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1 /*
2  * Xen SCSI backend driver
3  *
4  * Copyright (c) 2008, FUJITSU Limited
5  *
6  * Based on the blkback driver code.
7  * Adaption to kernel taget core infrastructure taken from vhost/scsi.c
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License version 2
11  * as published by the Free Software Foundation; or, when distributed
12  * separately from the Linux kernel or incorporated into other
13  * software packages, subject to the following license:
14  *
15  * Permission is hereby granted, free of charge, to any person obtaining a copy
16  * of this source file (the "Software"), to deal in the Software without
17  * restriction, including without limitation the rights to use, copy, modify,
18  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19  * and to permit persons to whom the Software is furnished to do so, subject to
20  * the following conditions:
21  *
22  * The above copyright notice and this permission notice shall be included in
23  * all copies or substantial portions of the Software.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31  * IN THE SOFTWARE.
32  */
33 
34 #include <stdarg.h>
35 
36 #include <linux/module.h>
37 #include <linux/utsname.h>
38 #include <linux/interrupt.h>
39 #include <linux/slab.h>
40 #include <linux/wait.h>
41 #include <linux/sched.h>
42 #include <linux/list.h>
43 #include <linux/gfp.h>
44 #include <linux/delay.h>
45 #include <linux/spinlock.h>
46 #include <linux/configfs.h>
47 
48 #include <generated/utsrelease.h>
49 
50 #include <scsi/scsi_dbg.h>
51 #include <scsi/scsi_eh.h>
52 #include <scsi/scsi_tcq.h>
53 
54 #include <target/target_core_base.h>
55 #include <target/target_core_fabric.h>
56 #include <target/target_core_configfs.h>
57 #include <target/target_core_fabric_configfs.h>
58 
59 #include <asm/hypervisor.h>
60 
61 #include <xen/xen.h>
62 #include <xen/balloon.h>
63 #include <xen/events.h>
64 #include <xen/xenbus.h>
65 #include <xen/grant_table.h>
66 #include <xen/page.h>
67 
68 #include <xen/interface/grant_table.h>
69 #include <xen/interface/io/vscsiif.h>
70 
71 #define DPRINTK(_f, _a...)			\
72 	pr_debug("(file=%s, line=%d) " _f, __FILE__ , __LINE__ , ## _a)
73 
74 #define VSCSI_VERSION	"v0.1"
75 #define VSCSI_NAMELEN	32
76 
77 struct ids_tuple {
78 	unsigned int hst;		/* host    */
79 	unsigned int chn;		/* channel */
80 	unsigned int tgt;		/* target  */
81 	unsigned int lun;		/* LUN     */
82 };
83 
84 struct v2p_entry {
85 	struct ids_tuple v;		/* translate from */
86 	struct scsiback_tpg *tpg;	/* translate to   */
87 	unsigned int lun;
88 	struct kref kref;
89 	struct list_head l;
90 };
91 
92 struct vscsibk_info {
93 	struct xenbus_device *dev;
94 
95 	domid_t domid;
96 	unsigned int irq;
97 
98 	struct vscsiif_back_ring ring;
99 	int ring_error;
100 
101 	spinlock_t ring_lock;
102 	atomic_t nr_unreplied_reqs;
103 
104 	spinlock_t v2p_lock;
105 	struct list_head v2p_entry_lists;
106 
107 	wait_queue_head_t waiting_to_free;
108 };
109 
110 /* theoretical maximum of grants for one request */
111 #define VSCSI_MAX_GRANTS	(SG_ALL + VSCSIIF_SG_TABLESIZE)
112 
113 /*
114  * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
115  * call to map/unmap grants. Don't choose it too large, as there are arrays
116  * with VSCSI_GRANT_BATCH elements allocated on the stack.
117  */
118 #define VSCSI_GRANT_BATCH	16
119 
120 struct vscsibk_pend {
121 	uint16_t rqid;
122 
123 	uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
124 	uint8_t cmd_len;
125 
126 	uint8_t sc_data_direction;
127 	uint16_t n_sg;		/* real length of SG list */
128 	uint16_t n_grants;	/* SG pages and potentially SG list */
129 	uint32_t data_len;
130 	uint32_t result;
131 
132 	struct vscsibk_info *info;
133 	struct v2p_entry *v2p;
134 	struct scatterlist *sgl;
135 
136 	uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
137 
138 	grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
139 	struct page *pages[VSCSI_MAX_GRANTS];
140 
141 	struct se_cmd se_cmd;
142 };
143 
144 struct scsiback_tmr {
145 	atomic_t tmr_complete;
146 	wait_queue_head_t tmr_wait;
147 };
148 
149 struct scsiback_nexus {
150 	/* Pointer to TCM session for I_T Nexus */
151 	struct se_session *tvn_se_sess;
152 };
153 
154 struct scsiback_tport {
155 	/* SCSI protocol the tport is providing */
156 	u8 tport_proto_id;
157 	/* Binary World Wide unique Port Name for pvscsi Target port */
158 	u64 tport_wwpn;
159 	/* ASCII formatted WWPN for pvscsi Target port */
160 	char tport_name[VSCSI_NAMELEN];
161 	/* Returned by scsiback_make_tport() */
162 	struct se_wwn tport_wwn;
163 };
164 
165 struct scsiback_tpg {
166 	/* scsiback port target portal group tag for TCM */
167 	u16 tport_tpgt;
168 	/* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
169 	int tv_tpg_port_count;
170 	/* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
171 	int tv_tpg_fe_count;
172 	/* list for scsiback_list */
173 	struct list_head tv_tpg_list;
174 	/* Used to protect access for tpg_nexus */
175 	struct mutex tv_tpg_mutex;
176 	/* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
177 	struct scsiback_nexus *tpg_nexus;
178 	/* Pointer back to scsiback_tport */
179 	struct scsiback_tport *tport;
180 	/* Returned by scsiback_make_tpg() */
181 	struct se_portal_group se_tpg;
182 	/* alias used in xenstore */
183 	char param_alias[VSCSI_NAMELEN];
184 	/* list of info structures related to this target portal group */
185 	struct list_head info_list;
186 };
187 
188 #define SCSIBACK_INVALID_HANDLE (~0)
189 
190 static bool log_print_stat;
191 module_param(log_print_stat, bool, 0644);
192 
193 static int scsiback_max_buffer_pages = 1024;
194 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
195 MODULE_PARM_DESC(max_buffer_pages,
196 "Maximum number of free pages to keep in backend buffer");
197 
198 static struct kmem_cache *scsiback_cachep;
199 static DEFINE_SPINLOCK(free_pages_lock);
200 static int free_pages_num;
201 static LIST_HEAD(scsiback_free_pages);
202 
203 /* Global spinlock to protect scsiback TPG list */
204 static DEFINE_MUTEX(scsiback_mutex);
205 static LIST_HEAD(scsiback_list);
206 
207 /* Local pointer to allocated TCM configfs fabric module */
208 static struct target_fabric_configfs *scsiback_fabric_configfs;
209 
scsiback_get(struct vscsibk_info * info)210 static void scsiback_get(struct vscsibk_info *info)
211 {
212 	atomic_inc(&info->nr_unreplied_reqs);
213 }
214 
scsiback_put(struct vscsibk_info * info)215 static void scsiback_put(struct vscsibk_info *info)
216 {
217 	if (atomic_dec_and_test(&info->nr_unreplied_reqs))
218 		wake_up(&info->waiting_to_free);
219 }
220 
put_free_pages(struct page ** page,int num)221 static void put_free_pages(struct page **page, int num)
222 {
223 	unsigned long flags;
224 	int i = free_pages_num + num, n = num;
225 
226 	if (num == 0)
227 		return;
228 	if (i > scsiback_max_buffer_pages) {
229 		n = min(num, i - scsiback_max_buffer_pages);
230 		free_xenballooned_pages(n, page + num - n);
231 		n = num - n;
232 	}
233 	spin_lock_irqsave(&free_pages_lock, flags);
234 	for (i = 0; i < n; i++)
235 		list_add(&page[i]->lru, &scsiback_free_pages);
236 	free_pages_num += n;
237 	spin_unlock_irqrestore(&free_pages_lock, flags);
238 }
239 
get_free_page(struct page ** page)240 static int get_free_page(struct page **page)
241 {
242 	unsigned long flags;
243 
244 	spin_lock_irqsave(&free_pages_lock, flags);
245 	if (list_empty(&scsiback_free_pages)) {
246 		spin_unlock_irqrestore(&free_pages_lock, flags);
247 		return alloc_xenballooned_pages(1, page, false);
248 	}
249 	page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
250 	list_del(&page[0]->lru);
251 	free_pages_num--;
252 	spin_unlock_irqrestore(&free_pages_lock, flags);
253 	return 0;
254 }
255 
vaddr_page(struct page * page)256 static unsigned long vaddr_page(struct page *page)
257 {
258 	unsigned long pfn = page_to_pfn(page);
259 
260 	return (unsigned long)pfn_to_kaddr(pfn);
261 }
262 
vaddr(struct vscsibk_pend * req,int seg)263 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
264 {
265 	return vaddr_page(req->pages[seg]);
266 }
267 
scsiback_print_status(char * sense_buffer,int errors,struct vscsibk_pend * pending_req)268 static void scsiback_print_status(char *sense_buffer, int errors,
269 					struct vscsibk_pend *pending_req)
270 {
271 	struct scsiback_tpg *tpg = pending_req->v2p->tpg;
272 
273 	pr_err("xen-pvscsi[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
274 	       tpg->tport->tport_name, pending_req->v2p->lun,
275 	       pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
276 	       host_byte(errors), driver_byte(errors));
277 
278 	if (CHECK_CONDITION & status_byte(errors))
279 		__scsi_print_sense("xen-pvscsi", sense_buffer,
280 				   SCSI_SENSE_BUFFERSIZE);
281 }
282 
scsiback_fast_flush_area(struct vscsibk_pend * req)283 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
284 {
285 	struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
286 	struct page *pages[VSCSI_GRANT_BATCH];
287 	unsigned int i, invcount = 0;
288 	grant_handle_t handle;
289 	int err;
290 
291 	kfree(req->sgl);
292 	req->sgl = NULL;
293 	req->n_sg = 0;
294 
295 	if (!req->n_grants)
296 		return;
297 
298 	for (i = 0; i < req->n_grants; i++) {
299 		handle = req->grant_handles[i];
300 		if (handle == SCSIBACK_INVALID_HANDLE)
301 			continue;
302 		gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
303 				    GNTMAP_host_map, handle);
304 		req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
305 		pages[invcount] = req->pages[i];
306 		put_page(pages[invcount]);
307 		invcount++;
308 		if (invcount < VSCSI_GRANT_BATCH)
309 			continue;
310 		err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
311 		BUG_ON(err);
312 		invcount = 0;
313 	}
314 
315 	if (invcount) {
316 		err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
317 		BUG_ON(err);
318 	}
319 
320 	put_free_pages(req->pages, req->n_grants);
321 	req->n_grants = 0;
322 }
323 
scsiback_free_translation_entry(struct kref * kref)324 static void scsiback_free_translation_entry(struct kref *kref)
325 {
326 	struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
327 	struct scsiback_tpg *tpg = entry->tpg;
328 
329 	mutex_lock(&tpg->tv_tpg_mutex);
330 	tpg->tv_tpg_fe_count--;
331 	mutex_unlock(&tpg->tv_tpg_mutex);
332 
333 	kfree(entry);
334 }
335 
scsiback_do_resp_with_sense(char * sense_buffer,int32_t result,uint32_t resid,struct vscsibk_pend * pending_req)336 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
337 			uint32_t resid, struct vscsibk_pend *pending_req)
338 {
339 	struct vscsiif_response *ring_res;
340 	struct vscsibk_info *info = pending_req->info;
341 	int notify;
342 	struct scsi_sense_hdr sshdr;
343 	unsigned long flags;
344 	unsigned len;
345 
346 	spin_lock_irqsave(&info->ring_lock, flags);
347 
348 	ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
349 	info->ring.rsp_prod_pvt++;
350 
351 	ring_res->rslt   = result;
352 	ring_res->rqid   = pending_req->rqid;
353 
354 	if (sense_buffer != NULL &&
355 	    scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
356 				 &sshdr)) {
357 		len = min_t(unsigned, 8 + sense_buffer[7],
358 			    VSCSIIF_SENSE_BUFFERSIZE);
359 		memcpy(ring_res->sense_buffer, sense_buffer, len);
360 		ring_res->sense_len = len;
361 	} else {
362 		ring_res->sense_len = 0;
363 	}
364 
365 	ring_res->residual_len = resid;
366 
367 	RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
368 	spin_unlock_irqrestore(&info->ring_lock, flags);
369 
370 	if (notify)
371 		notify_remote_via_irq(info->irq);
372 
373 	if (pending_req->v2p)
374 		kref_put(&pending_req->v2p->kref,
375 			 scsiback_free_translation_entry);
376 }
377 
scsiback_cmd_done(struct vscsibk_pend * pending_req)378 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
379 {
380 	struct vscsibk_info *info = pending_req->info;
381 	unsigned char *sense_buffer;
382 	unsigned int resid;
383 	int errors;
384 
385 	sense_buffer = pending_req->sense_buffer;
386 	resid        = pending_req->se_cmd.residual_count;
387 	errors       = pending_req->result;
388 
389 	if (errors && log_print_stat)
390 		scsiback_print_status(sense_buffer, errors, pending_req);
391 
392 	scsiback_fast_flush_area(pending_req);
393 	scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
394 	scsiback_put(info);
395 }
396 
scsiback_cmd_exec(struct vscsibk_pend * pending_req)397 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
398 {
399 	struct se_cmd *se_cmd = &pending_req->se_cmd;
400 	struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
401 	int rc;
402 
403 	memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE);
404 
405 	memset(se_cmd, 0, sizeof(*se_cmd));
406 
407 	scsiback_get(pending_req->info);
408 	rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
409 			pending_req->sense_buffer, pending_req->v2p->lun,
410 			pending_req->data_len, 0,
411 			pending_req->sc_data_direction, 0,
412 			pending_req->sgl, pending_req->n_sg,
413 			NULL, 0, NULL, 0);
414 	if (rc < 0) {
415 		transport_send_check_condition_and_sense(se_cmd,
416 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
417 		transport_generic_free_cmd(se_cmd, 0);
418 	}
419 }
420 
scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref * map,struct page ** pg,grant_handle_t * grant,int cnt)421 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
422 	struct page **pg, grant_handle_t *grant, int cnt)
423 {
424 	int err, i;
425 
426 	if (!cnt)
427 		return 0;
428 
429 	err = gnttab_map_refs(map, NULL, pg, cnt);
430 	BUG_ON(err);
431 	for (i = 0; i < cnt; i++) {
432 		if (unlikely(map[i].status != GNTST_okay)) {
433 			pr_err("xen-pvscsi: invalid buffer -- could not remap it\n");
434 			map[i].handle = SCSIBACK_INVALID_HANDLE;
435 			err = -ENOMEM;
436 		} else {
437 			get_page(pg[i]);
438 		}
439 		grant[i] = map[i].handle;
440 	}
441 	return err;
442 }
443 
scsiback_gnttab_data_map_list(struct vscsibk_pend * pending_req,struct scsiif_request_segment * seg,struct page ** pg,grant_handle_t * grant,int cnt,u32 flags)444 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
445 			struct scsiif_request_segment *seg, struct page **pg,
446 			grant_handle_t *grant, int cnt, u32 flags)
447 {
448 	int mapcount = 0, i, err = 0;
449 	struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
450 	struct vscsibk_info *info = pending_req->info;
451 
452 	for (i = 0; i < cnt; i++) {
453 		if (get_free_page(pg + mapcount)) {
454 			put_free_pages(pg, mapcount);
455 			pr_err("xen-pvscsi: no grant page\n");
456 			return -ENOMEM;
457 		}
458 		gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
459 				  flags, seg[i].gref, info->domid);
460 		mapcount++;
461 		if (mapcount < VSCSI_GRANT_BATCH)
462 			continue;
463 		err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
464 		pg += mapcount;
465 		grant += mapcount;
466 		pending_req->n_grants += mapcount;
467 		if (err)
468 			return err;
469 		mapcount = 0;
470 	}
471 	err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
472 	pending_req->n_grants += mapcount;
473 	return err;
474 }
475 
scsiback_gnttab_data_map(struct vscsiif_request * ring_req,struct vscsibk_pend * pending_req)476 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
477 					struct vscsibk_pend *pending_req)
478 {
479 	u32 flags;
480 	int i, err, n_segs, i_seg = 0;
481 	struct page **pg;
482 	struct scsiif_request_segment *seg;
483 	unsigned long end_seg = 0;
484 	unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
485 	unsigned int nr_sgl = 0;
486 	struct scatterlist *sg;
487 	grant_handle_t *grant;
488 
489 	pending_req->n_sg = 0;
490 	pending_req->n_grants = 0;
491 	pending_req->data_len = 0;
492 
493 	nr_segments &= ~VSCSIIF_SG_GRANT;
494 	if (!nr_segments)
495 		return 0;
496 
497 	if (nr_segments > VSCSIIF_SG_TABLESIZE) {
498 		DPRINTK("xen-pvscsi: invalid parameter nr_seg = %d\n",
499 			ring_req->nr_segments);
500 		return -EINVAL;
501 	}
502 
503 	if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
504 		err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
505 			pending_req->pages, pending_req->grant_handles,
506 			nr_segments, GNTMAP_host_map | GNTMAP_readonly);
507 		if (err)
508 			return err;
509 		nr_sgl = nr_segments;
510 		nr_segments = 0;
511 		for (i = 0; i < nr_sgl; i++) {
512 			n_segs = ring_req->seg[i].length /
513 				 sizeof(struct scsiif_request_segment);
514 			if ((unsigned)ring_req->seg[i].offset +
515 			    (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
516 			    n_segs * sizeof(struct scsiif_request_segment) !=
517 			    ring_req->seg[i].length)
518 				return -EINVAL;
519 			nr_segments += n_segs;
520 		}
521 		if (nr_segments > SG_ALL) {
522 			DPRINTK("xen-pvscsi: invalid nr_seg = %d\n",
523 				nr_segments);
524 			return -EINVAL;
525 		}
526 	}
527 
528 	/* free of (sgl) in fast_flush_area()*/
529 	pending_req->sgl = kmalloc_array(nr_segments,
530 					sizeof(struct scatterlist), GFP_KERNEL);
531 	if (!pending_req->sgl)
532 		return -ENOMEM;
533 
534 	sg_init_table(pending_req->sgl, nr_segments);
535 	pending_req->n_sg = nr_segments;
536 
537 	flags = GNTMAP_host_map;
538 	if (pending_req->sc_data_direction == DMA_TO_DEVICE)
539 		flags |= GNTMAP_readonly;
540 
541 	pg = pending_req->pages + nr_sgl;
542 	grant = pending_req->grant_handles + nr_sgl;
543 	if (!nr_sgl) {
544 		seg = ring_req->seg;
545 		err = scsiback_gnttab_data_map_list(pending_req, seg,
546 			pg, grant, nr_segments, flags);
547 		if (err)
548 			return err;
549 	} else {
550 		for (i = 0; i < nr_sgl; i++) {
551 			seg = (struct scsiif_request_segment *)(
552 			      vaddr(pending_req, i) + ring_req->seg[i].offset);
553 			n_segs = ring_req->seg[i].length /
554 				 sizeof(struct scsiif_request_segment);
555 			err = scsiback_gnttab_data_map_list(pending_req, seg,
556 				pg, grant, n_segs, flags);
557 			if (err)
558 				return err;
559 			pg += n_segs;
560 			grant += n_segs;
561 		}
562 		end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
563 		seg = (struct scsiif_request_segment *)end_seg;
564 		end_seg += ring_req->seg[0].length;
565 		pg = pending_req->pages + nr_sgl;
566 	}
567 
568 	for_each_sg(pending_req->sgl, sg, nr_segments, i) {
569 		sg_set_page(sg, pg[i], seg->length, seg->offset);
570 		pending_req->data_len += seg->length;
571 		seg++;
572 		if (nr_sgl && (unsigned long)seg >= end_seg) {
573 			i_seg++;
574 			end_seg = vaddr(pending_req, i_seg) +
575 				  ring_req->seg[i_seg].offset;
576 			seg = (struct scsiif_request_segment *)end_seg;
577 			end_seg += ring_req->seg[i_seg].length;
578 		}
579 		if (sg->offset >= PAGE_SIZE ||
580 		    sg->length > PAGE_SIZE ||
581 		    sg->offset + sg->length > PAGE_SIZE)
582 			return -EINVAL;
583 	}
584 
585 	return 0;
586 }
587 
scsiback_disconnect(struct vscsibk_info * info)588 static void scsiback_disconnect(struct vscsibk_info *info)
589 {
590 	wait_event(info->waiting_to_free,
591 		atomic_read(&info->nr_unreplied_reqs) == 0);
592 
593 	unbind_from_irqhandler(info->irq, info);
594 	info->irq = 0;
595 	xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
596 }
597 
scsiback_device_action(struct vscsibk_pend * pending_req,enum tcm_tmreq_table act,int tag)598 static void scsiback_device_action(struct vscsibk_pend *pending_req,
599 	enum tcm_tmreq_table act, int tag)
600 {
601 	int rc, err = FAILED;
602 	struct scsiback_tpg *tpg = pending_req->v2p->tpg;
603 	struct se_cmd *se_cmd = &pending_req->se_cmd;
604 	struct scsiback_tmr *tmr;
605 
606 	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
607 	if (!tmr)
608 		goto out;
609 
610 	init_waitqueue_head(&tmr->tmr_wait);
611 
612 	transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
613 		tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, MSG_SIMPLE_TAG,
614 		&pending_req->sense_buffer[0]);
615 
616 	rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
617 	if (rc < 0)
618 		goto out;
619 
620 	se_cmd->se_tmr_req->ref_task_tag = tag;
621 
622 	if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0)
623 		goto out;
624 
625 	transport_generic_handle_tmr(se_cmd);
626 	wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
627 
628 	err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
629 		SUCCESS : FAILED;
630 
631 out:
632 	if (tmr) {
633 		transport_generic_free_cmd(&pending_req->se_cmd, 1);
634 		kfree(tmr);
635 	}
636 
637 	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
638 
639 	kmem_cache_free(scsiback_cachep, pending_req);
640 }
641 
642 /*
643   Perform virtual to physical translation
644 */
scsiback_do_translation(struct vscsibk_info * info,struct ids_tuple * v)645 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
646 			struct ids_tuple *v)
647 {
648 	struct v2p_entry *entry;
649 	struct list_head *head = &(info->v2p_entry_lists);
650 	unsigned long flags;
651 
652 	spin_lock_irqsave(&info->v2p_lock, flags);
653 	list_for_each_entry(entry, head, l) {
654 		if ((entry->v.chn == v->chn) &&
655 		    (entry->v.tgt == v->tgt) &&
656 		    (entry->v.lun == v->lun)) {
657 			kref_get(&entry->kref);
658 			goto out;
659 		}
660 	}
661 	entry = NULL;
662 
663 out:
664 	spin_unlock_irqrestore(&info->v2p_lock, flags);
665 	return entry;
666 }
667 
prepare_pending_reqs(struct vscsibk_info * info,struct vscsiif_request * ring_req,struct vscsibk_pend * pending_req)668 static int prepare_pending_reqs(struct vscsibk_info *info,
669 				struct vscsiif_request *ring_req,
670 				struct vscsibk_pend *pending_req)
671 {
672 	struct v2p_entry *v2p;
673 	struct ids_tuple vir;
674 
675 	pending_req->rqid       = ring_req->rqid;
676 	pending_req->info       = info;
677 
678 	vir.chn = ring_req->channel;
679 	vir.tgt = ring_req->id;
680 	vir.lun = ring_req->lun;
681 
682 	v2p = scsiback_do_translation(info, &vir);
683 	if (!v2p) {
684 		pending_req->v2p = NULL;
685 		DPRINTK("xen-pvscsi: doesn't exist.\n");
686 		return -ENODEV;
687 	}
688 	pending_req->v2p = v2p;
689 
690 	/* request range check from frontend */
691 	pending_req->sc_data_direction = ring_req->sc_data_direction;
692 	if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
693 		(pending_req->sc_data_direction != DMA_TO_DEVICE) &&
694 		(pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
695 		(pending_req->sc_data_direction != DMA_NONE)) {
696 		DPRINTK("xen-pvscsi: invalid parameter data_dir = %d\n",
697 			pending_req->sc_data_direction);
698 		return -EINVAL;
699 	}
700 
701 	pending_req->cmd_len = ring_req->cmd_len;
702 	if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
703 		DPRINTK("xen-pvscsi: invalid parameter cmd_len = %d\n",
704 			pending_req->cmd_len);
705 		return -EINVAL;
706 	}
707 	memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
708 
709 	return 0;
710 }
711 
scsiback_do_cmd_fn(struct vscsibk_info * info)712 static int scsiback_do_cmd_fn(struct vscsibk_info *info)
713 {
714 	struct vscsiif_back_ring *ring = &info->ring;
715 	struct vscsiif_request ring_req;
716 	struct vscsibk_pend *pending_req;
717 	RING_IDX rc, rp;
718 	int err, more_to_do;
719 	uint32_t result;
720 
721 	rc = ring->req_cons;
722 	rp = ring->sring->req_prod;
723 	rmb();	/* guest system is accessing ring, too */
724 
725 	if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
726 		rc = ring->rsp_prod_pvt;
727 		pr_warn("xen-pvscsi: Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
728 			   info->domid, rp, rc, rp - rc);
729 		info->ring_error = 1;
730 		return 0;
731 	}
732 
733 	while ((rc != rp)) {
734 		if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
735 			break;
736 		pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
737 		if (!pending_req)
738 			return 1;
739 
740 		ring_req = *RING_GET_REQUEST(ring, rc);
741 		ring->req_cons = ++rc;
742 
743 		err = prepare_pending_reqs(info, &ring_req, pending_req);
744 		if (err) {
745 			switch (err) {
746 			case -ENODEV:
747 				result = DID_NO_CONNECT;
748 				break;
749 			default:
750 				result = DRIVER_ERROR;
751 				break;
752 			}
753 			scsiback_do_resp_with_sense(NULL, result << 24, 0,
754 						    pending_req);
755 			kmem_cache_free(scsiback_cachep, pending_req);
756 			return 1;
757 		}
758 
759 		switch (ring_req.act) {
760 		case VSCSIIF_ACT_SCSI_CDB:
761 			if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
762 				scsiback_fast_flush_area(pending_req);
763 				scsiback_do_resp_with_sense(NULL,
764 					DRIVER_ERROR << 24, 0, pending_req);
765 				kmem_cache_free(scsiback_cachep, pending_req);
766 			} else {
767 				scsiback_cmd_exec(pending_req);
768 			}
769 			break;
770 		case VSCSIIF_ACT_SCSI_ABORT:
771 			scsiback_device_action(pending_req, TMR_ABORT_TASK,
772 				ring_req.ref_rqid);
773 			break;
774 		case VSCSIIF_ACT_SCSI_RESET:
775 			scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
776 			break;
777 		default:
778 			pr_err_ratelimited("xen-pvscsi: invalid request\n");
779 			scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
780 						    0, pending_req);
781 			kmem_cache_free(scsiback_cachep, pending_req);
782 			break;
783 		}
784 
785 		/* Yield point for this unbounded loop. */
786 		cond_resched();
787 	}
788 
789 	RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
790 	return more_to_do;
791 }
792 
scsiback_irq_fn(int irq,void * dev_id)793 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
794 {
795 	struct vscsibk_info *info = dev_id;
796 
797 	if (info->ring_error)
798 		return IRQ_HANDLED;
799 
800 	while (scsiback_do_cmd_fn(info))
801 		cond_resched();
802 
803 	return IRQ_HANDLED;
804 }
805 
scsiback_init_sring(struct vscsibk_info * info,grant_ref_t ring_ref,evtchn_port_t evtchn)806 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
807 			evtchn_port_t evtchn)
808 {
809 	void *area;
810 	struct vscsiif_sring *sring;
811 	int err;
812 
813 	if (info->irq)
814 		return -1;
815 
816 	err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
817 	if (err)
818 		return err;
819 
820 	sring = (struct vscsiif_sring *)area;
821 	BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
822 
823 	err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
824 	if (err < 0)
825 		goto unmap_page;
826 
827 	info->irq = err;
828 
829 	err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
830 				   IRQF_ONESHOT, "vscsiif-backend", info);
831 	if (err)
832 		goto free_irq;
833 
834 	return 0;
835 
836 free_irq:
837 	unbind_from_irqhandler(info->irq, info);
838 	info->irq = 0;
839 unmap_page:
840 	xenbus_unmap_ring_vfree(info->dev, area);
841 
842 	return err;
843 }
844 
scsiback_map(struct vscsibk_info * info)845 static int scsiback_map(struct vscsibk_info *info)
846 {
847 	struct xenbus_device *dev = info->dev;
848 	unsigned int ring_ref, evtchn;
849 	int err;
850 
851 	err = xenbus_gather(XBT_NIL, dev->otherend,
852 			"ring-ref", "%u", &ring_ref,
853 			"event-channel", "%u", &evtchn, NULL);
854 	if (err) {
855 		xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
856 		return err;
857 	}
858 
859 	return scsiback_init_sring(info, ring_ref, evtchn);
860 }
861 
862 /*
863   Add a new translation entry
864 */
scsiback_add_translation_entry(struct vscsibk_info * info,char * phy,struct ids_tuple * v)865 static int scsiback_add_translation_entry(struct vscsibk_info *info,
866 					  char *phy, struct ids_tuple *v)
867 {
868 	int err = 0;
869 	struct v2p_entry *entry;
870 	struct v2p_entry *new;
871 	struct list_head *head = &(info->v2p_entry_lists);
872 	unsigned long flags;
873 	char *lunp;
874 	unsigned int lun;
875 	struct scsiback_tpg *tpg_entry, *tpg = NULL;
876 	char *error = "doesn't exist";
877 
878 	lunp = strrchr(phy, ':');
879 	if (!lunp) {
880 		pr_err("xen-pvscsi: illegal format of physical device %s\n",
881 			phy);
882 		return -EINVAL;
883 	}
884 	*lunp = 0;
885 	lunp++;
886 	if (kstrtouint(lunp, 10, &lun) || lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
887 		pr_err("xen-pvscsi: lun number not valid: %s\n", lunp);
888 		return -EINVAL;
889 	}
890 
891 	mutex_lock(&scsiback_mutex);
892 	list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
893 		if (!strcmp(phy, tpg_entry->tport->tport_name) ||
894 		    !strcmp(phy, tpg_entry->param_alias)) {
895 			spin_lock(&tpg_entry->se_tpg.tpg_lun_lock);
896 			if (tpg_entry->se_tpg.tpg_lun_list[lun]->lun_status ==
897 			    TRANSPORT_LUN_STATUS_ACTIVE) {
898 				if (!tpg_entry->tpg_nexus)
899 					error = "nexus undefined";
900 				else
901 					tpg = tpg_entry;
902 			}
903 			spin_unlock(&tpg_entry->se_tpg.tpg_lun_lock);
904 			break;
905 		}
906 	}
907 	if (tpg) {
908 		mutex_lock(&tpg->tv_tpg_mutex);
909 		tpg->tv_tpg_fe_count++;
910 		mutex_unlock(&tpg->tv_tpg_mutex);
911 	}
912 	mutex_unlock(&scsiback_mutex);
913 
914 	if (!tpg) {
915 		pr_err("xen-pvscsi: %s:%d %s\n", phy, lun, error);
916 		return -ENODEV;
917 	}
918 
919 	new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
920 	if (new == NULL) {
921 		err = -ENOMEM;
922 		goto out_free;
923 	}
924 
925 	spin_lock_irqsave(&info->v2p_lock, flags);
926 
927 	/* Check double assignment to identical virtual ID */
928 	list_for_each_entry(entry, head, l) {
929 		if ((entry->v.chn == v->chn) &&
930 		    (entry->v.tgt == v->tgt) &&
931 		    (entry->v.lun == v->lun)) {
932 			pr_warn("xen-pvscsi: Virtual ID is already used. Assignment was not performed.\n");
933 			err = -EEXIST;
934 			goto out;
935 		}
936 
937 	}
938 
939 	/* Create a new translation entry and add to the list */
940 	kref_init(&new->kref);
941 	new->v = *v;
942 	new->tpg = tpg;
943 	new->lun = lun;
944 	list_add_tail(&new->l, head);
945 
946 out:
947 	spin_unlock_irqrestore(&info->v2p_lock, flags);
948 
949 out_free:
950 	if (err) {
951 		mutex_lock(&tpg->tv_tpg_mutex);
952 		tpg->tv_tpg_fe_count--;
953 		mutex_unlock(&tpg->tv_tpg_mutex);
954 		kfree(new);
955 	}
956 
957 	return err;
958 }
959 
__scsiback_del_translation_entry(struct v2p_entry * entry)960 static void __scsiback_del_translation_entry(struct v2p_entry *entry)
961 {
962 	list_del(&entry->l);
963 	kref_put(&entry->kref, scsiback_free_translation_entry);
964 }
965 
966 /*
967   Delete the translation entry specfied
968 */
scsiback_del_translation_entry(struct vscsibk_info * info,struct ids_tuple * v)969 static int scsiback_del_translation_entry(struct vscsibk_info *info,
970 					  struct ids_tuple *v)
971 {
972 	struct v2p_entry *entry;
973 	struct list_head *head = &(info->v2p_entry_lists);
974 	unsigned long flags;
975 
976 	spin_lock_irqsave(&info->v2p_lock, flags);
977 	/* Find out the translation entry specified */
978 	list_for_each_entry(entry, head, l) {
979 		if ((entry->v.chn == v->chn) &&
980 		    (entry->v.tgt == v->tgt) &&
981 		    (entry->v.lun == v->lun)) {
982 			goto found;
983 		}
984 	}
985 
986 	spin_unlock_irqrestore(&info->v2p_lock, flags);
987 	return 1;
988 
989 found:
990 	/* Delete the translation entry specfied */
991 	__scsiback_del_translation_entry(entry);
992 
993 	spin_unlock_irqrestore(&info->v2p_lock, flags);
994 	return 0;
995 }
996 
scsiback_do_add_lun(struct vscsibk_info * info,const char * state,char * phy,struct ids_tuple * vir)997 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
998 				char *phy, struct ids_tuple *vir)
999 {
1000 	if (!scsiback_add_translation_entry(info, phy, vir)) {
1001 		if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1002 				  "%d", XenbusStateInitialised)) {
1003 			pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1004 			scsiback_del_translation_entry(info, vir);
1005 		}
1006 	} else {
1007 		xenbus_printf(XBT_NIL, info->dev->nodename, state,
1008 			      "%d", XenbusStateClosed);
1009 	}
1010 }
1011 
scsiback_do_del_lun(struct vscsibk_info * info,const char * state,struct ids_tuple * vir)1012 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1013 				struct ids_tuple *vir)
1014 {
1015 	if (!scsiback_del_translation_entry(info, vir)) {
1016 		if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1017 				  "%d", XenbusStateClosed))
1018 			pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1019 	}
1020 }
1021 
1022 #define VSCSIBACK_OP_ADD_OR_DEL_LUN	1
1023 #define VSCSIBACK_OP_UPDATEDEV_STATE	2
1024 
scsiback_do_1lun_hotplug(struct vscsibk_info * info,int op,char * ent)1025 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1026 				     char *ent)
1027 {
1028 	int err;
1029 	struct ids_tuple vir;
1030 	char *val;
1031 	int device_state;
1032 	char phy[VSCSI_NAMELEN];
1033 	char str[64];
1034 	char state[64];
1035 	struct xenbus_device *dev = info->dev;
1036 
1037 	/* read status */
1038 	snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1039 	err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1040 	if (XENBUS_EXIST_ERR(err))
1041 		return;
1042 
1043 	/* physical SCSI device */
1044 	snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1045 	val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1046 	if (IS_ERR(val)) {
1047 		xenbus_printf(XBT_NIL, dev->nodename, state,
1048 			      "%d", XenbusStateClosed);
1049 		return;
1050 	}
1051 	strlcpy(phy, val, VSCSI_NAMELEN);
1052 	kfree(val);
1053 
1054 	/* virtual SCSI device */
1055 	snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1056 	err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1057 			   &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1058 	if (XENBUS_EXIST_ERR(err)) {
1059 		xenbus_printf(XBT_NIL, dev->nodename, state,
1060 			      "%d", XenbusStateClosed);
1061 		return;
1062 	}
1063 
1064 	switch (op) {
1065 	case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1066 		if (device_state == XenbusStateInitialising)
1067 			scsiback_do_add_lun(info, state, phy, &vir);
1068 		if (device_state == XenbusStateClosing)
1069 			scsiback_do_del_lun(info, state, &vir);
1070 		break;
1071 
1072 	case VSCSIBACK_OP_UPDATEDEV_STATE:
1073 		if (device_state == XenbusStateInitialised) {
1074 			/* modify vscsi-devs/dev-x/state */
1075 			if (xenbus_printf(XBT_NIL, dev->nodename, state,
1076 					  "%d", XenbusStateConnected)) {
1077 				pr_err("xen-pvscsi: xenbus_printf error %s\n",
1078 				       str);
1079 				scsiback_del_translation_entry(info, &vir);
1080 				xenbus_printf(XBT_NIL, dev->nodename, state,
1081 					      "%d", XenbusStateClosed);
1082 			}
1083 		}
1084 		break;
1085 	/*When it is necessary, processing is added here.*/
1086 	default:
1087 		break;
1088 	}
1089 }
1090 
scsiback_do_lun_hotplug(struct vscsibk_info * info,int op)1091 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1092 {
1093 	int i;
1094 	char **dir;
1095 	unsigned int ndir = 0;
1096 
1097 	dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1098 			       &ndir);
1099 	if (IS_ERR(dir))
1100 		return;
1101 
1102 	for (i = 0; i < ndir; i++)
1103 		scsiback_do_1lun_hotplug(info, op, dir[i]);
1104 
1105 	kfree(dir);
1106 }
1107 
scsiback_frontend_changed(struct xenbus_device * dev,enum xenbus_state frontend_state)1108 static void scsiback_frontend_changed(struct xenbus_device *dev,
1109 					enum xenbus_state frontend_state)
1110 {
1111 	struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1112 
1113 	switch (frontend_state) {
1114 	case XenbusStateInitialising:
1115 		break;
1116 
1117 	case XenbusStateInitialised:
1118 		if (scsiback_map(info))
1119 			break;
1120 
1121 		scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1122 		xenbus_switch_state(dev, XenbusStateConnected);
1123 		break;
1124 
1125 	case XenbusStateConnected:
1126 		scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1127 
1128 		if (dev->state == XenbusStateConnected)
1129 			break;
1130 
1131 		xenbus_switch_state(dev, XenbusStateConnected);
1132 		break;
1133 
1134 	case XenbusStateClosing:
1135 		if (info->irq)
1136 			scsiback_disconnect(info);
1137 
1138 		xenbus_switch_state(dev, XenbusStateClosing);
1139 		break;
1140 
1141 	case XenbusStateClosed:
1142 		xenbus_switch_state(dev, XenbusStateClosed);
1143 		if (xenbus_dev_is_online(dev))
1144 			break;
1145 		/* fall through if not online */
1146 	case XenbusStateUnknown:
1147 		device_unregister(&dev->dev);
1148 		break;
1149 
1150 	case XenbusStateReconfiguring:
1151 		scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1152 		xenbus_switch_state(dev, XenbusStateReconfigured);
1153 
1154 		break;
1155 
1156 	default:
1157 		xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1158 					frontend_state);
1159 		break;
1160 	}
1161 }
1162 
1163 /*
1164   Release the translation entry specfied
1165 */
scsiback_release_translation_entry(struct vscsibk_info * info)1166 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1167 {
1168 	struct v2p_entry *entry, *tmp;
1169 	struct list_head *head = &(info->v2p_entry_lists);
1170 	unsigned long flags;
1171 
1172 	spin_lock_irqsave(&info->v2p_lock, flags);
1173 
1174 	list_for_each_entry_safe(entry, tmp, head, l)
1175 		__scsiback_del_translation_entry(entry);
1176 
1177 	spin_unlock_irqrestore(&info->v2p_lock, flags);
1178 }
1179 
scsiback_remove(struct xenbus_device * dev)1180 static int scsiback_remove(struct xenbus_device *dev)
1181 {
1182 	struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1183 
1184 	if (info->irq)
1185 		scsiback_disconnect(info);
1186 
1187 	scsiback_release_translation_entry(info);
1188 
1189 	dev_set_drvdata(&dev->dev, NULL);
1190 
1191 	return 0;
1192 }
1193 
scsiback_probe(struct xenbus_device * dev,const struct xenbus_device_id * id)1194 static int scsiback_probe(struct xenbus_device *dev,
1195 			   const struct xenbus_device_id *id)
1196 {
1197 	int err;
1198 
1199 	struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1200 					    GFP_KERNEL);
1201 
1202 	DPRINTK("%p %d\n", dev, dev->otherend_id);
1203 
1204 	if (!info) {
1205 		xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1206 		return -ENOMEM;
1207 	}
1208 	info->dev = dev;
1209 	dev_set_drvdata(&dev->dev, info);
1210 
1211 	info->domid = dev->otherend_id;
1212 	spin_lock_init(&info->ring_lock);
1213 	info->ring_error = 0;
1214 	atomic_set(&info->nr_unreplied_reqs, 0);
1215 	init_waitqueue_head(&info->waiting_to_free);
1216 	info->dev = dev;
1217 	info->irq = 0;
1218 	INIT_LIST_HEAD(&info->v2p_entry_lists);
1219 	spin_lock_init(&info->v2p_lock);
1220 
1221 	err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1222 			    SG_ALL);
1223 	if (err)
1224 		xenbus_dev_error(dev, err, "writing feature-sg-grant");
1225 
1226 	err = xenbus_switch_state(dev, XenbusStateInitWait);
1227 	if (err)
1228 		goto fail;
1229 
1230 	return 0;
1231 
1232 fail:
1233 	pr_warn("xen-pvscsi: %s failed\n", __func__);
1234 	scsiback_remove(dev);
1235 
1236 	return err;
1237 }
1238 
scsiback_dump_proto_id(struct scsiback_tport * tport)1239 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1240 {
1241 	switch (tport->tport_proto_id) {
1242 	case SCSI_PROTOCOL_SAS:
1243 		return "SAS";
1244 	case SCSI_PROTOCOL_FCP:
1245 		return "FCP";
1246 	case SCSI_PROTOCOL_ISCSI:
1247 		return "iSCSI";
1248 	default:
1249 		break;
1250 	}
1251 
1252 	return "Unknown";
1253 }
1254 
scsiback_get_fabric_proto_ident(struct se_portal_group * se_tpg)1255 static u8 scsiback_get_fabric_proto_ident(struct se_portal_group *se_tpg)
1256 {
1257 	struct scsiback_tpg *tpg = container_of(se_tpg,
1258 				struct scsiback_tpg, se_tpg);
1259 	struct scsiback_tport *tport = tpg->tport;
1260 
1261 	switch (tport->tport_proto_id) {
1262 	case SCSI_PROTOCOL_SAS:
1263 		return sas_get_fabric_proto_ident(se_tpg);
1264 	case SCSI_PROTOCOL_FCP:
1265 		return fc_get_fabric_proto_ident(se_tpg);
1266 	case SCSI_PROTOCOL_ISCSI:
1267 		return iscsi_get_fabric_proto_ident(se_tpg);
1268 	default:
1269 		pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1270 			tport->tport_proto_id);
1271 		break;
1272 	}
1273 
1274 	return sas_get_fabric_proto_ident(se_tpg);
1275 }
1276 
scsiback_get_fabric_wwn(struct se_portal_group * se_tpg)1277 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1278 {
1279 	struct scsiback_tpg *tpg = container_of(se_tpg,
1280 				struct scsiback_tpg, se_tpg);
1281 	struct scsiback_tport *tport = tpg->tport;
1282 
1283 	return &tport->tport_name[0];
1284 }
1285 
scsiback_get_tag(struct se_portal_group * se_tpg)1286 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1287 {
1288 	struct scsiback_tpg *tpg = container_of(se_tpg,
1289 				struct scsiback_tpg, se_tpg);
1290 	return tpg->tport_tpgt;
1291 }
1292 
scsiback_get_default_depth(struct se_portal_group * se_tpg)1293 static u32 scsiback_get_default_depth(struct se_portal_group *se_tpg)
1294 {
1295 	return 1;
1296 }
1297 
1298 static u32
scsiback_get_pr_transport_id(struct se_portal_group * se_tpg,struct se_node_acl * se_nacl,struct t10_pr_registration * pr_reg,int * format_code,unsigned char * buf)1299 scsiback_get_pr_transport_id(struct se_portal_group *se_tpg,
1300 			      struct se_node_acl *se_nacl,
1301 			      struct t10_pr_registration *pr_reg,
1302 			      int *format_code,
1303 			      unsigned char *buf)
1304 {
1305 	struct scsiback_tpg *tpg = container_of(se_tpg,
1306 				struct scsiback_tpg, se_tpg);
1307 	struct scsiback_tport *tport = tpg->tport;
1308 
1309 	switch (tport->tport_proto_id) {
1310 	case SCSI_PROTOCOL_SAS:
1311 		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1312 					format_code, buf);
1313 	case SCSI_PROTOCOL_FCP:
1314 		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1315 					format_code, buf);
1316 	case SCSI_PROTOCOL_ISCSI:
1317 		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1318 					format_code, buf);
1319 	default:
1320 		pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1321 			tport->tport_proto_id);
1322 		break;
1323 	}
1324 
1325 	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1326 			format_code, buf);
1327 }
1328 
1329 static u32
scsiback_get_pr_transport_id_len(struct se_portal_group * se_tpg,struct se_node_acl * se_nacl,struct t10_pr_registration * pr_reg,int * format_code)1330 scsiback_get_pr_transport_id_len(struct se_portal_group *se_tpg,
1331 				  struct se_node_acl *se_nacl,
1332 				  struct t10_pr_registration *pr_reg,
1333 				  int *format_code)
1334 {
1335 	struct scsiback_tpg *tpg = container_of(se_tpg,
1336 				struct scsiback_tpg, se_tpg);
1337 	struct scsiback_tport *tport = tpg->tport;
1338 
1339 	switch (tport->tport_proto_id) {
1340 	case SCSI_PROTOCOL_SAS:
1341 		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1342 					format_code);
1343 	case SCSI_PROTOCOL_FCP:
1344 		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1345 					format_code);
1346 	case SCSI_PROTOCOL_ISCSI:
1347 		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1348 					format_code);
1349 	default:
1350 		pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1351 			tport->tport_proto_id);
1352 		break;
1353 	}
1354 
1355 	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1356 			format_code);
1357 }
1358 
1359 static char *
scsiback_parse_pr_out_transport_id(struct se_portal_group * se_tpg,const char * buf,u32 * out_tid_len,char ** port_nexus_ptr)1360 scsiback_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
1361 				    const char *buf,
1362 				    u32 *out_tid_len,
1363 				    char **port_nexus_ptr)
1364 {
1365 	struct scsiback_tpg *tpg = container_of(se_tpg,
1366 				struct scsiback_tpg, se_tpg);
1367 	struct scsiback_tport *tport = tpg->tport;
1368 
1369 	switch (tport->tport_proto_id) {
1370 	case SCSI_PROTOCOL_SAS:
1371 		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1372 					port_nexus_ptr);
1373 	case SCSI_PROTOCOL_FCP:
1374 		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1375 					port_nexus_ptr);
1376 	case SCSI_PROTOCOL_ISCSI:
1377 		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1378 					port_nexus_ptr);
1379 	default:
1380 		pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1381 			tport->tport_proto_id);
1382 		break;
1383 	}
1384 
1385 	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1386 			port_nexus_ptr);
1387 }
1388 
1389 static struct se_wwn *
scsiback_make_tport(struct target_fabric_configfs * tf,struct config_group * group,const char * name)1390 scsiback_make_tport(struct target_fabric_configfs *tf,
1391 		     struct config_group *group,
1392 		     const char *name)
1393 {
1394 	struct scsiback_tport *tport;
1395 	char *ptr;
1396 	u64 wwpn = 0;
1397 	int off = 0;
1398 
1399 	tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1400 	if (!tport)
1401 		return ERR_PTR(-ENOMEM);
1402 
1403 	tport->tport_wwpn = wwpn;
1404 	/*
1405 	 * Determine the emulated Protocol Identifier and Target Port Name
1406 	 * based on the incoming configfs directory name.
1407 	 */
1408 	ptr = strstr(name, "naa.");
1409 	if (ptr) {
1410 		tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1411 		goto check_len;
1412 	}
1413 	ptr = strstr(name, "fc.");
1414 	if (ptr) {
1415 		tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1416 		off = 3; /* Skip over "fc." */
1417 		goto check_len;
1418 	}
1419 	ptr = strstr(name, "iqn.");
1420 	if (ptr) {
1421 		tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1422 		goto check_len;
1423 	}
1424 
1425 	pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1426 	kfree(tport);
1427 	return ERR_PTR(-EINVAL);
1428 
1429 check_len:
1430 	if (strlen(name) >= VSCSI_NAMELEN) {
1431 		pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1432 			scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1433 		kfree(tport);
1434 		return ERR_PTR(-EINVAL);
1435 	}
1436 	snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1437 
1438 	pr_debug("xen-pvscsi: Allocated emulated Target %s Address: %s\n",
1439 		 scsiback_dump_proto_id(tport), name);
1440 
1441 	return &tport->tport_wwn;
1442 }
1443 
scsiback_drop_tport(struct se_wwn * wwn)1444 static void scsiback_drop_tport(struct se_wwn *wwn)
1445 {
1446 	struct scsiback_tport *tport = container_of(wwn,
1447 				struct scsiback_tport, tport_wwn);
1448 
1449 	pr_debug("xen-pvscsi: Deallocating emulated Target %s Address: %s\n",
1450 		 scsiback_dump_proto_id(tport), tport->tport_name);
1451 
1452 	kfree(tport);
1453 }
1454 
1455 static struct se_node_acl *
scsiback_alloc_fabric_acl(struct se_portal_group * se_tpg)1456 scsiback_alloc_fabric_acl(struct se_portal_group *se_tpg)
1457 {
1458 	return kzalloc(sizeof(struct se_node_acl), GFP_KERNEL);
1459 }
1460 
1461 static void
scsiback_release_fabric_acl(struct se_portal_group * se_tpg,struct se_node_acl * se_nacl)1462 scsiback_release_fabric_acl(struct se_portal_group *se_tpg,
1463 			     struct se_node_acl *se_nacl)
1464 {
1465 	kfree(se_nacl);
1466 }
1467 
scsiback_tpg_get_inst_index(struct se_portal_group * se_tpg)1468 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1469 {
1470 	return 1;
1471 }
1472 
scsiback_check_stop_free(struct se_cmd * se_cmd)1473 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1474 {
1475 	/*
1476 	 * Do not release struct se_cmd's containing a valid TMR
1477 	 * pointer.  These will be released directly in scsiback_device_action()
1478 	 * with transport_generic_free_cmd().
1479 	 */
1480 	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1481 		return 0;
1482 
1483 	transport_generic_free_cmd(se_cmd, 0);
1484 	return 1;
1485 }
1486 
scsiback_release_cmd(struct se_cmd * se_cmd)1487 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1488 {
1489 	struct vscsibk_pend *pending_req = container_of(se_cmd,
1490 				struct vscsibk_pend, se_cmd);
1491 
1492 	kmem_cache_free(scsiback_cachep, pending_req);
1493 }
1494 
scsiback_shutdown_session(struct se_session * se_sess)1495 static int scsiback_shutdown_session(struct se_session *se_sess)
1496 {
1497 	return 0;
1498 }
1499 
scsiback_close_session(struct se_session * se_sess)1500 static void scsiback_close_session(struct se_session *se_sess)
1501 {
1502 }
1503 
scsiback_sess_get_index(struct se_session * se_sess)1504 static u32 scsiback_sess_get_index(struct se_session *se_sess)
1505 {
1506 	return 0;
1507 }
1508 
scsiback_write_pending(struct se_cmd * se_cmd)1509 static int scsiback_write_pending(struct se_cmd *se_cmd)
1510 {
1511 	/* Go ahead and process the write immediately */
1512 	target_execute_cmd(se_cmd);
1513 
1514 	return 0;
1515 }
1516 
scsiback_write_pending_status(struct se_cmd * se_cmd)1517 static int scsiback_write_pending_status(struct se_cmd *se_cmd)
1518 {
1519 	return 0;
1520 }
1521 
scsiback_set_default_node_attrs(struct se_node_acl * nacl)1522 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1523 {
1524 }
1525 
scsiback_get_task_tag(struct se_cmd * se_cmd)1526 static u32 scsiback_get_task_tag(struct se_cmd *se_cmd)
1527 {
1528 	struct vscsibk_pend *pending_req = container_of(se_cmd,
1529 				struct vscsibk_pend, se_cmd);
1530 
1531 	return pending_req->rqid;
1532 }
1533 
scsiback_get_cmd_state(struct se_cmd * se_cmd)1534 static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1535 {
1536 	return 0;
1537 }
1538 
scsiback_queue_data_in(struct se_cmd * se_cmd)1539 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1540 {
1541 	struct vscsibk_pend *pending_req = container_of(se_cmd,
1542 				struct vscsibk_pend, se_cmd);
1543 
1544 	pending_req->result = SAM_STAT_GOOD;
1545 	scsiback_cmd_done(pending_req);
1546 	return 0;
1547 }
1548 
scsiback_queue_status(struct se_cmd * se_cmd)1549 static int scsiback_queue_status(struct se_cmd *se_cmd)
1550 {
1551 	struct vscsibk_pend *pending_req = container_of(se_cmd,
1552 				struct vscsibk_pend, se_cmd);
1553 
1554 	if (se_cmd->sense_buffer &&
1555 	    ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1556 	     (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1557 		pending_req->result = (DRIVER_SENSE << 24) |
1558 				      SAM_STAT_CHECK_CONDITION;
1559 	else
1560 		pending_req->result = se_cmd->scsi_status;
1561 
1562 	scsiback_cmd_done(pending_req);
1563 	return 0;
1564 }
1565 
scsiback_queue_tm_rsp(struct se_cmd * se_cmd)1566 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1567 {
1568 	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
1569 	struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
1570 
1571 	atomic_set(&tmr->tmr_complete, 1);
1572 	wake_up(&tmr->tmr_wait);
1573 }
1574 
scsiback_aborted_task(struct se_cmd * se_cmd)1575 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1576 {
1577 }
1578 
scsiback_tpg_param_show_alias(struct se_portal_group * se_tpg,char * page)1579 static ssize_t scsiback_tpg_param_show_alias(struct se_portal_group *se_tpg,
1580 					     char *page)
1581 {
1582 	struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1583 						se_tpg);
1584 	ssize_t rb;
1585 
1586 	mutex_lock(&tpg->tv_tpg_mutex);
1587 	rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1588 	mutex_unlock(&tpg->tv_tpg_mutex);
1589 
1590 	return rb;
1591 }
1592 
scsiback_tpg_param_store_alias(struct se_portal_group * se_tpg,const char * page,size_t count)1593 static ssize_t scsiback_tpg_param_store_alias(struct se_portal_group *se_tpg,
1594 					      const char *page, size_t count)
1595 {
1596 	struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1597 						se_tpg);
1598 	int len;
1599 
1600 	if (strlen(page) >= VSCSI_NAMELEN) {
1601 		pr_err("param alias: %s, exceeds max: %d\n", page,
1602 			VSCSI_NAMELEN);
1603 		return -EINVAL;
1604 	}
1605 
1606 	mutex_lock(&tpg->tv_tpg_mutex);
1607 	len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1608 	if (tpg->param_alias[len - 1] == '\n')
1609 		tpg->param_alias[len - 1] = '\0';
1610 	mutex_unlock(&tpg->tv_tpg_mutex);
1611 
1612 	return count;
1613 }
1614 
1615 TF_TPG_PARAM_ATTR(scsiback, alias, S_IRUGO | S_IWUSR);
1616 
1617 static struct configfs_attribute *scsiback_param_attrs[] = {
1618 	&scsiback_tpg_param_alias.attr,
1619 	NULL,
1620 };
1621 
scsiback_make_nexus(struct scsiback_tpg * tpg,const char * name)1622 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1623 				const char *name)
1624 {
1625 	struct se_portal_group *se_tpg;
1626 	struct se_session *se_sess;
1627 	struct scsiback_nexus *tv_nexus;
1628 
1629 	mutex_lock(&tpg->tv_tpg_mutex);
1630 	if (tpg->tpg_nexus) {
1631 		mutex_unlock(&tpg->tv_tpg_mutex);
1632 		pr_debug("tpg->tpg_nexus already exists\n");
1633 		return -EEXIST;
1634 	}
1635 	se_tpg = &tpg->se_tpg;
1636 
1637 	tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1638 	if (!tv_nexus) {
1639 		mutex_unlock(&tpg->tv_tpg_mutex);
1640 		return -ENOMEM;
1641 	}
1642 	/*
1643 	 *  Initialize the struct se_session pointer
1644 	 */
1645 	tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
1646 	if (IS_ERR(tv_nexus->tvn_se_sess)) {
1647 		mutex_unlock(&tpg->tv_tpg_mutex);
1648 		kfree(tv_nexus);
1649 		return -ENOMEM;
1650 	}
1651 	se_sess = tv_nexus->tvn_se_sess;
1652 	/*
1653 	 * Since we are running in 'demo mode' this call with generate a
1654 	 * struct se_node_acl for the scsiback struct se_portal_group with
1655 	 * the SCSI Initiator port name of the passed configfs group 'name'.
1656 	 */
1657 	tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1658 				se_tpg, (unsigned char *)name);
1659 	if (!tv_nexus->tvn_se_sess->se_node_acl) {
1660 		mutex_unlock(&tpg->tv_tpg_mutex);
1661 		pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
1662 			 name);
1663 		goto out;
1664 	}
1665 	/*
1666 	 * Now register the TCM pvscsi virtual I_T Nexus as active with the
1667 	 * call to __transport_register_session()
1668 	 */
1669 	__transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1670 			tv_nexus->tvn_se_sess, tv_nexus);
1671 	tpg->tpg_nexus = tv_nexus;
1672 
1673 	mutex_unlock(&tpg->tv_tpg_mutex);
1674 	return 0;
1675 
1676 out:
1677 	transport_free_session(se_sess);
1678 	kfree(tv_nexus);
1679 	return -ENOMEM;
1680 }
1681 
scsiback_drop_nexus(struct scsiback_tpg * tpg)1682 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1683 {
1684 	struct se_session *se_sess;
1685 	struct scsiback_nexus *tv_nexus;
1686 
1687 	mutex_lock(&tpg->tv_tpg_mutex);
1688 	tv_nexus = tpg->tpg_nexus;
1689 	if (!tv_nexus) {
1690 		mutex_unlock(&tpg->tv_tpg_mutex);
1691 		return -ENODEV;
1692 	}
1693 
1694 	se_sess = tv_nexus->tvn_se_sess;
1695 	if (!se_sess) {
1696 		mutex_unlock(&tpg->tv_tpg_mutex);
1697 		return -ENODEV;
1698 	}
1699 
1700 	if (tpg->tv_tpg_port_count != 0) {
1701 		mutex_unlock(&tpg->tv_tpg_mutex);
1702 		pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1703 			tpg->tv_tpg_port_count);
1704 		return -EBUSY;
1705 	}
1706 
1707 	if (tpg->tv_tpg_fe_count != 0) {
1708 		mutex_unlock(&tpg->tv_tpg_mutex);
1709 		pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1710 			tpg->tv_tpg_fe_count);
1711 		return -EBUSY;
1712 	}
1713 
1714 	pr_debug("xen-pvscsi: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1715 		scsiback_dump_proto_id(tpg->tport),
1716 		tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1717 
1718 	/*
1719 	 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1720 	 */
1721 	transport_deregister_session(tv_nexus->tvn_se_sess);
1722 	tpg->tpg_nexus = NULL;
1723 	mutex_unlock(&tpg->tv_tpg_mutex);
1724 
1725 	kfree(tv_nexus);
1726 	return 0;
1727 }
1728 
scsiback_tpg_show_nexus(struct se_portal_group * se_tpg,char * page)1729 static ssize_t scsiback_tpg_show_nexus(struct se_portal_group *se_tpg,
1730 					char *page)
1731 {
1732 	struct scsiback_tpg *tpg = container_of(se_tpg,
1733 				struct scsiback_tpg, se_tpg);
1734 	struct scsiback_nexus *tv_nexus;
1735 	ssize_t ret;
1736 
1737 	mutex_lock(&tpg->tv_tpg_mutex);
1738 	tv_nexus = tpg->tpg_nexus;
1739 	if (!tv_nexus) {
1740 		mutex_unlock(&tpg->tv_tpg_mutex);
1741 		return -ENODEV;
1742 	}
1743 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1744 			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1745 	mutex_unlock(&tpg->tv_tpg_mutex);
1746 
1747 	return ret;
1748 }
1749 
scsiback_tpg_store_nexus(struct se_portal_group * se_tpg,const char * page,size_t count)1750 static ssize_t scsiback_tpg_store_nexus(struct se_portal_group *se_tpg,
1751 					 const char *page,
1752 					 size_t count)
1753 {
1754 	struct scsiback_tpg *tpg = container_of(se_tpg,
1755 				struct scsiback_tpg, se_tpg);
1756 	struct scsiback_tport *tport_wwn = tpg->tport;
1757 	unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1758 	int ret;
1759 	/*
1760 	 * Shutdown the active I_T nexus if 'NULL' is passed..
1761 	 */
1762 	if (!strncmp(page, "NULL", 4)) {
1763 		ret = scsiback_drop_nexus(tpg);
1764 		return (!ret) ? count : ret;
1765 	}
1766 	/*
1767 	 * Otherwise make sure the passed virtual Initiator port WWN matches
1768 	 * the fabric protocol_id set in scsiback_make_tport(), and call
1769 	 * scsiback_make_nexus().
1770 	 */
1771 	if (strlen(page) >= VSCSI_NAMELEN) {
1772 		pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1773 			page, VSCSI_NAMELEN);
1774 		return -EINVAL;
1775 	}
1776 	snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1777 
1778 	ptr = strstr(i_port, "naa.");
1779 	if (ptr) {
1780 		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1781 			pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1782 				i_port, scsiback_dump_proto_id(tport_wwn));
1783 			return -EINVAL;
1784 		}
1785 		port_ptr = &i_port[0];
1786 		goto check_newline;
1787 	}
1788 	ptr = strstr(i_port, "fc.");
1789 	if (ptr) {
1790 		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1791 			pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1792 				i_port, scsiback_dump_proto_id(tport_wwn));
1793 			return -EINVAL;
1794 		}
1795 		port_ptr = &i_port[3]; /* Skip over "fc." */
1796 		goto check_newline;
1797 	}
1798 	ptr = strstr(i_port, "iqn.");
1799 	if (ptr) {
1800 		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1801 			pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1802 				i_port, scsiback_dump_proto_id(tport_wwn));
1803 			return -EINVAL;
1804 		}
1805 		port_ptr = &i_port[0];
1806 		goto check_newline;
1807 	}
1808 	pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1809 		i_port);
1810 	return -EINVAL;
1811 	/*
1812 	 * Clear any trailing newline for the NAA WWN
1813 	 */
1814 check_newline:
1815 	if (i_port[strlen(i_port) - 1] == '\n')
1816 		i_port[strlen(i_port) - 1] = '\0';
1817 
1818 	ret = scsiback_make_nexus(tpg, port_ptr);
1819 	if (ret < 0)
1820 		return ret;
1821 
1822 	return count;
1823 }
1824 
1825 TF_TPG_BASE_ATTR(scsiback, nexus, S_IRUGO | S_IWUSR);
1826 
1827 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1828 	&scsiback_tpg_nexus.attr,
1829 	NULL,
1830 };
1831 
1832 static ssize_t
scsiback_wwn_show_attr_version(struct target_fabric_configfs * tf,char * page)1833 scsiback_wwn_show_attr_version(struct target_fabric_configfs *tf,
1834 				char *page)
1835 {
1836 	return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1837 		UTS_RELEASE"\n",
1838 		VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1839 }
1840 
1841 TF_WWN_ATTR_RO(scsiback, version);
1842 
1843 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1844 	&scsiback_wwn_version.attr,
1845 	NULL,
1846 };
1847 
scsiback_get_fabric_name(void)1848 static char *scsiback_get_fabric_name(void)
1849 {
1850 	return "xen-pvscsi";
1851 }
1852 
scsiback_port_link(struct se_portal_group * se_tpg,struct se_lun * lun)1853 static int scsiback_port_link(struct se_portal_group *se_tpg,
1854 			       struct se_lun *lun)
1855 {
1856 	struct scsiback_tpg *tpg = container_of(se_tpg,
1857 				struct scsiback_tpg, se_tpg);
1858 
1859 	mutex_lock(&tpg->tv_tpg_mutex);
1860 	tpg->tv_tpg_port_count++;
1861 	mutex_unlock(&tpg->tv_tpg_mutex);
1862 
1863 	return 0;
1864 }
1865 
scsiback_port_unlink(struct se_portal_group * se_tpg,struct se_lun * lun)1866 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1867 				  struct se_lun *lun)
1868 {
1869 	struct scsiback_tpg *tpg = container_of(se_tpg,
1870 				struct scsiback_tpg, se_tpg);
1871 
1872 	mutex_lock(&tpg->tv_tpg_mutex);
1873 	tpg->tv_tpg_port_count--;
1874 	mutex_unlock(&tpg->tv_tpg_mutex);
1875 }
1876 
1877 static struct se_portal_group *
scsiback_make_tpg(struct se_wwn * wwn,struct config_group * group,const char * name)1878 scsiback_make_tpg(struct se_wwn *wwn,
1879 		   struct config_group *group,
1880 		   const char *name)
1881 {
1882 	struct scsiback_tport *tport = container_of(wwn,
1883 			struct scsiback_tport, tport_wwn);
1884 
1885 	struct scsiback_tpg *tpg;
1886 	u16 tpgt;
1887 	int ret;
1888 
1889 	if (strstr(name, "tpgt_") != name)
1890 		return ERR_PTR(-EINVAL);
1891 	ret = kstrtou16(name + 5, 10, &tpgt);
1892 	if (ret)
1893 		return ERR_PTR(ret);
1894 
1895 	tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1896 	if (!tpg)
1897 		return ERR_PTR(-ENOMEM);
1898 
1899 	mutex_init(&tpg->tv_tpg_mutex);
1900 	INIT_LIST_HEAD(&tpg->tv_tpg_list);
1901 	INIT_LIST_HEAD(&tpg->info_list);
1902 	tpg->tport = tport;
1903 	tpg->tport_tpgt = tpgt;
1904 
1905 	ret = core_tpg_register(&scsiback_fabric_configfs->tf_ops, wwn,
1906 				&tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
1907 	if (ret < 0) {
1908 		kfree(tpg);
1909 		return NULL;
1910 	}
1911 	mutex_lock(&scsiback_mutex);
1912 	list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1913 	mutex_unlock(&scsiback_mutex);
1914 
1915 	return &tpg->se_tpg;
1916 }
1917 
scsiback_drop_tpg(struct se_portal_group * se_tpg)1918 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1919 {
1920 	struct scsiback_tpg *tpg = container_of(se_tpg,
1921 				struct scsiback_tpg, se_tpg);
1922 
1923 	mutex_lock(&scsiback_mutex);
1924 	list_del(&tpg->tv_tpg_list);
1925 	mutex_unlock(&scsiback_mutex);
1926 	/*
1927 	 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1928 	 */
1929 	scsiback_drop_nexus(tpg);
1930 	/*
1931 	 * Deregister the se_tpg from TCM..
1932 	 */
1933 	core_tpg_deregister(se_tpg);
1934 	kfree(tpg);
1935 }
1936 
scsiback_check_true(struct se_portal_group * se_tpg)1937 static int scsiback_check_true(struct se_portal_group *se_tpg)
1938 {
1939 	return 1;
1940 }
1941 
scsiback_check_false(struct se_portal_group * se_tpg)1942 static int scsiback_check_false(struct se_portal_group *se_tpg)
1943 {
1944 	return 0;
1945 }
1946 
1947 static struct target_core_fabric_ops scsiback_ops = {
1948 	.get_fabric_name		= scsiback_get_fabric_name,
1949 	.get_fabric_proto_ident		= scsiback_get_fabric_proto_ident,
1950 	.tpg_get_wwn			= scsiback_get_fabric_wwn,
1951 	.tpg_get_tag			= scsiback_get_tag,
1952 	.tpg_get_default_depth		= scsiback_get_default_depth,
1953 	.tpg_get_pr_transport_id	= scsiback_get_pr_transport_id,
1954 	.tpg_get_pr_transport_id_len	= scsiback_get_pr_transport_id_len,
1955 	.tpg_parse_pr_out_transport_id	= scsiback_parse_pr_out_transport_id,
1956 	.tpg_check_demo_mode		= scsiback_check_true,
1957 	.tpg_check_demo_mode_cache	= scsiback_check_true,
1958 	.tpg_check_demo_mode_write_protect = scsiback_check_false,
1959 	.tpg_check_prod_mode_write_protect = scsiback_check_false,
1960 	.tpg_alloc_fabric_acl		= scsiback_alloc_fabric_acl,
1961 	.tpg_release_fabric_acl		= scsiback_release_fabric_acl,
1962 	.tpg_get_inst_index		= scsiback_tpg_get_inst_index,
1963 	.check_stop_free		= scsiback_check_stop_free,
1964 	.release_cmd			= scsiback_release_cmd,
1965 	.put_session			= NULL,
1966 	.shutdown_session		= scsiback_shutdown_session,
1967 	.close_session			= scsiback_close_session,
1968 	.sess_get_index			= scsiback_sess_get_index,
1969 	.sess_get_initiator_sid		= NULL,
1970 	.write_pending			= scsiback_write_pending,
1971 	.write_pending_status		= scsiback_write_pending_status,
1972 	.set_default_node_attributes	= scsiback_set_default_node_attrs,
1973 	.get_task_tag			= scsiback_get_task_tag,
1974 	.get_cmd_state			= scsiback_get_cmd_state,
1975 	.queue_data_in			= scsiback_queue_data_in,
1976 	.queue_status			= scsiback_queue_status,
1977 	.queue_tm_rsp			= scsiback_queue_tm_rsp,
1978 	.aborted_task			= scsiback_aborted_task,
1979 	/*
1980 	 * Setup callers for generic logic in target_core_fabric_configfs.c
1981 	 */
1982 	.fabric_make_wwn		= scsiback_make_tport,
1983 	.fabric_drop_wwn		= scsiback_drop_tport,
1984 	.fabric_make_tpg		= scsiback_make_tpg,
1985 	.fabric_drop_tpg		= scsiback_drop_tpg,
1986 	.fabric_post_link		= scsiback_port_link,
1987 	.fabric_pre_unlink		= scsiback_port_unlink,
1988 	.fabric_make_np			= NULL,
1989 	.fabric_drop_np			= NULL,
1990 #if 0
1991 	.fabric_make_nodeacl		= scsiback_make_nodeacl,
1992 	.fabric_drop_nodeacl		= scsiback_drop_nodeacl,
1993 #endif
1994 };
1995 
scsiback_register_configfs(void)1996 static int scsiback_register_configfs(void)
1997 {
1998 	struct target_fabric_configfs *fabric;
1999 	int ret;
2000 
2001 	pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
2002 		 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
2003 	/*
2004 	 * Register the top level struct config_item_type with TCM core
2005 	 */
2006 	fabric = target_fabric_configfs_init(THIS_MODULE, "xen-pvscsi");
2007 	if (IS_ERR(fabric))
2008 		return PTR_ERR(fabric);
2009 
2010 	/*
2011 	 * Setup fabric->tf_ops from our local scsiback_ops
2012 	 */
2013 	fabric->tf_ops = scsiback_ops;
2014 	/*
2015 	 * Setup default attribute lists for various fabric->tf_cit_tmpl
2016 	 */
2017 	fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = scsiback_wwn_attrs;
2018 	fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = scsiback_tpg_attrs;
2019 	fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
2020 	fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = scsiback_param_attrs;
2021 	fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
2022 	fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
2023 	fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
2024 	fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
2025 	fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
2026 	/*
2027 	 * Register the fabric for use within TCM
2028 	 */
2029 	ret = target_fabric_configfs_register(fabric);
2030 	if (ret < 0) {
2031 		target_fabric_configfs_free(fabric);
2032 		return ret;
2033 	}
2034 	/*
2035 	 * Setup our local pointer to *fabric
2036 	 */
2037 	scsiback_fabric_configfs = fabric;
2038 	pr_debug("xen-pvscsi: Set fabric -> scsiback_fabric_configfs\n");
2039 	return 0;
2040 };
2041 
scsiback_deregister_configfs(void)2042 static void scsiback_deregister_configfs(void)
2043 {
2044 	if (!scsiback_fabric_configfs)
2045 		return;
2046 
2047 	target_fabric_configfs_deregister(scsiback_fabric_configfs);
2048 	scsiback_fabric_configfs = NULL;
2049 	pr_debug("xen-pvscsi: Cleared scsiback_fabric_configfs\n");
2050 };
2051 
2052 static const struct xenbus_device_id scsiback_ids[] = {
2053 	{ "vscsi" },
2054 	{ "" }
2055 };
2056 
2057 static struct xenbus_driver scsiback_driver = {
2058 	.ids			= scsiback_ids,
2059 	.probe			= scsiback_probe,
2060 	.remove			= scsiback_remove,
2061 	.otherend_changed	= scsiback_frontend_changed
2062 };
2063 
scsiback_init_pend(void * p)2064 static void scsiback_init_pend(void *p)
2065 {
2066 	struct vscsibk_pend *pend = p;
2067 	int i;
2068 
2069 	memset(pend, 0, sizeof(*pend));
2070 	for (i = 0; i < VSCSI_MAX_GRANTS; i++)
2071 		pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
2072 }
2073 
scsiback_init(void)2074 static int __init scsiback_init(void)
2075 {
2076 	int ret;
2077 
2078 	if (!xen_domain())
2079 		return -ENODEV;
2080 
2081 	scsiback_cachep = kmem_cache_create("vscsiif_cache",
2082 		sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
2083 	if (!scsiback_cachep)
2084 		return -ENOMEM;
2085 
2086 	ret = xenbus_register_backend(&scsiback_driver);
2087 	if (ret)
2088 		goto out_cache_destroy;
2089 
2090 	ret = scsiback_register_configfs();
2091 	if (ret)
2092 		goto out_unregister_xenbus;
2093 
2094 	return 0;
2095 
2096 out_unregister_xenbus:
2097 	xenbus_unregister_driver(&scsiback_driver);
2098 out_cache_destroy:
2099 	kmem_cache_destroy(scsiback_cachep);
2100 	pr_err("xen-pvscsi: %s: error %d\n", __func__, ret);
2101 	return ret;
2102 }
2103 
scsiback_exit(void)2104 static void __exit scsiback_exit(void)
2105 {
2106 	struct page *page;
2107 
2108 	while (free_pages_num) {
2109 		if (get_free_page(&page))
2110 			BUG();
2111 		free_xenballooned_pages(1, &page);
2112 	}
2113 	scsiback_deregister_configfs();
2114 	xenbus_unregister_driver(&scsiback_driver);
2115 	kmem_cache_destroy(scsiback_cachep);
2116 }
2117 
2118 module_init(scsiback_init);
2119 module_exit(scsiback_exit);
2120 
2121 MODULE_DESCRIPTION("Xen SCSI backend driver");
2122 MODULE_LICENSE("Dual BSD/GPL");
2123 MODULE_ALIAS("xen-backend:vscsi");
2124 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
2125