1	// SPDX-License-Identifier: GPL-2.0-or-later
2	/*
3	* Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
4	* Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
5	* Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
6	*/
7	#include <linux/cdev.h>
8	#include <linux/debugfs.h>
9	#include <linux/completion.h>
10	#include <linux/device.h>
11	#include <linux/err.h>
12	#include <linux/freezer.h>
13	#include <linux/fs.h>
14	#include <linux/splice.h>
15	#include <linux/pagemap.h>
16	#include <linux/idr.h>
17	#include <linux/init.h>
18	#include <linux/list.h>
19	#include <linux/poll.h>
20	#include <linux/sched.h>
21	#include <linux/slab.h>
22	#include <linux/spinlock.h>
23	#include <linux/virtio.h>
24	#include <linux/virtio_console.h>
25	#include <linux/wait.h>
26	#include <linux/workqueue.h>
27	#include <linux/module.h>
28	#include <linux/dma-mapping.h>
29	#include "../tty/hvc/hvc_console.h"
30
31	#define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
32	#define VIRTCONS_MAX_PORTS 0x8000
33
34	/*
35	* This is a global struct for storing common data for all the devices
36	* this driver handles.
37	*
38	* Mainly, it has a linked list for all the consoles in one place so
39	* that callbacks from hvc for get_chars(), put_chars() work properly
40	* across multiple devices and multiple ports per device.
41	*/
42	struct ports_driver_data {
43	/* Used for exporting per-port information to debugfs */
44	struct dentry *debugfs_dir;
45
46	/* List of all the devices we're handling */
47	struct list_head portdevs;
48
49	/* All the console devices handled by this driver */
50	struct list_head consoles;
51	};
52
53	static struct ports_driver_data pdrvdata;
54
55	static const struct class port_class = {
56	.name = "virtio-ports",
57	};
58
59	static DEFINE_SPINLOCK(pdrvdata_lock);
60	static DECLARE_COMPLETION(early_console_added);
61
62	/* This struct holds information that's relevant only for console ports */
63	struct console {
64	/* We'll place all consoles in a list in the pdrvdata struct */
65	struct list_head list;
66
67	/* The hvc device associated with this console port */
68	struct hvc_struct *hvc;
69
70	/* The size of the console */
71	struct winsize ws;
72
73	/*
74	* This number identifies the number that we used to register
75	* with hvc in hvc_instantiate() and hvc_alloc(); this is the
76	* number passed on by the hvc callbacks to us to
77	* differentiate between the other console ports handled by
78	* this driver
79	*/
80	u32 vtermno;
81	};
82
83	static DEFINE_IDA(vtermno_ida);
84
85	struct port_buffer {
86	char *buf;
87
88	/* size of the buffer in *buf above */
89	size_t size;
90
91	/* used length of the buffer */
92	size_t len;
93	/* offset in the buf from which to consume data */
94	size_t offset;
95
96	/* DMA address of buffer */
97	dma_addr_t dma;
98
99	/* Device we got DMA memory from */
100	struct device *dev;
101
102	/* List of pending dma buffers to free */
103	struct list_head list;
104
105	/* If sgpages == 0 then buf is used */
106	unsigned int sgpages;
107
108	/* sg is used if spages > 0. sg must be the last in is struct */
109	struct scatterlist sg[] __counted_by(sgpages);
110	};
111
112	/*
113	* This is a per-device struct that stores data common to all the
114	* ports for that device (vdev->priv).
115	*/
116	struct ports_device {
117	/* Next portdev in the list, head is in the pdrvdata struct */
118	struct list_head list;
119
120	/*
121	* Workqueue handlers where we process deferred work after
122	* notification
123	*/
124	struct work_struct control_work;
125	struct work_struct config_work;
126
127	struct list_head ports;
128
129	/* To protect the list of ports */
130	spinlock_t ports_lock;
131
132	/* To protect the vq operations for the control channel */
133	spinlock_t c_ivq_lock;
134	spinlock_t c_ovq_lock;
135
136	/* max. number of ports this device can hold */
137	u32 max_nr_ports;
138
139	/* The virtio device we're associated with */
140	struct virtio_device *vdev;
141
142	/*
143	* A couple of virtqueues for the control channel: one for
144	* guest->host transfers, one for host->guest transfers
145	*/
146	struct virtqueue *c_ivq, *c_ovq;
147
148	/*
149	* A control packet buffer for guest->host requests, protected
150	* by c_ovq_lock.
151	*/
152	struct virtio_console_control cpkt;
153
154	/* Array of per-port IO virtqueues */
155	struct virtqueue **in_vqs, **out_vqs;
156
157	/* Major number for this device. Ports will be created as minors. */
158	int chr_major;
159	};
160
161	struct port_stats {
162	unsigned long bytes_sent, bytes_received, bytes_discarded;
163	};
164
165	/* This struct holds the per-port data */
166	struct port {
167	/* Next port in the list, head is in the ports_device */
168	struct list_head list;
169
170	/* Pointer to the parent virtio_console device */
171	struct ports_device *portdev;
172
173	/* The current buffer from which data has to be fed to readers */
174	struct port_buffer *inbuf;
175
176	/*
177	* To protect the operations on the in_vq associated with this
178	* port. Has to be a spinlock because it can be called from
179	* interrupt context (get_char()).
180	*/
181	spinlock_t inbuf_lock;
182
183	/* Protect the operations on the out_vq. */
184	spinlock_t outvq_lock;
185
186	/* The IO vqs for this port */
187	struct virtqueue *in_vq, *out_vq;
188
189	/* File in the debugfs directory that exposes this port's information */
190	struct dentry *debugfs_file;
191
192	/*
193	* Keep count of the bytes sent, received and discarded for
194	* this port for accounting and debugging purposes. These
195	* counts are not reset across port open / close events.
196	*/
197	struct port_stats stats;
198
199	/*
200	* The entries in this struct will be valid if this port is
201	* hooked up to an hvc console
202	*/
203	struct console cons;
204
205	/* Each port associates with a separate char device */
206	struct cdev *cdev;
207	struct device *dev;
208
209	/* Reference-counting to handle port hot-unplugs and file operations */
210	struct kref kref;
211
212	/* A waitqueue for poll() or blocking read operations */
213	wait_queue_head_t waitqueue;
214
215	/* The 'name' of the port that we expose via sysfs properties */
216	char *name;
217
218	/* We can notify apps of host connect / disconnect events via SIGIO */
219	struct fasync_struct *async_queue;
220
221	/* The 'id' to identify the port with the Host */
222	u32 id;
223
224	bool outvq_full;
225
226	/* Is the host device open */
227	bool host_connected;
228
229	/* We should allow only one process to open a port */
230	bool guest_connected;
231	};
232
233	/* This is the very early arch-specified put chars function. */
234	static int (*early_put_chars)(u32, const char *, int);
235
236	static struct port *find_port_by_vtermno(u32 vtermno)
237	{
238	struct port *port;
239	struct console *cons;
240	unsigned long flags;
241
242	spin_lock_irqsave(&pdrvdata_lock, flags);
243	list_for_each_entry(cons, &pdrvdata.consoles, list) {
244	if (cons->vtermno == vtermno) {
245	port = container_of(cons, struct port, cons);
246	goto out;
247	}
248	}
249	port = NULL;
250	out:
251	spin_unlock_irqrestore(lock: &pdrvdata_lock, flags);
252	return port;
253	}
254
255	static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
256	dev_t dev)
257	{
258	struct port *port;
259	unsigned long flags;
260
261	spin_lock_irqsave(&portdev->ports_lock, flags);
262	list_for_each_entry(port, &portdev->ports, list) {
263	if (port->cdev->dev == dev) {
264	kref_get(kref: &port->kref);
265	goto out;
266	}
267	}
268	port = NULL;
269	out:
270	spin_unlock_irqrestore(lock: &portdev->ports_lock, flags);
271
272	return port;
273	}
274
275	static struct port *find_port_by_devt(dev_t dev)
276	{
277	struct ports_device *portdev;
278	struct port *port;
279	unsigned long flags;
280
281	spin_lock_irqsave(&pdrvdata_lock, flags);
282	list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
283	port = find_port_by_devt_in_portdev(portdev, dev);
284	if (port)
285	goto out;
286	}
287	port = NULL;
288	out:
289	spin_unlock_irqrestore(lock: &pdrvdata_lock, flags);
290	return port;
291	}
292
293	static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
294	{
295	struct port *port;
296	unsigned long flags;
297
298	spin_lock_irqsave(&portdev->ports_lock, flags);
299	list_for_each_entry(port, &portdev->ports, list)
300	if (port->id == id)
301	goto out;
302	port = NULL;
303	out:
304	spin_unlock_irqrestore(lock: &portdev->ports_lock, flags);
305
306	return port;
307	}
308
309	static struct port *find_port_by_vq(struct ports_device *portdev,
310	struct virtqueue *vq)
311	{
312	struct port *port;
313	unsigned long flags;
314
315	spin_lock_irqsave(&portdev->ports_lock, flags);
316	list_for_each_entry(port, &portdev->ports, list)
317	if (port->in_vq == vq || port->out_vq == vq)
318	goto out;
319	port = NULL;
320	out:
321	spin_unlock_irqrestore(lock: &portdev->ports_lock, flags);
322	return port;
323	}
324
325	static bool is_console_port(struct port *port)
326	{
327	if (port->cons.hvc)
328	return true;
329	return false;
330	}
331
332	static bool is_rproc_serial(const struct virtio_device *vdev)
333	{
334	return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
335	}
336
337	static inline bool use_multiport(struct ports_device *portdev)
338	{
339	/*
340	* This condition can be true when put_chars is called from
341	* early_init
342	*/
343	if (!portdev->vdev)
344	return false;
345	return __virtio_test_bit(vdev: portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
346	}
347
348	static DEFINE_SPINLOCK(dma_bufs_lock);
349	static LIST_HEAD(pending_free_dma_bufs);
350
351	static void free_buf(struct port_buffer *buf, bool can_sleep)
352	{
353	unsigned int i;
354
355	for (i = 0; i < buf->sgpages; i++) {
356	struct page *page = sg_page(sg: &buf->sg[i]);
357	if (!page)
358	break;
359	put_page(page);
360	}
361
362	if (!buf->dev) {
363	kfree(objp: buf->buf);
364	} else if (is_rproc_enabled) {
365	unsigned long flags;
366
367	/* dma_free_coherent requires interrupts to be enabled. */
368	if (!can_sleep) {
369	/* queue up dma-buffers to be freed later */
370	spin_lock_irqsave(&dma_bufs_lock, flags);
371	list_add_tail(new: &buf->list, head: &pending_free_dma_bufs);
372	spin_unlock_irqrestore(lock: &dma_bufs_lock, flags);
373	return;
374	}
375	dma_free_coherent(dev: buf->dev, size: buf->size, cpu_addr: buf->buf, dma_handle: buf->dma);
376
377	/* Release device refcnt and allow it to be freed */
378	put_device(dev: buf->dev);
379	}
380
381	kfree(objp: buf);
382	}
383
384	static void reclaim_dma_bufs(void)
385	{
386	unsigned long flags;
387	struct port_buffer *buf, *tmp;
388	LIST_HEAD(tmp_list);
389
390	if (list_empty(head: &pending_free_dma_bufs))
391	return;
392
393	/* Create a copy of the pending_free_dma_bufs while holding the lock */
394	spin_lock_irqsave(&dma_bufs_lock, flags);
395	list_cut_position(list: &tmp_list, head: &pending_free_dma_bufs,
396	entry: pending_free_dma_bufs.prev);
397	spin_unlock_irqrestore(lock: &dma_bufs_lock, flags);
398
399	/* Release the dma buffers, without irqs enabled */
400	list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
401	list_del(entry: &buf->list);
402	free_buf(buf, can_sleep: true);
403	}
404	}
405
406	static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size,
407	int pages)
408	{
409	struct port_buffer *buf;
410
411	reclaim_dma_bufs();
412
413	/*
414	* Allocate buffer and the sg list. The sg list array is allocated
415	* directly after the port_buffer struct.
416	*/
417	buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
418	if (!buf)
419	goto fail;
420
421	buf->sgpages = pages;
422	if (pages > 0) {
423	buf->dev = NULL;
424	buf->buf = NULL;
425	return buf;
426	}
427
428	if (is_rproc_serial(vdev)) {
429	/*
430	* Allocate DMA memory from ancestor. When a virtio
431	* device is created by remoteproc, the DMA memory is
432	* associated with the parent device:
433	* virtioY => remoteprocX#vdevYbuffer.
434	*/
435	buf->dev = vdev->dev.parent;
436	if (!buf->dev)
437	goto free_buf;
438
439	/* Increase device refcnt to avoid freeing it */
440	get_device(dev: buf->dev);
441	buf->buf = dma_alloc_coherent(dev: buf->dev, size: buf_size, dma_handle: &buf->dma,
442	GFP_KERNEL);
443	} else {
444	buf->dev = NULL;
445	buf->buf = kmalloc(size: buf_size, GFP_KERNEL);
446	}
447
448	if (!buf->buf)
449	goto free_buf;
450	buf->len = 0;
451	buf->offset = 0;
452	buf->size = buf_size;
453	return buf;
454
455	free_buf:
456	kfree(objp: buf);
457	fail:
458	return NULL;
459	}
460
461	/* Callers should take appropriate locks */
462	static struct port_buffer *get_inbuf(struct port *port)
463	{
464	struct port_buffer *buf;
465	unsigned int len;
466
467	if (port->inbuf)
468	return port->inbuf;
469
470	buf = virtqueue_get_buf(vq: port->in_vq, len: &len);
471	if (buf) {
472	buf->len = min_t(size_t, len, buf->size);
473	buf->offset = 0;
474	port->stats.bytes_received += len;
475	}
476	return buf;
477	}
478
479	/*
480	* Create a scatter-gather list representing our input buffer and put
481	* it in the queue.
482	*
483	* Callers should take appropriate locks.
484	*/
485	static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
486	{
487	struct scatterlist sg[1];
488	int ret;
489
490	sg_init_one(sg, buf->buf, buf->size);
491
492	ret = virtqueue_add_inbuf(vq, sg, num: 1, data: buf, GFP_ATOMIC);
493	virtqueue_kick(vq);
494	if (!ret)
495	ret = vq->num_free;
496	return ret;
497	}
498
499	/* Discard any unread data this port has. Callers lockers. */
500	static void discard_port_data(struct port *port)
501	{
502	struct port_buffer *buf;
503	unsigned int err;
504
505	if (!port->portdev) {
506	/* Device has been unplugged. vqs are already gone. */
507	return;
508	}
509	buf = get_inbuf(port);
510
511	err = 0;
512	while (buf) {
513	port->stats.bytes_discarded += buf->len - buf->offset;
514	if (add_inbuf(vq: port->in_vq, buf) < 0) {
515	err++;
516	free_buf(buf, can_sleep: false);
517	}
518	port->inbuf = NULL;
519	buf = get_inbuf(port);
520	}
521	if (err)
522	dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
523	err);
524	}
525
526	static bool port_has_data(struct port *port)
527	{
528	unsigned long flags;
529	bool ret;
530
531	ret = false;
532	spin_lock_irqsave(&port->inbuf_lock, flags);
533	port->inbuf = get_inbuf(port);
534	if (port->inbuf)
535	ret = true;
536
537	spin_unlock_irqrestore(lock: &port->inbuf_lock, flags);
538	return ret;
539	}
540
541	static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
542	unsigned int event, unsigned int value)
543	{
544	struct scatterlist sg[1];
545	struct virtqueue *vq;
546	unsigned int len;
547
548	if (!use_multiport(portdev))
549	return 0;
550
551	vq = portdev->c_ovq;
552
553	spin_lock(lock: &portdev->c_ovq_lock);
554
555	portdev->cpkt.id = cpu_to_virtio32(vdev: portdev->vdev, val: port_id);
556	portdev->cpkt.event = cpu_to_virtio16(vdev: portdev->vdev, val: event);
557	portdev->cpkt.value = cpu_to_virtio16(vdev: portdev->vdev, val: value);
558
559	sg_init_one(sg, &portdev->cpkt, sizeof(struct virtio_console_control));
560
561	if (virtqueue_add_outbuf(vq, sg, num: 1, data: &portdev->cpkt, GFP_ATOMIC) == 0) {
562	virtqueue_kick(vq);
563	while (!virtqueue_get_buf(vq, len: &len)
564	&& !virtqueue_is_broken(vq))
565	cpu_relax();
566	}
567
568	spin_unlock(lock: &portdev->c_ovq_lock);
569	return 0;
570	}
571
572	static ssize_t send_control_msg(struct port *port, unsigned int event,
573	unsigned int value)
574	{
575	/* Did the port get unplugged before userspace closed it? */
576	if (port->portdev)
577	return __send_control_msg(portdev: port->portdev, port_id: port->id, event, value);
578	return 0;
579	}
580
581
582	/* Callers must take the port->outvq_lock */
583	static void reclaim_consumed_buffers(struct port *port)
584	{
585	struct port_buffer *buf;
586	unsigned int len;
587
588	if (!port->portdev) {
589	/* Device has been unplugged. vqs are already gone. */
590	return;
591	}
592	while ((buf = virtqueue_get_buf(vq: port->out_vq, len: &len))) {
593	free_buf(buf, can_sleep: false);
594	port->outvq_full = false;
595	}
596	}
597
598	static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
599	int nents, size_t in_count,
600	void *data, bool nonblock)
601	{
602	struct virtqueue *out_vq;
603	int err;
604	unsigned long flags;
605	unsigned int len;
606
607	out_vq = port->out_vq;
608
609	spin_lock_irqsave(&port->outvq_lock, flags);
610
611	reclaim_consumed_buffers(port);
612
613	err = virtqueue_add_outbuf(vq: out_vq, sg, num: nents, data, GFP_ATOMIC);
614
615	/* Tell Host to go! */
616	virtqueue_kick(vq: out_vq);
617
618	if (err) {
619	in_count = 0;
620	goto done;
621	}
622
623	if (out_vq->num_free == 0)
624	port->outvq_full = true;
625
626	if (nonblock)
627	goto done;
628
629	/*
630	* Wait till the host acknowledges it pushed out the data we
631	* sent. This is done for data from the hvc_console; the tty
632	* operations are performed with spinlocks held so we can't
633	* sleep here. An alternative would be to copy the data to a
634	* buffer and relax the spinning requirement. The downside is
635	* we need to kmalloc a GFP_ATOMIC buffer each time the
636	* console driver writes something out.
637	*/
638	while (!virtqueue_get_buf(vq: out_vq, len: &len)
639	&& !virtqueue_is_broken(vq: out_vq))
640	cpu_relax();
641	done:
642	spin_unlock_irqrestore(lock: &port->outvq_lock, flags);
643
644	port->stats.bytes_sent += in_count;
645	/*
646	* We're expected to return the amount of data we wrote -- all
647	* of it
648	*/
649	return in_count;
650	}
651
652	/*
653	* Give out the data that's requested from the buffer that we have
654	* queued up.
655	*/
656	static ssize_t fill_readbuf(struct port *port, char __user *out_buf,
657	size_t out_count, bool to_user)
658	{
659	struct port_buffer *buf;
660	unsigned long flags;
661
662	if (!out_count || !port_has_data(port))
663	return 0;
664
665	buf = port->inbuf;
666	out_count = min(out_count, buf->len - buf->offset);
667
668	if (to_user) {
669	ssize_t ret;
670
671	ret = copy_to_user(to: out_buf, from: buf->buf + buf->offset, n: out_count);
672	if (ret)
673	return -EFAULT;
674	} else {
675	memcpy((__force char *)out_buf, buf->buf + buf->offset,
676	out_count);
677	}
678
679	buf->offset += out_count;
680
681	if (buf->offset == buf->len) {
682	/*
683	* We're done using all the data in this buffer.
684	* Re-queue so that the Host can send us more data.
685	*/
686	spin_lock_irqsave(&port->inbuf_lock, flags);
687	port->inbuf = NULL;
688
689	if (add_inbuf(vq: port->in_vq, buf) < 0)
690	dev_warn(port->dev, "failed add_buf\n");
691
692	spin_unlock_irqrestore(lock: &port->inbuf_lock, flags);
693	}
694	/* Return the number of bytes actually copied */
695	return out_count;
696	}
697
698	/* The condition that must be true for polling to end */
699	static bool will_read_block(struct port *port)
700	{
701	if (!port->guest_connected) {
702	/* Port got hot-unplugged. Let's exit. */
703	return false;
704	}
705	return !port_has_data(port) && port->host_connected;
706	}
707
708	static bool will_write_block(struct port *port)
709	{
710	bool ret;
711
712	if (!port->guest_connected) {
713	/* Port got hot-unplugged. Let's exit. */
714	return false;
715	}
716	if (!port->host_connected)
717	return true;
718
719	spin_lock_irq(lock: &port->outvq_lock);
720	/*
721	* Check if the Host has consumed any buffers since we last
722	* sent data (this is only applicable for nonblocking ports).
723	*/
724	reclaim_consumed_buffers(port);
725	ret = port->outvq_full;
726	spin_unlock_irq(lock: &port->outvq_lock);
727
728	return ret;
729	}
730
731	static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
732	size_t count, loff_t *offp)
733	{
734	struct port *port;
735	ssize_t ret;
736
737	port = filp->private_data;
738
739	/* Port is hot-unplugged. */
740	if (!port->guest_connected)
741	return -ENODEV;
742
743	if (!port_has_data(port)) {
744	/*
745	* If nothing's connected on the host just return 0 in
746	* case of list_empty; this tells the userspace app
747	* that there's no connection
748	*/
749	if (!port->host_connected)
750	return 0;
751	if (filp->f_flags & O_NONBLOCK)
752	return -EAGAIN;
753
754	ret = wait_event_freezable(port->waitqueue,
755	!will_read_block(port));
756	if (ret < 0)
757	return ret;
758	}
759	/* Port got hot-unplugged while we were waiting above. */
760	if (!port->guest_connected)
761	return -ENODEV;
762	/*
763	* We could've received a disconnection message while we were
764	* waiting for more data.
765	*
766	* This check is not clubbed in the if() statement above as we
767	* might receive some data as well as the host could get
768	* disconnected after we got woken up from our wait. So we
769	* really want to give off whatever data we have and only then
770	* check for host_connected.
771	*/
772	if (!port_has_data(port) && !port->host_connected)
773	return 0;
774
775	return fill_readbuf(port, out_buf: ubuf, out_count: count, to_user: true);
776	}
777
778	static int wait_port_writable(struct port *port, bool nonblock)
779	{
780	int ret;
781
782	if (will_write_block(port)) {
783	if (nonblock)
784	return -EAGAIN;
785
786	ret = wait_event_freezable(port->waitqueue,
787	!will_write_block(port));
788	if (ret < 0)
789	return ret;
790	}
791	/* Port got hot-unplugged. */
792	if (!port->guest_connected)
793	return -ENODEV;
794
795	return 0;
796	}
797
798	static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
799	size_t count, loff_t *offp)
800	{
801	struct port *port;
802	struct port_buffer *buf;
803	ssize_t ret;
804	bool nonblock;
805	struct scatterlist sg[1];
806
807	/* Userspace could be out to fool us */
808	if (!count)
809	return 0;
810
811	port = filp->private_data;
812
813	nonblock = filp->f_flags & O_NONBLOCK;
814
815	ret = wait_port_writable(port, nonblock);
816	if (ret < 0)
817	return ret;
818
819	count = min((size_t)(32 * 1024), count);
820
821	buf = alloc_buf(vdev: port->portdev->vdev, buf_size: count, pages: 0);
822	if (!buf)
823	return -ENOMEM;
824
825	ret = copy_from_user(to: buf->buf, from: ubuf, n: count);
826	if (ret) {
827	ret = -EFAULT;
828	goto free_buf;
829	}
830
831	/*
832	* We now ask send_buf() to not spin for generic ports -- we
833	* can re-use the same code path that non-blocking file
834	* descriptors take for blocking file descriptors since the
835	* wait is already done and we're certain the write will go
836	* through to the host.
837	*/
838	nonblock = true;
839	sg_init_one(sg, buf->buf, count);
840	ret = __send_to_port(port, sg, nents: 1, in_count: count, data: buf, nonblock);
841
842	if (nonblock && ret > 0)
843	goto out;
844
845	free_buf:
846	free_buf(buf, can_sleep: true);
847	out:
848	return ret;
849	}
850
851	struct sg_list {
852	unsigned int n;
853	unsigned int size;
854	size_t len;
855	struct scatterlist *sg;
856	};
857
858	static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
859	struct splice_desc *sd)
860	{
861	struct sg_list *sgl = sd->u.data;
862	unsigned int offset, len;
863
864	if (sgl->n == sgl->size)
865	return 0;
866
867	/* Try lock this page */
868	if (pipe_buf_try_steal(pipe, buf)) {
869	/* Get reference and unlock page for moving */
870	get_page(page: buf->page);
871	unlock_page(page: buf->page);
872
873	len = min(buf->len, sd->len);
874	sg_set_page(sg: &(sgl->sg[sgl->n]), page: buf->page, len, offset: buf->offset);
875	} else {
876	/* Failback to copying a page */
877	struct page *page = alloc_page(GFP_KERNEL);
878	char *src;
879
880	if (!page)
881	return -ENOMEM;
882
883	offset = sd->pos & ~PAGE_MASK;
884
885	len = sd->len;
886	if (len + offset > PAGE_SIZE)
887	len = PAGE_SIZE - offset;
888
889	src = kmap_atomic(page: buf->page);
890	memcpy(page_address(page) + offset, src + buf->offset, len);
891	kunmap_atomic(src);
892
893	sg_set_page(sg: &(sgl->sg[sgl->n]), page, len, offset);
894	}
895	sgl->n++;
896	sgl->len += len;
897
898	return len;
899	}
900
901	/* Faster zero-copy write by splicing */
902	static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
903	struct file *filp, loff_t *ppos,
904	size_t len, unsigned int flags)
905	{
906	struct port *port = filp->private_data;
907	struct sg_list sgl;
908	ssize_t ret;
909	struct port_buffer *buf;
910	struct splice_desc sd = {
911	.total_len = len,
912	.flags = flags,
913	.pos = *ppos,
914	.u.data = &sgl,
915	};
916	unsigned int occupancy;
917
918	/*
919	* Rproc_serial does not yet support splice. To support splice
920	* pipe_to_sg() must allocate dma-buffers and copy content from
921	* regular pages to dma pages. And alloc_buf and free_buf must
922	* support allocating and freeing such a list of dma-buffers.
923	*/
924	if (is_rproc_serial(vdev: port->out_vq->vdev))
925	return -EINVAL;
926
927	pipe_lock(pipe);
928	ret = 0;
929	if (pipe_empty(head: pipe->head, tail: pipe->tail))
930	goto error_out;
931
932	ret = wait_port_writable(port, nonblock: filp->f_flags & O_NONBLOCK);
933	if (ret < 0)
934	goto error_out;
935
936	occupancy = pipe_occupancy(head: pipe->head, tail: pipe->tail);
937	buf = alloc_buf(vdev: port->portdev->vdev, buf_size: 0, pages: occupancy);
938
939	if (!buf) {
940	ret = -ENOMEM;
941	goto error_out;
942	}
943
944	sgl.n = 0;
945	sgl.len = 0;
946	sgl.size = occupancy;
947	sgl.sg = buf->sg;
948	sg_init_table(sgl.sg, sgl.size);
949	ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
950	pipe_unlock(pipe);
951	if (likely(ret > 0))
952	ret = __send_to_port(port, sg: buf->sg, nents: sgl.n, in_count: sgl.len, data: buf, nonblock: true);
953
954	if (unlikely(ret <= 0))
955	free_buf(buf, can_sleep: true);
956	return ret;
957
958	error_out:
959	pipe_unlock(pipe);
960	return ret;
961	}
962
963	static __poll_t port_fops_poll(struct file *filp, poll_table *wait)
964	{
965	struct port *port;
966	__poll_t ret;
967
968	port = filp->private_data;
969	poll_wait(filp, wait_address: &port->waitqueue, p: wait);
970
971	if (!port->guest_connected) {
972	/* Port got unplugged */
973	return EPOLLHUP;
974	}
975	ret = 0;
976	if (!will_read_block(port))
977	ret |= EPOLLIN | EPOLLRDNORM;
978	if (!will_write_block(port))
979	ret |= EPOLLOUT;
980	if (!port->host_connected)
981	ret |= EPOLLHUP;
982
983	return ret;
984	}
985
986	static void remove_port(struct kref *kref);
987
988	static int port_fops_release(struct inode *inode, struct file *filp)
989	{
990	struct port *port;
991
992	port = filp->private_data;
993
994	/* Notify host of port being closed */
995	send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, value: 0);
996
997	spin_lock_irq(lock: &port->inbuf_lock);
998	port->guest_connected = false;
999
1000	discard_port_data(port);
1001
1002	spin_unlock_irq(lock: &port->inbuf_lock);
1003
1004	spin_lock_irq(lock: &port->outvq_lock);
1005	reclaim_consumed_buffers(port);
1006	spin_unlock_irq(lock: &port->outvq_lock);
1007
1008	reclaim_dma_bufs();
1009	/*
1010	* Locks aren't necessary here as a port can't be opened after
1011	* unplug, and if a port isn't unplugged, a kref would already
1012	* exist for the port. Plus, taking ports_lock here would
1013	* create a dependency on other locks taken by functions
1014	* inside remove_port if we're the last holder of the port,
1015	* creating many problems.
1016	*/
1017	kref_put(kref: &port->kref, release: remove_port);
1018
1019	return 0;
1020	}
1021
1022	static int port_fops_open(struct inode *inode, struct file *filp)
1023	{
1024	struct cdev *cdev = inode->i_cdev;
1025	struct port *port;
1026	int ret;
1027
1028	/* We get the port with a kref here */
1029	port = find_port_by_devt(dev: cdev->dev);
1030	if (!port) {
1031	/* Port was unplugged before we could proceed */
1032	return -ENXIO;
1033	}
1034	filp->private_data = port;
1035
1036	/*
1037	* Don't allow opening of console port devices -- that's done
1038	* via /dev/hvc
1039	*/
1040	if (is_console_port(port)) {
1041	ret = -ENXIO;
1042	goto out;
1043	}
1044
1045	/* Allow only one process to open a particular port at a time */
1046	spin_lock_irq(lock: &port->inbuf_lock);
1047	if (port->guest_connected) {
1048	spin_unlock_irq(lock: &port->inbuf_lock);
1049	ret = -EBUSY;
1050	goto out;
1051	}
1052
1053	port->guest_connected = true;
1054	spin_unlock_irq(lock: &port->inbuf_lock);
1055
1056	spin_lock_irq(lock: &port->outvq_lock);
1057	/*
1058	* There might be a chance that we missed reclaiming a few
1059	* buffers in the window of the port getting previously closed
1060	* and opening now.
1061	*/
1062	reclaim_consumed_buffers(port);
1063	spin_unlock_irq(lock: &port->outvq_lock);
1064
1065	nonseekable_open(inode, filp);
1066
1067	/* Notify host of port being opened */
1068	send_control_msg(port: filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, value: 1);
1069
1070	return 0;
1071	out:
1072	kref_put(kref: &port->kref, release: remove_port);
1073	return ret;
1074	}
1075
1076	static int port_fops_fasync(int fd, struct file *filp, int mode)
1077	{
1078	struct port *port;
1079
1080	port = filp->private_data;
1081	return fasync_helper(fd, filp, mode, &port->async_queue);
1082	}
1083
1084	/*
1085	* The file operations that we support: programs in the guest can open
1086	* a console device, read from it, write to it, poll for data and
1087	* close it. The devices are at
1088	* /dev/vport<device number>p<port number>
1089	*/
1090	static const struct file_operations port_fops = {
1091	.owner = THIS_MODULE,
1092	.open = port_fops_open,
1093	.read = port_fops_read,
1094	.write = port_fops_write,
1095	.splice_write = port_fops_splice_write,
1096	.poll = port_fops_poll,
1097	.release = port_fops_release,
1098	.fasync = port_fops_fasync,
1099	.llseek = no_llseek,
1100	};
1101
1102	/*
1103	* The put_chars() callback is pretty straightforward.
1104	*
1105	* We turn the characters into a scatter-gather list, add it to the
1106	* output queue and then kick the Host. Then we sit here waiting for
1107	* it to finish: inefficient in theory, but in practice
1108	* implementations will do it immediately.
1109	*/
1110	static int put_chars(u32 vtermno, const char *buf, int count)
1111	{
1112	struct port *port;
1113	struct scatterlist sg[1];
1114	void *data;
1115	int ret;
1116
1117	if (unlikely(early_put_chars))
1118	return early_put_chars(vtermno, buf, count);
1119
1120	port = find_port_by_vtermno(vtermno);
1121	if (!port)
1122	return -EPIPE;
1123
1124	data = kmemdup(p: buf, size: count, GFP_ATOMIC);
1125	if (!data)
1126	return -ENOMEM;
1127
1128	sg_init_one(sg, data, count);
1129	ret = __send_to_port(port, sg, nents: 1, in_count: count, data, nonblock: false);
1130	kfree(objp: data);
1131	return ret;
1132	}
1133
1134	/*
1135	* get_chars() is the callback from the hvc_console infrastructure
1136	* when an interrupt is received.
1137	*
1138	* We call out to fill_readbuf that gets us the required data from the
1139	* buffers that are queued up.
1140	*/
1141	static int get_chars(u32 vtermno, char *buf, int count)
1142	{
1143	struct port *port;
1144
1145	/* If we've not set up the port yet, we have no input to give. */
1146	if (unlikely(early_put_chars))
1147	return 0;
1148
1149	port = find_port_by_vtermno(vtermno);
1150	if (!port)
1151	return -EPIPE;
1152
1153	/* If we don't have an input queue yet, we can't get input. */
1154	BUG_ON(!port->in_vq);
1155
1156	return fill_readbuf(port, out_buf: (__force char __user *)buf, out_count: count, to_user: false);
1157	}
1158
1159	static void resize_console(struct port *port)
1160	{
1161	struct virtio_device *vdev;
1162
1163	/* The port could have been hot-unplugged */
1164	if (!port || !is_console_port(port))
1165	return;
1166
1167	vdev = port->portdev->vdev;
1168
1169	/* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1170	if (!is_rproc_serial(vdev) &&
1171	virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1172	hvc_resize(hp: port->cons.hvc, ws: port->cons.ws);
1173	}
1174
1175	/* We set the configuration at this point, since we now have a tty */
1176	static int notifier_add_vio(struct hvc_struct *hp, int data)
1177	{
1178	struct port *port;
1179
1180	port = find_port_by_vtermno(vtermno: hp->vtermno);
1181	if (!port)
1182	return -EINVAL;
1183
1184	hp->irq_requested = 1;
1185	resize_console(port);
1186
1187	return 0;
1188	}
1189
1190	static void notifier_del_vio(struct hvc_struct *hp, int data)
1191	{
1192	hp->irq_requested = 0;
1193	}
1194
1195	/* The operations for console ports. */
1196	static const struct hv_ops hv_ops = {
1197	.get_chars = get_chars,
1198	.put_chars = put_chars,
1199	.notifier_add = notifier_add_vio,
1200	.notifier_del = notifier_del_vio,
1201	.notifier_hangup = notifier_del_vio,
1202	};
1203
1204	/*
1205	* Console drivers are initialized very early so boot messages can go
1206	* out, so we do things slightly differently from the generic virtio
1207	* initialization of the net and block drivers.
1208	*
1209	* At this stage, the console is output-only. It's too early to set
1210	* up a virtqueue, so we let the drivers do some boutique early-output
1211	* thing.
1212	*/
1213	int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
1214	{
1215	early_put_chars = put_chars;
1216	return hvc_instantiate(vtermno: 0, index: 0, ops: &hv_ops);
1217	}
1218
1219	static int init_port_console(struct port *port)
1220	{
1221	int ret;
1222
1223	/*
1224	* The Host's telling us this port is a console port. Hook it
1225	* up with an hvc console.
1226	*
1227	* To set up and manage our virtual console, we call
1228	* hvc_alloc().
1229	*
1230	* The first argument of hvc_alloc() is the virtual console
1231	* number. The second argument is the parameter for the
1232	* notification mechanism (like irq number). We currently
1233	* leave this as zero, virtqueues have implicit notifications.
1234	*
1235	* The third argument is a "struct hv_ops" containing the
1236	* put_chars() get_chars(), notifier_add() and notifier_del()
1237	* pointers. The final argument is the output buffer size: we
1238	* can do any size, so we put PAGE_SIZE here.
1239	*/
1240	ret = ida_alloc_min(ida: &vtermno_ida, min: 1, GFP_KERNEL);
1241	if (ret < 0)
1242	return ret;
1243
1244	port->cons.vtermno = ret;
1245	port->cons.hvc = hvc_alloc(vtermno: port->cons.vtermno, data: 0, ops: &hv_ops, PAGE_SIZE);
1246	if (IS_ERR(ptr: port->cons.hvc)) {
1247	ret = PTR_ERR(ptr: port->cons.hvc);
1248	dev_err(port->dev,
1249	"error %d allocating hvc for port\n", ret);
1250	port->cons.hvc = NULL;
1251	ida_free(&vtermno_ida, id: port->cons.vtermno);
1252	return ret;
1253	}
1254	spin_lock_irq(lock: &pdrvdata_lock);
1255	list_add_tail(new: &port->cons.list, head: &pdrvdata.consoles);
1256	spin_unlock_irq(lock: &pdrvdata_lock);
1257	port->guest_connected = true;
1258
1259	/*
1260	* Start using the new console output if this is the first
1261	* console to come up.
1262	*/
1263	if (early_put_chars)
1264	early_put_chars = NULL;
1265
1266	/* Notify host of port being opened */
1267	send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, value: 1);
1268
1269	return 0;
1270	}
1271
1272	static ssize_t show_port_name(struct device *dev,
1273	struct device_attribute *attr, char *buffer)
1274	{
1275	struct port *port;
1276
1277	port = dev_get_drvdata(dev);
1278
1279	return sprintf(buf: buffer, fmt: "%s\n", port->name);
1280	}
1281
1282	static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1283
1284	static struct attribute *port_sysfs_entries[] = {
1285	&dev_attr_name.attr,
1286	NULL
1287	};
1288
1289	static const struct attribute_group port_attribute_group = {
1290	.name = NULL, /* put in device directory */
1291	.attrs = port_sysfs_entries,
1292	};
1293
1294	static int port_debugfs_show(struct seq_file *s, void *data)
1295	{
1296	struct port *port = s->private;
1297
1298	seq_printf(m: s, fmt: "name: %s\n", port->name ? port->name : "");
1299	seq_printf(m: s, fmt: "guest_connected: %d\n", port->guest_connected);
1300	seq_printf(m: s, fmt: "host_connected: %d\n", port->host_connected);
1301	seq_printf(m: s, fmt: "outvq_full: %d\n", port->outvq_full);
1302	seq_printf(m: s, fmt: "bytes_sent: %lu\n", port->stats.bytes_sent);
1303	seq_printf(m: s, fmt: "bytes_received: %lu\n", port->stats.bytes_received);
1304	seq_printf(m: s, fmt: "bytes_discarded: %lu\n", port->stats.bytes_discarded);
1305	seq_printf(m: s, fmt: "is_console: %s\n",
1306	is_console_port(port) ? "yes" : "no");
1307	seq_printf(m: s, fmt: "console_vtermno: %u\n", port->cons.vtermno);
1308
1309	return 0;
1310	}
1311
1312	DEFINE_SHOW_ATTRIBUTE(port_debugfs);
1313
1314	static void set_console_size(struct port *port, u16 rows, u16 cols)
1315	{
1316	if (!port || !is_console_port(port))
1317	return;
1318
1319	port->cons.ws.ws_row = rows;
1320	port->cons.ws.ws_col = cols;
1321	}
1322
1323	static int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1324	{
1325	struct port_buffer *buf;
1326	int nr_added_bufs;
1327	int ret;
1328
1329	nr_added_bufs = 0;
1330	do {
1331	buf = alloc_buf(vdev: vq->vdev, PAGE_SIZE, pages: 0);
1332	if (!buf)
1333	return -ENOMEM;
1334
1335	spin_lock_irq(lock);
1336	ret = add_inbuf(vq, buf);
1337	if (ret < 0) {
1338	spin_unlock_irq(lock);
1339	free_buf(buf, can_sleep: true);
1340	return ret;
1341	}
1342	nr_added_bufs++;
1343	spin_unlock_irq(lock);
1344	} while (ret > 0);
1345
1346	return nr_added_bufs;
1347	}
1348
1349	static void send_sigio_to_port(struct port *port)
1350	{
1351	if (port->async_queue && port->guest_connected)
1352	kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1353	}
1354
1355	static int add_port(struct ports_device *portdev, u32 id)
1356	{
1357	char debugfs_name[16];
1358	struct port *port;
1359	dev_t devt;
1360	int err;
1361
1362	port = kmalloc(size: sizeof(*port), GFP_KERNEL);
1363	if (!port) {
1364	err = -ENOMEM;
1365	goto fail;
1366	}
1367	kref_init(kref: &port->kref);
1368
1369	port->portdev = portdev;
1370	port->id = id;
1371
1372	port->name = NULL;
1373	port->inbuf = NULL;
1374	port->cons.hvc = NULL;
1375	port->async_queue = NULL;
1376
1377	port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1378	port->cons.vtermno = 0;
1379
1380	port->host_connected = port->guest_connected = false;
1381	port->stats = (struct port_stats) { 0 };
1382
1383	port->outvq_full = false;
1384
1385	port->in_vq = portdev->in_vqs[port->id];
1386	port->out_vq = portdev->out_vqs[port->id];
1387
1388	port->cdev = cdev_alloc();
1389	if (!port->cdev) {
1390	dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1391	err = -ENOMEM;
1392	goto free_port;
1393	}
1394	port->cdev->ops = &port_fops;
1395
1396	devt = MKDEV(portdev->chr_major, id);
1397	err = cdev_add(port->cdev, devt, 1);
1398	if (err < 0) {
1399	dev_err(&port->portdev->vdev->dev,
1400	"Error %d adding cdev for port %u\n", err, id);
1401	goto free_cdev;
1402	}
1403	port->dev = device_create(&port_class, &port->portdev->vdev->dev,
1404	devt, port, "vport%up%u",
1405	port->portdev->vdev->index, id);
1406	if (IS_ERR(port->dev)) {
1407	err = PTR_ERR(port->dev);
1408	dev_err(&port->portdev->vdev->dev,
1409	"Error %d creating device for port %u\n",
1410	err, id);
1411	goto free_cdev;
1412	}
1413
1414	spin_lock_init(&port->inbuf_lock);
1415	spin_lock_init(&port->outvq_lock);
1416	init_waitqueue_head(&port->waitqueue);
1417
1418	/* We can safely ignore ENOSPC because it means
1419	* the queue already has buffers. Buffers are removed
1420	* only by virtcons_remove(), not by unplug_port()
1421	*/
1422	err = fill_queue(port->in_vq, &port->inbuf_lock);
1423	if (err < 0 && err != -ENOSPC) {
1424	dev_err(port->dev, "Error allocating inbufs\n");
1425	goto free_device;
1426	}
1427
1428	if (is_rproc_serial(port->portdev->vdev))
1429	/*
1430	* For rproc_serial assume remote processor is connected.
1431	* rproc_serial does not want the console port, only
1432	* the generic port implementation.
1433	*/
1434	port->host_connected = true;
1435	else if (!use_multiport(port->portdev)) {
1436	/*
1437	* If we're not using multiport support,
1438	* this has to be a console port.
1439	*/
1440	err = init_port_console(port);
1441	if (err)
1442	goto free_inbufs;
1443	}
1444
1445	spin_lock_irq(&portdev->ports_lock);
1446	list_add_tail(&port->list, &port->portdev->ports);
1447	spin_unlock_irq(&portdev->ports_lock);
1448
1449	/*
1450	* Tell the Host we're set so that it can send us various
1451	* configuration parameters for this port (eg, port name,
1452	* caching, whether this is a console port, etc.)
1453	*/
1454	send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1455
1456	/*
1457	* Finally, create the debugfs file that we can use to
1458	* inspect a port's state at any time
1459	*/
1460	snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
1461	port->portdev->vdev->index, id);
1462	port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1463	pdrvdata.debugfs_dir,
1464	port, &port_debugfs_fops);
1465	return 0;
1466
1467	free_inbufs:
1468	free_device:
1469	device_destroy(&port_class, port->dev->devt);
1470	free_cdev:
1471	cdev_del(port->cdev);
1472	free_port:
1473	kfree(port);
1474	fail:
1475	/* The host might want to notify management sw about port add failure */
1476	__send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1477	return err;
1478	}
1479
1480	/* No users remain, remove all port-specific data. */
1481	static void remove_port(struct kref *kref)
1482	{
1483	struct port *port;
1484
1485	port = container_of(kref, struct port, kref);
1486
1487	kfree(objp: port);
1488	}
1489
1490	static void remove_port_data(struct port *port)
1491	{
1492	spin_lock_irq(lock: &port->inbuf_lock);
1493	/* Remove unused data this port might have received. */
1494	discard_port_data(port);
1495	spin_unlock_irq(lock: &port->inbuf_lock);
1496
1497	spin_lock_irq(lock: &port->outvq_lock);
1498	reclaim_consumed_buffers(port);
1499	spin_unlock_irq(lock: &port->outvq_lock);
1500	}
1501
1502	/*
1503	* Port got unplugged. Remove port from portdev's list and drop the
1504	* kref reference. If no userspace has this port opened, it will
1505	* result in immediate removal the port.
1506	*/
1507	static void unplug_port(struct port *port)
1508	{
1509	spin_lock_irq(lock: &port->portdev->ports_lock);
1510	list_del(entry: &port->list);
1511	spin_unlock_irq(lock: &port->portdev->ports_lock);
1512
1513	spin_lock_irq(lock: &port->inbuf_lock);
1514	if (port->guest_connected) {
1515	/* Let the app know the port is going down. */
1516	send_sigio_to_port(port);
1517
1518	/* Do this after sigio is actually sent */
1519	port->guest_connected = false;
1520	port->host_connected = false;
1521
1522	wake_up_interruptible(&port->waitqueue);
1523	}
1524	spin_unlock_irq(lock: &port->inbuf_lock);
1525
1526	if (is_console_port(port)) {
1527	spin_lock_irq(lock: &pdrvdata_lock);
1528	list_del(entry: &port->cons.list);
1529	spin_unlock_irq(lock: &pdrvdata_lock);
1530	hvc_remove(hp: port->cons.hvc);
1531	ida_free(&vtermno_ida, id: port->cons.vtermno);
1532	}
1533
1534	remove_port_data(port);
1535
1536	/*
1537	* We should just assume the device itself has gone off --
1538	* else a close on an open port later will try to send out a
1539	* control message.
1540	*/
1541	port->portdev = NULL;
1542
1543	sysfs_remove_group(kobj: &port->dev->kobj, grp: &port_attribute_group);
1544	device_destroy(cls: &port_class, devt: port->dev->devt);
1545	cdev_del(port->cdev);
1546
1547	debugfs_remove(dentry: port->debugfs_file);
1548	kfree(objp: port->name);
1549
1550	/*
1551	* Locks around here are not necessary - a port can't be
1552	* opened after we removed the port struct from ports_list
1553	* above.
1554	*/
1555	kref_put(kref: &port->kref, release: remove_port);
1556	}
1557
1558	/* Any private messages that the Host and Guest want to share */
1559	static void handle_control_message(struct virtio_device *vdev,
1560	struct ports_device *portdev,
1561	struct port_buffer *buf)
1562	{
1563	struct virtio_console_control *cpkt;
1564	struct port *port;
1565	size_t name_size;
1566	int err;
1567
1568	cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1569
1570	port = find_port_by_id(portdev, id: virtio32_to_cpu(vdev, val: cpkt->id));
1571	if (!port &&
1572	cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1573	/* No valid header at start of buffer. Drop it. */
1574	dev_dbg(&portdev->vdev->dev,
1575	"Invalid index %u in control packet\n", cpkt->id);
1576	return;
1577	}
1578
1579	switch (virtio16_to_cpu(vdev, val: cpkt->event)) {
1580	case VIRTIO_CONSOLE_PORT_ADD:
1581	if (port) {
1582	dev_dbg(&portdev->vdev->dev,
1583	"Port %u already added\n", port->id);
1584	send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, value: 1);
1585	break;
1586	}
1587	if (virtio32_to_cpu(vdev, val: cpkt->id) >=
1588	portdev->max_nr_ports) {
1589	dev_warn(&portdev->vdev->dev,
1590	"Request for adding port with "
1591	"out-of-bound id %u, max. supported id: %u\n",
1592	cpkt->id, portdev->max_nr_ports - 1);
1593	break;
1594	}
1595	add_port(portdev, id: virtio32_to_cpu(vdev, val: cpkt->id));
1596	break;
1597	case VIRTIO_CONSOLE_PORT_REMOVE:
1598	unplug_port(port);
1599	break;
1600	case VIRTIO_CONSOLE_CONSOLE_PORT:
1601	if (!cpkt->value)
1602	break;
1603	if (is_console_port(port))
1604	break;
1605
1606	init_port_console(port);
1607	complete(&early_console_added);
1608	/*
1609	* Could remove the port here in case init fails - but
1610	* have to notify the host first.
1611	*/
1612	break;
1613	case VIRTIO_CONSOLE_RESIZE: {
1614	struct {
1615	__u16 rows;
1616	__u16 cols;
1617	} size;
1618
1619	if (!is_console_port(port))
1620	break;
1621
1622	memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1623	sizeof(size));
1624	set_console_size(port, rows: size.rows, cols: size.cols);
1625
1626	port->cons.hvc->irq_requested = 1;
1627	resize_console(port);
1628	break;
1629	}
1630	case VIRTIO_CONSOLE_PORT_OPEN:
1631	port->host_connected = virtio16_to_cpu(vdev, val: cpkt->value);
1632	wake_up_interruptible(&port->waitqueue);
1633	/*
1634	* If the host port got closed and the host had any
1635	* unconsumed buffers, we'll be able to reclaim them
1636	* now.
1637	*/
1638	spin_lock_irq(lock: &port->outvq_lock);
1639	reclaim_consumed_buffers(port);
1640	spin_unlock_irq(lock: &port->outvq_lock);
1641
1642	/*
1643	* If the guest is connected, it'll be interested in
1644	* knowing the host connection state changed.
1645	*/
1646	spin_lock_irq(lock: &port->inbuf_lock);
1647	send_sigio_to_port(port);
1648	spin_unlock_irq(lock: &port->inbuf_lock);
1649	break;
1650	case VIRTIO_CONSOLE_PORT_NAME:
1651	/*
1652	* If we woke up after hibernation, we can get this
1653	* again. Skip it in that case.
1654	*/
1655	if (port->name)
1656	break;
1657
1658	/*
1659	* Skip the size of the header and the cpkt to get the size
1660	* of the name that was sent
1661	*/
1662	name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1663
1664	port->name = kmalloc(size: name_size, GFP_KERNEL);
1665	if (!port->name) {
1666	dev_err(port->dev,
1667	"Not enough space to store port name\n");
1668	break;
1669	}
1670	strscpy(p: port->name, q: buf->buf + buf->offset + sizeof(*cpkt),
1671	size: name_size);
1672
1673	/*
1674	* Since we only have one sysfs attribute, 'name',
1675	* create it only if we have a name for the port.
1676	*/
1677	err = sysfs_create_group(kobj: &port->dev->kobj,
1678	grp: &port_attribute_group);
1679	if (err) {
1680	dev_err(port->dev,
1681	"Error %d creating sysfs device attributes\n",
1682	err);
1683	} else {
1684	/*
1685	* Generate a udev event so that appropriate
1686	* symlinks can be created based on udev
1687	* rules.
1688	*/
1689	kobject_uevent(kobj: &port->dev->kobj, action: KOBJ_CHANGE);
1690	}
1691	break;
1692	}
1693	}
1694
1695	static void control_work_handler(struct work_struct *work)
1696	{
1697	struct ports_device *portdev;
1698	struct virtqueue *vq;
1699	struct port_buffer *buf;
1700	unsigned int len;
1701
1702	portdev = container_of(work, struct ports_device, control_work);
1703	vq = portdev->c_ivq;
1704
1705	spin_lock(lock: &portdev->c_ivq_lock);
1706	while ((buf = virtqueue_get_buf(vq, len: &len))) {
1707	spin_unlock(lock: &portdev->c_ivq_lock);
1708
1709	buf->len = min_t(size_t, len, buf->size);
1710	buf->offset = 0;
1711
1712	handle_control_message(vdev: vq->vdev, portdev, buf);
1713
1714	spin_lock(lock: &portdev->c_ivq_lock);
1715	if (add_inbuf(vq: portdev->c_ivq, buf) < 0) {
1716	dev_warn(&portdev->vdev->dev,
1717	"Error adding buffer to queue\n");
1718	free_buf(buf, can_sleep: false);
1719	}
1720	}
1721	spin_unlock(lock: &portdev->c_ivq_lock);
1722	}
1723
1724	static void flush_bufs(struct virtqueue *vq, bool can_sleep)
1725	{
1726	struct port_buffer *buf;
1727	unsigned int len;
1728
1729	while ((buf = virtqueue_get_buf(vq, len: &len)))
1730	free_buf(buf, can_sleep);
1731	}
1732
1733	static void out_intr(struct virtqueue *vq)
1734	{
1735	struct port *port;
1736
1737	port = find_port_by_vq(portdev: vq->vdev->priv, vq);
1738	if (!port) {
1739	flush_bufs(vq, can_sleep: false);
1740	return;
1741	}
1742
1743	wake_up_interruptible(&port->waitqueue);
1744	}
1745
1746	static void in_intr(struct virtqueue *vq)
1747	{
1748	struct port *port;
1749	unsigned long flags;
1750
1751	port = find_port_by_vq(portdev: vq->vdev->priv, vq);
1752	if (!port) {
1753	flush_bufs(vq, can_sleep: false);
1754	return;
1755	}
1756
1757	spin_lock_irqsave(&port->inbuf_lock, flags);
1758	port->inbuf = get_inbuf(port);
1759
1760	/*
1761	* Normally the port should not accept data when the port is
1762	* closed. For generic serial ports, the host won't (shouldn't)
1763	* send data till the guest is connected. But this condition
1764	* can be reached when a console port is not yet connected (no
1765	* tty is spawned) and the other side sends out data over the
1766	* vring, or when a remote devices start sending data before
1767	* the ports are opened.
1768	*
1769	* A generic serial port will discard data if not connected,
1770	* while console ports and rproc-serial ports accepts data at
1771	* any time. rproc-serial is initiated with guest_connected to
1772	* false because port_fops_open expects this. Console ports are
1773	* hooked up with an HVC console and is initialized with
1774	* guest_connected to true.
1775	*/
1776
1777	if (!port->guest_connected && !is_rproc_serial(vdev: port->portdev->vdev))
1778	discard_port_data(port);
1779
1780	/* Send a SIGIO indicating new data in case the process asked for it */
1781	send_sigio_to_port(port);
1782
1783	spin_unlock_irqrestore(lock: &port->inbuf_lock, flags);
1784
1785	wake_up_interruptible(&port->waitqueue);
1786
1787	if (is_console_port(port) && hvc_poll(hp: port->cons.hvc))
1788	hvc_kick();
1789	}
1790
1791	static void control_intr(struct virtqueue *vq)
1792	{
1793	struct ports_device *portdev;
1794
1795	portdev = vq->vdev->priv;
1796	schedule_work(work: &portdev->control_work);
1797	}
1798
1799	static void config_intr(struct virtio_device *vdev)
1800	{
1801	struct ports_device *portdev;
1802
1803	portdev = vdev->priv;
1804
1805	if (!use_multiport(portdev))
1806	schedule_work(work: &portdev->config_work);
1807	}
1808
1809	static void config_work_handler(struct work_struct *work)
1810	{
1811	struct ports_device *portdev;
1812
1813	portdev = container_of(work, struct ports_device, config_work);
1814	if (!use_multiport(portdev)) {
1815	struct virtio_device *vdev;
1816	struct port *port;
1817	u16 rows, cols;
1818
1819	vdev = portdev->vdev;
1820	virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1821	virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1822
1823	port = find_port_by_id(portdev, id: 0);
1824	set_console_size(port, rows, cols);
1825
1826	/*
1827	* We'll use this way of resizing only for legacy
1828	* support. For newer userspace
1829	* (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1830	* to indicate console size changes so that it can be
1831	* done per-port.
1832	*/
1833	resize_console(port);
1834	}
1835	}
1836
1837	static int init_vqs(struct ports_device *portdev)
1838	{
1839	vq_callback_t **io_callbacks;
1840	char **io_names;
1841	struct virtqueue **vqs;
1842	u32 i, j, nr_ports, nr_queues;
1843	int err;
1844
1845	nr_ports = portdev->max_nr_ports;
1846	nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1847
1848	vqs = kmalloc_array(n: nr_queues, size: sizeof(struct virtqueue *), GFP_KERNEL);
1849	io_callbacks = kmalloc_array(n: nr_queues, size: sizeof(vq_callback_t *),
1850	GFP_KERNEL);
1851	io_names = kmalloc_array(n: nr_queues, size: sizeof(char *), GFP_KERNEL);
1852	portdev->in_vqs = kmalloc_array(n: nr_ports, size: sizeof(struct virtqueue *),
1853	GFP_KERNEL);
1854	portdev->out_vqs = kmalloc_array(n: nr_ports, size: sizeof(struct virtqueue *),
1855	GFP_KERNEL);
1856	if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1857	!portdev->out_vqs) {
1858	err = -ENOMEM;
1859	goto free;
1860	}
1861
1862	/*
1863	* For backward compat (newer host but older guest), the host
1864	* spawns a console port first and also inits the vqs for port
1865	* 0 before others.
1866	*/
1867	j = 0;
1868	io_callbacks[j] = in_intr;
1869	io_callbacks[j + 1] = out_intr;
1870	io_names[j] = "input";
1871	io_names[j + 1] = "output";
1872	j += 2;
1873
1874	if (use_multiport(portdev)) {
1875	io_callbacks[j] = control_intr;
1876	io_callbacks[j + 1] = NULL;
1877	io_names[j] = "control-i";
1878	io_names[j + 1] = "control-o";
1879
1880	for (i = 1; i < nr_ports; i++) {
1881	j += 2;
1882	io_callbacks[j] = in_intr;
1883	io_callbacks[j + 1] = out_intr;
1884	io_names[j] = "input";
1885	io_names[j + 1] = "output";
1886	}
1887	}
1888	/* Find the queues. */
1889	err = virtio_find_vqs(vdev: portdev->vdev, nvqs: nr_queues, vqs,
1890	callbacks: io_callbacks,
1891	names: (const char **)io_names, NULL);
1892	if (err)
1893	goto free;
1894
1895	j = 0;
1896	portdev->in_vqs[0] = vqs[0];
1897	portdev->out_vqs[0] = vqs[1];
1898	j += 2;
1899	if (use_multiport(portdev)) {
1900	portdev->c_ivq = vqs[j];
1901	portdev->c_ovq = vqs[j + 1];
1902
1903	for (i = 1; i < nr_ports; i++) {
1904	j += 2;
1905	portdev->in_vqs[i] = vqs[j];
1906	portdev->out_vqs[i] = vqs[j + 1];
1907	}
1908	}
1909	kfree(objp: io_names);
1910	kfree(objp: io_callbacks);
1911	kfree(objp: vqs);
1912
1913	return 0;
1914
1915	free:
1916	kfree(objp: portdev->out_vqs);
1917	kfree(objp: portdev->in_vqs);
1918	kfree(objp: io_names);
1919	kfree(objp: io_callbacks);
1920	kfree(objp: vqs);
1921
1922	return err;
1923	}
1924
1925	static const struct file_operations portdev_fops = {
1926	.owner = THIS_MODULE,
1927	};
1928
1929	static void remove_vqs(struct ports_device *portdev)
1930	{
1931	struct virtqueue *vq;
1932
1933	virtio_device_for_each_vq(portdev->vdev, vq) {
1934	struct port_buffer *buf;
1935
1936	flush_bufs(vq, can_sleep: true);
1937	while ((buf = virtqueue_detach_unused_buf(vq)))
1938	free_buf(buf, can_sleep: true);
1939	cond_resched();
1940	}
1941	portdev->vdev->config->del_vqs(portdev->vdev);
1942	kfree(objp: portdev->in_vqs);
1943	kfree(objp: portdev->out_vqs);
1944	}
1945
1946	static void virtcons_remove(struct virtio_device *vdev)
1947	{
1948	struct ports_device *portdev;
1949	struct port *port, *port2;
1950
1951	portdev = vdev->priv;
1952
1953	spin_lock_irq(lock: &pdrvdata_lock);
1954	list_del(entry: &portdev->list);
1955	spin_unlock_irq(lock: &pdrvdata_lock);
1956
1957	/* Device is going away, exit any polling for buffers */
1958	virtio_break_device(dev: vdev);
1959	if (use_multiport(portdev))
1960	flush_work(work: &portdev->control_work);
1961	else
1962	flush_work(work: &portdev->config_work);
1963
1964	/* Disable interrupts for vqs */
1965	virtio_reset_device(dev: vdev);
1966	/* Finish up work that's lined up */
1967	if (use_multiport(portdev))
1968	cancel_work_sync(work: &portdev->control_work);
1969	else
1970	cancel_work_sync(work: &portdev->config_work);
1971
1972	list_for_each_entry_safe(port, port2, &portdev->ports, list)
1973	unplug_port(port);
1974
1975	unregister_chrdev(major: portdev->chr_major, name: "virtio-portsdev");
1976
1977	/*
1978	* When yanking out a device, we immediately lose the
1979	* (device-side) queues. So there's no point in keeping the
1980	* guest side around till we drop our final reference. This
1981	* also means that any ports which are in an open state will
1982	* have to just stop using the port, as the vqs are going
1983	* away.
1984	*/
1985	remove_vqs(portdev);
1986	kfree(objp: portdev);
1987	}
1988
1989	/*
1990	* Once we're further in boot, we get probed like any other virtio
1991	* device.
1992	*
1993	* If the host also supports multiple console ports, we check the
1994	* config space to see how many ports the host has spawned. We
1995	* initialize each port found.
1996	*/
1997	static int virtcons_probe(struct virtio_device *vdev)
1998	{
1999	struct ports_device *portdev;
2000	int err;
2001	bool multiport;
2002	bool early = early_put_chars != NULL;
2003
2004	/* We only need a config space if features are offered */
2005	if (!vdev->config->get &&
2006	(virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
2007	|| virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
2008	dev_err(&vdev->dev, "%s failure: config access disabled\n",
2009	__func__);
2010	return -EINVAL;
2011	}
2012
2013	/* Ensure to read early_put_chars now */
2014	barrier();
2015
2016	portdev = kmalloc(size: sizeof(*portdev), GFP_KERNEL);
2017	if (!portdev) {
2018	err = -ENOMEM;
2019	goto fail;
2020	}
2021
2022	/* Attach this portdev to this virtio_device, and vice-versa. */
2023	portdev->vdev = vdev;
2024	vdev->priv = portdev;
2025
2026	portdev->chr_major = register_chrdev(major: 0, name: "virtio-portsdev",
2027	fops: &portdev_fops);
2028	if (portdev->chr_major < 0) {
2029	dev_err(&vdev->dev,
2030	"Error %d registering chrdev for device %u\n",
2031	portdev->chr_major, vdev->index);
2032	err = portdev->chr_major;
2033	goto free;
2034	}
2035
2036	multiport = false;
2037	portdev->max_nr_ports = 1;
2038
2039	/* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2040	if (!is_rproc_serial(vdev) &&
2041	virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2042	struct virtio_console_config, max_nr_ports,
2043	&portdev->max_nr_ports) == 0) {
2044	if (portdev->max_nr_ports == 0 ||
2045	portdev->max_nr_ports > VIRTCONS_MAX_PORTS) {
2046	dev_err(&vdev->dev,
2047	"Invalidate max_nr_ports %d",
2048	portdev->max_nr_ports);
2049	err = -EINVAL;
2050	goto free;
2051	}
2052	multiport = true;
2053	}
2054
2055	err = init_vqs(portdev);
2056	if (err < 0) {
2057	dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2058	goto free_chrdev;
2059	}
2060
2061	spin_lock_init(&portdev->ports_lock);
2062	INIT_LIST_HEAD(list: &portdev->ports);
2063	INIT_LIST_HEAD(list: &portdev->list);
2064
2065	virtio_device_ready(dev: portdev->vdev);
2066
2067	INIT_WORK(&portdev->config_work, &config_work_handler);
2068	INIT_WORK(&portdev->control_work, &control_work_handler);
2069
2070	if (multiport) {
2071	spin_lock_init(&portdev->c_ivq_lock);
2072	spin_lock_init(&portdev->c_ovq_lock);
2073
2074	err = fill_queue(vq: portdev->c_ivq, lock: &portdev->c_ivq_lock);
2075	if (err < 0) {
2076	dev_err(&vdev->dev,
2077	"Error allocating buffers for control queue\n");
2078	/*
2079	* The host might want to notify mgmt sw about device
2080	* add failure.
2081	*/
2082	__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2083	VIRTIO_CONSOLE_DEVICE_READY, value: 0);
2084	/* Device was functional: we need full cleanup. */
2085	virtcons_remove(vdev);
2086	return err;
2087	}
2088	} else {
2089	/*
2090	* For backward compatibility: Create a console port
2091	* if we're running on older host.
2092	*/
2093	add_port(portdev, id: 0);
2094	}
2095
2096	spin_lock_irq(lock: &pdrvdata_lock);
2097	list_add_tail(new: &portdev->list, head: &pdrvdata.portdevs);
2098	spin_unlock_irq(lock: &pdrvdata_lock);
2099
2100	__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2101	VIRTIO_CONSOLE_DEVICE_READY, value: 1);
2102
2103	/*
2104	* If there was an early virtio console, assume that there are no
2105	* other consoles. We need to wait until the hvc_alloc matches the
2106	* hvc_instantiate, otherwise tty_open will complain, resulting in
2107	* a "Warning: unable to open an initial console" boot failure.
2108	* Without multiport this is done in add_port above. With multiport
2109	* this might take some host<->guest communication - thus we have to
2110	* wait.
2111	*/
2112	if (multiport && early)
2113	wait_for_completion(&early_console_added);
2114
2115	return 0;
2116
2117	free_chrdev:
2118	unregister_chrdev(major: portdev->chr_major, name: "virtio-portsdev");
2119	free:
2120	kfree(objp: portdev);
2121	fail:
2122	return err;
2123	}
2124
2125	static const struct virtio_device_id id_table[] = {
2126	{ VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2127	{ 0 },
2128	};
2129	MODULE_DEVICE_TABLE(virtio, id_table);
2130
2131	static const unsigned int features[] = {
2132	VIRTIO_CONSOLE_F_SIZE,
2133	VIRTIO_CONSOLE_F_MULTIPORT,
2134	};
2135
2136	static const struct virtio_device_id rproc_serial_id_table[] = {
2137	#if IS_ENABLED(CONFIG_REMOTEPROC)
2138	{ VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2139	#endif
2140	{ 0 },
2141	};
2142	MODULE_DEVICE_TABLE(virtio, rproc_serial_id_table);
2143
2144	static const unsigned int rproc_serial_features[] = {
2145	};
2146
2147	#ifdef CONFIG_PM_SLEEP
2148	static int virtcons_freeze(struct virtio_device *vdev)
2149	{
2150	struct ports_device *portdev;
2151	struct port *port;
2152
2153	portdev = vdev->priv;
2154
2155	virtio_reset_device(dev: vdev);
2156
2157	if (use_multiport(portdev))
2158	virtqueue_disable_cb(vq: portdev->c_ivq);
2159	cancel_work_sync(work: &portdev->control_work);
2160	cancel_work_sync(work: &portdev->config_work);
2161	/*
2162	* Once more: if control_work_handler() was running, it would
2163	* enable the cb as the last step.
2164	*/
2165	if (use_multiport(portdev))
2166	virtqueue_disable_cb(vq: portdev->c_ivq);
2167
2168	list_for_each_entry(port, &portdev->ports, list) {
2169	virtqueue_disable_cb(vq: port->in_vq);
2170	virtqueue_disable_cb(vq: port->out_vq);
2171	/*
2172	* We'll ask the host later if the new invocation has
2173	* the port opened or closed.
2174	*/
2175	port->host_connected = false;
2176	remove_port_data(port);
2177	}
2178	remove_vqs(portdev);
2179
2180	return 0;
2181	}
2182
2183	static int virtcons_restore(struct virtio_device *vdev)
2184	{
2185	struct ports_device *portdev;
2186	struct port *port;
2187	int ret;
2188
2189	portdev = vdev->priv;
2190
2191	ret = init_vqs(portdev);
2192	if (ret)
2193	return ret;
2194
2195	virtio_device_ready(dev: portdev->vdev);
2196
2197	if (use_multiport(portdev))
2198	fill_queue(vq: portdev->c_ivq, lock: &portdev->c_ivq_lock);
2199
2200	list_for_each_entry(port, &portdev->ports, list) {
2201	port->in_vq = portdev->in_vqs[port->id];
2202	port->out_vq = portdev->out_vqs[port->id];
2203
2204	fill_queue(vq: port->in_vq, lock: &port->inbuf_lock);
2205
2206	/* Get port open/close status on the host */
2207	send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, value: 1);
2208
2209	/*
2210	* If a port was open at the time of suspending, we
2211	* have to let the host know that it's still open.
2212	*/
2213	if (port->guest_connected)
2214	send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, value: 1);
2215	}
2216	return 0;
2217	}
2218	#endif
2219
2220	static struct virtio_driver virtio_console = {
2221	.feature_table = features,
2222	.feature_table_size = ARRAY_SIZE(features),
2223	.driver.name = KBUILD_MODNAME,
2224	.driver.owner = THIS_MODULE,
2225	.id_table = id_table,
2226	.probe = virtcons_probe,
2227	.remove = virtcons_remove,
2228	.config_changed = config_intr,
2229	#ifdef CONFIG_PM_SLEEP
2230	.freeze = virtcons_freeze,
2231	.restore = virtcons_restore,
2232	#endif
2233	};
2234
2235	static struct virtio_driver virtio_rproc_serial = {
2236	.feature_table = rproc_serial_features,
2237	.feature_table_size = ARRAY_SIZE(rproc_serial_features),
2238	.driver.name = "virtio_rproc_serial",
2239	.driver.owner = THIS_MODULE,
2240	.id_table = rproc_serial_id_table,
2241	.probe = virtcons_probe,
2242	.remove = virtcons_remove,
2243	};
2244
2245	static int __init virtio_console_init(void)
2246	{
2247	int err;
2248
2249	err = class_register(class: &port_class);
2250	if (err)
2251	return err;
2252
2253	pdrvdata.debugfs_dir = debugfs_create_dir(name: "virtio-ports", NULL);
2254	INIT_LIST_HEAD(list: &pdrvdata.consoles);
2255	INIT_LIST_HEAD(list: &pdrvdata.portdevs);
2256
2257	err = register_virtio_driver(drv: &virtio_console);
2258	if (err < 0) {
2259	pr_err("Error %d registering virtio driver\n", err);
2260	goto free;
2261	}
2262	err = register_virtio_driver(drv: &virtio_rproc_serial);
2263	if (err < 0) {
2264	pr_err("Error %d registering virtio rproc serial driver\n",
2265	err);
2266	goto unregister;
2267	}
2268	return 0;
2269	unregister:
2270	unregister_virtio_driver(drv: &virtio_console);
2271	free:
2272	debugfs_remove_recursive(dentry: pdrvdata.debugfs_dir);
2273	class_unregister(class: &port_class);
2274	return err;
2275	}
2276
2277	static void __exit virtio_console_fini(void)
2278	{
2279	reclaim_dma_bufs();
2280
2281	unregister_virtio_driver(drv: &virtio_console);
2282	unregister_virtio_driver(drv: &virtio_rproc_serial);
2283
2284	class_unregister(class: &port_class);
2285	debugfs_remove_recursive(dentry: pdrvdata.debugfs_dir);
2286	}
2287	module_init(virtio_console_init);
2288	module_exit(virtio_console_fini);
2289
2290	MODULE_DESCRIPTION("Virtio console driver");
2291	MODULE_LICENSE("GPL");
2292