drivers/staging/unisys/visorhba/visorhba_main.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2012 - 2015 UNISYS CORPORATION
   4  * All rights reserved.
   5  */
   6
   7 #include <linux/debugfs.h>
   8 #include <linux/kthread.h>
   9 #include <linux/idr.h>
  10 #include <linux/module.h>
  11 #include <linux/seq_file.h>
  12 #include <linux/visorbus.h>
  13 #include <scsi/scsi.h>
  14 #include <scsi/scsi_host.h>
  15 #include <scsi/scsi_cmnd.h>
  16 #include <scsi/scsi_device.h>
  17
  18 #include "iochannel.h"
  19
  20 /* The Send and Receive Buffers of the IO Queue may both be full */
  21
  22 #define IOS_ERROR_THRESHOLD  1000
  23 #define MAX_PENDING_REQUESTS (MIN_NUMSIGNALS * 2)
  24 #define VISORHBA_ERROR_COUNT 30
  25
  26 static struct dentry *visorhba_debugfs_dir;
  27
  28 /* GUIDS for HBA channel type supported by this driver */
  29 static struct visor_channeltype_descriptor visorhba_channel_types[] = {
  30         /* Note that the only channel type we expect to be reported by the
  31          * bus driver is the VISOR_VHBA channel.
  32          */
  33         { VISOR_VHBA_CHANNEL_GUID, "sparvhba", sizeof(struct channel_header),
  34           VISOR_VHBA_CHANNEL_VERSIONID },
  35         {}
  36 };
  37
  38 MODULE_DEVICE_TABLE(visorbus, visorhba_channel_types);
  39 MODULE_ALIAS("visorbus:" VISOR_VHBA_CHANNEL_GUID_STR);
  40
  41 struct visordisk_info {
  42         struct scsi_device *sdev;
  43         u32 valid;
  44         atomic_t ios_threshold;
  45         atomic_t error_count;
  46         struct visordisk_info *next;
  47 };
  48
  49 struct scsipending {
  50         struct uiscmdrsp cmdrsp;
  51         /* The Data being tracked */
  52         void *sent;
  53         /* Type of pointer that is being stored */
  54         char cmdtype;
  55 };
  56
  57 /* Each scsi_host has a host_data area that contains this struct. */
  58 struct visorhba_devdata {
  59         struct Scsi_Host *scsihost;
  60         struct visor_device *dev;
  61         struct list_head dev_info_list;
  62         /* Tracks the requests that have been forwarded to
  63          * the IOVM and haven't returned yet
  64          */
  65         struct scsipending pending[MAX_PENDING_REQUESTS];
  66         /* Start search for next pending free slot here */
  67         unsigned int nextinsert;
  68         /* lock to protect data in devdata */
  69         spinlock_t privlock;
  70         bool serverdown;
  71         bool serverchangingstate;
  72         unsigned long long acquire_failed_cnt;
  73         unsigned long long interrupts_rcvd;
  74         unsigned long long interrupts_notme;
  75         unsigned long long interrupts_disabled;
  76         u64 __iomem *flags_addr;
  77         atomic_t interrupt_rcvd;
  78         wait_queue_head_t rsp_queue;
  79         struct visordisk_info head;
  80         unsigned int max_buff_len;
  81         int devnum;
  82         struct task_struct *thread;
  83         int thread_wait_ms;
  84
  85         /*
  86          * allows us to pass int handles back-and-forth between us and
  87          * iovm, instead of raw pointers
  88          */
  89         struct idr idr;
  90
  91         struct dentry *debugfs_dir;
  92         struct dentry *debugfs_info;
  93 };
  94
  95 struct visorhba_devices_open {
  96         struct visorhba_devdata *devdata;
  97 };
  98
  99 /*
 100  * visor_thread_start - Starts a thread for the device
 101  * @threadfn:   Function the thread starts
 102  * @thrcontext: Context to pass to the thread, i.e. devdata
 103  * @name:       String describing name of thread
 104  *
 105  * Starts a thread for the device.
 106  *
 107  * Return: The task_struct * denoting the thread on success,
 108  *         or NULL on failure
 109  */
 110 static struct task_struct *visor_thread_start(int (*threadfn)(void *),
 111                                               void *thrcontext, char *name)
 112 {
 113         struct task_struct *task;
 114
 115         task = kthread_run(threadfn, thrcontext, "%s", name);
 116         if (IS_ERR(task)) {
 117                 pr_err("visorbus failed to start thread\n");
 118                 return NULL;
 119         }
 120         return task;
 121 }
 122
 123 /*
 124  * visor_thread_stop - Stops the thread if it is running
 125  * @task: Description of process to stop
 126  */
 127 static void visor_thread_stop(struct task_struct *task)
 128 {
 129         kthread_stop(task);
 130 }
 131
 132 /*
 133  * add_scsipending_entry - Save off io command that is pending in
 134  *                         Service Partition
 135  * @devdata: Pointer to devdata
 136  * @cmdtype: Specifies the type of command pending
 137  * @new:     The command to be saved
 138  *
 139  * Saves off the io command that is being handled by the Service
 140  * Partition so that it can be handled when it completes. If new is
 141  * NULL it is assumed the entry refers only to the cmdrsp.
 142  *
 143  * Return: Insert_location where entry was added on success,
 144  *         -EBUSY if it can't
 145  */
 146 static int add_scsipending_entry(struct visorhba_devdata *devdata,
 147                                  char cmdtype, void *new)
 148 {
 149         unsigned long flags;
 150         struct scsipending *entry;
 151         int insert_location;
 152
 153         spin_lock_irqsave(&devdata->privlock, flags);
 154         insert_location = devdata->nextinsert;
 155         while (devdata->pending[insert_location].sent) {
 156                 insert_location = (insert_location + 1) % MAX_PENDING_REQUESTS;
 157                 if (insert_location == (int)devdata->nextinsert) {
 158                         spin_unlock_irqrestore(&devdata->privlock, flags);
 159                         return -EBUSY;
 160                 }
 161         }
 162
 163         entry = &devdata->pending[insert_location];
 164         memset(&entry->cmdrsp, 0, sizeof(entry->cmdrsp));
 165         entry->cmdtype = cmdtype;
 166         if (new)
 167                 entry->sent = new;
 168         /* wants to send cmdrsp */
 169         else
 170                 entry->sent = &entry->cmdrsp;
 171         devdata->nextinsert = (insert_location + 1) % MAX_PENDING_REQUESTS;
 172         spin_unlock_irqrestore(&devdata->privlock, flags);
 173
 174         return insert_location;
 175 }
 176
 177 /*
 178  * del_scsipending_ent - Removes an entry from the pending array
 179  * @devdata: Device holding the pending array
 180  * @del:     Entry to remove
 181  *
 182  * Removes the entry pointed at by del and returns it.
 183  *
 184  * Return: The scsipending entry pointed to on success, NULL on failure
 185  */
 186 static void *del_scsipending_ent(struct visorhba_devdata *devdata, int del)
 187 {
 188         unsigned long flags;
 189         void *sent;
 190
 191         if (del >= MAX_PENDING_REQUESTS)
 192                 return NULL;
 193
 194         spin_lock_irqsave(&devdata->privlock, flags);
 195         sent = devdata->pending[del].sent;
 196         devdata->pending[del].cmdtype = 0;
 197         devdata->pending[del].sent = NULL;
 198         spin_unlock_irqrestore(&devdata->privlock, flags);
 199
 200         return sent;
 201 }
 202
 203 /*
 204  * get_scsipending_cmdrsp - Return the cmdrsp stored in a pending entry
 205  * @ddata: Device holding the pending array
 206  * @ent:   Entry that stores the cmdrsp
 207  *
 208  * Each scsipending entry has a cmdrsp in it. The cmdrsp is only valid
 209  * if the "sent" field is not NULL.
 210  *
 211  * Return: A pointer to the cmdrsp, NULL on failure
 212  */
 213 static struct uiscmdrsp *get_scsipending_cmdrsp(struct visorhba_devdata *ddata,
 214                                                 int ent)
 215 {
 216         if (ddata->pending[ent].sent)
 217                 return &ddata->pending[ent].cmdrsp;
 218
 219         return NULL;
 220 }
 221
 222 /*
 223  * simple_idr_get - Associate a provided pointer with an int value
 224  *                  1 <= value <= INT_MAX, and return this int value;
 225  *                  the pointer value can be obtained later by passing
 226  *                  this int value to idr_find()
 227  * @idrtable: The data object maintaining the pointer<-->int mappings
 228  * @p:        The pointer value to be remembered
 229  * @lock:     A spinlock used when exclusive access to idrtable is needed
 230  *
 231  * Return: The id number mapped to pointer 'p', 0 on failure
 232  */
 233 static unsigned int simple_idr_get(struct idr *idrtable, void *p,
 234                                    spinlock_t *lock)
 235 {
 236         int id;
 237         unsigned long flags;
 238
 239         idr_preload(GFP_KERNEL);
 240         spin_lock_irqsave(lock, flags);
 241         id = idr_alloc(idrtable, p, 1, INT_MAX, GFP_NOWAIT);
 242         spin_unlock_irqrestore(lock, flags);
 243         idr_preload_end();
 244         /* failure */
 245         if (id < 0)
 246                 return 0;
 247         /* idr_alloc() guarantees > 0 */
 248         return (unsigned int)(id);
 249 }
 250
 251 /*
 252  * setup_scsitaskmgmt_handles - Stash the necessary handles so that the
 253  *                              completion processing logic for a taskmgmt
 254  *                              cmd will be able to find who to wake up
 255  *                              and where to stash the result
 256  * @idrtable: The data object maintaining the pointer<-->int mappings
 257  * @lock:     A spinlock used when exclusive access to idrtable is needed
 258  * @cmdrsp:   Response from the IOVM
 259  * @event:    The event handle to associate with an id
 260  * @result:   The location to place the result of the event handle into
 261  */
 262 static void setup_scsitaskmgmt_handles(struct idr *idrtable, spinlock_t *lock,
 263                                        struct uiscmdrsp *cmdrsp,
 264                                        wait_queue_head_t *event, int *result)
 265 {
 266         /* specify the event that has to be triggered when this */
 267         /* cmd is complete */
 268         cmdrsp->scsitaskmgmt.notify_handle =
 269                 simple_idr_get(idrtable, event, lock);
 270         cmdrsp->scsitaskmgmt.notifyresult_handle =
 271                 simple_idr_get(idrtable, result, lock);
 272 }
 273
 274 /*
 275  * cleanup_scsitaskmgmt_handles - Forget handles created by
 276  *                                setup_scsitaskmgmt_handles()
 277  * @idrtable: The data object maintaining the pointer<-->int mappings
 278  * @cmdrsp:   Response from the IOVM
 279  */
 280 static void cleanup_scsitaskmgmt_handles(struct idr *idrtable,
 281                                          struct uiscmdrsp *cmdrsp)
 282 {
 283         if (cmdrsp->scsitaskmgmt.notify_handle)
 284                 idr_remove(idrtable, cmdrsp->scsitaskmgmt.notify_handle);
 285         if (cmdrsp->scsitaskmgmt.notifyresult_handle)
 286                 idr_remove(idrtable, cmdrsp->scsitaskmgmt.notifyresult_handle);
 287 }
 288
 289 /*
 290  * forward_taskmgmt_command - Send taskmegmt command to the Service
 291  *                            Partition
 292  * @tasktype: Type of taskmgmt command
 293  * @scsidev:  Scsidev that issued command
 294  *
 295  * Create a cmdrsp packet and send it to the Service Partition
 296  * that will service this request.
 297  *
 298  * Return: Int representing whether command was queued successfully or not
 299  */
 300 static int forward_taskmgmt_command(enum task_mgmt_types tasktype,
 301                                     struct scsi_device *scsidev)
 302 {
 303         struct uiscmdrsp *cmdrsp;
 304         struct visorhba_devdata *devdata =
 305                 (struct visorhba_devdata *)scsidev->host->hostdata;
 306         int notifyresult = 0xffff;
 307         wait_queue_head_t notifyevent;
 308         int scsicmd_id;
 309
 310         if (devdata->serverdown || devdata->serverchangingstate)
 311                 return FAILED;
 312
 313         scsicmd_id = add_scsipending_entry(devdata, CMD_SCSITASKMGMT_TYPE,
 314                                            NULL);
 315         if (scsicmd_id < 0)
 316                 return FAILED;
 317
 318         cmdrsp = get_scsipending_cmdrsp(devdata, scsicmd_id);
 319
 320         init_waitqueue_head(&notifyevent);
 321
 322         /* issue TASK_MGMT_ABORT_TASK */
 323         cmdrsp->cmdtype = CMD_SCSITASKMGMT_TYPE;
 324         setup_scsitaskmgmt_handles(&devdata->idr, &devdata->privlock, cmdrsp,
 325                                    &notifyevent, &notifyresult);
 326
 327         /* save destination */
 328         cmdrsp->scsitaskmgmt.tasktype = tasktype;
 329         cmdrsp->scsitaskmgmt.vdest.channel = scsidev->channel;
 330         cmdrsp->scsitaskmgmt.vdest.id = scsidev->id;
 331         cmdrsp->scsitaskmgmt.vdest.lun = scsidev->lun;
 332         cmdrsp->scsitaskmgmt.handle = scsicmd_id;
 333
 334         dev_dbg(&scsidev->sdev_gendev,
 335                 "visorhba: initiating type=%d taskmgmt command\n", tasktype);
 336         if (visorchannel_signalinsert(devdata->dev->visorchannel,
 337                                       IOCHAN_TO_IOPART,
 338                                       cmdrsp))
 339                 goto err_del_scsipending_ent;
 340
 341         /* It can take the Service Partition up to 35 seconds to complete
 342          * an IO in some cases, so wait 45 seconds and error out
 343          */
 344         if (!wait_event_timeout(notifyevent, notifyresult != 0xffff,
 345                                 msecs_to_jiffies(45000)))
 346                 goto err_del_scsipending_ent;
 347
 348         dev_dbg(&scsidev->sdev_gendev,
 349                 "visorhba: taskmgmt type=%d success; result=0x%x\n",
 350                  tasktype, notifyresult);
 351         cleanup_scsitaskmgmt_handles(&devdata->idr, cmdrsp);
 352         return SUCCESS;
 353
 354 err_del_scsipending_ent:
 355         dev_dbg(&scsidev->sdev_gendev,
 356                 "visorhba: taskmgmt type=%d not executed\n", tasktype);
 357         del_scsipending_ent(devdata, scsicmd_id);
 358         cleanup_scsitaskmgmt_handles(&devdata->idr, cmdrsp);
 359         return FAILED;
 360 }
 361
 362 /*
 363  * visorhba_abort_handler - Send TASK_MGMT_ABORT_TASK
 364  * @scsicmd: The scsicmd that needs aborted
 365  *
 366  * Return: SUCCESS if inserted, FAILED otherwise
 367  */
 368 static int visorhba_abort_handler(struct scsi_cmnd *scsicmd)
 369 {
 370         /* issue TASK_MGMT_ABORT_TASK */
 371         struct scsi_device *scsidev;
 372         struct visordisk_info *vdisk;
 373         int rtn;
 374
 375         scsidev = scsicmd->device;
 376         vdisk = scsidev->hostdata;
 377         if (atomic_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
 378                 atomic_inc(&vdisk->error_count);
 379         else
 380                 atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
 381         rtn = forward_taskmgmt_command(TASK_MGMT_ABORT_TASK, scsidev);
 382         if (rtn == SUCCESS) {
 383                 scsicmd->result = DID_ABORT << 16;
 384                 scsicmd->scsi_done(scsicmd);
 385         }
 386         return rtn;
 387 }
 388
 389 /*
 390  * visorhba_device_reset_handler - Send TASK_MGMT_LUN_RESET
 391  * @scsicmd: The scsicmd that needs aborted
 392  *
 393  * Return: SUCCESS if inserted, FAILED otherwise
 394  */
 395 static int visorhba_device_reset_handler(struct scsi_cmnd *scsicmd)
 396 {
 397         /* issue TASK_MGMT_LUN_RESET */
 398         struct scsi_device *scsidev;
 399         struct visordisk_info *vdisk;
 400         int rtn;
 401
 402         scsidev = scsicmd->device;
 403         vdisk = scsidev->hostdata;
 404         if (atomic_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
 405                 atomic_inc(&vdisk->error_count);
 406         else
 407                 atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
 408         rtn = forward_taskmgmt_command(TASK_MGMT_LUN_RESET, scsidev);
 409         if (rtn == SUCCESS) {
 410                 scsicmd->result = DID_RESET << 16;
 411                 scsicmd->scsi_done(scsicmd);
 412         }
 413         return rtn;
 414 }
 415
 416 /*
 417  * visorhba_bus_reset_handler - Send TASK_MGMT_TARGET_RESET for each
 418  *                              target on the bus
 419  * @scsicmd: The scsicmd that needs aborted
 420  *
 421  * Return: SUCCESS if inserted, FAILED otherwise
 422  */
 423 static int visorhba_bus_reset_handler(struct scsi_cmnd *scsicmd)
 424 {
 425         struct scsi_device *scsidev;
 426         struct visordisk_info *vdisk;
 427         int rtn;
 428
 429         scsidev = scsicmd->device;
 430         shost_for_each_device(scsidev, scsidev->host) {
 431                 vdisk = scsidev->hostdata;
 432                 if (atomic_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
 433                         atomic_inc(&vdisk->error_count);
 434                 else
 435                         atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
 436         }
 437         rtn = forward_taskmgmt_command(TASK_MGMT_BUS_RESET, scsidev);
 438         if (rtn == SUCCESS) {
 439                 scsicmd->result = DID_RESET << 16;
 440                 scsicmd->scsi_done(scsicmd);
 441         }
 442         return rtn;
 443 }
 444
 445 /*
 446  * visorhba_host_reset_handler - Not supported
 447  * @scsicmd: The scsicmd that needs to be aborted
 448  *
 449  * Return: Not supported, return SUCCESS
 450  */
 451 static int visorhba_host_reset_handler(struct scsi_cmnd *scsicmd)
 452 {
 453         /* issue TASK_MGMT_TARGET_RESET for each target on each bus for host */
 454         return SUCCESS;
 455 }
 456
 457 /*
 458  * visorhba_get_info - Get information about SCSI device
 459  * @shp: Scsi host that is requesting information
 460  *
 461  * Return: String with visorhba information
 462  */
 463 static const char *visorhba_get_info(struct Scsi_Host *shp)
 464 {
 465         /* Return version string */
 466         return "visorhba";
 467 }
 468
 469 /*
 470  * dma_data_dir_linux_to_spar - convert dma_data_direction value to
 471  *                              Unisys-specific equivalent
 472  * @d: dma direction value to convert
 473  *
 474  * Returns the Unisys-specific dma direction value corresponding to @d
 475  */
 476 static u32 dma_data_dir_linux_to_spar(enum dma_data_direction d)
 477 {
 478         switch (d) {
 479         case DMA_BIDIRECTIONAL:
 480                 return UIS_DMA_BIDIRECTIONAL;
 481         case DMA_TO_DEVICE:
 482                 return UIS_DMA_TO_DEVICE;
 483         case DMA_FROM_DEVICE:
 484                 return UIS_DMA_FROM_DEVICE;
 485         case DMA_NONE:
 486                 return UIS_DMA_NONE;
 487         default:
 488                 return UIS_DMA_NONE;
 489         }
 490 }
 491
 492 /*
 493  * visorhba_queue_command_lck - Queues command to the Service Partition
 494  * @scsicmd:            Command to be queued
 495  * @vsiorhba_cmnd_done: Done command to call when scsicmd is returned
 496  *
 497  * Queues to scsicmd to the ServicePartition after converting it to a
 498  * uiscmdrsp structure.
 499  *
 500  * Return: 0 if successfully queued to the Service Partition, otherwise
 501  *         error code
 502  */
 503 static int visorhba_queue_command_lck(struct scsi_cmnd *scsicmd,
 504                                       void (*visorhba_cmnd_done)
 505                                            (struct scsi_cmnd *))
 506 {
 507         struct uiscmdrsp *cmdrsp;
 508         struct scsi_device *scsidev = scsicmd->device;
 509         int insert_location;
 510         unsigned char *cdb = scsicmd->cmnd;
 511         struct Scsi_Host *scsihost = scsidev->host;
 512         unsigned int i;
 513         struct visorhba_devdata *devdata =
 514                 (struct visorhba_devdata *)scsihost->hostdata;
 515         struct scatterlist *sg = NULL;
 516         struct scatterlist *sglist = NULL;
 517
 518         if (devdata->serverdown || devdata->serverchangingstate)
 519                 return SCSI_MLQUEUE_DEVICE_BUSY;
 520
 521         insert_location = add_scsipending_entry(devdata, CMD_SCSI_TYPE,
 522                                                 (void *)scsicmd);
 523         if (insert_location < 0)
 524                 return SCSI_MLQUEUE_DEVICE_BUSY;
 525
 526         cmdrsp = get_scsipending_cmdrsp(devdata, insert_location);
 527         cmdrsp->cmdtype = CMD_SCSI_TYPE;
 528         /* save the pending insertion location. Deletion from pending
 529          * will return the scsicmd pointer for completion
 530          */
 531         cmdrsp->scsi.handle = insert_location;
 532
 533         /* save done function that we have call when cmd is complete */
 534         scsicmd->scsi_done = visorhba_cmnd_done;
 535         /* save destination */
 536         cmdrsp->scsi.vdest.channel = scsidev->channel;
 537         cmdrsp->scsi.vdest.id = scsidev->id;
 538         cmdrsp->scsi.vdest.lun = scsidev->lun;
 539         /* save datadir */
 540         cmdrsp->scsi.data_dir =
 541                 dma_data_dir_linux_to_spar(scsicmd->sc_data_direction);
 542         memcpy(cmdrsp->scsi.cmnd, cdb, MAX_CMND_SIZE);
 543         cmdrsp->scsi.bufflen = scsi_bufflen(scsicmd);
 544
 545         /* keep track of the max buffer length so far. */
 546         if (cmdrsp->scsi.bufflen > devdata->max_buff_len)
 547                 devdata->max_buff_len = cmdrsp->scsi.bufflen;
 548
 549         if (scsi_sg_count(scsicmd) > MAX_PHYS_INFO)
 550                 goto err_del_scsipending_ent;
 551
 552         /* convert buffer to phys information  */
 553         /* buffer is scatterlist - copy it out */
 554         sglist = scsi_sglist(scsicmd);
 555
 556         for_each_sg(sglist, sg, scsi_sg_count(scsicmd), i) {
 557                 cmdrsp->scsi.gpi_list[i].address = sg_phys(sg);
 558                 cmdrsp->scsi.gpi_list[i].length = sg->length;
 559         }
 560         cmdrsp->scsi.guest_phys_entries = scsi_sg_count(scsicmd);
 561
 562         if (visorchannel_signalinsert(devdata->dev->visorchannel,
 563                                       IOCHAN_TO_IOPART,
 564                                       cmdrsp))
 565                 /* queue must be full and we aren't going to wait */
 566                 goto err_del_scsipending_ent;
 567
 568         return 0;
 569
 570 err_del_scsipending_ent:
 571         del_scsipending_ent(devdata, insert_location);
 572         return SCSI_MLQUEUE_DEVICE_BUSY;
 573 }
 574
 575 #ifdef DEF_SCSI_QCMD
 576 static DEF_SCSI_QCMD(visorhba_queue_command)
 577 #else
 578 #define visorhba_queue_command visorhba_queue_command_lck
 579 #endif
 580
 581 /*
 582  * visorhba_slave_alloc - Called when new disk is discovered
 583  * @scsidev: New disk
 584  *
 585  * Create a new visordisk_info structure and add it to our
 586  * list of vdisks.
 587  *
 588  * Return: 0 on success, -ENOMEM on failure.
 589  */
 590 static int visorhba_slave_alloc(struct scsi_device *scsidev)
 591 {
 592         /* this is called by the midlayer before scan for new devices --
 593          * LLD can alloc any struct & do init if needed.
 594          */
 595         struct visordisk_info *vdisk;
 596         struct visorhba_devdata *devdata;
 597         struct Scsi_Host *scsihost = (struct Scsi_Host *)scsidev->host;
 598
 599         /* already allocated return success */
 600         if (scsidev->hostdata)
 601                 return 0;
 602
 603         /* even though we errored, treat as success */
 604         devdata = (struct visorhba_devdata *)scsihost->hostdata;
 605         if (!devdata)
 606                 return 0;
 607
 608         vdisk = kzalloc(sizeof(*vdisk), GFP_ATOMIC);
 609         if (!vdisk)
 610                 return -ENOMEM;
 611
 612         vdisk->sdev = scsidev;
 613         scsidev->hostdata = vdisk;
 614         return 0;
 615 }
 616
 617 /*
 618  * visorhba_slave_destroy - Disk is going away, clean up resources.
 619  * @scsidev: Scsi device to destroy
 620  */
 621 static void visorhba_slave_destroy(struct scsi_device *scsidev)
 622 {
 623         /* midlevel calls this after device has been quiesced and
 624          * before it is to be deleted.
 625          */
 626         struct visordisk_info *vdisk;
 627
 628         vdisk = scsidev->hostdata;
 629         scsidev->hostdata = NULL;
 630         kfree(vdisk);
 631 }
 632
 633 static struct scsi_host_template visorhba_driver_template = {
 634         .name = "Unisys Visor HBA",
 635         .info = visorhba_get_info,
 636         .queuecommand = visorhba_queue_command,
 637         .eh_abort_handler = visorhba_abort_handler,
 638         .eh_device_reset_handler = visorhba_device_reset_handler,
 639         .eh_bus_reset_handler = visorhba_bus_reset_handler,
 640         .eh_host_reset_handler = visorhba_host_reset_handler,
 641         .shost_attrs = NULL,
 642 #define visorhba_MAX_CMNDS 128
 643         .can_queue = visorhba_MAX_CMNDS,
 644         .sg_tablesize = 64,
 645         .this_id = -1,
 646         .slave_alloc = visorhba_slave_alloc,
 647         .slave_destroy = visorhba_slave_destroy,
 648 };
 649
 650 /*
 651  * info_debugfs_show - Debugfs interface to dump visorhba states
 652  * @seq: The sequence file to write information to
 653  * @v:   Unused, but needed for use with seq file single_open invocation
 654  *
 655  * Presents a file in the debugfs tree named: /visorhba/vbus<x>:dev<y>/info.
 656  *
 657  * Return: SUCCESS
 658  */
 659 static int info_debugfs_show(struct seq_file *seq, void *v)
 660 {
 661         struct visorhba_devdata *devdata = seq->private;
 662
 663         seq_printf(seq, "max_buff_len = %u\n", devdata->max_buff_len);
 664         seq_printf(seq, "interrupts_rcvd = %llu\n", devdata->interrupts_rcvd);
 665         seq_printf(seq, "interrupts_disabled = %llu\n",
 666                    devdata->interrupts_disabled);
 667         seq_printf(seq, "interrupts_notme = %llu\n",
 668                    devdata->interrupts_notme);
 669         seq_printf(seq, "flags_addr = %p\n", devdata->flags_addr);
 670         if (devdata->flags_addr) {
 671                 u64 phys_flags_addr =
 672                         virt_to_phys((__force  void *)devdata->flags_addr);
 673                 seq_printf(seq, "phys_flags_addr = 0x%016llx\n",
 674                            phys_flags_addr);
 675                 seq_printf(seq, "FeatureFlags = %llu\n",
 676                            (u64)readq(devdata->flags_addr));
 677         }
 678         seq_printf(seq, "acquire_failed_cnt = %llu\n",
 679                    devdata->acquire_failed_cnt);
 680
 681         return 0;
 682 }
 683 DEFINE_SHOW_ATTRIBUTE(info_debugfs);
 684
 685 /*
 686  * complete_taskmgmt_command - Complete task management
 687  * @idrtable: The data object maintaining the pointer<-->int mappings
 688  * @cmdrsp:   Response from the IOVM
 689  * @result:   The result of the task management command
 690  *
 691  * Service Partition returned the result of the task management
 692  * command. Wake up anyone waiting for it.
 693  */
 694 static void complete_taskmgmt_command(struct idr *idrtable,
 695                                       struct uiscmdrsp *cmdrsp, int result)
 696 {
 697         wait_queue_head_t *wq =
 698                 idr_find(idrtable, cmdrsp->scsitaskmgmt.notify_handle);
 699         int *scsi_result_ptr =
 700                 idr_find(idrtable, cmdrsp->scsitaskmgmt.notifyresult_handle);
 701         if (unlikely(!(wq && scsi_result_ptr))) {
 702                 pr_err("visorhba: no completion context; cmd will time out\n");
 703                 return;
 704         }
 705
 706         /* copy the result of the taskmgmt and
 707          * wake up the error handler that is waiting for this
 708          */
 709         pr_debug("visorhba: notifying initiator with result=0x%x\n", result);
 710         *scsi_result_ptr = result;
 711         wake_up_all(wq);
 712 }
 713
 714 /*
 715  * visorhba_serverdown_complete - Called when we are done cleaning up
 716  *                                from serverdown
 717  * @devdata: Visorhba instance on which to complete serverdown
 718  *
 719  * Called when we are done cleanning up from serverdown, stop processing
 720  * queue, fail pending IOs.
 721  */
 722 static void visorhba_serverdown_complete(struct visorhba_devdata *devdata)
 723 {
 724         int i;
 725         struct scsipending *pendingdel = NULL;
 726         struct scsi_cmnd *scsicmd = NULL;
 727         struct uiscmdrsp *cmdrsp;
 728         unsigned long flags;
 729
 730         /* Stop using the IOVM response queue (queue should be drained
 731          * by the end)
 732          */
 733         visor_thread_stop(devdata->thread);
 734
 735         /* Fail commands that weren't completed */
 736         spin_lock_irqsave(&devdata->privlock, flags);
 737         for (i = 0; i < MAX_PENDING_REQUESTS; i++) {
 738                 pendingdel = &devdata->pending[i];
 739                 switch (pendingdel->cmdtype) {
 740                 case CMD_SCSI_TYPE:
 741                         scsicmd = pendingdel->sent;
 742                         scsicmd->result = DID_RESET << 16;
 743                         if (scsicmd->scsi_done)
 744                                 scsicmd->scsi_done(scsicmd);
 745                         break;
 746                 case CMD_SCSITASKMGMT_TYPE:
 747                         cmdrsp = pendingdel->sent;
 748                         complete_taskmgmt_command(&devdata->idr, cmdrsp,
 749                                                   TASK_MGMT_FAILED);
 750                         break;
 751                 default:
 752                         break;
 753                 }
 754                 pendingdel->cmdtype = 0;
 755                 pendingdel->sent = NULL;
 756         }
 757         spin_unlock_irqrestore(&devdata->privlock, flags);
 758
 759         devdata->serverdown = true;
 760         devdata->serverchangingstate = false;
 761 }
 762
 763 /*
 764  * visorhba_serverdown - Got notified that the IOVM is down
 765  * @devdata: Visorhba that is being serviced by downed IOVM
 766  *
 767  * Something happened to the IOVM, return immediately and
 768  * schedule cleanup work.
 769  *
 770  * Return: 0 on success, -EINVAL on failure
 771  */
 772 static int visorhba_serverdown(struct visorhba_devdata *devdata)
 773 {
 774         if (!devdata->serverdown && !devdata->serverchangingstate) {
 775                 devdata->serverchangingstate = true;
 776                 visorhba_serverdown_complete(devdata);
 777         } else if (devdata->serverchangingstate) {
 778                 return -EINVAL;
 779         }
 780         return 0;
 781 }
 782
 783 /*
 784  * do_scsi_linuxstat - Scsi command returned linuxstat
 785  * @cmdrsp:  Response from IOVM
 786  * @scsicmd: Command issued
 787  *
 788  * Don't log errors for disk-not-present inquiries.
 789  */
 790 static void do_scsi_linuxstat(struct uiscmdrsp *cmdrsp,
 791                               struct scsi_cmnd *scsicmd)
 792 {
 793         struct visordisk_info *vdisk;
 794         struct scsi_device *scsidev;
 795
 796         scsidev = scsicmd->device;
 797         memcpy(scsicmd->sense_buffer, cmdrsp->scsi.sensebuf, MAX_SENSE_SIZE);
 798
 799         /* Do not log errors for disk-not-present inquiries */
 800         if (cmdrsp->scsi.cmnd[0] == INQUIRY &&
 801             (host_byte(cmdrsp->scsi.linuxstat) == DID_NO_CONNECT) &&
 802             cmdrsp->scsi.addlstat == ADDL_SEL_TIMEOUT)
 803                 return;
 804         /* Okay see what our error_count is here.... */
 805         vdisk = scsidev->hostdata;
 806         if (atomic_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT) {
 807                 atomic_inc(&vdisk->error_count);
 808                 atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
 809         }
 810 }
 811
 812 static int set_no_disk_inquiry_result(unsigned char *buf, size_t len,
 813                                       bool is_lun0)
 814 {
 815         if (len < NO_DISK_INQUIRY_RESULT_LEN)
 816                 return -EINVAL;
 817         memset(buf, 0, NO_DISK_INQUIRY_RESULT_LEN);
 818         buf[2] = SCSI_SPC2_VER;
 819         if (is_lun0) {
 820                 buf[0] = DEV_DISK_CAPABLE_NOT_PRESENT;
 821                 buf[3] = DEV_HISUPPORT;
 822         } else {
 823                 buf[0] = DEV_NOT_CAPABLE;
 824         }
 825         buf[4] = NO_DISK_INQUIRY_RESULT_LEN - 5;
 826         strncpy(buf + 8, "DELLPSEUDO DEVICE .", NO_DISK_INQUIRY_RESULT_LEN - 8);
 827         return 0;
 828 }
 829
 830 /*
 831  * do_scsi_nolinuxstat - Scsi command didn't have linuxstat
 832  * @cmdrsp:  Response from IOVM
 833  * @scsicmd: Command issued
 834  *
 835  * Handle response when no linuxstat was returned.
 836  */
 837 static void do_scsi_nolinuxstat(struct uiscmdrsp *cmdrsp,
 838                                 struct scsi_cmnd *scsicmd)
 839 {
 840         struct scsi_device *scsidev;
 841         unsigned char *buf;
 842         struct scatterlist *sg;
 843         unsigned int i;
 844         char *this_page;
 845         char *this_page_orig;
 846         int bufind = 0;
 847         struct visordisk_info *vdisk;
 848
 849         scsidev = scsicmd->device;
 850         if (cmdrsp->scsi.cmnd[0] == INQUIRY &&
 851             cmdrsp->scsi.bufflen >= MIN_INQUIRY_RESULT_LEN) {
 852                 if (cmdrsp->scsi.no_disk_result == 0)
 853                         return;
 854
 855                 buf = kzalloc(36, GFP_KERNEL);
 856                 if (!buf)
 857                         return;
 858
 859                 /* Linux scsi code wants a device at Lun 0
 860                  * to issue report luns, but we don't want
 861                  * a disk there so we'll present a processor
 862                  * there.
 863                  */
 864                 set_no_disk_inquiry_result(buf, (size_t)cmdrsp->scsi.bufflen,
 865                                            scsidev->lun == 0);
 866
 867                 if (scsi_sg_count(scsicmd) == 0) {
 868                         memcpy(scsi_sglist(scsicmd), buf,
 869                                cmdrsp->scsi.bufflen);
 870                         kfree(buf);
 871                         return;
 872                 }
 873
 874                 scsi_for_each_sg(scsicmd, sg, scsi_sg_count(scsicmd), i) {
 875                         this_page_orig = kmap_atomic(sg_page(sg));
 876                         this_page = (void *)((unsigned long)this_page_orig |
 877                                              sg->offset);
 878                         memcpy(this_page, buf + bufind, sg->length);
 879                         kunmap_atomic(this_page_orig);
 880                 }
 881                 kfree(buf);
 882         } else {
 883                 vdisk = scsidev->hostdata;
 884                 if (atomic_read(&vdisk->ios_threshold) > 0) {
 885                         atomic_dec(&vdisk->ios_threshold);
 886                         if (atomic_read(&vdisk->ios_threshold) == 0)
 887                                 atomic_set(&vdisk->error_count, 0);
 888                 }
 889         }
 890 }
 891
 892 /*
 893  * complete_scsi_command - Complete a scsi command
 894  * @uiscmdrsp: Response from Service Partition
 895  * @scsicmd:   The scsi command
 896  *
 897  * Response was returned by the Service Partition. Finish it and send
 898  * completion to the scsi midlayer.
 899  */
 900 static void complete_scsi_command(struct uiscmdrsp *cmdrsp,
 901                                   struct scsi_cmnd *scsicmd)
 902 {
 903         /* take what we need out of cmdrsp and complete the scsicmd */
 904         scsicmd->result = cmdrsp->scsi.linuxstat;
 905         if (cmdrsp->scsi.linuxstat)
 906                 do_scsi_linuxstat(cmdrsp, scsicmd);
 907         else
 908                 do_scsi_nolinuxstat(cmdrsp, scsicmd);
 909
 910         scsicmd->scsi_done(scsicmd);
 911 }
 912
 913 /*
 914  * drain_queue - Pull responses out of iochannel
 915  * @cmdrsp:  Response from the IOSP
 916  * @devdata: Device that owns this iochannel
 917  *
 918  * Pulls responses out of the iochannel and process the responses.
 919  */
 920 static void drain_queue(struct uiscmdrsp *cmdrsp,
 921                         struct visorhba_devdata *devdata)
 922 {
 923         struct scsi_cmnd *scsicmd;
 924
 925         while (1) {
 926                 /* queue empty */
 927                 if (visorchannel_signalremove(devdata->dev->visorchannel,
 928                                               IOCHAN_FROM_IOPART,
 929                                               cmdrsp))
 930                         break;
 931                 if (cmdrsp->cmdtype == CMD_SCSI_TYPE) {
 932                         /* scsicmd location is returned by the
 933                          * deletion
 934                          */
 935                         scsicmd = del_scsipending_ent(devdata,
 936                                                       cmdrsp->scsi.handle);
 937                         if (!scsicmd)
 938                                 break;
 939                         /* complete the orig cmd */
 940                         complete_scsi_command(cmdrsp, scsicmd);
 941                 } else if (cmdrsp->cmdtype == CMD_SCSITASKMGMT_TYPE) {
 942                         if (!del_scsipending_ent(devdata,
 943                                                  cmdrsp->scsitaskmgmt.handle))
 944                                 break;
 945                         complete_taskmgmt_command(&devdata->idr, cmdrsp,
 946                                                   cmdrsp->scsitaskmgmt.result);
 947                 } else if (cmdrsp->cmdtype == CMD_NOTIFYGUEST_TYPE)
 948                         dev_err_once(&devdata->dev->device,
 949                                      "ignoring unsupported NOTIFYGUEST\n");
 950                 /* cmdrsp is now available for re-use */
 951         }
 952 }
 953
 954 /*
 955  * process_incoming_rsps - Process responses from IOSP
 956  * @v:  Void pointer to visorhba_devdata
 957  *
 958  * Main function for the thread that processes the responses
 959  * from the IO Service Partition. When the queue is empty, wait
 960  * to check to see if it is full again.
 961  *
 962  * Return: 0 on success, -ENOMEM on failure
 963  */
 964 static int process_incoming_rsps(void *v)
 965 {
 966         struct visorhba_devdata *devdata = v;
 967         struct uiscmdrsp *cmdrsp = NULL;
 968         const int size = sizeof(*cmdrsp);
 969
 970         cmdrsp = kmalloc(size, GFP_ATOMIC);
 971         if (!cmdrsp)
 972                 return -ENOMEM;
 973
 974         while (1) {
 975                 if (kthread_should_stop())
 976                         break;
 977                 wait_event_interruptible_timeout(
 978                         devdata->rsp_queue, (atomic_read(
 979                                              &devdata->interrupt_rcvd) == 1),
 980                                 msecs_to_jiffies(devdata->thread_wait_ms));
 981                 /* drain queue */
 982                 drain_queue(cmdrsp, devdata);
 983         }
 984         kfree(cmdrsp);
 985         return 0;
 986 }
 987
 988 /*
 989  * visorhba_pause - Function to handle visorbus pause messages
 990  * @dev:           Device that is pausing
 991  * @complete_func: Function to call when finished
 992  *
 993  * Something has happened to the IO Service Partition that is
 994  * handling this device. Quiet this device and reset commands
 995  * so that the Service Partition can be corrected.
 996  *
 997  * Return: SUCCESS
 998  */
 999 static int visorhba_pause(struct visor_device *dev,
1000                           visorbus_state_complete_func complete_func)
1001 {
1002         struct visorhba_devdata *devdata = dev_get_drvdata(&dev->device);
1003
1004         visorhba_serverdown(devdata);
1005         complete_func(dev, 0);
1006         return 0;
1007 }
1008
1009 /*
1010  * visorhba_resume - Function called when the IO Service Partition is back
1011  * @dev:           Device that is pausing
1012  * @complete_func: Function to call when finished
1013  *
1014  * Yay! The IO Service Partition is back, the channel has been wiped
1015  * so lets re-establish connection and start processing responses.
1016  *
1017  * Return: 0 on success, -EINVAL on failure
1018  */
1019 static int visorhba_resume(struct visor_device *dev,
1020                            visorbus_state_complete_func complete_func)
1021 {
1022         struct visorhba_devdata *devdata;
1023
1024         devdata = dev_get_drvdata(&dev->device);
1025         if (!devdata)
1026                 return -EINVAL;
1027
1028         if (devdata->serverdown && !devdata->serverchangingstate)
1029                 devdata->serverchangingstate = true;
1030
1031         devdata->thread = visor_thread_start(process_incoming_rsps, devdata,
1032                                              "vhba_incming");
1033         devdata->serverdown = false;
1034         devdata->serverchangingstate = false;
1035
1036         return 0;
1037 }
1038
1039 /*
1040  * visorhba_probe - Device has been discovered; do acquire
1041  * @dev: visor_device that was discovered
1042  *
1043  * A new HBA was discovered; do the initial connections of it.
1044  *
1045  * Return: 0 on success, otherwise error code
1046  */
1047 static int visorhba_probe(struct visor_device *dev)
1048 {
1049         struct Scsi_Host *scsihost;
1050         struct vhba_config_max max;
1051         struct visorhba_devdata *devdata = NULL;
1052         int err, channel_offset;
1053         u64 features;
1054
1055         scsihost = scsi_host_alloc(&visorhba_driver_template,
1056                                    sizeof(*devdata));
1057         if (!scsihost)
1058                 return -ENODEV;
1059
1060         channel_offset = offsetof(struct visor_io_channel, vhba.max);
1061         err = visorbus_read_channel(dev, channel_offset, &max,
1062                                     sizeof(struct vhba_config_max));
1063         if (err < 0)
1064                 goto err_scsi_host_put;
1065
1066         scsihost->max_id = (unsigned int)max.max_id;
1067         scsihost->max_lun = (unsigned int)max.max_lun;
1068         scsihost->cmd_per_lun = (unsigned int)max.cmd_per_lun;
1069         scsihost->max_sectors =
1070             (unsigned short)(max.max_io_size >> 9);
1071         scsihost->sg_tablesize =
1072             (unsigned short)(max.max_io_size / PAGE_SIZE);
1073         if (scsihost->sg_tablesize > MAX_PHYS_INFO)
1074                 scsihost->sg_tablesize = MAX_PHYS_INFO;
1075         err = scsi_add_host(scsihost, &dev->device);
1076         if (err < 0)
1077                 goto err_scsi_host_put;
1078
1079         devdata = (struct visorhba_devdata *)scsihost->hostdata;
1080         devdata->dev = dev;
1081         dev_set_drvdata(&dev->device, devdata);
1082
1083         devdata->debugfs_dir = debugfs_create_dir(dev_name(&dev->device),
1084                                                   visorhba_debugfs_dir);
1085         if (!devdata->debugfs_dir) {
1086                 err = -ENOMEM;
1087                 goto err_scsi_remove_host;
1088         }
1089         devdata->debugfs_info =
1090                 debugfs_create_file("info", 0440,
1091                                     devdata->debugfs_dir, devdata,
1092                                     &info_debugfs_fops);
1093         if (!devdata->debugfs_info) {
1094                 err = -ENOMEM;
1095                 goto err_debugfs_dir;
1096         }
1097
1098         init_waitqueue_head(&devdata->rsp_queue);
1099         spin_lock_init(&devdata->privlock);
1100         devdata->serverdown = false;
1101         devdata->serverchangingstate = false;
1102         devdata->scsihost = scsihost;
1103
1104         channel_offset = offsetof(struct visor_io_channel,
1105                                   channel_header.features);
1106         err = visorbus_read_channel(dev, channel_offset, &features, 8);
1107         if (err)
1108                 goto err_debugfs_info;
1109         features |= VISOR_CHANNEL_IS_POLLING;
1110         err = visorbus_write_channel(dev, channel_offset, &features, 8);
1111         if (err)
1112                 goto err_debugfs_info;
1113
1114         idr_init(&devdata->idr);
1115
1116         devdata->thread_wait_ms = 2;
1117         devdata->thread = visor_thread_start(process_incoming_rsps, devdata,
1118                                              "vhba_incoming");
1119
1120         scsi_scan_host(scsihost);
1121
1122         return 0;
1123
1124 err_debugfs_info:
1125         debugfs_remove(devdata->debugfs_info);
1126
1127 err_debugfs_dir:
1128         debugfs_remove_recursive(devdata->debugfs_dir);
1129
1130 err_scsi_remove_host:
1131         scsi_remove_host(scsihost);
1132
1133 err_scsi_host_put:
1134         scsi_host_put(scsihost);
1135         return err;
1136 }
1137
1138 /*
1139  * visorhba_remove - Remove a visorhba device
1140  * @dev: Device to remove
1141  *
1142  * Removes the visorhba device.
1143  */
1144 static void visorhba_remove(struct visor_device *dev)
1145 {
1146         struct visorhba_devdata *devdata = dev_get_drvdata(&dev->device);
1147         struct Scsi_Host *scsihost = NULL;
1148
1149         if (!devdata)
1150                 return;
1151
1152         scsihost = devdata->scsihost;
1153         visor_thread_stop(devdata->thread);
1154         scsi_remove_host(scsihost);
1155         scsi_host_put(scsihost);
1156
1157         idr_destroy(&devdata->idr);
1158
1159         dev_set_drvdata(&dev->device, NULL);
1160         debugfs_remove(devdata->debugfs_info);
1161         debugfs_remove_recursive(devdata->debugfs_dir);
1162 }
1163
1164 /* This is used to tell the visorbus driver which types of visor devices
1165  * we support, and what functions to call when a visor device that we support
1166  * is attached or removed.
1167  */
1168 static struct visor_driver visorhba_driver = {
1169         .name = "visorhba",
1170         .owner = THIS_MODULE,
1171         .channel_types = visorhba_channel_types,
1172         .probe = visorhba_probe,
1173         .remove = visorhba_remove,
1174         .pause = visorhba_pause,
1175         .resume = visorhba_resume,
1176         .channel_interrupt = NULL,
1177 };
1178
1179 /*
1180  * visorhba_init - Driver init routine
1181  *
1182  * Initialize the visorhba driver and register it with visorbus
1183  * to handle s-Par virtual host bus adapter.
1184  *
1185  * Return: 0 on success, error code otherwise
1186  */
1187 static int visorhba_init(void)
1188 {
1189         int rc;
1190
1191         visorhba_debugfs_dir = debugfs_create_dir("visorhba", NULL);
1192         if (!visorhba_debugfs_dir)
1193                 return -ENOMEM;
1194
1195         rc = visorbus_register_visor_driver(&visorhba_driver);
1196         if (rc)
1197                 goto cleanup_debugfs;
1198
1199         return 0;
1200
1201 cleanup_debugfs:
1202         debugfs_remove_recursive(visorhba_debugfs_dir);
1203
1204         return rc;
1205 }
1206
1207 /*
1208  * visorhba_exit - Driver exit routine
1209  *
1210  * Unregister driver from the bus and free up memory.
1211  */
1212 static void visorhba_exit(void)
1213 {
1214         visorbus_unregister_visor_driver(&visorhba_driver);
1215         debugfs_remove_recursive(visorhba_debugfs_dir);
1216 }
1217
1218 module_init(visorhba_init);
1219 module_exit(visorhba_exit);
1220
1221 MODULE_AUTHOR("Unisys");
1222 MODULE_LICENSE("GPL");
1223 MODULE_DESCRIPTION("s-Par HBA driver for virtual SCSI host busses");