linux_dsm_epyc7002/drivers/misc/mei/bus.c
Alexander Usyskin b5958faa34 mei: bus: move hw module get/put to probe/release
Fix unbalanced module reference counting during internal reset, which
prevents the drivers unloading.
Tracking mei_me/txe modules on mei client bus via
mei_cldev_enable/disable is error prone due to possible internal
reset flow, where clients are disconnected underneath.
Moving reference counting to probe and release of mei bus client
driver solves this issue in simplest way, as each client provides only
a single connection to a client bus driver.

Cc: <stable@vger.kernel.org>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-26 11:53:56 +01:00

1153 lines
24 KiB
C

/*
* Intel Management Engine Interface (Intel MEI) Linux driver
* Copyright (c) 2012-2013, 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/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include <linux/mei_cl_bus.h>
#include "mei_dev.h"
#include "client.h"
#define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
/**
* __mei_cl_send - internal client send (write)
*
* @cl: host client
* @buf: buffer to send
* @length: buffer length
* @mode: sending mode
*
* Return: written size bytes or < 0 on error
*/
ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
unsigned int mode)
{
struct mei_device *bus;
struct mei_cl_cb *cb;
ssize_t rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
bus = cl->dev;
mutex_lock(&bus->device_lock);
if (bus->dev_state != MEI_DEV_ENABLED) {
rets = -ENODEV;
goto out;
}
if (!mei_cl_is_connected(cl)) {
rets = -ENODEV;
goto out;
}
/* Check if we have an ME client device */
if (!mei_me_cl_is_active(cl->me_cl)) {
rets = -ENOTTY;
goto out;
}
if (length > mei_cl_mtu(cl)) {
rets = -EFBIG;
goto out;
}
while (cl->tx_cb_queued >= bus->tx_queue_limit) {
mutex_unlock(&bus->device_lock);
rets = wait_event_interruptible(cl->tx_wait,
cl->writing_state == MEI_WRITE_COMPLETE ||
(!mei_cl_is_connected(cl)));
mutex_lock(&bus->device_lock);
if (rets) {
if (signal_pending(current))
rets = -EINTR;
goto out;
}
if (!mei_cl_is_connected(cl)) {
rets = -ENODEV;
goto out;
}
}
cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
if (!cb) {
rets = -ENOMEM;
goto out;
}
cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
memcpy(cb->buf.data, buf, length);
rets = mei_cl_write(cl, cb);
out:
mutex_unlock(&bus->device_lock);
return rets;
}
/**
* __mei_cl_recv - internal client receive (read)
*
* @cl: host client
* @buf: buffer to receive
* @length: buffer length
* @mode: io mode
* @timeout: recv timeout, 0 for infinite timeout
*
* Return: read size in bytes of < 0 on error
*/
ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
unsigned int mode, unsigned long timeout)
{
struct mei_device *bus;
struct mei_cl_cb *cb;
size_t r_length;
ssize_t rets;
bool nonblock = !!(mode & MEI_CL_IO_RX_NONBLOCK);
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
bus = cl->dev;
mutex_lock(&bus->device_lock);
if (bus->dev_state != MEI_DEV_ENABLED) {
rets = -ENODEV;
goto out;
}
cb = mei_cl_read_cb(cl, NULL);
if (cb)
goto copy;
rets = mei_cl_read_start(cl, length, NULL);
if (rets && rets != -EBUSY)
goto out;
if (nonblock) {
rets = -EAGAIN;
goto out;
}
/* wait on event only if there is no other waiter */
/* synchronized under device mutex */
if (!waitqueue_active(&cl->rx_wait)) {
mutex_unlock(&bus->device_lock);
if (timeout) {
rets = wait_event_interruptible_timeout
(cl->rx_wait,
(!list_empty(&cl->rd_completed)) ||
(!mei_cl_is_connected(cl)),
msecs_to_jiffies(timeout));
if (rets == 0)
return -ETIME;
if (rets < 0) {
if (signal_pending(current))
return -EINTR;
return -ERESTARTSYS;
}
} else {
if (wait_event_interruptible
(cl->rx_wait,
(!list_empty(&cl->rd_completed)) ||
(!mei_cl_is_connected(cl)))) {
if (signal_pending(current))
return -EINTR;
return -ERESTARTSYS;
}
}
mutex_lock(&bus->device_lock);
if (!mei_cl_is_connected(cl)) {
rets = -ENODEV;
goto out;
}
}
cb = mei_cl_read_cb(cl, NULL);
if (!cb) {
rets = 0;
goto out;
}
copy:
if (cb->status) {
rets = cb->status;
goto free;
}
r_length = min_t(size_t, length, cb->buf_idx);
memcpy(buf, cb->buf.data, r_length);
rets = r_length;
free:
mei_io_cb_free(cb);
out:
mutex_unlock(&bus->device_lock);
return rets;
}
/**
* mei_cldev_send - me device send (write)
*
* @cldev: me client device
* @buf: buffer to send
* @length: buffer length
*
* Return: written size in bytes or < 0 on error
*/
ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
struct mei_cl *cl = cldev->cl;
return __mei_cl_send(cl, buf, length, MEI_CL_IO_TX_BLOCKING);
}
EXPORT_SYMBOL_GPL(mei_cldev_send);
/**
* mei_cldev_recv_nonblock - non block client receive (read)
*
* @cldev: me client device
* @buf: buffer to receive
* @length: buffer length
*
* Return: read size in bytes of < 0 on error
* -EAGAIN if function will block.
*/
ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
size_t length)
{
struct mei_cl *cl = cldev->cl;
return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK, 0);
}
EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
/**
* mei_cldev_recv - client receive (read)
*
* @cldev: me client device
* @buf: buffer to receive
* @length: buffer length
*
* Return: read size in bytes of < 0 on error
*/
ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
struct mei_cl *cl = cldev->cl;
return __mei_cl_recv(cl, buf, length, 0, 0);
}
EXPORT_SYMBOL_GPL(mei_cldev_recv);
/**
* mei_cl_bus_rx_work - dispatch rx event for a bus device
*
* @work: work
*/
static void mei_cl_bus_rx_work(struct work_struct *work)
{
struct mei_cl_device *cldev;
struct mei_device *bus;
cldev = container_of(work, struct mei_cl_device, rx_work);
bus = cldev->bus;
if (cldev->rx_cb)
cldev->rx_cb(cldev);
mutex_lock(&bus->device_lock);
mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
mutex_unlock(&bus->device_lock);
}
/**
* mei_cl_bus_notif_work - dispatch FW notif event for a bus device
*
* @work: work
*/
static void mei_cl_bus_notif_work(struct work_struct *work)
{
struct mei_cl_device *cldev;
cldev = container_of(work, struct mei_cl_device, notif_work);
if (cldev->notif_cb)
cldev->notif_cb(cldev);
}
/**
* mei_cl_bus_notify_event - schedule notify cb on bus client
*
* @cl: host client
*
* Return: true if event was scheduled
* false if the client is not waiting for event
*/
bool mei_cl_bus_notify_event(struct mei_cl *cl)
{
struct mei_cl_device *cldev = cl->cldev;
if (!cldev || !cldev->notif_cb)
return false;
if (!cl->notify_ev)
return false;
schedule_work(&cldev->notif_work);
cl->notify_ev = false;
return true;
}
/**
* mei_cl_bus_rx_event - schedule rx event
*
* @cl: host client
*
* Return: true if event was scheduled
* false if the client is not waiting for event
*/
bool mei_cl_bus_rx_event(struct mei_cl *cl)
{
struct mei_cl_device *cldev = cl->cldev;
if (!cldev || !cldev->rx_cb)
return false;
schedule_work(&cldev->rx_work);
return true;
}
/**
* mei_cldev_register_rx_cb - register Rx event callback
*
* @cldev: me client devices
* @rx_cb: callback function
*
* Return: 0 on success
* -EALREADY if an callback is already registered
* <0 on other errors
*/
int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb)
{
struct mei_device *bus = cldev->bus;
int ret;
if (!rx_cb)
return -EINVAL;
if (cldev->rx_cb)
return -EALREADY;
cldev->rx_cb = rx_cb;
INIT_WORK(&cldev->rx_work, mei_cl_bus_rx_work);
mutex_lock(&bus->device_lock);
ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
mutex_unlock(&bus->device_lock);
if (ret && ret != -EBUSY)
return ret;
return 0;
}
EXPORT_SYMBOL_GPL(mei_cldev_register_rx_cb);
/**
* mei_cldev_register_notif_cb - register FW notification event callback
*
* @cldev: me client devices
* @notif_cb: callback function
*
* Return: 0 on success
* -EALREADY if an callback is already registered
* <0 on other errors
*/
int mei_cldev_register_notif_cb(struct mei_cl_device *cldev,
mei_cldev_cb_t notif_cb)
{
struct mei_device *bus = cldev->bus;
int ret;
if (!notif_cb)
return -EINVAL;
if (cldev->notif_cb)
return -EALREADY;
cldev->notif_cb = notif_cb;
INIT_WORK(&cldev->notif_work, mei_cl_bus_notif_work);
mutex_lock(&bus->device_lock);
ret = mei_cl_notify_request(cldev->cl, NULL, 1);
mutex_unlock(&bus->device_lock);
if (ret)
return ret;
return 0;
}
EXPORT_SYMBOL_GPL(mei_cldev_register_notif_cb);
/**
* mei_cldev_get_drvdata - driver data getter
*
* @cldev: mei client device
*
* Return: driver private data
*/
void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
{
return dev_get_drvdata(&cldev->dev);
}
EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
/**
* mei_cldev_set_drvdata - driver data setter
*
* @cldev: mei client device
* @data: data to store
*/
void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
{
dev_set_drvdata(&cldev->dev, data);
}
EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
/**
* mei_cldev_uuid - return uuid of the underlying me client
*
* @cldev: mei client device
*
* Return: me client uuid
*/
const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
{
return mei_me_cl_uuid(cldev->me_cl);
}
EXPORT_SYMBOL_GPL(mei_cldev_uuid);
/**
* mei_cldev_ver - return protocol version of the underlying me client
*
* @cldev: mei client device
*
* Return: me client protocol version
*/
u8 mei_cldev_ver(const struct mei_cl_device *cldev)
{
return mei_me_cl_ver(cldev->me_cl);
}
EXPORT_SYMBOL_GPL(mei_cldev_ver);
/**
* mei_cldev_enabled - check whether the device is enabled
*
* @cldev: mei client device
*
* Return: true if me client is initialized and connected
*/
bool mei_cldev_enabled(struct mei_cl_device *cldev)
{
return mei_cl_is_connected(cldev->cl);
}
EXPORT_SYMBOL_GPL(mei_cldev_enabled);
/**
* mei_cl_bus_module_get - acquire module of the underlying
* hw driver.
*
* @cldev: mei client device
*
* Return: true on success; false if the module was removed.
*/
static bool mei_cl_bus_module_get(struct mei_cl_device *cldev)
{
return try_module_get(cldev->bus->dev->driver->owner);
}
/**
* mei_cl_bus_module_put - release the underlying hw module.
*
* @cldev: mei client device
*/
static void mei_cl_bus_module_put(struct mei_cl_device *cldev)
{
module_put(cldev->bus->dev->driver->owner);
}
/**
* mei_cldev_enable - enable me client device
* create connection with me client
*
* @cldev: me client device
*
* Return: 0 on success and < 0 on error
*/
int mei_cldev_enable(struct mei_cl_device *cldev)
{
struct mei_device *bus = cldev->bus;
struct mei_cl *cl;
int ret;
cl = cldev->cl;
mutex_lock(&bus->device_lock);
if (cl->state == MEI_FILE_UNINITIALIZED) {
ret = mei_cl_link(cl);
if (ret)
goto out;
/* update pointers */
cl->cldev = cldev;
}
if (mei_cl_is_connected(cl)) {
ret = 0;
goto out;
}
if (!mei_me_cl_is_active(cldev->me_cl)) {
dev_err(&cldev->dev, "me client is not active\n");
ret = -ENOTTY;
goto out;
}
ret = mei_cl_connect(cl, cldev->me_cl, NULL);
if (ret < 0)
dev_err(&cldev->dev, "cannot connect\n");
out:
mutex_unlock(&bus->device_lock);
return ret;
}
EXPORT_SYMBOL_GPL(mei_cldev_enable);
/**
* mei_cldev_unregister_callbacks - internal wrapper for unregistering
* callbacks.
*
* @cldev: client device
*/
static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
{
if (cldev->rx_cb) {
cancel_work_sync(&cldev->rx_work);
cldev->rx_cb = NULL;
}
if (cldev->notif_cb) {
cancel_work_sync(&cldev->notif_work);
cldev->notif_cb = NULL;
}
}
/**
* mei_cldev_disable - disable me client device
* disconnect form the me client
*
* @cldev: me client device
*
* Return: 0 on success and < 0 on error
*/
int mei_cldev_disable(struct mei_cl_device *cldev)
{
struct mei_device *bus;
struct mei_cl *cl;
int err;
if (!cldev)
return -ENODEV;
cl = cldev->cl;
bus = cldev->bus;
mei_cldev_unregister_callbacks(cldev);
mutex_lock(&bus->device_lock);
if (!mei_cl_is_connected(cl)) {
dev_dbg(bus->dev, "Already disconnected\n");
err = 0;
goto out;
}
err = mei_cl_disconnect(cl);
if (err < 0)
dev_err(bus->dev, "Could not disconnect from the ME client\n");
out:
/* Flush queues and remove any pending read */
mei_cl_flush_queues(cl, NULL);
mei_cl_unlink(cl);
mutex_unlock(&bus->device_lock);
return err;
}
EXPORT_SYMBOL_GPL(mei_cldev_disable);
/**
* mei_cl_device_find - find matching entry in the driver id table
*
* @cldev: me client device
* @cldrv: me client driver
*
* Return: id on success; NULL if no id is matching
*/
static const
struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
struct mei_cl_driver *cldrv)
{
const struct mei_cl_device_id *id;
const uuid_le *uuid;
u8 version;
bool match;
uuid = mei_me_cl_uuid(cldev->me_cl);
version = mei_me_cl_ver(cldev->me_cl);
id = cldrv->id_table;
while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
if (!uuid_le_cmp(*uuid, id->uuid)) {
match = true;
if (cldev->name[0])
if (strncmp(cldev->name, id->name,
sizeof(id->name)))
match = false;
if (id->version != MEI_CL_VERSION_ANY)
if (id->version != version)
match = false;
if (match)
return id;
}
id++;
}
return NULL;
}
/**
* mei_cl_device_match - device match function
*
* @dev: device
* @drv: driver
*
* Return: 1 if matching device was found 0 otherwise
*/
static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
const struct mei_cl_device_id *found_id;
if (!cldev)
return 0;
if (!cldev->do_match)
return 0;
if (!cldrv || !cldrv->id_table)
return 0;
found_id = mei_cl_device_find(cldev, cldrv);
if (found_id)
return 1;
return 0;
}
/**
* mei_cl_device_probe - bus probe function
*
* @dev: device
*
* Return: 0 on success; < 0 otherwise
*/
static int mei_cl_device_probe(struct device *dev)
{
struct mei_cl_device *cldev;
struct mei_cl_driver *cldrv;
const struct mei_cl_device_id *id;
int ret;
cldev = to_mei_cl_device(dev);
cldrv = to_mei_cl_driver(dev->driver);
if (!cldev)
return 0;
if (!cldrv || !cldrv->probe)
return -ENODEV;
id = mei_cl_device_find(cldev, cldrv);
if (!id)
return -ENODEV;
if (!mei_cl_bus_module_get(cldev)) {
dev_err(&cldev->dev, "get hw module failed");
return -ENODEV;
}
ret = cldrv->probe(cldev, id);
if (ret) {
mei_cl_bus_module_put(cldev);
return ret;
}
__module_get(THIS_MODULE);
return 0;
}
/**
* mei_cl_device_remove - remove device from the bus
*
* @dev: device
*
* Return: 0 on success; < 0 otherwise
*/
static int mei_cl_device_remove(struct device *dev)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
struct mei_cl_driver *cldrv;
int ret = 0;
if (!cldev || !dev->driver)
return 0;
cldrv = to_mei_cl_driver(dev->driver);
if (cldrv->remove)
ret = cldrv->remove(cldev);
mei_cldev_unregister_callbacks(cldev);
mei_cl_bus_module_put(cldev);
module_put(THIS_MODULE);
dev->driver = NULL;
return ret;
}
static ssize_t name_show(struct device *dev, struct device_attribute *a,
char *buf)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
}
static DEVICE_ATTR_RO(name);
static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
char *buf)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
return scnprintf(buf, PAGE_SIZE, "%pUl", uuid);
}
static DEVICE_ATTR_RO(uuid);
static ssize_t version_show(struct device *dev, struct device_attribute *a,
char *buf)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
u8 version = mei_me_cl_ver(cldev->me_cl);
return scnprintf(buf, PAGE_SIZE, "%02X", version);
}
static DEVICE_ATTR_RO(version);
static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
char *buf)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
u8 version = mei_me_cl_ver(cldev->me_cl);
return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
cldev->name, uuid, version);
}
static DEVICE_ATTR_RO(modalias);
static struct attribute *mei_cldev_attrs[] = {
&dev_attr_name.attr,
&dev_attr_uuid.attr,
&dev_attr_version.attr,
&dev_attr_modalias.attr,
NULL,
};
ATTRIBUTE_GROUPS(mei_cldev);
/**
* mei_cl_device_uevent - me client bus uevent handler
*
* @dev: device
* @env: uevent kobject
*
* Return: 0 on success -ENOMEM on when add_uevent_var fails
*/
static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
u8 version = mei_me_cl_ver(cldev->me_cl);
if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
return -ENOMEM;
if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
return -ENOMEM;
if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
return -ENOMEM;
if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
cldev->name, uuid, version))
return -ENOMEM;
return 0;
}
static struct bus_type mei_cl_bus_type = {
.name = "mei",
.dev_groups = mei_cldev_groups,
.match = mei_cl_device_match,
.probe = mei_cl_device_probe,
.remove = mei_cl_device_remove,
.uevent = mei_cl_device_uevent,
};
static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
{
if (bus)
get_device(bus->dev);
return bus;
}
static void mei_dev_bus_put(struct mei_device *bus)
{
if (bus)
put_device(bus->dev);
}
static void mei_cl_bus_dev_release(struct device *dev)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
if (!cldev)
return;
mei_me_cl_put(cldev->me_cl);
mei_dev_bus_put(cldev->bus);
mei_cl_unlink(cldev->cl);
kfree(cldev->cl);
kfree(cldev);
}
static const struct device_type mei_cl_device_type = {
.release = mei_cl_bus_dev_release,
};
/**
* mei_cl_bus_set_name - set device name for me client device
*
* @cldev: me client device
*/
static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
{
dev_set_name(&cldev->dev, "mei:%s:%pUl:%02X",
cldev->name,
mei_me_cl_uuid(cldev->me_cl),
mei_me_cl_ver(cldev->me_cl));
}
/**
* mei_cl_bus_dev_alloc - initialize and allocate mei client device
*
* @bus: mei device
* @me_cl: me client
*
* Return: allocated device structur or NULL on allocation failure
*/
static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
struct mei_me_client *me_cl)
{
struct mei_cl_device *cldev;
struct mei_cl *cl;
cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
if (!cldev)
return NULL;
cl = mei_cl_allocate(bus);
if (!cl) {
kfree(cldev);
return NULL;
}
device_initialize(&cldev->dev);
cldev->dev.parent = bus->dev;
cldev->dev.bus = &mei_cl_bus_type;
cldev->dev.type = &mei_cl_device_type;
cldev->bus = mei_dev_bus_get(bus);
cldev->me_cl = mei_me_cl_get(me_cl);
cldev->cl = cl;
mei_cl_bus_set_name(cldev);
cldev->is_added = 0;
INIT_LIST_HEAD(&cldev->bus_list);
return cldev;
}
/**
* mei_cl_dev_setup - setup me client device
* run fix up routines and set the device name
*
* @bus: mei device
* @cldev: me client device
*
* Return: true if the device is eligible for enumeration
*/
static bool mei_cl_bus_dev_setup(struct mei_device *bus,
struct mei_cl_device *cldev)
{
cldev->do_match = 1;
mei_cl_bus_dev_fixup(cldev);
/* the device name can change during fix up */
if (cldev->do_match)
mei_cl_bus_set_name(cldev);
return cldev->do_match == 1;
}
/**
* mei_cl_bus_dev_add - add me client devices
*
* @cldev: me client device
*
* Return: 0 on success; < 0 on failre
*/
static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
{
int ret;
dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
mei_me_cl_uuid(cldev->me_cl),
mei_me_cl_ver(cldev->me_cl));
ret = device_add(&cldev->dev);
if (!ret)
cldev->is_added = 1;
return ret;
}
/**
* mei_cl_bus_dev_stop - stop the driver
*
* @cldev: me client device
*/
static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
{
if (cldev->is_added)
device_release_driver(&cldev->dev);
}
/**
* mei_cl_bus_dev_destroy - destroy me client devices object
*
* @cldev: me client device
*
* Locking: called under "dev->cl_bus_lock" lock
*/
static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
{
WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
if (!cldev->is_added)
return;
device_del(&cldev->dev);
list_del_init(&cldev->bus_list);
cldev->is_added = 0;
put_device(&cldev->dev);
}
/**
* mei_cl_bus_remove_device - remove a devices form the bus
*
* @cldev: me client device
*/
static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
{
mei_cl_bus_dev_stop(cldev);
mei_cl_bus_dev_destroy(cldev);
}
/**
* mei_cl_bus_remove_devices - remove all devices form the bus
*
* @bus: mei device
*/
void mei_cl_bus_remove_devices(struct mei_device *bus)
{
struct mei_cl_device *cldev, *next;
mutex_lock(&bus->cl_bus_lock);
list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
mei_cl_bus_remove_device(cldev);
mutex_unlock(&bus->cl_bus_lock);
}
/**
* mei_cl_bus_dev_init - allocate and initializes an mei client devices
* based on me client
*
* @bus: mei device
* @me_cl: me client
*
* Locking: called under "dev->cl_bus_lock" lock
*/
static void mei_cl_bus_dev_init(struct mei_device *bus,
struct mei_me_client *me_cl)
{
struct mei_cl_device *cldev;
WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
if (me_cl->bus_added)
return;
cldev = mei_cl_bus_dev_alloc(bus, me_cl);
if (!cldev)
return;
me_cl->bus_added = true;
list_add_tail(&cldev->bus_list, &bus->device_list);
}
/**
* mei_cl_bus_rescan - scan me clients list and add create
* devices for eligible clients
*
* @bus: mei device
*/
static void mei_cl_bus_rescan(struct mei_device *bus)
{
struct mei_cl_device *cldev, *n;
struct mei_me_client *me_cl;
mutex_lock(&bus->cl_bus_lock);
down_read(&bus->me_clients_rwsem);
list_for_each_entry(me_cl, &bus->me_clients, list)
mei_cl_bus_dev_init(bus, me_cl);
up_read(&bus->me_clients_rwsem);
list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
if (!mei_me_cl_is_active(cldev->me_cl)) {
mei_cl_bus_remove_device(cldev);
continue;
}
if (cldev->is_added)
continue;
if (mei_cl_bus_dev_setup(bus, cldev))
mei_cl_bus_dev_add(cldev);
else {
list_del_init(&cldev->bus_list);
put_device(&cldev->dev);
}
}
mutex_unlock(&bus->cl_bus_lock);
dev_dbg(bus->dev, "rescan end");
}
void mei_cl_bus_rescan_work(struct work_struct *work)
{
struct mei_device *bus =
container_of(work, struct mei_device, bus_rescan_work);
mei_cl_bus_rescan(bus);
}
int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
struct module *owner)
{
int err;
cldrv->driver.name = cldrv->name;
cldrv->driver.owner = owner;
cldrv->driver.bus = &mei_cl_bus_type;
err = driver_register(&cldrv->driver);
if (err)
return err;
pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
return 0;
}
EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
{
driver_unregister(&cldrv->driver);
pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
}
EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
int __init mei_cl_bus_init(void)
{
return bus_register(&mei_cl_bus_type);
}
void __exit mei_cl_bus_exit(void)
{
bus_unregister(&mei_cl_bus_type);
}