OpenCloudOS-Kernel/drivers/misc/mei/bus.c

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/*
* 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_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->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);
int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length)
{
struct mei_device *dev;
struct mei_msg_hdr mei_hdr;
struct mei_cl_cb *cb;
int me_cl_id, err;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
if (cl->state != MEI_FILE_CONNECTED)
return -ENODEV;
cb = mei_io_cb_init(cl, NULL);
if (!cb)
return -ENOMEM;
err = mei_io_cb_alloc_req_buf(cb, length);
if (err < 0) {
mei_io_cb_free(cb);
return err;
}
memcpy(cb->request_buffer.data, buf, length);
cb->fop_type = MEI_FOP_WRITE;
dev = cl->dev;
mutex_lock(&dev->device_lock);
/* Check if we have an ME client device */
me_cl_id = mei_me_cl_by_id(dev, cl->me_client_id);
if (me_cl_id == dev->me_clients_num) {
err = -ENODEV;
goto out_err;
}
if (length > dev->me_clients[me_cl_id].props.max_msg_length) {
err = -EINVAL;
goto out_err;
}
err = mei_cl_flow_ctrl_creds(cl);
if (err < 0)
goto out_err;
/* Host buffer is not ready, we queue the request */
if (err == 0 || !dev->hbuf_is_ready) {
cb->buf_idx = 0;
mei_hdr.msg_complete = 0;
cl->writing_state = MEI_WRITING;
list_add_tail(&cb->list, &dev->write_list.list);
mutex_unlock(&dev->device_lock);
return length;
}
dev->hbuf_is_ready = false;
/* Check for a maximum length */
if (length > mei_hbuf_max_len(dev)) {
mei_hdr.length = mei_hbuf_max_len(dev);
mei_hdr.msg_complete = 0;
} else {
mei_hdr.length = length;
mei_hdr.msg_complete = 1;
}
mei_hdr.host_addr = cl->host_client_id;
mei_hdr.me_addr = cl->me_client_id;
mei_hdr.reserved = 0;
if (mei_write_message(dev, &mei_hdr, buf)) {
err = -EIO;
goto out_err;
}
cl->writing_state = MEI_WRITING;
cb->buf_idx = mei_hdr.length;
if (!mei_hdr.msg_complete) {
list_add_tail(&cb->list, &dev->write_list.list);
} else {
if (mei_cl_flow_ctrl_reduce(cl)) {
err = -EIO;
goto out_err;
}
list_add_tail(&cb->list, &dev->write_waiting_list.list);
}
mutex_unlock(&dev->device_lock);
return mei_hdr.length;
out_err:
mutex_unlock(&dev->device_lock);
mei_io_cb_free(cb);
return err;
}
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);
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;
}
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);
}
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);
return 0;
}
EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);