = md->phys_addr >> PAGE_SHIFT;
 425         if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
 426                 pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 427                            md->phys_addr, va);
 428 }
 429 
 430 void __init efi_map_region(efi_memory_desc_t *md)
 431 {
 432         unsigned long size = md->num_pages << PAGE_SHIFT;
 433         u64 pa = md->phys_addr;
 434 
 435         if (efi_enabled(EFI_OLD_MEMMAP))
 436                 return old_map_region(md);
 437 
 438         /*
 439          * Make sure the 1:1 mappings are present as a catch-all for b0rked
 440          * firmware which doesn't update all internal pointers after switching
 441          * to virtual mode and would otherwise crap on us.
 442          */
 443         __map_region(md, md->phys_addr);
 444 
 445         /*
 446          * Enforce the 1:1 mapping as the default virtual address when
 447          * booting in EFI mixed mode, because even though we may be
 448          * running a 64-bit kernel, the firmware may only be 32-bit.
 449          */
 450         if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
 451                 md->virt_addr = md->phys_addr;
 452                 return;
 453         }
 454 
 455         efi_va -= size;
 456 
 457         /* Is PA 2M-aligned? */
 458         if (!(pa & (PMD_SIZE - 1))) {
 459                 efi_va &= PMD_MASK;
 460         } else {
 461                 u64 pa_offset = pa & (PMD_SIZE - 1);
 462                 u64 prev_va = efi_va;
 463 
 464                 /* get us the same offset within this 2M page */
 465                 efi_va = (efi_va & PMD_MASK) + pa_offset;
 466 
 467                 if (efi_va > prev_va)
 468                         efi_va -= PMD_SIZE;
 469         }
 470 
 471         if (efi_va < EFI_VA_END) {
 472                 pr_warn(FW_WARN "VA address range overflow!\n");
 473                 return;
 474         }
 475 
 476         /* Do the VA map */
 477         __map_region(md, efi_va);
 478         md->virt_addr = efi_va;
 479 }
 480 
 481 /*
 482  * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 483  * md->virt_addr is the original virtual address which had been mapped in kexec
 484  * 1st kernel.
 485  */
 486 void __init efi_map_region_fixed(efi_memory_desc_t *md)
 487 {
 488         __map_region(md, md->phys_addr);
 489         __map_region(md, md->virt_addr);
 490 }
 491 
 492 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
 493                                  u32 type, u64 attribute)
 494 {
 495         unsigned long last_map_pfn;
 496 
 497         if (type == EFI_MEMORY_MAPPED_IO)
 498                 return ioremap(phys_addr, size);
 499 
 500         last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
 501         if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
 502                 unsigned long top = last_map_pfn << PAGE_SHIFT;
 503                 efi_ioremap(top, size - (top - phys_addr), type, attribute);
 504         }
 505 
 506         if (!(attribute & EFI_MEMORY_WB))
 507                 efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
 508 
 509         return (void __iomem *)__va(phys_addr);
 510 }
 511 
 512 void __init parse_efi_setup(u64 phys_addr, u32 data_len)
 513 {
 514         efi_setup = phys_addr + sizeof(struct setup_data);
 515 }
 516 
 517 static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
 518 {
 519         unsigned long pfn;
 520         pgd_t *pgd = efi_mm.pgd;
 521         int err1, err2;
 522 
 523         /* Update the 1:1 mapping */
 524         pfn = md->phys_addr >> PAGE_SHIFT;
 525         err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
 526         if (err1) {
 527                 pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
 528                            md->phys_addr, md->virt_addr);
 529         }
 530 
 531         err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
 532         if (err2) {
 533                 pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
 534                            md->phys_addr, md->virt_addr);
 535         }
 536 
 537         return err1 || err2;
 538 }
 539 
 540 static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
 541 {
 542         unsigned long pf = 0;
 543 
 544         if (md->attribute & EFI_MEMORY_XP)
 545                 pf |= _PAGE_NX;
 546 
 547         if (!(md->attribute & EFI_MEMORY_RO))
 548                 pf |= _PAGE_RW;
 549 
 550         if (sev_active())
 551                 pf |= _PAGE_ENC;
 552 
 553         return efi_update_mappings(md, pf);
 554 }
 555 
 556 void __init efi_runtime_update_mappings(void)
 557 {
 558         efi_memory_desc_t *md;
 559 
 560         if (efi_enabled(EFI_OLD_MEMMAP)) {
 561                 if (__supported_pte_mask & _PAGE_NX)
 562                         runtime_code_page_mkexec();
 563                 return;
 564         }
 565 
 566         /*
 567          * Use the EFI Memory Attribute Table for mapping permissions if it
 568          * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
 569          */
 570         if (efi_enabled(EFI_MEM_ATTR)) {
 571                 efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
 572                 return;
 573         }
 574 
 575         /*
 576          * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
 577          * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
 578          * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
 579          * published by the firmware. Even if we find a buggy implementation of
 580          * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
 581          * EFI_PROPERTIES_TABLE, because of the same reason.
 582          */
 583 
 584         if (!efi_enabled(EFI_NX_PE_DATA))
 585                 return;
 586 
 587         for_each_efi_memory_desc(md) {
 588                 unsigned long pf = 0;
 589 
 590                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
 591                         continue;
 592 
 593                 if (!(md->attribute & EFI_MEMORY_WB))
 594                         pf |= _PAGE_PCD;
 595 
 596                 if ((md->attribute & EFI_MEMORY_XP) ||
 597                         (md->type == EFI_RUNTIME_SERVICES_DATA))
 598                         pf |= _PAGE_NX;
 599 
 600                 if (!(md->attribute & EFI_MEMORY_RO) &&
 601                         (md->type != EFI_RUNTIME_SERVICES_CODE))
 602                         pf |= _PAGE_RW;
 603 
 604                 if (sev_active())
 605                         pf |= _PAGE_ENC;
 606 
 607                 efi_update_mappings(md, pf);
 608         }
 609 }
 610 
 611 void __init efi_dump_pagetable(void)
 612 {
 613 #ifdef CONFIG_EFI_PGT_DUMP
 614         if (efi_enabled(EFI_OLD_MEMMAP))
 615                 ptdump_walk_pgd_level(NULL, swapper_pg_dir);
 616         else
 617                 ptdump_walk_pgd_level(NULL, efi_mm.pgd);
 618 #endif
 619 }
 620 
 621 /*
 622  * Makes the calling thread switch to/from efi_mm context. Can be used
 623  * in a kernel thread and user context. Preemption needs to remain disabled
 624  * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
 625  * can not change under us.
 626  * It should be ensured that there are no concurent calls to this function.
 627  */
 628 void efi_switch_mm(struct mm_struct *mm)
 629 {
 630         efi_scratch.prev_mm = current->active_mm;
 631         current->active_mm = mm;
 632         switch_mm(efi_scratch.prev_mm, mm, NULL);
 633 }
 634 
 635 #ifdef CONFIG_EFI_MIXED
 636 extern efi_status_t efi64_thunk(u32, ...);
 637 
 638 static DEFINE_SPINLOCK(efi_runtime_lock);
 639 
 640 #define runtime_service32(func)                                          \
 641 ({                                                                       \
 642         u32 table = (u32)(unsigned long)efi.systab;                      \
 643         u32 *rt, *___f;                                                  \
 644                                                                          \
 645         rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime));  \
 646         ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
 647         *___f;                                                           \
 648 })
 649 
 650 /*
 651  * Switch to the EFI page tables early so that we can access the 1:1
 652  * runtime services mappings which are not mapped in any other page
 653  * tables. This function must be called before runtime_service32().
 654  *
 655  * Also, disable interrupts because the IDT points to 64-bit handlers,
 656  * which aren't going to function correctly when we switch to 32-bit.
 657  */
 658 #define efi_thunk(f, ...)                                               \
 659 ({                                                                      \
 660         efi_status_t __s;                                               \
 661         u32 __func;                                                     \
 662                                                                         \
 663         arch_efi_call_virt_setup();                                     \
 664                                                                         \
 665         __func = runtime_service32(f);                                  \
 666         __s = efi64_thunk(__func, __VA_ARGS__);                         \
 667                                                                         \
 668         arch_efi_call_virt_teardown();                                  \
 669                                                                         \
 670         __s;                                                            \
 671 })
 672 
 673 efi_status_t efi_thunk_set_virtual_address_map(
 674         void *phys_set_virtual_address_map,
 675         unsigned long memory_map_size,
 676         unsigned long descriptor_size,
 677         u32 descriptor_version,
 678         efi_memory_desc_t *virtual_map)
 679 {
 680         efi_status_t status;
 681         unsigned long flags;
 682         u32 func;
 683 
 684         efi_sync_low_kernel_mappings();
 685         local_irq_save(flags);
 686 
 687         efi_switch_mm(&efi_mm);
 688 
 689         func = (u32)(unsigned long)phys_set_virtual_address_map;
 690         status = efi64_thunk(func, memory_map_size, descriptor_size,
 691                              descriptor_version, virtual_map);
 692 
 693         efi_switch_mm(efi_scratch.prev_mm);
 694         local_irq_restore(flags);
 695 
 696         return status;
 697 }
 698 
 699 static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 700 {
 701         efi_status_t status;
 702         u32 phys_tm, phys_tc;
 703         unsigned long flags;
 704 
 705         spin_lock(&rtc_lock);
 706         spin_lock_irqsave(&efi_runtime_lock, flags);
 707 
 708         phys_tm = virt_to_phys_or_null(tm);
 709         phys_tc = virt_to_phys_or_null(tc);
 710 
 711         status = efi_thunk(get_time, phys_tm, phys_tc);
 712 
 713         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 714         spin_unlock(&rtc_lock);
 715 
 716         return status;
 717 }
 718 
 719 static efi_status_t efi_thunk_set_time(efi_time_t *tm)
 720 {
 721         efi_status_t status;
 722         u32 phys_tm;
 723         unsigned long flags;
 724 
 725         spin_lock(&rtc_lock);
 726         spin_lock_irqsave(&efi_runtime_lock, flags);
 727 
 728         phys_tm = virt_to_phys_or_null(tm);
 729 
 730         status = efi_thunk(set_time, phys_tm);
 731 
 732         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 733         spin_unlock(&rtc_lock);
 734 
 735         return status;
 736 }
 737 
 738 static efi_status_t
 739 efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
 740                           efi_time_t *tm)
 741 {
 742         efi_status_t status;
 743         u32 phys_enabled, phys_pending, phys_tm;
 744         unsigned long flags;
 745 
 746         spin_lock(&rtc_lock);
 747         spin_lock_irqsave(&efi_runtime_lock, flags);
 748 
 749         phys_enabled = virt_to_phys_or_null(enabled);
 750         phys_pending = virt_to_phys_or_null(pending);
 751         phys_tm = virt_to_phys_or_null(tm);
 752 
 753         status = efi_thunk(get_wakeup_time, phys_enabled,
 754                              phys_pending, phys_tm);
 755 
 756         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 757         spin_unlock(&rtc_lock);
 758 
 759         return status;
 760 }
 761 
 762 static efi_status_t
 763 efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 764 {
 765         efi_status_t status;
 766         u32 phys_tm;
 767         unsigned long flags;
 768 
 769         spin_lock(&rtc_lock);
 770         spin_lock_irqsave(&efi_runtime_lock, flags);
 771 
 772         phys_tm = virt_to_phys_or_null(tm);
 773 
 774         status = efi_thunk(set_wakeup_time, enabled, phys_tm);
 775 
 776         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 777         spin_unlock(&rtc_lock);
 778 
 779         return status;
 780 }
 781 
 782 static unsigned long efi_name_size(efi_char16_t *name)
 783 {
 784         return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
 785 }
 786 
 787 static efi_status_t
 788 efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
 789                        u32 *attr, unsigned long *data_size, void *data)
 790 {
 791         u8 buf[24] __aligned(8);
 792         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 793         efi_status_t status;
 794         u32 phys_name, phys_vendor, phys_attr;
 795         u32 phys_data_size, phys_data;
 796         unsigned long flags;
 797 
 798         spin_lock_irqsave(&efi_runtime_lock, flags);
 799 
 800         *vnd = *vendor;
 801 
 802         phys_data_size = virt_to_phys_or_null(data_size);
 803         phys_vendor = virt_to_phys_or_null(vnd);
 804         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 805         phys_attr = virt_to_phys_or_null(attr);
 806         phys_data = virt_to_phys_or_null_size(data, *data_size);
 807 
 808         if (!phys_name || (data && !phys_data))
 809                 status = EFI_INVALID_PARAMETER;
 810         else
 811                 status = efi_thunk(get_variable, phys_name, phys_vendor,
 812                                    phys_attr, phys_data_size, phys_data);
 813 
 814         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 815 
 816         return status;
 817 }
 818 
 819 static efi_status_t
 820 efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
 821                        u32 attr, unsigned long data_size, void *data)
 822 {
 823         u8 buf[24] __aligned(8);
 824         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 825         u32 phys_name, phys_vendor, phys_data;
 826         efi_status_t status;
 827         unsigned long flags;
 828 
 829         spin_lock_irqsave(&efi_runtime_lock, flags);
 830 
 831         *vnd = *vendor;
 832 
 833         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 834         phys_vendor = virt_to_phys_or_null(vnd);
 835         phys_data = virt_to_phys_or_null_size(data, data_size);
 836 
 837         if (!phys_name || (data && !phys_data))
 838                 status = EFI_INVALID_PARAMETER;
 839         else
 840                 status = efi_thunk(set_variable, phys_name, phys_vendor,
 841                                    attr, data_size, phys_data);
 842 
 843         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 844 
 845         return status;
 846 }
 847 
 848 static efi_status_t
 849 efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
 850                                    u32 attr, unsigned long data_size,
 851                                    void *data)
 852 {
 853         u8 buf[24] __aligned(8);
 854         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 855         u32 phys_name, phys_vendor, phys_data;
 856         efi_status_t status;
 857         unsigned long flags;
 858 
 859         if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
 860                 return EFI_NOT_READY;
 861 
 862         *vnd = *vendor;
 863 
 864         phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
 865         phys_vendor = virt_to_phys_or_null(vnd);
 866         phys_data = virt_to_phys_or_null_size(data, data_size);
 867 
 868         if (!phys_name || (data && !phys_data))
 869                 status = EFI_INVALID_PARAMETER;
 870         else
 871                 status = efi_thunk(set_variable, phys_name, phys_vendor,
 872                                    attr, data_size, phys_data);
 873 
 874         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 875 
 876         return status;
 877 }
 878 
 879 static efi_status_t
 880 efi_thunk_get_next_variable(unsigned long *name_size,
 881                             efi_char16_t *name,
 882                             efi_guid_t *vendor)
 883 {
 884         u8 buf[24] __aligned(8);
 885         efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
 886         efi_status_t status;
 887         u32 phys_name_size, phys_name, phys_vendor;
 888         unsigned long flags;
 889 
 890         spin_lock_irqsave(&efi_runtime_lock, flags);
 891 
 892         *vnd = *vendor;
 893 
 894         phys_name_size = virt_to_phys_or_null(name_size);
 895         phys_vendor = virt_to_phys_or_null(vnd);
 896         phys_name = virt_to_phys_or_null_size(name, *name_size);
 897 
 898         if (!phys_name)
 899                 status = EFI_INVALID_PARAMETER;
 900         else
 901                 status = efi_thunk(get_next_variable, phys_name_size,
 902                                    phys_name, phys_vendor);
 903 
 904         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 905 
 906         *vendor = *vnd;
 907         return status;
 908 }
 909 
 910 static efi_status_t
 911 efi_thunk_get_next_high_mono_count(u32 *count)
 912 {
 913         efi_status_t status;
 914         u32 phys_count;
 915         unsigned long flags;
 916 
 917         spin_lock_irqsave(&efi_runtime_lock, flags);
 918 
 919         phys_count = virt_to_phys_or_null(count);
 920         status = efi_thunk(get_next_high_mono_count, phys_count);
 921 
 922         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 923 
 924         return status;
 925 }
 926 
 927 static void
 928 efi_thunk_reset_system(int reset_type, efi_status_t status,
 929                        unsigned long data_size, efi_char16_t *data)
 930 {
 931         u32 phys_data;
 932         unsigned long flags;
 933 
 934         spin_lock_irqsave(&efi_runtime_lock, flags);
 935 
 936         phys_data = virt_to_phys_or_null_size(data, data_size);
 937 
 938         efi_thunk(reset_system, reset_type, status, data_size, phys_data);
 939 
 940         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 941 }
 942 
 943 static efi_status_t
 944 efi_thunk_update_capsule(efi_capsule_header_t **capsules,
 945                          unsigned long count, unsigned long sg_list)
 946 {
 947         /*
 948          * To properly support this function we would need to repackage
 949          * 'capsules' because the firmware doesn't understand 64-bit
 950          * pointers.
 951          */
 952         return EFI_UNSUPPORTED;
 953 }
 954 
 955 static efi_status_t
 956 efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
 957                               u64 *remaining_space,
 958                               u64 *max_variable_size)
 959 {
 960         efi_status_t status;
 961         u32 phys_storage, phys_remaining, phys_max;
 962         unsigned long flags;
 963 
 964         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 965                 return EFI_UNSUPPORTED;
 966 
 967         spin_lock_irqsave(&efi_runtime_lock, flags);
 968 
 969         phys_storage = virt_to_phys_or_null(storage_space);
 970         phys_remaining = virt_to_phys_or_null(remaining_space);
 971         phys_max = virt_to_phys_or_null(max_variable_size);
 972 
 973         status = efi_thunk(query_variable_info, attr, phys_storage,
 974                            phys_remaining, phys_max);
 975 
 976         spin_unlock_irqrestore(&efi_runtime_lock, flags);
 977 
 978         return status;
 979 }
 980 
 981 static efi_status_t
 982 efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
 983                                           u64 *remaining_space,
 984                                           u64 *max_variable_size)
 985 {
 986         efi_status_t status;
 987         u32 phys_storage, phys_remaining, phys_max;
 988         unsigned long flags;
 989 
 990         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 991                 return EFI_UNSUPPORTED;
 992 
 993         if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
 994                 return EFI_NOT_READY;
 995 
 996         phys_storage = virt_to_phys_or_null(storage_space);
 997         phys_remaining = virt_to_phys_or_null(remaining_space);
 998         phys_max = virt_to_phys_or_null(max_variable_size);
 999 
1000         status = efi_thunk(query_variable_info, attr, phys_storage,
1001                            phys_remaining, phys_max);
1002 
1003         spin_unlock_irqrestore(&efi_runtime_lock, flags);
1004 
1005         return status;
1006 }
1007 
1008 static efi_status_t
1009 efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
1010                              unsigned long count, u64 *max_size,
1011                              int *reset_type)
1012 {
1013         /*
1014          * To properly support this function we would need to repackage
1015          * 'capsules' because the firmware doesn't understand 64-bit
1016          * pointers.
1017          */
1018         return EFI_UNSUPPORTED;
1019 }
1020 
1021 void efi_thunk_runtime_setup(void)
1022 {
1023         efi.get_time = efi_thunk_get_time;
1024         efi.set_time = efi_thunk_set_time;
1025         efi.get_wakeup_time = efi_thunk_get_wakeup_time;
1026         efi.set_wakeup_time = efi_thunk_set_wakeup_time;
1027         efi.get_variable = efi_thunk_get_variable;
1028         efi.get_next_variable = efi_thunk_get_next_variable;
1029         efi.set_variable = efi_thunk_set_variable;
1030         efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
1031         efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
1032         efi.reset_system = efi_thunk_reset_system;
1033         efi.query_variable_info = efi_thunk_query_variable_info;
1034         efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
1035         efi.update_capsule = efi_thunk_update_capsule;
1036         efi.query_capsule_caps = efi_thunk_query_capsule_caps;
1037 }
1038 #endif /* CONFIG_EFI_MIXED */
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root/arch/x86/platform/efi/efi_64.c

DEFINITIONS
