Merge branch 'master' into upstream
[linux-2.6] / drivers / scsi / ibmvscsi / ibmvscsi.c
1 /* ------------------------------------------------------------
2  * ibmvscsi.c
3  * (C) Copyright IBM Corporation 1994, 2004
4  * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
5  *          Santiago Leon (santil@us.ibm.com)
6  *          Dave Boutcher (sleddog@us.ibm.com)
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
21  * USA
22  *
23  * ------------------------------------------------------------
24  * Emulation of a SCSI host adapter for Virtual I/O devices
25  *
26  * This driver supports the SCSI adapter implemented by the IBM
27  * Power5 firmware.  That SCSI adapter is not a physical adapter,
28  * but allows Linux SCSI peripheral drivers to directly
29  * access devices in another logical partition on the physical system.
30  *
31  * The virtual adapter(s) are present in the open firmware device
32  * tree just like real adapters.
33  *
34  * One of the capabilities provided on these systems is the ability
35  * to DMA between partitions.  The architecture states that for VSCSI,
36  * the server side is allowed to DMA to and from the client.  The client
37  * is never trusted to DMA to or from the server directly.
38  *
39  * Messages are sent between partitions on a "Command/Response Queue" 
40  * (CRQ), which is just a buffer of 16 byte entries in the receiver's 
41  * Senders cannot access the buffer directly, but send messages by
42  * making a hypervisor call and passing in the 16 bytes.  The hypervisor
43  * puts the message in the next 16 byte space in round-robbin fashion,
44  * turns on the high order bit of the message (the valid bit), and 
45  * generates an interrupt to the receiver (if interrupts are turned on.) 
46  * The receiver just turns off the valid bit when they have copied out
47  * the message.
48  *
49  * The VSCSI client builds a SCSI Remote Protocol (SRP) Information Unit
50  * (IU) (as defined in the T10 standard available at www.t10.org), gets 
51  * a DMA address for the message, and sends it to the server as the
52  * payload of a CRQ message.  The server DMAs the SRP IU and processes it,
53  * including doing any additional data transfers.  When it is done, it
54  * DMAs the SRP response back to the same address as the request came from,
55  * and sends a CRQ message back to inform the client that the request has
56  * completed.
57  *
58  * Note that some of the underlying infrastructure is different between
59  * machines conforming to the "RS/6000 Platform Architecture" (RPA) and
60  * the older iSeries hypervisor models.  To support both, some low level
61  * routines have been broken out into rpa_vscsi.c and iseries_vscsi.c.
62  * The Makefile should pick one, not two, not zero, of these.
63  *
64  * TODO: This is currently pretty tied to the IBM i/pSeries hypervisor
65  * interfaces.  It would be really nice to abstract this above an RDMA
66  * layer.
67  */
68
69 #include <linux/module.h>
70 #include <linux/moduleparam.h>
71 #include <linux/dma-mapping.h>
72 #include <linux/delay.h>
73 #include <asm/vio.h>
74 #include <scsi/scsi.h>
75 #include <scsi/scsi_cmnd.h>
76 #include <scsi/scsi_host.h>
77 #include <scsi/scsi_device.h>
78 #include "ibmvscsi.h"
79
80 /* The values below are somewhat arbitrary default values, but 
81  * OS/400 will use 3 busses (disks, CDs, tapes, I think.)
82  * Note that there are 3 bits of channel value, 6 bits of id, and
83  * 5 bits of LUN.
84  */
85 static int max_id = 64;
86 static int max_channel = 3;
87 static int init_timeout = 5;
88 static int max_requests = 50;
89
90 #define IBMVSCSI_VERSION "1.5.8"
91
92 MODULE_DESCRIPTION("IBM Virtual SCSI");
93 MODULE_AUTHOR("Dave Boutcher");
94 MODULE_LICENSE("GPL");
95 MODULE_VERSION(IBMVSCSI_VERSION);
96
97 module_param_named(max_id, max_id, int, S_IRUGO | S_IWUSR);
98 MODULE_PARM_DESC(max_id, "Largest ID value for each channel");
99 module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
100 MODULE_PARM_DESC(max_channel, "Largest channel value");
101 module_param_named(init_timeout, init_timeout, int, S_IRUGO | S_IWUSR);
102 MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
103 module_param_named(max_requests, max_requests, int, S_IRUGO | S_IWUSR);
104 MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
105
106 /* ------------------------------------------------------------
107  * Routines for the event pool and event structs
108  */
109 /**
110  * initialize_event_pool: - Allocates and initializes the event pool for a host
111  * @pool:       event_pool to be initialized
112  * @size:       Number of events in pool
113  * @hostdata:   ibmvscsi_host_data who owns the event pool
114  *
115  * Returns zero on success.
116 */
117 static int initialize_event_pool(struct event_pool *pool,
118                                  int size, struct ibmvscsi_host_data *hostdata)
119 {
120         int i;
121
122         pool->size = size;
123         pool->next = 0;
124         pool->events = kcalloc(pool->size, sizeof(*pool->events), GFP_KERNEL);
125         if (!pool->events)
126                 return -ENOMEM;
127
128         pool->iu_storage =
129             dma_alloc_coherent(hostdata->dev,
130                                pool->size * sizeof(*pool->iu_storage),
131                                &pool->iu_token, 0);
132         if (!pool->iu_storage) {
133                 kfree(pool->events);
134                 return -ENOMEM;
135         }
136
137         for (i = 0; i < pool->size; ++i) {
138                 struct srp_event_struct *evt = &pool->events[i];
139                 memset(&evt->crq, 0x00, sizeof(evt->crq));
140                 atomic_set(&evt->free, 1);
141                 evt->crq.valid = 0x80;
142                 evt->crq.IU_length = sizeof(*evt->xfer_iu);
143                 evt->crq.IU_data_ptr = pool->iu_token + 
144                         sizeof(*evt->xfer_iu) * i;
145                 evt->xfer_iu = pool->iu_storage + i;
146                 evt->hostdata = hostdata;
147                 evt->ext_list = NULL;
148                 evt->ext_list_token = 0;
149         }
150
151         return 0;
152 }
153
154 /**
155  * release_event_pool: - Frees memory of an event pool of a host
156  * @pool:       event_pool to be released
157  * @hostdata:   ibmvscsi_host_data who owns the even pool
158  *
159  * Returns zero on success.
160 */
161 static void release_event_pool(struct event_pool *pool,
162                                struct ibmvscsi_host_data *hostdata)
163 {
164         int i, in_use = 0;
165         for (i = 0; i < pool->size; ++i) {
166                 if (atomic_read(&pool->events[i].free) != 1)
167                         ++in_use;
168                 if (pool->events[i].ext_list) {
169                         dma_free_coherent(hostdata->dev,
170                                   SG_ALL * sizeof(struct srp_direct_buf),
171                                   pool->events[i].ext_list,
172                                   pool->events[i].ext_list_token);
173                 }
174         }
175         if (in_use)
176                 printk(KERN_WARNING
177                        "ibmvscsi: releasing event pool with %d "
178                        "events still in use?\n", in_use);
179         kfree(pool->events);
180         dma_free_coherent(hostdata->dev,
181                           pool->size * sizeof(*pool->iu_storage),
182                           pool->iu_storage, pool->iu_token);
183 }
184
185 /**
186  * valid_event_struct: - Determines if event is valid.
187  * @pool:       event_pool that contains the event
188  * @evt:        srp_event_struct to be checked for validity
189  *
190  * Returns zero if event is invalid, one otherwise.
191 */
192 static int valid_event_struct(struct event_pool *pool,
193                                 struct srp_event_struct *evt)
194 {
195         int index = evt - pool->events;
196         if (index < 0 || index >= pool->size)   /* outside of bounds */
197                 return 0;
198         if (evt != pool->events + index)        /* unaligned */
199                 return 0;
200         return 1;
201 }
202
203 /**
204  * ibmvscsi_free-event_struct: - Changes status of event to "free"
205  * @pool:       event_pool that contains the event
206  * @evt:        srp_event_struct to be modified
207  *
208 */
209 static void free_event_struct(struct event_pool *pool,
210                                        struct srp_event_struct *evt)
211 {
212         if (!valid_event_struct(pool, evt)) {
213                 printk(KERN_ERR
214                        "ibmvscsi: Freeing invalid event_struct %p "
215                        "(not in pool %p)\n", evt, pool->events);
216                 return;
217         }
218         if (atomic_inc_return(&evt->free) != 1) {
219                 printk(KERN_ERR
220                        "ibmvscsi: Freeing event_struct %p "
221                        "which is not in use!\n", evt);
222                 return;
223         }
224 }
225
226 /**
227  * get_evt_struct: - Gets the next free event in pool
228  * @pool:       event_pool that contains the events to be searched
229  *
230  * Returns the next event in "free" state, and NULL if none are free.
231  * Note that no synchronization is done here, we assume the host_lock
232  * will syncrhonze things.
233 */
234 static struct srp_event_struct *get_event_struct(struct event_pool *pool)
235 {
236         int i;
237         int poolsize = pool->size;
238         int offset = pool->next;
239
240         for (i = 0; i < poolsize; i++) {
241                 offset = (offset + 1) % poolsize;
242                 if (!atomic_dec_if_positive(&pool->events[offset].free)) {
243                         pool->next = offset;
244                         return &pool->events[offset];
245                 }
246         }
247
248         printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
249         return NULL;
250 }
251
252 /**
253  * init_event_struct: Initialize fields in an event struct that are always 
254  *                    required.
255  * @evt:        The event
256  * @done:       Routine to call when the event is responded to
257  * @format:     SRP or MAD format
258  * @timeout:    timeout value set in the CRQ
259  */
260 static void init_event_struct(struct srp_event_struct *evt_struct,
261                               void (*done) (struct srp_event_struct *),
262                               u8 format,
263                               int timeout)
264 {
265         evt_struct->cmnd = NULL;
266         evt_struct->cmnd_done = NULL;
267         evt_struct->sync_srp = NULL;
268         evt_struct->crq.format = format;
269         evt_struct->crq.timeout = timeout;
270         evt_struct->done = done;
271 }
272
273 /* ------------------------------------------------------------
274  * Routines for receiving SCSI responses from the hosting partition
275  */
276
277 /**
278  * set_srp_direction: Set the fields in the srp related to data
279  *     direction and number of buffers based on the direction in
280  *     the scsi_cmnd and the number of buffers
281  */
282 static void set_srp_direction(struct scsi_cmnd *cmd,
283                               struct srp_cmd *srp_cmd, 
284                               int numbuf)
285 {
286         u8 fmt;
287
288         if (numbuf == 0)
289                 return;
290         
291         if (numbuf == 1)
292                 fmt = SRP_DATA_DESC_DIRECT;
293         else {
294                 fmt = SRP_DATA_DESC_INDIRECT;
295                 numbuf = min(numbuf, MAX_INDIRECT_BUFS);
296
297                 if (cmd->sc_data_direction == DMA_TO_DEVICE)
298                         srp_cmd->data_out_desc_cnt = numbuf;
299                 else
300                         srp_cmd->data_in_desc_cnt = numbuf;
301         }
302
303         if (cmd->sc_data_direction == DMA_TO_DEVICE)
304                 srp_cmd->buf_fmt = fmt << 4;
305         else
306                 srp_cmd->buf_fmt = fmt;
307 }
308
309 static void unmap_sg_list(int num_entries,
310                 struct device *dev,
311                 struct srp_direct_buf *md)
312 {
313         int i;
314
315         for (i = 0; i < num_entries; ++i)
316                 dma_unmap_single(dev, md[i].va, md[i].len, DMA_BIDIRECTIONAL);
317 }
318
319 /**
320  * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
321  * @cmd:        srp_cmd whose additional_data member will be unmapped
322  * @dev:        device for which the memory is mapped
323  *
324 */
325 static void unmap_cmd_data(struct srp_cmd *cmd,
326                            struct srp_event_struct *evt_struct,
327                            struct device *dev)
328 {
329         u8 out_fmt, in_fmt;
330
331         out_fmt = cmd->buf_fmt >> 4;
332         in_fmt = cmd->buf_fmt & ((1U << 4) - 1);
333
334         if (out_fmt == SRP_NO_DATA_DESC && in_fmt == SRP_NO_DATA_DESC)
335                 return;
336         else if (out_fmt == SRP_DATA_DESC_DIRECT ||
337                  in_fmt == SRP_DATA_DESC_DIRECT) {
338                 struct srp_direct_buf *data =
339                         (struct srp_direct_buf *) cmd->add_data;
340                 dma_unmap_single(dev, data->va, data->len, DMA_BIDIRECTIONAL);
341         } else {
342                 struct srp_indirect_buf *indirect =
343                         (struct srp_indirect_buf *) cmd->add_data;
344                 int num_mapped = indirect->table_desc.len /
345                         sizeof(struct srp_direct_buf);
346
347                 if (num_mapped <= MAX_INDIRECT_BUFS) {
348                         unmap_sg_list(num_mapped, dev, &indirect->desc_list[0]);
349                         return;
350                 }
351
352                 unmap_sg_list(num_mapped, dev, evt_struct->ext_list);
353         }
354 }
355
356 static int map_sg_list(int num_entries, 
357                        struct scatterlist *sg,
358                        struct srp_direct_buf *md)
359 {
360         int i;
361         u64 total_length = 0;
362
363         for (i = 0; i < num_entries; ++i) {
364                 struct srp_direct_buf *descr = md + i;
365                 struct scatterlist *sg_entry = &sg[i];
366                 descr->va = sg_dma_address(sg_entry);
367                 descr->len = sg_dma_len(sg_entry);
368                 descr->key = 0;
369                 total_length += sg_dma_len(sg_entry);
370         }
371         return total_length;
372 }
373
374 /**
375  * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
376  * @cmd:        Scsi_Cmnd with the scatterlist
377  * @srp_cmd:    srp_cmd that contains the memory descriptor
378  * @dev:        device for which to map dma memory
379  *
380  * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
381  * Returns 1 on success.
382 */
383 static int map_sg_data(struct scsi_cmnd *cmd,
384                        struct srp_event_struct *evt_struct,
385                        struct srp_cmd *srp_cmd, struct device *dev)
386 {
387
388         int sg_mapped;
389         u64 total_length = 0;
390         struct scatterlist *sg = cmd->request_buffer;
391         struct srp_direct_buf *data =
392                 (struct srp_direct_buf *) srp_cmd->add_data;
393         struct srp_indirect_buf *indirect =
394                 (struct srp_indirect_buf *) data;
395
396         sg_mapped = dma_map_sg(dev, sg, cmd->use_sg, DMA_BIDIRECTIONAL);
397
398         if (sg_mapped == 0)
399                 return 0;
400
401         set_srp_direction(cmd, srp_cmd, sg_mapped);
402
403         /* special case; we can use a single direct descriptor */
404         if (sg_mapped == 1) {
405                 data->va = sg_dma_address(&sg[0]);
406                 data->len = sg_dma_len(&sg[0]);
407                 data->key = 0;
408                 return 1;
409         }
410
411         if (sg_mapped > SG_ALL) {
412                 printk(KERN_ERR
413                        "ibmvscsi: More than %d mapped sg entries, got %d\n",
414                        SG_ALL, sg_mapped);
415                 return 0;
416         }
417
418         indirect->table_desc.va = 0;
419         indirect->table_desc.len = sg_mapped * sizeof(struct srp_direct_buf);
420         indirect->table_desc.key = 0;
421
422         if (sg_mapped <= MAX_INDIRECT_BUFS) {
423                 total_length = map_sg_list(sg_mapped, sg,
424                                            &indirect->desc_list[0]);
425                 indirect->len = total_length;
426                 return 1;
427         }
428
429         /* get indirect table */
430         if (!evt_struct->ext_list) {
431                 evt_struct->ext_list = (struct srp_direct_buf *)
432                         dma_alloc_coherent(dev, 
433                                            SG_ALL * sizeof(struct srp_direct_buf),
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->len = total_length;
446         indirect->table_desc.va = evt_struct->ext_list_token;
447         indirect->table_desc.len = sg_mapped * sizeof(indirect->desc_list[0]);
448         memcpy(indirect->desc_list, evt_struct->ext_list,
449                MAX_INDIRECT_BUFS * sizeof(struct srp_direct_buf));
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 srp_direct_buf *data =
467                 (struct srp_direct_buf *) srp_cmd->add_data;
468
469         data->va =
470                 dma_map_single(dev, cmd->request_buffer,
471                                cmd->request_bufflen,
472                                DMA_BIDIRECTIONAL);
473         if (dma_mapping_error(data->va)) {
474                 printk(KERN_ERR
475                        "ibmvscsi: Unable to map request_buffer for command!\n");
476                 return 0;
477         }
478         data->len = cmd->request_bufflen;
479         data->key = 0;
480
481         set_srp_direction(cmd, srp_cmd, 1);
482
483         return 1;
484 }
485
486 /**
487  * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
488  * @cmd:        struct scsi_cmnd with the memory to be mapped
489  * @srp_cmd:    srp_cmd that contains the memory descriptor
490  * @dev:        dma device for which to map dma memory
491  *
492  * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds 
493  * Returns 1 on success.
494 */
495 static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
496                                 struct srp_event_struct *evt_struct,
497                                 struct srp_cmd *srp_cmd, struct device *dev)
498 {
499         switch (cmd->sc_data_direction) {
500         case DMA_FROM_DEVICE:
501         case DMA_TO_DEVICE:
502                 break;
503         case DMA_NONE:
504                 return 1;
505         case DMA_BIDIRECTIONAL:
506                 printk(KERN_ERR
507                        "ibmvscsi: Can't map DMA_BIDIRECTIONAL to read/write\n");
508                 return 0;
509         default:
510                 printk(KERN_ERR
511                        "ibmvscsi: Unknown data direction 0x%02x; can't map!\n",
512                        cmd->sc_data_direction);
513                 return 0;
514         }
515
516         if (!cmd->request_buffer)
517                 return 1;
518         if (cmd->use_sg)
519                 return map_sg_data(cmd, evt_struct, srp_cmd, dev);
520         return map_single_data(cmd, srp_cmd, dev);
521 }
522
523 /* ------------------------------------------------------------
524  * Routines for sending and receiving SRPs
525  */
526 /**
527  * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
528  * @evt_struct: evt_struct to be sent
529  * @hostdata:   ibmvscsi_host_data of host
530  *
531  * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
532  * Note that this routine assumes that host_lock is held for synchronization
533 */
534 static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
535                                    struct ibmvscsi_host_data *hostdata)
536 {
537         u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
538         int rc;
539
540         /* If we have exhausted our request limit, just fail this request.
541          * Note that there are rare cases involving driver generated requests 
542          * (such as task management requests) that the mid layer may think we
543          * can handle more requests (can_queue) when we actually can't
544          */
545         if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
546             (atomic_dec_if_positive(&hostdata->request_limit) < 0))
547                 goto send_error;
548
549         /* Copy the IU into the transfer area */
550         *evt_struct->xfer_iu = evt_struct->iu;
551         evt_struct->xfer_iu->srp.rsp.tag = (u64)evt_struct;
552
553         /* Add this to the sent list.  We need to do this 
554          * before we actually send 
555          * in case it comes back REALLY fast
556          */
557         list_add_tail(&evt_struct->list, &hostdata->sent);
558
559         if ((rc =
560              ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
561                 list_del(&evt_struct->list);
562
563                 printk(KERN_ERR "ibmvscsi: send error %d\n",
564                        rc);
565                 goto send_error;
566         }
567
568         return 0;
569
570  send_error:
571         unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
572
573         free_event_struct(&hostdata->pool, evt_struct);
574         return SCSI_MLQUEUE_HOST_BUSY;
575 }
576
577 /**
578  * handle_cmd_rsp: -  Handle responses from commands
579  * @evt_struct: srp_event_struct to be handled
580  *
581  * Used as a callback by when sending scsi cmds.
582  * Gets called by ibmvscsi_handle_crq()
583 */
584 static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
585 {
586         struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
587         struct scsi_cmnd *cmnd = evt_struct->cmnd;
588
589         if (unlikely(rsp->opcode != SRP_RSP)) {
590                 if (printk_ratelimit())
591                         printk(KERN_WARNING 
592                                "ibmvscsi: bad SRP RSP type %d\n",
593                                rsp->opcode);
594         }
595         
596         if (cmnd) {
597                 cmnd->result = rsp->status;
598                 if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
599                         memcpy(cmnd->sense_buffer,
600                                rsp->data,
601                                rsp->sense_data_len);
602                 unmap_cmd_data(&evt_struct->iu.srp.cmd, 
603                                evt_struct, 
604                                evt_struct->hostdata->dev);
605
606                 if (rsp->flags & SRP_RSP_FLAG_DOOVER)
607                         cmnd->resid = rsp->data_out_res_cnt;
608                 else if (rsp->flags & SRP_RSP_FLAG_DIOVER)
609                         cmnd->resid = rsp->data_in_res_cnt;
610         }
611
612         if (evt_struct->cmnd_done)
613                 evt_struct->cmnd_done(cmnd);
614 }
615
616 /**
617  * lun_from_dev: - Returns the lun of the scsi device
618  * @dev:        struct scsi_device
619  *
620 */
621 static inline u16 lun_from_dev(struct scsi_device *dev)
622 {
623         return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
624 }
625
626 /**
627  * ibmvscsi_queue: - The queuecommand function of the scsi template 
628  * @cmd:        struct scsi_cmnd to be executed
629  * @done:       Callback function to be called when cmd is completed
630 */
631 static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
632                                  void (*done) (struct scsi_cmnd *))
633 {
634         struct srp_cmd *srp_cmd;
635         struct srp_event_struct *evt_struct;
636         struct srp_indirect_buf *indirect;
637         struct ibmvscsi_host_data *hostdata =
638                 (struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
639         u16 lun = lun_from_dev(cmnd->device);
640         u8 out_fmt, in_fmt;
641
642         evt_struct = get_event_struct(&hostdata->pool);
643         if (!evt_struct)
644                 return SCSI_MLQUEUE_HOST_BUSY;
645
646         /* Set up the actual SRP IU */
647         srp_cmd = &evt_struct->iu.srp.cmd;
648         memset(srp_cmd, 0x00, SRP_MAX_IU_LEN);
649         srp_cmd->opcode = SRP_CMD;
650         memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
651         srp_cmd->lun = ((u64) lun) << 48;
652
653         if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
654                 printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
655                 free_event_struct(&hostdata->pool, evt_struct);
656                 return SCSI_MLQUEUE_HOST_BUSY;
657         }
658
659         init_event_struct(evt_struct,
660                           handle_cmd_rsp,
661                           VIOSRP_SRP_FORMAT,
662                           cmnd->timeout_per_command/HZ);
663
664         evt_struct->cmnd = cmnd;
665         evt_struct->cmnd_done = done;
666
667         /* Fix up dma address of the buffer itself */
668         indirect = (struct srp_indirect_buf *) srp_cmd->add_data;
669         out_fmt = srp_cmd->buf_fmt >> 4;
670         in_fmt = srp_cmd->buf_fmt & ((1U << 4) - 1);
671         if ((in_fmt == SRP_DATA_DESC_INDIRECT ||
672              out_fmt == SRP_DATA_DESC_INDIRECT) &&
673             indirect->table_desc.va == 0) {
674                 indirect->table_desc.va = evt_struct->crq.IU_data_ptr +
675                         offsetof(struct srp_cmd, add_data) +
676                         offsetof(struct srp_indirect_buf, desc_list);
677         }
678
679         return ibmvscsi_send_srp_event(evt_struct, hostdata);
680 }
681
682 /* ------------------------------------------------------------
683  * Routines for driver initialization
684  */
685 /**
686  * adapter_info_rsp: - Handle response to MAD adapter info request
687  * @evt_struct: srp_event_struct with the response
688  *
689  * Used as a "done" callback by when sending adapter_info. Gets called
690  * by ibmvscsi_handle_crq()
691 */
692 static void adapter_info_rsp(struct srp_event_struct *evt_struct)
693 {
694         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
695         dma_unmap_single(hostdata->dev,
696                          evt_struct->iu.mad.adapter_info.buffer,
697                          evt_struct->iu.mad.adapter_info.common.length,
698                          DMA_BIDIRECTIONAL);
699
700         if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
701                 printk("ibmvscsi: error %d getting adapter info\n",
702                        evt_struct->xfer_iu->mad.adapter_info.common.status);
703         } else {
704                 printk("ibmvscsi: host srp version: %s, "
705                        "host partition %s (%d), OS %d, max io %u\n",
706                        hostdata->madapter_info.srp_version,
707                        hostdata->madapter_info.partition_name,
708                        hostdata->madapter_info.partition_number,
709                        hostdata->madapter_info.os_type,
710                        hostdata->madapter_info.port_max_txu[0]);
711                 
712                 if (hostdata->madapter_info.port_max_txu[0]) 
713                         hostdata->host->max_sectors = 
714                                 hostdata->madapter_info.port_max_txu[0] >> 9;
715                 
716                 if (hostdata->madapter_info.os_type == 3 &&
717                     strcmp(hostdata->madapter_info.srp_version, "1.6a") <= 0) {
718                         printk("ibmvscsi: host (Ver. %s) doesn't support large"
719                                "transfers\n",
720                                hostdata->madapter_info.srp_version);
721                         printk("ibmvscsi: limiting scatterlists to %d\n",
722                                MAX_INDIRECT_BUFS);
723                         hostdata->host->sg_tablesize = MAX_INDIRECT_BUFS;
724                 }
725         }
726 }
727
728 /**
729  * send_mad_adapter_info: - Sends the mad adapter info request
730  *      and stores the result so it can be retrieved with
731  *      sysfs.  We COULD consider causing a failure if the
732  *      returned SRP version doesn't match ours.
733  * @hostdata:   ibmvscsi_host_data of host
734  * 
735  * Returns zero if successful.
736 */
737 static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
738 {
739         struct viosrp_adapter_info *req;
740         struct srp_event_struct *evt_struct;
741         dma_addr_t addr;
742
743         evt_struct = get_event_struct(&hostdata->pool);
744         if (!evt_struct) {
745                 printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
746                        "for ADAPTER_INFO_REQ!\n");
747                 return;
748         }
749
750         init_event_struct(evt_struct,
751                           adapter_info_rsp,
752                           VIOSRP_MAD_FORMAT,
753                           init_timeout * HZ);
754         
755         req = &evt_struct->iu.mad.adapter_info;
756         memset(req, 0x00, sizeof(*req));
757         
758         req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
759         req->common.length = sizeof(hostdata->madapter_info);
760         req->buffer = addr = dma_map_single(hostdata->dev,
761                                             &hostdata->madapter_info,
762                                             sizeof(hostdata->madapter_info),
763                                             DMA_BIDIRECTIONAL);
764
765         if (dma_mapping_error(req->buffer)) {
766                 printk(KERN_ERR
767                        "ibmvscsi: Unable to map request_buffer "
768                        "for adapter_info!\n");
769                 free_event_struct(&hostdata->pool, evt_struct);
770                 return;
771         }
772         
773         if (ibmvscsi_send_srp_event(evt_struct, hostdata)) {
774                 printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
775                 dma_unmap_single(hostdata->dev,
776                                  addr,
777                                  sizeof(hostdata->madapter_info),
778                                  DMA_BIDIRECTIONAL);
779         }
780 };
781
782 /**
783  * login_rsp: - Handle response to SRP login request
784  * @evt_struct: srp_event_struct with the response
785  *
786  * Used as a "done" callback by when sending srp_login. Gets called
787  * by ibmvscsi_handle_crq()
788 */
789 static void login_rsp(struct srp_event_struct *evt_struct)
790 {
791         struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
792         switch (evt_struct->xfer_iu->srp.login_rsp.opcode) {
793         case SRP_LOGIN_RSP:     /* it worked! */
794                 break;
795         case SRP_LOGIN_REJ:     /* refused! */
796                 printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REJ reason %u\n",
797                        evt_struct->xfer_iu->srp.login_rej.reason);
798                 /* Login failed.  */
799                 atomic_set(&hostdata->request_limit, -1);
800                 return;
801         default:
802                 printk(KERN_ERR
803                        "ibmvscsi: Invalid login response typecode 0x%02x!\n",
804                        evt_struct->xfer_iu->srp.login_rsp.opcode);
805                 /* Login failed.  */
806                 atomic_set(&hostdata->request_limit, -1);
807                 return;
808         }
809
810         printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");
811
812         if (evt_struct->xfer_iu->srp.login_rsp.req_lim_delta >
813             (max_requests - 2))
814                 evt_struct->xfer_iu->srp.login_rsp.req_lim_delta =
815                     max_requests - 2;
816
817         /* Now we know what the real request-limit is */
818         atomic_set(&hostdata->request_limit,
819                    evt_struct->xfer_iu->srp.login_rsp.req_lim_delta);
820
821         hostdata->host->can_queue =
822             evt_struct->xfer_iu->srp.login_rsp.req_lim_delta - 2;
823
824         if (hostdata->host->can_queue < 1) {
825                 printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
826                 return;
827         }
828
829         /* If we had any pending I/Os, kick them */
830         scsi_unblock_requests(hostdata->host);
831
832         send_mad_adapter_info(hostdata);
833         return;
834 }
835
836 /**
837  * send_srp_login: - Sends the srp login
838  * @hostdata:   ibmvscsi_host_data of host
839  * 
840  * Returns zero if successful.
841 */
842 static int send_srp_login(struct ibmvscsi_host_data *hostdata)
843 {
844         int rc;
845         unsigned long flags;
846         struct srp_login_req *login;
847         struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
848         if (!evt_struct) {
849                 printk(KERN_ERR
850                        "ibmvscsi: couldn't allocate an event for login req!\n");
851                 return FAILED;
852         }
853
854         init_event_struct(evt_struct,
855                           login_rsp,
856                           VIOSRP_SRP_FORMAT,
857                           init_timeout * HZ);
858
859         login = &evt_struct->iu.srp.login_req;
860         memset(login, 0x00, sizeof(struct srp_login_req));
861         login->opcode = SRP_LOGIN_REQ;
862         login->req_it_iu_len = sizeof(union srp_iu);
863         login->req_buf_fmt = SRP_BUF_FORMAT_DIRECT | SRP_BUF_FORMAT_INDIRECT;
864         
865         spin_lock_irqsave(hostdata->host->host_lock, flags);
866         /* Start out with a request limit of 1, since this is negotiated in
867          * the login request we are just sending
868          */
869         atomic_set(&hostdata->request_limit, 1);
870
871         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
872         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
873         printk("ibmvscsic: sent SRP login\n");
874         return rc;
875 };
876
877 /**
878  * sync_completion: Signal that a synchronous command has completed
879  * Note that after returning from this call, the evt_struct is freed.
880  * the caller waiting on this completion shouldn't touch the evt_struct
881  * again.
882  */
883 static void sync_completion(struct srp_event_struct *evt_struct)
884 {
885         /* copy the response back */
886         if (evt_struct->sync_srp)
887                 *evt_struct->sync_srp = *evt_struct->xfer_iu;
888         
889         complete(&evt_struct->comp);
890 }
891
892 /**
893  * ibmvscsi_abort: Abort a command...from scsi host template
894  * send this over to the server and wait synchronously for the response
895  */
896 static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
897 {
898         struct ibmvscsi_host_data *hostdata =
899             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
900         struct srp_tsk_mgmt *tsk_mgmt;
901         struct srp_event_struct *evt;
902         struct srp_event_struct *tmp_evt, *found_evt;
903         union viosrp_iu srp_rsp;
904         int rsp_rc;
905         unsigned long flags;
906         u16 lun = lun_from_dev(cmd->device);
907
908         /* First, find this command in our sent list so we can figure
909          * out the correct tag
910          */
911         spin_lock_irqsave(hostdata->host->host_lock, flags);
912         found_evt = NULL;
913         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
914                 if (tmp_evt->cmnd == cmd) {
915                         found_evt = tmp_evt;
916                         break;
917                 }
918         }
919
920         if (!found_evt) {
921                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
922                 return FAILED;
923         }
924
925         evt = get_event_struct(&hostdata->pool);
926         if (evt == NULL) {
927                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
928                 printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
929                 return FAILED;
930         }
931         
932         init_event_struct(evt,
933                           sync_completion,
934                           VIOSRP_SRP_FORMAT,
935                           init_timeout * HZ);
936
937         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
938         
939         /* Set up an abort SRP command */
940         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
941         tsk_mgmt->opcode = SRP_TSK_MGMT;
942         tsk_mgmt->lun = ((u64) lun) << 48;
943         tsk_mgmt->tsk_mgmt_func = SRP_TSK_ABORT_TASK;
944         tsk_mgmt->task_tag = (u64) found_evt;
945
946         printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
947                tsk_mgmt->lun, tsk_mgmt->task_tag);
948
949         evt->sync_srp = &srp_rsp;
950         init_completion(&evt->comp);
951         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);
952         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
953         if (rsp_rc != 0) {
954                 printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
955                 return FAILED;
956         }
957
958         wait_for_completion(&evt->comp);
959
960         /* make sure we got a good response */
961         if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
962                 if (printk_ratelimit())
963                         printk(KERN_WARNING 
964                                "ibmvscsi: abort bad SRP RSP type %d\n",
965                                srp_rsp.srp.rsp.opcode);
966                 return FAILED;
967         }
968
969         if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
970                 rsp_rc = *((int *)srp_rsp.srp.rsp.data);
971         else
972                 rsp_rc = srp_rsp.srp.rsp.status;
973
974         if (rsp_rc) {
975                 if (printk_ratelimit())
976                         printk(KERN_WARNING 
977                                "ibmvscsi: abort code %d for task tag 0x%lx\n",
978                                rsp_rc,
979                                tsk_mgmt->task_tag);
980                 return FAILED;
981         }
982
983         /* Because we dropped the spinlock above, it's possible
984          * The event is no longer in our list.  Make sure it didn't
985          * complete while we were aborting
986          */
987         spin_lock_irqsave(hostdata->host->host_lock, flags);
988         found_evt = NULL;
989         list_for_each_entry(tmp_evt, &hostdata->sent, list) {
990                 if (tmp_evt->cmnd == cmd) {
991                         found_evt = tmp_evt;
992                         break;
993                 }
994         }
995
996         if (found_evt == NULL) {
997                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
998                 printk(KERN_INFO
999                        "ibmvscsi: aborted task tag 0x%lx completed\n",
1000                        tsk_mgmt->task_tag);
1001                 return SUCCESS;
1002         }
1003
1004         printk(KERN_INFO
1005                "ibmvscsi: successfully aborted task tag 0x%lx\n",
1006                tsk_mgmt->task_tag);
1007
1008         cmd->result = (DID_ABORT << 16);
1009         list_del(&found_evt->list);
1010         unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
1011                        found_evt->hostdata->dev);
1012         free_event_struct(&found_evt->hostdata->pool, found_evt);
1013         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1014         atomic_inc(&hostdata->request_limit);
1015         return SUCCESS;
1016 }
1017
1018 /**
1019  * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host 
1020  * template send this over to the server and wait synchronously for the 
1021  * response
1022  */
1023 static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
1024 {
1025         struct ibmvscsi_host_data *hostdata =
1026             (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
1027
1028         struct srp_tsk_mgmt *tsk_mgmt;
1029         struct srp_event_struct *evt;
1030         struct srp_event_struct *tmp_evt, *pos;
1031         union viosrp_iu srp_rsp;
1032         int rsp_rc;
1033         unsigned long flags;
1034         u16 lun = lun_from_dev(cmd->device);
1035
1036         spin_lock_irqsave(hostdata->host->host_lock, flags);
1037         evt = get_event_struct(&hostdata->pool);
1038         if (evt == NULL) {
1039                 spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1040                 printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
1041                 return FAILED;
1042         }
1043         
1044         init_event_struct(evt,
1045                           sync_completion,
1046                           VIOSRP_SRP_FORMAT,
1047                           init_timeout * HZ);
1048
1049         tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1050
1051         /* Set up a lun reset SRP command */
1052         memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1053         tsk_mgmt->opcode = SRP_TSK_MGMT;
1054         tsk_mgmt->lun = ((u64) lun) << 48;
1055         tsk_mgmt->tsk_mgmt_func = SRP_TSK_LUN_RESET;
1056
1057         printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
1058                tsk_mgmt->lun);
1059
1060         evt->sync_srp = &srp_rsp;
1061         init_completion(&evt->comp);
1062         rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);
1063         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1064         if (rsp_rc != 0) {
1065                 printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
1066                 return FAILED;
1067         }
1068
1069         wait_for_completion(&evt->comp);
1070
1071         /* make sure we got a good response */
1072         if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
1073                 if (printk_ratelimit())
1074                         printk(KERN_WARNING 
1075                                "ibmvscsi: reset bad SRP RSP type %d\n",
1076                                srp_rsp.srp.rsp.opcode);
1077                 return FAILED;
1078         }
1079
1080         if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
1081                 rsp_rc = *((int *)srp_rsp.srp.rsp.data);
1082         else
1083                 rsp_rc = srp_rsp.srp.rsp.status;
1084
1085         if (rsp_rc) {
1086                 if (printk_ratelimit())
1087                         printk(KERN_WARNING 
1088                                "ibmvscsi: reset code %d for task tag 0x%lx\n",
1089                                rsp_rc, tsk_mgmt->task_tag);
1090                 return FAILED;
1091         }
1092
1093         /* We need to find all commands for this LUN that have not yet been
1094          * responded to, and fail them with DID_RESET
1095          */
1096         spin_lock_irqsave(hostdata->host->host_lock, flags);
1097         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1098                 if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1099                         if (tmp_evt->cmnd)
1100                                 tmp_evt->cmnd->result = (DID_RESET << 16);
1101                         list_del(&tmp_evt->list);
1102                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
1103                                        tmp_evt->hostdata->dev);
1104                         free_event_struct(&tmp_evt->hostdata->pool,
1105                                                    tmp_evt);
1106                         atomic_inc(&hostdata->request_limit);
1107                         if (tmp_evt->cmnd_done)
1108                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1109                         else if (tmp_evt->done)
1110                                 tmp_evt->done(tmp_evt);
1111                 }
1112         }
1113         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1114         return SUCCESS;
1115 }
1116
1117 /**
1118  * purge_requests: Our virtual adapter just shut down.  purge any sent requests
1119  * @hostdata:    the adapter
1120  */
1121 static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)
1122 {
1123         struct srp_event_struct *tmp_evt, *pos;
1124         unsigned long flags;
1125
1126         spin_lock_irqsave(hostdata->host->host_lock, flags);
1127         list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1128                 list_del(&tmp_evt->list);
1129                 if (tmp_evt->cmnd) {
1130                         tmp_evt->cmnd->result = (error_code << 16);
1131                         unmap_cmd_data(&tmp_evt->iu.srp.cmd, 
1132                                        tmp_evt, 
1133                                        tmp_evt->hostdata->dev);
1134                         if (tmp_evt->cmnd_done)
1135                                 tmp_evt->cmnd_done(tmp_evt->cmnd);
1136                 } else {
1137                         if (tmp_evt->done) {
1138                                 tmp_evt->done(tmp_evt);
1139                         }
1140                 }
1141                 free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
1142         }
1143         spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1144 }
1145
1146 /**
1147  * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1148  * @crq:        Command/Response queue
1149  * @hostdata:   ibmvscsi_host_data of host
1150  *
1151 */
1152 void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1153                          struct ibmvscsi_host_data *hostdata)
1154 {
1155         unsigned long flags;
1156         struct srp_event_struct *evt_struct =
1157             (struct srp_event_struct *)crq->IU_data_ptr;
1158         switch (crq->valid) {
1159         case 0xC0:              /* initialization */
1160                 switch (crq->format) {
1161                 case 0x01:      /* Initialization message */
1162                         printk(KERN_INFO "ibmvscsi: partner initialized\n");
1163                         /* Send back a response */
1164                         if (ibmvscsi_send_crq(hostdata,
1165                                               0xC002000000000000LL, 0) == 0) {
1166                                 /* Now login */
1167                                 send_srp_login(hostdata);
1168                         } else {
1169                                 printk(KERN_ERR
1170                                        "ibmvscsi: Unable to send init rsp\n");
1171                         }
1172
1173                         break;
1174                 case 0x02:      /* Initialization response */
1175                         printk(KERN_INFO
1176                                "ibmvscsi: partner initialization complete\n");
1177
1178                         /* Now login */
1179                         send_srp_login(hostdata);
1180                         break;
1181                 default:
1182                         printk(KERN_ERR "ibmvscsi: unknown crq message type\n");
1183                 }
1184                 return;
1185         case 0xFF:      /* Hypervisor telling us the connection is closed */
1186                 scsi_block_requests(hostdata->host);
1187                 if (crq->format == 0x06) {
1188                         /* We need to re-setup the interpartition connection */
1189                         printk(KERN_INFO
1190                                "ibmvscsi: Re-enabling adapter!\n");
1191                         atomic_set(&hostdata->request_limit, -1);
1192                         purge_requests(hostdata, DID_REQUEUE);
1193                         if (ibmvscsi_reenable_crq_queue(&hostdata->queue,
1194                                                         hostdata) == 0)
1195                                 if (ibmvscsi_send_crq(hostdata,
1196                                                       0xC001000000000000LL, 0))
1197                                         printk(KERN_ERR
1198                                                "ibmvscsi: transmit error after"
1199                                                " enable\n");
1200                 } else {
1201                         printk(KERN_INFO
1202                                "ibmvscsi: Virtual adapter failed rc %d!\n",
1203                                crq->format);
1204
1205                         atomic_set(&hostdata->request_limit, -1);
1206                         purge_requests(hostdata, DID_ERROR);
1207                         ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
1208                 }
1209                 scsi_unblock_requests(hostdata->host);
1210                 return;
1211         case 0x80:              /* real payload */
1212                 break;
1213         default:
1214                 printk(KERN_ERR
1215                        "ibmvscsi: got an invalid message type 0x%02x\n",
1216                        crq->valid);
1217                 return;
1218         }
1219
1220         /* The only kind of payload CRQs we should get are responses to
1221          * things we send. Make sure this response is to something we
1222          * actually sent
1223          */
1224         if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1225                 printk(KERN_ERR
1226                        "ibmvscsi: returned correlation_token 0x%p is invalid!\n",
1227                        (void *)crq->IU_data_ptr);
1228                 return;
1229         }
1230
1231         if (atomic_read(&evt_struct->free)) {
1232                 printk(KERN_ERR
1233                        "ibmvscsi: received duplicate  correlation_token 0x%p!\n",
1234                        (void *)crq->IU_data_ptr);
1235                 return;
1236         }
1237
1238         if (crq->format == VIOSRP_SRP_FORMAT)
1239                 atomic_add(evt_struct->xfer_iu->srp.rsp.req_lim_delta,
1240                            &hostdata->request_limit);
1241
1242         if (evt_struct->done)
1243                 evt_struct->done(evt_struct);
1244         else
1245                 printk(KERN_ERR
1246                        "ibmvscsi: returned done() is NULL; not running it!\n");
1247
1248         /*
1249          * Lock the host_lock before messing with these structures, since we
1250          * are running in a task context
1251          */
1252         spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1253         list_del(&evt_struct->list);
1254         free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1255         spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1256 }
1257
1258 /**
1259  * ibmvscsi_get_host_config: Send the command to the server to get host
1260  * configuration data.  The data is opaque to us.
1261  */
1262 static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
1263                                    unsigned char *buffer, int length)
1264 {
1265         struct viosrp_host_config *host_config;
1266         struct srp_event_struct *evt_struct;
1267         dma_addr_t addr;
1268         int rc;
1269
1270         evt_struct = get_event_struct(&hostdata->pool);
1271         if (!evt_struct) {
1272                 printk(KERN_ERR
1273                        "ibmvscsi: could't allocate event for HOST_CONFIG!\n");
1274                 return -1;
1275         }
1276
1277         init_event_struct(evt_struct,
1278                           sync_completion,
1279                           VIOSRP_MAD_FORMAT,
1280                           init_timeout * HZ);
1281
1282         host_config = &evt_struct->iu.mad.host_config;
1283
1284         /* Set up a lun reset SRP command */
1285         memset(host_config, 0x00, sizeof(*host_config));
1286         host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
1287         host_config->common.length = length;
1288         host_config->buffer = addr = dma_map_single(hostdata->dev, buffer,
1289                                                     length,
1290                                                     DMA_BIDIRECTIONAL);
1291
1292         if (dma_mapping_error(host_config->buffer)) {
1293                 printk(KERN_ERR
1294                        "ibmvscsi: dma_mapping error " "getting host config\n");
1295                 free_event_struct(&hostdata->pool, evt_struct);
1296                 return -1;
1297         }
1298
1299         init_completion(&evt_struct->comp);
1300         rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
1301         if (rc == 0)
1302                 wait_for_completion(&evt_struct->comp);
1303         dma_unmap_single(hostdata->dev, addr, length, DMA_BIDIRECTIONAL);
1304
1305         return rc;
1306 }
1307
1308 /* ------------------------------------------------------------
1309  * sysfs attributes
1310  */
1311 static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
1312 {
1313         struct Scsi_Host *shost = class_to_shost(class_dev);
1314         struct ibmvscsi_host_data *hostdata =
1315             (struct ibmvscsi_host_data *)shost->hostdata;
1316         int len;
1317
1318         len = snprintf(buf, PAGE_SIZE, "%s\n",
1319                        hostdata->madapter_info.srp_version);
1320         return len;
1321 }
1322
1323 static struct class_device_attribute ibmvscsi_host_srp_version = {
1324         .attr = {
1325                  .name = "srp_version",
1326                  .mode = S_IRUGO,
1327                  },
1328         .show = show_host_srp_version,
1329 };
1330
1331 static ssize_t show_host_partition_name(struct class_device *class_dev,
1332                                         char *buf)
1333 {
1334         struct Scsi_Host *shost = class_to_shost(class_dev);
1335         struct ibmvscsi_host_data *hostdata =
1336             (struct ibmvscsi_host_data *)shost->hostdata;
1337         int len;
1338
1339         len = snprintf(buf, PAGE_SIZE, "%s\n",
1340                        hostdata->madapter_info.partition_name);
1341         return len;
1342 }
1343
1344 static struct class_device_attribute ibmvscsi_host_partition_name = {
1345         .attr = {
1346                  .name = "partition_name",
1347                  .mode = S_IRUGO,
1348                  },
1349         .show = show_host_partition_name,
1350 };
1351
1352 static ssize_t show_host_partition_number(struct class_device *class_dev,
1353                                           char *buf)
1354 {
1355         struct Scsi_Host *shost = class_to_shost(class_dev);
1356         struct ibmvscsi_host_data *hostdata =
1357             (struct ibmvscsi_host_data *)shost->hostdata;
1358         int len;
1359
1360         len = snprintf(buf, PAGE_SIZE, "%d\n",
1361                        hostdata->madapter_info.partition_number);
1362         return len;
1363 }
1364
1365 static struct class_device_attribute ibmvscsi_host_partition_number = {
1366         .attr = {
1367                  .name = "partition_number",
1368                  .mode = S_IRUGO,
1369                  },
1370         .show = show_host_partition_number,
1371 };
1372
1373 static ssize_t show_host_mad_version(struct class_device *class_dev, char *buf)
1374 {
1375         struct Scsi_Host *shost = class_to_shost(class_dev);
1376         struct ibmvscsi_host_data *hostdata =
1377             (struct ibmvscsi_host_data *)shost->hostdata;
1378         int len;
1379
1380         len = snprintf(buf, PAGE_SIZE, "%d\n",
1381                        hostdata->madapter_info.mad_version);
1382         return len;
1383 }
1384
1385 static struct class_device_attribute ibmvscsi_host_mad_version = {
1386         .attr = {
1387                  .name = "mad_version",
1388                  .mode = S_IRUGO,
1389                  },
1390         .show = show_host_mad_version,
1391 };
1392
1393 static ssize_t show_host_os_type(struct class_device *class_dev, char *buf)
1394 {
1395         struct Scsi_Host *shost = class_to_shost(class_dev);
1396         struct ibmvscsi_host_data *hostdata =
1397             (struct ibmvscsi_host_data *)shost->hostdata;
1398         int len;
1399
1400         len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
1401         return len;
1402 }
1403
1404 static struct class_device_attribute ibmvscsi_host_os_type = {
1405         .attr = {
1406                  .name = "os_type",
1407                  .mode = S_IRUGO,
1408                  },
1409         .show = show_host_os_type,
1410 };
1411
1412 static ssize_t show_host_config(struct class_device *class_dev, char *buf)
1413 {
1414         struct Scsi_Host *shost = class_to_shost(class_dev);
1415         struct ibmvscsi_host_data *hostdata =
1416             (struct ibmvscsi_host_data *)shost->hostdata;
1417
1418         /* returns null-terminated host config data */
1419         if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
1420                 return strlen(buf);
1421         else
1422                 return 0;
1423 }
1424
1425 static struct class_device_attribute ibmvscsi_host_config = {
1426         .attr = {
1427                  .name = "config",
1428                  .mode = S_IRUGO,
1429                  },
1430         .show = show_host_config,
1431 };
1432
1433 static struct class_device_attribute *ibmvscsi_attrs[] = {
1434         &ibmvscsi_host_srp_version,
1435         &ibmvscsi_host_partition_name,
1436         &ibmvscsi_host_partition_number,
1437         &ibmvscsi_host_mad_version,
1438         &ibmvscsi_host_os_type,
1439         &ibmvscsi_host_config,
1440         NULL
1441 };
1442
1443 /* ------------------------------------------------------------
1444  * SCSI driver registration
1445  */
1446 static struct scsi_host_template driver_template = {
1447         .module = THIS_MODULE,
1448         .name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
1449         .proc_name = "ibmvscsi",
1450         .queuecommand = ibmvscsi_queuecommand,
1451         .eh_abort_handler = ibmvscsi_eh_abort_handler,
1452         .eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
1453         .cmd_per_lun = 16,
1454         .can_queue = 1,         /* Updated after SRP_LOGIN */
1455         .this_id = -1,
1456         .sg_tablesize = SG_ALL,
1457         .use_clustering = ENABLE_CLUSTERING,
1458         .shost_attrs = ibmvscsi_attrs,
1459 };
1460
1461 /**
1462  * Called by bus code for each adapter
1463  */
1464 static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
1465 {
1466         struct ibmvscsi_host_data *hostdata;
1467         struct Scsi_Host *host;
1468         struct device *dev = &vdev->dev;
1469         unsigned long wait_switch = 0;
1470
1471         vdev->dev.driver_data = NULL;
1472
1473         host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
1474         if (!host) {
1475                 printk(KERN_ERR "ibmvscsi: couldn't allocate host data\n");
1476                 goto scsi_host_alloc_failed;
1477         }
1478
1479         hostdata = (struct ibmvscsi_host_data *)host->hostdata;
1480         memset(hostdata, 0x00, sizeof(*hostdata));
1481         INIT_LIST_HEAD(&hostdata->sent);
1482         hostdata->host = host;
1483         hostdata->dev = dev;
1484         atomic_set(&hostdata->request_limit, -1);
1485         hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
1486
1487         if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
1488                                     max_requests) != 0) {
1489                 printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
1490                 goto init_crq_failed;
1491         }
1492         if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
1493                 printk(KERN_ERR "ibmvscsi: couldn't initialize event pool\n");
1494                 goto init_pool_failed;
1495         }
1496
1497         host->max_lun = 8;
1498         host->max_id = max_id;
1499         host->max_channel = max_channel;
1500
1501         if (scsi_add_host(hostdata->host, hostdata->dev))
1502                 goto add_host_failed;
1503
1504         /* Try to send an initialization message.  Note that this is allowed
1505          * to fail if the other end is not acive.  In that case we don't
1506          * want to scan
1507          */
1508         if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0) {
1509                 /*
1510                  * Wait around max init_timeout secs for the adapter to finish
1511                  * initializing. When we are done initializing, we will have a
1512                  * valid request_limit.  We don't want Linux scanning before
1513                  * we are ready.
1514                  */
1515                 for (wait_switch = jiffies + (init_timeout * HZ);
1516                      time_before(jiffies, wait_switch) &&
1517                      atomic_read(&hostdata->request_limit) < 2;) {
1518
1519                         msleep(10);
1520                 }
1521
1522                 /* if we now have a valid request_limit, initiate a scan */
1523                 if (atomic_read(&hostdata->request_limit) > 0)
1524                         scsi_scan_host(host);
1525         }
1526
1527         vdev->dev.driver_data = hostdata;
1528         return 0;
1529
1530       add_host_failed:
1531         release_event_pool(&hostdata->pool, hostdata);
1532       init_pool_failed:
1533         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_requests);
1534       init_crq_failed:
1535         scsi_host_put(host);
1536       scsi_host_alloc_failed:
1537         return -1;
1538 }
1539
1540 static int ibmvscsi_remove(struct vio_dev *vdev)
1541 {
1542         struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
1543         release_event_pool(&hostdata->pool, hostdata);
1544         ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
1545                                    max_requests);
1546         
1547         scsi_remove_host(hostdata->host);
1548         scsi_host_put(hostdata->host);
1549
1550         return 0;
1551 }
1552
1553 /**
1554  * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we 
1555  * support.
1556  */
1557 static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
1558         {"vscsi", "IBM,v-scsi"},
1559         { "", "" }
1560 };
1561 MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
1562
1563 static struct vio_driver ibmvscsi_driver = {
1564         .id_table = ibmvscsi_device_table,
1565         .probe = ibmvscsi_probe,
1566         .remove = ibmvscsi_remove,
1567         .driver = {
1568                 .name = "ibmvscsi",
1569                 .owner = THIS_MODULE,
1570         }
1571 };
1572
1573 int __init ibmvscsi_module_init(void)
1574 {
1575         return vio_register_driver(&ibmvscsi_driver);
1576 }
1577
1578 void __exit ibmvscsi_module_exit(void)
1579 {
1580         vio_unregister_driver(&ibmvscsi_driver);
1581 }
1582
1583 module_init(ibmvscsi_module_init);
1584 module_exit(ibmvscsi_module_exit);