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4fe74b1c PB |
1 | /* |
2 | * Virtio SCSI HBA driver | |
3 | * | |
4 | * Copyright IBM Corp. 2010 | |
5 | * Copyright Red Hat, Inc. 2011 | |
6 | * | |
7 | * Authors: | |
8 | * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> | |
9 | * Paolo Bonzini <pbonzini@redhat.com> | |
10 | * | |
11 | * This work is licensed under the terms of the GNU GPL, version 2 or later. | |
12 | * See the COPYING file in the top-level directory. | |
13 | * | |
14 | */ | |
15 | ||
ba06d1e1 WG |
16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
17 | ||
4fe74b1c PB |
18 | #include <linux/module.h> |
19 | #include <linux/slab.h> | |
20 | #include <linux/mempool.h> | |
21 | #include <linux/virtio.h> | |
22 | #include <linux/virtio_ids.h> | |
23 | #include <linux/virtio_config.h> | |
24 | #include <linux/virtio_scsi.h> | |
9141a4ca | 25 | #include <linux/cpu.h> |
4fe74b1c PB |
26 | #include <scsi/scsi_host.h> |
27 | #include <scsi/scsi_device.h> | |
28 | #include <scsi/scsi_cmnd.h> | |
29 | ||
30 | #define VIRTIO_SCSI_MEMPOOL_SZ 64 | |
365a7150 | 31 | #define VIRTIO_SCSI_EVENT_LEN 8 |
9141a4ca | 32 | #define VIRTIO_SCSI_VQ_BASE 2 |
4fe74b1c PB |
33 | |
34 | /* Command queue element */ | |
35 | struct virtio_scsi_cmd { | |
36 | struct scsi_cmnd *sc; | |
37 | struct completion *comp; | |
38 | union { | |
39 | struct virtio_scsi_cmd_req cmd; | |
40 | struct virtio_scsi_ctrl_tmf_req tmf; | |
41 | struct virtio_scsi_ctrl_an_req an; | |
42 | } req; | |
43 | union { | |
44 | struct virtio_scsi_cmd_resp cmd; | |
45 | struct virtio_scsi_ctrl_tmf_resp tmf; | |
46 | struct virtio_scsi_ctrl_an_resp an; | |
47 | struct virtio_scsi_event evt; | |
48 | } resp; | |
49 | } ____cacheline_aligned_in_smp; | |
50 | ||
365a7150 CM |
51 | struct virtio_scsi_event_node { |
52 | struct virtio_scsi *vscsi; | |
53 | struct virtio_scsi_event event; | |
54 | struct work_struct work; | |
55 | }; | |
56 | ||
139fe45a PB |
57 | struct virtio_scsi_vq { |
58 | /* Protects vq */ | |
59 | spinlock_t vq_lock; | |
60 | ||
61 | struct virtqueue *vq; | |
62 | }; | |
63 | ||
9141a4ca PB |
64 | /* |
65 | * Per-target queue state. | |
66 | * | |
67 | * This struct holds the data needed by the queue steering policy. When a | |
68 | * target is sent multiple requests, we need to drive them to the same queue so | |
69 | * that FIFO processing order is kept. However, if a target was idle, we can | |
70 | * choose a queue arbitrarily. In this case the queue is chosen according to | |
71 | * the current VCPU, so the driver expects the number of request queues to be | |
72 | * equal to the number of VCPUs. This makes it easy and fast to select the | |
73 | * queue, and also lets the driver optimize the IRQ affinity for the virtqueues | |
74 | * (each virtqueue's affinity is set to the CPU that "owns" the queue). | |
75 | * | |
76 | * An interesting effect of this policy is that only writes to req_vq need to | |
77 | * take the tgt_lock. Read can be done outside the lock because: | |
78 | * | |
79 | * - writes of req_vq only occur when atomic_inc_return(&tgt->reqs) returns 1. | |
80 | * In that case, no other CPU is reading req_vq: even if they were in | |
81 | * virtscsi_queuecommand_multi, they would be spinning on tgt_lock. | |
82 | * | |
83 | * - reads of req_vq only occur when the target is not idle (reqs != 0). | |
84 | * A CPU that enters virtscsi_queuecommand_multi will not modify req_vq. | |
85 | * | |
86 | * Similarly, decrements of reqs are never concurrent with writes of req_vq. | |
87 | * Thus they can happen outside the tgt_lock, provided of course we make reqs | |
88 | * an atomic_t. | |
89 | */ | |
2bd37f0f | 90 | struct virtio_scsi_target_state { |
9141a4ca | 91 | /* This spinlock never held at the same time as vq_lock. */ |
2bd37f0f | 92 | spinlock_t tgt_lock; |
9141a4ca PB |
93 | |
94 | /* Count of outstanding requests. */ | |
95 | atomic_t reqs; | |
96 | ||
97 | /* Currently active virtqueue for requests sent to this target. */ | |
98 | struct virtio_scsi_vq *req_vq; | |
2bd37f0f PB |
99 | }; |
100 | ||
4fe74b1c PB |
101 | /* Driver instance state */ |
102 | struct virtio_scsi { | |
4fe74b1c | 103 | struct virtio_device *vdev; |
2bd37f0f | 104 | |
365a7150 CM |
105 | /* Get some buffers ready for event vq */ |
106 | struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; | |
9141a4ca PB |
107 | |
108 | u32 num_queues; | |
109 | ||
110 | /* If the affinity hint is set for virtqueues */ | |
111 | bool affinity_hint_set; | |
112 | ||
113 | struct virtio_scsi_vq ctrl_vq; | |
114 | struct virtio_scsi_vq event_vq; | |
115 | struct virtio_scsi_vq req_vqs[]; | |
4fe74b1c PB |
116 | }; |
117 | ||
118 | static struct kmem_cache *virtscsi_cmd_cache; | |
119 | static mempool_t *virtscsi_cmd_pool; | |
120 | ||
121 | static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) | |
122 | { | |
123 | return vdev->priv; | |
124 | } | |
125 | ||
126 | static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) | |
127 | { | |
128 | if (!resid) | |
129 | return; | |
130 | ||
131 | if (!scsi_bidi_cmnd(sc)) { | |
132 | scsi_set_resid(sc, resid); | |
133 | return; | |
134 | } | |
135 | ||
136 | scsi_in(sc)->resid = min(resid, scsi_in(sc)->length); | |
137 | scsi_out(sc)->resid = resid - scsi_in(sc)->resid; | |
138 | } | |
139 | ||
140 | /** | |
141 | * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done | |
142 | * | |
143 | * Called with vq_lock held. | |
144 | */ | |
7f82b3c9 | 145 | static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) |
4fe74b1c PB |
146 | { |
147 | struct virtio_scsi_cmd *cmd = buf; | |
148 | struct scsi_cmnd *sc = cmd->sc; | |
149 | struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; | |
9141a4ca PB |
150 | struct virtio_scsi_target_state *tgt = |
151 | scsi_target(sc->device)->hostdata; | |
4fe74b1c PB |
152 | |
153 | dev_dbg(&sc->device->sdev_gendev, | |
154 | "cmd %p response %u status %#02x sense_len %u\n", | |
155 | sc, resp->response, resp->status, resp->sense_len); | |
156 | ||
157 | sc->result = resp->status; | |
158 | virtscsi_compute_resid(sc, resp->resid); | |
159 | switch (resp->response) { | |
160 | case VIRTIO_SCSI_S_OK: | |
161 | set_host_byte(sc, DID_OK); | |
162 | break; | |
163 | case VIRTIO_SCSI_S_OVERRUN: | |
164 | set_host_byte(sc, DID_ERROR); | |
165 | break; | |
166 | case VIRTIO_SCSI_S_ABORTED: | |
167 | set_host_byte(sc, DID_ABORT); | |
168 | break; | |
169 | case VIRTIO_SCSI_S_BAD_TARGET: | |
170 | set_host_byte(sc, DID_BAD_TARGET); | |
171 | break; | |
172 | case VIRTIO_SCSI_S_RESET: | |
173 | set_host_byte(sc, DID_RESET); | |
174 | break; | |
175 | case VIRTIO_SCSI_S_BUSY: | |
176 | set_host_byte(sc, DID_BUS_BUSY); | |
177 | break; | |
178 | case VIRTIO_SCSI_S_TRANSPORT_FAILURE: | |
179 | set_host_byte(sc, DID_TRANSPORT_DISRUPTED); | |
180 | break; | |
181 | case VIRTIO_SCSI_S_TARGET_FAILURE: | |
182 | set_host_byte(sc, DID_TARGET_FAILURE); | |
183 | break; | |
184 | case VIRTIO_SCSI_S_NEXUS_FAILURE: | |
185 | set_host_byte(sc, DID_NEXUS_FAILURE); | |
186 | break; | |
187 | default: | |
188 | scmd_printk(KERN_WARNING, sc, "Unknown response %d", | |
189 | resp->response); | |
190 | /* fall through */ | |
191 | case VIRTIO_SCSI_S_FAILURE: | |
192 | set_host_byte(sc, DID_ERROR); | |
193 | break; | |
194 | } | |
195 | ||
196 | WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE); | |
197 | if (sc->sense_buffer) { | |
198 | memcpy(sc->sense_buffer, resp->sense, | |
199 | min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE)); | |
200 | if (resp->sense_len) | |
201 | set_driver_byte(sc, DRIVER_SENSE); | |
202 | } | |
203 | ||
204 | mempool_free(cmd, virtscsi_cmd_pool); | |
205 | sc->scsi_done(sc); | |
9141a4ca PB |
206 | |
207 | atomic_dec(&tgt->reqs); | |
4fe74b1c PB |
208 | } |
209 | ||
10f34f64 PB |
210 | static void virtscsi_vq_done(struct virtio_scsi *vscsi, |
211 | struct virtio_scsi_vq *virtscsi_vq, | |
7f82b3c9 | 212 | void (*fn)(struct virtio_scsi *vscsi, void *buf)) |
4fe74b1c | 213 | { |
4fe74b1c | 214 | void *buf; |
4fe74b1c | 215 | unsigned int len; |
10f34f64 PB |
216 | unsigned long flags; |
217 | struct virtqueue *vq = virtscsi_vq->vq; | |
4fe74b1c | 218 | |
10f34f64 | 219 | spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); |
4fe74b1c PB |
220 | do { |
221 | virtqueue_disable_cb(vq); | |
222 | while ((buf = virtqueue_get_buf(vq, &len)) != NULL) | |
7f82b3c9 | 223 | fn(vscsi, buf); |
4fe74b1c | 224 | } while (!virtqueue_enable_cb(vq)); |
10f34f64 | 225 | spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); |
4fe74b1c PB |
226 | } |
227 | ||
228 | static void virtscsi_req_done(struct virtqueue *vq) | |
229 | { | |
139fe45a PB |
230 | struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); |
231 | struct virtio_scsi *vscsi = shost_priv(sh); | |
9141a4ca PB |
232 | int index = vq->index - VIRTIO_SCSI_VQ_BASE; |
233 | struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; | |
234 | ||
235 | /* | |
236 | * Read req_vq before decrementing the reqs field in | |
237 | * virtscsi_complete_cmd. | |
238 | * | |
239 | * With barriers: | |
240 | * | |
241 | * CPU #0 virtscsi_queuecommand_multi (CPU #1) | |
242 | * ------------------------------------------------------------ | |
243 | * lock vq_lock | |
244 | * read req_vq | |
245 | * read reqs (reqs = 1) | |
246 | * write reqs (reqs = 0) | |
247 | * increment reqs (reqs = 1) | |
248 | * write req_vq | |
249 | * | |
250 | * Possible reordering without barriers: | |
251 | * | |
252 | * CPU #0 virtscsi_queuecommand_multi (CPU #1) | |
253 | * ------------------------------------------------------------ | |
254 | * lock vq_lock | |
255 | * read reqs (reqs = 1) | |
256 | * write reqs (reqs = 0) | |
257 | * increment reqs (reqs = 1) | |
258 | * write req_vq | |
259 | * read (wrong) req_vq | |
260 | * | |
261 | * We do not need a full smp_rmb, because req_vq is required to get | |
262 | * to tgt->reqs: tgt is &vscsi->tgt[sc->device->id], where sc is stored | |
263 | * in the virtqueue as the user token. | |
264 | */ | |
265 | smp_read_barrier_depends(); | |
266 | ||
267 | virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); | |
4fe74b1c PB |
268 | }; |
269 | ||
7f82b3c9 | 270 | static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) |
4fe74b1c PB |
271 | { |
272 | struct virtio_scsi_cmd *cmd = buf; | |
273 | ||
274 | if (cmd->comp) | |
275 | complete_all(cmd->comp); | |
e4594bb5 PB |
276 | else |
277 | mempool_free(cmd, virtscsi_cmd_pool); | |
4fe74b1c PB |
278 | } |
279 | ||
280 | static void virtscsi_ctrl_done(struct virtqueue *vq) | |
281 | { | |
139fe45a PB |
282 | struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); |
283 | struct virtio_scsi *vscsi = shost_priv(sh); | |
139fe45a | 284 | |
10f34f64 | 285 | virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); |
4fe74b1c PB |
286 | }; |
287 | ||
365a7150 CM |
288 | static int virtscsi_kick_event(struct virtio_scsi *vscsi, |
289 | struct virtio_scsi_event_node *event_node) | |
290 | { | |
4614e51c | 291 | int err; |
365a7150 CM |
292 | struct scatterlist sg; |
293 | unsigned long flags; | |
294 | ||
2e9c9dfd | 295 | sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); |
365a7150 CM |
296 | |
297 | spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); | |
298 | ||
bf958291 RR |
299 | err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, |
300 | GFP_ATOMIC); | |
4614e51c | 301 | if (!err) |
365a7150 CM |
302 | virtqueue_kick(vscsi->event_vq.vq); |
303 | ||
304 | spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); | |
305 | ||
4614e51c | 306 | return err; |
365a7150 CM |
307 | } |
308 | ||
309 | static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) | |
310 | { | |
311 | int i; | |
312 | ||
313 | for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { | |
314 | vscsi->event_list[i].vscsi = vscsi; | |
315 | virtscsi_kick_event(vscsi, &vscsi->event_list[i]); | |
316 | } | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
321 | static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) | |
322 | { | |
323 | int i; | |
324 | ||
325 | for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) | |
326 | cancel_work_sync(&vscsi->event_list[i].work); | |
327 | } | |
328 | ||
329 | static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, | |
9141a4ca | 330 | struct virtio_scsi_event *event) |
365a7150 CM |
331 | { |
332 | struct scsi_device *sdev; | |
333 | struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); | |
334 | unsigned int target = event->lun[1]; | |
335 | unsigned int lun = (event->lun[2] << 8) | event->lun[3]; | |
336 | ||
337 | switch (event->reason) { | |
338 | case VIRTIO_SCSI_EVT_RESET_RESCAN: | |
339 | scsi_add_device(shost, 0, target, lun); | |
340 | break; | |
341 | case VIRTIO_SCSI_EVT_RESET_REMOVED: | |
342 | sdev = scsi_device_lookup(shost, 0, target, lun); | |
343 | if (sdev) { | |
344 | scsi_remove_device(sdev); | |
345 | scsi_device_put(sdev); | |
346 | } else { | |
347 | pr_err("SCSI device %d 0 %d %d not found\n", | |
348 | shost->host_no, target, lun); | |
349 | } | |
350 | break; | |
351 | default: | |
352 | pr_info("Unsupport virtio scsi event reason %x\n", event->reason); | |
353 | } | |
354 | } | |
355 | ||
865b58c0 PB |
356 | static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, |
357 | struct virtio_scsi_event *event) | |
358 | { | |
359 | struct scsi_device *sdev; | |
360 | struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); | |
361 | unsigned int target = event->lun[1]; | |
362 | unsigned int lun = (event->lun[2] << 8) | event->lun[3]; | |
363 | u8 asc = event->reason & 255; | |
364 | u8 ascq = event->reason >> 8; | |
365 | ||
366 | sdev = scsi_device_lookup(shost, 0, target, lun); | |
367 | if (!sdev) { | |
368 | pr_err("SCSI device %d 0 %d %d not found\n", | |
369 | shost->host_no, target, lun); | |
370 | return; | |
371 | } | |
372 | ||
373 | /* Handle "Parameters changed", "Mode parameters changed", and | |
374 | "Capacity data has changed". */ | |
375 | if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) | |
376 | scsi_rescan_device(&sdev->sdev_gendev); | |
377 | ||
378 | scsi_device_put(sdev); | |
379 | } | |
380 | ||
365a7150 CM |
381 | static void virtscsi_handle_event(struct work_struct *work) |
382 | { | |
383 | struct virtio_scsi_event_node *event_node = | |
384 | container_of(work, struct virtio_scsi_event_node, work); | |
385 | struct virtio_scsi *vscsi = event_node->vscsi; | |
386 | struct virtio_scsi_event *event = &event_node->event; | |
387 | ||
388 | if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) { | |
389 | event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED; | |
390 | scsi_scan_host(virtio_scsi_host(vscsi->vdev)); | |
391 | } | |
392 | ||
393 | switch (event->event) { | |
394 | case VIRTIO_SCSI_T_NO_EVENT: | |
395 | break; | |
396 | case VIRTIO_SCSI_T_TRANSPORT_RESET: | |
397 | virtscsi_handle_transport_reset(vscsi, event); | |
398 | break; | |
865b58c0 PB |
399 | case VIRTIO_SCSI_T_PARAM_CHANGE: |
400 | virtscsi_handle_param_change(vscsi, event); | |
401 | break; | |
365a7150 CM |
402 | default: |
403 | pr_err("Unsupport virtio scsi event %x\n", event->event); | |
404 | } | |
405 | virtscsi_kick_event(vscsi, event_node); | |
406 | } | |
407 | ||
7f82b3c9 | 408 | static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) |
365a7150 CM |
409 | { |
410 | struct virtio_scsi_event_node *event_node = buf; | |
411 | ||
412 | INIT_WORK(&event_node->work, virtscsi_handle_event); | |
413 | schedule_work(&event_node->work); | |
414 | } | |
415 | ||
4fe74b1c PB |
416 | static void virtscsi_event_done(struct virtqueue *vq) |
417 | { | |
139fe45a PB |
418 | struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); |
419 | struct virtio_scsi *vscsi = shost_priv(sh); | |
139fe45a | 420 | |
10f34f64 | 421 | virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); |
4fe74b1c PB |
422 | }; |
423 | ||
4fe74b1c | 424 | /** |
682993b4 WG |
425 | * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue |
426 | * @vq : the struct virtqueue we're talking about | |
4fe74b1c | 427 | * @cmd : command structure |
4fe74b1c PB |
428 | * @req_size : size of the request buffer |
429 | * @resp_size : size of the response buffer | |
682993b4 | 430 | * @gfp : flags to use for memory allocations |
4fe74b1c | 431 | */ |
682993b4 WG |
432 | static int virtscsi_add_cmd(struct virtqueue *vq, |
433 | struct virtio_scsi_cmd *cmd, | |
434 | size_t req_size, size_t resp_size, gfp_t gfp) | |
4fe74b1c PB |
435 | { |
436 | struct scsi_cmnd *sc = cmd->sc; | |
682993b4 WG |
437 | struct scatterlist *sgs[4], req, resp; |
438 | struct sg_table *out, *in; | |
439 | unsigned out_num = 0, in_num = 0; | |
440 | ||
441 | out = in = NULL; | |
442 | ||
443 | if (sc && sc->sc_data_direction != DMA_NONE) { | |
444 | if (sc->sc_data_direction != DMA_FROM_DEVICE) | |
445 | out = &scsi_out(sc)->table; | |
446 | if (sc->sc_data_direction != DMA_TO_DEVICE) | |
447 | in = &scsi_in(sc)->table; | |
448 | } | |
4fe74b1c | 449 | |
4fe74b1c | 450 | /* Request header. */ |
682993b4 WG |
451 | sg_init_one(&req, &cmd->req, req_size); |
452 | sgs[out_num++] = &req; | |
4fe74b1c PB |
453 | |
454 | /* Data-out buffer. */ | |
682993b4 WG |
455 | if (out) |
456 | sgs[out_num++] = out->sgl; | |
4fe74b1c PB |
457 | |
458 | /* Response header. */ | |
682993b4 WG |
459 | sg_init_one(&resp, &cmd->resp, resp_size); |
460 | sgs[out_num + in_num++] = &resp; | |
4fe74b1c PB |
461 | |
462 | /* Data-in buffer */ | |
682993b4 WG |
463 | if (in) |
464 | sgs[out_num + in_num++] = in->sgl; | |
4fe74b1c | 465 | |
682993b4 | 466 | return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp); |
4fe74b1c PB |
467 | } |
468 | ||
682993b4 | 469 | static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq, |
4fe74b1c PB |
470 | struct virtio_scsi_cmd *cmd, |
471 | size_t req_size, size_t resp_size, gfp_t gfp) | |
472 | { | |
4fe74b1c | 473 | unsigned long flags; |
4614e51c RR |
474 | int err; |
475 | bool needs_kick = false; | |
4fe74b1c | 476 | |
682993b4 WG |
477 | spin_lock_irqsave(&vq->vq_lock, flags); |
478 | err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size, gfp); | |
4614e51c RR |
479 | if (!err) |
480 | needs_kick = virtqueue_kick_prepare(vq->vq); | |
139fe45a | 481 | |
bce750b1 | 482 | spin_unlock_irqrestore(&vq->vq_lock, flags); |
4fe74b1c | 483 | |
4614e51c | 484 | if (needs_kick) |
139fe45a | 485 | virtqueue_notify(vq->vq); |
4614e51c | 486 | return err; |
4fe74b1c PB |
487 | } |
488 | ||
9141a4ca PB |
489 | static int virtscsi_queuecommand(struct virtio_scsi *vscsi, |
490 | struct virtio_scsi_vq *req_vq, | |
491 | struct scsi_cmnd *sc) | |
4fe74b1c | 492 | { |
4fe74b1c PB |
493 | struct virtio_scsi_cmd *cmd; |
494 | int ret; | |
495 | ||
2bd37f0f PB |
496 | struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); |
497 | BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); | |
498 | ||
499 | /* TODO: check feature bit and fail if unsupported? */ | |
500 | BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); | |
501 | ||
4fe74b1c PB |
502 | dev_dbg(&sc->device->sdev_gendev, |
503 | "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); | |
504 | ||
505 | ret = SCSI_MLQUEUE_HOST_BUSY; | |
506 | cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC); | |
507 | if (!cmd) | |
508 | goto out; | |
509 | ||
510 | memset(cmd, 0, sizeof(*cmd)); | |
511 | cmd->sc = sc; | |
512 | cmd->req.cmd = (struct virtio_scsi_cmd_req){ | |
513 | .lun[0] = 1, | |
514 | .lun[1] = sc->device->id, | |
515 | .lun[2] = (sc->device->lun >> 8) | 0x40, | |
516 | .lun[3] = sc->device->lun & 0xff, | |
517 | .tag = (unsigned long)sc, | |
518 | .task_attr = VIRTIO_SCSI_S_SIMPLE, | |
519 | .prio = 0, | |
520 | .crn = 0, | |
521 | }; | |
522 | ||
523 | BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); | |
524 | memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); | |
525 | ||
9141a4ca | 526 | if (virtscsi_kick_cmd(req_vq, cmd, |
4fe74b1c | 527 | sizeof cmd->req.cmd, sizeof cmd->resp.cmd, |
4614e51c | 528 | GFP_ATOMIC) == 0) |
4fe74b1c | 529 | ret = 0; |
b56d1003 EN |
530 | else |
531 | mempool_free(cmd, virtscsi_cmd_pool); | |
4fe74b1c PB |
532 | |
533 | out: | |
534 | return ret; | |
535 | } | |
536 | ||
9141a4ca PB |
537 | static int virtscsi_queuecommand_single(struct Scsi_Host *sh, |
538 | struct scsi_cmnd *sc) | |
539 | { | |
540 | struct virtio_scsi *vscsi = shost_priv(sh); | |
541 | struct virtio_scsi_target_state *tgt = | |
542 | scsi_target(sc->device)->hostdata; | |
543 | ||
544 | atomic_inc(&tgt->reqs); | |
545 | return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc); | |
546 | } | |
547 | ||
548 | static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi, | |
549 | struct virtio_scsi_target_state *tgt) | |
550 | { | |
551 | struct virtio_scsi_vq *vq; | |
552 | unsigned long flags; | |
553 | u32 queue_num; | |
554 | ||
555 | spin_lock_irqsave(&tgt->tgt_lock, flags); | |
556 | ||
557 | /* | |
558 | * The memory barrier after atomic_inc_return matches | |
559 | * the smp_read_barrier_depends() in virtscsi_req_done. | |
560 | */ | |
561 | if (atomic_inc_return(&tgt->reqs) > 1) | |
562 | vq = ACCESS_ONCE(tgt->req_vq); | |
563 | else { | |
564 | queue_num = smp_processor_id(); | |
565 | while (unlikely(queue_num >= vscsi->num_queues)) | |
566 | queue_num -= vscsi->num_queues; | |
567 | ||
568 | tgt->req_vq = vq = &vscsi->req_vqs[queue_num]; | |
569 | } | |
570 | ||
571 | spin_unlock_irqrestore(&tgt->tgt_lock, flags); | |
572 | return vq; | |
573 | } | |
574 | ||
575 | static int virtscsi_queuecommand_multi(struct Scsi_Host *sh, | |
576 | struct scsi_cmnd *sc) | |
577 | { | |
578 | struct virtio_scsi *vscsi = shost_priv(sh); | |
579 | struct virtio_scsi_target_state *tgt = | |
580 | scsi_target(sc->device)->hostdata; | |
581 | struct virtio_scsi_vq *req_vq = virtscsi_pick_vq(vscsi, tgt); | |
582 | ||
583 | return virtscsi_queuecommand(vscsi, req_vq, sc); | |
584 | } | |
585 | ||
4fe74b1c PB |
586 | static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) |
587 | { | |
588 | DECLARE_COMPLETION_ONSTACK(comp); | |
e4594bb5 | 589 | int ret = FAILED; |
4fe74b1c PB |
590 | |
591 | cmd->comp = ∁ | |
682993b4 | 592 | if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd, |
e4594bb5 PB |
593 | sizeof cmd->req.tmf, sizeof cmd->resp.tmf, |
594 | GFP_NOIO) < 0) | |
595 | goto out; | |
4fe74b1c PB |
596 | |
597 | wait_for_completion(&comp); | |
e4594bb5 PB |
598 | if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || |
599 | cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) | |
600 | ret = SUCCESS; | |
4fe74b1c | 601 | |
e4594bb5 PB |
602 | out: |
603 | mempool_free(cmd, virtscsi_cmd_pool); | |
604 | return ret; | |
4fe74b1c PB |
605 | } |
606 | ||
607 | static int virtscsi_device_reset(struct scsi_cmnd *sc) | |
608 | { | |
609 | struct virtio_scsi *vscsi = shost_priv(sc->device->host); | |
610 | struct virtio_scsi_cmd *cmd; | |
611 | ||
612 | sdev_printk(KERN_INFO, sc->device, "device reset\n"); | |
613 | cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); | |
614 | if (!cmd) | |
615 | return FAILED; | |
616 | ||
617 | memset(cmd, 0, sizeof(*cmd)); | |
618 | cmd->sc = sc; | |
619 | cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ | |
620 | .type = VIRTIO_SCSI_T_TMF, | |
621 | .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET, | |
622 | .lun[0] = 1, | |
623 | .lun[1] = sc->device->id, | |
624 | .lun[2] = (sc->device->lun >> 8) | 0x40, | |
625 | .lun[3] = sc->device->lun & 0xff, | |
626 | }; | |
627 | return virtscsi_tmf(vscsi, cmd); | |
628 | } | |
629 | ||
630 | static int virtscsi_abort(struct scsi_cmnd *sc) | |
631 | { | |
632 | struct virtio_scsi *vscsi = shost_priv(sc->device->host); | |
633 | struct virtio_scsi_cmd *cmd; | |
634 | ||
635 | scmd_printk(KERN_INFO, sc, "abort\n"); | |
636 | cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); | |
637 | if (!cmd) | |
638 | return FAILED; | |
639 | ||
640 | memset(cmd, 0, sizeof(*cmd)); | |
641 | cmd->sc = sc; | |
642 | cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ | |
643 | .type = VIRTIO_SCSI_T_TMF, | |
644 | .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, | |
645 | .lun[0] = 1, | |
646 | .lun[1] = sc->device->id, | |
647 | .lun[2] = (sc->device->lun >> 8) | 0x40, | |
648 | .lun[3] = sc->device->lun & 0xff, | |
649 | .tag = (unsigned long)sc, | |
650 | }; | |
651 | return virtscsi_tmf(vscsi, cmd); | |
652 | } | |
653 | ||
5c370194 WG |
654 | static int virtscsi_target_alloc(struct scsi_target *starget) |
655 | { | |
656 | struct virtio_scsi_target_state *tgt = | |
657 | kmalloc(sizeof(*tgt), GFP_KERNEL); | |
658 | if (!tgt) | |
659 | return -ENOMEM; | |
660 | ||
661 | spin_lock_init(&tgt->tgt_lock); | |
9141a4ca PB |
662 | atomic_set(&tgt->reqs, 0); |
663 | tgt->req_vq = NULL; | |
5c370194 WG |
664 | |
665 | starget->hostdata = tgt; | |
666 | return 0; | |
667 | } | |
668 | ||
669 | static void virtscsi_target_destroy(struct scsi_target *starget) | |
670 | { | |
671 | struct virtio_scsi_target_state *tgt = starget->hostdata; | |
672 | kfree(tgt); | |
673 | } | |
674 | ||
9141a4ca PB |
675 | static struct scsi_host_template virtscsi_host_template_single = { |
676 | .module = THIS_MODULE, | |
677 | .name = "Virtio SCSI HBA", | |
678 | .proc_name = "virtio_scsi", | |
679 | .this_id = -1, | |
680 | .queuecommand = virtscsi_queuecommand_single, | |
681 | .eh_abort_handler = virtscsi_abort, | |
682 | .eh_device_reset_handler = virtscsi_device_reset, | |
683 | ||
684 | .can_queue = 1024, | |
685 | .dma_boundary = UINT_MAX, | |
686 | .use_clustering = ENABLE_CLUSTERING, | |
687 | .target_alloc = virtscsi_target_alloc, | |
688 | .target_destroy = virtscsi_target_destroy, | |
689 | }; | |
690 | ||
691 | static struct scsi_host_template virtscsi_host_template_multi = { | |
4fe74b1c PB |
692 | .module = THIS_MODULE, |
693 | .name = "Virtio SCSI HBA", | |
694 | .proc_name = "virtio_scsi", | |
4fe74b1c | 695 | .this_id = -1, |
9141a4ca | 696 | .queuecommand = virtscsi_queuecommand_multi, |
4fe74b1c PB |
697 | .eh_abort_handler = virtscsi_abort, |
698 | .eh_device_reset_handler = virtscsi_device_reset, | |
699 | ||
700 | .can_queue = 1024, | |
701 | .dma_boundary = UINT_MAX, | |
702 | .use_clustering = ENABLE_CLUSTERING, | |
5c370194 WG |
703 | .target_alloc = virtscsi_target_alloc, |
704 | .target_destroy = virtscsi_target_destroy, | |
4fe74b1c PB |
705 | }; |
706 | ||
707 | #define virtscsi_config_get(vdev, fld) \ | |
708 | ({ \ | |
709 | typeof(((struct virtio_scsi_config *)0)->fld) __val; \ | |
710 | vdev->config->get(vdev, \ | |
711 | offsetof(struct virtio_scsi_config, fld), \ | |
712 | &__val, sizeof(__val)); \ | |
713 | __val; \ | |
714 | }) | |
715 | ||
716 | #define virtscsi_config_set(vdev, fld, val) \ | |
717 | (void)({ \ | |
718 | typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \ | |
719 | vdev->config->set(vdev, \ | |
720 | offsetof(struct virtio_scsi_config, fld), \ | |
721 | &__val, sizeof(__val)); \ | |
722 | }) | |
723 | ||
9141a4ca PB |
724 | static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) |
725 | { | |
726 | int i; | |
727 | int cpu; | |
728 | ||
729 | /* In multiqueue mode, when the number of cpu is equal | |
730 | * to the number of request queues, we let the qeueues | |
731 | * to be private to one cpu by setting the affinity hint | |
732 | * to eliminate the contention. | |
733 | */ | |
734 | if ((vscsi->num_queues == 1 || | |
735 | vscsi->num_queues != num_online_cpus()) && affinity) { | |
736 | if (vscsi->affinity_hint_set) | |
737 | affinity = false; | |
738 | else | |
739 | return; | |
740 | } | |
741 | ||
742 | if (affinity) { | |
743 | i = 0; | |
744 | for_each_online_cpu(cpu) { | |
745 | virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu); | |
746 | i++; | |
747 | } | |
748 | ||
749 | vscsi->affinity_hint_set = true; | |
750 | } else { | |
751 | for (i = 0; i < vscsi->num_queues - VIRTIO_SCSI_VQ_BASE; i++) | |
752 | virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1); | |
753 | ||
754 | vscsi->affinity_hint_set = false; | |
755 | } | |
756 | } | |
757 | ||
758 | static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) | |
759 | { | |
760 | get_online_cpus(); | |
761 | __virtscsi_set_affinity(vscsi, affinity); | |
762 | put_online_cpus(); | |
763 | } | |
764 | ||
139fe45a PB |
765 | static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, |
766 | struct virtqueue *vq) | |
767 | { | |
768 | spin_lock_init(&virtscsi_vq->vq_lock); | |
769 | virtscsi_vq->vq = vq; | |
770 | } | |
771 | ||
59057fbc NB |
772 | static void virtscsi_scan(struct virtio_device *vdev) |
773 | { | |
774 | struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv; | |
775 | ||
776 | scsi_scan_host(shost); | |
777 | } | |
778 | ||
2bd37f0f PB |
779 | static void virtscsi_remove_vqs(struct virtio_device *vdev) |
780 | { | |
9141a4ca PB |
781 | struct Scsi_Host *sh = virtio_scsi_host(vdev); |
782 | struct virtio_scsi *vscsi = shost_priv(sh); | |
783 | ||
784 | virtscsi_set_affinity(vscsi, false); | |
785 | ||
2bd37f0f PB |
786 | /* Stop all the virtqueues. */ |
787 | vdev->config->reset(vdev); | |
788 | ||
2bd37f0f PB |
789 | vdev->config->del_vqs(vdev); |
790 | } | |
791 | ||
4fe74b1c | 792 | static int virtscsi_init(struct virtio_device *vdev, |
5c370194 | 793 | struct virtio_scsi *vscsi) |
4fe74b1c PB |
794 | { |
795 | int err; | |
9141a4ca PB |
796 | u32 i; |
797 | u32 num_vqs; | |
798 | vq_callback_t **callbacks; | |
799 | const char **names; | |
800 | struct virtqueue **vqs; | |
801 | ||
802 | num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; | |
803 | vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL); | |
804 | callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL); | |
805 | names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL); | |
806 | ||
807 | if (!callbacks || !vqs || !names) { | |
808 | err = -ENOMEM; | |
809 | goto out; | |
810 | } | |
2bd37f0f | 811 | |
9141a4ca PB |
812 | callbacks[0] = virtscsi_ctrl_done; |
813 | callbacks[1] = virtscsi_event_done; | |
814 | names[0] = "control"; | |
815 | names[1] = "event"; | |
816 | for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { | |
817 | callbacks[i] = virtscsi_req_done; | |
818 | names[i] = "request"; | |
819 | } | |
4fe74b1c PB |
820 | |
821 | /* Discover virtqueues and write information to configuration. */ | |
9141a4ca | 822 | err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names); |
4fe74b1c | 823 | if (err) |
9141a4ca | 824 | goto out; |
4fe74b1c | 825 | |
139fe45a PB |
826 | virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); |
827 | virtscsi_init_vq(&vscsi->event_vq, vqs[1]); | |
9141a4ca PB |
828 | for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) |
829 | virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], | |
830 | vqs[i]); | |
831 | ||
832 | virtscsi_set_affinity(vscsi, true); | |
4fe74b1c PB |
833 | |
834 | virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); | |
835 | virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); | |
2bd37f0f | 836 | |
365a7150 CM |
837 | if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) |
838 | virtscsi_kick_event_all(vscsi); | |
839 | ||
9141a4ca PB |
840 | err = 0; |
841 | ||
842 | out: | |
843 | kfree(names); | |
844 | kfree(callbacks); | |
845 | kfree(vqs); | |
846 | if (err) | |
847 | virtscsi_remove_vqs(vdev); | |
2bd37f0f | 848 | return err; |
4fe74b1c PB |
849 | } |
850 | ||
6f039790 | 851 | static int virtscsi_probe(struct virtio_device *vdev) |
4fe74b1c PB |
852 | { |
853 | struct Scsi_Host *shost; | |
854 | struct virtio_scsi *vscsi; | |
855 | int err; | |
2bd37f0f | 856 | u32 sg_elems, num_targets; |
4fe74b1c | 857 | u32 cmd_per_lun; |
9141a4ca PB |
858 | u32 num_queues; |
859 | struct scsi_host_template *hostt; | |
860 | ||
861 | /* We need to know how many queues before we allocate. */ | |
862 | num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; | |
4fe74b1c | 863 | |
2bd37f0f | 864 | num_targets = virtscsi_config_get(vdev, max_target) + 1; |
4fe74b1c | 865 | |
9141a4ca PB |
866 | if (num_queues == 1) |
867 | hostt = &virtscsi_host_template_single; | |
868 | else | |
869 | hostt = &virtscsi_host_template_multi; | |
870 | ||
871 | shost = scsi_host_alloc(hostt, | |
872 | sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); | |
4fe74b1c PB |
873 | if (!shost) |
874 | return -ENOMEM; | |
875 | ||
2bd37f0f | 876 | sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; |
4fe74b1c PB |
877 | shost->sg_tablesize = sg_elems; |
878 | vscsi = shost_priv(shost); | |
879 | vscsi->vdev = vdev; | |
9141a4ca | 880 | vscsi->num_queues = num_queues; |
4fe74b1c PB |
881 | vdev->priv = shost; |
882 | ||
5c370194 | 883 | err = virtscsi_init(vdev, vscsi); |
4fe74b1c PB |
884 | if (err) |
885 | goto virtscsi_init_failed; | |
886 | ||
887 | cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; | |
888 | shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); | |
889 | shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; | |
9da5f5ac PB |
890 | |
891 | /* LUNs > 256 are reported with format 1, so they go in the range | |
892 | * 16640-32767. | |
893 | */ | |
894 | shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; | |
2bd37f0f | 895 | shost->max_id = num_targets; |
4fe74b1c PB |
896 | shost->max_channel = 0; |
897 | shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; | |
898 | err = scsi_add_host(shost, &vdev->dev); | |
899 | if (err) | |
900 | goto scsi_add_host_failed; | |
59057fbc NB |
901 | /* |
902 | * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan() | |
903 | * after VIRTIO_CONFIG_S_DRIVER_OK has been set.. | |
904 | */ | |
4fe74b1c PB |
905 | return 0; |
906 | ||
907 | scsi_add_host_failed: | |
908 | vdev->config->del_vqs(vdev); | |
909 | virtscsi_init_failed: | |
910 | scsi_host_put(shost); | |
911 | return err; | |
912 | } | |
913 | ||
6f039790 | 914 | static void virtscsi_remove(struct virtio_device *vdev) |
4fe74b1c PB |
915 | { |
916 | struct Scsi_Host *shost = virtio_scsi_host(vdev); | |
365a7150 CM |
917 | struct virtio_scsi *vscsi = shost_priv(shost); |
918 | ||
919 | if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) | |
920 | virtscsi_cancel_event_work(vscsi); | |
4fe74b1c PB |
921 | |
922 | scsi_remove_host(shost); | |
923 | ||
924 | virtscsi_remove_vqs(vdev); | |
925 | scsi_host_put(shost); | |
926 | } | |
927 | ||
928 | #ifdef CONFIG_PM | |
929 | static int virtscsi_freeze(struct virtio_device *vdev) | |
930 | { | |
931 | virtscsi_remove_vqs(vdev); | |
932 | return 0; | |
933 | } | |
934 | ||
935 | static int virtscsi_restore(struct virtio_device *vdev) | |
936 | { | |
937 | struct Scsi_Host *sh = virtio_scsi_host(vdev); | |
938 | struct virtio_scsi *vscsi = shost_priv(sh); | |
939 | ||
5c370194 | 940 | return virtscsi_init(vdev, vscsi); |
4fe74b1c PB |
941 | } |
942 | #endif | |
943 | ||
944 | static struct virtio_device_id id_table[] = { | |
945 | { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, | |
946 | { 0 }, | |
947 | }; | |
948 | ||
365a7150 | 949 | static unsigned int features[] = { |
865b58c0 PB |
950 | VIRTIO_SCSI_F_HOTPLUG, |
951 | VIRTIO_SCSI_F_CHANGE, | |
365a7150 CM |
952 | }; |
953 | ||
4fe74b1c | 954 | static struct virtio_driver virtio_scsi_driver = { |
365a7150 CM |
955 | .feature_table = features, |
956 | .feature_table_size = ARRAY_SIZE(features), | |
4fe74b1c PB |
957 | .driver.name = KBUILD_MODNAME, |
958 | .driver.owner = THIS_MODULE, | |
959 | .id_table = id_table, | |
960 | .probe = virtscsi_probe, | |
59057fbc | 961 | .scan = virtscsi_scan, |
4fe74b1c PB |
962 | #ifdef CONFIG_PM |
963 | .freeze = virtscsi_freeze, | |
964 | .restore = virtscsi_restore, | |
965 | #endif | |
6f039790 | 966 | .remove = virtscsi_remove, |
4fe74b1c PB |
967 | }; |
968 | ||
969 | static int __init init(void) | |
970 | { | |
971 | int ret = -ENOMEM; | |
972 | ||
973 | virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); | |
974 | if (!virtscsi_cmd_cache) { | |
ba06d1e1 | 975 | pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); |
4fe74b1c PB |
976 | goto error; |
977 | } | |
978 | ||
979 | ||
980 | virtscsi_cmd_pool = | |
981 | mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, | |
982 | virtscsi_cmd_cache); | |
983 | if (!virtscsi_cmd_pool) { | |
ba06d1e1 | 984 | pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); |
4fe74b1c PB |
985 | goto error; |
986 | } | |
987 | ret = register_virtio_driver(&virtio_scsi_driver); | |
988 | if (ret < 0) | |
989 | goto error; | |
990 | ||
991 | return 0; | |
992 | ||
993 | error: | |
994 | if (virtscsi_cmd_pool) { | |
995 | mempool_destroy(virtscsi_cmd_pool); | |
996 | virtscsi_cmd_pool = NULL; | |
997 | } | |
998 | if (virtscsi_cmd_cache) { | |
999 | kmem_cache_destroy(virtscsi_cmd_cache); | |
1000 | virtscsi_cmd_cache = NULL; | |
1001 | } | |
1002 | return ret; | |
1003 | } | |
1004 | ||
1005 | static void __exit fini(void) | |
1006 | { | |
1007 | unregister_virtio_driver(&virtio_scsi_driver); | |
1008 | mempool_destroy(virtscsi_cmd_pool); | |
1009 | kmem_cache_destroy(virtscsi_cmd_cache); | |
1010 | } | |
1011 | module_init(init); | |
1012 | module_exit(fini); | |
1013 | ||
1014 | MODULE_DEVICE_TABLE(virtio, id_table); | |
1015 | MODULE_DESCRIPTION("Virtio SCSI HBA driver"); | |
1016 | MODULE_LICENSE("GPL"); |