linux/drivers/misc/mei/bus.c
Samuel Ortiz bbedf2fc20 mei: bus: Reset event_cb when disabling a device
After cancelling all reads from the disable hook, we need to reset the
event_cb pointer as well or else we won't be able to set a new one up
when re-enabling the device.

Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-21 09:57:55 -07:00

531 lines
11 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.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/mei_cl_bus.h>
#include "mei_dev.h"
#include "hw-me.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)
static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
{
struct mei_cl_device *device = to_mei_cl_device(dev);
struct mei_cl_driver *driver = to_mei_cl_driver(drv);
const struct mei_cl_device_id *id;
if (!device)
return 0;
if (!driver || !driver->id_table)
return 0;
id = driver->id_table;
while (id->name[0]) {
if (!strcmp(dev_name(dev), id->name))
return 1;
id++;
}
return 0;
}
static int mei_cl_device_probe(struct device *dev)
{
struct mei_cl_device *device = to_mei_cl_device(dev);
struct mei_cl_driver *driver;
struct mei_cl_device_id id;
if (!device)
return 0;
driver = to_mei_cl_driver(dev->driver);
if (!driver || !driver->probe)
return -ENODEV;
dev_dbg(dev, "Device probe\n");
strncpy(id.name, dev_name(dev), MEI_CL_NAME_SIZE);
return driver->probe(device, &id);
}
static int mei_cl_device_remove(struct device *dev)
{
struct mei_cl_device *device = to_mei_cl_device(dev);
struct mei_cl_driver *driver;
if (!device || !dev->driver)
return 0;
if (device->event_cb) {
device->event_cb = NULL;
cancel_work_sync(&device->event_work);
}
driver = to_mei_cl_driver(dev->driver);
if (!driver->remove) {
dev->driver = NULL;
return 0;
}
return driver->remove(device);
}
static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
char *buf)
{
int len;
len = snprintf(buf, PAGE_SIZE, "mei:%s\n", dev_name(dev));
return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
}
static struct device_attribute mei_cl_dev_attrs[] = {
__ATTR_RO(modalias),
__ATTR_NULL,
};
static int mei_cl_uevent(struct device *dev, struct kobj_uevent_env *env)
{
if (add_uevent_var(env, "MODALIAS=mei:%s", dev_name(dev)))
return -ENOMEM;
return 0;
}
static struct bus_type mei_cl_bus_type = {
.name = "mei",
.dev_attrs = mei_cl_dev_attrs,
.match = mei_cl_device_match,
.probe = mei_cl_device_probe,
.remove = mei_cl_device_remove,
.uevent = mei_cl_uevent,
};
static void mei_cl_dev_release(struct device *dev)
{
kfree(to_mei_cl_device(dev));
}
static struct device_type mei_cl_device_type = {
.release = mei_cl_dev_release,
};
static struct mei_cl *mei_bus_find_mei_cl_by_uuid(struct mei_device *dev,
uuid_le uuid)
{
struct mei_cl *cl, *next;
list_for_each_entry_safe(cl, next, &dev->device_list, device_link) {
if (!uuid_le_cmp(uuid, cl->device_uuid))
return cl;
}
return NULL;
}
struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
uuid_le uuid, char *name,
struct mei_cl_ops *ops)
{
struct mei_cl_device *device;
struct mei_cl *cl;
int status;
cl = mei_bus_find_mei_cl_by_uuid(dev, uuid);
if (cl == NULL)
return NULL;
device = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
if (!device)
return NULL;
device->cl = cl;
device->ops = ops;
device->dev.parent = &dev->pdev->dev;
device->dev.bus = &mei_cl_bus_type;
device->dev.type = &mei_cl_device_type;
dev_set_name(&device->dev, "%s", name);
status = device_register(&device->dev);
if (status) {
dev_err(&dev->pdev->dev, "Failed to register MEI device\n");
kfree(device);
return NULL;
}
cl->device = device;
dev_dbg(&device->dev, "client %s registered\n", name);
return device;
}
EXPORT_SYMBOL_GPL(mei_cl_add_device);
void mei_cl_remove_device(struct mei_cl_device *device)
{
device_unregister(&device->dev);
}
EXPORT_SYMBOL_GPL(mei_cl_remove_device);
int __mei_cl_driver_register(struct mei_cl_driver *driver, struct module *owner)
{
int err;
driver->driver.name = driver->name;
driver->driver.owner = owner;
driver->driver.bus = &mei_cl_bus_type;
err = driver_register(&driver->driver);
if (err)
return err;
pr_debug("mei: driver [%s] registered\n", driver->driver.name);
return 0;
}
EXPORT_SYMBOL_GPL(__mei_cl_driver_register);
void mei_cl_driver_unregister(struct mei_cl_driver *driver)
{
driver_unregister(&driver->driver);
pr_debug("mei: driver [%s] unregistered\n", driver->driver.name);
}
EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);
static int ___mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
bool blocking)
{
struct mei_device *dev;
struct mei_cl_cb *cb;
int id;
int rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
if (cl->state != MEI_FILE_CONNECTED)
return -ENODEV;
/* Check if we have an ME client device */
id = mei_me_cl_by_id(dev, cl->me_client_id);
if (id < 0)
return -ENODEV;
if (length > dev->me_clients[id].props.max_msg_length)
return -EINVAL;
cb = mei_io_cb_init(cl, NULL);
if (!cb)
return -ENOMEM;
rets = mei_io_cb_alloc_req_buf(cb, length);
if (rets < 0) {
mei_io_cb_free(cb);
return rets;
}
memcpy(cb->request_buffer.data, buf, length);
mutex_lock(&dev->device_lock);
rets = mei_cl_write(cl, cb, blocking);
mutex_unlock(&dev->device_lock);
if (rets < 0)
mei_io_cb_free(cb);
return rets;
}
int __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
{
struct mei_device *dev;
struct mei_cl_cb *cb;
size_t r_length;
int err;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (!cl->read_cb) {
err = mei_cl_read_start(cl, length);
if (err < 0) {
mutex_unlock(&dev->device_lock);
return err;
}
}
if (cl->reading_state != MEI_READ_COMPLETE &&
!waitqueue_active(&cl->rx_wait)) {
mutex_unlock(&dev->device_lock);
if (wait_event_interruptible(cl->rx_wait,
(MEI_READ_COMPLETE == cl->reading_state))) {
if (signal_pending(current))
return -EINTR;
return -ERESTARTSYS;
}
mutex_lock(&dev->device_lock);
}
cb = cl->read_cb;
if (cl->reading_state != MEI_READ_COMPLETE) {
r_length = 0;
goto out;
}
r_length = min_t(size_t, length, cb->buf_idx);
memcpy(buf, cb->response_buffer.data, r_length);
mei_io_cb_free(cb);
cl->reading_state = MEI_IDLE;
cl->read_cb = NULL;
out:
mutex_unlock(&dev->device_lock);
return r_length;
}
inline int __mei_cl_async_send(struct mei_cl *cl, u8 *buf, size_t length)
{
return ___mei_cl_send(cl, buf, length, 0);
}
inline int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length)
{
return ___mei_cl_send(cl, buf, length, 1);
}
int mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length)
{
struct mei_cl *cl = device->cl;
if (cl == NULL)
return -ENODEV;
if (device->ops && device->ops->send)
return device->ops->send(device, buf, length);
return __mei_cl_send(cl, buf, length);
}
EXPORT_SYMBOL_GPL(mei_cl_send);
int mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length)
{
struct mei_cl *cl = device->cl;
if (cl == NULL)
return -ENODEV;
if (device->ops && device->ops->recv)
return device->ops->recv(device, buf, length);
return __mei_cl_recv(cl, buf, length);
}
EXPORT_SYMBOL_GPL(mei_cl_recv);
static void mei_bus_event_work(struct work_struct *work)
{
struct mei_cl_device *device;
device = container_of(work, struct mei_cl_device, event_work);
if (device->event_cb)
device->event_cb(device, device->events, device->event_context);
device->events = 0;
/* Prepare for the next read */
mei_cl_read_start(device->cl, 0);
}
int mei_cl_register_event_cb(struct mei_cl_device *device,
mei_cl_event_cb_t event_cb, void *context)
{
if (device->event_cb)
return -EALREADY;
device->events = 0;
device->event_cb = event_cb;
device->event_context = context;
INIT_WORK(&device->event_work, mei_bus_event_work);
mei_cl_read_start(device->cl, 0);
return 0;
}
EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
void *mei_cl_get_drvdata(const struct mei_cl_device *device)
{
return dev_get_drvdata(&device->dev);
}
EXPORT_SYMBOL_GPL(mei_cl_get_drvdata);
void mei_cl_set_drvdata(struct mei_cl_device *device, void *data)
{
dev_set_drvdata(&device->dev, data);
}
EXPORT_SYMBOL_GPL(mei_cl_set_drvdata);
int mei_cl_enable_device(struct mei_cl_device *device)
{
int err;
struct mei_device *dev;
struct mei_cl *cl = device->cl;
if (cl == NULL)
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
cl->state = MEI_FILE_CONNECTING;
err = mei_cl_connect(cl, NULL);
if (err < 0) {
mutex_unlock(&dev->device_lock);
dev_err(&dev->pdev->dev, "Could not connect to the ME client");
return err;
}
mutex_unlock(&dev->device_lock);
if (device->event_cb && !cl->read_cb)
mei_cl_read_start(device->cl, 0);
if (!device->ops || !device->ops->enable)
return 0;
return device->ops->enable(device);
}
EXPORT_SYMBOL_GPL(mei_cl_enable_device);
int mei_cl_disable_device(struct mei_cl_device *device)
{
int err;
struct mei_device *dev;
struct mei_cl *cl = device->cl;
if (cl == NULL)
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (cl->state != MEI_FILE_CONNECTED) {
mutex_unlock(&dev->device_lock);
dev_err(&dev->pdev->dev, "Already disconnected");
return 0;
}
cl->state = MEI_FILE_DISCONNECTING;
err = mei_cl_disconnect(cl);
if (err < 0) {
mutex_unlock(&dev->device_lock);
dev_err(&dev->pdev->dev,
"Could not disconnect from the ME client");
return err;
}
/* Flush queues and remove any pending read */
mei_cl_flush_queues(cl);
if (cl->read_cb) {
struct mei_cl_cb *cb = NULL;
cb = mei_cl_find_read_cb(cl);
/* Remove entry from read list */
if (cb)
list_del(&cb->list);
cb = cl->read_cb;
cl->read_cb = NULL;
if (cb) {
mei_io_cb_free(cb);
cb = NULL;
}
}
device->event_cb = NULL;
mutex_unlock(&dev->device_lock);
if (!device->ops || !device->ops->disable)
return 0;
return device->ops->disable(device);
}
EXPORT_SYMBOL_GPL(mei_cl_disable_device);
void mei_cl_bus_rx_event(struct mei_cl *cl)
{
struct mei_cl_device *device = cl->device;
if (!device || !device->event_cb)
return;
set_bit(MEI_CL_EVENT_RX, &device->events);
schedule_work(&device->event_work);
}
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);
}