drivers/firmware/efi/arm-init.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Extensible Firmware Interface
   4  *
   5  * Based on Extensible Firmware Interface Specification version 2.4
   6  *
   7  * Copyright (C) 2013 - 2015 Linaro Ltd.
   8  */
   9
  10 #define pr_fmt(fmt)     "efi: " fmt
  11
  12 #include <linux/efi.h>
  13 #include <linux/init.h>
  14 #include <linux/memblock.h>
  15 #include <linux/mm_types.h>
  16 #include <linux/of.h>
  17 #include <linux/of_fdt.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/screen_info.h>
  20
  21 #include <asm/efi.h>
  22
  23 u64 efi_system_table;
  24
  25 static int __init is_memory(efi_memory_desc_t *md)
  26 {
  27         if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
  28                 return 1;
  29         return 0;
  30 }
  31
  32 /*
  33  * Translate a EFI virtual address into a physical address: this is necessary,
  34  * as some data members of the EFI system table are virtually remapped after
  35  * SetVirtualAddressMap() has been called.
  36  */
  37 static phys_addr_t efi_to_phys(unsigned long addr)
  38 {
  39         efi_memory_desc_t *md;
  40
  41         for_each_efi_memory_desc(md) {
  42                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
  43                         continue;
  44                 if (md->virt_addr == 0)
  45                         /* no virtual mapping has been installed by the stub */
  46                         break;
  47                 if (md->virt_addr <= addr &&
  48                     (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
  49                         return md->phys_addr + addr - md->virt_addr;
  50         }
  51         return addr;
  52 }
  53
  54 static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
  55
  56 static __initdata efi_config_table_type_t arch_tables[] = {
  57         {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
  58         {NULL_GUID, NULL, NULL}
  59 };
  60
  61 static void __init init_screen_info(void)
  62 {
  63         struct screen_info *si;
  64
  65         if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
  66                 si = early_memremap_ro(screen_info_table, sizeof(*si));
  67                 if (!si) {
  68                         pr_err("Could not map screen_info config table\n");
  69                         return;
  70                 }
  71                 screen_info = *si;
  72                 early_memunmap(si, sizeof(*si));
  73
  74                 /* dummycon on ARM needs non-zero values for columns/lines */
  75                 screen_info.orig_video_cols = 80;
  76                 screen_info.orig_video_lines = 25;
  77         }
  78
  79         if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
  80             memblock_is_map_memory(screen_info.lfb_base))
  81                 memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
  82 }
  83
  84 static int __init uefi_init(void)
  85 {
  86         efi_char16_t *c16;
  87         void *config_tables;
  88         size_t table_size;
  89         char vendor[100] = "unknown";
  90         int i, retval;
  91
  92         efi.systab = early_memremap_ro(efi_system_table,
  93                                        sizeof(efi_system_table_t));
  94         if (efi.systab == NULL) {
  95                 pr_warn("Unable to map EFI system table.\n");
  96                 return -ENOMEM;
  97         }
  98
  99         set_bit(EFI_BOOT, &efi.flags);
 100         if (IS_ENABLED(CONFIG_64BIT))
 101                 set_bit(EFI_64BIT, &efi.flags);
 102
 103         /*
 104          * Verify the EFI Table
 105          */
 106         if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 107                 pr_err("System table signature incorrect\n");
 108                 retval = -EINVAL;
 109                 goto out;
 110         }
 111         if ((efi.systab->hdr.revision >> 16) < 2)
 112                 pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
 113                         efi.systab->hdr.revision >> 16,
 114                         efi.systab->hdr.revision & 0xffff);
 115
 116         efi.runtime_version = efi.systab->hdr.revision;
 117
 118         /* Show what we know for posterity */
 119         c16 = early_memremap_ro(efi_to_phys(efi.systab->fw_vendor),
 120                                 sizeof(vendor) * sizeof(efi_char16_t));
 121         if (c16) {
 122                 for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
 123                         vendor[i] = c16[i];
 124                 vendor[i] = '\0';
 125                 early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
 126         }
 127
 128         pr_info("EFI v%u.%.02u by %s\n",
 129                 efi.systab->hdr.revision >> 16,
 130                 efi.systab->hdr.revision & 0xffff, vendor);
 131
 132         table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
 133         config_tables = early_memremap_ro(efi_to_phys(efi.systab->tables),
 134                                           table_size);
 135         if (config_tables == NULL) {
 136                 pr_warn("Unable to map EFI config table array.\n");
 137                 retval = -ENOMEM;
 138                 goto out;
 139         }
 140         retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
 141                                          sizeof(efi_config_table_t),
 142                                          arch_tables);
 143
 144         if (!retval)
 145                 efi.config_table = (unsigned long)efi.systab->tables;
 146
 147         early_memunmap(config_tables, table_size);
 148 out:
 149         early_memunmap(efi.systab,  sizeof(efi_system_table_t));
 150         return retval;
 151 }
 152
 153 /*
 154  * Return true for regions that can be used as System RAM.
 155  */
 156 static __init int is_usable_memory(efi_memory_desc_t *md)
 157 {
 158         switch (md->type) {
 159         case EFI_LOADER_CODE:
 160         case EFI_LOADER_DATA:
 161         case EFI_ACPI_RECLAIM_MEMORY:
 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_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                         /* keep ACPI reclaim memory intact for kexec etc. */
 216                         if (md->type == EFI_ACPI_RECLAIM_MEMORY)
 217                                 memblock_reserve(paddr, size);
 218                 }
 219         }
 220 }
 221
 222 void __init efi_init(void)
 223 {
 224         struct efi_memory_map_data data;
 225         struct efi_fdt_params params;
 226
 227         /* Grab UEFI information placed in FDT by stub */
 228         if (!efi_get_fdt_params(&params))
 229                 return;
 230
 231         efi_system_table = params.system_table;
 232
 233         data.desc_version = params.desc_ver;
 234         data.desc_size = params.desc_size;
 235         data.size = params.mmap_size;
 236         data.phys_map = params.mmap;
 237
 238         if (efi_memmap_init_early(&data) < 0) {
 239                 /*
 240                 * If we are booting via UEFI, the UEFI memory map is the only
 241                 * description of memory we have, so there is little point in
 242                 * proceeding if we cannot access it.
 243                 */
 244                 panic("Unable to map EFI memory map.\n");
 245         }
 246
 247         WARN(efi.memmap.desc_version != 1,
 248              "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
 249               efi.memmap.desc_version);
 250
 251         if (uefi_init() < 0) {
 252                 efi_memmap_unmap();
 253                 return;
 254         }
 255
 256         reserve_regions();
 257         efi_esrt_init();
 258
 259         memblock_reserve(params.mmap & PAGE_MASK,
 260                          PAGE_ALIGN(params.mmap_size +
 261                                     (params.mmap & ~PAGE_MASK)));
 262
 263         init_screen_info();
 264
 265         /* ARM does not permit early mappings to persist across paging_init() */
 266         if (IS_ENABLED(CONFIG_ARM))
 267                 efi_memmap_unmap();
 268 }
 269
 270 static int __init register_gop_device(void)
 271 {
 272         void *pd;
 273
 274         if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
 275                 return 0;
 276
 277         pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
 278                                            &screen_info, sizeof(screen_info));
 279         return PTR_ERR_OR_ZERO(pd);
 280 }
 281 subsys_initcall(register_gop_device);