blob: 9630b1275557978dd45a5e4a0322192bbc30af42 [file] [log] [blame]
Dominique Martinet024b7d62021-11-02 22:12:01 +09001// SPDX-License-Identifier: GPL-2.0-only
Stefano Stabellini868eb122017-04-05 12:03:57 -07002/*
3 * linux/fs/9p/trans_xen
4 *
5 * Xen transport layer.
6 *
7 * Copyright (C) 2017 by Stefano Stabellini <stefano@aporeto.com>
Stefano Stabellini868eb122017-04-05 12:03:57 -07008 */
9
10#include <xen/events.h>
11#include <xen/grant_table.h>
12#include <xen/xen.h>
13#include <xen/xenbus.h>
14#include <xen/interface/io/9pfs.h>
15
16#include <linux/module.h>
Stefano Stabellini71ebd712017-04-05 12:03:58 -070017#include <linux/spinlock.h>
Stefano Stabellini868eb122017-04-05 12:03:57 -070018#include <net/9p/9p.h>
19#include <net/9p/client.h>
20#include <net/9p/transport.h>
21
Stefano Stabellini71ebd712017-04-05 12:03:58 -070022#define XEN_9PFS_NUM_RINGS 2
Stefano Stabellini36f99672020-05-21 12:32:42 -070023#define XEN_9PFS_RING_ORDER 9
24#define XEN_9PFS_RING_SIZE(ring) XEN_FLEX_RING_SIZE(ring->intf->ring_order)
Stefano Stabellini71ebd712017-04-05 12:03:58 -070025
26struct xen_9pfs_header {
27 uint32_t size;
28 uint8_t id;
29 uint16_t tag;
30
31 /* uint8_t sdata[]; */
32} __attribute__((packed));
33
34/* One per ring, more than one per 9pfs share */
35struct xen_9pfs_dataring {
36 struct xen_9pfs_front_priv *priv;
37
38 struct xen_9pfs_data_intf *intf;
39 grant_ref_t ref;
40 int evtchn;
41 int irq;
42 /* protect a ring from concurrent accesses */
43 spinlock_t lock;
44
45 struct xen_9pfs_data data;
46 wait_queue_head_t wq;
47 struct work_struct work;
48};
49
50/* One per 9pfs share */
51struct xen_9pfs_front_priv {
52 struct list_head list;
53 struct xenbus_device *dev;
54 char *tag;
55 struct p9_client *client;
56
57 int num_rings;
58 struct xen_9pfs_dataring *rings;
59};
60
61static LIST_HEAD(xen_9pfs_devs);
62static DEFINE_RWLOCK(xen_9pfs_lock);
63
Stefano Stabellinif023f182017-04-05 12:03:59 -070064/* We don't currently allow canceling of requests */
Stefano Stabellini868eb122017-04-05 12:03:57 -070065static int p9_xen_cancel(struct p9_client *client, struct p9_req_t *req)
66{
Stefano Stabellinif023f182017-04-05 12:03:59 -070067 return 1;
Stefano Stabellini868eb122017-04-05 12:03:57 -070068}
69
70static int p9_xen_create(struct p9_client *client, const char *addr, char *args)
71{
Stefano Stabellinif023f182017-04-05 12:03:59 -070072 struct xen_9pfs_front_priv *priv;
73
Tomas Bortoli10aa1452018-07-27 13:05:58 +020074 if (addr == NULL)
75 return -EINVAL;
76
Stefano Stabellinif023f182017-04-05 12:03:59 -070077 read_lock(&xen_9pfs_lock);
78 list_for_each_entry(priv, &xen_9pfs_devs, list) {
79 if (!strcmp(priv->tag, addr)) {
80 priv->client = client;
81 read_unlock(&xen_9pfs_lock);
82 return 0;
83 }
84 }
85 read_unlock(&xen_9pfs_lock);
86 return -EINVAL;
Stefano Stabellini868eb122017-04-05 12:03:57 -070087}
88
89static void p9_xen_close(struct p9_client *client)
90{
Stefano Stabellinif023f182017-04-05 12:03:59 -070091 struct xen_9pfs_front_priv *priv;
92
93 read_lock(&xen_9pfs_lock);
94 list_for_each_entry(priv, &xen_9pfs_devs, list) {
95 if (priv->client == client) {
96 priv->client = NULL;
97 read_unlock(&xen_9pfs_lock);
98 return;
99 }
100 }
101 read_unlock(&xen_9pfs_lock);
102}
103
104static bool p9_xen_write_todo(struct xen_9pfs_dataring *ring, RING_IDX size)
105{
106 RING_IDX cons, prod;
107
108 cons = ring->intf->out_cons;
109 prod = ring->intf->out_prod;
110 virt_mb();
111
Stefano Stabellini36f99672020-05-21 12:32:42 -0700112 return XEN_9PFS_RING_SIZE(ring) -
113 xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) >= size;
Stefano Stabellini868eb122017-04-05 12:03:57 -0700114}
115
116static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req)
117{
Harshvardhan Jha732b33d2021-07-27 05:37:10 +0530118 struct xen_9pfs_front_priv *priv;
Stefano Stabellinif023f182017-04-05 12:03:59 -0700119 RING_IDX cons, prod, masked_cons, masked_prod;
120 unsigned long flags;
Dominique Martinet523adb62018-07-30 05:55:19 +0000121 u32 size = p9_req->tc.size;
Stefano Stabellinif023f182017-04-05 12:03:59 -0700122 struct xen_9pfs_dataring *ring;
123 int num;
124
125 read_lock(&xen_9pfs_lock);
126 list_for_each_entry(priv, &xen_9pfs_devs, list) {
127 if (priv->client == client)
128 break;
129 }
130 read_unlock(&xen_9pfs_lock);
Harshvardhan Jha732b33d2021-07-27 05:37:10 +0530131 if (list_entry_is_head(priv, &xen_9pfs_devs, list))
Stefano Stabellinif023f182017-04-05 12:03:59 -0700132 return -EINVAL;
133
Dominique Martinet523adb62018-07-30 05:55:19 +0000134 num = p9_req->tc.tag % priv->num_rings;
Stefano Stabellinif023f182017-04-05 12:03:59 -0700135 ring = &priv->rings[num];
136
137again:
Tuomas Tynkkynen9523fea2017-09-06 17:59:08 +0300138 while (wait_event_killable(ring->wq,
139 p9_xen_write_todo(ring, size)) != 0)
Stefano Stabellinif023f182017-04-05 12:03:59 -0700140 ;
141
142 spin_lock_irqsave(&ring->lock, flags);
143 cons = ring->intf->out_cons;
144 prod = ring->intf->out_prod;
145 virt_mb();
146
Stefano Stabellini36f99672020-05-21 12:32:42 -0700147 if (XEN_9PFS_RING_SIZE(ring) -
148 xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) < size) {
Stefano Stabellinif023f182017-04-05 12:03:59 -0700149 spin_unlock_irqrestore(&ring->lock, flags);
150 goto again;
151 }
152
Stefano Stabellini36f99672020-05-21 12:32:42 -0700153 masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE(ring));
154 masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
Stefano Stabellinif023f182017-04-05 12:03:59 -0700155
Dominique Martinet523adb62018-07-30 05:55:19 +0000156 xen_9pfs_write_packet(ring->data.out, p9_req->tc.sdata, size,
Stefano Stabellini36f99672020-05-21 12:32:42 -0700157 &masked_prod, masked_cons,
158 XEN_9PFS_RING_SIZE(ring));
Stefano Stabellinif023f182017-04-05 12:03:59 -0700159
Dominique Martinet1a4f69ef2022-12-05 21:39:01 +0900160 WRITE_ONCE(p9_req->status, REQ_STATUS_SENT);
Stefano Stabellinif023f182017-04-05 12:03:59 -0700161 virt_wmb(); /* write ring before updating pointer */
162 prod += size;
163 ring->intf->out_prod = prod;
164 spin_unlock_irqrestore(&ring->lock, flags);
165 notify_remote_via_irq(ring->irq);
Kent Overstreet8b11ff02022-07-03 21:08:18 -0400166 p9_req_put(client, p9_req);
Stefano Stabellinif023f182017-04-05 12:03:59 -0700167
Stefano Stabellini868eb122017-04-05 12:03:57 -0700168 return 0;
169}
170
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700171static void p9_xen_response(struct work_struct *work)
172{
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700173 struct xen_9pfs_front_priv *priv;
174 struct xen_9pfs_dataring *ring;
175 RING_IDX cons, prod, masked_cons, masked_prod;
176 struct xen_9pfs_header h;
177 struct p9_req_t *req;
178 int status;
179
180 ring = container_of(work, struct xen_9pfs_dataring, work);
181 priv = ring->priv;
182
183 while (1) {
184 cons = ring->intf->in_cons;
185 prod = ring->intf->in_prod;
186 virt_rmb();
187
Stefano Stabellini36f99672020-05-21 12:32:42 -0700188 if (xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) <
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700189 sizeof(h)) {
190 notify_remote_via_irq(ring->irq);
191 return;
192 }
193
Stefano Stabellini36f99672020-05-21 12:32:42 -0700194 masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE(ring));
195 masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700196
197 /* First, read just the header */
198 xen_9pfs_read_packet(&h, ring->data.in, sizeof(h),
199 masked_prod, &masked_cons,
Stefano Stabellini36f99672020-05-21 12:32:42 -0700200 XEN_9PFS_RING_SIZE(ring));
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700201
202 req = p9_tag_lookup(priv->client, h.tag);
203 if (!req || req->status != REQ_STATUS_SENT) {
204 dev_warn(&priv->dev->dev, "Wrong req tag=%x\n", h.tag);
205 cons += h.size;
206 virt_mb();
207 ring->intf->in_cons = cons;
208 continue;
209 }
210
Dominique Martinet391c18c2022-11-18 22:44:41 +0900211 if (h.size > req->rc.capacity) {
212 dev_warn(&priv->dev->dev,
213 "requested packet size too big: %d for tag %d with capacity %zd\n",
214 h.size, h.tag, req->rc.capacity);
Dominique Martinet1a4f69ef2022-12-05 21:39:01 +0900215 WRITE_ONCE(req->status, REQ_STATUS_ERROR);
Dominique Martinet391c18c2022-11-18 22:44:41 +0900216 goto recv_error;
217 }
218
Dominique Martinetf15e0062022-11-22 09:06:56 +0900219 req->rc.size = h.size;
220 req->rc.id = h.id;
221 req->rc.tag = h.tag;
Dominique Martinet523adb62018-07-30 05:55:19 +0000222 req->rc.offset = 0;
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700223
Stefano Stabellini36f99672020-05-21 12:32:42 -0700224 masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring));
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700225 /* Then, read the whole packet (including the header) */
Dominique Martinet523adb62018-07-30 05:55:19 +0000226 xen_9pfs_read_packet(req->rc.sdata, ring->data.in, h.size,
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700227 masked_prod, &masked_cons,
Stefano Stabellini36f99672020-05-21 12:32:42 -0700228 XEN_9PFS_RING_SIZE(ring));
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700229
Dominique Martinet391c18c2022-11-18 22:44:41 +0900230recv_error:
Stefano Stabellinif66c72b2017-04-05 12:04:00 -0700231 virt_mb();
232 cons += h.size;
233 ring->intf->in_cons = cons;
234
235 status = (req->status != REQ_STATUS_ERROR) ?
236 REQ_STATUS_RCVD : REQ_STATUS_ERROR;
237
238 p9_client_cb(priv->client, req, status);
239 }
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700240}
241
242static irqreturn_t xen_9pfs_front_event_handler(int irq, void *r)
243{
244 struct xen_9pfs_dataring *ring = r;
245
246 if (!ring || !ring->priv->client) {
247 /* ignore spurious interrupt */
248 return IRQ_HANDLED;
249 }
250
251 wake_up_interruptible(&ring->wq);
252 schedule_work(&ring->work);
253
254 return IRQ_HANDLED;
255}
256
Stefano Stabellini868eb122017-04-05 12:03:57 -0700257static struct p9_trans_module p9_xen_trans = {
258 .name = "xen",
Stefano Stabellini36f99672020-05-21 12:32:42 -0700259 .maxsize = 1 << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT - 2),
Christian Schoenebeck01d205d2022-07-15 23:33:09 +0200260 .pooled_rbuffers = false,
Stefano Stabellini868eb122017-04-05 12:03:57 -0700261 .def = 1,
262 .create = p9_xen_create,
263 .close = p9_xen_close,
264 .request = p9_xen_request,
265 .cancel = p9_xen_cancel,
266 .owner = THIS_MODULE,
267};
268
269static const struct xenbus_device_id xen_9pfs_front_ids[] = {
270 { "9pfs" },
271 { "" }
272};
273
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700274static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv)
275{
276 int i, j;
277
278 write_lock(&xen_9pfs_lock);
279 list_del(&priv->list);
280 write_unlock(&xen_9pfs_lock);
281
282 for (i = 0; i < priv->num_rings; i++) {
283 if (!priv->rings[i].intf)
284 break;
285 if (priv->rings[i].irq > 0)
286 unbind_from_irqhandler(priv->rings[i].irq, priv->dev);
287 if (priv->rings[i].data.in) {
Stefano Stabellini36f99672020-05-21 12:32:42 -0700288 for (j = 0;
289 j < (1 << priv->rings[i].intf->ring_order);
290 j++) {
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700291 grant_ref_t ref;
292
293 ref = priv->rings[i].intf->ref[j];
Juergen Gross49f8b452022-05-24 13:46:30 +0200294 gnttab_end_foreign_access(ref, NULL);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700295 }
Juergen Gross5cadd4b2022-03-07 09:48:55 +0100296 free_pages_exact(priv->rings[i].data.in,
297 1UL << (priv->rings[i].intf->ring_order +
298 XEN_PAGE_SHIFT));
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700299 }
Juergen Gross49f8b452022-05-24 13:46:30 +0200300 gnttab_end_foreign_access(priv->rings[i].ref, NULL);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700301 free_page((unsigned long)priv->rings[i].intf);
302 }
303 kfree(priv->rings);
304 kfree(priv->tag);
305 kfree(priv);
306}
307
Stefano Stabellini868eb122017-04-05 12:03:57 -0700308static int xen_9pfs_front_remove(struct xenbus_device *dev)
309{
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700310 struct xen_9pfs_front_priv *priv = dev_get_drvdata(&dev->dev);
311
312 dev_set_drvdata(&dev->dev, NULL);
313 xen_9pfs_front_free(priv);
Stefano Stabellini868eb122017-04-05 12:03:57 -0700314 return 0;
315}
316
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700317static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev,
Stefano Stabellini36f99672020-05-21 12:32:42 -0700318 struct xen_9pfs_dataring *ring,
319 unsigned int order)
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700320{
321 int i = 0;
322 int ret = -ENOMEM;
323 void *bytes = NULL;
324
325 init_waitqueue_head(&ring->wq);
326 spin_lock_init(&ring->lock);
327 INIT_WORK(&ring->work, p9_xen_response);
328
329 ring->intf = (struct xen_9pfs_data_intf *)get_zeroed_page(GFP_KERNEL);
330 if (!ring->intf)
331 return ret;
332 ret = gnttab_grant_foreign_access(dev->otherend_id,
333 virt_to_gfn(ring->intf), 0);
334 if (ret < 0)
335 goto out;
336 ring->ref = ret;
Juergen Gross5cadd4b2022-03-07 09:48:55 +0100337 bytes = alloc_pages_exact(1UL << (order + XEN_PAGE_SHIFT),
338 GFP_KERNEL | __GFP_ZERO);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700339 if (!bytes) {
340 ret = -ENOMEM;
341 goto out;
342 }
Stefano Stabellini36f99672020-05-21 12:32:42 -0700343 for (; i < (1 << order); i++) {
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700344 ret = gnttab_grant_foreign_access(
345 dev->otherend_id, virt_to_gfn(bytes) + i, 0);
346 if (ret < 0)
347 goto out;
348 ring->intf->ref[i] = ret;
349 }
Stefano Stabellini36f99672020-05-21 12:32:42 -0700350 ring->intf->ring_order = order;
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700351 ring->data.in = bytes;
Stefano Stabellini36f99672020-05-21 12:32:42 -0700352 ring->data.out = bytes + XEN_FLEX_RING_SIZE(order);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700353
354 ret = xenbus_alloc_evtchn(dev, &ring->evtchn);
355 if (ret)
356 goto out;
357 ring->irq = bind_evtchn_to_irqhandler(ring->evtchn,
358 xen_9pfs_front_event_handler,
359 0, "xen_9pfs-frontend", ring);
360 if (ring->irq >= 0)
361 return 0;
362
363 xenbus_free_evtchn(dev, ring->evtchn);
364 ret = ring->irq;
365out:
366 if (bytes) {
367 for (i--; i >= 0; i--)
Juergen Gross49f8b452022-05-24 13:46:30 +0200368 gnttab_end_foreign_access(ring->intf->ref[i], NULL);
Juergen Gross5cadd4b2022-03-07 09:48:55 +0100369 free_pages_exact(bytes, 1UL << (order + XEN_PAGE_SHIFT));
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700370 }
Juergen Gross49f8b452022-05-24 13:46:30 +0200371 gnttab_end_foreign_access(ring->ref, NULL);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700372 free_page((unsigned long)ring->intf);
373 return ret;
374}
375
Stefano Stabellini868eb122017-04-05 12:03:57 -0700376static int xen_9pfs_front_probe(struct xenbus_device *dev,
377 const struct xenbus_device_id *id)
378{
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700379 int ret, i;
380 struct xenbus_transaction xbt;
381 struct xen_9pfs_front_priv *priv = NULL;
382 char *versions;
Stefano Stabellini31d47262017-04-13 10:57:56 -0700383 unsigned int max_rings, max_ring_order, len = 0;
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700384
385 versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len);
Dominique Martinet2f9ad0a2018-08-14 02:43:48 +0000386 if (IS_ERR(versions))
387 return PTR_ERR(versions);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700388 if (strcmp(versions, "1")) {
389 kfree(versions);
390 return -EINVAL;
391 }
392 kfree(versions);
393 max_rings = xenbus_read_unsigned(dev->otherend, "max-rings", 0);
394 if (max_rings < XEN_9PFS_NUM_RINGS)
395 return -EINVAL;
396 max_ring_order = xenbus_read_unsigned(dev->otherend,
397 "max-ring-page-order", 0);
Stefano Stabellini36f99672020-05-21 12:32:42 -0700398 if (max_ring_order > XEN_9PFS_RING_ORDER)
399 max_ring_order = XEN_9PFS_RING_ORDER;
400 if (p9_xen_trans.maxsize > XEN_FLEX_RING_SIZE(max_ring_order))
401 p9_xen_trans.maxsize = XEN_FLEX_RING_SIZE(max_ring_order) / 2;
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700402
403 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
404 if (!priv)
405 return -ENOMEM;
406
407 priv->dev = dev;
408 priv->num_rings = XEN_9PFS_NUM_RINGS;
409 priv->rings = kcalloc(priv->num_rings, sizeof(*priv->rings),
410 GFP_KERNEL);
411 if (!priv->rings) {
412 kfree(priv);
413 return -ENOMEM;
414 }
415
416 for (i = 0; i < priv->num_rings; i++) {
417 priv->rings[i].priv = priv;
Stefano Stabellini36f99672020-05-21 12:32:42 -0700418 ret = xen_9pfs_front_alloc_dataring(dev, &priv->rings[i],
419 max_ring_order);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700420 if (ret < 0)
421 goto error;
422 }
423
424 again:
425 ret = xenbus_transaction_start(&xbt);
426 if (ret) {
427 xenbus_dev_fatal(dev, ret, "starting transaction");
428 goto error;
429 }
430 ret = xenbus_printf(xbt, dev->nodename, "version", "%u", 1);
431 if (ret)
432 goto error_xenbus;
433 ret = xenbus_printf(xbt, dev->nodename, "num-rings", "%u",
434 priv->num_rings);
435 if (ret)
436 goto error_xenbus;
437 for (i = 0; i < priv->num_rings; i++) {
438 char str[16];
439
440 BUILD_BUG_ON(XEN_9PFS_NUM_RINGS > 9);
Ye Bin316a1be2020-10-09 16:05:52 +0800441 sprintf(str, "ring-ref%d", i);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700442 ret = xenbus_printf(xbt, dev->nodename, str, "%d",
443 priv->rings[i].ref);
444 if (ret)
445 goto error_xenbus;
446
Ye Bin316a1be2020-10-09 16:05:52 +0800447 sprintf(str, "event-channel-%d", i);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700448 ret = xenbus_printf(xbt, dev->nodename, str, "%u",
449 priv->rings[i].evtchn);
450 if (ret)
451 goto error_xenbus;
452 }
453 priv->tag = xenbus_read(xbt, dev->nodename, "tag", NULL);
Wei Yongjun14e39952017-05-16 14:22:47 +0000454 if (IS_ERR(priv->tag)) {
455 ret = PTR_ERR(priv->tag);
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700456 goto error_xenbus;
457 }
458 ret = xenbus_transaction_end(xbt, 0);
459 if (ret) {
460 if (ret == -EAGAIN)
461 goto again;
462 xenbus_dev_fatal(dev, ret, "completing transaction");
463 goto error;
464 }
465
466 write_lock(&xen_9pfs_lock);
467 list_add_tail(&priv->list, &xen_9pfs_devs);
468 write_unlock(&xen_9pfs_lock);
469 dev_set_drvdata(&dev->dev, priv);
470 xenbus_switch_state(dev, XenbusStateInitialised);
471
Stefano Stabellini868eb122017-04-05 12:03:57 -0700472 return 0;
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700473
474 error_xenbus:
475 xenbus_transaction_end(xbt, 1);
476 xenbus_dev_fatal(dev, ret, "writing xenstore");
477 error:
478 dev_set_drvdata(&dev->dev, NULL);
479 xen_9pfs_front_free(priv);
480 return ret;
Stefano Stabellini868eb122017-04-05 12:03:57 -0700481}
482
483static int xen_9pfs_front_resume(struct xenbus_device *dev)
484{
Colin Ian King680a28462018-05-09 10:48:33 +0100485 dev_warn(&dev->dev, "suspend/resume unsupported\n");
Stefano Stabellini868eb122017-04-05 12:03:57 -0700486 return 0;
487}
488
489static void xen_9pfs_front_changed(struct xenbus_device *dev,
490 enum xenbus_state backend_state)
491{
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700492 switch (backend_state) {
493 case XenbusStateReconfiguring:
494 case XenbusStateReconfigured:
495 case XenbusStateInitialising:
496 case XenbusStateInitialised:
497 case XenbusStateUnknown:
498 break;
499
500 case XenbusStateInitWait:
501 break;
502
503 case XenbusStateConnected:
504 xenbus_switch_state(dev, XenbusStateConnected);
505 break;
506
507 case XenbusStateClosed:
508 if (dev->state == XenbusStateClosed)
509 break;
Gustavo A. R. Silvadf561f662020-08-23 17:36:59 -0500510 fallthrough; /* Missed the backend's CLOSING state */
Stefano Stabellini71ebd712017-04-05 12:03:58 -0700511 case XenbusStateClosing:
512 xenbus_frontend_closed(dev);
513 break;
514 }
Stefano Stabellini868eb122017-04-05 12:03:57 -0700515}
516
517static struct xenbus_driver xen_9pfs_front_driver = {
518 .ids = xen_9pfs_front_ids,
519 .probe = xen_9pfs_front_probe,
520 .remove = xen_9pfs_front_remove,
521 .resume = xen_9pfs_front_resume,
522 .otherend_changed = xen_9pfs_front_changed,
523};
524
Xiu Jianfeng0664c63a2022-09-09 18:35:46 +0800525static int __init p9_trans_xen_init(void)
Stefano Stabellini868eb122017-04-05 12:03:57 -0700526{
YueHaibing80a316f2019-04-30 22:39:33 +0800527 int rc;
528
Stefano Stabellini868eb122017-04-05 12:03:57 -0700529 if (!xen_domain())
530 return -ENODEV;
531
532 pr_info("Initialising Xen transport for 9pfs\n");
533
534 v9fs_register_trans(&p9_xen_trans);
YueHaibing80a316f2019-04-30 22:39:33 +0800535 rc = xenbus_register_frontend(&xen_9pfs_front_driver);
536 if (rc)
537 v9fs_unregister_trans(&p9_xen_trans);
538
539 return rc;
Stefano Stabellini868eb122017-04-05 12:03:57 -0700540}
541module_init(p9_trans_xen_init);
Thomas Weißschuh4cd82a52021-10-17 15:46:11 +0200542MODULE_ALIAS_9P("xen");
Stefano Stabellini868eb122017-04-05 12:03:57 -0700543
Xiu Jianfeng0664c63a2022-09-09 18:35:46 +0800544static void __exit p9_trans_xen_exit(void)
Stefano Stabellini868eb122017-04-05 12:03:57 -0700545{
546 v9fs_unregister_trans(&p9_xen_trans);
547 return xenbus_unregister_driver(&xen_9pfs_front_driver);
548}
549module_exit(p9_trans_xen_exit);
Stephen Hemmingerd5422962018-01-08 08:23:18 -0800550
Thomas Weißschuh99aa6732021-11-03 20:38:22 +0100551MODULE_ALIAS("xen:9pfs");
Stephen Hemmingerd5422962018-01-08 08:23:18 -0800552MODULE_AUTHOR("Stefano Stabellini <stefano@aporeto.com>");
553MODULE_DESCRIPTION("Xen Transport for 9P");
554MODULE_LICENSE("GPL");