bus.c 10.7 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
/*
 * 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>
19
#include <linux/sched.h>
20 21 22 23 24 25 26 27 28
#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"
29 30
#include "hw-me.h"
#include "client.h"
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86

#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;

87 88 89 90 91
	if (device->event_cb) {
		device->event_cb = NULL;
		cancel_work_sync(&device->event_work);
	}

92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142
	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,
};

143 144 145 146 147 148 149 150 151 152 153 154 155
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,
156 157
					uuid_le uuid, char *name,
					struct mei_cl_ops *ops)
158 159
{
	struct mei_cl_device *device;
160
	struct mei_cl *cl;
161 162
	int status;

163 164 165 166
	cl = mei_bus_find_mei_cl_by_uuid(dev, uuid);
	if (cl == NULL)
		return NULL;

167 168 169 170
	device = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
	if (!device)
		return NULL;

171
	device->cl = cl;
172
	device->ops = ops;
173 174

	device->dev.parent = &dev->pdev->dev;
175 176 177 178 179 180
	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);
181 182 183 184 185 186 187
	if (status) {
		dev_err(&dev->pdev->dev, "Failed to register MEI device\n");
		kfree(device);
		return NULL;
	}

	cl->device = device;
188 189 190 191 192 193 194 195 196 197 198 199

	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);
200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225

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);
226

227 228
static int ___mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
			bool blocking)
229 230 231
{
	struct mei_device *dev;
	struct mei_cl_cb *cb;
T
Tomas Winkler 已提交
232 233
	int id;
	int rets;
234 235 236 237

	if (WARN_ON(!cl || !cl->dev))
		return -ENODEV;

T
Tomas Winkler 已提交
238 239
	dev = cl->dev;

240 241 242
	if (cl->state != MEI_FILE_CONNECTED)
		return -ENODEV;

T
Tomas Winkler 已提交
243 244 245 246 247 248 249 250
	/* 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;

251 252 253 254
	cb = mei_io_cb_init(cl, NULL);
	if (!cb)
		return -ENOMEM;

T
Tomas Winkler 已提交
255 256
	rets = mei_io_cb_alloc_req_buf(cb, length);
	if (rets < 0) {
257
		mei_io_cb_free(cb);
T
Tomas Winkler 已提交
258
		return rets;
259 260 261 262 263 264
	}

	memcpy(cb->request_buffer.data, buf, length);

	mutex_lock(&dev->device_lock);

T
Tomas Winkler 已提交
265
	rets = mei_cl_write(cl, cb, blocking);
266 267

	mutex_unlock(&dev->device_lock);
T
Tomas Winkler 已提交
268 269
	if (rets < 0)
		mei_io_cb_free(cb);
270

T
Tomas Winkler 已提交
271
	return rets;
272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288
}

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) {
T
Tomas Winkler 已提交
289
		err = mei_cl_read_start(cl, length);
290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330
		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;
}

331 332 333 334 335 336 337 338 339 340
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);
}

341 342
int mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length)
{
343
	struct mei_cl *cl = device->cl;
344

345 346
	if (cl == NULL)
		return -ENODEV;
347 348 349 350 351 352 353 354 355 356

	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)
{
357
	struct mei_cl *cl =  device->cl;
358

359 360
	if (cl == NULL)
		return -ENODEV;
361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380

	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 */
T
Tomas Winkler 已提交
381
	mei_cl_read_start(device->cl, 0);
382 383 384 385 386 387 388 389 390 391 392 393 394
}

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);

T
Tomas Winkler 已提交
395
	mei_cl_read_start(device->cl, 0);
396 397 398 399

	return 0;
}
EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
400

401 402 403 404 405 406 407 408 409 410 411 412
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);

413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438
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)
T
Tomas Winkler 已提交
439
		mei_cl_read_start(device->cl, 0);
440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507

	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;
		}
	}

	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);

508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528
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);
}