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8beb8d4c JG |
1 | /* |
2 | * Xen SCSI frontend driver | |
3 | * | |
4 | * Copyright (c) 2008, FUJITSU Limited | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License version 2 | |
8 | * as published by the Free Software Foundation; or, when distributed | |
9 | * separately from the Linux kernel or incorporated into other | |
10 | * software packages, subject to the following license: | |
11 | * | |
12 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
13 | * of this source file (the "Software"), to deal in the Software without | |
14 | * restriction, including without limitation the rights to use, copy, modify, | |
15 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
16 | * and to permit persons to whom the Software is furnished to do so, subject to | |
17 | * the following conditions: | |
18 | * | |
19 | * The above copyright notice and this permission notice shall be included in | |
20 | * all copies or substantial portions of the Software. | |
21 | * | |
22 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
23 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
24 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
25 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
26 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
27 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
28 | * IN THE SOFTWARE. | |
29 | */ | |
30 | ||
31 | #include <linux/module.h> | |
32 | #include <linux/kernel.h> | |
33 | #include <linux/device.h> | |
34 | #include <linux/wait.h> | |
35 | #include <linux/interrupt.h> | |
36 | #include <linux/mutex.h> | |
37 | #include <linux/spinlock.h> | |
38 | #include <linux/sched.h> | |
39 | #include <linux/blkdev.h> | |
40 | #include <linux/pfn.h> | |
41 | #include <linux/slab.h> | |
42 | #include <linux/bitops.h> | |
43 | ||
44 | #include <scsi/scsi_cmnd.h> | |
45 | #include <scsi/scsi_device.h> | |
46 | #include <scsi/scsi.h> | |
47 | #include <scsi/scsi_host.h> | |
48 | ||
49 | #include <xen/xen.h> | |
50 | #include <xen/xenbus.h> | |
51 | #include <xen/grant_table.h> | |
52 | #include <xen/events.h> | |
53 | #include <xen/page.h> | |
54 | ||
55 | #include <xen/interface/grant_table.h> | |
56 | #include <xen/interface/io/vscsiif.h> | |
57 | #include <xen/interface/io/protocols.h> | |
58 | ||
59 | #include <asm/xen/hypervisor.h> | |
60 | ||
8beb8d4c JG |
61 | #define VSCSIFRONT_OP_ADD_LUN 1 |
62 | #define VSCSIFRONT_OP_DEL_LUN 2 | |
85617dc7 | 63 | #define VSCSIFRONT_OP_READD_LUN 3 |
8beb8d4c JG |
64 | |
65 | /* Tuning point. */ | |
66 | #define VSCSIIF_DEFAULT_CMD_PER_LUN 10 | |
67 | #define VSCSIIF_MAX_TARGET 64 | |
68 | #define VSCSIIF_MAX_LUN 255 | |
69 | ||
70 | #define VSCSIIF_RING_SIZE __CONST_RING_SIZE(vscsiif, PAGE_SIZE) | |
71 | #define VSCSIIF_MAX_REQS VSCSIIF_RING_SIZE | |
72 | ||
73 | #define vscsiif_grants_sg(_sg) (PFN_UP((_sg) * \ | |
74 | sizeof(struct scsiif_request_segment))) | |
75 | ||
76 | struct vscsifrnt_shadow { | |
77 | /* command between backend and frontend */ | |
78 | unsigned char act; | |
3da96be5 | 79 | uint8_t nr_segments; |
8beb8d4c | 80 | uint16_t rqid; |
3da96be5 | 81 | uint16_t ref_rqid; |
8beb8d4c | 82 | |
6d1c2f48 JG |
83 | bool inflight; |
84 | ||
8beb8d4c JG |
85 | unsigned int nr_grants; /* number of grants in gref[] */ |
86 | struct scsiif_request_segment *sg; /* scatter/gather elements */ | |
3da96be5 | 87 | struct scsiif_request_segment seg[VSCSIIF_SG_TABLESIZE]; |
8beb8d4c JG |
88 | |
89 | /* Do reset or abort function. */ | |
90 | wait_queue_head_t wq_reset; /* reset work queue */ | |
91 | int wait_reset; /* reset work queue condition */ | |
92 | int32_t rslt_reset; /* reset response status: */ | |
93 | /* SUCCESS or FAILED or: */ | |
94 | #define RSLT_RESET_WAITING 0 | |
95 | #define RSLT_RESET_ERR -1 | |
96 | ||
97 | /* Requested struct scsi_cmnd is stored from kernel. */ | |
98 | struct scsi_cmnd *sc; | |
99 | int gref[vscsiif_grants_sg(SG_ALL) + SG_ALL]; | |
100 | }; | |
101 | ||
102 | struct vscsifrnt_info { | |
103 | struct xenbus_device *dev; | |
104 | ||
105 | struct Scsi_Host *host; | |
6d1c2f48 JG |
106 | enum { |
107 | STATE_INACTIVE, | |
108 | STATE_ACTIVE, | |
109 | STATE_ERROR | |
110 | } host_active; | |
8beb8d4c JG |
111 | |
112 | unsigned int evtchn; | |
113 | unsigned int irq; | |
114 | ||
115 | grant_ref_t ring_ref; | |
116 | struct vscsiif_front_ring ring; | |
117 | struct vscsiif_response ring_rsp; | |
118 | ||
119 | spinlock_t shadow_lock; | |
120 | DECLARE_BITMAP(shadow_free_bitmap, VSCSIIF_MAX_REQS); | |
121 | struct vscsifrnt_shadow *shadow[VSCSIIF_MAX_REQS]; | |
122 | ||
85617dc7 | 123 | /* Following items are protected by the host lock. */ |
8beb8d4c | 124 | wait_queue_head_t wq_sync; |
85617dc7 | 125 | wait_queue_head_t wq_pause; |
8beb8d4c | 126 | unsigned int wait_ring_available:1; |
85617dc7 JG |
127 | unsigned int waiting_pause:1; |
128 | unsigned int pause:1; | |
129 | unsigned callers; | |
8beb8d4c JG |
130 | |
131 | char dev_state_path[64]; | |
132 | struct task_struct *curr; | |
133 | }; | |
134 | ||
135 | static DEFINE_MUTEX(scsifront_mutex); | |
136 | ||
137 | static void scsifront_wake_up(struct vscsifrnt_info *info) | |
138 | { | |
139 | info->wait_ring_available = 0; | |
140 | wake_up(&info->wq_sync); | |
141 | } | |
142 | ||
143 | static int scsifront_get_rqid(struct vscsifrnt_info *info) | |
144 | { | |
145 | unsigned long flags; | |
146 | int free; | |
147 | ||
148 | spin_lock_irqsave(&info->shadow_lock, flags); | |
149 | ||
150 | free = find_first_bit(info->shadow_free_bitmap, VSCSIIF_MAX_REQS); | |
151 | __clear_bit(free, info->shadow_free_bitmap); | |
152 | ||
153 | spin_unlock_irqrestore(&info->shadow_lock, flags); | |
154 | ||
155 | return free; | |
156 | } | |
157 | ||
158 | static int _scsifront_put_rqid(struct vscsifrnt_info *info, uint32_t id) | |
159 | { | |
160 | int empty = bitmap_empty(info->shadow_free_bitmap, VSCSIIF_MAX_REQS); | |
161 | ||
162 | __set_bit(id, info->shadow_free_bitmap); | |
163 | info->shadow[id] = NULL; | |
164 | ||
165 | return empty || info->wait_ring_available; | |
166 | } | |
167 | ||
168 | static void scsifront_put_rqid(struct vscsifrnt_info *info, uint32_t id) | |
169 | { | |
170 | unsigned long flags; | |
171 | int kick; | |
172 | ||
173 | spin_lock_irqsave(&info->shadow_lock, flags); | |
174 | kick = _scsifront_put_rqid(info, id); | |
175 | spin_unlock_irqrestore(&info->shadow_lock, flags); | |
176 | ||
177 | if (kick) | |
178 | scsifront_wake_up(info); | |
179 | } | |
180 | ||
3da96be5 JG |
181 | static int scsifront_do_request(struct vscsifrnt_info *info, |
182 | struct vscsifrnt_shadow *shadow) | |
8beb8d4c JG |
183 | { |
184 | struct vscsiif_front_ring *ring = &(info->ring); | |
185 | struct vscsiif_request *ring_req; | |
3da96be5 | 186 | struct scsi_cmnd *sc = shadow->sc; |
8beb8d4c | 187 | uint32_t id; |
3da96be5 JG |
188 | int i, notify; |
189 | ||
190 | if (RING_FULL(&info->ring)) | |
191 | return -EBUSY; | |
8beb8d4c JG |
192 | |
193 | id = scsifront_get_rqid(info); /* use id in response */ | |
194 | if (id >= VSCSIIF_MAX_REQS) | |
3da96be5 | 195 | return -EBUSY; |
8beb8d4c | 196 | |
3da96be5 JG |
197 | info->shadow[id] = shadow; |
198 | shadow->rqid = id; | |
8beb8d4c | 199 | |
3da96be5 | 200 | ring_req = RING_GET_REQUEST(&(info->ring), ring->req_prod_pvt); |
8beb8d4c JG |
201 | ring->req_prod_pvt++; |
202 | ||
3da96be5 JG |
203 | ring_req->rqid = id; |
204 | ring_req->act = shadow->act; | |
205 | ring_req->ref_rqid = shadow->ref_rqid; | |
206 | ring_req->nr_segments = shadow->nr_segments; | |
8beb8d4c | 207 | |
3da96be5 JG |
208 | ring_req->id = sc->device->id; |
209 | ring_req->lun = sc->device->lun; | |
210 | ring_req->channel = sc->device->channel; | |
211 | ring_req->cmd_len = sc->cmd_len; | |
8beb8d4c | 212 | |
3da96be5 JG |
213 | BUG_ON(sc->cmd_len > VSCSIIF_MAX_COMMAND_SIZE); |
214 | ||
215 | memcpy(ring_req->cmnd, sc->cmnd, sc->cmd_len); | |
216 | ||
217 | ring_req->sc_data_direction = (uint8_t)sc->sc_data_direction; | |
80ca10b6 | 218 | ring_req->timeout_per_command = scsi_cmd_to_rq(sc)->timeout / HZ; |
3da96be5 JG |
219 | |
220 | for (i = 0; i < (shadow->nr_segments & ~VSCSIIF_SG_GRANT); i++) | |
221 | ring_req->seg[i] = shadow->seg[i]; | |
8beb8d4c | 222 | |
6d1c2f48 JG |
223 | shadow->inflight = true; |
224 | ||
8beb8d4c JG |
225 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(ring, notify); |
226 | if (notify) | |
227 | notify_remote_via_irq(info->irq); | |
3da96be5 JG |
228 | |
229 | return 0; | |
8beb8d4c JG |
230 | } |
231 | ||
6d1c2f48 JG |
232 | static void scsifront_set_error(struct vscsifrnt_info *info, const char *msg) |
233 | { | |
234 | shost_printk(KERN_ERR, info->host, KBUILD_MODNAME "%s\n" | |
235 | "Disabling device for further use\n", msg); | |
236 | info->host_active = STATE_ERROR; | |
237 | } | |
238 | ||
3da96be5 JG |
239 | static void scsifront_gnttab_done(struct vscsifrnt_info *info, |
240 | struct vscsifrnt_shadow *shadow) | |
8beb8d4c | 241 | { |
8beb8d4c JG |
242 | int i; |
243 | ||
3da96be5 | 244 | if (shadow->sc->sc_data_direction == DMA_NONE) |
8beb8d4c JG |
245 | return; |
246 | ||
3da96be5 | 247 | for (i = 0; i < shadow->nr_grants; i++) { |
33172ab5 | 248 | if (unlikely(!gnttab_try_end_foreign_access(shadow->gref[i]))) { |
6d1c2f48 JG |
249 | scsifront_set_error(info, "grant still in use by backend"); |
250 | return; | |
8beb8d4c | 251 | } |
8beb8d4c JG |
252 | } |
253 | ||
3da96be5 | 254 | kfree(shadow->sg); |
8beb8d4c JG |
255 | } |
256 | ||
a2f6751d JG |
257 | static unsigned int scsifront_host_byte(int32_t rslt) |
258 | { | |
259 | switch (XEN_VSCSIIF_RSLT_HOST(rslt)) { | |
260 | case XEN_VSCSIIF_RSLT_HOST_OK: | |
261 | return DID_OK; | |
262 | case XEN_VSCSIIF_RSLT_HOST_NO_CONNECT: | |
263 | return DID_NO_CONNECT; | |
264 | case XEN_VSCSIIF_RSLT_HOST_BUS_BUSY: | |
265 | return DID_BUS_BUSY; | |
266 | case XEN_VSCSIIF_RSLT_HOST_TIME_OUT: | |
267 | return DID_TIME_OUT; | |
268 | case XEN_VSCSIIF_RSLT_HOST_BAD_TARGET: | |
269 | return DID_BAD_TARGET; | |
270 | case XEN_VSCSIIF_RSLT_HOST_ABORT: | |
271 | return DID_ABORT; | |
272 | case XEN_VSCSIIF_RSLT_HOST_PARITY: | |
273 | return DID_PARITY; | |
274 | case XEN_VSCSIIF_RSLT_HOST_ERROR: | |
275 | return DID_ERROR; | |
276 | case XEN_VSCSIIF_RSLT_HOST_RESET: | |
277 | return DID_RESET; | |
278 | case XEN_VSCSIIF_RSLT_HOST_BAD_INTR: | |
279 | return DID_BAD_INTR; | |
280 | case XEN_VSCSIIF_RSLT_HOST_PASSTHROUGH: | |
281 | return DID_PASSTHROUGH; | |
282 | case XEN_VSCSIIF_RSLT_HOST_SOFT_ERROR: | |
283 | return DID_SOFT_ERROR; | |
284 | case XEN_VSCSIIF_RSLT_HOST_IMM_RETRY: | |
285 | return DID_IMM_RETRY; | |
286 | case XEN_VSCSIIF_RSLT_HOST_REQUEUE: | |
287 | return DID_REQUEUE; | |
288 | case XEN_VSCSIIF_RSLT_HOST_TRANSPORT_DISRUPTED: | |
289 | return DID_TRANSPORT_DISRUPTED; | |
290 | case XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST: | |
291 | return DID_TRANSPORT_FAILFAST; | |
a2f6751d JG |
292 | case XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL: |
293 | return DID_TRANSPORT_MARGINAL; | |
294 | default: | |
295 | return DID_ERROR; | |
296 | } | |
297 | } | |
298 | ||
8beb8d4c JG |
299 | static void scsifront_cdb_cmd_done(struct vscsifrnt_info *info, |
300 | struct vscsiif_response *ring_rsp) | |
301 | { | |
3da96be5 | 302 | struct vscsifrnt_shadow *shadow; |
8beb8d4c JG |
303 | struct scsi_cmnd *sc; |
304 | uint32_t id; | |
305 | uint8_t sense_len; | |
306 | ||
307 | id = ring_rsp->rqid; | |
3da96be5 JG |
308 | shadow = info->shadow[id]; |
309 | sc = shadow->sc; | |
8beb8d4c JG |
310 | |
311 | BUG_ON(sc == NULL); | |
312 | ||
3da96be5 | 313 | scsifront_gnttab_done(info, shadow); |
6d1c2f48 JG |
314 | if (info->host_active == STATE_ERROR) |
315 | return; | |
8beb8d4c JG |
316 | scsifront_put_rqid(info, id); |
317 | ||
a2f6751d JG |
318 | set_host_byte(sc, scsifront_host_byte(ring_rsp->rslt)); |
319 | set_status_byte(sc, XEN_VSCSIIF_RSLT_STATUS(ring_rsp->rslt)); | |
8beb8d4c JG |
320 | scsi_set_resid(sc, ring_rsp->residual_len); |
321 | ||
322 | sense_len = min_t(uint8_t, VSCSIIF_SENSE_BUFFERSIZE, | |
323 | ring_rsp->sense_len); | |
324 | ||
325 | if (sense_len) | |
326 | memcpy(sc->sense_buffer, ring_rsp->sense_buffer, sense_len); | |
327 | ||
fd17badb | 328 | scsi_done(sc); |
8beb8d4c JG |
329 | } |
330 | ||
331 | static void scsifront_sync_cmd_done(struct vscsifrnt_info *info, | |
332 | struct vscsiif_response *ring_rsp) | |
333 | { | |
334 | uint16_t id = ring_rsp->rqid; | |
335 | unsigned long flags; | |
336 | struct vscsifrnt_shadow *shadow = info->shadow[id]; | |
337 | int kick; | |
338 | ||
339 | spin_lock_irqsave(&info->shadow_lock, flags); | |
340 | shadow->wait_reset = 1; | |
341 | switch (shadow->rslt_reset) { | |
342 | case RSLT_RESET_WAITING: | |
a2f6751d JG |
343 | if (ring_rsp->rslt == XEN_VSCSIIF_RSLT_RESET_SUCCESS) |
344 | shadow->rslt_reset = SUCCESS; | |
345 | else | |
346 | shadow->rslt_reset = FAILED; | |
8beb8d4c JG |
347 | break; |
348 | case RSLT_RESET_ERR: | |
349 | kick = _scsifront_put_rqid(info, id); | |
350 | spin_unlock_irqrestore(&info->shadow_lock, flags); | |
351 | kfree(shadow); | |
352 | if (kick) | |
353 | scsifront_wake_up(info); | |
354 | return; | |
355 | default: | |
6d1c2f48 | 356 | scsifront_set_error(info, "bad reset state"); |
8beb8d4c JG |
357 | break; |
358 | } | |
359 | spin_unlock_irqrestore(&info->shadow_lock, flags); | |
360 | ||
361 | wake_up(&shadow->wq_reset); | |
362 | } | |
363 | ||
85617dc7 JG |
364 | static void scsifront_do_response(struct vscsifrnt_info *info, |
365 | struct vscsiif_response *ring_rsp) | |
366 | { | |
6d1c2f48 JG |
367 | struct vscsifrnt_shadow *shadow; |
368 | ||
369 | if (ring_rsp->rqid >= VSCSIIF_MAX_REQS || | |
370 | !info->shadow[ring_rsp->rqid]->inflight) { | |
371 | scsifront_set_error(info, "illegal rqid returned by backend!"); | |
85617dc7 | 372 | return; |
6d1c2f48 JG |
373 | } |
374 | shadow = info->shadow[ring_rsp->rqid]; | |
375 | shadow->inflight = false; | |
85617dc7 | 376 | |
6d1c2f48 | 377 | if (shadow->act == VSCSIIF_ACT_SCSI_CDB) |
85617dc7 JG |
378 | scsifront_cdb_cmd_done(info, ring_rsp); |
379 | else | |
380 | scsifront_sync_cmd_done(info, ring_rsp); | |
381 | } | |
382 | ||
6d1c2f48 JG |
383 | static int scsifront_ring_drain(struct vscsifrnt_info *info, |
384 | unsigned int *eoiflag) | |
8beb8d4c | 385 | { |
6d1c2f48 | 386 | struct vscsiif_response ring_rsp; |
8beb8d4c JG |
387 | RING_IDX i, rp; |
388 | int more_to_do = 0; | |
8beb8d4c | 389 | |
6d1c2f48 JG |
390 | rp = READ_ONCE(info->ring.sring->rsp_prod); |
391 | virt_rmb(); /* ordering required respective to backend */ | |
392 | if (RING_RESPONSE_PROD_OVERFLOW(&info->ring, rp)) { | |
393 | scsifront_set_error(info, "illegal number of responses"); | |
394 | return 0; | |
395 | } | |
8beb8d4c | 396 | for (i = info->ring.rsp_cons; i != rp; i++) { |
6d1c2f48 JG |
397 | RING_COPY_RESPONSE(&info->ring, i, &ring_rsp); |
398 | scsifront_do_response(info, &ring_rsp); | |
399 | if (info->host_active == STATE_ERROR) | |
400 | return 0; | |
401 | *eoiflag &= ~XEN_EOI_FLAG_SPURIOUS; | |
8beb8d4c JG |
402 | } |
403 | ||
404 | info->ring.rsp_cons = i; | |
405 | ||
406 | if (i != info->ring.req_prod_pvt) | |
407 | RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do); | |
408 | else | |
409 | info->ring.sring->rsp_event = i + 1; | |
410 | ||
85617dc7 JG |
411 | return more_to_do; |
412 | } | |
413 | ||
6d1c2f48 JG |
414 | static int scsifront_cmd_done(struct vscsifrnt_info *info, |
415 | unsigned int *eoiflag) | |
85617dc7 JG |
416 | { |
417 | int more_to_do; | |
418 | unsigned long flags; | |
419 | ||
420 | spin_lock_irqsave(info->host->host_lock, flags); | |
421 | ||
6d1c2f48 | 422 | more_to_do = scsifront_ring_drain(info, eoiflag); |
85617dc7 | 423 | |
8beb8d4c JG |
424 | info->wait_ring_available = 0; |
425 | ||
426 | spin_unlock_irqrestore(info->host->host_lock, flags); | |
427 | ||
428 | wake_up(&info->wq_sync); | |
429 | ||
430 | return more_to_do; | |
431 | } | |
432 | ||
433 | static irqreturn_t scsifront_irq_fn(int irq, void *dev_id) | |
434 | { | |
435 | struct vscsifrnt_info *info = dev_id; | |
6d1c2f48 JG |
436 | unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS; |
437 | ||
438 | if (info->host_active == STATE_ERROR) { | |
439 | xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); | |
440 | return IRQ_HANDLED; | |
441 | } | |
8beb8d4c | 442 | |
6d1c2f48 | 443 | while (scsifront_cmd_done(info, &eoiflag)) |
8beb8d4c JG |
444 | /* Yield point for this unbounded loop. */ |
445 | cond_resched(); | |
446 | ||
6d1c2f48 JG |
447 | xen_irq_lateeoi(irq, eoiflag); |
448 | ||
8beb8d4c JG |
449 | return IRQ_HANDLED; |
450 | } | |
451 | ||
85617dc7 JG |
452 | static void scsifront_finish_all(struct vscsifrnt_info *info) |
453 | { | |
6d1c2f48 | 454 | unsigned int i, dummy; |
85617dc7 JG |
455 | struct vscsiif_response resp; |
456 | ||
6d1c2f48 | 457 | scsifront_ring_drain(info, &dummy); |
85617dc7 JG |
458 | |
459 | for (i = 0; i < VSCSIIF_MAX_REQS; i++) { | |
460 | if (test_bit(i, info->shadow_free_bitmap)) | |
461 | continue; | |
462 | resp.rqid = i; | |
463 | resp.sense_len = 0; | |
464 | resp.rslt = DID_RESET << 16; | |
465 | resp.residual_len = 0; | |
466 | scsifront_do_response(info, &resp); | |
467 | } | |
468 | } | |
469 | ||
8beb8d4c JG |
470 | static int map_data_for_request(struct vscsifrnt_info *info, |
471 | struct scsi_cmnd *sc, | |
8beb8d4c JG |
472 | struct vscsifrnt_shadow *shadow) |
473 | { | |
474 | grant_ref_t gref_head; | |
475 | struct page *page; | |
476 | int err, ref, ref_cnt = 0; | |
477 | int grant_ro = (sc->sc_data_direction == DMA_TO_DEVICE); | |
478 | unsigned int i, off, len, bytes; | |
479 | unsigned int data_len = scsi_bufflen(sc); | |
480 | unsigned int data_grants = 0, seg_grants = 0; | |
481 | struct scatterlist *sg; | |
8beb8d4c JG |
482 | struct scsiif_request_segment *seg; |
483 | ||
8beb8d4c JG |
484 | if (sc->sc_data_direction == DMA_NONE || !data_len) |
485 | return 0; | |
486 | ||
487 | scsi_for_each_sg(sc, sg, scsi_sg_count(sc), i) | |
488 | data_grants += PFN_UP(sg->offset + sg->length); | |
489 | ||
490 | if (data_grants > VSCSIIF_SG_TABLESIZE) { | |
491 | if (data_grants > info->host->sg_tablesize) { | |
492 | shost_printk(KERN_ERR, info->host, KBUILD_MODNAME | |
493 | "Unable to map request_buffer for command!\n"); | |
494 | return -E2BIG; | |
495 | } | |
496 | seg_grants = vscsiif_grants_sg(data_grants); | |
497 | shadow->sg = kcalloc(data_grants, | |
d9b1e637 | 498 | sizeof(struct scsiif_request_segment), GFP_ATOMIC); |
8beb8d4c JG |
499 | if (!shadow->sg) |
500 | return -ENOMEM; | |
501 | } | |
3da96be5 | 502 | seg = shadow->sg ? : shadow->seg; |
8beb8d4c JG |
503 | |
504 | err = gnttab_alloc_grant_references(seg_grants + data_grants, | |
505 | &gref_head); | |
506 | if (err) { | |
507 | kfree(shadow->sg); | |
508 | shost_printk(KERN_ERR, info->host, KBUILD_MODNAME | |
509 | "gnttab_alloc_grant_references() error\n"); | |
510 | return -ENOMEM; | |
511 | } | |
512 | ||
513 | if (seg_grants) { | |
514 | page = virt_to_page(seg); | |
6483e313 | 515 | off = offset_in_page(seg); |
8beb8d4c JG |
516 | len = sizeof(struct scsiif_request_segment) * data_grants; |
517 | while (len > 0) { | |
518 | bytes = min_t(unsigned int, len, PAGE_SIZE - off); | |
519 | ||
520 | ref = gnttab_claim_grant_reference(&gref_head); | |
521 | BUG_ON(ref == -ENOSPC); | |
522 | ||
8beb8d4c | 523 | gnttab_grant_foreign_access_ref(ref, |
0df4f266 JG |
524 | info->dev->otherend_id, |
525 | xen_page_to_gfn(page), 1); | |
8beb8d4c | 526 | shadow->gref[ref_cnt] = ref; |
3da96be5 JG |
527 | shadow->seg[ref_cnt].gref = ref; |
528 | shadow->seg[ref_cnt].offset = (uint16_t)off; | |
529 | shadow->seg[ref_cnt].length = (uint16_t)bytes; | |
8beb8d4c JG |
530 | |
531 | page++; | |
532 | len -= bytes; | |
533 | off = 0; | |
534 | ref_cnt++; | |
535 | } | |
536 | BUG_ON(seg_grants < ref_cnt); | |
537 | seg_grants = ref_cnt; | |
538 | } | |
539 | ||
540 | scsi_for_each_sg(sc, sg, scsi_sg_count(sc), i) { | |
541 | page = sg_page(sg); | |
542 | off = sg->offset; | |
543 | len = sg->length; | |
544 | ||
545 | while (len > 0 && data_len > 0) { | |
546 | /* | |
547 | * sg sends a scatterlist that is larger than | |
548 | * the data_len it wants transferred for certain | |
549 | * IO sizes. | |
550 | */ | |
551 | bytes = min_t(unsigned int, len, PAGE_SIZE - off); | |
552 | bytes = min(bytes, data_len); | |
553 | ||
554 | ref = gnttab_claim_grant_reference(&gref_head); | |
555 | BUG_ON(ref == -ENOSPC); | |
556 | ||
8beb8d4c | 557 | gnttab_grant_foreign_access_ref(ref, |
0df4f266 JG |
558 | info->dev->otherend_id, |
559 | xen_page_to_gfn(page), | |
560 | grant_ro); | |
8beb8d4c JG |
561 | |
562 | shadow->gref[ref_cnt] = ref; | |
563 | seg->gref = ref; | |
564 | seg->offset = (uint16_t)off; | |
565 | seg->length = (uint16_t)bytes; | |
566 | ||
567 | page++; | |
568 | seg++; | |
569 | len -= bytes; | |
570 | data_len -= bytes; | |
571 | off = 0; | |
572 | ref_cnt++; | |
573 | } | |
574 | } | |
575 | ||
576 | if (seg_grants) | |
3da96be5 | 577 | shadow->nr_segments = VSCSIIF_SG_GRANT | seg_grants; |
8beb8d4c | 578 | else |
3da96be5 | 579 | shadow->nr_segments = (uint8_t)ref_cnt; |
8beb8d4c JG |
580 | shadow->nr_grants = ref_cnt; |
581 | ||
582 | return 0; | |
583 | } | |
584 | ||
85617dc7 JG |
585 | static int scsifront_enter(struct vscsifrnt_info *info) |
586 | { | |
587 | if (info->pause) | |
588 | return 1; | |
589 | info->callers++; | |
590 | return 0; | |
591 | } | |
592 | ||
593 | static void scsifront_return(struct vscsifrnt_info *info) | |
594 | { | |
595 | info->callers--; | |
596 | if (info->callers) | |
597 | return; | |
598 | ||
599 | if (!info->waiting_pause) | |
600 | return; | |
601 | ||
602 | info->waiting_pause = 0; | |
603 | wake_up(&info->wq_pause); | |
604 | } | |
605 | ||
8beb8d4c JG |
606 | static int scsifront_queuecommand(struct Scsi_Host *shost, |
607 | struct scsi_cmnd *sc) | |
608 | { | |
609 | struct vscsifrnt_info *info = shost_priv(shost); | |
8beb8d4c JG |
610 | struct vscsifrnt_shadow *shadow = scsi_cmd_priv(sc); |
611 | unsigned long flags; | |
612 | int err; | |
3da96be5 | 613 | |
6d1c2f48 JG |
614 | if (info->host_active == STATE_ERROR) |
615 | return SCSI_MLQUEUE_HOST_BUSY; | |
616 | ||
3da96be5 | 617 | sc->result = 0; |
3da96be5 JG |
618 | |
619 | shadow->sc = sc; | |
620 | shadow->act = VSCSIIF_ACT_SCSI_CDB; | |
8beb8d4c JG |
621 | |
622 | spin_lock_irqsave(shost->host_lock, flags); | |
85617dc7 JG |
623 | if (scsifront_enter(info)) { |
624 | spin_unlock_irqrestore(shost->host_lock, flags); | |
625 | return SCSI_MLQUEUE_HOST_BUSY; | |
626 | } | |
8beb8d4c | 627 | |
3da96be5 | 628 | err = map_data_for_request(info, sc, shadow); |
8beb8d4c JG |
629 | if (err < 0) { |
630 | pr_debug("%s: err %d\n", __func__, err); | |
85617dc7 | 631 | scsifront_return(info); |
8beb8d4c JG |
632 | spin_unlock_irqrestore(shost->host_lock, flags); |
633 | if (err == -ENOMEM) | |
634 | return SCSI_MLQUEUE_HOST_BUSY; | |
635 | sc->result = DID_ERROR << 16; | |
fd17badb | 636 | scsi_done(sc); |
8beb8d4c JG |
637 | return 0; |
638 | } | |
639 | ||
3da96be5 JG |
640 | if (scsifront_do_request(info, shadow)) { |
641 | scsifront_gnttab_done(info, shadow); | |
642 | goto busy; | |
643 | } | |
644 | ||
85617dc7 | 645 | scsifront_return(info); |
8beb8d4c JG |
646 | spin_unlock_irqrestore(shost->host_lock, flags); |
647 | ||
648 | return 0; | |
649 | ||
650 | busy: | |
85617dc7 | 651 | scsifront_return(info); |
8beb8d4c JG |
652 | spin_unlock_irqrestore(shost->host_lock, flags); |
653 | pr_debug("%s: busy\n", __func__); | |
654 | return SCSI_MLQUEUE_HOST_BUSY; | |
655 | } | |
656 | ||
657 | /* | |
658 | * Any exception handling (reset or abort) must be forwarded to the backend. | |
659 | * We have to wait until an answer is returned. This answer contains the | |
660 | * result to be returned to the requestor. | |
661 | */ | |
662 | static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act) | |
663 | { | |
664 | struct Scsi_Host *host = sc->device->host; | |
665 | struct vscsifrnt_info *info = shost_priv(host); | |
666 | struct vscsifrnt_shadow *shadow, *s = scsi_cmd_priv(sc); | |
8beb8d4c JG |
667 | int err = 0; |
668 | ||
6d1c2f48 JG |
669 | if (info->host_active == STATE_ERROR) |
670 | return FAILED; | |
671 | ||
3da96be5 | 672 | shadow = kzalloc(sizeof(*shadow), GFP_NOIO); |
8beb8d4c JG |
673 | if (!shadow) |
674 | return FAILED; | |
675 | ||
3da96be5 JG |
676 | shadow->act = act; |
677 | shadow->rslt_reset = RSLT_RESET_WAITING; | |
678 | shadow->sc = sc; | |
679 | shadow->ref_rqid = s->rqid; | |
680 | init_waitqueue_head(&shadow->wq_reset); | |
681 | ||
7921a11c DV |
682 | spin_lock_irq(host->host_lock); |
683 | ||
8beb8d4c | 684 | for (;;) { |
3da96be5 JG |
685 | if (scsifront_enter(info)) |
686 | goto fail; | |
687 | ||
688 | if (!scsifront_do_request(info, shadow)) | |
689 | break; | |
690 | ||
691 | scsifront_return(info); | |
692 | if (err) | |
693 | goto fail; | |
8beb8d4c JG |
694 | info->wait_ring_available = 1; |
695 | spin_unlock_irq(host->host_lock); | |
696 | err = wait_event_interruptible(info->wq_sync, | |
697 | !info->wait_ring_available); | |
698 | spin_lock_irq(host->host_lock); | |
699 | } | |
700 | ||
8beb8d4c JG |
701 | spin_unlock_irq(host->host_lock); |
702 | err = wait_event_interruptible(shadow->wq_reset, shadow->wait_reset); | |
703 | spin_lock_irq(host->host_lock); | |
704 | ||
705 | if (!err) { | |
706 | err = shadow->rslt_reset; | |
707 | scsifront_put_rqid(info, shadow->rqid); | |
708 | kfree(shadow); | |
709 | } else { | |
710 | spin_lock(&info->shadow_lock); | |
711 | shadow->rslt_reset = RSLT_RESET_ERR; | |
712 | spin_unlock(&info->shadow_lock); | |
713 | err = FAILED; | |
714 | } | |
715 | ||
85617dc7 | 716 | scsifront_return(info); |
8beb8d4c JG |
717 | spin_unlock_irq(host->host_lock); |
718 | return err; | |
3da96be5 JG |
719 | |
720 | fail: | |
721 | spin_unlock_irq(host->host_lock); | |
722 | kfree(shadow); | |
723 | return FAILED; | |
8beb8d4c JG |
724 | } |
725 | ||
726 | static int scsifront_eh_abort_handler(struct scsi_cmnd *sc) | |
727 | { | |
728 | pr_debug("%s\n", __func__); | |
729 | return scsifront_action_handler(sc, VSCSIIF_ACT_SCSI_ABORT); | |
730 | } | |
731 | ||
732 | static int scsifront_dev_reset_handler(struct scsi_cmnd *sc) | |
733 | { | |
734 | pr_debug("%s\n", __func__); | |
735 | return scsifront_action_handler(sc, VSCSIIF_ACT_SCSI_RESET); | |
736 | } | |
737 | ||
738 | static int scsifront_sdev_configure(struct scsi_device *sdev) | |
739 | { | |
740 | struct vscsifrnt_info *info = shost_priv(sdev->host); | |
93efbd39 | 741 | int err; |
8beb8d4c | 742 | |
6d1c2f48 JG |
743 | if (info->host_active == STATE_ERROR) |
744 | return -EIO; | |
745 | ||
73c7881b | 746 | if (current == info->curr) { |
93efbd39 | 747 | err = xenbus_printf(XBT_NIL, info->dev->nodename, |
8beb8d4c | 748 | info->dev_state_path, "%d", XenbusStateConnected); |
93efbd39 ZJ |
749 | if (err) { |
750 | xenbus_dev_error(info->dev, err, | |
751 | "%s: writing dev_state_path", __func__); | |
752 | return err; | |
753 | } | |
754 | } | |
8beb8d4c JG |
755 | |
756 | return 0; | |
757 | } | |
758 | ||
759 | static void scsifront_sdev_destroy(struct scsi_device *sdev) | |
760 | { | |
761 | struct vscsifrnt_info *info = shost_priv(sdev->host); | |
93efbd39 | 762 | int err; |
8beb8d4c | 763 | |
73c7881b | 764 | if (current == info->curr) { |
93efbd39 | 765 | err = xenbus_printf(XBT_NIL, info->dev->nodename, |
8beb8d4c | 766 | info->dev_state_path, "%d", XenbusStateClosed); |
93efbd39 ZJ |
767 | if (err) |
768 | xenbus_dev_error(info->dev, err, | |
769 | "%s: writing dev_state_path", __func__); | |
770 | } | |
8beb8d4c JG |
771 | } |
772 | ||
65e5447a | 773 | static const struct scsi_host_template scsifront_sht = { |
8beb8d4c JG |
774 | .module = THIS_MODULE, |
775 | .name = "Xen SCSI frontend driver", | |
776 | .queuecommand = scsifront_queuecommand, | |
777 | .eh_abort_handler = scsifront_eh_abort_handler, | |
778 | .eh_device_reset_handler = scsifront_dev_reset_handler, | |
779 | .slave_configure = scsifront_sdev_configure, | |
780 | .slave_destroy = scsifront_sdev_destroy, | |
781 | .cmd_per_lun = VSCSIIF_DEFAULT_CMD_PER_LUN, | |
782 | .can_queue = VSCSIIF_MAX_REQS, | |
783 | .this_id = -1, | |
784 | .cmd_size = sizeof(struct vscsifrnt_shadow), | |
785 | .sg_tablesize = VSCSIIF_SG_TABLESIZE, | |
8beb8d4c JG |
786 | .proc_name = "scsifront", |
787 | }; | |
788 | ||
789 | static int scsifront_alloc_ring(struct vscsifrnt_info *info) | |
790 | { | |
791 | struct xenbus_device *dev = info->dev; | |
792 | struct vscsiif_sring *sring; | |
caa427d2 | 793 | int err; |
8beb8d4c JG |
794 | |
795 | /***** Frontend to Backend ring start *****/ | |
caa427d2 JG |
796 | err = xenbus_setup_ring(dev, GFP_KERNEL, (void **)&sring, 1, |
797 | &info->ring_ref); | |
798 | if (err) | |
8beb8d4c | 799 | return err; |
8beb8d4c | 800 | |
caa427d2 | 801 | XEN_FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE); |
8beb8d4c JG |
802 | |
803 | err = xenbus_alloc_evtchn(dev, &info->evtchn); | |
804 | if (err) { | |
805 | xenbus_dev_fatal(dev, err, "xenbus_alloc_evtchn"); | |
806 | goto free_gnttab; | |
807 | } | |
808 | ||
6d1c2f48 | 809 | err = bind_evtchn_to_irq_lateeoi(info->evtchn); |
8beb8d4c JG |
810 | if (err <= 0) { |
811 | xenbus_dev_fatal(dev, err, "bind_evtchn_to_irq"); | |
812 | goto free_gnttab; | |
813 | } | |
814 | ||
815 | info->irq = err; | |
816 | ||
817 | err = request_threaded_irq(info->irq, NULL, scsifront_irq_fn, | |
818 | IRQF_ONESHOT, "scsifront", info); | |
819 | if (err) { | |
820 | xenbus_dev_fatal(dev, err, "request_threaded_irq"); | |
821 | goto free_irq; | |
822 | } | |
823 | ||
824 | return 0; | |
825 | ||
826 | /* free resource */ | |
827 | free_irq: | |
828 | unbind_from_irqhandler(info->irq, info); | |
829 | free_gnttab: | |
caa427d2 | 830 | xenbus_teardown_ring((void **)&sring, 1, &info->ring_ref); |
8beb8d4c JG |
831 | |
832 | return err; | |
833 | } | |
834 | ||
85617dc7 JG |
835 | static void scsifront_free_ring(struct vscsifrnt_info *info) |
836 | { | |
837 | unbind_from_irqhandler(info->irq, info); | |
caa427d2 | 838 | xenbus_teardown_ring((void **)&info->ring.sring, 1, &info->ring_ref); |
85617dc7 JG |
839 | } |
840 | ||
8beb8d4c JG |
841 | static int scsifront_init_ring(struct vscsifrnt_info *info) |
842 | { | |
843 | struct xenbus_device *dev = info->dev; | |
844 | struct xenbus_transaction xbt; | |
845 | int err; | |
846 | ||
847 | pr_debug("%s\n", __func__); | |
848 | ||
849 | err = scsifront_alloc_ring(info); | |
850 | if (err) | |
851 | return err; | |
852 | pr_debug("%s: %u %u\n", __func__, info->ring_ref, info->evtchn); | |
853 | ||
854 | again: | |
855 | err = xenbus_transaction_start(&xbt); | |
856 | if (err) | |
857 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
858 | ||
859 | err = xenbus_printf(xbt, dev->nodename, "ring-ref", "%u", | |
860 | info->ring_ref); | |
861 | if (err) { | |
862 | xenbus_dev_fatal(dev, err, "%s", "writing ring-ref"); | |
863 | goto fail; | |
864 | } | |
865 | ||
866 | err = xenbus_printf(xbt, dev->nodename, "event-channel", "%u", | |
867 | info->evtchn); | |
868 | ||
869 | if (err) { | |
870 | xenbus_dev_fatal(dev, err, "%s", "writing event-channel"); | |
871 | goto fail; | |
872 | } | |
873 | ||
874 | err = xenbus_transaction_end(xbt, 0); | |
875 | if (err) { | |
876 | if (err == -EAGAIN) | |
877 | goto again; | |
878 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
879 | goto free_sring; | |
880 | } | |
881 | ||
882 | return 0; | |
883 | ||
884 | fail: | |
885 | xenbus_transaction_end(xbt, 1); | |
886 | free_sring: | |
85617dc7 | 887 | scsifront_free_ring(info); |
8beb8d4c JG |
888 | |
889 | return err; | |
890 | } | |
891 | ||
892 | ||
893 | static int scsifront_probe(struct xenbus_device *dev, | |
894 | const struct xenbus_device_id *id) | |
895 | { | |
896 | struct vscsifrnt_info *info; | |
897 | struct Scsi_Host *host; | |
898 | int err = -ENOMEM; | |
899 | char name[TASK_COMM_LEN]; | |
900 | ||
901 | host = scsi_host_alloc(&scsifront_sht, sizeof(*info)); | |
902 | if (!host) { | |
903 | xenbus_dev_fatal(dev, err, "fail to allocate scsi host"); | |
904 | return err; | |
905 | } | |
73c7881b | 906 | info = shost_priv(host); |
8beb8d4c JG |
907 | |
908 | dev_set_drvdata(&dev->dev, info); | |
909 | info->dev = dev; | |
910 | ||
911 | bitmap_fill(info->shadow_free_bitmap, VSCSIIF_MAX_REQS); | |
912 | ||
913 | err = scsifront_init_ring(info); | |
914 | if (err) { | |
915 | scsi_host_put(host); | |
916 | return err; | |
917 | } | |
918 | ||
919 | init_waitqueue_head(&info->wq_sync); | |
85617dc7 | 920 | init_waitqueue_head(&info->wq_pause); |
8beb8d4c JG |
921 | spin_lock_init(&info->shadow_lock); |
922 | ||
923 | snprintf(name, TASK_COMM_LEN, "vscsiif.%d", host->host_no); | |
924 | ||
925 | host->max_id = VSCSIIF_MAX_TARGET; | |
926 | host->max_channel = 0; | |
927 | host->max_lun = VSCSIIF_MAX_LUN; | |
928 | host->max_sectors = (host->sg_tablesize - 1) * PAGE_SIZE / 512; | |
929 | host->max_cmd_len = VSCSIIF_MAX_COMMAND_SIZE; | |
930 | ||
931 | err = scsi_add_host(host, &dev->dev); | |
932 | if (err) { | |
933 | dev_err(&dev->dev, "fail to add scsi host %d\n", err); | |
934 | goto free_sring; | |
935 | } | |
936 | info->host = host; | |
6d1c2f48 | 937 | info->host_active = STATE_ACTIVE; |
8beb8d4c JG |
938 | |
939 | xenbus_switch_state(dev, XenbusStateInitialised); | |
940 | ||
941 | return 0; | |
942 | ||
943 | free_sring: | |
85617dc7 | 944 | scsifront_free_ring(info); |
8beb8d4c JG |
945 | scsi_host_put(host); |
946 | return err; | |
947 | } | |
948 | ||
85617dc7 JG |
949 | static int scsifront_resume(struct xenbus_device *dev) |
950 | { | |
951 | struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev); | |
952 | struct Scsi_Host *host = info->host; | |
953 | int err; | |
954 | ||
955 | spin_lock_irq(host->host_lock); | |
956 | ||
957 | /* Finish all still pending commands. */ | |
958 | scsifront_finish_all(info); | |
959 | ||
960 | spin_unlock_irq(host->host_lock); | |
961 | ||
962 | /* Reconnect to dom0. */ | |
963 | scsifront_free_ring(info); | |
964 | err = scsifront_init_ring(info); | |
965 | if (err) { | |
966 | dev_err(&dev->dev, "fail to resume %d\n", err); | |
967 | scsi_host_put(host); | |
968 | return err; | |
969 | } | |
970 | ||
971 | xenbus_switch_state(dev, XenbusStateInitialised); | |
972 | ||
973 | return 0; | |
974 | } | |
975 | ||
976 | static int scsifront_suspend(struct xenbus_device *dev) | |
977 | { | |
978 | struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev); | |
979 | struct Scsi_Host *host = info->host; | |
980 | int err = 0; | |
981 | ||
982 | /* No new commands for the backend. */ | |
983 | spin_lock_irq(host->host_lock); | |
984 | info->pause = 1; | |
985 | while (info->callers && !err) { | |
986 | info->waiting_pause = 1; | |
987 | info->wait_ring_available = 0; | |
988 | spin_unlock_irq(host->host_lock); | |
989 | wake_up(&info->wq_sync); | |
990 | err = wait_event_interruptible(info->wq_pause, | |
991 | !info->waiting_pause); | |
992 | spin_lock_irq(host->host_lock); | |
993 | } | |
994 | spin_unlock_irq(host->host_lock); | |
995 | return err; | |
996 | } | |
997 | ||
7cffcade | 998 | static void scsifront_remove(struct xenbus_device *dev) |
8beb8d4c JG |
999 | { |
1000 | struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev); | |
1001 | ||
1002 | pr_debug("%s: %s removed\n", __func__, dev->nodename); | |
1003 | ||
1004 | mutex_lock(&scsifront_mutex); | |
6d1c2f48 | 1005 | if (info->host_active != STATE_INACTIVE) { |
8beb8d4c JG |
1006 | /* Scsi_host not yet removed */ |
1007 | scsi_remove_host(info->host); | |
6d1c2f48 | 1008 | info->host_active = STATE_INACTIVE; |
8beb8d4c JG |
1009 | } |
1010 | mutex_unlock(&scsifront_mutex); | |
1011 | ||
85617dc7 | 1012 | scsifront_free_ring(info); |
8beb8d4c | 1013 | scsi_host_put(info->host); |
8beb8d4c JG |
1014 | } |
1015 | ||
1016 | static void scsifront_disconnect(struct vscsifrnt_info *info) | |
1017 | { | |
1018 | struct xenbus_device *dev = info->dev; | |
1019 | struct Scsi_Host *host = info->host; | |
1020 | ||
1021 | pr_debug("%s: %s disconnect\n", __func__, dev->nodename); | |
1022 | ||
1023 | /* | |
1024 | * When this function is executed, all devices of | |
1025 | * Frontend have been deleted. | |
1026 | * Therefore, it need not block I/O before remove_host. | |
1027 | */ | |
1028 | ||
1029 | mutex_lock(&scsifront_mutex); | |
6d1c2f48 | 1030 | if (info->host_active != STATE_INACTIVE) { |
8beb8d4c | 1031 | scsi_remove_host(host); |
6d1c2f48 | 1032 | info->host_active = STATE_INACTIVE; |
8beb8d4c JG |
1033 | } |
1034 | mutex_unlock(&scsifront_mutex); | |
1035 | ||
1036 | xenbus_frontend_closed(dev); | |
1037 | } | |
1038 | ||
1039 | static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op) | |
1040 | { | |
1041 | struct xenbus_device *dev = info->dev; | |
1042 | int i, err = 0; | |
1043 | char str[64]; | |
1044 | char **dir; | |
1045 | unsigned int dir_n = 0; | |
1046 | unsigned int device_state; | |
1047 | unsigned int hst, chn, tgt, lun; | |
1048 | struct scsi_device *sdev; | |
1049 | ||
6d1c2f48 JG |
1050 | if (info->host_active == STATE_ERROR) |
1051 | return; | |
1052 | ||
8beb8d4c JG |
1053 | dir = xenbus_directory(XBT_NIL, dev->otherend, "vscsi-devs", &dir_n); |
1054 | if (IS_ERR(dir)) | |
1055 | return; | |
1056 | ||
1057 | /* mark current task as the one allowed to modify device states */ | |
1058 | BUG_ON(info->curr); | |
1059 | info->curr = current; | |
1060 | ||
1061 | for (i = 0; i < dir_n; i++) { | |
1062 | /* read status */ | |
1063 | snprintf(str, sizeof(str), "vscsi-devs/%s/state", dir[i]); | |
1064 | err = xenbus_scanf(XBT_NIL, dev->otherend, str, "%u", | |
1065 | &device_state); | |
1066 | if (XENBUS_EXIST_ERR(err)) | |
1067 | continue; | |
1068 | ||
1069 | /* virtual SCSI device */ | |
1070 | snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", dir[i]); | |
1071 | err = xenbus_scanf(XBT_NIL, dev->otherend, str, | |
1072 | "%u:%u:%u:%u", &hst, &chn, &tgt, &lun); | |
1073 | if (XENBUS_EXIST_ERR(err)) | |
1074 | continue; | |
1075 | ||
1076 | /* | |
1077 | * Front device state path, used in slave_configure called | |
1078 | * on successfull scsi_add_device, and in slave_destroy called | |
1079 | * on remove of a device. | |
1080 | */ | |
1081 | snprintf(info->dev_state_path, sizeof(info->dev_state_path), | |
1082 | "vscsi-devs/%s/state", dir[i]); | |
1083 | ||
1084 | switch (op) { | |
1085 | case VSCSIFRONT_OP_ADD_LUN: | |
1086 | if (device_state != XenbusStateInitialised) | |
1087 | break; | |
1088 | ||
1089 | if (scsi_add_device(info->host, chn, tgt, lun)) { | |
1090 | dev_err(&dev->dev, "scsi_add_device\n"); | |
93efbd39 | 1091 | err = xenbus_printf(XBT_NIL, dev->nodename, |
8beb8d4c JG |
1092 | info->dev_state_path, |
1093 | "%d", XenbusStateClosed); | |
93efbd39 ZJ |
1094 | if (err) |
1095 | xenbus_dev_error(dev, err, | |
1096 | "%s: writing dev_state_path", __func__); | |
8beb8d4c JG |
1097 | } |
1098 | break; | |
1099 | case VSCSIFRONT_OP_DEL_LUN: | |
1100 | if (device_state != XenbusStateClosing) | |
1101 | break; | |
1102 | ||
1103 | sdev = scsi_device_lookup(info->host, chn, tgt, lun); | |
1104 | if (sdev) { | |
1105 | scsi_remove_device(sdev); | |
1106 | scsi_device_put(sdev); | |
1107 | } | |
1108 | break; | |
85617dc7 | 1109 | case VSCSIFRONT_OP_READD_LUN: |
93efbd39 ZJ |
1110 | if (device_state == XenbusStateConnected) { |
1111 | err = xenbus_printf(XBT_NIL, dev->nodename, | |
85617dc7 JG |
1112 | info->dev_state_path, |
1113 | "%d", XenbusStateConnected); | |
93efbd39 ZJ |
1114 | if (err) |
1115 | xenbus_dev_error(dev, err, | |
1116 | "%s: writing dev_state_path", __func__); | |
1117 | } | |
85617dc7 | 1118 | break; |
8beb8d4c JG |
1119 | default: |
1120 | break; | |
1121 | } | |
1122 | } | |
1123 | ||
1124 | info->curr = NULL; | |
1125 | ||
1126 | kfree(dir); | |
1127 | } | |
1128 | ||
1129 | static void scsifront_read_backend_params(struct xenbus_device *dev, | |
1130 | struct vscsifrnt_info *info) | |
1131 | { | |
85617dc7 | 1132 | unsigned int sg_grant, nr_segs; |
8beb8d4c JG |
1133 | struct Scsi_Host *host = info->host; |
1134 | ||
1080b38d | 1135 | sg_grant = xenbus_read_unsigned(dev->otherend, "feature-sg-grant", 0); |
85617dc7 JG |
1136 | nr_segs = min_t(unsigned int, sg_grant, SG_ALL); |
1137 | nr_segs = max_t(unsigned int, nr_segs, VSCSIIF_SG_TABLESIZE); | |
1138 | nr_segs = min_t(unsigned int, nr_segs, | |
8beb8d4c JG |
1139 | VSCSIIF_SG_TABLESIZE * PAGE_SIZE / |
1140 | sizeof(struct scsiif_request_segment)); | |
85617dc7 JG |
1141 | |
1142 | if (!info->pause && sg_grant) | |
1143 | dev_info(&dev->dev, "using up to %d SG entries\n", nr_segs); | |
1144 | else if (info->pause && nr_segs < host->sg_tablesize) | |
1145 | dev_warn(&dev->dev, | |
1146 | "SG entries decreased from %d to %u - device may not work properly anymore\n", | |
1147 | host->sg_tablesize, nr_segs); | |
1148 | ||
1149 | host->sg_tablesize = nr_segs; | |
1150 | host->max_sectors = (nr_segs - 1) * PAGE_SIZE / 512; | |
8beb8d4c JG |
1151 | } |
1152 | ||
1153 | static void scsifront_backend_changed(struct xenbus_device *dev, | |
1154 | enum xenbus_state backend_state) | |
1155 | { | |
1156 | struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev); | |
1157 | ||
1158 | pr_debug("%s: %p %u %u\n", __func__, dev, dev->state, backend_state); | |
1159 | ||
1160 | switch (backend_state) { | |
1161 | case XenbusStateUnknown: | |
1162 | case XenbusStateInitialising: | |
1163 | case XenbusStateInitWait: | |
1164 | case XenbusStateInitialised: | |
1165 | break; | |
1166 | ||
1167 | case XenbusStateConnected: | |
1168 | scsifront_read_backend_params(dev, info); | |
85617dc7 JG |
1169 | |
1170 | if (info->pause) { | |
1171 | scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_READD_LUN); | |
1172 | xenbus_switch_state(dev, XenbusStateConnected); | |
1173 | info->pause = 0; | |
1174 | return; | |
1175 | } | |
1176 | ||
8beb8d4c JG |
1177 | if (xenbus_read_driver_state(dev->nodename) == |
1178 | XenbusStateInitialised) | |
1179 | scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_ADD_LUN); | |
1180 | ||
1181 | if (dev->state != XenbusStateConnected) | |
1182 | xenbus_switch_state(dev, XenbusStateConnected); | |
1183 | break; | |
1184 | ||
1185 | case XenbusStateClosed: | |
1186 | if (dev->state == XenbusStateClosed) | |
1187 | break; | |
df561f66 | 1188 | fallthrough; /* Missed the backend's Closing state */ |
8beb8d4c JG |
1189 | case XenbusStateClosing: |
1190 | scsifront_disconnect(info); | |
1191 | break; | |
1192 | ||
1193 | case XenbusStateReconfiguring: | |
1194 | scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_DEL_LUN); | |
1195 | xenbus_switch_state(dev, XenbusStateReconfiguring); | |
1196 | break; | |
1197 | ||
1198 | case XenbusStateReconfigured: | |
1199 | scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_ADD_LUN); | |
1200 | xenbus_switch_state(dev, XenbusStateConnected); | |
1201 | break; | |
1202 | } | |
1203 | } | |
1204 | ||
1205 | static const struct xenbus_device_id scsifront_ids[] = { | |
1206 | { "vscsi" }, | |
1207 | { "" } | |
1208 | }; | |
1209 | ||
95afae48 DV |
1210 | static struct xenbus_driver scsifront_driver = { |
1211 | .ids = scsifront_ids, | |
8beb8d4c JG |
1212 | .probe = scsifront_probe, |
1213 | .remove = scsifront_remove, | |
85617dc7 JG |
1214 | .resume = scsifront_resume, |
1215 | .suspend = scsifront_suspend, | |
8beb8d4c | 1216 | .otherend_changed = scsifront_backend_changed, |
95afae48 | 1217 | }; |
8beb8d4c JG |
1218 | |
1219 | static int __init scsifront_init(void) | |
1220 | { | |
1221 | if (!xen_domain()) | |
1222 | return -ENODEV; | |
1223 | ||
1224 | return xenbus_register_frontend(&scsifront_driver); | |
1225 | } | |
1226 | module_init(scsifront_init); | |
1227 | ||
1228 | static void __exit scsifront_exit(void) | |
1229 | { | |
1230 | xenbus_unregister_driver(&scsifront_driver); | |
1231 | } | |
1232 | module_exit(scsifront_exit); | |
1233 | ||
1234 | MODULE_DESCRIPTION("Xen SCSI frontend driver"); | |
1235 | MODULE_LICENSE("GPL"); | |
1236 | MODULE_ALIAS("xen:vscsi"); | |
1237 | MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); |