Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
[linux-2.6] / drivers / scsi / ibmvscsi / ibmvscsi.c
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-robbin 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 <asm/vio.h>
74 #include <scsi/scsi.h>
75 #include <scsi/scsi_cmnd.h>
76 #include <scsi/scsi_host.h>
77 #include <scsi/scsi_device.h>
78 #include "ibmvscsi.h"
79
80 /* The values below are somewhat arbitrary default values, but 
81  * OS/400 will use 3 busses (disks, CDs, tapes, I think.)
82  * Note that there are 3 bits of channel value, 6 bits of id, and
83  * 5 bits of LUN.
84  */
85 static int max_id = 64;
86 static int max_channel = 3;
87 static int init_timeout = 5;
88 static int max_requests = 50;
89
90 #define IBMVSCSI_VERSION "1.5.8"
91
92 MODULE_DESCRIPTION("IBM Virtual SCSI");
93 MODULE_AUTHOR("Dave Boutcher");
94 MODULE_LICENSE("GPL");
95 MODULE_VERSION(IBMVSCSI_VERSION);
96
97 module_param_named(max_id, max_id, int, S_IRUGO | S_IWUSR);
98 MODULE_PARM_DESC(max_id, "Largest ID value for each channel");
99 module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
100 MODULE_PARM_DESC(max_channel, "Largest channel value");
101 module_param_named(init_timeout, init_timeout, int, S_IRUGO | S_IWUSR);
102 MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
103 module_param_named(max_requests, max_requests, int, S_IRUGO | S_IWUSR);
104 MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
105
106 /* ------------------------------------------------------------
107  * Routines for the event pool and event structs
108  */
109 /**
110  * initialize_event_pool: - Allocates and initializes the event pool for a host
111  * @pool:       event_pool to be initialized
112  * @size:       Number of events in pool
113  * @hostdata:   ibmvscsi_host_data who owns the event pool
114  *
115  * Returns zero on success.
116 */
117 static int initialize_event_pool(struct event_pool *pool,
118                                  int size, struct ibmvscsi_host_data *hostdata)
119 {
120         int i;
121
122         pool->size = size;
123         pool->next = 0;
124         pool->events = kmalloc(pool->size * sizeof(*pool->events), GFP_KERNEL);
125         if (!pool->events)
126                 return -ENOMEM;
127         memset(pool->events, 0x00, pool->size * sizeof(*pool->events));
128
129         pool->iu_storage =
130             dma_alloc_coherent(hostdata->dev,
131                                pool->size * sizeof(*pool->iu_storage),
132                                &pool->iu_token, 0);
133         if (!pool->iu_storage) {
134                 kfree(pool->events);
135                 return -ENOMEM;
136         }
137
138         for (i = 0; i < pool->size; ++i) {
139                 struct srp_event_struct *evt = &pool->events[i];
140                 memset(&evt->crq, 0x00, sizeof(evt->crq));
141                 atomic_set(&evt->free, 1);
142                 evt->crq.valid = 0x80;
143                 evt->crq.IU_length = sizeof(*evt->xfer_iu);
144                 evt->crq.IU_data_ptr = pool->iu_token + 
145                         sizeof(*evt->xfer_iu) * i;
146                 evt->xfer_iu = pool->iu_storage + i;
147                 evt->hostdata = hostdata;
148                 evt->ext_list = NULL;
149                 evt->ext_list_token = 0;
150         }
151
152         return 0;
153 }
154
155 /**
156  * release_event_pool: - Frees memory of an event pool of a host
157  * @pool:       event_pool to be released
158  * @hostdata:   ibmvscsi_host_data who owns the even pool
159  *
160  * Returns zero on success.
161 */
162 static void release_event_pool(struct event_pool *pool,
163                                struct ibmvscsi_host_data *hostdata)
164 {
165         int i, in_use = 0;
166         for (i = 0; i < pool->size; ++i) {
167                 if (atomic_read(&pool->events[i].free) != 1)
168                         ++in_use;
169                 if (pool->events[i].ext_list) {
170                         dma_free_coherent(hostdata->dev,
171                                   SG_ALL * sizeof(struct memory_descriptor),
172                                   pool->events[i].ext_list,
173                                   pool->events[i].ext_list_token);
174                 }
175         }
176         if (in_use)
177                 printk(KERN_WARNING
178                        "ibmvscsi: releasing event pool with %d "
179                        "events still in use?\n", in_use);
180         kfree(pool->events);
181         dma_free_coherent(hostdata->dev,
182                           pool->size * sizeof(*pool->iu_storage),
183                           pool->iu_storage, pool->iu_token);
184 }
185
186 /**
187  * valid_event_struct: - Determines if event is valid.
188  * @pool:       event_pool that contains the event
189  * @evt:        srp_event_struct to be checked for validity
190  *
191  * Returns zero if event is invalid, one otherwise.
192 */
193 static int valid_event_struct(struct event_pool *pool,
194                                 struct srp_event_struct *evt)
195 {
196         int index = evt - pool->events;
197         if (index < 0 || index >= pool->size)   /* outside of bounds */
198                 return 0;
199         if (evt != pool->events + index)        /* unaligned */
200                 return 0;
201         return 1;
202 }
203
204 /**
205  * ibmvscsi_free-event_struct: - Changes status of event to "free"
206  * @pool:       event_pool that contains the event
207  * @evt:        srp_event_struct to be modified
208  *
209 */
210 static void free_event_struct(struct event_pool *pool,
211                                        struct srp_event_struct *evt)
212 {
213         if (!valid_event_struct(pool, evt)) {
214                 printk(KERN_ERR
215                        "ibmvscsi: Freeing invalid event_struct %p "
216                        "(not in pool %p)\n", evt, pool->events);
217                 return;
218         }
219         if (atomic_inc_return(&evt->free) != 1) {
220                 printk(KERN_ERR
221                        "ibmvscsi: Freeing event_struct %p "
222                        "which is not in use!\n", evt);
223                 return;
224         }
225 }
226
227 /**
228  * get_evt_struct: - Gets the next free event in pool
229  * @pool:       event_pool that contains the events to be searched
230  *
231  * Returns the next event in "free" state, and NULL if none are free.
232  * Note that no synchronization is done here, we assume the host_lock
233  * will syncrhonze things.
234 */
235 static struct srp_event_struct *get_event_struct(struct event_pool *pool)
236 {
237         int i;
238         int poolsize = pool->size;
239         int offset = pool->next;
240
241         for (i = 0; i < poolsize; i++) {
242                 offset = (offset + 1) % poolsize;
243                 if (!atomic_dec_if_positive(&pool->events[offset].free)) {
244                         pool->next = offset;
245                         return &pool->events[offset];
246                 }
247         }
248
249         printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
250         return NULL;
251 }
252
253 /**
254  * init_event_struct: Initialize fields in an event struct that are always 
255  *                    required.
256  * @evt:        The event
257  * @done:       Routine to call when the event is responded to
258  * @format:     SRP or MAD format
259  * @timeout:    timeout value set in the CRQ
260  */
261 static void init_event_struct(struct srp_event_struct *evt_struct,
262                               void (*done) (struct srp_event_struct *),
263                               u8 format,
264                               int timeout)
265 {
266         evt_struct->cmnd = NULL;
267         evt_struct->cmnd_done = NULL;
268         evt_struct->sync_srp = NULL;
269         evt_struct->crq.format = format;
270         evt_struct->crq.timeout = timeout;
271         evt_struct->done = done;
272 }
273
274 /* ------------------------------------------------------------
275  * Routines for receiving SCSI responses from the hosting partition
276  */
277
278 /**
279  * set_srp_direction: Set the fields in the srp related to data
280  *     direction and number of buffers based on the direction in
281  *     the scsi_cmnd and the number of buffers
282  */
283 static void set_srp_direction(struct scsi_cmnd *cmd,
284                               struct srp_cmd *srp_cmd, 
285                               int numbuf)
286 {
287         if (numbuf == 0)
288                 return;
289         
290         if (numbuf == 1) {
291                 if (cmd->sc_data_direction == DMA_TO_DEVICE)
292                         srp_cmd->data_out_format = SRP_DIRECT_BUFFER;
293                 else 
294                         srp_cmd->data_in_format = SRP_DIRECT_BUFFER;
295         } else {
296                 if (cmd->sc_data_direction == DMA_TO_DEVICE) {
297                         srp_cmd->data_out_format = SRP_INDIRECT_BUFFER;
298                         srp_cmd->data_out_count =
299                                 numbuf < MAX_INDIRECT_BUFS ?
300                                         numbuf: MAX_INDIRECT_BUFS;
301                 } else {
302                         srp_cmd->data_in_format = SRP_INDIRECT_BUFFER;
303                         srp_cmd->data_in_count =
304                                 numbuf < MAX_INDIRECT_BUFS ?
305                                         numbuf: MAX_INDIRECT_BUFS;
306                 }
307         }
308 }
309
310 static void unmap_sg_list(int num_entries, 
311                 struct device *dev,
312                 struct memory_descriptor *md)
313
314         int i;
315
316         for (i = 0; i < num_entries; ++i) {
317                 dma_unmap_single(dev,
318                         md[i].virtual_address,
319                         md[i].length, DMA_BIDIRECTIONAL);
320         }
321 }
322
323 /**
324  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
325  * @cmd:        srp_cmd whose additional_data member will be unmapped
326  * @dev:        device for which the memory is mapped
327  *
328 */
329 static void unmap_cmd_data(struct srp_cmd *cmd,
330                            struct srp_event_struct *evt_struct,
331                            struct device *dev)
332 {
333         if ((cmd->data_out_format == SRP_NO_BUFFER) &&
334             (cmd->data_in_format == SRP_NO_BUFFER))
335                 return;
336         else if ((cmd->data_out_format == SRP_DIRECT_BUFFER) ||
337                  (cmd->data_in_format == SRP_DIRECT_BUFFER)) {
338                 struct memory_descriptor *data =
339                         (struct memory_descriptor *)cmd->additional_data;
340                 dma_unmap_single(dev, data->virtual_address, data->length,
341                                  DMA_BIDIRECTIONAL);
342         } else {
343                 struct indirect_descriptor *indirect =
344                         (struct indirect_descriptor *)cmd->additional_data;
345                 int num_mapped = indirect->head.length / 
346                         sizeof(indirect->list[0]);
347
348                 if (num_mapped <= MAX_INDIRECT_BUFS) {
349                         unmap_sg_list(num_mapped, dev, &indirect->list[0]);
350                         return;
351                 }
352
353                 unmap_sg_list(num_mapped, dev, evt_struct->ext_list);
354         }
355 }
356
357 static int map_sg_list(int num_entries, 
358                        struct scatterlist *sg,
359                        struct memory_descriptor *md)
360 {
361         int i;
362         u64 total_length = 0;
363
364         for (i = 0; i < num_entries; ++i) {
365                 struct memory_descriptor *descr = md + i;
366                 struct scatterlist *sg_entry = &sg[i];
367                 descr->virtual_address = sg_dma_address(sg_entry);
368                 descr->length = sg_dma_len(sg_entry);
369                 descr->memory_handle = 0;
370                 total_length += sg_dma_len(sg_entry);
371         }
372         return total_length;
373 }
374
375 /**
376  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
377  * @cmd:        Scsi_Cmnd with the scatterlist
378  * @srp_cmd:    srp_cmd that contains the memory descriptor
379  * @dev:        device for which to map dma memory
380  *
381  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
382  * Returns 1 on success.
383 */
384 static int map_sg_data(struct scsi_cmnd *cmd,
385                        struct srp_event_struct *evt_struct,
386                        struct srp_cmd *srp_cmd, struct device *dev)
387 {
388
389         int sg_mapped;
390         u64 total_length = 0;
391         struct scatterlist *sg = cmd->request_buffer;
392         struct memory_descriptor *data =
393             (struct memory_descriptor *)srp_cmd->additional_data;
394         struct indirect_descriptor *indirect =
395             (struct indirect_descriptor *)data;
396
397         sg_mapped = dma_map_sg(dev, sg, cmd->use_sg, DMA_BIDIRECTIONAL);
398
399         if (sg_mapped == 0)
400                 return 0;
401
402         set_srp_direction(cmd, srp_cmd, sg_mapped);
403
404         /* special case; we can use a single direct descriptor */
405         if (sg_mapped == 1) {
406                 data->virtual_address = sg_dma_address(&sg[0]);
407                 data->length = sg_dma_len(&sg[0]);
408                 data->memory_handle = 0;
409                 return 1;
410         }
411
412         if (sg_mapped > SG_ALL) {
413                 printk(KERN_ERR
414                        "ibmvscsi: More than %d mapped sg entries, got %d\n",
415                        SG_ALL, sg_mapped);
416                 return 0;
417         }
418
419         indirect->head.virtual_address = 0;
420         indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
421         indirect->head.memory_handle = 0;
422
423         if (sg_mapped <= MAX_INDIRECT_BUFS) {
424                 total_length = map_sg_list(sg_mapped, sg, &indirect->list[0]);
425                 indirect->total_length = total_length;
426                 return 1;
427         }
428
429         /* get indirect table */
430         if (!evt_struct->ext_list) {
431                 evt_struct->ext_list =(struct memory_descriptor*)
432                         dma_alloc_coherent(dev, 
433                                 SG_ALL * sizeof(struct memory_descriptor),
434                                 &evt_struct->ext_list_token, 0);
435                 if (!evt_struct->ext_list) {
436                     printk(KERN_ERR
437                         "ibmvscsi: Can't allocate memory for indirect table\n");
438                         return 0;
439                         
440                 }
441         }
442
443         total_length = map_sg_list(sg_mapped, sg, evt_struct->ext_list);        
444
445         indirect->total_length = total_length;
446         indirect->head.virtual_address = evt_struct->ext_list_token;
447         indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
448         memcpy(indirect->list, evt_struct->ext_list,
449                 MAX_INDIRECT_BUFS * sizeof(struct memory_descriptor));
450         
451         return 1;
452 }
453
454 /**
455  * map_single_data: - Maps memory and initializes memory decriptor fields
456  * @cmd:        struct scsi_cmnd with the memory to be mapped
457  * @srp_cmd:    srp_cmd that contains the memory descriptor
458  * @dev:        device for which to map dma memory
459  *
460  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
461  * Returns 1 on success.
462 */
463 static int map_single_data(struct scsi_cmnd *cmd,
464                            struct srp_cmd *srp_cmd, struct device *dev)
465 {
466         struct memory_descriptor *data =
467             (struct memory_descriptor *)srp_cmd->additional_data;
468
469         data->virtual_address =
470                 dma_map_single(dev, cmd->request_buffer,
471                                cmd->request_bufflen,
472                                DMA_BIDIRECTIONAL);
473         if (dma_mapping_error(data->virtual_address)) {
474                 printk(KERN_ERR
475                        "ibmvscsi: Unable to map request_buffer for command!\n");
476                 return 0;
477         }
478         data->length = cmd->request_bufflen;
479         data->memory_handle = 0;
480
481         set_srp_direction(cmd, srp_cmd, 1);
482
483         return 1;
484 }
485
486 /**
487  * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
488  * @cmd:        struct scsi_cmnd with the memory to be mapped
489  * @srp_cmd:    srp_cmd that contains the memory descriptor
490  * @dev:        dma device for which to map dma memory
491  *
492  * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds 
493  * Returns 1 on success.
494 */
495 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
496                                 struct srp_event_struct *evt_struct,
497                                 struct srp_cmd *srp_cmd, struct device *dev)
498 {
499         switch (cmd->sc_data_direction) {
500         case DMA_FROM_DEVICE:
501         case DMA_TO_DEVICE:
502                 break;
503         case DMA_NONE:
504                 return 1;
505         case DMA_BIDIRECTIONAL:
506                 printk(KERN_ERR
507                        "ibmvscsi: Can't map DMA_BIDIRECTIONAL to read/write\n");
508                 return 0;
509         default:
510                 printk(KERN_ERR
511                        "ibmvscsi: Unknown data direction 0x%02x; can't map!\n",
512                        cmd->sc_data_direction);
513                 return 0;
514         }
515
516         if (!cmd->request_buffer)
517                 return 1;
518         if (cmd->use_sg)
519                 return map_sg_data(cmd, evt_struct, srp_cmd, dev);
520         return map_single_data(cmd, srp_cmd, dev);
521 }
522
523 /* ------------------------------------------------------------
524  * Routines for sending and receiving SRPs
525  */
526 /**
527  * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
528  * @evt_struct: evt_struct to be sent
529  * @hostdata:   ibmvscsi_host_data of host
530  *
531  * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
532  * Note that this routine assumes that host_lock is held for synchronization
533 */
534 static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
535                                    struct ibmvscsi_host_data *hostdata)
536 {
537         u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
538         int rc;
539
540         /* If we have exhausted our request limit, just fail this request.
541          * Note that there are rare cases involving driver generated requests 
542          * (such as task management requests) that the mid layer may think we
543          * can handle more requests (can_queue) when we actually can't
544          */
545         if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
546             (atomic_dec_if_positive(&hostdata->request_limit) < 0))
547                 goto send_error;
548
549         /* Copy the IU into the transfer area */
550         *evt_struct->xfer_iu = evt_struct->iu;
551         evt_struct->xfer_iu->srp.generic.tag = (u64)evt_struct;
552
553         /* Add this to the sent list.  We need to do this 
554          * before we actually send 
555          * in case it comes back REALLY fast
556          */
557         list_add_tail(&evt_struct->list, &hostdata->sent);
558
559         if ((rc =
560              ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
561                 list_del(&evt_struct->list);
562
563                 printk(KERN_ERR "ibmvscsi: send error %d\n",
564                        rc);
565                 goto send_error;
566         }
567
568         return 0;
569
570  send_error:
571         unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
572
573         free_event_struct(&hostdata->pool, evt_struct);
574         return SCSI_MLQUEUE_HOST_BUSY;
575 }
576
577 /**
578  * handle_cmd_rsp: -  Handle responses from commands
579  * @evt_struct: srp_event_struct to be handled
580  *
581  * Used as a callback by when sending scsi cmds.
582  * Gets called by ibmvscsi_handle_crq()
583 */
584 static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
585 {
586         struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
587         struct scsi_cmnd *cmnd = evt_struct->cmnd;
588
589         if (unlikely(rsp->type != SRP_RSP_TYPE)) {
590                 if (printk_ratelimit())
591                         printk(KERN_WARNING 
592                                "ibmvscsi: bad SRP RSP type %d\n",
593                                rsp->type);
594         }
595         
596         if (cmnd) {
597                 cmnd->result = rsp->status;
598                 if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
599                         memcpy(cmnd->sense_buffer,
600                                rsp->sense_and_response_data,
601                                rsp->sense_data_list_length);
602                 unmap_cmd_data(&evt_struct->iu.srp.cmd, 
603                                evt_struct, 
604                                evt_struct->hostdata->dev);
605
606                 if (rsp->doover)
607                         cmnd->resid = rsp->data_out_residual_count;
608                 else if (rsp->diover)
609                         cmnd->resid = rsp->data_in_residual_count;
610         }
611
612         if (evt_struct->cmnd_done)
613                 evt_struct->cmnd_done(cmnd);
614 }
615
616 /**
617  * lun_from_dev: - Returns the lun of the scsi device
618  * @dev:        struct scsi_device
619  *
620 */
621 static inline u16 lun_from_dev(struct scsi_device *dev)
622 {
623         return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
624 }
625
626 /**
627  * ibmvscsi_queue: - The queuecommand function of the scsi template 
628  * @cmd:        struct scsi_cmnd to be executed
629  * @done:       Callback function to be called when cmd is completed
630 */
631 static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
632                                  void (*done) (struct scsi_cmnd *))
633 {
634         struct srp_cmd *srp_cmd;
635         struct srp_event_struct *evt_struct;
636         struct indirect_descriptor *indirect;
637         struct ibmvscsi_host_data *hostdata =
638                 (struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
639         u16 lun = lun_from_dev(cmnd->device);
640
641         evt_struct = get_event_struct(&hostdata->pool);
642         if (!evt_struct)
643                 return SCSI_MLQUEUE_HOST_BUSY;
644
645         /* Set up the actual SRP IU */
646         srp_cmd = &evt_struct->iu.srp.cmd;
647         memset(srp_cmd, 0x00, sizeof(*srp_cmd));
648         srp_cmd->type = SRP_CMD_TYPE;
649         memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
650         srp_cmd->lun = ((u64) lun) << 48;
651
652         if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
653                 printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
654                 free_event_struct(&hostdata->pool, evt_struct);
655                 return SCSI_MLQUEUE_HOST_BUSY;
656         }
657
658         init_event_struct(evt_struct,
659                           handle_cmd_rsp,
660                           VIOSRP_SRP_FORMAT,
661                           cmnd->timeout_per_command/HZ);
662
663         evt_struct->cmnd = cmnd;
664         evt_struct->cmnd_done = done;
665
666         /* Fix up dma address of the buffer itself */
667         indirect = (struct indirect_descriptor *)srp_cmd->additional_data;
668         if (((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
669             (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) &&
670             (indirect->head.virtual_address == 0)) {
671                 indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
672                     offsetof(struct srp_cmd, additional_data) +
673                     offsetof(struct indirect_descriptor, list);
674         }
675
676         return ibmvscsi_send_srp_event(evt_struct, hostdata);
677 }
678
679 /* ------------------------------------------------------------
680  * Routines for driver initialization
681  */
682 /**
683  * adapter_info_rsp: - Handle response to MAD adapter info request
684  * @evt_struct: srp_event_struct with the response
685  *
686  * Used as a "done" callback by when sending adapter_info. Gets called
687  * by ibmvscsi_handle_crq()
688 */
689 static void adapter_info_rsp(struct srp_event_struct *evt_struct)
690 {
691         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
692         dma_unmap_single(hostdata->dev,
693                          evt_struct->iu.mad.adapter_info.buffer,
694                          evt_struct->iu.mad.adapter_info.common.length,
695                          DMA_BIDIRECTIONAL);
696
697         if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
698                 printk("ibmvscsi: error %d getting adapter info\n",
699                        evt_struct->xfer_iu->mad.adapter_info.common.status);
700         } else {
701                 printk("ibmvscsi: host srp version: %s, "
702                        "host partition %s (%d), OS %d, max io %u\n",
703                        hostdata->madapter_info.srp_version,
704                        hostdata->madapter_info.partition_name,
705                        hostdata->madapter_info.partition_number,
706                        hostdata->madapter_info.os_type,
707                        hostdata->madapter_info.port_max_txu[0]);
708                 
709                 if (hostdata->madapter_info.port_max_txu[0]) 
710                         hostdata->host->max_sectors = 
711                                 hostdata->madapter_info.port_max_txu[0] >> 9;
712                 
713                 if (hostdata->madapter_info.os_type == 3 &&
714                     strcmp(hostdata->madapter_info.srp_version, "1.6a") <= 0) {
715                         printk("ibmvscsi: host (Ver. %s) doesn't support large"
716                                "transfers\n",
717                                hostdata->madapter_info.srp_version);
718                         printk("ibmvscsi: limiting scatterlists to %d\n",
719                                MAX_INDIRECT_BUFS);
720                         hostdata->host->sg_tablesize = MAX_INDIRECT_BUFS;
721                 }
722         }
723 }
724
725 /**
726  * send_mad_adapter_info: - Sends the mad adapter info request
727  *      and stores the result so it can be retrieved with
728  *      sysfs.  We COULD consider causing a failure if the
729  *      returned SRP version doesn't match ours.
730  * @hostdata:   ibmvscsi_host_data of host
731  * 
732  * Returns zero if successful.
733 */
734 static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
735 {
736         struct viosrp_adapter_info *req;
737         struct srp_event_struct *evt_struct;
738         
739         evt_struct = get_event_struct(&hostdata->pool);
740         if (!evt_struct) {
741                 printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
742                        "for ADAPTER_INFO_REQ!\n");
743                 return;
744         }
745
746         init_event_struct(evt_struct,
747                           adapter_info_rsp,
748                           VIOSRP_MAD_FORMAT,
749                           init_timeout * HZ);
750         
751         req = &evt_struct->iu.mad.adapter_info;
752         memset(req, 0x00, sizeof(*req));
753         
754         req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
755         req->common.length = sizeof(hostdata->madapter_info);
756         req->buffer = dma_map_single(hostdata->dev,
757                                      &hostdata->madapter_info,
758                                      sizeof(hostdata->madapter_info),
759                                      DMA_BIDIRECTIONAL);
760
761         if (dma_mapping_error(req->buffer)) {
762                 printk(KERN_ERR
763                        "ibmvscsi: Unable to map request_buffer "
764                        "for adapter_info!\n");
765                 free_event_struct(&hostdata->pool, evt_struct);
766                 return;
767         }
768         
769         if (ibmvscsi_send_srp_event(evt_struct, hostdata))
770                 printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
771 };
772
773 /**
774  * login_rsp: - Handle response to SRP login request
775  * @evt_struct: srp_event_struct with the response
776  *
777  * Used as a "done" callback by when sending srp_login. Gets called
778  * by ibmvscsi_handle_crq()
779 */
780 static void login_rsp(struct srp_event_struct *evt_struct)
781 {
782         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
783         switch (evt_struct->xfer_iu->srp.generic.type) {
784         case SRP_LOGIN_RSP_TYPE:        /* it worked! */
785                 break;
786         case SRP_LOGIN_REJ_TYPE:        /* refused! */
787                 printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REJ reason %u\n",
788                        evt_struct->xfer_iu->srp.login_rej.reason);
789                 /* Login failed.  */
790                 atomic_set(&hostdata->request_limit, -1);
791                 return;
792         default:
793                 printk(KERN_ERR
794                        "ibmvscsi: Invalid login response typecode 0x%02x!\n",
795                        evt_struct->xfer_iu->srp.generic.type);
796                 /* Login failed.  */
797                 atomic_set(&hostdata->request_limit, -1);
798                 return;
799         }
800
801         printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");
802
803         if (evt_struct->xfer_iu->srp.login_rsp.request_limit_delta >
804             (max_requests - 2))
805                 evt_struct->xfer_iu->srp.login_rsp.request_limit_delta =
806                     max_requests - 2;
807
808         /* Now we know what the real request-limit is */
809         atomic_set(&hostdata->request_limit,
810                    evt_struct->xfer_iu->srp.login_rsp.request_limit_delta);
811
812         hostdata->host->can_queue =
813             evt_struct->xfer_iu->srp.login_rsp.request_limit_delta - 2;
814
815         if (hostdata->host->can_queue < 1) {
816                 printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
817                 return;
818         }
819
820         /* If we had any pending I/Os, kick them */
821         scsi_unblock_requests(hostdata->host);
822
823         send_mad_adapter_info(hostdata);
824         return;
825 }
826
827 /**
828  * send_srp_login: - Sends the srp login
829  * @hostdata:   ibmvscsi_host_data of host
830  * 
831  * Returns zero if successful.
832 */
833 static int send_srp_login(struct ibmvscsi_host_data *hostdata)
834 {
835         int rc;
836         unsigned long flags;
837         struct srp_login_req *login;
838         struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
839         if (!evt_struct) {
840                 printk(KERN_ERR
841                        "ibmvscsi: couldn't allocate an event for login req!\n");
842                 return FAILED;
843         }
844
845         init_event_struct(evt_struct,
846                           login_rsp,
847                           VIOSRP_SRP_FORMAT,
848                           init_timeout * HZ);
849
850         login = &evt_struct->iu.srp.login_req;
851         memset(login, 0x00, sizeof(struct srp_login_req));
852         login->type = SRP_LOGIN_REQ_TYPE;
853         login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
854         login->required_buffer_formats = 0x0006;
855         
856         /* Start out with a request limit of 1, since this is negotiated in
857          * the login request we are just sending
858          */
859         atomic_set(&hostdata->request_limit, 1);
860
861         spin_lock_irqsave(hostdata->host->host_lock, flags);
862         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
863         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
864         return rc;
865 };
866
867 /**
868  * sync_completion: Signal that a synchronous command has completed
869  * Note that after returning from this call, the evt_struct is freed.
870  * the caller waiting on this completion shouldn't touch the evt_struct
871  * again.
872  */
873 static void sync_completion(struct srp_event_struct *evt_struct)
874 {
875         /* copy the response back */
876         if (evt_struct->sync_srp)
877                 *evt_struct->sync_srp = *evt_struct->xfer_iu;
878         
879         complete(&evt_struct->comp);
880 }
881
882 /**
883  * ibmvscsi_abort: Abort a command...from scsi host template
884  * send this over to the server and wait synchronously for the response
885  */
886 static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
887 {
888         struct ibmvscsi_host_data *hostdata =
889             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
890         struct srp_tsk_mgmt *tsk_mgmt;
891         struct srp_event_struct *evt;
892         struct srp_event_struct *tmp_evt, *found_evt;
893         union viosrp_iu srp_rsp;
894         int rsp_rc;
895         unsigned long flags;
896         u16 lun = lun_from_dev(cmd->device);
897
898         /* First, find this command in our sent list so we can figure
899          * out the correct tag
900          */
901         spin_lock_irqsave(hostdata->host->host_lock, flags);
902         found_evt = NULL;
903         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
904                 if (tmp_evt->cmnd == cmd) {
905                         found_evt = tmp_evt;
906                         break;
907                 }
908         }
909
910         if (!found_evt) {
911                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
912                 return FAILED;
913         }
914
915         evt = get_event_struct(&hostdata->pool);
916         if (evt == NULL) {
917                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
918                 printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
919                 return FAILED;
920         }
921         
922         init_event_struct(evt,
923                           sync_completion,
924                           VIOSRP_SRP_FORMAT,
925                           init_timeout * HZ);
926
927         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
928         
929         /* Set up an abort SRP command */
930         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
931         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
932         tsk_mgmt->lun = ((u64) lun) << 48;
933         tsk_mgmt->task_mgmt_flags = 0x01;       /* ABORT TASK */
934         tsk_mgmt->managed_task_tag = (u64) found_evt;
935
936         printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
937                tsk_mgmt->lun, tsk_mgmt->managed_task_tag);
938
939         evt->sync_srp = &srp_rsp;
940         init_completion(&evt->comp);
941         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);
942         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
943         if (rsp_rc != 0) {
944                 printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
945                 return FAILED;
946         }
947
948         wait_for_completion(&evt->comp);
949
950         /* make sure we got a good response */
951         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
952                 if (printk_ratelimit())
953                         printk(KERN_WARNING 
954                                "ibmvscsi: abort bad SRP RSP type %d\n",
955                                srp_rsp.srp.generic.type);
956                 return FAILED;
957         }
958
959         if (srp_rsp.srp.rsp.rspvalid)
960                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
961         else
962                 rsp_rc = srp_rsp.srp.rsp.status;
963
964         if (rsp_rc) {
965                 if (printk_ratelimit())
966                         printk(KERN_WARNING 
967                        "ibmvscsi: abort code %d for task tag 0x%lx\n",
968                                rsp_rc,
969                                tsk_mgmt->managed_task_tag);
970                 return FAILED;
971         }
972
973         /* Because we dropped the spinlock above, it's possible
974          * The event is no longer in our list.  Make sure it didn't
975          * complete while we were aborting
976          */
977         spin_lock_irqsave(hostdata->host->host_lock, flags);
978         found_evt = NULL;
979         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
980                 if (tmp_evt->cmnd == cmd) {
981                         found_evt = tmp_evt;
982                         break;
983                 }
984         }
985
986         if (found_evt == NULL) {
987                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
988                 printk(KERN_INFO
989                        "ibmvscsi: aborted task tag 0x%lx completed\n",
990                        tsk_mgmt->managed_task_tag);
991                 return SUCCESS;
992         }
993
994         printk(KERN_INFO
995                "ibmvscsi: successfully aborted task tag 0x%lx\n",
996                tsk_mgmt->managed_task_tag);
997
998         cmd->result = (DID_ABORT << 16);
999         list_del(&found_evt->list);
1000         unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
1001                        found_evt->hostdata->dev);
1002         free_event_struct(&found_evt->hostdata->pool, found_evt);
1003         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1004         atomic_inc(&hostdata->request_limit);
1005         return SUCCESS;
1006 }
1007
1008 /**
1009  * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host 
1010  * template send this over to the server and wait synchronously for the 
1011  * response
1012  */
1013 static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
1014 {
1015         struct ibmvscsi_host_data *hostdata =
1016             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
1017
1018         struct srp_tsk_mgmt *tsk_mgmt;
1019         struct srp_event_struct *evt;
1020         struct srp_event_struct *tmp_evt, *pos;
1021         union viosrp_iu srp_rsp;
1022         int rsp_rc;
1023         unsigned long flags;
1024         u16 lun = lun_from_dev(cmd->device);
1025
1026         spin_lock_irqsave(hostdata->host->host_lock, flags);
1027         evt = get_event_struct(&hostdata->pool);
1028         if (evt == NULL) {
1029                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1030                 printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
1031                 return FAILED;
1032         }
1033         
1034         init_event_struct(evt,
1035                           sync_completion,
1036                           VIOSRP_SRP_FORMAT,
1037                           init_timeout * HZ);
1038
1039         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1040
1041         /* Set up a lun reset SRP command */
1042         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1043         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
1044         tsk_mgmt->lun = ((u64) lun) << 48;
1045         tsk_mgmt->task_mgmt_flags = 0x08;       /* LUN RESET */
1046
1047         printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
1048                tsk_mgmt->lun);
1049
1050         evt->sync_srp = &srp_rsp;
1051         init_completion(&evt->comp);
1052         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);
1053         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1054         if (rsp_rc != 0) {
1055                 printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
1056                 return FAILED;
1057         }
1058
1059         wait_for_completion(&evt->comp);
1060
1061         /* make sure we got a good response */
1062         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
1063                 if (printk_ratelimit())
1064                         printk(KERN_WARNING 
1065                                "ibmvscsi: reset bad SRP RSP type %d\n",
1066                                srp_rsp.srp.generic.type);
1067                 return FAILED;
1068         }
1069
1070         if (srp_rsp.srp.rsp.rspvalid)
1071                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
1072         else
1073                 rsp_rc = srp_rsp.srp.rsp.status;
1074
1075         if (rsp_rc) {
1076                 if (printk_ratelimit())
1077                         printk(KERN_WARNING 
1078                                "ibmvscsi: reset code %d for task tag 0x%lx\n",
1079                        rsp_rc,
1080                                tsk_mgmt->managed_task_tag);
1081                 return FAILED;
1082         }
1083
1084         /* We need to find all commands for this LUN that have not yet been
1085          * responded to, and fail them with DID_RESET
1086          */
1087         spin_lock_irqsave(hostdata->host->host_lock, flags);
1088         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1089                 if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1090                         if (tmp_evt->cmnd)
1091                                 tmp_evt->cmnd->result = (DID_RESET << 16);
1092                         list_del(&tmp_evt->list);
1093                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
1094                                        tmp_evt->hostdata->dev);
1095                         free_event_struct(&tmp_evt->hostdata->pool,
1096                                                    tmp_evt);
1097                         atomic_inc(&hostdata->request_limit);
1098                         if (tmp_evt->cmnd_done)
1099                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1100                         else if (tmp_evt->done)
1101                                 tmp_evt->done(tmp_evt);
1102                 }
1103         }
1104         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1105         return SUCCESS;
1106 }
1107
1108 /**
1109  * purge_requests: Our virtual adapter just shut down.  purge any sent requests
1110  * @hostdata:    the adapter
1111  */
1112 static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)
1113 {
1114         struct srp_event_struct *tmp_evt, *pos;
1115         unsigned long flags;
1116
1117         spin_lock_irqsave(hostdata->host->host_lock, flags);
1118         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1119                 list_del(&tmp_evt->list);
1120                 if (tmp_evt->cmnd) {
1121                         tmp_evt->cmnd->result = (error_code << 16);
1122                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, 
1123                                        tmp_evt, 
1124                                        tmp_evt->hostdata->dev);
1125                         if (tmp_evt->cmnd_done)
1126                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1127                 } else {
1128                         if (tmp_evt->done) {
1129                                 tmp_evt->done(tmp_evt);
1130                         }
1131                 }
1132                 free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
1133         }
1134         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1135 }
1136
1137 /**
1138  * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1139  * @crq:        Command/Response queue
1140  * @hostdata:   ibmvscsi_host_data of host
1141  *
1142 */
1143 void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1144                          struct ibmvscsi_host_data *hostdata)
1145 {
1146         unsigned long flags;
1147         struct srp_event_struct *evt_struct =
1148             (struct srp_event_struct *)crq->IU_data_ptr;
1149         switch (crq->valid) {
1150         case 0xC0:              /* initialization */
1151                 switch (crq->format) {
1152                 case 0x01:      /* Initialization message */
1153                         printk(KERN_INFO "ibmvscsi: partner initialized\n");
1154                         /* Send back a response */
1155                         if (ibmvscsi_send_crq(hostdata,
1156                                               0xC002000000000000LL, 0) == 0) {
1157                                 /* Now login */
1158                                 send_srp_login(hostdata);
1159                         } else {
1160                                 printk(KERN_ERR
1161                                        "ibmvscsi: Unable to send init rsp\n");
1162                         }
1163
1164                         break;
1165                 case 0x02:      /* Initialization response */
1166                         printk(KERN_INFO
1167                                "ibmvscsi: partner initialization complete\n");
1168
1169                         /* Now login */
1170                         send_srp_login(hostdata);
1171                         break;
1172                 default:
1173                         printk(KERN_ERR "ibmvscsi: unknown crq message type\n");
1174                 }
1175                 return;
1176         case 0xFF:      /* Hypervisor telling us the connection is closed */
1177                 scsi_block_requests(hostdata->host);
1178                 if (crq->format == 0x06) {
1179                         /* We need to re-setup the interpartition connection */
1180                         printk(KERN_INFO
1181                                "ibmvscsi: Re-enabling adapter!\n");
1182                         purge_requests(hostdata, DID_REQUEUE);
1183                         if (ibmvscsi_reenable_crq_queue(&hostdata->queue,
1184                                                         hostdata) == 0)
1185                                 if (ibmvscsi_send_crq(hostdata,
1186                                                       0xC001000000000000LL, 0))
1187                                         printk(KERN_ERR
1188                                                "ibmvscsi: transmit error after"
1189                                                " enable\n");
1190                 } else {
1191                         printk(KERN_INFO
1192                                "ibmvscsi: Virtual adapter failed rc %d!\n",
1193                                crq->format);
1194
1195                         atomic_set(&hostdata->request_limit, -1);
1196                         purge_requests(hostdata, DID_ERROR);
1197                         ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
1198                 }
1199                 scsi_unblock_requests(hostdata->host);
1200                 return;
1201         case 0x80:              /* real payload */
1202                 break;
1203         default:
1204                 printk(KERN_ERR
1205                        "ibmvscsi: got an invalid message type 0x%02x\n",
1206                        crq->valid);
1207                 return;
1208         }
1209
1210         /* The only kind of payload CRQs we should get are responses to
1211          * things we send. Make sure this response is to something we
1212          * actually sent
1213          */
1214         if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1215                 printk(KERN_ERR
1216                        "ibmvscsi: returned correlation_token 0x%p is invalid!\n",
1217                        (void *)crq->IU_data_ptr);
1218                 return;
1219         }
1220
1221         if (atomic_read(&evt_struct->free)) {
1222                 printk(KERN_ERR
1223                        "ibmvscsi: received duplicate  correlation_token 0x%p!\n",
1224                        (void *)crq->IU_data_ptr);
1225                 return;
1226         }
1227
1228         if (crq->format == VIOSRP_SRP_FORMAT)
1229                 atomic_add(evt_struct->xfer_iu->srp.rsp.request_limit_delta,
1230                            &hostdata->request_limit);
1231
1232         if (evt_struct->done)
1233                 evt_struct->done(evt_struct);
1234         else
1235                 printk(KERN_ERR
1236                        "ibmvscsi: returned done() is NULL; not running it!\n");
1237
1238         /*
1239          * Lock the host_lock before messing with these structures, since we
1240          * are running in a task context
1241          */
1242         spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1243         list_del(&evt_struct->list);
1244         free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1245         spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1246 }
1247
1248 /**
1249  * ibmvscsi_get_host_config: Send the command to the server to get host
1250  * configuration data.  The data is opaque to us.
1251  */
1252 static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
1253                                    unsigned char *buffer, int length)
1254 {
1255         struct viosrp_host_config *host_config;
1256         struct srp_event_struct *evt_struct;
1257         int rc;
1258
1259         evt_struct = get_event_struct(&hostdata->pool);
1260         if (!evt_struct) {
1261                 printk(KERN_ERR
1262                        "ibmvscsi: could't allocate event for HOST_CONFIG!\n");
1263                 return -1;
1264         }
1265
1266         init_event_struct(evt_struct,
1267                           sync_completion,
1268                           VIOSRP_MAD_FORMAT,
1269                           init_timeout * HZ);
1270
1271         host_config = &evt_struct->iu.mad.host_config;
1272
1273         /* Set up a lun reset SRP command */
1274         memset(host_config, 0x00, sizeof(*host_config));
1275         host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
1276         host_config->common.length = length;
1277         host_config->buffer = dma_map_single(hostdata->dev, buffer, length,
1278                                             DMA_BIDIRECTIONAL);
1279
1280         if (dma_mapping_error(host_config->buffer)) {
1281                 printk(KERN_ERR
1282                        "ibmvscsi: dma_mapping error " "getting host config\n");
1283                 free_event_struct(&hostdata->pool, evt_struct);
1284                 return -1;
1285         }
1286
1287         init_completion(&evt_struct->comp);
1288         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
1289         if (rc == 0) {
1290                 wait_for_completion(&evt_struct->comp);
1291                 dma_unmap_single(hostdata->dev, host_config->buffer,
1292                                  length, DMA_BIDIRECTIONAL);
1293         }
1294
1295         return rc;
1296 }
1297
1298 /* ------------------------------------------------------------
1299  * sysfs attributes
1300  */
1301 static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
1302 {
1303         struct Scsi_Host *shost = class_to_shost(class_dev);
1304         struct ibmvscsi_host_data *hostdata =
1305             (struct ibmvscsi_host_data *)shost->hostdata;
1306         int len;
1307
1308         len = snprintf(buf, PAGE_SIZE, "%s\n",
1309                        hostdata->madapter_info.srp_version);
1310         return len;
1311 }
1312
1313 static struct class_device_attribute ibmvscsi_host_srp_version = {
1314         .attr = {
1315                  .name = "srp_version",
1316                  .mode = S_IRUGO,
1317                  },
1318         .show = show_host_srp_version,
1319 };
1320
1321 static ssize_t show_host_partition_name(struct class_device *class_dev,
1322                                         char *buf)
1323 {
1324         struct Scsi_Host *shost = class_to_shost(class_dev);
1325         struct ibmvscsi_host_data *hostdata =
1326             (struct ibmvscsi_host_data *)shost->hostdata;
1327         int len;
1328
1329         len = snprintf(buf, PAGE_SIZE, "%s\n",
1330                        hostdata->madapter_info.partition_name);
1331         return len;
1332 }
1333
1334 static struct class_device_attribute ibmvscsi_host_partition_name = {
1335         .attr = {
1336                  .name = "partition_name",
1337                  .mode = S_IRUGO,
1338                  },
1339         .show = show_host_partition_name,
1340 };
1341
1342 static ssize_t show_host_partition_number(struct class_device *class_dev,
1343                                           char *buf)
1344 {
1345         struct Scsi_Host *shost = class_to_shost(class_dev);
1346         struct ibmvscsi_host_data *hostdata =
1347             (struct ibmvscsi_host_data *)shost->hostdata;
1348         int len;
1349
1350         len = snprintf(buf, PAGE_SIZE, "%d\n",
1351                        hostdata->madapter_info.partition_number);
1352         return len;
1353 }
1354
1355 static struct class_device_attribute ibmvscsi_host_partition_number = {
1356         .attr = {
1357                  .name = "partition_number",
1358                  .mode = S_IRUGO,
1359                  },
1360         .show = show_host_partition_number,
1361 };
1362
1363 static ssize_t show_host_mad_version(struct class_device *class_dev, char *buf)
1364 {
1365         struct Scsi_Host *shost = class_to_shost(class_dev);
1366         struct ibmvscsi_host_data *hostdata =
1367             (struct ibmvscsi_host_data *)shost->hostdata;
1368         int len;
1369
1370         len = snprintf(buf, PAGE_SIZE, "%d\n",
1371                        hostdata->madapter_info.mad_version);
1372         return len;
1373 }
1374
1375 static struct class_device_attribute ibmvscsi_host_mad_version = {
1376         .attr = {
1377                  .name = "mad_version",
1378                  .mode = S_IRUGO,
1379                  },
1380         .show = show_host_mad_version,
1381 };
1382
1383 static ssize_t show_host_os_type(struct class_device *class_dev, char *buf)
1384 {
1385         struct Scsi_Host *shost = class_to_shost(class_dev);
1386         struct ibmvscsi_host_data *hostdata =
1387             (struct ibmvscsi_host_data *)shost->hostdata;
1388         int len;
1389
1390         len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
1391         return len;
1392 }
1393
1394 static struct class_device_attribute ibmvscsi_host_os_type = {
1395         .attr = {
1396                  .name = "os_type",
1397                  .mode = S_IRUGO,
1398                  },
1399         .show = show_host_os_type,
1400 };
1401
1402 static ssize_t show_host_config(struct class_device *class_dev, char *buf)
1403 {
1404         struct Scsi_Host *shost = class_to_shost(class_dev);
1405         struct ibmvscsi_host_data *hostdata =
1406             (struct ibmvscsi_host_data *)shost->hostdata;
1407
1408         /* returns null-terminated host config data */
1409         if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
1410                 return strlen(buf);
1411         else
1412                 return 0;
1413 }
1414
1415 static struct class_device_attribute ibmvscsi_host_config = {
1416         .attr = {
1417                  .name = "config",
1418                  .mode = S_IRUGO,
1419                  },
1420         .show = show_host_config,
1421 };
1422
1423 static struct class_device_attribute *ibmvscsi_attrs[] = {
1424         &ibmvscsi_host_srp_version,
1425         &ibmvscsi_host_partition_name,
1426         &ibmvscsi_host_partition_number,
1427         &ibmvscsi_host_mad_version,
1428         &ibmvscsi_host_os_type,
1429         &ibmvscsi_host_config,
1430         NULL
1431 };
1432
1433 /* ------------------------------------------------------------
1434  * SCSI driver registration
1435  */
1436 static struct scsi_host_template driver_template = {
1437         .module = THIS_MODULE,
1438         .name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
1439         .proc_name = "ibmvscsi",
1440         .queuecommand = ibmvscsi_queuecommand,
1441         .eh_abort_handler = ibmvscsi_eh_abort_handler,
1442         .eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
1443         .cmd_per_lun = 16,
1444         .can_queue = 1,         /* Updated after SRP_LOGIN */
1445         .this_id = -1,
1446         .sg_tablesize = SG_ALL,
1447         .use_clustering = ENABLE_CLUSTERING,
1448         .shost_attrs = ibmvscsi_attrs,
1449 };
1450
1451 /**
1452  * Called by bus code for each adapter
1453  */
1454 static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1455 {
1456         struct ibmvscsi_host_data *hostdata;
1457         struct Scsi_Host *host;
1458         struct device *dev = &vdev->dev;
1459         unsigned long wait_switch = 0;
1460
1461         vdev->dev.driver_data = NULL;
1462
1463         host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
1464         if (!host) {
1465                 printk(KERN_ERR "ibmvscsi: couldn't allocate host data\n");
1466                 goto scsi_host_alloc_failed;
1467         }
1468
1469         hostdata = (struct ibmvscsi_host_data *)host->hostdata;
1470         memset(hostdata, 0x00, sizeof(*hostdata));
1471         INIT_LIST_HEAD(&hostdata->sent);
1472         hostdata->host = host;
1473         hostdata->dev = dev;
1474         atomic_set(&hostdata->request_limit, -1);
1475         hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
1476
1477         if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
1478                                     max_requests) != 0) {
1479                 printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
1480                 goto init_crq_failed;
1481         }
1482         if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
1483                 printk(KERN_ERR "ibmvscsi: couldn't initialize event pool\n");
1484                 goto init_pool_failed;
1485         }
1486
1487         host->max_lun = 8;
1488         host->max_id = max_id;
1489         host->max_channel = max_channel;
1490
1491         if (scsi_add_host(hostdata->host, hostdata->dev))
1492                 goto add_host_failed;
1493
1494         /* Try to send an initialization message.  Note that this is allowed
1495          * to fail if the other end is not acive.  In that case we don't
1496          * want to scan
1497          */
1498         if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0) {
1499                 /*
1500                  * Wait around max init_timeout secs for the adapter to finish
1501                  * initializing. When we are done initializing, we will have a
1502                  * valid request_limit.  We don't want Linux scanning before
1503                  * we are ready.
1504                  */
1505                 for (wait_switch = jiffies + (init_timeout * HZ);
1506                      time_before(jiffies, wait_switch) &&
1507                      atomic_read(&hostdata->request_limit) < 2;) {
1508
1509                         msleep(10);
1510                 }
1511
1512                 /* if we now have a valid request_limit, initiate a scan */
1513                 if (atomic_read(&hostdata->request_limit) > 0)
1514                         scsi_scan_host(host);
1515         }
1516
1517         vdev->dev.driver_data = hostdata;
1518         return 0;
1519
1520       add_host_failed:
1521         release_event_pool(&hostdata->pool, hostdata);
1522       init_pool_failed:
1523         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_requests);
1524       init_crq_failed:
1525         scsi_host_put(host);
1526       scsi_host_alloc_failed:
1527         return -1;
1528 }
1529
1530 static int ibmvscsi_remove(struct vio_dev *vdev)
1531 {
1532         struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
1533         release_event_pool(&hostdata->pool, hostdata);
1534         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
1535                                    max_requests);
1536         
1537         scsi_remove_host(hostdata->host);
1538         scsi_host_put(hostdata->host);
1539
1540         return 0;
1541 }
1542
1543 /**
1544  * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we 
1545  * support.
1546  */
1547 static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
1548         {"vscsi", "IBM,v-scsi"},
1549         { "", "" }
1550 };
1551 MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
1552
1553 static struct vio_driver ibmvscsi_driver = {
1554         .id_table = ibmvscsi_device_table,
1555         .probe = ibmvscsi_probe,
1556         .remove = ibmvscsi_remove,
1557         .driver = {
1558                 .name = "ibmvscsi",
1559                 .owner = THIS_MODULE,
1560         }
1561 };
1562
1563 int __init ibmvscsi_module_init(void)
1564 {
1565         return vio_register_driver(&ibmvscsi_driver);
1566 }
1567
1568 void __exit ibmvscsi_module_exit(void)
1569 {
1570         vio_unregister_driver(&ibmvscsi_driver);
1571 }
1572
1573 module_init(ibmvscsi_module_init);
1574 module_exit(ibmvscsi_module_exit);