drivers/vfio/mdev/mdev_sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * File attributes for Mediated devices
   4  *
   5  * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
   6  *     Author: Neo Jia <cjia@nvidia.com>
   7  *             Kirti Wankhede <kwankhede@nvidia.com>
   8  */
   9
  10 #include <linux/sysfs.h>
  11 #include <linux/ctype.h>
  12 #include <linux/slab.h>
  13 #include <linux/mdev.h>
  14
  15 #include "mdev_private.h"
  16
  17 struct mdev_type_attribute {
  18         struct attribute attr;
  19         ssize_t (*show)(struct mdev_type *mtype,
  20                         struct mdev_type_attribute *attr, char *buf);
  21         ssize_t (*store)(struct mdev_type *mtype,
  22                          struct mdev_type_attribute *attr, const char *buf,
  23                          size_t count);
  24 };
  25
  26 #define MDEV_TYPE_ATTR_RO(_name) \
  27         struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
  28 #define MDEV_TYPE_ATTR_WO(_name) \
  29         struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
  30
  31 static ssize_t mdev_type_attr_show(struct kobject *kobj,
  32                                      struct attribute *__attr, char *buf)
  33 {
  34         struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
  35         struct mdev_type *type = to_mdev_type(kobj);
  36         ssize_t ret = -EIO;
  37
  38         if (attr->show)
  39                 ret = attr->show(type, attr, buf);
  40         return ret;
  41 }
  42
  43 static ssize_t mdev_type_attr_store(struct kobject *kobj,
  44                                       struct attribute *__attr,
  45                                       const char *buf, size_t count)
  46 {
  47         struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
  48         struct mdev_type *type = to_mdev_type(kobj);
  49         ssize_t ret = -EIO;
  50
  51         if (attr->store)
  52                 ret = attr->store(type, attr, buf, count);
  53         return ret;
  54 }
  55
  56 static const struct sysfs_ops mdev_type_sysfs_ops = {
  57         .show = mdev_type_attr_show,
  58         .store = mdev_type_attr_store,
  59 };
  60
  61 static ssize_t create_store(struct mdev_type *mtype,
  62                             struct mdev_type_attribute *attr, const char *buf,
  63                             size_t count)
  64 {
  65         char *str;
  66         guid_t uuid;
  67         int ret;
  68
  69         if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
  70                 return -EINVAL;
  71
  72         str = kstrndup(buf, count, GFP_KERNEL);
  73         if (!str)
  74                 return -ENOMEM;
  75
  76         ret = guid_parse(str, &uuid);
  77         kfree(str);
  78         if (ret)
  79                 return ret;
  80
  81         ret = mdev_device_create(mtype, &uuid);
  82         if (ret)
  83                 return ret;
  84
  85         return count;
  86 }
  87 static MDEV_TYPE_ATTR_WO(create);
  88
  89 static ssize_t device_api_show(struct mdev_type *mtype,
  90                                struct mdev_type_attribute *attr, char *buf)
  91 {
  92         return sysfs_emit(buf, "%s\n", mtype->parent->mdev_driver->device_api);
  93 }
  94 static MDEV_TYPE_ATTR_RO(device_api);
  95
  96 static ssize_t name_show(struct mdev_type *mtype,
  97                          struct mdev_type_attribute *attr, char *buf)
  98 {
  99         return sprintf(buf, "%s\n",
 100                 mtype->pretty_name ? mtype->pretty_name : mtype->sysfs_name);
 101 }
 102
 103 static MDEV_TYPE_ATTR_RO(name);
 104
 105 static ssize_t available_instances_show(struct mdev_type *mtype,
 106                                         struct mdev_type_attribute *attr,
 107                                         char *buf)
 108 {
 109         struct mdev_driver *drv = mtype->parent->mdev_driver;
 110
 111         if (drv->get_available)
 112                 return sysfs_emit(buf, "%u\n", drv->get_available(mtype));
 113         return sysfs_emit(buf, "%u\n",
 114                           atomic_read(&mtype->parent->available_instances));
 115 }
 116 static MDEV_TYPE_ATTR_RO(available_instances);
 117
 118 static ssize_t description_show(struct mdev_type *mtype,
 119                                 struct mdev_type_attribute *attr,
 120                                 char *buf)
 121 {
 122         return mtype->parent->mdev_driver->show_description(mtype, buf);
 123 }
 124 static MDEV_TYPE_ATTR_RO(description);
 125
 126 static struct attribute *mdev_types_core_attrs[] = {
 127         &mdev_type_attr_create.attr,
 128         &mdev_type_attr_device_api.attr,
 129         &mdev_type_attr_name.attr,
 130         &mdev_type_attr_available_instances.attr,
 131         &mdev_type_attr_description.attr,
 132         NULL,
 133 };
 134
 135 static umode_t mdev_types_core_is_visible(struct kobject *kobj,
 136                                           struct attribute *attr, int n)
 137 {
 138         if (attr == &mdev_type_attr_description.attr &&
 139             !to_mdev_type(kobj)->parent->mdev_driver->show_description)
 140                 return 0;
 141         return attr->mode;
 142 }
 143
 144 static struct attribute_group mdev_type_core_group = {
 145         .attrs = mdev_types_core_attrs,
 146         .is_visible = mdev_types_core_is_visible,
 147 };
 148
 149 static const struct attribute_group *mdev_type_groups[] = {
 150         &mdev_type_core_group,
 151         NULL,
 152 };
 153
 154 static void mdev_type_release(struct kobject *kobj)
 155 {
 156         struct mdev_type *type = to_mdev_type(kobj);
 157
 158         pr_debug("Releasing group %s\n", kobj->name);
 159         /* Pairs with the get in add_mdev_supported_type() */
 160         put_device(type->parent->dev);
 161 }
 162
 163 static struct kobj_type mdev_type_ktype = {
 164         .sysfs_ops      = &mdev_type_sysfs_ops,
 165         .release        = mdev_type_release,
 166         .default_groups = mdev_type_groups,
 167 };
 168
 169 static int mdev_type_add(struct mdev_parent *parent, struct mdev_type *type)
 170 {
 171         int ret;
 172
 173         type->kobj.kset = parent->mdev_types_kset;
 174         type->parent = parent;
 175         /* Pairs with the put in mdev_type_release() */
 176         get_device(parent->dev);
 177
 178         ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,
 179                                    "%s-%s", dev_driver_string(parent->dev),
 180                                    type->sysfs_name);
 181         if (ret) {
 182                 kobject_put(&type->kobj);
 183                 return ret;
 184         }
 185
 186         type->devices_kobj = kobject_create_and_add("devices", &type->kobj);
 187         if (!type->devices_kobj) {
 188                 ret = -ENOMEM;
 189                 goto attr_devices_failed;
 190         }
 191
 192         return 0;
 193
 194 attr_devices_failed:
 195         kobject_del(&type->kobj);
 196         kobject_put(&type->kobj);
 197         return ret;
 198 }
 199
 200 static void mdev_type_remove(struct mdev_type *type)
 201 {
 202         kobject_put(type->devices_kobj);
 203         kobject_del(&type->kobj);
 204         kobject_put(&type->kobj);
 205 }
 206
 207 /* mdev sysfs functions */
 208 void parent_remove_sysfs_files(struct mdev_parent *parent)
 209 {
 210         int i;
 211
 212         for (i = 0; i < parent->nr_types; i++)
 213                 mdev_type_remove(parent->types[i]);
 214         kset_unregister(parent->mdev_types_kset);
 215 }
 216
 217 int parent_create_sysfs_files(struct mdev_parent *parent)
 218 {
 219         int ret, i;
 220
 221         parent->mdev_types_kset = kset_create_and_add("mdev_supported_types",
 222                                                NULL, &parent->dev->kobj);
 223         if (!parent->mdev_types_kset)
 224                 return -ENOMEM;
 225
 226         for (i = 0; i < parent->nr_types; i++) {
 227                 ret = mdev_type_add(parent, parent->types[i]);
 228                 if (ret)
 229                         goto out_err;
 230         }
 231         return 0;
 232
 233 out_err:
 234         while (--i >= 0)
 235                 mdev_type_remove(parent->types[i]);
 236         return 0;
 237 }
 238
 239 static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
 240                             const char *buf, size_t count)
 241 {
 242         struct mdev_device *mdev = to_mdev_device(dev);
 243         unsigned long val;
 244
 245         if (kstrtoul(buf, 0, &val) < 0)
 246                 return -EINVAL;
 247
 248         if (val && device_remove_file_self(dev, attr)) {
 249                 int ret;
 250
 251                 ret = mdev_device_remove(mdev);
 252                 if (ret)
 253                         return ret;
 254         }
 255
 256         return count;
 257 }
 258
 259 static DEVICE_ATTR_WO(remove);
 260
 261 static struct attribute *mdev_device_attrs[] = {
 262         &dev_attr_remove.attr,
 263         NULL,
 264 };
 265
 266 static const struct attribute_group mdev_device_group = {
 267         .attrs = mdev_device_attrs,
 268 };
 269
 270 const struct attribute_group *mdev_device_groups[] = {
 271         &mdev_device_group,
 272         NULL
 273 };
 274
 275 int mdev_create_sysfs_files(struct mdev_device *mdev)
 276 {
 277         struct mdev_type *type = mdev->type;
 278         struct kobject *kobj = &mdev->dev.kobj;
 279         int ret;
 280
 281         ret = sysfs_create_link(type->devices_kobj, kobj, dev_name(&mdev->dev));
 282         if (ret)
 283                 return ret;
 284
 285         ret = sysfs_create_link(kobj, &type->kobj, "mdev_type");
 286         if (ret)
 287                 goto type_link_failed;
 288         return ret;
 289
 290 type_link_failed:
 291         sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
 292         return ret;
 293 }
 294
 295 void mdev_remove_sysfs_files(struct mdev_device *mdev)
 296 {
 297         struct kobject *kobj = &mdev->dev.kobj;
 298
 299         sysfs_remove_link(kobj, "mdev_type");
 300         sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
 301 }