LXR linux/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
  23u64 efi_system_table;
  24
  25static 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 */
  37static 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
  54static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
  55
  56static __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
  61static 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
  84static 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);
 148out:
 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 */
 156static __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
 178static __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
 222void __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
 270static 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}
 281subsys_initcall(register_gop_device);
 282