https://github.com/torvalds/linux
Tip revision: 9ffecb10283508260936b96022d4ee43a7798b4c authored by Linus Torvalds on 27 September 2015, 11:50:08 UTC
Linux 4.3-rc3
Linux 4.3-rc3
Tip revision: 9ffecb1
bus.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.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)
#define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
/**
* __mei_cl_send - internal client send (write)
*
* @cl: host client
* @buf: buffer to send
* @length: buffer length
* @blocking: wait for write completion
*
* Return: written size bytes or < 0 on error
*/
ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
bool blocking)
{
struct mei_device *bus;
struct mei_cl_cb *cb = NULL;
ssize_t rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
bus = cl->dev;
mutex_lock(&bus->device_lock);
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;
}
cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
if (!cb) {
rets = -ENOMEM;
goto out;
}
memcpy(cb->buf.data, buf, length);
rets = mei_cl_write(cl, cb, blocking);
out:
mutex_unlock(&bus->device_lock);
if (rets < 0)
mei_io_cb_free(cb);
return rets;
}
/**
* __mei_cl_recv - internal client receive (read)
*
* @cl: host client
* @buf: buffer to send
* @length: buffer length
*
* Return: read size in bytes of < 0 on error
*/
ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
{
struct mei_device *bus;
struct mei_cl_cb *cb;
size_t r_length;
ssize_t rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
bus = cl->dev;
mutex_lock(&bus->device_lock);
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;
/* wait on event only if there is no other waiter */
if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
mutex_unlock(&bus->device_lock);
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 = -EBUSY;
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_cl_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_cl_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
struct mei_cl *cl = cldev->cl;
if (cl == NULL)
return -ENODEV;
return __mei_cl_send(cl, buf, length, 1);
}
EXPORT_SYMBOL_GPL(mei_cl_send);
/**
* mei_cl_recv - client receive (read)
*
* @cldev: me client device
* @buf: buffer to send
* @length: buffer length
*
* Return: read size in bytes of < 0 on error
*/
ssize_t mei_cl_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
struct mei_cl *cl = cldev->cl;
if (cl == NULL)
return -ENODEV;
return __mei_cl_recv(cl, buf, length);
}
EXPORT_SYMBOL_GPL(mei_cl_recv);
/**
* mei_bus_event_work - dispatch rx event for a bus device
* and schedule new work
*
* @work: work
*/
static void mei_bus_event_work(struct work_struct *work)
{
struct mei_cl_device *cldev;
cldev = container_of(work, struct mei_cl_device, event_work);
if (cldev->event_cb)
cldev->event_cb(cldev, cldev->events, cldev->event_context);
cldev->events = 0;
/* Prepare for the next read */
if (cldev->events_mask & BIT(MEI_CL_EVENT_RX))
mei_cl_read_start(cldev->cl, 0, NULL);
}
/**
* mei_cl_bus_notify_event - schedule notify cb on bus client
*
* @cl: host client
*/
void mei_cl_bus_notify_event(struct mei_cl *cl)
{
struct mei_cl_device *cldev = cl->cldev;
if (!cldev || !cldev->event_cb)
return;
if (!(cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)))
return;
if (!cl->notify_ev)
return;
set_bit(MEI_CL_EVENT_NOTIF, &cldev->events);
schedule_work(&cldev->event_work);
cl->notify_ev = false;
}
/**
* mei_cl_bus_rx_event - schedule rx evenet
*
* @cl: host client
*/
void mei_cl_bus_rx_event(struct mei_cl *cl)
{
struct mei_cl_device *cldev = cl->cldev;
if (!cldev || !cldev->event_cb)
return;
if (!(cldev->events_mask & BIT(MEI_CL_EVENT_RX)))
return;
set_bit(MEI_CL_EVENT_RX, &cldev->events);
schedule_work(&cldev->event_work);
}
/**
* mei_cl_register_event_cb - register event callback
*
* @cldev: me client devices
* @event_cb: callback function
* @events_mask: requested events bitmask
* @context: driver context data
*
* Return: 0 on success
* -EALREADY if an callback is already registered
* <0 on other errors
*/
int mei_cl_register_event_cb(struct mei_cl_device *cldev,
unsigned long events_mask,
mei_cl_event_cb_t event_cb, void *context)
{
int ret;
if (cldev->event_cb)
return -EALREADY;
cldev->events = 0;
cldev->events_mask = events_mask;
cldev->event_cb = event_cb;
cldev->event_context = context;
INIT_WORK(&cldev->event_work, mei_bus_event_work);
if (cldev->events_mask & BIT(MEI_CL_EVENT_RX)) {
ret = mei_cl_read_start(cldev->cl, 0, NULL);
if (ret && ret != -EBUSY)
return ret;
}
if (cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)) {
mutex_lock(&cldev->cl->dev->device_lock);
ret = mei_cl_notify_request(cldev->cl, NULL, event_cb ? 1 : 0);
mutex_unlock(&cldev->cl->dev->device_lock);
if (ret)
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
/**
* mei_cl_get_drvdata - driver data getter
*
* @cldev: mei client device
*
* Return: driver private data
*/
void *mei_cl_get_drvdata(const struct mei_cl_device *cldev)
{
return dev_get_drvdata(&cldev->dev);
}
EXPORT_SYMBOL_GPL(mei_cl_get_drvdata);
/**
* mei_cl_set_drvdata - driver data setter
*
* @cldev: mei client device
* @data: data to store
*/
void mei_cl_set_drvdata(struct mei_cl_device *cldev, void *data)
{
dev_set_drvdata(&cldev->dev, data);
}
EXPORT_SYMBOL_GPL(mei_cl_set_drvdata);
/**
* mei_cl_enable_device - enable me client device
* create connection with me client
*
* @cldev: me client device
*
* Return: 0 on success and < 0 on error
*/
int mei_cl_enable_device(struct mei_cl_device *cldev)
{
struct mei_device *bus = cldev->bus;
struct mei_cl *cl;
int ret;
cl = cldev->cl;
if (!cl) {
mutex_lock(&bus->device_lock);
cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
mutex_unlock(&bus->device_lock);
if (IS_ERR(cl))
return PTR_ERR(cl);
/* update pointers */
cldev->cl = cl;
cl->cldev = cldev;
}
mutex_lock(&bus->device_lock);
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_cl_enable_device);
/**
* mei_cl_disable_device - disable me client device
* disconnect form the me client
*
* @cldev: me client device
*
* Return: 0 on success and < 0 on error
*/
int mei_cl_disable_device(struct mei_cl_device *cldev)
{
struct mei_device *bus;
struct mei_cl *cl;
int err;
if (!cldev || !cldev->cl)
return -ENODEV;
cl = cldev->cl;
bus = cldev->bus;
cldev->event_cb = NULL;
mutex_lock(&bus->device_lock);
if (!mei_cl_is_connected(cl)) {
dev_err(bus->dev, "Already disconnected");
err = 0;
goto out;
}
err = mei_cl_disconnect(cl);
if (err < 0)
dev_err(bus->dev, "Could not disconnect from the ME client");
out:
/* Flush queues and remove any pending read */
mei_cl_flush_queues(cl, NULL);
mei_cl_unlink(cl);
kfree(cl);
cldev->cl = NULL;
mutex_unlock(&bus->device_lock);
return err;
}
EXPORT_SYMBOL_GPL(mei_cl_disable_device);
/**
* 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;
uuid = mei_me_cl_uuid(cldev->me_cl);
id = cldrv->id_table;
while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
if (!uuid_le_cmp(*uuid, id->uuid)) {
if (!cldev->name[0])
return id;
if (!strncmp(cldev->name, id->name, sizeof(id->name)))
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;
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;
__module_get(THIS_MODULE);
return cldrv->probe(cldev, id);
}
/**
* 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;
if (cldev->event_cb) {
cldev->event_cb = NULL;
cancel_work_sync(&cldev->event_work);
}
cldrv = to_mei_cl_driver(dev->driver);
if (cldrv->remove)
ret = cldrv->remove(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);
size_t len;
len = snprintf(buf, PAGE_SIZE, "%s", cldev->name);
return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
}
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);
size_t len;
len = snprintf(buf, PAGE_SIZE, "%pUl", uuid);
return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
}
static DEVICE_ATTR_RO(uuid);
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);
size_t len;
len = snprintf(buf, PAGE_SIZE, "mei:%s:" MEI_CL_UUID_FMT ":",
cldev->name, MEI_CL_UUID_ARGS(uuid->b));
return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
}
static DEVICE_ATTR_RO(modalias);
static struct attribute *mei_cl_dev_attrs[] = {
&dev_attr_name.attr,
&dev_attr_uuid.attr,
&dev_attr_modalias.attr,
NULL,
};
ATTRIBUTE_GROUPS(mei_cl_dev);
/**
* 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);
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:" MEI_CL_UUID_FMT ":",
cldev->name, MEI_CL_UUID_ARGS(uuid->b)))
return -ENOMEM;
return 0;
}
static struct bus_type mei_cl_bus_type = {
.name = "mei",
.dev_groups = mei_cl_dev_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_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);
kfree(cldev);
}
static struct device_type mei_cl_device_type = {
.release = mei_cl_dev_release,
};
/**
* mei_cl_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_dev_alloc(struct mei_device *bus,
struct mei_me_client *me_cl)
{
struct mei_cl_device *cldev;
cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
if (!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->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_dev_setup(struct mei_device *bus,
struct mei_cl_device *cldev)
{
cldev->do_match = 1;
mei_cl_dev_fixup(cldev);
if (cldev->do_match)
dev_set_name(&cldev->dev, "mei:%s:%pUl",
cldev->name, mei_me_cl_uuid(cldev->me_cl));
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\n", mei_me_cl_uuid(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
*/
static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
{
if (!cldev->is_added)
return;
device_del(&cldev->dev);
mutex_lock(&cldev->bus->cl_bus_lock);
list_del_init(&cldev->bus_list);
mutex_unlock(&cldev->bus->cl_bus_lock);
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;
list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
mei_cl_bus_remove_device(cldev);
}
/**
* mei_cl_dev_init - allocate and initializes an mei client devices
* based on me client
*
* @bus: mei device
* @me_cl: me client
*/
static void mei_cl_dev_init(struct mei_device *bus, struct mei_me_client *me_cl)
{
struct mei_cl_device *cldev;
dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
if (me_cl->bus_added)
return;
cldev = mei_cl_dev_alloc(bus, me_cl);
if (!cldev)
return;
mutex_lock(&cldev->bus->cl_bus_lock);
me_cl->bus_added = true;
list_add_tail(&cldev->bus_list, &bus->device_list);
mutex_unlock(&cldev->bus->cl_bus_lock);
}
/**
* mei_cl_bus_rescan - scan me clients list and add create
* devices for eligible clients
*
* @bus: mei device
*/
void mei_cl_bus_rescan(struct mei_device *bus)
{
struct mei_cl_device *cldev, *n;
struct mei_me_client *me_cl;
down_read(&bus->me_clients_rwsem);
list_for_each_entry(me_cl, &bus->me_clients, list)
mei_cl_dev_init(bus, me_cl);
up_read(&bus->me_clients_rwsem);
mutex_lock(&bus->cl_bus_lock);
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_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");
}
int __mei_cl_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_cl_driver_register);
void mei_cl_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_cl_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);
}