xref: /openbmc/linux/samples/vfio-mdev/mtty.c (revision 9aa2cba7)
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/kernel.h>
16 #include <linux/fs.h>
17 #include <linux/poll.h>
18 #include <linux/slab.h>
19 #include <linux/cdev.h>
20 #include <linux/sched.h>
21 #include <linux/wait.h>
22 #include <linux/vfio.h>
23 #include <linux/iommu.h>
24 #include <linux/sysfs.h>
25 #include <linux/ctype.h>
26 #include <linux/file.h>
27 #include <linux/mdev.h>
28 #include <linux/pci.h>
29 #include <linux/serial.h>
30 #include <uapi/linux/serial_reg.h>
31 #include <linux/eventfd.h>
32 /*
33  * #defines
34  */
35 
36 #define VERSION_STRING  "0.1"
37 #define DRIVER_AUTHOR   "NVIDIA Corporation"
38 
39 #define MTTY_CLASS_NAME "mtty"
40 
41 #define MTTY_NAME       "mtty"
42 
43 #define MTTY_STRING_LEN		16
44 
45 #define MTTY_CONFIG_SPACE_SIZE  0xff
46 #define MTTY_IO_BAR_SIZE        0x8
47 #define MTTY_MMIO_BAR_SIZE      0x100000
48 
49 #define STORE_LE16(addr, val)   (*(u16 *)addr = val)
50 #define STORE_LE32(addr, val)   (*(u32 *)addr = val)
51 
52 #define MAX_FIFO_SIZE   16
53 
54 #define CIRCULAR_BUF_INC_IDX(idx)    (idx = (idx + 1) & (MAX_FIFO_SIZE - 1))
55 
56 #define MTTY_VFIO_PCI_OFFSET_SHIFT   40
57 
58 #define MTTY_VFIO_PCI_OFFSET_TO_INDEX(off)   (off >> MTTY_VFIO_PCI_OFFSET_SHIFT)
59 #define MTTY_VFIO_PCI_INDEX_TO_OFFSET(index) \
60 				((u64)(index) << MTTY_VFIO_PCI_OFFSET_SHIFT)
61 #define MTTY_VFIO_PCI_OFFSET_MASK    \
62 				(((u64)(1) << MTTY_VFIO_PCI_OFFSET_SHIFT) - 1)
63 #define MAX_MTTYS	24
64 
65 /*
66  * Global Structures
67  */
68 
69 static struct mtty_dev {
70 	dev_t		vd_devt;
71 	struct class	*vd_class;
72 	struct cdev	vd_cdev;
73 	struct idr	vd_idr;
74 	struct device	dev;
75 	struct mdev_parent parent;
76 } mtty_dev;
77 
78 struct mdev_region_info {
79 	u64 start;
80 	u64 phys_start;
81 	u32 size;
82 	u64 vfio_offset;
83 };
84 
85 #if defined(DEBUG_REGS)
86 static const char *wr_reg[] = {
87 	"TX",
88 	"IER",
89 	"FCR",
90 	"LCR",
91 	"MCR",
92 	"LSR",
93 	"MSR",
94 	"SCR"
95 };
96 
97 static const char *rd_reg[] = {
98 	"RX",
99 	"IER",
100 	"IIR",
101 	"LCR",
102 	"MCR",
103 	"LSR",
104 	"MSR",
105 	"SCR"
106 };
107 #endif
108 
109 /* loop back buffer */
110 struct rxtx {
111 	u8 fifo[MAX_FIFO_SIZE];
112 	u8 head, tail;
113 	u8 count;
114 };
115 
116 struct serial_port {
117 	u8 uart_reg[8];         /* 8 registers */
118 	struct rxtx rxtx;       /* loop back buffer */
119 	bool dlab;
120 	bool overrun;
121 	u16 divisor;
122 	u8 fcr;                 /* FIFO control register */
123 	u8 max_fifo_size;
124 	u8 intr_trigger_level;  /* interrupt trigger level */
125 };
126 
127 /* State of each mdev device */
128 struct mdev_state {
129 	struct vfio_device vdev;
130 	struct eventfd_ctx *intx_evtfd;
131 	struct eventfd_ctx *msi_evtfd;
132 	int irq_index;
133 	u8 *vconfig;
134 	struct mutex ops_lock;
135 	struct mdev_device *mdev;
136 	struct mdev_region_info region_info[VFIO_PCI_NUM_REGIONS];
137 	u32 bar_mask[VFIO_PCI_NUM_REGIONS];
138 	struct list_head next;
139 	struct serial_port s[2];
140 	struct mutex rxtx_lock;
141 	struct vfio_device_info dev_info;
142 	int nr_ports;
143 	u8 intx_mask:1;
144 };
145 
146 static struct mtty_type {
147 	struct mdev_type type;
148 	int nr_ports;
149 } mtty_types[2] = {
150 	{ .nr_ports = 1, .type.sysfs_name = "1",
151 	  .type.pretty_name = "Single port serial" },
152 	{ .nr_ports = 2, .type.sysfs_name = "2",
153 	  .type.pretty_name = "Dual port serial" },
154 };
155 
156 static struct mdev_type *mtty_mdev_types[] = {
157 	&mtty_types[0].type,
158 	&mtty_types[1].type,
159 };
160 
161 static atomic_t mdev_avail_ports = ATOMIC_INIT(MAX_MTTYS);
162 
163 static const struct file_operations vd_fops = {
164 	.owner          = THIS_MODULE,
165 };
166 
167 static const struct vfio_device_ops mtty_dev_ops;
168 
169 /* Helper functions */
170 
171 static void dump_buffer(u8 *buf, uint32_t count)
172 {
173 #if defined(DEBUG)
174 	int i;
175 
176 	pr_info("Buffer:\n");
177 	for (i = 0; i < count; i++) {
178 		pr_info("%2x ", *(buf + i));
179 		if ((i + 1) % 16 == 0)
180 			pr_info("\n");
181 	}
182 #endif
183 }
184 
185 static bool is_intx(struct mdev_state *mdev_state)
186 {
187 	return mdev_state->irq_index == VFIO_PCI_INTX_IRQ_INDEX;
188 }
189 
190 static bool is_msi(struct mdev_state *mdev_state)
191 {
192 	return mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX;
193 }
194 
195 static bool is_noirq(struct mdev_state *mdev_state)
196 {
197 	return !is_intx(mdev_state) && !is_msi(mdev_state);
198 }
199 
200 static void mtty_trigger_interrupt(struct mdev_state *mdev_state)
201 {
202 	lockdep_assert_held(&mdev_state->ops_lock);
203 
204 	if (is_msi(mdev_state)) {
205 		if (mdev_state->msi_evtfd)
206 			eventfd_signal(mdev_state->msi_evtfd, 1);
207 	} else if (is_intx(mdev_state)) {
208 		if (mdev_state->intx_evtfd && !mdev_state->intx_mask) {
209 			eventfd_signal(mdev_state->intx_evtfd, 1);
210 			mdev_state->intx_mask = true;
211 		}
212 	}
213 }
214 
215 static void mtty_create_config_space(struct mdev_state *mdev_state)
216 {
217 	/* PCI dev ID */
218 	STORE_LE32((u32 *) &mdev_state->vconfig[0x0], 0x32534348);
219 
220 	/* Control: I/O+, Mem-, BusMaster- */
221 	STORE_LE16((u16 *) &mdev_state->vconfig[0x4], 0x0001);
222 
223 	/* Status: capabilities list absent */
224 	STORE_LE16((u16 *) &mdev_state->vconfig[0x6], 0x0200);
225 
226 	/* Rev ID */
227 	mdev_state->vconfig[0x8] =  0x10;
228 
229 	/* programming interface class : 16550-compatible serial controller */
230 	mdev_state->vconfig[0x9] =  0x02;
231 
232 	/* Sub class : 00 */
233 	mdev_state->vconfig[0xa] =  0x00;
234 
235 	/* Base class : Simple Communication controllers */
236 	mdev_state->vconfig[0xb] =  0x07;
237 
238 	/* base address registers */
239 	/* BAR0: IO space */
240 	STORE_LE32((u32 *) &mdev_state->vconfig[0x10], 0x000001);
241 	mdev_state->bar_mask[0] = ~(MTTY_IO_BAR_SIZE) + 1;
242 
243 	if (mdev_state->nr_ports == 2) {
244 		/* BAR1: IO space */
245 		STORE_LE32((u32 *) &mdev_state->vconfig[0x14], 0x000001);
246 		mdev_state->bar_mask[1] = ~(MTTY_IO_BAR_SIZE) + 1;
247 	}
248 
249 	/* Subsystem ID */
250 	STORE_LE32((u32 *) &mdev_state->vconfig[0x2c], 0x32534348);
251 
252 	mdev_state->vconfig[0x34] =  0x00;   /* Cap Ptr */
253 	mdev_state->vconfig[0x3d] =  0x01;   /* interrupt pin (INTA#) */
254 
255 	/* Vendor specific data */
256 	mdev_state->vconfig[0x40] =  0x23;
257 	mdev_state->vconfig[0x43] =  0x80;
258 	mdev_state->vconfig[0x44] =  0x23;
259 	mdev_state->vconfig[0x48] =  0x23;
260 	mdev_state->vconfig[0x4c] =  0x23;
261 
262 	mdev_state->vconfig[0x60] =  0x50;
263 	mdev_state->vconfig[0x61] =  0x43;
264 	mdev_state->vconfig[0x62] =  0x49;
265 	mdev_state->vconfig[0x63] =  0x20;
266 	mdev_state->vconfig[0x64] =  0x53;
267 	mdev_state->vconfig[0x65] =  0x65;
268 	mdev_state->vconfig[0x66] =  0x72;
269 	mdev_state->vconfig[0x67] =  0x69;
270 	mdev_state->vconfig[0x68] =  0x61;
271 	mdev_state->vconfig[0x69] =  0x6c;
272 	mdev_state->vconfig[0x6a] =  0x2f;
273 	mdev_state->vconfig[0x6b] =  0x55;
274 	mdev_state->vconfig[0x6c] =  0x41;
275 	mdev_state->vconfig[0x6d] =  0x52;
276 	mdev_state->vconfig[0x6e] =  0x54;
277 }
278 
279 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
280 				 u8 *buf, u32 count)
281 {
282 	u32 cfg_addr, bar_mask, bar_index = 0;
283 
284 	switch (offset) {
285 	case 0x04: /* device control */
286 	case 0x06: /* device status */
287 		/* do nothing */
288 		break;
289 	case 0x3c:  /* interrupt line */
290 		mdev_state->vconfig[0x3c] = buf[0];
291 		break;
292 	case 0x3d:
293 		/*
294 		 * Interrupt Pin is hardwired to INTA.
295 		 * This field is write protected by hardware
296 		 */
297 		break;
298 	case 0x10:  /* BAR0 */
299 	case 0x14:  /* BAR1 */
300 		if (offset == 0x10)
301 			bar_index = 0;
302 		else if (offset == 0x14)
303 			bar_index = 1;
304 
305 		if ((mdev_state->nr_ports == 1) && (bar_index == 1)) {
306 			STORE_LE32(&mdev_state->vconfig[offset], 0);
307 			break;
308 		}
309 
310 		cfg_addr = *(u32 *)buf;
311 		pr_info("BAR%d addr 0x%x\n", bar_index, cfg_addr);
312 
313 		if (cfg_addr == 0xffffffff) {
314 			bar_mask = mdev_state->bar_mask[bar_index];
315 			cfg_addr = (cfg_addr & bar_mask);
316 		}
317 
318 		cfg_addr |= (mdev_state->vconfig[offset] & 0x3ul);
319 		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
320 		break;
321 	case 0x18:  /* BAR2 */
322 	case 0x1c:  /* BAR3 */
323 	case 0x20:  /* BAR4 */
324 		STORE_LE32(&mdev_state->vconfig[offset], 0);
325 		break;
326 	default:
327 		pr_info("PCI config write @0x%x of %d bytes not handled\n",
328 			offset, count);
329 		break;
330 	}
331 }
332 
333 static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
334 				u16 offset, u8 *buf, u32 count)
335 {
336 	u8 data = *buf;
337 
338 	/* Handle data written by guest */
339 	switch (offset) {
340 	case UART_TX:
341 		/* if DLAB set, data is LSB of divisor */
342 		if (mdev_state->s[index].dlab) {
343 			mdev_state->s[index].divisor |= data;
344 			break;
345 		}
346 
347 		mutex_lock(&mdev_state->rxtx_lock);
348 
349 		/* save in TX buffer */
350 		if (mdev_state->s[index].rxtx.count <
351 				mdev_state->s[index].max_fifo_size) {
352 			mdev_state->s[index].rxtx.fifo[
353 					mdev_state->s[index].rxtx.head] = data;
354 			mdev_state->s[index].rxtx.count++;
355 			CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.head);
356 			mdev_state->s[index].overrun = false;
357 
358 			/*
359 			 * Trigger interrupt if receive data interrupt is
360 			 * enabled and fifo reached trigger level
361 			 */
362 			if ((mdev_state->s[index].uart_reg[UART_IER] &
363 						UART_IER_RDI) &&
364 			   (mdev_state->s[index].rxtx.count ==
365 				    mdev_state->s[index].intr_trigger_level)) {
366 				/* trigger interrupt */
367 #if defined(DEBUG_INTR)
368 				pr_err("Serial port %d: Fifo level trigger\n",
369 					index);
370 #endif
371 				mtty_trigger_interrupt(mdev_state);
372 			}
373 		} else {
374 #if defined(DEBUG_INTR)
375 			pr_err("Serial port %d: Buffer Overflow\n", index);
376 #endif
377 			mdev_state->s[index].overrun = true;
378 
379 			/*
380 			 * Trigger interrupt if receiver line status interrupt
381 			 * is enabled
382 			 */
383 			if (mdev_state->s[index].uart_reg[UART_IER] &
384 								UART_IER_RLSI)
385 				mtty_trigger_interrupt(mdev_state);
386 		}
387 		mutex_unlock(&mdev_state->rxtx_lock);
388 		break;
389 
390 	case UART_IER:
391 		/* if DLAB set, data is MSB of divisor */
392 		if (mdev_state->s[index].dlab)
393 			mdev_state->s[index].divisor |= (u16)data << 8;
394 		else {
395 			mdev_state->s[index].uart_reg[offset] = data;
396 			mutex_lock(&mdev_state->rxtx_lock);
397 			if ((data & UART_IER_THRI) &&
398 			    (mdev_state->s[index].rxtx.head ==
399 					mdev_state->s[index].rxtx.tail)) {
400 #if defined(DEBUG_INTR)
401 				pr_err("Serial port %d: IER_THRI write\n",
402 					index);
403 #endif
404 				mtty_trigger_interrupt(mdev_state);
405 			}
406 
407 			mutex_unlock(&mdev_state->rxtx_lock);
408 		}
409 
410 		break;
411 
412 	case UART_FCR:
413 		mdev_state->s[index].fcr = data;
414 
415 		mutex_lock(&mdev_state->rxtx_lock);
416 		if (data & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)) {
417 			/* clear loop back FIFO */
418 			mdev_state->s[index].rxtx.count = 0;
419 			mdev_state->s[index].rxtx.head = 0;
420 			mdev_state->s[index].rxtx.tail = 0;
421 		}
422 		mutex_unlock(&mdev_state->rxtx_lock);
423 
424 		switch (data & UART_FCR_TRIGGER_MASK) {
425 		case UART_FCR_TRIGGER_1:
426 			mdev_state->s[index].intr_trigger_level = 1;
427 			break;
428 
429 		case UART_FCR_TRIGGER_4:
430 			mdev_state->s[index].intr_trigger_level = 4;
431 			break;
432 
433 		case UART_FCR_TRIGGER_8:
434 			mdev_state->s[index].intr_trigger_level = 8;
435 			break;
436 
437 		case UART_FCR_TRIGGER_14:
438 			mdev_state->s[index].intr_trigger_level = 14;
439 			break;
440 		}
441 
442 		/*
443 		 * Set trigger level to 1 otherwise or  implement timer with
444 		 * timeout of 4 characters and on expiring that timer set
445 		 * Recevice data timeout in IIR register
446 		 */
447 		mdev_state->s[index].intr_trigger_level = 1;
448 		if (data & UART_FCR_ENABLE_FIFO)
449 			mdev_state->s[index].max_fifo_size = MAX_FIFO_SIZE;
450 		else {
451 			mdev_state->s[index].max_fifo_size = 1;
452 			mdev_state->s[index].intr_trigger_level = 1;
453 		}
454 
455 		break;
456 
457 	case UART_LCR:
458 		if (data & UART_LCR_DLAB) {
459 			mdev_state->s[index].dlab = true;
460 			mdev_state->s[index].divisor = 0;
461 		} else
462 			mdev_state->s[index].dlab = false;
463 
464 		mdev_state->s[index].uart_reg[offset] = data;
465 		break;
466 
467 	case UART_MCR:
468 		mdev_state->s[index].uart_reg[offset] = data;
469 
470 		if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
471 				(data & UART_MCR_OUT2)) {
472 #if defined(DEBUG_INTR)
473 			pr_err("Serial port %d: MCR_OUT2 write\n", index);
474 #endif
475 			mtty_trigger_interrupt(mdev_state);
476 		}
477 
478 		if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
479 				(data & (UART_MCR_RTS | UART_MCR_DTR))) {
480 #if defined(DEBUG_INTR)
481 			pr_err("Serial port %d: MCR RTS/DTR write\n", index);
482 #endif
483 			mtty_trigger_interrupt(mdev_state);
484 		}
485 		break;
486 
487 	case UART_LSR:
488 	case UART_MSR:
489 		/* do nothing */
490 		break;
491 
492 	case UART_SCR:
493 		mdev_state->s[index].uart_reg[offset] = data;
494 		break;
495 
496 	default:
497 		break;
498 	}
499 }
500 
501 static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
502 			    u16 offset, u8 *buf, u32 count)
503 {
504 	/* Handle read requests by guest */
505 	switch (offset) {
506 	case UART_RX:
507 		/* if DLAB set, data is LSB of divisor */
508 		if (mdev_state->s[index].dlab) {
509 			*buf  = (u8)mdev_state->s[index].divisor;
510 			break;
511 		}
512 
513 		mutex_lock(&mdev_state->rxtx_lock);
514 		/* return data in tx buffer */
515 		if (mdev_state->s[index].rxtx.head !=
516 				 mdev_state->s[index].rxtx.tail) {
517 			*buf = mdev_state->s[index].rxtx.fifo[
518 						mdev_state->s[index].rxtx.tail];
519 			mdev_state->s[index].rxtx.count--;
520 			CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.tail);
521 		}
522 
523 		if (mdev_state->s[index].rxtx.head ==
524 				mdev_state->s[index].rxtx.tail) {
525 		/*
526 		 *  Trigger interrupt if tx buffer empty interrupt is
527 		 *  enabled and fifo is empty
528 		 */
529 #if defined(DEBUG_INTR)
530 			pr_err("Serial port %d: Buffer Empty\n", index);
531 #endif
532 			if (mdev_state->s[index].uart_reg[UART_IER] &
533 							 UART_IER_THRI)
534 				mtty_trigger_interrupt(mdev_state);
535 		}
536 		mutex_unlock(&mdev_state->rxtx_lock);
537 
538 		break;
539 
540 	case UART_IER:
541 		if (mdev_state->s[index].dlab) {
542 			*buf = (u8)(mdev_state->s[index].divisor >> 8);
543 			break;
544 		}
545 		*buf = mdev_state->s[index].uart_reg[offset] & 0x0f;
546 		break;
547 
548 	case UART_IIR:
549 	{
550 		u8 ier = mdev_state->s[index].uart_reg[UART_IER];
551 		*buf = 0;
552 
553 		mutex_lock(&mdev_state->rxtx_lock);
554 		/* Interrupt priority 1: Parity, overrun, framing or break */
555 		if ((ier & UART_IER_RLSI) && mdev_state->s[index].overrun)
556 			*buf |= UART_IIR_RLSI;
557 
558 		/* Interrupt priority 2: Fifo trigger level reached */
559 		if ((ier & UART_IER_RDI) &&
560 		    (mdev_state->s[index].rxtx.count >=
561 		      mdev_state->s[index].intr_trigger_level))
562 			*buf |= UART_IIR_RDI;
563 
564 		/* Interrupt priotiry 3: transmitter holding register empty */
565 		if ((ier & UART_IER_THRI) &&
566 		    (mdev_state->s[index].rxtx.head ==
567 				mdev_state->s[index].rxtx.tail))
568 			*buf |= UART_IIR_THRI;
569 
570 		/* Interrupt priotiry 4: Modem status: CTS, DSR, RI or DCD  */
571 		if ((ier & UART_IER_MSI) &&
572 		    (mdev_state->s[index].uart_reg[UART_MCR] &
573 				 (UART_MCR_RTS | UART_MCR_DTR)))
574 			*buf |= UART_IIR_MSI;
575 
576 		/* bit0: 0=> interrupt pending, 1=> no interrupt is pending */
577 		if (*buf == 0)
578 			*buf = UART_IIR_NO_INT;
579 
580 		/* set bit 6 & 7 to be 16550 compatible */
581 		*buf |= 0xC0;
582 		mutex_unlock(&mdev_state->rxtx_lock);
583 	}
584 	break;
585 
586 	case UART_LCR:
587 	case UART_MCR:
588 		*buf = mdev_state->s[index].uart_reg[offset];
589 		break;
590 
591 	case UART_LSR:
592 	{
593 		u8 lsr = 0;
594 
595 		mutex_lock(&mdev_state->rxtx_lock);
596 		/* atleast one char in FIFO */
597 		if (mdev_state->s[index].rxtx.head !=
598 				 mdev_state->s[index].rxtx.tail)
599 			lsr |= UART_LSR_DR;
600 
601 		/* if FIFO overrun */
602 		if (mdev_state->s[index].overrun)
603 			lsr |= UART_LSR_OE;
604 
605 		/* transmit FIFO empty and tramsitter empty */
606 		if (mdev_state->s[index].rxtx.head ==
607 				 mdev_state->s[index].rxtx.tail)
608 			lsr |= UART_LSR_TEMT | UART_LSR_THRE;
609 
610 		mutex_unlock(&mdev_state->rxtx_lock);
611 		*buf = lsr;
612 		break;
613 	}
614 	case UART_MSR:
615 		*buf = UART_MSR_DSR | UART_MSR_DDSR | UART_MSR_DCD;
616 
617 		mutex_lock(&mdev_state->rxtx_lock);
618 		/* if AFE is 1 and FIFO have space, set CTS bit */
619 		if (mdev_state->s[index].uart_reg[UART_MCR] &
620 						 UART_MCR_AFE) {
621 			if (mdev_state->s[index].rxtx.count <
622 					mdev_state->s[index].max_fifo_size)
623 				*buf |= UART_MSR_CTS | UART_MSR_DCTS;
624 		} else
625 			*buf |= UART_MSR_CTS | UART_MSR_DCTS;
626 		mutex_unlock(&mdev_state->rxtx_lock);
627 
628 		break;
629 
630 	case UART_SCR:
631 		*buf = mdev_state->s[index].uart_reg[offset];
632 		break;
633 
634 	default:
635 		break;
636 	}
637 }
638 
639 static void mdev_read_base(struct mdev_state *mdev_state)
640 {
641 	int index, pos;
642 	u32 start_lo, start_hi;
643 	u32 mem_type;
644 
645 	pos = PCI_BASE_ADDRESS_0;
646 
647 	for (index = 0; index <= VFIO_PCI_BAR5_REGION_INDEX; index++) {
648 
649 		if (!mdev_state->region_info[index].size)
650 			continue;
651 
652 		start_lo = (*(u32 *)(mdev_state->vconfig + pos)) &
653 			PCI_BASE_ADDRESS_MEM_MASK;
654 		mem_type = (*(u32 *)(mdev_state->vconfig + pos)) &
655 			PCI_BASE_ADDRESS_MEM_TYPE_MASK;
656 
657 		switch (mem_type) {
658 		case PCI_BASE_ADDRESS_MEM_TYPE_64:
659 			start_hi = (*(u32 *)(mdev_state->vconfig + pos + 4));
660 			pos += 4;
661 			break;
662 		case PCI_BASE_ADDRESS_MEM_TYPE_32:
663 		case PCI_BASE_ADDRESS_MEM_TYPE_1M:
664 			/* 1M mem BAR treated as 32-bit BAR */
665 		default:
666 			/* mem unknown type treated as 32-bit BAR */
667 			start_hi = 0;
668 			break;
669 		}
670 		pos += 4;
671 		mdev_state->region_info[index].start = ((u64)start_hi << 32) |
672 							start_lo;
673 	}
674 }
675 
676 static ssize_t mdev_access(struct mdev_state *mdev_state, u8 *buf, size_t count,
677 			   loff_t pos, bool is_write)
678 {
679 	unsigned int index;
680 	loff_t offset;
681 	int ret = 0;
682 
683 	if (!buf)
684 		return -EINVAL;
685 
686 	mutex_lock(&mdev_state->ops_lock);
687 
688 	index = MTTY_VFIO_PCI_OFFSET_TO_INDEX(pos);
689 	offset = pos & MTTY_VFIO_PCI_OFFSET_MASK;
690 	switch (index) {
691 	case VFIO_PCI_CONFIG_REGION_INDEX:
692 
693 #if defined(DEBUG)
694 		pr_info("%s: PCI config space %s at offset 0x%llx\n",
695 			 __func__, is_write ? "write" : "read", offset);
696 #endif
697 		if (is_write) {
698 			dump_buffer(buf, count);
699 			handle_pci_cfg_write(mdev_state, offset, buf, count);
700 		} else {
701 			memcpy(buf, (mdev_state->vconfig + offset), count);
702 			dump_buffer(buf, count);
703 		}
704 
705 		break;
706 
707 	case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
708 		if (!mdev_state->region_info[index].start)
709 			mdev_read_base(mdev_state);
710 
711 		if (is_write) {
712 			dump_buffer(buf, count);
713 
714 #if defined(DEBUG_REGS)
715 			pr_info("%s: BAR%d  WR @0x%llx %s val:0x%02x dlab:%d\n",
716 				__func__, index, offset, wr_reg[offset],
717 				*buf, mdev_state->s[index].dlab);
718 #endif
719 			handle_bar_write(index, mdev_state, offset, buf, count);
720 		} else {
721 			handle_bar_read(index, mdev_state, offset, buf, count);
722 			dump_buffer(buf, count);
723 
724 #if defined(DEBUG_REGS)
725 			pr_info("%s: BAR%d  RD @0x%llx %s val:0x%02x dlab:%d\n",
726 				__func__, index, offset, rd_reg[offset],
727 				*buf, mdev_state->s[index].dlab);
728 #endif
729 		}
730 		break;
731 
732 	default:
733 		ret = -1;
734 		goto accessfailed;
735 	}
736 
737 	ret = count;
738 
739 
740 accessfailed:
741 	mutex_unlock(&mdev_state->ops_lock);
742 
743 	return ret;
744 }
745 
746 static int mtty_init_dev(struct vfio_device *vdev)
747 {
748 	struct mdev_state *mdev_state =
749 		container_of(vdev, struct mdev_state, vdev);
750 	struct mdev_device *mdev = to_mdev_device(vdev->dev);
751 	struct mtty_type *type =
752 		container_of(mdev->type, struct mtty_type, type);
753 	int avail_ports = atomic_read(&mdev_avail_ports);
754 	int ret;
755 
756 	do {
757 		if (avail_ports < type->nr_ports)
758 			return -ENOSPC;
759 	} while (!atomic_try_cmpxchg(&mdev_avail_ports,
760 				     &avail_ports,
761 				     avail_ports - type->nr_ports));
762 
763 	mdev_state->nr_ports = type->nr_ports;
764 	mdev_state->irq_index = -1;
765 	mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE;
766 	mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE;
767 	mutex_init(&mdev_state->rxtx_lock);
768 
769 	mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL);
770 	if (!mdev_state->vconfig) {
771 		ret = -ENOMEM;
772 		goto err_nr_ports;
773 	}
774 
775 	mutex_init(&mdev_state->ops_lock);
776 	mdev_state->mdev = mdev;
777 	mtty_create_config_space(mdev_state);
778 	return 0;
779 
780 err_nr_ports:
781 	atomic_add(type->nr_ports, &mdev_avail_ports);
782 	return ret;
783 }
784 
785 static int mtty_probe(struct mdev_device *mdev)
786 {
787 	struct mdev_state *mdev_state;
788 	int ret;
789 
790 	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
791 				       &mtty_dev_ops);
792 	if (IS_ERR(mdev_state))
793 		return PTR_ERR(mdev_state);
794 
795 	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
796 	if (ret)
797 		goto err_put_vdev;
798 	dev_set_drvdata(&mdev->dev, mdev_state);
799 	return 0;
800 
801 err_put_vdev:
802 	vfio_put_device(&mdev_state->vdev);
803 	return ret;
804 }
805 
806 static void mtty_release_dev(struct vfio_device *vdev)
807 {
808 	struct mdev_state *mdev_state =
809 		container_of(vdev, struct mdev_state, vdev);
810 
811 	atomic_add(mdev_state->nr_ports, &mdev_avail_ports);
812 	kfree(mdev_state->vconfig);
813 }
814 
815 static void mtty_remove(struct mdev_device *mdev)
816 {
817 	struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
818 
819 	vfio_unregister_group_dev(&mdev_state->vdev);
820 	vfio_put_device(&mdev_state->vdev);
821 }
822 
823 static int mtty_reset(struct mdev_state *mdev_state)
824 {
825 	pr_info("%s: called\n", __func__);
826 
827 	return 0;
828 }
829 
830 static ssize_t mtty_read(struct vfio_device *vdev, char __user *buf,
831 			 size_t count, loff_t *ppos)
832 {
833 	struct mdev_state *mdev_state =
834 		container_of(vdev, struct mdev_state, vdev);
835 	unsigned int done = 0;
836 	int ret;
837 
838 	while (count) {
839 		size_t filled;
840 
841 		if (count >= 4 && !(*ppos % 4)) {
842 			u32 val;
843 
844 			ret =  mdev_access(mdev_state, (u8 *)&val, sizeof(val),
845 					   *ppos, false);
846 			if (ret <= 0)
847 				goto read_err;
848 
849 			if (copy_to_user(buf, &val, sizeof(val)))
850 				goto read_err;
851 
852 			filled = 4;
853 		} else if (count >= 2 && !(*ppos % 2)) {
854 			u16 val;
855 
856 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
857 					  *ppos, false);
858 			if (ret <= 0)
859 				goto read_err;
860 
861 			if (copy_to_user(buf, &val, sizeof(val)))
862 				goto read_err;
863 
864 			filled = 2;
865 		} else {
866 			u8 val;
867 
868 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
869 					  *ppos, false);
870 			if (ret <= 0)
871 				goto read_err;
872 
873 			if (copy_to_user(buf, &val, sizeof(val)))
874 				goto read_err;
875 
876 			filled = 1;
877 		}
878 
879 		count -= filled;
880 		done += filled;
881 		*ppos += filled;
882 		buf += filled;
883 	}
884 
885 	return done;
886 
887 read_err:
888 	return -EFAULT;
889 }
890 
891 static ssize_t mtty_write(struct vfio_device *vdev, const char __user *buf,
892 		   size_t count, loff_t *ppos)
893 {
894 	struct mdev_state *mdev_state =
895 		container_of(vdev, struct mdev_state, vdev);
896 	unsigned int done = 0;
897 	int ret;
898 
899 	while (count) {
900 		size_t filled;
901 
902 		if (count >= 4 && !(*ppos % 4)) {
903 			u32 val;
904 
905 			if (copy_from_user(&val, buf, sizeof(val)))
906 				goto write_err;
907 
908 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
909 					  *ppos, true);
910 			if (ret <= 0)
911 				goto write_err;
912 
913 			filled = 4;
914 		} else if (count >= 2 && !(*ppos % 2)) {
915 			u16 val;
916 
917 			if (copy_from_user(&val, buf, sizeof(val)))
918 				goto write_err;
919 
920 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
921 					  *ppos, true);
922 			if (ret <= 0)
923 				goto write_err;
924 
925 			filled = 2;
926 		} else {
927 			u8 val;
928 
929 			if (copy_from_user(&val, buf, sizeof(val)))
930 				goto write_err;
931 
932 			ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
933 					  *ppos, true);
934 			if (ret <= 0)
935 				goto write_err;
936 
937 			filled = 1;
938 		}
939 		count -= filled;
940 		done += filled;
941 		*ppos += filled;
942 		buf += filled;
943 	}
944 
945 	return done;
946 write_err:
947 	return -EFAULT;
948 }
949 
950 static void mtty_disable_intx(struct mdev_state *mdev_state)
951 {
952 	if (mdev_state->intx_evtfd) {
953 		eventfd_ctx_put(mdev_state->intx_evtfd);
954 		mdev_state->intx_evtfd = NULL;
955 		mdev_state->intx_mask = false;
956 		mdev_state->irq_index = -1;
957 	}
958 }
959 
960 static void mtty_disable_msi(struct mdev_state *mdev_state)
961 {
962 	if (mdev_state->msi_evtfd) {
963 		eventfd_ctx_put(mdev_state->msi_evtfd);
964 		mdev_state->msi_evtfd = NULL;
965 		mdev_state->irq_index = -1;
966 	}
967 }
968 
969 static int mtty_set_irqs(struct mdev_state *mdev_state, uint32_t flags,
970 			 unsigned int index, unsigned int start,
971 			 unsigned int count, void *data)
972 {
973 	int ret = 0;
974 
975 	mutex_lock(&mdev_state->ops_lock);
976 	switch (index) {
977 	case VFIO_PCI_INTX_IRQ_INDEX:
978 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
979 		case VFIO_IRQ_SET_ACTION_MASK:
980 			if (!is_intx(mdev_state) || start != 0 || count != 1) {
981 				ret = -EINVAL;
982 				break;
983 			}
984 
985 			if (flags & VFIO_IRQ_SET_DATA_NONE) {
986 				mdev_state->intx_mask = true;
987 			} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
988 				uint8_t mask = *(uint8_t *)data;
989 
990 				if (mask)
991 					mdev_state->intx_mask = true;
992 			} else if (flags &  VFIO_IRQ_SET_DATA_EVENTFD) {
993 				ret = -ENOTTY; /* No support for mask fd */
994 			}
995 			break;
996 		case VFIO_IRQ_SET_ACTION_UNMASK:
997 			if (!is_intx(mdev_state) || start != 0 || count != 1) {
998 				ret = -EINVAL;
999 				break;
1000 			}
1001 
1002 			if (flags & VFIO_IRQ_SET_DATA_NONE) {
1003 				mdev_state->intx_mask = false;
1004 			} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
1005 				uint8_t mask = *(uint8_t *)data;
1006 
1007 				if (mask)
1008 					mdev_state->intx_mask = false;
1009 			} else if (flags &  VFIO_IRQ_SET_DATA_EVENTFD) {
1010 				ret = -ENOTTY; /* No support for unmask fd */
1011 			}
1012 			break;
1013 		case VFIO_IRQ_SET_ACTION_TRIGGER:
1014 			if (is_intx(mdev_state) && !count &&
1015 			    (flags & VFIO_IRQ_SET_DATA_NONE)) {
1016 				mtty_disable_intx(mdev_state);
1017 				break;
1018 			}
1019 
1020 			if (!(is_intx(mdev_state) || is_noirq(mdev_state)) ||
1021 			    start != 0 || count != 1) {
1022 				ret = -EINVAL;
1023 				break;
1024 			}
1025 
1026 			if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
1027 				int fd = *(int *)data;
1028 				struct eventfd_ctx *evt;
1029 
1030 				mtty_disable_intx(mdev_state);
1031 
1032 				if (fd < 0)
1033 					break;
1034 
1035 				evt = eventfd_ctx_fdget(fd);
1036 				if (IS_ERR(evt)) {
1037 					ret = PTR_ERR(evt);
1038 					break;
1039 				}
1040 				mdev_state->intx_evtfd = evt;
1041 				mdev_state->irq_index = index;
1042 				break;
1043 			}
1044 
1045 			if (!is_intx(mdev_state)) {
1046 				ret = -EINVAL;
1047 				break;
1048 			}
1049 
1050 			if (flags & VFIO_IRQ_SET_DATA_NONE) {
1051 				mtty_trigger_interrupt(mdev_state);
1052 			} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
1053 				uint8_t trigger = *(uint8_t *)data;
1054 
1055 				if (trigger)
1056 					mtty_trigger_interrupt(mdev_state);
1057 			}
1058 			break;
1059 		}
1060 		break;
1061 	case VFIO_PCI_MSI_IRQ_INDEX:
1062 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
1063 		case VFIO_IRQ_SET_ACTION_MASK:
1064 		case VFIO_IRQ_SET_ACTION_UNMASK:
1065 			ret = -ENOTTY;
1066 			break;
1067 		case VFIO_IRQ_SET_ACTION_TRIGGER:
1068 			if (is_msi(mdev_state) && !count &&
1069 			    (flags & VFIO_IRQ_SET_DATA_NONE)) {
1070 				mtty_disable_msi(mdev_state);
1071 				break;
1072 			}
1073 
1074 			if (!(is_msi(mdev_state) || is_noirq(mdev_state)) ||
1075 			    start != 0 || count != 1) {
1076 				ret = -EINVAL;
1077 				break;
1078 			}
1079 
1080 			if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
1081 				int fd = *(int *)data;
1082 				struct eventfd_ctx *evt;
1083 
1084 				mtty_disable_msi(mdev_state);
1085 
1086 				if (fd < 0)
1087 					break;
1088 
1089 				evt = eventfd_ctx_fdget(fd);
1090 				if (IS_ERR(evt)) {
1091 					ret = PTR_ERR(evt);
1092 					break;
1093 				}
1094 				mdev_state->msi_evtfd = evt;
1095 				mdev_state->irq_index = index;
1096 				break;
1097 			}
1098 
1099 			if (!is_msi(mdev_state)) {
1100 				ret = -EINVAL;
1101 				break;
1102 			}
1103 
1104 			if (flags & VFIO_IRQ_SET_DATA_NONE) {
1105 				mtty_trigger_interrupt(mdev_state);
1106 			} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
1107 				uint8_t trigger = *(uint8_t *)data;
1108 
1109 				if (trigger)
1110 					mtty_trigger_interrupt(mdev_state);
1111 			}
1112 			break;
1113 		}
1114 		break;
1115 	case VFIO_PCI_MSIX_IRQ_INDEX:
1116 		dev_dbg(mdev_state->vdev.dev, "%s: MSIX_IRQ\n", __func__);
1117 		ret = -ENOTTY;
1118 		break;
1119 	case VFIO_PCI_ERR_IRQ_INDEX:
1120 		dev_dbg(mdev_state->vdev.dev, "%s: ERR_IRQ\n", __func__);
1121 		ret = -ENOTTY;
1122 		break;
1123 	case VFIO_PCI_REQ_IRQ_INDEX:
1124 		dev_dbg(mdev_state->vdev.dev, "%s: REQ_IRQ\n", __func__);
1125 		ret = -ENOTTY;
1126 		break;
1127 	}
1128 
1129 	mutex_unlock(&mdev_state->ops_lock);
1130 	return ret;
1131 }
1132 
1133 static int mtty_get_region_info(struct mdev_state *mdev_state,
1134 			 struct vfio_region_info *region_info,
1135 			 u16 *cap_type_id, void **cap_type)
1136 {
1137 	unsigned int size = 0;
1138 	u32 bar_index;
1139 
1140 	bar_index = region_info->index;
1141 	if (bar_index >= VFIO_PCI_NUM_REGIONS)
1142 		return -EINVAL;
1143 
1144 	mutex_lock(&mdev_state->ops_lock);
1145 
1146 	switch (bar_index) {
1147 	case VFIO_PCI_CONFIG_REGION_INDEX:
1148 		size = MTTY_CONFIG_SPACE_SIZE;
1149 		break;
1150 	case VFIO_PCI_BAR0_REGION_INDEX:
1151 		size = MTTY_IO_BAR_SIZE;
1152 		break;
1153 	case VFIO_PCI_BAR1_REGION_INDEX:
1154 		if (mdev_state->nr_ports == 2)
1155 			size = MTTY_IO_BAR_SIZE;
1156 		break;
1157 	default:
1158 		size = 0;
1159 		break;
1160 	}
1161 
1162 	mdev_state->region_info[bar_index].size = size;
1163 	mdev_state->region_info[bar_index].vfio_offset =
1164 		MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
1165 
1166 	region_info->size = size;
1167 	region_info->offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
1168 	region_info->flags = VFIO_REGION_INFO_FLAG_READ |
1169 		VFIO_REGION_INFO_FLAG_WRITE;
1170 	mutex_unlock(&mdev_state->ops_lock);
1171 	return 0;
1172 }
1173 
1174 static int mtty_get_irq_info(struct vfio_irq_info *irq_info)
1175 {
1176 	if (irq_info->index != VFIO_PCI_INTX_IRQ_INDEX &&
1177 	    irq_info->index != VFIO_PCI_MSI_IRQ_INDEX)
1178 		return -EINVAL;
1179 
1180 	irq_info->flags = VFIO_IRQ_INFO_EVENTFD;
1181 	irq_info->count = 1;
1182 
1183 	if (irq_info->index == VFIO_PCI_INTX_IRQ_INDEX)
1184 		irq_info->flags |= VFIO_IRQ_INFO_MASKABLE |
1185 				   VFIO_IRQ_INFO_AUTOMASKED;
1186 	else
1187 		irq_info->flags |= VFIO_IRQ_INFO_NORESIZE;
1188 
1189 	return 0;
1190 }
1191 
1192 static int mtty_get_device_info(struct vfio_device_info *dev_info)
1193 {
1194 	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1195 	dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
1196 	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1197 
1198 	return 0;
1199 }
1200 
1201 static long mtty_ioctl(struct vfio_device *vdev, unsigned int cmd,
1202 			unsigned long arg)
1203 {
1204 	struct mdev_state *mdev_state =
1205 		container_of(vdev, struct mdev_state, vdev);
1206 	int ret = 0;
1207 	unsigned long minsz;
1208 
1209 	switch (cmd) {
1210 	case VFIO_DEVICE_GET_INFO:
1211 	{
1212 		struct vfio_device_info info;
1213 
1214 		minsz = offsetofend(struct vfio_device_info, num_irqs);
1215 
1216 		if (copy_from_user(&info, (void __user *)arg, minsz))
1217 			return -EFAULT;
1218 
1219 		if (info.argsz < minsz)
1220 			return -EINVAL;
1221 
1222 		ret = mtty_get_device_info(&info);
1223 		if (ret)
1224 			return ret;
1225 
1226 		memcpy(&mdev_state->dev_info, &info, sizeof(info));
1227 
1228 		if (copy_to_user((void __user *)arg, &info, minsz))
1229 			return -EFAULT;
1230 
1231 		return 0;
1232 	}
1233 	case VFIO_DEVICE_GET_REGION_INFO:
1234 	{
1235 		struct vfio_region_info info;
1236 		u16 cap_type_id = 0;
1237 		void *cap_type = NULL;
1238 
1239 		minsz = offsetofend(struct vfio_region_info, offset);
1240 
1241 		if (copy_from_user(&info, (void __user *)arg, minsz))
1242 			return -EFAULT;
1243 
1244 		if (info.argsz < minsz)
1245 			return -EINVAL;
1246 
1247 		ret = mtty_get_region_info(mdev_state, &info, &cap_type_id,
1248 					   &cap_type);
1249 		if (ret)
1250 			return ret;
1251 
1252 		if (copy_to_user((void __user *)arg, &info, minsz))
1253 			return -EFAULT;
1254 
1255 		return 0;
1256 	}
1257 
1258 	case VFIO_DEVICE_GET_IRQ_INFO:
1259 	{
1260 		struct vfio_irq_info info;
1261 
1262 		minsz = offsetofend(struct vfio_irq_info, count);
1263 
1264 		if (copy_from_user(&info, (void __user *)arg, minsz))
1265 			return -EFAULT;
1266 
1267 		if ((info.argsz < minsz) ||
1268 		    (info.index >= mdev_state->dev_info.num_irqs))
1269 			return -EINVAL;
1270 
1271 		ret = mtty_get_irq_info(&info);
1272 		if (ret)
1273 			return ret;
1274 
1275 		if (copy_to_user((void __user *)arg, &info, minsz))
1276 			return -EFAULT;
1277 
1278 		return 0;
1279 	}
1280 	case VFIO_DEVICE_SET_IRQS:
1281 	{
1282 		struct vfio_irq_set hdr;
1283 		u8 *data = NULL, *ptr = NULL;
1284 		size_t data_size = 0;
1285 
1286 		minsz = offsetofend(struct vfio_irq_set, count);
1287 
1288 		if (copy_from_user(&hdr, (void __user *)arg, minsz))
1289 			return -EFAULT;
1290 
1291 		ret = vfio_set_irqs_validate_and_prepare(&hdr,
1292 						mdev_state->dev_info.num_irqs,
1293 						VFIO_PCI_NUM_IRQS,
1294 						&data_size);
1295 		if (ret)
1296 			return ret;
1297 
1298 		if (data_size) {
1299 			ptr = data = memdup_user((void __user *)(arg + minsz),
1300 						 data_size);
1301 			if (IS_ERR(data))
1302 				return PTR_ERR(data);
1303 		}
1304 
1305 		ret = mtty_set_irqs(mdev_state, hdr.flags, hdr.index, hdr.start,
1306 				    hdr.count, data);
1307 
1308 		kfree(ptr);
1309 		return ret;
1310 	}
1311 	case VFIO_DEVICE_RESET:
1312 		return mtty_reset(mdev_state);
1313 	}
1314 	return -ENOTTY;
1315 }
1316 
1317 static ssize_t
1318 sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
1319 		     char *buf)
1320 {
1321 	return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
1322 }
1323 
1324 static DEVICE_ATTR_RO(sample_mdev_dev);
1325 
1326 static struct attribute *mdev_dev_attrs[] = {
1327 	&dev_attr_sample_mdev_dev.attr,
1328 	NULL,
1329 };
1330 
1331 static const struct attribute_group mdev_dev_group = {
1332 	.name  = "vendor",
1333 	.attrs = mdev_dev_attrs,
1334 };
1335 
1336 static const struct attribute_group *mdev_dev_groups[] = {
1337 	&mdev_dev_group,
1338 	NULL,
1339 };
1340 
1341 static unsigned int mtty_get_available(struct mdev_type *mtype)
1342 {
1343 	struct mtty_type *type = container_of(mtype, struct mtty_type, type);
1344 
1345 	return atomic_read(&mdev_avail_ports) / type->nr_ports;
1346 }
1347 
1348 static void mtty_close(struct vfio_device *vdev)
1349 {
1350 	struct mdev_state *mdev_state =
1351 				container_of(vdev, struct mdev_state, vdev);
1352 
1353 	mtty_disable_intx(mdev_state);
1354 	mtty_disable_msi(mdev_state);
1355 }
1356 
1357 static const struct vfio_device_ops mtty_dev_ops = {
1358 	.name = "vfio-mtty",
1359 	.init = mtty_init_dev,
1360 	.release = mtty_release_dev,
1361 	.read = mtty_read,
1362 	.write = mtty_write,
1363 	.ioctl = mtty_ioctl,
1364 	.bind_iommufd	= vfio_iommufd_emulated_bind,
1365 	.unbind_iommufd	= vfio_iommufd_emulated_unbind,
1366 	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
1367 	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
1368 	.close_device	= mtty_close,
1369 };
1370 
1371 static struct mdev_driver mtty_driver = {
1372 	.device_api = VFIO_DEVICE_API_PCI_STRING,
1373 	.driver = {
1374 		.name = "mtty",
1375 		.owner = THIS_MODULE,
1376 		.mod_name = KBUILD_MODNAME,
1377 		.dev_groups = mdev_dev_groups,
1378 	},
1379 	.probe = mtty_probe,
1380 	.remove	= mtty_remove,
1381 	.get_available = mtty_get_available,
1382 };
1383 
1384 static void mtty_device_release(struct device *dev)
1385 {
1386 	dev_dbg(dev, "mtty: released\n");
1387 }
1388 
1389 static int __init mtty_dev_init(void)
1390 {
1391 	int ret = 0;
1392 
1393 	pr_info("mtty_dev: %s\n", __func__);
1394 
1395 	memset(&mtty_dev, 0, sizeof(mtty_dev));
1396 
1397 	idr_init(&mtty_dev.vd_idr);
1398 
1399 	ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK + 1,
1400 				  MTTY_NAME);
1401 
1402 	if (ret < 0) {
1403 		pr_err("Error: failed to register mtty_dev, err:%d\n", ret);
1404 		return ret;
1405 	}
1406 
1407 	cdev_init(&mtty_dev.vd_cdev, &vd_fops);
1408 	cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK + 1);
1409 
1410 	pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt));
1411 
1412 	ret = mdev_register_driver(&mtty_driver);
1413 	if (ret)
1414 		goto err_cdev;
1415 
1416 	mtty_dev.vd_class = class_create(MTTY_CLASS_NAME);
1417 
1418 	if (IS_ERR(mtty_dev.vd_class)) {
1419 		pr_err("Error: failed to register mtty_dev class\n");
1420 		ret = PTR_ERR(mtty_dev.vd_class);
1421 		goto err_driver;
1422 	}
1423 
1424 	mtty_dev.dev.class = mtty_dev.vd_class;
1425 	mtty_dev.dev.release = mtty_device_release;
1426 	dev_set_name(&mtty_dev.dev, "%s", MTTY_NAME);
1427 
1428 	ret = device_register(&mtty_dev.dev);
1429 	if (ret)
1430 		goto err_put;
1431 
1432 	ret = mdev_register_parent(&mtty_dev.parent, &mtty_dev.dev,
1433 				   &mtty_driver, mtty_mdev_types,
1434 				   ARRAY_SIZE(mtty_mdev_types));
1435 	if (ret)
1436 		goto err_device;
1437 	return 0;
1438 
1439 err_device:
1440 	device_del(&mtty_dev.dev);
1441 err_put:
1442 	put_device(&mtty_dev.dev);
1443 	class_destroy(mtty_dev.vd_class);
1444 err_driver:
1445 	mdev_unregister_driver(&mtty_driver);
1446 err_cdev:
1447 	cdev_del(&mtty_dev.vd_cdev);
1448 	unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
1449 	return ret;
1450 }
1451 
1452 static void __exit mtty_dev_exit(void)
1453 {
1454 	mtty_dev.dev.bus = NULL;
1455 	mdev_unregister_parent(&mtty_dev.parent);
1456 
1457 	device_unregister(&mtty_dev.dev);
1458 	idr_destroy(&mtty_dev.vd_idr);
1459 	mdev_unregister_driver(&mtty_driver);
1460 	cdev_del(&mtty_dev.vd_cdev);
1461 	unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
1462 	class_destroy(mtty_dev.vd_class);
1463 	mtty_dev.vd_class = NULL;
1464 	pr_info("mtty_dev: Unloaded!\n");
1465 }
1466 
1467 module_init(mtty_dev_init)
1468 module_exit(mtty_dev_exit)
1469 
1470 MODULE_LICENSE("GPL v2");
1471 MODULE_INFO(supported, "Test driver that simulate serial port over PCI");
1472 MODULE_VERSION(VERSION_STRING);
1473 MODULE_AUTHOR(DRIVER_AUTHOR);
1474