LXR linux/arch/x86/include/asm/e820/types.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_E820_TYPES_H
   3#define _ASM_E820_TYPES_H
   4
   5#include <uapi/asm/bootparam.h>
   6
   7/*
   8 * These are the E820 types known to the kernel:
   9 */
  10enum e820_type {
  11        E820_TYPE_RAM           = 1,
  12        E820_TYPE_RESERVED      = 2,
  13        E820_TYPE_ACPI          = 3,
  14        E820_TYPE_NVS           = 4,
  15        E820_TYPE_UNUSABLE      = 5,
  16        E820_TYPE_PMEM          = 7,
  17
  18        /*
  19         * This is a non-standardized way to represent ADR or
  20         * NVDIMM regions that persist over a reboot.
  21         *
  22         * The kernel will ignore their special capabilities
  23         * unless the CONFIG_X86_PMEM_LEGACY=y option is set.
  24         *
  25         * ( Note that older platforms also used 6 for the same
  26         *   type of memory, but newer versions switched to 12 as
  27         *   6 was assigned differently. Some time they will learn... )
  28         */
  29        E820_TYPE_PRAM          = 12,
  30
  31        /*
  32         * Special-purpose memory is indicated to the system via the
  33         * EFI_MEMORY_SP attribute. Define an e820 translation of this
  34         * memory type for the purpose of reserving this range and
  35         * marking it with the IORES_DESC_SOFT_RESERVED designation.
  36         */
  37        E820_TYPE_SOFT_RESERVED = 0xefffffff,
  38
  39        /*
  40         * Reserved RAM used by the kernel itself if
  41         * CONFIG_INTEL_TXT=y is enabled, memory of this type
  42         * will be included in the S3 integrity calculation
  43         * and so should not include any memory that the BIOS
  44         * might alter over the S3 transition:
  45         */
  46        E820_TYPE_RESERVED_KERN = 128,
  47};
  48
  49/*
  50 * A single E820 map entry, describing a memory range of [addr...addr+size-1],
  51 * of 'type' memory type:
  52 *
  53 * (We pack it because there can be thousands of them on large systems.)
  54 */
  55struct e820_entry {
  56        u64                     addr;
  57        u64                     size;
  58        enum e820_type          type;
  59} __attribute__((packed));
  60
  61/*
  62 * The legacy E820 BIOS limits us to 128 (E820_MAX_ENTRIES_ZEROPAGE) nodes
  63 * due to the constrained space in the zeropage.
  64 *
  65 * On large systems we can easily have thousands of nodes with RAM,
  66 * which cannot be fit into so few entries - so we have a mechanism
  67 * to extend the e820 table size at build-time, via the E820_MAX_ENTRIES
  68 * define below.
  69 *
  70 * ( Those extra entries are enumerated via the EFI memory map, not
  71 *   via the legacy zeropage mechanism. )
  72 *
  73 * Size our internal memory map tables to have room for these additional
  74 * entries, based on a heuristic calculation: up to three entries per
  75 * NUMA node, plus E820_MAX_ENTRIES_ZEROPAGE for some extra space.
  76 *
  77 * This allows for bootstrap/firmware quirks such as possible duplicate
  78 * E820 entries that might need room in the same arrays, prior to the
  79 * call to e820__update_table() to remove duplicates.  The allowance
  80 * of three memory map entries per node is "enough" entries for
  81 * the initial hardware platform motivating this mechanism to make
  82 * use of additional EFI map entries.  Future platforms may want
  83 * to allow more than three entries per node or otherwise refine
  84 * this size.
  85 */
  86
  87#include <linux/numa.h>
  88
  89#define E820_MAX_ENTRIES        (E820_MAX_ENTRIES_ZEROPAGE + 3*MAX_NUMNODES)
  90
  91/*
  92 * The whole array of E820 entries:
  93 */
  94struct e820_table {
  95        __u32 nr_entries;
  96        struct e820_entry entries[E820_MAX_ENTRIES];
  97};
  98
  99/*
 100 * Various well-known legacy memory ranges in physical memory:
 101 */
 102#define ISA_START_ADDRESS       0x000a0000
 103#define ISA_END_ADDRESS         0x00100000
 104
 105#define BIOS_BEGIN              0x000a0000
 106#define BIOS_END                0x00100000
 107
 108#define HIGH_MEMORY             0x00100000
 109
 110#define BIOS_ROM_BASE           0xffe00000
 111#define BIOS_ROM_END            0xffffffff
 112
 113#endif /* _ASM_E820_TYPES_H */
 114