- 根目录:
- drivers
- misc
- mei
- amthif.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.
*
*/
#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/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 <linux/slab.h>
#include <linux/mei.h>
#include "mei_dev.h"
#include "hbm.h"
#include "client.h"
const uuid_le mei_amthif_guid = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d,
0xac, 0xa8, 0x46, 0xe0,
0xff, 0x65, 0x81, 0x4c);
/**
* mei_amthif_reset_params - initializes mei device iamthif
*
* @dev: the device structure
*/
void mei_amthif_reset_params(struct mei_device *dev)
{
/* reset iamthif parameters. */
dev->iamthif_current_cb = NULL;
dev->iamthif_msg_buf_size = 0;
dev->iamthif_msg_buf_index = 0;
dev->iamthif_canceled = false;
dev->iamthif_ioctl = false;
dev->iamthif_state = MEI_IAMTHIF_IDLE;
dev->iamthif_timer = 0;
dev->iamthif_stall_timer = 0;
dev->iamthif_open_count = 0;
}
/**
* mei_amthif_host_init - mei initialization amthif client.
*
* @dev: the device structure
*
* Return: 0 on success, <0 on failure.
*/
int mei_amthif_host_init(struct mei_device *dev)
{
struct mei_cl *cl = &dev->iamthif_cl;
struct mei_me_client *me_cl;
unsigned char *msg_buf;
int ret;
dev->iamthif_state = MEI_IAMTHIF_IDLE;
mei_cl_init(cl, dev);
me_cl = mei_me_cl_by_uuid(dev, &mei_amthif_guid);
if (!me_cl) {
dev_info(dev->dev, "amthif: failed to find the client");
return -ENOTTY;
}
cl->me_client_id = me_cl->client_id;
cl->cl_uuid = me_cl->props.protocol_name;
/* Assign iamthif_mtu to the value received from ME */
dev->iamthif_mtu = me_cl->props.max_msg_length;
dev_dbg(dev->dev, "IAMTHIF_MTU = %d\n", dev->iamthif_mtu);
kfree(dev->iamthif_msg_buf);
dev->iamthif_msg_buf = NULL;
/* allocate storage for ME message buffer */
msg_buf = kcalloc(dev->iamthif_mtu,
sizeof(unsigned char), GFP_KERNEL);
if (!msg_buf)
return -ENOMEM;
dev->iamthif_msg_buf = msg_buf;
ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
if (ret < 0) {
dev_err(dev->dev,
"amthif: failed link client %d\n", ret);
return ret;
}
ret = mei_cl_connect(cl, NULL);
dev->iamthif_state = MEI_IAMTHIF_IDLE;
return ret;
}
/**
* mei_amthif_find_read_list_entry - finds a amthilist entry for current file
*
* @dev: the device structure
* @file: pointer to file object
*
* Return: returned a list entry on success, NULL on failure.
*/
struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
struct file *file)
{
struct mei_cl_cb *cb;
list_for_each_entry(cb, &dev->amthif_rd_complete_list.list, list)
if (cb->file_object == file)
return cb;
return NULL;
}
/**
* mei_amthif_read - read data from AMTHIF client
*
* @dev: the device structure
* @file: pointer to file object
* @ubuf: pointer to user data in user space
* @length: data length to read
* @offset: data read offset
*
* Locking: called under "dev->device_lock" lock
*
* Return:
* returned data length on success,
* zero if no data to read,
* negative on failure.
*/
int mei_amthif_read(struct mei_device *dev, struct file *file,
char __user *ubuf, size_t length, loff_t *offset)
{
struct mei_cl *cl = file->private_data;
struct mei_cl_cb *cb;
unsigned long timeout;
int rets;
int wait_ret;
/* Only possible if we are in timeout */
if (!cl) {
dev_err(dev->dev, "bad file ext.\n");
return -ETIME;
}
dev_dbg(dev->dev, "checking amthif data\n");
cb = mei_amthif_find_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->dev, "waiting for amthif data\n");
while (cb == NULL) {
/* unlock the Mutex */
mutex_unlock(&dev->device_lock);
wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
(cb = mei_amthif_find_read_list_entry(dev, file)));
/* Locking again the Mutex */
mutex_lock(&dev->device_lock);
if (wait_ret)
return -ERESTARTSYS;
dev_dbg(dev->dev, "woke up from sleep\n");
}
dev_dbg(dev->dev, "Got amthif data\n");
dev->iamthif_timer = 0;
if (cb) {
timeout = cb->read_time +
mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
dev_dbg(dev->dev, "amthif timeout = %lud\n",
timeout);
if (time_after(jiffies, timeout)) {
dev_dbg(dev->dev, "amthif Time out\n");
/* 15 sec for the message has expired */
list_del(&cb->list);
rets = -ETIME;
goto free;
}
}
/* if the whole message will fit remove it from the list */
if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
list_del(&cb->list);
else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
/* end of the message has been reached */
list_del(&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->dev, "amthif cb->response_buffer size - %d\n",
cb->response_buffer.size);
dev_dbg(dev->dev, "amthif cb->buf_idx - %lu\n", cb->buf_idx);
/* length is being truncated to PAGE_SIZE, however,
* the buf_idx may point beyond */
length = min_t(size_t, length, (cb->buf_idx - *offset));
if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
dev_dbg(dev->dev, "failed to copy data to userland\n");
rets = -EFAULT;
} else {
rets = length;
if ((*offset + length) < cb->buf_idx) {
*offset += length;
goto out;
}
}
free:
dev_dbg(dev->dev, "free amthif cb memory.\n");
*offset = 0;
mei_io_cb_free(cb);
out:
return rets;
}
/**
* mei_amthif_send_cmd - send amthif command to the ME
*
* @dev: the device structure
* @cb: mei call back struct
*
* Return: 0 on success, <0 on failure.
*
*/
static int mei_amthif_send_cmd(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->dev, "write data to amthif 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_cl_flow_ctrl_creds(&dev->iamthif_cl);
if (ret < 0)
return ret;
if (ret && mei_hbuf_acquire(dev)) {
ret = 0;
if (cb->request_buffer.size > mei_hbuf_max_len(dev)) {
mei_hdr.length = mei_hbuf_max_len(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;
mei_hdr.internal = 0;
dev->iamthif_msg_buf_index += mei_hdr.length;
ret = mei_write_message(dev, &mei_hdr, dev->iamthif_msg_buf);
if (ret)
return ret;
if (mei_hdr.msg_complete) {
if (mei_cl_flow_ctrl_reduce(&dev->iamthif_cl))
return -EIO;
dev->iamthif_flow_control_pending = true;
dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
dev_dbg(dev->dev, "add amthif cb to write waiting list\n");
dev->iamthif_current_cb = cb;
dev->iamthif_file_object = cb->file_object;
list_add_tail(&cb->list, &dev->write_waiting_list.list);
} else {
dev_dbg(dev->dev, "message does not complete, so add amthif cb to write list.\n");
list_add_tail(&cb->list, &dev->write_list.list);
}
} else {
list_add_tail(&cb->list, &dev->write_list.list);
}
return 0;
}
/**
* mei_amthif_write - write amthif data to amthif client
*
* @dev: the device structure
* @cb: mei call back struct
*
* Return: 0 on success, <0 on failure.
*
*/
int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *cb)
{
int ret;
if (!dev || !cb)
return -ENODEV;
ret = mei_io_cb_alloc_resp_buf(cb, dev->iamthif_mtu);
if (ret)
return ret;
cb->fop_type = MEI_FOP_WRITE;
if (!list_empty(&dev->amthif_cmd_list.list) ||
dev->iamthif_state != MEI_IAMTHIF_IDLE) {
dev_dbg(dev->dev,
"amthif state = %d\n", dev->iamthif_state);
dev_dbg(dev->dev, "AMTHIF: add cb to the wait list\n");
list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
return 0;
}
return mei_amthif_send_cmd(dev, cb);
}
/**
* mei_amthif_run_next_cmd - send next amt command from queue
*
* @dev: the device structure
*/
void mei_amthif_run_next_cmd(struct mei_device *dev)
{
struct mei_cl_cb *cb;
struct mei_cl_cb *next;
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->dev, "complete amthif cmd_list cb.\n");
list_for_each_entry_safe(cb, next, &dev->amthif_cmd_list.list, list) {
list_del(&cb->list);
if (!cb->cl)
continue;
status = mei_amthif_send_cmd(dev, cb);
if (status)
dev_warn(dev->dev, "amthif write failed status = %d\n",
status);
break;
}
}
unsigned int mei_amthif_poll(struct mei_device *dev,
struct file *file, poll_table *wait)
{
unsigned int mask = 0;
poll_wait(file, &dev->iamthif_cl.wait, wait);
mutex_lock(&dev->device_lock);
if (!mei_cl_is_connected(&dev->iamthif_cl)) {
mask = POLLERR;
} else if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
dev->iamthif_file_object == file) {
mask |= (POLLIN | POLLRDNORM);
dev_dbg(dev->dev, "run next amthif cb\n");
mei_amthif_run_next_cmd(dev);
}
mutex_unlock(&dev->device_lock);
return mask;
}
/**
* mei_amthif_irq_write - write iamthif command in irq thread context.
*
* @cl: private data of the file object.
* @cb: callback block.
* @cmpl_list: complete list.
*
* Return: 0, OK; otherwise, error.
*/
int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
struct mei_cl_cb *cmpl_list)
{
struct mei_device *dev = cl->dev;
struct mei_msg_hdr mei_hdr;
size_t len = dev->iamthif_msg_buf_size - dev->iamthif_msg_buf_index;
u32 msg_slots = mei_data2slots(len);
int slots;
int rets;
rets = mei_cl_flow_ctrl_creds(cl);
if (rets < 0)
return rets;
if (rets == 0) {
cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
return 0;
}
mei_hdr.host_addr = cl->host_client_id;
mei_hdr.me_addr = cl->me_client_id;
mei_hdr.reserved = 0;
mei_hdr.internal = 0;
slots = mei_hbuf_empty_slots(dev);
if (slots >= msg_slots) {
mei_hdr.length = len;
mei_hdr.msg_complete = 1;
/* Split the message only if we can write the whole host buffer */
} else if (slots == dev->hbuf_depth) {
msg_slots = slots;
len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
mei_hdr.length = len;
mei_hdr.msg_complete = 0;
} else {
/* wait for next time the host buffer is empty */
return 0;
}
dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(&mei_hdr));
rets = mei_write_message(dev, &mei_hdr,
dev->iamthif_msg_buf + dev->iamthif_msg_buf_index);
if (rets) {
dev->iamthif_state = MEI_IAMTHIF_IDLE;
cl->status = rets;
list_del(&cb->list);
return rets;
}
if (mei_cl_flow_ctrl_reduce(cl))
return -EIO;
dev->iamthif_msg_buf_index += mei_hdr.length;
cl->status = 0;
if (mei_hdr.msg_complete) {
dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
dev->iamthif_flow_control_pending = true;
/* save iamthif cb sent to amthif client */
cb->buf_idx = dev->iamthif_msg_buf_index;
dev->iamthif_current_cb = cb;
list_move_tail(&cb->list, &dev->write_waiting_list.list);
}
return 0;
}
/**
* mei_amthif_irq_read_msg - read routine after ISR to
* handle the read amthif message
*
* @dev: the device structure
* @mei_hdr: header of amthif message
* @complete_list: An instance of our list structure
*
* Return: 0 on success, <0 on failure.
*/
int mei_amthif_irq_read_msg(struct mei_device *dev,
struct mei_msg_hdr *mei_hdr,
struct mei_cl_cb *complete_list)
{
struct mei_cl_cb *cb;
unsigned char *buffer;
BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);
buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);
mei_read_slots(dev, buffer, mei_hdr->length);
dev->iamthif_msg_buf_index += mei_hdr->length;
if (!mei_hdr->msg_complete)
return 0;
dev_dbg(dev->dev, "amthif_message_buffer_index =%d\n",
mei_hdr->length);
dev_dbg(dev->dev, "completed amthif read.\n ");
if (!dev->iamthif_current_cb)
return -ENODEV;
cb = dev->iamthif_current_cb;
dev->iamthif_current_cb = NULL;
if (!cb->cl)
return -ENODEV;
dev->iamthif_stall_timer = 0;
cb->buf_idx = dev->iamthif_msg_buf_index;
cb->read_time = jiffies;
if (dev->iamthif_ioctl) {
/* found the iamthif cb */
dev_dbg(dev->dev, "complete the amthif read cb.\n ");
dev_dbg(dev->dev, "add the amthif read cb to complete.\n ");
list_add_tail(&cb->list, &complete_list->list);
}
return 0;
}
/**
* mei_amthif_irq_read - prepares to read amthif data.
*
* @dev: the device structure.
* @slots: free slots.
*
* Return: 0, OK; otherwise, error.
*/
int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
{
u32 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
if (*slots < msg_slots)
return -EMSGSIZE;
*slots -= msg_slots;
if (mei_hbm_cl_flow_control_req(dev, &dev->iamthif_cl)) {
dev_dbg(dev->dev, "iamthif flow control failed\n");
return -EIO;
}
dev_dbg(dev->dev, "iamthif flow control success\n");
dev->iamthif_state = MEI_IAMTHIF_READING;
dev->iamthif_flow_control_pending = false;
dev->iamthif_msg_buf_index = 0;
dev->iamthif_msg_buf_size = 0;
dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
return 0;
}
/**
* mei_amthif_complete - complete amthif callback.
*
* @dev: the device structure.
* @cb: callback block.
*/
void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
{
if (dev->iamthif_canceled != 1) {
dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
dev->iamthif_stall_timer = 0;
memcpy(cb->response_buffer.data,
dev->iamthif_msg_buf,
dev->iamthif_msg_buf_index);
list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
dev_dbg(dev->dev, "amthif read completed\n");
dev->iamthif_timer = jiffies;
dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
dev->iamthif_timer);
} else {
mei_amthif_run_next_cmd(dev);
}
dev_dbg(dev->dev, "completing amthif call back.\n");
wake_up_interruptible(&dev->iamthif_cl.wait);
}
/**
* mei_clear_list - removes all callbacks associated with file
* from mei_cb_list
*
* @dev: device structure.
* @file: file structure
* @mei_cb_list: callbacks list
*
* mei_clear_list is called to clear resources associated with file
* when application calls close function or Ctrl-C was pressed
*
* Return: true if callback removed from the list, false otherwise
*/
static bool mei_clear_list(struct mei_device *dev,
const struct file *file, struct list_head *mei_cb_list)
{
struct mei_cl_cb *cb_pos = NULL;
struct mei_cl_cb *cb_next = NULL;
bool removed = false;
/* list all list member */
list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
/* check if list member associated with a file */
if (file == cb_pos->file_object) {
/* remove member from the list */
list_del(&cb_pos->list);
/* check if cb equal to current iamthif cb */
if (dev->iamthif_current_cb == cb_pos) {
dev->iamthif_current_cb = NULL;
/* send flow control to iamthif client */
mei_hbm_cl_flow_control_req(dev,
&dev->iamthif_cl);
}
/* free all allocated buffers */
mei_io_cb_free(cb_pos);
cb_pos = NULL;
removed = true;
}
}
return removed;
}
/**
* mei_clear_lists - removes all callbacks associated with file
*
* @dev: device structure
* @file: file structure
*
* mei_clear_lists is called to clear resources associated with file
* when application calls close function or Ctrl-C was pressed
*
* Return: true if callback removed from the list, false otherwise
*/
static bool mei_clear_lists(struct mei_device *dev, struct file *file)
{
bool removed = false;
/* remove callbacks associated with a file */
mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
removed = true;
mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
removed = true;
if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
removed = true;
if (mei_clear_list(dev, file, &dev->write_list.list))
removed = true;
/* check if iamthif_current_cb not NULL */
if (dev->iamthif_current_cb && !removed) {
/* check file and iamthif current cb association */
if (dev->iamthif_current_cb->file_object == file) {
/* remove cb */
mei_io_cb_free(dev->iamthif_current_cb);
dev->iamthif_current_cb = NULL;
removed = true;
}
}
return removed;
}
/**
* mei_amthif_release - the release function
*
* @dev: device structure
* @file: pointer to file structure
*
* Return: 0 on success, <0 on error
*/
int mei_amthif_release(struct mei_device *dev, struct file *file)
{
if (dev->iamthif_open_count > 0)
dev->iamthif_open_count--;
if (dev->iamthif_file_object == file &&
dev->iamthif_state != MEI_IAMTHIF_IDLE) {
dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
dev->iamthif_state);
dev->iamthif_canceled = true;
if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
dev_dbg(dev->dev, "run next amthif iamthif cb\n");
mei_amthif_run_next_cmd(dev);
}
}
if (mei_clear_lists(dev, file))
dev->iamthif_state = MEI_IAMTHIF_IDLE;
return 0;
}