iorw.c

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/*
 *
 * Intel Management Engine Interface (Intel MEI) Linux driver
 * Copyright (c) 2003-2012, 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/kernel.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/aio.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/list.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/uuid.h>
#include <linux/jiffies.h>
#include <linux/uaccess.h>


#include "mei_dev.h"
#include "hw.h"
#include <linux/mei.h>
#include "interface.h"

int mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
{
    int i;
    for (i = 0; i < dev->me_clients_num; i++)
        if (dev->me_clients[i].client_id == client_id)
            break;
    if (WARN_ON(dev->me_clients[i].client_id != client_id))
        return -ENOENT;

    if (i == dev->me_clients_num)
        return -ENOENT;

    return i;
}

int mei_ioctl_connect_client(struct file *file,
            struct mei_connect_client_data *data)
{
    struct mei_device *dev;
    struct mei_cl_cb *cb;
    struct mei_client *client;
    struct mei_cl *cl;
    struct mei_cl *cl_pos = NULL;
    struct mei_cl *cl_next = NULL;
    long timeout = CONNECT_TIMEOUT;
    int i;
    int err;
    int rets;

    cl = file->private_data;
    if (WARN_ON(!cl || !cl->dev))
        return -ENODEV;

    dev = cl->dev;

    dev_dbg(&dev->pdev->dev, "mei_ioctl_connect_client() Entry\n");


    /* buffered ioctl cb */
    cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
    if (!cb) {
        rets = -ENOMEM;
        goto end;
    }
    INIT_LIST_HEAD(&cb->cb_list);

    cb->major_file_operations = MEI_IOCTL;

    if (dev->dev_state != MEI_DEV_ENABLED) {
        rets = -ENODEV;
        goto end;
    }
    if (cl->state != MEI_FILE_INITIALIZING &&
        cl->state != MEI_FILE_DISCONNECTED) {
        rets = -EBUSY;
        goto end;
    }

    /* find ME client we're trying to connect to */
    i = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
    if (i >= 0 && !dev->me_clients[i].props.fixed_address) {
        cl->me_client_id = dev->me_clients[i].client_id;
        cl->state = MEI_FILE_CONNECTING;
    }

    dev_dbg(&dev->pdev->dev, "Connect to FW Client ID = %d\n",
            cl->me_client_id);
    dev_dbg(&dev->pdev->dev, "FW Client - Protocol Version = %d\n",
            dev->me_clients[i].props.protocol_version);
    dev_dbg(&dev->pdev->dev, "FW Client - Max Msg Len = %d\n",
            dev->me_clients[i].props.max_msg_length);

    /* if we're connecting to amthi client then we will use the
     * existing connection
     */
    if (uuid_le_cmp(data->in_client_uuid, mei_amthi_guid) == 0) {
        dev_dbg(&dev->pdev->dev, "FW Client is amthi\n");
        if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
            rets = -ENODEV;
            goto end;
        }
        clear_bit(cl->host_client_id, dev->host_clients_map);
        list_for_each_entry_safe(cl_pos, cl_next,
                     &dev->file_list, link) {
            if (mei_cl_cmp_id(cl, cl_pos)) {
                dev_dbg(&dev->pdev->dev,
                    "remove file private data node host"
                    " client = %d, ME client = %d.\n",
                    cl_pos->host_client_id,
                    cl_pos->me_client_id);
                list_del(&cl_pos->link);
            }

        }
        dev_dbg(&dev->pdev->dev, "free file private data memory.\n");
        kfree(cl);

        cl = NULL;
        file->private_data = &dev->iamthif_cl;

        client = &data->out_client_properties;
        client->max_msg_length =
            dev->me_clients[i].props.max_msg_length;
        client->protocol_version =
            dev->me_clients[i].props.protocol_version;
        rets = dev->iamthif_cl.status;

        goto end;
    }

    if (cl->state != MEI_FILE_CONNECTING) {
        rets = -ENODEV;
        goto end;
    }


    /* prepare the output buffer */
    client = &data->out_client_properties;
    client->max_msg_length = dev->me_clients[i].props.max_msg_length;
    client->protocol_version = dev->me_clients[i].props.protocol_version;
    dev_dbg(&dev->pdev->dev, "Can connect?\n");
    if (dev->mei_host_buffer_is_empty
        && !mei_other_client_is_connecting(dev, cl)) {
        dev_dbg(&dev->pdev->dev, "Sending Connect Message\n");
        dev->mei_host_buffer_is_empty = false;
        if (mei_connect(dev, cl)) {
            dev_dbg(&dev->pdev->dev, "Sending connect message - failed\n");
            rets = -ENODEV;
            goto end;
        } else {
            dev_dbg(&dev->pdev->dev, "Sending connect message - succeeded\n");
            cl->timer_count = MEI_CONNECT_TIMEOUT;
            cb->file_private = cl;
            list_add_tail(&cb->cb_list,
                      &dev->ctrl_rd_list.mei_cb.
                      cb_list);
        }


    } else {
        dev_dbg(&dev->pdev->dev, "Queuing the connect request due to device busy\n");
        cb->file_private = cl;
        dev_dbg(&dev->pdev->dev, "add connect cb to control write list.\n");
        list_add_tail(&cb->cb_list,
                  &dev->ctrl_wr_list.mei_cb.cb_list);
    }
    mutex_unlock(&dev->device_lock);
    err = wait_event_timeout(dev->wait_recvd_msg,
            (MEI_FILE_CONNECTED == cl->state ||
             MEI_FILE_DISCONNECTED == cl->state),
            timeout * HZ);

    mutex_lock(&dev->device_lock);
    if (MEI_FILE_CONNECTED == cl->state) {
        dev_dbg(&dev->pdev->dev, "successfully connected to FW client.\n");
        rets = cl->status;
        goto end;
    } else {
        dev_dbg(&dev->pdev->dev, "failed to connect to FW client.cl->state = %d.\n",
            cl->state);
        if (!err) {
            dev_dbg(&dev->pdev->dev,
                "wait_event_interruptible_timeout failed on client"
                " connect message fw response message.\n");
        }
        rets = -EFAULT;

        mei_io_list_flush(&dev->ctrl_rd_list, cl);
        mei_io_list_flush(&dev->ctrl_wr_list, cl);
        goto end;
    }
    rets = 0;
end:
    dev_dbg(&dev->pdev->dev, "free connect cb memory.");
    kfree(cb);
    return rets;
}

struct mei_cl_cb *find_amthi_read_list_entry(
        struct mei_device *dev,
        struct file *file)
{
    struct mei_cl *cl_temp;
    struct mei_cl_cb *pos = NULL;
    struct mei_cl_cb *next = NULL;

    list_for_each_entry_safe(pos, next,
        &dev->amthi_read_complete_list.mei_cb.cb_list, cb_list) {
        cl_temp = (struct mei_cl *)pos->file_private;
        if (cl_temp && cl_temp == &dev->iamthif_cl &&
            pos->file_object == file)
            return pos;
    }
    return NULL;
}

int amthi_read(struct mei_device *dev, struct file *file,
           char __user *ubuf, size_t length, loff_t *offset)
{
    int rets;
    int wait_ret;
    struct mei_cl_cb *cb = NULL;
    struct mei_cl *cl = file->private_data;
    unsigned long timeout;
    int i;

    /* Only Posible if we are in timeout */
    if (!cl || cl != &dev->iamthif_cl) {
        dev_dbg(&dev->pdev->dev, "bad file ext.\n");
        return -ETIMEDOUT;
    }

    i = mei_me_cl_by_id(dev, dev->iamthif_cl.me_client_id);

    if (i < 0) {
        dev_dbg(&dev->pdev->dev, "amthi client not found.\n");
        return -ENODEV;
    }
    dev_dbg(&dev->pdev->dev, "checking amthi data\n");
    cb = find_amthi_read_list_entry(dev, file);

    /* Check for if we can block or not*/
    if (cb == NULL && file->f_flags & O_NONBLOCK)
        return -EAGAIN;


    dev_dbg(&dev->pdev->dev, "waiting for amthi data\n");
    while (cb == NULL) {
        /* unlock the Mutex */
        mutex_unlock(&dev->device_lock);

        wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
            (cb = find_amthi_read_list_entry(dev, file)));

        if (wait_ret)
            return -ERESTARTSYS;

        dev_dbg(&dev->pdev->dev, "woke up from sleep\n");

        /* Locking again the Mutex */
        mutex_lock(&dev->device_lock);
    }


    dev_dbg(&dev->pdev->dev, "Got amthi data\n");
    dev->iamthif_timer = 0;

    if (cb) {
        timeout = cb->read_time + msecs_to_jiffies(IAMTHIF_READ_TIMER);
        dev_dbg(&dev->pdev->dev, "amthi timeout = %lud\n",
                timeout);

        if  (time_after(jiffies, timeout)) {
            dev_dbg(&dev->pdev->dev, "amthi Time out\n");
            /* 15 sec for the message has expired */
            list_del(&cb->cb_list);
            rets = -ETIMEDOUT;
            goto free;
        }
    }
    /* if the whole message will fit remove it from the list */
    if (cb->information >= *offset && length >= (cb->information - *offset))
        list_del(&cb->cb_list);
    else if (cb->information > 0 && cb->information <= *offset) {
        /* end of the message has been reached */
        list_del(&cb->cb_list);
        rets = 0;
        goto free;
    }
        /* else means that not full buffer will be read and do not
         * remove message from deletion list
         */

    dev_dbg(&dev->pdev->dev, "amthi cb->response_buffer size - %d\n",
        cb->response_buffer.size);
    dev_dbg(&dev->pdev->dev, "amthi cb->information - %lu\n",
        cb->information);

    /* length is being turncated to PAGE_SIZE, however,
     * the information may be longer */
    length = min_t(size_t, length, (cb->information - *offset));

    if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length))
        rets = -EFAULT;
    else {
        rets = length;
        if ((*offset + length) < cb->information) {
            *offset += length;
            goto out;
        }
    }
free:
    dev_dbg(&dev->pdev->dev, "free amthi cb memory.\n");
    *offset = 0;
    mei_free_cb_private(cb);
out:
    return rets;
}

int mei_start_read(struct mei_device *dev, struct mei_cl *cl)
{
    struct mei_cl_cb *cb;
    int rets = 0;
    int i;

    if (cl->state != MEI_FILE_CONNECTED)
        return -ENODEV;

    if (dev->dev_state != MEI_DEV_ENABLED)
        return -ENODEV;

    dev_dbg(&dev->pdev->dev, "check if read is pending.\n");
    if (cl->read_pending || cl->read_cb) {
        dev_dbg(&dev->pdev->dev, "read is pending.\n");
        return -EBUSY;
    }

    cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
    if (!cb)
        return -ENOMEM;

    dev_dbg(&dev->pdev->dev, "allocation call back successful. host client = %d, ME client = %d\n",
        cl->host_client_id, cl->me_client_id);
    i = mei_me_cl_by_id(dev, cl->me_client_id);
    if (i < 0) {
        rets = -ENODEV;
        goto unlock;
    }

    cb->response_buffer.size = dev->me_clients[i].props.max_msg_length;
    cb->response_buffer.data =
            kmalloc(cb->response_buffer.size, GFP_KERNEL);
    if (!cb->response_buffer.data) {
        rets = -ENOMEM;
        goto unlock;
    }
    dev_dbg(&dev->pdev->dev, "allocation call back data success.\n");
    cb->major_file_operations = MEI_READ;
    /* make sure information is zero before we start */
    cb->information = 0;
    cb->file_private = (void *) cl;
    cl->read_cb = cb;
    if (dev->mei_host_buffer_is_empty) {
        dev->mei_host_buffer_is_empty = false;
        if (mei_send_flow_control(dev, cl)) {
            rets = -ENODEV;
            goto unlock;
        }
        list_add_tail(&cb->cb_list, &dev->read_list.mei_cb.cb_list);
    } else {
        list_add_tail(&cb->cb_list, &dev->ctrl_wr_list.mei_cb.cb_list);
    }
    return rets;
unlock:
    mei_free_cb_private(cb);
    return rets;
}

int amthi_write(struct mei_device *dev, struct mei_cl_cb *cb)
{
    struct mei_msg_hdr mei_hdr;
    int ret;

    if (!dev || !cb)
        return -ENODEV;

    dev_dbg(&dev->pdev->dev, "write data to amthi client.\n");

    dev->iamthif_state = MEI_IAMTHIF_WRITING;
    dev->iamthif_current_cb = cb;
    dev->iamthif_file_object = cb->file_object;
    dev->iamthif_canceled = false;
    dev->iamthif_ioctl = true;
    dev->iamthif_msg_buf_size = cb->request_buffer.size;
    memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
           cb->request_buffer.size);

    ret = mei_flow_ctrl_creds(dev, &dev->iamthif_cl);
    if (ret < 0)
        return ret;

    if (ret && dev->mei_host_buffer_is_empty) {
        ret = 0;
        dev->mei_host_buffer_is_empty = false;
        if (cb->request_buffer.size > mei_hbuf_max_data(dev)) {
            mei_hdr.length = mei_hbuf_max_data(dev);
            mei_hdr.msg_complete = 0;
        } else {
            mei_hdr.length = cb->request_buffer.size;
            mei_hdr.msg_complete = 1;
        }

        mei_hdr.host_addr = dev->iamthif_cl.host_client_id;
        mei_hdr.me_addr = dev->iamthif_cl.me_client_id;
        mei_hdr.reserved = 0;
        dev->iamthif_msg_buf_index += mei_hdr.length;
        if (mei_write_message(dev, &mei_hdr,
                    (unsigned char *)(dev->iamthif_msg_buf),
                    mei_hdr.length))
            return -ENODEV;

        if (mei_hdr.msg_complete) {
            if (mei_flow_ctrl_reduce(dev, &dev->iamthif_cl))
                return -ENODEV;
            dev->iamthif_flow_control_pending = true;
            dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
            dev_dbg(&dev->pdev->dev, "add amthi cb to write waiting list\n");
            dev->iamthif_current_cb = cb;
            dev->iamthif_file_object = cb->file_object;
            list_add_tail(&cb->cb_list,
                      &dev->write_waiting_list.mei_cb.cb_list);
        } else {
            dev_dbg(&dev->pdev->dev, "message does not complete, "
                    "so add amthi cb to write list.\n");
            list_add_tail(&cb->cb_list,
                      &dev->write_list.mei_cb.cb_list);
        }
    } else {
        if (!(dev->mei_host_buffer_is_empty))
            dev_dbg(&dev->pdev->dev, "host buffer is not empty");

        dev_dbg(&dev->pdev->dev, "No flow control credentials, "
                "so add iamthif cb to write list.\n");
        list_add_tail(&cb->cb_list, &dev->write_list.mei_cb.cb_list);
    }
    return 0;
}

void mei_run_next_iamthif_cmd(struct mei_device *dev)
{
    struct mei_cl *cl_tmp;
    struct mei_cl_cb *pos = NULL;
    struct mei_cl_cb *next = NULL;
    int status;

    if (!dev)
        return;

    dev->iamthif_msg_buf_size = 0;
    dev->iamthif_msg_buf_index = 0;
    dev->iamthif_canceled = false;
    dev->iamthif_ioctl = true;
    dev->iamthif_state = MEI_IAMTHIF_IDLE;
    dev->iamthif_timer = 0;
    dev->iamthif_file_object = NULL;

    dev_dbg(&dev->pdev->dev, "complete amthi cmd_list cb.\n");

    list_for_each_entry_safe(pos, next,
            &dev->amthi_cmd_list.mei_cb.cb_list, cb_list) {
        list_del(&pos->cb_list);
        cl_tmp = (struct mei_cl *)pos->file_private;

        if (cl_tmp && cl_tmp == &dev->iamthif_cl) {
            status = amthi_write(dev, pos);
            if (status) {
                dev_dbg(&dev->pdev->dev,
                    "amthi write failed status = %d\n",
                        status);
                return;
            }
            break;
        }
    }
}

void mei_free_cb_private(struct mei_cl_cb *cb)
{
    if (cb == NULL)
        return;

    kfree(cb->request_buffer.data);
    kfree(cb->response_buffer.data);
    kfree(cb);
}