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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);
Greg Kurz39e0a6b2018-01-22 22:02:05 +0100163 if (len)
164 p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
Venkateswararao Jujjuri (JV)a01a9842011-03-14 14:12:49 -0700165 }
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500166}
167
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600168/**
169 * pack_sg_list - pack a scatter gather list from a linear buffer
170 * @sg: scatter/gather list to pack into
171 * @start: which segment of the sg_list to start at
172 * @limit: maximum segment to pack data to
173 * @data: data to pack into scatter/gather list
174 * @count: amount of data to pack into the scatter/gather list
175 *
176 * sg_lists have multiple segments of various sizes. This will pack
177 * arbitrary data into an existing scatter gather list, segmenting the
178 * data as necessary within constraints.
179 *
180 */
181
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530182static int pack_sg_list(struct scatterlist *sg, int start,
183 int limit, char *data, int count)
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600184{
185 int s;
186 int index = start;
187
188 while (count) {
189 s = rest_of_page(data);
190 if (s > count)
191 s = count;
jiangyiwenb69ef7c2018-08-03 12:11:34 +0800192 BUG_ON(index >= limit);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030193 /* Make sure we don't terminate early. */
194 sg_unmark_end(&sg[index]);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600195 sg_set_buf(&sg[index++], data, s);
196 count -= s;
197 data += s;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600198 }
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030199 if (index-start)
200 sg_mark_end(&sg[index - 1]);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600201 return index-start;
202}
203
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500204/* We don't currently allow canceling of virtio requests */
205static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
206{
207 return 1;
208}
209
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600210/**
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800211 * pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer,
212 * this takes a list of pages.
213 * @sg: scatter/gather list to pack into
214 * @start: which segment of the sg_list to start at
Ben Hutchings2c530402012-07-10 10:55:09 +0000215 * @pdata: a list of pages to add into sg.
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530216 * @nr_pages: number of pages to pack into the scatter/gather list
Al Viro4f3b35c2015-04-01 19:57:53 -0400217 * @offs: amount of data in the beginning of first page _not_ to pack
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800218 * @count: amount of data to pack into the scatter/gather list
219 */
220static int
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530221pack_sg_list_p(struct scatterlist *sg, int start, int limit,
Al Viro4f3b35c2015-04-01 19:57:53 -0400222 struct page **pdata, int nr_pages, size_t offs, int count)
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800223{
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530224 int i = 0, s;
Al Viro4f3b35c2015-04-01 19:57:53 -0400225 int data_off = offs;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800226 int index = start;
227
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530228 BUG_ON(nr_pages > (limit - start));
229 /*
230 * if the first page doesn't start at
231 * page boundary find the offset
232 */
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530233 while (nr_pages) {
Al Viro4f3b35c2015-04-01 19:57:53 -0400234 s = PAGE_SIZE - data_off;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530235 if (s > count)
236 s = count;
jiangyiwenb69ef7c2018-08-03 12:11:34 +0800237 BUG_ON(index >= limit);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030238 /* Make sure we don't terminate early. */
239 sg_unmark_end(&sg[index]);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530240 sg_set_page(&sg[index++], pdata[i++], s, data_off);
241 data_off = 0;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800242 count -= s;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530243 nr_pages--;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800244 }
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030245
246 if (index-start)
247 sg_mark_end(&sg[index - 1]);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530248 return index - start;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800249}
250
251/**
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500252 * p9_virtio_request - issue a request
Abhishek Kulkarni0e155972009-07-19 13:41:55 -0600253 * @client: client instance issuing the request
254 * @req: request to be issued
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600255 *
256 */
257
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600258static int
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500259p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600260{
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530261 int err;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030262 int in, out, out_sgs, in_sgs;
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700263 unsigned long flags;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530264 struct virtio_chan *chan = client->trans;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030265 struct scatterlist *sgs[2];
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600266
Joe Perches5d385152011-11-28 10:40:46 -0800267 p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600268
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700269 req->status = REQ_STATUS_SENT;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530270req_retry:
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700271 spin_lock_irqsave(&chan->lock, flags);
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800272
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030273 out_sgs = in_sgs = 0;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800274 /* Handle out VirtIO ring buffers */
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530275 out = pack_sg_list(chan->sg, 0,
276 VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030277 if (out)
278 sgs[out_sgs++] = chan->sg;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800279
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530280 in = pack_sg_list(chan->sg, out,
281 VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030282 if (in)
283 sgs[out_sgs + in_sgs++] = chan->sg + out;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600284
Al Viro474fe9f2015-07-12 21:06:44 -0400285 err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req,
Rusty Russellf96fde42012-01-12 15:44:42 +1030286 GFP_ATOMIC);
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700287 if (err < 0) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700288 if (err == -ENOSPC) {
289 chan->ring_bufs_avail = 0;
290 spin_unlock_irqrestore(&chan->lock, flags);
Tuomas Tynkkynen8bd466c2017-09-06 17:59:08 +0300291 err = wait_event_killable(*chan->vc_wq,
292 chan->ring_bufs_avail);
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700293 if (err == -ERESTARTSYS)
294 return err;
295
Joe Perches5d385152011-11-28 10:40:46 -0800296 p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530297 goto req_retry;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700298 } else {
299 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800300 p9_debug(P9_DEBUG_TRANS,
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030301 "virtio rpc add_sgs returned failure\n");
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700302 return -EIO;
303 }
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600304 }
Michael S. Tsirkindc3f5e62010-04-13 16:11:50 +0300305 virtqueue_kick(chan->vq);
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700306 spin_unlock_irqrestore(&chan->lock, flags);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600307
Joe Perches5d385152011-11-28 10:40:46 -0800308 p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600309 return 0;
310}
311
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530312static int p9_get_mapped_pages(struct virtio_chan *chan,
Al Viro4f3b35c2015-04-01 19:57:53 -0400313 struct page ***pages,
314 struct iov_iter *data,
315 int count,
316 size_t *offs,
317 int *need_drop)
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530318{
Al Viro4f3b35c2015-04-01 19:57:53 -0400319 int nr_pages;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530320 int err;
Al Viro4f3b35c2015-04-01 19:57:53 -0400321
322 if (!iov_iter_count(data))
323 return 0;
324
325 if (!(data->type & ITER_KVEC)) {
326 int n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530327 /*
328 * We allow only p9_max_pages pinned. We wait for the
329 * Other zc request to finish here
330 */
331 if (atomic_read(&vp_pinned) >= chan->p9_max_pages) {
Tuomas Tynkkynen8bd466c2017-09-06 17:59:08 +0300332 err = wait_event_killable(vp_wq,
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530333 (atomic_read(&vp_pinned) < chan->p9_max_pages));
334 if (err == -ERESTARTSYS)
335 return err;
336 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400337 n = iov_iter_get_pages_alloc(data, pages, count, offs);
338 if (n < 0)
339 return n;
340 *need_drop = 1;
341 nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530342 atomic_add(nr_pages, &vp_pinned);
Al Viro4f3b35c2015-04-01 19:57:53 -0400343 return n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530344 } else {
345 /* kernel buffer, no need to pin pages */
Al Viro4f3b35c2015-04-01 19:57:53 -0400346 int index;
347 size_t len;
348 void *p;
349
350 /* we'd already checked that it's non-empty */
351 while (1) {
352 len = iov_iter_single_seg_count(data);
353 if (likely(len)) {
354 p = data->kvec->iov_base + data->iov_offset;
355 break;
356 }
357 iov_iter_advance(data, 0);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530358 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400359 if (len > count)
360 len = count;
361
362 nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) -
363 (unsigned long)p / PAGE_SIZE;
364
365 *pages = kmalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
366 if (!*pages)
367 return -ENOMEM;
368
369 *need_drop = 0;
Al Viro222e4ad2016-01-02 13:31:21 -0500370 p -= (*offs = offset_in_page(p));
Al Viro4f3b35c2015-04-01 19:57:53 -0400371 for (index = 0; index < nr_pages; index++) {
372 if (is_vmalloc_addr(p))
373 (*pages)[index] = vmalloc_to_page(p);
374 else
375 (*pages)[index] = kmap_to_page(p);
376 p += PAGE_SIZE;
377 }
378 return len;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530379 }
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530380}
381
382/**
383 * p9_virtio_zc_request - issue a zero copy request
384 * @client: client instance issuing the request
385 * @req: request to be issued
386 * @uidata: user bffer that should be ued for zero copy read
387 * @uodata: user buffer that shoud be user for zero copy write
388 * @inlen: read buffer size
389 * @olen: write buffer size
390 * @hdrlen: reader header size, This is the size of response protocol data
391 *
392 */
393static int
394p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
Al Viro4f3b35c2015-04-01 19:57:53 -0400395 struct iov_iter *uidata, struct iov_iter *uodata,
396 int inlen, int outlen, int in_hdr_len)
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530397{
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030398 int in, out, err, out_sgs, in_sgs;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530399 unsigned long flags;
400 int in_nr_pages = 0, out_nr_pages = 0;
401 struct page **in_pages = NULL, **out_pages = NULL;
402 struct virtio_chan *chan = client->trans;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030403 struct scatterlist *sgs[4];
Al Viro4f3b35c2015-04-01 19:57:53 -0400404 size_t offs;
405 int need_drop = 0;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530406
Joe Perches5d385152011-11-28 10:40:46 -0800407 p9_debug(P9_DEBUG_TRANS, "virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530408
409 if (uodata) {
Chirantan Ekbote5c451542018-07-16 17:35:29 -0700410 __le32 sz;
Al Viro4f3b35c2015-04-01 19:57:53 -0400411 int n = p9_get_mapped_pages(chan, &out_pages, uodata,
412 outlen, &offs, &need_drop);
413 if (n < 0)
414 return n;
415 out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
416 if (n != outlen) {
417 __le32 v = cpu_to_le32(n);
418 memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
419 outlen = n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530420 }
Chirantan Ekbote5c451542018-07-16 17:35:29 -0700421 /* The size field of the message must include the length of the
422 * header and the length of the data. We didn't actually know
423 * the length of the data until this point so add it in now.
424 */
425 sz = cpu_to_le32(req->tc->size + outlen);
426 memcpy(&req->tc->sdata[0], &sz, sizeof(sz));
Al Viro4f3b35c2015-04-01 19:57:53 -0400427 } else if (uidata) {
428 int n = p9_get_mapped_pages(chan, &in_pages, uidata,
429 inlen, &offs, &need_drop);
430 if (n < 0)
431 return n;
432 in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
433 if (n != inlen) {
434 __le32 v = cpu_to_le32(n);
435 memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
436 inlen = n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530437 }
438 }
439 req->status = REQ_STATUS_SENT;
440req_retry_pinned:
441 spin_lock_irqsave(&chan->lock, flags);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030442
443 out_sgs = in_sgs = 0;
444
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530445 /* out data */
446 out = pack_sg_list(chan->sg, 0,
447 VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
448
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030449 if (out)
450 sgs[out_sgs++] = chan->sg;
451
452 if (out_pages) {
453 sgs[out_sgs++] = chan->sg + out;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530454 out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
Al Viro4f3b35c2015-04-01 19:57:53 -0400455 out_pages, out_nr_pages, offs, outlen);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030456 }
457
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530458 /*
459 * Take care of in data
460 * For example TREAD have 11.
461 * 11 is the read/write header = PDU Header(7) + IO Size (4).
462 * Arrange in such a way that server places header in the
463 * alloced memory and payload onto the user buffer.
464 */
465 in = pack_sg_list(chan->sg, out,
466 VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030467 if (in)
468 sgs[out_sgs + in_sgs++] = chan->sg + out;
469
470 if (in_pages) {
471 sgs[out_sgs + in_sgs++] = chan->sg + out + in;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530472 in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
Al Viro4f3b35c2015-04-01 19:57:53 -0400473 in_pages, in_nr_pages, offs, inlen);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030474 }
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530475
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030476 BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
Al Viro474fe9f2015-07-12 21:06:44 -0400477 err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req,
Rusty Russellf96fde42012-01-12 15:44:42 +1030478 GFP_ATOMIC);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530479 if (err < 0) {
480 if (err == -ENOSPC) {
481 chan->ring_bufs_avail = 0;
482 spin_unlock_irqrestore(&chan->lock, flags);
Tuomas Tynkkynen8bd466c2017-09-06 17:59:08 +0300483 err = wait_event_killable(*chan->vc_wq,
484 chan->ring_bufs_avail);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530485 if (err == -ERESTARTSYS)
486 goto err_out;
487
Joe Perches5d385152011-11-28 10:40:46 -0800488 p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530489 goto req_retry_pinned;
490 } else {
491 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800492 p9_debug(P9_DEBUG_TRANS,
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030493 "virtio rpc add_sgs returned failure\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530494 err = -EIO;
495 goto err_out;
496 }
497 }
498 virtqueue_kick(chan->vq);
499 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800500 p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
Tuomas Tynkkynen8bd466c2017-09-06 17:59:08 +0300501 err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530502 /*
503 * Non kernel buffers are pinned, unpin them
504 */
505err_out:
Al Viro4f3b35c2015-04-01 19:57:53 -0400506 if (need_drop) {
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530507 if (in_pages) {
508 p9_release_pages(in_pages, in_nr_pages);
509 atomic_sub(in_nr_pages, &vp_pinned);
510 }
511 if (out_pages) {
512 p9_release_pages(out_pages, out_nr_pages);
513 atomic_sub(out_nr_pages, &vp_pinned);
514 }
515 /* wakeup anybody waiting for slots to pin pages */
516 wake_up(&vp_wq);
517 }
Vegard Nossum1b8553c2016-08-03 19:59:47 +0300518 kvfree(in_pages);
519 kvfree(out_pages);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530520 return err;
521}
522
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000523static ssize_t p9_mount_tag_show(struct device *dev,
524 struct device_attribute *attr, char *buf)
525{
526 struct virtio_chan *chan;
527 struct virtio_device *vdev;
528
529 vdev = dev_to_virtio(dev);
530 chan = vdev->priv;
531
Andrey Ryabinin179a5bc2015-01-27 16:00:19 +0300532 memcpy(buf, chan->tag, chan->tag_len);
533 buf[chan->tag_len] = 0;
534
535 return chan->tag_len + 1;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000536}
537
538static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);
539
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600540/**
541 * p9_virtio_probe - probe for existence of 9P virtio channels
542 * @vdev: virtio device to probe
543 *
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000544 * This probes for existing virtio channels.
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600545 *
546 */
547
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600548static int p9_virtio_probe(struct virtio_device *vdev)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500549{
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000550 __u16 tag_len;
551 char *tag;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500552 int err;
553 struct virtio_chan *chan;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500554
Michael S. Tsirkin7754f532015-01-12 16:23:37 +0200555 if (!vdev->config->get) {
556 dev_err(&vdev->dev, "%s failure: config access disabled\n",
557 __func__);
558 return -EINVAL;
559 }
560
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000561 chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL);
562 if (!chan) {
Joe Perches5d385152011-11-28 10:40:46 -0800563 pr_err("Failed to allocate virtio 9P channel\n");
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500564 err = -ENOMEM;
565 goto fail;
566 }
567
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600568 chan->vdev = vdev;
569
570 /* We expect one virtqueue, for requests. */
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600571 chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600572 if (IS_ERR(chan->vq)) {
573 err = PTR_ERR(chan->vq);
Jean-Philippe Brucker45b7e1d2018-07-17 19:14:45 -0700574 goto out_free_chan;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500575 }
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600576 chan->vq->vdev->priv = chan;
577 spin_lock_init(&chan->lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500578
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600579 sg_init_table(chan->sg, VIRTQUEUE_NUM);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500580
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500581 chan->inuse = false;
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000582 if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
Rusty Russell855e0c52013-10-14 18:11:51 +1030583 virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000584 } else {
585 err = -EINVAL;
586 goto out_free_vq;
587 }
588 tag = kmalloc(tag_len, GFP_KERNEL);
589 if (!tag) {
590 err = -ENOMEM;
591 goto out_free_vq;
592 }
Rusty Russell855e0c52013-10-14 18:11:51 +1030593
594 virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag),
595 tag, tag_len);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000596 chan->tag = tag;
597 chan->tag_len = tag_len;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000598 err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
599 if (err) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700600 goto out_free_tag;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000601 }
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700602 chan->vc_wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
603 if (!chan->vc_wq) {
604 err = -ENOMEM;
605 goto out_free_tag;
606 }
607 init_waitqueue_head(chan->vc_wq);
608 chan->ring_bufs_avail = 1;
Venkateswararao Jujjuri (JV)68da9ba2011-03-18 15:49:48 -0700609 /* Ceiling limit to avoid denial of service attacks */
610 chan->p9_max_pages = nr_free_buffer_pages()/4;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700611
Michael S. Tsirkin64b4cc32014-10-15 10:22:31 +1030612 virtio_device_ready(vdev);
613
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000614 mutex_lock(&virtio_9p_lock);
615 list_add_tail(&chan->chan_list, &virtio_chan_list);
616 mutex_unlock(&virtio_9p_lock);
Michael Marineaue0d6cb92013-08-11 00:53:45 -0400617
618 /* Let udev rules use the new mount_tag attribute. */
619 kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
620
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500621 return 0;
622
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700623out_free_tag:
624 kfree(tag);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600625out_free_vq:
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600626 vdev->config->del_vqs(vdev);
Jean-Philippe Brucker45b7e1d2018-07-17 19:14:45 -0700627out_free_chan:
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000628 kfree(chan);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500629fail:
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500630 return err;
631}
632
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600633
634/**
635 * p9_virtio_create - allocate a new virtio channel
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500636 * @client: client instance invoking this transport
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600637 * @devname: string identifying the channel to connect to (unused)
638 * @args: args passed from sys_mount() for per-transport options (unused)
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600639 *
640 * This sets up a transport channel for 9p communication. Right now
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500641 * we only match the first available channel, but eventually we couldlook up
642 * alternate channels by matching devname versus a virtio_config entry.
643 * We use a simple reference count mechanism to ensure that only a single
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600644 * mount has a channel open at a time.
645 *
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600646 */
647
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500648static int
649p9_virtio_create(struct p9_client *client, const char *devname, char *args)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500650{
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000651 struct virtio_chan *chan;
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000652 int ret = -ENOENT;
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000653 int found = 0;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500654
Tomas Bortoli3ac733e2018-07-27 13:05:58 +0200655 if (devname == NULL)
656 return -EINVAL;
657
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600658 mutex_lock(&virtio_9p_lock);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000659 list_for_each_entry(chan, &virtio_chan_list, chan_list) {
Sven Eckelmann0b204062010-09-27 15:54:44 -0700660 if (!strncmp(devname, chan->tag, chan->tag_len) &&
661 strlen(devname) == chan->tag_len) {
Aneesh Kumar K.Vf75580c2010-02-15 17:27:00 +0000662 if (!chan->inuse) {
663 chan->inuse = true;
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000664 found = 1;
Aneesh Kumar K.Vf75580c2010-02-15 17:27:00 +0000665 break;
666 }
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000667 ret = -EBUSY;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500668 }
669 }
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600670 mutex_unlock(&virtio_9p_lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500671
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000672 if (!found) {
Aneesh Kumar K.Vc7c72c52015-09-03 13:36:51 +0530673 pr_err("no channels available for device %s\n", devname);
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000674 return ret;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500675 }
676
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500677 client->trans = (void *)chan;
Eric Van Hensbergen562ada62010-01-15 18:54:03 -0600678 client->status = Connected;
Eric Van Hensbergenfea511a2008-10-13 18:45:23 -0500679 chan->client = client;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500680
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500681 return 0;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500682}
683
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600684/**
685 * p9_virtio_remove - clean up resources associated with a virtio device
686 * @vdev: virtio device to remove
687 *
688 */
689
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600690static void p9_virtio_remove(struct virtio_device *vdev)
691{
692 struct virtio_chan *chan = vdev->priv;
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030693 unsigned long warning_time;
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600694
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000695 mutex_lock(&virtio_9p_lock);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030696
697 /* Remove self from list so we don't get new users. */
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000698 list_del(&chan->chan_list);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030699 warning_time = jiffies;
700
701 /* Wait for existing users to close. */
702 while (chan->inuse) {
703 mutex_unlock(&virtio_9p_lock);
704 msleep(250);
705 if (time_after(jiffies, warning_time + 10 * HZ)) {
706 dev_emerg(&vdev->dev,
707 "p9_virtio_remove: waiting for device in use.\n");
708 warning_time = jiffies;
709 }
710 mutex_lock(&virtio_9p_lock);
711 }
712
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000713 mutex_unlock(&virtio_9p_lock);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030714
Pierre Morelea52bf82015-07-09 14:58:26 +0200715 vdev->config->reset(vdev);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030716 vdev->config->del_vqs(vdev);
717
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000718 sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
Michael Marineaue0d6cb92013-08-11 00:53:45 -0400719 kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000720 kfree(chan->tag);
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700721 kfree(chan->vc_wq);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000722 kfree(chan);
723
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600724}
725
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500726static struct virtio_device_id id_table[] = {
727 { VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID },
728 { 0 },
729};
730
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000731static unsigned int features[] = {
732 VIRTIO_9P_MOUNT_TAG,
733};
734
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500735/* The standard "struct lguest_driver": */
736static struct virtio_driver p9_virtio_drv = {
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000737 .feature_table = features,
738 .feature_table_size = ARRAY_SIZE(features),
739 .driver.name = KBUILD_MODNAME,
740 .driver.owner = THIS_MODULE,
741 .id_table = id_table,
742 .probe = p9_virtio_probe,
743 .remove = p9_virtio_remove,
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500744};
745
746static struct p9_trans_module p9_virtio_trans = {
747 .name = "virtio",
748 .create = p9_virtio_create,
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500749 .close = p9_virtio_close,
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500750 .request = p9_virtio_request,
Arnd Bergmanndc893e12013-03-08 12:43:31 -0800751 .zc_request = p9_virtio_zc_request,
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500752 .cancel = p9_virtio_cancel,
Aneesh Kumar K.Vb49d8b52011-08-17 16:56:04 +0000753 /*
754 * We leave one entry for input and one entry for response
755 * headers. We also skip one more entry to accomodate, address
756 * that are not at page boundary, that can result in an extra
757 * page in zero copy.
758 */
759 .maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3),
Eric Van Hensbergenf94741f2013-11-12 10:20:03 -0600760 .def = 1,
Tejun Heo72029fe2008-09-24 16:22:23 -0500761 .owner = THIS_MODULE,
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500762};
763
764/* The standard init function */
765static int __init p9_virtio_init(void)
766{
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000767 INIT_LIST_HEAD(&virtio_chan_list);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500768
769 v9fs_register_trans(&p9_virtio_trans);
770 return register_virtio_driver(&p9_virtio_drv);
771}
772
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600773static void __exit p9_virtio_cleanup(void)
774{
775 unregister_virtio_driver(&p9_virtio_drv);
Tejun Heo72029fe2008-09-24 16:22:23 -0500776 v9fs_unregister_trans(&p9_virtio_trans);
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600777}
778
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500779module_init(p9_virtio_init);
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600780module_exit(p9_virtio_cleanup);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500781
782MODULE_DEVICE_TABLE(virtio, id_table);
783MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
784MODULE_DESCRIPTION("Virtio 9p Transport");
785MODULE_LICENSE("GPL");