Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[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 "1.5.7"
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         struct scsi_cmnd *cmnd;
538         u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
539         int rc;
540
541         /* If we have exhausted our request limit, just fail this request.
542          * Note that there are rare cases involving driver generated requests 
543          * (such as task management requests) that the mid layer may think we
544          * can handle more requests (can_queue) when we actually can't
545          */
546         if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
547             (atomic_dec_if_positive(&hostdata->request_limit) < 0)) {
548                 /* See if the adapter is disabled */
549                 if (atomic_read(&hostdata->request_limit) < 0)
550                         goto send_error;
551         
552                 printk(KERN_WARNING 
553                        "ibmvscsi: Warning, request_limit exceeded\n");
554                 unmap_cmd_data(&evt_struct->iu.srp.cmd,
555                                evt_struct,
556                                hostdata->dev);
557                 free_event_struct(&hostdata->pool, evt_struct);
558                 return SCSI_MLQUEUE_HOST_BUSY;
559         }
560
561         /* Copy the IU into the transfer area */
562         *evt_struct->xfer_iu = evt_struct->iu;
563         evt_struct->xfer_iu->srp.generic.tag = (u64)evt_struct;
564
565         /* Add this to the sent list.  We need to do this 
566          * before we actually send 
567          * in case it comes back REALLY fast
568          */
569         list_add_tail(&evt_struct->list, &hostdata->sent);
570
571         if ((rc =
572              ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
573                 list_del(&evt_struct->list);
574
575                 printk(KERN_ERR "ibmvscsi: failed to send event struct rc %d\n",
576                        rc);
577                 goto send_error;
578         }
579
580         return 0;
581
582  send_error:
583         unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
584
585         if ((cmnd = evt_struct->cmnd) != NULL) {
586                 cmnd->result = DID_ERROR << 16;
587                 evt_struct->cmnd_done(cmnd);
588         } else if (evt_struct->done)
589                 evt_struct->done(evt_struct);
590         
591         free_event_struct(&hostdata->pool, evt_struct);
592         return 0;
593 }
594
595 /**
596  * handle_cmd_rsp: -  Handle responses from commands
597  * @evt_struct: srp_event_struct to be handled
598  *
599  * Used as a callback by when sending scsi cmds.
600  * Gets called by ibmvscsi_handle_crq()
601 */
602 static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
603 {
604         struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
605         struct scsi_cmnd *cmnd = evt_struct->cmnd;
606
607         if (unlikely(rsp->type != SRP_RSP_TYPE)) {
608                 if (printk_ratelimit())
609                         printk(KERN_WARNING 
610                                "ibmvscsi: bad SRP RSP type %d\n",
611                                rsp->type);
612         }
613         
614         if (cmnd) {
615                 cmnd->result = rsp->status;
616                 if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
617                         memcpy(cmnd->sense_buffer,
618                                rsp->sense_and_response_data,
619                                rsp->sense_data_list_length);
620                 unmap_cmd_data(&evt_struct->iu.srp.cmd, 
621                                evt_struct, 
622                                evt_struct->hostdata->dev);
623
624                 if (rsp->doover)
625                         cmnd->resid = rsp->data_out_residual_count;
626                 else if (rsp->diover)
627                         cmnd->resid = rsp->data_in_residual_count;
628         }
629
630         if (evt_struct->cmnd_done)
631                 evt_struct->cmnd_done(cmnd);
632 }
633
634 /**
635  * lun_from_dev: - Returns the lun of the scsi device
636  * @dev:        struct scsi_device
637  *
638 */
639 static inline u16 lun_from_dev(struct scsi_device *dev)
640 {
641         return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
642 }
643
644 /**
645  * ibmvscsi_queue: - The queuecommand function of the scsi template 
646  * @cmd:        struct scsi_cmnd to be executed
647  * @done:       Callback function to be called when cmd is completed
648 */
649 static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
650                                  void (*done) (struct scsi_cmnd *))
651 {
652         struct srp_cmd *srp_cmd;
653         struct srp_event_struct *evt_struct;
654         struct indirect_descriptor *indirect;
655         struct ibmvscsi_host_data *hostdata =
656                 (struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
657         u16 lun = lun_from_dev(cmnd->device);
658
659         evt_struct = get_event_struct(&hostdata->pool);
660         if (!evt_struct)
661                 return SCSI_MLQUEUE_HOST_BUSY;
662
663         /* Set up the actual SRP IU */
664         srp_cmd = &evt_struct->iu.srp.cmd;
665         memset(srp_cmd, 0x00, sizeof(*srp_cmd));
666         srp_cmd->type = SRP_CMD_TYPE;
667         memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
668         srp_cmd->lun = ((u64) lun) << 48;
669
670         if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
671                 printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
672                 free_event_struct(&hostdata->pool, evt_struct);
673                 return SCSI_MLQUEUE_HOST_BUSY;
674         }
675
676         init_event_struct(evt_struct,
677                           handle_cmd_rsp,
678                           VIOSRP_SRP_FORMAT,
679                           cmnd->timeout_per_command/HZ);
680
681         evt_struct->cmnd = cmnd;
682         evt_struct->cmnd_done = done;
683
684         /* Fix up dma address of the buffer itself */
685         indirect = (struct indirect_descriptor *)srp_cmd->additional_data;
686         if (((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
687             (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) &&
688             (indirect->head.virtual_address == 0)) {
689                 indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
690                     offsetof(struct srp_cmd, additional_data) +
691                     offsetof(struct indirect_descriptor, list);
692         }
693
694         return ibmvscsi_send_srp_event(evt_struct, hostdata);
695 }
696
697 /* ------------------------------------------------------------
698  * Routines for driver initialization
699  */
700 /**
701  * adapter_info_rsp: - Handle response to MAD adapter info request
702  * @evt_struct: srp_event_struct with the response
703  *
704  * Used as a "done" callback by when sending adapter_info. Gets called
705  * by ibmvscsi_handle_crq()
706 */
707 static void adapter_info_rsp(struct srp_event_struct *evt_struct)
708 {
709         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
710         dma_unmap_single(hostdata->dev,
711                          evt_struct->iu.mad.adapter_info.buffer,
712                          evt_struct->iu.mad.adapter_info.common.length,
713                          DMA_BIDIRECTIONAL);
714
715         if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
716                 printk("ibmvscsi: error %d getting adapter info\n",
717                        evt_struct->xfer_iu->mad.adapter_info.common.status);
718         } else {
719                 printk("ibmvscsi: host srp version: %s, "
720                        "host partition %s (%d), OS %d, max io %u\n",
721                        hostdata->madapter_info.srp_version,
722                        hostdata->madapter_info.partition_name,
723                        hostdata->madapter_info.partition_number,
724                        hostdata->madapter_info.os_type,
725                        hostdata->madapter_info.port_max_txu[0]);
726                 
727                 if (hostdata->madapter_info.port_max_txu[0]) 
728                         hostdata->host->max_sectors = 
729                                 hostdata->madapter_info.port_max_txu[0] >> 9;
730         }
731 }
732
733 /**
734  * send_mad_adapter_info: - Sends the mad adapter info request
735  *      and stores the result so it can be retrieved with
736  *      sysfs.  We COULD consider causing a failure if the
737  *      returned SRP version doesn't match ours.
738  * @hostdata:   ibmvscsi_host_data of host
739  * 
740  * Returns zero if successful.
741 */
742 static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
743 {
744         struct viosrp_adapter_info *req;
745         struct srp_event_struct *evt_struct;
746         
747         evt_struct = get_event_struct(&hostdata->pool);
748         if (!evt_struct) {
749                 printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
750                        "for ADAPTER_INFO_REQ!\n");
751                 return;
752         }
753
754         init_event_struct(evt_struct,
755                           adapter_info_rsp,
756                           VIOSRP_MAD_FORMAT,
757                           init_timeout * HZ);
758         
759         req = &evt_struct->iu.mad.adapter_info;
760         memset(req, 0x00, sizeof(*req));
761         
762         req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
763         req->common.length = sizeof(hostdata->madapter_info);
764         req->buffer = dma_map_single(hostdata->dev,
765                                      &hostdata->madapter_info,
766                                      sizeof(hostdata->madapter_info),
767                                      DMA_BIDIRECTIONAL);
768
769         if (dma_mapping_error(req->buffer)) {
770                 printk(KERN_ERR
771                        "ibmvscsi: Unable to map request_buffer "
772                        "for adapter_info!\n");
773                 free_event_struct(&hostdata->pool, evt_struct);
774                 return;
775         }
776         
777         if (ibmvscsi_send_srp_event(evt_struct, hostdata))
778                 printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
779 };
780
781 /**
782  * login_rsp: - Handle response to SRP login request
783  * @evt_struct: srp_event_struct with the response
784  *
785  * Used as a "done" callback by when sending srp_login. Gets called
786  * by ibmvscsi_handle_crq()
787 */
788 static void login_rsp(struct srp_event_struct *evt_struct)
789 {
790         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
791         switch (evt_struct->xfer_iu->srp.generic.type) {
792         case SRP_LOGIN_RSP_TYPE:        /* it worked! */
793                 break;
794         case SRP_LOGIN_REJ_TYPE:        /* refused! */
795                 printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REQ rejected\n");
796                 /* Login failed.  */
797                 atomic_set(&hostdata->request_limit, -1);
798                 return;
799         default:
800                 printk(KERN_ERR
801                        "ibmvscsi: Invalid login response typecode 0x%02x!\n",
802                        evt_struct->xfer_iu->srp.generic.type);
803                 /* Login failed.  */
804                 atomic_set(&hostdata->request_limit, -1);
805                 return;
806         }
807
808         printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");
809
810         if (evt_struct->xfer_iu->srp.login_rsp.request_limit_delta >
811             (max_requests - 2))
812                 evt_struct->xfer_iu->srp.login_rsp.request_limit_delta =
813                     max_requests - 2;
814
815         /* Now we know what the real request-limit is */
816         atomic_set(&hostdata->request_limit,
817                    evt_struct->xfer_iu->srp.login_rsp.request_limit_delta);
818
819         hostdata->host->can_queue =
820             evt_struct->xfer_iu->srp.login_rsp.request_limit_delta - 2;
821
822         if (hostdata->host->can_queue < 1) {
823                 printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
824                 return;
825         }
826
827         send_mad_adapter_info(hostdata);
828         return;
829 }
830
831 /**
832  * send_srp_login: - Sends the srp login
833  * @hostdata:   ibmvscsi_host_data of host
834  * 
835  * Returns zero if successful.
836 */
837 static int send_srp_login(struct ibmvscsi_host_data *hostdata)
838 {
839         int rc;
840         unsigned long flags;
841         struct srp_login_req *login;
842         struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
843         if (!evt_struct) {
844                 printk(KERN_ERR
845                        "ibmvscsi: couldn't allocate an event for login req!\n");
846                 return FAILED;
847         }
848
849         init_event_struct(evt_struct,
850                           login_rsp,
851                           VIOSRP_SRP_FORMAT,
852                           init_timeout * HZ);
853
854         login = &evt_struct->iu.srp.login_req;
855         login->type = SRP_LOGIN_REQ_TYPE;
856         login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
857         login->required_buffer_formats = 0x0006;
858         
859         /* Start out with a request limit of 1, since this is negotiated in
860          * the login request we are just sending
861          */
862         atomic_set(&hostdata->request_limit, 1);
863
864         spin_lock_irqsave(hostdata->host->host_lock, flags);
865         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
866         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
867         return rc;
868 };
869
870 /**
871  * sync_completion: Signal that a synchronous command has completed
872  * Note that after returning from this call, the evt_struct is freed.
873  * the caller waiting on this completion shouldn't touch the evt_struct
874  * again.
875  */
876 static void sync_completion(struct srp_event_struct *evt_struct)
877 {
878         /* copy the response back */
879         if (evt_struct->sync_srp)
880                 *evt_struct->sync_srp = *evt_struct->xfer_iu;
881         
882         complete(&evt_struct->comp);
883 }
884
885 /**
886  * ibmvscsi_abort: Abort a command...from scsi host template
887  * send this over to the server and wait synchronously for the response
888  */
889 static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
890 {
891         struct ibmvscsi_host_data *hostdata =
892             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
893         struct srp_tsk_mgmt *tsk_mgmt;
894         struct srp_event_struct *evt;
895         struct srp_event_struct *tmp_evt, *found_evt;
896         union viosrp_iu srp_rsp;
897         int rsp_rc;
898         unsigned long flags;
899         u16 lun = lun_from_dev(cmd->device);
900
901         /* First, find this command in our sent list so we can figure
902          * out the correct tag
903          */
904         spin_lock_irqsave(hostdata->host->host_lock, flags);
905         found_evt = NULL;
906         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
907                 if (tmp_evt->cmnd == cmd) {
908                         found_evt = tmp_evt;
909                         break;
910                 }
911         }
912
913         if (!found_evt) {
914                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
915                 return FAILED;
916         }
917
918         evt = get_event_struct(&hostdata->pool);
919         if (evt == NULL) {
920                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
921                 printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
922                 return FAILED;
923         }
924         
925         init_event_struct(evt,
926                           sync_completion,
927                           VIOSRP_SRP_FORMAT,
928                           init_timeout * HZ);
929
930         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
931         
932         /* Set up an abort SRP command */
933         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
934         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
935         tsk_mgmt->lun = ((u64) lun) << 48;
936         tsk_mgmt->task_mgmt_flags = 0x01;       /* ABORT TASK */
937         tsk_mgmt->managed_task_tag = (u64) found_evt;
938
939         printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
940                tsk_mgmt->lun, tsk_mgmt->managed_task_tag);
941
942         evt->sync_srp = &srp_rsp;
943         init_completion(&evt->comp);
944         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);
945         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
946         if (rsp_rc != 0) {
947                 printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
948                 return FAILED;
949         }
950
951         wait_for_completion(&evt->comp);
952
953         /* make sure we got a good response */
954         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
955                 if (printk_ratelimit())
956                         printk(KERN_WARNING 
957                                "ibmvscsi: abort bad SRP RSP type %d\n",
958                                srp_rsp.srp.generic.type);
959                 return FAILED;
960         }
961
962         if (srp_rsp.srp.rsp.rspvalid)
963                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
964         else
965                 rsp_rc = srp_rsp.srp.rsp.status;
966
967         if (rsp_rc) {
968                 if (printk_ratelimit())
969                         printk(KERN_WARNING 
970                        "ibmvscsi: abort code %d for task tag 0x%lx\n",
971                                rsp_rc,
972                                tsk_mgmt->managed_task_tag);
973                 return FAILED;
974         }
975
976         /* Because we dropped the spinlock above, it's possible
977          * The event is no longer in our list.  Make sure it didn't
978          * complete while we were aborting
979          */
980         spin_lock_irqsave(hostdata->host->host_lock, flags);
981         found_evt = NULL;
982         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
983                 if (tmp_evt->cmnd == cmd) {
984                         found_evt = tmp_evt;
985                         break;
986                 }
987         }
988
989         if (found_evt == NULL) {
990                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
991                 printk(KERN_INFO
992                        "ibmvscsi: aborted task tag 0x%lx completed\n",
993                        tsk_mgmt->managed_task_tag);
994                 return SUCCESS;
995         }
996
997         printk(KERN_INFO
998                "ibmvscsi: successfully aborted task tag 0x%lx\n",
999                tsk_mgmt->managed_task_tag);
1000
1001         cmd->result = (DID_ABORT << 16);
1002         list_del(&found_evt->list);
1003         unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
1004                        found_evt->hostdata->dev);
1005         free_event_struct(&found_evt->hostdata->pool, found_evt);
1006         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1007         atomic_inc(&hostdata->request_limit);
1008         return SUCCESS;
1009 }
1010
1011 /**
1012  * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host 
1013  * template send this over to the server and wait synchronously for the 
1014  * response
1015  */
1016 static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
1017 {
1018         struct ibmvscsi_host_data *hostdata =
1019             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
1020
1021         struct srp_tsk_mgmt *tsk_mgmt;
1022         struct srp_event_struct *evt;
1023         struct srp_event_struct *tmp_evt, *pos;
1024         union viosrp_iu srp_rsp;
1025         int rsp_rc;
1026         unsigned long flags;
1027         u16 lun = lun_from_dev(cmd->device);
1028
1029         spin_lock_irqsave(hostdata->host->host_lock, flags);
1030         evt = get_event_struct(&hostdata->pool);
1031         if (evt == NULL) {
1032                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1033                 printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
1034                 return FAILED;
1035         }
1036         
1037         init_event_struct(evt,
1038                           sync_completion,
1039                           VIOSRP_SRP_FORMAT,
1040                           init_timeout * HZ);
1041
1042         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1043
1044         /* Set up a lun reset SRP command */
1045         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1046         tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
1047         tsk_mgmt->lun = ((u64) lun) << 48;
1048         tsk_mgmt->task_mgmt_flags = 0x08;       /* LUN RESET */
1049
1050         printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
1051                tsk_mgmt->lun);
1052
1053         evt->sync_srp = &srp_rsp;
1054         init_completion(&evt->comp);
1055         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);
1056         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1057         if (rsp_rc != 0) {
1058                 printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
1059                 return FAILED;
1060         }
1061
1062         wait_for_completion(&evt->comp);
1063
1064         /* make sure we got a good response */
1065         if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
1066                 if (printk_ratelimit())
1067                         printk(KERN_WARNING 
1068                                "ibmvscsi: reset bad SRP RSP type %d\n",
1069                                srp_rsp.srp.generic.type);
1070                 return FAILED;
1071         }
1072
1073         if (srp_rsp.srp.rsp.rspvalid)
1074                 rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
1075         else
1076                 rsp_rc = srp_rsp.srp.rsp.status;
1077
1078         if (rsp_rc) {
1079                 if (printk_ratelimit())
1080                         printk(KERN_WARNING 
1081                                "ibmvscsi: reset code %d for task tag 0x%lx\n",
1082                        rsp_rc,
1083                                tsk_mgmt->managed_task_tag);
1084                 return FAILED;
1085         }
1086
1087         /* We need to find all commands for this LUN that have not yet been
1088          * responded to, and fail them with DID_RESET
1089          */
1090         spin_lock_irqsave(hostdata->host->host_lock, flags);
1091         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1092                 if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1093                         if (tmp_evt->cmnd)
1094                                 tmp_evt->cmnd->result = (DID_RESET << 16);
1095                         list_del(&tmp_evt->list);
1096                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
1097                                        tmp_evt->hostdata->dev);
1098                         free_event_struct(&tmp_evt->hostdata->pool,
1099                                                    tmp_evt);
1100                         atomic_inc(&hostdata->request_limit);
1101                         if (tmp_evt->cmnd_done)
1102                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1103                         else if (tmp_evt->done)
1104                                 tmp_evt->done(tmp_evt);
1105                 }
1106         }
1107         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1108         return SUCCESS;
1109 }
1110
1111 /**
1112  * purge_requests: Our virtual adapter just shut down.  purge any sent requests
1113  * @hostdata:    the adapter
1114  */
1115 static void purge_requests(struct ibmvscsi_host_data *hostdata)
1116 {
1117         struct srp_event_struct *tmp_evt, *pos;
1118         unsigned long flags;
1119
1120         spin_lock_irqsave(hostdata->host->host_lock, flags);
1121         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1122                 list_del(&tmp_evt->list);
1123                 if (tmp_evt->cmnd) {
1124                         tmp_evt->cmnd->result = (DID_ERROR << 16);
1125                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, 
1126                                        tmp_evt, 
1127                                        tmp_evt->hostdata->dev);
1128                         if (tmp_evt->cmnd_done)
1129                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1130                 } else {
1131                         if (tmp_evt->done) {
1132                                 tmp_evt->done(tmp_evt);
1133                         }
1134                 }
1135                 free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
1136         }
1137         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1138 }
1139
1140 /**
1141  * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1142  * @crq:        Command/Response queue
1143  * @hostdata:   ibmvscsi_host_data of host
1144  *
1145 */
1146 void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1147                          struct ibmvscsi_host_data *hostdata)
1148 {
1149         unsigned long flags;
1150         struct srp_event_struct *evt_struct =
1151             (struct srp_event_struct *)crq->IU_data_ptr;
1152         switch (crq->valid) {
1153         case 0xC0:              /* initialization */
1154                 switch (crq->format) {
1155                 case 0x01:      /* Initialization message */
1156                         printk(KERN_INFO "ibmvscsi: partner initialized\n");
1157                         /* Send back a response */
1158                         if (ibmvscsi_send_crq(hostdata,
1159                                               0xC002000000000000LL, 0) == 0) {
1160                                 /* Now login */
1161                                 send_srp_login(hostdata);
1162                         } else {
1163                                 printk(KERN_ERR
1164                                        "ibmvscsi: Unable to send init rsp\n");
1165                         }
1166
1167                         break;
1168                 case 0x02:      /* Initialization response */
1169                         printk(KERN_INFO
1170                                "ibmvscsi: partner initialization complete\n");
1171
1172                         /* Now login */
1173                         send_srp_login(hostdata);
1174                         break;
1175                 default:
1176                         printk(KERN_ERR "ibmvscsi: unknown crq message type\n");
1177                 }
1178                 return;
1179         case 0xFF:              /* Hypervisor telling us the connection is closed */
1180                 printk(KERN_INFO "ibmvscsi: Virtual adapter failed!\n");
1181
1182                 atomic_set(&hostdata->request_limit, -1);
1183                 purge_requests(hostdata);
1184                 ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
1185                 return;
1186         case 0x80:              /* real payload */
1187                 break;
1188         default:
1189                 printk(KERN_ERR
1190                        "ibmvscsi: got an invalid message type 0x%02x\n",
1191                        crq->valid);
1192                 return;
1193         }
1194
1195         /* The only kind of payload CRQs we should get are responses to
1196          * things we send. Make sure this response is to something we
1197          * actually sent
1198          */
1199         if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1200                 printk(KERN_ERR
1201                        "ibmvscsi: returned correlation_token 0x%p is invalid!\n",
1202                        (void *)crq->IU_data_ptr);
1203                 return;
1204         }
1205
1206         if (atomic_read(&evt_struct->free)) {
1207                 printk(KERN_ERR
1208                        "ibmvscsi: received duplicate  correlation_token 0x%p!\n",
1209                        (void *)crq->IU_data_ptr);
1210                 return;
1211         }
1212
1213         if (crq->format == VIOSRP_SRP_FORMAT)
1214                 atomic_add(evt_struct->xfer_iu->srp.rsp.request_limit_delta,
1215                            &hostdata->request_limit);
1216
1217         if (evt_struct->done)
1218                 evt_struct->done(evt_struct);
1219         else
1220                 printk(KERN_ERR
1221                        "ibmvscsi: returned done() is NULL; not running it!\n");
1222
1223         /*
1224          * Lock the host_lock before messing with these structures, since we
1225          * are running in a task context
1226          */
1227         spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1228         list_del(&evt_struct->list);
1229         free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1230         spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1231 }
1232
1233 /**
1234  * ibmvscsi_get_host_config: Send the command to the server to get host
1235  * configuration data.  The data is opaque to us.
1236  */
1237 static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
1238                                    unsigned char *buffer, int length)
1239 {
1240         struct viosrp_host_config *host_config;
1241         struct srp_event_struct *evt_struct;
1242         int rc;
1243
1244         evt_struct = get_event_struct(&hostdata->pool);
1245         if (!evt_struct) {
1246                 printk(KERN_ERR
1247                        "ibmvscsi: could't allocate event for HOST_CONFIG!\n");
1248                 return -1;
1249         }
1250
1251         init_event_struct(evt_struct,
1252                           sync_completion,
1253                           VIOSRP_MAD_FORMAT,
1254                           init_timeout * HZ);
1255
1256         host_config = &evt_struct->iu.mad.host_config;
1257
1258         /* Set up a lun reset SRP command */
1259         memset(host_config, 0x00, sizeof(*host_config));
1260         host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
1261         host_config->common.length = length;
1262         host_config->buffer = dma_map_single(hostdata->dev, buffer, length,
1263                                             DMA_BIDIRECTIONAL);
1264
1265         if (dma_mapping_error(host_config->buffer)) {
1266                 printk(KERN_ERR
1267                        "ibmvscsi: dma_mapping error " "getting host config\n");
1268                 free_event_struct(&hostdata->pool, evt_struct);
1269                 return -1;
1270         }
1271
1272         init_completion(&evt_struct->comp);
1273         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
1274         if (rc == 0) {
1275                 wait_for_completion(&evt_struct->comp);
1276                 dma_unmap_single(hostdata->dev, host_config->buffer,
1277                                  length, DMA_BIDIRECTIONAL);
1278         }
1279
1280         return rc;
1281 }
1282
1283 /* ------------------------------------------------------------
1284  * sysfs attributes
1285  */
1286 static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
1287 {
1288         struct Scsi_Host *shost = class_to_shost(class_dev);
1289         struct ibmvscsi_host_data *hostdata =
1290             (struct ibmvscsi_host_data *)shost->hostdata;
1291         int len;
1292
1293         len = snprintf(buf, PAGE_SIZE, "%s\n",
1294                        hostdata->madapter_info.srp_version);
1295         return len;
1296 }
1297
1298 static struct class_device_attribute ibmvscsi_host_srp_version = {
1299         .attr = {
1300                  .name = "srp_version",
1301                  .mode = S_IRUGO,
1302                  },
1303         .show = show_host_srp_version,
1304 };
1305
1306 static ssize_t show_host_partition_name(struct class_device *class_dev,
1307                                         char *buf)
1308 {
1309         struct Scsi_Host *shost = class_to_shost(class_dev);
1310         struct ibmvscsi_host_data *hostdata =
1311             (struct ibmvscsi_host_data *)shost->hostdata;
1312         int len;
1313
1314         len = snprintf(buf, PAGE_SIZE, "%s\n",
1315                        hostdata->madapter_info.partition_name);
1316         return len;
1317 }
1318
1319 static struct class_device_attribute ibmvscsi_host_partition_name = {
1320         .attr = {
1321                  .name = "partition_name",
1322                  .mode = S_IRUGO,
1323                  },
1324         .show = show_host_partition_name,
1325 };
1326
1327 static ssize_t show_host_partition_number(struct class_device *class_dev,
1328                                           char *buf)
1329 {
1330         struct Scsi_Host *shost = class_to_shost(class_dev);
1331         struct ibmvscsi_host_data *hostdata =
1332             (struct ibmvscsi_host_data *)shost->hostdata;
1333         int len;
1334
1335         len = snprintf(buf, PAGE_SIZE, "%d\n",
1336                        hostdata->madapter_info.partition_number);
1337         return len;
1338 }
1339
1340 static struct class_device_attribute ibmvscsi_host_partition_number = {
1341         .attr = {
1342                  .name = "partition_number",
1343                  .mode = S_IRUGO,
1344                  },
1345         .show = show_host_partition_number,
1346 };
1347
1348 static ssize_t show_host_mad_version(struct class_device *class_dev, char *buf)
1349 {
1350         struct Scsi_Host *shost = class_to_shost(class_dev);
1351         struct ibmvscsi_host_data *hostdata =
1352             (struct ibmvscsi_host_data *)shost->hostdata;
1353         int len;
1354
1355         len = snprintf(buf, PAGE_SIZE, "%d\n",
1356                        hostdata->madapter_info.mad_version);
1357         return len;
1358 }
1359
1360 static struct class_device_attribute ibmvscsi_host_mad_version = {
1361         .attr = {
1362                  .name = "mad_version",
1363                  .mode = S_IRUGO,
1364                  },
1365         .show = show_host_mad_version,
1366 };
1367
1368 static ssize_t show_host_os_type(struct class_device *class_dev, char *buf)
1369 {
1370         struct Scsi_Host *shost = class_to_shost(class_dev);
1371         struct ibmvscsi_host_data *hostdata =
1372             (struct ibmvscsi_host_data *)shost->hostdata;
1373         int len;
1374
1375         len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
1376         return len;
1377 }
1378
1379 static struct class_device_attribute ibmvscsi_host_os_type = {
1380         .attr = {
1381                  .name = "os_type",
1382                  .mode = S_IRUGO,
1383                  },
1384         .show = show_host_os_type,
1385 };
1386
1387 static ssize_t show_host_config(struct class_device *class_dev, char *buf)
1388 {
1389         struct Scsi_Host *shost = class_to_shost(class_dev);
1390         struct ibmvscsi_host_data *hostdata =
1391             (struct ibmvscsi_host_data *)shost->hostdata;
1392
1393         /* returns null-terminated host config data */
1394         if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
1395                 return strlen(buf);
1396         else
1397                 return 0;
1398 }
1399
1400 static struct class_device_attribute ibmvscsi_host_config = {
1401         .attr = {
1402                  .name = "config",
1403                  .mode = S_IRUGO,
1404                  },
1405         .show = show_host_config,
1406 };
1407
1408 static struct class_device_attribute *ibmvscsi_attrs[] = {
1409         &ibmvscsi_host_srp_version,
1410         &ibmvscsi_host_partition_name,
1411         &ibmvscsi_host_partition_number,
1412         &ibmvscsi_host_mad_version,
1413         &ibmvscsi_host_os_type,
1414         &ibmvscsi_host_config,
1415         NULL
1416 };
1417
1418 /* ------------------------------------------------------------
1419  * SCSI driver registration
1420  */
1421 static struct scsi_host_template driver_template = {
1422         .module = THIS_MODULE,
1423         .name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
1424         .proc_name = "ibmvscsi",
1425         .queuecommand = ibmvscsi_queuecommand,
1426         .eh_abort_handler = ibmvscsi_eh_abort_handler,
1427         .eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
1428         .cmd_per_lun = 16,
1429         .can_queue = 1,         /* Updated after SRP_LOGIN */
1430         .this_id = -1,
1431         .sg_tablesize = SG_ALL,
1432         .use_clustering = ENABLE_CLUSTERING,
1433         .shost_attrs = ibmvscsi_attrs,
1434 };
1435
1436 /**
1437  * Called by bus code for each adapter
1438  */
1439 static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1440 {
1441         struct ibmvscsi_host_data *hostdata;
1442         struct Scsi_Host *host;
1443         struct device *dev = &vdev->dev;
1444         unsigned long wait_switch = 0;
1445
1446         vdev->dev.driver_data = NULL;
1447
1448         host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
1449         if (!host) {
1450                 printk(KERN_ERR "ibmvscsi: couldn't allocate host data\n");
1451                 goto scsi_host_alloc_failed;
1452         }
1453
1454         hostdata = (struct ibmvscsi_host_data *)host->hostdata;
1455         memset(hostdata, 0x00, sizeof(*hostdata));
1456         INIT_LIST_HEAD(&hostdata->sent);
1457         hostdata->host = host;
1458         hostdata->dev = dev;
1459         atomic_set(&hostdata->request_limit, -1);
1460         hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
1461
1462         if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
1463                                     max_requests) != 0) {
1464                 printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
1465                 goto init_crq_failed;
1466         }
1467         if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
1468                 printk(KERN_ERR "ibmvscsi: couldn't initialize event pool\n");
1469                 goto init_pool_failed;
1470         }
1471
1472         host->max_lun = 8;
1473         host->max_id = max_id;
1474         host->max_channel = max_channel;
1475
1476         if (scsi_add_host(hostdata->host, hostdata->dev))
1477                 goto add_host_failed;
1478
1479         /* Try to send an initialization message.  Note that this is allowed
1480          * to fail if the other end is not acive.  In that case we don't
1481          * want to scan
1482          */
1483         if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0) {
1484                 /*
1485                  * Wait around max init_timeout secs for the adapter to finish
1486                  * initializing. When we are done initializing, we will have a
1487                  * valid request_limit.  We don't want Linux scanning before
1488                  * we are ready.
1489                  */
1490                 for (wait_switch = jiffies + (init_timeout * HZ);
1491                      time_before(jiffies, wait_switch) &&
1492                      atomic_read(&hostdata->request_limit) < 2;) {
1493
1494                         msleep(10);
1495                 }
1496
1497                 /* if we now have a valid request_limit, initiate a scan */
1498                 if (atomic_read(&hostdata->request_limit) > 0)
1499                         scsi_scan_host(host);
1500         }
1501
1502         vdev->dev.driver_data = hostdata;
1503         return 0;
1504
1505       add_host_failed:
1506         release_event_pool(&hostdata->pool, hostdata);
1507       init_pool_failed:
1508         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_requests);
1509       init_crq_failed:
1510         scsi_host_put(host);
1511       scsi_host_alloc_failed:
1512         return -1;
1513 }
1514
1515 static int ibmvscsi_remove(struct vio_dev *vdev)
1516 {
1517         struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
1518         release_event_pool(&hostdata->pool, hostdata);
1519         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
1520                                    max_requests);
1521         
1522         scsi_remove_host(hostdata->host);
1523         scsi_host_put(hostdata->host);
1524
1525         return 0;
1526 }
1527
1528 /**
1529  * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we 
1530  * support.
1531  */
1532 static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
1533         {"vscsi", "IBM,v-scsi"},
1534         { "", "" }
1535 };
1536
1537 MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
1538 static struct vio_driver ibmvscsi_driver = {
1539         .name = "ibmvscsi",
1540         .id_table = ibmvscsi_device_table,
1541         .probe = ibmvscsi_probe,
1542         .remove = ibmvscsi_remove
1543 };
1544
1545 int __init ibmvscsi_module_init(void)
1546 {
1547         return vio_register_driver(&ibmvscsi_driver);
1548 }
1549
1550 void __exit ibmvscsi_module_exit(void)
1551 {
1552         vio_unregister_driver(&ibmvscsi_driver);
1553 }
1554
1555 module_init(ibmvscsi_module_init);
1556 module_exit(ibmvscsi_module_exit);