drivers/firmware/efi/arm-init.c

   1 /*
   2  * Extensible Firmware Interface
   3  *
   4  * Based on Extensible Firmware Interface Specification version 2.4
   5  *
   6  * Copyright (C) 2013 - 2015 Linaro Ltd.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  */
  13
  14 #include <linux/efi.h>
  15 #include <linux/init.h>
  16 #include <linux/memblock.h>
  17 #include <linux/mm_types.h>
  18 #include <linux/of.h>
  19 #include <linux/of_fdt.h>
  20
  21 #include <asm/efi.h>
  22
  23 struct efi_memory_map memmap;
  24
  25 u64 efi_system_table;
  26
  27 static int __init is_normal_ram(efi_memory_desc_t *md)
  28 {
  29         if (md->attribute & EFI_MEMORY_WB)
  30                 return 1;
  31         return 0;
  32 }
  33
  34 /*
  35  * Translate a EFI virtual address into a physical address: this is necessary,
  36  * as some data members of the EFI system table are virtually remapped after
  37  * SetVirtualAddressMap() has been called.
  38  */
  39 static phys_addr_t efi_to_phys(unsigned long addr)
  40 {
  41         efi_memory_desc_t *md;
  42
  43         for_each_efi_memory_desc(&memmap, md) {
  44                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
  45                         continue;
  46                 if (md->virt_addr == 0)
  47                         /* no virtual mapping has been installed by the stub */
  48                         break;
  49                 if (md->virt_addr <= addr &&
  50                     (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
  51                         return md->phys_addr + addr - md->virt_addr;
  52         }
  53         return addr;
  54 }
  55
  56 static int __init uefi_init(void)
  57 {
  58         efi_char16_t *c16;
  59         void *config_tables;
  60         size_t table_size;
  61         char vendor[100] = "unknown";
  62         int i, retval;
  63
  64         efi.systab = early_memremap_ro(efi_system_table,
  65                                        sizeof(efi_system_table_t));
  66         if (efi.systab == NULL) {
  67                 pr_warn("Unable to map EFI system table.\n");
  68                 return -ENOMEM;
  69         }
  70
  71         set_bit(EFI_BOOT, &efi.flags);
  72         if (IS_ENABLED(CONFIG_64BIT))
  73                 set_bit(EFI_64BIT, &efi.flags);
  74
  75         /*
  76          * Verify the EFI Table
  77          */
  78         if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
  79                 pr_err("System table signature incorrect\n");
  80                 retval = -EINVAL;
  81                 goto out;
  82         }
  83         if ((efi.systab->hdr.revision >> 16) < 2)
  84                 pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
  85                         efi.systab->hdr.revision >> 16,
  86                         efi.systab->hdr.revision & 0xffff);
  87
  88         /* Show what we know for posterity */
  89         c16 = early_memremap_ro(efi_to_phys(efi.systab->fw_vendor),
  90                                 sizeof(vendor) * sizeof(efi_char16_t));
  91         if (c16) {
  92                 for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
  93                         vendor[i] = c16[i];
  94                 vendor[i] = '\0';
  95                 early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
  96         }
  97
  98         pr_info("EFI v%u.%.02u by %s\n",
  99                 efi.systab->hdr.revision >> 16,
 100                 efi.systab->hdr.revision & 0xffff, vendor);
 101
 102         table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
 103         config_tables = early_memremap_ro(efi_to_phys(efi.systab->tables),
 104                                           table_size);
 105         if (config_tables == NULL) {
 106                 pr_warn("Unable to map EFI config table array.\n");
 107                 retval = -ENOMEM;
 108                 goto out;
 109         }
 110         retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
 111                                          sizeof(efi_config_table_t), NULL);
 112
 113         early_memunmap(config_tables, table_size);
 114 out:
 115         early_memunmap(efi.systab,  sizeof(efi_system_table_t));
 116         return retval;
 117 }
 118
 119 /*
 120  * Return true for RAM regions we want to permanently reserve.
 121  */
 122 static __init int is_reserve_region(efi_memory_desc_t *md)
 123 {
 124         switch (md->type) {
 125         case EFI_LOADER_CODE:
 126         case EFI_LOADER_DATA:
 127         case EFI_BOOT_SERVICES_CODE:
 128         case EFI_BOOT_SERVICES_DATA:
 129         case EFI_CONVENTIONAL_MEMORY:
 130         case EFI_PERSISTENT_MEMORY:
 131                 return 0;
 132         default:
 133                 break;
 134         }
 135         return is_normal_ram(md);
 136 }
 137
 138 static __init void reserve_regions(void)
 139 {
 140         efi_memory_desc_t *md;
 141         u64 paddr, npages, size;
 142
 143         if (efi_enabled(EFI_DBG))
 144                 pr_info("Processing EFI memory map:\n");
 145
 146         for_each_efi_memory_desc(&memmap, md) {
 147                 paddr = md->phys_addr;
 148                 npages = md->num_pages;
 149
 150                 if (efi_enabled(EFI_DBG)) {
 151                         char buf[64];
 152
 153                         pr_info("  0x%012llx-0x%012llx %s",
 154                                 paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
 155                                 efi_md_typeattr_format(buf, sizeof(buf), md));
 156                 }
 157
 158                 memrange_efi_to_native(&paddr, &npages);
 159                 size = npages << PAGE_SHIFT;
 160
 161                 if (is_normal_ram(md))
 162                         early_init_dt_add_memory_arch(paddr, size);
 163
 164                 if (is_reserve_region(md)) {
 165                         memblock_mark_nomap(paddr, size);
 166                         if (efi_enabled(EFI_DBG))
 167                                 pr_cont("*");
 168                 }
 169
 170                 if (efi_enabled(EFI_DBG))
 171                         pr_cont("\n");
 172         }
 173
 174         set_bit(EFI_MEMMAP, &efi.flags);
 175 }
 176
 177 void __init efi_init(void)
 178 {
 179         struct efi_fdt_params params;
 180
 181         /* Grab UEFI information placed in FDT by stub */
 182         if (!efi_get_fdt_params(&params))
 183                 return;
 184
 185         efi_system_table = params.system_table;
 186
 187         memmap.phys_map = params.mmap;
 188         memmap.map = early_memremap_ro(params.mmap, params.mmap_size);
 189         if (memmap.map == NULL) {
 190                 /*
 191                 * If we are booting via UEFI, the UEFI memory map is the only
 192                 * description of memory we have, so there is little point in
 193                 * proceeding if we cannot access it.
 194                 */
 195                 panic("Unable to map EFI memory map.\n");
 196         }
 197         memmap.map_end = memmap.map + params.mmap_size;
 198         memmap.desc_size = params.desc_size;
 199         memmap.desc_version = params.desc_ver;
 200
 201         if (uefi_init() < 0)
 202                 return;
 203
 204         reserve_regions();
 205         early_memunmap(memmap.map, params.mmap_size);
 206
 207         if (IS_ENABLED(CONFIG_ARM)) {
 208                 /*
 209                  * ARM currently does not allow ioremap_cache() to be called on
 210                  * memory regions that are covered by struct page. So remove the
 211                  * UEFI memory map from the linear mapping.
 212                  */
 213                 memblock_mark_nomap(params.mmap & PAGE_MASK,
 214                                     PAGE_ALIGN(params.mmap_size +
 215                                                (params.mmap & ~PAGE_MASK)));
 216         } else {
 217                 memblock_reserve(params.mmap & PAGE_MASK,
 218                                  PAGE_ALIGN(params.mmap_size +
 219                                             (params.mmap & ~PAGE_MASK)));
 220         }
 221 }