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Commit 79563db9 authored by Tomas Winkler's avatar Tomas Winkler Committed by Greg Kroah-Hartman
Browse files

mei: add reference counting for me clients 



To support dynamic addition and removal of
me clients we add reference counter.

Update kdoc with locking requirements.

Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3542f6b1

drivers/misc/mei/amthif.c

+8 −6
Original line number Diff line number Diff line
@@ -97,23 +97,25 @@ int mei_amthif_host_init(struct mei_device *dev) 
	/* allocate storage for ME message buffer */

	msg_buf = kcalloc(dev->iamthif_mtu,

			sizeof(unsigned char), GFP_KERNEL);

	if (!msg_buf)

		return -ENOMEM;

	if (!msg_buf) {

		ret = -ENOMEM;

		goto out;

	}



	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;

		dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);

		goto out;

	}



	ret = mei_cl_connect(cl, NULL);



	dev->iamthif_state = MEI_IAMTHIF_IDLE;



out:

	mei_me_cl_put(me_cl);

	return ret;

}

drivers/misc/mei/bus.c

+23 −16
Original line number Diff line number Diff line
@@ -228,8 +228,8 @@ static ssize_t ___mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length, 
			bool blocking)

{

	struct mei_device *dev;

	struct mei_me_client *me_cl;

	struct mei_cl_cb *cb;

	struct mei_me_client *me_cl = NULL;

	struct mei_cl_cb *cb = NULL;

	ssize_t rets;



	if (WARN_ON(!cl || !cl->dev))
@@ -237,33 +237,40 @@ static ssize_t ___mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length, 


	dev = cl->dev;



	if (cl->state != MEI_FILE_CONNECTED)

		return -ENODEV;

	mutex_lock(&dev->device_lock);

	if (cl->state != MEI_FILE_CONNECTED) {

		rets = -ENODEV;

		goto out;

	}



	/* Check if we have an ME client device */

	me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id);

	if (!me_cl)

		return -ENOTTY;

	if (!me_cl) {

		rets = -ENOTTY;

		goto out;

	}



	if (length > me_cl->props.max_msg_length)

		return -EFBIG;

	if (length > me_cl->props.max_msg_length) {

		rets = -EFBIG;

		goto out;

	}



	cb = mei_io_cb_init(cl, NULL);

	if (!cb)

		return -ENOMEM;

	if (!cb) {

		rets = -ENOMEM;

		goto out;

	}



	rets = mei_io_cb_alloc_req_buf(cb, length);

	if (rets < 0) {

		mei_io_cb_free(cb);

		return rets;

	}

	if (rets < 0)

		goto out;



	memcpy(cb->request_buffer.data, buf, length);



	mutex_lock(&dev->device_lock);



	rets = mei_cl_write(cl, cb, blocking);



out:

	mei_me_cl_put(me_cl);

	mutex_unlock(&dev->device_lock);

	if (rets < 0)

		mei_io_cb_free(cb);

drivers/misc/mei/client.c

+129 −23
Original line number Diff line number Diff line
@@ -26,8 +26,64 @@ 
#include "hbm.h"

#include "client.h"



/**

 * mei_me_cl_init - initialize me client

 *

 * @me_cl: me client

 */

void mei_me_cl_init(struct mei_me_client *me_cl)

{

	INIT_LIST_HEAD(&me_cl->list);

	kref_init(&me_cl->refcnt);

}



/**

 * mei_me_cl_get - increases me client refcount

 *

 * @me_cl: me client

 *

 * Locking: called under "dev->device_lock" lock

 *

 * Return: me client or NULL

 */

struct mei_me_client *mei_me_cl_get(struct mei_me_client *me_cl)

{

	if (me_cl)

		kref_get(&me_cl->refcnt);



	return me_cl;

}



/**

 * mei_me_cl_release - unlink and free me client

 *

 * Locking: called under "dev->device_lock" lock

 *

 * @ref: me_client refcount

 */

static void mei_me_cl_release(struct kref *ref)

{

	struct mei_me_client *me_cl =

		container_of(ref, struct mei_me_client, refcnt);

	list_del(&me_cl->list);

	kfree(me_cl);

}

/**

 * mei_me_cl_put - decrease me client refcount and free client if necessary

 *

 * Locking: called under "dev->device_lock" lock

 *

 * @me_cl: me client

 */

void mei_me_cl_put(struct mei_me_client *me_cl)

{

	if (me_cl)

		kref_put(&me_cl->refcnt, mei_me_cl_release);

}



/**

 * mei_me_cl_by_uuid - locate me client by uuid

 *	increases ref count

 *

 * @dev: mei device

 * @uuid: me client uuid
@@ -43,13 +99,14 @@ struct mei_me_client *mei_me_cl_by_uuid(const struct mei_device *dev, 


	list_for_each_entry(me_cl, &dev->me_clients, list)

		if (uuid_le_cmp(*uuid, me_cl->props.protocol_name) == 0)

			return me_cl;

			return mei_me_cl_get(me_cl);



	return NULL;

}



/**

 * mei_me_cl_by_id - locate me client by client id

 *	increases ref count

 *

 * @dev: the device structure

 * @client_id: me client id
@@ -65,12 +122,14 @@ struct mei_me_client *mei_me_cl_by_id(struct mei_device *dev, u8 client_id) 


	list_for_each_entry(me_cl, &dev->me_clients, list)

		if (me_cl->client_id == client_id)

			return me_cl;

			return mei_me_cl_get(me_cl);



	return NULL;

}



/**

 * mei_me_cl_by_uuid_id - locate me client by client id and uuid

 *	increases ref count

 *

 * @dev: the device structure

 * @uuid: me client uuid
@@ -88,32 +147,68 @@ struct mei_me_client *mei_me_cl_by_uuid_id(struct mei_device *dev, 
	list_for_each_entry(me_cl, &dev->me_clients, list)

		if (uuid_le_cmp(*uuid, me_cl->props.protocol_name) == 0 &&

		    me_cl->client_id == client_id)

			return me_cl;

			return mei_me_cl_get(me_cl);



	return NULL;

}



/**

 * mei_me_cl_remove - remove me client matching uuid and client_id

 * mei_me_cl_rm_by_uuid - remove all me clients matching uuid

 *

 * @dev: the device structure

 * @uuid: me client uuid

 * @client_id: me client address

 *

 * Locking: called under "dev->device_lock" lock

 */

void mei_me_cl_remove(struct mei_device *dev, const uuid_le *uuid, u8 client_id)

void mei_me_cl_rm_by_uuid(struct mei_device *dev, const uuid_le *uuid)

{

	struct mei_me_client *me_cl, *next;



	dev_dbg(dev->dev, "remove %pUl\n", uuid);

	list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)

		if (uuid_le_cmp(*uuid, me_cl->props.protocol_name) == 0)

			mei_me_cl_put(me_cl);

}



/**

 * mei_me_cl_rm_by_uuid_id - remove all me clients matching client id

 *

 * @dev: the device structure

 * @uuid: me client uuid

 * @id: me client id

 *

 * Locking: called under "dev->device_lock" lock

 */

void mei_me_cl_rm_by_uuid_id(struct mei_device *dev, const uuid_le *uuid, u8 id)

{

	struct mei_me_client *me_cl, *next;

	const uuid_le *pn;



	dev_dbg(dev->dev, "remove %pUl %d\n", uuid, id);

	list_for_each_entry_safe(me_cl, next, &dev->me_clients, list) {

		if (uuid_le_cmp(*uuid, me_cl->props.protocol_name) == 0 &&

		    me_cl->client_id == client_id) {

			list_del(&me_cl->list);

			kfree(me_cl);

			break;

		pn =  &me_cl->props.protocol_name;

		if (me_cl->client_id == id && uuid_le_cmp(*uuid, *pn) == 0)

			mei_me_cl_put(me_cl);

	}

}



/**

 * mei_me_cl_rm_all - remove all me clients

 *

 * @dev: the device structure

 *

 * Locking: called under "dev->device_lock" lock

 */

void mei_me_cl_rm_all(struct mei_device *dev)

{

	struct mei_me_client *me_cl, *next;



	list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)

			mei_me_cl_put(me_cl);

}







/**

 * mei_cl_cmp_id - tells if the clients are the same

 *
@@ -695,6 +790,7 @@ int mei_cl_flow_ctrl_creds(struct mei_cl *cl) 
{

	struct mei_device *dev;

	struct mei_me_client *me_cl;

	int rets = 0;



	if (WARN_ON(!cl || !cl->dev))

		return -EINVAL;
@@ -710,12 +806,13 @@ int mei_cl_flow_ctrl_creds(struct mei_cl *cl) 
		return -ENOENT;

	}



	if (me_cl->mei_flow_ctrl_creds) {

	if (me_cl->mei_flow_ctrl_creds > 0) {

		rets = 1;

		if (WARN_ON(me_cl->props.single_recv_buf == 0))

			return -EINVAL;

		return 1;

			rets = -EINVAL;

	}

	return 0;

	mei_me_cl_put(me_cl);

	return rets;

}



/**
@@ -732,6 +829,7 @@ int mei_cl_flow_ctrl_reduce(struct mei_cl *cl) 
{

	struct mei_device *dev;

	struct mei_me_client *me_cl;

	int rets;



	if (WARN_ON(!cl || !cl->dev))

		return -EINVAL;
@@ -745,15 +843,22 @@ int mei_cl_flow_ctrl_reduce(struct mei_cl *cl) 
	}



	if (me_cl->props.single_recv_buf) {

		if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))

			return -EINVAL;

		if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0)) {

			rets = -EINVAL;

			goto out;

		}

		me_cl->mei_flow_ctrl_creds--;

	} else {

		if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))

			return -EINVAL;

		if (WARN_ON(cl->mei_flow_ctrl_creds <= 0)) {

			rets = -EINVAL;

			goto out;

		}

		cl->mei_flow_ctrl_creds--;

	}

	return 0;

	rets = 0;

out:

	mei_me_cl_put(me_cl);

	return rets;

}



/**
@@ -788,6 +893,9 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length) 
		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);

		return  -ENOTTY;

	}

	/* always allocate at least client max message */

	length = max_t(size_t, length, me_cl->props.max_msg_length);

	mei_me_cl_put(me_cl);



	rets = pm_runtime_get(dev->dev);

	if (rets < 0 && rets != -EINPROGRESS) {
@@ -802,8 +910,6 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length) 
		goto out;

	}



	/* always allocate at least client max message */

	length = max_t(size_t, length, me_cl->props.max_msg_length);

	rets = mei_io_cb_alloc_resp_buf(cb, length);

	if (rets)

		goto out;

drivers/misc/mei/client.h

+12 −5
Original line number Diff line number Diff line
@@ -24,15 +24,22 @@ 


#include "mei_dev.h"



/*

 * reference counting base function

 */

void mei_me_cl_init(struct mei_me_client *me_cl);

void mei_me_cl_put(struct mei_me_client *me_cl);

struct mei_me_client *mei_me_cl_get(struct mei_me_client *me_cl);



struct mei_me_client *mei_me_cl_by_uuid(const struct mei_device *dev,

					const uuid_le *cuuid);

					const uuid_le *uuid);

struct mei_me_client *mei_me_cl_by_id(struct mei_device *dev, u8 client_id);



struct mei_me_client *mei_me_cl_by_uuid_id(struct mei_device *dev,

					   const uuid_le *uuid, u8 client_id);



void mei_me_cl_remove(struct mei_device *dev,

		      const uuid_le *uuid, u8 client_id);

void mei_me_cl_rm_by_uuid(struct mei_device *dev, const uuid_le *uuid);

void mei_me_cl_rm_by_uuid_id(struct mei_device *dev,

			     const uuid_le *uuid, u8 id);

void mei_me_cl_rm_all(struct mei_device *dev);



/*

 * MEI IO Functions

drivers/misc/mei/debugfs.c

+20 −12
Original line number Diff line number Diff line
@@ -21,20 +21,22 @@ 
#include <linux/mei.h>



#include "mei_dev.h"

#include "client.h"

#include "hw.h"



static ssize_t mei_dbgfs_read_meclients(struct file *fp, char __user *ubuf,

					size_t cnt, loff_t *ppos)

{

	struct mei_device *dev = fp->private_data;

	struct mei_me_client *me_cl;

	struct mei_me_client *me_cl, *n;

	size_t bufsz = 1;

	char *buf;

	int i = 0;

	int pos = 0;

	int ret;



#define HDR "  |id|fix|         UUID                       |con|msg len|sb|\n"

#define HDR \

"  |id|fix|         UUID                       |con|msg len|sb|refc|\n"



	mutex_lock(&dev->device_lock);
@@ -54,16 +56,22 @@ static ssize_t mei_dbgfs_read_meclients(struct file *fp, char __user *ubuf, 
	if (dev->dev_state != MEI_DEV_ENABLED)

		goto out;



	list_for_each_entry(me_cl, &dev->me_clients, list) {

	list_for_each_entry_safe(me_cl, n, &dev->me_clients, list) {



		me_cl = mei_me_cl_get(me_cl);

		if (me_cl) {

			pos += scnprintf(buf + pos, bufsz - pos,

			"%2d|%2d|%3d|%pUl|%3d|%7d|%2d|\n",

				"%2d|%2d|%3d|%pUl|%3d|%7d|%2d|%4d|\n",

				i++, me_cl->client_id,

				me_cl->props.fixed_address,

				&me_cl->props.protocol_name,

				me_cl->props.max_number_of_connections,

				me_cl->props.max_msg_length,

			me_cl->props.single_recv_buf);

				me_cl->props.single_recv_buf,

				atomic_read(&me_cl->refcnt.refcount));

		}



		mei_me_cl_put(me_cl);

	}

out:

	mutex_unlock(&dev->device_lock);