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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;
jiangyiwen1d2e1e32018-08-03 12:11:34 +0800195 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;
jiangyiwen1d2e1e32018-08-03 12:11:34 +0800240 BUG_ON(index >= limit);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030241 /* Make sure we don't terminate early. */
242 sg_unmark_end(&sg[index]);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530243 sg_set_page(&sg[index++], pdata[i++], s, data_off);
244 data_off = 0;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800245 count -= s;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530246 nr_pages--;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800247 }
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030248
249 if (index-start)
250 sg_mark_end(&sg[index - 1]);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530251 return index - start;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800252}
253
254/**
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500255 * p9_virtio_request - issue a request
Abhishek Kulkarni0e155972009-07-19 13:41:55 -0600256 * @client: client instance issuing the request
257 * @req: request to be issued
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600258 *
259 */
260
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600261static int
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500262p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600263{
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530264 int err;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030265 int in, out, out_sgs, in_sgs;
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700266 unsigned long flags;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530267 struct virtio_chan *chan = client->trans;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030268 struct scatterlist *sgs[2];
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600269
Joe Perches5d385152011-11-28 10:40:46 -0800270 p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600271
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700272 req->status = REQ_STATUS_SENT;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530273req_retry:
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700274 spin_lock_irqsave(&chan->lock, flags);
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800275
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030276 out_sgs = in_sgs = 0;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800277 /* Handle out VirtIO ring buffers */
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530278 out = pack_sg_list(chan->sg, 0,
279 VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030280 if (out)
281 sgs[out_sgs++] = chan->sg;
Venkateswararao Jujjuri (JV)40388662011-01-28 15:22:36 -0800282
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530283 in = pack_sg_list(chan->sg, out,
284 VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030285 if (in)
286 sgs[out_sgs + in_sgs++] = chan->sg + out;
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600287
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030288 err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
Rusty Russellf96fde42012-01-12 15:44:42 +1030289 GFP_ATOMIC);
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700290 if (err < 0) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700291 if (err == -ENOSPC) {
292 chan->ring_bufs_avail = 0;
293 spin_unlock_irqrestore(&chan->lock, flags);
Tuomas Tynkkynenfd3c3952017-09-06 17:59:08 +0300294 err = wait_event_killable(*chan->vc_wq,
295 chan->ring_bufs_avail);
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700296 if (err == -ERESTARTSYS)
297 return err;
298
Joe Perches5d385152011-11-28 10:40:46 -0800299 p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530300 goto req_retry;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700301 } else {
302 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800303 p9_debug(P9_DEBUG_TRANS,
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030304 "virtio rpc add_sgs returned failure\n");
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700305 return -EIO;
306 }
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600307 }
Michael S. Tsirkindc3f5e62010-04-13 16:11:50 +0300308 virtqueue_kick(chan->vq);
Venkateswararao Jujjuri (JV)419b3952010-09-29 18:06:54 -0700309 spin_unlock_irqrestore(&chan->lock, flags);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600310
Joe Perches5d385152011-11-28 10:40:46 -0800311 p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600312 return 0;
313}
314
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530315static int p9_get_mapped_pages(struct virtio_chan *chan,
Al Viro4f3b35c2015-04-01 19:57:53 -0400316 struct page ***pages,
317 struct iov_iter *data,
318 int count,
319 size_t *offs,
320 int *need_drop)
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530321{
Al Viro4f3b35c2015-04-01 19:57:53 -0400322 int nr_pages;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530323 int err;
Al Viro4f3b35c2015-04-01 19:57:53 -0400324
325 if (!iov_iter_count(data))
326 return 0;
327
328 if (!(data->type & ITER_KVEC)) {
329 int n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530330 /*
331 * We allow only p9_max_pages pinned. We wait for the
332 * Other zc request to finish here
333 */
334 if (atomic_read(&vp_pinned) >= chan->p9_max_pages) {
Tuomas Tynkkynenfd3c3952017-09-06 17:59:08 +0300335 err = wait_event_killable(vp_wq,
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530336 (atomic_read(&vp_pinned) < chan->p9_max_pages));
337 if (err == -ERESTARTSYS)
338 return err;
339 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400340 n = iov_iter_get_pages_alloc(data, pages, count, offs);
341 if (n < 0)
342 return n;
343 *need_drop = 1;
344 nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530345 atomic_add(nr_pages, &vp_pinned);
Al Viro4f3b35c2015-04-01 19:57:53 -0400346 return n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530347 } else {
348 /* kernel buffer, no need to pin pages */
Al Viro4f3b35c2015-04-01 19:57:53 -0400349 int index;
350 size_t len;
351 void *p;
352
353 /* we'd already checked that it's non-empty */
354 while (1) {
355 len = iov_iter_single_seg_count(data);
356 if (likely(len)) {
357 p = data->kvec->iov_base + data->iov_offset;
358 break;
359 }
360 iov_iter_advance(data, 0);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530361 }
Al Viro4f3b35c2015-04-01 19:57:53 -0400362 if (len > count)
363 len = count;
364
365 nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) -
366 (unsigned long)p / PAGE_SIZE;
367
368 *pages = kmalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
369 if (!*pages)
370 return -ENOMEM;
371
372 *need_drop = 0;
373 p -= (*offs = (unsigned long)p % PAGE_SIZE);
374 for (index = 0; index < nr_pages; index++) {
375 if (is_vmalloc_addr(p))
376 (*pages)[index] = vmalloc_to_page(p);
377 else
378 (*pages)[index] = kmap_to_page(p);
379 p += PAGE_SIZE;
380 }
381 return len;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530382 }
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530383}
384
385/**
386 * p9_virtio_zc_request - issue a zero copy request
387 * @client: client instance issuing the request
388 * @req: request to be issued
389 * @uidata: user bffer that should be ued for zero copy read
390 * @uodata: user buffer that shoud be user for zero copy write
391 * @inlen: read buffer size
392 * @olen: write buffer size
393 * @hdrlen: reader header size, This is the size of response protocol data
394 *
395 */
396static int
397p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
Al Viro4f3b35c2015-04-01 19:57:53 -0400398 struct iov_iter *uidata, struct iov_iter *uodata,
399 int inlen, int outlen, int in_hdr_len)
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530400{
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030401 int in, out, err, out_sgs, in_sgs;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530402 unsigned long flags;
403 int in_nr_pages = 0, out_nr_pages = 0;
404 struct page **in_pages = NULL, **out_pages = NULL;
405 struct virtio_chan *chan = client->trans;
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030406 struct scatterlist *sgs[4];
Al Viro4f3b35c2015-04-01 19:57:53 -0400407 size_t offs;
408 int need_drop = 0;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530409
Joe Perches5d385152011-11-28 10:40:46 -0800410 p9_debug(P9_DEBUG_TRANS, "virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530411
412 if (uodata) {
Chirantan Ekbotec9f7c992018-07-16 17:35:29 -0700413 __le32 sz;
Al Viro4f3b35c2015-04-01 19:57:53 -0400414 int n = p9_get_mapped_pages(chan, &out_pages, uodata,
415 outlen, &offs, &need_drop);
416 if (n < 0)
417 return n;
418 out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
419 if (n != outlen) {
420 __le32 v = cpu_to_le32(n);
421 memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
422 outlen = n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530423 }
Chirantan Ekbotec9f7c992018-07-16 17:35:29 -0700424 /* The size field of the message must include the length of the
425 * header and the length of the data. We didn't actually know
426 * the length of the data until this point so add it in now.
427 */
428 sz = cpu_to_le32(req->tc->size + outlen);
429 memcpy(&req->tc->sdata[0], &sz, sizeof(sz));
Al Viro4f3b35c2015-04-01 19:57:53 -0400430 } else if (uidata) {
431 int n = p9_get_mapped_pages(chan, &in_pages, uidata,
432 inlen, &offs, &need_drop);
433 if (n < 0)
434 return n;
435 in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
436 if (n != inlen) {
437 __le32 v = cpu_to_le32(n);
438 memcpy(&req->tc->sdata[req->tc->size - 4], &v, 4);
439 inlen = n;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530440 }
441 }
442 req->status = REQ_STATUS_SENT;
443req_retry_pinned:
444 spin_lock_irqsave(&chan->lock, flags);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030445
446 out_sgs = in_sgs = 0;
447
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530448 /* out data */
449 out = pack_sg_list(chan->sg, 0,
450 VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
451
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030452 if (out)
453 sgs[out_sgs++] = chan->sg;
454
455 if (out_pages) {
456 sgs[out_sgs++] = chan->sg + out;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530457 out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
Al Viro4f3b35c2015-04-01 19:57:53 -0400458 out_pages, out_nr_pages, offs, outlen);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030459 }
460
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530461 /*
462 * Take care of in data
463 * For example TREAD have 11.
464 * 11 is the read/write header = PDU Header(7) + IO Size (4).
465 * Arrange in such a way that server places header in the
466 * alloced memory and payload onto the user buffer.
467 */
468 in = pack_sg_list(chan->sg, out,
469 VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030470 if (in)
471 sgs[out_sgs + in_sgs++] = chan->sg + out;
472
473 if (in_pages) {
474 sgs[out_sgs + in_sgs++] = chan->sg + out + in;
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530475 in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
Al Viro4f3b35c2015-04-01 19:57:53 -0400476 in_pages, in_nr_pages, offs, inlen);
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030477 }
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530478
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030479 BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
480 err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
Rusty Russellf96fde42012-01-12 15:44:42 +1030481 GFP_ATOMIC);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530482 if (err < 0) {
483 if (err == -ENOSPC) {
484 chan->ring_bufs_avail = 0;
485 spin_unlock_irqrestore(&chan->lock, flags);
Tuomas Tynkkynenfd3c3952017-09-06 17:59:08 +0300486 err = wait_event_killable(*chan->vc_wq,
487 chan->ring_bufs_avail);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530488 if (err == -ERESTARTSYS)
489 goto err_out;
490
Joe Perches5d385152011-11-28 10:40:46 -0800491 p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530492 goto req_retry_pinned;
493 } else {
494 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800495 p9_debug(P9_DEBUG_TRANS,
Rusty Russell0b36f1a2013-03-20 15:44:30 +1030496 "virtio rpc add_sgs returned failure\n");
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530497 err = -EIO;
498 goto err_out;
499 }
500 }
501 virtqueue_kick(chan->vq);
502 spin_unlock_irqrestore(&chan->lock, flags);
Joe Perches5d385152011-11-28 10:40:46 -0800503 p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
Tuomas Tynkkynenfd3c3952017-09-06 17:59:08 +0300504 err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530505 /*
506 * Non kernel buffers are pinned, unpin them
507 */
508err_out:
Al Viro4f3b35c2015-04-01 19:57:53 -0400509 if (need_drop) {
Aneesh Kumar K.Vabfa0342011-08-16 10:50:10 +0530510 if (in_pages) {
511 p9_release_pages(in_pages, in_nr_pages);
512 atomic_sub(in_nr_pages, &vp_pinned);
513 }
514 if (out_pages) {
515 p9_release_pages(out_pages, out_nr_pages);
516 atomic_sub(out_nr_pages, &vp_pinned);
517 }
518 /* wakeup anybody waiting for slots to pin pages */
519 wake_up(&vp_wq);
520 }
521 kfree(in_pages);
522 kfree(out_pages);
523 return err;
524}
525
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000526static ssize_t p9_mount_tag_show(struct device *dev,
527 struct device_attribute *attr, char *buf)
528{
529 struct virtio_chan *chan;
530 struct virtio_device *vdev;
531
532 vdev = dev_to_virtio(dev);
533 chan = vdev->priv;
534
Andrey Ryabinin179a5bc2015-01-27 16:00:19 +0300535 memcpy(buf, chan->tag, chan->tag_len);
536 buf[chan->tag_len] = 0;
537
538 return chan->tag_len + 1;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000539}
540
541static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);
542
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600543/**
544 * p9_virtio_probe - probe for existence of 9P virtio channels
545 * @vdev: virtio device to probe
546 *
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000547 * This probes for existing virtio channels.
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600548 *
549 */
550
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600551static int p9_virtio_probe(struct virtio_device *vdev)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500552{
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000553 __u16 tag_len;
554 char *tag;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500555 int err;
556 struct virtio_chan *chan;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500557
Michael S. Tsirkin7754f532015-01-12 16:23:37 +0200558 if (!vdev->config->get) {
559 dev_err(&vdev->dev, "%s failure: config access disabled\n",
560 __func__);
561 return -EINVAL;
562 }
563
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000564 chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL);
565 if (!chan) {
Joe Perches5d385152011-11-28 10:40:46 -0800566 pr_err("Failed to allocate virtio 9P channel\n");
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500567 err = -ENOMEM;
568 goto fail;
569 }
570
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600571 chan->vdev = vdev;
572
573 /* We expect one virtqueue, for requests. */
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600574 chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600575 if (IS_ERR(chan->vq)) {
576 err = PTR_ERR(chan->vq);
Jean-Philippe Brucker75c55cb2018-07-17 19:14:45 -0700577 goto out_free_chan;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500578 }
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600579 chan->vq->vdev->priv = chan;
580 spin_lock_init(&chan->lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500581
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600582 sg_init_table(chan->sg, VIRTQUEUE_NUM);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500583
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500584 chan->inuse = false;
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000585 if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
Rusty Russell855e0c52013-10-14 18:11:51 +1030586 virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000587 } else {
588 err = -EINVAL;
589 goto out_free_vq;
590 }
591 tag = kmalloc(tag_len, GFP_KERNEL);
592 if (!tag) {
593 err = -ENOMEM;
594 goto out_free_vq;
595 }
Rusty Russell855e0c52013-10-14 18:11:51 +1030596
597 virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag),
598 tag, tag_len);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000599 chan->tag = tag;
600 chan->tag_len = tag_len;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000601 err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
602 if (err) {
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700603 goto out_free_tag;
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000604 }
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700605 chan->vc_wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
606 if (!chan->vc_wq) {
607 err = -ENOMEM;
608 goto out_free_tag;
609 }
610 init_waitqueue_head(chan->vc_wq);
611 chan->ring_bufs_avail = 1;
Venkateswararao Jujjuri (JV)68da9ba2011-03-18 15:49:48 -0700612 /* Ceiling limit to avoid denial of service attacks */
613 chan->p9_max_pages = nr_free_buffer_pages()/4;
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700614
Michael S. Tsirkin64b4cc32014-10-15 10:22:31 +1030615 virtio_device_ready(vdev);
616
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000617 mutex_lock(&virtio_9p_lock);
618 list_add_tail(&chan->chan_list, &virtio_chan_list);
619 mutex_unlock(&virtio_9p_lock);
Michael Marineaue0d6cb92013-08-11 00:53:45 -0400620
621 /* Let udev rules use the new mount_tag attribute. */
622 kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
623
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500624 return 0;
625
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700626out_free_tag:
627 kfree(tag);
Eric Van Hensbergene2735b72008-02-06 19:25:58 -0600628out_free_vq:
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600629 vdev->config->del_vqs(vdev);
Jean-Philippe Brucker75c55cb2018-07-17 19:14:45 -0700630out_free_chan:
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000631 kfree(chan);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500632fail:
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500633 return err;
634}
635
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600636
637/**
638 * p9_virtio_create - allocate a new virtio channel
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500639 * @client: client instance invoking this transport
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600640 * @devname: string identifying the channel to connect to (unused)
641 * @args: args passed from sys_mount() for per-transport options (unused)
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600642 *
643 * This sets up a transport channel for 9p communication. Right now
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500644 * we only match the first available channel, but eventually we couldlook up
645 * alternate channels by matching devname versus a virtio_config entry.
646 * We use a simple reference count mechanism to ensure that only a single
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600647 * mount has a channel open at a time.
648 *
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600649 */
650
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500651static int
652p9_virtio_create(struct p9_client *client, const char *devname, char *args)
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500653{
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000654 struct virtio_chan *chan;
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000655 int ret = -ENOENT;
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000656 int found = 0;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500657
Tomas Bortoli6f9c6112018-07-27 13:05:58 +0200658 if (devname == NULL)
659 return -EINVAL;
660
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600661 mutex_lock(&virtio_9p_lock);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000662 list_for_each_entry(chan, &virtio_chan_list, chan_list) {
Sven Eckelmann0b204062010-09-27 15:54:44 -0700663 if (!strncmp(devname, chan->tag, chan->tag_len) &&
664 strlen(devname) == chan->tag_len) {
Aneesh Kumar K.Vf75580c2010-02-15 17:27:00 +0000665 if (!chan->inuse) {
666 chan->inuse = true;
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000667 found = 1;
Aneesh Kumar K.Vf75580c2010-02-15 17:27:00 +0000668 break;
669 }
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000670 ret = -EBUSY;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500671 }
672 }
Josef 'Jeff' Sipekc1549492008-03-07 11:39:13 -0600673 mutex_unlock(&virtio_9p_lock);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500674
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000675 if (!found) {
Joe Perches5d385152011-11-28 10:40:46 -0800676 pr_err("no channels available\n");
Aneesh Kumar K.Vc1a7c222010-02-15 17:27:02 +0000677 return ret;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500678 }
679
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500680 client->trans = (void *)chan;
Eric Van Hensbergen562ada62010-01-15 18:54:03 -0600681 client->status = Connected;
Eric Van Hensbergenfea511a2008-10-13 18:45:23 -0500682 chan->client = client;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500683
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500684 return 0;
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500685}
686
Eric Van Hensbergenee443992008-03-05 07:08:09 -0600687/**
688 * p9_virtio_remove - clean up resources associated with a virtio device
689 * @vdev: virtio device to remove
690 *
691 */
692
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600693static void p9_virtio_remove(struct virtio_device *vdev)
694{
695 struct virtio_chan *chan = vdev->priv;
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030696 unsigned long warning_time;
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600697
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000698 mutex_lock(&virtio_9p_lock);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030699
700 /* Remove self from list so we don't get new users. */
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000701 list_del(&chan->chan_list);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030702 warning_time = jiffies;
703
704 /* Wait for existing users to close. */
705 while (chan->inuse) {
706 mutex_unlock(&virtio_9p_lock);
707 msleep(250);
708 if (time_after(jiffies, warning_time + 10 * HZ)) {
709 dev_emerg(&vdev->dev,
710 "p9_virtio_remove: waiting for device in use.\n");
711 warning_time = jiffies;
712 }
713 mutex_lock(&virtio_9p_lock);
714 }
715
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000716 mutex_unlock(&virtio_9p_lock);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030717
Pierre Morelea52bf82015-07-09 14:58:26 +0200718 vdev->config->reset(vdev);
Michael S. Tsirkin8051a2a2015-03-12 11:53:41 +1030719 vdev->config->del_vqs(vdev);
720
Aneesh Kumar K.V86c84372010-03-06 04:44:15 +0000721 sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
Michael Marineaue0d6cb92013-08-11 00:53:45 -0400722 kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000723 kfree(chan->tag);
Venkateswararao Jujjuri (JV)52f44e02010-09-29 18:33:41 -0700724 kfree(chan->vc_wq);
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000725 kfree(chan);
726
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600727}
728
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500729static struct virtio_device_id id_table[] = {
730 { VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID },
731 { 0 },
732};
733
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000734static unsigned int features[] = {
735 VIRTIO_9P_MOUNT_TAG,
736};
737
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500738/* The standard "struct lguest_driver": */
739static struct virtio_driver p9_virtio_drv = {
Aneesh Kumar K.V97ee9b02010-03-06 04:44:14 +0000740 .feature_table = features,
741 .feature_table_size = ARRAY_SIZE(features),
742 .driver.name = KBUILD_MODNAME,
743 .driver.owner = THIS_MODULE,
744 .id_table = id_table,
745 .probe = p9_virtio_probe,
746 .remove = p9_virtio_remove,
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500747};
748
749static struct p9_trans_module p9_virtio_trans = {
750 .name = "virtio",
751 .create = p9_virtio_create,
Eric Van Hensbergen8b81ef52008-10-13 18:45:25 -0500752 .close = p9_virtio_close,
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500753 .request = p9_virtio_request,
Arnd Bergmanndc893e12013-03-08 12:43:31 -0800754 .zc_request = p9_virtio_zc_request,
Eric Van Hensbergen91b85342008-10-13 18:45:21 -0500755 .cancel = p9_virtio_cancel,
Aneesh Kumar K.Vb49d8b52011-08-17 16:56:04 +0000756 /*
757 * We leave one entry for input and one entry for response
758 * headers. We also skip one more entry to accomodate, address
759 * that are not at page boundary, that can result in an extra
760 * page in zero copy.
761 */
762 .maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3),
Eric Van Hensbergenf94741f2013-11-12 10:20:03 -0600763 .def = 1,
Tejun Heo72029fe2008-09-24 16:22:23 -0500764 .owner = THIS_MODULE,
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500765};
766
767/* The standard init function */
768static int __init p9_virtio_init(void)
769{
Aneesh Kumar K.V37c1209d42010-02-15 17:27:01 +0000770 INIT_LIST_HEAD(&virtio_chan_list);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500771
772 v9fs_register_trans(&p9_virtio_trans);
773 return register_virtio_driver(&p9_virtio_drv);
774}
775
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600776static void __exit p9_virtio_cleanup(void)
777{
778 unregister_virtio_driver(&p9_virtio_drv);
Tejun Heo72029fe2008-09-24 16:22:23 -0500779 v9fs_unregister_trans(&p9_virtio_trans);
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600780}
781
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500782module_init(p9_virtio_init);
Eric Van Hensbergenf3933542008-02-06 19:25:04 -0600783module_exit(p9_virtio_cleanup);
Eric Van Hensbergenb530cc72007-10-23 13:47:31 -0500784
785MODULE_DEVICE_TABLE(virtio, id_table);
786MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
787MODULE_DESCRIPTION("Virtio 9p Transport");
788MODULE_LICENSE("GPL");