[SCSI] IBM VSCSI Client: sending client info to server
[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 "1.5.6"
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         }
149
150         return 0;
151 }
152
153 /**
154  * release_event_pool: - Frees memory of an event pool of a host
155  * @pool:       event_pool to be released
156  * @hostdata:   ibmvscsi_host_data who owns the even pool
157  *
158  * Returns zero on success.
159 */
160 static void release_event_pool(struct event_pool *pool,
161                                struct ibmvscsi_host_data *hostdata)
162 {
163         int i, in_use = 0;
164         for (i = 0; i < pool->size; ++i)
165                 if (atomic_read(&pool->events[i].free) != 1)
166                         ++in_use;
167         if (in_use)
168                 printk(KERN_WARNING
169                        "ibmvscsi: releasing event pool with %d "
170                        "events still in use?\n", in_use);
171         kfree(pool->events);
172         dma_free_coherent(hostdata->dev,
173                           pool->size * sizeof(*pool->iu_storage),
174                           pool->iu_storage, pool->iu_token);
175 }
176
177 /**
178  * valid_event_struct: - Determines if event is valid.
179  * @pool:       event_pool that contains the event
180  * @evt:        srp_event_struct to be checked for validity
181  *
182  * Returns zero if event is invalid, one otherwise.
183 */
184 static int valid_event_struct(struct event_pool *pool,
185                                 struct srp_event_struct *evt)
186 {
187         int index = evt - pool->events;
188         if (index < 0 || index >= pool->size)   /* outside of bounds */
189                 return 0;
190         if (evt != pool->events + index)        /* unaligned */
191                 return 0;
192         return 1;
193 }
194
195 /**
196  * ibmvscsi_free-event_struct: - Changes status of event to "free"
197  * @pool:       event_pool that contains the event
198  * @evt:        srp_event_struct to be modified
199  *
200 */
201 static void free_event_struct(struct event_pool *pool,
202                                        struct srp_event_struct *evt)
203 {
204         if (!valid_event_struct(pool, evt)) {
205                 printk(KERN_ERR
206                        "ibmvscsi: Freeing invalid event_struct %p "
207                        "(not in pool %p)\n", evt, pool->events);
208                 return;
209         }
210         if (atomic_inc_return(&evt->free) != 1) {
211                 printk(KERN_ERR
212                        "ibmvscsi: Freeing event_struct %p "
213                        "which is not in use!\n", evt);
214                 return;
215         }
216 }
217
218 /**
219  * get_evt_struct: - Gets the next free event in pool
220  * @pool:       event_pool that contains the events to be searched
221  *
222  * Returns the next event in "free" state, and NULL if none are free.
223  * Note that no synchronization is done here, we assume the host_lock
224  * will syncrhonze things.
225 */
226 static struct srp_event_struct *get_event_struct(struct event_pool *pool)
227 {
228         int i;
229         int poolsize = pool->size;
230         int offset = pool->next;
231
232         for (i = 0; i < poolsize; i++) {
233                 offset = (offset + 1) % poolsize;
234                 if (!atomic_dec_if_positive(&pool->events[offset].free)) {
235                         pool->next = offset;
236                         return &pool->events[offset];
237                 }
238         }
239
240         printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
241         return NULL;
242 }
243
244 /**
245  * init_event_struct: Initialize fields in an event struct that are always 
246  *                    required.
247  * @evt:        The event
248  * @done:       Routine to call when the event is responded to
249  * @format:     SRP or MAD format
250  * @timeout:    timeout value set in the CRQ
251  */
252 static void init_event_struct(struct srp_event_struct *evt_struct,
253                               void (*done) (struct srp_event_struct *),
254                               u8 format,
255                               int timeout)
256 {
257         evt_struct->cmnd = NULL;
258         evt_struct->cmnd_done = NULL;
259         evt_struct->sync_srp = NULL;
260         evt_struct->crq.format = format;
261         evt_struct->crq.timeout = timeout;
262         evt_struct->done = done;
263 }
264
265 /* ------------------------------------------------------------
266  * Routines for receiving SCSI responses from the hosting partition
267  */
268
269 /**
270  * set_srp_direction: Set the fields in the srp related to data
271  *     direction and number of buffers based on the direction in
272  *     the scsi_cmnd and the number of buffers
273  */
274 static void set_srp_direction(struct scsi_cmnd *cmd,
275                               struct srp_cmd *srp_cmd, 
276                               int numbuf)
277 {
278         if (numbuf == 0)
279                 return;
280         
281         if (numbuf == 1) {
282                 if (cmd->sc_data_direction == DMA_TO_DEVICE)
283                         srp_cmd->data_out_format = SRP_DIRECT_BUFFER;
284                 else 
285                         srp_cmd->data_in_format = SRP_DIRECT_BUFFER;
286         } else {
287                 if (cmd->sc_data_direction == DMA_TO_DEVICE) {
288                         srp_cmd->data_out_format = SRP_INDIRECT_BUFFER;
289                         srp_cmd->data_out_count = numbuf;
290                 } else {
291                         srp_cmd->data_in_format = SRP_INDIRECT_BUFFER;
292                         srp_cmd->data_in_count = numbuf;
293                 }
294         }
295 }
296
297 /**
298  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
299  * @cmd:        srp_cmd whose additional_data member will be unmapped
300  * @dev:        device for which the memory is mapped
301  *
302 */
303 static void unmap_cmd_data(struct srp_cmd *cmd, struct device *dev)
304 {
305         int i;
306
307         if ((cmd->data_out_format == SRP_NO_BUFFER) &&
308             (cmd->data_in_format == SRP_NO_BUFFER))
309                 return;
310         else if ((cmd->data_out_format == SRP_DIRECT_BUFFER) ||
311                  (cmd->data_in_format == SRP_DIRECT_BUFFER)) {
312                 struct memory_descriptor *data =
313                         (struct memory_descriptor *)cmd->additional_data;
314                 dma_unmap_single(dev, data->virtual_address, data->length,
315                                  DMA_BIDIRECTIONAL);
316         } else {
317                 struct indirect_descriptor *indirect =
318                         (struct indirect_descriptor *)cmd->additional_data;
319                 int num_mapped = indirect->head.length / 
320                         sizeof(indirect->list[0]);
321                 for (i = 0; i < num_mapped; ++i) {
322                         struct memory_descriptor *data = &indirect->list[i];
323                         dma_unmap_single(dev,
324                                          data->virtual_address,
325                                          data->length, DMA_BIDIRECTIONAL);
326                 }
327         }
328 }
329
330 /**
331  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
332  * @cmd:        Scsi_Cmnd with the scatterlist
333  * @srp_cmd:    srp_cmd that contains the memory descriptor
334  * @dev:        device for which to map dma memory
335  *
336  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
337  * Returns 1 on success.
338 */
339 static int map_sg_data(struct scsi_cmnd *cmd,
340                        struct srp_cmd *srp_cmd, struct device *dev)
341 {
342
343         int i, sg_mapped;
344         u64 total_length = 0;
345         struct scatterlist *sg = cmd->request_buffer;
346         struct memory_descriptor *data =
347             (struct memory_descriptor *)srp_cmd->additional_data;
348         struct indirect_descriptor *indirect =
349             (struct indirect_descriptor *)data;
350
351         sg_mapped = dma_map_sg(dev, sg, cmd->use_sg, DMA_BIDIRECTIONAL);
352
353         if (sg_mapped == 0)
354                 return 0;
355
356         set_srp_direction(cmd, srp_cmd, sg_mapped);
357
358         /* special case; we can use a single direct descriptor */
359         if (sg_mapped == 1) {
360                 data->virtual_address = sg_dma_address(&sg[0]);
361                 data->length = sg_dma_len(&sg[0]);
362                 data->memory_handle = 0;
363                 return 1;
364         }
365
366         if (sg_mapped > MAX_INDIRECT_BUFS) {
367                 printk(KERN_ERR
368                        "ibmvscsi: More than %d mapped sg entries, got %d\n",
369                        MAX_INDIRECT_BUFS, sg_mapped);
370                 return 0;
371         }
372
373         indirect->head.virtual_address = 0;
374         indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
375         indirect->head.memory_handle = 0;
376         for (i = 0; i < sg_mapped; ++i) {
377                 struct memory_descriptor *descr = &indirect->list[i];
378                 struct scatterlist *sg_entry = &sg[i];
379                 descr->virtual_address = sg_dma_address(sg_entry);
380                 descr->length = sg_dma_len(sg_entry);
381                 descr->memory_handle = 0;
382                 total_length += sg_dma_len(sg_entry);
383         }
384         indirect->total_length = total_length;
385
386         return 1;
387 }
388
389 /**
390  * map_single_data: - Maps memory and initializes memory decriptor fields
391  * @cmd:        struct scsi_cmnd with the memory to be mapped
392  * @srp_cmd:    srp_cmd that contains the memory descriptor
393  * @dev:        device for which to map dma memory
394  *
395  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
396  * Returns 1 on success.
397 */
398 static int map_single_data(struct scsi_cmnd *cmd,
399                            struct srp_cmd *srp_cmd, struct device *dev)
400 {
401         struct memory_descriptor *data =
402             (struct memory_descriptor *)srp_cmd->additional_data;
403
404         data->virtual_address =
405                 dma_map_single(dev, cmd->request_buffer,
406                                cmd->request_bufflen,
407                                DMA_BIDIRECTIONAL);
408         if (dma_mapping_error(data->virtual_address)) {
409                 printk(KERN_ERR
410                        "ibmvscsi: Unable to map request_buffer for command!\n");
411                 return 0;
412         }
413         data->length = cmd->request_bufflen;
414         data->memory_handle = 0;
415
416         set_srp_direction(cmd, srp_cmd, 1);
417
418         return 1;
419 }
420
421 /**
422  * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
423  * @cmd:        struct scsi_cmnd with the memory to be mapped
424  * @srp_cmd:    srp_cmd that contains the memory descriptor
425  * @dev:        dma device for which to map dma memory
426  *
427  * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds 
428  * Returns 1 on success.
429 */
430 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
431                                 struct srp_cmd *srp_cmd, struct device *dev)
432 {
433         switch (cmd->sc_data_direction) {
434         case DMA_FROM_DEVICE:
435         case DMA_TO_DEVICE:
436                 break;
437         case DMA_NONE:
438                 return 1;
439         case DMA_BIDIRECTIONAL:
440                 printk(KERN_ERR
441                        "ibmvscsi: Can't map DMA_BIDIRECTIONAL to read/write\n");
442                 return 0;
443         default:
444                 printk(KERN_ERR
445                        "ibmvscsi: Unknown data direction 0x%02x; can't map!\n",
446                        cmd->sc_data_direction);
447                 return 0;
448         }
449
450         if (!cmd->request_buffer)
451                 return 1;
452         if (cmd->use_sg)
453                 return map_sg_data(cmd, srp_cmd, dev);
454         return map_single_data(cmd, srp_cmd, dev);
455 }
456
457 /* ------------------------------------------------------------
458  * Routines for sending and receiving SRPs
459  */
460 /**
461  * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
462  * @evt_struct: evt_struct to be sent
463  * @hostdata:   ibmvscsi_host_data of host
464  *
465  * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
466  * Note that this routine assumes that host_lock is held for synchronization
467 */
468 static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
469                                    struct ibmvscsi_host_data *hostdata)
470 {
471         struct scsi_cmnd *cmnd;
472         u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
473         int rc;
474
475         /* If we have exhausted our request limit, just fail this request.
476          * Note that there are rare cases involving driver generated requests 
477          * (such as task management requests) that the mid layer may think we
478          * can handle more requests (can_queue) when we actually can't
479          */
480         if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
481             (atomic_dec_if_positive(&hostdata->request_limit) < 0)) {
482                 /* See if the adapter is disabled */
483                 if (atomic_read(&hostdata->request_limit) < 0)
484                         goto send_error;
485         
486                 printk(KERN_WARNING 
487                        "ibmvscsi: Warning, request_limit exceeded\n");
488                 unmap_cmd_data(&evt_struct->iu.srp.cmd,
489                                hostdata->dev);
490                 free_event_struct(&hostdata->pool, evt_struct);
491                 return SCSI_MLQUEUE_HOST_BUSY;
492         }
493
494         /* Copy the IU into the transfer area */
495         *evt_struct->xfer_iu = evt_struct->iu;
496         evt_struct->xfer_iu->srp.generic.tag = (u64)evt_struct;
497
498         /* Add this to the sent list.  We need to do this 
499          * before we actually send 
500          * in case it comes back REALLY fast
501          */
502         list_add_tail(&evt_struct->list, &hostdata->sent);
503
504         if ((rc =
505              ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
506                 list_del(&evt_struct->list);
507
508                 printk(KERN_ERR "ibmvscsi: failed to send event struct rc %d\n",
509                        rc);
510                 goto send_error;
511         }
512
513         return 0;
514
515  send_error:
516         unmap_cmd_data(&evt_struct->iu.srp.cmd, hostdata->dev);
517
518         if ((cmnd = evt_struct->cmnd) != NULL) {
519                 cmnd->result = DID_ERROR << 16;
520                 evt_struct->cmnd_done(cmnd);
521         } else if (evt_struct->done)
522                 evt_struct->done(evt_struct);
523         
524         free_event_struct(&hostdata->pool, evt_struct);
525         return 0;
526 }
527
528 /**
529  * handle_cmd_rsp: -  Handle responses from commands
530  * @evt_struct: srp_event_struct to be handled
531  *
532  * Used as a callback by when sending scsi cmds.
533  * Gets called by ibmvscsi_handle_crq()
534 */
535 static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
536 {
537         struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
538         struct scsi_cmnd *cmnd = evt_struct->cmnd;
539
540         if (unlikely(rsp->type != SRP_RSP_TYPE)) {
541                 if (printk_ratelimit())
542                         printk(KERN_WARNING 
543                                "ibmvscsi: bad SRP RSP type %d\n",
544                                rsp->type);
545         }
546         
547         if (cmnd) {
548                 cmnd->result = rsp->status;
549                 if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
550                         memcpy(cmnd->sense_buffer,
551                                rsp->sense_and_response_data,
552                                rsp->sense_data_list_length);
553                 unmap_cmd_data(&evt_struct->iu.srp.cmd, 
554                                evt_struct->hostdata->dev);
555
556                 if (rsp->doover)
557                         cmnd->resid = rsp->data_out_residual_count;
558                 else if (rsp->diover)
559                         cmnd->resid = rsp->data_in_residual_count;
560         }
561
562         if (evt_struct->cmnd_done)
563                 evt_struct->cmnd_done(cmnd);
564 }
565
566 /**
567  * lun_from_dev: - Returns the lun of the scsi device
568  * @dev:        struct scsi_device
569  *
570 */
571 static inline u16 lun_from_dev(struct scsi_device *dev)
572 {
573         return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
574 }
575
576 /**
577  * ibmvscsi_queue: - The queuecommand function of the scsi template 
578  * @cmd:        struct scsi_cmnd to be executed
579  * @done:       Callback function to be called when cmd is completed
580 */
581 static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
582                                  void (*done) (struct scsi_cmnd *))
583 {
584         struct srp_cmd *srp_cmd;
585         struct srp_event_struct *evt_struct;
586         struct ibmvscsi_host_data *hostdata =
587                 (struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
588         u16 lun = lun_from_dev(cmnd->device);
589
590         evt_struct = get_event_struct(&hostdata->pool);
591         if (!evt_struct)
592                 return SCSI_MLQUEUE_HOST_BUSY;
593
594         init_event_struct(evt_struct,
595                           handle_cmd_rsp,
596                           VIOSRP_SRP_FORMAT,
597                           cmnd->timeout);
598
599         evt_struct->cmnd = cmnd;
600         evt_struct->cmnd_done = done;
601
602         /* Set up the actual SRP IU */
603         srp_cmd = &evt_struct->iu.srp.cmd;
604         memset(srp_cmd, 0x00, sizeof(*srp_cmd));
605         srp_cmd->type = SRP_CMD_TYPE;
606         memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
607         srp_cmd->lun = ((u64) lun) << 48;
608
609         if (!map_data_for_srp_cmd(cmnd, srp_cmd, hostdata->dev)) {
610                 printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
611                 free_event_struct(&hostdata->pool, evt_struct);
612                 return SCSI_MLQUEUE_HOST_BUSY;
613         }
614
615         /* Fix up dma address of the buffer itself */
616         if ((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
617             (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) {
618                 struct indirect_descriptor *indirect =
619                     (struct indirect_descriptor *)srp_cmd->additional_data;
620                 indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
621                     offsetof(struct srp_cmd, additional_data) +
622                     offsetof(struct indirect_descriptor, list);
623         }
624
625         return ibmvscsi_send_srp_event(evt_struct, hostdata);
626 }
627
628 /* ------------------------------------------------------------
629  * Routines for driver initialization
630  */
631 /**
632  * adapter_info_rsp: - Handle response to MAD adapter info request
633  * @evt_struct: srp_event_struct with the response
634  *
635  * Used as a "done" callback by when sending adapter_info. Gets called
636  * by ibmvscsi_handle_crq()
637 */
638 static void adapter_info_rsp(struct srp_event_struct *evt_struct)
639 {
640         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
641         dma_unmap_single(hostdata->dev,
642                          evt_struct->iu.mad.adapter_info.buffer,
643                          evt_struct->iu.mad.adapter_info.common.length,
644                          DMA_BIDIRECTIONAL);
645
646         if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
647                 printk("ibmvscsi: error %d getting adapter info\n",
648                        evt_struct->xfer_iu->mad.adapter_info.common.status);
649         } else {
650                 printk("ibmvscsi: host srp version: %s, "
651                        "host partition %s (%d), OS %d, max io %u\n",
652                        hostdata->madapter_info.srp_version,
653                        hostdata->madapter_info.partition_name,
654                        hostdata->madapter_info.partition_number,
655                        hostdata->madapter_info.os_type,
656                        hostdata->madapter_info.port_max_txu[0]);
657                 
658                 if (hostdata->madapter_info.port_max_txu[0]) 
659                         hostdata->host->max_sectors = 
660                                 hostdata->madapter_info.port_max_txu[0] >> 9;
661         }
662 }
663
664 /**
665  * send_mad_adapter_info: - Sends the mad adapter info request
666  *      and stores the result so it can be retrieved with
667  *      sysfs.  We COULD consider causing a failure if the
668  *      returned SRP version doesn't match ours.
669  * @hostdata:   ibmvscsi_host_data of host
670  * 
671  * Returns zero if successful.
672 */
673 static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
674 {
675         struct viosrp_adapter_info *req;
676         struct srp_event_struct *evt_struct;
677         
678         evt_struct = get_event_struct(&hostdata->pool);
679         if (!evt_struct) {
680                 printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
681                        "for ADAPTER_INFO_REQ!\n");
682                 return;
683         }
684
685         init_event_struct(evt_struct,
686                           adapter_info_rsp,
687                           VIOSRP_MAD_FORMAT,
688                           init_timeout * HZ);
689         
690         req = &evt_struct->iu.mad.adapter_info;
691         memset(req, 0x00, sizeof(*req));
692         
693         req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
694         req->common.length = sizeof(hostdata->madapter_info);
695         req->buffer = dma_map_single(hostdata->dev,
696                                      &hostdata->madapter_info,
697                                      sizeof(hostdata->madapter_info),
698                                      DMA_BIDIRECTIONAL);
699
700         if (dma_mapping_error(req->buffer)) {
701                 printk(KERN_ERR
702                        "ibmvscsi: Unable to map request_buffer "
703                        "for adapter_info!\n");
704                 free_event_struct(&hostdata->pool, evt_struct);
705                 return;
706         }
707         
708         if (ibmvscsi_send_srp_event(evt_struct, hostdata))
709                 printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
710 };
711
712 /**
713  * login_rsp: - Handle response to SRP login request
714  * @evt_struct: srp_event_struct with the response
715  *
716  * Used as a "done" callback by when sending srp_login. Gets called
717  * by ibmvscsi_handle_crq()
718 */
719 static void login_rsp(struct srp_event_struct *evt_struct)
720 {
721         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
722         switch (evt_struct->xfer_iu->srp.generic.type) {
723         case SRP_LOGIN_RSP_TYPE:        /* it worked! */
724                 break;
725         case SRP_LOGIN_REJ_TYPE:        /* refused! */
726                 printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REQ rejected\n");
727                 /* Login failed.  */
728                 atomic_set(&hostdata->request_limit, -1);
729                 return;
730         default:
731                 printk(KERN_ERR
732                        "ibmvscsi: Invalid login response typecode 0x%02x!\n",
733                        evt_struct->xfer_iu->srp.generic.type);
734                 /* Login failed.  */
735                 atomic_set(&hostdata->request_limit, -1);
736                 return;
737         }
738
739         printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");
740
741         if (evt_struct->xfer_iu->srp.login_rsp.request_limit_delta >
742             (max_requests - 2))
743                 evt_struct->xfer_iu->srp.login_rsp.request_limit_delta =
744                     max_requests - 2;
745
746         /* Now we know what the real request-limit is */
747         atomic_set(&hostdata->request_limit,
748                    evt_struct->xfer_iu->srp.login_rsp.request_limit_delta);
749
750         hostdata->host->can_queue =
751             evt_struct->xfer_iu->srp.login_rsp.request_limit_delta - 2;
752
753         if (hostdata->host->can_queue < 1) {
754                 printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
755                 return;
756         }
757
758         send_mad_adapter_info(hostdata);
759         return;
760 }
761
762 /**
763  * send_srp_login: - Sends the srp login
764  * @hostdata:   ibmvscsi_host_data of host
765  * 
766  * Returns zero if successful.
767 */
768 static int send_srp_login(struct ibmvscsi_host_data *hostdata)
769 {
770         int rc;
771         unsigned long flags;
772         struct srp_login_req *login;
773         struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
774         if (!evt_struct) {
775                 printk(KERN_ERR
776                        "ibmvscsi: couldn't allocate an event for login req!\n");
777                 return FAILED;
778         }
779
780         init_event_struct(evt_struct,
781                           login_rsp,
782                           VIOSRP_SRP_FORMAT,
783                           init_timeout * HZ);
784
785         login = &evt_struct->iu.srp.login_req;
786         login->type = SRP_LOGIN_REQ_TYPE;
787         login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
788         login->required_buffer_formats = 0x0006;
789         
790         /* Start out with a request limit of 1, since this is negotiated in
791          * the login request we are just sending
792          */
793         atomic_set(&hostdata->request_limit, 1);
794
795         spin_lock_irqsave(hostdata->host->host_lock, flags);
796         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
797         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
798         return rc;
799 };
800
801 /**
802  * sync_completion: Signal that a synchronous command has completed
803  * Note that after returning from this call, the evt_struct is freed.
804  * the caller waiting on this completion shouldn't touch the evt_struct
805  * again.
806  */
807 static void sync_completion(struct srp_event_struct *evt_struct)
808 {
809         /* copy the response back */
810         if (evt_struct->sync_srp)
811                 *evt_struct->sync_srp = *evt_struct->xfer_iu;
812         
813         complete(&evt_struct->comp);
814 }
815
816 /**
817  * ibmvscsi_abort: Abort a command...from scsi host template
818  * send this over to the server and wait synchronously for the response
819  */
820 static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
821 {
822         struct ibmvscsi_host_data *hostdata =
823             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
824         struct srp_tsk_mgmt *tsk_mgmt;
825         struct srp_event_struct *evt;
826         struct srp_event_struct *tmp_evt, *found_evt;
827         union viosrp_iu srp_rsp;
828         int rsp_rc;
829         u16 lun = lun_from_dev(cmd->device);
830
831         /* First, find this command in our sent list so we can figure
832          * out the correct tag
833          */
834         found_evt = NULL;
835         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
836                 if (tmp_evt->cmnd == cmd) {
837                         found_evt = tmp_evt;
838                         break;
839                 }
840         }
841
842         if (!found_evt) 
843                 return FAILED;
844
845         evt = get_event_struct(&hostdata->pool);
846         if (evt == NULL) {
847                 printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
848                 return FAILED;
849         }
850         
851         init_event_struct(evt,
852                           sync_completion,
853                           VIOSRP_SRP_FORMAT,
854                           init_timeout * HZ);
855
856         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
857         
858         /* Set up an abort SRP command */
859         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
860         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
861         tsk_mgmt->lun = ((u64) lun) << 48;
862         tsk_mgmt->task_mgmt_flags = 0x01;       /* ABORT TASK */
863         tsk_mgmt->managed_task_tag = (u64) found_evt;
864
865         printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
866                tsk_mgmt->lun, tsk_mgmt->managed_task_tag);
867
868         evt->sync_srp = &srp_rsp;
869         init_completion(&evt->comp);
870         if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
871                 printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
872                 return FAILED;
873         }
874
875         wait_for_completion(&evt->comp);
876
877         /* make sure we got a good response */
878         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
879                 if (printk_ratelimit())
880                         printk(KERN_WARNING 
881                                "ibmvscsi: abort bad SRP RSP type %d\n",
882                                srp_rsp.srp.generic.type);
883                 return FAILED;
884         }
885
886         if (srp_rsp.srp.rsp.rspvalid)
887                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
888         else
889                 rsp_rc = srp_rsp.srp.rsp.status;
890
891         if (rsp_rc) {
892                 if (printk_ratelimit())
893                         printk(KERN_WARNING 
894                        "ibmvscsi: abort code %d for task tag 0x%lx\n",
895                                rsp_rc,
896                                tsk_mgmt->managed_task_tag);
897                 return FAILED;
898         }
899
900         /* Because we dropped the spinlock above, it's possible
901          * The event is no longer in our list.  Make sure it didn't
902          * complete while we were aborting
903          */
904         found_evt = NULL;
905         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
906                 if (tmp_evt->cmnd == cmd) {
907                         found_evt = tmp_evt;
908                         break;
909                 }
910         }
911
912         if (found_evt == NULL) {
913                 printk(KERN_INFO
914                        "ibmvscsi: aborted task tag 0x%lx completed\n",
915                        tsk_mgmt->managed_task_tag);
916                 return SUCCESS;
917         }
918
919         printk(KERN_INFO
920                "ibmvscsi: successfully aborted task tag 0x%lx\n",
921                tsk_mgmt->managed_task_tag);
922
923         cmd->result = (DID_ABORT << 16);
924         list_del(&found_evt->list);
925         unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt->hostdata->dev);
926         free_event_struct(&found_evt->hostdata->pool, found_evt);
927         atomic_inc(&hostdata->request_limit);
928         return SUCCESS;
929 }
930
931 /**
932  * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host 
933  * template send this over to the server and wait synchronously for the 
934  * response
935  */
936 static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
937 {
938         struct ibmvscsi_host_data *hostdata =
939             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
940
941         struct srp_tsk_mgmt *tsk_mgmt;
942         struct srp_event_struct *evt;
943         struct srp_event_struct *tmp_evt, *pos;
944         union viosrp_iu srp_rsp;
945         int rsp_rc;
946         u16 lun = lun_from_dev(cmd->device);
947
948         evt = get_event_struct(&hostdata->pool);
949         if (evt == NULL) {
950                 printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
951                 return FAILED;
952         }
953         
954         init_event_struct(evt,
955                           sync_completion,
956                           VIOSRP_SRP_FORMAT,
957                           init_timeout * HZ);
958
959         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
960
961         /* Set up a lun reset SRP command */
962         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
963         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
964         tsk_mgmt->lun = ((u64) lun) << 48;
965         tsk_mgmt->task_mgmt_flags = 0x08;       /* LUN RESET */
966
967         printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
968                tsk_mgmt->lun);
969
970         evt->sync_srp = &srp_rsp;
971         init_completion(&evt->comp);
972         if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
973                 printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
974                 return FAILED;
975         }
976
977         wait_for_completion(&evt->comp);
978
979         /* make sure we got a good response */
980         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
981                 if (printk_ratelimit())
982                         printk(KERN_WARNING 
983                                "ibmvscsi: reset bad SRP RSP type %d\n",
984                                srp_rsp.srp.generic.type);
985                 return FAILED;
986         }
987
988         if (srp_rsp.srp.rsp.rspvalid)
989                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
990         else
991                 rsp_rc = srp_rsp.srp.rsp.status;
992
993         if (rsp_rc) {
994                 if (printk_ratelimit())
995                         printk(KERN_WARNING 
996                                "ibmvscsi: reset code %d for task tag 0x%lx\n",
997                        rsp_rc,
998                                tsk_mgmt->managed_task_tag);
999                 return FAILED;
1000         }
1001
1002         /* We need to find all commands for this LUN that have not yet been
1003          * responded to, and fail them with DID_RESET
1004          */
1005         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1006                 if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1007                         if (tmp_evt->cmnd)
1008                                 tmp_evt->cmnd->result = (DID_RESET << 16);
1009                         list_del(&tmp_evt->list);
1010                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt->hostdata->dev);
1011                         free_event_struct(&tmp_evt->hostdata->pool,
1012                                                    tmp_evt);
1013                         atomic_inc(&hostdata->request_limit);
1014                         if (tmp_evt->cmnd_done)
1015                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1016                         else if (tmp_evt->done)
1017                                 tmp_evt->done(tmp_evt);
1018                 }
1019         }
1020         return SUCCESS;
1021 }
1022
1023 /**
1024  * purge_requests: Our virtual adapter just shut down.  purge any sent requests
1025  * @hostdata:    the adapter
1026  */
1027 static void purge_requests(struct ibmvscsi_host_data *hostdata)
1028 {
1029         struct srp_event_struct *tmp_evt, *pos;
1030         unsigned long flags;
1031
1032         spin_lock_irqsave(hostdata->host->host_lock, flags);
1033         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1034                 list_del(&tmp_evt->list);
1035                 if (tmp_evt->cmnd) {
1036                         tmp_evt->cmnd->result = (DID_ERROR << 16);
1037                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, 
1038                                        tmp_evt->hostdata->dev);
1039                         if (tmp_evt->cmnd_done)
1040                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1041                 } else {
1042                         if (tmp_evt->done) {
1043                                 tmp_evt->done(tmp_evt);
1044                         }
1045                 }
1046                 free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
1047         }
1048         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1049 }
1050
1051 /**
1052  * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1053  * @crq:        Command/Response queue
1054  * @hostdata:   ibmvscsi_host_data of host
1055  *
1056 */
1057 void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1058                          struct ibmvscsi_host_data *hostdata)
1059 {
1060         unsigned long flags;
1061         struct srp_event_struct *evt_struct =
1062             (struct srp_event_struct *)crq->IU_data_ptr;
1063         switch (crq->valid) {
1064         case 0xC0:              /* initialization */
1065                 switch (crq->format) {
1066                 case 0x01:      /* Initialization message */
1067                         printk(KERN_INFO "ibmvscsi: partner initialized\n");
1068                         /* Send back a response */
1069                         if (ibmvscsi_send_crq(hostdata,
1070                                               0xC002000000000000LL, 0) == 0) {
1071                                 /* Now login */
1072                                 send_srp_login(hostdata);
1073                         } else {
1074                                 printk(KERN_ERR
1075                                        "ibmvscsi: Unable to send init rsp\n");
1076                         }
1077
1078                         break;
1079                 case 0x02:      /* Initialization response */
1080                         printk(KERN_INFO
1081                                "ibmvscsi: partner initialization complete\n");
1082
1083                         /* Now login */
1084                         send_srp_login(hostdata);
1085                         break;
1086                 default:
1087                         printk(KERN_ERR "ibmvscsi: unknown crq message type\n");
1088                 }
1089                 return;
1090         case 0xFF:              /* Hypervisor telling us the connection is closed */
1091                 printk(KERN_INFO "ibmvscsi: Virtual adapter failed!\n");
1092
1093                 atomic_set(&hostdata->request_limit, -1);
1094                 purge_requests(hostdata);
1095                 ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
1096                 return;
1097         case 0x80:              /* real payload */
1098                 break;
1099         default:
1100                 printk(KERN_ERR
1101                        "ibmvscsi: got an invalid message type 0x%02x\n",
1102                        crq->valid);
1103                 return;
1104         }
1105
1106         /* The only kind of payload CRQs we should get are responses to
1107          * things we send. Make sure this response is to something we
1108          * actually sent
1109          */
1110         if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1111                 printk(KERN_ERR
1112                        "ibmvscsi: returned correlation_token 0x%p is invalid!\n",
1113                        (void *)crq->IU_data_ptr);
1114                 return;
1115         }
1116
1117         if (atomic_read(&evt_struct->free)) {
1118                 printk(KERN_ERR
1119                        "ibmvscsi: received duplicate  correlation_token 0x%p!\n",
1120                        (void *)crq->IU_data_ptr);
1121                 return;
1122         }
1123
1124         if (crq->format == VIOSRP_SRP_FORMAT)
1125                 atomic_add(evt_struct->xfer_iu->srp.rsp.request_limit_delta,
1126                            &hostdata->request_limit);
1127
1128         if (evt_struct->done)
1129                 evt_struct->done(evt_struct);
1130         else
1131                 printk(KERN_ERR
1132                        "ibmvscsi: returned done() is NULL; not running it!\n");
1133
1134         /*
1135          * Lock the host_lock before messing with these structures, since we
1136          * are running in a task context
1137          */
1138         spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1139         list_del(&evt_struct->list);
1140         free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1141         spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1142 }
1143
1144 /**
1145  * ibmvscsi_get_host_config: Send the command to the server to get host
1146  * configuration data.  The data is opaque to us.
1147  */
1148 static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
1149                                    unsigned char *buffer, int length)
1150 {
1151         struct viosrp_host_config *host_config;
1152         struct srp_event_struct *evt_struct;
1153         int rc;
1154
1155         evt_struct = get_event_struct(&hostdata->pool);
1156         if (!evt_struct) {
1157                 printk(KERN_ERR
1158                        "ibmvscsi: could't allocate event for HOST_CONFIG!\n");
1159                 return -1;
1160         }
1161
1162         init_event_struct(evt_struct,
1163                           sync_completion,
1164                           VIOSRP_MAD_FORMAT,
1165                           init_timeout * HZ);
1166
1167         host_config = &evt_struct->iu.mad.host_config;
1168
1169         /* Set up a lun reset SRP command */
1170         memset(host_config, 0x00, sizeof(*host_config));
1171         host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
1172         host_config->common.length = length;
1173         host_config->buffer = dma_map_single(hostdata->dev, buffer, length,
1174                                             DMA_BIDIRECTIONAL);
1175
1176         if (dma_mapping_error(host_config->buffer)) {
1177                 printk(KERN_ERR
1178                        "ibmvscsi: dma_mapping error " "getting host config\n");
1179                 free_event_struct(&hostdata->pool, evt_struct);
1180                 return -1;
1181         }
1182
1183         init_completion(&evt_struct->comp);
1184         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
1185         if (rc == 0) {
1186                 wait_for_completion(&evt_struct->comp);
1187                 dma_unmap_single(hostdata->dev, host_config->buffer,
1188                                  length, DMA_BIDIRECTIONAL);
1189         }
1190
1191         return rc;
1192 }
1193
1194 /* ------------------------------------------------------------
1195  * sysfs attributes
1196  */
1197 static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
1198 {
1199         struct Scsi_Host *shost = class_to_shost(class_dev);
1200         struct ibmvscsi_host_data *hostdata =
1201             (struct ibmvscsi_host_data *)shost->hostdata;
1202         int len;
1203
1204         len = snprintf(buf, PAGE_SIZE, "%s\n",
1205                        hostdata->madapter_info.srp_version);
1206         return len;
1207 }
1208
1209 static struct class_device_attribute ibmvscsi_host_srp_version = {
1210         .attr = {
1211                  .name = "srp_version",
1212                  .mode = S_IRUGO,
1213                  },
1214         .show = show_host_srp_version,
1215 };
1216
1217 static ssize_t show_host_partition_name(struct class_device *class_dev,
1218                                         char *buf)
1219 {
1220         struct Scsi_Host *shost = class_to_shost(class_dev);
1221         struct ibmvscsi_host_data *hostdata =
1222             (struct ibmvscsi_host_data *)shost->hostdata;
1223         int len;
1224
1225         len = snprintf(buf, PAGE_SIZE, "%s\n",
1226                        hostdata->madapter_info.partition_name);
1227         return len;
1228 }
1229
1230 static struct class_device_attribute ibmvscsi_host_partition_name = {
1231         .attr = {
1232                  .name = "partition_name",
1233                  .mode = S_IRUGO,
1234                  },
1235         .show = show_host_partition_name,
1236 };
1237
1238 static ssize_t show_host_partition_number(struct class_device *class_dev,
1239                                           char *buf)
1240 {
1241         struct Scsi_Host *shost = class_to_shost(class_dev);
1242         struct ibmvscsi_host_data *hostdata =
1243             (struct ibmvscsi_host_data *)shost->hostdata;
1244         int len;
1245
1246         len = snprintf(buf, PAGE_SIZE, "%d\n",
1247                        hostdata->madapter_info.partition_number);
1248         return len;
1249 }
1250
1251 static struct class_device_attribute ibmvscsi_host_partition_number = {
1252         .attr = {
1253                  .name = "partition_number",
1254                  .mode = S_IRUGO,
1255                  },
1256         .show = show_host_partition_number,
1257 };
1258
1259 static ssize_t show_host_mad_version(struct class_device *class_dev, char *buf)
1260 {
1261         struct Scsi_Host *shost = class_to_shost(class_dev);
1262         struct ibmvscsi_host_data *hostdata =
1263             (struct ibmvscsi_host_data *)shost->hostdata;
1264         int len;
1265
1266         len = snprintf(buf, PAGE_SIZE, "%d\n",
1267                        hostdata->madapter_info.mad_version);
1268         return len;
1269 }
1270
1271 static struct class_device_attribute ibmvscsi_host_mad_version = {
1272         .attr = {
1273                  .name = "mad_version",
1274                  .mode = S_IRUGO,
1275                  },
1276         .show = show_host_mad_version,
1277 };
1278
1279 static ssize_t show_host_os_type(struct class_device *class_dev, char *buf)
1280 {
1281         struct Scsi_Host *shost = class_to_shost(class_dev);
1282         struct ibmvscsi_host_data *hostdata =
1283             (struct ibmvscsi_host_data *)shost->hostdata;
1284         int len;
1285
1286         len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
1287         return len;
1288 }
1289
1290 static struct class_device_attribute ibmvscsi_host_os_type = {
1291         .attr = {
1292                  .name = "os_type",
1293                  .mode = S_IRUGO,
1294                  },
1295         .show = show_host_os_type,
1296 };
1297
1298 static ssize_t show_host_config(struct class_device *class_dev, char *buf)
1299 {
1300         struct Scsi_Host *shost = class_to_shost(class_dev);
1301         struct ibmvscsi_host_data *hostdata =
1302             (struct ibmvscsi_host_data *)shost->hostdata;
1303
1304         /* returns null-terminated host config data */
1305         if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
1306                 return strlen(buf);
1307         else
1308                 return 0;
1309 }
1310
1311 static struct class_device_attribute ibmvscsi_host_config = {
1312         .attr = {
1313                  .name = "config",
1314                  .mode = S_IRUGO,
1315                  },
1316         .show = show_host_config,
1317 };
1318
1319 static struct class_device_attribute *ibmvscsi_attrs[] = {
1320         &ibmvscsi_host_srp_version,
1321         &ibmvscsi_host_partition_name,
1322         &ibmvscsi_host_partition_number,
1323         &ibmvscsi_host_mad_version,
1324         &ibmvscsi_host_os_type,
1325         &ibmvscsi_host_config,
1326         NULL
1327 };
1328
1329 /* ------------------------------------------------------------
1330  * SCSI driver registration
1331  */
1332 static struct scsi_host_template driver_template = {
1333         .module = THIS_MODULE,
1334         .name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
1335         .proc_name = "ibmvscsi",
1336         .queuecommand = ibmvscsi_queuecommand,
1337         .eh_abort_handler = ibmvscsi_eh_abort_handler,
1338         .eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
1339         .cmd_per_lun = 16,
1340         .can_queue = 1,         /* Updated after SRP_LOGIN */
1341         .this_id = -1,
1342         .sg_tablesize = MAX_INDIRECT_BUFS,
1343         .use_clustering = ENABLE_CLUSTERING,
1344         .shost_attrs = ibmvscsi_attrs,
1345 };
1346
1347 /**
1348  * Called by bus code for each adapter
1349  */
1350 static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1351 {
1352         struct ibmvscsi_host_data *hostdata;
1353         struct Scsi_Host *host;
1354         struct device *dev = &vdev->dev;
1355         unsigned long wait_switch = 0;
1356
1357         vdev->dev.driver_data = NULL;
1358
1359         host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
1360         if (!host) {
1361                 printk(KERN_ERR "ibmvscsi: couldn't allocate host data\n");
1362                 goto scsi_host_alloc_failed;
1363         }
1364
1365         hostdata = (struct ibmvscsi_host_data *)host->hostdata;
1366         memset(hostdata, 0x00, sizeof(*hostdata));
1367         INIT_LIST_HEAD(&hostdata->sent);
1368         hostdata->host = host;
1369         hostdata->dev = dev;
1370         atomic_set(&hostdata->request_limit, -1);
1371         hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
1372
1373         if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
1374                                     max_requests) != 0) {
1375                 printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
1376                 goto init_crq_failed;
1377         }
1378         if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
1379                 printk(KERN_ERR "ibmvscsi: couldn't initialize event pool\n");
1380                 goto init_pool_failed;
1381         }
1382
1383         host->max_lun = 8;
1384         host->max_id = max_id;
1385         host->max_channel = max_channel;
1386
1387         if (scsi_add_host(hostdata->host, hostdata->dev))
1388                 goto add_host_failed;
1389
1390         /* Try to send an initialization message.  Note that this is allowed
1391          * to fail if the other end is not acive.  In that case we don't
1392          * want to scan
1393          */
1394         if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0) {
1395                 /*
1396                  * Wait around max init_timeout secs for the adapter to finish
1397                  * initializing. When we are done initializing, we will have a
1398                  * valid request_limit.  We don't want Linux scanning before
1399                  * we are ready.
1400                  */
1401                 for (wait_switch = jiffies + (init_timeout * HZ);
1402                      time_before(jiffies, wait_switch) &&
1403                      atomic_read(&hostdata->request_limit) < 2;) {
1404
1405                         msleep(10);
1406                 }
1407
1408                 /* if we now have a valid request_limit, initiate a scan */
1409                 if (atomic_read(&hostdata->request_limit) > 0)
1410                         scsi_scan_host(host);
1411         }
1412
1413         vdev->dev.driver_data = hostdata;
1414         return 0;
1415
1416       add_host_failed:
1417         release_event_pool(&hostdata->pool, hostdata);
1418       init_pool_failed:
1419         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_requests);
1420       init_crq_failed:
1421         scsi_host_put(host);
1422       scsi_host_alloc_failed:
1423         return -1;
1424 }
1425
1426 static int ibmvscsi_remove(struct vio_dev *vdev)
1427 {
1428         struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
1429         release_event_pool(&hostdata->pool, hostdata);
1430         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
1431                                    max_requests);
1432         
1433         scsi_remove_host(hostdata->host);
1434         scsi_host_put(hostdata->host);
1435
1436         return 0;
1437 }
1438
1439 /**
1440  * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we 
1441  * support.
1442  */
1443 static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
1444         {"vscsi", "IBM,v-scsi"},
1445         {0,}
1446 };
1447
1448 MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
1449 static struct vio_driver ibmvscsi_driver = {
1450         .name = "ibmvscsi",
1451         .id_table = ibmvscsi_device_table,
1452         .probe = ibmvscsi_probe,
1453         .remove = ibmvscsi_remove
1454 };
1455
1456 int __init ibmvscsi_module_init(void)
1457 {
1458         return vio_register_driver(&ibmvscsi_driver);
1459 }
1460
1461 void __exit ibmvscsi_module_exit(void)
1462 {
1463         vio_unregister_driver(&ibmvscsi_driver);
1464 }
1465
1466 module_init(ibmvscsi_module_init);
1467 module_exit(ibmvscsi_module_exit);