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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{
Al Viro222e4ad2016-01-02 13:31:21 -0500108 return PAGE_SIZE - offset_in_page(data);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500109}
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;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600146 unsigned int len;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600147 struct p9_req_t *req;
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700148 unsigned long flags;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500149
Joe Perches5d385152011-11-28 10:40:46 -0800150 p9_debug(P9_DEBUG_TRANS, ": request done\n");
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500151
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700152 while (1) {
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700153 spin_lock_irqsave(&chan->lock, flags);
Al Viro474fe9f2015-07-12 21:06:44 -0400154 req = virtqueue_get_buf(chan->vq, &len);
155 if (req == NULL) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700156 spin_unlock_irqrestore(&chan->lock, flags);
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700157 break;
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700158 }
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700159 chan->ring_bufs_avail = 1;
160 spin_unlock_irqrestore(&chan->lock, flags);
161 /* Wakeup if anyone waiting for VirtIO ring space. */
162 wake_up(chan->vc_wq);
Dominique Martinet2b6e72e2014-01-17 18:31:00 +0100163 p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700164 }
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500165}
166
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600167/**
168 * pack_sg_list - pack a scatter gather list from a linear buffer
169 * @sg: scatter/gather list to pack into
170 * @start: which segment of the sg_list to start at
171 * @limit: maximum segment to pack data to
172 * @data: data to pack into scatter/gather list
173 * @count: amount of data to pack into the scatter/gather list
174 *
175 * sg_lists have multiple segments of various sizes. This will pack
176 * arbitrary data into an existing scatter gather list, segmenting the
177 * data as necessary within constraints.
178 *
179 */
180
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530181static int pack_sg_list(struct scatterlist *sg, int start,
182 int limit, char *data, int count)
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600183{
184 int s;
185 int index = start;
186
187 while (count) {
188 s = rest_of_page(data);
189 if (s > count)
190 s = count;
Sasha Levin5fcb08b2012-06-11 10:18:13 -0500191 BUG_ON(index > limit);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030192 /* Make sure we don't terminate early. */
193 sg_unmark_end(&sg[index]);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600194 sg_set_buf(&sg[index++], data, s);
195 count -= s;
196 data += s;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600197 }
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030198 if (index-start)
199 sg_mark_end(&sg[index - 1]);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600200 return index-start;
201}
202
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500203/* We don't currently allow canceling of virtio requests */
204static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
205{
206 return 1;
207}
208
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600209/**
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800210 * pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer,
211 * this takes a list of pages.
212 * @sg: scatter/gather list to pack into
213 * @start: which segment of the sg_list to start at
Ben Hutchings2c530402012-07-10 10:55:09 +0000214 * @pdata: a list of pages to add into sg.
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530215 * @nr_pages: number of pages to pack into the scatter/gather list
Al Viro4f3b35c2015-04-01 19:57:53 -0400216 * @offs: amount of data in the beginning of first page _not_ to pack
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800217 * @count: amount of data to pack into the scatter/gather list
218 */
219static int
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530220pack_sg_list_p(struct scatterlist *sg, int start, int limit,
Al Viro4f3b35c2015-04-01 19:57:53 -0400221 struct page **pdata, int nr_pages, size_t offs, int count)
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800222{
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530223 int i = 0, s;
Al Viro4f3b35c2015-04-01 19:57:53 -0400224 int data_off = offs;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800225 int index = start;
226
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530227 BUG_ON(nr_pages > (limit - start));
228 /*
229 * if the first page doesn't start at
230 * page boundary find the offset
231 */
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530232 while (nr_pages) {
Al Viro4f3b35c2015-04-01 19:57:53 -0400233 s = PAGE_SIZE - data_off;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530234 if (s > count)
235 s = count;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030236 /* Make sure we don't terminate early. */
237 sg_unmark_end(&sg[index]);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530238 sg_set_page(&sg[index++], pdata[i++], s, data_off);
239 data_off = 0;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800240 count -= s;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530241 nr_pages--;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800242 }
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030243
244 if (index-start)
245 sg_mark_end(&sg[index - 1]);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530246 return index - start;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800247}
248
249/**
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500250 * p9_virtio_request - issue a request
Abhishek Kulkarni0e155972009-07-19 13:41:55 -0600251 * @client: client instance issuing the request
252 * @req: request to be issued
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600253 *
254 */
255
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600256static int
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500257p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600258{
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530259 int err;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030260 int in, out, out_sgs, in_sgs;
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700261 unsigned long flags;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530262 struct virtio_chan *chan = client->trans;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030263 struct scatterlist *sgs[2];
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600264
Joe Perches5d385152011-11-28 10:40:46 -0800265 p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600266
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700267 req->status = REQ_STATUS_SENT;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530268req_retry:
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700269 spin_lock_irqsave(&chan->lock, flags);
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800270
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030271 out_sgs = in_sgs = 0;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800272 /* Handle out VirtIO ring buffers */
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530273 out = pack_sg_list(chan->sg, 0,
274 VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030275 if (out)
276 sgs[out_sgs++] = chan->sg;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800277
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530278 in = pack_sg_list(chan->sg, out,
279 VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030280 if (in)
281 sgs[out_sgs + in_sgs++] = chan->sg + out;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600282
Al Viro474fe9f2015-07-12 21:06:44 -0400283 err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req,
Rusty Russellf96fde42012-01-12 15:44:42 +1030284 GFP_ATOMIC);
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700285 if (err < 0) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700286 if (err == -ENOSPC) {
287 chan->ring_bufs_avail = 0;
288 spin_unlock_irqrestore(&chan->lock, flags);
289 err = wait_event_interruptible(*chan->vc_wq,
290 chan->ring_bufs_avail);
291 if (err == -ERESTARTSYS)
292 return err;
293
Joe Perches5d385152011-11-28 10:40:46 -0800294 p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530295 goto req_retry;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700296 } else {
297 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800298 p9_debug(P9_DEBUG_TRANS,
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030299 "virtio rpc add_sgs returned failure\n");
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700300 return -EIO;
301 }
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600302 }
Michael S. Tsirkindc3f5e62010-04-13 16:11:50 +0300303 virtqueue_kick(chan->vq);
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700304 spin_unlock_irqrestore(&chan->lock, flags);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600305
Joe Perches5d385152011-11-28 10:40:46 -0800306 p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600307 return 0;
308}
309
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530310static int p9_get_mapped_pages(struct virtio_chan *chan,
Al Viro4f3b35c2015-04-01 19:57:53 -0400311 struct page ***pages,
312 struct iov_iter *data,
313 int count,
314 size_t *offs,
315 int *need_drop)
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530316{
Al Viro4f3b35c2015-04-01 19:57:53 -0400317 int nr_pages;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530318 int err;
Al Viro4f3b35c2015-04-01 19:57:53 -0400319
320 if (!iov_iter_count(data))
321 return 0;
322
323 if (!(data->type & ITER_KVEC)) {
324 int n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530325 /*
326 * We allow only p9_max_pages pinned. We wait for the
327 * Other zc request to finish here
328 */
329 if (atomic_read(&vp_pinned) >= chan->p9_max_pages) {
330 err = wait_event_interruptible(vp_wq,
331 (atomic_read(&vp_pinned) < chan->p9_max_pages));
332 if (err == -ERESTARTSYS)
333 return err;
334 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400335 n = iov_iter_get_pages_alloc(data, pages, count, offs);
336 if (n < 0)
337 return n;
338 *need_drop = 1;
339 nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530340 atomic_add(nr_pages, &vp_pinned);
Al Viro4f3b35c2015-04-01 19:57:53 -0400341 return n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530342 } else {
343 /* kernel buffer, no need to pin pages */
Al Viro4f3b35c2015-04-01 19:57:53 -0400344 int index;
345 size_t len;
346 void *p;
347
348 /* we'd already checked that it's non-empty */
349 while (1) {
350 len = iov_iter_single_seg_count(data);
351 if (likely(len)) {
352 p = data->kvec->iov_base + data->iov_offset;
353 break;
354 }
355 iov_iter_advance(data, 0);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530356 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400357 if (len > count)
358 len = count;
359
360 nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) -
361 (unsigned long)p / PAGE_SIZE;
362
363 *pages = kmalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
364 if (!*pages)
365 return -ENOMEM;
366
367 *need_drop = 0;
Al Viro222e4ad2016-01-02 13:31:21 -0500368 p -= (*offs = offset_in_page(p));
Al Viro4f3b35c2015-04-01 19:57:53 -0400369 for (index = 0; index < nr_pages; index++) {
370 if (is_vmalloc_addr(p))
371 (*pages)[index] = vmalloc_to_page(p);
372 else
373 (*pages)[index] = kmap_to_page(p);
374 p += PAGE_SIZE;
375 }
376 return len;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530377 }
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530378}
379
380/**
381 * p9_virtio_zc_request - issue a zero copy request
382 * @client: client instance issuing the request
383 * @req: request to be issued
384 * @uidata: user bffer that should be ued for zero copy read
385 * @uodata: user buffer that shoud be user for zero copy write
386 * @inlen: read buffer size
387 * @olen: write buffer size
388 * @hdrlen: reader header size, This is the size of response protocol data
389 *
390 */
391static int
392p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
Al Viro4f3b35c2015-04-01 19:57:53 -0400393 struct iov_iter *uidata, struct iov_iter *uodata,
394 int inlen, int outlen, int in_hdr_len)
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530395{
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030396 int in, out, err, out_sgs, in_sgs;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530397 unsigned long flags;
398 int in_nr_pages = 0, out_nr_pages = 0;
399 struct page **in_pages = NULL, **out_pages = NULL;
400 struct virtio_chan *chan = client->trans;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030401 struct scatterlist *sgs[4];
Al Viro4f3b35c2015-04-01 19:57:53 -0400402 size_t offs;
403 int need_drop = 0;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530404
Joe Perches5d385152011-11-28 10:40:46 -0800405 p9_debug(P9_DEBUG_TRANS, "virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530406
407 if (uodata) {
Al Viro4f3b35c2015-04-01 19:57:53 -0400408 int n = p9_get_mapped_pages(chan, &out_pages, uodata,
409 outlen, &offs, &need_drop);
410 if (n < 0)
411 return n;
412 out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
413 if (n != outlen) {
414 __le32 v = cpu_to_le32(n);
415 memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
416 outlen = n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530417 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400418 } else if (uidata) {
419 int n = p9_get_mapped_pages(chan, &in_pages, uidata,
420 inlen, &offs, &need_drop);
421 if (n < 0)
422 return n;
423 in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
424 if (n != inlen) {
425 __le32 v = cpu_to_le32(n);
426 memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
427 inlen = n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530428 }
429 }
430 req->status = REQ_STATUS_SENT;
431req_retry_pinned:
432 spin_lock_irqsave(&chan->lock, flags);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030433
434 out_sgs = in_sgs = 0;
435
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530436 /* out data */
437 out = pack_sg_list(chan->sg, 0,
438 VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
439
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030440 if (out)
441 sgs[out_sgs++] = chan->sg;
442
443 if (out_pages) {
444 sgs[out_sgs++] = chan->sg + out;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530445 out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
Al Viro4f3b35c2015-04-01 19:57:53 -0400446 out_pages, out_nr_pages, offs, outlen);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030447 }
448
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530449 /*
450 * Take care of in data
451 * For example TREAD have 11.
452 * 11 is the read/write header = PDU Header(7) + IO Size (4).
453 * Arrange in such a way that server places header in the
454 * alloced memory and payload onto the user buffer.
455 */
456 in = pack_sg_list(chan->sg, out,
457 VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030458 if (in)
459 sgs[out_sgs + in_sgs++] = chan->sg + out;
460
461 if (in_pages) {
462 sgs[out_sgs + in_sgs++] = chan->sg + out + in;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530463 in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
Al Viro4f3b35c2015-04-01 19:57:53 -0400464 in_pages, in_nr_pages, offs, inlen);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030465 }
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530466
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030467 BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
Al Viro474fe9f2015-07-12 21:06:44 -0400468 err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req,
Rusty Russellf96fde42012-01-12 15:44:42 +1030469 GFP_ATOMIC);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530470 if (err < 0) {
471 if (err == -ENOSPC) {
472 chan->ring_bufs_avail = 0;
473 spin_unlock_irqrestore(&chan->lock, flags);
474 err = wait_event_interruptible(*chan->vc_wq,
475 chan->ring_bufs_avail);
476 if (err == -ERESTARTSYS)
477 goto err_out;
478
Joe Perches5d385152011-11-28 10:40:46 -0800479 p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530480 goto req_retry_pinned;
481 } else {
482 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800483 p9_debug(P9_DEBUG_TRANS,
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030484 "virtio rpc add_sgs returned failure\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530485 err = -EIO;
486 goto err_out;
487 }
488 }
489 virtqueue_kick(chan->vq);
490 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800491 p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530492 err = wait_event_interruptible(*req->wq,
493 req->status >= REQ_STATUS_RCVD);
494 /*
495 * Non kernel buffers are pinned, unpin them
496 */
497err_out:
Al Viro4f3b35c2015-04-01 19:57:53 -0400498 if (need_drop) {
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530499 if (in_pages) {
500 p9_release_pages(in_pages, in_nr_pages);
501 atomic_sub(in_nr_pages, &vp_pinned);
502 }
503 if (out_pages) {
504 p9_release_pages(out_pages, out_nr_pages);
505 atomic_sub(out_nr_pages, &vp_pinned);
506 }
507 /* wakeup anybody waiting for slots to pin pages */
508 wake_up(&vp_wq);
509 }
510 kfree(in_pages);
511 kfree(out_pages);
512 return err;
513}
514
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000515static ssize_t p9_mount_tag_show(struct device *dev,
516 struct device_attribute *attr, char *buf)
517{
518 struct virtio_chan *chan;
519 struct virtio_device *vdev;
520
521 vdev = dev_to_virtio(dev);
522 chan = vdev->priv;
523
Andrey Ryabinin179a5bc2015-01-27 16:00:19 +0300524 memcpy(buf, chan->tag, chan->tag_len);
525 buf[chan->tag_len] = 0;
526
527 return chan->tag_len + 1;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000528}
529
530static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);
531
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600532/**
533 * p9_virtio_probe - probe for existence of 9P virtio channels
534 * @vdev: virtio device to probe
535 *
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000536 * This probes for existing virtio channels.
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600537 *
538 */
539
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600540static int p9_virtio_probe(struct virtio_device *vdev)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500541{
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000542 __u16 tag_len;
543 char *tag;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500544 int err;
545 struct virtio_chan *chan;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500546
Michael S. Tsirkin7754f532015-01-12 16:23:37 +0200547 if (!vdev->config->get) {
548 dev_err(&vdev->dev, "%s failure: config access disabled\n",
549 __func__);
550 return -EINVAL;
551 }
552
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000553 chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL);
554 if (!chan) {
Joe Perches5d385152011-11-28 10:40:46 -0800555 pr_err("Failed to allocate virtio 9P channel\n");
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500556 err = -ENOMEM;
557 goto fail;
558 }
559
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600560 chan->vdev = vdev;
561
562 /* We expect one virtqueue, for requests. */
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600563 chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600564 if (IS_ERR(chan->vq)) {
565 err = PTR_ERR(chan->vq);
566 goto out_free_vq;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500567 }
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600568 chan->vq->vdev->priv = chan;
569 spin_lock_init(&chan->lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500570
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600571 sg_init_table(chan->sg, VIRTQUEUE_NUM);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500572
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500573 chan->inuse = false;
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000574 if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
Rusty Russell855e0c52013-10-14 18:11:51 +1030575 virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000576 } else {
577 err = -EINVAL;
578 goto out_free_vq;
579 }
580 tag = kmalloc(tag_len, GFP_KERNEL);
581 if (!tag) {
582 err = -ENOMEM;
583 goto out_free_vq;
584 }
Rusty Russell855e0c52013-10-14 18:11:51 +1030585
586 virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag),
587 tag, tag_len);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000588 chan->tag = tag;
589 chan->tag_len = tag_len;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000590 err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
591 if (err) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700592 goto out_free_tag;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000593 }
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700594 chan->vc_wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
595 if (!chan->vc_wq) {
596 err = -ENOMEM;
597 goto out_free_tag;
598 }
599 init_waitqueue_head(chan->vc_wq);
600 chan->ring_bufs_avail = 1;
Venkateswararao Jujjuri (JV)68da9ba2011-03-18 15:49:48 -0700601 /* Ceiling limit to avoid denial of service attacks */
602 chan->p9_max_pages = nr_free_buffer_pages()/4;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700603
Michael S. Tsirkin64b4cc32014-10-15 10:22:31 +1030604 virtio_device_ready(vdev);
605
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000606 mutex_lock(&virtio_9p_lock);
607 list_add_tail(&chan->chan_list, &virtio_chan_list);
608 mutex_unlock(&virtio_9p_lock);
Michael Marineaue0d6cb92013-08-11 00:53:45 -0400609
610 /* Let udev rules use the new mount_tag attribute. */
611 kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
612
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500613 return 0;
614
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700615out_free_tag:
616 kfree(tag);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600617out_free_vq:
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600618 vdev->config->del_vqs(vdev);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000619 kfree(chan);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500620fail:
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500621 return err;
622}
623
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600624
625/**
626 * p9_virtio_create - allocate a new virtio channel
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500627 * @client: client instance invoking this transport
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600628 * @devname: string identifying the channel to connect to (unused)
629 * @args: args passed from sys_mount() for per-transport options (unused)
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600630 *
631 * This sets up a transport channel for 9p communication. Right now
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500632 * we only match the first available channel, but eventually we couldlook up
633 * alternate channels by matching devname versus a virtio_config entry.
634 * We use a simple reference count mechanism to ensure that only a single
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600635 * mount has a channel open at a time.
636 *
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600637 */
638
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500639static int
640p9_virtio_create(struct p9_client *client, const char *devname, char *args)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500641{
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000642 struct virtio_chan *chan;
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000643 int ret = -ENOENT;
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000644 int found = 0;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500645
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600646 mutex_lock(&virtio_9p_lock);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000647 list_for_each_entry(chan, &virtio_chan_list, chan_list) {
Sven Eckelmann0b204062010-09-27 15:54:44 -0700648 if (!strncmp(devname, chan->tag, chan->tag_len) &&
649 strlen(devname) == chan->tag_len) {
Aneesh Kumar K.Vf75580c2010-02-15 17:27:00 +0000650 if (!chan->inuse) {
651 chan->inuse = true;
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000652 found = 1;
Aneesh Kumar K.Vf75580c2010-02-15 17:27:00 +0000653 break;
654 }
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000655 ret = -EBUSY;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500656 }
657 }
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600658 mutex_unlock(&virtio_9p_lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500659
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000660 if (!found) {
Aneesh Kumar K.Vc7c72c52015-09-03 13:36:51 +0530661 pr_err("no channels available for device %s\n", devname);
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000662 return ret;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500663 }
664
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500665 client->trans = (void *)chan;
Eric Van Hensbergen562ada62010-01-15 18:54:03 -0600666 client->status = Connected;
Eric Van Hensbergenfea511a2008-10-13 18:45:23 -0500667 chan->client = client;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500668
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500669 return 0;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500670}
671
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600672/**
673 * p9_virtio_remove - clean up resources associated with a virtio device
674 * @vdev: virtio device to remove
675 *
676 */
677
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600678static void p9_virtio_remove(struct virtio_device *vdev)
679{
680 struct virtio_chan *chan = vdev->priv;
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030681 unsigned long warning_time;
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600682
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000683 mutex_lock(&virtio_9p_lock);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030684
685 /* Remove self from list so we don't get new users. */
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000686 list_del(&chan->chan_list);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030687 warning_time = jiffies;
688
689 /* Wait for existing users to close. */
690 while (chan->inuse) {
691 mutex_unlock(&virtio_9p_lock);
692 msleep(250);
693 if (time_after(jiffies, warning_time + 10 * HZ)) {
694 dev_emerg(&vdev->dev,
695 "p9_virtio_remove: waiting for device in use.\n");
696 warning_time = jiffies;
697 }
698 mutex_lock(&virtio_9p_lock);
699 }
700
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000701 mutex_unlock(&virtio_9p_lock);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030702
Pierre Morelea52bf82015-07-09 14:58:26 +0200703 vdev->config->reset(vdev);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030704 vdev->config->del_vqs(vdev);
705
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000706 sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
Michael Marineaue0d6cb92013-08-11 00:53:45 -0400707 kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000708 kfree(chan->tag);
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700709 kfree(chan->vc_wq);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000710 kfree(chan);
711
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600712}
713
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500714static struct virtio_device_id id_table[] = {
715 { VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID },
716 { 0 },
717};
718
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000719static unsigned int features[] = {
720 VIRTIO_9P_MOUNT_TAG,
721};
722
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500723/* The standard "struct lguest_driver": */
724static struct virtio_driver p9_virtio_drv = {
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000725 .feature_table = features,
726 .feature_table_size = ARRAY_SIZE(features),
727 .driver.name = KBUILD_MODNAME,
728 .driver.owner = THIS_MODULE,
729 .id_table = id_table,
730 .probe = p9_virtio_probe,
731 .remove = p9_virtio_remove,
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500732};
733
734static struct p9_trans_module p9_virtio_trans = {
735 .name = "virtio",
736 .create = p9_virtio_create,
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500737 .close = p9_virtio_close,
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500738 .request = p9_virtio_request,
Arnd Bergmanndc893e12013-03-08 12:43:31 -0800739 .zc_request = p9_virtio_zc_request,
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500740 .cancel = p9_virtio_cancel,
Aneesh Kumar K.Vb49d8b52011-08-17 16:56:04 +0000741 /*
742 * We leave one entry for input and one entry for response
743 * headers. We also skip one more entry to accomodate, address
744 * that are not at page boundary, that can result in an extra
745 * page in zero copy.
746 */
747 .maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3),
Eric Van Hensbergenf94741f2013-11-12 10:20:03 -0600748 .def = 1,
Tejun Heo72029fe2008-09-24 16:22:23 -0500749 .owner = THIS_MODULE,
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500750};
751
752/* The standard init function */
753static int __init p9_virtio_init(void)
754{
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000755 INIT_LIST_HEAD(&virtio_chan_list);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500756
757 v9fs_register_trans(&p9_virtio_trans);
758 return register_virtio_driver(&p9_virtio_drv);
759}
760
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600761static void __exit p9_virtio_cleanup(void)
762{
763 unregister_virtio_driver(&p9_virtio_drv);
Tejun Heo72029fe2008-09-24 16:22:23 -0500764 v9fs_unregister_trans(&p9_virtio_trans);
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600765}
766
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500767module_init(p9_virtio_init);
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600768module_exit(p9_virtio_cleanup);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500769
770MODULE_DEVICE_TABLE(virtio, id_table);
771MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
772MODULE_DESCRIPTION("Virtio 9p Transport");
773MODULE_LICENSE("GPL");