xref: /openbmc/linux/samples/vfio-mdev/mtty.c (revision 99a15348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Mediated virtual PCI serial host device driver
4  *
5  * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
6  *     Author: Neo Jia <cjia@nvidia.com>
7  *             Kirti Wankhede <kwankhede@nvidia.com>
8  *
9  * Sample driver that creates mdev device that simulates serial port over PCI
10  * card.
11  */
12 
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/device.h>
16 #include <linux/kernel.h>
17 #include <linux/fs.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/cdev.h>
21 #include <linux/sched.h>
22 #include <linux/wait.h>
23 #include <linux/uuid.h>
24 #include <linux/vfio.h>
25 #include <linux/iommu.h>
26 #include <linux/sysfs.h>
27 #include <linux/ctype.h>
28 #include <linux/file.h>
29 #include <linux/mdev.h>
30 #include <linux/pci.h>
31 #include <linux/serial.h>
32 #include <uapi/linux/serial_reg.h>
33 #include <linux/eventfd.h>
34 /*
35  * #defines
36  */
37 
38 #define VERSION_STRING  "0.1"
39 #define DRIVER_AUTHOR   "NVIDIA Corporation"
40 
41 #define MTTY_CLASS_NAME "mtty"
42 
43 #define MTTY_NAME       "mtty"
44 
45 #define MTTY_STRING_LEN		16
46 
47 #define MTTY_CONFIG_SPACE_SIZE  0xff
48 #define MTTY_IO_BAR_SIZE        0x8
49 #define MTTY_MMIO_BAR_SIZE      0x100000
50 
51 #define STORE_LE16(addr, val)   (*(u16 *)addr = val)
52 #define STORE_LE32(addr, val)   (*(u32 *)addr = val)
53 
54 #define MAX_FIFO_SIZE   16
55 
56 #define CIRCULAR_BUF_INC_IDX(idx)    (idx = (idx + 1) & (MAX_FIFO_SIZE - 1))
57 
58 #define MTTY_VFIO_PCI_OFFSET_SHIFT   40
59 
60 #define MTTY_VFIO_PCI_OFFSET_TO_INDEX(off)   (off >> MTTY_VFIO_PCI_OFFSET_SHIFT)
61 #define MTTY_VFIO_PCI_INDEX_TO_OFFSET(index) \
62 				((u64)(index) << MTTY_VFIO_PCI_OFFSET_SHIFT)
63 #define MTTY_VFIO_PCI_OFFSET_MASK    \
64 				(((u64)(1) << MTTY_VFIO_PCI_OFFSET_SHIFT) - 1)
65 #define MAX_MTTYS	24
66 
67 /*
68  * Global Structures
69  */
70 
71 static struct mtty_dev {
72 	dev_t		vd_devt;
73 	struct class	*vd_class;
74 	struct cdev	vd_cdev;
75 	struct idr	vd_idr;
76 	struct device	dev;
77 } mtty_dev;
78 
79 struct mdev_region_info {
80 	u64 start;
81 	u64 phys_start;
82 	u32 size;
83 	u64 vfio_offset;
84 };
85 
86 #if defined(DEBUG_REGS)
87 static const char *wr_reg[] = {
88 	"TX",
89 	"IER",
90 	"FCR",
91 	"LCR",
92 	"MCR",
93 	"LSR",
94 	"MSR",
95 	"SCR"
96 };
97 
98 static const char *rd_reg[] = {
99 	"RX",
100 	"IER",
101 	"IIR",
102 	"LCR",
103 	"MCR",
104 	"LSR",
105 	"MSR",
106 	"SCR"
107 };
108 #endif
109 
110 /* loop back buffer */
111 struct rxtx {
112 	u8 fifo[MAX_FIFO_SIZE];
113 	u8 head, tail;
114 	u8 count;
115 };
116 
117 struct serial_port {
118 	u8 uart_reg[8];         /* 8 registers */
119 	struct rxtx rxtx;       /* loop back buffer */
120 	bool dlab;
121 	bool overrun;
122 	u16 divisor;
123 	u8 fcr;                 /* FIFO control register */
124 	u8 max_fifo_size;
125 	u8 intr_trigger_level;  /* interrupt trigger level */
126 };
127 
128 /* State of each mdev device */
129 struct mdev_state {
130 	struct vfio_device vdev;
131 	int irq_fd;
132 	struct eventfd_ctx *intx_evtfd;
133 	struct eventfd_ctx *msi_evtfd;
134 	int irq_index;
135 	u8 *vconfig;
136 	struct mutex ops_lock;
137 	struct mdev_device *mdev;
138 	struct mdev_region_info region_info[VFIO_PCI_NUM_REGIONS];
139 	u32 bar_mask[VFIO_PCI_NUM_REGIONS];
140 	struct list_head next;
141 	struct serial_port s[2];
142 	struct mutex rxtx_lock;
143 	struct vfio_device_info dev_info;
144 	int nr_ports;
145 };
146 
147 static atomic_t mdev_avail_ports = ATOMIC_INIT(MAX_MTTYS);
148 
149 static const struct file_operations vd_fops = {
150 	.owner          = THIS_MODULE,
151 };
152 
153 static const struct vfio_device_ops mtty_dev_ops;
154 
155 /* function prototypes */
156 
157 static int mtty_trigger_interrupt(struct mdev_state *mdev_state);
158 
159 /* Helper functions */
160 
161 static void dump_buffer(u8 *buf, uint32_t count)
162 {
163 #if defined(DEBUG)
164 	int i;
165 
166 	pr_info("Buffer:\n");
167 	for (i = 0; i < count; i++) {
168 		pr_info("%2x ", *(buf + i));
169 		if ((i + 1) % 16 == 0)
170 			pr_info("\n");
171 	}
172 #endif
173 }
174 
175 static void mtty_create_config_space(struct mdev_state *mdev_state)
176 {
177 	/* PCI dev ID */
178 	STORE_LE32((u32 *) &mdev_state->vconfig[0x0], 0x32534348);
179 
180 	/* Control: I/O+, Mem-, BusMaster- */
181 	STORE_LE16((u16 *) &mdev_state->vconfig[0x4], 0x0001);
182 
183 	/* Status: capabilities list absent */
184 	STORE_LE16((u16 *) &mdev_state->vconfig[0x6], 0x0200);
185 
186 	/* Rev ID */
187 	mdev_state->vconfig[0x8] =  0x10;
188 
189 	/* programming interface class : 16550-compatible serial controller */
190 	mdev_state->vconfig[0x9] =  0x02;
191 
192 	/* Sub class : 00 */
193 	mdev_state->vconfig[0xa] =  0x00;
194 
195 	/* Base class : Simple Communication controllers */
196 	mdev_state->vconfig[0xb] =  0x07;
197 
198 	/* base address registers */
199 	/* BAR0: IO space */
200 	STORE_LE32((u32 *) &mdev_state->vconfig[0x10], 0x000001);
201 	mdev_state->bar_mask[0] = ~(MTTY_IO_BAR_SIZE) + 1;
202 
203 	if (mdev_state->nr_ports == 2) {
204 		/* BAR1: IO space */
205 		STORE_LE32((u32 *) &mdev_state->vconfig[0x14], 0x000001);
206 		mdev_state->bar_mask[1] = ~(MTTY_IO_BAR_SIZE) + 1;
207 	}
208 
209 	/* Subsystem ID */
210 	STORE_LE32((u32 *) &mdev_state->vconfig[0x2c], 0x32534348);
211 
212 	mdev_state->vconfig[0x34] =  0x00;   /* Cap Ptr */
213 	mdev_state->vconfig[0x3d] =  0x01;   /* interrupt pin (INTA#) */
214 
215 	/* Vendor specific data */
216 	mdev_state->vconfig[0x40] =  0x23;
217 	mdev_state->vconfig[0x43] =  0x80;
218 	mdev_state->vconfig[0x44] =  0x23;
219 	mdev_state->vconfig[0x48] =  0x23;
220 	mdev_state->vconfig[0x4c] =  0x23;
221 
222 	mdev_state->vconfig[0x60] =  0x50;
223 	mdev_state->vconfig[0x61] =  0x43;
224 	mdev_state->vconfig[0x62] =  0x49;
225 	mdev_state->vconfig[0x63] =  0x20;
226 	mdev_state->vconfig[0x64] =  0x53;
227 	mdev_state->vconfig[0x65] =  0x65;
228 	mdev_state->vconfig[0x66] =  0x72;
229 	mdev_state->vconfig[0x67] =  0x69;
230 	mdev_state->vconfig[0x68] =  0x61;
231 	mdev_state->vconfig[0x69] =  0x6c;
232 	mdev_state->vconfig[0x6a] =  0x2f;
233 	mdev_state->vconfig[0x6b] =  0x55;
234 	mdev_state->vconfig[0x6c] =  0x41;
235 	mdev_state->vconfig[0x6d] =  0x52;
236 	mdev_state->vconfig[0x6e] =  0x54;
237 }
238 
239 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
240 				 u8 *buf, u32 count)
241 {
242 	u32 cfg_addr, bar_mask, bar_index = 0;
243 
244 	switch (offset) {
245 	case 0x04: /* device control */
246 	case 0x06: /* device status */
247 		/* do nothing */
248 		break;
249 	case 0x3c:  /* interrupt line */
250 		mdev_state->vconfig[0x3c] = buf[0];
251 		break;
252 	case 0x3d:
253 		/*
254 		 * Interrupt Pin is hardwired to INTA.
255 		 * This field is write protected by hardware
256 		 */
257 		break;
258 	case 0x10:  /* BAR0 */
259 	case 0x14:  /* BAR1 */
260 		if (offset == 0x10)
261 			bar_index = 0;
262 		else if (offset == 0x14)
263 			bar_index = 1;
264 
265 		if ((mdev_state->nr_ports == 1) && (bar_index == 1)) {
266 			STORE_LE32(&mdev_state->vconfig[offset], 0);
267 			break;
268 		}
269 
270 		cfg_addr = *(u32 *)buf;
271 		pr_info("BAR%d addr 0x%x\n", bar_index, cfg_addr);
272 
273 		if (cfg_addr == 0xffffffff) {
274 			bar_mask = mdev_state->bar_mask[bar_index];
275 			cfg_addr = (cfg_addr & bar_mask);
276 		}
277 
278 		cfg_addr |= (mdev_state->vconfig[offset] & 0x3ul);
279 		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
280 		break;
281 	case 0x18:  /* BAR2 */
282 	case 0x1c:  /* BAR3 */
283 	case 0x20:  /* BAR4 */
284 		STORE_LE32(&mdev_state->vconfig[offset], 0);
285 		break;
286 	default:
287 		pr_info("PCI config write @0x%x of %d bytes not handled\n",
288 			offset, count);
289 		break;
290 	}
291 }
292 
293 static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
294 				u16 offset, u8 *buf, u32 count)
295 {
296 	u8 data = *buf;
297 
298 	/* Handle data written by guest */
299 	switch (offset) {
300 	case UART_TX:
301 		/* if DLAB set, data is LSB of divisor */
302 		if (mdev_state->s[index].dlab) {
303 			mdev_state->s[index].divisor |= data;
304 			break;
305 		}
306 
307 		mutex_lock(&mdev_state->rxtx_lock);
308 
309 		/* save in TX buffer */
310 		if (mdev_state->s[index].rxtx.count <
311 				mdev_state->s[index].max_fifo_size) {
312 			mdev_state->s[index].rxtx.fifo[
313 					mdev_state->s[index].rxtx.head] = data;
314 			mdev_state->s[index].rxtx.count++;
315 			CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.head);
316 			mdev_state->s[index].overrun = false;
317 
318 			/*
319 			 * Trigger interrupt if receive data interrupt is
320 			 * enabled and fifo reached trigger level
321 			 */
322 			if ((mdev_state->s[index].uart_reg[UART_IER] &
323 						UART_IER_RDI) &&
324 			   (mdev_state->s[index].rxtx.count ==
325 				    mdev_state->s[index].intr_trigger_level)) {
326 				/* trigger interrupt */
327 #if defined(DEBUG_INTR)
328 				pr_err("Serial port %d: Fifo level trigger\n",
329 					index);
330 #endif
331 				mtty_trigger_interrupt(mdev_state);
332 			}
333 		} else {
334 #if defined(DEBUG_INTR)
335 			pr_err("Serial port %d: Buffer Overflow\n", index);
336 #endif
337 			mdev_state->s[index].overrun = true;
338 
339 			/*
340 			 * Trigger interrupt if receiver line status interrupt
341 			 * is enabled
342 			 */
343 			if (mdev_state->s[index].uart_reg[UART_IER] &
344 								UART_IER_RLSI)
345 				mtty_trigger_interrupt(mdev_state);
346 		}
347 		mutex_unlock(&mdev_state->rxtx_lock);
348 		break;
349 
350 	case UART_IER:
351 		/* if DLAB set, data is MSB of divisor */
352 		if (mdev_state->s[index].dlab)
353 			mdev_state->s[index].divisor |= (u16)data << 8;
354 		else {
355 			mdev_state->s[index].uart_reg[offset] = data;
356 			mutex_lock(&mdev_state->rxtx_lock);
357 			if ((data & UART_IER_THRI) &&
358 			    (mdev_state->s[index].rxtx.head ==
359 					mdev_state->s[index].rxtx.tail)) {
360 #if defined(DEBUG_INTR)
361 				pr_err("Serial port %d: IER_THRI write\n",
362 					index);
363 #endif
364 				mtty_trigger_interrupt(mdev_state);
365 			}
366 
367 			mutex_unlock(&mdev_state->rxtx_lock);
368 		}
369 
370 		break;
371 
372 	case UART_FCR:
373 		mdev_state->s[index].fcr = data;
374 
375 		mutex_lock(&mdev_state->rxtx_lock);
376 		if (data & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)) {
377 			/* clear loop back FIFO */
378 			mdev_state->s[index].rxtx.count = 0;
379 			mdev_state->s[index].rxtx.head = 0;
380 			mdev_state->s[index].rxtx.tail = 0;
381 		}
382 		mutex_unlock(&mdev_state->rxtx_lock);
383 
384 		switch (data & UART_FCR_TRIGGER_MASK) {
385 		case UART_FCR_TRIGGER_1:
386 			mdev_state->s[index].intr_trigger_level = 1;
387 			break;
388 
389 		case UART_FCR_TRIGGER_4:
390 			mdev_state->s[index].intr_trigger_level = 4;
391 			break;
392 
393 		case UART_FCR_TRIGGER_8:
394 			mdev_state->s[index].intr_trigger_level = 8;
395 			break;
396 
397 		case UART_FCR_TRIGGER_14:
398 			mdev_state->s[index].intr_trigger_level = 14;
399 			break;
400 		}
401 
402 		/*
403 		 * Set trigger level to 1 otherwise or  implement timer with
404 		 * timeout of 4 characters and on expiring that timer set
405 		 * Recevice data timeout in IIR register
406 		 */
407 		mdev_state->s[index].intr_trigger_level = 1;
408 		if (data & UART_FCR_ENABLE_FIFO)
409 			mdev_state->s[index].max_fifo_size = MAX_FIFO_SIZE;
410 		else {
411 			mdev_state->s[index].max_fifo_size = 1;
412 			mdev_state->s[index].intr_trigger_level = 1;
413 		}
414 
415 		break;
416 
417 	case UART_LCR:
418 		if (data & UART_LCR_DLAB) {
419 			mdev_state->s[index].dlab = true;
420 			mdev_state->s[index].divisor = 0;
421 		} else
422 			mdev_state->s[index].dlab = false;
423 
424 		mdev_state->s[index].uart_reg[offset] = data;
425 		break;
426 
427 	case UART_MCR:
428 		mdev_state->s[index].uart_reg[offset] = data;
429 
430 		if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
431 				(data & UART_MCR_OUT2)) {
432 #if defined(DEBUG_INTR)
433 			pr_err("Serial port %d: MCR_OUT2 write\n", index);
434 #endif
435 			mtty_trigger_interrupt(mdev_state);
436 		}
437 
438 		if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
439 				(data & (UART_MCR_RTS | UART_MCR_DTR))) {
440 #if defined(DEBUG_INTR)
441 			pr_err("Serial port %d: MCR RTS/DTR write\n", index);
442 #endif
443 			mtty_trigger_interrupt(mdev_state);
444 		}
445 		break;
446 
447 	case UART_LSR:
448 	case UART_MSR:
449 		/* do nothing */
450 		break;
451 
452 	case UART_SCR:
453 		mdev_state->s[index].uart_reg[offset] = data;
454 		break;
455 
456 	default:
457 		break;
458 	}
459 }
460 
461 static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
462 			    u16 offset, u8 *buf, u32 count)
463 {
464 	/* Handle read requests by guest */
465 	switch (offset) {
466 	case UART_RX:
467 		/* if DLAB set, data is LSB of divisor */
468 		if (mdev_state->s[index].dlab) {
469 			*buf  = (u8)mdev_state->s[index].divisor;
470 			break;
471 		}
472 
473 		mutex_lock(&mdev_state->rxtx_lock);
474 		/* return data in tx buffer */
475 		if (mdev_state->s[index].rxtx.head !=
476 				 mdev_state->s[index].rxtx.tail) {
477 			*buf = mdev_state->s[index].rxtx.fifo[
478 						mdev_state->s[index].rxtx.tail];
479 			mdev_state->s[index].rxtx.count--;
480 			CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.tail);
481 		}
482 
483 		if (mdev_state->s[index].rxtx.head ==
484 				mdev_state->s[index].rxtx.tail) {
485 		/*
486 		 *  Trigger interrupt if tx buffer empty interrupt is
487 		 *  enabled and fifo is empty
488 		 */
489 #if defined(DEBUG_INTR)
490 			pr_err("Serial port %d: Buffer Empty\n", index);
491 #endif
492 			if (mdev_state->s[index].uart_reg[UART_IER] &
493 							 UART_IER_THRI)
494 				mtty_trigger_interrupt(mdev_state);
495 		}
496 		mutex_unlock(&mdev_state->rxtx_lock);
497 
498 		break;
499 
500 	case UART_IER:
501 		if (mdev_state->s[index].dlab) {
502 			*buf = (u8)(mdev_state->s[index].divisor >> 8);
503 			break;
504 		}
505 		*buf = mdev_state->s[index].uart_reg[offset] & 0x0f;
506 		break;
507 
508 	case UART_IIR:
509 	{
510 		u8 ier = mdev_state->s[index].uart_reg[UART_IER];
511 		*buf = 0;
512 
513 		mutex_lock(&mdev_state->rxtx_lock);
514 		/* Interrupt priority 1: Parity, overrun, framing or break */
515 		if ((ier & UART_IER_RLSI) && mdev_state->s[index].overrun)
516 			*buf |= UART_IIR_RLSI;
517 
518 		/* Interrupt priority 2: Fifo trigger level reached */
519 		if ((ier & UART_IER_RDI) &&
520 		    (mdev_state->s[index].rxtx.count >=
521 		      mdev_state->s[index].intr_trigger_level))
522 			*buf |= UART_IIR_RDI;
523 
524 		/* Interrupt priotiry 3: transmitter holding register empty */
525 		if ((ier & UART_IER_THRI) &&
526 		    (mdev_state->s[index].rxtx.head ==
527 				mdev_state->s[index].rxtx.tail))
528 			*buf |= UART_IIR_THRI;
529 
530 		/* Interrupt priotiry 4: Modem status: CTS, DSR, RI or DCD  */
531 		if ((ier & UART_IER_MSI) &&
532 		    (mdev_state->s[index].uart_reg[UART_MCR] &
533 				 (UART_MCR_RTS | UART_MCR_DTR)))
534 			*buf |= UART_IIR_MSI;
535 
536 		/* bit0: 0=> interrupt pending, 1=> no interrupt is pending */
537 		if (*buf == 0)
538 			*buf = UART_IIR_NO_INT;
539 
540 		/* set bit 6 & 7 to be 16550 compatible */
541 		*buf |= 0xC0;
542 		mutex_unlock(&mdev_state->rxtx_lock);
543 	}
544 	break;
545 
546 	case UART_LCR:
547 	case UART_MCR:
548 		*buf = mdev_state->s[index].uart_reg[offset];
549 		break;
550 
551 	case UART_LSR:
552 	{
553 		u8 lsr = 0;
554 
555 		mutex_lock(&mdev_state->rxtx_lock);
556 		/* atleast one char in FIFO */
557 		if (mdev_state->s[index].rxtx.head !=
558 				 mdev_state->s[index].rxtx.tail)
559 			lsr |= UART_LSR_DR;
560 
561 		/* if FIFO overrun */
562 		if (mdev_state->s[index].overrun)
563 			lsr |= UART_LSR_OE;
564 
565 		/* transmit FIFO empty and tramsitter empty */
566 		if (mdev_state->s[index].rxtx.head ==
567 				 mdev_state->s[index].rxtx.tail)
568 			lsr |= UART_LSR_TEMT | UART_LSR_THRE;
569 
570 		mutex_unlock(&mdev_state->rxtx_lock);
571 		*buf = lsr;
572 		break;
573 	}
574 	case UART_MSR:
575 		*buf = UART_MSR_DSR | UART_MSR_DDSR | UART_MSR_DCD;
576 
577 		mutex_lock(&mdev_state->rxtx_lock);
578 		/* if AFE is 1 and FIFO have space, set CTS bit */
579 		if (mdev_state->s[index].uart_reg[UART_MCR] &
580 						 UART_MCR_AFE) {
581 			if (mdev_state->s[index].rxtx.count <
582 					mdev_state->s[index].max_fifo_size)
583 				*buf |= UART_MSR_CTS | UART_MSR_DCTS;
584 		} else
585 			*buf |= UART_MSR_CTS | UART_MSR_DCTS;
586 		mutex_unlock(&mdev_state->rxtx_lock);
587 
588 		break;
589 
590 	case UART_SCR:
591 		*buf = mdev_state->s[index].uart_reg[offset];
592 		break;
593 
594 	default:
595 		break;
596 	}
597 }
598 
599 static void mdev_read_base(struct mdev_state *mdev_state)
600 {
601 	int index, pos;
602 	u32 start_lo, start_hi;
603 	u32 mem_type;
604 
605 	pos = PCI_BASE_ADDRESS_0;
606 
607 	for (index = 0; index <= VFIO_PCI_BAR5_REGION_INDEX; index++) {
608 
609 		if (!mdev_state->region_info[index].size)
610 			continue;
611 
612 		start_lo = (*(u32 *)(mdev_state->vconfig + pos)) &
613 			PCI_BASE_ADDRESS_MEM_MASK;
614 		mem_type = (*(u32 *)(mdev_state->vconfig + pos)) &
615 			PCI_BASE_ADDRESS_MEM_TYPE_MASK;
616 
617 		switch (mem_type) {
618 		case PCI_BASE_ADDRESS_MEM_TYPE_64:
619 			start_hi = (*(u32 *)(mdev_state->vconfig + pos + 4));
620 			pos += 4;
621 			break;
622 		case PCI_BASE_ADDRESS_MEM_TYPE_32:
623 		case PCI_BASE_ADDRESS_MEM_TYPE_1M:
624 			/* 1M mem BAR treated as 32-bit BAR */
625 		default:
626 			/* mem unknown type treated as 32-bit BAR */
627 			start_hi = 0;
628 			break;
629 		}
630 		pos += 4;
631 		mdev_state->region_info[index].start = ((u64)start_hi << 32) |
632 							start_lo;
633 	}
634 }
635 
636 static ssize_t mdev_access(struct mdev_state *mdev_state, u8 *buf, size_t count,
637 			   loff_t pos, bool is_write)
638 {
639 	unsigned int index;
640 	loff_t offset;
641 	int ret = 0;
642 
643 	if (!buf)
644 		return -EINVAL;
645 
646 	mutex_lock(&mdev_state->ops_lock);
647 
648 	index = MTTY_VFIO_PCI_OFFSET_TO_INDEX(pos);
649 	offset = pos & MTTY_VFIO_PCI_OFFSET_MASK;
650 	switch (index) {
651 	case VFIO_PCI_CONFIG_REGION_INDEX:
652 
653 #if defined(DEBUG)
654 		pr_info("%s: PCI config space %s at offset 0x%llx\n",
655 			 __func__, is_write ? "write" : "read", offset);
656 #endif
657 		if (is_write) {
658 			dump_buffer(buf, count);
659 			handle_pci_cfg_write(mdev_state, offset, buf, count);
660 		} else {
661 			memcpy(buf, (mdev_state->vconfig + offset), count);
662 			dump_buffer(buf, count);
663 		}
664 
665 		break;
666 
667 	case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
668 		if (!mdev_state->region_info[index].start)
669 			mdev_read_base(mdev_state);
670 
671 		if (is_write) {
672 			dump_buffer(buf, count);
673 
674 #if defined(DEBUG_REGS)
675 			pr_info("%s: BAR%d  WR @0x%llx %s val:0x%02x dlab:%d\n",
676 				__func__, index, offset, wr_reg[offset],
677 				*buf, mdev_state->s[index].dlab);
678 #endif
679 			handle_bar_write(index, mdev_state, offset, buf, count);
680 		} else {
681 			handle_bar_read(index, mdev_state, offset, buf, count);
682 			dump_buffer(buf, count);
683 
684 #if defined(DEBUG_REGS)
685 			pr_info("%s: BAR%d  RD @0x%llx %s val:0x%02x dlab:%d\n",
686 				__func__, index, offset, rd_reg[offset],
687 				*buf, mdev_state->s[index].dlab);
688 #endif
689 		}
690 		break;
691 
692 	default:
693 		ret = -1;
694 		goto accessfailed;
695 	}
696 
697 	ret = count;
698 
699 
700 accessfailed:
701 	mutex_unlock(&mdev_state->ops_lock);
702 
703 	return ret;
704 }
705 
706 static int mtty_probe(struct mdev_device *mdev)
707 {
708 	struct mdev_state *mdev_state;
709 	int nr_ports = mdev_get_type_group_id(mdev) + 1;
710 	int avail_ports = atomic_read(&mdev_avail_ports);
711 	int ret;
712 
713 	do {
714 		if (avail_ports < nr_ports)
715 			return -ENOSPC;
716 	} while (!atomic_try_cmpxchg(&mdev_avail_ports,
717 				     &avail_ports, avail_ports - nr_ports));
718 
719 	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
720 	if (mdev_state == NULL) {
721 		ret = -ENOMEM;
722 		goto err_nr_ports;
723 	}
724 
725 	vfio_init_group_dev(&mdev_state->vdev, &mdev->dev, &mtty_dev_ops);
726 
727 	mdev_state->nr_ports = nr_ports;
728 	mdev_state->irq_index = -1;
729 	mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE;
730 	mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE;
731 	mutex_init(&mdev_state->rxtx_lock);
732 	mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL);
733 
734 	if (mdev_state->vconfig == NULL) {
735 		ret = -ENOMEM;
736 		goto err_state;
737 	}
738 
739 	mutex_init(&mdev_state->ops_lock);
740 	mdev_state->mdev = mdev;
741 
742 	mtty_create_config_space(mdev_state);
743 
744 	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
745 	if (ret)
746 		goto err_vconfig;
747 	dev_set_drvdata(&mdev->dev, mdev_state);
748 	return 0;
749 
750 err_vconfig:
751 	kfree(mdev_state->vconfig);
752 err_state:
753 	vfio_uninit_group_dev(&mdev_state->vdev);
754 	kfree(mdev_state);
755 err_nr_ports:
756 	atomic_add(nr_ports, &mdev_avail_ports);
757 	return ret;
758 }
759 
760 static void mtty_remove(struct mdev_device *mdev)
761 {
762 	struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
763 	int nr_ports = mdev_state->nr_ports;
764 
765 	vfio_unregister_group_dev(&mdev_state->vdev);
766 
767 	kfree(mdev_state->vconfig);
768 	vfio_uninit_group_dev(&mdev_state->vdev);
769 	kfree(mdev_state);
770 	atomic_add(nr_ports, &mdev_avail_ports);
771 }
772 
773 static int mtty_reset(struct mdev_state *mdev_state)
774 {
775 	pr_info("%s: called\n", __func__);
776 
777 	return 0;
778 }
779 
780 static ssize_t mtty_read(struct vfio_device *vdev, char __user *buf,
781 			 size_t count, loff_t *ppos)
782 {
783 	struct mdev_state *mdev_state =
784 		container_of(vdev, struct mdev_state, vdev);
785 	unsigned int done = 0;
786 	int ret;
787 
788 	while (count) {
789 		size_t filled;
790 
791 		if (count >= 4 && !(*ppos % 4)) {
792 			u32 val;
793 
794 			ret =  mdev_access(mdev_state, (u8 *)&val, sizeof(val),
795 					   *ppos, false);
796 			if (ret <= 0)
797 				goto read_err;
798 
799 			if (copy_to_user(buf, &val, sizeof(val)))
800 				goto read_err;
801 
802 			filled = 4;
803 		} else if (count >= 2 && !(*ppos % 2)) {
804 			u16 val;
805 
806 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
807 					  *ppos, false);
808 			if (ret <= 0)
809 				goto read_err;
810 
811 			if (copy_to_user(buf, &val, sizeof(val)))
812 				goto read_err;
813 
814 			filled = 2;
815 		} else {
816 			u8 val;
817 
818 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
819 					  *ppos, false);
820 			if (ret <= 0)
821 				goto read_err;
822 
823 			if (copy_to_user(buf, &val, sizeof(val)))
824 				goto read_err;
825 
826 			filled = 1;
827 		}
828 
829 		count -= filled;
830 		done += filled;
831 		*ppos += filled;
832 		buf += filled;
833 	}
834 
835 	return done;
836 
837 read_err:
838 	return -EFAULT;
839 }
840 
841 static ssize_t mtty_write(struct vfio_device *vdev, const char __user *buf,
842 		   size_t count, loff_t *ppos)
843 {
844 	struct mdev_state *mdev_state =
845 		container_of(vdev, struct mdev_state, vdev);
846 	unsigned int done = 0;
847 	int ret;
848 
849 	while (count) {
850 		size_t filled;
851 
852 		if (count >= 4 && !(*ppos % 4)) {
853 			u32 val;
854 
855 			if (copy_from_user(&val, buf, sizeof(val)))
856 				goto write_err;
857 
858 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
859 					  *ppos, true);
860 			if (ret <= 0)
861 				goto write_err;
862 
863 			filled = 4;
864 		} else if (count >= 2 && !(*ppos % 2)) {
865 			u16 val;
866 
867 			if (copy_from_user(&val, buf, sizeof(val)))
868 				goto write_err;
869 
870 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
871 					  *ppos, true);
872 			if (ret <= 0)
873 				goto write_err;
874 
875 			filled = 2;
876 		} else {
877 			u8 val;
878 
879 			if (copy_from_user(&val, buf, sizeof(val)))
880 				goto write_err;
881 
882 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
883 					  *ppos, true);
884 			if (ret <= 0)
885 				goto write_err;
886 
887 			filled = 1;
888 		}
889 		count -= filled;
890 		done += filled;
891 		*ppos += filled;
892 		buf += filled;
893 	}
894 
895 	return done;
896 write_err:
897 	return -EFAULT;
898 }
899 
900 static int mtty_set_irqs(struct mdev_state *mdev_state, uint32_t flags,
901 			 unsigned int index, unsigned int start,
902 			 unsigned int count, void *data)
903 {
904 	int ret = 0;
905 
906 	mutex_lock(&mdev_state->ops_lock);
907 	switch (index) {
908 	case VFIO_PCI_INTX_IRQ_INDEX:
909 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
910 		case VFIO_IRQ_SET_ACTION_MASK:
911 		case VFIO_IRQ_SET_ACTION_UNMASK:
912 			break;
913 		case VFIO_IRQ_SET_ACTION_TRIGGER:
914 		{
915 			if (flags & VFIO_IRQ_SET_DATA_NONE) {
916 				pr_info("%s: disable INTx\n", __func__);
917 				if (mdev_state->intx_evtfd)
918 					eventfd_ctx_put(mdev_state->intx_evtfd);
919 				break;
920 			}
921 
922 			if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
923 				int fd = *(int *)data;
924 
925 				if (fd > 0) {
926 					struct eventfd_ctx *evt;
927 
928 					evt = eventfd_ctx_fdget(fd);
929 					if (IS_ERR(evt)) {
930 						ret = PTR_ERR(evt);
931 						break;
932 					}
933 					mdev_state->intx_evtfd = evt;
934 					mdev_state->irq_fd = fd;
935 					mdev_state->irq_index = index;
936 					break;
937 				}
938 			}
939 			break;
940 		}
941 		}
942 		break;
943 	case VFIO_PCI_MSI_IRQ_INDEX:
944 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
945 		case VFIO_IRQ_SET_ACTION_MASK:
946 		case VFIO_IRQ_SET_ACTION_UNMASK:
947 			break;
948 		case VFIO_IRQ_SET_ACTION_TRIGGER:
949 			if (flags & VFIO_IRQ_SET_DATA_NONE) {
950 				if (mdev_state->msi_evtfd)
951 					eventfd_ctx_put(mdev_state->msi_evtfd);
952 				pr_info("%s: disable MSI\n", __func__);
953 				mdev_state->irq_index = VFIO_PCI_INTX_IRQ_INDEX;
954 				break;
955 			}
956 			if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
957 				int fd = *(int *)data;
958 				struct eventfd_ctx *evt;
959 
960 				if (fd <= 0)
961 					break;
962 
963 				if (mdev_state->msi_evtfd)
964 					break;
965 
966 				evt = eventfd_ctx_fdget(fd);
967 				if (IS_ERR(evt)) {
968 					ret = PTR_ERR(evt);
969 					break;
970 				}
971 				mdev_state->msi_evtfd = evt;
972 				mdev_state->irq_fd = fd;
973 				mdev_state->irq_index = index;
974 			}
975 			break;
976 	}
977 	break;
978 	case VFIO_PCI_MSIX_IRQ_INDEX:
979 		pr_info("%s: MSIX_IRQ\n", __func__);
980 		break;
981 	case VFIO_PCI_ERR_IRQ_INDEX:
982 		pr_info("%s: ERR_IRQ\n", __func__);
983 		break;
984 	case VFIO_PCI_REQ_IRQ_INDEX:
985 		pr_info("%s: REQ_IRQ\n", __func__);
986 		break;
987 	}
988 
989 	mutex_unlock(&mdev_state->ops_lock);
990 	return ret;
991 }
992 
993 static int mtty_trigger_interrupt(struct mdev_state *mdev_state)
994 {
995 	int ret = -1;
996 
997 	if ((mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX) &&
998 	    (!mdev_state->msi_evtfd))
999 		return -EINVAL;
1000 	else if ((mdev_state->irq_index == VFIO_PCI_INTX_IRQ_INDEX) &&
1001 		 (!mdev_state->intx_evtfd)) {
1002 		pr_info("%s: Intr eventfd not found\n", __func__);
1003 		return -EINVAL;
1004 	}
1005 
1006 	if (mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX)
1007 		ret = eventfd_signal(mdev_state->msi_evtfd, 1);
1008 	else
1009 		ret = eventfd_signal(mdev_state->intx_evtfd, 1);
1010 
1011 #if defined(DEBUG_INTR)
1012 	pr_info("Intx triggered\n");
1013 #endif
1014 	if (ret != 1)
1015 		pr_err("%s: eventfd signal failed (%d)\n", __func__, ret);
1016 
1017 	return ret;
1018 }
1019 
1020 static int mtty_get_region_info(struct mdev_state *mdev_state,
1021 			 struct vfio_region_info *region_info,
1022 			 u16 *cap_type_id, void **cap_type)
1023 {
1024 	unsigned int size = 0;
1025 	u32 bar_index;
1026 
1027 	bar_index = region_info->index;
1028 	if (bar_index >= VFIO_PCI_NUM_REGIONS)
1029 		return -EINVAL;
1030 
1031 	mutex_lock(&mdev_state->ops_lock);
1032 
1033 	switch (bar_index) {
1034 	case VFIO_PCI_CONFIG_REGION_INDEX:
1035 		size = MTTY_CONFIG_SPACE_SIZE;
1036 		break;
1037 	case VFIO_PCI_BAR0_REGION_INDEX:
1038 		size = MTTY_IO_BAR_SIZE;
1039 		break;
1040 	case VFIO_PCI_BAR1_REGION_INDEX:
1041 		if (mdev_state->nr_ports == 2)
1042 			size = MTTY_IO_BAR_SIZE;
1043 		break;
1044 	default:
1045 		size = 0;
1046 		break;
1047 	}
1048 
1049 	mdev_state->region_info[bar_index].size = size;
1050 	mdev_state->region_info[bar_index].vfio_offset =
1051 		MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
1052 
1053 	region_info->size = size;
1054 	region_info->offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
1055 	region_info->flags = VFIO_REGION_INFO_FLAG_READ |
1056 		VFIO_REGION_INFO_FLAG_WRITE;
1057 	mutex_unlock(&mdev_state->ops_lock);
1058 	return 0;
1059 }
1060 
1061 static int mtty_get_irq_info(struct vfio_irq_info *irq_info)
1062 {
1063 	switch (irq_info->index) {
1064 	case VFIO_PCI_INTX_IRQ_INDEX:
1065 	case VFIO_PCI_MSI_IRQ_INDEX:
1066 	case VFIO_PCI_REQ_IRQ_INDEX:
1067 		break;
1068 
1069 	default:
1070 		return -EINVAL;
1071 	}
1072 
1073 	irq_info->flags = VFIO_IRQ_INFO_EVENTFD;
1074 	irq_info->count = 1;
1075 
1076 	if (irq_info->index == VFIO_PCI_INTX_IRQ_INDEX)
1077 		irq_info->flags |= (VFIO_IRQ_INFO_MASKABLE |
1078 				VFIO_IRQ_INFO_AUTOMASKED);
1079 	else
1080 		irq_info->flags |= VFIO_IRQ_INFO_NORESIZE;
1081 
1082 	return 0;
1083 }
1084 
1085 static int mtty_get_device_info(struct vfio_device_info *dev_info)
1086 {
1087 	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1088 	dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
1089 	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1090 
1091 	return 0;
1092 }
1093 
1094 static long mtty_ioctl(struct vfio_device *vdev, unsigned int cmd,
1095 			unsigned long arg)
1096 {
1097 	struct mdev_state *mdev_state =
1098 		container_of(vdev, struct mdev_state, vdev);
1099 	int ret = 0;
1100 	unsigned long minsz;
1101 
1102 	switch (cmd) {
1103 	case VFIO_DEVICE_GET_INFO:
1104 	{
1105 		struct vfio_device_info info;
1106 
1107 		minsz = offsetofend(struct vfio_device_info, num_irqs);
1108 
1109 		if (copy_from_user(&info, (void __user *)arg, minsz))
1110 			return -EFAULT;
1111 
1112 		if (info.argsz < minsz)
1113 			return -EINVAL;
1114 
1115 		ret = mtty_get_device_info(&info);
1116 		if (ret)
1117 			return ret;
1118 
1119 		memcpy(&mdev_state->dev_info, &info, sizeof(info));
1120 
1121 		if (copy_to_user((void __user *)arg, &info, minsz))
1122 			return -EFAULT;
1123 
1124 		return 0;
1125 	}
1126 	case VFIO_DEVICE_GET_REGION_INFO:
1127 	{
1128 		struct vfio_region_info info;
1129 		u16 cap_type_id = 0;
1130 		void *cap_type = NULL;
1131 
1132 		minsz = offsetofend(struct vfio_region_info, offset);
1133 
1134 		if (copy_from_user(&info, (void __user *)arg, minsz))
1135 			return -EFAULT;
1136 
1137 		if (info.argsz < minsz)
1138 			return -EINVAL;
1139 
1140 		ret = mtty_get_region_info(mdev_state, &info, &cap_type_id,
1141 					   &cap_type);
1142 		if (ret)
1143 			return ret;
1144 
1145 		if (copy_to_user((void __user *)arg, &info, minsz))
1146 			return -EFAULT;
1147 
1148 		return 0;
1149 	}
1150 
1151 	case VFIO_DEVICE_GET_IRQ_INFO:
1152 	{
1153 		struct vfio_irq_info info;
1154 
1155 		minsz = offsetofend(struct vfio_irq_info, count);
1156 
1157 		if (copy_from_user(&info, (void __user *)arg, minsz))
1158 			return -EFAULT;
1159 
1160 		if ((info.argsz < minsz) ||
1161 		    (info.index >= mdev_state->dev_info.num_irqs))
1162 			return -EINVAL;
1163 
1164 		ret = mtty_get_irq_info(&info);
1165 		if (ret)
1166 			return ret;
1167 
1168 		if (copy_to_user((void __user *)arg, &info, minsz))
1169 			return -EFAULT;
1170 
1171 		return 0;
1172 	}
1173 	case VFIO_DEVICE_SET_IRQS:
1174 	{
1175 		struct vfio_irq_set hdr;
1176 		u8 *data = NULL, *ptr = NULL;
1177 		size_t data_size = 0;
1178 
1179 		minsz = offsetofend(struct vfio_irq_set, count);
1180 
1181 		if (copy_from_user(&hdr, (void __user *)arg, minsz))
1182 			return -EFAULT;
1183 
1184 		ret = vfio_set_irqs_validate_and_prepare(&hdr,
1185 						mdev_state->dev_info.num_irqs,
1186 						VFIO_PCI_NUM_IRQS,
1187 						&data_size);
1188 		if (ret)
1189 			return ret;
1190 
1191 		if (data_size) {
1192 			ptr = data = memdup_user((void __user *)(arg + minsz),
1193 						 data_size);
1194 			if (IS_ERR(data))
1195 				return PTR_ERR(data);
1196 		}
1197 
1198 		ret = mtty_set_irqs(mdev_state, hdr.flags, hdr.index, hdr.start,
1199 				    hdr.count, data);
1200 
1201 		kfree(ptr);
1202 		return ret;
1203 	}
1204 	case VFIO_DEVICE_RESET:
1205 		return mtty_reset(mdev_state);
1206 	}
1207 	return -ENOTTY;
1208 }
1209 
1210 static ssize_t
1211 sample_mtty_dev_show(struct device *dev, struct device_attribute *attr,
1212 		     char *buf)
1213 {
1214 	return sprintf(buf, "This is phy device\n");
1215 }
1216 
1217 static DEVICE_ATTR_RO(sample_mtty_dev);
1218 
1219 static struct attribute *mtty_dev_attrs[] = {
1220 	&dev_attr_sample_mtty_dev.attr,
1221 	NULL,
1222 };
1223 
1224 static const struct attribute_group mtty_dev_group = {
1225 	.name  = "mtty_dev",
1226 	.attrs = mtty_dev_attrs,
1227 };
1228 
1229 static const struct attribute_group *mtty_dev_groups[] = {
1230 	&mtty_dev_group,
1231 	NULL,
1232 };
1233 
1234 static ssize_t
1235 sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
1236 		     char *buf)
1237 {
1238 	if (mdev_from_dev(dev))
1239 		return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
1240 
1241 	return sprintf(buf, "\n");
1242 }
1243 
1244 static DEVICE_ATTR_RO(sample_mdev_dev);
1245 
1246 static struct attribute *mdev_dev_attrs[] = {
1247 	&dev_attr_sample_mdev_dev.attr,
1248 	NULL,
1249 };
1250 
1251 static const struct attribute_group mdev_dev_group = {
1252 	.name  = "vendor",
1253 	.attrs = mdev_dev_attrs,
1254 };
1255 
1256 static const struct attribute_group *mdev_dev_groups[] = {
1257 	&mdev_dev_group,
1258 	NULL,
1259 };
1260 
1261 static ssize_t name_show(struct mdev_type *mtype,
1262 			 struct mdev_type_attribute *attr, char *buf)
1263 {
1264 	static const char *name_str[2] = { "Single port serial",
1265 					   "Dual port serial" };
1266 
1267 	return sysfs_emit(buf, "%s\n",
1268 			  name_str[mtype_get_type_group_id(mtype)]);
1269 }
1270 
1271 static MDEV_TYPE_ATTR_RO(name);
1272 
1273 static ssize_t available_instances_show(struct mdev_type *mtype,
1274 					struct mdev_type_attribute *attr,
1275 					char *buf)
1276 {
1277 	unsigned int ports = mtype_get_type_group_id(mtype) + 1;
1278 
1279 	return sprintf(buf, "%d\n", atomic_read(&mdev_avail_ports) / ports);
1280 }
1281 
1282 static MDEV_TYPE_ATTR_RO(available_instances);
1283 
1284 static ssize_t device_api_show(struct mdev_type *mtype,
1285 			       struct mdev_type_attribute *attr, char *buf)
1286 {
1287 	return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
1288 }
1289 
1290 static MDEV_TYPE_ATTR_RO(device_api);
1291 
1292 static struct attribute *mdev_types_attrs[] = {
1293 	&mdev_type_attr_name.attr,
1294 	&mdev_type_attr_device_api.attr,
1295 	&mdev_type_attr_available_instances.attr,
1296 	NULL,
1297 };
1298 
1299 static struct attribute_group mdev_type_group1 = {
1300 	.name  = "1",
1301 	.attrs = mdev_types_attrs,
1302 };
1303 
1304 static struct attribute_group mdev_type_group2 = {
1305 	.name  = "2",
1306 	.attrs = mdev_types_attrs,
1307 };
1308 
1309 static struct attribute_group *mdev_type_groups[] = {
1310 	&mdev_type_group1,
1311 	&mdev_type_group2,
1312 	NULL,
1313 };
1314 
1315 static const struct vfio_device_ops mtty_dev_ops = {
1316 	.name = "vfio-mtty",
1317 	.read = mtty_read,
1318 	.write = mtty_write,
1319 	.ioctl = mtty_ioctl,
1320 };
1321 
1322 static struct mdev_driver mtty_driver = {
1323 	.driver = {
1324 		.name = "mtty",
1325 		.owner = THIS_MODULE,
1326 		.mod_name = KBUILD_MODNAME,
1327 		.dev_groups = mdev_dev_groups,
1328 	},
1329 	.probe = mtty_probe,
1330 	.remove	= mtty_remove,
1331 };
1332 
1333 static const struct mdev_parent_ops mdev_fops = {
1334 	.owner                  = THIS_MODULE,
1335 	.device_driver		= &mtty_driver,
1336 	.dev_attr_groups        = mtty_dev_groups,
1337 	.supported_type_groups  = mdev_type_groups,
1338 };
1339 
1340 static void mtty_device_release(struct device *dev)
1341 {
1342 	dev_dbg(dev, "mtty: released\n");
1343 }
1344 
1345 static int __init mtty_dev_init(void)
1346 {
1347 	int ret = 0;
1348 
1349 	pr_info("mtty_dev: %s\n", __func__);
1350 
1351 	memset(&mtty_dev, 0, sizeof(mtty_dev));
1352 
1353 	idr_init(&mtty_dev.vd_idr);
1354 
1355 	ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK + 1,
1356 				  MTTY_NAME);
1357 
1358 	if (ret < 0) {
1359 		pr_err("Error: failed to register mtty_dev, err:%d\n", ret);
1360 		return ret;
1361 	}
1362 
1363 	cdev_init(&mtty_dev.vd_cdev, &vd_fops);
1364 	cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK + 1);
1365 
1366 	pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt));
1367 
1368 	ret = mdev_register_driver(&mtty_driver);
1369 	if (ret)
1370 		goto err_cdev;
1371 
1372 	mtty_dev.vd_class = class_create(THIS_MODULE, MTTY_CLASS_NAME);
1373 
1374 	if (IS_ERR(mtty_dev.vd_class)) {
1375 		pr_err("Error: failed to register mtty_dev class\n");
1376 		ret = PTR_ERR(mtty_dev.vd_class);
1377 		goto err_driver;
1378 	}
1379 
1380 	mtty_dev.dev.class = mtty_dev.vd_class;
1381 	mtty_dev.dev.release = mtty_device_release;
1382 	dev_set_name(&mtty_dev.dev, "%s", MTTY_NAME);
1383 
1384 	ret = device_register(&mtty_dev.dev);
1385 	if (ret)
1386 		goto err_class;
1387 
1388 	ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
1389 	if (ret)
1390 		goto err_device;
1391 	return 0;
1392 
1393 err_device:
1394 	device_unregister(&mtty_dev.dev);
1395 err_class:
1396 	class_destroy(mtty_dev.vd_class);
1397 err_driver:
1398 	mdev_unregister_driver(&mtty_driver);
1399 err_cdev:
1400 	cdev_del(&mtty_dev.vd_cdev);
1401 	unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
1402 	return ret;
1403 }
1404 
1405 static void __exit mtty_dev_exit(void)
1406 {
1407 	mtty_dev.dev.bus = NULL;
1408 	mdev_unregister_device(&mtty_dev.dev);
1409 
1410 	device_unregister(&mtty_dev.dev);
1411 	idr_destroy(&mtty_dev.vd_idr);
1412 	mdev_unregister_driver(&mtty_driver);
1413 	cdev_del(&mtty_dev.vd_cdev);
1414 	unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
1415 	class_destroy(mtty_dev.vd_class);
1416 	mtty_dev.vd_class = NULL;
1417 	pr_info("mtty_dev: Unloaded!\n");
1418 }
1419 
1420 module_init(mtty_dev_init)
1421 module_exit(mtty_dev_exit)
1422 
1423 MODULE_LICENSE("GPL v2");
1424 MODULE_INFO(supported, "Test driver that simulate serial port over PCI");
1425 MODULE_VERSION(VERSION_STRING);
1426 MODULE_AUTHOR(DRIVER_AUTHOR);
1427