ibmvscsi.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* ------------------------------------------------------------
   3 * ibmvscsi.c
   4 * (C) Copyright IBM Corporation 1994, 2004
   5 * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
   6 *          Santiago Leon (santil@us.ibm.com)
   7 *          Dave Boutcher (sleddog@us.ibm.com)
   8 *
   9 * ------------------------------------------------------------
  10 * Emulation of a SCSI host adapter for Virtual I/O devices
  11 *
  12 * This driver supports the SCSI adapter implemented by the IBM
  13 * Power5 firmware.  That SCSI adapter is not a physical adapter,
  14 * but allows Linux SCSI peripheral drivers to directly
  15 * access devices in another logical partition on the physical system.
  16 *
  17 * The virtual adapter(s) are present in the open firmware device
  18 * tree just like real adapters.
  19 *
  20 * One of the capabilities provided on these systems is the ability
  21 * to DMA between partitions.  The architecture states that for VSCSI,
  22 * the server side is allowed to DMA to and from the client.  The client
  23 * is never trusted to DMA to or from the server directly.
  24 *
  25 * Messages are sent between partitions on a "Command/Response Queue" 
  26 * (CRQ), which is just a buffer of 16 byte entries in the receiver's 
  27 * Senders cannot access the buffer directly, but send messages by
  28 * making a hypervisor call and passing in the 16 bytes.  The hypervisor
  29 * puts the message in the next 16 byte space in round-robin fashion,
  30 * turns on the high order bit of the message (the valid bit), and 
  31 * generates an interrupt to the receiver (if interrupts are turned on.) 
  32 * The receiver just turns off the valid bit when they have copied out
  33 * the message.
  34 *
  35 * The VSCSI client builds a SCSI Remote Protocol (SRP) Information Unit
  36 * (IU) (as defined in the T10 standard available at www.t10.org), gets 
  37 * a DMA address for the message, and sends it to the server as the
  38 * payload of a CRQ message.  The server DMAs the SRP IU and processes it,
  39 * including doing any additional data transfers.  When it is done, it
  40 * DMAs the SRP response back to the same address as the request came from,
  41 * and sends a CRQ message back to inform the client that the request has
  42 * completed.
  43 *
  44 * TODO: This is currently pretty tied to the IBM pSeries hypervisor
  45 * interfaces.  It would be really nice to abstract this above an RDMA
  46 * layer.
  47 */
  48
  49#include <linux/module.h>
  50#include <linux/moduleparam.h>
  51#include <linux/dma-mapping.h>
  52#include <linux/delay.h>
  53#include <linux/slab.h>
  54#include <linux/of.h>
  55#include <linux/pm.h>
  56#include <linux/kthread.h>
  57#include <asm/firmware.h>
  58#include <asm/vio.h>
  59#include <scsi/scsi.h>
  60#include <scsi/scsi_cmnd.h>
  61#include <scsi/scsi_host.h>
  62#include <scsi/scsi_device.h>
  63#include <scsi/scsi_transport_srp.h>
  64#include "ibmvscsi.h"
  65
  66/* The values below are somewhat arbitrary default values, but 
  67 * OS/400 will use 3 busses (disks, CDs, tapes, I think.)
  68 * Note that there are 3 bits of channel value, 6 bits of id, and
  69 * 5 bits of LUN.
  70 */
  71static int max_id = 64;
  72static int max_channel = 3;
  73static int init_timeout = 300;
  74static int login_timeout = 60;
  75static int info_timeout = 30;
  76static int abort_timeout = 60;
  77static int reset_timeout = 60;
  78static int max_requests = IBMVSCSI_MAX_REQUESTS_DEFAULT;
  79static int max_events = IBMVSCSI_MAX_REQUESTS_DEFAULT + 2;
  80static int fast_fail = 1;
  81static int client_reserve = 1;
  82static char partition_name[96] = "UNKNOWN";
  83static unsigned int partition_number = -1;
  84static LIST_HEAD(ibmvscsi_head);
  85static DEFINE_SPINLOCK(ibmvscsi_driver_lock);
  86
  87static struct scsi_transport_template *ibmvscsi_transport_template;
  88
  89#define IBMVSCSI_VERSION "1.5.9"
  90
  91MODULE_DESCRIPTION("IBM Virtual SCSI");
  92MODULE_AUTHOR("Dave Boutcher");
  93MODULE_LICENSE("GPL");
  94MODULE_VERSION(IBMVSCSI_VERSION);
  95
  96module_param_named(max_id, max_id, int, S_IRUGO | S_IWUSR);
  97MODULE_PARM_DESC(max_id, "Largest ID value for each channel [Default=64]");
  98module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
  99MODULE_PARM_DESC(max_channel, "Largest channel value [Default=3]");
 100module_param_named(init_timeout, init_timeout, int, S_IRUGO | S_IWUSR);
 101MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
 102module_param_named(max_requests, max_requests, int, S_IRUGO);
 103MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
 104module_param_named(fast_fail, fast_fail, int, S_IRUGO | S_IWUSR);
 105MODULE_PARM_DESC(fast_fail, "Enable fast fail. [Default=1]");
 106module_param_named(client_reserve, client_reserve, int, S_IRUGO );
 107MODULE_PARM_DESC(client_reserve, "Attempt client managed reserve/release");
 108
 109static void ibmvscsi_handle_crq(struct viosrp_crq *crq,
 110				struct ibmvscsi_host_data *hostdata);
 111
 112/* ------------------------------------------------------------
 113 * Routines for managing the command/response queue
 114 */
 115/**
 116 * ibmvscsi_handle_event: - Interrupt handler for crq events
 117 * @irq:	number of irq to handle, not used
 118 * @dev_instance: ibmvscsi_host_data of host that received interrupt
 119 *
 120 * Disables interrupts and schedules srp_task
 121 * Always returns IRQ_HANDLED
 122 */
 123static irqreturn_t ibmvscsi_handle_event(int irq, void *dev_instance)
 124{
 125	struct ibmvscsi_host_data *hostdata =
 126	    (struct ibmvscsi_host_data *)dev_instance;
 127	vio_disable_interrupts(to_vio_dev(hostdata->dev));
 128	tasklet_schedule(&hostdata->srp_task);
 129	return IRQ_HANDLED;
 130}
 131
 132/**
 133 * ibmvscsi_release_crq_queue() - Deallocates data and unregisters CRQ
 134 * @queue:		crq_queue to initialize and register
 135 * @hostdata:		ibmvscsi_host_data of host
 136 * @max_requests:	maximum requests (unused)
 137 *
 138 * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
 139 * the crq with the hypervisor.
 140 */
 141static void ibmvscsi_release_crq_queue(struct crq_queue *queue,
 142				       struct ibmvscsi_host_data *hostdata,
 143				       int max_requests)
 144{
 145	long rc = 0;
 146	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 147	free_irq(vdev->irq, (void *)hostdata);
 148	tasklet_kill(&hostdata->srp_task);
 149	do {
 150		if (rc)
 151			msleep(100);
 152		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 153	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 154	dma_unmap_single(hostdata->dev,
 155			 queue->msg_token,
 156			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
 157	free_page((unsigned long)queue->msgs);
 158}
 159
 160/**
 161 * crq_queue_next_crq: - Returns the next entry in message queue
 162 * @queue:	crq_queue to use
 163 *
 164 * Returns pointer to next entry in queue, or NULL if there are no new
 165 * entried in the CRQ.
 166 */
 167static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
 168{
 169	struct viosrp_crq *crq;
 170	unsigned long flags;
 171
 172	spin_lock_irqsave(&queue->lock, flags);
 173	crq = &queue->msgs[queue->cur];
 174	if (crq->valid != VIOSRP_CRQ_FREE) {
 175		if (++queue->cur == queue->size)
 176			queue->cur = 0;
 177
 178		/* Ensure the read of the valid bit occurs before reading any
 179		 * other bits of the CRQ entry
 180		 */
 181		rmb();
 182	} else
 183		crq = NULL;
 184	spin_unlock_irqrestore(&queue->lock, flags);
 185
 186	return crq;
 187}
 188
 189/**
 190 * ibmvscsi_send_crq: - Send a CRQ
 191 * @hostdata:	the adapter
 192 * @word1:	the first 64 bits of the data
 193 * @word2:	the second 64 bits of the data
 194 */
 195static int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata,
 196			     u64 word1, u64 word2)
 197{
 198	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 199
 200	/*
 201	 * Ensure the command buffer is flushed to memory before handing it
 202	 * over to the VIOS to prevent it from fetching any stale data.
 203	 */
 204	mb();
 205	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 206}
 207
 208/**
 209 * ibmvscsi_task: - Process srps asynchronously
 210 * @data:	ibmvscsi_host_data of host
 211 */
 212static void ibmvscsi_task(void *data)
 213{
 214	struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
 215	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 216	struct viosrp_crq *crq;
 217	int done = 0;
 218
 219	while (!done) {
 220		/* Pull all the valid messages off the CRQ */
 221		while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 222			ibmvscsi_handle_crq(crq, hostdata);
 223			crq->valid = VIOSRP_CRQ_FREE;
 224			wmb();
 225		}
 226
 227		vio_enable_interrupts(vdev);
 228		crq = crq_queue_next_crq(&hostdata->queue);
 229		if (crq != NULL) {
 230			vio_disable_interrupts(vdev);
 231			ibmvscsi_handle_crq(crq, hostdata);
 232			crq->valid = VIOSRP_CRQ_FREE;
 233			wmb();
 234		} else {
 235			done = 1;
 236		}
 237	}
 238}
 239
 240static void gather_partition_info(void)
 241{
 242	const char *ppartition_name;
 243	const __be32 *p_number_ptr;
 244
 245	/* Retrieve information about this partition */
 246	if (!of_root)
 247		return;
 248
 249	of_node_get(of_root);
 250
 251	ppartition_name = of_get_property(of_root, "ibm,partition-name", NULL);
 252	if (ppartition_name)
 253		strscpy(partition_name, ppartition_name,
 254				sizeof(partition_name));
 255	p_number_ptr = of_get_property(of_root, "ibm,partition-no", NULL);
 256	if (p_number_ptr)
 257		partition_number = of_read_number(p_number_ptr, 1);
 258	of_node_put(of_root);
 259}
 260
 261static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
 262{
 263	memset(&hostdata->madapter_info, 0x00,
 264			sizeof(hostdata->madapter_info));
 265
 266	dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
 267	strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
 268
 269	strscpy(hostdata->madapter_info.partition_name, partition_name,
 270			sizeof(hostdata->madapter_info.partition_name));
 271
 272	hostdata->madapter_info.partition_number =
 273					cpu_to_be32(partition_number);
 274
 275	hostdata->madapter_info.mad_version = cpu_to_be32(SRP_MAD_VERSION_1);
 276	hostdata->madapter_info.os_type = cpu_to_be32(SRP_MAD_OS_LINUX);
 277}
 278
 279/**
 280 * ibmvscsi_reset_crq_queue() - resets a crq after a failure
 281 * @queue:	crq_queue to initialize and register
 282 * @hostdata:	ibmvscsi_host_data of host
 283 */
 284static int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
 285				    struct ibmvscsi_host_data *hostdata)
 286{
 287	int rc = 0;
 288	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 289
 290	/* Close the CRQ */
 291	do {
 292		if (rc)
 293			msleep(100);
 294		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 295	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 296
 297	/* Clean out the queue */
 298	memset(queue->msgs, 0x00, PAGE_SIZE);
 299	queue->cur = 0;
 300
 301	set_adapter_info(hostdata);
 302
 303	/* And re-open it again */
 304	rc = plpar_hcall_norets(H_REG_CRQ,
 305				vdev->unit_address,
 306				queue->msg_token, PAGE_SIZE);
 307	if (rc == H_CLOSED) {
 308		/* Adapter is good, but other end is not ready */
 309		dev_warn(hostdata->dev, "Partner adapter not ready\n");
 310	} else if (rc != 0) {
 311		dev_warn(hostdata->dev, "couldn't register crq--rc 0x%x\n", rc);
 312	}
 313	return rc;
 314}
 315
 316/**
 317 * ibmvscsi_init_crq_queue() - Initializes and registers CRQ with hypervisor
 318 * @queue:		crq_queue to initialize and register
 319 * @hostdata:		ibmvscsi_host_data of host
 320 * @max_requests:	maximum requests (unused)
 321 *
 322 * Allocates a page for messages, maps it for dma, and registers
 323 * the crq with the hypervisor.
 324 * Returns zero on success.
 325 */
 326static int ibmvscsi_init_crq_queue(struct crq_queue *queue,
 327				   struct ibmvscsi_host_data *hostdata,
 328				   int max_requests)
 329{
 330	int rc;
 331	int retrc;
 332	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 333
 334	queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
 335
 336	if (!queue->msgs)
 337		goto malloc_failed;
 338	queue->size = PAGE_SIZE / sizeof(*queue->msgs);
 339
 340	queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
 341					  queue->size * sizeof(*queue->msgs),
 342					  DMA_BIDIRECTIONAL);
 343
 344	if (dma_mapping_error(hostdata->dev, queue->msg_token))
 345		goto map_failed;
 346
 347	gather_partition_info();
 348	set_adapter_info(hostdata);
 349
 350	retrc = rc = plpar_hcall_norets(H_REG_CRQ,
 351				vdev->unit_address,
 352				queue->msg_token, PAGE_SIZE);
 353	if (rc == H_RESOURCE)
 354		/* maybe kexecing and resource is busy. try a reset */
 355		rc = ibmvscsi_reset_crq_queue(queue,
 356					      hostdata);
 357
 358	if (rc == H_CLOSED) {
 359		/* Adapter is good, but other end is not ready */
 360		dev_warn(hostdata->dev, "Partner adapter not ready\n");
 361		retrc = 0;
 362	} else if (rc != 0) {
 363		dev_warn(hostdata->dev, "Error %d opening adapter\n", rc);
 364		goto reg_crq_failed;
 365	}
 366
 367	queue->cur = 0;
 368	spin_lock_init(&queue->lock);
 369
 370	tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
 371		     (unsigned long)hostdata);
 372
 373	if (request_irq(vdev->irq,
 374			ibmvscsi_handle_event,
 375			0, "ibmvscsi", (void *)hostdata) != 0) {
 376		dev_err(hostdata->dev, "couldn't register irq 0x%x\n",
 377			vdev->irq);
 378		goto req_irq_failed;
 379	}
 380
 381	rc = vio_enable_interrupts(vdev);
 382	if (rc != 0) {
 383		dev_err(hostdata->dev, "Error %d enabling interrupts!!!\n", rc);
 384		goto req_irq_failed;
 385	}
 386
 387	return retrc;
 388
 389      req_irq_failed:
 390	tasklet_kill(&hostdata->srp_task);
 391	rc = 0;
 392	do {
 393		if (rc)
 394			msleep(100);
 395		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 396	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 397      reg_crq_failed:
 398	dma_unmap_single(hostdata->dev,
 399			 queue->msg_token,
 400			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
 401      map_failed:
 402	free_page((unsigned long)queue->msgs);
 403      malloc_failed:
 404	return -1;
 405}
 406
 407/**
 408 * ibmvscsi_reenable_crq_queue() - reenables a crq after
 409 * @queue:	crq_queue to initialize and register
 410 * @hostdata:	ibmvscsi_host_data of host
 411 */
 412static int ibmvscsi_reenable_crq_queue(struct crq_queue *queue,
 413				       struct ibmvscsi_host_data *hostdata)
 414{
 415	int rc = 0;
 416	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 417
 418	set_adapter_info(hostdata);
 419
 420	/* Re-enable the CRQ */
 421	do {
 422		if (rc)
 423			msleep(100);
 424		rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
 425	} while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 426
 427	if (rc)
 428		dev_err(hostdata->dev, "Error %d enabling adapter\n", rc);
 429	return rc;
 430}
 431
 432/* ------------------------------------------------------------
 433 * Routines for the event pool and event structs
 434 */
 435/**
 436 * initialize_event_pool: - Allocates and initializes the event pool for a host
 437 * @pool:	event_pool to be initialized
 438 * @size:	Number of events in pool
 439 * @hostdata:	ibmvscsi_host_data who owns the event pool
 440 *
 441 * Returns zero on success.
 442 */
 443static int initialize_event_pool(struct event_pool *pool,
 444				 int size, struct ibmvscsi_host_data *hostdata)
 445{
 446	int i;
 447
 448	pool->size = size;
 449	pool->next = 0;
 450	pool->events = kcalloc(pool->size, sizeof(*pool->events), GFP_KERNEL);
 451	if (!pool->events)
 452		return -ENOMEM;
 453
 454	pool->iu_storage =
 455	    dma_alloc_coherent(hostdata->dev,
 456			       pool->size * sizeof(*pool->iu_storage),
 457			       &pool->iu_token, GFP_KERNEL);
 458	if (!pool->iu_storage) {
 459		kfree(pool->events);
 460		return -ENOMEM;
 461	}
 462
 463	for (i = 0; i < pool->size; ++i) {
 464		struct srp_event_struct *evt = &pool->events[i];
 465		memset(&evt->crq, 0x00, sizeof(evt->crq));
 466		atomic_set(&evt->free, 1);
 467		evt->crq.valid = VIOSRP_CRQ_CMD_RSP;
 468		evt->crq.IU_length = cpu_to_be16(sizeof(*evt->xfer_iu));
 469		evt->crq.IU_data_ptr = cpu_to_be64(pool->iu_token +
 470			sizeof(*evt->xfer_iu) * i);
 471		evt->xfer_iu = pool->iu_storage + i;
 472		evt->hostdata = hostdata;
 473		evt->ext_list = NULL;
 474		evt->ext_list_token = 0;
 475	}
 476
 477	return 0;
 478}
 479
 480/**
 481 * release_event_pool() - Frees memory of an event pool of a host
 482 * @pool:	event_pool to be released
 483 * @hostdata:	ibmvscsi_host_data who owns the even pool
 484 *
 485 * Returns zero on success.
 486 */
 487static void release_event_pool(struct event_pool *pool,
 488			       struct ibmvscsi_host_data *hostdata)
 489{
 490	int i, in_use = 0;
 491	for (i = 0; i < pool->size; ++i) {
 492		if (atomic_read(&pool->events[i].free) != 1)
 493			++in_use;
 494		if (pool->events[i].ext_list) {
 495			dma_free_coherent(hostdata->dev,
 496				  SG_ALL * sizeof(struct srp_direct_buf),
 497				  pool->events[i].ext_list,
 498				  pool->events[i].ext_list_token);
 499		}
 500	}
 501	if (in_use)
 502		dev_warn(hostdata->dev, "releasing event pool with %d "
 503			 "events still in use?\n", in_use);
 504	kfree(pool->events);
 505	dma_free_coherent(hostdata->dev,
 506			  pool->size * sizeof(*pool->iu_storage),
 507			  pool->iu_storage, pool->iu_token);
 508}
 509
 510/**
 511 * valid_event_struct: - Determines if event is valid.
 512 * @pool:	event_pool that contains the event
 513 * @evt:	srp_event_struct to be checked for validity
 514 *
 515 * Returns zero if event is invalid, one otherwise.
 516*/
 517static int valid_event_struct(struct event_pool *pool,
 518				struct srp_event_struct *evt)
 519{
 520	int index = evt - pool->events;
 521	if (index < 0 || index >= pool->size)	/* outside of bounds */
 522		return 0;
 523	if (evt != pool->events + index)	/* unaligned */
 524		return 0;
 525	return 1;
 526}
 527
 528/**
 529 * free_event_struct() - Changes status of event to "free"
 530 * @pool:	event_pool that contains the event
 531 * @evt:	srp_event_struct to be modified
 532 */
 533static void free_event_struct(struct event_pool *pool,
 534				       struct srp_event_struct *evt)
 535{
 536	if (!valid_event_struct(pool, evt)) {
 537		dev_err(evt->hostdata->dev, "Freeing invalid event_struct %p "
 538			"(not in pool %p)\n", evt, pool->events);
 539		return;
 540	}
 541	if (atomic_inc_return(&evt->free) != 1) {
 542		dev_err(evt->hostdata->dev, "Freeing event_struct %p "
 543			"which is not in use!\n", evt);
 544		return;
 545	}
 546}
 547
 548/**
 549 * get_event_struct() - Gets the next free event in pool
 550 * @pool:	event_pool that contains the events to be searched
 551 *
 552 * Returns the next event in "free" state, and NULL if none are free.
 553 * Note that no synchronization is done here, we assume the host_lock
 554 * will syncrhonze things.
 555*/
 556static struct srp_event_struct *get_event_struct(struct event_pool *pool)
 557{
 558	int i;
 559	int poolsize = pool->size;
 560	int offset = pool->next;
 561
 562	for (i = 0; i < poolsize; i++) {
 563		offset = (offset + 1) % poolsize;
 564		if (!atomic_dec_if_positive(&pool->events[offset].free)) {
 565			pool->next = offset;
 566			return &pool->events[offset];
 567		}
 568	}
 569
 570	printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
 571	return NULL;
 572}
 573
 574/**
 575 * init_event_struct: Initialize fields in an event struct that are always 
 576 *                    required.
 577 * @evt_struct: The event
 578 * @done:       Routine to call when the event is responded to
 579 * @format:     SRP or MAD format
 580 * @timeout:    timeout value set in the CRQ
 581 */
 582static void init_event_struct(struct srp_event_struct *evt_struct,
 583			      void (*done) (struct srp_event_struct *),
 584			      u8 format,
 585			      int timeout)
 586{
 587	evt_struct->cmnd = NULL;
 588	evt_struct->cmnd_done = NULL;
 589	evt_struct->sync_srp = NULL;
 590	evt_struct->crq.format = format;
 591	evt_struct->crq.timeout = cpu_to_be16(timeout);
 592	evt_struct->done = done;
 593}
 594
 595/* ------------------------------------------------------------
 596 * Routines for receiving SCSI responses from the hosting partition
 597 */
 598
 599/*
 600 * set_srp_direction: Set the fields in the srp related to data
 601 *     direction and number of buffers based on the direction in
 602 *     the scsi_cmnd and the number of buffers
 603 */
 604static void set_srp_direction(struct scsi_cmnd *cmd,
 605			      struct srp_cmd *srp_cmd, 
 606			      int numbuf)
 607{
 608	u8 fmt;
 609
 610	if (numbuf == 0)
 611		return;
 612	
 613	if (numbuf == 1)
 614		fmt = SRP_DATA_DESC_DIRECT;
 615	else {
 616		fmt = SRP_DATA_DESC_INDIRECT;
 617		numbuf = min(numbuf, MAX_INDIRECT_BUFS);
 618
 619		if (cmd->sc_data_direction == DMA_TO_DEVICE)
 620			srp_cmd->data_out_desc_cnt = numbuf;
 621		else
 622			srp_cmd->data_in_desc_cnt = numbuf;
 623	}
 624
 625	if (cmd->sc_data_direction == DMA_TO_DEVICE)
 626		srp_cmd->buf_fmt = fmt << 4;
 627	else
 628		srp_cmd->buf_fmt = fmt;
 629}
 630
 631/**
 632 * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
 633 * @cmd:	srp_cmd whose additional_data member will be unmapped
 634 * @evt_struct: the event
 635 * @dev:	device for which the memory is mapped
 636 */
 637static void unmap_cmd_data(struct srp_cmd *cmd,
 638			   struct srp_event_struct *evt_struct,
 639			   struct device *dev)
 640{
 641	u8 out_fmt, in_fmt;
 642
 643	out_fmt = cmd->buf_fmt >> 4;
 644	in_fmt = cmd->buf_fmt & ((1U << 4) - 1);
 645
 646	if (out_fmt == SRP_NO_DATA_DESC && in_fmt == SRP_NO_DATA_DESC)
 647		return;
 648
 649	if (evt_struct->cmnd)
 650		scsi_dma_unmap(evt_struct->cmnd);
 651}
 652
 653static int map_sg_list(struct scsi_cmnd *cmd, int nseg,
 654		       struct srp_direct_buf *md)
 655{
 656	int i;
 657	struct scatterlist *sg;
 658	u64 total_length = 0;
 659
 660	scsi_for_each_sg(cmd, sg, nseg, i) {
 661		struct srp_direct_buf *descr = md + i;
 662		descr->va = cpu_to_be64(sg_dma_address(sg));
 663		descr->len = cpu_to_be32(sg_dma_len(sg));
 664		descr->key = 0;
 665		total_length += sg_dma_len(sg);
 666 	}
 667	return total_length;
 668}
 669
 670/**
 671 * map_sg_data: - Maps dma for a scatterlist and initializes descriptor fields
 672 * @cmd:	struct scsi_cmnd with the scatterlist
 673 * @evt_struct:	struct srp_event_struct to map
 674 * @srp_cmd:	srp_cmd that contains the memory descriptor
 675 * @dev:	device for which to map dma memory
 676 *
 677 * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
 678 * Returns 1 on success.
 679*/
 680static int map_sg_data(struct scsi_cmnd *cmd,
 681		       struct srp_event_struct *evt_struct,
 682		       struct srp_cmd *srp_cmd, struct device *dev)
 683{
 684
 685	int sg_mapped;
 686	u64 total_length = 0;
 687	struct srp_direct_buf *data =
 688		(struct srp_direct_buf *) srp_cmd->add_data;
 689	struct srp_indirect_buf *indirect =
 690		(struct srp_indirect_buf *) data;
 691
 692	sg_mapped = scsi_dma_map(cmd);
 693	if (!sg_mapped)
 694		return 1;
 695	else if (sg_mapped < 0)
 696		return 0;
 697
 698	set_srp_direction(cmd, srp_cmd, sg_mapped);
 699
 700	/* special case; we can use a single direct descriptor */
 701	if (sg_mapped == 1) {
 702		map_sg_list(cmd, sg_mapped, data);
 703		return 1;
 704	}
 705
 706	indirect->table_desc.va = 0;
 707	indirect->table_desc.len = cpu_to_be32(sg_mapped *
 708					       sizeof(struct srp_direct_buf));
 709	indirect->table_desc.key = 0;
 710
 711	if (sg_mapped <= MAX_INDIRECT_BUFS) {
 712		total_length = map_sg_list(cmd, sg_mapped,
 713					   &indirect->desc_list[0]);
 714		indirect->len = cpu_to_be32(total_length);
 715		return 1;
 716	}
 717
 718	/* get indirect table */
 719	if (!evt_struct->ext_list) {
 720		evt_struct->ext_list = dma_alloc_coherent(dev,
 721					   SG_ALL * sizeof(struct srp_direct_buf),
 722					   &evt_struct->ext_list_token, 0);
 723		if (!evt_struct->ext_list) {
 724			if (!firmware_has_feature(FW_FEATURE_CMO))
 725				sdev_printk(KERN_ERR, cmd->device,
 726				            "Can't allocate memory "
 727				            "for indirect table\n");
 728			scsi_dma_unmap(cmd);
 729			return 0;
 730		}
 731	}
 732
 733	total_length = map_sg_list(cmd, sg_mapped, evt_struct->ext_list);
 734
 735	indirect->len = cpu_to_be32(total_length);
 736	indirect->table_desc.va = cpu_to_be64(evt_struct->ext_list_token);
 737	indirect->table_desc.len = cpu_to_be32(sg_mapped *
 738					       sizeof(indirect->desc_list[0]));
 739	memcpy(indirect->desc_list, evt_struct->ext_list,
 740	       MAX_INDIRECT_BUFS * sizeof(struct srp_direct_buf));
 741 	return 1;
 742}
 743
 744/**
 745 * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
 746 * @cmd:	struct scsi_cmnd with the memory to be mapped
 747 * @evt_struct:	struct srp_event_struct to map
 748 * @srp_cmd:	srp_cmd that contains the memory descriptor
 749 * @dev:	dma device for which to map dma memory
 750 *
 751 * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds 
 752 * Returns 1 on success.
 753*/
 754static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
 755				struct srp_event_struct *evt_struct,
 756				struct srp_cmd *srp_cmd, struct device *dev)
 757{
 758	switch (cmd->sc_data_direction) {
 759	case DMA_FROM_DEVICE:
 760	case DMA_TO_DEVICE:
 761		break;
 762	case DMA_NONE:
 763		return 1;
 764	case DMA_BIDIRECTIONAL:
 765		sdev_printk(KERN_ERR, cmd->device,
 766			    "Can't map DMA_BIDIRECTIONAL to read/write\n");
 767		return 0;
 768	default:
 769		sdev_printk(KERN_ERR, cmd->device,
 770			    "Unknown data direction 0x%02x; can't map!\n",
 771			    cmd->sc_data_direction);
 772		return 0;
 773	}
 774
 775	return map_sg_data(cmd, evt_struct, srp_cmd, dev);
 776}
 777
 778/**
 779 * purge_requests: Our virtual adapter just shut down.  purge any sent requests
 780 * @hostdata:    the adapter
 781 * @error_code:  error code to return as the 'result'
 782 */
 783static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)
 784{
 785	struct srp_event_struct *evt;
 786	unsigned long flags;
 787
 788	spin_lock_irqsave(hostdata->host->host_lock, flags);
 789	while (!list_empty(&hostdata->sent)) {
 790		evt = list_first_entry(&hostdata->sent, struct srp_event_struct, list);
 791		list_del(&evt->list);
 792		timer_delete(&evt->timer);
 793
 794		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 795		if (evt->cmnd) {
 796			evt->cmnd->result = (error_code << 16);
 797			unmap_cmd_data(&evt->iu.srp.cmd, evt,
 798				       evt->hostdata->dev);
 799			if (evt->cmnd_done)
 800				evt->cmnd_done(evt->cmnd);
 801		} else if (evt->done && evt->crq.format != VIOSRP_MAD_FORMAT &&
 802			   evt->iu.srp.login_req.opcode != SRP_LOGIN_REQ)
 803			evt->done(evt);
 804		free_event_struct(&evt->hostdata->pool, evt);
 805		spin_lock_irqsave(hostdata->host->host_lock, flags);
 806	}
 807	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 808}
 809
 810/**
 811 * ibmvscsi_set_request_limit - Set the adapter request_limit in response to
 812 * an adapter failure, reset, or SRP Login. Done under host lock to prevent
 813 * race with SCSI command submission.
 814 * @hostdata:	adapter to adjust
 815 * @limit:	new request limit
 816 */
 817static void ibmvscsi_set_request_limit(struct ibmvscsi_host_data *hostdata, int limit)
 818{
 819	unsigned long flags;
 820
 821	spin_lock_irqsave(hostdata->host->host_lock, flags);
 822	atomic_set(&hostdata->request_limit, limit);
 823	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
 824}
 825
 826/**
 827 * ibmvscsi_reset_host - Reset the connection to the server
 828 * @hostdata:	struct ibmvscsi_host_data to reset
 829*/
 830static void ibmvscsi_reset_host(struct ibmvscsi_host_data *hostdata)
 831{
 832	scsi_block_requests(hostdata->host);
 833	ibmvscsi_set_request_limit(hostdata, 0);
 834
 835	purge_requests(hostdata, DID_ERROR);
 836	hostdata->action = IBMVSCSI_HOST_ACTION_RESET;
 837	wake_up(&hostdata->work_wait_q);
 838}
 839
 840/**
 841 * ibmvscsi_timeout - Internal command timeout handler
 842 * @t:	struct srp_event_struct that timed out
 843 *
 844 * Called when an internally generated command times out
 845*/
 846static void ibmvscsi_timeout(struct timer_list *t)
 847{
 848	struct srp_event_struct *evt_struct = timer_container_of(evt_struct,
 849								 t, timer);
 850	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
 851
 852	dev_err(hostdata->dev, "Command timed out (%x). Resetting connection\n",
 853		evt_struct->iu.srp.cmd.opcode);
 854
 855	ibmvscsi_reset_host(hostdata);
 856}
 857
 858
 859/* ------------------------------------------------------------
 860 * Routines for sending and receiving SRPs
 861 */
 862/**
 863 * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
 864 * @evt_struct:	evt_struct to be sent
 865 * @hostdata:	ibmvscsi_host_data of host
 866 * @timeout:	timeout in seconds - 0 means do not time command
 867 *
 868 * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
 869 * Note that this routine assumes that host_lock is held for synchronization
 870*/
 871static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
 872				   struct ibmvscsi_host_data *hostdata,
 873				   unsigned long timeout)
 874{
 875	__be64 *crq_as_u64 = (__be64 *)&evt_struct->crq;
 876	int request_status = 0;
 877	int rc;
 878	int srp_req = 0;
 879
 880	/* If we have exhausted our request limit, just fail this request,
 881	 * unless it is for a reset or abort.
 882	 * Note that there are rare cases involving driver generated requests 
 883	 * (such as task management requests) that the mid layer may think we
 884	 * can handle more requests (can_queue) when we actually can't
 885	 */
 886	if (evt_struct->crq.format == VIOSRP_SRP_FORMAT) {
 887		srp_req = 1;
 888		request_status =
 889			atomic_dec_if_positive(&hostdata->request_limit);
 890		/* If request limit was -1 when we started, it is now even
 891		 * less than that
 892		 */
 893		if (request_status < -1)
 894			goto send_error;
 895		/* Otherwise, we may have run out of requests. */
 896		/* If request limit was 0 when we started the adapter is in the
 897		 * process of performing a login with the server adapter, or
 898		 * we may have run out of requests.
 899		 */
 900		else if (request_status == -1 &&
 901		         evt_struct->iu.srp.login_req.opcode != SRP_LOGIN_REQ)
 902			goto send_busy;
 903		/* Abort and reset calls should make it through.
 904		 * Nothing except abort and reset should use the last two
 905		 * slots unless we had two or less to begin with.
 906		 */
 907		else if (request_status < 2 &&
 908		         evt_struct->iu.srp.cmd.opcode != SRP_TSK_MGMT) {
 909			/* In the case that we have less than two requests
 910			 * available, check the server limit as a combination
 911			 * of the request limit and the number of requests
 912			 * in-flight (the size of the send list).  If the
 913			 * server limit is greater than 2, return busy so
 914			 * that the last two are reserved for reset and abort.
 915			 */
 916			int server_limit = request_status;
 917			struct srp_event_struct *tmp_evt;
 918
 919			list_for_each_entry(tmp_evt, &hostdata->sent, list) {
 920				server_limit++;
 921			}
 922
 923			if (server_limit > 2)
 924				goto send_busy;
 925		}
 926	}
 927
 928	/* Copy the IU into the transfer area */
 929	*evt_struct->xfer_iu = evt_struct->iu;
 930	evt_struct->xfer_iu->srp.rsp.tag = (u64)evt_struct;
 931
 932	/* Add this to the sent list.  We need to do this 
 933	 * before we actually send 
 934	 * in case it comes back REALLY fast
 935	 */
 936	list_add_tail(&evt_struct->list, &hostdata->sent);
 937
 938	timer_setup(&evt_struct->timer, ibmvscsi_timeout, 0);
 939	if (timeout) {
 940		evt_struct->timer.expires = jiffies + (timeout * HZ);
 941		add_timer(&evt_struct->timer);
 942	}
 943
 944	rc = ibmvscsi_send_crq(hostdata, be64_to_cpu(crq_as_u64[0]),
 945			       be64_to_cpu(crq_as_u64[1]));
 946	if (rc != 0) {
 947		list_del(&evt_struct->list);
 948		timer_delete(&evt_struct->timer);
 949
 950		/* If send_crq returns H_CLOSED, return SCSI_MLQUEUE_HOST_BUSY.
 951		 * Firmware will send a CRQ with a transport event (0xFF) to
 952		 * tell this client what has happened to the transport.  This
 953		 * will be handled in ibmvscsi_handle_crq()
 954		 */
 955		if (rc == H_CLOSED) {
 956			dev_warn(hostdata->dev, "send warning. "
 957			         "Receive queue closed, will retry.\n");
 958			goto send_busy;
 959		}
 960		dev_err(hostdata->dev, "send error %d\n", rc);
 961		if (srp_req)
 962			atomic_inc(&hostdata->request_limit);
 963		goto send_error;
 964	}
 965
 966	return 0;
 967
 968 send_busy:
 969	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
 970
 971	free_event_struct(&hostdata->pool, evt_struct);
 972	if (srp_req && request_status != -1)
 973		atomic_inc(&hostdata->request_limit);
 974	return SCSI_MLQUEUE_HOST_BUSY;
 975
 976 send_error:
 977	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
 978
 979	if (evt_struct->cmnd != NULL) {
 980		evt_struct->cmnd->result = DID_ERROR << 16;
 981		evt_struct->cmnd_done(evt_struct->cmnd);
 982	} else if (evt_struct->done)
 983		evt_struct->done(evt_struct);
 984
 985	free_event_struct(&hostdata->pool, evt_struct);
 986	return 0;
 987}
 988
 989/**
 990 * handle_cmd_rsp: -  Handle responses from commands
 991 * @evt_struct:	srp_event_struct to be handled
 992 *
 993 * Used as a callback by when sending scsi cmds.
 994 * Gets called by ibmvscsi_handle_crq()
 995*/
 996static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
 997{
 998	struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
 999	struct scsi_cmnd *cmnd = evt_struct->cmnd;
1000
1001	if (unlikely(rsp->opcode != SRP_RSP)) {
1002		if (printk_ratelimit())
1003			dev_warn(evt_struct->hostdata->dev,
1004				 "bad SRP RSP type %#02x\n", rsp->opcode);
1005	}
1006	
1007	if (cmnd) {
1008		cmnd->result |= rsp->status;
1009		if (scsi_status_is_check_condition(cmnd->result))
1010			memcpy(cmnd->sense_buffer,
1011			       rsp->data,
1012			       be32_to_cpu(rsp->sense_data_len));
1013		unmap_cmd_data(&evt_struct->iu.srp.cmd, 
1014			       evt_struct, 
1015			       evt_struct->hostdata->dev);
1016
1017		if (rsp->flags & SRP_RSP_FLAG_DOOVER)
1018			scsi_set_resid(cmnd,
1019				       be32_to_cpu(rsp->data_out_res_cnt));
1020		else if (rsp->flags & SRP_RSP_FLAG_DIOVER)
1021			scsi_set_resid(cmnd, be32_to_cpu(rsp->data_in_res_cnt));
1022	}
1023
1024	if (evt_struct->cmnd_done)
1025		evt_struct->cmnd_done(cmnd);
1026}
1027
1028/**
1029 * lun_from_dev: - Returns the lun of the scsi device
1030 * @dev:	struct scsi_device
1031 *
1032*/
1033static inline u16 lun_from_dev(struct scsi_device *dev)
1034{
1035	return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
1036}
1037
1038/**
1039 * ibmvscsi_queuecommand_lck() - The queuecommand function of the scsi template
1040 * @cmnd:	struct scsi_cmnd to be executed
1041 * @done:	Callback function to be called when cmd is completed
1042*/
1043static int ibmvscsi_queuecommand_lck(struct scsi_cmnd *cmnd)
1044{
1045	void (*done)(struct scsi_cmnd *) = scsi_done;
1046	struct srp_cmd *srp_cmd;
1047	struct srp_event_struct *evt_struct;
1048	struct srp_indirect_buf *indirect;
1049	struct ibmvscsi_host_data *hostdata = shost_priv(cmnd->device->host);
1050	u16 lun = lun_from_dev(cmnd->device);
1051	u8 out_fmt, in_fmt;
1052
1053	cmnd->result = (DID_OK << 16);
1054	evt_struct = get_event_struct(&hostdata->pool);
1055	if (!evt_struct)
1056		return SCSI_MLQUEUE_HOST_BUSY;
1057
1058	/* Set up the actual SRP IU */
1059	BUILD_BUG_ON(sizeof(evt_struct->iu.srp) != SRP_MAX_IU_LEN);
1060	memset(&evt_struct->iu.srp, 0x00, sizeof(evt_struct->iu.srp));
1061	srp_cmd = &evt_struct->iu.srp.cmd;
1062	srp_cmd->opcode = SRP_CMD;
1063	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(srp_cmd->cdb));
1064	int_to_scsilun(lun, &srp_cmd->lun);
1065
1066	if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
1067		if (!firmware_has_feature(FW_FEATURE_CMO))
1068			sdev_printk(KERN_ERR, cmnd->device,
1069			            "couldn't convert cmd to srp_cmd\n");
1070		free_event_struct(&hostdata->pool, evt_struct);
1071		return SCSI_MLQUEUE_HOST_BUSY;
1072	}
1073
1074	init_event_struct(evt_struct,
1075			  handle_cmd_rsp,
1076			  VIOSRP_SRP_FORMAT,
1077			  scsi_cmd_to_rq(cmnd)->timeout / HZ);
1078
1079	evt_struct->cmnd = cmnd;
1080	evt_struct->cmnd_done = done;
1081
1082	/* Fix up dma address of the buffer itself */
1083	indirect = (struct srp_indirect_buf *) srp_cmd->add_data;
1084	out_fmt = srp_cmd->buf_fmt >> 4;
1085	in_fmt = srp_cmd->buf_fmt & ((1U << 4) - 1);
1086	if ((in_fmt == SRP_DATA_DESC_INDIRECT ||
1087	     out_fmt == SRP_DATA_DESC_INDIRECT) &&
1088	    indirect->table_desc.va == 0) {
1089		indirect->table_desc.va =
1090			cpu_to_be64(be64_to_cpu(evt_struct->crq.IU_data_ptr) +
1091			offsetof(struct srp_cmd, add_data) +
1092			offsetof(struct srp_indirect_buf, desc_list));
1093	}
1094
1095	return ibmvscsi_send_srp_event(evt_struct, hostdata, 0);
1096}
1097
1098static DEF_SCSI_QCMD(ibmvscsi_queuecommand)
1099
1100/* ------------------------------------------------------------
1101 * Routines for driver initialization
1102 */
1103
1104/**
1105 * map_persist_bufs: - Pre-map persistent data for adapter logins
1106 * @hostdata:   ibmvscsi_host_data of host
1107 *
1108 * Map the capabilities and adapter info DMA buffers to avoid runtime failures.
1109 * Return 1 on error, 0 on success.
1110 */
1111static int map_persist_bufs(struct ibmvscsi_host_data *hostdata)
1112{
1113
1114	hostdata->caps_addr = dma_map_single(hostdata->dev, &hostdata->caps,
1115					     sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
1116
1117	if (dma_mapping_error(hostdata->dev, hostdata->caps_addr)) {
1118		dev_err(hostdata->dev, "Unable to map capabilities buffer!\n");
1119		return 1;
1120	}
1121
1122	hostdata->adapter_info_addr = dma_map_single(hostdata->dev,
1123						     &hostdata->madapter_info,
1124						     sizeof(hostdata->madapter_info),
1125						     DMA_BIDIRECTIONAL);
1126	if (dma_mapping_error(hostdata->dev, hostdata->adapter_info_addr)) {
1127		dev_err(hostdata->dev, "Unable to map adapter info buffer!\n");
1128		dma_unmap_single(hostdata->dev, hostdata->caps_addr,
1129				 sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
1130		return 1;
1131	}
1132
1133	return 0;
1134}
1135
1136/**
1137 * unmap_persist_bufs: - Unmap persistent data needed for adapter logins
1138 * @hostdata:   ibmvscsi_host_data of host
1139 *
1140 * Unmap the capabilities and adapter info DMA buffers
1141 */
1142static void unmap_persist_bufs(struct ibmvscsi_host_data *hostdata)
1143{
1144	dma_unmap_single(hostdata->dev, hostdata->caps_addr,
1145			 sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
1146
1147	dma_unmap_single(hostdata->dev, hostdata->adapter_info_addr,
1148			 sizeof(hostdata->madapter_info), DMA_BIDIRECTIONAL);
1149}
1150
1151/**
1152 * login_rsp: - Handle response to SRP login request
1153 * @evt_struct:	srp_event_struct with the response
1154 *
1155 * Used as a "done" callback by when sending srp_login. Gets called
1156 * by ibmvscsi_handle_crq()
1157*/
1158static void login_rsp(struct srp_event_struct *evt_struct)
1159{
1160	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
1161	switch (evt_struct->xfer_iu->srp.login_rsp.opcode) {
1162	case SRP_LOGIN_RSP:	/* it worked! */
1163		break;
1164	case SRP_LOGIN_REJ:	/* refused! */
1165		dev_info(hostdata->dev, "SRP_LOGIN_REJ reason %u\n",
1166			 evt_struct->xfer_iu->srp.login_rej.reason);
1167		/* Login failed.  */
1168		ibmvscsi_set_request_limit(hostdata, -1);
1169		return;
1170	default:
1171		dev_err(hostdata->dev, "Invalid login response typecode 0x%02x!\n",
1172			evt_struct->xfer_iu->srp.login_rsp.opcode);
1173		/* Login failed.  */
1174		ibmvscsi_set_request_limit(hostdata, -1);
1175		return;
1176	}
1177
1178	dev_info(hostdata->dev, "SRP_LOGIN succeeded\n");
1179	hostdata->client_migrated = 0;
1180
1181	/* Now we know what the real request-limit is.
1182	 * This value is set rather than added to request_limit because
1183	 * request_limit could have been set to -1 by this client.
1184	 */
1185	ibmvscsi_set_request_limit(hostdata,
1186		   be32_to_cpu(evt_struct->xfer_iu->srp.login_rsp.req_lim_delta));
1187
1188	/* If we had any pending I/Os, kick them */
1189	hostdata->action = IBMVSCSI_HOST_ACTION_UNBLOCK;
1190	wake_up(&hostdata->work_wait_q);
1191}
1192
1193/**
1194 * send_srp_login: - Sends the srp login
1195 * @hostdata:	ibmvscsi_host_data of host
1196 *
1197 * Returns zero if successful.
1198*/
1199static int send_srp_login(struct ibmvscsi_host_data *hostdata)
1200{
1201	int rc;
1202	unsigned long flags;
1203	struct srp_login_req *login;
1204	struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
1205
1206	BUG_ON(!evt_struct);
1207	init_event_struct(evt_struct, login_rsp,
1208			  VIOSRP_SRP_FORMAT, login_timeout);
1209
1210	login = &evt_struct->iu.srp.login_req;
1211	memset(login, 0, sizeof(*login));
1212	login->opcode = SRP_LOGIN_REQ;
1213	login->req_it_iu_len = cpu_to_be32(sizeof(union srp_iu));
1214	login->req_buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
1215					 SRP_BUF_FORMAT_INDIRECT);
1216
1217	/* Start out with a request limit of 0, since this is negotiated in
1218	 * the login request we are just sending and login requests always
1219	 * get sent by the driver regardless of request_limit.
1220	 */
1221	ibmvscsi_set_request_limit(hostdata, 0);
1222
1223	spin_lock_irqsave(hostdata->host->host_lock, flags);
1224	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, login_timeout * 2);
1225	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1226	dev_info(hostdata->dev, "sent SRP login\n");
1227	return rc;
1228};
1229
1230/**
1231 * capabilities_rsp: - Handle response to MAD adapter capabilities request
1232 * @evt_struct:	srp_event_struct with the response
1233 *
1234 * Used as a "done" callback by when sending adapter_info.
1235 */
1236static void capabilities_rsp(struct srp_event_struct *evt_struct)
1237{
1238	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
1239
1240	if (evt_struct->xfer_iu->mad.capabilities.common.status) {
1241		dev_err(hostdata->dev, "error 0x%X getting capabilities info\n",
1242			evt_struct->xfer_iu->mad.capabilities.common.status);
1243	} else {
1244		if (hostdata->caps.migration.common.server_support !=
1245		    cpu_to_be16(SERVER_SUPPORTS_CAP))
1246			dev_info(hostdata->dev, "Partition migration not supported\n");
1247
1248		if (client_reserve) {
1249			if (hostdata->caps.reserve.common.server_support ==
1250			    cpu_to_be16(SERVER_SUPPORTS_CAP))
1251				dev_info(hostdata->dev, "Client reserve enabled\n");
1252			else
1253				dev_info(hostdata->dev, "Client reserve not supported\n");
1254		}
1255	}
1256
1257	send_srp_login(hostdata);
1258}
1259
1260/**
1261 * send_mad_capabilities: - Sends the mad capabilities request
1262 *      and stores the result so it can be retrieved with
1263 * @hostdata:	ibmvscsi_host_data of host
1264 */
1265static void send_mad_capabilities(struct ibmvscsi_host_data *hostdata)
1266{
1267	struct viosrp_capabilities *req;
1268	struct srp_event_struct *evt_struct;
1269	unsigned long flags;
1270	struct device_node *of_node = hostdata->dev->of_node;
1271	const char *location;
1272
1273	evt_struct = get_event_struct(&hostdata->pool);
1274	BUG_ON(!evt_struct);
1275
1276	init_event_struct(evt_struct, capabilities_rsp,
1277			  VIOSRP_MAD_FORMAT, info_timeout);
1278
1279	req = &evt_struct->iu.mad.capabilities;
1280	memset(req, 0, sizeof(*req));
1281
1282	hostdata->caps.flags = cpu_to_be32(CAP_LIST_SUPPORTED);
1283	if (hostdata->client_migrated)
1284		hostdata->caps.flags |= cpu_to_be32(CLIENT_MIGRATED);
1285
1286	strscpy(hostdata->caps.name, dev_name(&hostdata->host->shost_gendev),
1287		sizeof(hostdata->caps.name));
1288
1289	location = of_get_property(of_node, "ibm,loc-code", NULL);
1290	location = location ? location : dev_name(hostdata->dev);
1291	strscpy(hostdata->caps.loc, location, sizeof(hostdata->caps.loc));
1292
1293	req->common.type = cpu_to_be32(VIOSRP_CAPABILITIES_TYPE);
1294	req->buffer = cpu_to_be64(hostdata->caps_addr);
1295
1296	hostdata->caps.migration.common.cap_type =
1297				cpu_to_be32(MIGRATION_CAPABILITIES);
1298	hostdata->caps.migration.common.length =
1299				cpu_to_be16(sizeof(hostdata->caps.migration));
1300	hostdata->caps.migration.common.server_support =
1301				cpu_to_be16(SERVER_SUPPORTS_CAP);
1302	hostdata->caps.migration.ecl = cpu_to_be32(1);
1303
1304	if (client_reserve) {
1305		hostdata->caps.reserve.common.cap_type =
1306					cpu_to_be32(RESERVATION_CAPABILITIES);
1307		hostdata->caps.reserve.common.length =
1308				cpu_to_be16(sizeof(hostdata->caps.reserve));
1309		hostdata->caps.reserve.common.server_support =
1310				cpu_to_be16(SERVER_SUPPORTS_CAP);
1311		hostdata->caps.reserve.type =
1312				cpu_to_be32(CLIENT_RESERVE_SCSI_2);
1313		req->common.length =
1314				cpu_to_be16(sizeof(hostdata->caps));
1315	} else
1316		req->common.length = cpu_to_be16(sizeof(hostdata->caps) -
1317						sizeof(hostdata->caps.reserve));
1318
1319	spin_lock_irqsave(hostdata->host->host_lock, flags);
1320	if (ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2))
1321		dev_err(hostdata->dev, "couldn't send CAPABILITIES_REQ!\n");
1322	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1323};
1324
1325/**
1326 * fast_fail_rsp: - Handle response to MAD enable fast fail
1327 * @evt_struct:	srp_event_struct with the response
1328 *
1329 * Used as a "done" callback by when sending enable fast fail. Gets called
1330 * by ibmvscsi_handle_crq()
1331 */
1332static void fast_fail_rsp(struct srp_event_struct *evt_struct)
1333{
1334	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
1335	u16 status = be16_to_cpu(evt_struct->xfer_iu->mad.fast_fail.common.status);
1336
1337	if (status == VIOSRP_MAD_NOT_SUPPORTED)
1338		dev_err(hostdata->dev, "fast_fail not supported in server\n");
1339	else if (status == VIOSRP_MAD_FAILED)
1340		dev_err(hostdata->dev, "fast_fail request failed\n");
1341	else if (status != VIOSRP_MAD_SUCCESS)
1342		dev_err(hostdata->dev, "error 0x%X enabling fast_fail\n", status);
1343
1344	send_mad_capabilities(hostdata);
1345}
1346
1347/**
1348 * enable_fast_fail() - Start host initialization
1349 * @hostdata:	ibmvscsi_host_data of host
1350 *
1351 * Returns zero if successful.
1352 */
1353static int enable_fast_fail(struct ibmvscsi_host_data *hostdata)
1354{
1355	int rc;
1356	unsigned long flags;
1357	struct viosrp_fast_fail *fast_fail_mad;
1358	struct srp_event_struct *evt_struct;
1359
1360	if (!fast_fail) {
1361		send_mad_capabilities(hostdata);
1362		return 0;
1363	}
1364
1365	evt_struct = get_event_struct(&hostdata->pool);
1366	BUG_ON(!evt_struct);
1367
1368	init_event_struct(evt_struct, fast_fail_rsp, VIOSRP_MAD_FORMAT, info_timeout);
1369
1370	fast_fail_mad = &evt_struct->iu.mad.fast_fail;
1371	memset(fast_fail_mad, 0, sizeof(*fast_fail_mad));
1372	fast_fail_mad->common.type = cpu_to_be32(VIOSRP_ENABLE_FAST_FAIL);
1373	fast_fail_mad->common.length = cpu_to_be16(sizeof(*fast_fail_mad));
1374
1375	spin_lock_irqsave(hostdata->host->host_lock, flags);
1376	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2);
1377	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1378	return rc;
1379}
1380
1381/**
1382 * adapter_info_rsp: - Handle response to MAD adapter info request
1383 * @evt_struct:	srp_event_struct with the response
1384 *
1385 * Used as a "done" callback by when sending adapter_info. Gets called
1386 * by ibmvscsi_handle_crq()
1387*/
1388static void adapter_info_rsp(struct srp_event_struct *evt_struct)
1389{
1390	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
1391
1392	if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
1393		dev_err(hostdata->dev, "error %d getting adapter info\n",
1394			evt_struct->xfer_iu->mad.adapter_info.common.status);
1395	} else {
1396		dev_info(hostdata->dev, "host srp version: %s, "
1397			 "host partition %s (%d), OS %d, max io %u\n",
1398			 hostdata->madapter_info.srp_version,
1399			 hostdata->madapter_info.partition_name,
1400			 be32_to_cpu(hostdata->madapter_info.partition_number),
1401			 be32_to_cpu(hostdata->madapter_info.os_type),
1402			 be32_to_cpu(hostdata->madapter_info.port_max_txu[0]));
1403		
1404		if (hostdata->madapter_info.port_max_txu[0]) 
1405			hostdata->host->max_sectors = 
1406				be32_to_cpu(hostdata->madapter_info.port_max_txu[0]) >> 9;
1407		
1408		if (be32_to_cpu(hostdata->madapter_info.os_type) == SRP_MAD_OS_AIX &&
1409		    strcmp(hostdata->madapter_info.srp_version, "1.6a") <= 0) {
1410			dev_err(hostdata->dev, "host (Ver. %s) doesn't support large transfers\n",
1411				hostdata->madapter_info.srp_version);
1412			dev_err(hostdata->dev, "limiting scatterlists to %d\n",
1413				MAX_INDIRECT_BUFS);
1414			hostdata->host->sg_tablesize = MAX_INDIRECT_BUFS;
1415		}
1416
1417		if (be32_to_cpu(hostdata->madapter_info.os_type) == SRP_MAD_OS_AIX) {
1418			enable_fast_fail(hostdata);
1419			return;
1420		}
1421	}
1422
1423	send_srp_login(hostdata);
1424}
1425
1426/**
1427 * send_mad_adapter_info: - Sends the mad adapter info request
1428 *      and stores the result so it can be retrieved with
1429 *      sysfs.  We COULD consider causing a failure if the
1430 *      returned SRP version doesn't match ours.
1431 * @hostdata:	ibmvscsi_host_data of host
1432 * 
1433 * Returns zero if successful.
1434*/
1435static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
1436{
1437	struct viosrp_adapter_info *req;
1438	struct srp_event_struct *evt_struct;
1439	unsigned long flags;
1440
1441	evt_struct = get_event_struct(&hostdata->pool);
1442	BUG_ON(!evt_struct);
1443
1444	init_event_struct(evt_struct,
1445			  adapter_info_rsp,
1446			  VIOSRP_MAD_FORMAT,
1447			  info_timeout);
1448	
1449	req = &evt_struct->iu.mad.adapter_info;
1450	memset(req, 0x00, sizeof(*req));
1451	
1452	req->common.type = cpu_to_be32(VIOSRP_ADAPTER_INFO_TYPE);
1453	req->common.length = cpu_to_be16(sizeof(hostdata->madapter_info));
1454	req->buffer = cpu_to_be64(hostdata->adapter_info_addr);
1455
1456	spin_lock_irqsave(hostdata->host->host_lock, flags);
1457	if (ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2))
1458		dev_err(hostdata->dev, "couldn't send ADAPTER_INFO_REQ!\n");
1459	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1460};
1461
1462/*
1463 * init_adapter() - Start virtual adapter initialization sequence
1464 */
1465static void init_adapter(struct ibmvscsi_host_data *hostdata)
1466{
1467	send_mad_adapter_info(hostdata);
1468}
1469
1470/*
1471 * sync_completion: Signal that a synchronous command has completed
1472 * Note that after returning from this call, the evt_struct is freed.
1473 * the caller waiting on this completion shouldn't touch the evt_struct
1474 * again.
1475 */
1476static void sync_completion(struct srp_event_struct *evt_struct)
1477{
1478	/* copy the response back */
1479	if (evt_struct->sync_srp)
1480		*evt_struct->sync_srp = *evt_struct->xfer_iu;
1481	
1482	complete(&evt_struct->comp);
1483}
1484
1485/*
1486 * ibmvscsi_eh_abort_handler: Abort a command...from scsi host template
1487 * send this over to the server and wait synchronously for the response
1488 */
1489static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
1490{
1491	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
1492	struct srp_tsk_mgmt *tsk_mgmt;
1493	struct srp_event_struct *evt;
1494	struct srp_event_struct *tmp_evt, *found_evt;
1495	union viosrp_iu srp_rsp;
1496	int rsp_rc;
1497	unsigned long flags;
1498	u16 lun = lun_from_dev(cmd->device);
1499	unsigned long wait_switch = 0;
1500
1501	/* First, find this command in our sent list so we can figure
1502	 * out the correct tag
1503	 */
1504	spin_lock_irqsave(hostdata->host->host_lock, flags);
1505	wait_switch = jiffies + (init_timeout * HZ);
1506	do {
1507		found_evt = NULL;
1508		list_for_each_entry(tmp_evt, &hostdata->sent, list) {
1509			if (tmp_evt->cmnd == cmd) {
1510				found_evt = tmp_evt;
1511				break;
1512			}
1513		}
1514
1515		if (!found_evt) {
1516			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1517			return SUCCESS;
1518		}
1519
1520		evt = get_event_struct(&hostdata->pool);
1521		if (evt == NULL) {
1522			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1523			sdev_printk(KERN_ERR, cmd->device,
1524				"failed to allocate abort event\n");
1525			return FAILED;
1526		}
1527	
1528		init_event_struct(evt,
1529				  sync_completion,
1530				  VIOSRP_SRP_FORMAT,
1531				  abort_timeout);
1532
1533		tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1534	
1535		/* Set up an abort SRP command */
1536		memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1537		tsk_mgmt->opcode = SRP_TSK_MGMT;
1538		int_to_scsilun(lun, &tsk_mgmt->lun);
1539		tsk_mgmt->tsk_mgmt_func = SRP_TSK_ABORT_TASK;
1540		tsk_mgmt->task_tag = (u64) found_evt;
1541
1542		evt->sync_srp = &srp_rsp;
1543
1544		init_completion(&evt->comp);
1545		rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, abort_timeout * 2);
1546
1547		if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)
1548			break;
1549
1550		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1551		msleep(10);
1552		spin_lock_irqsave(hostdata->host->host_lock, flags);
1553	} while (time_before(jiffies, wait_switch));
1554
1555	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1556
1557	if (rsp_rc != 0) {
1558		sdev_printk(KERN_ERR, cmd->device,
1559			    "failed to send abort() event. rc=%d\n", rsp_rc);
1560		return FAILED;
1561	}
1562
1563	sdev_printk(KERN_INFO, cmd->device,
1564                    "aborting command. lun 0x%llx, tag 0x%llx\n",
1565		    (((u64) lun) << 48), (u64) found_evt);
1566
1567	wait_for_completion(&evt->comp);
1568
1569	/* make sure we got a good response */
1570	if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
1571		if (printk_ratelimit())
1572			sdev_printk(KERN_WARNING, cmd->device, "abort bad SRP RSP type %d\n",
1573				    srp_rsp.srp.rsp.opcode);
1574		return FAILED;
1575	}
1576
1577	if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
1578		rsp_rc = *((int *)srp_rsp.srp.rsp.data);
1579	else
1580		rsp_rc = srp_rsp.srp.rsp.status;
1581
1582	if (rsp_rc) {
1583		if (printk_ratelimit())
1584			sdev_printk(KERN_WARNING, cmd->device,
1585				    "abort code %d for task tag 0x%llx\n",
1586				    rsp_rc, tsk_mgmt->task_tag);
1587		return FAILED;
1588	}
1589
1590	/* Because we dropped the spinlock above, it's possible
1591	 * The event is no longer in our list.  Make sure it didn't
1592	 * complete while we were aborting
1593	 */
1594	spin_lock_irqsave(hostdata->host->host_lock, flags);
1595	found_evt = NULL;
1596	list_for_each_entry(tmp_evt, &hostdata->sent, list) {
1597		if (tmp_evt->cmnd == cmd) {
1598			found_evt = tmp_evt;
1599			break;
1600		}
1601	}
1602
1603	if (found_evt == NULL) {
1604		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1605		sdev_printk(KERN_INFO, cmd->device, "aborted task tag 0x%llx completed\n",
1606			    tsk_mgmt->task_tag);
1607		return SUCCESS;
1608	}
1609
1610	sdev_printk(KERN_INFO, cmd->device, "successfully aborted task tag 0x%llx\n",
1611		    tsk_mgmt->task_tag);
1612
1613	cmd->result = (DID_ABORT << 16);
1614	list_del(&found_evt->list);
1615	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
1616		       found_evt->hostdata->dev);
1617	free_event_struct(&found_evt->hostdata->pool, found_evt);
1618	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1619	atomic_inc(&hostdata->request_limit);
1620	return SUCCESS;
1621}
1622
1623/*
1624 * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host 
1625 * template send this over to the server and wait synchronously for the 
1626 * response
1627 */
1628static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
1629{
1630	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
1631	struct srp_tsk_mgmt *tsk_mgmt;
1632	struct srp_event_struct *evt;
1633	struct srp_event_struct *tmp_evt, *pos;
1634	union viosrp_iu srp_rsp;
1635	int rsp_rc;
1636	unsigned long flags;
1637	u16 lun = lun_from_dev(cmd->device);
1638	unsigned long wait_switch = 0;
1639
1640	spin_lock_irqsave(hostdata->host->host_lock, flags);
1641	wait_switch = jiffies + (init_timeout * HZ);
1642	do {
1643		evt = get_event_struct(&hostdata->pool);
1644		if (evt == NULL) {
1645			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1646			sdev_printk(KERN_ERR, cmd->device,
1647				"failed to allocate reset event\n");
1648			return FAILED;
1649		}
1650	
1651		init_event_struct(evt,
1652				  sync_completion,
1653				  VIOSRP_SRP_FORMAT,
1654				  reset_timeout);
1655
1656		tsk_mgmt = &evt->iu.srp.tsk_mgmt;
1657
1658		/* Set up a lun reset SRP command */
1659		memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
1660		tsk_mgmt->opcode = SRP_TSK_MGMT;
1661		int_to_scsilun(lun, &tsk_mgmt->lun);
1662		tsk_mgmt->tsk_mgmt_func = SRP_TSK_LUN_RESET;
1663
1664		evt->sync_srp = &srp_rsp;
1665
1666		init_completion(&evt->comp);
1667		rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, reset_timeout * 2);
1668
1669		if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)
1670			break;
1671
1672		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1673		msleep(10);
1674		spin_lock_irqsave(hostdata->host->host_lock, flags);
1675	} while (time_before(jiffies, wait_switch));
1676
1677	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1678
1679	if (rsp_rc != 0) {
1680		sdev_printk(KERN_ERR, cmd->device,
1681			    "failed to send reset event. rc=%d\n", rsp_rc);
1682		return FAILED;
1683	}
1684
1685	sdev_printk(KERN_INFO, cmd->device, "resetting device. lun 0x%llx\n",
1686		    (((u64) lun) << 48));
1687
1688	wait_for_completion(&evt->comp);
1689
1690	/* make sure we got a good response */
1691	if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
1692		if (printk_ratelimit())
1693			sdev_printk(KERN_WARNING, cmd->device, "reset bad SRP RSP type %d\n",
1694				    srp_rsp.srp.rsp.opcode);
1695		return FAILED;
1696	}
1697
1698	if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
1699		rsp_rc = *((int *)srp_rsp.srp.rsp.data);
1700	else
1701		rsp_rc = srp_rsp.srp.rsp.status;
1702
1703	if (rsp_rc) {
1704		if (printk_ratelimit())
1705			sdev_printk(KERN_WARNING, cmd->device,
1706				    "reset code %d for task tag 0x%llx\n",
1707				    rsp_rc, tsk_mgmt->task_tag);
1708		return FAILED;
1709	}
1710
1711	/* We need to find all commands for this LUN that have not yet been
1712	 * responded to, and fail them with DID_RESET
1713	 */
1714	spin_lock_irqsave(hostdata->host->host_lock, flags);
1715	list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
1716		if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
1717			if (tmp_evt->cmnd)
1718				tmp_evt->cmnd->result = (DID_RESET << 16);
1719			list_del(&tmp_evt->list);
1720			unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
1721				       tmp_evt->hostdata->dev);
1722			free_event_struct(&tmp_evt->hostdata->pool,
1723						   tmp_evt);
1724			atomic_inc(&hostdata->request_limit);
1725			if (tmp_evt->cmnd_done)
1726				tmp_evt->cmnd_done(tmp_evt->cmnd);
1727			else if (tmp_evt->done)
1728				tmp_evt->done(tmp_evt);
1729		}
1730	}
1731	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
1732	return SUCCESS;
1733}
1734
1735/**
1736 * ibmvscsi_eh_host_reset_handler - Reset the connection to the server
1737 * @cmd:	struct scsi_cmnd having problems
1738*/
1739static int ibmvscsi_eh_host_reset_handler(struct scsi_cmnd *cmd)
1740{
1741	unsigned long wait_switch = 0;
1742	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
1743
1744	dev_err(hostdata->dev, "Resetting connection due to error recovery\n");
1745
1746	ibmvscsi_reset_host(hostdata);
1747
1748	for (wait_switch = jiffies + (init_timeout * HZ);
1749	     time_before(jiffies, wait_switch) &&
1750		     atomic_read(&hostdata->request_limit) < 2;) {
1751
1752		msleep(10);
1753	}
1754
1755	if (atomic_read(&hostdata->request_limit) <= 0)
1756		return FAILED;
1757
1758	return SUCCESS;
1759}
1760
1761/**
1762 * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
1763 * @crq:	Command/Response queue
1764 * @hostdata:	ibmvscsi_host_data of host
1765 *
1766*/
1767static void ibmvscsi_handle_crq(struct viosrp_crq *crq,
1768				struct ibmvscsi_host_data *hostdata)
1769{
1770	long rc;
1771	unsigned long flags;
1772	/* The hypervisor copies our tag value here so no byteswapping */
1773	struct srp_event_struct *evt_struct =
1774			(__force struct srp_event_struct *)crq->IU_data_ptr;
1775	switch (crq->valid) {
1776	case VIOSRP_CRQ_INIT_RSP:		/* initialization */
1777		switch (crq->format) {
1778		case VIOSRP_CRQ_INIT:	/* Initialization message */
1779			dev_info(hostdata->dev, "partner initialized\n");
1780			/* Send back a response */
1781			rc = ibmvscsi_send_crq(hostdata, 0xC002000000000000LL, 0);
1782			if (rc == 0) {
1783				/* Now login */
1784				init_adapter(hostdata);
1785			} else {
1786				dev_err(hostdata->dev, "Unable to send init rsp. rc=%ld\n", rc);
1787			}
1788
1789			break;
1790		case VIOSRP_CRQ_INIT_COMPLETE:	/* Initialization response */
1791			dev_info(hostdata->dev, "partner initialization complete\n");
1792
1793			/* Now login */
1794			init_adapter(hostdata);
1795			break;
1796		default:
1797			dev_err(hostdata->dev, "unknown crq message type: %d\n", crq->format);
1798		}
1799		return;
1800	case VIOSRP_CRQ_XPORT_EVENT:	/* Hypervisor telling us the connection is closed */
1801		scsi_block_requests(hostdata->host);
1802		ibmvscsi_set_request_limit(hostdata, 0);
1803		if (crq->format == 0x06) {
1804			/* We need to re-setup the interpartition connection */
1805			dev_info(hostdata->dev, "Re-enabling adapter!\n");
1806			hostdata->client_migrated = 1;
1807			hostdata->action = IBMVSCSI_HOST_ACTION_REENABLE;
1808			purge_requests(hostdata, DID_REQUEUE);
1809			wake_up(&hostdata->work_wait_q);
1810		} else {
1811			dev_err(hostdata->dev, "Virtual adapter failed rc %d!\n",
1812				crq->format);
1813			ibmvscsi_reset_host(hostdata);
1814		}
1815		return;
1816	case VIOSRP_CRQ_CMD_RSP:		/* real payload */
1817		break;
1818	default:
1819		dev_err(hostdata->dev, "got an invalid message type 0x%02x\n",
1820			crq->valid);
1821		return;
1822	}
1823
1824	/* The only kind of payload CRQs we should get are responses to
1825	 * things we send. Make sure this response is to something we
1826	 * actually sent
1827	 */
1828	if (!valid_event_struct(&hostdata->pool, evt_struct)) {
1829		dev_err(hostdata->dev, "returned correlation_token 0x%p is invalid!\n",
1830		       evt_struct);
1831		return;
1832	}
1833
1834	if (atomic_read(&evt_struct->free)) {
1835		dev_err(hostdata->dev, "received duplicate correlation_token 0x%p!\n",
1836			evt_struct);
1837		return;
1838	}
1839
1840	if (crq->format == VIOSRP_SRP_FORMAT)
1841		atomic_add(be32_to_cpu(evt_struct->xfer_iu->srp.rsp.req_lim_delta),
1842			   &hostdata->request_limit);
1843
1844	timer_delete(&evt_struct->timer);
1845
1846	if ((crq->status != VIOSRP_OK && crq->status != VIOSRP_OK2) && evt_struct->cmnd)
1847		evt_struct->cmnd->result = DID_ERROR << 16;
1848	if (evt_struct->done)
1849		evt_struct->done(evt_struct);
1850	else
1851		dev_err(hostdata->dev, "returned done() is NULL; not running it!\n");
1852
1853	/*
1854	 * Lock the host_lock before messing with these structures, since we
1855	 * are running in a task context
1856	 */
1857	spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
1858	list_del(&evt_struct->list);
1859	free_event_struct(&evt_struct->hostdata->pool, evt_struct);
1860	spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
1861}
1862
1863/**
1864 * ibmvscsi_sdev_configure: Set the "allow_restart" flag for each disk.
1865 * @sdev:	struct scsi_device device to configure
1866 * @lim:	Request queue limits
1867 *
1868 * Enable allow_restart for a device if it is a disk.  Adjust the
1869 * queue_depth here also as is required by the documentation for
1870 * struct scsi_host_template.
1871 */
1872static int ibmvscsi_sdev_configure(struct scsi_device *sdev,
1873				   struct queue_limits *lim)
1874{
1875	struct Scsi_Host *shost = sdev->host;
1876	unsigned long lock_flags = 0;
1877
1878	spin_lock_irqsave(shost->host_lock, lock_flags);
1879	if (sdev->type == TYPE_DISK) {
1880		sdev->allow_restart = 1;
1881		blk_queue_rq_timeout(sdev->request_queue, 120 * HZ);
1882	}
1883	spin_unlock_irqrestore(shost->host_lock, lock_flags);
1884	return 0;
1885}
1886
1887/**
1888 * ibmvscsi_change_queue_depth - Change the device's queue depth
1889 * @sdev:	scsi device struct
1890 * @qdepth:	depth to set
1891 *
1892 * Return value:
1893 * 	actual depth set
1894 **/
1895static int ibmvscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
1896{
1897	if (qdepth > IBMVSCSI_MAX_CMDS_PER_LUN)
1898		qdepth = IBMVSCSI_MAX_CMDS_PER_LUN;
1899	return scsi_change_queue_depth(sdev, qdepth);
1900}
1901
1902/* ------------------------------------------------------------
1903 * sysfs attributes
1904 */
1905static ssize_t show_host_vhost_loc(struct device *dev,
1906				   struct device_attribute *attr, char *buf)
1907{
1908	struct Scsi_Host *shost = class_to_shost(dev);
1909	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1910	int len;
1911
1912	len = snprintf(buf, sizeof(hostdata->caps.loc), "%s\n",
1913		       hostdata->caps.loc);
1914	return len;
1915}
1916
1917static struct device_attribute ibmvscsi_host_vhost_loc = {
1918	.attr = {
1919		 .name = "vhost_loc",
1920		 .mode = S_IRUGO,
1921		 },
1922	.show = show_host_vhost_loc,
1923};
1924
1925static ssize_t show_host_vhost_name(struct device *dev,
1926				    struct device_attribute *attr, char *buf)
1927{
1928	struct Scsi_Host *shost = class_to_shost(dev);
1929	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1930	int len;
1931
1932	len = snprintf(buf, sizeof(hostdata->caps.name), "%s\n",
1933		       hostdata->caps.name);
1934	return len;
1935}
1936
1937static struct device_attribute ibmvscsi_host_vhost_name = {
1938	.attr = {
1939		 .name = "vhost_name",
1940		 .mode = S_IRUGO,
1941		 },
1942	.show = show_host_vhost_name,
1943};
1944
1945static ssize_t show_host_srp_version(struct device *dev,
1946				     struct device_attribute *attr, char *buf)
1947{
1948	struct Scsi_Host *shost = class_to_shost(dev);
1949	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1950	int len;
1951
1952	len = snprintf(buf, PAGE_SIZE, "%s\n",
1953		       hostdata->madapter_info.srp_version);
1954	return len;
1955}
1956
1957static struct device_attribute ibmvscsi_host_srp_version = {
1958	.attr = {
1959		 .name = "srp_version",
1960		 .mode = S_IRUGO,
1961		 },
1962	.show = show_host_srp_version,
1963};
1964
1965static ssize_t show_host_partition_name(struct device *dev,
1966					struct device_attribute *attr,
1967					char *buf)
1968{
1969	struct Scsi_Host *shost = class_to_shost(dev);
1970	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1971	int len;
1972
1973	len = snprintf(buf, PAGE_SIZE, "%s\n",
1974		       hostdata->madapter_info.partition_name);
1975	return len;
1976}
1977
1978static struct device_attribute ibmvscsi_host_partition_name = {
1979	.attr = {
1980		 .name = "partition_name",
1981		 .mode = S_IRUGO,
1982		 },
1983	.show = show_host_partition_name,
1984};
1985
1986static ssize_t show_host_partition_number(struct device *dev,
1987					  struct device_attribute *attr,
1988					  char *buf)
1989{
1990	struct Scsi_Host *shost = class_to_shost(dev);
1991	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
1992	int len;
1993
1994	len = snprintf(buf, PAGE_SIZE, "%d\n",
1995		       be32_to_cpu(hostdata->madapter_info.partition_number));
1996	return len;
1997}
1998
1999static struct device_attribute ibmvscsi_host_partition_number = {
2000	.attr = {
2001		 .name = "partition_number",
2002		 .mode = S_IRUGO,
2003		 },
2004	.show = show_host_partition_number,
2005};
2006
2007static ssize_t show_host_mad_version(struct device *dev,
2008				     struct device_attribute *attr, char *buf)
2009{
2010	struct Scsi_Host *shost = class_to_shost(dev);
2011	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
2012	int len;
2013
2014	len = snprintf(buf, PAGE_SIZE, "%d\n",
2015		       be32_to_cpu(hostdata->madapter_info.mad_version));
2016	return len;
2017}
2018
2019static struct device_attribute ibmvscsi_host_mad_version = {
2020	.attr = {
2021		 .name = "mad_version",
2022		 .mode = S_IRUGO,
2023		 },
2024	.show = show_host_mad_version,
2025};
2026
2027static ssize_t show_host_os_type(struct device *dev,
2028				 struct device_attribute *attr, char *buf)
2029{
2030	struct Scsi_Host *shost = class_to_shost(dev);
2031	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
2032	int len;
2033
2034	len = snprintf(buf, PAGE_SIZE, "%d\n",
2035		       be32_to_cpu(hostdata->madapter_info.os_type));
2036	return len;
2037}
2038
2039static struct device_attribute ibmvscsi_host_os_type = {
2040	.attr = {
2041		 .name = "os_type",
2042		 .mode = S_IRUGO,
2043		 },
2044	.show = show_host_os_type,
2045};
2046
2047static ssize_t show_host_config(struct device *dev,
2048				struct device_attribute *attr, char *buf)
2049{
2050	return 0;
2051}
2052
2053static struct device_attribute ibmvscsi_host_config = {
2054	.attr = {
2055		.name = "config",
2056		.mode = S_IRUGO,
2057		},
2058	.show = show_host_config,
2059};
2060
2061static int ibmvscsi_host_reset(struct Scsi_Host *shost, int reset_type)
2062{
2063	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
2064
2065	dev_info(hostdata->dev, "Initiating adapter reset!\n");
2066	ibmvscsi_reset_host(hostdata);
2067
2068	return 0;
2069}
2070
2071static struct attribute *ibmvscsi_host_attrs[] = {
2072	&ibmvscsi_host_vhost_loc.attr,
2073	&ibmvscsi_host_vhost_name.attr,
2074	&ibmvscsi_host_srp_version.attr,
2075	&ibmvscsi_host_partition_name.attr,
2076	&ibmvscsi_host_partition_number.attr,
2077	&ibmvscsi_host_mad_version.attr,
2078	&ibmvscsi_host_os_type.attr,
2079	&ibmvscsi_host_config.attr,
2080	NULL
2081};
2082
2083ATTRIBUTE_GROUPS(ibmvscsi_host);
2084
2085/* ------------------------------------------------------------
2086 * SCSI driver registration
2087 */
2088static struct scsi_host_template driver_template = {
2089	.module = THIS_MODULE,
2090	.name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
2091	.proc_name = "ibmvscsi",
2092	.queuecommand = ibmvscsi_queuecommand,
2093	.eh_timed_out = srp_timed_out,
2094	.eh_abort_handler = ibmvscsi_eh_abort_handler,
2095	.eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
2096	.eh_host_reset_handler = ibmvscsi_eh_host_reset_handler,
2097	.sdev_configure = ibmvscsi_sdev_configure,
2098	.change_queue_depth = ibmvscsi_change_queue_depth,
2099	.host_reset = ibmvscsi_host_reset,
2100	.cmd_per_lun = IBMVSCSI_CMDS_PER_LUN_DEFAULT,
2101	.can_queue = IBMVSCSI_MAX_REQUESTS_DEFAULT,
2102	.this_id = -1,
2103	.sg_tablesize = SG_ALL,
2104	.shost_groups = ibmvscsi_host_groups,
2105};
2106
2107/**
2108 * ibmvscsi_get_desired_dma - Calculate IO memory desired by the driver
2109 *
2110 * @vdev: struct vio_dev for the device whose desired IO mem is to be returned
2111 *
2112 * Return value:
2113 *	Number of bytes of IO data the driver will need to perform well.
2114 */
2115static unsigned long ibmvscsi_get_desired_dma(struct vio_dev *vdev)
2116{
2117	/* iu_storage data allocated in initialize_event_pool */
2118	unsigned long desired_io = max_events * sizeof(union viosrp_iu);
2119
2120	/* add io space for sg data */
2121	desired_io += (IBMVSCSI_MAX_SECTORS_DEFAULT * 512 *
2122	                     IBMVSCSI_CMDS_PER_LUN_DEFAULT);
2123
2124	return desired_io;
2125}
2126
2127static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata)
2128{
2129	unsigned long flags;
2130	int rc;
2131	char *action = "reset";
2132
2133	spin_lock_irqsave(hostdata->host->host_lock, flags);
2134	switch (hostdata->action) {
2135	case IBMVSCSI_HOST_ACTION_UNBLOCK:
2136		rc = 0;
2137		break;
2138	case IBMVSCSI_HOST_ACTION_RESET:
2139		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
2140		rc = ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
2141		spin_lock_irqsave(hostdata->host->host_lock, flags);
2142		if (!rc)
2143			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);
2144		vio_enable_interrupts(to_vio_dev(hostdata->dev));
2145		break;
2146	case IBMVSCSI_HOST_ACTION_REENABLE:
2147		action = "enable";
2148		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
2149		rc = ibmvscsi_reenable_crq_queue(&hostdata->queue, hostdata);
2150		spin_lock_irqsave(hostdata->host->host_lock, flags);
2151		if (!rc)
2152			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);
2153		break;
2154	case IBMVSCSI_HOST_ACTION_NONE:
2155	default:
2156		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
2157		return;
2158	}
2159
2160	hostdata->action = IBMVSCSI_HOST_ACTION_NONE;
2161	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
2162
2163	if (rc) {
2164		ibmvscsi_set_request_limit(hostdata, -1);
2165		dev_err(hostdata->dev, "error after %s\n", action);
2166	}
2167
2168	scsi_unblock_requests(hostdata->host);
2169}
2170
2171static int __ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)
2172{
2173	if (kthread_should_stop())
2174		return 1;
2175	switch (hostdata->action) {
2176	case IBMVSCSI_HOST_ACTION_NONE:
2177		return 0;
2178	case IBMVSCSI_HOST_ACTION_RESET:
2179	case IBMVSCSI_HOST_ACTION_REENABLE:
2180	case IBMVSCSI_HOST_ACTION_UNBLOCK:
2181	default:
2182		break;
2183	}
2184
2185	return 1;
2186}
2187
2188static int ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)
2189{
2190	unsigned long flags;
2191	int rc;
2192
2193	spin_lock_irqsave(hostdata->host->host_lock, flags);
2194	rc = __ibmvscsi_work_to_do(hostdata);
2195	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
2196
2197	return rc;
2198}
2199
2200static int ibmvscsi_work(void *data)
2201{
2202	struct ibmvscsi_host_data *hostdata = data;
2203	int rc;
2204
2205	set_user_nice(current, MIN_NICE);
2206
2207	while (1) {
2208		rc = wait_event_interruptible(hostdata->work_wait_q,
2209					      ibmvscsi_work_to_do(hostdata));
2210
2211		BUG_ON(rc);
2212
2213		if (kthread_should_stop())
2214			break;
2215
2216		ibmvscsi_do_work(hostdata);
2217	}
2218
2219	return 0;
2220}
2221
2222/*
2223 * Called by bus code for each adapter
2224 */
2225static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
2226{
2227	struct ibmvscsi_host_data *hostdata;
2228	struct Scsi_Host *host;
2229	struct device *dev = &vdev->dev;
2230	struct srp_rport_identifiers ids;
2231	struct srp_rport *rport;
2232	unsigned long wait_switch = 0;
2233	int rc;
2234
2235	dev_set_drvdata(&vdev->dev, NULL);
2236
2237	host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
2238	if (!host) {
2239		dev_err(&vdev->dev, "couldn't allocate host data\n");
2240		goto scsi_host_alloc_failed;
2241	}
2242
2243	host->transportt = ibmvscsi_transport_template;
2244	hostdata = shost_priv(host);
2245	memset(hostdata, 0x00, sizeof(*hostdata));
2246	INIT_LIST_HEAD(&hostdata->sent);
2247	init_waitqueue_head(&hostdata->work_wait_q);
2248	hostdata->host = host;
2249	hostdata->dev = dev;
2250	ibmvscsi_set_request_limit(hostdata, -1);
2251	hostdata->host->max_sectors = IBMVSCSI_MAX_SECTORS_DEFAULT;
2252
2253	if (map_persist_bufs(hostdata)) {
2254		dev_err(&vdev->dev, "couldn't map persistent buffers\n");
2255		goto persist_bufs_failed;
2256	}
2257
2258	hostdata->work_thread = kthread_run(ibmvscsi_work, hostdata, "%s_%d",
2259					    "ibmvscsi", host->host_no);
2260
2261	if (IS_ERR(hostdata->work_thread)) {
2262		dev_err(&vdev->dev, "couldn't initialize kthread. rc=%ld\n",
2263			PTR_ERR(hostdata->work_thread));
2264		goto init_crq_failed;
2265	}
2266
2267	rc = ibmvscsi_init_crq_queue(&hostdata->queue, hostdata, max_events);
2268	if (rc != 0 && rc != H_RESOURCE) {
2269		dev_err(&vdev->dev, "couldn't initialize crq. rc=%d\n", rc);
2270		goto kill_kthread;
2271	}
2272	if (initialize_event_pool(&hostdata->pool, max_events, hostdata) != 0) {
2273		dev_err(&vdev->dev, "couldn't initialize event pool\n");
2274		goto init_pool_failed;
2275	}
2276
2277	host->max_lun = IBMVSCSI_MAX_LUN;
2278	host->max_id = max_id;
2279	host->max_channel = max_channel;
2280	host->max_cmd_len = 16;
2281
2282	dev_info(dev,
2283		 "Maximum ID: %d Maximum LUN: %llu Maximum Channel: %d\n",
2284		 host->max_id, host->max_lun, host->max_channel);
2285
2286	if (scsi_add_host(hostdata->host, hostdata->dev))
2287		goto add_host_failed;
2288
2289	/* we don't have a proper target_port_id so let's use the fake one */
2290	memcpy(ids.port_id, hostdata->madapter_info.partition_name,
2291	       sizeof(ids.port_id));
2292	ids.roles = SRP_RPORT_ROLE_TARGET;
2293	rport = srp_rport_add(host, &ids);
2294	if (IS_ERR(rport))
2295		goto add_srp_port_failed;
2296
2297	/* Try to send an initialization message.  Note that this is allowed
2298	 * to fail if the other end is not acive.  In that case we don't
2299	 * want to scan
2300	 */
2301	if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0
2302	    || rc == H_RESOURCE) {
2303		/*
2304		 * Wait around max init_timeout secs for the adapter to finish
2305		 * initializing. When we are done initializing, we will have a
2306		 * valid request_limit.  We don't want Linux scanning before
2307		 * we are ready.
2308		 */
2309		for (wait_switch = jiffies + (init_timeout * HZ);
2310		     time_before(jiffies, wait_switch) &&
2311		     atomic_read(&hostdata->request_limit) < 2;) {
2312
2313			msleep(10);
2314		}
2315
2316		/* if we now have a valid request_limit, initiate a scan */
2317		if (atomic_read(&hostdata->request_limit) > 0)
2318			scsi_scan_host(host);
2319	}
2320
2321	dev_set_drvdata(&vdev->dev, hostdata);
2322	spin_lock(&ibmvscsi_driver_lock);
2323	list_add_tail(&hostdata->host_list, &ibmvscsi_head);
2324	spin_unlock(&ibmvscsi_driver_lock);
2325	return 0;
2326
2327      add_srp_port_failed:
2328	scsi_remove_host(hostdata->host);
2329      add_host_failed:
2330	release_event_pool(&hostdata->pool, hostdata);
2331      init_pool_failed:
2332	ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_events);
2333      kill_kthread:
2334      kthread_stop(hostdata->work_thread);
2335      init_crq_failed:
2336	unmap_persist_bufs(hostdata);
2337      persist_bufs_failed:
2338	scsi_host_put(host);
2339      scsi_host_alloc_failed:
2340	return -1;
2341}
2342
2343static void ibmvscsi_remove(struct vio_dev *vdev)
2344{
2345	struct ibmvscsi_host_data *hostdata = dev_get_drvdata(&vdev->dev);
2346
2347	srp_remove_host(hostdata->host);
2348	scsi_remove_host(hostdata->host);
2349
2350	purge_requests(hostdata, DID_ERROR);
2351	release_event_pool(&hostdata->pool, hostdata);
2352
2353	ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
2354					max_events);
2355
2356	kthread_stop(hostdata->work_thread);
2357	unmap_persist_bufs(hostdata);
2358
2359	spin_lock(&ibmvscsi_driver_lock);
2360	list_del(&hostdata->host_list);
2361	spin_unlock(&ibmvscsi_driver_lock);
2362
2363	scsi_host_put(hostdata->host);
2364}
2365
2366/**
2367 * ibmvscsi_resume: Resume from suspend
2368 * @dev:	device struct
2369 *
2370 * We may have lost an interrupt across suspend/resume, so kick the
2371 * interrupt handler
2372 */
2373static int ibmvscsi_resume(struct device *dev)
2374{
2375	struct ibmvscsi_host_data *hostdata = dev_get_drvdata(dev);
2376	vio_disable_interrupts(to_vio_dev(hostdata->dev));
2377	tasklet_schedule(&hostdata->srp_task);
2378
2379	return 0;
2380}
2381
2382/*
2383 * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we 
2384 * support.
2385 */
2386static const struct vio_device_id ibmvscsi_device_table[] = {
2387	{"vscsi", "IBM,v-scsi"},
2388	{ "", "" }
2389};
2390MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
2391
2392static const struct dev_pm_ops ibmvscsi_pm_ops = {
2393	.resume = ibmvscsi_resume
2394};
2395
2396static struct vio_driver ibmvscsi_driver = {
2397	.id_table = ibmvscsi_device_table,
2398	.probe = ibmvscsi_probe,
2399	.remove = ibmvscsi_remove,
2400	.get_desired_dma = ibmvscsi_get_desired_dma,
2401	.name = "ibmvscsi",
2402	.pm = &ibmvscsi_pm_ops,
2403};
2404
2405static struct srp_function_template ibmvscsi_transport_functions = {
2406};
2407
2408static int __init ibmvscsi_module_init(void)
2409{
2410	int ret;
2411
2412	/* Ensure we have two requests to do error recovery */
2413	driver_template.can_queue = max_requests;
2414	max_events = max_requests + 2;
2415
2416	if (!firmware_has_feature(FW_FEATURE_VIO))
2417		return -ENODEV;
2418
2419	ibmvscsi_transport_template =
2420		srp_attach_transport(&ibmvscsi_transport_functions);
2421	if (!ibmvscsi_transport_template)
2422		return -ENOMEM;
2423
2424	ret = vio_register_driver(&ibmvscsi_driver);
2425	if (ret)
2426		srp_release_transport(ibmvscsi_transport_template);
2427	return ret;
2428}
2429
2430static void __exit ibmvscsi_module_exit(void)
2431{
2432	vio_unregister_driver(&ibmvscsi_driver);
2433	srp_release_transport(ibmvscsi_transport_template);
2434}
2435
2436module_init(ibmvscsi_module_init);
2437module_exit(ibmvscsi_module_exit);