[deliverable/linux.git] / 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/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_canceled = 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
 * @me_cl: me client
 *
 * Return: 0 on success, <0 on failure.
 */
int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
{
	struct mei_cl *cl = &dev->iamthif_cl;
	int ret;

	dev->iamthif_state = MEI_IAMTHIF_IDLE;

	mei_cl_init(cl, dev);

	ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
	if (ret < 0) {
		dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);
		return ret;
	}

	ret = mei_cl_connect(cl, me_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");
	}

	if (cb->status) {
		rets = cb->status;
		dev_dbg(dev->dev, "read operation failed %d\n", rets);
		goto free;
	}

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

	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_init(&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_init(&cb->list);
	else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
		/* end of the message has been reached */
		list_del_init(&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->buf size - %d\n",
	    cb->buf.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->buf.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_read_start - queue message for sending read credential
 *
 * @cl: host client
 * @file: file pointer of message recipient
 *
 * Return: 0 on success, <0 on failure.
 */
static int mei_amthif_read_start(struct mei_cl *cl, struct file *file)
{
	struct mei_device *dev = cl->dev;
	struct mei_cl_cb *cb;
	int rets;

	cb = mei_io_cb_init(cl, MEI_FOP_READ, file);
	if (!cb) {
		rets = -ENOMEM;
		goto err;
	}

	rets = mei_io_cb_alloc_buf(cb, mei_cl_mtu(cl));
	if (rets)
		goto err;

	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);

	dev->iamthif_state = MEI_IAMTHIF_READING;
	dev->iamthif_file_object = cb->file_object;
	dev->iamthif_current_cb = cb;

	return 0;
err:
	mei_io_cb_free(cb);
	return rets;
}

/**
 * mei_amthif_send_cmd - send amthif command to the ME
 *
 * @cl: the host client
 * @cb: mei call back struct
 *
 * Return: 0 on success, <0 on failure.
 */
static int mei_amthif_send_cmd(struct mei_cl *cl, struct mei_cl_cb *cb)
{
	struct mei_device *dev;
	int ret;

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

	dev = cl->dev;

	dev->iamthif_state = MEI_IAMTHIF_WRITING;
	dev->iamthif_current_cb = cb;
	dev->iamthif_file_object = cb->file_object;
	dev->iamthif_canceled = false;

	ret = mei_cl_write(cl, cb, false);
	if (ret < 0)
		return ret;

	if (cb->completed)
		cb->status = mei_amthif_read_start(cl, cb->file_object);

	return 0;
}

/**
 * mei_amthif_run_next_cmd - send next amt command from queue
 *
 * @dev: the device structure
 *
 * Return: 0 on success, <0 on failure.
 */
int mei_amthif_run_next_cmd(struct mei_device *dev)
{
	struct mei_cl *cl = &dev->iamthif_cl;
	struct mei_cl_cb *cb;

	dev->iamthif_canceled = false;
	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");

	cb = list_first_entry_or_null(&dev->amthif_cmd_list.list,
					typeof(*cb), list);
	if (!cb)
		return 0;

	list_del_init(&cb->list);
	return mei_amthif_send_cmd(cl, cb);
}

/**
 * mei_amthif_write - write amthif data to amthif client
 *
 * @cl: host client
 * @cb: mei call back struct
 *
 * Return: 0 on success, <0 on failure.
 */
int mei_amthif_write(struct mei_cl *cl, struct mei_cl_cb *cb)
{

	struct mei_device *dev;

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

	if (WARN_ON(!cb))
		return -EINVAL;

	dev = cl->dev;

	list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
	return mei_amthif_run_next_cmd(dev);
}

/**
 * mei_amthif_poll - the amthif poll function
 *
 * @dev: the device structure
 * @file: pointer to file structure
 * @wait: pointer to poll_table structure
 *
 * Return: poll mask
 *
 * Locking: called under "dev->device_lock" lock
 */

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);

	if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
	    dev->iamthif_file_object == file) {

		mask |= POLLIN | POLLRDNORM;
		mei_amthif_run_next_cmd(dev);
	}

	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)
{
	int ret;

	ret = mei_cl_irq_write(cl, cb, cmpl_list);
	if (ret)
		return ret;

	if (cb->completed)
		cb->status = mei_amthif_read_start(cl, cb->file_object);

	return 0;
}

/**
 * mei_amthif_irq_read_msg - read routine after ISR to
 *			handle the read amthif message
 *
 * @cl: mei client
 * @mei_hdr: header of amthif message
 * @cmpl_list: completed callbacks list
 *
 * Return: -ENODEV if cb is NULL 0 otherwise; error message is in cb->status
 */
int mei_amthif_irq_read_msg(struct mei_cl *cl,
			    struct mei_msg_hdr *mei_hdr,
			    struct mei_cl_cb *cmpl_list)
{
	struct mei_device *dev;
	int ret;

	dev = cl->dev;

	if (dev->iamthif_state != MEI_IAMTHIF_READING)
		return 0;

	ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
	if (ret)
		return ret;

	if (!mei_hdr->msg_complete)
		return 0;

	dev_dbg(dev->dev, "completed amthif read.\n ");
	dev->iamthif_current_cb = NULL;
	dev->iamthif_stall_timer = 0;

	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 (cb->fop_type == MEI_FOP_WRITE) {
		if (!cb->status) {
			dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
			mei_io_cb_free(cb);
			return;
		}
		/*
		 * in case of error enqueue the write cb to complete read list
		 * so it can be propagated to the reader
		 */
		list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
		wake_up_interruptible(&dev->iamthif_cl.wait);
		return;
	}

	if (dev->iamthif_canceled != 1) {
		dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
		dev->iamthif_stall_timer = 0;
		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 *cl = &dev->iamthif_cl;
	struct mei_cl_cb *cb, *next;
	bool removed = false;

	/* list all list member */
	list_for_each_entry_safe(cb, next, mei_cb_list, list) {
		/* check if list member associated with a file */
		if (file == cb->file_object) {
			/* check if cb equal to current iamthif cb */
			if (dev->iamthif_current_cb == cb) {
				dev->iamthif_current_cb = NULL;
				/* send flow control to iamthif client */
				mei_hbm_cl_flow_control_req(dev, cl);
			}
			/* free all allocated buffers */
			mei_io_cb_free(cb);
			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;
}
Commit	Line	Data
19838fb8 TW	1	/*
	2	*
	3	* Intel Management Engine Interface (Intel MEI) Linux driver
	4	* Copyright (c) 2003-2012, Intel Corporation.
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	*/
	16
	17	#include <linux/kernel.h>
	18	#include <linux/fs.h>
	19	#include <linux/errno.h>
	20	#include <linux/types.h>
	21	#include <linux/fcntl.h>
19838fb8 TW	22	#include <linux/ioctl.h>
	23	#include <linux/cdev.h>
	24	#include <linux/list.h>
	25	#include <linux/delay.h>
	26	#include <linux/sched.h>
	27	#include <linux/uuid.h>
	28	#include <linux/jiffies.h>
	29	#include <linux/uaccess.h>
1f180359	30	#include <linux/slab.h>
19838fb8	31
47a73801	32	#include <linux/mei.h>
19838fb8 TW	33
19838fb8 TW	34	#include "mei_dev.h"
0edb23fc	35	#include "hbm.h"
90e0b5f1	36	#include "client.h"
19838fb8	37
1a1aca42 TW	38	const uuid_le mei_amthif_guid = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d,
	39	0xac, 0xa8, 0x46, 0xe0,
	40	0xff, 0x65, 0x81, 0x4c);
19838fb8 TW	41
	42	/**
	43	* mei_amthif_reset_params - initializes mei device iamthif
	44	*
	45	* @dev: the device structure
	46	*/
	47	void mei_amthif_reset_params(struct mei_device *dev)
	48	{
	49	/* reset iamthif parameters. */
	50	dev->iamthif_current_cb = NULL;
19838fb8	51	dev->iamthif_canceled = false;
19838fb8 TW	52	dev->iamthif_state = MEI_IAMTHIF_IDLE;
19838fb8 TW	53	dev->iamthif_timer = 0;
4a704575	54	dev->iamthif_stall_timer = 0;
22f96a0e	55	dev->iamthif_open_count = 0;
19838fb8 TW	56	}
	57
	58	/**
393b148f	59	* mei_amthif_host_init - mei initialization amthif client.
19838fb8 TW	60	*
19838fb8 TW	61	* @dev: the device structure
d49ed64a	62	* @me_cl: me client
19838fb8	63	*
ce23139c	64	* Return: 0 on success, <0 on failure.
19838fb8	65	*/
d49ed64a	66	int mei_amthif_host_init(struct mei_device dev, struct mei_me_client me_cl)
19838fb8	67	{
781d0d89	68	struct mei_cl *cl = &dev->iamthif_cl;
d320832f	69	int ret;
19838fb8	70
6222f7bf TW	71	dev->iamthif_state = MEI_IAMTHIF_IDLE;
6222f7bf TW	72
781d0d89	73	mei_cl_init(cl, dev);
19838fb8	74
781d0d89	75	ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
781d0d89	76	if (ret < 0) {
79563db9	77	dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);
d49ed64a	78	return ret;
781d0d89 TW	79	}
781d0d89 TW	80
d49ed64a	81	ret = mei_cl_connect(cl, me_cl, NULL);
64092858 TW	82
	83	dev->iamthif_state = MEI_IAMTHIF_IDLE;
	84
	85	return ret;
19838fb8 TW	86	}
	87
	88	/**
	89	* mei_amthif_find_read_list_entry - finds a amthilist entry for current file
	90	*
	91	* @dev: the device structure
	92	* @file: pointer to file object
	93	*
a8605ea2	94	* Return: returned a list entry on success, NULL on failure.
19838fb8 TW	95	*/
	96	struct mei_cl_cb mei_amthif_find_read_list_entry(struct mei_device dev,
	97	struct file *file)
	98	{
31f88f57	99	struct mei_cl_cb *cb;
92db1555	100
05e314e2 AU	101	list_for_each_entry(cb, &dev->amthif_rd_complete_list.list, list)
05e314e2 AU	102	if (cb->file_object == file)
31f88f57	103	return cb;
19838fb8 TW	104	return NULL;
	105	}
	106
	107
	108	/**
	109	* mei_amthif_read - read data from AMTHIF client
	110	*
	111	* @dev: the device structure
19838fb8	112	* @file: pointer to file object
a8605ea2	113	* @ubuf: pointer to user data in user space
19838fb8 TW	114	* @length: data length to read
	115	* @offset: data read offset
	116	*
	117	* Locking: called under "dev->device_lock" lock
	118	*
a8605ea2	119	* Return:
19838fb8 TW	120	* returned data length on success,
	121	* zero if no data to read,
	122	* negative on failure.
	123	*/
	124	int mei_amthif_read(struct mei_device dev, struct file file,
	125	char __user ubuf, size_t length, loff_t offset)
	126	{
19838fb8	127	struct mei_cl *cl = file->private_data;
d320832f	128	struct mei_cl_cb *cb;
19838fb8	129	unsigned long timeout;
d320832f TW	130	int rets;
d320832f TW	131	int wait_ret;
19838fb8	132
83ce0741	133	/* Only possible if we are in timeout */
05e314e2	134	if (!cl) {
2bf94cab	135	dev_err(dev->dev, "bad file ext.\n");
7ca96aa2	136	return -ETIME;
19838fb8 TW	137	}
19838fb8 TW	138
2bf94cab	139	dev_dbg(dev->dev, "checking amthif data\n");
19838fb8 TW	140	cb = mei_amthif_find_read_list_entry(dev, file);
	141
	142	/* Check for if we can block or not*/
	143	if (cb == NULL && file->f_flags & O_NONBLOCK)
	144	return -EAGAIN;
	145
	146
2bf94cab	147	dev_dbg(dev->dev, "waiting for amthif data\n");
19838fb8 TW	148	while (cb == NULL) {
	149	/* unlock the Mutex */
	150	mutex_unlock(&dev->device_lock);
	151
	152	wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
	153	(cb = mei_amthif_find_read_list_entry(dev, file)));
	154
e6028db0 AK	155	/* Locking again the Mutex */
	156	mutex_lock(&dev->device_lock);
	157
19838fb8 TW	158	if (wait_ret)
	159	return -ERESTARTSYS;
	160
2bf94cab	161	dev_dbg(dev->dev, "woke up from sleep\n");
19838fb8 TW	162	}
19838fb8 TW	163
db4756fd TW	164	if (cb->status) {
	165	rets = cb->status;
	166	dev_dbg(dev->dev, "read operation failed %d\n", rets);
	167	goto free;
	168	}
19838fb8	169
2bf94cab	170	dev_dbg(dev->dev, "Got amthif data\n");
19838fb8 TW	171	dev->iamthif_timer = 0;
19838fb8 TW	172
db4756fd TW	173	timeout = cb->read_time +
	174	mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
	175	dev_dbg(dev->dev, "amthif timeout = %lud\n",
	176	timeout);
	177
	178	if (time_after(jiffies, timeout)) {
	179	dev_dbg(dev->dev, "amthif Time out\n");
	180	/* 15 sec for the message has expired */
928fa666	181	list_del_init(&cb->list);
db4756fd TW	182	rets = -ETIME;
db4756fd TW	183	goto free;
19838fb8 TW	184	}
	185	/* if the whole message will fit remove it from the list */
	186	if (cb->buf_idx >= offset && length >= (cb->buf_idx - offset))
928fa666	187	list_del_init(&cb->list);
19838fb8 TW	188	else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
19838fb8 TW	189	/* end of the message has been reached */
928fa666	190	list_del_init(&cb->list);
19838fb8 TW	191	rets = 0;
	192	goto free;
	193	}
	194	/* else means that not full buffer will be read and do not
	195	* remove message from deletion list
	196	*/
	197
5db7514d TW	198	dev_dbg(dev->dev, "amthif cb->buf size - %d\n",
5db7514d TW	199	cb->buf.size);
2bf94cab	200	dev_dbg(dev->dev, "amthif cb->buf_idx - %lu\n", cb->buf_idx);
19838fb8	201
83ce0741	202	/* length is being truncated to PAGE_SIZE, however,
19838fb8 TW	203	* the buf_idx may point beyond */
	204	length = min_t(size_t, length, (cb->buf_idx - *offset));
	205
5db7514d	206	if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
2bf94cab	207	dev_dbg(dev->dev, "failed to copy data to userland\n");
19838fb8	208	rets = -EFAULT;
34e267d0	209	} else {
19838fb8 TW	210	rets = length;
	211	if ((*offset + length) < cb->buf_idx) {
	212	*offset += length;
	213	goto out;
	214	}
	215	}
	216	free:
2bf94cab	217	dev_dbg(dev->dev, "free amthif cb memory.\n");
19838fb8 TW	218	*offset = 0;
	219	mei_io_cb_free(cb);
	220	out:
	221	return rets;
	222	}
	223
	224	/**
c54bf3ab	225	* mei_amthif_read_start - queue message for sending read credential
19838fb8	226	*
c54bf3ab TW	227	* @cl: host client
c54bf3ab TW	228	* @file: file pointer of message recipient
19838fb8	229	*
a8605ea2	230	* Return: 0 on success, <0 on failure.
19838fb8	231	*/
c54bf3ab	232	static int mei_amthif_read_start(struct mei_cl cl, struct file file)
19838fb8	233	{
c54bf3ab TW	234	struct mei_device *dev = cl->dev;
c54bf3ab TW	235	struct mei_cl_cb *cb;
c54bf3ab	236	int rets;
19838fb8	237
bca67d68	238	cb = mei_io_cb_init(cl, MEI_FOP_READ, file);
c54bf3ab TW	239	if (!cb) {
	240	rets = -ENOMEM;
	241	goto err;
	242	}
19838fb8	243
9e239362	244	rets = mei_io_cb_alloc_buf(cb, mei_cl_mtu(cl));
c54bf3ab TW	245	if (rets)
c54bf3ab TW	246	goto err;
19838fb8	247
c54bf3ab	248	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
19838fb8	249
c54bf3ab TW	250	dev->iamthif_state = MEI_IAMTHIF_READING;
	251	dev->iamthif_file_object = cb->file_object;
	252	dev->iamthif_current_cb = cb;
19838fb8	253
19838fb8	254	return 0;
c54bf3ab TW	255	err:
	256	mei_io_cb_free(cb);
	257	return rets;
19838fb8 TW	258	}
19838fb8 TW	259
ab5c4a56	260	/**
ab5c4a56	261	* mei_amthif_send_cmd - send amthif command to the ME
ab5c4a56	262	*
8660172e	263	* @cl: the host client
ab5c4a56 TW	264	* @cb: mei call back struct
ab5c4a56 TW	265	*
a8605ea2	266	* Return: 0 on success, <0 on failure.
ab5c4a56	267	*/
8660172e	268	static int mei_amthif_send_cmd(struct mei_cl cl, struct mei_cl_cb cb)
ab5c4a56	269	{
8660172e	270	struct mei_device *dev;
ab5c4a56 TW	271	int ret;
ab5c4a56 TW	272
8660172e	273	if (!cl->dev \|\| !cb)
ab5c4a56 TW	274	return -ENODEV;
ab5c4a56 TW	275
8660172e	276	dev = cl->dev;
19838fb8 TW	277
	278	dev->iamthif_state = MEI_IAMTHIF_WRITING;
	279	dev->iamthif_current_cb = cb;
	280	dev->iamthif_file_object = cb->file_object;
	281	dev->iamthif_canceled = false;
19838fb8	282
8660172e	283	ret = mei_cl_write(cl, cb, false);
19838fb8	284	if (ret < 0)
ab5c4a56 TW	285	return ret;
ab5c4a56 TW	286
8660172e TW	287	if (cb->completed)
8660172e TW	288	cb->status = mei_amthif_read_start(cl, cb->file_object);
ab5c4a56	289
19838fb8	290	return 0;
ab5c4a56	291	}
19838fb8 TW	292
19838fb8 TW	293	/**
ce23139c	294	* mei_amthif_run_next_cmd - send next amt command from queue
19838fb8 TW	295	*
19838fb8 TW	296	* @dev: the device structure
ab5c4a56	297	*
a8605ea2	298	* Return: 0 on success, <0 on failure.
19838fb8	299	*/
8660172e	300	int mei_amthif_run_next_cmd(struct mei_device *dev)
19838fb8	301	{
8660172e	302	struct mei_cl *cl = &dev->iamthif_cl;
05e314e2	303	struct mei_cl_cb *cb;
19838fb8	304
19838fb8	305	dev->iamthif_canceled = false;
19838fb8 TW	306	dev->iamthif_state = MEI_IAMTHIF_IDLE;
	307	dev->iamthif_timer = 0;
	308	dev->iamthif_file_object = NULL;
	309
2bf94cab	310	dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");
19838fb8	311
140c7553 AU	312	cb = list_first_entry_or_null(&dev->amthif_cmd_list.list,
	313	typeof(*cb), list);
	314	if (!cb)
8660172e TW	315	return 0;
8660172e TW	316
c54bf3ab	317	list_del_init(&cb->list);
8660172e	318	return mei_amthif_send_cmd(cl, cb);
19838fb8 TW	319	}
19838fb8 TW	320
8660172e TW	321	/**
	322	* mei_amthif_write - write amthif data to amthif client
	323	*
	324	* @cl: host client
	325	* @cb: mei call back struct
	326	*
	327	* Return: 0 on success, <0 on failure.
	328	*/
	329	int mei_amthif_write(struct mei_cl cl, struct mei_cl_cb cb)
	330	{
	331
	332	struct mei_device *dev;
	333
	334	if (WARN_ON(!cl \|\| !cl->dev))
	335	return -ENODEV;
	336
	337	if (WARN_ON(!cb))
	338	return -EINVAL;
	339
	340	dev = cl->dev;
	341
8660172e TW	342	list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
	343	return mei_amthif_run_next_cmd(dev);
	344	}
744f0f2f	345
1d9013f0 TW	346	/**
	347	* mei_amthif_poll - the amthif poll function
	348	*
	349	* @dev: the device structure
	350	* @file: pointer to file structure
	351	* @wait: pointer to poll_table structure
	352	*
	353	* Return: poll mask
	354	*
	355	* Locking: called under "dev->device_lock" lock
	356	*/
744f0f2f TW	357
	358	unsigned int mei_amthif_poll(struct mei_device *dev,
	359	struct file file, poll_table wait)
	360	{
	361	unsigned int mask = 0;
b950ac1d	362
744f0f2f	363	poll_wait(file, &dev->iamthif_cl.wait, wait);
b950ac1d	364
1d9013f0 TW	365	if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
1d9013f0 TW	366	dev->iamthif_file_object == file) {
b950ac1d	367
1d9013f0	368	mask \|= POLLIN \| POLLRDNORM;
744f0f2f TW	369	mei_amthif_run_next_cmd(dev);
744f0f2f TW	370	}
b950ac1d	371
744f0f2f TW	372	return mask;
	373	}
	374
	375
	376
19838fb8	377	/**
9d098192	378	* mei_amthif_irq_write - write iamthif command in irq thread context.
19838fb8	379	*
19838fb8	380	* @cl: private data of the file object.
a8605ea2	381	* @cb: callback block.
19838fb8 TW	382	* @cmpl_list: complete list.
19838fb8 TW	383	*
a8605ea2	384	* Return: 0, OK; otherwise, error.
19838fb8	385	*/
9d098192 TW	386	int mei_amthif_irq_write(struct mei_cl cl, struct mei_cl_cb cb,
9d098192 TW	387	struct mei_cl_cb *cmpl_list)
19838fb8	388	{
8660172e	389	int ret;
24c656e5	390
8660172e TW	391	ret = mei_cl_irq_write(cl, cb, cmpl_list);
	392	if (ret)
	393	return ret;
19838fb8	394
8660172e	395	if (cb->completed)
c54bf3ab	396	cb->status = mei_amthif_read_start(cl, cb->file_object);
24c656e5	397
19838fb8 TW	398	return 0;
	399	}
	400
	401	/**
ce23139c	402	* mei_amthif_irq_read_msg - read routine after ISR to
1a1aca42	403	* handle the read amthif message
19838fb8	404	*
db4756fd	405	* @cl: mei client
1a1aca42	406	* @mei_hdr: header of amthif message
331e4187	407	* @cmpl_list: completed callbacks list
19838fb8	408	*
331e4187	409	* Return: -ENODEV if cb is NULL 0 otherwise; error message is in cb->status
19838fb8	410	*/
db4756fd	411	int mei_amthif_irq_read_msg(struct mei_cl *cl,
5ceb46e2	412	struct mei_msg_hdr *mei_hdr,
331e4187	413	struct mei_cl_cb *cmpl_list)
19838fb8	414	{
db4756fd	415	struct mei_device *dev;
331e4187	416	int ret;
19838fb8	417
db4756fd	418	dev = cl->dev;
19838fb8	419
db4756fd	420	if (dev->iamthif_state != MEI_IAMTHIF_READING)
331e4187	421	return 0;
19838fb8	422
331e4187 TW	423	ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
	424	if (ret)
	425	return ret;
19838fb8 TW	426
	427	if (!mei_hdr->msg_complete)
	428	return 0;
	429
2bf94cab	430	dev_dbg(dev->dev, "completed amthif read.\n ");
19838fb8	431	dev->iamthif_current_cb = NULL;
19838fb8	432	dev->iamthif_stall_timer = 0;
19838fb8	433
19838fb8 TW	434	return 0;
	435	}
	436
	437	/**
	438	* mei_amthif_complete - complete amthif callback.
	439	*
	440	* @dev: the device structure.
a8605ea2	441	* @cb: callback block.
19838fb8 TW	442	*/
	443	void mei_amthif_complete(struct mei_device dev, struct mei_cl_cb cb)
	444	{
c54bf3ab TW	445
	446	if (cb->fop_type == MEI_FOP_WRITE) {
	447	if (!cb->status) {
	448	dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
	449	mei_io_cb_free(cb);
	450	return;
	451	}
	452	/*
	453	* in case of error enqueue the write cb to complete read list
	454	* so it can be propagated to the reader
	455	*/
	456	list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
	457	wake_up_interruptible(&dev->iamthif_cl.wait);
	458	return;
	459	}
	460
19838fb8 TW	461	if (dev->iamthif_canceled != 1) {
	462	dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
	463	dev->iamthif_stall_timer = 0;
e773efc4	464	list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
2bf94cab	465	dev_dbg(dev->dev, "amthif read completed\n");
19838fb8	466	dev->iamthif_timer = jiffies;
2bf94cab	467	dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
c54bf3ab	468	dev->iamthif_timer);
19838fb8 TW	469	} else {
	470	mei_amthif_run_next_cmd(dev);
	471	}
	472
2bf94cab	473	dev_dbg(dev->dev, "completing amthif call back.\n");
19838fb8 TW	474	wake_up_interruptible(&dev->iamthif_cl.wait);
	475	}
	476
a562d5c2 TW	477	/**
	478	* mei_clear_list - removes all callbacks associated with file
	479	* from mei_cb_list
	480	*
	481	* @dev: device structure.
	482	* @file: file structure
	483	* @mei_cb_list: callbacks list
	484	*
	485	* mei_clear_list is called to clear resources associated with file
	486	* when application calls close function or Ctrl-C was pressed
	487	*
a8605ea2	488	* Return: true if callback removed from the list, false otherwise
a562d5c2 TW	489	*/
	490	static bool mei_clear_list(struct mei_device *dev,
	491	const struct file file, struct list_head mei_cb_list)
	492	{
928fa666 TW	493	struct mei_cl *cl = &dev->iamthif_cl;
928fa666 TW	494	struct mei_cl_cb cb, next;
a562d5c2 TW	495	bool removed = false;
	496
	497	/* list all list member */
928fa666	498	list_for_each_entry_safe(cb, next, mei_cb_list, list) {
a562d5c2	499	/* check if list member associated with a file */
928fa666	500	if (file == cb->file_object) {
a562d5c2	501	/* check if cb equal to current iamthif cb */
928fa666	502	if (dev->iamthif_current_cb == cb) {
a562d5c2 TW	503	dev->iamthif_current_cb = NULL;
a562d5c2 TW	504	/* send flow control to iamthif client */
928fa666	505	mei_hbm_cl_flow_control_req(dev, cl);
a562d5c2 TW	506	}
a562d5c2 TW	507	/* free all allocated buffers */
928fa666	508	mei_io_cb_free(cb);
a562d5c2 TW	509	removed = true;
	510	}
	511	}
	512	return removed;
	513	}
	514
	515	/**
	516	* mei_clear_lists - removes all callbacks associated with file
	517	*
	518	* @dev: device structure
	519	* @file: file structure
	520	*
	521	* mei_clear_lists is called to clear resources associated with file
	522	* when application calls close function or Ctrl-C was pressed
	523	*
a8605ea2	524	* Return: true if callback removed from the list, false otherwise
a562d5c2 TW	525	*/
	526	static bool mei_clear_lists(struct mei_device dev, struct file file)
	527	{
	528	bool removed = false;
	529
	530	/* remove callbacks associated with a file */
	531	mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
	532	if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
	533	removed = true;
19838fb8	534
a562d5c2 TW	535	mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
	536
	537	if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
	538	removed = true;
	539
	540	if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
	541	removed = true;
	542
	543	if (mei_clear_list(dev, file, &dev->write_list.list))
	544	removed = true;
	545
	546	/* check if iamthif_current_cb not NULL */
	547	if (dev->iamthif_current_cb && !removed) {
	548	/* check file and iamthif current cb association */
	549	if (dev->iamthif_current_cb->file_object == file) {
	550	/* remove cb */
	551	mei_io_cb_free(dev->iamthif_current_cb);
	552	dev->iamthif_current_cb = NULL;
	553	removed = true;
	554	}
	555	}
	556	return removed;
	557	}
	558
	559	/**
	560	* mei_amthif_release - the release function
	561	*
393b148f	562	* @dev: device structure
a562d5c2 TW	563	* @file: pointer to file structure
a562d5c2 TW	564	*
a8605ea2	565	* Return: 0 on success, <0 on error
a562d5c2 TW	566	*/
	567	int mei_amthif_release(struct mei_device dev, struct file file)
	568	{
22f96a0e TW	569	if (dev->iamthif_open_count > 0)
22f96a0e TW	570	dev->iamthif_open_count--;
a562d5c2 TW	571
	572	if (dev->iamthif_file_object == file &&
	573	dev->iamthif_state != MEI_IAMTHIF_IDLE) {
	574
2bf94cab	575	dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
a562d5c2 TW	576	dev->iamthif_state);
	577	dev->iamthif_canceled = true;
	578	if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
2bf94cab	579	dev_dbg(dev->dev, "run next amthif iamthif cb\n");
a562d5c2 TW	580	mei_amthif_run_next_cmd(dev);
	581	}
	582	}
	583
	584	if (mei_clear_lists(dev, file))
	585	dev->iamthif_state = MEI_IAMTHIF_IDLE;
	586
	587	return 0;
	588	}