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 #define pr_fmt(fmt)     "efi: " fmt
  15
  16 #include <linux/efi.h>
  17 #include <linux/init.h>
  18 #include <linux/memblock.h>
  19 #include <linux/mm_types.h>
  20 #include <linux/of.h>
  21 #include <linux/of_fdt.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/screen_info.h>
  24
  25 #include <asm/efi.h>
  26
  27 u64 efi_system_table;
  28
  29 static int __init is_memory(efi_memory_desc_t *md)
  30 {
  31         if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
  32                 return 1;
  33         return 0;
  34 }
  35
  36 /*
  37  * Translate a EFI virtual address into a physical address: this is necessary,
  38  * as some data members of the EFI system table are virtually remapped after
  39  * SetVirtualAddressMap() has been called.
  40  */
  41 static phys_addr_t efi_to_phys(unsigned long addr)
  42 {
  43         efi_memory_desc_t *md;
  44
  45         for_each_efi_memory_desc(md) {
  46                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
  47                         continue;
  48                 if (md->virt_addr == 0)
  49                         /* no virtual mapping has been installed by the stub */
  50                         break;
  51                 if (md->virt_addr <= addr &&
  52                     (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
  53                         return md->phys_addr + addr - md->virt_addr;
  54         }
  55         return addr;
  56 }
  57
  58 static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
  59
  60 static __initdata efi_config_table_type_t arch_tables[] = {
  61         {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
  62         {NULL_GUID, NULL, NULL}
  63 };
  64
  65 static void __init init_screen_info(void)
  66 {
  67         struct screen_info *si;
  68
  69         if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
  70                 si = early_memremap_ro(screen_info_table, sizeof(*si));
  71                 if (!si) {
  72                         pr_err("Could not map screen_info config table\n");
  73                         return;
  74                 }
  75                 screen_info = *si;
  76                 early_memunmap(si, sizeof(*si));
  77
  78                 /* dummycon on ARM needs non-zero values for columns/lines */
  79                 screen_info.orig_video_cols = 80;
  80                 screen_info.orig_video_lines = 25;
  81         }
  82
  83         if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
  84             memblock_is_map_memory(screen_info.lfb_base))
  85                 memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
  86 }
  87
  88 static int __init uefi_init(void)
  89 {
  90         efi_char16_t *c16;
  91         void *config_tables;
  92         size_t table_size;
  93         char vendor[100] = "unknown";
  94         int i, retval;
  95
  96         efi.systab = early_memremap_ro(efi_system_table,
  97                                        sizeof(efi_system_table_t));
  98         if (efi.systab == NULL) {
  99                 pr_warn("Unable to map EFI system table.\n");
 100                 return -ENOMEM;
 101         }
 102
 103         set_bit(EFI_BOOT, &efi.flags);
 104         if (IS_ENABLED(CONFIG_64BIT))
 105                 set_bit(EFI_64BIT, &efi.flags);
 106
 107         /*
 108          * Verify the EFI Table
 109          */
 110         if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 111                 pr_err("System table signature incorrect\n");
 112                 retval = -EINVAL;
 113                 goto out;
 114         }
 115         if ((efi.systab->hdr.revision >> 16) < 2)
 116                 pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
 117                         efi.systab->hdr.revision >> 16,
 118                         efi.systab->hdr.revision & 0xffff);
 119
 120         efi.runtime_version = efi.systab->hdr.revision;
 121
 122         /* Show what we know for posterity */
 123         c16 = early_memremap_ro(efi_to_phys(efi.systab->fw_vendor),
 124                                 sizeof(vendor) * sizeof(efi_char16_t));
 125         if (c16) {
 126                 for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
 127                         vendor[i] = c16[i];
 128                 vendor[i] = '\0';
 129                 early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
 130         }
 131
 132         pr_info("EFI v%u.%.02u by %s\n",
 133                 efi.systab->hdr.revision >> 16,
 134                 efi.systab->hdr.revision & 0xffff, vendor);
 135
 136         table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
 137         config_tables = early_memremap_ro(efi_to_phys(efi.systab->tables),
 138                                           table_size);
 139         if (config_tables == NULL) {
 140                 pr_warn("Unable to map EFI config table array.\n");
 141                 retval = -ENOMEM;
 142                 goto out;
 143         }
 144         retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
 145                                          sizeof(efi_config_table_t),
 146                                          arch_tables);
 147
 148         early_memunmap(config_tables, table_size);
 149 out:
 150         early_memunmap(efi.systab,  sizeof(efi_system_table_t));
 151         return retval;
 152 }
 153
 154 /*
 155  * Return true for regions that can be used as System RAM.
 156  */
 157 static __init int is_usable_memory(efi_memory_desc_t *md)
 158 {
 159         switch (md->type) {
 160         case EFI_LOADER_CODE:
 161         case EFI_LOADER_DATA:
 162         case EFI_BOOT_SERVICES_CODE:
 163         case EFI_BOOT_SERVICES_DATA:
 164         case EFI_CONVENTIONAL_MEMORY:
 165         case EFI_PERSISTENT_MEMORY:
 166                 /*
 167                  * According to the spec, these regions are no longer reserved
 168                  * after calling ExitBootServices(). However, we can only use
 169                  * them as System RAM if they can be mapped writeback cacheable.
 170                  */
 171                 return (md->attribute & EFI_MEMORY_WB);
 172         default:
 173                 break;
 174         }
 175         return false;
 176 }
 177
 178 static __init void reserve_regions(void)
 179 {
 180         efi_memory_desc_t *md;
 181         u64 paddr, npages, size;
 182
 183         if (efi_enabled(EFI_DBG))
 184                 pr_info("Processing EFI memory map:\n");
 185
 186         /*
 187          * Discard memblocks discovered so far: if there are any at this
 188          * point, they originate from memory nodes in the DT, and UEFI
 189          * uses its own memory map instead.
 190          */
 191         memblock_dump_all();
 192         memblock_remove(0, (phys_addr_t)ULLONG_MAX);
 193
 194         for_each_efi_memory_desc(md) {
 195                 paddr = md->phys_addr;
 196                 npages = md->num_pages;
 197
 198                 if (efi_enabled(EFI_DBG)) {
 199                         char buf[64];
 200
 201                         pr_info("  0x%012llx-0x%012llx %s\n",
 202                                 paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
 203                                 efi_md_typeattr_format(buf, sizeof(buf), md));
 204                 }
 205
 206                 memrange_efi_to_native(&paddr, &npages);
 207                 size = npages << PAGE_SHIFT;
 208
 209                 if (is_memory(md)) {
 210                         early_init_dt_add_memory_arch(paddr, size);
 211
 212                         if (!is_usable_memory(md))
 213                                 memblock_mark_nomap(paddr, size);
 214                 }
 215         }
 216 }
 217
 218 void __init efi_init(void)
 219 {
 220         struct efi_memory_map_data data;
 221         struct efi_fdt_params params;
 222
 223         /* Grab UEFI information placed in FDT by stub */
 224         if (!efi_get_fdt_params(&params))
 225                 return;
 226
 227         efi_system_table = params.system_table;
 228
 229         data.desc_version = params.desc_ver;
 230         data.desc_size = params.desc_size;
 231         data.size = params.mmap_size;
 232         data.phys_map = params.mmap;
 233
 234         if (efi_memmap_init_early(&data) < 0) {
 235                 /*
 236                 * If we are booting via UEFI, the UEFI memory map is the only
 237                 * description of memory we have, so there is little point in
 238                 * proceeding if we cannot access it.
 239                 */
 240                 panic("Unable to map EFI memory map.\n");
 241         }
 242
 243         WARN(efi.memmap.desc_version != 1,
 244              "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
 245               efi.memmap.desc_version);
 246
 247         if (uefi_init() < 0) {
 248                 efi_memmap_unmap();
 249                 return;
 250         }
 251
 252         reserve_regions();
 253         efi_esrt_init();
 254         efi_memmap_unmap();
 255
 256         memblock_reserve(params.mmap & PAGE_MASK,
 257                          PAGE_ALIGN(params.mmap_size +
 258                                     (params.mmap & ~PAGE_MASK)));
 259
 260         init_screen_info();
 261 }
 262
 263 static int __init register_gop_device(void)
 264 {
 265         void *pd;
 266
 267         if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
 268                 return 0;
 269
 270         pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
 271                                            &screen_info, sizeof(screen_info));
 272         return PTR_ERR_OR_ZERO(pd);
 273 }
 274 subsys_initcall(register_gop_device);