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024b7d6a | 1 | // SPDX-License-Identifier: GPL-2.0-only |
868eb122 SS |
2 | /* |
3 | * linux/fs/9p/trans_xen | |
4 | * | |
5 | * Xen transport layer. | |
6 | * | |
7 | * Copyright (C) 2017 by Stefano Stabellini <stefano@aporeto.com> | |
868eb122 SS |
8 | */ |
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> | |
71ebd719 | 17 | #include <linux/spinlock.h> |
868eb122 SS |
18 | #include <net/9p/9p.h> |
19 | #include <net/9p/client.h> | |
20 | #include <net/9p/transport.h> | |
21 | ||
71ebd719 | 22 | #define XEN_9PFS_NUM_RINGS 2 |
36f99675 SS |
23 | #define XEN_9PFS_RING_ORDER 9 |
24 | #define XEN_9PFS_RING_SIZE(ring) XEN_FLEX_RING_SIZE(ring->intf->ring_order) | |
71ebd719 SS |
25 | |
26 | struct 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 */ | |
35 | struct 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 */ | |
51 | struct xen_9pfs_front_priv { | |
52 | struct list_head list; | |
53 | struct xenbus_device *dev; | |
54 | char *tag; | |
55 | struct p9_client *client; | |
56 | ||
71ebd719 SS |
57 | struct xen_9pfs_dataring *rings; |
58 | }; | |
59 | ||
60 | static LIST_HEAD(xen_9pfs_devs); | |
61 | static DEFINE_RWLOCK(xen_9pfs_lock); | |
62 | ||
f023f18d | 63 | /* We don't currently allow canceling of requests */ |
868eb122 SS |
64 | static int p9_xen_cancel(struct p9_client *client, struct p9_req_t *req) |
65 | { | |
f023f18d | 66 | return 1; |
868eb122 SS |
67 | } |
68 | ||
69 | static int p9_xen_create(struct p9_client *client, const char *addr, char *args) | |
70 | { | |
f023f18d SS |
71 | struct xen_9pfs_front_priv *priv; |
72 | ||
10aa1452 TB |
73 | if (addr == NULL) |
74 | return -EINVAL; | |
75 | ||
f023f18d SS |
76 | read_lock(&xen_9pfs_lock); |
77 | list_for_each_entry(priv, &xen_9pfs_devs, list) { | |
78 | if (!strcmp(priv->tag, addr)) { | |
79 | priv->client = client; | |
80 | read_unlock(&xen_9pfs_lock); | |
81 | return 0; | |
82 | } | |
83 | } | |
84 | read_unlock(&xen_9pfs_lock); | |
85 | return -EINVAL; | |
868eb122 SS |
86 | } |
87 | ||
88 | static void p9_xen_close(struct p9_client *client) | |
89 | { | |
f023f18d SS |
90 | struct xen_9pfs_front_priv *priv; |
91 | ||
92 | read_lock(&xen_9pfs_lock); | |
93 | list_for_each_entry(priv, &xen_9pfs_devs, list) { | |
94 | if (priv->client == client) { | |
95 | priv->client = NULL; | |
96 | read_unlock(&xen_9pfs_lock); | |
97 | return; | |
98 | } | |
99 | } | |
100 | read_unlock(&xen_9pfs_lock); | |
101 | } | |
102 | ||
103 | static bool p9_xen_write_todo(struct xen_9pfs_dataring *ring, RING_IDX size) | |
104 | { | |
105 | RING_IDX cons, prod; | |
106 | ||
107 | cons = ring->intf->out_cons; | |
108 | prod = ring->intf->out_prod; | |
109 | virt_mb(); | |
110 | ||
36f99675 SS |
111 | return XEN_9PFS_RING_SIZE(ring) - |
112 | xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) >= size; | |
868eb122 SS |
113 | } |
114 | ||
115 | static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req) | |
116 | { | |
732b33d0 | 117 | struct xen_9pfs_front_priv *priv; |
f023f18d SS |
118 | RING_IDX cons, prod, masked_cons, masked_prod; |
119 | unsigned long flags; | |
523adb6c | 120 | u32 size = p9_req->tc.size; |
f023f18d SS |
121 | struct xen_9pfs_dataring *ring; |
122 | int num; | |
123 | ||
124 | read_lock(&xen_9pfs_lock); | |
125 | list_for_each_entry(priv, &xen_9pfs_devs, list) { | |
126 | if (priv->client == client) | |
127 | break; | |
128 | } | |
129 | read_unlock(&xen_9pfs_lock); | |
732b33d0 | 130 | if (list_entry_is_head(priv, &xen_9pfs_devs, list)) |
f023f18d SS |
131 | return -EINVAL; |
132 | ||
39763480 | 133 | num = p9_req->tc.tag % XEN_9PFS_NUM_RINGS; |
f023f18d SS |
134 | ring = &priv->rings[num]; |
135 | ||
136 | again: | |
9523feac TT |
137 | while (wait_event_killable(ring->wq, |
138 | p9_xen_write_todo(ring, size)) != 0) | |
f023f18d SS |
139 | ; |
140 | ||
141 | spin_lock_irqsave(&ring->lock, flags); | |
142 | cons = ring->intf->out_cons; | |
143 | prod = ring->intf->out_prod; | |
144 | virt_mb(); | |
145 | ||
36f99675 SS |
146 | if (XEN_9PFS_RING_SIZE(ring) - |
147 | xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) < size) { | |
f023f18d SS |
148 | spin_unlock_irqrestore(&ring->lock, flags); |
149 | goto again; | |
150 | } | |
151 | ||
36f99675 SS |
152 | masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE(ring)); |
153 | masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring)); | |
f023f18d | 154 | |
523adb6c | 155 | xen_9pfs_write_packet(ring->data.out, p9_req->tc.sdata, size, |
36f99675 SS |
156 | &masked_prod, masked_cons, |
157 | XEN_9PFS_RING_SIZE(ring)); | |
f023f18d | 158 | |
1a4f69ef | 159 | WRITE_ONCE(p9_req->status, REQ_STATUS_SENT); |
f023f18d SS |
160 | virt_wmb(); /* write ring before updating pointer */ |
161 | prod += size; | |
162 | ring->intf->out_prod = prod; | |
163 | spin_unlock_irqrestore(&ring->lock, flags); | |
164 | notify_remote_via_irq(ring->irq); | |
8b11ff09 | 165 | p9_req_put(client, p9_req); |
f023f18d | 166 | |
868eb122 SS |
167 | return 0; |
168 | } | |
169 | ||
71ebd719 SS |
170 | static void p9_xen_response(struct work_struct *work) |
171 | { | |
f66c72be SS |
172 | struct xen_9pfs_front_priv *priv; |
173 | struct xen_9pfs_dataring *ring; | |
174 | RING_IDX cons, prod, masked_cons, masked_prod; | |
175 | struct xen_9pfs_header h; | |
176 | struct p9_req_t *req; | |
177 | int status; | |
178 | ||
179 | ring = container_of(work, struct xen_9pfs_dataring, work); | |
180 | priv = ring->priv; | |
181 | ||
182 | while (1) { | |
183 | cons = ring->intf->in_cons; | |
184 | prod = ring->intf->in_prod; | |
185 | virt_rmb(); | |
186 | ||
36f99675 | 187 | if (xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) < |
f66c72be SS |
188 | sizeof(h)) { |
189 | notify_remote_via_irq(ring->irq); | |
190 | return; | |
191 | } | |
192 | ||
36f99675 SS |
193 | masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE(ring)); |
194 | masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring)); | |
f66c72be SS |
195 | |
196 | /* First, read just the header */ | |
197 | xen_9pfs_read_packet(&h, ring->data.in, sizeof(h), | |
198 | masked_prod, &masked_cons, | |
36f99675 | 199 | XEN_9PFS_RING_SIZE(ring)); |
f66c72be SS |
200 | |
201 | req = p9_tag_lookup(priv->client, h.tag); | |
202 | if (!req || req->status != REQ_STATUS_SENT) { | |
203 | dev_warn(&priv->dev->dev, "Wrong req tag=%x\n", h.tag); | |
204 | cons += h.size; | |
205 | virt_mb(); | |
206 | ring->intf->in_cons = cons; | |
207 | continue; | |
208 | } | |
209 | ||
391c18cf DM |
210 | if (h.size > req->rc.capacity) { |
211 | dev_warn(&priv->dev->dev, | |
212 | "requested packet size too big: %d for tag %d with capacity %zd\n", | |
213 | h.size, h.tag, req->rc.capacity); | |
1a4f69ef | 214 | WRITE_ONCE(req->status, REQ_STATUS_ERROR); |
391c18cf DM |
215 | goto recv_error; |
216 | } | |
217 | ||
f15e006b DM |
218 | req->rc.size = h.size; |
219 | req->rc.id = h.id; | |
220 | req->rc.tag = h.tag; | |
523adb6c | 221 | req->rc.offset = 0; |
f66c72be | 222 | |
36f99675 | 223 | masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring)); |
f66c72be | 224 | /* Then, read the whole packet (including the header) */ |
523adb6c | 225 | xen_9pfs_read_packet(req->rc.sdata, ring->data.in, h.size, |
f66c72be | 226 | masked_prod, &masked_cons, |
36f99675 | 227 | XEN_9PFS_RING_SIZE(ring)); |
f66c72be | 228 | |
391c18cf | 229 | recv_error: |
f66c72be SS |
230 | virt_mb(); |
231 | cons += h.size; | |
232 | ring->intf->in_cons = cons; | |
233 | ||
234 | status = (req->status != REQ_STATUS_ERROR) ? | |
235 | REQ_STATUS_RCVD : REQ_STATUS_ERROR; | |
236 | ||
237 | p9_client_cb(priv->client, req, status); | |
238 | } | |
71ebd719 SS |
239 | } |
240 | ||
241 | static irqreturn_t xen_9pfs_front_event_handler(int irq, void *r) | |
242 | { | |
243 | struct xen_9pfs_dataring *ring = r; | |
244 | ||
245 | if (!ring || !ring->priv->client) { | |
246 | /* ignore spurious interrupt */ | |
247 | return IRQ_HANDLED; | |
248 | } | |
249 | ||
250 | wake_up_interruptible(&ring->wq); | |
251 | schedule_work(&ring->work); | |
252 | ||
253 | return IRQ_HANDLED; | |
254 | } | |
255 | ||
868eb122 SS |
256 | static struct p9_trans_module p9_xen_trans = { |
257 | .name = "xen", | |
36f99675 | 258 | .maxsize = 1 << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT - 2), |
01d205d9 | 259 | .pooled_rbuffers = false, |
868eb122 SS |
260 | .def = 1, |
261 | .create = p9_xen_create, | |
262 | .close = p9_xen_close, | |
263 | .request = p9_xen_request, | |
264 | .cancel = p9_xen_cancel, | |
265 | .owner = THIS_MODULE, | |
266 | }; | |
267 | ||
268 | static const struct xenbus_device_id xen_9pfs_front_ids[] = { | |
269 | { "9pfs" }, | |
270 | { "" } | |
271 | }; | |
272 | ||
71ebd719 SS |
273 | static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv) |
274 | { | |
275 | int i, j; | |
276 | ||
277 | write_lock(&xen_9pfs_lock); | |
278 | list_del(&priv->list); | |
279 | write_unlock(&xen_9pfs_lock); | |
280 | ||
39763480 | 281 | for (i = 0; i < XEN_9PFS_NUM_RINGS; i++) { |
ea4f1009 ZW |
282 | struct xen_9pfs_dataring *ring = &priv->rings[i]; |
283 | ||
284 | cancel_work_sync(&ring->work); | |
285 | ||
71ebd719 SS |
286 | if (!priv->rings[i].intf) |
287 | break; | |
288 | if (priv->rings[i].irq > 0) | |
289 | unbind_from_irqhandler(priv->rings[i].irq, priv->dev); | |
290 | if (priv->rings[i].data.in) { | |
36f99675 SS |
291 | for (j = 0; |
292 | j < (1 << priv->rings[i].intf->ring_order); | |
293 | j++) { | |
71ebd719 SS |
294 | grant_ref_t ref; |
295 | ||
296 | ref = priv->rings[i].intf->ref[j]; | |
49f8b459 | 297 | gnttab_end_foreign_access(ref, NULL); |
71ebd719 | 298 | } |
5cadd4bb JG |
299 | free_pages_exact(priv->rings[i].data.in, |
300 | 1UL << (priv->rings[i].intf->ring_order + | |
301 | XEN_PAGE_SHIFT)); | |
71ebd719 | 302 | } |
49f8b459 | 303 | gnttab_end_foreign_access(priv->rings[i].ref, NULL); |
71ebd719 SS |
304 | free_page((unsigned long)priv->rings[i].intf); |
305 | } | |
306 | kfree(priv->rings); | |
307 | kfree(priv->tag); | |
308 | kfree(priv); | |
309 | } | |
310 | ||
7cffcade | 311 | static void xen_9pfs_front_remove(struct xenbus_device *dev) |
868eb122 | 312 | { |
71ebd719 SS |
313 | struct xen_9pfs_front_priv *priv = dev_get_drvdata(&dev->dev); |
314 | ||
315 | dev_set_drvdata(&dev->dev, NULL); | |
316 | xen_9pfs_front_free(priv); | |
868eb122 SS |
317 | } |
318 | ||
71ebd719 | 319 | static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev, |
36f99675 SS |
320 | struct xen_9pfs_dataring *ring, |
321 | unsigned int order) | |
71ebd719 SS |
322 | { |
323 | int i = 0; | |
324 | int ret = -ENOMEM; | |
325 | void *bytes = NULL; | |
326 | ||
327 | init_waitqueue_head(&ring->wq); | |
328 | spin_lock_init(&ring->lock); | |
329 | INIT_WORK(&ring->work, p9_xen_response); | |
330 | ||
331 | ring->intf = (struct xen_9pfs_data_intf *)get_zeroed_page(GFP_KERNEL); | |
332 | if (!ring->intf) | |
333 | return ret; | |
334 | ret = gnttab_grant_foreign_access(dev->otherend_id, | |
335 | virt_to_gfn(ring->intf), 0); | |
336 | if (ret < 0) | |
337 | goto out; | |
338 | ring->ref = ret; | |
5cadd4bb JG |
339 | bytes = alloc_pages_exact(1UL << (order + XEN_PAGE_SHIFT), |
340 | GFP_KERNEL | __GFP_ZERO); | |
71ebd719 SS |
341 | if (!bytes) { |
342 | ret = -ENOMEM; | |
343 | goto out; | |
344 | } | |
36f99675 | 345 | for (; i < (1 << order); i++) { |
71ebd719 SS |
346 | ret = gnttab_grant_foreign_access( |
347 | dev->otherend_id, virt_to_gfn(bytes) + i, 0); | |
348 | if (ret < 0) | |
349 | goto out; | |
350 | ring->intf->ref[i] = ret; | |
351 | } | |
36f99675 | 352 | ring->intf->ring_order = order; |
71ebd719 | 353 | ring->data.in = bytes; |
36f99675 | 354 | ring->data.out = bytes + XEN_FLEX_RING_SIZE(order); |
71ebd719 SS |
355 | |
356 | ret = xenbus_alloc_evtchn(dev, &ring->evtchn); | |
357 | if (ret) | |
358 | goto out; | |
359 | ring->irq = bind_evtchn_to_irqhandler(ring->evtchn, | |
360 | xen_9pfs_front_event_handler, | |
361 | 0, "xen_9pfs-frontend", ring); | |
362 | if (ring->irq >= 0) | |
363 | return 0; | |
364 | ||
365 | xenbus_free_evtchn(dev, ring->evtchn); | |
366 | ret = ring->irq; | |
367 | out: | |
368 | if (bytes) { | |
369 | for (i--; i >= 0; i--) | |
49f8b459 | 370 | gnttab_end_foreign_access(ring->intf->ref[i], NULL); |
5cadd4bb | 371 | free_pages_exact(bytes, 1UL << (order + XEN_PAGE_SHIFT)); |
71ebd719 | 372 | } |
49f8b459 | 373 | gnttab_end_foreign_access(ring->ref, NULL); |
71ebd719 SS |
374 | free_page((unsigned long)ring->intf); |
375 | return ret; | |
376 | } | |
377 | ||
c15fe55d | 378 | static int xen_9pfs_front_init(struct xenbus_device *dev) |
868eb122 | 379 | { |
71ebd719 SS |
380 | int ret, i; |
381 | struct xenbus_transaction xbt; | |
c15fe55d | 382 | struct xen_9pfs_front_priv *priv = dev_get_drvdata(&dev->dev); |
f1956f4e | 383 | char *versions, *v; |
31d47266 | 384 | unsigned int max_rings, max_ring_order, len = 0; |
71ebd719 SS |
385 | |
386 | versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len); | |
2f9ad0ac DM |
387 | if (IS_ERR(versions)) |
388 | return PTR_ERR(versions); | |
f1956f4e JG |
389 | for (v = versions; *v; v++) { |
390 | if (simple_strtoul(v, &v, 10) == 1) { | |
391 | v = NULL; | |
392 | break; | |
393 | } | |
394 | } | |
395 | if (v) { | |
71ebd719 SS |
396 | kfree(versions); |
397 | return -EINVAL; | |
398 | } | |
399 | kfree(versions); | |
400 | max_rings = xenbus_read_unsigned(dev->otherend, "max-rings", 0); | |
401 | if (max_rings < XEN_9PFS_NUM_RINGS) | |
402 | return -EINVAL; | |
403 | max_ring_order = xenbus_read_unsigned(dev->otherend, | |
404 | "max-ring-page-order", 0); | |
36f99675 SS |
405 | if (max_ring_order > XEN_9PFS_RING_ORDER) |
406 | max_ring_order = XEN_9PFS_RING_ORDER; | |
407 | if (p9_xen_trans.maxsize > XEN_FLEX_RING_SIZE(max_ring_order)) | |
408 | p9_xen_trans.maxsize = XEN_FLEX_RING_SIZE(max_ring_order) / 2; | |
71ebd719 | 409 | |
39763480 | 410 | priv->rings = kcalloc(XEN_9PFS_NUM_RINGS, sizeof(*priv->rings), |
71ebd719 SS |
411 | GFP_KERNEL); |
412 | if (!priv->rings) { | |
413 | kfree(priv); | |
414 | return -ENOMEM; | |
415 | } | |
416 | ||
39763480 | 417 | for (i = 0; i < XEN_9PFS_NUM_RINGS; i++) { |
71ebd719 | 418 | priv->rings[i].priv = priv; |
36f99675 SS |
419 | ret = xen_9pfs_front_alloc_dataring(dev, &priv->rings[i], |
420 | max_ring_order); | |
71ebd719 SS |
421 | if (ret < 0) |
422 | goto error; | |
423 | } | |
424 | ||
425 | again: | |
426 | ret = xenbus_transaction_start(&xbt); | |
427 | if (ret) { | |
428 | xenbus_dev_fatal(dev, ret, "starting transaction"); | |
429 | goto error; | |
430 | } | |
431 | ret = xenbus_printf(xbt, dev->nodename, "version", "%u", 1); | |
432 | if (ret) | |
433 | goto error_xenbus; | |
434 | ret = xenbus_printf(xbt, dev->nodename, "num-rings", "%u", | |
39763480 | 435 | XEN_9PFS_NUM_RINGS); |
71ebd719 SS |
436 | if (ret) |
437 | goto error_xenbus; | |
39763480 DM |
438 | |
439 | for (i = 0; i < XEN_9PFS_NUM_RINGS; i++) { | |
71ebd719 SS |
440 | char str[16]; |
441 | ||
442 | BUILD_BUG_ON(XEN_9PFS_NUM_RINGS > 9); | |
316a1bef | 443 | sprintf(str, "ring-ref%d", i); |
71ebd719 SS |
444 | ret = xenbus_printf(xbt, dev->nodename, str, "%d", |
445 | priv->rings[i].ref); | |
446 | if (ret) | |
447 | goto error_xenbus; | |
448 | ||
316a1bef | 449 | sprintf(str, "event-channel-%d", i); |
71ebd719 SS |
450 | ret = xenbus_printf(xbt, dev->nodename, str, "%u", |
451 | priv->rings[i].evtchn); | |
452 | if (ret) | |
453 | goto error_xenbus; | |
454 | } | |
455 | priv->tag = xenbus_read(xbt, dev->nodename, "tag", NULL); | |
14e3995e WY |
456 | if (IS_ERR(priv->tag)) { |
457 | ret = PTR_ERR(priv->tag); | |
71ebd719 SS |
458 | goto error_xenbus; |
459 | } | |
460 | ret = xenbus_transaction_end(xbt, 0); | |
461 | if (ret) { | |
462 | if (ret == -EAGAIN) | |
463 | goto again; | |
464 | xenbus_dev_fatal(dev, ret, "completing transaction"); | |
465 | goto error; | |
466 | } | |
467 | ||
868eb122 | 468 | return 0; |
71ebd719 SS |
469 | |
470 | error_xenbus: | |
471 | xenbus_transaction_end(xbt, 1); | |
472 | xenbus_dev_fatal(dev, ret, "writing xenstore"); | |
473 | error: | |
71ebd719 SS |
474 | xen_9pfs_front_free(priv); |
475 | return ret; | |
868eb122 SS |
476 | } |
477 | ||
c15fe55d JG |
478 | static int xen_9pfs_front_probe(struct xenbus_device *dev, |
479 | const struct xenbus_device_id *id) | |
480 | { | |
481 | struct xen_9pfs_front_priv *priv = NULL; | |
482 | ||
483 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
484 | if (!priv) | |
485 | return -ENOMEM; | |
486 | ||
487 | priv->dev = dev; | |
488 | dev_set_drvdata(&dev->dev, priv); | |
489 | ||
490 | write_lock(&xen_9pfs_lock); | |
491 | list_add_tail(&priv->list, &xen_9pfs_devs); | |
492 | write_unlock(&xen_9pfs_lock); | |
493 | ||
494 | return 0; | |
495 | } | |
496 | ||
868eb122 SS |
497 | static int xen_9pfs_front_resume(struct xenbus_device *dev) |
498 | { | |
680a2846 | 499 | dev_warn(&dev->dev, "suspend/resume unsupported\n"); |
868eb122 SS |
500 | return 0; |
501 | } | |
502 | ||
503 | static void xen_9pfs_front_changed(struct xenbus_device *dev, | |
504 | enum xenbus_state backend_state) | |
505 | { | |
71ebd719 SS |
506 | switch (backend_state) { |
507 | case XenbusStateReconfiguring: | |
508 | case XenbusStateReconfigured: | |
509 | case XenbusStateInitialising: | |
510 | case XenbusStateInitialised: | |
511 | case XenbusStateUnknown: | |
512 | break; | |
513 | ||
514 | case XenbusStateInitWait: | |
c15fe55d JG |
515 | if (!xen_9pfs_front_init(dev)) |
516 | xenbus_switch_state(dev, XenbusStateInitialised); | |
71ebd719 SS |
517 | break; |
518 | ||
519 | case XenbusStateConnected: | |
520 | xenbus_switch_state(dev, XenbusStateConnected); | |
521 | break; | |
522 | ||
523 | case XenbusStateClosed: | |
524 | if (dev->state == XenbusStateClosed) | |
525 | break; | |
df561f66 | 526 | fallthrough; /* Missed the backend's CLOSING state */ |
71ebd719 SS |
527 | case XenbusStateClosing: |
528 | xenbus_frontend_closed(dev); | |
529 | break; | |
530 | } | |
868eb122 SS |
531 | } |
532 | ||
533 | static struct xenbus_driver xen_9pfs_front_driver = { | |
534 | .ids = xen_9pfs_front_ids, | |
535 | .probe = xen_9pfs_front_probe, | |
536 | .remove = xen_9pfs_front_remove, | |
537 | .resume = xen_9pfs_front_resume, | |
538 | .otherend_changed = xen_9pfs_front_changed, | |
539 | }; | |
540 | ||
0664c63a | 541 | static int __init p9_trans_xen_init(void) |
868eb122 | 542 | { |
80a316ff Y |
543 | int rc; |
544 | ||
868eb122 SS |
545 | if (!xen_domain()) |
546 | return -ENODEV; | |
547 | ||
548 | pr_info("Initialising Xen transport for 9pfs\n"); | |
549 | ||
550 | v9fs_register_trans(&p9_xen_trans); | |
80a316ff Y |
551 | rc = xenbus_register_frontend(&xen_9pfs_front_driver); |
552 | if (rc) | |
553 | v9fs_unregister_trans(&p9_xen_trans); | |
554 | ||
555 | return rc; | |
868eb122 SS |
556 | } |
557 | module_init(p9_trans_xen_init); | |
4cd82a5b | 558 | MODULE_ALIAS_9P("xen"); |
868eb122 | 559 | |
0664c63a | 560 | static void __exit p9_trans_xen_exit(void) |
868eb122 SS |
561 | { |
562 | v9fs_unregister_trans(&p9_xen_trans); | |
563 | return xenbus_unregister_driver(&xen_9pfs_front_driver); | |
564 | } | |
565 | module_exit(p9_trans_xen_exit); | |
d542296a | 566 | |
99aa673e | 567 | MODULE_ALIAS("xen:9pfs"); |
d542296a SH |
568 | MODULE_AUTHOR("Stefano Stabellini <stefano@aporeto.com>"); |
569 | MODULE_DESCRIPTION("Xen Transport for 9P"); | |
570 | MODULE_LICENSE("GPL"); |