linux/drivers/firmware/efi/runtime-map.c
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   1/*
   2 * linux/drivers/efi/runtime-map.c
   3 * Copyright (C) 2013 Red Hat, Inc., Dave Young <dyoung@redhat.com>
   4 *
   5 * This file is released under the GPLv2.
   6 */
   7
   8#include <linux/string.h>
   9#include <linux/kernel.h>
  10#include <linux/module.h>
  11#include <linux/types.h>
  12#include <linux/efi.h>
  13#include <linux/slab.h>
  14
  15#include <asm/setup.h>
  16
  17struct efi_runtime_map_entry {
  18        efi_memory_desc_t md;
  19        struct kobject kobj;   /* kobject for each entry */
  20};
  21
  22static struct efi_runtime_map_entry **map_entries;
  23
  24struct map_attribute {
  25        struct attribute attr;
  26        ssize_t (*show)(struct efi_runtime_map_entry *entry, char *buf);
  27};
  28
  29static inline struct map_attribute *to_map_attr(struct attribute *attr)
  30{
  31        return container_of(attr, struct map_attribute, attr);
  32}
  33
  34static ssize_t type_show(struct efi_runtime_map_entry *entry, char *buf)
  35{
  36        return snprintf(buf, PAGE_SIZE, "0x%x\n", entry->md.type);
  37}
  38
  39#define EFI_RUNTIME_FIELD(var) entry->md.var
  40
  41#define EFI_RUNTIME_U64_ATTR_SHOW(name) \
  42static ssize_t name##_show(struct efi_runtime_map_entry *entry, char *buf) \
  43{ \
  44        return snprintf(buf, PAGE_SIZE, "0x%llx\n", EFI_RUNTIME_FIELD(name)); \
  45}
  46
  47EFI_RUNTIME_U64_ATTR_SHOW(phys_addr);
  48EFI_RUNTIME_U64_ATTR_SHOW(virt_addr);
  49EFI_RUNTIME_U64_ATTR_SHOW(num_pages);
  50EFI_RUNTIME_U64_ATTR_SHOW(attribute);
  51
  52static inline struct efi_runtime_map_entry *to_map_entry(struct kobject *kobj)
  53{
  54        return container_of(kobj, struct efi_runtime_map_entry, kobj);
  55}
  56
  57static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr,
  58                              char *buf)
  59{
  60        struct efi_runtime_map_entry *entry = to_map_entry(kobj);
  61        struct map_attribute *map_attr = to_map_attr(attr);
  62
  63        return map_attr->show(entry, buf);
  64}
  65
  66static struct map_attribute map_type_attr = __ATTR_RO(type);
  67static struct map_attribute map_phys_addr_attr   = __ATTR_RO(phys_addr);
  68static struct map_attribute map_virt_addr_attr  = __ATTR_RO(virt_addr);
  69static struct map_attribute map_num_pages_attr  = __ATTR_RO(num_pages);
  70static struct map_attribute map_attribute_attr  = __ATTR_RO(attribute);
  71
  72/*
  73 * These are default attributes that are added for every memmap entry.
  74 */
  75static struct attribute *def_attrs[] = {
  76        &map_type_attr.attr,
  77        &map_phys_addr_attr.attr,
  78        &map_virt_addr_attr.attr,
  79        &map_num_pages_attr.attr,
  80        &map_attribute_attr.attr,
  81        NULL
  82};
  83
  84static const struct sysfs_ops map_attr_ops = {
  85        .show = map_attr_show,
  86};
  87
  88static void map_release(struct kobject *kobj)
  89{
  90        struct efi_runtime_map_entry *entry;
  91
  92        entry = to_map_entry(kobj);
  93        kfree(entry);
  94}
  95
  96static struct kobj_type __refdata map_ktype = {
  97        .sysfs_ops      = &map_attr_ops,
  98        .default_attrs  = def_attrs,
  99        .release        = map_release,
 100};
 101
 102static struct kset *map_kset;
 103
 104static struct efi_runtime_map_entry *
 105add_sysfs_runtime_map_entry(struct kobject *kobj, int nr,
 106                            efi_memory_desc_t *md)
 107{
 108        int ret;
 109        struct efi_runtime_map_entry *entry;
 110
 111        if (!map_kset) {
 112                map_kset = kset_create_and_add("runtime-map", NULL, kobj);
 113                if (!map_kset)
 114                        return ERR_PTR(-ENOMEM);
 115        }
 116
 117        entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 118        if (!entry) {
 119                kset_unregister(map_kset);
 120                map_kset = NULL;
 121                return ERR_PTR(-ENOMEM);
 122        }
 123
 124        memcpy(&entry->md, md, sizeof(efi_memory_desc_t));
 125
 126        kobject_init(&entry->kobj, &map_ktype);
 127        entry->kobj.kset = map_kset;
 128        ret = kobject_add(&entry->kobj, NULL, "%d", nr);
 129        if (ret) {
 130                kobject_put(&entry->kobj);
 131                kset_unregister(map_kset);
 132                map_kset = NULL;
 133                return ERR_PTR(ret);
 134        }
 135
 136        return entry;
 137}
 138
 139int efi_get_runtime_map_size(void)
 140{
 141        return efi.memmap.nr_map * efi.memmap.desc_size;
 142}
 143
 144int efi_get_runtime_map_desc_size(void)
 145{
 146        return efi.memmap.desc_size;
 147}
 148
 149int efi_runtime_map_copy(void *buf, size_t bufsz)
 150{
 151        size_t sz = efi_get_runtime_map_size();
 152
 153        if (sz > bufsz)
 154                sz = bufsz;
 155
 156        memcpy(buf, efi.memmap.map, sz);
 157        return 0;
 158}
 159
 160int __init efi_runtime_map_init(struct kobject *efi_kobj)
 161{
 162        int i, j, ret = 0;
 163        struct efi_runtime_map_entry *entry;
 164        efi_memory_desc_t *md;
 165
 166        if (!efi_enabled(EFI_MEMMAP))
 167                return 0;
 168
 169        map_entries = kzalloc(efi.memmap.nr_map * sizeof(entry), GFP_KERNEL);
 170        if (!map_entries) {
 171                ret = -ENOMEM;
 172                goto out;
 173        }
 174
 175        i = 0;
 176        for_each_efi_memory_desc(md) {
 177                entry = add_sysfs_runtime_map_entry(efi_kobj, i, md);
 178                if (IS_ERR(entry)) {
 179                        ret = PTR_ERR(entry);
 180                        goto out_add_entry;
 181                }
 182                *(map_entries + i++) = entry;
 183        }
 184
 185        return 0;
 186out_add_entry:
 187        for (j = i - 1; j >= 0; j--) {
 188                entry = *(map_entries + j);
 189                kobject_put(&entry->kobj);
 190        }
 191out:
 192        return ret;
 193}
 194