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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
416efba0 SS |
2 | /* |
3 | * (c) 2017 Stefano Stabellini <stefano@aporeto.com> | |
416efba0 SS |
4 | */ |
5 | ||
6 | #include <linux/module.h> | |
2195046b SS |
7 | #include <linux/net.h> |
8 | #include <linux/socket.h> | |
9 | ||
10 | #include <net/sock.h> | |
416efba0 SS |
11 | |
12 | #include <xen/events.h> | |
13 | #include <xen/grant_table.h> | |
14 | #include <xen/xen.h> | |
15 | #include <xen/xenbus.h> | |
16 | #include <xen/interface/io/pvcalls.h> | |
17 | ||
2195046b SS |
18 | #include "pvcalls-front.h" |
19 | ||
aa7ba376 SS |
20 | #define PVCALLS_INVALID_ID UINT_MAX |
21 | #define PVCALLS_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER | |
22 | #define PVCALLS_NR_RSP_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE) | |
45ddce21 | 23 | #define PVCALLS_FRONT_MAX_SPIN 5000 |
aa7ba376 | 24 | |
beee1fbe SS |
25 | static struct proto pvcalls_proto = { |
26 | .name = "PVCalls", | |
27 | .owner = THIS_MODULE, | |
28 | .obj_size = sizeof(struct sock), | |
29 | }; | |
30 | ||
aa7ba376 SS |
31 | struct pvcalls_bedata { |
32 | struct xen_pvcalls_front_ring ring; | |
33 | grant_ref_t ref; | |
34 | int irq; | |
35 | ||
36 | struct list_head socket_mappings; | |
37 | spinlock_t socket_lock; | |
38 | ||
39 | wait_queue_head_t inflight_req; | |
40 | struct xen_pvcalls_response rsp[PVCALLS_NR_RSP_PER_RING]; | |
41 | }; | |
42 | /* Only one front/back connection supported. */ | |
43 | static struct xenbus_device *pvcalls_front_dev; | |
44 | static atomic_t pvcalls_refcount; | |
45 | ||
46 | /* first increment refcount, then proceed */ | |
47 | #define pvcalls_enter() { \ | |
48 | atomic_inc(&pvcalls_refcount); \ | |
49 | } | |
50 | ||
51 | /* first complete other operations, then decrement refcount */ | |
52 | #define pvcalls_exit() { \ | |
53 | atomic_dec(&pvcalls_refcount); \ | |
54 | } | |
55 | ||
56 | struct sock_mapping { | |
57 | bool active_socket; | |
58 | struct list_head list; | |
59 | struct socket *sock; | |
64d68718 | 60 | atomic_t refcount; |
cb1c7d9b SS |
61 | union { |
62 | struct { | |
63 | int irq; | |
64 | grant_ref_t ref; | |
65 | struct pvcalls_data_intf *ring; | |
66 | struct pvcalls_data data; | |
67 | struct mutex in_mutex; | |
68 | struct mutex out_mutex; | |
69 | ||
70 | wait_queue_head_t inflight_conn_req; | |
71 | } active; | |
67ea9893 | 72 | struct { |
d811bcee SS |
73 | /* |
74 | * Socket status, needs to be 64-bit aligned due to the | |
75 | * test_and_* functions which have this requirement on arm64. | |
76 | */ | |
67ea9893 SS |
77 | #define PVCALLS_STATUS_UNINITALIZED 0 |
78 | #define PVCALLS_STATUS_BIND 1 | |
79 | #define PVCALLS_STATUS_LISTEN 2 | |
d811bcee | 80 | uint8_t status __attribute__((aligned(8))); |
9774c6cc SS |
81 | /* |
82 | * Internal state-machine flags. | |
83 | * Only one accept operation can be inflight for a socket. | |
84 | * Only one poll operation can be inflight for a given socket. | |
d811bcee SS |
85 | * flags needs to be 64-bit aligned due to the test_and_* |
86 | * functions which have this requirement on arm64. | |
9774c6cc SS |
87 | */ |
88 | #define PVCALLS_FLAG_ACCEPT_INFLIGHT 0 | |
5842c835 SS |
89 | #define PVCALLS_FLAG_POLL_INFLIGHT 1 |
90 | #define PVCALLS_FLAG_POLL_RET 2 | |
d811bcee | 91 | uint8_t flags __attribute__((aligned(8))); |
9774c6cc SS |
92 | uint32_t inflight_req_id; |
93 | struct sock_mapping *accept_map; | |
94 | wait_queue_head_t inflight_accept_req; | |
67ea9893 | 95 | } passive; |
cb1c7d9b | 96 | }; |
aa7ba376 SS |
97 | }; |
98 | ||
64d68718 SS |
99 | static inline struct sock_mapping *pvcalls_enter_sock(struct socket *sock) |
100 | { | |
101 | struct sock_mapping *map; | |
102 | ||
103 | if (!pvcalls_front_dev || | |
104 | dev_get_drvdata(&pvcalls_front_dev->dev) == NULL) | |
105 | return ERR_PTR(-ENOTCONN); | |
106 | ||
107 | map = (struct sock_mapping *)sock->sk->sk_send_head; | |
108 | if (map == NULL) | |
109 | return ERR_PTR(-ENOTSOCK); | |
110 | ||
111 | pvcalls_enter(); | |
112 | atomic_inc(&map->refcount); | |
113 | return map; | |
114 | } | |
115 | ||
116 | static inline void pvcalls_exit_sock(struct socket *sock) | |
117 | { | |
118 | struct sock_mapping *map; | |
119 | ||
120 | map = (struct sock_mapping *)sock->sk->sk_send_head; | |
121 | atomic_dec(&map->refcount); | |
122 | pvcalls_exit(); | |
123 | } | |
124 | ||
2195046b SS |
125 | static inline int get_request(struct pvcalls_bedata *bedata, int *req_id) |
126 | { | |
127 | *req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1); | |
128 | if (RING_FULL(&bedata->ring) || | |
129 | bedata->rsp[*req_id].req_id != PVCALLS_INVALID_ID) | |
130 | return -EAGAIN; | |
131 | return 0; | |
132 | } | |
133 | ||
45ddce21 SS |
134 | static bool pvcalls_front_write_todo(struct sock_mapping *map) |
135 | { | |
136 | struct pvcalls_data_intf *intf = map->active.ring; | |
137 | RING_IDX cons, prod, size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
138 | int32_t error; | |
139 | ||
140 | error = intf->out_error; | |
141 | if (error == -ENOTCONN) | |
142 | return false; | |
143 | if (error != 0) | |
144 | return true; | |
145 | ||
146 | cons = intf->out_cons; | |
147 | prod = intf->out_prod; | |
148 | return !!(size - pvcalls_queued(prod, cons, size)); | |
149 | } | |
150 | ||
ae0d0405 SS |
151 | static bool pvcalls_front_read_todo(struct sock_mapping *map) |
152 | { | |
153 | struct pvcalls_data_intf *intf = map->active.ring; | |
154 | RING_IDX cons, prod; | |
155 | int32_t error; | |
156 | ||
157 | cons = intf->in_cons; | |
158 | prod = intf->in_prod; | |
159 | error = intf->in_error; | |
160 | return (error != 0 || | |
161 | pvcalls_queued(prod, cons, | |
162 | XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) != 0); | |
163 | } | |
164 | ||
aa7ba376 SS |
165 | static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id) |
166 | { | |
2195046b SS |
167 | struct xenbus_device *dev = dev_id; |
168 | struct pvcalls_bedata *bedata; | |
169 | struct xen_pvcalls_response *rsp; | |
170 | uint8_t *src, *dst; | |
171 | int req_id = 0, more = 0, done = 0; | |
172 | ||
173 | if (dev == NULL) | |
174 | return IRQ_HANDLED; | |
175 | ||
176 | pvcalls_enter(); | |
177 | bedata = dev_get_drvdata(&dev->dev); | |
178 | if (bedata == NULL) { | |
179 | pvcalls_exit(); | |
180 | return IRQ_HANDLED; | |
181 | } | |
182 | ||
183 | again: | |
184 | while (RING_HAS_UNCONSUMED_RESPONSES(&bedata->ring)) { | |
185 | rsp = RING_GET_RESPONSE(&bedata->ring, bedata->ring.rsp_cons); | |
186 | ||
187 | req_id = rsp->req_id; | |
5842c835 SS |
188 | if (rsp->cmd == PVCALLS_POLL) { |
189 | struct sock_mapping *map = (struct sock_mapping *)(uintptr_t) | |
190 | rsp->u.poll.id; | |
191 | ||
192 | clear_bit(PVCALLS_FLAG_POLL_INFLIGHT, | |
193 | (void *)&map->passive.flags); | |
194 | /* | |
195 | * clear INFLIGHT, then set RET. It pairs with | |
196 | * the checks at the beginning of | |
197 | * pvcalls_front_poll_passive. | |
198 | */ | |
199 | smp_wmb(); | |
200 | set_bit(PVCALLS_FLAG_POLL_RET, | |
201 | (void *)&map->passive.flags); | |
202 | } else { | |
203 | dst = (uint8_t *)&bedata->rsp[req_id] + | |
204 | sizeof(rsp->req_id); | |
205 | src = (uint8_t *)rsp + sizeof(rsp->req_id); | |
206 | memcpy(dst, src, sizeof(*rsp) - sizeof(rsp->req_id)); | |
207 | /* | |
208 | * First copy the rest of the data, then req_id. It is | |
209 | * paired with the barrier when accessing bedata->rsp. | |
210 | */ | |
211 | smp_wmb(); | |
212 | bedata->rsp[req_id].req_id = req_id; | |
213 | } | |
2195046b SS |
214 | |
215 | done = 1; | |
216 | bedata->ring.rsp_cons++; | |
217 | } | |
218 | ||
219 | RING_FINAL_CHECK_FOR_RESPONSES(&bedata->ring, more); | |
220 | if (more) | |
221 | goto again; | |
222 | if (done) | |
223 | wake_up(&bedata->inflight_req); | |
224 | pvcalls_exit(); | |
aa7ba376 SS |
225 | return IRQ_HANDLED; |
226 | } | |
227 | ||
228 | static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, | |
229 | struct sock_mapping *map) | |
230 | { | |
235a71c5 SS |
231 | int i; |
232 | ||
233 | unbind_from_irqhandler(map->active.irq, map); | |
234 | ||
235 | spin_lock(&bedata->socket_lock); | |
236 | if (!list_empty(&map->list)) | |
237 | list_del_init(&map->list); | |
238 | spin_unlock(&bedata->socket_lock); | |
239 | ||
240 | for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) | |
241 | gnttab_end_foreign_access(map->active.ring->ref[i], 0, 0); | |
242 | gnttab_end_foreign_access(map->active.ref, 0, 0); | |
243 | free_page((unsigned long)map->active.ring); | |
244 | ||
245 | kfree(map); | |
aa7ba376 SS |
246 | } |
247 | ||
cb1c7d9b SS |
248 | static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map) |
249 | { | |
250 | struct sock_mapping *map = sock_map; | |
251 | ||
252 | if (map == NULL) | |
253 | return IRQ_HANDLED; | |
254 | ||
255 | wake_up_interruptible(&map->active.inflight_conn_req); | |
256 | ||
257 | return IRQ_HANDLED; | |
258 | } | |
259 | ||
2195046b SS |
260 | int pvcalls_front_socket(struct socket *sock) |
261 | { | |
262 | struct pvcalls_bedata *bedata; | |
263 | struct sock_mapping *map = NULL; | |
264 | struct xen_pvcalls_request *req; | |
265 | int notify, req_id, ret; | |
266 | ||
267 | /* | |
268 | * PVCalls only supports domain AF_INET, | |
269 | * type SOCK_STREAM and protocol 0 sockets for now. | |
270 | * | |
271 | * Check socket type here, AF_INET and protocol checks are done | |
272 | * by the caller. | |
273 | */ | |
274 | if (sock->type != SOCK_STREAM) | |
275 | return -EOPNOTSUPP; | |
276 | ||
277 | pvcalls_enter(); | |
278 | if (!pvcalls_front_dev) { | |
279 | pvcalls_exit(); | |
280 | return -EACCES; | |
281 | } | |
282 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
283 | ||
284 | map = kzalloc(sizeof(*map), GFP_KERNEL); | |
285 | if (map == NULL) { | |
286 | pvcalls_exit(); | |
287 | return -ENOMEM; | |
288 | } | |
289 | ||
290 | spin_lock(&bedata->socket_lock); | |
291 | ||
292 | ret = get_request(bedata, &req_id); | |
293 | if (ret < 0) { | |
294 | kfree(map); | |
295 | spin_unlock(&bedata->socket_lock); | |
296 | pvcalls_exit(); | |
297 | return ret; | |
298 | } | |
299 | ||
300 | /* | |
301 | * sock->sk->sk_send_head is not used for ip sockets: reuse the | |
302 | * field to store a pointer to the struct sock_mapping | |
303 | * corresponding to the socket. This way, we can easily get the | |
304 | * struct sock_mapping from the struct socket. | |
305 | */ | |
306 | sock->sk->sk_send_head = (void *)map; | |
307 | list_add_tail(&map->list, &bedata->socket_mappings); | |
308 | ||
309 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
310 | req->req_id = req_id; | |
311 | req->cmd = PVCALLS_SOCKET; | |
312 | req->u.socket.id = (uintptr_t) map; | |
313 | req->u.socket.domain = AF_INET; | |
314 | req->u.socket.type = SOCK_STREAM; | |
315 | req->u.socket.protocol = IPPROTO_IP; | |
316 | ||
317 | bedata->ring.req_prod_pvt++; | |
318 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
319 | spin_unlock(&bedata->socket_lock); | |
320 | if (notify) | |
321 | notify_remote_via_irq(bedata->irq); | |
322 | ||
323 | wait_event(bedata->inflight_req, | |
324 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
325 | ||
326 | /* read req_id, then the content */ | |
327 | smp_rmb(); | |
328 | ret = bedata->rsp[req_id].ret; | |
329 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
330 | ||
331 | pvcalls_exit(); | |
332 | return ret; | |
333 | } | |
334 | ||
9f51c05d WY |
335 | static void free_active_ring(struct sock_mapping *map) |
336 | { | |
b4711098 WY |
337 | if (!map->active.ring) |
338 | return; | |
339 | ||
9f51c05d WY |
340 | free_pages((unsigned long)map->active.data.in, |
341 | map->active.ring->ring_order); | |
342 | free_page((unsigned long)map->active.ring); | |
343 | } | |
344 | ||
345 | static int alloc_active_ring(struct sock_mapping *map) | |
346 | { | |
347 | void *bytes; | |
348 | ||
349 | map->active.ring = (struct pvcalls_data_intf *) | |
350 | get_zeroed_page(GFP_KERNEL); | |
351 | if (!map->active.ring) | |
352 | goto out; | |
353 | ||
354 | map->active.ring->ring_order = PVCALLS_RING_ORDER; | |
355 | bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, | |
356 | PVCALLS_RING_ORDER); | |
357 | if (!bytes) | |
358 | goto out; | |
359 | ||
360 | map->active.data.in = bytes; | |
361 | map->active.data.out = bytes + | |
362 | XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
363 | ||
364 | return 0; | |
365 | ||
366 | out: | |
367 | free_active_ring(map); | |
368 | return -ENOMEM; | |
369 | } | |
370 | ||
0102e4ef | 371 | static int create_active(struct sock_mapping *map, evtchn_port_t *evtchn) |
cb1c7d9b SS |
372 | { |
373 | void *bytes; | |
374 | int ret = -ENOMEM, irq = -1, i; | |
375 | ||
0102e4ef | 376 | *evtchn = 0; |
cb1c7d9b SS |
377 | init_waitqueue_head(&map->active.inflight_conn_req); |
378 | ||
9f51c05d | 379 | bytes = map->active.data.in; |
cb1c7d9b SS |
380 | for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) |
381 | map->active.ring->ref[i] = gnttab_grant_foreign_access( | |
382 | pvcalls_front_dev->otherend_id, | |
383 | pfn_to_gfn(virt_to_pfn(bytes) + i), 0); | |
384 | ||
385 | map->active.ref = gnttab_grant_foreign_access( | |
386 | pvcalls_front_dev->otherend_id, | |
387 | pfn_to_gfn(virt_to_pfn((void *)map->active.ring)), 0); | |
388 | ||
cb1c7d9b SS |
389 | ret = xenbus_alloc_evtchn(pvcalls_front_dev, evtchn); |
390 | if (ret) | |
391 | goto out_error; | |
392 | irq = bind_evtchn_to_irqhandler(*evtchn, pvcalls_front_conn_handler, | |
393 | 0, "pvcalls-frontend", map); | |
394 | if (irq < 0) { | |
395 | ret = irq; | |
396 | goto out_error; | |
397 | } | |
398 | ||
399 | map->active.irq = irq; | |
400 | map->active_socket = true; | |
401 | mutex_init(&map->active.in_mutex); | |
402 | mutex_init(&map->active.out_mutex); | |
403 | ||
404 | return 0; | |
405 | ||
406 | out_error: | |
0102e4ef | 407 | if (*evtchn > 0) |
cb1c7d9b | 408 | xenbus_free_evtchn(pvcalls_front_dev, *evtchn); |
cb1c7d9b SS |
409 | return ret; |
410 | } | |
411 | ||
412 | int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr, | |
413 | int addr_len, int flags) | |
414 | { | |
415 | struct pvcalls_bedata *bedata; | |
416 | struct sock_mapping *map = NULL; | |
417 | struct xen_pvcalls_request *req; | |
0102e4ef YY |
418 | int notify, req_id, ret; |
419 | evtchn_port_t evtchn; | |
cb1c7d9b SS |
420 | |
421 | if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM) | |
422 | return -EOPNOTSUPP; | |
423 | ||
64d68718 SS |
424 | map = pvcalls_enter_sock(sock); |
425 | if (IS_ERR(map)) | |
426 | return PTR_ERR(map); | |
cb1c7d9b SS |
427 | |
428 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
9f51c05d WY |
429 | ret = alloc_active_ring(map); |
430 | if (ret < 0) { | |
431 | pvcalls_exit_sock(sock); | |
432 | return ret; | |
433 | } | |
cb1c7d9b | 434 | |
cb1c7d9b SS |
435 | spin_lock(&bedata->socket_lock); |
436 | ret = get_request(bedata, &req_id); | |
437 | if (ret < 0) { | |
438 | spin_unlock(&bedata->socket_lock); | |
9f51c05d | 439 | free_active_ring(map); |
64d68718 | 440 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
441 | return ret; |
442 | } | |
443 | ret = create_active(map, &evtchn); | |
444 | if (ret < 0) { | |
445 | spin_unlock(&bedata->socket_lock); | |
9f51c05d | 446 | free_active_ring(map); |
64d68718 | 447 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
448 | return ret; |
449 | } | |
450 | ||
451 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
452 | req->req_id = req_id; | |
453 | req->cmd = PVCALLS_CONNECT; | |
454 | req->u.connect.id = (uintptr_t)map; | |
455 | req->u.connect.len = addr_len; | |
456 | req->u.connect.flags = flags; | |
457 | req->u.connect.ref = map->active.ref; | |
458 | req->u.connect.evtchn = evtchn; | |
459 | memcpy(req->u.connect.addr, addr, sizeof(*addr)); | |
460 | ||
461 | map->sock = sock; | |
462 | ||
463 | bedata->ring.req_prod_pvt++; | |
464 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
465 | spin_unlock(&bedata->socket_lock); | |
466 | ||
467 | if (notify) | |
468 | notify_remote_via_irq(bedata->irq); | |
469 | ||
470 | wait_event(bedata->inflight_req, | |
471 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
472 | ||
473 | /* read req_id, then the content */ | |
474 | smp_rmb(); | |
475 | ret = bedata->rsp[req_id].ret; | |
476 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
64d68718 | 477 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
478 | return ret; |
479 | } | |
480 | ||
45ddce21 SS |
481 | static int __write_ring(struct pvcalls_data_intf *intf, |
482 | struct pvcalls_data *data, | |
483 | struct iov_iter *msg_iter, | |
484 | int len) | |
485 | { | |
486 | RING_IDX cons, prod, size, masked_prod, masked_cons; | |
487 | RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
488 | int32_t error; | |
489 | ||
490 | error = intf->out_error; | |
491 | if (error < 0) | |
492 | return error; | |
493 | cons = intf->out_cons; | |
494 | prod = intf->out_prod; | |
495 | /* read indexes before continuing */ | |
496 | virt_mb(); | |
497 | ||
498 | size = pvcalls_queued(prod, cons, array_size); | |
d90a1ca6 | 499 | if (size > array_size) |
45ddce21 | 500 | return -EINVAL; |
d90a1ca6 SS |
501 | if (size == array_size) |
502 | return 0; | |
45ddce21 SS |
503 | if (len > array_size - size) |
504 | len = array_size - size; | |
505 | ||
506 | masked_prod = pvcalls_mask(prod, array_size); | |
507 | masked_cons = pvcalls_mask(cons, array_size); | |
508 | ||
509 | if (masked_prod < masked_cons) { | |
510 | len = copy_from_iter(data->out + masked_prod, len, msg_iter); | |
511 | } else { | |
512 | if (len > array_size - masked_prod) { | |
513 | int ret = copy_from_iter(data->out + masked_prod, | |
514 | array_size - masked_prod, msg_iter); | |
515 | if (ret != array_size - masked_prod) { | |
516 | len = ret; | |
517 | goto out; | |
518 | } | |
519 | len = ret + copy_from_iter(data->out, len - ret, msg_iter); | |
520 | } else { | |
521 | len = copy_from_iter(data->out + masked_prod, len, msg_iter); | |
522 | } | |
523 | } | |
524 | out: | |
525 | /* write to ring before updating pointer */ | |
526 | virt_wmb(); | |
527 | intf->out_prod += len; | |
528 | ||
529 | return len; | |
530 | } | |
531 | ||
532 | int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg, | |
533 | size_t len) | |
534 | { | |
45ddce21 SS |
535 | struct sock_mapping *map; |
536 | int sent, tot_sent = 0; | |
537 | int count = 0, flags; | |
538 | ||
539 | flags = msg->msg_flags; | |
540 | if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB)) | |
541 | return -EOPNOTSUPP; | |
542 | ||
64d68718 SS |
543 | map = pvcalls_enter_sock(sock); |
544 | if (IS_ERR(map)) | |
545 | return PTR_ERR(map); | |
45ddce21 | 546 | |
45ddce21 SS |
547 | mutex_lock(&map->active.out_mutex); |
548 | if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) { | |
549 | mutex_unlock(&map->active.out_mutex); | |
64d68718 | 550 | pvcalls_exit_sock(sock); |
45ddce21 SS |
551 | return -EAGAIN; |
552 | } | |
553 | if (len > INT_MAX) | |
554 | len = INT_MAX; | |
555 | ||
556 | again: | |
557 | count++; | |
558 | sent = __write_ring(map->active.ring, | |
559 | &map->active.data, &msg->msg_iter, | |
560 | len); | |
561 | if (sent > 0) { | |
562 | len -= sent; | |
563 | tot_sent += sent; | |
564 | notify_remote_via_irq(map->active.irq); | |
565 | } | |
566 | if (sent >= 0 && len > 0 && count < PVCALLS_FRONT_MAX_SPIN) | |
567 | goto again; | |
568 | if (sent < 0) | |
569 | tot_sent = sent; | |
570 | ||
571 | mutex_unlock(&map->active.out_mutex); | |
64d68718 | 572 | pvcalls_exit_sock(sock); |
45ddce21 SS |
573 | return tot_sent; |
574 | } | |
575 | ||
ae0d0405 SS |
576 | static int __read_ring(struct pvcalls_data_intf *intf, |
577 | struct pvcalls_data *data, | |
578 | struct iov_iter *msg_iter, | |
579 | size_t len, int flags) | |
580 | { | |
581 | RING_IDX cons, prod, size, masked_prod, masked_cons; | |
582 | RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
583 | int32_t error; | |
584 | ||
585 | cons = intf->in_cons; | |
586 | prod = intf->in_prod; | |
587 | error = intf->in_error; | |
588 | /* get pointers before reading from the ring */ | |
589 | virt_rmb(); | |
ae0d0405 SS |
590 | |
591 | size = pvcalls_queued(prod, cons, array_size); | |
592 | masked_prod = pvcalls_mask(prod, array_size); | |
593 | masked_cons = pvcalls_mask(cons, array_size); | |
594 | ||
595 | if (size == 0) | |
b79470b6 | 596 | return error ?: size; |
ae0d0405 SS |
597 | |
598 | if (len > size) | |
599 | len = size; | |
600 | ||
601 | if (masked_prod > masked_cons) { | |
602 | len = copy_to_iter(data->in + masked_cons, len, msg_iter); | |
603 | } else { | |
604 | if (len > (array_size - masked_cons)) { | |
605 | int ret = copy_to_iter(data->in + masked_cons, | |
606 | array_size - masked_cons, msg_iter); | |
607 | if (ret != array_size - masked_cons) { | |
608 | len = ret; | |
609 | goto out; | |
610 | } | |
611 | len = ret + copy_to_iter(data->in, len - ret, msg_iter); | |
612 | } else { | |
613 | len = copy_to_iter(data->in + masked_cons, len, msg_iter); | |
614 | } | |
615 | } | |
616 | out: | |
617 | /* read data from the ring before increasing the index */ | |
618 | virt_mb(); | |
619 | if (!(flags & MSG_PEEK)) | |
620 | intf->in_cons += len; | |
621 | ||
622 | return len; | |
623 | } | |
624 | ||
625 | int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, | |
626 | int flags) | |
627 | { | |
ae0d0405 SS |
628 | int ret; |
629 | struct sock_mapping *map; | |
630 | ||
631 | if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC)) | |
632 | return -EOPNOTSUPP; | |
633 | ||
64d68718 SS |
634 | map = pvcalls_enter_sock(sock); |
635 | if (IS_ERR(map)) | |
636 | return PTR_ERR(map); | |
ae0d0405 | 637 | |
ae0d0405 SS |
638 | mutex_lock(&map->active.in_mutex); |
639 | if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) | |
640 | len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
641 | ||
642 | while (!(flags & MSG_DONTWAIT) && !pvcalls_front_read_todo(map)) { | |
643 | wait_event_interruptible(map->active.inflight_conn_req, | |
644 | pvcalls_front_read_todo(map)); | |
645 | } | |
646 | ret = __read_ring(map->active.ring, &map->active.data, | |
647 | &msg->msg_iter, len, flags); | |
648 | ||
649 | if (ret > 0) | |
650 | notify_remote_via_irq(map->active.irq); | |
651 | if (ret == 0) | |
652 | ret = (flags & MSG_DONTWAIT) ? -EAGAIN : 0; | |
653 | if (ret == -ENOTCONN) | |
654 | ret = 0; | |
655 | ||
656 | mutex_unlock(&map->active.in_mutex); | |
64d68718 | 657 | pvcalls_exit_sock(sock); |
ae0d0405 SS |
658 | return ret; |
659 | } | |
660 | ||
67ea9893 SS |
661 | int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len) |
662 | { | |
663 | struct pvcalls_bedata *bedata; | |
664 | struct sock_mapping *map = NULL; | |
665 | struct xen_pvcalls_request *req; | |
666 | int notify, req_id, ret; | |
667 | ||
668 | if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM) | |
669 | return -EOPNOTSUPP; | |
670 | ||
64d68718 SS |
671 | map = pvcalls_enter_sock(sock); |
672 | if (IS_ERR(map)) | |
673 | return PTR_ERR(map); | |
67ea9893 SS |
674 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
675 | ||
67ea9893 SS |
676 | spin_lock(&bedata->socket_lock); |
677 | ret = get_request(bedata, &req_id); | |
678 | if (ret < 0) { | |
679 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 680 | pvcalls_exit_sock(sock); |
67ea9893 SS |
681 | return ret; |
682 | } | |
683 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
684 | req->req_id = req_id; | |
685 | map->sock = sock; | |
686 | req->cmd = PVCALLS_BIND; | |
687 | req->u.bind.id = (uintptr_t)map; | |
688 | memcpy(req->u.bind.addr, addr, sizeof(*addr)); | |
689 | req->u.bind.len = addr_len; | |
690 | ||
9774c6cc SS |
691 | init_waitqueue_head(&map->passive.inflight_accept_req); |
692 | ||
67ea9893 SS |
693 | map->active_socket = false; |
694 | ||
695 | bedata->ring.req_prod_pvt++; | |
696 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
697 | spin_unlock(&bedata->socket_lock); | |
698 | if (notify) | |
699 | notify_remote_via_irq(bedata->irq); | |
700 | ||
701 | wait_event(bedata->inflight_req, | |
702 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
703 | ||
704 | /* read req_id, then the content */ | |
705 | smp_rmb(); | |
706 | ret = bedata->rsp[req_id].ret; | |
707 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
708 | ||
709 | map->passive.status = PVCALLS_STATUS_BIND; | |
64d68718 | 710 | pvcalls_exit_sock(sock); |
67ea9893 SS |
711 | return 0; |
712 | } | |
713 | ||
1853f11d SS |
714 | int pvcalls_front_listen(struct socket *sock, int backlog) |
715 | { | |
716 | struct pvcalls_bedata *bedata; | |
717 | struct sock_mapping *map; | |
718 | struct xen_pvcalls_request *req; | |
719 | int notify, req_id, ret; | |
720 | ||
64d68718 SS |
721 | map = pvcalls_enter_sock(sock); |
722 | if (IS_ERR(map)) | |
723 | return PTR_ERR(map); | |
1853f11d SS |
724 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
725 | ||
1853f11d | 726 | if (map->passive.status != PVCALLS_STATUS_BIND) { |
64d68718 | 727 | pvcalls_exit_sock(sock); |
1853f11d SS |
728 | return -EOPNOTSUPP; |
729 | } | |
730 | ||
731 | spin_lock(&bedata->socket_lock); | |
732 | ret = get_request(bedata, &req_id); | |
733 | if (ret < 0) { | |
734 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 735 | pvcalls_exit_sock(sock); |
1853f11d SS |
736 | return ret; |
737 | } | |
738 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
739 | req->req_id = req_id; | |
740 | req->cmd = PVCALLS_LISTEN; | |
741 | req->u.listen.id = (uintptr_t) map; | |
742 | req->u.listen.backlog = backlog; | |
743 | ||
744 | bedata->ring.req_prod_pvt++; | |
745 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
746 | spin_unlock(&bedata->socket_lock); | |
747 | if (notify) | |
748 | notify_remote_via_irq(bedata->irq); | |
749 | ||
750 | wait_event(bedata->inflight_req, | |
751 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
752 | ||
753 | /* read req_id, then the content */ | |
754 | smp_rmb(); | |
755 | ret = bedata->rsp[req_id].ret; | |
756 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
757 | ||
758 | map->passive.status = PVCALLS_STATUS_LISTEN; | |
64d68718 | 759 | pvcalls_exit_sock(sock); |
1853f11d SS |
760 | return ret; |
761 | } | |
762 | ||
9774c6cc SS |
763 | int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags) |
764 | { | |
765 | struct pvcalls_bedata *bedata; | |
766 | struct sock_mapping *map; | |
767 | struct sock_mapping *map2 = NULL; | |
768 | struct xen_pvcalls_request *req; | |
0102e4ef YY |
769 | int notify, req_id, ret, nonblock; |
770 | evtchn_port_t evtchn; | |
9774c6cc | 771 | |
64d68718 SS |
772 | map = pvcalls_enter_sock(sock); |
773 | if (IS_ERR(map)) | |
774 | return PTR_ERR(map); | |
9774c6cc SS |
775 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
776 | ||
9774c6cc | 777 | if (map->passive.status != PVCALLS_STATUS_LISTEN) { |
64d68718 | 778 | pvcalls_exit_sock(sock); |
9774c6cc SS |
779 | return -EINVAL; |
780 | } | |
781 | ||
782 | nonblock = flags & SOCK_NONBLOCK; | |
783 | /* | |
784 | * Backend only supports 1 inflight accept request, will return | |
785 | * errors for the others | |
786 | */ | |
787 | if (test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
788 | (void *)&map->passive.flags)) { | |
789 | req_id = READ_ONCE(map->passive.inflight_req_id); | |
790 | if (req_id != PVCALLS_INVALID_ID && | |
791 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id) { | |
792 | map2 = map->passive.accept_map; | |
793 | goto received; | |
794 | } | |
795 | if (nonblock) { | |
64d68718 | 796 | pvcalls_exit_sock(sock); |
9774c6cc SS |
797 | return -EAGAIN; |
798 | } | |
799 | if (wait_event_interruptible(map->passive.inflight_accept_req, | |
800 | !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
801 | (void *)&map->passive.flags))) { | |
64d68718 | 802 | pvcalls_exit_sock(sock); |
9774c6cc SS |
803 | return -EINTR; |
804 | } | |
805 | } | |
806 | ||
9f51c05d WY |
807 | map2 = kzalloc(sizeof(*map2), GFP_KERNEL); |
808 | if (map2 == NULL) { | |
9774c6cc SS |
809 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, |
810 | (void *)&map->passive.flags); | |
9f51c05d WY |
811 | pvcalls_exit_sock(sock); |
812 | return -ENOMEM; | |
813 | } | |
814 | ret = alloc_active_ring(map2); | |
815 | if (ret < 0) { | |
816 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
817 | (void *)&map->passive.flags); | |
818 | kfree(map2); | |
64d68718 | 819 | pvcalls_exit_sock(sock); |
9774c6cc SS |
820 | return ret; |
821 | } | |
9f51c05d WY |
822 | spin_lock(&bedata->socket_lock); |
823 | ret = get_request(bedata, &req_id); | |
824 | if (ret < 0) { | |
9774c6cc SS |
825 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, |
826 | (void *)&map->passive.flags); | |
827 | spin_unlock(&bedata->socket_lock); | |
9f51c05d WY |
828 | free_active_ring(map2); |
829 | kfree(map2); | |
64d68718 | 830 | pvcalls_exit_sock(sock); |
9f51c05d | 831 | return ret; |
9774c6cc | 832 | } |
9f51c05d | 833 | |
9774c6cc SS |
834 | ret = create_active(map2, &evtchn); |
835 | if (ret < 0) { | |
9f51c05d | 836 | free_active_ring(map2); |
9774c6cc SS |
837 | kfree(map2); |
838 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
839 | (void *)&map->passive.flags); | |
840 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 841 | pvcalls_exit_sock(sock); |
9774c6cc SS |
842 | return ret; |
843 | } | |
844 | list_add_tail(&map2->list, &bedata->socket_mappings); | |
845 | ||
846 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
847 | req->req_id = req_id; | |
848 | req->cmd = PVCALLS_ACCEPT; | |
849 | req->u.accept.id = (uintptr_t) map; | |
850 | req->u.accept.ref = map2->active.ref; | |
851 | req->u.accept.id_new = (uintptr_t) map2; | |
852 | req->u.accept.evtchn = evtchn; | |
853 | map->passive.accept_map = map2; | |
854 | ||
855 | bedata->ring.req_prod_pvt++; | |
856 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
857 | spin_unlock(&bedata->socket_lock); | |
858 | if (notify) | |
859 | notify_remote_via_irq(bedata->irq); | |
860 | /* We could check if we have received a response before returning. */ | |
861 | if (nonblock) { | |
862 | WRITE_ONCE(map->passive.inflight_req_id, req_id); | |
64d68718 | 863 | pvcalls_exit_sock(sock); |
9774c6cc SS |
864 | return -EAGAIN; |
865 | } | |
866 | ||
867 | if (wait_event_interruptible(bedata->inflight_req, | |
868 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) { | |
64d68718 | 869 | pvcalls_exit_sock(sock); |
9774c6cc SS |
870 | return -EINTR; |
871 | } | |
872 | /* read req_id, then the content */ | |
873 | smp_rmb(); | |
874 | ||
875 | received: | |
876 | map2->sock = newsock; | |
beee1fbe | 877 | newsock->sk = sk_alloc(sock_net(sock->sk), PF_INET, GFP_KERNEL, &pvcalls_proto, false); |
9774c6cc SS |
878 | if (!newsock->sk) { |
879 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
880 | map->passive.inflight_req_id = PVCALLS_INVALID_ID; | |
881 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
882 | (void *)&map->passive.flags); | |
883 | pvcalls_front_free_map(bedata, map2); | |
64d68718 | 884 | pvcalls_exit_sock(sock); |
9774c6cc SS |
885 | return -ENOMEM; |
886 | } | |
887 | newsock->sk->sk_send_head = (void *)map2; | |
888 | ||
889 | ret = bedata->rsp[req_id].ret; | |
890 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
891 | map->passive.inflight_req_id = PVCALLS_INVALID_ID; | |
892 | ||
893 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags); | |
894 | wake_up(&map->passive.inflight_accept_req); | |
895 | ||
64d68718 | 896 | pvcalls_exit_sock(sock); |
9774c6cc SS |
897 | return ret; |
898 | } | |
899 | ||
afc9a42b | 900 | static __poll_t pvcalls_front_poll_passive(struct file *file, |
5842c835 SS |
901 | struct pvcalls_bedata *bedata, |
902 | struct sock_mapping *map, | |
903 | poll_table *wait) | |
904 | { | |
905 | int notify, req_id, ret; | |
906 | struct xen_pvcalls_request *req; | |
907 | ||
908 | if (test_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
909 | (void *)&map->passive.flags)) { | |
910 | uint32_t req_id = READ_ONCE(map->passive.inflight_req_id); | |
911 | ||
912 | if (req_id != PVCALLS_INVALID_ID && | |
913 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id) | |
a9a08845 | 914 | return EPOLLIN | EPOLLRDNORM; |
5842c835 SS |
915 | |
916 | poll_wait(file, &map->passive.inflight_accept_req, wait); | |
917 | return 0; | |
918 | } | |
919 | ||
920 | if (test_and_clear_bit(PVCALLS_FLAG_POLL_RET, | |
921 | (void *)&map->passive.flags)) | |
a9a08845 | 922 | return EPOLLIN | EPOLLRDNORM; |
5842c835 SS |
923 | |
924 | /* | |
925 | * First check RET, then INFLIGHT. No barriers necessary to | |
926 | * ensure execution ordering because of the conditional | |
927 | * instructions creating control dependencies. | |
928 | */ | |
929 | ||
930 | if (test_and_set_bit(PVCALLS_FLAG_POLL_INFLIGHT, | |
931 | (void *)&map->passive.flags)) { | |
932 | poll_wait(file, &bedata->inflight_req, wait); | |
933 | return 0; | |
934 | } | |
935 | ||
936 | spin_lock(&bedata->socket_lock); | |
937 | ret = get_request(bedata, &req_id); | |
938 | if (ret < 0) { | |
939 | spin_unlock(&bedata->socket_lock); | |
940 | return ret; | |
941 | } | |
942 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
943 | req->req_id = req_id; | |
944 | req->cmd = PVCALLS_POLL; | |
945 | req->u.poll.id = (uintptr_t) map; | |
946 | ||
947 | bedata->ring.req_prod_pvt++; | |
948 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
949 | spin_unlock(&bedata->socket_lock); | |
950 | if (notify) | |
951 | notify_remote_via_irq(bedata->irq); | |
952 | ||
953 | poll_wait(file, &bedata->inflight_req, wait); | |
954 | return 0; | |
955 | } | |
956 | ||
afc9a42b | 957 | static __poll_t pvcalls_front_poll_active(struct file *file, |
5842c835 SS |
958 | struct pvcalls_bedata *bedata, |
959 | struct sock_mapping *map, | |
960 | poll_table *wait) | |
961 | { | |
afc9a42b | 962 | __poll_t mask = 0; |
5842c835 SS |
963 | int32_t in_error, out_error; |
964 | struct pvcalls_data_intf *intf = map->active.ring; | |
965 | ||
966 | out_error = intf->out_error; | |
967 | in_error = intf->in_error; | |
968 | ||
969 | poll_wait(file, &map->active.inflight_conn_req, wait); | |
970 | if (pvcalls_front_write_todo(map)) | |
a9a08845 | 971 | mask |= EPOLLOUT | EPOLLWRNORM; |
5842c835 | 972 | if (pvcalls_front_read_todo(map)) |
a9a08845 | 973 | mask |= EPOLLIN | EPOLLRDNORM; |
5842c835 | 974 | if (in_error != 0 || out_error != 0) |
a9a08845 | 975 | mask |= EPOLLERR; |
5842c835 SS |
976 | |
977 | return mask; | |
978 | } | |
979 | ||
afc9a42b | 980 | __poll_t pvcalls_front_poll(struct file *file, struct socket *sock, |
5842c835 SS |
981 | poll_table *wait) |
982 | { | |
983 | struct pvcalls_bedata *bedata; | |
984 | struct sock_mapping *map; | |
afc9a42b | 985 | __poll_t ret; |
5842c835 | 986 | |
64d68718 SS |
987 | map = pvcalls_enter_sock(sock); |
988 | if (IS_ERR(map)) | |
a9a08845 | 989 | return EPOLLNVAL; |
5842c835 SS |
990 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
991 | ||
5842c835 SS |
992 | if (map->active_socket) |
993 | ret = pvcalls_front_poll_active(file, bedata, map, wait); | |
994 | else | |
995 | ret = pvcalls_front_poll_passive(file, bedata, map, wait); | |
64d68718 | 996 | pvcalls_exit_sock(sock); |
5842c835 SS |
997 | return ret; |
998 | } | |
999 | ||
235a71c5 SS |
1000 | int pvcalls_front_release(struct socket *sock) |
1001 | { | |
1002 | struct pvcalls_bedata *bedata; | |
1003 | struct sock_mapping *map; | |
1004 | int req_id, notify, ret; | |
1005 | struct xen_pvcalls_request *req; | |
1006 | ||
1007 | if (sock->sk == NULL) | |
1008 | return 0; | |
1009 | ||
64d68718 SS |
1010 | map = pvcalls_enter_sock(sock); |
1011 | if (IS_ERR(map)) { | |
1012 | if (PTR_ERR(map) == -ENOTCONN) | |
1013 | return -EIO; | |
1014 | else | |
1015 | return 0; | |
235a71c5 | 1016 | } |
235a71c5 SS |
1017 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
1018 | ||
235a71c5 SS |
1019 | spin_lock(&bedata->socket_lock); |
1020 | ret = get_request(bedata, &req_id); | |
1021 | if (ret < 0) { | |
1022 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 1023 | pvcalls_exit_sock(sock); |
235a71c5 SS |
1024 | return ret; |
1025 | } | |
1026 | sock->sk->sk_send_head = NULL; | |
1027 | ||
1028 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
1029 | req->req_id = req_id; | |
1030 | req->cmd = PVCALLS_RELEASE; | |
1031 | req->u.release.id = (uintptr_t)map; | |
1032 | ||
1033 | bedata->ring.req_prod_pvt++; | |
1034 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
1035 | spin_unlock(&bedata->socket_lock); | |
1036 | if (notify) | |
1037 | notify_remote_via_irq(bedata->irq); | |
1038 | ||
1039 | wait_event(bedata->inflight_req, | |
1040 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
1041 | ||
1042 | if (map->active_socket) { | |
1043 | /* | |
1044 | * Set in_error and wake up inflight_conn_req to force | |
1045 | * recvmsg waiters to exit. | |
1046 | */ | |
1047 | map->active.ring->in_error = -EBADF; | |
1048 | wake_up_interruptible(&map->active.inflight_conn_req); | |
1049 | ||
1050 | /* | |
646d944c SS |
1051 | * We need to make sure that sendmsg/recvmsg on this socket have |
1052 | * not started before we've cleared sk_send_head here. The | |
64d68718 SS |
1053 | * easiest way to guarantee this is to see that no pvcalls |
1054 | * (other than us) is in progress on this socket. | |
235a71c5 | 1055 | */ |
64d68718 | 1056 | while (atomic_read(&map->refcount) > 1) |
235a71c5 SS |
1057 | cpu_relax(); |
1058 | ||
1059 | pvcalls_front_free_map(bedata, map); | |
1060 | } else { | |
d1a75e08 SS |
1061 | wake_up(&bedata->inflight_req); |
1062 | wake_up(&map->passive.inflight_accept_req); | |
1063 | ||
1064 | while (atomic_read(&map->refcount) > 1) | |
1065 | cpu_relax(); | |
1066 | ||
235a71c5 SS |
1067 | spin_lock(&bedata->socket_lock); |
1068 | list_del(&map->list); | |
1069 | spin_unlock(&bedata->socket_lock); | |
96283f9a SS |
1070 | if (READ_ONCE(map->passive.inflight_req_id) != PVCALLS_INVALID_ID && |
1071 | READ_ONCE(map->passive.inflight_req_id) != 0) { | |
235a71c5 SS |
1072 | pvcalls_front_free_map(bedata, |
1073 | map->passive.accept_map); | |
1074 | } | |
1075 | kfree(map); | |
1076 | } | |
1077 | WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); | |
1078 | ||
1079 | pvcalls_exit(); | |
1080 | return 0; | |
1081 | } | |
1082 | ||
416efba0 SS |
1083 | static const struct xenbus_device_id pvcalls_front_ids[] = { |
1084 | { "pvcalls" }, | |
1085 | { "" } | |
1086 | }; | |
1087 | ||
1088 | static int pvcalls_front_remove(struct xenbus_device *dev) | |
1089 | { | |
aa7ba376 SS |
1090 | struct pvcalls_bedata *bedata; |
1091 | struct sock_mapping *map = NULL, *n; | |
1092 | ||
1093 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
1094 | dev_set_drvdata(&dev->dev, NULL); | |
1095 | pvcalls_front_dev = NULL; | |
1096 | if (bedata->irq >= 0) | |
1097 | unbind_from_irqhandler(bedata->irq, dev); | |
1098 | ||
cb1c7d9b SS |
1099 | list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { |
1100 | map->sock->sk->sk_send_head = NULL; | |
1101 | if (map->active_socket) { | |
1102 | map->active.ring->in_error = -EBADF; | |
1103 | wake_up_interruptible(&map->active.inflight_conn_req); | |
1104 | } | |
1105 | } | |
1106 | ||
aa7ba376 SS |
1107 | smp_mb(); |
1108 | while (atomic_read(&pvcalls_refcount) > 0) | |
1109 | cpu_relax(); | |
1110 | list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { | |
1111 | if (map->active_socket) { | |
1112 | /* No need to lock, refcount is 0 */ | |
1113 | pvcalls_front_free_map(bedata, map); | |
1114 | } else { | |
1115 | list_del(&map->list); | |
1116 | kfree(map); | |
1117 | } | |
1118 | } | |
1ab134ca | 1119 | if (bedata->ref != -1) |
aa7ba376 SS |
1120 | gnttab_end_foreign_access(bedata->ref, 0, 0); |
1121 | kfree(bedata->ring.sring); | |
1122 | kfree(bedata); | |
1123 | xenbus_switch_state(dev, XenbusStateClosed); | |
416efba0 SS |
1124 | return 0; |
1125 | } | |
1126 | ||
1127 | static int pvcalls_front_probe(struct xenbus_device *dev, | |
1128 | const struct xenbus_device_id *id) | |
1129 | { | |
0102e4ef YY |
1130 | int ret = -ENOMEM, i; |
1131 | evtchn_port_t evtchn; | |
21968190 SS |
1132 | unsigned int max_page_order, function_calls, len; |
1133 | char *versions; | |
1134 | grant_ref_t gref_head = 0; | |
1135 | struct xenbus_transaction xbt; | |
1136 | struct pvcalls_bedata *bedata = NULL; | |
1137 | struct xen_pvcalls_sring *sring; | |
1138 | ||
1139 | if (pvcalls_front_dev != NULL) { | |
1140 | dev_err(&dev->dev, "only one PV Calls connection supported\n"); | |
1141 | return -EINVAL; | |
1142 | } | |
1143 | ||
1144 | versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len); | |
8c71fa88 DC |
1145 | if (IS_ERR(versions)) |
1146 | return PTR_ERR(versions); | |
21968190 SS |
1147 | if (!len) |
1148 | return -EINVAL; | |
1149 | if (strcmp(versions, "1")) { | |
1150 | kfree(versions); | |
1151 | return -EINVAL; | |
1152 | } | |
1153 | kfree(versions); | |
1154 | max_page_order = xenbus_read_unsigned(dev->otherend, | |
1155 | "max-page-order", 0); | |
1156 | if (max_page_order < PVCALLS_RING_ORDER) | |
1157 | return -ENODEV; | |
1158 | function_calls = xenbus_read_unsigned(dev->otherend, | |
1159 | "function-calls", 0); | |
1160 | /* See XENBUS_FUNCTIONS_CALLS in pvcalls.h */ | |
1161 | if (function_calls != 1) | |
1162 | return -ENODEV; | |
1163 | pr_info("%s max-page-order is %u\n", __func__, max_page_order); | |
1164 | ||
1165 | bedata = kzalloc(sizeof(struct pvcalls_bedata), GFP_KERNEL); | |
1166 | if (!bedata) | |
1167 | return -ENOMEM; | |
1168 | ||
1169 | dev_set_drvdata(&dev->dev, bedata); | |
1170 | pvcalls_front_dev = dev; | |
1171 | init_waitqueue_head(&bedata->inflight_req); | |
1172 | INIT_LIST_HEAD(&bedata->socket_mappings); | |
1173 | spin_lock_init(&bedata->socket_lock); | |
1174 | bedata->irq = -1; | |
1175 | bedata->ref = -1; | |
1176 | ||
1177 | for (i = 0; i < PVCALLS_NR_RSP_PER_RING; i++) | |
1178 | bedata->rsp[i].req_id = PVCALLS_INVALID_ID; | |
1179 | ||
1180 | sring = (struct xen_pvcalls_sring *) __get_free_page(GFP_KERNEL | | |
1181 | __GFP_ZERO); | |
1182 | if (!sring) | |
1183 | goto error; | |
1184 | SHARED_RING_INIT(sring); | |
1185 | FRONT_RING_INIT(&bedata->ring, sring, XEN_PAGE_SIZE); | |
1186 | ||
1187 | ret = xenbus_alloc_evtchn(dev, &evtchn); | |
1188 | if (ret) | |
1189 | goto error; | |
1190 | ||
1191 | bedata->irq = bind_evtchn_to_irqhandler(evtchn, | |
1192 | pvcalls_front_event_handler, | |
1193 | 0, "pvcalls-frontend", dev); | |
1194 | if (bedata->irq < 0) { | |
1195 | ret = bedata->irq; | |
1196 | goto error; | |
1197 | } | |
1198 | ||
1199 | ret = gnttab_alloc_grant_references(1, &gref_head); | |
1200 | if (ret < 0) | |
1201 | goto error; | |
95110ac8 CIK |
1202 | ret = gnttab_claim_grant_reference(&gref_head); |
1203 | if (ret < 0) | |
21968190 | 1204 | goto error; |
95110ac8 | 1205 | bedata->ref = ret; |
21968190 SS |
1206 | gnttab_grant_foreign_access_ref(bedata->ref, dev->otherend_id, |
1207 | virt_to_gfn((void *)sring), 0); | |
1208 | ||
1209 | again: | |
1210 | ret = xenbus_transaction_start(&xbt); | |
1211 | if (ret) { | |
1212 | xenbus_dev_fatal(dev, ret, "starting transaction"); | |
1213 | goto error; | |
1214 | } | |
1215 | ret = xenbus_printf(xbt, dev->nodename, "version", "%u", 1); | |
1216 | if (ret) | |
1217 | goto error_xenbus; | |
1218 | ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", bedata->ref); | |
1219 | if (ret) | |
1220 | goto error_xenbus; | |
1221 | ret = xenbus_printf(xbt, dev->nodename, "port", "%u", | |
1222 | evtchn); | |
1223 | if (ret) | |
1224 | goto error_xenbus; | |
1225 | ret = xenbus_transaction_end(xbt, 0); | |
1226 | if (ret) { | |
1227 | if (ret == -EAGAIN) | |
1228 | goto again; | |
1229 | xenbus_dev_fatal(dev, ret, "completing transaction"); | |
1230 | goto error; | |
1231 | } | |
1232 | xenbus_switch_state(dev, XenbusStateInitialised); | |
1233 | ||
416efba0 | 1234 | return 0; |
21968190 SS |
1235 | |
1236 | error_xenbus: | |
1237 | xenbus_transaction_end(xbt, 1); | |
1238 | xenbus_dev_fatal(dev, ret, "writing xenstore"); | |
1239 | error: | |
1240 | pvcalls_front_remove(dev); | |
1241 | return ret; | |
416efba0 SS |
1242 | } |
1243 | ||
1244 | static void pvcalls_front_changed(struct xenbus_device *dev, | |
1245 | enum xenbus_state backend_state) | |
1246 | { | |
21968190 SS |
1247 | switch (backend_state) { |
1248 | case XenbusStateReconfiguring: | |
1249 | case XenbusStateReconfigured: | |
1250 | case XenbusStateInitialising: | |
1251 | case XenbusStateInitialised: | |
1252 | case XenbusStateUnknown: | |
1253 | break; | |
1254 | ||
1255 | case XenbusStateInitWait: | |
1256 | break; | |
1257 | ||
1258 | case XenbusStateConnected: | |
1259 | xenbus_switch_state(dev, XenbusStateConnected); | |
1260 | break; | |
1261 | ||
1262 | case XenbusStateClosed: | |
1263 | if (dev->state == XenbusStateClosed) | |
1264 | break; | |
3d8765d4 GS |
1265 | /* Missed the backend's CLOSING state */ |
1266 | /* fall through */ | |
21968190 SS |
1267 | case XenbusStateClosing: |
1268 | xenbus_frontend_closed(dev); | |
1269 | break; | |
1270 | } | |
416efba0 SS |
1271 | } |
1272 | ||
1273 | static struct xenbus_driver pvcalls_front_driver = { | |
1274 | .ids = pvcalls_front_ids, | |
1275 | .probe = pvcalls_front_probe, | |
1276 | .remove = pvcalls_front_remove, | |
1277 | .otherend_changed = pvcalls_front_changed, | |
1278 | }; | |
1279 | ||
1280 | static int __init pvcalls_frontend_init(void) | |
1281 | { | |
1282 | if (!xen_domain()) | |
1283 | return -ENODEV; | |
1284 | ||
1285 | pr_info("Initialising Xen pvcalls frontend driver\n"); | |
1286 | ||
1287 | return xenbus_register_frontend(&pvcalls_front_driver); | |
1288 | } | |
1289 | ||
1290 | module_init(pvcalls_frontend_init); | |
24e7f84d BO |
1291 | |
1292 | MODULE_DESCRIPTION("Xen PV Calls frontend driver"); | |
1293 | MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>"); | |
1294 | MODULE_LICENSE("GPL"); |