drivers/vfio/mdev/mdev_sysfs.c

   1 /*
   2  * File attributes for Mediated devices
   3  *
   4  * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
   5  *     Author: Neo Jia <cjia@nvidia.com>
   6  *             Kirti Wankhede <kwankhede@nvidia.com>
   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 #include <linux/sysfs.h>
  14 #include <linux/ctype.h>
  15 #include <linux/device.h>
  16 #include <linux/slab.h>
  17 #include <linux/uuid.h>
  18 #include <linux/mdev.h>
  19
  20 #include "mdev_private.h"
  21
  22 /* Static functions */
  23
  24 static ssize_t mdev_type_attr_show(struct kobject *kobj,
  25                                      struct attribute *__attr, char *buf)
  26 {
  27         struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
  28         struct mdev_type *type = to_mdev_type(kobj);
  29         ssize_t ret = -EIO;
  30
  31         if (attr->show)
  32                 ret = attr->show(kobj, type->parent->dev, buf);
  33         return ret;
  34 }
  35
  36 static ssize_t mdev_type_attr_store(struct kobject *kobj,
  37                                       struct attribute *__attr,
  38                                       const char *buf, size_t count)
  39 {
  40         struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
  41         struct mdev_type *type = to_mdev_type(kobj);
  42         ssize_t ret = -EIO;
  43
  44         if (attr->store)
  45                 ret = attr->store(&type->kobj, type->parent->dev, buf, count);
  46         return ret;
  47 }
  48
  49 static const struct sysfs_ops mdev_type_sysfs_ops = {
  50         .show = mdev_type_attr_show,
  51         .store = mdev_type_attr_store,
  52 };
  53
  54 static ssize_t create_store(struct kobject *kobj, struct device *dev,
  55                             const char *buf, size_t count)
  56 {
  57         char *str;
  58         uuid_le uuid;
  59         int ret;
  60
  61         if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
  62                 return -EINVAL;
  63
  64         str = kstrndup(buf, count, GFP_KERNEL);
  65         if (!str)
  66                 return -ENOMEM;
  67
  68         ret = uuid_le_to_bin(str, &uuid);
  69         kfree(str);
  70         if (ret)
  71                 return ret;
  72
  73         ret = mdev_device_create(kobj, dev, uuid);
  74         if (ret)
  75                 return ret;
  76
  77         return count;
  78 }
  79
  80 MDEV_TYPE_ATTR_WO(create);
  81
  82 static void mdev_type_release(struct kobject *kobj)
  83 {
  84         struct mdev_type *type = to_mdev_type(kobj);
  85
  86         pr_debug("Releasing group %s\n", kobj->name);
  87         kfree(type);
  88 }
  89
  90 static struct kobj_type mdev_type_ktype = {
  91         .sysfs_ops = &mdev_type_sysfs_ops,
  92         .release = mdev_type_release,
  93 };
  94
  95 struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
  96                                           struct attribute_group *group)
  97 {
  98         struct mdev_type *type;
  99         int ret;
 100
 101         if (!group->name) {
 102                 pr_err("%s: Type name empty!\n", __func__);
 103                 return ERR_PTR(-EINVAL);
 104         }
 105
 106         type = kzalloc(sizeof(*type), GFP_KERNEL);
 107         if (!type)
 108                 return ERR_PTR(-ENOMEM);
 109
 110         type->kobj.kset = parent->mdev_types_kset;
 111
 112         ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,
 113                                    "%s-%s", dev_driver_string(parent->dev),
 114                                    group->name);
 115         if (ret) {
 116                 kfree(type);
 117                 return ERR_PTR(ret);
 118         }
 119
 120         ret = sysfs_create_file(&type->kobj, &mdev_type_attr_create.attr);
 121         if (ret)
 122                 goto attr_create_failed;
 123
 124         type->devices_kobj = kobject_create_and_add("devices", &type->kobj);
 125         if (!type->devices_kobj) {
 126                 ret = -ENOMEM;
 127                 goto attr_devices_failed;
 128         }
 129
 130         ret = sysfs_create_files(&type->kobj,
 131                                  (const struct attribute **)group->attrs);
 132         if (ret) {
 133                 ret = -ENOMEM;
 134                 goto attrs_failed;
 135         }
 136
 137         type->group = group;
 138         type->parent = parent;
 139         return type;
 140
 141 attrs_failed:
 142         kobject_put(type->devices_kobj);
 143 attr_devices_failed:
 144         sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
 145 attr_create_failed:
 146         kobject_del(&type->kobj);
 147         kobject_put(&type->kobj);
 148         return ERR_PTR(ret);
 149 }
 150
 151 static void remove_mdev_supported_type(struct mdev_type *type)
 152 {
 153         sysfs_remove_files(&type->kobj,
 154                            (const struct attribute **)type->group->attrs);
 155         kobject_put(type->devices_kobj);
 156         sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
 157         kobject_del(&type->kobj);
 158         kobject_put(&type->kobj);
 159 }
 160
 161 static int add_mdev_supported_type_groups(struct mdev_parent *parent)
 162 {
 163         int i;
 164
 165         for (i = 0; parent->ops->supported_type_groups[i]; i++) {
 166                 struct mdev_type *type;
 167
 168                 type = add_mdev_supported_type(parent,
 169                                         parent->ops->supported_type_groups[i]);
 170                 if (IS_ERR(type)) {
 171                         struct mdev_type *ltype, *tmp;
 172
 173                         list_for_each_entry_safe(ltype, tmp, &parent->type_list,
 174                                                   next) {
 175                                 list_del(&ltype->next);
 176                                 remove_mdev_supported_type(ltype);
 177                         }
 178                         return PTR_ERR(type);
 179                 }
 180                 list_add(&type->next, &parent->type_list);
 181         }
 182         return 0;
 183 }
 184
 185 /* mdev sysfs functions */
 186 void parent_remove_sysfs_files(struct mdev_parent *parent)
 187 {
 188         struct mdev_type *type, *tmp;
 189
 190         list_for_each_entry_safe(type, tmp, &parent->type_list, next) {
 191                 list_del(&type->next);
 192                 remove_mdev_supported_type(type);
 193         }
 194
 195         sysfs_remove_groups(&parent->dev->kobj, parent->ops->dev_attr_groups);
 196         kset_unregister(parent->mdev_types_kset);
 197 }
 198
 199 int parent_create_sysfs_files(struct mdev_parent *parent)
 200 {
 201         int ret;
 202
 203         parent->mdev_types_kset = kset_create_and_add("mdev_supported_types",
 204                                                NULL, &parent->dev->kobj);
 205
 206         if (!parent->mdev_types_kset)
 207                 return -ENOMEM;
 208
 209         INIT_LIST_HEAD(&parent->type_list);
 210
 211         ret = sysfs_create_groups(&parent->dev->kobj,
 212                                   parent->ops->dev_attr_groups);
 213         if (ret)
 214                 goto create_err;
 215
 216         ret = add_mdev_supported_type_groups(parent);
 217         if (ret)
 218                 sysfs_remove_groups(&parent->dev->kobj,
 219                                     parent->ops->dev_attr_groups);
 220         else
 221                 return ret;
 222
 223 create_err:
 224         kset_unregister(parent->mdev_types_kset);
 225         return ret;
 226 }
 227
 228 static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
 229                             const char *buf, size_t count)
 230 {
 231         unsigned long val;
 232
 233         if (kstrtoul(buf, 0, &val) < 0)
 234                 return -EINVAL;
 235
 236         if (val && device_remove_file_self(dev, attr)) {
 237                 int ret;
 238
 239                 ret = mdev_device_remove(dev, false);
 240                 if (ret) {
 241                         device_create_file(dev, attr);
 242                         return ret;
 243                 }
 244         }
 245
 246         return count;
 247 }
 248
 249 static DEVICE_ATTR_WO(remove);
 250
 251 static const struct attribute *mdev_device_attrs[] = {
 252         &dev_attr_remove.attr,
 253         NULL,
 254 };
 255
 256 int  mdev_create_sysfs_files(struct device *dev, struct mdev_type *type)
 257 {
 258         int ret;
 259
 260         ret = sysfs_create_link(type->devices_kobj, &dev->kobj, dev_name(dev));
 261         if (ret)
 262                 return ret;
 263
 264         ret = sysfs_create_link(&dev->kobj, &type->kobj, "mdev_type");
 265         if (ret)
 266                 goto type_link_failed;
 267
 268         ret = sysfs_create_files(&dev->kobj, mdev_device_attrs);
 269         if (ret)
 270                 goto create_files_failed;
 271
 272         return ret;
 273
 274 create_files_failed:
 275         sysfs_remove_link(&dev->kobj, "mdev_type");
 276 type_link_failed:
 277         sysfs_remove_link(type->devices_kobj, dev_name(dev));
 278         return ret;
 279 }
 280
 281 void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type)
 282 {
 283         sysfs_remove_link(&dev->kobj, "mdev_type");
 284         sysfs_remove_link(type->devices_kobj, dev_name(dev));
 285         sysfs_remove_files(&dev->kobj, mdev_device_attrs);
 286 }