![Tomas Winkler](/assets/img/avatar_default.png)
Mei bus receive and send function may return either number of transmitted bytes or errno. It is better to use ssize_t type for that purpose that mixing size_t with int. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
546 lines
11 KiB
C
546 lines
11 KiB
C
/*
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* Intel Management Engine Interface (Intel MEI) Linux driver
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* Copyright (c) 2012-2013, Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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*/
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/interrupt.h>
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#include <linux/mei_cl_bus.h>
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#include "mei_dev.h"
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#include "client.h"
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#define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
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#define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
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static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
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{
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struct mei_cl_device *device = to_mei_cl_device(dev);
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struct mei_cl_driver *driver = to_mei_cl_driver(drv);
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const struct mei_cl_device_id *id;
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if (!device)
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return 0;
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if (!driver || !driver->id_table)
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return 0;
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id = driver->id_table;
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while (id->name[0]) {
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if (!strncmp(dev_name(dev), id->name, sizeof(id->name)))
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return 1;
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id++;
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}
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return 0;
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}
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static int mei_cl_device_probe(struct device *dev)
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{
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struct mei_cl_device *device = to_mei_cl_device(dev);
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struct mei_cl_driver *driver;
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struct mei_cl_device_id id;
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if (!device)
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return 0;
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driver = to_mei_cl_driver(dev->driver);
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if (!driver || !driver->probe)
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return -ENODEV;
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dev_dbg(dev, "Device probe\n");
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strlcpy(id.name, dev_name(dev), sizeof(id.name));
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return driver->probe(device, &id);
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}
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static int mei_cl_device_remove(struct device *dev)
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{
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struct mei_cl_device *device = to_mei_cl_device(dev);
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struct mei_cl_driver *driver;
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if (!device || !dev->driver)
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return 0;
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if (device->event_cb) {
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device->event_cb = NULL;
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cancel_work_sync(&device->event_work);
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}
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driver = to_mei_cl_driver(dev->driver);
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if (!driver->remove) {
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dev->driver = NULL;
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return 0;
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}
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return driver->remove(device);
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}
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static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
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char *buf)
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{
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int len;
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len = snprintf(buf, PAGE_SIZE, "mei:%s\n", dev_name(dev));
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return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
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}
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static DEVICE_ATTR_RO(modalias);
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static struct attribute *mei_cl_dev_attrs[] = {
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&dev_attr_modalias.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(mei_cl_dev);
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static int mei_cl_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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if (add_uevent_var(env, "MODALIAS=mei:%s", dev_name(dev)))
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return -ENOMEM;
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return 0;
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}
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static struct bus_type mei_cl_bus_type = {
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.name = "mei",
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.dev_groups = mei_cl_dev_groups,
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.match = mei_cl_device_match,
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.probe = mei_cl_device_probe,
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.remove = mei_cl_device_remove,
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.uevent = mei_cl_uevent,
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};
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static void mei_cl_dev_release(struct device *dev)
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{
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kfree(to_mei_cl_device(dev));
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}
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static struct device_type mei_cl_device_type = {
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.release = mei_cl_dev_release,
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};
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struct mei_cl *mei_cl_bus_find_cl_by_uuid(struct mei_device *dev,
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uuid_le uuid)
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{
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struct mei_cl *cl;
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list_for_each_entry(cl, &dev->device_list, device_link) {
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if (!uuid_le_cmp(uuid, cl->cl_uuid))
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return cl;
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}
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return NULL;
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}
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struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
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uuid_le uuid, char *name,
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struct mei_cl_ops *ops)
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{
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struct mei_cl_device *device;
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struct mei_cl *cl;
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int status;
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cl = mei_cl_bus_find_cl_by_uuid(dev, uuid);
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if (cl == NULL)
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return NULL;
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device = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
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if (!device)
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return NULL;
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device->cl = cl;
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device->ops = ops;
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device->dev.parent = dev->dev;
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device->dev.bus = &mei_cl_bus_type;
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device->dev.type = &mei_cl_device_type;
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dev_set_name(&device->dev, "%s", name);
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status = device_register(&device->dev);
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if (status) {
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dev_err(dev->dev, "Failed to register MEI device\n");
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kfree(device);
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return NULL;
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}
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cl->device = device;
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dev_dbg(&device->dev, "client %s registered\n", name);
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return device;
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}
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EXPORT_SYMBOL_GPL(mei_cl_add_device);
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void mei_cl_remove_device(struct mei_cl_device *device)
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{
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device_unregister(&device->dev);
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}
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EXPORT_SYMBOL_GPL(mei_cl_remove_device);
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int __mei_cl_driver_register(struct mei_cl_driver *driver, struct module *owner)
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{
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int err;
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driver->driver.name = driver->name;
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driver->driver.owner = owner;
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driver->driver.bus = &mei_cl_bus_type;
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err = driver_register(&driver->driver);
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if (err)
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return err;
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pr_debug("mei: driver [%s] registered\n", driver->driver.name);
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return 0;
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}
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EXPORT_SYMBOL_GPL(__mei_cl_driver_register);
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void mei_cl_driver_unregister(struct mei_cl_driver *driver)
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{
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driver_unregister(&driver->driver);
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pr_debug("mei: driver [%s] unregistered\n", driver->driver.name);
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}
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EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);
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static ssize_t ___mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
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bool blocking)
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{
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struct mei_device *dev;
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struct mei_me_client *me_cl;
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struct mei_cl_cb *cb;
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ssize_t rets;
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if (WARN_ON(!cl || !cl->dev))
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return -ENODEV;
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dev = cl->dev;
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if (cl->state != MEI_FILE_CONNECTED)
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return -ENODEV;
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/* Check if we have an ME client device */
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me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id);
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if (!me_cl)
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return -ENOTTY;
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if (length > me_cl->props.max_msg_length)
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return -EFBIG;
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cb = mei_io_cb_init(cl, NULL);
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if (!cb)
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return -ENOMEM;
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rets = mei_io_cb_alloc_req_buf(cb, length);
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if (rets < 0) {
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mei_io_cb_free(cb);
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return rets;
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}
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memcpy(cb->request_buffer.data, buf, length);
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mutex_lock(&dev->device_lock);
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rets = mei_cl_write(cl, cb, blocking);
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mutex_unlock(&dev->device_lock);
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if (rets < 0)
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mei_io_cb_free(cb);
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return rets;
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}
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ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
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{
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struct mei_device *dev;
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struct mei_cl_cb *cb;
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size_t r_length;
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ssize_t rets;
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if (WARN_ON(!cl || !cl->dev))
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return -ENODEV;
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dev = cl->dev;
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mutex_lock(&dev->device_lock);
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if (!cl->read_cb) {
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rets = mei_cl_read_start(cl, length);
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if (rets < 0)
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goto out;
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}
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if (cl->reading_state != MEI_READ_COMPLETE &&
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!waitqueue_active(&cl->rx_wait)) {
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mutex_unlock(&dev->device_lock);
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if (wait_event_interruptible(cl->rx_wait,
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cl->reading_state == MEI_READ_COMPLETE ||
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mei_cl_is_transitioning(cl))) {
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if (signal_pending(current))
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return -EINTR;
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return -ERESTARTSYS;
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}
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mutex_lock(&dev->device_lock);
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}
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cb = cl->read_cb;
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if (cl->reading_state != MEI_READ_COMPLETE) {
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rets = 0;
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goto out;
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}
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r_length = min_t(size_t, length, cb->buf_idx);
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memcpy(buf, cb->response_buffer.data, r_length);
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rets = r_length;
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mei_io_cb_free(cb);
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cl->reading_state = MEI_IDLE;
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cl->read_cb = NULL;
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out:
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mutex_unlock(&dev->device_lock);
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return rets;
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}
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inline ssize_t __mei_cl_async_send(struct mei_cl *cl, u8 *buf, size_t length)
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{
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return ___mei_cl_send(cl, buf, length, 0);
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}
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inline ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length)
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{
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return ___mei_cl_send(cl, buf, length, 1);
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}
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ssize_t mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length)
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{
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struct mei_cl *cl = device->cl;
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if (cl == NULL)
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return -ENODEV;
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if (device->ops && device->ops->send)
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return device->ops->send(device, buf, length);
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return __mei_cl_send(cl, buf, length);
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}
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EXPORT_SYMBOL_GPL(mei_cl_send);
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ssize_t mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length)
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{
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struct mei_cl *cl = device->cl;
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if (cl == NULL)
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return -ENODEV;
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if (device->ops && device->ops->recv)
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return device->ops->recv(device, buf, length);
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return __mei_cl_recv(cl, buf, length);
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}
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EXPORT_SYMBOL_GPL(mei_cl_recv);
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static void mei_bus_event_work(struct work_struct *work)
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{
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struct mei_cl_device *device;
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device = container_of(work, struct mei_cl_device, event_work);
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if (device->event_cb)
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device->event_cb(device, device->events, device->event_context);
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device->events = 0;
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/* Prepare for the next read */
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mei_cl_read_start(device->cl, 0);
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}
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int mei_cl_register_event_cb(struct mei_cl_device *device,
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mei_cl_event_cb_t event_cb, void *context)
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{
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if (device->event_cb)
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return -EALREADY;
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device->events = 0;
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device->event_cb = event_cb;
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device->event_context = context;
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INIT_WORK(&device->event_work, mei_bus_event_work);
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mei_cl_read_start(device->cl, 0);
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return 0;
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}
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EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
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void *mei_cl_get_drvdata(const struct mei_cl_device *device)
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{
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return dev_get_drvdata(&device->dev);
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}
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EXPORT_SYMBOL_GPL(mei_cl_get_drvdata);
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void mei_cl_set_drvdata(struct mei_cl_device *device, void *data)
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{
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dev_set_drvdata(&device->dev, data);
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}
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EXPORT_SYMBOL_GPL(mei_cl_set_drvdata);
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int mei_cl_enable_device(struct mei_cl_device *device)
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{
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int err;
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struct mei_device *dev;
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struct mei_cl *cl = device->cl;
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if (cl == NULL)
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return -ENODEV;
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dev = cl->dev;
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mutex_lock(&dev->device_lock);
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err = mei_cl_connect(cl, NULL);
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if (err < 0) {
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mutex_unlock(&dev->device_lock);
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dev_err(dev->dev, "Could not connect to the ME client");
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return err;
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}
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mutex_unlock(&dev->device_lock);
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if (device->event_cb && !cl->read_cb)
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mei_cl_read_start(device->cl, 0);
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if (!device->ops || !device->ops->enable)
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return 0;
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return device->ops->enable(device);
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}
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EXPORT_SYMBOL_GPL(mei_cl_enable_device);
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int mei_cl_disable_device(struct mei_cl_device *device)
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{
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int err;
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struct mei_device *dev;
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struct mei_cl *cl = device->cl;
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if (cl == NULL)
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return -ENODEV;
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dev = cl->dev;
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mutex_lock(&dev->device_lock);
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if (cl->state != MEI_FILE_CONNECTED) {
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mutex_unlock(&dev->device_lock);
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dev_err(dev->dev, "Already disconnected");
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return 0;
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}
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cl->state = MEI_FILE_DISCONNECTING;
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err = mei_cl_disconnect(cl);
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if (err < 0) {
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mutex_unlock(&dev->device_lock);
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dev_err(dev->dev,
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"Could not disconnect from the ME client");
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return err;
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}
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/* Flush queues and remove any pending read */
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mei_cl_flush_queues(cl);
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if (cl->read_cb) {
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struct mei_cl_cb *cb = NULL;
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cb = mei_cl_find_read_cb(cl);
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/* Remove entry from read list */
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if (cb)
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list_del(&cb->list);
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cb = cl->read_cb;
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cl->read_cb = NULL;
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if (cb) {
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mei_io_cb_free(cb);
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cb = NULL;
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}
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}
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device->event_cb = NULL;
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mutex_unlock(&dev->device_lock);
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if (!device->ops || !device->ops->disable)
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return 0;
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return device->ops->disable(device);
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}
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EXPORT_SYMBOL_GPL(mei_cl_disable_device);
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void mei_cl_bus_rx_event(struct mei_cl *cl)
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{
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struct mei_cl_device *device = cl->device;
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if (!device || !device->event_cb)
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return;
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set_bit(MEI_CL_EVENT_RX, &device->events);
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schedule_work(&device->event_work);
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}
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void mei_cl_bus_remove_devices(struct mei_device *dev)
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{
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struct mei_cl *cl, *next;
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mutex_lock(&dev->device_lock);
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list_for_each_entry_safe(cl, next, &dev->device_list, device_link) {
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if (cl->device)
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mei_cl_remove_device(cl->device);
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list_del(&cl->device_link);
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mei_cl_unlink(cl);
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kfree(cl);
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}
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mutex_unlock(&dev->device_lock);
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}
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int __init mei_cl_bus_init(void)
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{
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return bus_register(&mei_cl_bus_type);
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}
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void __exit mei_cl_bus_exit(void)
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{
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bus_unregister(&mei_cl_bus_type);
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}
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