xref: /linux/samples/vfio-mdev/mtty.c (revision aaa44952bbd1d4db14a4d676bf9595bb5db7e7b0)
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 	int irq_fd;
131 	struct eventfd_ctx *intx_evtfd;
132 	struct eventfd_ctx *msi_evtfd;
133 	int irq_index;
134 	u8 *vconfig;
135 	struct mutex ops_lock;
136 	struct mdev_device *mdev;
137 	struct mdev_region_info region_info[VFIO_PCI_NUM_REGIONS];
138 	u32 bar_mask[VFIO_PCI_NUM_REGIONS];
139 	struct list_head next;
140 	struct serial_port s[2];
141 	struct mutex rxtx_lock;
142 	struct vfio_device_info dev_info;
143 	int nr_ports;
144 };
145 
146 static struct mutex mdev_list_lock;
147 static struct list_head mdev_devices_list;
148 
149 static const struct file_operations vd_fops = {
150 	.owner          = THIS_MODULE,
151 };
152 
153 /* function prototypes */
154 
155 static int mtty_trigger_interrupt(struct mdev_state *mdev_state);
156 
157 /* Helper functions */
158 
159 static void dump_buffer(u8 *buf, uint32_t count)
160 {
161 #if defined(DEBUG)
162 	int i;
163 
164 	pr_info("Buffer:\n");
165 	for (i = 0; i < count; i++) {
166 		pr_info("%2x ", *(buf + i));
167 		if ((i + 1) % 16 == 0)
168 			pr_info("\n");
169 	}
170 #endif
171 }
172 
173 static void mtty_create_config_space(struct mdev_state *mdev_state)
174 {
175 	/* PCI dev ID */
176 	STORE_LE32((u32 *) &mdev_state->vconfig[0x0], 0x32534348);
177 
178 	/* Control: I/O+, Mem-, BusMaster- */
179 	STORE_LE16((u16 *) &mdev_state->vconfig[0x4], 0x0001);
180 
181 	/* Status: capabilities list absent */
182 	STORE_LE16((u16 *) &mdev_state->vconfig[0x6], 0x0200);
183 
184 	/* Rev ID */
185 	mdev_state->vconfig[0x8] =  0x10;
186 
187 	/* programming interface class : 16550-compatible serial controller */
188 	mdev_state->vconfig[0x9] =  0x02;
189 
190 	/* Sub class : 00 */
191 	mdev_state->vconfig[0xa] =  0x00;
192 
193 	/* Base class : Simple Communication controllers */
194 	mdev_state->vconfig[0xb] =  0x07;
195 
196 	/* base address registers */
197 	/* BAR0: IO space */
198 	STORE_LE32((u32 *) &mdev_state->vconfig[0x10], 0x000001);
199 	mdev_state->bar_mask[0] = ~(MTTY_IO_BAR_SIZE) + 1;
200 
201 	if (mdev_state->nr_ports == 2) {
202 		/* BAR1: IO space */
203 		STORE_LE32((u32 *) &mdev_state->vconfig[0x14], 0x000001);
204 		mdev_state->bar_mask[1] = ~(MTTY_IO_BAR_SIZE) + 1;
205 	}
206 
207 	/* Subsystem ID */
208 	STORE_LE32((u32 *) &mdev_state->vconfig[0x2c], 0x32534348);
209 
210 	mdev_state->vconfig[0x34] =  0x00;   /* Cap Ptr */
211 	mdev_state->vconfig[0x3d] =  0x01;   /* interrupt pin (INTA#) */
212 
213 	/* Vendor specific data */
214 	mdev_state->vconfig[0x40] =  0x23;
215 	mdev_state->vconfig[0x43] =  0x80;
216 	mdev_state->vconfig[0x44] =  0x23;
217 	mdev_state->vconfig[0x48] =  0x23;
218 	mdev_state->vconfig[0x4c] =  0x23;
219 
220 	mdev_state->vconfig[0x60] =  0x50;
221 	mdev_state->vconfig[0x61] =  0x43;
222 	mdev_state->vconfig[0x62] =  0x49;
223 	mdev_state->vconfig[0x63] =  0x20;
224 	mdev_state->vconfig[0x64] =  0x53;
225 	mdev_state->vconfig[0x65] =  0x65;
226 	mdev_state->vconfig[0x66] =  0x72;
227 	mdev_state->vconfig[0x67] =  0x69;
228 	mdev_state->vconfig[0x68] =  0x61;
229 	mdev_state->vconfig[0x69] =  0x6c;
230 	mdev_state->vconfig[0x6a] =  0x2f;
231 	mdev_state->vconfig[0x6b] =  0x55;
232 	mdev_state->vconfig[0x6c] =  0x41;
233 	mdev_state->vconfig[0x6d] =  0x52;
234 	mdev_state->vconfig[0x6e] =  0x54;
235 }
236 
237 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
238 				 u8 *buf, u32 count)
239 {
240 	u32 cfg_addr, bar_mask, bar_index = 0;
241 
242 	switch (offset) {
243 	case 0x04: /* device control */
244 	case 0x06: /* device status */
245 		/* do nothing */
246 		break;
247 	case 0x3c:  /* interrupt line */
248 		mdev_state->vconfig[0x3c] = buf[0];
249 		break;
250 	case 0x3d:
251 		/*
252 		 * Interrupt Pin is hardwired to INTA.
253 		 * This field is write protected by hardware
254 		 */
255 		break;
256 	case 0x10:  /* BAR0 */
257 	case 0x14:  /* BAR1 */
258 		if (offset == 0x10)
259 			bar_index = 0;
260 		else if (offset == 0x14)
261 			bar_index = 1;
262 
263 		if ((mdev_state->nr_ports == 1) && (bar_index == 1)) {
264 			STORE_LE32(&mdev_state->vconfig[offset], 0);
265 			break;
266 		}
267 
268 		cfg_addr = *(u32 *)buf;
269 		pr_info("BAR%d addr 0x%x\n", bar_index, cfg_addr);
270 
271 		if (cfg_addr == 0xffffffff) {
272 			bar_mask = mdev_state->bar_mask[bar_index];
273 			cfg_addr = (cfg_addr & bar_mask);
274 		}
275 
276 		cfg_addr |= (mdev_state->vconfig[offset] & 0x3ul);
277 		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
278 		break;
279 	case 0x18:  /* BAR2 */
280 	case 0x1c:  /* BAR3 */
281 	case 0x20:  /* BAR4 */
282 		STORE_LE32(&mdev_state->vconfig[offset], 0);
283 		break;
284 	default:
285 		pr_info("PCI config write @0x%x of %d bytes not handled\n",
286 			offset, count);
287 		break;
288 	}
289 }
290 
291 static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
292 				u16 offset, u8 *buf, u32 count)
293 {
294 	u8 data = *buf;
295 
296 	/* Handle data written by guest */
297 	switch (offset) {
298 	case UART_TX:
299 		/* if DLAB set, data is LSB of divisor */
300 		if (mdev_state->s[index].dlab) {
301 			mdev_state->s[index].divisor |= data;
302 			break;
303 		}
304 
305 		mutex_lock(&mdev_state->rxtx_lock);
306 
307 		/* save in TX buffer */
308 		if (mdev_state->s[index].rxtx.count <
309 				mdev_state->s[index].max_fifo_size) {
310 			mdev_state->s[index].rxtx.fifo[
311 					mdev_state->s[index].rxtx.head] = data;
312 			mdev_state->s[index].rxtx.count++;
313 			CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.head);
314 			mdev_state->s[index].overrun = false;
315 
316 			/*
317 			 * Trigger interrupt if receive data interrupt is
318 			 * enabled and fifo reached trigger level
319 			 */
320 			if ((mdev_state->s[index].uart_reg[UART_IER] &
321 						UART_IER_RDI) &&
322 			   (mdev_state->s[index].rxtx.count ==
323 				    mdev_state->s[index].intr_trigger_level)) {
324 				/* trigger interrupt */
325 #if defined(DEBUG_INTR)
326 				pr_err("Serial port %d: Fifo level trigger\n",
327 					index);
328 #endif
329 				mtty_trigger_interrupt(mdev_state);
330 			}
331 		} else {
332 #if defined(DEBUG_INTR)
333 			pr_err("Serial port %d: Buffer Overflow\n", index);
334 #endif
335 			mdev_state->s[index].overrun = true;
336 
337 			/*
338 			 * Trigger interrupt if receiver line status interrupt
339 			 * is enabled
340 			 */
341 			if (mdev_state->s[index].uart_reg[UART_IER] &
342 								UART_IER_RLSI)
343 				mtty_trigger_interrupt(mdev_state);
344 		}
345 		mutex_unlock(&mdev_state->rxtx_lock);
346 		break;
347 
348 	case UART_IER:
349 		/* if DLAB set, data is MSB of divisor */
350 		if (mdev_state->s[index].dlab)
351 			mdev_state->s[index].divisor |= (u16)data << 8;
352 		else {
353 			mdev_state->s[index].uart_reg[offset] = data;
354 			mutex_lock(&mdev_state->rxtx_lock);
355 			if ((data & UART_IER_THRI) &&
356 			    (mdev_state->s[index].rxtx.head ==
357 					mdev_state->s[index].rxtx.tail)) {
358 #if defined(DEBUG_INTR)
359 				pr_err("Serial port %d: IER_THRI write\n",
360 					index);
361 #endif
362 				mtty_trigger_interrupt(mdev_state);
363 			}
364 
365 			mutex_unlock(&mdev_state->rxtx_lock);
366 		}
367 
368 		break;
369 
370 	case UART_FCR:
371 		mdev_state->s[index].fcr = data;
372 
373 		mutex_lock(&mdev_state->rxtx_lock);
374 		if (data & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)) {
375 			/* clear loop back FIFO */
376 			mdev_state->s[index].rxtx.count = 0;
377 			mdev_state->s[index].rxtx.head = 0;
378 			mdev_state->s[index].rxtx.tail = 0;
379 		}
380 		mutex_unlock(&mdev_state->rxtx_lock);
381 
382 		switch (data & UART_FCR_TRIGGER_MASK) {
383 		case UART_FCR_TRIGGER_1:
384 			mdev_state->s[index].intr_trigger_level = 1;
385 			break;
386 
387 		case UART_FCR_TRIGGER_4:
388 			mdev_state->s[index].intr_trigger_level = 4;
389 			break;
390 
391 		case UART_FCR_TRIGGER_8:
392 			mdev_state->s[index].intr_trigger_level = 8;
393 			break;
394 
395 		case UART_FCR_TRIGGER_14:
396 			mdev_state->s[index].intr_trigger_level = 14;
397 			break;
398 		}
399 
400 		/*
401 		 * Set trigger level to 1 otherwise or  implement timer with
402 		 * timeout of 4 characters and on expiring that timer set
403 		 * Recevice data timeout in IIR register
404 		 */
405 		mdev_state->s[index].intr_trigger_level = 1;
406 		if (data & UART_FCR_ENABLE_FIFO)
407 			mdev_state->s[index].max_fifo_size = MAX_FIFO_SIZE;
408 		else {
409 			mdev_state->s[index].max_fifo_size = 1;
410 			mdev_state->s[index].intr_trigger_level = 1;
411 		}
412 
413 		break;
414 
415 	case UART_LCR:
416 		if (data & UART_LCR_DLAB) {
417 			mdev_state->s[index].dlab = true;
418 			mdev_state->s[index].divisor = 0;
419 		} else
420 			mdev_state->s[index].dlab = false;
421 
422 		mdev_state->s[index].uart_reg[offset] = data;
423 		break;
424 
425 	case UART_MCR:
426 		mdev_state->s[index].uart_reg[offset] = data;
427 
428 		if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
429 				(data & UART_MCR_OUT2)) {
430 #if defined(DEBUG_INTR)
431 			pr_err("Serial port %d: MCR_OUT2 write\n", index);
432 #endif
433 			mtty_trigger_interrupt(mdev_state);
434 		}
435 
436 		if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
437 				(data & (UART_MCR_RTS | UART_MCR_DTR))) {
438 #if defined(DEBUG_INTR)
439 			pr_err("Serial port %d: MCR RTS/DTR write\n", index);
440 #endif
441 			mtty_trigger_interrupt(mdev_state);
442 		}
443 		break;
444 
445 	case UART_LSR:
446 	case UART_MSR:
447 		/* do nothing */
448 		break;
449 
450 	case UART_SCR:
451 		mdev_state->s[index].uart_reg[offset] = data;
452 		break;
453 
454 	default:
455 		break;
456 	}
457 }
458 
459 static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
460 			    u16 offset, u8 *buf, u32 count)
461 {
462 	/* Handle read requests by guest */
463 	switch (offset) {
464 	case UART_RX:
465 		/* if DLAB set, data is LSB of divisor */
466 		if (mdev_state->s[index].dlab) {
467 			*buf  = (u8)mdev_state->s[index].divisor;
468 			break;
469 		}
470 
471 		mutex_lock(&mdev_state->rxtx_lock);
472 		/* return data in tx buffer */
473 		if (mdev_state->s[index].rxtx.head !=
474 				 mdev_state->s[index].rxtx.tail) {
475 			*buf = mdev_state->s[index].rxtx.fifo[
476 						mdev_state->s[index].rxtx.tail];
477 			mdev_state->s[index].rxtx.count--;
478 			CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.tail);
479 		}
480 
481 		if (mdev_state->s[index].rxtx.head ==
482 				mdev_state->s[index].rxtx.tail) {
483 		/*
484 		 *  Trigger interrupt if tx buffer empty interrupt is
485 		 *  enabled and fifo is empty
486 		 */
487 #if defined(DEBUG_INTR)
488 			pr_err("Serial port %d: Buffer Empty\n", index);
489 #endif
490 			if (mdev_state->s[index].uart_reg[UART_IER] &
491 							 UART_IER_THRI)
492 				mtty_trigger_interrupt(mdev_state);
493 		}
494 		mutex_unlock(&mdev_state->rxtx_lock);
495 
496 		break;
497 
498 	case UART_IER:
499 		if (mdev_state->s[index].dlab) {
500 			*buf = (u8)(mdev_state->s[index].divisor >> 8);
501 			break;
502 		}
503 		*buf = mdev_state->s[index].uart_reg[offset] & 0x0f;
504 		break;
505 
506 	case UART_IIR:
507 	{
508 		u8 ier = mdev_state->s[index].uart_reg[UART_IER];
509 		*buf = 0;
510 
511 		mutex_lock(&mdev_state->rxtx_lock);
512 		/* Interrupt priority 1: Parity, overrun, framing or break */
513 		if ((ier & UART_IER_RLSI) && mdev_state->s[index].overrun)
514 			*buf |= UART_IIR_RLSI;
515 
516 		/* Interrupt priority 2: Fifo trigger level reached */
517 		if ((ier & UART_IER_RDI) &&
518 		    (mdev_state->s[index].rxtx.count >=
519 		      mdev_state->s[index].intr_trigger_level))
520 			*buf |= UART_IIR_RDI;
521 
522 		/* Interrupt priotiry 3: transmitter holding register empty */
523 		if ((ier & UART_IER_THRI) &&
524 		    (mdev_state->s[index].rxtx.head ==
525 				mdev_state->s[index].rxtx.tail))
526 			*buf |= UART_IIR_THRI;
527 
528 		/* Interrupt priotiry 4: Modem status: CTS, DSR, RI or DCD  */
529 		if ((ier & UART_IER_MSI) &&
530 		    (mdev_state->s[index].uart_reg[UART_MCR] &
531 				 (UART_MCR_RTS | UART_MCR_DTR)))
532 			*buf |= UART_IIR_MSI;
533 
534 		/* bit0: 0=> interrupt pending, 1=> no interrupt is pending */
535 		if (*buf == 0)
536 			*buf = UART_IIR_NO_INT;
537 
538 		/* set bit 6 & 7 to be 16550 compatible */
539 		*buf |= 0xC0;
540 		mutex_unlock(&mdev_state->rxtx_lock);
541 	}
542 	break;
543 
544 	case UART_LCR:
545 	case UART_MCR:
546 		*buf = mdev_state->s[index].uart_reg[offset];
547 		break;
548 
549 	case UART_LSR:
550 	{
551 		u8 lsr = 0;
552 
553 		mutex_lock(&mdev_state->rxtx_lock);
554 		/* atleast one char in FIFO */
555 		if (mdev_state->s[index].rxtx.head !=
556 				 mdev_state->s[index].rxtx.tail)
557 			lsr |= UART_LSR_DR;
558 
559 		/* if FIFO overrun */
560 		if (mdev_state->s[index].overrun)
561 			lsr |= UART_LSR_OE;
562 
563 		/* transmit FIFO empty and tramsitter empty */
564 		if (mdev_state->s[index].rxtx.head ==
565 				 mdev_state->s[index].rxtx.tail)
566 			lsr |= UART_LSR_TEMT | UART_LSR_THRE;
567 
568 		mutex_unlock(&mdev_state->rxtx_lock);
569 		*buf = lsr;
570 		break;
571 	}
572 	case UART_MSR:
573 		*buf = UART_MSR_DSR | UART_MSR_DDSR | UART_MSR_DCD;
574 
575 		mutex_lock(&mdev_state->rxtx_lock);
576 		/* if AFE is 1 and FIFO have space, set CTS bit */
577 		if (mdev_state->s[index].uart_reg[UART_MCR] &
578 						 UART_MCR_AFE) {
579 			if (mdev_state->s[index].rxtx.count <
580 					mdev_state->s[index].max_fifo_size)
581 				*buf |= UART_MSR_CTS | UART_MSR_DCTS;
582 		} else
583 			*buf |= UART_MSR_CTS | UART_MSR_DCTS;
584 		mutex_unlock(&mdev_state->rxtx_lock);
585 
586 		break;
587 
588 	case UART_SCR:
589 		*buf = mdev_state->s[index].uart_reg[offset];
590 		break;
591 
592 	default:
593 		break;
594 	}
595 }
596 
597 static void mdev_read_base(struct mdev_state *mdev_state)
598 {
599 	int index, pos;
600 	u32 start_lo, start_hi;
601 	u32 mem_type;
602 
603 	pos = PCI_BASE_ADDRESS_0;
604 
605 	for (index = 0; index <= VFIO_PCI_BAR5_REGION_INDEX; index++) {
606 
607 		if (!mdev_state->region_info[index].size)
608 			continue;
609 
610 		start_lo = (*(u32 *)(mdev_state->vconfig + pos)) &
611 			PCI_BASE_ADDRESS_MEM_MASK;
612 		mem_type = (*(u32 *)(mdev_state->vconfig + pos)) &
613 			PCI_BASE_ADDRESS_MEM_TYPE_MASK;
614 
615 		switch (mem_type) {
616 		case PCI_BASE_ADDRESS_MEM_TYPE_64:
617 			start_hi = (*(u32 *)(mdev_state->vconfig + pos + 4));
618 			pos += 4;
619 			break;
620 		case PCI_BASE_ADDRESS_MEM_TYPE_32:
621 		case PCI_BASE_ADDRESS_MEM_TYPE_1M:
622 			/* 1M mem BAR treated as 32-bit BAR */
623 		default:
624 			/* mem unknown type treated as 32-bit BAR */
625 			start_hi = 0;
626 			break;
627 		}
628 		pos += 4;
629 		mdev_state->region_info[index].start = ((u64)start_hi << 32) |
630 							start_lo;
631 	}
632 }
633 
634 static ssize_t mdev_access(struct mdev_device *mdev, u8 *buf, size_t count,
635 			   loff_t pos, bool is_write)
636 {
637 	struct mdev_state *mdev_state;
638 	unsigned int index;
639 	loff_t offset;
640 	int ret = 0;
641 
642 	if (!mdev || !buf)
643 		return -EINVAL;
644 
645 	mdev_state = mdev_get_drvdata(mdev);
646 	if (!mdev_state) {
647 		pr_err("%s mdev_state not found\n", __func__);
648 		return -EINVAL;
649 	}
650 
651 	mutex_lock(&mdev_state->ops_lock);
652 
653 	index = MTTY_VFIO_PCI_OFFSET_TO_INDEX(pos);
654 	offset = pos & MTTY_VFIO_PCI_OFFSET_MASK;
655 	switch (index) {
656 	case VFIO_PCI_CONFIG_REGION_INDEX:
657 
658 #if defined(DEBUG)
659 		pr_info("%s: PCI config space %s at offset 0x%llx\n",
660 			 __func__, is_write ? "write" : "read", offset);
661 #endif
662 		if (is_write) {
663 			dump_buffer(buf, count);
664 			handle_pci_cfg_write(mdev_state, offset, buf, count);
665 		} else {
666 			memcpy(buf, (mdev_state->vconfig + offset), count);
667 			dump_buffer(buf, count);
668 		}
669 
670 		break;
671 
672 	case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
673 		if (!mdev_state->region_info[index].start)
674 			mdev_read_base(mdev_state);
675 
676 		if (is_write) {
677 			dump_buffer(buf, count);
678 
679 #if defined(DEBUG_REGS)
680 			pr_info("%s: BAR%d  WR @0x%llx %s val:0x%02x dlab:%d\n",
681 				__func__, index, offset, wr_reg[offset],
682 				*buf, mdev_state->s[index].dlab);
683 #endif
684 			handle_bar_write(index, mdev_state, offset, buf, count);
685 		} else {
686 			handle_bar_read(index, mdev_state, offset, buf, count);
687 			dump_buffer(buf, count);
688 
689 #if defined(DEBUG_REGS)
690 			pr_info("%s: BAR%d  RD @0x%llx %s val:0x%02x dlab:%d\n",
691 				__func__, index, offset, rd_reg[offset],
692 				*buf, mdev_state->s[index].dlab);
693 #endif
694 		}
695 		break;
696 
697 	default:
698 		ret = -1;
699 		goto accessfailed;
700 	}
701 
702 	ret = count;
703 
704 
705 accessfailed:
706 	mutex_unlock(&mdev_state->ops_lock);
707 
708 	return ret;
709 }
710 
711 static int mtty_create(struct mdev_device *mdev)
712 {
713 	struct mdev_state *mdev_state;
714 	int nr_ports = mdev_get_type_group_id(mdev) + 1;
715 
716 	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
717 	if (mdev_state == NULL)
718 		return -ENOMEM;
719 
720 	mdev_state->nr_ports = nr_ports;
721 	mdev_state->irq_index = -1;
722 	mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE;
723 	mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE;
724 	mutex_init(&mdev_state->rxtx_lock);
725 	mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL);
726 
727 	if (mdev_state->vconfig == NULL) {
728 		kfree(mdev_state);
729 		return -ENOMEM;
730 	}
731 
732 	mutex_init(&mdev_state->ops_lock);
733 	mdev_state->mdev = mdev;
734 	mdev_set_drvdata(mdev, mdev_state);
735 
736 	mtty_create_config_space(mdev_state);
737 
738 	mutex_lock(&mdev_list_lock);
739 	list_add(&mdev_state->next, &mdev_devices_list);
740 	mutex_unlock(&mdev_list_lock);
741 
742 	return 0;
743 }
744 
745 static int mtty_remove(struct mdev_device *mdev)
746 {
747 	struct mdev_state *mds, *tmp_mds;
748 	struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
749 	int ret = -EINVAL;
750 
751 	mutex_lock(&mdev_list_lock);
752 	list_for_each_entry_safe(mds, tmp_mds, &mdev_devices_list, next) {
753 		if (mdev_state == mds) {
754 			list_del(&mdev_state->next);
755 			mdev_set_drvdata(mdev, NULL);
756 			kfree(mdev_state->vconfig);
757 			kfree(mdev_state);
758 			ret = 0;
759 			break;
760 		}
761 	}
762 	mutex_unlock(&mdev_list_lock);
763 
764 	return ret;
765 }
766 
767 static int mtty_reset(struct mdev_device *mdev)
768 {
769 	struct mdev_state *mdev_state;
770 
771 	if (!mdev)
772 		return -EINVAL;
773 
774 	mdev_state = mdev_get_drvdata(mdev);
775 	if (!mdev_state)
776 		return -EINVAL;
777 
778 	pr_info("%s: called\n", __func__);
779 
780 	return 0;
781 }
782 
783 static ssize_t mtty_read(struct mdev_device *mdev, char __user *buf,
784 			 size_t count, loff_t *ppos)
785 {
786 	unsigned int done = 0;
787 	int ret;
788 
789 	while (count) {
790 		size_t filled;
791 
792 		if (count >= 4 && !(*ppos % 4)) {
793 			u32 val;
794 
795 			ret =  mdev_access(mdev, (u8 *)&val, sizeof(val),
796 					   *ppos, false);
797 			if (ret <= 0)
798 				goto read_err;
799 
800 			if (copy_to_user(buf, &val, sizeof(val)))
801 				goto read_err;
802 
803 			filled = 4;
804 		} else if (count >= 2 && !(*ppos % 2)) {
805 			u16 val;
806 
807 			ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
808 					  *ppos, false);
809 			if (ret <= 0)
810 				goto read_err;
811 
812 			if (copy_to_user(buf, &val, sizeof(val)))
813 				goto read_err;
814 
815 			filled = 2;
816 		} else {
817 			u8 val;
818 
819 			ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
820 					  *ppos, false);
821 			if (ret <= 0)
822 				goto read_err;
823 
824 			if (copy_to_user(buf, &val, sizeof(val)))
825 				goto read_err;
826 
827 			filled = 1;
828 		}
829 
830 		count -= filled;
831 		done += filled;
832 		*ppos += filled;
833 		buf += filled;
834 	}
835 
836 	return done;
837 
838 read_err:
839 	return -EFAULT;
840 }
841 
842 static ssize_t mtty_write(struct mdev_device *mdev, const char __user *buf,
843 		   size_t count, loff_t *ppos)
844 {
845 	unsigned int done = 0;
846 	int ret;
847 
848 	while (count) {
849 		size_t filled;
850 
851 		if (count >= 4 && !(*ppos % 4)) {
852 			u32 val;
853 
854 			if (copy_from_user(&val, buf, sizeof(val)))
855 				goto write_err;
856 
857 			ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
858 					  *ppos, true);
859 			if (ret <= 0)
860 				goto write_err;
861 
862 			filled = 4;
863 		} else if (count >= 2 && !(*ppos % 2)) {
864 			u16 val;
865 
866 			if (copy_from_user(&val, buf, sizeof(val)))
867 				goto write_err;
868 
869 			ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
870 					  *ppos, true);
871 			if (ret <= 0)
872 				goto write_err;
873 
874 			filled = 2;
875 		} else {
876 			u8 val;
877 
878 			if (copy_from_user(&val, buf, sizeof(val)))
879 				goto write_err;
880 
881 			ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
882 					  *ppos, true);
883 			if (ret <= 0)
884 				goto write_err;
885 
886 			filled = 1;
887 		}
888 		count -= filled;
889 		done += filled;
890 		*ppos += filled;
891 		buf += filled;
892 	}
893 
894 	return done;
895 write_err:
896 	return -EFAULT;
897 }
898 
899 static int mtty_set_irqs(struct mdev_device *mdev, uint32_t flags,
900 			 unsigned int index, unsigned int start,
901 			 unsigned int count, void *data)
902 {
903 	int ret = 0;
904 	struct mdev_state *mdev_state;
905 
906 	if (!mdev)
907 		return -EINVAL;
908 
909 	mdev_state = mdev_get_drvdata(mdev);
910 	if (!mdev_state)
911 		return -EINVAL;
912 
913 	mutex_lock(&mdev_state->ops_lock);
914 	switch (index) {
915 	case VFIO_PCI_INTX_IRQ_INDEX:
916 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
917 		case VFIO_IRQ_SET_ACTION_MASK:
918 		case VFIO_IRQ_SET_ACTION_UNMASK:
919 			break;
920 		case VFIO_IRQ_SET_ACTION_TRIGGER:
921 		{
922 			if (flags & VFIO_IRQ_SET_DATA_NONE) {
923 				pr_info("%s: disable INTx\n", __func__);
924 				if (mdev_state->intx_evtfd)
925 					eventfd_ctx_put(mdev_state->intx_evtfd);
926 				break;
927 			}
928 
929 			if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
930 				int fd = *(int *)data;
931 
932 				if (fd > 0) {
933 					struct eventfd_ctx *evt;
934 
935 					evt = eventfd_ctx_fdget(fd);
936 					if (IS_ERR(evt)) {
937 						ret = PTR_ERR(evt);
938 						break;
939 					}
940 					mdev_state->intx_evtfd = evt;
941 					mdev_state->irq_fd = fd;
942 					mdev_state->irq_index = index;
943 					break;
944 				}
945 			}
946 			break;
947 		}
948 		}
949 		break;
950 	case VFIO_PCI_MSI_IRQ_INDEX:
951 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
952 		case VFIO_IRQ_SET_ACTION_MASK:
953 		case VFIO_IRQ_SET_ACTION_UNMASK:
954 			break;
955 		case VFIO_IRQ_SET_ACTION_TRIGGER:
956 			if (flags & VFIO_IRQ_SET_DATA_NONE) {
957 				if (mdev_state->msi_evtfd)
958 					eventfd_ctx_put(mdev_state->msi_evtfd);
959 				pr_info("%s: disable MSI\n", __func__);
960 				mdev_state->irq_index = VFIO_PCI_INTX_IRQ_INDEX;
961 				break;
962 			}
963 			if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
964 				int fd = *(int *)data;
965 				struct eventfd_ctx *evt;
966 
967 				if (fd <= 0)
968 					break;
969 
970 				if (mdev_state->msi_evtfd)
971 					break;
972 
973 				evt = eventfd_ctx_fdget(fd);
974 				if (IS_ERR(evt)) {
975 					ret = PTR_ERR(evt);
976 					break;
977 				}
978 				mdev_state->msi_evtfd = evt;
979 				mdev_state->irq_fd = fd;
980 				mdev_state->irq_index = index;
981 			}
982 			break;
983 	}
984 	break;
985 	case VFIO_PCI_MSIX_IRQ_INDEX:
986 		pr_info("%s: MSIX_IRQ\n", __func__);
987 		break;
988 	case VFIO_PCI_ERR_IRQ_INDEX:
989 		pr_info("%s: ERR_IRQ\n", __func__);
990 		break;
991 	case VFIO_PCI_REQ_IRQ_INDEX:
992 		pr_info("%s: REQ_IRQ\n", __func__);
993 		break;
994 	}
995 
996 	mutex_unlock(&mdev_state->ops_lock);
997 	return ret;
998 }
999 
1000 static int mtty_trigger_interrupt(struct mdev_state *mdev_state)
1001 {
1002 	int ret = -1;
1003 
1004 	if ((mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX) &&
1005 	    (!mdev_state->msi_evtfd))
1006 		return -EINVAL;
1007 	else if ((mdev_state->irq_index == VFIO_PCI_INTX_IRQ_INDEX) &&
1008 		 (!mdev_state->intx_evtfd)) {
1009 		pr_info("%s: Intr eventfd not found\n", __func__);
1010 		return -EINVAL;
1011 	}
1012 
1013 	if (mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX)
1014 		ret = eventfd_signal(mdev_state->msi_evtfd, 1);
1015 	else
1016 		ret = eventfd_signal(mdev_state->intx_evtfd, 1);
1017 
1018 #if defined(DEBUG_INTR)
1019 	pr_info("Intx triggered\n");
1020 #endif
1021 	if (ret != 1)
1022 		pr_err("%s: eventfd signal failed (%d)\n", __func__, ret);
1023 
1024 	return ret;
1025 }
1026 
1027 static int mtty_get_region_info(struct mdev_device *mdev,
1028 			 struct vfio_region_info *region_info,
1029 			 u16 *cap_type_id, void **cap_type)
1030 {
1031 	unsigned int size = 0;
1032 	struct mdev_state *mdev_state;
1033 	u32 bar_index;
1034 
1035 	if (!mdev)
1036 		return -EINVAL;
1037 
1038 	mdev_state = mdev_get_drvdata(mdev);
1039 	if (!mdev_state)
1040 		return -EINVAL;
1041 
1042 	bar_index = region_info->index;
1043 	if (bar_index >= VFIO_PCI_NUM_REGIONS)
1044 		return -EINVAL;
1045 
1046 	mutex_lock(&mdev_state->ops_lock);
1047 
1048 	switch (bar_index) {
1049 	case VFIO_PCI_CONFIG_REGION_INDEX:
1050 		size = MTTY_CONFIG_SPACE_SIZE;
1051 		break;
1052 	case VFIO_PCI_BAR0_REGION_INDEX:
1053 		size = MTTY_IO_BAR_SIZE;
1054 		break;
1055 	case VFIO_PCI_BAR1_REGION_INDEX:
1056 		if (mdev_state->nr_ports == 2)
1057 			size = MTTY_IO_BAR_SIZE;
1058 		break;
1059 	default:
1060 		size = 0;
1061 		break;
1062 	}
1063 
1064 	mdev_state->region_info[bar_index].size = size;
1065 	mdev_state->region_info[bar_index].vfio_offset =
1066 		MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
1067 
1068 	region_info->size = size;
1069 	region_info->offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
1070 	region_info->flags = VFIO_REGION_INFO_FLAG_READ |
1071 		VFIO_REGION_INFO_FLAG_WRITE;
1072 	mutex_unlock(&mdev_state->ops_lock);
1073 	return 0;
1074 }
1075 
1076 static int mtty_get_irq_info(struct mdev_device *mdev,
1077 			     struct vfio_irq_info *irq_info)
1078 {
1079 	switch (irq_info->index) {
1080 	case VFIO_PCI_INTX_IRQ_INDEX:
1081 	case VFIO_PCI_MSI_IRQ_INDEX:
1082 	case VFIO_PCI_REQ_IRQ_INDEX:
1083 		break;
1084 
1085 	default:
1086 		return -EINVAL;
1087 	}
1088 
1089 	irq_info->flags = VFIO_IRQ_INFO_EVENTFD;
1090 	irq_info->count = 1;
1091 
1092 	if (irq_info->index == VFIO_PCI_INTX_IRQ_INDEX)
1093 		irq_info->flags |= (VFIO_IRQ_INFO_MASKABLE |
1094 				VFIO_IRQ_INFO_AUTOMASKED);
1095 	else
1096 		irq_info->flags |= VFIO_IRQ_INFO_NORESIZE;
1097 
1098 	return 0;
1099 }
1100 
1101 static int mtty_get_device_info(struct mdev_device *mdev,
1102 			 struct vfio_device_info *dev_info)
1103 {
1104 	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1105 	dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
1106 	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1107 
1108 	return 0;
1109 }
1110 
1111 static long mtty_ioctl(struct mdev_device *mdev, unsigned int cmd,
1112 			unsigned long arg)
1113 {
1114 	int ret = 0;
1115 	unsigned long minsz;
1116 	struct mdev_state *mdev_state;
1117 
1118 	if (!mdev)
1119 		return -EINVAL;
1120 
1121 	mdev_state = mdev_get_drvdata(mdev);
1122 	if (!mdev_state)
1123 		return -ENODEV;
1124 
1125 	switch (cmd) {
1126 	case VFIO_DEVICE_GET_INFO:
1127 	{
1128 		struct vfio_device_info info;
1129 
1130 		minsz = offsetofend(struct vfio_device_info, num_irqs);
1131 
1132 		if (copy_from_user(&info, (void __user *)arg, minsz))
1133 			return -EFAULT;
1134 
1135 		if (info.argsz < minsz)
1136 			return -EINVAL;
1137 
1138 		ret = mtty_get_device_info(mdev, &info);
1139 		if (ret)
1140 			return ret;
1141 
1142 		memcpy(&mdev_state->dev_info, &info, sizeof(info));
1143 
1144 		if (copy_to_user((void __user *)arg, &info, minsz))
1145 			return -EFAULT;
1146 
1147 		return 0;
1148 	}
1149 	case VFIO_DEVICE_GET_REGION_INFO:
1150 	{
1151 		struct vfio_region_info info;
1152 		u16 cap_type_id = 0;
1153 		void *cap_type = NULL;
1154 
1155 		minsz = offsetofend(struct vfio_region_info, offset);
1156 
1157 		if (copy_from_user(&info, (void __user *)arg, minsz))
1158 			return -EFAULT;
1159 
1160 		if (info.argsz < minsz)
1161 			return -EINVAL;
1162 
1163 		ret = mtty_get_region_info(mdev, &info, &cap_type_id,
1164 					   &cap_type);
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 
1174 	case VFIO_DEVICE_GET_IRQ_INFO:
1175 	{
1176 		struct vfio_irq_info info;
1177 
1178 		minsz = offsetofend(struct vfio_irq_info, count);
1179 
1180 		if (copy_from_user(&info, (void __user *)arg, minsz))
1181 			return -EFAULT;
1182 
1183 		if ((info.argsz < minsz) ||
1184 		    (info.index >= mdev_state->dev_info.num_irqs))
1185 			return -EINVAL;
1186 
1187 		ret = mtty_get_irq_info(mdev, &info);
1188 		if (ret)
1189 			return ret;
1190 
1191 		if (copy_to_user((void __user *)arg, &info, minsz))
1192 			return -EFAULT;
1193 
1194 		return 0;
1195 	}
1196 	case VFIO_DEVICE_SET_IRQS:
1197 	{
1198 		struct vfio_irq_set hdr;
1199 		u8 *data = NULL, *ptr = NULL;
1200 		size_t data_size = 0;
1201 
1202 		minsz = offsetofend(struct vfio_irq_set, count);
1203 
1204 		if (copy_from_user(&hdr, (void __user *)arg, minsz))
1205 			return -EFAULT;
1206 
1207 		ret = vfio_set_irqs_validate_and_prepare(&hdr,
1208 						mdev_state->dev_info.num_irqs,
1209 						VFIO_PCI_NUM_IRQS,
1210 						&data_size);
1211 		if (ret)
1212 			return ret;
1213 
1214 		if (data_size) {
1215 			ptr = data = memdup_user((void __user *)(arg + minsz),
1216 						 data_size);
1217 			if (IS_ERR(data))
1218 				return PTR_ERR(data);
1219 		}
1220 
1221 		ret = mtty_set_irqs(mdev, hdr.flags, hdr.index, hdr.start,
1222 				    hdr.count, data);
1223 
1224 		kfree(ptr);
1225 		return ret;
1226 	}
1227 	case VFIO_DEVICE_RESET:
1228 		return mtty_reset(mdev);
1229 	}
1230 	return -ENOTTY;
1231 }
1232 
1233 static int mtty_open(struct mdev_device *mdev)
1234 {
1235 	pr_info("%s\n", __func__);
1236 	return 0;
1237 }
1238 
1239 static void mtty_close(struct mdev_device *mdev)
1240 {
1241 	pr_info("%s\n", __func__);
1242 }
1243 
1244 static ssize_t
1245 sample_mtty_dev_show(struct device *dev, struct device_attribute *attr,
1246 		     char *buf)
1247 {
1248 	return sprintf(buf, "This is phy device\n");
1249 }
1250 
1251 static DEVICE_ATTR_RO(sample_mtty_dev);
1252 
1253 static struct attribute *mtty_dev_attrs[] = {
1254 	&dev_attr_sample_mtty_dev.attr,
1255 	NULL,
1256 };
1257 
1258 static const struct attribute_group mtty_dev_group = {
1259 	.name  = "mtty_dev",
1260 	.attrs = mtty_dev_attrs,
1261 };
1262 
1263 static const struct attribute_group *mtty_dev_groups[] = {
1264 	&mtty_dev_group,
1265 	NULL,
1266 };
1267 
1268 static ssize_t
1269 sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
1270 		     char *buf)
1271 {
1272 	if (mdev_from_dev(dev))
1273 		return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
1274 
1275 	return sprintf(buf, "\n");
1276 }
1277 
1278 static DEVICE_ATTR_RO(sample_mdev_dev);
1279 
1280 static struct attribute *mdev_dev_attrs[] = {
1281 	&dev_attr_sample_mdev_dev.attr,
1282 	NULL,
1283 };
1284 
1285 static const struct attribute_group mdev_dev_group = {
1286 	.name  = "vendor",
1287 	.attrs = mdev_dev_attrs,
1288 };
1289 
1290 static const struct attribute_group *mdev_dev_groups[] = {
1291 	&mdev_dev_group,
1292 	NULL,
1293 };
1294 
1295 static ssize_t name_show(struct mdev_type *mtype,
1296 			 struct mdev_type_attribute *attr, char *buf)
1297 {
1298 	static const char *name_str[2] = { "Single port serial",
1299 					   "Dual port serial" };
1300 
1301 	return sysfs_emit(buf, "%s\n",
1302 			  name_str[mtype_get_type_group_id(mtype)]);
1303 }
1304 
1305 static MDEV_TYPE_ATTR_RO(name);
1306 
1307 static ssize_t available_instances_show(struct mdev_type *mtype,
1308 					struct mdev_type_attribute *attr,
1309 					char *buf)
1310 {
1311 	struct mdev_state *mds;
1312 	unsigned int ports = mtype_get_type_group_id(mtype) + 1;
1313 	int used = 0;
1314 
1315 	list_for_each_entry(mds, &mdev_devices_list, next)
1316 		used += mds->nr_ports;
1317 
1318 	return sprintf(buf, "%d\n", (MAX_MTTYS - used)/ports);
1319 }
1320 
1321 static MDEV_TYPE_ATTR_RO(available_instances);
1322 
1323 static ssize_t device_api_show(struct mdev_type *mtype,
1324 			       struct mdev_type_attribute *attr, char *buf)
1325 {
1326 	return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
1327 }
1328 
1329 static MDEV_TYPE_ATTR_RO(device_api);
1330 
1331 static struct attribute *mdev_types_attrs[] = {
1332 	&mdev_type_attr_name.attr,
1333 	&mdev_type_attr_device_api.attr,
1334 	&mdev_type_attr_available_instances.attr,
1335 	NULL,
1336 };
1337 
1338 static struct attribute_group mdev_type_group1 = {
1339 	.name  = "1",
1340 	.attrs = mdev_types_attrs,
1341 };
1342 
1343 static struct attribute_group mdev_type_group2 = {
1344 	.name  = "2",
1345 	.attrs = mdev_types_attrs,
1346 };
1347 
1348 static struct attribute_group *mdev_type_groups[] = {
1349 	&mdev_type_group1,
1350 	&mdev_type_group2,
1351 	NULL,
1352 };
1353 
1354 static const struct mdev_parent_ops mdev_fops = {
1355 	.owner                  = THIS_MODULE,
1356 	.dev_attr_groups        = mtty_dev_groups,
1357 	.mdev_attr_groups       = mdev_dev_groups,
1358 	.supported_type_groups  = mdev_type_groups,
1359 	.create                 = mtty_create,
1360 	.remove			= mtty_remove,
1361 	.open                   = mtty_open,
1362 	.release                = mtty_close,
1363 	.read                   = mtty_read,
1364 	.write                  = mtty_write,
1365 	.ioctl		        = mtty_ioctl,
1366 };
1367 
1368 static void mtty_device_release(struct device *dev)
1369 {
1370 	dev_dbg(dev, "mtty: released\n");
1371 }
1372 
1373 static int __init mtty_dev_init(void)
1374 {
1375 	int ret = 0;
1376 
1377 	pr_info("mtty_dev: %s\n", __func__);
1378 
1379 	memset(&mtty_dev, 0, sizeof(mtty_dev));
1380 
1381 	idr_init(&mtty_dev.vd_idr);
1382 
1383 	ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK + 1,
1384 				  MTTY_NAME);
1385 
1386 	if (ret < 0) {
1387 		pr_err("Error: failed to register mtty_dev, err:%d\n", ret);
1388 		return ret;
1389 	}
1390 
1391 	cdev_init(&mtty_dev.vd_cdev, &vd_fops);
1392 	cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK + 1);
1393 
1394 	pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt));
1395 
1396 	mtty_dev.vd_class = class_create(THIS_MODULE, MTTY_CLASS_NAME);
1397 
1398 	if (IS_ERR(mtty_dev.vd_class)) {
1399 		pr_err("Error: failed to register mtty_dev class\n");
1400 		ret = PTR_ERR(mtty_dev.vd_class);
1401 		goto failed1;
1402 	}
1403 
1404 	mtty_dev.dev.class = mtty_dev.vd_class;
1405 	mtty_dev.dev.release = mtty_device_release;
1406 	dev_set_name(&mtty_dev.dev, "%s", MTTY_NAME);
1407 
1408 	ret = device_register(&mtty_dev.dev);
1409 	if (ret)
1410 		goto failed2;
1411 
1412 	ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
1413 	if (ret)
1414 		goto failed3;
1415 
1416 	mutex_init(&mdev_list_lock);
1417 	INIT_LIST_HEAD(&mdev_devices_list);
1418 
1419 	goto all_done;
1420 
1421 failed3:
1422 
1423 	device_unregister(&mtty_dev.dev);
1424 failed2:
1425 	class_destroy(mtty_dev.vd_class);
1426 
1427 failed1:
1428 	cdev_del(&mtty_dev.vd_cdev);
1429 	unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
1430 
1431 all_done:
1432 	return ret;
1433 }
1434 
1435 static void __exit mtty_dev_exit(void)
1436 {
1437 	mtty_dev.dev.bus = NULL;
1438 	mdev_unregister_device(&mtty_dev.dev);
1439 
1440 	device_unregister(&mtty_dev.dev);
1441 	idr_destroy(&mtty_dev.vd_idr);
1442 	cdev_del(&mtty_dev.vd_cdev);
1443 	unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
1444 	class_destroy(mtty_dev.vd_class);
1445 	mtty_dev.vd_class = NULL;
1446 	pr_info("mtty_dev: Unloaded!\n");
1447 }
1448 
1449 module_init(mtty_dev_init)
1450 module_exit(mtty_dev_exit)
1451 
1452 MODULE_LICENSE("GPL v2");
1453 MODULE_INFO(supported, "Test driver that simulate serial port over PCI");
1454 MODULE_VERSION(VERSION_STRING);
1455 MODULE_AUTHOR(DRIVER_AUTHOR);
1456