LXR linux/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
  27u64 efi_system_table;
  28
  29static 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 */
  41static 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
  58static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
  59
  60static __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
  65static 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
  88static 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);
 149out:
 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 */
 157static __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
 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_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
 218void __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                return;
 249
 250        reserve_regions();
 251        efi_memattr_init();
 252        efi_esrt_init();
 253        efi_memmap_unmap();
 254
 255        memblock_reserve(params.mmap & PAGE_MASK,
 256                         PAGE_ALIGN(params.mmap_size +
 257                                    (params.mmap & ~PAGE_MASK)));
 258
 259        init_screen_info();
 260}
 261
 262static int __init register_gop_device(void)
 263{
 264        void *pd;
 265
 266        if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
 267                return 0;
 268
 269        pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
 270                                           &screen_info, sizeof(screen_info));
 271        return PTR_ERR_OR_ZERO(pd);
 272}
 273subsys_initcall(register_gop_device);
 274