v4.19.13 snapshot.
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
new file mode 100644
index 0000000..4d77a6a
--- /dev/null
+++ b/drivers/misc/mei/main.c
@@ -0,0 +1,1022 @@
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2018, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ */
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/ioctl.h>
+#include <linux/cdev.h>
+#include <linux/sched/signal.h>
+#include <linux/uuid.h>
+#include <linux/compat.h>
+#include <linux/jiffies.h>
+#include <linux/interrupt.h>
+
+#include <linux/mei.h>
+
+#include "mei_dev.h"
+#include "client.h"
+
+/**
+ * mei_open - the open function
+ *
+ * @inode: pointer to inode structure
+ * @file: pointer to file structure
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int mei_open(struct inode *inode, struct file *file)
+{
+ struct mei_device *dev;
+ struct mei_cl *cl;
+
+ int err;
+
+ dev = container_of(inode->i_cdev, struct mei_device, cdev);
+ if (!dev)
+ return -ENODEV;
+
+ mutex_lock(&dev->device_lock);
+
+ if (dev->dev_state != MEI_DEV_ENABLED) {
+ dev_dbg(dev->dev, "dev_state != MEI_ENABLED dev_state = %s\n",
+ mei_dev_state_str(dev->dev_state));
+ err = -ENODEV;
+ goto err_unlock;
+ }
+
+ cl = mei_cl_alloc_linked(dev);
+ if (IS_ERR(cl)) {
+ err = PTR_ERR(cl);
+ goto err_unlock;
+ }
+
+ cl->fp = file;
+ file->private_data = cl;
+
+ mutex_unlock(&dev->device_lock);
+
+ return nonseekable_open(inode, file);
+
+err_unlock:
+ mutex_unlock(&dev->device_lock);
+ return err;
+}
+
+/**
+ * mei_release - the release function
+ *
+ * @inode: pointer to inode structure
+ * @file: pointer to file structure
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int mei_release(struct inode *inode, struct file *file)
+{
+ struct mei_cl *cl = file->private_data;
+ struct mei_device *dev;
+ int rets;
+
+ if (WARN_ON(!cl || !cl->dev))
+ return -ENODEV;
+
+ dev = cl->dev;
+
+ mutex_lock(&dev->device_lock);
+
+ rets = mei_cl_disconnect(cl);
+
+ mei_cl_flush_queues(cl, file);
+ cl_dbg(dev, cl, "removing\n");
+
+ mei_cl_unlink(cl);
+
+ file->private_data = NULL;
+
+ kfree(cl);
+
+ mutex_unlock(&dev->device_lock);
+ return rets;
+}
+
+
+/**
+ * mei_read - the read function.
+ *
+ * @file: pointer to file structure
+ * @ubuf: pointer to user buffer
+ * @length: buffer length
+ * @offset: data offset in buffer
+ *
+ * Return: >=0 data length on success , <0 on error
+ */
+static ssize_t mei_read(struct file *file, char __user *ubuf,
+ size_t length, loff_t *offset)
+{
+ struct mei_cl *cl = file->private_data;
+ struct mei_device *dev;
+ struct mei_cl_cb *cb = NULL;
+ bool nonblock = !!(file->f_flags & O_NONBLOCK);
+ ssize_t rets;
+
+ if (WARN_ON(!cl || !cl->dev))
+ return -ENODEV;
+
+ dev = cl->dev;
+
+
+ mutex_lock(&dev->device_lock);
+ if (dev->dev_state != MEI_DEV_ENABLED) {
+ rets = -ENODEV;
+ goto out;
+ }
+
+ if (length == 0) {
+ rets = 0;
+ goto out;
+ }
+
+ if (ubuf == NULL) {
+ rets = -EMSGSIZE;
+ goto out;
+ }
+
+ cb = mei_cl_read_cb(cl, file);
+ if (cb)
+ goto copy_buffer;
+
+ if (*offset > 0)
+ *offset = 0;
+
+ rets = mei_cl_read_start(cl, length, file);
+ if (rets && rets != -EBUSY) {
+ cl_dbg(dev, cl, "mei start read failure status = %zd\n", rets);
+ goto out;
+ }
+
+ if (nonblock) {
+ rets = -EAGAIN;
+ goto out;
+ }
+
+ mutex_unlock(&dev->device_lock);
+ if (wait_event_interruptible(cl->rx_wait,
+ !list_empty(&cl->rd_completed) ||
+ !mei_cl_is_connected(cl))) {
+ if (signal_pending(current))
+ return -EINTR;
+ return -ERESTARTSYS;
+ }
+ mutex_lock(&dev->device_lock);
+
+ if (!mei_cl_is_connected(cl)) {
+ rets = -ENODEV;
+ goto out;
+ }
+
+ cb = mei_cl_read_cb(cl, file);
+ if (!cb) {
+ rets = 0;
+ goto out;
+ }
+
+copy_buffer:
+ /* now copy the data to user space */
+ if (cb->status) {
+ rets = cb->status;
+ cl_dbg(dev, cl, "read operation failed %zd\n", rets);
+ goto free;
+ }
+
+ cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
+ cb->buf.size, cb->buf_idx, *offset);
+ if (*offset >= cb->buf_idx) {
+ rets = 0;
+ goto free;
+ }
+
+ /* length is being truncated to PAGE_SIZE,
+ * however buf_idx may point beyond that */
+ length = min_t(size_t, length, cb->buf_idx - *offset);
+
+ if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
+ dev_dbg(dev->dev, "failed to copy data to userland\n");
+ rets = -EFAULT;
+ goto free;
+ }
+
+ rets = length;
+ *offset += length;
+ /* not all data was read, keep the cb */
+ if (*offset < cb->buf_idx)
+ goto out;
+
+free:
+ mei_io_cb_free(cb);
+ *offset = 0;
+
+out:
+ cl_dbg(dev, cl, "end mei read rets = %zd\n", rets);
+ mutex_unlock(&dev->device_lock);
+ return rets;
+}
+/**
+ * mei_write - the write function.
+ *
+ * @file: pointer to file structure
+ * @ubuf: pointer to user buffer
+ * @length: buffer length
+ * @offset: data offset in buffer
+ *
+ * Return: >=0 data length on success , <0 on error
+ */
+static ssize_t mei_write(struct file *file, const char __user *ubuf,
+ size_t length, loff_t *offset)
+{
+ struct mei_cl *cl = file->private_data;
+ struct mei_cl_cb *cb;
+ struct mei_device *dev;
+ ssize_t rets;
+
+ if (WARN_ON(!cl || !cl->dev))
+ return -ENODEV;
+
+ dev = cl->dev;
+
+ mutex_lock(&dev->device_lock);
+
+ if (dev->dev_state != MEI_DEV_ENABLED) {
+ rets = -ENODEV;
+ goto out;
+ }
+
+ if (!mei_cl_is_connected(cl)) {
+ cl_err(dev, cl, "is not connected");
+ rets = -ENODEV;
+ goto out;
+ }
+
+ if (!mei_me_cl_is_active(cl->me_cl)) {
+ rets = -ENOTTY;
+ goto out;
+ }
+
+ if (length > mei_cl_mtu(cl)) {
+ rets = -EFBIG;
+ goto out;
+ }
+
+ if (length == 0) {
+ rets = 0;
+ goto out;
+ }
+
+ while (cl->tx_cb_queued >= dev->tx_queue_limit) {
+ if (file->f_flags & O_NONBLOCK) {
+ rets = -EAGAIN;
+ goto out;
+ }
+ mutex_unlock(&dev->device_lock);
+ rets = wait_event_interruptible(cl->tx_wait,
+ cl->writing_state == MEI_WRITE_COMPLETE ||
+ (!mei_cl_is_connected(cl)));
+ mutex_lock(&dev->device_lock);
+ if (rets) {
+ if (signal_pending(current))
+ rets = -EINTR;
+ goto out;
+ }
+ if (!mei_cl_is_connected(cl)) {
+ rets = -ENODEV;
+ goto out;
+ }
+ }
+
+ cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
+ if (!cb) {
+ rets = -ENOMEM;
+ goto out;
+ }
+
+ rets = copy_from_user(cb->buf.data, ubuf, length);
+ if (rets) {
+ dev_dbg(dev->dev, "failed to copy data from userland\n");
+ rets = -EFAULT;
+ mei_io_cb_free(cb);
+ goto out;
+ }
+
+ rets = mei_cl_write(cl, cb);
+out:
+ mutex_unlock(&dev->device_lock);
+ return rets;
+}
+
+/**
+ * mei_ioctl_connect_client - the connect to fw client IOCTL function
+ *
+ * @file: private data of the file object
+ * @data: IOCTL connect data, input and output parameters
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+static int mei_ioctl_connect_client(struct file *file,
+ struct mei_connect_client_data *data)
+{
+ struct mei_device *dev;
+ struct mei_client *client;
+ struct mei_me_client *me_cl;
+ struct mei_cl *cl;
+ int rets;
+
+ cl = file->private_data;
+ dev = cl->dev;
+
+ if (dev->dev_state != MEI_DEV_ENABLED)
+ return -ENODEV;
+
+ if (cl->state != MEI_FILE_INITIALIZING &&
+ cl->state != MEI_FILE_DISCONNECTED)
+ return -EBUSY;
+
+ /* find ME client we're trying to connect to */
+ me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
+ if (!me_cl) {
+ dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
+ &data->in_client_uuid);
+ rets = -ENOTTY;
+ goto end;
+ }
+
+ if (me_cl->props.fixed_address) {
+ bool forbidden = dev->override_fixed_address ?
+ !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
+ if (forbidden) {
+ dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
+ &data->in_client_uuid);
+ rets = -ENOTTY;
+ goto end;
+ }
+ }
+
+ dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
+ me_cl->client_id);
+ dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
+ me_cl->props.protocol_version);
+ dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
+ me_cl->props.max_msg_length);
+
+ /* prepare the output buffer */
+ client = &data->out_client_properties;
+ client->max_msg_length = me_cl->props.max_msg_length;
+ client->protocol_version = me_cl->props.protocol_version;
+ dev_dbg(dev->dev, "Can connect?\n");
+
+ rets = mei_cl_connect(cl, me_cl, file);
+
+end:
+ mei_me_cl_put(me_cl);
+ return rets;
+}
+
+/**
+ * mei_ioctl_client_notify_request -
+ * propagate event notification request to client
+ *
+ * @file: pointer to file structure
+ * @request: 0 - disable, 1 - enable
+ *
+ * Return: 0 on success , <0 on error
+ */
+static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
+{
+ struct mei_cl *cl = file->private_data;
+
+ if (request != MEI_HBM_NOTIFICATION_START &&
+ request != MEI_HBM_NOTIFICATION_STOP)
+ return -EINVAL;
+
+ return mei_cl_notify_request(cl, file, (u8)request);
+}
+
+/**
+ * mei_ioctl_client_notify_get - wait for notification request
+ *
+ * @file: pointer to file structure
+ * @notify_get: 0 - disable, 1 - enable
+ *
+ * Return: 0 on success , <0 on error
+ */
+static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
+{
+ struct mei_cl *cl = file->private_data;
+ bool notify_ev;
+ bool block = (file->f_flags & O_NONBLOCK) == 0;
+ int rets;
+
+ rets = mei_cl_notify_get(cl, block, ¬ify_ev);
+ if (rets)
+ return rets;
+
+ *notify_get = notify_ev ? 1 : 0;
+ return 0;
+}
+
+/**
+ * mei_ioctl - the IOCTL function
+ *
+ * @file: pointer to file structure
+ * @cmd: ioctl command
+ * @data: pointer to mei message structure
+ *
+ * Return: 0 on success , <0 on error
+ */
+static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
+{
+ struct mei_device *dev;
+ struct mei_cl *cl = file->private_data;
+ struct mei_connect_client_data connect_data;
+ u32 notify_get, notify_req;
+ int rets;
+
+
+ if (WARN_ON(!cl || !cl->dev))
+ return -ENODEV;
+
+ dev = cl->dev;
+
+ dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
+
+ mutex_lock(&dev->device_lock);
+ if (dev->dev_state != MEI_DEV_ENABLED) {
+ rets = -ENODEV;
+ goto out;
+ }
+
+ switch (cmd) {
+ case IOCTL_MEI_CONNECT_CLIENT:
+ dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
+ if (copy_from_user(&connect_data, (char __user *)data,
+ sizeof(struct mei_connect_client_data))) {
+ dev_dbg(dev->dev, "failed to copy data from userland\n");
+ rets = -EFAULT;
+ goto out;
+ }
+
+ rets = mei_ioctl_connect_client(file, &connect_data);
+ if (rets)
+ goto out;
+
+ /* if all is ok, copying the data back to user. */
+ if (copy_to_user((char __user *)data, &connect_data,
+ sizeof(struct mei_connect_client_data))) {
+ dev_dbg(dev->dev, "failed to copy data to userland\n");
+ rets = -EFAULT;
+ goto out;
+ }
+
+ break;
+
+ case IOCTL_MEI_NOTIFY_SET:
+ dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
+ if (copy_from_user(¬ify_req,
+ (char __user *)data, sizeof(notify_req))) {
+ dev_dbg(dev->dev, "failed to copy data from userland\n");
+ rets = -EFAULT;
+ goto out;
+ }
+ rets = mei_ioctl_client_notify_request(file, notify_req);
+ break;
+
+ case IOCTL_MEI_NOTIFY_GET:
+ dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
+ rets = mei_ioctl_client_notify_get(file, ¬ify_get);
+ if (rets)
+ goto out;
+
+ dev_dbg(dev->dev, "copy connect data to user\n");
+ if (copy_to_user((char __user *)data,
+ ¬ify_get, sizeof(notify_get))) {
+ dev_dbg(dev->dev, "failed to copy data to userland\n");
+ rets = -EFAULT;
+ goto out;
+
+ }
+ break;
+
+ default:
+ rets = -ENOIOCTLCMD;
+ }
+
+out:
+ mutex_unlock(&dev->device_lock);
+ return rets;
+}
+
+/**
+ * mei_compat_ioctl - the compat IOCTL function
+ *
+ * @file: pointer to file structure
+ * @cmd: ioctl command
+ * @data: pointer to mei message structure
+ *
+ * Return: 0 on success , <0 on error
+ */
+#ifdef CONFIG_COMPAT
+static long mei_compat_ioctl(struct file *file,
+ unsigned int cmd, unsigned long data)
+{
+ return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
+}
+#endif
+
+
+/**
+ * mei_poll - the poll function
+ *
+ * @file: pointer to file structure
+ * @wait: pointer to poll_table structure
+ *
+ * Return: poll mask
+ */
+static __poll_t mei_poll(struct file *file, poll_table *wait)
+{
+ __poll_t req_events = poll_requested_events(wait);
+ struct mei_cl *cl = file->private_data;
+ struct mei_device *dev;
+ __poll_t mask = 0;
+ bool notify_en;
+
+ if (WARN_ON(!cl || !cl->dev))
+ return EPOLLERR;
+
+ dev = cl->dev;
+
+ mutex_lock(&dev->device_lock);
+
+ notify_en = cl->notify_en && (req_events & EPOLLPRI);
+
+ if (dev->dev_state != MEI_DEV_ENABLED ||
+ !mei_cl_is_connected(cl)) {
+ mask = EPOLLERR;
+ goto out;
+ }
+
+ if (notify_en) {
+ poll_wait(file, &cl->ev_wait, wait);
+ if (cl->notify_ev)
+ mask |= EPOLLPRI;
+ }
+
+ if (req_events & (EPOLLIN | EPOLLRDNORM)) {
+ poll_wait(file, &cl->rx_wait, wait);
+
+ if (!list_empty(&cl->rd_completed))
+ mask |= EPOLLIN | EPOLLRDNORM;
+ else
+ mei_cl_read_start(cl, mei_cl_mtu(cl), file);
+ }
+
+ if (req_events & (POLLOUT | POLLWRNORM)) {
+ poll_wait(file, &cl->tx_wait, wait);
+ if (cl->tx_cb_queued < dev->tx_queue_limit)
+ mask |= POLLOUT | POLLWRNORM;
+ }
+
+out:
+ mutex_unlock(&dev->device_lock);
+ return mask;
+}
+
+/**
+ * mei_cl_is_write_queued - check if the client has pending writes.
+ *
+ * @cl: writing host client
+ *
+ * Return: true if client is writing, false otherwise.
+ */
+static bool mei_cl_is_write_queued(struct mei_cl *cl)
+{
+ struct mei_device *dev = cl->dev;
+ struct mei_cl_cb *cb;
+
+ list_for_each_entry(cb, &dev->write_list, list)
+ if (cb->cl == cl)
+ return true;
+ list_for_each_entry(cb, &dev->write_waiting_list, list)
+ if (cb->cl == cl)
+ return true;
+ return false;
+}
+
+/**
+ * mei_fsync - the fsync handler
+ *
+ * @fp: pointer to file structure
+ * @start: unused
+ * @end: unused
+ * @datasync: unused
+ *
+ * Return: 0 on success, -ENODEV if client is not connected
+ */
+static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
+{
+ struct mei_cl *cl = fp->private_data;
+ struct mei_device *dev;
+ int rets;
+
+ if (WARN_ON(!cl || !cl->dev))
+ return -ENODEV;
+
+ dev = cl->dev;
+
+ mutex_lock(&dev->device_lock);
+
+ if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
+ rets = -ENODEV;
+ goto out;
+ }
+
+ while (mei_cl_is_write_queued(cl)) {
+ mutex_unlock(&dev->device_lock);
+ rets = wait_event_interruptible(cl->tx_wait,
+ cl->writing_state == MEI_WRITE_COMPLETE ||
+ !mei_cl_is_connected(cl));
+ mutex_lock(&dev->device_lock);
+ if (rets) {
+ if (signal_pending(current))
+ rets = -EINTR;
+ goto out;
+ }
+ if (!mei_cl_is_connected(cl)) {
+ rets = -ENODEV;
+ goto out;
+ }
+ }
+ rets = 0;
+out:
+ mutex_unlock(&dev->device_lock);
+ return rets;
+}
+
+/**
+ * mei_fasync - asynchronous io support
+ *
+ * @fd: file descriptor
+ * @file: pointer to file structure
+ * @band: band bitmap
+ *
+ * Return: negative on error,
+ * 0 if it did no changes,
+ * and positive a process was added or deleted
+ */
+static int mei_fasync(int fd, struct file *file, int band)
+{
+
+ struct mei_cl *cl = file->private_data;
+
+ if (!mei_cl_is_connected(cl))
+ return -ENODEV;
+
+ return fasync_helper(fd, file, band, &cl->ev_async);
+}
+
+/**
+ * fw_status_show - mei device fw_status attribute show method
+ *
+ * @device: device pointer
+ * @attr: attribute pointer
+ * @buf: char out buffer
+ *
+ * Return: number of the bytes printed into buf or error
+ */
+static ssize_t fw_status_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ struct mei_device *dev = dev_get_drvdata(device);
+ struct mei_fw_status fw_status;
+ int err, i;
+ ssize_t cnt = 0;
+
+ mutex_lock(&dev->device_lock);
+ err = mei_fw_status(dev, &fw_status);
+ mutex_unlock(&dev->device_lock);
+ if (err) {
+ dev_err(device, "read fw_status error = %d\n", err);
+ return err;
+ }
+
+ for (i = 0; i < fw_status.count; i++)
+ cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
+ fw_status.status[i]);
+ return cnt;
+}
+static DEVICE_ATTR_RO(fw_status);
+
+/**
+ * hbm_ver_show - display HBM protocol version negotiated with FW
+ *
+ * @device: device pointer
+ * @attr: attribute pointer
+ * @buf: char out buffer
+ *
+ * Return: number of the bytes printed into buf or error
+ */
+static ssize_t hbm_ver_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ struct mei_device *dev = dev_get_drvdata(device);
+ struct hbm_version ver;
+
+ mutex_lock(&dev->device_lock);
+ ver = dev->version;
+ mutex_unlock(&dev->device_lock);
+
+ return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
+}
+static DEVICE_ATTR_RO(hbm_ver);
+
+/**
+ * hbm_ver_drv_show - display HBM protocol version advertised by driver
+ *
+ * @device: device pointer
+ * @attr: attribute pointer
+ * @buf: char out buffer
+ *
+ * Return: number of the bytes printed into buf or error
+ */
+static ssize_t hbm_ver_drv_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
+}
+static DEVICE_ATTR_RO(hbm_ver_drv);
+
+static ssize_t tx_queue_limit_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ struct mei_device *dev = dev_get_drvdata(device);
+ u8 size = 0;
+
+ mutex_lock(&dev->device_lock);
+ size = dev->tx_queue_limit;
+ mutex_unlock(&dev->device_lock);
+
+ return snprintf(buf, PAGE_SIZE, "%u\n", size);
+}
+
+static ssize_t tx_queue_limit_store(struct device *device,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct mei_device *dev = dev_get_drvdata(device);
+ u8 limit;
+ unsigned int inp;
+ int err;
+
+ err = kstrtouint(buf, 10, &inp);
+ if (err)
+ return err;
+ if (inp > MEI_TX_QUEUE_LIMIT_MAX || inp < MEI_TX_QUEUE_LIMIT_MIN)
+ return -EINVAL;
+ limit = inp;
+
+ mutex_lock(&dev->device_lock);
+ dev->tx_queue_limit = limit;
+ mutex_unlock(&dev->device_lock);
+
+ return count;
+}
+static DEVICE_ATTR_RW(tx_queue_limit);
+
+/**
+ * fw_ver_show - display ME FW version
+ *
+ * @device: device pointer
+ * @attr: attribute pointer
+ * @buf: char out buffer
+ *
+ * Return: number of the bytes printed into buf or error
+ */
+static ssize_t fw_ver_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ struct mei_device *dev = dev_get_drvdata(device);
+ struct mei_fw_version *ver;
+ ssize_t cnt = 0;
+ int i;
+
+ ver = dev->fw_ver;
+
+ for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++)
+ cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%u:%u.%u.%u.%u\n",
+ ver[i].platform, ver[i].major, ver[i].minor,
+ ver[i].hotfix, ver[i].buildno);
+ return cnt;
+}
+static DEVICE_ATTR_RO(fw_ver);
+
+static struct attribute *mei_attrs[] = {
+ &dev_attr_fw_status.attr,
+ &dev_attr_hbm_ver.attr,
+ &dev_attr_hbm_ver_drv.attr,
+ &dev_attr_tx_queue_limit.attr,
+ &dev_attr_fw_ver.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(mei);
+
+/*
+ * file operations structure will be used for mei char device.
+ */
+static const struct file_operations mei_fops = {
+ .owner = THIS_MODULE,
+ .read = mei_read,
+ .unlocked_ioctl = mei_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = mei_compat_ioctl,
+#endif
+ .open = mei_open,
+ .release = mei_release,
+ .write = mei_write,
+ .poll = mei_poll,
+ .fsync = mei_fsync,
+ .fasync = mei_fasync,
+ .llseek = no_llseek
+};
+
+static struct class *mei_class;
+static dev_t mei_devt;
+#define MEI_MAX_DEVS MINORMASK
+static DEFINE_MUTEX(mei_minor_lock);
+static DEFINE_IDR(mei_idr);
+
+/**
+ * mei_minor_get - obtain next free device minor number
+ *
+ * @dev: device pointer
+ *
+ * Return: allocated minor, or -ENOSPC if no free minor left
+ */
+static int mei_minor_get(struct mei_device *dev)
+{
+ int ret;
+
+ mutex_lock(&mei_minor_lock);
+ ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
+ if (ret >= 0)
+ dev->minor = ret;
+ else if (ret == -ENOSPC)
+ dev_err(dev->dev, "too many mei devices\n");
+
+ mutex_unlock(&mei_minor_lock);
+ return ret;
+}
+
+/**
+ * mei_minor_free - mark device minor number as free
+ *
+ * @dev: device pointer
+ */
+static void mei_minor_free(struct mei_device *dev)
+{
+ mutex_lock(&mei_minor_lock);
+ idr_remove(&mei_idr, dev->minor);
+ mutex_unlock(&mei_minor_lock);
+}
+
+int mei_register(struct mei_device *dev, struct device *parent)
+{
+ struct device *clsdev; /* class device */
+ int ret, devno;
+
+ ret = mei_minor_get(dev);
+ if (ret < 0)
+ return ret;
+
+ /* Fill in the data structures */
+ devno = MKDEV(MAJOR(mei_devt), dev->minor);
+ cdev_init(&dev->cdev, &mei_fops);
+ dev->cdev.owner = parent->driver->owner;
+
+ /* Add the device */
+ ret = cdev_add(&dev->cdev, devno, 1);
+ if (ret) {
+ dev_err(parent, "unable to add device %d:%d\n",
+ MAJOR(mei_devt), dev->minor);
+ goto err_dev_add;
+ }
+
+ clsdev = device_create_with_groups(mei_class, parent, devno,
+ dev, mei_groups,
+ "mei%d", dev->minor);
+
+ if (IS_ERR(clsdev)) {
+ dev_err(parent, "unable to create device %d:%d\n",
+ MAJOR(mei_devt), dev->minor);
+ ret = PTR_ERR(clsdev);
+ goto err_dev_create;
+ }
+
+ ret = mei_dbgfs_register(dev, dev_name(clsdev));
+ if (ret) {
+ dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
+ goto err_dev_dbgfs;
+ }
+
+ return 0;
+
+err_dev_dbgfs:
+ device_destroy(mei_class, devno);
+err_dev_create:
+ cdev_del(&dev->cdev);
+err_dev_add:
+ mei_minor_free(dev);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mei_register);
+
+void mei_deregister(struct mei_device *dev)
+{
+ int devno;
+
+ devno = dev->cdev.dev;
+ cdev_del(&dev->cdev);
+
+ mei_dbgfs_deregister(dev);
+
+ device_destroy(mei_class, devno);
+
+ mei_minor_free(dev);
+}
+EXPORT_SYMBOL_GPL(mei_deregister);
+
+static int __init mei_init(void)
+{
+ int ret;
+
+ mei_class = class_create(THIS_MODULE, "mei");
+ if (IS_ERR(mei_class)) {
+ pr_err("couldn't create class\n");
+ ret = PTR_ERR(mei_class);
+ goto err;
+ }
+
+ ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
+ if (ret < 0) {
+ pr_err("unable to allocate char dev region\n");
+ goto err_class;
+ }
+
+ ret = mei_cl_bus_init();
+ if (ret < 0) {
+ pr_err("unable to initialize bus\n");
+ goto err_chrdev;
+ }
+
+ return 0;
+
+err_chrdev:
+ unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
+err_class:
+ class_destroy(mei_class);
+err:
+ return ret;
+}
+
+static void __exit mei_exit(void)
+{
+ unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
+ class_destroy(mei_class);
+ mei_cl_bus_exit();
+}
+
+module_init(mei_init);
+module_exit(mei_exit);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
+MODULE_LICENSE("GPL v2");
+