xref: /openbmc/linux/drivers/scsi/ibmvscsi/ibmvscsi.c (revision 4800cd83)
1 /* ------------------------------------------------------------
2  * ibmvscsi.c
3  * (C) Copyright IBM Corporation 1994, 2004
4  * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
5  *          Santiago Leon (santil@us.ibm.com)
6  *          Dave Boutcher (sleddog@us.ibm.com)
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
21  * USA
22  *
23  * ------------------------------------------------------------
24  * Emulation of a SCSI host adapter for Virtual I/O devices
25  *
26  * This driver supports the SCSI adapter implemented by the IBM
27  * Power5 firmware.  That SCSI adapter is not a physical adapter,
28  * but allows Linux SCSI peripheral drivers to directly
29  * access devices in another logical partition on the physical system.
30  *
31  * The virtual adapter(s) are present in the open firmware device
32  * tree just like real adapters.
33  *
34  * One of the capabilities provided on these systems is the ability
35  * to DMA between partitions.  The architecture states that for VSCSI,
36  * the server side is allowed to DMA to and from the client.  The client
37  * is never trusted to DMA to or from the server directly.
38  *
39  * Messages are sent between partitions on a "Command/Response Queue"
40  * (CRQ), which is just a buffer of 16 byte entries in the receiver's
41  * Senders cannot access the buffer directly, but send messages by
42  * making a hypervisor call and passing in the 16 bytes.  The hypervisor
43  * puts the message in the next 16 byte space in round-robin fashion,
44  * turns on the high order bit of the message (the valid bit), and
45  * generates an interrupt to the receiver (if interrupts are turned on.)
46  * The receiver just turns off the valid bit when they have copied out
47  * the message.
48  *
49  * The VSCSI client builds a SCSI Remote Protocol (SRP) Information Unit
50  * (IU) (as defined in the T10 standard available at www.t10.org), gets
51  * a DMA address for the message, and sends it to the server as the
52  * payload of a CRQ message.  The server DMAs the SRP IU and processes it,
53  * including doing any additional data transfers.  When it is done, it
54  * DMAs the SRP response back to the same address as the request came from,
55  * and sends a CRQ message back to inform the client that the request has
56  * completed.
57  *
58  * Note that some of the underlying infrastructure is different between
59  * machines conforming to the "RS/6000 Platform Architecture" (RPA) and
60  * the older iSeries hypervisor models.  To support both, some low level
61  * routines have been broken out into rpa_vscsi.c and iseries_vscsi.c.
62  * The Makefile should pick one, not two, not zero, of these.
63  *
64  * TODO: This is currently pretty tied to the IBM i/pSeries hypervisor
65  * interfaces.  It would be really nice to abstract this above an RDMA
66  * layer.
67  */
68 
69 #include <linux/module.h>
70 #include <linux/moduleparam.h>
71 #include <linux/dma-mapping.h>
72 #include <linux/delay.h>
73 #include <linux/slab.h>
74 #include <linux/of.h>
75 #include <linux/pm.h>
76 #include <linux/kthread.h>
77 #include <asm/firmware.h>
78 #include <asm/vio.h>
79 #include <scsi/scsi.h>
80 #include <scsi/scsi_cmnd.h>
81 #include <scsi/scsi_host.h>
82 #include <scsi/scsi_device.h>
83 #include <scsi/scsi_transport_srp.h>
84 #include "ibmvscsi.h"
85 
86 /* The values below are somewhat arbitrary default values, but
87  * OS/400 will use 3 busses (disks, CDs, tapes, I think.)
88  * Note that there are 3 bits of channel value, 6 bits of id, and
89  * 5 bits of LUN.
90  */
91 static int max_id = 64;
92 static int max_channel = 3;
93 static int init_timeout = 300;
94 static int login_timeout = 60;
95 static int info_timeout = 30;
96 static int abort_timeout = 60;
97 static int reset_timeout = 60;
98 static int max_requests = IBMVSCSI_MAX_REQUESTS_DEFAULT;
99 static int max_events = IBMVSCSI_MAX_REQUESTS_DEFAULT + 2;
100 static int fast_fail = 1;
101 static int client_reserve = 1;
102 
103 static struct scsi_transport_template *ibmvscsi_transport_template;
104 
105 #define IBMVSCSI_VERSION "1.5.9"
106 
107 static struct ibmvscsi_ops *ibmvscsi_ops;
108 
109 MODULE_DESCRIPTION("IBM Virtual SCSI");
110 MODULE_AUTHOR("Dave Boutcher");
111 MODULE_LICENSE("GPL");
112 MODULE_VERSION(IBMVSCSI_VERSION);
113 
114 module_param_named(max_id, max_id, int, S_IRUGO | S_IWUSR);
115 MODULE_PARM_DESC(max_id, "Largest ID value for each channel");
116 module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
117 MODULE_PARM_DESC(max_channel, "Largest channel value");
118 module_param_named(init_timeout, init_timeout, int, S_IRUGO | S_IWUSR);
119 MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
120 module_param_named(max_requests, max_requests, int, S_IRUGO);
121 MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
122 module_param_named(fast_fail, fast_fail, int, S_IRUGO | S_IWUSR);
123 MODULE_PARM_DESC(fast_fail, "Enable fast fail. [Default=1]");
124 module_param_named(client_reserve, client_reserve, int, S_IRUGO );
125 MODULE_PARM_DESC(client_reserve, "Attempt client managed reserve/release");
126 
127 /* ------------------------------------------------------------
128  * Routines for the event pool and event structs
129  */
130 /**
131  * initialize_event_pool: - Allocates and initializes the event pool for a host
132  * @pool:	event_pool to be initialized
133  * @size:	Number of events in pool
134  * @hostdata:	ibmvscsi_host_data who owns the event pool
135  *
136  * Returns zero on success.
137 */
138 static int initialize_event_pool(struct event_pool *pool,
139 				 int size, struct ibmvscsi_host_data *hostdata)
140 {
141 	int i;
142 
143 	pool->size = size;
144 	pool->next = 0;
145 	pool->events = kcalloc(pool->size, sizeof(*pool->events), GFP_KERNEL);
146 	if (!pool->events)
147 		return -ENOMEM;
148 
149 	pool->iu_storage =
150 	    dma_alloc_coherent(hostdata->dev,
151 			       pool->size * sizeof(*pool->iu_storage),
152 			       &pool->iu_token, 0);
153 	if (!pool->iu_storage) {
154 		kfree(pool->events);
155 		return -ENOMEM;
156 	}
157 
158 	for (i = 0; i < pool->size; ++i) {
159 		struct srp_event_struct *evt = &pool->events[i];
160 		memset(&evt->crq, 0x00, sizeof(evt->crq));
161 		atomic_set(&evt->free, 1);
162 		evt->crq.valid = 0x80;
163 		evt->crq.IU_length = sizeof(*evt->xfer_iu);
164 		evt->crq.IU_data_ptr = pool->iu_token +
165 			sizeof(*evt->xfer_iu) * i;
166 		evt->xfer_iu = pool->iu_storage + i;
167 		evt->hostdata = hostdata;
168 		evt->ext_list = NULL;
169 		evt->ext_list_token = 0;
170 	}
171 
172 	return 0;
173 }
174 
175 /**
176  * release_event_pool: - Frees memory of an event pool of a host
177  * @pool:	event_pool to be released
178  * @hostdata:	ibmvscsi_host_data who owns the even pool
179  *
180  * Returns zero on success.
181 */
182 static void release_event_pool(struct event_pool *pool,
183 			       struct ibmvscsi_host_data *hostdata)
184 {
185 	int i, in_use = 0;
186 	for (i = 0; i < pool->size; ++i) {
187 		if (atomic_read(&pool->events[i].free) != 1)
188 			++in_use;
189 		if (pool->events[i].ext_list) {
190 			dma_free_coherent(hostdata->dev,
191 				  SG_ALL * sizeof(struct srp_direct_buf),
192 				  pool->events[i].ext_list,
193 				  pool->events[i].ext_list_token);
194 		}
195 	}
196 	if (in_use)
197 		dev_warn(hostdata->dev, "releasing event pool with %d "
198 			 "events still in use?\n", in_use);
199 	kfree(pool->events);
200 	dma_free_coherent(hostdata->dev,
201 			  pool->size * sizeof(*pool->iu_storage),
202 			  pool->iu_storage, pool->iu_token);
203 }
204 
205 /**
206  * valid_event_struct: - Determines if event is valid.
207  * @pool:	event_pool that contains the event
208  * @evt:	srp_event_struct to be checked for validity
209  *
210  * Returns zero if event is invalid, one otherwise.
211 */
212 static int valid_event_struct(struct event_pool *pool,
213 				struct srp_event_struct *evt)
214 {
215 	int index = evt - pool->events;
216 	if (index < 0 || index >= pool->size)	/* outside of bounds */
217 		return 0;
218 	if (evt != pool->events + index)	/* unaligned */
219 		return 0;
220 	return 1;
221 }
222 
223 /**
224  * ibmvscsi_free-event_struct: - Changes status of event to "free"
225  * @pool:	event_pool that contains the event
226  * @evt:	srp_event_struct to be modified
227  *
228 */
229 static void free_event_struct(struct event_pool *pool,
230 				       struct srp_event_struct *evt)
231 {
232 	if (!valid_event_struct(pool, evt)) {
233 		dev_err(evt->hostdata->dev, "Freeing invalid event_struct %p "
234 			"(not in pool %p)\n", evt, pool->events);
235 		return;
236 	}
237 	if (atomic_inc_return(&evt->free) != 1) {
238 		dev_err(evt->hostdata->dev, "Freeing event_struct %p "
239 			"which is not in use!\n", evt);
240 		return;
241 	}
242 }
243 
244 /**
245  * get_evt_struct: - Gets the next free event in pool
246  * @pool:	event_pool that contains the events to be searched
247  *
248  * Returns the next event in "free" state, and NULL if none are free.
249  * Note that no synchronization is done here, we assume the host_lock
250  * will syncrhonze things.
251 */
252 static struct srp_event_struct *get_event_struct(struct event_pool *pool)
253 {
254 	int i;
255 	int poolsize = pool->size;
256 	int offset = pool->next;
257 
258 	for (i = 0; i < poolsize; i++) {
259 		offset = (offset + 1) % poolsize;
260 		if (!atomic_dec_if_positive(&pool->events[offset].free)) {
261 			pool->next = offset;
262 			return &pool->events[offset];
263 		}
264 	}
265 
266 	printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
267 	return NULL;
268 }
269 
270 /**
271  * init_event_struct: Initialize fields in an event struct that are always
272  *                    required.
273  * @evt:        The event
274  * @done:       Routine to call when the event is responded to
275  * @format:     SRP or MAD format
276  * @timeout:    timeout value set in the CRQ
277  */
278 static void init_event_struct(struct srp_event_struct *evt_struct,
279 			      void (*done) (struct srp_event_struct *),
280 			      u8 format,
281 			      int timeout)
282 {
283 	evt_struct->cmnd = NULL;
284 	evt_struct->cmnd_done = NULL;
285 	evt_struct->sync_srp = NULL;
286 	evt_struct->crq.format = format;
287 	evt_struct->crq.timeout = timeout;
288 	evt_struct->done = done;
289 }
290 
291 /* ------------------------------------------------------------
292  * Routines for receiving SCSI responses from the hosting partition
293  */
294 
295 /**
296  * set_srp_direction: Set the fields in the srp related to data
297  *     direction and number of buffers based on the direction in
298  *     the scsi_cmnd and the number of buffers
299  */
300 static void set_srp_direction(struct scsi_cmnd *cmd,
301 			      struct srp_cmd *srp_cmd,
302 			      int numbuf)
303 {
304 	u8 fmt;
305 
306 	if (numbuf == 0)
307 		return;
308 
309 	if (numbuf == 1)
310 		fmt = SRP_DATA_DESC_DIRECT;
311 	else {
312 		fmt = SRP_DATA_DESC_INDIRECT;
313 		numbuf = min(numbuf, MAX_INDIRECT_BUFS);
314 
315 		if (cmd->sc_data_direction == DMA_TO_DEVICE)
316 			srp_cmd->data_out_desc_cnt = numbuf;
317 		else
318 			srp_cmd->data_in_desc_cnt = numbuf;
319 	}
320 
321 	if (cmd->sc_data_direction == DMA_TO_DEVICE)
322 		srp_cmd->buf_fmt = fmt << 4;
323 	else
324 		srp_cmd->buf_fmt = fmt;
325 }
326 
327 /**
328  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
329  * @cmd:	srp_cmd whose additional_data member will be unmapped
330  * @dev:	device for which the memory is mapped
331  *
332 */
333 static void unmap_cmd_data(struct srp_cmd *cmd,
334 			   struct srp_event_struct *evt_struct,
335 			   struct device *dev)
336 {
337 	u8 out_fmt, in_fmt;
338 
339 	out_fmt = cmd->buf_fmt >> 4;
340 	in_fmt = cmd->buf_fmt & ((1U << 4) - 1);
341 
342 	if (out_fmt == SRP_NO_DATA_DESC && in_fmt == SRP_NO_DATA_DESC)
343 		return;
344 
345 	if (evt_struct->cmnd)
346 		scsi_dma_unmap(evt_struct->cmnd);
347 }
348 
349 static int map_sg_list(struct scsi_cmnd *cmd, int nseg,
350 		       struct srp_direct_buf *md)
351 {
352 	int i;
353 	struct scatterlist *sg;
354 	u64 total_length = 0;
355 
356 	scsi_for_each_sg(cmd, sg, nseg, i) {
357 		struct srp_direct_buf *descr = md + i;
358 		descr->va = sg_dma_address(sg);
359 		descr->len = sg_dma_len(sg);
360 		descr->key = 0;
361 		total_length += sg_dma_len(sg);
362  	}
363 	return total_length;
364 }
365 
366 /**
367  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
368  * @cmd:	Scsi_Cmnd with the scatterlist
369  * @srp_cmd:	srp_cmd that contains the memory descriptor
370  * @dev:	device for which to map dma memory
371  *
372  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
373  * Returns 1 on success.
374 */
375 static int map_sg_data(struct scsi_cmnd *cmd,
376 		       struct srp_event_struct *evt_struct,
377 		       struct srp_cmd *srp_cmd, struct device *dev)
378 {
379 
380 	int sg_mapped;
381 	u64 total_length = 0;
382 	struct srp_direct_buf *data =
383 		(struct srp_direct_buf *) srp_cmd->add_data;
384 	struct srp_indirect_buf *indirect =
385 		(struct srp_indirect_buf *) data;
386 
387 	sg_mapped = scsi_dma_map(cmd);
388 	if (!sg_mapped)
389 		return 1;
390 	else if (sg_mapped < 0)
391 		return 0;
392 
393 	set_srp_direction(cmd, srp_cmd, sg_mapped);
394 
395 	/* special case; we can use a single direct descriptor */
396 	if (sg_mapped == 1) {
397 		map_sg_list(cmd, sg_mapped, data);
398 		return 1;
399 	}
400 
401 	indirect->table_desc.va = 0;
402 	indirect->table_desc.len = sg_mapped * sizeof(struct srp_direct_buf);
403 	indirect->table_desc.key = 0;
404 
405 	if (sg_mapped <= MAX_INDIRECT_BUFS) {
406 		total_length = map_sg_list(cmd, sg_mapped,
407 					   &indirect->desc_list[0]);
408 		indirect->len = total_length;
409 		return 1;
410 	}
411 
412 	/* get indirect table */
413 	if (!evt_struct->ext_list) {
414 		evt_struct->ext_list = (struct srp_direct_buf *)
415 			dma_alloc_coherent(dev,
416 					   SG_ALL * sizeof(struct srp_direct_buf),
417 					   &evt_struct->ext_list_token, 0);
418 		if (!evt_struct->ext_list) {
419 			if (!firmware_has_feature(FW_FEATURE_CMO))
420 				sdev_printk(KERN_ERR, cmd->device,
421 				            "Can't allocate memory "
422 				            "for indirect table\n");
423 			scsi_dma_unmap(cmd);
424 			return 0;
425 		}
426 	}
427 
428 	total_length = map_sg_list(cmd, sg_mapped, evt_struct->ext_list);
429 
430 	indirect->len = total_length;
431 	indirect->table_desc.va = evt_struct->ext_list_token;
432 	indirect->table_desc.len = sg_mapped * sizeof(indirect->desc_list[0]);
433 	memcpy(indirect->desc_list, evt_struct->ext_list,
434 	       MAX_INDIRECT_BUFS * sizeof(struct srp_direct_buf));
435  	return 1;
436 }
437 
438 /**
439  * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
440  * @cmd:	struct scsi_cmnd with the memory to be mapped
441  * @srp_cmd:	srp_cmd that contains the memory descriptor
442  * @dev:	dma device for which to map dma memory
443  *
444  * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds
445  * Returns 1 on success.
446 */
447 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
448 				struct srp_event_struct *evt_struct,
449 				struct srp_cmd *srp_cmd, struct device *dev)
450 {
451 	switch (cmd->sc_data_direction) {
452 	case DMA_FROM_DEVICE:
453 	case DMA_TO_DEVICE:
454 		break;
455 	case DMA_NONE:
456 		return 1;
457 	case DMA_BIDIRECTIONAL:
458 		sdev_printk(KERN_ERR, cmd->device,
459 			    "Can't map DMA_BIDIRECTIONAL to read/write\n");
460 		return 0;
461 	default:
462 		sdev_printk(KERN_ERR, cmd->device,
463 			    "Unknown data direction 0x%02x; can't map!\n",
464 			    cmd->sc_data_direction);
465 		return 0;
466 	}
467 
468 	return map_sg_data(cmd, evt_struct, srp_cmd, dev);
469 }
470 
471 /**
472  * purge_requests: Our virtual adapter just shut down.  purge any sent requests
473  * @hostdata:    the adapter
474  */
475 static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)
476 {
477 	struct srp_event_struct *evt;
478 	unsigned long flags;
479 
480 	spin_lock_irqsave(hostdata->host->host_lock, flags);
481 	while (!list_empty(&hostdata->sent)) {
482 		evt = list_first_entry(&hostdata->sent, struct srp_event_struct, list);
483 		list_del(&evt->list);
484 		del_timer(&evt->timer);
485 
486 		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
487 		if (evt->cmnd) {
488 			evt->cmnd->result = (error_code << 16);
489 			unmap_cmd_data(&evt->iu.srp.cmd, evt,
490 				       evt->hostdata->dev);
491 			if (evt->cmnd_done)
492 				evt->cmnd_done(evt->cmnd);
493 		} else if (evt->done)
494 			evt->done(evt);
495 		free_event_struct(&evt->hostdata->pool, evt);
496 		spin_lock_irqsave(hostdata->host->host_lock, flags);
497 	}
498 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
499 }
500 
501 /**
502  * ibmvscsi_reset_host - Reset the connection to the server
503  * @hostdata:	struct ibmvscsi_host_data to reset
504 */
505 static void ibmvscsi_reset_host(struct ibmvscsi_host_data *hostdata)
506 {
507 	scsi_block_requests(hostdata->host);
508 	atomic_set(&hostdata->request_limit, 0);
509 
510 	purge_requests(hostdata, DID_ERROR);
511 	hostdata->reset_crq = 1;
512 	wake_up(&hostdata->work_wait_q);
513 }
514 
515 /**
516  * ibmvscsi_timeout - Internal command timeout handler
517  * @evt_struct:	struct srp_event_struct that timed out
518  *
519  * Called when an internally generated command times out
520 */
521 static void ibmvscsi_timeout(struct srp_event_struct *evt_struct)
522 {
523 	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
524 
525 	dev_err(hostdata->dev, "Command timed out (%x). Resetting connection\n",
526 		evt_struct->iu.srp.cmd.opcode);
527 
528 	ibmvscsi_reset_host(hostdata);
529 }
530 
531 
532 /* ------------------------------------------------------------
533  * Routines for sending and receiving SRPs
534  */
535 /**
536  * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
537  * @evt_struct:	evt_struct to be sent
538  * @hostdata:	ibmvscsi_host_data of host
539  * @timeout:	timeout in seconds - 0 means do not time command
540  *
541  * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
542  * Note that this routine assumes that host_lock is held for synchronization
543 */
544 static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
545 				   struct ibmvscsi_host_data *hostdata,
546 				   unsigned long timeout)
547 {
548 	u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
549 	int request_status = 0;
550 	int rc;
551 	int srp_req = 0;
552 
553 	/* If we have exhausted our request limit, just fail this request,
554 	 * unless it is for a reset or abort.
555 	 * Note that there are rare cases involving driver generated requests
556 	 * (such as task management requests) that the mid layer may think we
557 	 * can handle more requests (can_queue) when we actually can't
558 	 */
559 	if (evt_struct->crq.format == VIOSRP_SRP_FORMAT) {
560 		srp_req = 1;
561 		request_status =
562 			atomic_dec_if_positive(&hostdata->request_limit);
563 		/* If request limit was -1 when we started, it is now even
564 		 * less than that
565 		 */
566 		if (request_status < -1)
567 			goto send_error;
568 		/* Otherwise, we may have run out of requests. */
569 		/* If request limit was 0 when we started the adapter is in the
570 		 * process of performing a login with the server adapter, or
571 		 * we may have run out of requests.
572 		 */
573 		else if (request_status == -1 &&
574 		         evt_struct->iu.srp.login_req.opcode != SRP_LOGIN_REQ)
575 			goto send_busy;
576 		/* Abort and reset calls should make it through.
577 		 * Nothing except abort and reset should use the last two
578 		 * slots unless we had two or less to begin with.
579 		 */
580 		else if (request_status < 2 &&
581 		         evt_struct->iu.srp.cmd.opcode != SRP_TSK_MGMT) {
582 			/* In the case that we have less than two requests
583 			 * available, check the server limit as a combination
584 			 * of the request limit and the number of requests
585 			 * in-flight (the size of the send list).  If the
586 			 * server limit is greater than 2, return busy so
587 			 * that the last two are reserved for reset and abort.
588 			 */
589 			int server_limit = request_status;
590 			struct srp_event_struct *tmp_evt;
591 
592 			list_for_each_entry(tmp_evt, &hostdata->sent, list) {
593 				server_limit++;
594 			}
595 
596 			if (server_limit > 2)
597 				goto send_busy;
598 		}
599 	}
600 
601 	/* Copy the IU into the transfer area */
602 	*evt_struct->xfer_iu = evt_struct->iu;
603 	evt_struct->xfer_iu->srp.rsp.tag = (u64)evt_struct;
604 
605 	/* Add this to the sent list.  We need to do this
606 	 * before we actually send
607 	 * in case it comes back REALLY fast
608 	 */
609 	list_add_tail(&evt_struct->list, &hostdata->sent);
610 
611 	init_timer(&evt_struct->timer);
612 	if (timeout) {
613 		evt_struct->timer.data = (unsigned long) evt_struct;
614 		evt_struct->timer.expires = jiffies + (timeout * HZ);
615 		evt_struct->timer.function = (void (*)(unsigned long))ibmvscsi_timeout;
616 		add_timer(&evt_struct->timer);
617 	}
618 
619 	if ((rc =
620 	     ibmvscsi_ops->send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
621 		list_del(&evt_struct->list);
622 		del_timer(&evt_struct->timer);
623 
624 		/* If send_crq returns H_CLOSED, return SCSI_MLQUEUE_HOST_BUSY.
625 		 * Firmware will send a CRQ with a transport event (0xFF) to
626 		 * tell this client what has happened to the transport.  This
627 		 * will be handled in ibmvscsi_handle_crq()
628 		 */
629 		if (rc == H_CLOSED) {
630 			dev_warn(hostdata->dev, "send warning. "
631 			         "Receive queue closed, will retry.\n");
632 			goto send_busy;
633 		}
634 		dev_err(hostdata->dev, "send error %d\n", rc);
635 		if (srp_req)
636 			atomic_inc(&hostdata->request_limit);
637 		goto send_error;
638 	}
639 
640 	return 0;
641 
642  send_busy:
643 	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
644 
645 	free_event_struct(&hostdata->pool, evt_struct);
646 	if (srp_req && request_status != -1)
647 		atomic_inc(&hostdata->request_limit);
648 	return SCSI_MLQUEUE_HOST_BUSY;
649 
650  send_error:
651 	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
652 
653 	if (evt_struct->cmnd != NULL) {
654 		evt_struct->cmnd->result = DID_ERROR << 16;
655 		evt_struct->cmnd_done(evt_struct->cmnd);
656 	} else if (evt_struct->done)
657 		evt_struct->done(evt_struct);
658 
659 	free_event_struct(&hostdata->pool, evt_struct);
660 	return 0;
661 }
662 
663 /**
664  * handle_cmd_rsp: -  Handle responses from commands
665  * @evt_struct:	srp_event_struct to be handled
666  *
667  * Used as a callback by when sending scsi cmds.
668  * Gets called by ibmvscsi_handle_crq()
669 */
670 static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
671 {
672 	struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
673 	struct scsi_cmnd *cmnd = evt_struct->cmnd;
674 
675 	if (unlikely(rsp->opcode != SRP_RSP)) {
676 		if (printk_ratelimit())
677 			dev_warn(evt_struct->hostdata->dev,
678 				 "bad SRP RSP type %d\n", rsp->opcode);
679 	}
680 
681 	if (cmnd) {
682 		cmnd->result |= rsp->status;
683 		if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
684 			memcpy(cmnd->sense_buffer,
685 			       rsp->data,
686 			       rsp->sense_data_len);
687 		unmap_cmd_data(&evt_struct->iu.srp.cmd,
688 			       evt_struct,
689 			       evt_struct->hostdata->dev);
690 
691 		if (rsp->flags & SRP_RSP_FLAG_DOOVER)
692 			scsi_set_resid(cmnd, rsp->data_out_res_cnt);
693 		else if (rsp->flags & SRP_RSP_FLAG_DIOVER)
694 			scsi_set_resid(cmnd, rsp->data_in_res_cnt);
695 	}
696 
697 	if (evt_struct->cmnd_done)
698 		evt_struct->cmnd_done(cmnd);
699 }
700 
701 /**
702  * lun_from_dev: - Returns the lun of the scsi device
703  * @dev:	struct scsi_device
704  *
705 */
706 static inline u16 lun_from_dev(struct scsi_device *dev)
707 {
708 	return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
709 }
710 
711 /**
712  * ibmvscsi_queue: - The queuecommand function of the scsi template
713  * @cmd:	struct scsi_cmnd to be executed
714  * @done:	Callback function to be called when cmd is completed
715 */
716 static int ibmvscsi_queuecommand_lck(struct scsi_cmnd *cmnd,
717 				 void (*done) (struct scsi_cmnd *))
718 {
719 	struct srp_cmd *srp_cmd;
720 	struct srp_event_struct *evt_struct;
721 	struct srp_indirect_buf *indirect;
722 	struct ibmvscsi_host_data *hostdata = shost_priv(cmnd->device->host);
723 	u16 lun = lun_from_dev(cmnd->device);
724 	u8 out_fmt, in_fmt;
725 
726 	cmnd->result = (DID_OK << 16);
727 	evt_struct = get_event_struct(&hostdata->pool);
728 	if (!evt_struct)
729 		return SCSI_MLQUEUE_HOST_BUSY;
730 
731 	/* Set up the actual SRP IU */
732 	srp_cmd = &evt_struct->iu.srp.cmd;
733 	memset(srp_cmd, 0x00, SRP_MAX_IU_LEN);
734 	srp_cmd->opcode = SRP_CMD;
735 	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(srp_cmd->cdb));
736 	srp_cmd->lun = ((u64) lun) << 48;
737 
738 	if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
739 		if (!firmware_has_feature(FW_FEATURE_CMO))
740 			sdev_printk(KERN_ERR, cmnd->device,
741 			            "couldn't convert cmd to srp_cmd\n");
742 		free_event_struct(&hostdata->pool, evt_struct);
743 		return SCSI_MLQUEUE_HOST_BUSY;
744 	}
745 
746 	init_event_struct(evt_struct,
747 			  handle_cmd_rsp,
748 			  VIOSRP_SRP_FORMAT,
749 			  cmnd->request->timeout/HZ);
750 
751 	evt_struct->cmnd = cmnd;
752 	evt_struct->cmnd_done = done;
753 
754 	/* Fix up dma address of the buffer itself */
755 	indirect = (struct srp_indirect_buf *) srp_cmd->add_data;
756 	out_fmt = srp_cmd->buf_fmt >> 4;
757 	in_fmt = srp_cmd->buf_fmt & ((1U << 4) - 1);
758 	if ((in_fmt == SRP_DATA_DESC_INDIRECT ||
759 	     out_fmt == SRP_DATA_DESC_INDIRECT) &&
760 	    indirect->table_desc.va == 0) {
761 		indirect->table_desc.va = evt_struct->crq.IU_data_ptr +
762 			offsetof(struct srp_cmd, add_data) +
763 			offsetof(struct srp_indirect_buf, desc_list);
764 	}
765 
766 	return ibmvscsi_send_srp_event(evt_struct, hostdata, 0);
767 }
768 
769 static DEF_SCSI_QCMD(ibmvscsi_queuecommand)
770 
771 /* ------------------------------------------------------------
772  * Routines for driver initialization
773  */
774 
775 /**
776  * map_persist_bufs: - Pre-map persistent data for adapter logins
777  * @hostdata:   ibmvscsi_host_data of host
778  *
779  * Map the capabilities and adapter info DMA buffers to avoid runtime failures.
780  * Return 1 on error, 0 on success.
781  */
782 static int map_persist_bufs(struct ibmvscsi_host_data *hostdata)
783 {
784 
785 	hostdata->caps_addr = dma_map_single(hostdata->dev, &hostdata->caps,
786 					     sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
787 
788 	if (dma_mapping_error(hostdata->dev, hostdata->caps_addr)) {
789 		dev_err(hostdata->dev, "Unable to map capabilities buffer!\n");
790 		return 1;
791 	}
792 
793 	hostdata->adapter_info_addr = dma_map_single(hostdata->dev,
794 						     &hostdata->madapter_info,
795 						     sizeof(hostdata->madapter_info),
796 						     DMA_BIDIRECTIONAL);
797 	if (dma_mapping_error(hostdata->dev, hostdata->adapter_info_addr)) {
798 		dev_err(hostdata->dev, "Unable to map adapter info buffer!\n");
799 		dma_unmap_single(hostdata->dev, hostdata->caps_addr,
800 				 sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
801 		return 1;
802 	}
803 
804 	return 0;
805 }
806 
807 /**
808  * unmap_persist_bufs: - Unmap persistent data needed for adapter logins
809  * @hostdata:   ibmvscsi_host_data of host
810  *
811  * Unmap the capabilities and adapter info DMA buffers
812  */
813 static void unmap_persist_bufs(struct ibmvscsi_host_data *hostdata)
814 {
815 	dma_unmap_single(hostdata->dev, hostdata->caps_addr,
816 			 sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
817 
818 	dma_unmap_single(hostdata->dev, hostdata->adapter_info_addr,
819 			 sizeof(hostdata->madapter_info), DMA_BIDIRECTIONAL);
820 }
821 
822 /**
823  * login_rsp: - Handle response to SRP login request
824  * @evt_struct:	srp_event_struct with the response
825  *
826  * Used as a "done" callback by when sending srp_login. Gets called
827  * by ibmvscsi_handle_crq()
828 */
829 static void login_rsp(struct srp_event_struct *evt_struct)
830 {
831 	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
832 	switch (evt_struct->xfer_iu->srp.login_rsp.opcode) {
833 	case SRP_LOGIN_RSP:	/* it worked! */
834 		break;
835 	case SRP_LOGIN_REJ:	/* refused! */
836 		dev_info(hostdata->dev, "SRP_LOGIN_REJ reason %u\n",
837 			 evt_struct->xfer_iu->srp.login_rej.reason);
838 		/* Login failed.  */
839 		atomic_set(&hostdata->request_limit, -1);
840 		return;
841 	default:
842 		dev_err(hostdata->dev, "Invalid login response typecode 0x%02x!\n",
843 			evt_struct->xfer_iu->srp.login_rsp.opcode);
844 		/* Login failed.  */
845 		atomic_set(&hostdata->request_limit, -1);
846 		return;
847 	}
848 
849 	dev_info(hostdata->dev, "SRP_LOGIN succeeded\n");
850 	hostdata->client_migrated = 0;
851 
852 	/* Now we know what the real request-limit is.
853 	 * This value is set rather than added to request_limit because
854 	 * request_limit could have been set to -1 by this client.
855 	 */
856 	atomic_set(&hostdata->request_limit,
857 		   evt_struct->xfer_iu->srp.login_rsp.req_lim_delta);
858 
859 	/* If we had any pending I/Os, kick them */
860 	scsi_unblock_requests(hostdata->host);
861 }
862 
863 /**
864  * send_srp_login: - Sends the srp login
865  * @hostdata:	ibmvscsi_host_data of host
866  *
867  * Returns zero if successful.
868 */
869 static int send_srp_login(struct ibmvscsi_host_data *hostdata)
870 {
871 	int rc;
872 	unsigned long flags;
873 	struct srp_login_req *login;
874 	struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
875 
876 	BUG_ON(!evt_struct);
877 	init_event_struct(evt_struct, login_rsp,
878 			  VIOSRP_SRP_FORMAT, login_timeout);
879 
880 	login = &evt_struct->iu.srp.login_req;
881 	memset(login, 0, sizeof(*login));
882 	login->opcode = SRP_LOGIN_REQ;
883 	login->req_it_iu_len = sizeof(union srp_iu);
884 	login->req_buf_fmt = SRP_BUF_FORMAT_DIRECT | SRP_BUF_FORMAT_INDIRECT;
885 
886 	spin_lock_irqsave(hostdata->host->host_lock, flags);
887 	/* Start out with a request limit of 0, since this is negotiated in
888 	 * the login request we are just sending and login requests always
889 	 * get sent by the driver regardless of request_limit.
890 	 */
891 	atomic_set(&hostdata->request_limit, 0);
892 
893 	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, login_timeout * 2);
894 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
895 	dev_info(hostdata->dev, "sent SRP login\n");
896 	return rc;
897 };
898 
899 /**
900  * capabilities_rsp: - Handle response to MAD adapter capabilities request
901  * @evt_struct:	srp_event_struct with the response
902  *
903  * Used as a "done" callback by when sending adapter_info.
904  */
905 static void capabilities_rsp(struct srp_event_struct *evt_struct)
906 {
907 	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
908 
909 	if (evt_struct->xfer_iu->mad.capabilities.common.status) {
910 		dev_err(hostdata->dev, "error 0x%X getting capabilities info\n",
911 			evt_struct->xfer_iu->mad.capabilities.common.status);
912 	} else {
913 		if (hostdata->caps.migration.common.server_support != SERVER_SUPPORTS_CAP)
914 			dev_info(hostdata->dev, "Partition migration not supported\n");
915 
916 		if (client_reserve) {
917 			if (hostdata->caps.reserve.common.server_support ==
918 			    SERVER_SUPPORTS_CAP)
919 				dev_info(hostdata->dev, "Client reserve enabled\n");
920 			else
921 				dev_info(hostdata->dev, "Client reserve not supported\n");
922 		}
923 	}
924 
925 	send_srp_login(hostdata);
926 }
927 
928 /**
929  * send_mad_capabilities: - Sends the mad capabilities request
930  *      and stores the result so it can be retrieved with
931  * @hostdata:	ibmvscsi_host_data of host
932  */
933 static void send_mad_capabilities(struct ibmvscsi_host_data *hostdata)
934 {
935 	struct viosrp_capabilities *req;
936 	struct srp_event_struct *evt_struct;
937 	unsigned long flags;
938 	struct device_node *of_node = hostdata->dev->of_node;
939 	const char *location;
940 
941 	evt_struct = get_event_struct(&hostdata->pool);
942 	BUG_ON(!evt_struct);
943 
944 	init_event_struct(evt_struct, capabilities_rsp,
945 			  VIOSRP_MAD_FORMAT, info_timeout);
946 
947 	req = &evt_struct->iu.mad.capabilities;
948 	memset(req, 0, sizeof(*req));
949 
950 	hostdata->caps.flags = CAP_LIST_SUPPORTED;
951 	if (hostdata->client_migrated)
952 		hostdata->caps.flags |= CLIENT_MIGRATED;
953 
954 	strncpy(hostdata->caps.name, dev_name(&hostdata->host->shost_gendev),
955 		sizeof(hostdata->caps.name));
956 	hostdata->caps.name[sizeof(hostdata->caps.name) - 1] = '\0';
957 
958 	location = of_get_property(of_node, "ibm,loc-code", NULL);
959 	location = location ? location : dev_name(hostdata->dev);
960 	strncpy(hostdata->caps.loc, location, sizeof(hostdata->caps.loc));
961 	hostdata->caps.loc[sizeof(hostdata->caps.loc) - 1] = '\0';
962 
963 	req->common.type = VIOSRP_CAPABILITIES_TYPE;
964 	req->buffer = hostdata->caps_addr;
965 
966 	hostdata->caps.migration.common.cap_type = MIGRATION_CAPABILITIES;
967 	hostdata->caps.migration.common.length = sizeof(hostdata->caps.migration);
968 	hostdata->caps.migration.common.server_support = SERVER_SUPPORTS_CAP;
969 	hostdata->caps.migration.ecl = 1;
970 
971 	if (client_reserve) {
972 		hostdata->caps.reserve.common.cap_type = RESERVATION_CAPABILITIES;
973 		hostdata->caps.reserve.common.length = sizeof(hostdata->caps.reserve);
974 		hostdata->caps.reserve.common.server_support = SERVER_SUPPORTS_CAP;
975 		hostdata->caps.reserve.type = CLIENT_RESERVE_SCSI_2;
976 		req->common.length = sizeof(hostdata->caps);
977 	} else
978 		req->common.length = sizeof(hostdata->caps) - sizeof(hostdata->caps.reserve);
979 
980 	spin_lock_irqsave(hostdata->host->host_lock, flags);
981 	if (ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2))
982 		dev_err(hostdata->dev, "couldn't send CAPABILITIES_REQ!\n");
983 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
984 };
985 
986 /**
987  * fast_fail_rsp: - Handle response to MAD enable fast fail
988  * @evt_struct:	srp_event_struct with the response
989  *
990  * Used as a "done" callback by when sending enable fast fail. Gets called
991  * by ibmvscsi_handle_crq()
992  */
993 static void fast_fail_rsp(struct srp_event_struct *evt_struct)
994 {
995 	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
996 	u8 status = evt_struct->xfer_iu->mad.fast_fail.common.status;
997 
998 	if (status == VIOSRP_MAD_NOT_SUPPORTED)
999 		dev_err(hostdata->dev, "fast_fail not supported in server\n");
1000 	else if (status == VIOSRP_MAD_FAILED)
1001 		dev_err(hostdata->dev, "fast_fail request failed\n");
1002 	else if (status != VIOSRP_MAD_SUCCESS)
1003 		dev_err(hostdata->dev, "error 0x%X enabling fast_fail\n", status);
1004 
1005 	send_mad_capabilities(hostdata);
1006 }
1007 
1008 /**
1009  * init_host - Start host initialization
1010  * @hostdata:	ibmvscsi_host_data of host
1011  *
1012  * Returns zero if successful.
1013  */
1014 static int enable_fast_fail(struct ibmvscsi_host_data *hostdata)
1015 {
1016 	int rc;
1017 	unsigned long flags;
1018 	struct viosrp_fast_fail *fast_fail_mad;
1019 	struct srp_event_struct *evt_struct;
1020 
1021 	if (!fast_fail) {
1022 		send_mad_capabilities(hostdata);
1023 		return 0;
1024 	}
1025 
1026 	evt_struct = get_event_struct(&hostdata->pool);
1027 	BUG_ON(!evt_struct);
1028 
1029 	init_event_struct(evt_struct, fast_fail_rsp, VIOSRP_MAD_FORMAT, info_timeout);
1030 
1031 	fast_fail_mad = &evt_struct->iu.mad.fast_fail;
1032 	memset(fast_fail_mad, 0, sizeof(*fast_fail_mad));
1033 	fast_fail_mad->common.type = VIOSRP_ENABLE_FAST_FAIL;
1034 	fast_fail_mad->common.length = sizeof(*fast_fail_mad);
1035 
1036 	spin_lock_irqsave(hostdata->host->host_lock, flags);
1037 	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2);
1038 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1039 	return rc;
1040 }
1041 
1042 /**
1043  * adapter_info_rsp: - Handle response to MAD adapter info request
1044  * @evt_struct:	srp_event_struct with the response
1045  *
1046  * Used as a "done" callback by when sending adapter_info. Gets called
1047  * by ibmvscsi_handle_crq()
1048 */
1049 static void adapter_info_rsp(struct srp_event_struct *evt_struct)
1050 {
1051 	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
1052 
1053 	if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
1054 		dev_err(hostdata->dev, "error %d getting adapter info\n",
1055 			evt_struct->xfer_iu->mad.adapter_info.common.status);
1056 	} else {
1057 		dev_info(hostdata->dev, "host srp version: %s, "
1058 			 "host partition %s (%d), OS %d, max io %u\n",
1059 			 hostdata->madapter_info.srp_version,
1060 			 hostdata->madapter_info.partition_name,
1061 			 hostdata->madapter_info.partition_number,
1062 			 hostdata->madapter_info.os_type,
1063 			 hostdata->madapter_info.port_max_txu[0]);
1064 
1065 		if (hostdata->madapter_info.port_max_txu[0])
1066 			hostdata->host->max_sectors =
1067 				hostdata->madapter_info.port_max_txu[0] >> 9;
1068 
1069 		if (hostdata->madapter_info.os_type == 3 &&
1070 		    strcmp(hostdata->madapter_info.srp_version, "1.6a") <= 0) {
1071 			dev_err(hostdata->dev, "host (Ver. %s) doesn't support large transfers\n",
1072 				hostdata->madapter_info.srp_version);
1073 			dev_err(hostdata->dev, "limiting scatterlists to %d\n",
1074 				MAX_INDIRECT_BUFS);
1075 			hostdata->host->sg_tablesize = MAX_INDIRECT_BUFS;
1076 		}
1077 
1078 		if (hostdata->madapter_info.os_type == 3) {
1079 			enable_fast_fail(hostdata);
1080 			return;
1081 		}
1082 	}
1083 
1084 	send_srp_login(hostdata);
1085 }
1086 
1087 /**
1088  * send_mad_adapter_info: - Sends the mad adapter info request
1089  *      and stores the result so it can be retrieved with
1090  *      sysfs.  We COULD consider causing a failure if the
1091  *      returned SRP version doesn't match ours.
1092  * @hostdata:	ibmvscsi_host_data of host
1093  *
1094  * Returns zero if successful.
1095 */
1096 static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
1097 {
1098 	struct viosrp_adapter_info *req;
1099 	struct srp_event_struct *evt_struct;
1100 	unsigned long flags;
1101 
1102 	evt_struct = get_event_struct(&hostdata->pool);
1103 	BUG_ON(!evt_struct);
1104 
1105 	init_event_struct(evt_struct,
1106 			  adapter_info_rsp,
1107 			  VIOSRP_MAD_FORMAT,
1108 			  info_timeout);
1109 
1110 	req = &evt_struct->iu.mad.adapter_info;
1111 	memset(req, 0x00, sizeof(*req));
1112 
1113 	req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
1114 	req->common.length = sizeof(hostdata->madapter_info);
1115 	req->buffer = hostdata->adapter_info_addr;
1116 
1117 	spin_lock_irqsave(hostdata->host->host_lock, flags);
1118 	if (ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2))
1119 		dev_err(hostdata->dev, "couldn't send ADAPTER_INFO_REQ!\n");
1120 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1121 };
1122 
1123 /**
1124  * init_adapter: Start virtual adapter initialization sequence
1125  *
1126  */
1127 static void init_adapter(struct ibmvscsi_host_data *hostdata)
1128 {
1129 	send_mad_adapter_info(hostdata);
1130 }
1131 
1132 /**
1133  * sync_completion: Signal that a synchronous command has completed
1134  * Note that after returning from this call, the evt_struct is freed.
1135  * the caller waiting on this completion shouldn't touch the evt_struct
1136  * again.
1137  */
1138 static void sync_completion(struct srp_event_struct *evt_struct)
1139 {
1140 	/* copy the response back */
1141 	if (evt_struct->sync_srp)
1142 		*evt_struct->sync_srp = *evt_struct->xfer_iu;
1143 
1144 	complete(&evt_struct->comp);
1145 }
1146 
1147 /**
1148  * ibmvscsi_abort: Abort a command...from scsi host template
1149  * send this over to the server and wait synchronously for the response
1150  */
1151 static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
1152 {
1153 	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
1154 	struct srp_tsk_mgmt *tsk_mgmt;
1155 	struct srp_event_struct *evt;
1156 	struct srp_event_struct *tmp_evt, *found_evt;
1157 	union viosrp_iu srp_rsp;
1158 	int rsp_rc;
1159 	unsigned long flags;
1160 	u16 lun = lun_from_dev(cmd->device);
1161 	unsigned long wait_switch = 0;
1162 
1163 	/* First, find this command in our sent list so we can figure
1164 	 * out the correct tag
1165 	 */
1166 	spin_lock_irqsave(hostdata->host->host_lock, flags);
1167 	wait_switch = jiffies + (init_timeout * HZ);
1168 	do {
1169 		found_evt = NULL;
1170 		list_for_each_entry(tmp_evt, &hostdata->sent, list) {
1171 			if (tmp_evt->cmnd == cmd) {
1172 				found_evt = tmp_evt;
1173 				break;
1174 			}
1175 		}
1176 
1177 		if (!found_evt) {
1178 			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1179 			return SUCCESS;
1180 		}
1181 
1182 		evt = get_event_struct(&hostdata->pool);
1183 		if (evt == NULL) {
1184 			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1185 			sdev_printk(KERN_ERR, cmd->device,
1186 				"failed to allocate abort event\n");
1187 			return FAILED;
1188 		}
1189 
1190 		init_event_struct(evt,
1191 				  sync_completion,
1192 				  VIOSRP_SRP_FORMAT,
1193 				  abort_timeout);
1194 
1195 		tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1196 
1197 		/* Set up an abort SRP command */
1198 		memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1199 		tsk_mgmt->opcode = SRP_TSK_MGMT;
1200 		tsk_mgmt->lun = ((u64) lun) << 48;
1201 		tsk_mgmt->tsk_mgmt_func = SRP_TSK_ABORT_TASK;
1202 		tsk_mgmt->task_tag = (u64) found_evt;
1203 
1204 		evt->sync_srp = &srp_rsp;
1205 
1206 		init_completion(&evt->comp);
1207 		rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, abort_timeout * 2);
1208 
1209 		if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)
1210 			break;
1211 
1212 		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1213 		msleep(10);
1214 		spin_lock_irqsave(hostdata->host->host_lock, flags);
1215 	} while (time_before(jiffies, wait_switch));
1216 
1217 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1218 
1219 	if (rsp_rc != 0) {
1220 		sdev_printk(KERN_ERR, cmd->device,
1221 			    "failed to send abort() event. rc=%d\n", rsp_rc);
1222 		return FAILED;
1223 	}
1224 
1225 	sdev_printk(KERN_INFO, cmd->device,
1226                     "aborting command. lun 0x%llx, tag 0x%llx\n",
1227 		    (((u64) lun) << 48), (u64) found_evt);
1228 
1229 	wait_for_completion(&evt->comp);
1230 
1231 	/* make sure we got a good response */
1232 	if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
1233 		if (printk_ratelimit())
1234 			sdev_printk(KERN_WARNING, cmd->device, "abort bad SRP RSP type %d\n",
1235 				    srp_rsp.srp.rsp.opcode);
1236 		return FAILED;
1237 	}
1238 
1239 	if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
1240 		rsp_rc = *((int *)srp_rsp.srp.rsp.data);
1241 	else
1242 		rsp_rc = srp_rsp.srp.rsp.status;
1243 
1244 	if (rsp_rc) {
1245 		if (printk_ratelimit())
1246 			sdev_printk(KERN_WARNING, cmd->device,
1247 				    "abort code %d for task tag 0x%llx\n",
1248 				    rsp_rc, tsk_mgmt->task_tag);
1249 		return FAILED;
1250 	}
1251 
1252 	/* Because we dropped the spinlock above, it's possible
1253 	 * The event is no longer in our list.  Make sure it didn't
1254 	 * complete while we were aborting
1255 	 */
1256 	spin_lock_irqsave(hostdata->host->host_lock, flags);
1257 	found_evt = NULL;
1258 	list_for_each_entry(tmp_evt, &hostdata->sent, list) {
1259 		if (tmp_evt->cmnd == cmd) {
1260 			found_evt = tmp_evt;
1261 			break;
1262 		}
1263 	}
1264 
1265 	if (found_evt == NULL) {
1266 		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1267 		sdev_printk(KERN_INFO, cmd->device, "aborted task tag 0x%llx completed\n",
1268 			    tsk_mgmt->task_tag);
1269 		return SUCCESS;
1270 	}
1271 
1272 	sdev_printk(KERN_INFO, cmd->device, "successfully aborted task tag 0x%llx\n",
1273 		    tsk_mgmt->task_tag);
1274 
1275 	cmd->result = (DID_ABORT << 16);
1276 	list_del(&found_evt->list);
1277 	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
1278 		       found_evt->hostdata->dev);
1279 	free_event_struct(&found_evt->hostdata->pool, found_evt);
1280 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1281 	atomic_inc(&hostdata->request_limit);
1282 	return SUCCESS;
1283 }
1284 
1285 /**
1286  * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host
1287  * template send this over to the server and wait synchronously for the
1288  * response
1289  */
1290 static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
1291 {
1292 	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
1293 	struct srp_tsk_mgmt *tsk_mgmt;
1294 	struct srp_event_struct *evt;
1295 	struct srp_event_struct *tmp_evt, *pos;
1296 	union viosrp_iu srp_rsp;
1297 	int rsp_rc;
1298 	unsigned long flags;
1299 	u16 lun = lun_from_dev(cmd->device);
1300 	unsigned long wait_switch = 0;
1301 
1302 	spin_lock_irqsave(hostdata->host->host_lock, flags);
1303 	wait_switch = jiffies + (init_timeout * HZ);
1304 	do {
1305 		evt = get_event_struct(&hostdata->pool);
1306 		if (evt == NULL) {
1307 			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1308 			sdev_printk(KERN_ERR, cmd->device,
1309 				"failed to allocate reset event\n");
1310 			return FAILED;
1311 		}
1312 
1313 		init_event_struct(evt,
1314 				  sync_completion,
1315 				  VIOSRP_SRP_FORMAT,
1316 				  reset_timeout);
1317 
1318 		tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1319 
1320 		/* Set up a lun reset SRP command */
1321 		memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1322 		tsk_mgmt->opcode = SRP_TSK_MGMT;
1323 		tsk_mgmt->lun = ((u64) lun) << 48;
1324 		tsk_mgmt->tsk_mgmt_func = SRP_TSK_LUN_RESET;
1325 
1326 		evt->sync_srp = &srp_rsp;
1327 
1328 		init_completion(&evt->comp);
1329 		rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, reset_timeout * 2);
1330 
1331 		if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)
1332 			break;
1333 
1334 		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1335 		msleep(10);
1336 		spin_lock_irqsave(hostdata->host->host_lock, flags);
1337 	} while (time_before(jiffies, wait_switch));
1338 
1339 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1340 
1341 	if (rsp_rc != 0) {
1342 		sdev_printk(KERN_ERR, cmd->device,
1343 			    "failed to send reset event. rc=%d\n", rsp_rc);
1344 		return FAILED;
1345 	}
1346 
1347 	sdev_printk(KERN_INFO, cmd->device, "resetting device. lun 0x%llx\n",
1348 		    (((u64) lun) << 48));
1349 
1350 	wait_for_completion(&evt->comp);
1351 
1352 	/* make sure we got a good response */
1353 	if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
1354 		if (printk_ratelimit())
1355 			sdev_printk(KERN_WARNING, cmd->device, "reset bad SRP RSP type %d\n",
1356 				    srp_rsp.srp.rsp.opcode);
1357 		return FAILED;
1358 	}
1359 
1360 	if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
1361 		rsp_rc = *((int *)srp_rsp.srp.rsp.data);
1362 	else
1363 		rsp_rc = srp_rsp.srp.rsp.status;
1364 
1365 	if (rsp_rc) {
1366 		if (printk_ratelimit())
1367 			sdev_printk(KERN_WARNING, cmd->device,
1368 				    "reset code %d for task tag 0x%llx\n",
1369 				    rsp_rc, tsk_mgmt->task_tag);
1370 		return FAILED;
1371 	}
1372 
1373 	/* We need to find all commands for this LUN that have not yet been
1374 	 * responded to, and fail them with DID_RESET
1375 	 */
1376 	spin_lock_irqsave(hostdata->host->host_lock, flags);
1377 	list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1378 		if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1379 			if (tmp_evt->cmnd)
1380 				tmp_evt->cmnd->result = (DID_RESET << 16);
1381 			list_del(&tmp_evt->list);
1382 			unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
1383 				       tmp_evt->hostdata->dev);
1384 			free_event_struct(&tmp_evt->hostdata->pool,
1385 						   tmp_evt);
1386 			atomic_inc(&hostdata->request_limit);
1387 			if (tmp_evt->cmnd_done)
1388 				tmp_evt->cmnd_done(tmp_evt->cmnd);
1389 			else if (tmp_evt->done)
1390 				tmp_evt->done(tmp_evt);
1391 		}
1392 	}
1393 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1394 	return SUCCESS;
1395 }
1396 
1397 /**
1398  * ibmvscsi_eh_host_reset_handler - Reset the connection to the server
1399  * @cmd:	struct scsi_cmnd having problems
1400 */
1401 static int ibmvscsi_eh_host_reset_handler(struct scsi_cmnd *cmd)
1402 {
1403 	unsigned long wait_switch = 0;
1404 	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
1405 
1406 	dev_err(hostdata->dev, "Resetting connection due to error recovery\n");
1407 
1408 	ibmvscsi_reset_host(hostdata);
1409 
1410 	for (wait_switch = jiffies + (init_timeout * HZ);
1411 	     time_before(jiffies, wait_switch) &&
1412 		     atomic_read(&hostdata->request_limit) < 2;) {
1413 
1414 		msleep(10);
1415 	}
1416 
1417 	if (atomic_read(&hostdata->request_limit) <= 0)
1418 		return FAILED;
1419 
1420 	return SUCCESS;
1421 }
1422 
1423 /**
1424  * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1425  * @crq:	Command/Response queue
1426  * @hostdata:	ibmvscsi_host_data of host
1427  *
1428 */
1429 void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1430 			 struct ibmvscsi_host_data *hostdata)
1431 {
1432 	long rc;
1433 	unsigned long flags;
1434 	struct srp_event_struct *evt_struct =
1435 	    (struct srp_event_struct *)crq->IU_data_ptr;
1436 	switch (crq->valid) {
1437 	case 0xC0:		/* initialization */
1438 		switch (crq->format) {
1439 		case 0x01:	/* Initialization message */
1440 			dev_info(hostdata->dev, "partner initialized\n");
1441 			/* Send back a response */
1442 			if ((rc = ibmvscsi_ops->send_crq(hostdata,
1443 							 0xC002000000000000LL, 0)) == 0) {
1444 				/* Now login */
1445 				init_adapter(hostdata);
1446 			} else {
1447 				dev_err(hostdata->dev, "Unable to send init rsp. rc=%ld\n", rc);
1448 			}
1449 
1450 			break;
1451 		case 0x02:	/* Initialization response */
1452 			dev_info(hostdata->dev, "partner initialization complete\n");
1453 
1454 			/* Now login */
1455 			init_adapter(hostdata);
1456 			break;
1457 		default:
1458 			dev_err(hostdata->dev, "unknown crq message type: %d\n", crq->format);
1459 		}
1460 		return;
1461 	case 0xFF:	/* Hypervisor telling us the connection is closed */
1462 		scsi_block_requests(hostdata->host);
1463 		atomic_set(&hostdata->request_limit, 0);
1464 		if (crq->format == 0x06) {
1465 			/* We need to re-setup the interpartition connection */
1466 			dev_info(hostdata->dev, "Re-enabling adapter!\n");
1467 			hostdata->client_migrated = 1;
1468 			hostdata->reenable_crq = 1;
1469 			purge_requests(hostdata, DID_REQUEUE);
1470 			wake_up(&hostdata->work_wait_q);
1471 		} else {
1472 			dev_err(hostdata->dev, "Virtual adapter failed rc %d!\n",
1473 				crq->format);
1474 			ibmvscsi_reset_host(hostdata);
1475 		}
1476 		return;
1477 	case 0x80:		/* real payload */
1478 		break;
1479 	default:
1480 		dev_err(hostdata->dev, "got an invalid message type 0x%02x\n",
1481 			crq->valid);
1482 		return;
1483 	}
1484 
1485 	/* The only kind of payload CRQs we should get are responses to
1486 	 * things we send. Make sure this response is to something we
1487 	 * actually sent
1488 	 */
1489 	if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1490 		dev_err(hostdata->dev, "returned correlation_token 0x%p is invalid!\n",
1491 		       (void *)crq->IU_data_ptr);
1492 		return;
1493 	}
1494 
1495 	if (atomic_read(&evt_struct->free)) {
1496 		dev_err(hostdata->dev, "received duplicate correlation_token 0x%p!\n",
1497 			(void *)crq->IU_data_ptr);
1498 		return;
1499 	}
1500 
1501 	if (crq->format == VIOSRP_SRP_FORMAT)
1502 		atomic_add(evt_struct->xfer_iu->srp.rsp.req_lim_delta,
1503 			   &hostdata->request_limit);
1504 
1505 	del_timer(&evt_struct->timer);
1506 
1507 	if ((crq->status != VIOSRP_OK && crq->status != VIOSRP_OK2) && evt_struct->cmnd)
1508 		evt_struct->cmnd->result = DID_ERROR << 16;
1509 	if (evt_struct->done)
1510 		evt_struct->done(evt_struct);
1511 	else
1512 		dev_err(hostdata->dev, "returned done() is NULL; not running it!\n");
1513 
1514 	/*
1515 	 * Lock the host_lock before messing with these structures, since we
1516 	 * are running in a task context
1517 	 */
1518 	spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1519 	list_del(&evt_struct->list);
1520 	free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1521 	spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1522 }
1523 
1524 /**
1525  * ibmvscsi_get_host_config: Send the command to the server to get host
1526  * configuration data.  The data is opaque to us.
1527  */
1528 static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
1529 				   unsigned char *buffer, int length)
1530 {
1531 	struct viosrp_host_config *host_config;
1532 	struct srp_event_struct *evt_struct;
1533 	unsigned long flags;
1534 	dma_addr_t addr;
1535 	int rc;
1536 
1537 	evt_struct = get_event_struct(&hostdata->pool);
1538 	if (!evt_struct) {
1539 		dev_err(hostdata->dev, "couldn't allocate event for HOST_CONFIG!\n");
1540 		return -1;
1541 	}
1542 
1543 	init_event_struct(evt_struct,
1544 			  sync_completion,
1545 			  VIOSRP_MAD_FORMAT,
1546 			  info_timeout);
1547 
1548 	host_config = &evt_struct->iu.mad.host_config;
1549 
1550 	/* Set up a lun reset SRP command */
1551 	memset(host_config, 0x00, sizeof(*host_config));
1552 	host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
1553 	host_config->common.length = length;
1554 	host_config->buffer = addr = dma_map_single(hostdata->dev, buffer,
1555 						    length,
1556 						    DMA_BIDIRECTIONAL);
1557 
1558 	if (dma_mapping_error(hostdata->dev, host_config->buffer)) {
1559 		if (!firmware_has_feature(FW_FEATURE_CMO))
1560 			dev_err(hostdata->dev,
1561 			        "dma_mapping error getting host config\n");
1562 		free_event_struct(&hostdata->pool, evt_struct);
1563 		return -1;
1564 	}
1565 
1566 	init_completion(&evt_struct->comp);
1567 	spin_lock_irqsave(hostdata->host->host_lock, flags);
1568 	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2);
1569 	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1570 	if (rc == 0)
1571 		wait_for_completion(&evt_struct->comp);
1572 	dma_unmap_single(hostdata->dev, addr, length, DMA_BIDIRECTIONAL);
1573 
1574 	return rc;
1575 }
1576 
1577 /**
1578  * ibmvscsi_slave_configure: Set the "allow_restart" flag for each disk.
1579  * @sdev:	struct scsi_device device to configure
1580  *
1581  * Enable allow_restart for a device if it is a disk.  Adjust the
1582  * queue_depth here also as is required by the documentation for
1583  * struct scsi_host_template.
1584  */
1585 static int ibmvscsi_slave_configure(struct scsi_device *sdev)
1586 {
1587 	struct Scsi_Host *shost = sdev->host;
1588 	unsigned long lock_flags = 0;
1589 
1590 	spin_lock_irqsave(shost->host_lock, lock_flags);
1591 	if (sdev->type == TYPE_DISK) {
1592 		sdev->allow_restart = 1;
1593 		blk_queue_rq_timeout(sdev->request_queue, 120 * HZ);
1594 	}
1595 	scsi_adjust_queue_depth(sdev, 0, shost->cmd_per_lun);
1596 	spin_unlock_irqrestore(shost->host_lock, lock_flags);
1597 	return 0;
1598 }
1599 
1600 /**
1601  * ibmvscsi_change_queue_depth - Change the device's queue depth
1602  * @sdev:	scsi device struct
1603  * @qdepth:	depth to set
1604  * @reason:	calling context
1605  *
1606  * Return value:
1607  * 	actual depth set
1608  **/
1609 static int ibmvscsi_change_queue_depth(struct scsi_device *sdev, int qdepth,
1610 				       int reason)
1611 {
1612 	if (reason != SCSI_QDEPTH_DEFAULT)
1613 		return -EOPNOTSUPP;
1614 
1615 	if (qdepth > IBMVSCSI_MAX_CMDS_PER_LUN)
1616 		qdepth = IBMVSCSI_MAX_CMDS_PER_LUN;
1617 
1618 	scsi_adjust_queue_depth(sdev, 0, qdepth);
1619 	return sdev->queue_depth;
1620 }
1621 
1622 /* ------------------------------------------------------------
1623  * sysfs attributes
1624  */
1625 static ssize_t show_host_vhost_loc(struct device *dev,
1626 				   struct device_attribute *attr, char *buf)
1627 {
1628 	struct Scsi_Host *shost = class_to_shost(dev);
1629 	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1630 	int len;
1631 
1632 	len = snprintf(buf, sizeof(hostdata->caps.loc), "%s\n",
1633 		       hostdata->caps.loc);
1634 	return len;
1635 }
1636 
1637 static struct device_attribute ibmvscsi_host_vhost_loc = {
1638 	.attr = {
1639 		 .name = "vhost_loc",
1640 		 .mode = S_IRUGO,
1641 		 },
1642 	.show = show_host_vhost_loc,
1643 };
1644 
1645 static ssize_t show_host_vhost_name(struct device *dev,
1646 				    struct device_attribute *attr, char *buf)
1647 {
1648 	struct Scsi_Host *shost = class_to_shost(dev);
1649 	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1650 	int len;
1651 
1652 	len = snprintf(buf, sizeof(hostdata->caps.name), "%s\n",
1653 		       hostdata->caps.name);
1654 	return len;
1655 }
1656 
1657 static struct device_attribute ibmvscsi_host_vhost_name = {
1658 	.attr = {
1659 		 .name = "vhost_name",
1660 		 .mode = S_IRUGO,
1661 		 },
1662 	.show = show_host_vhost_name,
1663 };
1664 
1665 static ssize_t show_host_srp_version(struct device *dev,
1666 				     struct device_attribute *attr, char *buf)
1667 {
1668 	struct Scsi_Host *shost = class_to_shost(dev);
1669 	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1670 	int len;
1671 
1672 	len = snprintf(buf, PAGE_SIZE, "%s\n",
1673 		       hostdata->madapter_info.srp_version);
1674 	return len;
1675 }
1676 
1677 static struct device_attribute ibmvscsi_host_srp_version = {
1678 	.attr = {
1679 		 .name = "srp_version",
1680 		 .mode = S_IRUGO,
1681 		 },
1682 	.show = show_host_srp_version,
1683 };
1684 
1685 static ssize_t show_host_partition_name(struct device *dev,
1686 					struct device_attribute *attr,
1687 					char *buf)
1688 {
1689 	struct Scsi_Host *shost = class_to_shost(dev);
1690 	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1691 	int len;
1692 
1693 	len = snprintf(buf, PAGE_SIZE, "%s\n",
1694 		       hostdata->madapter_info.partition_name);
1695 	return len;
1696 }
1697 
1698 static struct device_attribute ibmvscsi_host_partition_name = {
1699 	.attr = {
1700 		 .name = "partition_name",
1701 		 .mode = S_IRUGO,
1702 		 },
1703 	.show = show_host_partition_name,
1704 };
1705 
1706 static ssize_t show_host_partition_number(struct device *dev,
1707 					  struct device_attribute *attr,
1708 					  char *buf)
1709 {
1710 	struct Scsi_Host *shost = class_to_shost(dev);
1711 	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1712 	int len;
1713 
1714 	len = snprintf(buf, PAGE_SIZE, "%d\n",
1715 		       hostdata->madapter_info.partition_number);
1716 	return len;
1717 }
1718 
1719 static struct device_attribute ibmvscsi_host_partition_number = {
1720 	.attr = {
1721 		 .name = "partition_number",
1722 		 .mode = S_IRUGO,
1723 		 },
1724 	.show = show_host_partition_number,
1725 };
1726 
1727 static ssize_t show_host_mad_version(struct device *dev,
1728 				     struct device_attribute *attr, char *buf)
1729 {
1730 	struct Scsi_Host *shost = class_to_shost(dev);
1731 	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1732 	int len;
1733 
1734 	len = snprintf(buf, PAGE_SIZE, "%d\n",
1735 		       hostdata->madapter_info.mad_version);
1736 	return len;
1737 }
1738 
1739 static struct device_attribute ibmvscsi_host_mad_version = {
1740 	.attr = {
1741 		 .name = "mad_version",
1742 		 .mode = S_IRUGO,
1743 		 },
1744 	.show = show_host_mad_version,
1745 };
1746 
1747 static ssize_t show_host_os_type(struct device *dev,
1748 				 struct device_attribute *attr, char *buf)
1749 {
1750 	struct Scsi_Host *shost = class_to_shost(dev);
1751 	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1752 	int len;
1753 
1754 	len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
1755 	return len;
1756 }
1757 
1758 static struct device_attribute ibmvscsi_host_os_type = {
1759 	.attr = {
1760 		 .name = "os_type",
1761 		 .mode = S_IRUGO,
1762 		 },
1763 	.show = show_host_os_type,
1764 };
1765 
1766 static ssize_t show_host_config(struct device *dev,
1767 				struct device_attribute *attr, char *buf)
1768 {
1769 	struct Scsi_Host *shost = class_to_shost(dev);
1770 	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1771 
1772 	/* returns null-terminated host config data */
1773 	if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
1774 		return strlen(buf);
1775 	else
1776 		return 0;
1777 }
1778 
1779 static struct device_attribute ibmvscsi_host_config = {
1780 	.attr = {
1781 		 .name = "config",
1782 		 .mode = S_IRUGO,
1783 		 },
1784 	.show = show_host_config,
1785 };
1786 
1787 static struct device_attribute *ibmvscsi_attrs[] = {
1788 	&ibmvscsi_host_vhost_loc,
1789 	&ibmvscsi_host_vhost_name,
1790 	&ibmvscsi_host_srp_version,
1791 	&ibmvscsi_host_partition_name,
1792 	&ibmvscsi_host_partition_number,
1793 	&ibmvscsi_host_mad_version,
1794 	&ibmvscsi_host_os_type,
1795 	&ibmvscsi_host_config,
1796 	NULL
1797 };
1798 
1799 /* ------------------------------------------------------------
1800  * SCSI driver registration
1801  */
1802 static struct scsi_host_template driver_template = {
1803 	.module = THIS_MODULE,
1804 	.name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
1805 	.proc_name = "ibmvscsi",
1806 	.queuecommand = ibmvscsi_queuecommand,
1807 	.eh_abort_handler = ibmvscsi_eh_abort_handler,
1808 	.eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
1809 	.eh_host_reset_handler = ibmvscsi_eh_host_reset_handler,
1810 	.slave_configure = ibmvscsi_slave_configure,
1811 	.change_queue_depth = ibmvscsi_change_queue_depth,
1812 	.cmd_per_lun = IBMVSCSI_CMDS_PER_LUN_DEFAULT,
1813 	.can_queue = IBMVSCSI_MAX_REQUESTS_DEFAULT,
1814 	.this_id = -1,
1815 	.sg_tablesize = SG_ALL,
1816 	.use_clustering = ENABLE_CLUSTERING,
1817 	.shost_attrs = ibmvscsi_attrs,
1818 };
1819 
1820 /**
1821  * ibmvscsi_get_desired_dma - Calculate IO memory desired by the driver
1822  *
1823  * @vdev: struct vio_dev for the device whose desired IO mem is to be returned
1824  *
1825  * Return value:
1826  *	Number of bytes of IO data the driver will need to perform well.
1827  */
1828 static unsigned long ibmvscsi_get_desired_dma(struct vio_dev *vdev)
1829 {
1830 	/* iu_storage data allocated in initialize_event_pool */
1831 	unsigned long desired_io = max_events * sizeof(union viosrp_iu);
1832 
1833 	/* add io space for sg data */
1834 	desired_io += (IBMVSCSI_MAX_SECTORS_DEFAULT * 512 *
1835 	                     IBMVSCSI_CMDS_PER_LUN_DEFAULT);
1836 
1837 	return desired_io;
1838 }
1839 
1840 static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata)
1841 {
1842 	int rc;
1843 	char *action = "reset";
1844 
1845 	if (hostdata->reset_crq) {
1846 		smp_rmb();
1847 		hostdata->reset_crq = 0;
1848 
1849 		rc = ibmvscsi_ops->reset_crq_queue(&hostdata->queue, hostdata);
1850 		if (!rc)
1851 			rc = ibmvscsi_ops->send_crq(hostdata, 0xC001000000000000LL, 0);
1852 		if (!rc)
1853 			rc = vio_enable_interrupts(to_vio_dev(hostdata->dev));
1854 	} else if (hostdata->reenable_crq) {
1855 		smp_rmb();
1856 		action = "enable";
1857 		rc = ibmvscsi_ops->reenable_crq_queue(&hostdata->queue, hostdata);
1858 		hostdata->reenable_crq = 0;
1859 		if (!rc)
1860 			rc = ibmvscsi_ops->send_crq(hostdata, 0xC001000000000000LL, 0);
1861 	} else
1862 		return;
1863 
1864 	if (rc) {
1865 		atomic_set(&hostdata->request_limit, -1);
1866 		dev_err(hostdata->dev, "error after %s\n", action);
1867 	}
1868 
1869 	scsi_unblock_requests(hostdata->host);
1870 }
1871 
1872 static int ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)
1873 {
1874 	if (kthread_should_stop())
1875 		return 1;
1876 	else if (hostdata->reset_crq) {
1877 		smp_rmb();
1878 		return 1;
1879 	} else if (hostdata->reenable_crq) {
1880 		smp_rmb();
1881 		return 1;
1882 	}
1883 
1884 	return 0;
1885 }
1886 
1887 static int ibmvscsi_work(void *data)
1888 {
1889 	struct ibmvscsi_host_data *hostdata = data;
1890 	int rc;
1891 
1892 	set_user_nice(current, -20);
1893 
1894 	while (1) {
1895 		rc = wait_event_interruptible(hostdata->work_wait_q,
1896 					      ibmvscsi_work_to_do(hostdata));
1897 
1898 		BUG_ON(rc);
1899 
1900 		if (kthread_should_stop())
1901 			break;
1902 
1903 		ibmvscsi_do_work(hostdata);
1904 	}
1905 
1906 	return 0;
1907 }
1908 
1909 /**
1910  * Called by bus code for each adapter
1911  */
1912 static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1913 {
1914 	struct ibmvscsi_host_data *hostdata;
1915 	struct Scsi_Host *host;
1916 	struct device *dev = &vdev->dev;
1917 	struct srp_rport_identifiers ids;
1918 	struct srp_rport *rport;
1919 	unsigned long wait_switch = 0;
1920 	int rc;
1921 
1922 	dev_set_drvdata(&vdev->dev, NULL);
1923 
1924 	host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
1925 	if (!host) {
1926 		dev_err(&vdev->dev, "couldn't allocate host data\n");
1927 		goto scsi_host_alloc_failed;
1928 	}
1929 
1930 	host->transportt = ibmvscsi_transport_template;
1931 	hostdata = shost_priv(host);
1932 	memset(hostdata, 0x00, sizeof(*hostdata));
1933 	INIT_LIST_HEAD(&hostdata->sent);
1934 	init_waitqueue_head(&hostdata->work_wait_q);
1935 	hostdata->host = host;
1936 	hostdata->dev = dev;
1937 	atomic_set(&hostdata->request_limit, -1);
1938 	hostdata->host->max_sectors = IBMVSCSI_MAX_SECTORS_DEFAULT;
1939 
1940 	if (map_persist_bufs(hostdata)) {
1941 		dev_err(&vdev->dev, "couldn't map persistent buffers\n");
1942 		goto persist_bufs_failed;
1943 	}
1944 
1945 	hostdata->work_thread = kthread_run(ibmvscsi_work, hostdata, "%s_%d",
1946 					    "ibmvscsi", host->host_no);
1947 
1948 	if (IS_ERR(hostdata->work_thread)) {
1949 		dev_err(&vdev->dev, "couldn't initialize kthread. rc=%ld\n",
1950 			PTR_ERR(hostdata->work_thread));
1951 		goto init_crq_failed;
1952 	}
1953 
1954 	rc = ibmvscsi_ops->init_crq_queue(&hostdata->queue, hostdata, max_events);
1955 	if (rc != 0 && rc != H_RESOURCE) {
1956 		dev_err(&vdev->dev, "couldn't initialize crq. rc=%d\n", rc);
1957 		goto kill_kthread;
1958 	}
1959 	if (initialize_event_pool(&hostdata->pool, max_events, hostdata) != 0) {
1960 		dev_err(&vdev->dev, "couldn't initialize event pool\n");
1961 		goto init_pool_failed;
1962 	}
1963 
1964 	host->max_lun = 8;
1965 	host->max_id = max_id;
1966 	host->max_channel = max_channel;
1967 	host->max_cmd_len = 16;
1968 
1969 	if (scsi_add_host(hostdata->host, hostdata->dev))
1970 		goto add_host_failed;
1971 
1972 	/* we don't have a proper target_port_id so let's use the fake one */
1973 	memcpy(ids.port_id, hostdata->madapter_info.partition_name,
1974 	       sizeof(ids.port_id));
1975 	ids.roles = SRP_RPORT_ROLE_TARGET;
1976 	rport = srp_rport_add(host, &ids);
1977 	if (IS_ERR(rport))
1978 		goto add_srp_port_failed;
1979 
1980 	/* Try to send an initialization message.  Note that this is allowed
1981 	 * to fail if the other end is not acive.  In that case we don't
1982 	 * want to scan
1983 	 */
1984 	if (ibmvscsi_ops->send_crq(hostdata, 0xC001000000000000LL, 0) == 0
1985 	    || rc == H_RESOURCE) {
1986 		/*
1987 		 * Wait around max init_timeout secs for the adapter to finish
1988 		 * initializing. When we are done initializing, we will have a
1989 		 * valid request_limit.  We don't want Linux scanning before
1990 		 * we are ready.
1991 		 */
1992 		for (wait_switch = jiffies + (init_timeout * HZ);
1993 		     time_before(jiffies, wait_switch) &&
1994 		     atomic_read(&hostdata->request_limit) < 2;) {
1995 
1996 			msleep(10);
1997 		}
1998 
1999 		/* if we now have a valid request_limit, initiate a scan */
2000 		if (atomic_read(&hostdata->request_limit) > 0)
2001 			scsi_scan_host(host);
2002 	}
2003 
2004 	dev_set_drvdata(&vdev->dev, hostdata);
2005 	return 0;
2006 
2007       add_srp_port_failed:
2008 	scsi_remove_host(hostdata->host);
2009       add_host_failed:
2010 	release_event_pool(&hostdata->pool, hostdata);
2011       init_pool_failed:
2012 	ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata, max_events);
2013       kill_kthread:
2014       kthread_stop(hostdata->work_thread);
2015       init_crq_failed:
2016 	unmap_persist_bufs(hostdata);
2017       persist_bufs_failed:
2018 	scsi_host_put(host);
2019       scsi_host_alloc_failed:
2020 	return -1;
2021 }
2022 
2023 static int ibmvscsi_remove(struct vio_dev *vdev)
2024 {
2025 	struct ibmvscsi_host_data *hostdata = dev_get_drvdata(&vdev->dev);
2026 	unmap_persist_bufs(hostdata);
2027 	release_event_pool(&hostdata->pool, hostdata);
2028 	ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata,
2029 					max_events);
2030 
2031 	kthread_stop(hostdata->work_thread);
2032 	srp_remove_host(hostdata->host);
2033 	scsi_remove_host(hostdata->host);
2034 	scsi_host_put(hostdata->host);
2035 
2036 	return 0;
2037 }
2038 
2039 /**
2040  * ibmvscsi_resume: Resume from suspend
2041  * @dev:	device struct
2042  *
2043  * We may have lost an interrupt across suspend/resume, so kick the
2044  * interrupt handler
2045  */
2046 static int ibmvscsi_resume(struct device *dev)
2047 {
2048 	struct ibmvscsi_host_data *hostdata = dev_get_drvdata(dev);
2049 	return ibmvscsi_ops->resume(hostdata);
2050 }
2051 
2052 /**
2053  * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we
2054  * support.
2055  */
2056 static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
2057 	{"vscsi", "IBM,v-scsi"},
2058 	{ "", "" }
2059 };
2060 MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
2061 
2062 static struct dev_pm_ops ibmvscsi_pm_ops = {
2063 	.resume = ibmvscsi_resume
2064 };
2065 
2066 static struct vio_driver ibmvscsi_driver = {
2067 	.id_table = ibmvscsi_device_table,
2068 	.probe = ibmvscsi_probe,
2069 	.remove = ibmvscsi_remove,
2070 	.get_desired_dma = ibmvscsi_get_desired_dma,
2071 	.driver = {
2072 		.name = "ibmvscsi",
2073 		.owner = THIS_MODULE,
2074 		.pm = &ibmvscsi_pm_ops,
2075 	}
2076 };
2077 
2078 static struct srp_function_template ibmvscsi_transport_functions = {
2079 };
2080 
2081 int __init ibmvscsi_module_init(void)
2082 {
2083 	int ret;
2084 
2085 	/* Ensure we have two requests to do error recovery */
2086 	driver_template.can_queue = max_requests;
2087 	max_events = max_requests + 2;
2088 
2089 	if (firmware_has_feature(FW_FEATURE_ISERIES))
2090 		ibmvscsi_ops = &iseriesvscsi_ops;
2091 	else if (firmware_has_feature(FW_FEATURE_VIO))
2092 		ibmvscsi_ops = &rpavscsi_ops;
2093 	else
2094 		return -ENODEV;
2095 
2096 	ibmvscsi_transport_template =
2097 		srp_attach_transport(&ibmvscsi_transport_functions);
2098 	if (!ibmvscsi_transport_template)
2099 		return -ENOMEM;
2100 
2101 	ret = vio_register_driver(&ibmvscsi_driver);
2102 	if (ret)
2103 		srp_release_transport(ibmvscsi_transport_template);
2104 	return ret;
2105 }
2106 
2107 void __exit ibmvscsi_module_exit(void)
2108 {
2109 	vio_unregister_driver(&ibmvscsi_driver);
2110 	srp_release_transport(ibmvscsi_transport_template);
2111 }
2112 
2113 module_init(ibmvscsi_module_init);
2114 module_exit(ibmvscsi_module_exit);
2115