linux/drivers/misc/mei/main.c
Tomas Winkler 9b0d5efc42 mei: revamp hbm state machine
1. Rename init_clients_state to hbm_state and use
MEI_HBM_ prefix for HBM states

2. Remove recvd_msg and use hbm state for synchronizing
hbm protocol has successful start.
We can wake up the hbm event from start response handler
and remove the hack from the interrupt thread

3. mei_hbm_start_wait function encapsulate start completion
waiting

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-19 10:58:21 -07:00

746 lines
16 KiB
C

/*
*
* 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.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/device.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/poll.h>
#include <linux/init.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/sched.h>
#include <linux/uuid.h>
#include <linux/compat.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/miscdevice.h>
#include <linux/mei.h>
#include "mei_dev.h"
#include "hw-me.h"
#include "client.h"
/**
* mei_open - the open function
*
* @inode: pointer to inode structure
* @file: pointer to file structure
e
* returns 0 on success, <0 on error
*/
static int mei_open(struct inode *inode, struct file *file)
{
struct miscdevice *misc = file->private_data;
struct pci_dev *pdev;
struct mei_cl *cl;
struct mei_device *dev;
int err;
err = -ENODEV;
if (!misc->parent)
goto out;
pdev = container_of(misc->parent, struct pci_dev, dev);
dev = pci_get_drvdata(pdev);
if (!dev)
goto out;
mutex_lock(&dev->device_lock);
err = -ENOMEM;
cl = mei_cl_allocate(dev);
if (!cl)
goto out_unlock;
err = -ENODEV;
if (dev->dev_state != MEI_DEV_ENABLED) {
dev_dbg(&dev->pdev->dev, "dev_state != MEI_ENABLED dev_state = %s\n",
mei_dev_state_str(dev->dev_state));
goto out_unlock;
}
err = -EMFILE;
if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
dev_err(&dev->pdev->dev, "open_handle_count exceded %d",
MEI_MAX_OPEN_HANDLE_COUNT);
goto out_unlock;
}
err = mei_cl_link(cl, MEI_HOST_CLIENT_ID_ANY);
if (err)
goto out_unlock;
file->private_data = cl;
mutex_unlock(&dev->device_lock);
return nonseekable_open(inode, file);
out_unlock:
mutex_unlock(&dev->device_lock);
kfree(cl);
out:
return err;
}
/**
* mei_release - the release function
*
* @inode: pointer to inode structure
* @file: pointer to file structure
*
* returns 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_cl_cb *cb;
struct mei_device *dev;
int rets = 0;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_release(dev, file);
goto out;
}
if (cl->state == MEI_FILE_CONNECTED) {
cl->state = MEI_FILE_DISCONNECTING;
dev_dbg(&dev->pdev->dev,
"disconnecting client host client = %d, "
"ME client = %d\n",
cl->host_client_id,
cl->me_client_id);
rets = mei_cl_disconnect(cl);
}
mei_cl_flush_queues(cl);
dev_dbg(&dev->pdev->dev, "remove client host client = %d, ME client = %d\n",
cl->host_client_id,
cl->me_client_id);
if (dev->open_handle_count > 0) {
clear_bit(cl->host_client_id, dev->host_clients_map);
dev->open_handle_count--;
}
mei_cl_unlink(cl);
/* free read cb */
cb = NULL;
if (cl->read_cb) {
cb = mei_cl_find_read_cb(cl);
/* Remove entry from read list */
if (cb)
list_del(&cb->list);
cb = cl->read_cb;
cl->read_cb = NULL;
}
file->private_data = NULL;
if (cb) {
mei_io_cb_free(cb);
cb = NULL;
}
kfree(cl);
out:
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
*
* returns >=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_cl_cb *cb_pos = NULL;
struct mei_cl_cb *cb = NULL;
struct mei_device *dev;
int i;
int rets;
int err;
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 ((cl->sm_state & MEI_WD_STATE_INDEPENDENCE_MSG_SENT) == 0) {
/* Do not allow to read watchdog client */
i = mei_me_cl_by_uuid(dev, &mei_wd_guid);
if (i >= 0) {
struct mei_me_client *me_client = &dev->me_clients[i];
if (cl->me_client_id == me_client->client_id) {
rets = -EBADF;
goto out;
}
}
} else {
cl->sm_state &= ~MEI_WD_STATE_INDEPENDENCE_MSG_SENT;
}
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_read(dev, file, ubuf, length, offset);
goto out;
}
if (cl->read_cb && cl->read_cb->buf_idx > *offset) {
cb = cl->read_cb;
goto copy_buffer;
} else if (cl->read_cb && cl->read_cb->buf_idx > 0 &&
cl->read_cb->buf_idx <= *offset) {
cb = cl->read_cb;
rets = 0;
goto free;
} else if ((!cl->read_cb || !cl->read_cb->buf_idx) && *offset > 0) {
/*Offset needs to be cleaned for contiguous reads*/
*offset = 0;
rets = 0;
goto out;
}
err = mei_cl_read_start(cl);
if (err && err != -EBUSY) {
dev_dbg(&dev->pdev->dev,
"mei start read failure with status = %d\n", err);
rets = err;
goto out;
}
if (MEI_READ_COMPLETE != cl->reading_state &&
!waitqueue_active(&cl->rx_wait)) {
if (file->f_flags & O_NONBLOCK) {
rets = -EAGAIN;
goto out;
}
mutex_unlock(&dev->device_lock);
if (wait_event_interruptible(cl->rx_wait,
(MEI_READ_COMPLETE == cl->reading_state ||
MEI_FILE_INITIALIZING == cl->state ||
MEI_FILE_DISCONNECTED == cl->state ||
MEI_FILE_DISCONNECTING == cl->state))) {
if (signal_pending(current))
return -EINTR;
return -ERESTARTSYS;
}
mutex_lock(&dev->device_lock);
if (MEI_FILE_INITIALIZING == cl->state ||
MEI_FILE_DISCONNECTED == cl->state ||
MEI_FILE_DISCONNECTING == cl->state) {
rets = -EBUSY;
goto out;
}
}
cb = cl->read_cb;
if (!cb) {
rets = -ENODEV;
goto out;
}
if (cl->reading_state != MEI_READ_COMPLETE) {
rets = 0;
goto out;
}
/* now copy the data to user space */
copy_buffer:
dev_dbg(&dev->pdev->dev, "cb->response_buffer size - %d\n",
cb->response_buffer.size);
dev_dbg(&dev->pdev->dev, "cb->buf_idx - %lu\n", cb->buf_idx);
if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
rets = -EMSGSIZE;
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->response_buffer.data + *offset, length)) {
rets = -EFAULT;
goto free;
}
rets = length;
*offset += length;
if ((unsigned long)*offset < cb->buf_idx)
goto out;
free:
cb_pos = mei_cl_find_read_cb(cl);
/* Remove entry from read list */
if (cb_pos)
list_del(&cb_pos->list);
mei_io_cb_free(cb);
cl->reading_state = MEI_IDLE;
cl->read_cb = NULL;
out:
dev_dbg(&dev->pdev->dev, "end mei read rets= %d\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
*
* returns >=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 *write_cb = NULL;
struct mei_device *dev;
unsigned long timeout = 0;
int rets;
int id;
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;
}
id = mei_me_cl_by_id(dev, cl->me_client_id);
if (id < 0) {
rets = -ENODEV;
goto out;
}
if (length > dev->me_clients[id].props.max_msg_length || length <= 0) {
rets = -EMSGSIZE;
goto out;
}
if (cl->state != MEI_FILE_CONNECTED) {
dev_err(&dev->pdev->dev, "host client = %d, is not connected to ME client = %d",
cl->host_client_id, cl->me_client_id);
rets = -ENODEV;
goto out;
}
if (cl == &dev->iamthif_cl) {
write_cb = mei_amthif_find_read_list_entry(dev, file);
if (write_cb) {
timeout = write_cb->read_time +
mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
if (time_after(jiffies, timeout) ||
cl->reading_state == MEI_READ_COMPLETE) {
*offset = 0;
list_del(&write_cb->list);
mei_io_cb_free(write_cb);
write_cb = NULL;
}
}
}
/* free entry used in read */
if (cl->reading_state == MEI_READ_COMPLETE) {
*offset = 0;
write_cb = mei_cl_find_read_cb(cl);
if (write_cb) {
list_del(&write_cb->list);
mei_io_cb_free(write_cb);
write_cb = NULL;
cl->reading_state = MEI_IDLE;
cl->read_cb = NULL;
}
} else if (cl->reading_state == MEI_IDLE)
*offset = 0;
write_cb = mei_io_cb_init(cl, file);
if (!write_cb) {
dev_err(&dev->pdev->dev, "write cb allocation failed\n");
rets = -ENOMEM;
goto out;
}
rets = mei_io_cb_alloc_req_buf(write_cb, length);
if (rets)
goto out;
rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
if (rets)
goto out;
cl->sm_state = 0;
if (length == 4 &&
((memcmp(mei_wd_state_independence_msg[0],
write_cb->request_buffer.data, 4) == 0) ||
(memcmp(mei_wd_state_independence_msg[1],
write_cb->request_buffer.data, 4) == 0) ||
(memcmp(mei_wd_state_independence_msg[2],
write_cb->request_buffer.data, 4) == 0)))
cl->sm_state |= MEI_WD_STATE_INDEPENDENCE_MSG_SENT;
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_write(dev, write_cb);
if (rets) {
dev_err(&dev->pdev->dev,
"amthif write failed with status = %d\n", rets);
goto out;
}
mutex_unlock(&dev->device_lock);
return length;
}
rets = mei_cl_write(cl, write_cb, false);
out:
mutex_unlock(&dev->device_lock);
if (rets < 0)
mei_io_cb_free(write_cb);
return rets;
}
/**
* mei_ioctl_connect_client - the connect to fw client IOCTL function
*
* @dev: the device structure
* @data: IOCTL connect data, input and output parameters
* @file: private data of the file object
*
* Locking: called under "dev->device_lock" lock
*
* returns 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_cl *cl;
int i;
int rets;
cl = file->private_data;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
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 amthif client then we will use the
* existing connection
*/
if (uuid_le_cmp(data->in_client_uuid, mei_amthif_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);
mei_cl_unlink(cl);
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");
rets = mei_cl_connect(cl, file);
end:
dev_dbg(&dev->pdev->dev, "free connect cb memory.");
return rets;
}
/**
* mei_ioctl - the IOCTL function
*
* @file: pointer to file structure
* @cmd: ioctl command
* @data: pointer to mei message structure
*
* returns 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 = NULL;
int rets;
if (cmd != IOCTL_MEI_CONNECT_CLIENT)
return -EINVAL;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
dev_dbg(&dev->pdev->dev, "IOCTL cmd = 0x%x", cmd);
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
rets = -ENODEV;
goto out;
}
dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
connect_data = kzalloc(sizeof(struct mei_connect_client_data),
GFP_KERNEL);
if (!connect_data) {
rets = -ENOMEM;
goto out;
}
dev_dbg(&dev->pdev->dev, "copy connect data from user\n");
if (copy_from_user(connect_data, (char __user *)data,
sizeof(struct mei_connect_client_data))) {
dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
rets = -EFAULT;
goto out;
}
rets = mei_ioctl_connect_client(file, connect_data);
/* if all is ok, copying the data back to user. */
if (rets)
goto out;
dev_dbg(&dev->pdev->dev, "copy connect data to user\n");
if (copy_to_user((char __user *)data, connect_data,
sizeof(struct mei_connect_client_data))) {
dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
rets = -EFAULT;
goto out;
}
out:
kfree(connect_data);
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
*
* returns 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
*
* returns poll mask
*/
static unsigned int mei_poll(struct file *file, poll_table *wait)
{
struct mei_cl *cl = file->private_data;
struct mei_device *dev;
unsigned int mask = 0;
if (WARN_ON(!cl || !cl->dev))
return mask;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED)
goto out;
if (cl == &dev->iamthif_cl) {
mask = mei_amthif_poll(dev, file, wait);
goto out;
}
mutex_unlock(&dev->device_lock);
poll_wait(file, &cl->tx_wait, wait);
mutex_lock(&dev->device_lock);
if (MEI_WRITE_COMPLETE == cl->writing_state)
mask |= (POLLIN | POLLRDNORM);
out:
mutex_unlock(&dev->device_lock);
return mask;
}
/*
* 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,
.llseek = no_llseek
};
/*
* Misc Device Struct
*/
static struct miscdevice mei_misc_device = {
.name = "mei",
.fops = &mei_fops,
.minor = MISC_DYNAMIC_MINOR,
};
int mei_register(struct mei_device *dev)
{
int ret;
mei_misc_device.parent = &dev->pdev->dev;
ret = misc_register(&mei_misc_device);
if (ret)
return ret;
if (mei_dbgfs_register(dev, mei_misc_device.name))
dev_err(&dev->pdev->dev, "cannot register debugfs\n");
return 0;
}
EXPORT_SYMBOL_GPL(mei_register);
void mei_deregister(struct mei_device *dev)
{
mei_dbgfs_deregister(dev);
misc_deregister(&mei_misc_device);
mei_misc_device.parent = NULL;
}
EXPORT_SYMBOL_GPL(mei_deregister);
static int __init mei_init(void)
{
return mei_cl_bus_init();
}
static void __exit mei_exit(void)
{
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");