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0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (c) 2003-2020, Intel Corporation. All rights reserved.
0004  * Intel Management Engine Interface (Intel MEI) Linux driver
0005  */
0006 
0007 #include <linux/module.h>
0008 #include <linux/moduleparam.h>
0009 #include <linux/kernel.h>
0010 #include <linux/device.h>
0011 #include <linux/slab.h>
0012 #include <linux/fs.h>
0013 #include <linux/errno.h>
0014 #include <linux/types.h>
0015 #include <linux/fcntl.h>
0016 #include <linux/poll.h>
0017 #include <linux/init.h>
0018 #include <linux/ioctl.h>
0019 #include <linux/cdev.h>
0020 #include <linux/sched/signal.h>
0021 #include <linux/uuid.h>
0022 #include <linux/compat.h>
0023 #include <linux/jiffies.h>
0024 #include <linux/interrupt.h>
0025 
0026 #include <linux/mei.h>
0027 
0028 #include "mei_dev.h"
0029 #include "client.h"
0030 
0031 static struct class *mei_class;
0032 static dev_t mei_devt;
0033 #define MEI_MAX_DEVS  MINORMASK
0034 static DEFINE_MUTEX(mei_minor_lock);
0035 static DEFINE_IDR(mei_idr);
0036 
0037 /**
0038  * mei_open - the open function
0039  *
0040  * @inode: pointer to inode structure
0041  * @file: pointer to file structure
0042  *
0043  * Return: 0 on success, <0 on error
0044  */
0045 static int mei_open(struct inode *inode, struct file *file)
0046 {
0047     struct mei_device *dev;
0048     struct mei_cl *cl;
0049 
0050     int err;
0051 
0052     dev = container_of(inode->i_cdev, struct mei_device, cdev);
0053 
0054     mutex_lock(&dev->device_lock);
0055 
0056     if (dev->dev_state != MEI_DEV_ENABLED) {
0057         dev_dbg(dev->dev, "dev_state != MEI_ENABLED  dev_state = %s\n",
0058             mei_dev_state_str(dev->dev_state));
0059         err = -ENODEV;
0060         goto err_unlock;
0061     }
0062 
0063     cl = mei_cl_alloc_linked(dev);
0064     if (IS_ERR(cl)) {
0065         err = PTR_ERR(cl);
0066         goto err_unlock;
0067     }
0068 
0069     cl->fp = file;
0070     file->private_data = cl;
0071 
0072     mutex_unlock(&dev->device_lock);
0073 
0074     return nonseekable_open(inode, file);
0075 
0076 err_unlock:
0077     mutex_unlock(&dev->device_lock);
0078     return err;
0079 }
0080 
0081 /**
0082  * mei_cl_vtag_remove_by_fp - remove vtag that corresponds to fp from list
0083  *
0084  * @cl: host client
0085  * @fp: pointer to file structure
0086  *
0087  */
0088 static void mei_cl_vtag_remove_by_fp(const struct mei_cl *cl,
0089                      const struct file *fp)
0090 {
0091     struct mei_cl_vtag *vtag_l, *next;
0092 
0093     list_for_each_entry_safe(vtag_l, next, &cl->vtag_map, list) {
0094         if (vtag_l->fp == fp) {
0095             list_del(&vtag_l->list);
0096             kfree(vtag_l);
0097             return;
0098         }
0099     }
0100 }
0101 
0102 /**
0103  * mei_release - the release function
0104  *
0105  * @inode: pointer to inode structure
0106  * @file: pointer to file structure
0107  *
0108  * Return: 0 on success, <0 on error
0109  */
0110 static int mei_release(struct inode *inode, struct file *file)
0111 {
0112     struct mei_cl *cl = file->private_data;
0113     struct mei_device *dev;
0114     int rets;
0115 
0116     if (WARN_ON(!cl || !cl->dev))
0117         return -ENODEV;
0118 
0119     dev = cl->dev;
0120 
0121     mutex_lock(&dev->device_lock);
0122 
0123     mei_cl_vtag_remove_by_fp(cl, file);
0124 
0125     if (!list_empty(&cl->vtag_map)) {
0126         cl_dbg(dev, cl, "not the last vtag\n");
0127         mei_cl_flush_queues(cl, file);
0128         rets = 0;
0129         goto out;
0130     }
0131 
0132     rets = mei_cl_disconnect(cl);
0133     /*
0134      * Check again: This is necessary since disconnect releases the lock
0135      * and another client can connect in the meantime.
0136      */
0137     if (!list_empty(&cl->vtag_map)) {
0138         cl_dbg(dev, cl, "not the last vtag after disconnect\n");
0139         mei_cl_flush_queues(cl, file);
0140         goto out;
0141     }
0142 
0143     mei_cl_flush_queues(cl, NULL);
0144     cl_dbg(dev, cl, "removing\n");
0145 
0146     mei_cl_unlink(cl);
0147     kfree(cl);
0148 
0149 out:
0150     file->private_data = NULL;
0151 
0152     mutex_unlock(&dev->device_lock);
0153     return rets;
0154 }
0155 
0156 
0157 /**
0158  * mei_read - the read function.
0159  *
0160  * @file: pointer to file structure
0161  * @ubuf: pointer to user buffer
0162  * @length: buffer length
0163  * @offset: data offset in buffer
0164  *
0165  * Return: >=0 data length on success , <0 on error
0166  */
0167 static ssize_t mei_read(struct file *file, char __user *ubuf,
0168             size_t length, loff_t *offset)
0169 {
0170     struct mei_cl *cl = file->private_data;
0171     struct mei_device *dev;
0172     struct mei_cl_cb *cb = NULL;
0173     bool nonblock = !!(file->f_flags & O_NONBLOCK);
0174     ssize_t rets;
0175 
0176     if (WARN_ON(!cl || !cl->dev))
0177         return -ENODEV;
0178 
0179     dev = cl->dev;
0180 
0181 
0182     mutex_lock(&dev->device_lock);
0183     if (dev->dev_state != MEI_DEV_ENABLED) {
0184         rets = -ENODEV;
0185         goto out;
0186     }
0187 
0188     if (length == 0) {
0189         rets = 0;
0190         goto out;
0191     }
0192 
0193     if (ubuf == NULL) {
0194         rets = -EMSGSIZE;
0195         goto out;
0196     }
0197 
0198     cb = mei_cl_read_cb(cl, file);
0199     if (cb)
0200         goto copy_buffer;
0201 
0202     if (*offset > 0)
0203         *offset = 0;
0204 
0205     rets = mei_cl_read_start(cl, length, file);
0206     if (rets && rets != -EBUSY) {
0207         cl_dbg(dev, cl, "mei start read failure status = %zd\n", rets);
0208         goto out;
0209     }
0210 
0211     if (nonblock) {
0212         rets = -EAGAIN;
0213         goto out;
0214     }
0215 
0216     mutex_unlock(&dev->device_lock);
0217     if (wait_event_interruptible(cl->rx_wait,
0218                      mei_cl_read_cb(cl, file) ||
0219                      !mei_cl_is_connected(cl))) {
0220         if (signal_pending(current))
0221             return -EINTR;
0222         return -ERESTARTSYS;
0223     }
0224     mutex_lock(&dev->device_lock);
0225 
0226     if (!mei_cl_is_connected(cl)) {
0227         rets = -ENODEV;
0228         goto out;
0229     }
0230 
0231     cb = mei_cl_read_cb(cl, file);
0232     if (!cb) {
0233         rets = 0;
0234         goto out;
0235     }
0236 
0237 copy_buffer:
0238     /* now copy the data to user space */
0239     if (cb->status) {
0240         rets = cb->status;
0241         cl_dbg(dev, cl, "read operation failed %zd\n", rets);
0242         goto free;
0243     }
0244 
0245     cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
0246            cb->buf.size, cb->buf_idx, *offset);
0247     if (*offset >= cb->buf_idx) {
0248         rets = 0;
0249         goto free;
0250     }
0251 
0252     /* length is being truncated to PAGE_SIZE,
0253      * however buf_idx may point beyond that */
0254     length = min_t(size_t, length, cb->buf_idx - *offset);
0255 
0256     if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
0257         dev_dbg(dev->dev, "failed to copy data to userland\n");
0258         rets = -EFAULT;
0259         goto free;
0260     }
0261 
0262     rets = length;
0263     *offset += length;
0264     /* not all data was read, keep the cb */
0265     if (*offset < cb->buf_idx)
0266         goto out;
0267 
0268 free:
0269     mei_cl_del_rd_completed(cl, cb);
0270     *offset = 0;
0271 
0272 out:
0273     cl_dbg(dev, cl, "end mei read rets = %zd\n", rets);
0274     mutex_unlock(&dev->device_lock);
0275     return rets;
0276 }
0277 
0278 /**
0279  * mei_cl_vtag_by_fp - obtain the vtag by file pointer
0280  *
0281  * @cl: host client
0282  * @fp: pointer to file structure
0283  *
0284  * Return: vtag value on success, otherwise 0
0285  */
0286 static u8 mei_cl_vtag_by_fp(const struct mei_cl *cl, const struct file *fp)
0287 {
0288     struct mei_cl_vtag *cl_vtag;
0289 
0290     if (!fp)
0291         return 0;
0292 
0293     list_for_each_entry(cl_vtag, &cl->vtag_map, list)
0294         if (cl_vtag->fp == fp)
0295             return cl_vtag->vtag;
0296     return 0;
0297 }
0298 
0299 /**
0300  * mei_write - the write function.
0301  *
0302  * @file: pointer to file structure
0303  * @ubuf: pointer to user buffer
0304  * @length: buffer length
0305  * @offset: data offset in buffer
0306  *
0307  * Return: >=0 data length on success , <0 on error
0308  */
0309 static ssize_t mei_write(struct file *file, const char __user *ubuf,
0310              size_t length, loff_t *offset)
0311 {
0312     struct mei_cl *cl = file->private_data;
0313     struct mei_cl_cb *cb;
0314     struct mei_device *dev;
0315     ssize_t rets;
0316 
0317     if (WARN_ON(!cl || !cl->dev))
0318         return -ENODEV;
0319 
0320     dev = cl->dev;
0321 
0322     mutex_lock(&dev->device_lock);
0323 
0324     if (dev->dev_state != MEI_DEV_ENABLED) {
0325         rets = -ENODEV;
0326         goto out;
0327     }
0328 
0329     if (!mei_cl_is_connected(cl)) {
0330         cl_err(dev, cl, "is not connected");
0331         rets = -ENODEV;
0332         goto out;
0333     }
0334 
0335     if (!mei_me_cl_is_active(cl->me_cl)) {
0336         rets = -ENOTTY;
0337         goto out;
0338     }
0339 
0340     if (length > mei_cl_mtu(cl)) {
0341         rets = -EFBIG;
0342         goto out;
0343     }
0344 
0345     if (length == 0) {
0346         rets = 0;
0347         goto out;
0348     }
0349 
0350     while (cl->tx_cb_queued >= dev->tx_queue_limit) {
0351         if (file->f_flags & O_NONBLOCK) {
0352             rets = -EAGAIN;
0353             goto out;
0354         }
0355         mutex_unlock(&dev->device_lock);
0356         rets = wait_event_interruptible(cl->tx_wait,
0357                 cl->writing_state == MEI_WRITE_COMPLETE ||
0358                 (!mei_cl_is_connected(cl)));
0359         mutex_lock(&dev->device_lock);
0360         if (rets) {
0361             if (signal_pending(current))
0362                 rets = -EINTR;
0363             goto out;
0364         }
0365         if (!mei_cl_is_connected(cl)) {
0366             rets = -ENODEV;
0367             goto out;
0368         }
0369     }
0370 
0371     cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
0372     if (!cb) {
0373         rets = -ENOMEM;
0374         goto out;
0375     }
0376     cb->vtag = mei_cl_vtag_by_fp(cl, file);
0377 
0378     rets = copy_from_user(cb->buf.data, ubuf, length);
0379     if (rets) {
0380         dev_dbg(dev->dev, "failed to copy data from userland\n");
0381         rets = -EFAULT;
0382         mei_io_cb_free(cb);
0383         goto out;
0384     }
0385 
0386     rets = mei_cl_write(cl, cb);
0387 out:
0388     mutex_unlock(&dev->device_lock);
0389     return rets;
0390 }
0391 
0392 /**
0393  * mei_ioctl_connect_client - the connect to fw client IOCTL function
0394  *
0395  * @file: private data of the file object
0396  * @in_client_uuid: requested UUID for connection
0397  * @client: IOCTL connect data, output parameters
0398  *
0399  * Locking: called under "dev->device_lock" lock
0400  *
0401  * Return: 0 on success, <0 on failure.
0402  */
0403 static int mei_ioctl_connect_client(struct file *file,
0404                     const uuid_le *in_client_uuid,
0405                     struct mei_client *client)
0406 {
0407     struct mei_device *dev;
0408     struct mei_me_client *me_cl;
0409     struct mei_cl *cl;
0410     int rets;
0411 
0412     cl = file->private_data;
0413     dev = cl->dev;
0414 
0415     if (cl->state != MEI_FILE_INITIALIZING &&
0416         cl->state != MEI_FILE_DISCONNECTED)
0417         return  -EBUSY;
0418 
0419     /* find ME client we're trying to connect to */
0420     me_cl = mei_me_cl_by_uuid(dev, in_client_uuid);
0421     if (!me_cl) {
0422         dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
0423             in_client_uuid);
0424         rets = -ENOTTY;
0425         goto end;
0426     }
0427 
0428     if (me_cl->props.fixed_address) {
0429         bool forbidden = dev->override_fixed_address ?
0430              !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
0431         if (forbidden) {
0432             dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
0433                 in_client_uuid);
0434             rets = -ENOTTY;
0435             goto end;
0436         }
0437     }
0438 
0439     dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
0440             me_cl->client_id);
0441     dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
0442             me_cl->props.protocol_version);
0443     dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
0444             me_cl->props.max_msg_length);
0445 
0446     /* prepare the output buffer */
0447     client->max_msg_length = me_cl->props.max_msg_length;
0448     client->protocol_version = me_cl->props.protocol_version;
0449     dev_dbg(dev->dev, "Can connect?\n");
0450 
0451     rets = mei_cl_connect(cl, me_cl, file);
0452 
0453 end:
0454     mei_me_cl_put(me_cl);
0455     return rets;
0456 }
0457 
0458 /**
0459  * mei_vt_support_check - check if client support vtags
0460  *
0461  * Locking: called under "dev->device_lock" lock
0462  *
0463  * @dev: mei_device
0464  * @uuid: client UUID
0465  *
0466  * Return:
0467  *  0 - supported
0468  *  -ENOTTY - no such client
0469  *  -EOPNOTSUPP - vtags are not supported by client
0470  */
0471 static int mei_vt_support_check(struct mei_device *dev, const uuid_le *uuid)
0472 {
0473     struct mei_me_client *me_cl;
0474     int ret;
0475 
0476     if (!dev->hbm_f_vt_supported)
0477         return -EOPNOTSUPP;
0478 
0479     me_cl = mei_me_cl_by_uuid(dev, uuid);
0480     if (!me_cl) {
0481         dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
0482             uuid);
0483         return -ENOTTY;
0484     }
0485     ret = me_cl->props.vt_supported ? 0 : -EOPNOTSUPP;
0486     mei_me_cl_put(me_cl);
0487 
0488     return ret;
0489 }
0490 
0491 /**
0492  * mei_ioctl_connect_vtag - connect to fw client with vtag IOCTL function
0493  *
0494  * @file: private data of the file object
0495  * @in_client_uuid: requested UUID for connection
0496  * @client: IOCTL connect data, output parameters
0497  * @vtag: vm tag
0498  *
0499  * Locking: called under "dev->device_lock" lock
0500  *
0501  * Return: 0 on success, <0 on failure.
0502  */
0503 static int mei_ioctl_connect_vtag(struct file *file,
0504                   const uuid_le *in_client_uuid,
0505                   struct mei_client *client,
0506                   u8 vtag)
0507 {
0508     struct mei_device *dev;
0509     struct mei_cl *cl;
0510     struct mei_cl *pos;
0511     struct mei_cl_vtag *cl_vtag;
0512 
0513     cl = file->private_data;
0514     dev = cl->dev;
0515 
0516     dev_dbg(dev->dev, "FW Client %pUl vtag %d\n", in_client_uuid, vtag);
0517 
0518     switch (cl->state) {
0519     case MEI_FILE_DISCONNECTED:
0520         if (mei_cl_vtag_by_fp(cl, file) != vtag) {
0521             dev_err(dev->dev, "reconnect with different vtag\n");
0522             return -EINVAL;
0523         }
0524         break;
0525     case MEI_FILE_INITIALIZING:
0526         /* malicious connect from another thread may push vtag */
0527         if (!IS_ERR(mei_cl_fp_by_vtag(cl, vtag))) {
0528             dev_err(dev->dev, "vtag already filled\n");
0529             return -EINVAL;
0530         }
0531 
0532         list_for_each_entry(pos, &dev->file_list, link) {
0533             if (pos == cl)
0534                 continue;
0535             if (!pos->me_cl)
0536                 continue;
0537 
0538             /* only search for same UUID */
0539             if (uuid_le_cmp(*mei_cl_uuid(pos), *in_client_uuid))
0540                 continue;
0541 
0542             /* if tag already exist try another fp */
0543             if (!IS_ERR(mei_cl_fp_by_vtag(pos, vtag)))
0544                 continue;
0545 
0546             /* replace cl with acquired one */
0547             dev_dbg(dev->dev, "replacing with existing cl\n");
0548             mei_cl_unlink(cl);
0549             kfree(cl);
0550             file->private_data = pos;
0551             cl = pos;
0552             break;
0553         }
0554 
0555         cl_vtag = mei_cl_vtag_alloc(file, vtag);
0556         if (IS_ERR(cl_vtag))
0557             return -ENOMEM;
0558 
0559         list_add_tail(&cl_vtag->list, &cl->vtag_map);
0560         break;
0561     default:
0562         return -EBUSY;
0563     }
0564 
0565     while (cl->state != MEI_FILE_INITIALIZING &&
0566            cl->state != MEI_FILE_DISCONNECTED &&
0567            cl->state != MEI_FILE_CONNECTED) {
0568         mutex_unlock(&dev->device_lock);
0569         wait_event_timeout(cl->wait,
0570                    (cl->state == MEI_FILE_CONNECTED ||
0571                     cl->state == MEI_FILE_DISCONNECTED ||
0572                     cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
0573                     cl->state == MEI_FILE_DISCONNECT_REPLY),
0574                    mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
0575         mutex_lock(&dev->device_lock);
0576     }
0577 
0578     if (!mei_cl_is_connected(cl))
0579         return mei_ioctl_connect_client(file, in_client_uuid, client);
0580 
0581     client->max_msg_length = cl->me_cl->props.max_msg_length;
0582     client->protocol_version = cl->me_cl->props.protocol_version;
0583 
0584     return 0;
0585 }
0586 
0587 /**
0588  * mei_ioctl_client_notify_request -
0589  *     propagate event notification request to client
0590  *
0591  * @file: pointer to file structure
0592  * @request: 0 - disable, 1 - enable
0593  *
0594  * Return: 0 on success , <0 on error
0595  */
0596 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
0597 {
0598     struct mei_cl *cl = file->private_data;
0599 
0600     if (request != MEI_HBM_NOTIFICATION_START &&
0601         request != MEI_HBM_NOTIFICATION_STOP)
0602         return -EINVAL;
0603 
0604     return mei_cl_notify_request(cl, file, (u8)request);
0605 }
0606 
0607 /**
0608  * mei_ioctl_client_notify_get -  wait for notification request
0609  *
0610  * @file: pointer to file structure
0611  * @notify_get: 0 - disable, 1 - enable
0612  *
0613  * Return: 0 on success , <0 on error
0614  */
0615 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
0616 {
0617     struct mei_cl *cl = file->private_data;
0618     bool notify_ev;
0619     bool block = (file->f_flags & O_NONBLOCK) == 0;
0620     int rets;
0621 
0622     rets = mei_cl_notify_get(cl, block, &notify_ev);
0623     if (rets)
0624         return rets;
0625 
0626     *notify_get = notify_ev ? 1 : 0;
0627     return 0;
0628 }
0629 
0630 /**
0631  * mei_ioctl - the IOCTL function
0632  *
0633  * @file: pointer to file structure
0634  * @cmd: ioctl command
0635  * @data: pointer to mei message structure
0636  *
0637  * Return: 0 on success , <0 on error
0638  */
0639 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
0640 {
0641     struct mei_device *dev;
0642     struct mei_cl *cl = file->private_data;
0643     struct mei_connect_client_data conn;
0644     struct mei_connect_client_data_vtag conn_vtag;
0645     const uuid_le *cl_uuid;
0646     struct mei_client *props;
0647     u8 vtag;
0648     u32 notify_get, notify_req;
0649     int rets;
0650 
0651 
0652     if (WARN_ON(!cl || !cl->dev))
0653         return -ENODEV;
0654 
0655     dev = cl->dev;
0656 
0657     dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
0658 
0659     mutex_lock(&dev->device_lock);
0660     if (dev->dev_state != MEI_DEV_ENABLED) {
0661         rets = -ENODEV;
0662         goto out;
0663     }
0664 
0665     switch (cmd) {
0666     case IOCTL_MEI_CONNECT_CLIENT:
0667         dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
0668         if (copy_from_user(&conn, (char __user *)data, sizeof(conn))) {
0669             dev_dbg(dev->dev, "failed to copy data from userland\n");
0670             rets = -EFAULT;
0671             goto out;
0672         }
0673         cl_uuid = &conn.in_client_uuid;
0674         props = &conn.out_client_properties;
0675         vtag = 0;
0676 
0677         rets = mei_vt_support_check(dev, cl_uuid);
0678         if (rets == -ENOTTY)
0679             goto out;
0680         if (!rets)
0681             rets = mei_ioctl_connect_vtag(file, cl_uuid, props,
0682                               vtag);
0683         else
0684             rets = mei_ioctl_connect_client(file, cl_uuid, props);
0685         if (rets)
0686             goto out;
0687 
0688         /* if all is ok, copying the data back to user. */
0689         if (copy_to_user((char __user *)data, &conn, sizeof(conn))) {
0690             dev_dbg(dev->dev, "failed to copy data to userland\n");
0691             rets = -EFAULT;
0692             goto out;
0693         }
0694 
0695         break;
0696 
0697     case IOCTL_MEI_CONNECT_CLIENT_VTAG:
0698         dev_dbg(dev->dev, "IOCTL_MEI_CONNECT_CLIENT_VTAG\n");
0699         if (copy_from_user(&conn_vtag, (char __user *)data,
0700                    sizeof(conn_vtag))) {
0701             dev_dbg(dev->dev, "failed to copy data from userland\n");
0702             rets = -EFAULT;
0703             goto out;
0704         }
0705 
0706         cl_uuid = &conn_vtag.connect.in_client_uuid;
0707         props = &conn_vtag.out_client_properties;
0708         vtag = conn_vtag.connect.vtag;
0709 
0710         rets = mei_vt_support_check(dev, cl_uuid);
0711         if (rets == -EOPNOTSUPP)
0712             dev_dbg(dev->dev, "FW Client %pUl does not support vtags\n",
0713                 cl_uuid);
0714         if (rets)
0715             goto out;
0716 
0717         if (!vtag) {
0718             dev_dbg(dev->dev, "vtag can't be zero\n");
0719             rets = -EINVAL;
0720             goto out;
0721         }
0722 
0723         rets = mei_ioctl_connect_vtag(file, cl_uuid, props, vtag);
0724         if (rets)
0725             goto out;
0726 
0727         /* if all is ok, copying the data back to user. */
0728         if (copy_to_user((char __user *)data, &conn_vtag,
0729                  sizeof(conn_vtag))) {
0730             dev_dbg(dev->dev, "failed to copy data to userland\n");
0731             rets = -EFAULT;
0732             goto out;
0733         }
0734 
0735         break;
0736 
0737     case IOCTL_MEI_NOTIFY_SET:
0738         dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
0739         if (copy_from_user(&notify_req,
0740                    (char __user *)data, sizeof(notify_req))) {
0741             dev_dbg(dev->dev, "failed to copy data from userland\n");
0742             rets = -EFAULT;
0743             goto out;
0744         }
0745         rets = mei_ioctl_client_notify_request(file, notify_req);
0746         break;
0747 
0748     case IOCTL_MEI_NOTIFY_GET:
0749         dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
0750         rets = mei_ioctl_client_notify_get(file, &notify_get);
0751         if (rets)
0752             goto out;
0753 
0754         dev_dbg(dev->dev, "copy connect data to user\n");
0755         if (copy_to_user((char __user *)data,
0756                 &notify_get, sizeof(notify_get))) {
0757             dev_dbg(dev->dev, "failed to copy data to userland\n");
0758             rets = -EFAULT;
0759             goto out;
0760 
0761         }
0762         break;
0763 
0764     default:
0765         rets = -ENOIOCTLCMD;
0766     }
0767 
0768 out:
0769     mutex_unlock(&dev->device_lock);
0770     return rets;
0771 }
0772 
0773 /**
0774  * mei_poll - the poll function
0775  *
0776  * @file: pointer to file structure
0777  * @wait: pointer to poll_table structure
0778  *
0779  * Return: poll mask
0780  */
0781 static __poll_t mei_poll(struct file *file, poll_table *wait)
0782 {
0783     __poll_t req_events = poll_requested_events(wait);
0784     struct mei_cl *cl = file->private_data;
0785     struct mei_device *dev;
0786     __poll_t mask = 0;
0787     bool notify_en;
0788 
0789     if (WARN_ON(!cl || !cl->dev))
0790         return EPOLLERR;
0791 
0792     dev = cl->dev;
0793 
0794     mutex_lock(&dev->device_lock);
0795 
0796     notify_en = cl->notify_en && (req_events & EPOLLPRI);
0797 
0798     if (dev->dev_state != MEI_DEV_ENABLED ||
0799         !mei_cl_is_connected(cl)) {
0800         mask = EPOLLERR;
0801         goto out;
0802     }
0803 
0804     if (notify_en) {
0805         poll_wait(file, &cl->ev_wait, wait);
0806         if (cl->notify_ev)
0807             mask |= EPOLLPRI;
0808     }
0809 
0810     if (req_events & (EPOLLIN | EPOLLRDNORM)) {
0811         poll_wait(file, &cl->rx_wait, wait);
0812 
0813         if (mei_cl_read_cb(cl, file))
0814             mask |= EPOLLIN | EPOLLRDNORM;
0815         else
0816             mei_cl_read_start(cl, mei_cl_mtu(cl), file);
0817     }
0818 
0819     if (req_events & (EPOLLOUT | EPOLLWRNORM)) {
0820         poll_wait(file, &cl->tx_wait, wait);
0821         if (cl->tx_cb_queued < dev->tx_queue_limit)
0822             mask |= EPOLLOUT | EPOLLWRNORM;
0823     }
0824 
0825 out:
0826     mutex_unlock(&dev->device_lock);
0827     return mask;
0828 }
0829 
0830 /**
0831  * mei_cl_is_write_queued - check if the client has pending writes.
0832  *
0833  * @cl: writing host client
0834  *
0835  * Return: true if client is writing, false otherwise.
0836  */
0837 static bool mei_cl_is_write_queued(struct mei_cl *cl)
0838 {
0839     struct mei_device *dev = cl->dev;
0840     struct mei_cl_cb *cb;
0841 
0842     list_for_each_entry(cb, &dev->write_list, list)
0843         if (cb->cl == cl)
0844             return true;
0845     list_for_each_entry(cb, &dev->write_waiting_list, list)
0846         if (cb->cl == cl)
0847             return true;
0848     return false;
0849 }
0850 
0851 /**
0852  * mei_fsync - the fsync handler
0853  *
0854  * @fp:       pointer to file structure
0855  * @start:    unused
0856  * @end:      unused
0857  * @datasync: unused
0858  *
0859  * Return: 0 on success, -ENODEV if client is not connected
0860  */
0861 static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
0862 {
0863     struct mei_cl *cl = fp->private_data;
0864     struct mei_device *dev;
0865     int rets;
0866 
0867     if (WARN_ON(!cl || !cl->dev))
0868         return -ENODEV;
0869 
0870     dev = cl->dev;
0871 
0872     mutex_lock(&dev->device_lock);
0873 
0874     if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
0875         rets = -ENODEV;
0876         goto out;
0877     }
0878 
0879     while (mei_cl_is_write_queued(cl)) {
0880         mutex_unlock(&dev->device_lock);
0881         rets = wait_event_interruptible(cl->tx_wait,
0882                 cl->writing_state == MEI_WRITE_COMPLETE ||
0883                 !mei_cl_is_connected(cl));
0884         mutex_lock(&dev->device_lock);
0885         if (rets) {
0886             if (signal_pending(current))
0887                 rets = -EINTR;
0888             goto out;
0889         }
0890         if (!mei_cl_is_connected(cl)) {
0891             rets = -ENODEV;
0892             goto out;
0893         }
0894     }
0895     rets = 0;
0896 out:
0897     mutex_unlock(&dev->device_lock);
0898     return rets;
0899 }
0900 
0901 /**
0902  * mei_fasync - asynchronous io support
0903  *
0904  * @fd: file descriptor
0905  * @file: pointer to file structure
0906  * @band: band bitmap
0907  *
0908  * Return: negative on error,
0909  *         0 if it did no changes,
0910  *         and positive a process was added or deleted
0911  */
0912 static int mei_fasync(int fd, struct file *file, int band)
0913 {
0914 
0915     struct mei_cl *cl = file->private_data;
0916 
0917     if (!mei_cl_is_connected(cl))
0918         return -ENODEV;
0919 
0920     return fasync_helper(fd, file, band, &cl->ev_async);
0921 }
0922 
0923 /**
0924  * trc_show - mei device trc attribute show method
0925  *
0926  * @device: device pointer
0927  * @attr: attribute pointer
0928  * @buf:  char out buffer
0929  *
0930  * Return: number of the bytes printed into buf or error
0931  */
0932 static ssize_t trc_show(struct device *device,
0933             struct device_attribute *attr, char *buf)
0934 {
0935     struct mei_device *dev = dev_get_drvdata(device);
0936     u32 trc;
0937     int ret;
0938 
0939     ret = mei_trc_status(dev, &trc);
0940     if (ret)
0941         return ret;
0942     return sprintf(buf, "%08X\n", trc);
0943 }
0944 static DEVICE_ATTR_RO(trc);
0945 
0946 /**
0947  * fw_status_show - mei device fw_status attribute show method
0948  *
0949  * @device: device pointer
0950  * @attr: attribute pointer
0951  * @buf:  char out buffer
0952  *
0953  * Return: number of the bytes printed into buf or error
0954  */
0955 static ssize_t fw_status_show(struct device *device,
0956         struct device_attribute *attr, char *buf)
0957 {
0958     struct mei_device *dev = dev_get_drvdata(device);
0959     struct mei_fw_status fw_status;
0960     int err, i;
0961     ssize_t cnt = 0;
0962 
0963     mutex_lock(&dev->device_lock);
0964     err = mei_fw_status(dev, &fw_status);
0965     mutex_unlock(&dev->device_lock);
0966     if (err) {
0967         dev_err(device, "read fw_status error = %d\n", err);
0968         return err;
0969     }
0970 
0971     for (i = 0; i < fw_status.count; i++)
0972         cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
0973                 fw_status.status[i]);
0974     return cnt;
0975 }
0976 static DEVICE_ATTR_RO(fw_status);
0977 
0978 /**
0979  * hbm_ver_show - display HBM protocol version negotiated with FW
0980  *
0981  * @device: device pointer
0982  * @attr: attribute pointer
0983  * @buf:  char out buffer
0984  *
0985  * Return: number of the bytes printed into buf or error
0986  */
0987 static ssize_t hbm_ver_show(struct device *device,
0988                 struct device_attribute *attr, char *buf)
0989 {
0990     struct mei_device *dev = dev_get_drvdata(device);
0991     struct hbm_version ver;
0992 
0993     mutex_lock(&dev->device_lock);
0994     ver = dev->version;
0995     mutex_unlock(&dev->device_lock);
0996 
0997     return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
0998 }
0999 static DEVICE_ATTR_RO(hbm_ver);
1000 
1001 /**
1002  * hbm_ver_drv_show - display HBM protocol version advertised by driver
1003  *
1004  * @device: device pointer
1005  * @attr: attribute pointer
1006  * @buf:  char out buffer
1007  *
1008  * Return: number of the bytes printed into buf or error
1009  */
1010 static ssize_t hbm_ver_drv_show(struct device *device,
1011                 struct device_attribute *attr, char *buf)
1012 {
1013     return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
1014 }
1015 static DEVICE_ATTR_RO(hbm_ver_drv);
1016 
1017 static ssize_t tx_queue_limit_show(struct device *device,
1018                    struct device_attribute *attr, char *buf)
1019 {
1020     struct mei_device *dev = dev_get_drvdata(device);
1021     u8 size = 0;
1022 
1023     mutex_lock(&dev->device_lock);
1024     size = dev->tx_queue_limit;
1025     mutex_unlock(&dev->device_lock);
1026 
1027     return sysfs_emit(buf, "%u\n", size);
1028 }
1029 
1030 static ssize_t tx_queue_limit_store(struct device *device,
1031                     struct device_attribute *attr,
1032                     const char *buf, size_t count)
1033 {
1034     struct mei_device *dev = dev_get_drvdata(device);
1035     u8 limit;
1036     unsigned int inp;
1037     int err;
1038 
1039     err = kstrtouint(buf, 10, &inp);
1040     if (err)
1041         return err;
1042     if (inp > MEI_TX_QUEUE_LIMIT_MAX || inp < MEI_TX_QUEUE_LIMIT_MIN)
1043         return -EINVAL;
1044     limit = inp;
1045 
1046     mutex_lock(&dev->device_lock);
1047     dev->tx_queue_limit = limit;
1048     mutex_unlock(&dev->device_lock);
1049 
1050     return count;
1051 }
1052 static DEVICE_ATTR_RW(tx_queue_limit);
1053 
1054 /**
1055  * fw_ver_show - display ME FW version
1056  *
1057  * @device: device pointer
1058  * @attr: attribute pointer
1059  * @buf:  char out buffer
1060  *
1061  * Return: number of the bytes printed into buf or error
1062  */
1063 static ssize_t fw_ver_show(struct device *device,
1064                struct device_attribute *attr, char *buf)
1065 {
1066     struct mei_device *dev = dev_get_drvdata(device);
1067     struct mei_fw_version *ver;
1068     ssize_t cnt = 0;
1069     int i;
1070 
1071     ver = dev->fw_ver;
1072 
1073     for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++)
1074         cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%u:%u.%u.%u.%u\n",
1075                  ver[i].platform, ver[i].major, ver[i].minor,
1076                  ver[i].hotfix, ver[i].buildno);
1077     return cnt;
1078 }
1079 static DEVICE_ATTR_RO(fw_ver);
1080 
1081 /**
1082  * dev_state_show - display device state
1083  *
1084  * @device: device pointer
1085  * @attr: attribute pointer
1086  * @buf:  char out buffer
1087  *
1088  * Return: number of the bytes printed into buf or error
1089  */
1090 static ssize_t dev_state_show(struct device *device,
1091                   struct device_attribute *attr, char *buf)
1092 {
1093     struct mei_device *dev = dev_get_drvdata(device);
1094     enum mei_dev_state dev_state;
1095 
1096     mutex_lock(&dev->device_lock);
1097     dev_state = dev->dev_state;
1098     mutex_unlock(&dev->device_lock);
1099 
1100     return sprintf(buf, "%s", mei_dev_state_str(dev_state));
1101 }
1102 static DEVICE_ATTR_RO(dev_state);
1103 
1104 /**
1105  * mei_set_devstate: set to new device state and notify sysfs file.
1106  *
1107  * @dev: mei_device
1108  * @state: new device state
1109  */
1110 void mei_set_devstate(struct mei_device *dev, enum mei_dev_state state)
1111 {
1112     struct device *clsdev;
1113 
1114     if (dev->dev_state == state)
1115         return;
1116 
1117     dev->dev_state = state;
1118 
1119     clsdev = class_find_device_by_devt(mei_class, dev->cdev.dev);
1120     if (clsdev) {
1121         sysfs_notify(&clsdev->kobj, NULL, "dev_state");
1122         put_device(clsdev);
1123     }
1124 }
1125 
1126 /**
1127  * kind_show - display device kind
1128  *
1129  * @device: device pointer
1130  * @attr: attribute pointer
1131  * @buf: char out buffer
1132  *
1133  * Return: number of the bytes printed into buf or error
1134  */
1135 static ssize_t kind_show(struct device *device,
1136              struct device_attribute *attr, char *buf)
1137 {
1138     struct mei_device *dev = dev_get_drvdata(device);
1139     ssize_t ret;
1140 
1141     if (dev->kind)
1142         ret = sprintf(buf, "%s\n", dev->kind);
1143     else
1144         ret = sprintf(buf, "%s\n", "mei");
1145 
1146     return ret;
1147 }
1148 static DEVICE_ATTR_RO(kind);
1149 
1150 static struct attribute *mei_attrs[] = {
1151     &dev_attr_fw_status.attr,
1152     &dev_attr_hbm_ver.attr,
1153     &dev_attr_hbm_ver_drv.attr,
1154     &dev_attr_tx_queue_limit.attr,
1155     &dev_attr_fw_ver.attr,
1156     &dev_attr_dev_state.attr,
1157     &dev_attr_trc.attr,
1158     &dev_attr_kind.attr,
1159     NULL
1160 };
1161 ATTRIBUTE_GROUPS(mei);
1162 
1163 /*
1164  * file operations structure will be used for mei char device.
1165  */
1166 static const struct file_operations mei_fops = {
1167     .owner = THIS_MODULE,
1168     .read = mei_read,
1169     .unlocked_ioctl = mei_ioctl,
1170     .compat_ioctl = compat_ptr_ioctl,
1171     .open = mei_open,
1172     .release = mei_release,
1173     .write = mei_write,
1174     .poll = mei_poll,
1175     .fsync = mei_fsync,
1176     .fasync = mei_fasync,
1177     .llseek = no_llseek
1178 };
1179 
1180 /**
1181  * mei_minor_get - obtain next free device minor number
1182  *
1183  * @dev:  device pointer
1184  *
1185  * Return: allocated minor, or -ENOSPC if no free minor left
1186  */
1187 static int mei_minor_get(struct mei_device *dev)
1188 {
1189     int ret;
1190 
1191     mutex_lock(&mei_minor_lock);
1192     ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
1193     if (ret >= 0)
1194         dev->minor = ret;
1195     else if (ret == -ENOSPC)
1196         dev_err(dev->dev, "too many mei devices\n");
1197 
1198     mutex_unlock(&mei_minor_lock);
1199     return ret;
1200 }
1201 
1202 /**
1203  * mei_minor_free - mark device minor number as free
1204  *
1205  * @dev:  device pointer
1206  */
1207 static void mei_minor_free(struct mei_device *dev)
1208 {
1209     mutex_lock(&mei_minor_lock);
1210     idr_remove(&mei_idr, dev->minor);
1211     mutex_unlock(&mei_minor_lock);
1212 }
1213 
1214 int mei_register(struct mei_device *dev, struct device *parent)
1215 {
1216     struct device *clsdev; /* class device */
1217     int ret, devno;
1218 
1219     ret = mei_minor_get(dev);
1220     if (ret < 0)
1221         return ret;
1222 
1223     /* Fill in the data structures */
1224     devno = MKDEV(MAJOR(mei_devt), dev->minor);
1225     cdev_init(&dev->cdev, &mei_fops);
1226     dev->cdev.owner = parent->driver->owner;
1227 
1228     /* Add the device */
1229     ret = cdev_add(&dev->cdev, devno, 1);
1230     if (ret) {
1231         dev_err(parent, "unable to add device %d:%d\n",
1232             MAJOR(mei_devt), dev->minor);
1233         goto err_dev_add;
1234     }
1235 
1236     clsdev = device_create_with_groups(mei_class, parent, devno,
1237                        dev, mei_groups,
1238                        "mei%d", dev->minor);
1239 
1240     if (IS_ERR(clsdev)) {
1241         dev_err(parent, "unable to create device %d:%d\n",
1242             MAJOR(mei_devt), dev->minor);
1243         ret = PTR_ERR(clsdev);
1244         goto err_dev_create;
1245     }
1246 
1247     mei_dbgfs_register(dev, dev_name(clsdev));
1248 
1249     return 0;
1250 
1251 err_dev_create:
1252     cdev_del(&dev->cdev);
1253 err_dev_add:
1254     mei_minor_free(dev);
1255     return ret;
1256 }
1257 EXPORT_SYMBOL_GPL(mei_register);
1258 
1259 void mei_deregister(struct mei_device *dev)
1260 {
1261     int devno;
1262 
1263     devno = dev->cdev.dev;
1264     cdev_del(&dev->cdev);
1265 
1266     mei_dbgfs_deregister(dev);
1267 
1268     device_destroy(mei_class, devno);
1269 
1270     mei_minor_free(dev);
1271 }
1272 EXPORT_SYMBOL_GPL(mei_deregister);
1273 
1274 static int __init mei_init(void)
1275 {
1276     int ret;
1277 
1278     mei_class = class_create(THIS_MODULE, "mei");
1279     if (IS_ERR(mei_class)) {
1280         pr_err("couldn't create class\n");
1281         ret = PTR_ERR(mei_class);
1282         goto err;
1283     }
1284 
1285     ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
1286     if (ret < 0) {
1287         pr_err("unable to allocate char dev region\n");
1288         goto err_class;
1289     }
1290 
1291     ret = mei_cl_bus_init();
1292     if (ret < 0) {
1293         pr_err("unable to initialize bus\n");
1294         goto err_chrdev;
1295     }
1296 
1297     return 0;
1298 
1299 err_chrdev:
1300     unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1301 err_class:
1302     class_destroy(mei_class);
1303 err:
1304     return ret;
1305 }
1306 
1307 static void __exit mei_exit(void)
1308 {
1309     unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1310     class_destroy(mei_class);
1311     mei_cl_bus_exit();
1312 }
1313 
1314 module_init(mei_init);
1315 module_exit(mei_exit);
1316 
1317 MODULE_AUTHOR("Intel Corporation");
1318 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
1319 MODULE_LICENSE("GPL v2");
1320
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