303 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * File attributes for Mediated devices4 *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 17struct 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 31static 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 43static 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 56static const struct sysfs_ops mdev_type_sysfs_ops = {57 .show = mdev_type_attr_show,58 .store = mdev_type_attr_store,59};60 61static 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}87static MDEV_TYPE_ATTR_WO(create);88 89static 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}94static MDEV_TYPE_ATTR_RO(device_api);95 96static ssize_t name_show(struct mdev_type *mtype,97 struct mdev_type_attribute *attr, char *buf)98{99 return sysfs_emit(buf, "%s\n",100 mtype->pretty_name ? mtype->pretty_name : mtype->sysfs_name);101}102 103static MDEV_TYPE_ATTR_RO(name);104 105static 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}116static MDEV_TYPE_ATTR_RO(available_instances);117 118static 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}124static MDEV_TYPE_ATTR_RO(description);125 126static 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 135static 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 144static struct attribute_group mdev_type_core_group = {145 .attrs = mdev_types_core_attrs,146 .is_visible = mdev_types_core_is_visible,147};148 149static const struct attribute_group *mdev_type_groups[] = {150 &mdev_type_core_group,151 NULL,152};153 154static 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 163static const 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 169static 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 194attr_devices_failed:195 kobject_del(&type->kobj);196 kobject_put(&type->kobj);197 return ret;198}199 200static 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 */208void 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 217int 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 233out_err:234 while (--i >= 0)235 mdev_type_remove(parent->types[i]);236 kset_unregister(parent->mdev_types_kset);237 return ret;238}239 240static ssize_t remove_store(struct device *dev, struct device_attribute *attr,241 const char *buf, size_t count)242{243 struct mdev_device *mdev = to_mdev_device(dev);244 unsigned long val;245 246 if (kstrtoul(buf, 0, &val) < 0)247 return -EINVAL;248 249 if (val && device_remove_file_self(dev, attr)) {250 int ret;251 252 ret = mdev_device_remove(mdev);253 if (ret)254 return ret;255 }256 257 return count;258}259 260static DEVICE_ATTR_WO(remove);261 262static struct attribute *mdev_device_attrs[] = {263 &dev_attr_remove.attr,264 NULL,265};266 267static const struct attribute_group mdev_device_group = {268 .attrs = mdev_device_attrs,269};270 271const struct attribute_group *mdev_device_groups[] = {272 &mdev_device_group,273 NULL274};275 276int mdev_create_sysfs_files(struct mdev_device *mdev)277{278 struct mdev_type *type = mdev->type;279 struct kobject *kobj = &mdev->dev.kobj;280 int ret;281 282 ret = sysfs_create_link(type->devices_kobj, kobj, dev_name(&mdev->dev));283 if (ret)284 return ret;285 286 ret = sysfs_create_link(kobj, &type->kobj, "mdev_type");287 if (ret)288 goto type_link_failed;289 return ret;290 291type_link_failed:292 sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));293 return ret;294}295 296void mdev_remove_sysfs_files(struct mdev_device *mdev)297{298 struct kobject *kobj = &mdev->dev.kobj;299 300 sysfs_remove_link(kobj, "mdev_type");301 sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));302}303