summaryrefslogtreecommitdiff
path: root/drivers/mailbox/mtk-cmdq-mailbox.c
blob: 49d9264145aa8475b1e4aa192217882fa1729628 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
87
88
89
90
91
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
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
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
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
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
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
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
439
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
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2018 MediaTek Inc.

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mailbox_controller.h>
#include <linux/mailbox/mtk-cmdq-mailbox.h>
#include <linux/of_device.h>

#define CMDQ_OP_CODE_MASK		(0xff << CMDQ_OP_CODE_SHIFT)
#define CMDQ_NUM_CMD(t)			(t->cmd_buf_size / CMDQ_INST_SIZE)

#define CMDQ_CURR_IRQ_STATUS		0x10
#define CMDQ_SYNC_TOKEN_UPDATE		0x68
#define CMDQ_THR_SLOT_CYCLES		0x30
#define CMDQ_THR_BASE			0x100
#define CMDQ_THR_SIZE			0x80
#define CMDQ_THR_WARM_RESET		0x00
#define CMDQ_THR_ENABLE_TASK		0x04
#define CMDQ_THR_SUSPEND_TASK		0x08
#define CMDQ_THR_CURR_STATUS		0x0c
#define CMDQ_THR_IRQ_STATUS		0x10
#define CMDQ_THR_IRQ_ENABLE		0x14
#define CMDQ_THR_CURR_ADDR		0x20
#define CMDQ_THR_END_ADDR		0x24
#define CMDQ_THR_WAIT_TOKEN		0x30
#define CMDQ_THR_PRIORITY		0x40

#define CMDQ_THR_ACTIVE_SLOT_CYCLES	0x3200
#define CMDQ_THR_ENABLED		0x1
#define CMDQ_THR_DISABLED		0x0
#define CMDQ_THR_SUSPEND		0x1
#define CMDQ_THR_RESUME			0x0
#define CMDQ_THR_STATUS_SUSPENDED	BIT(1)
#define CMDQ_THR_DO_WARM_RESET		BIT(0)
#define CMDQ_THR_IRQ_DONE		0x1
#define CMDQ_THR_IRQ_ERROR		0x12
#define CMDQ_THR_IRQ_EN			(CMDQ_THR_IRQ_ERROR | CMDQ_THR_IRQ_DONE)
#define CMDQ_THR_IS_WAITING		BIT(31)

#define CMDQ_JUMP_BY_OFFSET		0x10000000
#define CMDQ_JUMP_BY_PA			0x10000001

struct cmdq_thread {
	struct mbox_chan	*chan;
	void __iomem		*base;
	struct list_head	task_busy_list;
	u32			priority;
};

struct cmdq_task {
	struct cmdq		*cmdq;
	struct list_head	list_entry;
	dma_addr_t		pa_base;
	struct cmdq_thread	*thread;
	struct cmdq_pkt		*pkt; /* the packet sent from mailbox client */
};

struct cmdq {
	struct mbox_controller	mbox;
	void __iomem		*base;
	u32			irq;
	u32			thread_nr;
	u32			irq_mask;
	struct cmdq_thread	*thread;
	struct clk		*clock;
	bool			suspended;
	u8			shift_pa;
};

struct gce_plat {
	u32 thread_nr;
	u8 shift;
};

u8 cmdq_get_shift_pa(struct mbox_chan *chan)
{
	struct cmdq *cmdq = container_of(chan->mbox, struct cmdq, mbox);

	return cmdq->shift_pa;
}
EXPORT_SYMBOL(cmdq_get_shift_pa);

static int cmdq_thread_suspend(struct cmdq *cmdq, struct cmdq_thread *thread)
{
	u32 status;

	writel(CMDQ_THR_SUSPEND, thread->base + CMDQ_THR_SUSPEND_TASK);

	/* If already disabled, treat as suspended successful. */
	if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
		return 0;

	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_STATUS,
			status, status & CMDQ_THR_STATUS_SUSPENDED, 0, 10)) {
		dev_err(cmdq->mbox.dev, "suspend GCE thread 0x%x failed\n",
			(u32)(thread->base - cmdq->base));
		return -EFAULT;
	}

	return 0;
}

static void cmdq_thread_resume(struct cmdq_thread *thread)
{
	writel(CMDQ_THR_RESUME, thread->base + CMDQ_THR_SUSPEND_TASK);
}

static void cmdq_init(struct cmdq *cmdq)
{
	int i;

	WARN_ON(clk_enable(cmdq->clock) < 0);
	writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
	for (i = 0; i <= CMDQ_MAX_EVENT; i++)
		writel(i, cmdq->base + CMDQ_SYNC_TOKEN_UPDATE);
	clk_disable(cmdq->clock);
}

static int cmdq_thread_reset(struct cmdq *cmdq, struct cmdq_thread *thread)
{
	u32 warm_reset;

	writel(CMDQ_THR_DO_WARM_RESET, thread->base + CMDQ_THR_WARM_RESET);
	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_WARM_RESET,
			warm_reset, !(warm_reset & CMDQ_THR_DO_WARM_RESET),
			0, 10)) {
		dev_err(cmdq->mbox.dev, "reset GCE thread 0x%x failed\n",
			(u32)(thread->base - cmdq->base));
		return -EFAULT;
	}

	return 0;
}

static void cmdq_thread_disable(struct cmdq *cmdq, struct cmdq_thread *thread)
{
	cmdq_thread_reset(cmdq, thread);
	writel(CMDQ_THR_DISABLED, thread->base + CMDQ_THR_ENABLE_TASK);
}

/* notify GCE to re-fetch commands by setting GCE thread PC */
static void cmdq_thread_invalidate_fetched_data(struct cmdq_thread *thread)
{
	writel(readl(thread->base + CMDQ_THR_CURR_ADDR),
	       thread->base + CMDQ_THR_CURR_ADDR);
}

static void cmdq_task_insert_into_thread(struct cmdq_task *task)
{
	struct device *dev = task->cmdq->mbox.dev;
	struct cmdq_thread *thread = task->thread;
	struct cmdq_task *prev_task = list_last_entry(
			&thread->task_busy_list, typeof(*task), list_entry);
	u64 *prev_task_base = prev_task->pkt->va_base;

	/* let previous task jump to this task */
	dma_sync_single_for_cpu(dev, prev_task->pa_base,
				prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
	prev_task_base[CMDQ_NUM_CMD(prev_task->pkt) - 1] =
		(u64)CMDQ_JUMP_BY_PA << 32 | task->pa_base;
	dma_sync_single_for_device(dev, prev_task->pa_base,
				   prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);

	cmdq_thread_invalidate_fetched_data(thread);
}

static bool cmdq_thread_is_in_wfe(struct cmdq_thread *thread)
{
	return readl(thread->base + CMDQ_THR_WAIT_TOKEN) & CMDQ_THR_IS_WAITING;
}

static void cmdq_task_exec_done(struct cmdq_task *task, enum cmdq_cb_status sta)
{
	struct cmdq_task_cb *cb = &task->pkt->async_cb;
	struct cmdq_cb_data data;

	WARN_ON(cb->cb == (cmdq_async_flush_cb)NULL);
	data.sta = sta;
	data.data = cb->data;
	cb->cb(data);

	list_del(&task->list_entry);
}

static void cmdq_task_handle_error(struct cmdq_task *task)
{
	struct cmdq_thread *thread = task->thread;
	struct cmdq_task *next_task;
	struct cmdq *cmdq = task->cmdq;

	dev_err(cmdq->mbox.dev, "task 0x%p error\n", task);
	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
	next_task = list_first_entry_or_null(&thread->task_busy_list,
			struct cmdq_task, list_entry);
	if (next_task)
		writel(next_task->pa_base >> cmdq->shift_pa,
		       thread->base + CMDQ_THR_CURR_ADDR);
	cmdq_thread_resume(thread);
}

static void cmdq_thread_irq_handler(struct cmdq *cmdq,
				    struct cmdq_thread *thread)
{
	struct cmdq_task *task, *tmp, *curr_task = NULL;
	u32 curr_pa, irq_flag, task_end_pa;
	bool err;

	irq_flag = readl(thread->base + CMDQ_THR_IRQ_STATUS);
	writel(~irq_flag, thread->base + CMDQ_THR_IRQ_STATUS);

	/*
	 * When ISR call this function, another CPU core could run
	 * "release task" right before we acquire the spin lock, and thus
	 * reset / disable this GCE thread, so we need to check the enable
	 * bit of this GCE thread.
	 */
	if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
		return;

	if (irq_flag & CMDQ_THR_IRQ_ERROR)
		err = true;
	else if (irq_flag & CMDQ_THR_IRQ_DONE)
		err = false;
	else
		return;

	curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR) << cmdq->shift_pa;

	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
				 list_entry) {
		task_end_pa = task->pa_base + task->pkt->cmd_buf_size;
		if (curr_pa >= task->pa_base && curr_pa < task_end_pa)
			curr_task = task;

		if (!curr_task || curr_pa == task_end_pa - CMDQ_INST_SIZE) {
			cmdq_task_exec_done(task, CMDQ_CB_NORMAL);
			kfree(task);
		} else if (err) {
			cmdq_task_exec_done(task, CMDQ_CB_ERROR);
			cmdq_task_handle_error(curr_task);
			kfree(task);
		}

		if (curr_task)
			break;
	}

	if (list_empty(&thread->task_busy_list)) {
		cmdq_thread_disable(cmdq, thread);
		clk_disable(cmdq->clock);
	}
}

static irqreturn_t cmdq_irq_handler(int irq, void *dev)
{
	struct cmdq *cmdq = dev;
	unsigned long irq_status, flags = 0L;
	int bit;

	irq_status = readl(cmdq->base + CMDQ_CURR_IRQ_STATUS) & cmdq->irq_mask;
	if (!(irq_status ^ cmdq->irq_mask))
		return IRQ_NONE;

	for_each_clear_bit(bit, &irq_status, cmdq->thread_nr) {
		struct cmdq_thread *thread = &cmdq->thread[bit];

		spin_lock_irqsave(&thread->chan->lock, flags);
		cmdq_thread_irq_handler(cmdq, thread);
		spin_unlock_irqrestore(&thread->chan->lock, flags);
	}

	return IRQ_HANDLED;
}

static int cmdq_suspend(struct device *dev)
{
	struct cmdq *cmdq = dev_get_drvdata(dev);
	struct cmdq_thread *thread;
	int i;
	bool task_running = false;

	cmdq->suspended = true;

	for (i = 0; i < cmdq->thread_nr; i++) {
		thread = &cmdq->thread[i];
		if (!list_empty(&thread->task_busy_list)) {
			task_running = true;
			break;
		}
	}

	if (task_running)
		dev_warn(dev, "exist running task(s) in suspend\n");

	clk_unprepare(cmdq->clock);

	return 0;
}

static int cmdq_resume(struct device *dev)
{
	struct cmdq *cmdq = dev_get_drvdata(dev);

	WARN_ON(clk_prepare(cmdq->clock) < 0);
	cmdq->suspended = false;
	return 0;
}

static int cmdq_remove(struct platform_device *pdev)
{
	struct cmdq *cmdq = platform_get_drvdata(pdev);

	clk_unprepare(cmdq->clock);

	return 0;
}

static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
{
	struct cmdq_pkt *pkt = (struct cmdq_pkt *)data;
	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
	struct cmdq_task *task;
	unsigned long curr_pa, end_pa;

	/* Client should not flush new tasks if suspended. */
	WARN_ON(cmdq->suspended);

	task = kzalloc(sizeof(*task), GFP_ATOMIC);
	if (!task)
		return -ENOMEM;

	task->cmdq = cmdq;
	INIT_LIST_HEAD(&task->list_entry);
	task->pa_base = pkt->pa_base;
	task->thread = thread;
	task->pkt = pkt;

	if (list_empty(&thread->task_busy_list)) {
		WARN_ON(clk_enable(cmdq->clock) < 0);
		WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);

		writel(task->pa_base >> cmdq->shift_pa,
		       thread->base + CMDQ_THR_CURR_ADDR);
		writel((task->pa_base + pkt->cmd_buf_size) >> cmdq->shift_pa,
		       thread->base + CMDQ_THR_END_ADDR);

		writel(thread->priority, thread->base + CMDQ_THR_PRIORITY);
		writel(CMDQ_THR_IRQ_EN, thread->base + CMDQ_THR_IRQ_ENABLE);
		writel(CMDQ_THR_ENABLED, thread->base + CMDQ_THR_ENABLE_TASK);
	} else {
		WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
		curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR) <<
			cmdq->shift_pa;
		end_pa = readl(thread->base + CMDQ_THR_END_ADDR) <<
			cmdq->shift_pa;
		/* check boundary */
		if (curr_pa == end_pa - CMDQ_INST_SIZE ||
		    curr_pa == end_pa) {
			/* set to this task directly */
			writel(task->pa_base >> cmdq->shift_pa,
			       thread->base + CMDQ_THR_CURR_ADDR);
		} else {
			cmdq_task_insert_into_thread(task);
			smp_mb(); /* modify jump before enable thread */
		}
		writel((task->pa_base + pkt->cmd_buf_size) >> cmdq->shift_pa,
		       thread->base + CMDQ_THR_END_ADDR);
		cmdq_thread_resume(thread);
	}
	list_move_tail(&task->list_entry, &thread->task_busy_list);

	return 0;
}

static int cmdq_mbox_startup(struct mbox_chan *chan)
{
	return 0;
}

static void cmdq_mbox_shutdown(struct mbox_chan *chan)
{
}

static int cmdq_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
{
	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
	struct cmdq_task_cb *cb;
	struct cmdq_cb_data data;
	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
	struct cmdq_task *task, *tmp;
	unsigned long flags;
	u32 enable;

	spin_lock_irqsave(&thread->chan->lock, flags);
	if (list_empty(&thread->task_busy_list))
		goto out;

	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
	if (!cmdq_thread_is_in_wfe(thread))
		goto wait;

	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
				 list_entry) {
		cb = &task->pkt->async_cb;
		if (cb->cb) {
			data.sta = CMDQ_CB_ERROR;
			data.data = cb->data;
			cb->cb(data);
		}
		list_del(&task->list_entry);
		kfree(task);
	}

	cmdq_thread_resume(thread);
	cmdq_thread_disable(cmdq, thread);
	clk_disable(cmdq->clock);

out:
	spin_unlock_irqrestore(&thread->chan->lock, flags);
	return 0;

wait:
	cmdq_thread_resume(thread);
	spin_unlock_irqrestore(&thread->chan->lock, flags);
	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_ENABLE_TASK,
				      enable, enable == 0, 1, timeout)) {
		dev_err(cmdq->mbox.dev, "Fail to wait GCE thread 0x%x done\n",
			(u32)(thread->base - cmdq->base));

		return -EFAULT;
	}
	return 0;
}

static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
	.send_data = cmdq_mbox_send_data,
	.startup = cmdq_mbox_startup,
	.shutdown = cmdq_mbox_shutdown,
	.flush = cmdq_mbox_flush,
};

static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,
		const struct of_phandle_args *sp)
{
	int ind = sp->args[0];
	struct cmdq_thread *thread;

	if (ind >= mbox->num_chans)
		return ERR_PTR(-EINVAL);

	thread = (struct cmdq_thread *)mbox->chans[ind].con_priv;
	thread->priority = sp->args[1];
	thread->chan = &mbox->chans[ind];

	return &mbox->chans[ind];
}

static int cmdq_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct resource *res;
	struct cmdq *cmdq;
	int err, i;
	struct gce_plat *plat_data;

	cmdq = devm_kzalloc(dev, sizeof(*cmdq), GFP_KERNEL);
	if (!cmdq)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	cmdq->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(cmdq->base)) {
		dev_err(dev, "failed to ioremap gce\n");
		return PTR_ERR(cmdq->base);
	}

	cmdq->irq = platform_get_irq(pdev, 0);
	if (!cmdq->irq) {
		dev_err(dev, "failed to get irq\n");
		return -EINVAL;
	}

	plat_data = (struct gce_plat *)of_device_get_match_data(dev);
	if (!plat_data) {
		dev_err(dev, "failed to get match data\n");
		return -EINVAL;
	}

	cmdq->thread_nr = plat_data->thread_nr;
	cmdq->shift_pa = plat_data->shift;
	cmdq->irq_mask = GENMASK(cmdq->thread_nr - 1, 0);
	err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
			       "mtk_cmdq", cmdq);
	if (err < 0) {
		dev_err(dev, "failed to register ISR (%d)\n", err);
		return err;
	}

	dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
		dev, cmdq->base, cmdq->irq);

	cmdq->clock = devm_clk_get(dev, "gce");
	if (IS_ERR(cmdq->clock)) {
		dev_err(dev, "failed to get gce clk\n");
		return PTR_ERR(cmdq->clock);
	}

	cmdq->mbox.dev = dev;
	cmdq->mbox.chans = devm_kcalloc(dev, cmdq->thread_nr,
					sizeof(*cmdq->mbox.chans), GFP_KERNEL);
	if (!cmdq->mbox.chans)
		return -ENOMEM;

	cmdq->mbox.num_chans = cmdq->thread_nr;
	cmdq->mbox.ops = &cmdq_mbox_chan_ops;
	cmdq->mbox.of_xlate = cmdq_xlate;

	/* make use of TXDONE_BY_ACK */
	cmdq->mbox.txdone_irq = false;
	cmdq->mbox.txdone_poll = false;

	cmdq->thread = devm_kcalloc(dev, cmdq->thread_nr,
					sizeof(*cmdq->thread), GFP_KERNEL);
	if (!cmdq->thread)
		return -ENOMEM;

	for (i = 0; i < cmdq->thread_nr; i++) {
		cmdq->thread[i].base = cmdq->base + CMDQ_THR_BASE +
				CMDQ_THR_SIZE * i;
		INIT_LIST_HEAD(&cmdq->thread[i].task_busy_list);
		cmdq->mbox.chans[i].con_priv = (void *)&cmdq->thread[i];
	}

	err = devm_mbox_controller_register(dev, &cmdq->mbox);
	if (err < 0) {
		dev_err(dev, "failed to register mailbox: %d\n", err);
		return err;
	}

	platform_set_drvdata(pdev, cmdq);
	WARN_ON(clk_prepare(cmdq->clock) < 0);

	cmdq_init(cmdq);

	return 0;
}

static const struct dev_pm_ops cmdq_pm_ops = {
	.suspend = cmdq_suspend,
	.resume = cmdq_resume,
};

static const struct gce_plat gce_plat_v2 = {.thread_nr = 16};
static const struct gce_plat gce_plat_v3 = {.thread_nr = 24};

static const struct of_device_id cmdq_of_ids[] = {
	{.compatible = "mediatek,mt8173-gce", .data = (void *)&gce_plat_v2},
	{.compatible = "mediatek,mt8183-gce", .data = (void *)&gce_plat_v3},
	{}
};

static struct platform_driver cmdq_drv = {
	.probe = cmdq_probe,
	.remove = cmdq_remove,
	.driver = {
		.name = "mtk_cmdq",
		.pm = &cmdq_pm_ops,
		.of_match_table = cmdq_of_ids,
	}
};

static int __init cmdq_drv_init(void)
{
	return platform_driver_register(&cmdq_drv);
}

static void __exit cmdq_drv_exit(void)
{
	platform_driver_unregister(&cmdq_drv);
}

subsys_initcall(cmdq_drv_init);
module_exit(cmdq_drv_exit);

MODULE_LICENSE("GPL v2");