+static void mmc_host_classdev_release(struct class_device *dev)
+{
+ struct mmc_host *host = cls_dev_to_mmc_host(dev);
+ kfree(host);
+}
+
+static struct class mmc_host_class = {
+ .name = "mmc_host",
+ .release = mmc_host_classdev_release,
+};
+
+static DEFINE_IDR(mmc_host_idr);
+static DEFINE_SPINLOCK(mmc_host_lock);
+
+/*
+ * Internal function. Allocate a new MMC host.
+ */
+struct mmc_host *mmc_alloc_host_sysfs(int extra, struct device *dev)
+{
+ struct mmc_host *host;
+
+ host = kmalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
+ if (host) {
+ memset(host, 0, sizeof(struct mmc_host) + extra);
+
+ host->dev = dev;
+ host->class_dev.dev = host->dev;
+ host->class_dev.class = &mmc_host_class;
+ class_device_initialize(&host->class_dev);
+ }
+
+ return host;
+}
+
+/*
+ * Internal function. Register a new MMC host with the MMC class.
+ */
+int mmc_add_host_sysfs(struct mmc_host *host)
+{
+ int err;
+
+ if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
+ return -ENOMEM;
+
+ spin_lock(&mmc_host_lock);
+ err = idr_get_new(&mmc_host_idr, host, &host->index);
+ spin_unlock(&mmc_host_lock);
+ if (err)
+ return err;
+
+ snprintf(host->class_dev.class_id, BUS_ID_SIZE,
+ "mmc%d", host->index);
+
+ return class_device_add(&host->class_dev);
+}
+
+/*
+ * Internal function. Unregister a MMC host with the MMC class.
+ */
+void mmc_remove_host_sysfs(struct mmc_host *host)
+{
+ class_device_del(&host->class_dev);
+
+ spin_lock(&mmc_host_lock);
+ idr_remove(&mmc_host_idr, host->index);
+ spin_unlock(&mmc_host_lock);
+}
+
+/*
+ * Internal function. Free a MMC host.
+ */
+void mmc_free_host_sysfs(struct mmc_host *host)
+{
+ class_device_put(&host->class_dev);
+}
+
+