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Eric Van Hensbergenb530cc72007-10-23 13:47:31 -05001/*
Eric Van Hensbergenfea511a2008-10-13 18:45:23 -05002 * The Virtio 9p transport driver
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -05003 *
Eric Van Hensbergene2735b72008-02-06 19:25:58 -06004 * This is a block based transport driver based on the lguest block driver
5 * code.
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -05006 *
Eric Van Hensbergenfea511a2008-10-13 18:45:23 -05007 * Copyright (C) 2007, 2008 Eric Van Hensbergen, IBM Corporation
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -05008 *
9 * Based on virtio console driver
10 * Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2
14 * as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to:
23 * Free Software Foundation
24 * 51 Franklin Street, Fifth Floor
25 * Boston, MA 02111-1301 USA
26 *
27 */
28
Joe Perches5d385152011-11-28 10:40:46 -080029#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050031#include <linux/in.h>
32#include <linux/module.h>
33#include <linux/net.h>
34#include <linux/ipv6.h>
35#include <linux/errno.h>
36#include <linux/kernel.h>
37#include <linux/un.h>
38#include <linux/uaccess.h>
39#include <linux/inet.h>
40#include <linux/idr.h>
41#include <linux/file.h>
Will Deaconb9cdc882012-10-19 14:03:32 +010042#include <linux/highmem.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090043#include <linux/slab.h>
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050044#include <net/9p/9p.h>
45#include <linux/parser.h>
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -050046#include <net/9p/client.h>
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050047#include <net/9p/transport.h>
48#include <linux/scatterlist.h>
Venkateswararao Jujjuri (JV)68da9ba2011-03-18 15:49:48 -070049#include <linux/swap.h>
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050050#include <linux/virtio.h>
51#include <linux/virtio_9p.h>
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -080052#include "trans_common.h"
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050053
Eric Van Hensbergene2735b72008-02-06 19:25:58 -060054#define VIRTQUEUE_NUM 128
55
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050056/* a single mutex to manage channel initialization and attachment */
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -060057static DEFINE_MUTEX(virtio_9p_lock);
Venkateswararao Jujjuri (JV)68da9ba2011-03-18 15:49:48 -070058static DECLARE_WAIT_QUEUE_HEAD(vp_wq);
59static atomic_t vp_pinned = ATOMIC_INIT(0);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050060
Eric Van Hensbergenee443992008-03-05 07:08:09 -060061/**
62 * struct virtio_chan - per-instance transport information
63 * @initialized: whether the channel is initialized
64 * @inuse: whether the channel is in use
65 * @lock: protects multiple elements within this structure
Abhishek Kulkarni0e155972009-07-19 13:41:55 -060066 * @client: client instance
Eric Van Hensbergenee443992008-03-05 07:08:09 -060067 * @vdev: virtio dev associated with this channel
68 * @vq: virtio queue associated with this channel
Eric Van Hensbergenee443992008-03-05 07:08:09 -060069 * @sg: scatter gather list which is used to pack a request (protected?)
70 *
71 * We keep all per-channel information in a structure.
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050072 * This structure is allocated within the devices dev->mem space.
73 * A pointer to the structure will get put in the transport private.
Eric Van Hensbergenee443992008-03-05 07:08:09 -060074 *
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050075 */
Eric Van Hensbergenee443992008-03-05 07:08:09 -060076
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +000077struct virtio_chan {
Eric Van Hensbergenee443992008-03-05 07:08:09 -060078 bool inuse;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050079
Eric Van Hensbergene2735b72008-02-06 19:25:58 -060080 spinlock_t lock;
81
Eric Van Hensbergenfea511a2008-10-13 18:45:23 -050082 struct p9_client *client;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -050083 struct virtio_device *vdev;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -060084 struct virtqueue *vq;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -070085 int ring_bufs_avail;
86 wait_queue_head_t *vc_wq;
Venkateswararao Jujjuri (JV)68da9ba2011-03-18 15:49:48 -070087 /* This is global limit. Since we don't have a global structure,
88 * will be placing it in each channel.
89 */
Zhang Yanfei7293bfb2013-02-22 16:35:49 -080090 unsigned long p9_max_pages;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -060091 /* Scatterlist: can be too big for stack. */
92 struct scatterlist sg[VIRTQUEUE_NUM];
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +000093
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +000094 int tag_len;
95 /*
96 * tag name to identify a mount Non-null terminated
97 */
98 char *tag;
99
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000100 struct list_head chan_list;
101};
102
103static struct list_head virtio_chan_list;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500104
105/* How many bytes left in this page. */
106static unsigned int rest_of_page(void *data)
107{
108 return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE);
109}
110
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600111/**
112 * p9_virtio_close - reclaim resources of a channel
Abhishek Kulkarni0e155972009-07-19 13:41:55 -0600113 * @client: client instance
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600114 *
115 * This reclaims a channel by freeing its resources and
116 * reseting its inuse flag.
117 *
118 */
119
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500120static void p9_virtio_close(struct p9_client *client)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500121{
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500122 struct virtio_chan *chan = client->trans;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500123
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600124 mutex_lock(&virtio_9p_lock);
Aneesh Kumar K.Vfb786102010-02-08 11:50:32 +0000125 if (chan)
126 chan->inuse = false;
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600127 mutex_unlock(&virtio_9p_lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500128}
129
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600130/**
131 * req_done - callback which signals activity from the server
132 * @vq: virtio queue activity was received on
133 *
134 * This notifies us that the server has triggered some activity
135 * on the virtio channel - most likely a response to request we
136 * sent. Figure out which requests now have responses and wake up
137 * those threads.
138 *
139 * Bugs: could do with some additional sanity checking, but appears to work.
140 *
141 */
142
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600143static void req_done(struct virtqueue *vq)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500144{
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600145 struct virtio_chan *chan = vq->vdev->priv;
146 struct p9_fcall *rc;
147 unsigned int len;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600148 struct p9_req_t *req;
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700149 unsigned long flags;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500150
Joe Perches5d385152011-11-28 10:40:46 -0800151 p9_debug(P9_DEBUG_TRANS, ": request done\n");
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500152
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700153 while (1) {
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700154 spin_lock_irqsave(&chan->lock, flags);
155 rc = virtqueue_get_buf(chan->vq, &len);
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700156 if (rc == NULL) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700157 spin_unlock_irqrestore(&chan->lock, flags);
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700158 break;
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700159 }
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700160 chan->ring_bufs_avail = 1;
161 spin_unlock_irqrestore(&chan->lock, flags);
162 /* Wakeup if anyone waiting for VirtIO ring space. */
163 wake_up(chan->vc_wq);
Joe Perches5d385152011-11-28 10:40:46 -0800164 p9_debug(P9_DEBUG_TRANS, ": rc %p\n", rc);
165 p9_debug(P9_DEBUG_TRANS, ": lookup tag %d\n", rc->tag);
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700166 req = p9_tag_lookup(chan->client, rc->tag);
Dominique Martinet2b6e72e2014-01-17 18:31:00 +0100167 p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700168 }
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500169}
170
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600171/**
172 * pack_sg_list - pack a scatter gather list from a linear buffer
173 * @sg: scatter/gather list to pack into
174 * @start: which segment of the sg_list to start at
175 * @limit: maximum segment to pack data to
176 * @data: data to pack into scatter/gather list
177 * @count: amount of data to pack into the scatter/gather list
178 *
179 * sg_lists have multiple segments of various sizes. This will pack
180 * arbitrary data into an existing scatter gather list, segmenting the
181 * data as necessary within constraints.
182 *
183 */
184
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530185static int pack_sg_list(struct scatterlist *sg, int start,
186 int limit, char *data, int count)
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600187{
188 int s;
189 int index = start;
190
191 while (count) {
192 s = rest_of_page(data);
193 if (s > count)
194 s = count;
Sasha Levin5fcb08b2012-06-11 10:18:13 -0500195 BUG_ON(index > limit);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030196 /* Make sure we don't terminate early. */
197 sg_unmark_end(&sg[index]);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600198 sg_set_buf(&sg[index++], data, s);
199 count -= s;
200 data += s;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600201 }
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030202 if (index-start)
203 sg_mark_end(&sg[index - 1]);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600204 return index-start;
205}
206
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500207/* We don't currently allow canceling of virtio requests */
208static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
209{
210 return 1;
211}
212
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600213/**
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800214 * pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer,
215 * this takes a list of pages.
216 * @sg: scatter/gather list to pack into
217 * @start: which segment of the sg_list to start at
Ben Hutchings2c530402012-07-10 10:55:09 +0000218 * @pdata: a list of pages to add into sg.
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530219 * @nr_pages: number of pages to pack into the scatter/gather list
Al Viro4f3b35c2015-04-01 19:57:53 -0400220 * @offs: amount of data in the beginning of first page _not_ to pack
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800221 * @count: amount of data to pack into the scatter/gather list
222 */
223static int
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530224pack_sg_list_p(struct scatterlist *sg, int start, int limit,
Al Viro4f3b35c2015-04-01 19:57:53 -0400225 struct page **pdata, int nr_pages, size_t offs, int count)
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800226{
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530227 int i = 0, s;
Al Viro4f3b35c2015-04-01 19:57:53 -0400228 int data_off = offs;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800229 int index = start;
230
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530231 BUG_ON(nr_pages > (limit - start));
232 /*
233 * if the first page doesn't start at
234 * page boundary find the offset
235 */
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530236 while (nr_pages) {
Al Viro4f3b35c2015-04-01 19:57:53 -0400237 s = PAGE_SIZE - data_off;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530238 if (s > count)
239 s = count;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030240 /* Make sure we don't terminate early. */
241 sg_unmark_end(&sg[index]);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530242 sg_set_page(&sg[index++], pdata[i++], s, data_off);
243 data_off = 0;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800244 count -= s;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530245 nr_pages--;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800246 }
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030247
248 if (index-start)
249 sg_mark_end(&sg[index - 1]);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530250 return index - start;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800251}
252
253/**
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500254 * p9_virtio_request - issue a request
Abhishek Kulkarni0e155972009-07-19 13:41:55 -0600255 * @client: client instance issuing the request
256 * @req: request to be issued
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600257 *
258 */
259
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600260static int
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500261p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600262{
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530263 int err;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030264 int in, out, out_sgs, in_sgs;
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700265 unsigned long flags;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530266 struct virtio_chan *chan = client->trans;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030267 struct scatterlist *sgs[2];
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600268
Joe Perches5d385152011-11-28 10:40:46 -0800269 p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600270
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700271 req->status = REQ_STATUS_SENT;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530272req_retry:
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700273 spin_lock_irqsave(&chan->lock, flags);
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800274
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030275 out_sgs = in_sgs = 0;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800276 /* Handle out VirtIO ring buffers */
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530277 out = pack_sg_list(chan->sg, 0,
278 VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030279 if (out)
280 sgs[out_sgs++] = chan->sg;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800281
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530282 in = pack_sg_list(chan->sg, out,
283 VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030284 if (in)
285 sgs[out_sgs + in_sgs++] = chan->sg + out;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600286
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030287 err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
Rusty Russellf96fde42012-01-12 15:44:42 +1030288 GFP_ATOMIC);
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700289 if (err < 0) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700290 if (err == -ENOSPC) {
291 chan->ring_bufs_avail = 0;
292 spin_unlock_irqrestore(&chan->lock, flags);
293 err = wait_event_interruptible(*chan->vc_wq,
294 chan->ring_bufs_avail);
295 if (err == -ERESTARTSYS)
296 return err;
297
Joe Perches5d385152011-11-28 10:40:46 -0800298 p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530299 goto req_retry;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700300 } else {
301 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800302 p9_debug(P9_DEBUG_TRANS,
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030303 "virtio rpc add_sgs returned failure\n");
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700304 return -EIO;
305 }
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600306 }
Michael S. Tsirkindc3f5e62010-04-13 16:11:50 +0300307 virtqueue_kick(chan->vq);
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700308 spin_unlock_irqrestore(&chan->lock, flags);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600309
Joe Perches5d385152011-11-28 10:40:46 -0800310 p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600311 return 0;
312}
313
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530314static int p9_get_mapped_pages(struct virtio_chan *chan,
Al Viro4f3b35c2015-04-01 19:57:53 -0400315 struct page ***pages,
316 struct iov_iter *data,
317 int count,
318 size_t *offs,
319 int *need_drop)
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530320{
Al Viro4f3b35c2015-04-01 19:57:53 -0400321 int nr_pages;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530322 int err;
Al Viro4f3b35c2015-04-01 19:57:53 -0400323
324 if (!iov_iter_count(data))
325 return 0;
326
327 if (!(data->type & ITER_KVEC)) {
328 int n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530329 /*
330 * We allow only p9_max_pages pinned. We wait for the
331 * Other zc request to finish here
332 */
333 if (atomic_read(&vp_pinned) >= chan->p9_max_pages) {
334 err = wait_event_interruptible(vp_wq,
335 (atomic_read(&vp_pinned) < chan->p9_max_pages));
336 if (err == -ERESTARTSYS)
337 return err;
338 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400339 n = iov_iter_get_pages_alloc(data, pages, count, offs);
340 if (n < 0)
341 return n;
342 *need_drop = 1;
343 nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530344 atomic_add(nr_pages, &vp_pinned);
Al Viro4f3b35c2015-04-01 19:57:53 -0400345 return n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530346 } else {
347 /* kernel buffer, no need to pin pages */
Al Viro4f3b35c2015-04-01 19:57:53 -0400348 int index;
349 size_t len;
350 void *p;
351
352 /* we'd already checked that it's non-empty */
353 while (1) {
354 len = iov_iter_single_seg_count(data);
355 if (likely(len)) {
356 p = data->kvec->iov_base + data->iov_offset;
357 break;
358 }
359 iov_iter_advance(data, 0);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530360 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400361 if (len > count)
362 len = count;
363
364 nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) -
365 (unsigned long)p / PAGE_SIZE;
366
367 *pages = kmalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
368 if (!*pages)
369 return -ENOMEM;
370
371 *need_drop = 0;
372 p -= (*offs = (unsigned long)p % PAGE_SIZE);
373 for (index = 0; index < nr_pages; index++) {
374 if (is_vmalloc_addr(p))
375 (*pages)[index] = vmalloc_to_page(p);
376 else
377 (*pages)[index] = kmap_to_page(p);
378 p += PAGE_SIZE;
379 }
380 return len;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530381 }
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530382}
383
384/**
385 * p9_virtio_zc_request - issue a zero copy request
386 * @client: client instance issuing the request
387 * @req: request to be issued
388 * @uidata: user bffer that should be ued for zero copy read
389 * @uodata: user buffer that shoud be user for zero copy write
390 * @inlen: read buffer size
391 * @olen: write buffer size
392 * @hdrlen: reader header size, This is the size of response protocol data
393 *
394 */
395static int
396p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
Al Viro4f3b35c2015-04-01 19:57:53 -0400397 struct iov_iter *uidata, struct iov_iter *uodata,
398 int inlen, int outlen, int in_hdr_len)
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530399{
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030400 int in, out, err, out_sgs, in_sgs;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530401 unsigned long flags;
402 int in_nr_pages = 0, out_nr_pages = 0;
403 struct page **in_pages = NULL, **out_pages = NULL;
404 struct virtio_chan *chan = client->trans;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030405 struct scatterlist *sgs[4];
Al Viro4f3b35c2015-04-01 19:57:53 -0400406 size_t offs;
407 int need_drop = 0;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530408
Joe Perches5d385152011-11-28 10:40:46 -0800409 p9_debug(P9_DEBUG_TRANS, "virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530410
411 if (uodata) {
Al Viro4f3b35c2015-04-01 19:57:53 -0400412 int n = p9_get_mapped_pages(chan, &out_pages, uodata,
413 outlen, &offs, &need_drop);
414 if (n < 0)
415 return n;
416 out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
417 if (n != outlen) {
418 __le32 v = cpu_to_le32(n);
419 memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
420 outlen = n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530421 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400422 } else if (uidata) {
423 int n = p9_get_mapped_pages(chan, &in_pages, uidata,
424 inlen, &offs, &need_drop);
425 if (n < 0)
426 return n;
427 in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
428 if (n != inlen) {
429 __le32 v = cpu_to_le32(n);
430 memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
431 inlen = n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530432 }
433 }
434 req->status = REQ_STATUS_SENT;
435req_retry_pinned:
436 spin_lock_irqsave(&chan->lock, flags);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030437
438 out_sgs = in_sgs = 0;
439
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530440 /* out data */
441 out = pack_sg_list(chan->sg, 0,
442 VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
443
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030444 if (out)
445 sgs[out_sgs++] = chan->sg;
446
447 if (out_pages) {
448 sgs[out_sgs++] = chan->sg + out;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530449 out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
Al Viro4f3b35c2015-04-01 19:57:53 -0400450 out_pages, out_nr_pages, offs, outlen);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030451 }
452
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530453 /*
454 * Take care of in data
455 * For example TREAD have 11.
456 * 11 is the read/write header = PDU Header(7) + IO Size (4).
457 * Arrange in such a way that server places header in the
458 * alloced memory and payload onto the user buffer.
459 */
460 in = pack_sg_list(chan->sg, out,
461 VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030462 if (in)
463 sgs[out_sgs + in_sgs++] = chan->sg + out;
464
465 if (in_pages) {
466 sgs[out_sgs + in_sgs++] = chan->sg + out + in;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530467 in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
Al Viro4f3b35c2015-04-01 19:57:53 -0400468 in_pages, in_nr_pages, offs, inlen);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030469 }
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530470
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030471 BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
472 err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
Rusty Russellf96fde42012-01-12 15:44:42 +1030473 GFP_ATOMIC);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530474 if (err < 0) {
475 if (err == -ENOSPC) {
476 chan->ring_bufs_avail = 0;
477 spin_unlock_irqrestore(&chan->lock, flags);
478 err = wait_event_interruptible(*chan->vc_wq,
479 chan->ring_bufs_avail);
480 if (err == -ERESTARTSYS)
481 goto err_out;
482
Joe Perches5d385152011-11-28 10:40:46 -0800483 p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530484 goto req_retry_pinned;
485 } else {
486 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800487 p9_debug(P9_DEBUG_TRANS,
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030488 "virtio rpc add_sgs returned failure\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530489 err = -EIO;
490 goto err_out;
491 }
492 }
493 virtqueue_kick(chan->vq);
494 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800495 p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530496 err = wait_event_interruptible(*req->wq,
497 req->status >= REQ_STATUS_RCVD);
498 /*
499 * Non kernel buffers are pinned, unpin them
500 */
501err_out:
Al Viro4f3b35c2015-04-01 19:57:53 -0400502 if (need_drop) {
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530503 if (in_pages) {
504 p9_release_pages(in_pages, in_nr_pages);
505 atomic_sub(in_nr_pages, &vp_pinned);
506 }
507 if (out_pages) {
508 p9_release_pages(out_pages, out_nr_pages);
509 atomic_sub(out_nr_pages, &vp_pinned);
510 }
511 /* wakeup anybody waiting for slots to pin pages */
512 wake_up(&vp_wq);
513 }
514 kfree(in_pages);
515 kfree(out_pages);
516 return err;
517}
518
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000519static ssize_t p9_mount_tag_show(struct device *dev,
520 struct device_attribute *attr, char *buf)
521{
522 struct virtio_chan *chan;
523 struct virtio_device *vdev;
524
525 vdev = dev_to_virtio(dev);
526 chan = vdev->priv;
527
Andrey Ryabinin179a5bc2015-01-27 16:00:19 +0300528 memcpy(buf, chan->tag, chan->tag_len);
529 buf[chan->tag_len] = 0;
530
531 return chan->tag_len + 1;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000532}
533
534static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);
535
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600536/**
537 * p9_virtio_probe - probe for existence of 9P virtio channels
538 * @vdev: virtio device to probe
539 *
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000540 * This probes for existing virtio channels.
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600541 *
542 */
543
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600544static int p9_virtio_probe(struct virtio_device *vdev)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500545{
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000546 __u16 tag_len;
547 char *tag;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500548 int err;
549 struct virtio_chan *chan;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500550
Michael S. Tsirkin7754f532015-01-12 16:23:37 +0200551 if (!vdev->config->get) {
552 dev_err(&vdev->dev, "%s failure: config access disabled\n",
553 __func__);
554 return -EINVAL;
555 }
556
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000557 chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL);
558 if (!chan) {
Joe Perches5d385152011-11-28 10:40:46 -0800559 pr_err("Failed to allocate virtio 9P channel\n");
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500560 err = -ENOMEM;
561 goto fail;
562 }
563
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600564 chan->vdev = vdev;
565
566 /* We expect one virtqueue, for requests. */
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600567 chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600568 if (IS_ERR(chan->vq)) {
569 err = PTR_ERR(chan->vq);
570 goto out_free_vq;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500571 }
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600572 chan->vq->vdev->priv = chan;
573 spin_lock_init(&chan->lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500574
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600575 sg_init_table(chan->sg, VIRTQUEUE_NUM);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500576
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500577 chan->inuse = false;
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000578 if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
Rusty Russell855e0c52013-10-14 18:11:51 +1030579 virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000580 } else {
581 err = -EINVAL;
582 goto out_free_vq;
583 }
584 tag = kmalloc(tag_len, GFP_KERNEL);
585 if (!tag) {
586 err = -ENOMEM;
587 goto out_free_vq;
588 }
Rusty Russell855e0c52013-10-14 18:11:51 +1030589
590 virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag),
591 tag, tag_len);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000592 chan->tag = tag;
593 chan->tag_len = tag_len;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000594 err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
595 if (err) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700596 goto out_free_tag;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000597 }
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700598 chan->vc_wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
599 if (!chan->vc_wq) {
600 err = -ENOMEM;
601 goto out_free_tag;
602 }
603 init_waitqueue_head(chan->vc_wq);
604 chan->ring_bufs_avail = 1;
Venkateswararao Jujjuri (JV)68da9ba2011-03-18 15:49:48 -0700605 /* Ceiling limit to avoid denial of service attacks */
606 chan->p9_max_pages = nr_free_buffer_pages()/4;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700607
Michael S. Tsirkin64b4cc32014-10-15 10:22:31 +1030608 virtio_device_ready(vdev);
609
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000610 mutex_lock(&virtio_9p_lock);
611 list_add_tail(&chan->chan_list, &virtio_chan_list);
612 mutex_unlock(&virtio_9p_lock);
Michael Marineaue0d6cb92013-08-11 00:53:45 -0400613
614 /* Let udev rules use the new mount_tag attribute. */
615 kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
616
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500617 return 0;
618
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700619out_free_tag:
620 kfree(tag);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600621out_free_vq:
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600622 vdev->config->del_vqs(vdev);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000623 kfree(chan);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500624fail:
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500625 return err;
626}
627
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600628
629/**
630 * p9_virtio_create - allocate a new virtio channel
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500631 * @client: client instance invoking this transport
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600632 * @devname: string identifying the channel to connect to (unused)
633 * @args: args passed from sys_mount() for per-transport options (unused)
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600634 *
635 * This sets up a transport channel for 9p communication. Right now
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500636 * we only match the first available channel, but eventually we couldlook up
637 * alternate channels by matching devname versus a virtio_config entry.
638 * We use a simple reference count mechanism to ensure that only a single
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600639 * mount has a channel open at a time.
640 *
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600641 */
642
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500643static int
644p9_virtio_create(struct p9_client *client, const char *devname, char *args)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500645{
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000646 struct virtio_chan *chan;
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000647 int ret = -ENOENT;
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000648 int found = 0;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500649
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600650 mutex_lock(&virtio_9p_lock);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000651 list_for_each_entry(chan, &virtio_chan_list, chan_list) {
Sven Eckelmann0b204062010-09-27 15:54:44 -0700652 if (!strncmp(devname, chan->tag, chan->tag_len) &&
653 strlen(devname) == chan->tag_len) {
Aneesh Kumar K.Vf75580c2010-02-15 17:27:00 +0000654 if (!chan->inuse) {
655 chan->inuse = true;
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000656 found = 1;
Aneesh Kumar K.Vf75580c2010-02-15 17:27:00 +0000657 break;
658 }
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000659 ret = -EBUSY;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500660 }
661 }
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600662 mutex_unlock(&virtio_9p_lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500663
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000664 if (!found) {
Joe Perches5d385152011-11-28 10:40:46 -0800665 pr_err("no channels available\n");
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000666 return ret;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500667 }
668
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500669 client->trans = (void *)chan;
Eric Van Hensbergen562ada62010-01-15 18:54:03 -0600670 client->status = Connected;
Eric Van Hensbergenfea511a2008-10-13 18:45:23 -0500671 chan->client = client;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500672
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500673 return 0;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500674}
675
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600676/**
677 * p9_virtio_remove - clean up resources associated with a virtio device
678 * @vdev: virtio device to remove
679 *
680 */
681
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600682static void p9_virtio_remove(struct virtio_device *vdev)
683{
684 struct virtio_chan *chan = vdev->priv;
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030685 unsigned long warning_time;
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600686
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000687 mutex_lock(&virtio_9p_lock);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030688
689 /* Remove self from list so we don't get new users. */
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000690 list_del(&chan->chan_list);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030691 warning_time = jiffies;
692
693 /* Wait for existing users to close. */
694 while (chan->inuse) {
695 mutex_unlock(&virtio_9p_lock);
696 msleep(250);
697 if (time_after(jiffies, warning_time + 10 * HZ)) {
698 dev_emerg(&vdev->dev,
699 "p9_virtio_remove: waiting for device in use.\n");
700 warning_time = jiffies;
701 }
702 mutex_lock(&virtio_9p_lock);
703 }
704
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000705 mutex_unlock(&virtio_9p_lock);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030706
Pierre Morelea52bf82015-07-09 14:58:26 +0200707 vdev->config->reset(vdev);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030708 vdev->config->del_vqs(vdev);
709
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000710 sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
Michael Marineaue0d6cb92013-08-11 00:53:45 -0400711 kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000712 kfree(chan->tag);
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700713 kfree(chan->vc_wq);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000714 kfree(chan);
715
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600716}
717
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500718static struct virtio_device_id id_table[] = {
719 { VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID },
720 { 0 },
721};
722
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000723static unsigned int features[] = {
724 VIRTIO_9P_MOUNT_TAG,
725};
726
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500727/* The standard "struct lguest_driver": */
728static struct virtio_driver p9_virtio_drv = {
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000729 .feature_table = features,
730 .feature_table_size = ARRAY_SIZE(features),
731 .driver.name = KBUILD_MODNAME,
732 .driver.owner = THIS_MODULE,
733 .id_table = id_table,
734 .probe = p9_virtio_probe,
735 .remove = p9_virtio_remove,
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500736};
737
738static struct p9_trans_module p9_virtio_trans = {
739 .name = "virtio",
740 .create = p9_virtio_create,
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500741 .close = p9_virtio_close,
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500742 .request = p9_virtio_request,
Arnd Bergmanndc893e12013-03-08 12:43:31 -0800743 .zc_request = p9_virtio_zc_request,
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500744 .cancel = p9_virtio_cancel,
Aneesh Kumar K.Vb49d8b52011-08-17 16:56:04 +0000745 /*
746 * We leave one entry for input and one entry for response
747 * headers. We also skip one more entry to accomodate, address
748 * that are not at page boundary, that can result in an extra
749 * page in zero copy.
750 */
751 .maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3),
Eric Van Hensbergenf94741f2013-11-12 10:20:03 -0600752 .def = 1,
Tejun Heo72029fe2008-09-24 16:22:23 -0500753 .owner = THIS_MODULE,
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500754};
755
756/* The standard init function */
757static int __init p9_virtio_init(void)
758{
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000759 INIT_LIST_HEAD(&virtio_chan_list);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500760
761 v9fs_register_trans(&p9_virtio_trans);
762 return register_virtio_driver(&p9_virtio_drv);
763}
764
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600765static void __exit p9_virtio_cleanup(void)
766{
767 unregister_virtio_driver(&p9_virtio_drv);
Tejun Heo72029fe2008-09-24 16:22:23 -0500768 v9fs_unregister_trans(&p9_virtio_trans);
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600769}
770
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500771module_init(p9_virtio_init);
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600772module_exit(p9_virtio_cleanup);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500773
774MODULE_DEVICE_TABLE(virtio, id_table);
775MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
776MODULE_DESCRIPTION("Virtio 9p Transport");
777MODULE_LICENSE("GPL");