ib_srp.c 93.6 KB
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/*
 * Copyright (c) 2005 Cisco Systems.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/parser.h>
#include <linux/random.h>
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#include <linux/jiffies.h>
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#include <rdma/ib_cache.h>
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#include <linux/atomic.h>
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#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_dbg.h>
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#include <scsi/scsi_tcq.h>
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#include <scsi/srp.h>
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#include <scsi/scsi_transport_srp.h>
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#include "ib_srp.h"

#define DRV_NAME	"ib_srp"
#define PFX		DRV_NAME ": "
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#define DRV_VERSION	"1.0"
#define DRV_RELDATE	"July 1, 2013"
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MODULE_AUTHOR("Roland Dreier");
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MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator");
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MODULE_LICENSE("Dual BSD/GPL");
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MODULE_VERSION(DRV_VERSION);
MODULE_INFO(release_date, DRV_RELDATE);
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static unsigned int srp_sg_tablesize;
static unsigned int cmd_sg_entries;
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static unsigned int indirect_sg_entries;
static bool allow_ext_sg;
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static bool prefer_fr;
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static bool register_always;
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static int topspin_workarounds = 1;
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module_param(srp_sg_tablesize, uint, 0444);
MODULE_PARM_DESC(srp_sg_tablesize, "Deprecated name for cmd_sg_entries");
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module_param(cmd_sg_entries, uint, 0444);
MODULE_PARM_DESC(cmd_sg_entries,
		 "Default number of gather/scatter entries in the SRP command (default is 12, max 255)");
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module_param(indirect_sg_entries, uint, 0444);
MODULE_PARM_DESC(indirect_sg_entries,
		 "Default max number of gather/scatter entries (default is 12, max is " __stringify(SCSI_MAX_SG_CHAIN_SEGMENTS) ")");

module_param(allow_ext_sg, bool, 0444);
MODULE_PARM_DESC(allow_ext_sg,
		  "Default behavior when there are more than cmd_sg_entries S/G entries after mapping; fails the request when false (default false)");

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module_param(topspin_workarounds, int, 0444);
MODULE_PARM_DESC(topspin_workarounds,
		 "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");

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module_param(prefer_fr, bool, 0444);
MODULE_PARM_DESC(prefer_fr,
"Whether to use fast registration if both FMR and fast registration are supported");

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module_param(register_always, bool, 0444);
MODULE_PARM_DESC(register_always,
		 "Use memory registration even for contiguous memory regions");

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static const struct kernel_param_ops srp_tmo_ops;
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static int srp_reconnect_delay = 10;
module_param_cb(reconnect_delay, &srp_tmo_ops, &srp_reconnect_delay,
		S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(reconnect_delay, "Time between successive reconnect attempts");

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static int srp_fast_io_fail_tmo = 15;
module_param_cb(fast_io_fail_tmo, &srp_tmo_ops, &srp_fast_io_fail_tmo,
		S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(fast_io_fail_tmo,
		 "Number of seconds between the observation of a transport"
		 " layer error and failing all I/O. \"off\" means that this"
		 " functionality is disabled.");

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static int srp_dev_loss_tmo = 600;
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module_param_cb(dev_loss_tmo, &srp_tmo_ops, &srp_dev_loss_tmo,
		S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(dev_loss_tmo,
		 "Maximum number of seconds that the SRP transport should"
		 " insulate transport layer errors. After this time has been"
		 " exceeded the SCSI host is removed. Should be"
		 " between 1 and " __stringify(SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
		 " if fast_io_fail_tmo has not been set. \"off\" means that"
		 " this functionality is disabled.");

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static unsigned ch_count;
module_param(ch_count, uint, 0444);
MODULE_PARM_DESC(ch_count,
		 "Number of RDMA channels to use for communication with an SRP target. Using more than one channel improves performance if the HCA supports multiple completion vectors. The default value is the minimum of four times the number of online CPU sockets and the number of completion vectors supported by the HCA.");

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static void srp_add_one(struct ib_device *device);
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static void srp_remove_one(struct ib_device *device, void *client_data);
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static void srp_recv_completion(struct ib_cq *cq, void *ch_ptr);
static void srp_send_completion(struct ib_cq *cq, void *ch_ptr);
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static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);

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static struct scsi_transport_template *ib_srp_transport_template;
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static struct workqueue_struct *srp_remove_wq;
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static struct ib_client srp_client = {
	.name   = "srp",
	.add    = srp_add_one,
	.remove = srp_remove_one
};

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static struct ib_sa_client srp_sa_client;

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static int srp_tmo_get(char *buffer, const struct kernel_param *kp)
{
	int tmo = *(int *)kp->arg;

	if (tmo >= 0)
		return sprintf(buffer, "%d", tmo);
	else
		return sprintf(buffer, "off");
}

static int srp_tmo_set(const char *val, const struct kernel_param *kp)
{
	int tmo, res;

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	res = srp_parse_tmo(&tmo, val);
	if (res)
		goto out;

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	if (kp->arg == &srp_reconnect_delay)
		res = srp_tmo_valid(tmo, srp_fast_io_fail_tmo,
				    srp_dev_loss_tmo);
	else if (kp->arg == &srp_fast_io_fail_tmo)
		res = srp_tmo_valid(srp_reconnect_delay, tmo, srp_dev_loss_tmo);
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	else
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		res = srp_tmo_valid(srp_reconnect_delay, srp_fast_io_fail_tmo,
				    tmo);
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	if (res)
		goto out;
	*(int *)kp->arg = tmo;

out:
	return res;
}

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static const struct kernel_param_ops srp_tmo_ops = {
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	.get = srp_tmo_get,
	.set = srp_tmo_set,
};

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static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
{
	return (struct srp_target_port *) host->hostdata;
}

static const char *srp_target_info(struct Scsi_Host *host)
{
	return host_to_target(host)->target_name;
}

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static int srp_target_is_topspin(struct srp_target_port *target)
{
	static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
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	static const u8 cisco_oui[3]   = { 0x00, 0x1b, 0x0d };
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	return topspin_workarounds &&
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		(!memcmp(&target->ioc_guid, topspin_oui, sizeof topspin_oui) ||
		 !memcmp(&target->ioc_guid, cisco_oui, sizeof cisco_oui));
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}

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static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
				   gfp_t gfp_mask,
				   enum dma_data_direction direction)
{
	struct srp_iu *iu;

	iu = kmalloc(sizeof *iu, gfp_mask);
	if (!iu)
		goto out;

	iu->buf = kzalloc(size, gfp_mask);
	if (!iu->buf)
		goto out_free_iu;

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	iu->dma = ib_dma_map_single(host->srp_dev->dev, iu->buf, size,
				    direction);
	if (ib_dma_mapping_error(host->srp_dev->dev, iu->dma))
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		goto out_free_buf;

	iu->size      = size;
	iu->direction = direction;

	return iu;

out_free_buf:
	kfree(iu->buf);
out_free_iu:
	kfree(iu);
out:
	return NULL;
}

static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
{
	if (!iu)
		return;

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	ib_dma_unmap_single(host->srp_dev->dev, iu->dma, iu->size,
			    iu->direction);
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	kfree(iu->buf);
	kfree(iu);
}

static void srp_qp_event(struct ib_event *event, void *context)
{
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	pr_debug("QP event %s (%d)\n",
		 ib_event_msg(event->event), event->event);
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}

static int srp_init_qp(struct srp_target_port *target,
		       struct ib_qp *qp)
{
	struct ib_qp_attr *attr;
	int ret;

	attr = kmalloc(sizeof *attr, GFP_KERNEL);
	if (!attr)
		return -ENOMEM;

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	ret = ib_find_cached_pkey(target->srp_host->srp_dev->dev,
				  target->srp_host->port,
				  be16_to_cpu(target->pkey),
				  &attr->pkey_index);
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	if (ret)
		goto out;

	attr->qp_state        = IB_QPS_INIT;
	attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
				    IB_ACCESS_REMOTE_WRITE);
	attr->port_num        = target->srp_host->port;

	ret = ib_modify_qp(qp, attr,
			   IB_QP_STATE		|
			   IB_QP_PKEY_INDEX	|
			   IB_QP_ACCESS_FLAGS	|
			   IB_QP_PORT);

out:
	kfree(attr);
	return ret;
}

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static int srp_new_cm_id(struct srp_rdma_ch *ch)
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{
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	struct srp_target_port *target = ch->target;
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	struct ib_cm_id *new_cm_id;

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	new_cm_id = ib_create_cm_id(target->srp_host->srp_dev->dev,
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				    srp_cm_handler, ch);
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	if (IS_ERR(new_cm_id))
		return PTR_ERR(new_cm_id);

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	if (ch->cm_id)
		ib_destroy_cm_id(ch->cm_id);
	ch->cm_id = new_cm_id;
	ch->path.sgid = target->sgid;
	ch->path.dgid = target->orig_dgid;
	ch->path.pkey = target->pkey;
	ch->path.service_id = target->service_id;
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	return 0;
}

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static struct ib_fmr_pool *srp_alloc_fmr_pool(struct srp_target_port *target)
{
	struct srp_device *dev = target->srp_host->srp_dev;
	struct ib_fmr_pool_param fmr_param;

	memset(&fmr_param, 0, sizeof(fmr_param));
	fmr_param.pool_size	    = target->scsi_host->can_queue;
	fmr_param.dirty_watermark   = fmr_param.pool_size / 4;
	fmr_param.cache		    = 1;
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	fmr_param.max_pages_per_fmr = dev->max_pages_per_mr;
	fmr_param.page_shift	    = ilog2(dev->mr_page_size);
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	fmr_param.access	    = (IB_ACCESS_LOCAL_WRITE |
				       IB_ACCESS_REMOTE_WRITE |
				       IB_ACCESS_REMOTE_READ);

	return ib_create_fmr_pool(dev->pd, &fmr_param);
}

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/**
 * srp_destroy_fr_pool() - free the resources owned by a pool
 * @pool: Fast registration pool to be destroyed.
 */
static void srp_destroy_fr_pool(struct srp_fr_pool *pool)
{
	int i;
	struct srp_fr_desc *d;

	if (!pool)
		return;

	for (i = 0, d = &pool->desc[0]; i < pool->size; i++, d++) {
		if (d->frpl)
			ib_free_fast_reg_page_list(d->frpl);
		if (d->mr)
			ib_dereg_mr(d->mr);
	}
	kfree(pool);
}

/**
 * srp_create_fr_pool() - allocate and initialize a pool for fast registration
 * @device:            IB device to allocate fast registration descriptors for.
 * @pd:                Protection domain associated with the FR descriptors.
 * @pool_size:         Number of descriptors to allocate.
 * @max_page_list_len: Maximum fast registration work request page list length.
 */
static struct srp_fr_pool *srp_create_fr_pool(struct ib_device *device,
					      struct ib_pd *pd, int pool_size,
					      int max_page_list_len)
{
	struct srp_fr_pool *pool;
	struct srp_fr_desc *d;
	struct ib_mr *mr;
	struct ib_fast_reg_page_list *frpl;
	int i, ret = -EINVAL;

	if (pool_size <= 0)
		goto err;
	ret = -ENOMEM;
	pool = kzalloc(sizeof(struct srp_fr_pool) +
		       pool_size * sizeof(struct srp_fr_desc), GFP_KERNEL);
	if (!pool)
		goto err;
	pool->size = pool_size;
	pool->max_page_list_len = max_page_list_len;
	spin_lock_init(&pool->lock);
	INIT_LIST_HEAD(&pool->free_list);

	for (i = 0, d = &pool->desc[0]; i < pool->size; i++, d++) {
		mr = ib_alloc_fast_reg_mr(pd, max_page_list_len);
		if (IS_ERR(mr)) {
			ret = PTR_ERR(mr);
			goto destroy_pool;
		}
		d->mr = mr;
		frpl = ib_alloc_fast_reg_page_list(device, max_page_list_len);
		if (IS_ERR(frpl)) {
			ret = PTR_ERR(frpl);
			goto destroy_pool;
		}
		d->frpl = frpl;
		list_add_tail(&d->entry, &pool->free_list);
	}

out:
	return pool;

destroy_pool:
	srp_destroy_fr_pool(pool);

err:
	pool = ERR_PTR(ret);
	goto out;
}

/**
 * srp_fr_pool_get() - obtain a descriptor suitable for fast registration
 * @pool: Pool to obtain descriptor from.
 */
static struct srp_fr_desc *srp_fr_pool_get(struct srp_fr_pool *pool)
{
	struct srp_fr_desc *d = NULL;
	unsigned long flags;

	spin_lock_irqsave(&pool->lock, flags);
	if (!list_empty(&pool->free_list)) {
		d = list_first_entry(&pool->free_list, typeof(*d), entry);
		list_del(&d->entry);
	}
	spin_unlock_irqrestore(&pool->lock, flags);

	return d;
}

/**
 * srp_fr_pool_put() - put an FR descriptor back in the free list
 * @pool: Pool the descriptor was allocated from.
 * @desc: Pointer to an array of fast registration descriptor pointers.
 * @n:    Number of descriptors to put back.
 *
 * Note: The caller must already have queued an invalidation request for
 * desc->mr->rkey before calling this function.
 */
static void srp_fr_pool_put(struct srp_fr_pool *pool, struct srp_fr_desc **desc,
			    int n)
{
	unsigned long flags;
	int i;

	spin_lock_irqsave(&pool->lock, flags);
	for (i = 0; i < n; i++)
		list_add(&desc[i]->entry, &pool->free_list);
	spin_unlock_irqrestore(&pool->lock, flags);
}

static struct srp_fr_pool *srp_alloc_fr_pool(struct srp_target_port *target)
{
	struct srp_device *dev = target->srp_host->srp_dev;

	return srp_create_fr_pool(dev->dev, dev->pd,
				  target->scsi_host->can_queue,
				  dev->max_pages_per_mr);
}

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/**
 * srp_destroy_qp() - destroy an RDMA queue pair
 * @ch: SRP RDMA channel.
 *
 * Change a queue pair into the error state and wait until all receive
 * completions have been processed before destroying it. This avoids that
 * the receive completion handler can access the queue pair while it is
 * being destroyed.
 */
static void srp_destroy_qp(struct srp_rdma_ch *ch)
{
	static struct ib_qp_attr attr = { .qp_state = IB_QPS_ERR };
	static struct ib_recv_wr wr = { .wr_id = SRP_LAST_WR_ID };
	struct ib_recv_wr *bad_wr;
	int ret;

	/* Destroying a QP and reusing ch->done is only safe if not connected */
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	WARN_ON_ONCE(ch->connected);
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	ret = ib_modify_qp(ch->qp, &attr, IB_QP_STATE);
	WARN_ONCE(ret, "ib_cm_init_qp_attr() returned %d\n", ret);
	if (ret)
		goto out;

	init_completion(&ch->done);
	ret = ib_post_recv(ch->qp, &wr, &bad_wr);
	WARN_ONCE(ret, "ib_post_recv() returned %d\n", ret);
	if (ret == 0)
		wait_for_completion(&ch->done);

out:
	ib_destroy_qp(ch->qp);
}

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static int srp_create_ch_ib(struct srp_rdma_ch *ch)
491
{
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	struct srp_target_port *target = ch->target;
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	struct srp_device *dev = target->srp_host->srp_dev;
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	struct ib_qp_init_attr *init_attr;
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	struct ib_cq *recv_cq, *send_cq;
	struct ib_qp *qp;
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	struct ib_fmr_pool *fmr_pool = NULL;
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	struct srp_fr_pool *fr_pool = NULL;
	const int m = 1 + dev->use_fast_reg;
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	struct ib_cq_init_attr cq_attr = {};
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	int ret;

	init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
	if (!init_attr)
		return -ENOMEM;

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	/* + 1 for SRP_LAST_WR_ID */
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	cq_attr.cqe = target->queue_size + 1;
	cq_attr.comp_vector = ch->comp_vector;
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	recv_cq = ib_create_cq(dev->dev, srp_recv_completion, NULL, ch,
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			       &cq_attr);
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	if (IS_ERR(recv_cq)) {
		ret = PTR_ERR(recv_cq);
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		goto err;
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	}

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	cq_attr.cqe = m * target->queue_size;
	cq_attr.comp_vector = ch->comp_vector;
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	send_cq = ib_create_cq(dev->dev, srp_send_completion, NULL, ch,
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			       &cq_attr);
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	if (IS_ERR(send_cq)) {
		ret = PTR_ERR(send_cq);
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		goto err_recv_cq;
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	}

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	ib_req_notify_cq(recv_cq, IB_CQ_NEXT_COMP);
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	init_attr->event_handler       = srp_qp_event;
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	init_attr->cap.max_send_wr     = m * target->queue_size;
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	init_attr->cap.max_recv_wr     = target->queue_size + 1;
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	init_attr->cap.max_recv_sge    = 1;
	init_attr->cap.max_send_sge    = 1;
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	init_attr->sq_sig_type         = IB_SIGNAL_REQ_WR;
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	init_attr->qp_type             = IB_QPT_RC;
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	init_attr->send_cq             = send_cq;
	init_attr->recv_cq             = recv_cq;
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	qp = ib_create_qp(dev->pd, init_attr);
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	if (IS_ERR(qp)) {
		ret = PTR_ERR(qp);
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		goto err_send_cq;
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	}

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	ret = srp_init_qp(target, qp);
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	if (ret)
		goto err_qp;
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	if (dev->use_fast_reg && dev->has_fr) {
		fr_pool = srp_alloc_fr_pool(target);
		if (IS_ERR(fr_pool)) {
			ret = PTR_ERR(fr_pool);
			shost_printk(KERN_WARNING, target->scsi_host, PFX
				     "FR pool allocation failed (%d)\n", ret);
			goto err_qp;
		}
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		if (ch->fr_pool)
			srp_destroy_fr_pool(ch->fr_pool);
		ch->fr_pool = fr_pool;
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	} else if (!dev->use_fast_reg && dev->has_fmr) {
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		fmr_pool = srp_alloc_fmr_pool(target);
		if (IS_ERR(fmr_pool)) {
			ret = PTR_ERR(fmr_pool);
			shost_printk(KERN_WARNING, target->scsi_host, PFX
				     "FMR pool allocation failed (%d)\n", ret);
			goto err_qp;
		}
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		if (ch->fmr_pool)
			ib_destroy_fmr_pool(ch->fmr_pool);
		ch->fmr_pool = fmr_pool;
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	}

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	if (ch->qp)
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		srp_destroy_qp(ch);
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	if (ch->recv_cq)
		ib_destroy_cq(ch->recv_cq);
	if (ch->send_cq)
		ib_destroy_cq(ch->send_cq);
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	ch->qp = qp;
	ch->recv_cq = recv_cq;
	ch->send_cq = send_cq;
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	kfree(init_attr);
	return 0;

err_qp:
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	ib_destroy_qp(qp);
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err_send_cq:
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	ib_destroy_cq(send_cq);
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err_recv_cq:
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	ib_destroy_cq(recv_cq);
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err:
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	kfree(init_attr);
	return ret;
}

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/*
 * Note: this function may be called without srp_alloc_iu_bufs() having been
602
 * invoked. Hence the ch->[rt]x_ring checks.
603
 */
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static void srp_free_ch_ib(struct srp_target_port *target,
			   struct srp_rdma_ch *ch)
606
{
607
	struct srp_device *dev = target->srp_host->srp_dev;
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	int i;

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Bart Van Assche 已提交
610 611 612
	if (!ch->target)
		return;

613 614 615
	if (ch->cm_id) {
		ib_destroy_cm_id(ch->cm_id);
		ch->cm_id = NULL;
616 617
	}

B
Bart Van Assche 已提交
618 619 620 621
	/* If srp_new_cm_id() succeeded but srp_create_ch_ib() not, return. */
	if (!ch->qp)
		return;

622
	if (dev->use_fast_reg) {
623 624
		if (ch->fr_pool)
			srp_destroy_fr_pool(ch->fr_pool);
625
	} else {
626 627
		if (ch->fmr_pool)
			ib_destroy_fmr_pool(ch->fmr_pool);
628
	}
629
	srp_destroy_qp(ch);
630 631
	ib_destroy_cq(ch->send_cq);
	ib_destroy_cq(ch->recv_cq);
632

B
Bart Van Assche 已提交
633 634 635 636 637 638 639 640
	/*
	 * Avoid that the SCSI error handler tries to use this channel after
	 * it has been freed. The SCSI error handler can namely continue
	 * trying to perform recovery actions after scsi_remove_host()
	 * returned.
	 */
	ch->target = NULL;

641 642
	ch->qp = NULL;
	ch->send_cq = ch->recv_cq = NULL;
643

644
	if (ch->rx_ring) {
645
		for (i = 0; i < target->queue_size; ++i)
646 647 648
			srp_free_iu(target->srp_host, ch->rx_ring[i]);
		kfree(ch->rx_ring);
		ch->rx_ring = NULL;
649
	}
650
	if (ch->tx_ring) {
651
		for (i = 0; i < target->queue_size; ++i)
652 653 654
			srp_free_iu(target->srp_host, ch->tx_ring[i]);
		kfree(ch->tx_ring);
		ch->tx_ring = NULL;
655
	}
656 657 658 659
}

static void srp_path_rec_completion(int status,
				    struct ib_sa_path_rec *pathrec,
660
				    void *ch_ptr)
661
{
662 663
	struct srp_rdma_ch *ch = ch_ptr;
	struct srp_target_port *target = ch->target;
664

665
	ch->status = status;
666
	if (status)
667 668
		shost_printk(KERN_ERR, target->scsi_host,
			     PFX "Got failed path rec status %d\n", status);
669
	else
670 671
		ch->path = *pathrec;
	complete(&ch->done);
672 673
}

674
static int srp_lookup_path(struct srp_rdma_ch *ch)
675
{
676
	struct srp_target_port *target = ch->target;
677 678
	int ret;

679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699
	ch->path.numb_path = 1;

	init_completion(&ch->done);

	ch->path_query_id = ib_sa_path_rec_get(&srp_sa_client,
					       target->srp_host->srp_dev->dev,
					       target->srp_host->port,
					       &ch->path,
					       IB_SA_PATH_REC_SERVICE_ID |
					       IB_SA_PATH_REC_DGID	 |
					       IB_SA_PATH_REC_SGID	 |
					       IB_SA_PATH_REC_NUMB_PATH	 |
					       IB_SA_PATH_REC_PKEY,
					       SRP_PATH_REC_TIMEOUT_MS,
					       GFP_KERNEL,
					       srp_path_rec_completion,
					       ch, &ch->path_query);
	if (ch->path_query_id < 0)
		return ch->path_query_id;

	ret = wait_for_completion_interruptible(&ch->done);
700 701
	if (ret < 0)
		return ret;
702

703
	if (ch->status < 0)
704 705
		shost_printk(KERN_WARNING, target->scsi_host,
			     PFX "Path record query failed\n");
706

707
	return ch->status;
708 709
}

B
Bart Van Assche 已提交
710
static int srp_send_req(struct srp_rdma_ch *ch, bool multich)
711
{
712
	struct srp_target_port *target = ch->target;
713 714 715 716 717 718 719 720 721 722
	struct {
		struct ib_cm_req_param param;
		struct srp_login_req   priv;
	} *req = NULL;
	int status;

	req = kzalloc(sizeof *req, GFP_KERNEL);
	if (!req)
		return -ENOMEM;

723
	req->param.primary_path		      = &ch->path;
724 725
	req->param.alternate_path 	      = NULL;
	req->param.service_id 		      = target->service_id;
726 727
	req->param.qp_num		      = ch->qp->qp_num;
	req->param.qp_type		      = ch->qp->qp_type;
728 729 730 731 732 733 734 735 736 737 738 739 740 741
	req->param.private_data 	      = &req->priv;
	req->param.private_data_len 	      = sizeof req->priv;
	req->param.flow_control 	      = 1;

	get_random_bytes(&req->param.starting_psn, 4);
	req->param.starting_psn 	     &= 0xffffff;

	/*
	 * Pick some arbitrary defaults here; we could make these
	 * module parameters if anyone cared about setting them.
	 */
	req->param.responder_resources	      = 4;
	req->param.remote_cm_response_timeout = 20;
	req->param.local_cm_response_timeout  = 20;
742
	req->param.retry_count                = target->tl_retry_count;
743 744 745 746 747
	req->param.rnr_retry_count 	      = 7;
	req->param.max_cm_retries 	      = 15;

	req->priv.opcode     	= SRP_LOGIN_REQ;
	req->priv.tag        	= 0;
748
	req->priv.req_it_iu_len = cpu_to_be32(target->max_iu_len);
749 750
	req->priv.req_buf_fmt 	= cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
					      SRP_BUF_FORMAT_INDIRECT);
B
Bart Van Assche 已提交
751 752
	req->priv.req_flags	= (multich ? SRP_MULTICHAN_MULTI :
				   SRP_MULTICHAN_SINGLE);
753
	/*
R
Roland Dreier 已提交
754
	 * In the published SRP specification (draft rev. 16a), the
755 756 757 758 759 760 761 762 763
	 * port identifier format is 8 bytes of ID extension followed
	 * by 8 bytes of GUID.  Older drafts put the two halves in the
	 * opposite order, so that the GUID comes first.
	 *
	 * Targets conforming to these obsolete drafts can be
	 * recognized by the I/O Class they report.
	 */
	if (target->io_class == SRP_REV10_IB_IO_CLASS) {
		memcpy(req->priv.initiator_port_id,
764
		       &target->sgid.global.interface_id, 8);
765
		memcpy(req->priv.initiator_port_id + 8,
766
		       &target->initiator_ext, 8);
767 768 769 770
		memcpy(req->priv.target_port_id,     &target->ioc_guid, 8);
		memcpy(req->priv.target_port_id + 8, &target->id_ext, 8);
	} else {
		memcpy(req->priv.initiator_port_id,
771 772
		       &target->initiator_ext, 8);
		memcpy(req->priv.initiator_port_id + 8,
773
		       &target->sgid.global.interface_id, 8);
774 775 776 777
		memcpy(req->priv.target_port_id,     &target->id_ext, 8);
		memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
	}

778 779
	/*
	 * Topspin/Cisco SRP targets will reject our login unless we
780 781
	 * zero out the first 8 bytes of our initiator port ID and set
	 * the second 8 bytes to the local node GUID.
782
	 */
783
	if (srp_target_is_topspin(target)) {
784 785 786
		shost_printk(KERN_DEBUG, target->scsi_host,
			     PFX "Topspin/Cisco initiator port ID workaround "
			     "activated for target GUID %016llx\n",
787
			     be64_to_cpu(target->ioc_guid));
788
		memset(req->priv.initiator_port_id, 0, 8);
789
		memcpy(req->priv.initiator_port_id + 8,
790
		       &target->srp_host->srp_dev->dev->node_guid, 8);
791 792
	}

793
	status = ib_send_cm_req(ch->cm_id, &req->param);
794 795 796 797 798 799

	kfree(req);

	return status;
}

800 801 802 803 804 805 806 807 808 809 810 811
static bool srp_queue_remove_work(struct srp_target_port *target)
{
	bool changed = false;

	spin_lock_irq(&target->lock);
	if (target->state != SRP_TARGET_REMOVED) {
		target->state = SRP_TARGET_REMOVED;
		changed = true;
	}
	spin_unlock_irq(&target->lock);

	if (changed)
812
		queue_work(srp_remove_wq, &target->remove_work);
813 814 815 816

	return changed;
}

817 818
static void srp_disconnect_target(struct srp_target_port *target)
{
B
Bart Van Assche 已提交
819 820
	struct srp_rdma_ch *ch;
	int i;
821

822
	/* XXX should send SRP_I_LOGOUT request */
823

824 825 826 827 828 829
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		ch->connected = false;
		if (ch->cm_id && ib_send_cm_dreq(ch->cm_id, NULL, 0)) {
			shost_printk(KERN_DEBUG, target->scsi_host,
				     PFX "Sending CM DREQ failed\n");
830
		}
831
	}
832 833
}

834 835
static void srp_free_req_data(struct srp_target_port *target,
			      struct srp_rdma_ch *ch)
836
{
837 838
	struct srp_device *dev = target->srp_host->srp_dev;
	struct ib_device *ibdev = dev->dev;
839 840 841
	struct srp_request *req;
	int i;

842
	if (!ch->req_ring)
843 844 845
		return;

	for (i = 0; i < target->req_ring_size; ++i) {
846
		req = &ch->req_ring[i];
847 848 849 850
		if (dev->use_fast_reg)
			kfree(req->fr_list);
		else
			kfree(req->fmr_list);
851
		kfree(req->map_page);
852 853 854 855 856 857
		if (req->indirect_dma_addr) {
			ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
					    target->indirect_size,
					    DMA_TO_DEVICE);
		}
		kfree(req->indirect_desc);
858
	}
859

860 861
	kfree(ch->req_ring);
	ch->req_ring = NULL;
862 863
}

864
static int srp_alloc_req_data(struct srp_rdma_ch *ch)
865
{
866
	struct srp_target_port *target = ch->target;
867 868 869
	struct srp_device *srp_dev = target->srp_host->srp_dev;
	struct ib_device *ibdev = srp_dev->dev;
	struct srp_request *req;
870
	void *mr_list;
871 872 873
	dma_addr_t dma_addr;
	int i, ret = -ENOMEM;

874 875 876
	ch->req_ring = kcalloc(target->req_ring_size, sizeof(*ch->req_ring),
			       GFP_KERNEL);
	if (!ch->req_ring)
877 878 879
		goto out;

	for (i = 0; i < target->req_ring_size; ++i) {
880
		req = &ch->req_ring[i];
881 882 883 884 885 886 887 888
		mr_list = kmalloc(target->cmd_sg_cnt * sizeof(void *),
				  GFP_KERNEL);
		if (!mr_list)
			goto out;
		if (srp_dev->use_fast_reg)
			req->fr_list = mr_list;
		else
			req->fmr_list = mr_list;
889
		req->map_page = kmalloc(srp_dev->max_pages_per_mr *
890
					sizeof(void *), GFP_KERNEL);
891 892
		if (!req->map_page)
			goto out;
893
		req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
894
		if (!req->indirect_desc)
895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910
			goto out;

		dma_addr = ib_dma_map_single(ibdev, req->indirect_desc,
					     target->indirect_size,
					     DMA_TO_DEVICE);
		if (ib_dma_mapping_error(ibdev, dma_addr))
			goto out;

		req->indirect_dma_addr = dma_addr;
	}
	ret = 0;

out:
	return ret;
}

911 912 913 914 915 916 917 918 919 920 921 922 923 924 925
/**
 * srp_del_scsi_host_attr() - Remove attributes defined in the host template.
 * @shost: SCSI host whose attributes to remove from sysfs.
 *
 * Note: Any attributes defined in the host template and that did not exist
 * before invocation of this function will be ignored.
 */
static void srp_del_scsi_host_attr(struct Scsi_Host *shost)
{
	struct device_attribute **attr;

	for (attr = shost->hostt->shost_attrs; attr && *attr; ++attr)
		device_remove_file(&shost->shost_dev, *attr);
}

926 927
static void srp_remove_target(struct srp_target_port *target)
{
B
Bart Van Assche 已提交
928 929
	struct srp_rdma_ch *ch;
	int i;
930

931 932
	WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);

933
	srp_del_scsi_host_attr(target->scsi_host);
934
	srp_rport_get(target->rport);
935 936
	srp_remove_host(target->scsi_host);
	scsi_remove_host(target->scsi_host);
937
	srp_stop_rport_timers(target->rport);
938
	srp_disconnect_target(target);
B
Bart Van Assche 已提交
939 940 941 942
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		srp_free_ch_ib(target, ch);
	}
943
	cancel_work_sync(&target->tl_err_work);
944
	srp_rport_put(target->rport);
B
Bart Van Assche 已提交
945 946 947 948 949 950
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		srp_free_req_data(target, ch);
	}
	kfree(target->ch);
	target->ch = NULL;
951 952 953 954 955

	spin_lock(&target->srp_host->target_lock);
	list_del(&target->list);
	spin_unlock(&target->srp_host->target_lock);

956 957 958
	scsi_host_put(target->scsi_host);
}

D
David Howells 已提交
959
static void srp_remove_work(struct work_struct *work)
960
{
D
David Howells 已提交
961
	struct srp_target_port *target =
962
		container_of(work, struct srp_target_port, remove_work);
963

964
	WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);
965

966
	srp_remove_target(target);
967 968
}

969 970 971 972 973 974 975
static void srp_rport_delete(struct srp_rport *rport)
{
	struct srp_target_port *target = rport->lld_data;

	srp_queue_remove_work(target);
}

976 977 978 979 980 981 982 983 984 985 986 987 988 989
/**
 * srp_connected_ch() - number of connected channels
 * @target: SRP target port.
 */
static int srp_connected_ch(struct srp_target_port *target)
{
	int i, c = 0;

	for (i = 0; i < target->ch_count; i++)
		c += target->ch[i].connected;

	return c;
}

B
Bart Van Assche 已提交
990
static int srp_connect_ch(struct srp_rdma_ch *ch, bool multich)
991
{
992
	struct srp_target_port *target = ch->target;
993 994
	int ret;

995
	WARN_ON_ONCE(!multich && srp_connected_ch(target) > 0);
996

997
	ret = srp_lookup_path(ch);
998 999 1000 1001
	if (ret)
		return ret;

	while (1) {
1002
		init_completion(&ch->done);
B
Bart Van Assche 已提交
1003
		ret = srp_send_req(ch, multich);
1004 1005
		if (ret)
			return ret;
1006
		ret = wait_for_completion_interruptible(&ch->done);
1007 1008
		if (ret < 0)
			return ret;
1009 1010 1011 1012 1013 1014 1015

		/*
		 * The CM event handling code will set status to
		 * SRP_PORT_REDIRECT if we get a port redirect REJ
		 * back, or SRP_DLID_REDIRECT if we get a lid/qp
		 * redirect REJ back.
		 */
1016
		switch (ch->status) {
1017
		case 0:
1018
			ch->connected = true;
1019 1020 1021
			return 0;

		case SRP_PORT_REDIRECT:
1022
			ret = srp_lookup_path(ch);
1023 1024 1025 1026 1027 1028 1029
			if (ret)
				return ret;
			break;

		case SRP_DLID_REDIRECT:
			break;

D
David Dillow 已提交
1030 1031
		case SRP_STALE_CONN:
			shost_printk(KERN_ERR, target->scsi_host, PFX
1032
				     "giving up on stale connection\n");
1033 1034
			ch->status = -ECONNRESET;
			return ch->status;
D
David Dillow 已提交
1035

1036
		default:
1037
			return ch->status;
1038 1039 1040 1041
		}
	}
}

1042
static int srp_inv_rkey(struct srp_rdma_ch *ch, u32 rkey)
1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053
{
	struct ib_send_wr *bad_wr;
	struct ib_send_wr wr = {
		.opcode		    = IB_WR_LOCAL_INV,
		.wr_id		    = LOCAL_INV_WR_ID_MASK,
		.next		    = NULL,
		.num_sge	    = 0,
		.send_flags	    = 0,
		.ex.invalidate_rkey = rkey,
	};

1054
	return ib_post_send(ch->qp, &wr, &bad_wr);
1055 1056
}

1057
static void srp_unmap_data(struct scsi_cmnd *scmnd,
1058
			   struct srp_rdma_ch *ch,
1059 1060
			   struct srp_request *req)
{
1061
	struct srp_target_port *target = ch->target;
1062 1063 1064
	struct srp_device *dev = target->srp_host->srp_dev;
	struct ib_device *ibdev = dev->dev;
	int i, res;
1065

1066
	if (!scsi_sglist(scmnd) ||
1067 1068 1069 1070
	    (scmnd->sc_data_direction != DMA_TO_DEVICE &&
	     scmnd->sc_data_direction != DMA_FROM_DEVICE))
		return;

1071 1072 1073 1074
	if (dev->use_fast_reg) {
		struct srp_fr_desc **pfr;

		for (i = req->nmdesc, pfr = req->fr_list; i > 0; i--, pfr++) {
1075
			res = srp_inv_rkey(ch, (*pfr)->mr->rkey);
1076 1077 1078 1079 1080 1081 1082 1083 1084
			if (res < 0) {
				shost_printk(KERN_ERR, target->scsi_host, PFX
				  "Queueing INV WR for rkey %#x failed (%d)\n",
				  (*pfr)->mr->rkey, res);
				queue_work(system_long_wq,
					   &target->tl_err_work);
			}
		}
		if (req->nmdesc)
1085
			srp_fr_pool_put(ch->fr_pool, req->fr_list,
1086 1087 1088 1089 1090 1091 1092
					req->nmdesc);
	} else {
		struct ib_pool_fmr **pfmr;

		for (i = req->nmdesc, pfmr = req->fmr_list; i > 0; i--, pfmr++)
			ib_fmr_pool_unmap(*pfmr);
	}
1093

1094 1095
	ib_dma_unmap_sg(ibdev, scsi_sglist(scmnd), scsi_sg_count(scmnd),
			scmnd->sc_data_direction);
1096 1097
}

B
Bart Van Assche 已提交
1098 1099
/**
 * srp_claim_req - Take ownership of the scmnd associated with a request.
1100
 * @ch: SRP RDMA channel.
B
Bart Van Assche 已提交
1101
 * @req: SRP request.
1102
 * @sdev: If not NULL, only take ownership for this SCSI device.
B
Bart Van Assche 已提交
1103 1104 1105 1106 1107 1108
 * @scmnd: If NULL, take ownership of @req->scmnd. If not NULL, only take
 *         ownership of @req->scmnd if it equals @scmnd.
 *
 * Return value:
 * Either NULL or a pointer to the SCSI command the caller became owner of.
 */
1109
static struct scsi_cmnd *srp_claim_req(struct srp_rdma_ch *ch,
B
Bart Van Assche 已提交
1110
				       struct srp_request *req,
1111
				       struct scsi_device *sdev,
B
Bart Van Assche 已提交
1112 1113 1114 1115
				       struct scsi_cmnd *scmnd)
{
	unsigned long flags;

1116
	spin_lock_irqsave(&ch->lock, flags);
1117 1118 1119
	if (req->scmnd &&
	    (!sdev || req->scmnd->device == sdev) &&
	    (!scmnd || req->scmnd == scmnd)) {
B
Bart Van Assche 已提交
1120 1121 1122 1123 1124
		scmnd = req->scmnd;
		req->scmnd = NULL;
	} else {
		scmnd = NULL;
	}
1125
	spin_unlock_irqrestore(&ch->lock, flags);
B
Bart Van Assche 已提交
1126 1127 1128 1129 1130 1131

	return scmnd;
}

/**
 * srp_free_req() - Unmap data and add request to the free request list.
1132
 * @ch:     SRP RDMA channel.
1133 1134 1135
 * @req:    Request to be freed.
 * @scmnd:  SCSI command associated with @req.
 * @req_lim_delta: Amount to be added to @target->req_lim.
B
Bart Van Assche 已提交
1136
 */
1137 1138
static void srp_free_req(struct srp_rdma_ch *ch, struct srp_request *req,
			 struct scsi_cmnd *scmnd, s32 req_lim_delta)
1139
{
1140 1141
	unsigned long flags;

1142
	srp_unmap_data(scmnd, ch, req);
B
Bart Van Assche 已提交
1143

1144 1145 1146
	spin_lock_irqsave(&ch->lock, flags);
	ch->req_lim += req_lim_delta;
	spin_unlock_irqrestore(&ch->lock, flags);
1147 1148
}

1149 1150
static void srp_finish_req(struct srp_rdma_ch *ch, struct srp_request *req,
			   struct scsi_device *sdev, int result)
1151
{
1152
	struct scsi_cmnd *scmnd = srp_claim_req(ch, req, sdev, NULL);
B
Bart Van Assche 已提交
1153 1154

	if (scmnd) {
1155
		srp_free_req(ch, req, scmnd, 0);
1156
		scmnd->result = result;
B
Bart Van Assche 已提交
1157 1158
		scmnd->scsi_done(scmnd);
	}
1159 1160
}

1161
static void srp_terminate_io(struct srp_rport *rport)
1162
{
1163
	struct srp_target_port *target = rport->lld_data;
B
Bart Van Assche 已提交
1164
	struct srp_rdma_ch *ch;
1165 1166
	struct Scsi_Host *shost = target->scsi_host;
	struct scsi_device *sdev;
B
Bart Van Assche 已提交
1167
	int i, j;
1168

1169 1170 1171 1172 1173 1174 1175
	/*
	 * Invoking srp_terminate_io() while srp_queuecommand() is running
	 * is not safe. Hence the warning statement below.
	 */
	shost_for_each_device(sdev, shost)
		WARN_ON_ONCE(sdev->request_queue->request_fn_active);

B
Bart Van Assche 已提交
1176 1177
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
1178

B
Bart Van Assche 已提交
1179 1180 1181 1182 1183 1184
		for (j = 0; j < target->req_ring_size; ++j) {
			struct srp_request *req = &ch->req_ring[j];

			srp_finish_req(ch, req, NULL,
				       DID_TRANSPORT_FAILFAST << 16);
		}
1185 1186
	}
}
1187

1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199
/*
 * It is up to the caller to ensure that srp_rport_reconnect() calls are
 * serialized and that no concurrent srp_queuecommand(), srp_abort(),
 * srp_reset_device() or srp_reset_host() calls will occur while this function
 * is in progress. One way to realize that is not to call this function
 * directly but to call srp_reconnect_rport() instead since that last function
 * serializes calls of this function via rport->mutex and also blocks
 * srp_queuecommand() calls before invoking this function.
 */
static int srp_rport_reconnect(struct srp_rport *rport)
{
	struct srp_target_port *target = rport->lld_data;
B
Bart Van Assche 已提交
1200 1201 1202
	struct srp_rdma_ch *ch;
	int i, j, ret = 0;
	bool multich = false;
1203

1204
	srp_disconnect_target(target);
1205 1206 1207 1208

	if (target->state == SRP_TARGET_SCANNING)
		return -ENODEV;

1209
	/*
1210 1211 1212
	 * Now get a new local CM ID so that we avoid confusing the target in
	 * case things are really fouled up. Doing so also ensures that all CM
	 * callbacks will have finished before a new QP is allocated.
1213
	 */
B
Bart Van Assche 已提交
1214 1215 1216
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		ret += srp_new_cm_id(ch);
1217
	}
B
Bart Van Assche 已提交
1218 1219 1220 1221
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		for (j = 0; j < target->req_ring_size; ++j) {
			struct srp_request *req = &ch->req_ring[j];
1222

B
Bart Van Assche 已提交
1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233
			srp_finish_req(ch, req, NULL, DID_RESET << 16);
		}
	}
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		/*
		 * Whether or not creating a new CM ID succeeded, create a new
		 * QP. This guarantees that all completion callback function
		 * invocations have finished before request resetting starts.
		 */
		ret += srp_create_ch_ib(ch);
1234

B
Bart Van Assche 已提交
1235 1236 1237 1238
		INIT_LIST_HEAD(&ch->free_tx);
		for (j = 0; j < target->queue_size; ++j)
			list_add(&ch->tx_ring[j]->list, &ch->free_tx);
	}
1239 1240 1241

	target->qp_in_error = false;

B
Bart Van Assche 已提交
1242 1243
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
1244
		if (ret)
B
Bart Van Assche 已提交
1245 1246 1247 1248
			break;
		ret = srp_connect_ch(ch, multich);
		multich = true;
	}
1249

1250 1251 1252
	if (ret == 0)
		shost_printk(KERN_INFO, target->scsi_host,
			     PFX "reconnect succeeded\n");
1253 1254 1255 1256

	return ret;
}

1257 1258
static void srp_map_desc(struct srp_map_state *state, dma_addr_t dma_addr,
			 unsigned int dma_len, u32 rkey)
1259
{
1260
	struct srp_direct_buf *desc = state->desc;
1261

1262 1263 1264
	desc->va = cpu_to_be64(dma_addr);
	desc->key = cpu_to_be32(rkey);
	desc->len = cpu_to_be32(dma_len);
1265

1266 1267 1268 1269
	state->total_len += dma_len;
	state->desc++;
	state->ndesc++;
}
1270

1271
static int srp_map_finish_fmr(struct srp_map_state *state,
1272
			      struct srp_rdma_ch *ch)
1273 1274 1275
{
	struct ib_pool_fmr *fmr;
	u64 io_addr = 0;
1276

1277
	fmr = ib_fmr_pool_map_phys(ch->fmr_pool, state->pages,
1278 1279 1280
				   state->npages, io_addr);
	if (IS_ERR(fmr))
		return PTR_ERR(fmr);
1281

1282
	*state->next_fmr++ = fmr;
1283
	state->nmdesc++;
1284

1285
	srp_map_desc(state, 0, state->dma_len, fmr->fmr->rkey);
1286

1287 1288 1289
	return 0;
}

1290
static int srp_map_finish_fr(struct srp_map_state *state,
1291
			     struct srp_rdma_ch *ch)
1292
{
1293
	struct srp_target_port *target = ch->target;
1294 1295 1296 1297 1298 1299
	struct srp_device *dev = target->srp_host->srp_dev;
	struct ib_send_wr *bad_wr;
	struct ib_send_wr wr;
	struct srp_fr_desc *desc;
	u32 rkey;

1300
	desc = srp_fr_pool_get(ch->fr_pool);
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328
	if (!desc)
		return -ENOMEM;

	rkey = ib_inc_rkey(desc->mr->rkey);
	ib_update_fast_reg_key(desc->mr, rkey);

	memcpy(desc->frpl->page_list, state->pages,
	       sizeof(state->pages[0]) * state->npages);

	memset(&wr, 0, sizeof(wr));
	wr.opcode = IB_WR_FAST_REG_MR;
	wr.wr_id = FAST_REG_WR_ID_MASK;
	wr.wr.fast_reg.iova_start = state->base_dma_addr;
	wr.wr.fast_reg.page_list = desc->frpl;
	wr.wr.fast_reg.page_list_len = state->npages;
	wr.wr.fast_reg.page_shift = ilog2(dev->mr_page_size);
	wr.wr.fast_reg.length = state->dma_len;
	wr.wr.fast_reg.access_flags = (IB_ACCESS_LOCAL_WRITE |
				       IB_ACCESS_REMOTE_READ |
				       IB_ACCESS_REMOTE_WRITE);
	wr.wr.fast_reg.rkey = desc->mr->lkey;

	*state->next_fr++ = desc;
	state->nmdesc++;

	srp_map_desc(state, state->base_dma_addr, state->dma_len,
		     desc->mr->rkey);

1329
	return ib_post_send(ch->qp, &wr, &bad_wr);
1330 1331
}

1332
static int srp_finish_mapping(struct srp_map_state *state,
1333
			      struct srp_rdma_ch *ch)
1334
{
1335
	struct srp_target_port *target = ch->target;
1336 1337 1338 1339 1340
	int ret = 0;

	if (state->npages == 0)
		return 0;

1341
	if (state->npages == 1 && !register_always)
1342
		srp_map_desc(state, state->base_dma_addr, state->dma_len,
1343 1344
			     target->rkey);
	else
1345
		ret = target->srp_host->srp_dev->use_fast_reg ?
1346 1347
			srp_map_finish_fr(state, ch) :
			srp_map_finish_fmr(state, ch);
1348 1349 1350

	if (ret == 0) {
		state->npages = 0;
1351
		state->dma_len = 0;
1352 1353 1354 1355 1356
	}

	return ret;
}

1357 1358 1359 1360 1361 1362 1363 1364
static void srp_map_update_start(struct srp_map_state *state,
				 struct scatterlist *sg, int sg_index,
				 dma_addr_t dma_addr)
{
	state->unmapped_sg = sg;
	state->unmapped_index = sg_index;
	state->unmapped_addr = dma_addr;
}
1365

1366
static int srp_map_sg_entry(struct srp_map_state *state,
1367
			    struct srp_rdma_ch *ch,
1368
			    struct scatterlist *sg, int sg_index,
1369
			    bool use_mr)
1370
{
1371
	struct srp_target_port *target = ch->target;
1372 1373 1374 1375 1376 1377 1378 1379 1380 1381
	struct srp_device *dev = target->srp_host->srp_dev;
	struct ib_device *ibdev = dev->dev;
	dma_addr_t dma_addr = ib_sg_dma_address(ibdev, sg);
	unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
	unsigned int len;
	int ret;

	if (!dma_len)
		return 0;

1382 1383 1384 1385
	if (!use_mr) {
		/*
		 * Once we're in direct map mode for a request, we don't
		 * go back to FMR or FR mode, so no need to update anything
1386 1387 1388 1389
		 * other than the descriptor.
		 */
		srp_map_desc(state, dma_addr, dma_len, target->rkey);
		return 0;
1390
	}
1391

1392 1393 1394 1395 1396
	/*
	 * Since not all RDMA HW drivers support non-zero page offsets for
	 * FMR, if we start at an offset into a page, don't merge into the
	 * current FMR mapping. Finish it out, and use the kernel's MR for
	 * this sg entry.
1397
	 */
1398 1399
	if ((!dev->use_fast_reg && dma_addr & ~dev->mr_page_mask) ||
	    dma_len > dev->mr_max_size) {
1400
		ret = srp_finish_mapping(state, ch);
1401 1402 1403 1404 1405 1406
		if (ret)
			return ret;

		srp_map_desc(state, dma_addr, dma_len, target->rkey);
		srp_map_update_start(state, NULL, 0, 0);
		return 0;
1407 1408
	}

1409 1410 1411 1412 1413
	/*
	 * If this is the first sg that will be mapped via FMR or via FR, save
	 * our position. We need to know the first unmapped entry, its index,
	 * and the first unmapped address within that entry to be able to
	 * restart mapping after an error.
1414 1415 1416
	 */
	if (!state->unmapped_sg)
		srp_map_update_start(state, sg, sg_index, dma_addr);
1417

1418
	while (dma_len) {
1419 1420
		unsigned offset = dma_addr & ~dev->mr_page_mask;
		if (state->npages == dev->max_pages_per_mr || offset != 0) {
1421
			ret = srp_finish_mapping(state, ch);
1422 1423
			if (ret)
				return ret;
1424

1425 1426 1427
			srp_map_update_start(state, sg, sg_index, dma_addr);
		}

1428
		len = min_t(unsigned int, dma_len, dev->mr_page_size - offset);
1429

1430 1431
		if (!state->npages)
			state->base_dma_addr = dma_addr;
1432
		state->pages[state->npages++] = dma_addr & dev->mr_page_mask;
1433
		state->dma_len += len;
1434 1435 1436 1437
		dma_addr += len;
		dma_len -= len;
	}

1438 1439
	/*
	 * If the last entry of the MR wasn't a full page, then we need to
1440 1441 1442 1443
	 * close it out and start a new one -- we can only merge at page
	 * boundries.
	 */
	ret = 0;
1444
	if (len != dev->mr_page_size) {
1445
		ret = srp_finish_mapping(state, ch);
1446 1447 1448
		if (!ret)
			srp_map_update_start(state, NULL, 0, 0);
	}
1449 1450 1451
	return ret;
}

1452 1453 1454
static int srp_map_sg(struct srp_map_state *state, struct srp_rdma_ch *ch,
		      struct srp_request *req, struct scatterlist *scat,
		      int count)
1455
{
1456
	struct srp_target_port *target = ch->target;
1457 1458 1459
	struct srp_device *dev = target->srp_host->srp_dev;
	struct ib_device *ibdev = dev->dev;
	struct scatterlist *sg;
1460 1461
	int i;
	bool use_mr;
1462 1463 1464

	state->desc	= req->indirect_desc;
	state->pages	= req->map_page;
1465 1466
	if (dev->use_fast_reg) {
		state->next_fr = req->fr_list;
1467
		use_mr = !!ch->fr_pool;
1468 1469
	} else {
		state->next_fmr = req->fmr_list;
1470
		use_mr = !!ch->fmr_pool;
1471
	}
1472 1473

	for_each_sg(scat, sg, count, i) {
1474
		if (srp_map_sg_entry(state, ch, sg, i, use_mr)) {
1475 1476 1477 1478
			/*
			 * Memory registration failed, so backtrack to the
			 * first unmapped entry and continue on without using
			 * memory registration.
1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490
			 */
			dma_addr_t dma_addr;
			unsigned int dma_len;

backtrack:
			sg = state->unmapped_sg;
			i = state->unmapped_index;

			dma_addr = ib_sg_dma_address(ibdev, sg);
			dma_len = ib_sg_dma_len(ibdev, sg);
			dma_len -= (state->unmapped_addr - dma_addr);
			dma_addr = state->unmapped_addr;
1491
			use_mr = false;
1492 1493 1494 1495
			srp_map_desc(state, dma_addr, dma_len, target->rkey);
		}
	}

1496
	if (use_mr && srp_finish_mapping(state, ch))
1497 1498
		goto backtrack;

1499
	req->nmdesc = state->nmdesc;
1500 1501

	return 0;
1502 1503
}

1504
static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
1505 1506
			struct srp_request *req)
{
1507
	struct srp_target_port *target = ch->target;
1508
	struct scatterlist *scat;
1509
	struct srp_cmd *cmd = req->cmd->buf;
1510
	int len, nents, count;
1511 1512
	struct srp_device *dev;
	struct ib_device *ibdev;
1513 1514 1515 1516
	struct srp_map_state state;
	struct srp_indirect_buf *indirect_hdr;
	u32 table_len;
	u8 fmt;
1517

1518
	if (!scsi_sglist(scmnd) || scmnd->sc_data_direction == DMA_NONE)
1519 1520 1521 1522
		return sizeof (struct srp_cmd);

	if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
	    scmnd->sc_data_direction != DMA_TO_DEVICE) {
1523 1524 1525
		shost_printk(KERN_WARNING, target->scsi_host,
			     PFX "Unhandled data direction %d\n",
			     scmnd->sc_data_direction);
1526 1527 1528
		return -EINVAL;
	}

1529 1530
	nents = scsi_sg_count(scmnd);
	scat  = scsi_sglist(scmnd);
1531

1532
	dev = target->srp_host->srp_dev;
1533 1534 1535
	ibdev = dev->dev;

	count = ib_dma_map_sg(ibdev, scat, nents, scmnd->sc_data_direction);
1536 1537
	if (unlikely(count == 0))
		return -EIO;
1538 1539 1540

	fmt = SRP_DATA_DESC_DIRECT;
	len = sizeof (struct srp_cmd) +	sizeof (struct srp_direct_buf);
1541

1542
	if (count == 1 && !register_always) {
1543 1544 1545 1546 1547 1548
		/*
		 * The midlayer only generated a single gather/scatter
		 * entry, or DMA mapping coalesced everything to a
		 * single entry.  So a direct descriptor along with
		 * the DMA MR suffices.
		 */
1549
		struct srp_direct_buf *buf = (void *) cmd->add_data;
1550

1551
		buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));
1552
		buf->key = cpu_to_be32(target->rkey);
1553
		buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
1554

1555
		req->nmdesc = 0;
1556 1557 1558
		goto map_complete;
	}

1559 1560 1561
	/*
	 * We have more than one scatter/gather entry, so build our indirect
	 * descriptor table, trying to merge as many entries as we can.
1562 1563 1564
	 */
	indirect_hdr = (void *) cmd->add_data;

1565 1566 1567
	ib_dma_sync_single_for_cpu(ibdev, req->indirect_dma_addr,
				   target->indirect_size, DMA_TO_DEVICE);

1568
	memset(&state, 0, sizeof(state));
1569
	srp_map_sg(&state, ch, req, scat, count);
1570

1571 1572 1573 1574 1575
	/* We've mapped the request, now pull as much of the indirect
	 * descriptor table as we can into the command buffer. If this
	 * target is not using an external indirect table, we are
	 * guaranteed to fit into the command, as the SCSI layer won't
	 * give us more S/G entries than we allow.
1576 1577
	 */
	if (state.ndesc == 1) {
1578 1579
		/*
		 * Memory registration collapsed the sg-list into one entry,
1580 1581 1582
		 * so use a direct descriptor.
		 */
		struct srp_direct_buf *buf = (void *) cmd->add_data;
1583

1584
		*buf = req->indirect_desc[0];
1585
		goto map_complete;
1586 1587
	}

1588 1589 1590 1591 1592 1593 1594 1595
	if (unlikely(target->cmd_sg_cnt < state.ndesc &&
						!target->allow_ext_sg)) {
		shost_printk(KERN_ERR, target->scsi_host,
			     "Could not fit S/G list into SRP_CMD\n");
		return -EIO;
	}

	count = min(state.ndesc, target->cmd_sg_cnt);
1596 1597 1598 1599
	table_len = state.ndesc * sizeof (struct srp_direct_buf);

	fmt = SRP_DATA_DESC_INDIRECT;
	len = sizeof(struct srp_cmd) + sizeof (struct srp_indirect_buf);
1600
	len += count * sizeof (struct srp_direct_buf);
1601

1602 1603
	memcpy(indirect_hdr->desc_list, req->indirect_desc,
	       count * sizeof (struct srp_direct_buf));
1604

1605
	indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);
1606 1607 1608 1609 1610
	indirect_hdr->table_desc.key = cpu_to_be32(target->rkey);
	indirect_hdr->table_desc.len = cpu_to_be32(table_len);
	indirect_hdr->len = cpu_to_be32(state.total_len);

	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
1611
		cmd->data_out_desc_cnt = count;
1612
	else
1613 1614 1615 1616
		cmd->data_in_desc_cnt = count;

	ib_dma_sync_single_for_device(ibdev, req->indirect_dma_addr, table_len,
				      DMA_TO_DEVICE);
1617 1618

map_complete:
1619 1620 1621 1622 1623 1624 1625 1626
	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
		cmd->buf_fmt = fmt << 4;
	else
		cmd->buf_fmt = fmt;

	return len;
}

1627 1628 1629
/*
 * Return an IU and possible credit to the free pool
 */
1630
static void srp_put_tx_iu(struct srp_rdma_ch *ch, struct srp_iu *iu,
1631 1632 1633 1634
			  enum srp_iu_type iu_type)
{
	unsigned long flags;

1635 1636
	spin_lock_irqsave(&ch->lock, flags);
	list_add(&iu->list, &ch->free_tx);
1637
	if (iu_type != SRP_IU_RSP)
1638 1639
		++ch->req_lim;
	spin_unlock_irqrestore(&ch->lock, flags);
1640 1641
}

1642
/*
1643
 * Must be called with ch->lock held to protect req_lim and free_tx.
1644
 * If IU is not sent, it must be returned using srp_put_tx_iu().
1645 1646 1647 1648 1649 1650 1651 1652 1653 1654
 *
 * Note:
 * An upper limit for the number of allocated information units for each
 * request type is:
 * - SRP_IU_CMD: SRP_CMD_SQ_SIZE, since the SCSI mid-layer never queues
 *   more than Scsi_Host.can_queue requests.
 * - SRP_IU_TSK_MGMT: SRP_TSK_MGMT_SQ_SIZE.
 * - SRP_IU_RSP: 1, since a conforming SRP target never sends more than
 *   one unanswered SRP request to an initiator.
 */
1655
static struct srp_iu *__srp_get_tx_iu(struct srp_rdma_ch *ch,
1656 1657
				      enum srp_iu_type iu_type)
{
1658
	struct srp_target_port *target = ch->target;
1659 1660 1661
	s32 rsv = (iu_type == SRP_IU_TSK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;
	struct srp_iu *iu;

1662
	srp_send_completion(ch->send_cq, ch);
1663

1664
	if (list_empty(&ch->free_tx))
1665 1666 1667
		return NULL;

	/* Initiator responses to target requests do not consume credits */
1668
	if (iu_type != SRP_IU_RSP) {
1669
		if (ch->req_lim <= rsv) {
1670 1671 1672 1673
			++target->zero_req_lim;
			return NULL;
		}

1674
		--ch->req_lim;
1675 1676
	}

1677
	iu = list_first_entry(&ch->free_tx, struct srp_iu, list);
1678
	list_del(&iu->list);
1679 1680 1681
	return iu;
}

1682
static int srp_post_send(struct srp_rdma_ch *ch, struct srp_iu *iu, int len)
1683
{
1684
	struct srp_target_port *target = ch->target;
1685 1686 1687 1688 1689
	struct ib_sge list;
	struct ib_send_wr wr, *bad_wr;

	list.addr   = iu->dma;
	list.length = len;
1690
	list.lkey   = target->lkey;
1691 1692

	wr.next       = NULL;
1693
	wr.wr_id      = (uintptr_t) iu;
1694 1695 1696 1697 1698
	wr.sg_list    = &list;
	wr.num_sge    = 1;
	wr.opcode     = IB_WR_SEND;
	wr.send_flags = IB_SEND_SIGNALED;

1699
	return ib_post_send(ch->qp, &wr, &bad_wr);
1700 1701
}

1702
static int srp_post_recv(struct srp_rdma_ch *ch, struct srp_iu *iu)
1703
{
1704
	struct srp_target_port *target = ch->target;
1705
	struct ib_recv_wr wr, *bad_wr;
1706
	struct ib_sge list;
1707 1708 1709

	list.addr   = iu->dma;
	list.length = iu->size;
1710
	list.lkey   = target->lkey;
1711 1712

	wr.next     = NULL;
1713
	wr.wr_id    = (uintptr_t) iu;
1714 1715 1716
	wr.sg_list  = &list;
	wr.num_sge  = 1;

1717
	return ib_post_recv(ch->qp, &wr, &bad_wr);
1718 1719
}

1720
static void srp_process_rsp(struct srp_rdma_ch *ch, struct srp_rsp *rsp)
1721
{
1722
	struct srp_target_port *target = ch->target;
1723 1724 1725 1726 1727
	struct srp_request *req;
	struct scsi_cmnd *scmnd;
	unsigned long flags;

	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
1728 1729 1730
		spin_lock_irqsave(&ch->lock, flags);
		ch->req_lim += be32_to_cpu(rsp->req_lim_delta);
		spin_unlock_irqrestore(&ch->lock, flags);
1731

1732
		ch->tsk_mgmt_status = -1;
1733
		if (be32_to_cpu(rsp->resp_data_len) >= 4)
1734 1735
			ch->tsk_mgmt_status = rsp->data[3];
		complete(&ch->tsk_mgmt_done);
1736
	} else {
B
Bart Van Assche 已提交
1737 1738 1739 1740 1741
		scmnd = scsi_host_find_tag(target->scsi_host, rsp->tag);
		if (scmnd) {
			req = (void *)scmnd->host_scribble;
			scmnd = srp_claim_req(ch, req, NULL, scmnd);
		}
B
Bart Van Assche 已提交
1742
		if (!scmnd) {
1743
			shost_printk(KERN_ERR, target->scsi_host,
B
Bart Van Assche 已提交
1744 1745
				     "Null scmnd for RSP w/tag %#016llx received on ch %td / QP %#x\n",
				     rsp->tag, ch - target->ch, ch->qp->qp_num);
B
Bart Van Assche 已提交
1746

1747 1748 1749
			spin_lock_irqsave(&ch->lock, flags);
			ch->req_lim += be32_to_cpu(rsp->req_lim_delta);
			spin_unlock_irqrestore(&ch->lock, flags);
B
Bart Van Assche 已提交
1750 1751 1752

			return;
		}
1753 1754 1755 1756 1757 1758 1759 1760 1761
		scmnd->result = rsp->status;

		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
			memcpy(scmnd->sense_buffer, rsp->data +
			       be32_to_cpu(rsp->resp_data_len),
			       min_t(int, be32_to_cpu(rsp->sense_data_len),
				     SCSI_SENSE_BUFFERSIZE));
		}

B
Bart Van Assche 已提交
1762
		if (unlikely(rsp->flags & SRP_RSP_FLAG_DIUNDER))
1763
			scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt));
B
Bart Van Assche 已提交
1764 1765 1766 1767 1768 1769
		else if (unlikely(rsp->flags & SRP_RSP_FLAG_DIOVER))
			scsi_set_resid(scmnd, -be32_to_cpu(rsp->data_in_res_cnt));
		else if (unlikely(rsp->flags & SRP_RSP_FLAG_DOUNDER))
			scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
		else if (unlikely(rsp->flags & SRP_RSP_FLAG_DOOVER))
			scsi_set_resid(scmnd, -be32_to_cpu(rsp->data_out_res_cnt));
1770

1771
		srp_free_req(ch, req, scmnd,
B
Bart Van Assche 已提交
1772 1773
			     be32_to_cpu(rsp->req_lim_delta));

1774 1775
		scmnd->host_scribble = NULL;
		scmnd->scsi_done(scmnd);
1776 1777 1778
	}
}

1779
static int srp_response_common(struct srp_rdma_ch *ch, s32 req_delta,
1780 1781
			       void *rsp, int len)
{
1782
	struct srp_target_port *target = ch->target;
1783
	struct ib_device *dev = target->srp_host->srp_dev->dev;
1784 1785
	unsigned long flags;
	struct srp_iu *iu;
1786
	int err;
1787

1788 1789 1790 1791
	spin_lock_irqsave(&ch->lock, flags);
	ch->req_lim += req_delta;
	iu = __srp_get_tx_iu(ch, SRP_IU_RSP);
	spin_unlock_irqrestore(&ch->lock, flags);
1792

1793 1794 1795
	if (!iu) {
		shost_printk(KERN_ERR, target->scsi_host, PFX
			     "no IU available to send response\n");
1796
		return 1;
1797 1798 1799 1800 1801 1802
	}

	ib_dma_sync_single_for_cpu(dev, iu->dma, len, DMA_TO_DEVICE);
	memcpy(iu->buf, rsp, len);
	ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);

1803
	err = srp_post_send(ch, iu, len);
1804
	if (err) {
1805 1806
		shost_printk(KERN_ERR, target->scsi_host, PFX
			     "unable to post response: %d\n", err);
1807
		srp_put_tx_iu(ch, iu, SRP_IU_RSP);
1808
	}
1809 1810 1811 1812

	return err;
}

1813
static void srp_process_cred_req(struct srp_rdma_ch *ch,
1814 1815 1816 1817 1818 1819 1820 1821
				 struct srp_cred_req *req)
{
	struct srp_cred_rsp rsp = {
		.opcode = SRP_CRED_RSP,
		.tag = req->tag,
	};
	s32 delta = be32_to_cpu(req->req_lim_delta);

1822 1823
	if (srp_response_common(ch, delta, &rsp, sizeof(rsp)))
		shost_printk(KERN_ERR, ch->target->scsi_host, PFX
1824 1825 1826
			     "problems processing SRP_CRED_REQ\n");
}

1827
static void srp_process_aer_req(struct srp_rdma_ch *ch,
1828 1829
				struct srp_aer_req *req)
{
1830
	struct srp_target_port *target = ch->target;
1831 1832 1833 1834 1835 1836 1837
	struct srp_aer_rsp rsp = {
		.opcode = SRP_AER_RSP,
		.tag = req->tag,
	};
	s32 delta = be32_to_cpu(req->req_lim_delta);

	shost_printk(KERN_ERR, target->scsi_host, PFX
B
Bart Van Assche 已提交
1838
		     "ignoring AER for LUN %llu\n", scsilun_to_int(&req->lun));
1839

1840
	if (srp_response_common(ch, delta, &rsp, sizeof(rsp)))
1841 1842 1843 1844
		shost_printk(KERN_ERR, target->scsi_host, PFX
			     "problems processing SRP_AER_REQ\n");
}

1845
static void srp_handle_recv(struct srp_rdma_ch *ch, struct ib_wc *wc)
1846
{
1847
	struct srp_target_port *target = ch->target;
1848
	struct ib_device *dev = target->srp_host->srp_dev->dev;
1849
	struct srp_iu *iu = (struct srp_iu *) (uintptr_t) wc->wr_id;
1850
	int res;
1851 1852
	u8 opcode;

1853
	ib_dma_sync_single_for_cpu(dev, iu->dma, ch->max_ti_iu_len,
1854
				   DMA_FROM_DEVICE);
1855 1856 1857 1858

	opcode = *(u8 *) iu->buf;

	if (0) {
1859 1860
		shost_printk(KERN_ERR, target->scsi_host,
			     PFX "recv completion, opcode 0x%02x\n", opcode);
B
Bart Van Assche 已提交
1861 1862
		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 8, 1,
			       iu->buf, wc->byte_len, true);
1863 1864 1865 1866
	}

	switch (opcode) {
	case SRP_RSP:
1867
		srp_process_rsp(ch, iu->buf);
1868 1869
		break;

1870
	case SRP_CRED_REQ:
1871
		srp_process_cred_req(ch, iu->buf);
1872 1873 1874
		break;

	case SRP_AER_REQ:
1875
		srp_process_aer_req(ch, iu->buf);
1876 1877
		break;

1878 1879
	case SRP_T_LOGOUT:
		/* XXX Handle target logout */
1880 1881
		shost_printk(KERN_WARNING, target->scsi_host,
			     PFX "Got target logout request\n");
1882 1883 1884
		break;

	default:
1885 1886
		shost_printk(KERN_WARNING, target->scsi_host,
			     PFX "Unhandled SRP opcode 0x%02x\n", opcode);
1887 1888 1889
		break;
	}

1890
	ib_dma_sync_single_for_device(dev, iu->dma, ch->max_ti_iu_len,
1891
				      DMA_FROM_DEVICE);
1892

1893
	res = srp_post_recv(ch, iu);
1894 1895 1896
	if (res != 0)
		shost_printk(KERN_ERR, target->scsi_host,
			     PFX "Recv failed with error code %d\n", res);
1897 1898
}

1899 1900
/**
 * srp_tl_err_work() - handle a transport layer error
1901
 * @work: Work structure embedded in an SRP target port.
1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914
 *
 * Note: This function may get invoked before the rport has been created,
 * hence the target->rport test.
 */
static void srp_tl_err_work(struct work_struct *work)
{
	struct srp_target_port *target;

	target = container_of(work, struct srp_target_port, tl_err_work);
	if (target->rport)
		srp_start_tl_fail_timers(target->rport);
}

1915
static void srp_handle_qp_err(u64 wr_id, enum ib_wc_status wc_status,
1916
			      bool send_err, struct srp_rdma_ch *ch)
1917
{
1918 1919 1920 1921 1922 1923 1924
	struct srp_target_port *target = ch->target;

	if (wr_id == SRP_LAST_WR_ID) {
		complete(&ch->done);
		return;
	}

1925
	if (ch->connected && !target->qp_in_error) {
1926 1927
		if (wr_id & LOCAL_INV_WR_ID_MASK) {
			shost_printk(KERN_ERR, target->scsi_host, PFX
1928 1929
				     "LOCAL_INV failed with status %s (%d)\n",
				     ib_wc_status_msg(wc_status), wc_status);
1930 1931
		} else if (wr_id & FAST_REG_WR_ID_MASK) {
			shost_printk(KERN_ERR, target->scsi_host, PFX
1932 1933
				     "FAST_REG_MR failed status %s (%d)\n",
				     ib_wc_status_msg(wc_status), wc_status);
1934 1935
		} else {
			shost_printk(KERN_ERR, target->scsi_host,
1936
				     PFX "failed %s status %s (%d) for iu %p\n",
1937
				     send_err ? "send" : "receive",
1938 1939
				     ib_wc_status_msg(wc_status), wc_status,
				     (void *)(uintptr_t)wr_id);
1940
		}
1941
		queue_work(system_long_wq, &target->tl_err_work);
1942
	}
1943 1944 1945
	target->qp_in_error = true;
}

1946
static void srp_recv_completion(struct ib_cq *cq, void *ch_ptr)
1947
{
1948
	struct srp_rdma_ch *ch = ch_ptr;
1949 1950 1951 1952
	struct ib_wc wc;

	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
	while (ib_poll_cq(cq, 1, &wc) > 0) {
1953
		if (likely(wc.status == IB_WC_SUCCESS)) {
1954
			srp_handle_recv(ch, &wc);
1955
		} else {
1956
			srp_handle_qp_err(wc.wr_id, wc.status, false, ch);
1957
		}
1958 1959 1960
	}
}

1961
static void srp_send_completion(struct ib_cq *cq, void *ch_ptr)
1962
{
1963
	struct srp_rdma_ch *ch = ch_ptr;
1964
	struct ib_wc wc;
1965
	struct srp_iu *iu;
1966 1967

	while (ib_poll_cq(cq, 1, &wc) > 0) {
1968 1969
		if (likely(wc.status == IB_WC_SUCCESS)) {
			iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
1970
			list_add(&iu->list, &ch->free_tx);
1971
		} else {
1972
			srp_handle_qp_err(wc.wr_id, wc.status, true, ch);
1973
		}
1974 1975 1976
	}
}

1977
static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
1978
{
1979
	struct srp_target_port *target = host_to_target(shost);
1980
	struct srp_rport *rport = target->rport;
1981
	struct srp_rdma_ch *ch;
1982 1983 1984
	struct srp_request *req;
	struct srp_iu *iu;
	struct srp_cmd *cmd;
1985
	struct ib_device *dev;
1986
	unsigned long flags;
B
Bart Van Assche 已提交
1987 1988
	u32 tag;
	u16 idx;
1989
	int len, ret;
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
	const bool in_scsi_eh = !in_interrupt() && current == shost->ehandler;

	/*
	 * The SCSI EH thread is the only context from which srp_queuecommand()
	 * can get invoked for blocked devices (SDEV_BLOCK /
	 * SDEV_CREATED_BLOCK). Avoid racing with srp_reconnect_rport() by
	 * locking the rport mutex if invoked from inside the SCSI EH.
	 */
	if (in_scsi_eh)
		mutex_lock(&rport->mutex);
2000

2001 2002 2003
	scmnd->result = srp_chkready(target->rport);
	if (unlikely(scmnd->result))
		goto err;
2004

B
Bart Van Assche 已提交
2005 2006
	WARN_ON_ONCE(scmnd->request->tag < 0);
	tag = blk_mq_unique_tag(scmnd->request);
B
Bart Van Assche 已提交
2007
	ch = &target->ch[blk_mq_unique_tag_to_hwq(tag)];
B
Bart Van Assche 已提交
2008 2009 2010 2011
	idx = blk_mq_unique_tag_to_tag(tag);
	WARN_ONCE(idx >= target->req_ring_size, "%s: tag %#x: idx %d >= %d\n",
		  dev_name(&shost->shost_gendev), tag, idx,
		  target->req_ring_size);
2012 2013 2014 2015

	spin_lock_irqsave(&ch->lock, flags);
	iu = __srp_get_tx_iu(ch, SRP_IU_CMD);
	spin_unlock_irqrestore(&ch->lock, flags);
2016

B
Bart Van Assche 已提交
2017 2018 2019 2020
	if (!iu)
		goto err;

	req = &ch->req_ring[idx];
2021
	dev = target->srp_host->srp_dev->dev;
2022
	ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_iu_len,
2023
				   DMA_TO_DEVICE);
2024

2025
	scmnd->host_scribble = (void *) req;
2026 2027 2028 2029 2030

	cmd = iu->buf;
	memset(cmd, 0, sizeof *cmd);

	cmd->opcode = SRP_CMD;
B
Bart Van Assche 已提交
2031
	int_to_scsilun(scmnd->device->lun, &cmd->lun);
B
Bart Van Assche 已提交
2032
	cmd->tag    = tag;
2033 2034 2035 2036 2037
	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);

	req->scmnd    = scmnd;
	req->cmd      = iu;

2038
	len = srp_map_data(scmnd, ch, req);
2039
	if (len < 0) {
2040
		shost_printk(KERN_ERR, target->scsi_host,
2041 2042 2043 2044
			     PFX "Failed to map data (%d)\n", len);
		/*
		 * If we ran out of memory descriptors (-ENOMEM) because an
		 * application is queuing many requests with more than
2045
		 * max_pages_per_mr sg-list elements, tell the SCSI mid-layer
2046 2047 2048 2049
		 * to reduce queue depth temporarily.
		 */
		scmnd->result = len == -ENOMEM ?
			DID_OK << 16 | QUEUE_FULL << 1 : DID_ERROR << 16;
2050
		goto err_iu;
2051 2052
	}

2053
	ib_dma_sync_single_for_device(dev, iu->dma, target->max_iu_len,
2054
				      DMA_TO_DEVICE);
2055

2056
	if (srp_post_send(ch, iu, len)) {
2057
		shost_printk(KERN_ERR, target->scsi_host, PFX "Send failed\n");
2058 2059 2060
		goto err_unmap;
	}

2061 2062
	ret = 0;

2063 2064 2065 2066
unlock_rport:
	if (in_scsi_eh)
		mutex_unlock(&rport->mutex);

2067
	return ret;
2068 2069

err_unmap:
2070
	srp_unmap_data(scmnd, ch, req);
2071

2072
err_iu:
2073
	srp_put_tx_iu(ch, iu, SRP_IU_CMD);
2074

2075 2076 2077 2078 2079 2080
	/*
	 * Avoid that the loops that iterate over the request ring can
	 * encounter a dangling SCSI command pointer.
	 */
	req->scmnd = NULL;

2081 2082 2083 2084 2085 2086 2087
err:
	if (scmnd->result) {
		scmnd->scsi_done(scmnd);
		ret = 0;
	} else {
		ret = SCSI_MLQUEUE_HOST_BUSY;
	}
2088

2089
	goto unlock_rport;
2090 2091
}

2092 2093
/*
 * Note: the resources allocated in this function are freed in
2094
 * srp_free_ch_ib().
2095
 */
2096
static int srp_alloc_iu_bufs(struct srp_rdma_ch *ch)
2097
{
2098
	struct srp_target_port *target = ch->target;
2099 2100
	int i;

2101 2102 2103
	ch->rx_ring = kcalloc(target->queue_size, sizeof(*ch->rx_ring),
			      GFP_KERNEL);
	if (!ch->rx_ring)
2104
		goto err_no_ring;
2105 2106 2107
	ch->tx_ring = kcalloc(target->queue_size, sizeof(*ch->tx_ring),
			      GFP_KERNEL);
	if (!ch->tx_ring)
2108 2109 2110
		goto err_no_ring;

	for (i = 0; i < target->queue_size; ++i) {
2111 2112 2113 2114
		ch->rx_ring[i] = srp_alloc_iu(target->srp_host,
					      ch->max_ti_iu_len,
					      GFP_KERNEL, DMA_FROM_DEVICE);
		if (!ch->rx_ring[i])
2115 2116 2117
			goto err;
	}

2118
	for (i = 0; i < target->queue_size; ++i) {
2119 2120 2121 2122
		ch->tx_ring[i] = srp_alloc_iu(target->srp_host,
					      target->max_iu_len,
					      GFP_KERNEL, DMA_TO_DEVICE);
		if (!ch->tx_ring[i])
2123
			goto err;
2124

2125
		list_add(&ch->tx_ring[i]->list, &ch->free_tx);
2126 2127 2128 2129 2130
	}

	return 0;

err:
2131
	for (i = 0; i < target->queue_size; ++i) {
2132 2133
		srp_free_iu(target->srp_host, ch->rx_ring[i]);
		srp_free_iu(target->srp_host, ch->tx_ring[i]);
2134 2135
	}

2136 2137

err_no_ring:
2138 2139 2140 2141
	kfree(ch->tx_ring);
	ch->tx_ring = NULL;
	kfree(ch->rx_ring);
	ch->rx_ring = NULL;
2142

2143 2144 2145
	return -ENOMEM;
}

2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172
static uint32_t srp_compute_rq_tmo(struct ib_qp_attr *qp_attr, int attr_mask)
{
	uint64_t T_tr_ns, max_compl_time_ms;
	uint32_t rq_tmo_jiffies;

	/*
	 * According to section 11.2.4.2 in the IBTA spec (Modify Queue Pair,
	 * table 91), both the QP timeout and the retry count have to be set
	 * for RC QP's during the RTR to RTS transition.
	 */
	WARN_ON_ONCE((attr_mask & (IB_QP_TIMEOUT | IB_QP_RETRY_CNT)) !=
		     (IB_QP_TIMEOUT | IB_QP_RETRY_CNT));

	/*
	 * Set target->rq_tmo_jiffies to one second more than the largest time
	 * it can take before an error completion is generated. See also
	 * C9-140..142 in the IBTA spec for more information about how to
	 * convert the QP Local ACK Timeout value to nanoseconds.
	 */
	T_tr_ns = 4096 * (1ULL << qp_attr->timeout);
	max_compl_time_ms = qp_attr->retry_cnt * 4 * T_tr_ns;
	do_div(max_compl_time_ms, NSEC_PER_MSEC);
	rq_tmo_jiffies = msecs_to_jiffies(max_compl_time_ms + 1000);

	return rq_tmo_jiffies;
}

2173 2174
static void srp_cm_rep_handler(struct ib_cm_id *cm_id,
			       struct srp_login_rsp *lrsp,
2175
			       struct srp_rdma_ch *ch)
2176
{
2177
	struct srp_target_port *target = ch->target;
2178 2179 2180 2181 2182 2183
	struct ib_qp_attr *qp_attr = NULL;
	int attr_mask = 0;
	int ret;
	int i;

	if (lrsp->opcode == SRP_LOGIN_RSP) {
2184 2185
		ch->max_ti_iu_len = be32_to_cpu(lrsp->max_ti_iu_len);
		ch->req_lim       = be32_to_cpu(lrsp->req_lim_delta);
2186 2187 2188 2189 2190 2191

		/*
		 * Reserve credits for task management so we don't
		 * bounce requests back to the SCSI mid-layer.
		 */
		target->scsi_host->can_queue
2192
			= min(ch->req_lim - SRP_TSK_MGMT_SQ_SIZE,
2193
			      target->scsi_host->can_queue);
2194 2195 2196
		target->scsi_host->cmd_per_lun
			= min_t(int, target->scsi_host->can_queue,
				target->scsi_host->cmd_per_lun);
2197 2198 2199 2200 2201 2202 2203
	} else {
		shost_printk(KERN_WARNING, target->scsi_host,
			     PFX "Unhandled RSP opcode %#x\n", lrsp->opcode);
		ret = -ECONNRESET;
		goto error;
	}

2204 2205
	if (!ch->rx_ring) {
		ret = srp_alloc_iu_bufs(ch);
2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219
		if (ret)
			goto error;
	}

	ret = -ENOMEM;
	qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
	if (!qp_attr)
		goto error;

	qp_attr->qp_state = IB_QPS_RTR;
	ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
	if (ret)
		goto error_free;

2220
	ret = ib_modify_qp(ch->qp, qp_attr, attr_mask);
2221 2222 2223
	if (ret)
		goto error_free;

2224
	for (i = 0; i < target->queue_size; i++) {
2225 2226 2227
		struct srp_iu *iu = ch->rx_ring[i];

		ret = srp_post_recv(ch, iu);
2228 2229 2230 2231 2232 2233 2234 2235 2236
		if (ret)
			goto error_free;
	}

	qp_attr->qp_state = IB_QPS_RTS;
	ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
	if (ret)
		goto error_free;

2237 2238
	target->rq_tmo_jiffies = srp_compute_rq_tmo(qp_attr, attr_mask);

2239
	ret = ib_modify_qp(ch->qp, qp_attr, attr_mask);
2240 2241 2242 2243 2244 2245 2246 2247 2248
	if (ret)
		goto error_free;

	ret = ib_send_cm_rtu(cm_id, NULL, 0);

error_free:
	kfree(qp_attr);

error:
2249
	ch->status = ret;
2250 2251
}

2252 2253
static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
			       struct ib_cm_event *event,
2254
			       struct srp_rdma_ch *ch)
2255
{
2256
	struct srp_target_port *target = ch->target;
2257
	struct Scsi_Host *shost = target->scsi_host;
2258 2259 2260 2261 2262 2263
	struct ib_class_port_info *cpi;
	int opcode;

	switch (event->param.rej_rcvd.reason) {
	case IB_CM_REJ_PORT_CM_REDIRECT:
		cpi = event->param.rej_rcvd.ari;
2264 2265
		ch->path.dlid = cpi->redirect_lid;
		ch->path.pkey = cpi->redirect_pkey;
2266
		cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
2267
		memcpy(ch->path.dgid.raw, cpi->redirect_gid, 16);
2268

2269
		ch->status = ch->path.dlid ?
2270 2271 2272 2273
			SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
		break;

	case IB_CM_REJ_PORT_REDIRECT:
2274
		if (srp_target_is_topspin(target)) {
2275 2276 2277 2278 2279
			/*
			 * Topspin/Cisco SRP gateways incorrectly send
			 * reject reason code 25 when they mean 24
			 * (port redirect).
			 */
2280
			memcpy(ch->path.dgid.raw,
2281 2282
			       event->param.rej_rcvd.ari, 16);

2283 2284
			shost_printk(KERN_DEBUG, shost,
				     PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
2285 2286
				     be64_to_cpu(ch->path.dgid.global.subnet_prefix),
				     be64_to_cpu(ch->path.dgid.global.interface_id));
2287

2288
			ch->status = SRP_PORT_REDIRECT;
2289
		} else {
2290 2291
			shost_printk(KERN_WARNING, shost,
				     "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
2292
			ch->status = -ECONNRESET;
2293 2294 2295 2296
		}
		break;

	case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
2297 2298
		shost_printk(KERN_WARNING, shost,
			    "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
2299
		ch->status = -ECONNRESET;
2300 2301 2302 2303 2304 2305 2306 2307 2308
		break;

	case IB_CM_REJ_CONSUMER_DEFINED:
		opcode = *(u8 *) event->private_data;
		if (opcode == SRP_LOGIN_REJ) {
			struct srp_login_rej *rej = event->private_data;
			u32 reason = be32_to_cpu(rej->reason);

			if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
2309 2310
				shost_printk(KERN_WARNING, shost,
					     PFX "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
2311
			else
B
Bart Van Assche 已提交
2312 2313
				shost_printk(KERN_WARNING, shost, PFX
					     "SRP LOGIN from %pI6 to %pI6 REJECTED, reason 0x%08x\n",
2314 2315
					     target->sgid.raw,
					     target->orig_dgid.raw, reason);
2316
		} else
2317 2318 2319
			shost_printk(KERN_WARNING, shost,
				     "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
				     " opcode 0x%02x\n", opcode);
2320
		ch->status = -ECONNRESET;
2321 2322
		break;

D
David Dillow 已提交
2323 2324
	case IB_CM_REJ_STALE_CONN:
		shost_printk(KERN_WARNING, shost, "  REJ reason: stale connection\n");
2325
		ch->status = SRP_STALE_CONN;
D
David Dillow 已提交
2326 2327
		break;

2328
	default:
2329 2330
		shost_printk(KERN_WARNING, shost, "  REJ reason 0x%x\n",
			     event->param.rej_rcvd.reason);
2331
		ch->status = -ECONNRESET;
2332 2333 2334 2335 2336
	}
}

static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
{
2337 2338
	struct srp_rdma_ch *ch = cm_id->context;
	struct srp_target_port *target = ch->target;
2339 2340 2341 2342
	int comp = 0;

	switch (event->event) {
	case IB_CM_REQ_ERROR:
2343 2344
		shost_printk(KERN_DEBUG, target->scsi_host,
			     PFX "Sending CM REQ failed\n");
2345
		comp = 1;
2346
		ch->status = -ECONNRESET;
2347 2348 2349 2350
		break;

	case IB_CM_REP_RECEIVED:
		comp = 1;
2351
		srp_cm_rep_handler(cm_id, event->private_data, ch);
2352 2353 2354
		break;

	case IB_CM_REJ_RECEIVED:
2355
		shost_printk(KERN_DEBUG, target->scsi_host, PFX "REJ received\n");
2356 2357
		comp = 1;

2358
		srp_cm_rej_handler(cm_id, event, ch);
2359 2360
		break;

2361
	case IB_CM_DREQ_RECEIVED:
2362 2363
		shost_printk(KERN_WARNING, target->scsi_host,
			     PFX "DREQ received - connection closed\n");
2364
		ch->connected = false;
2365
		if (ib_send_cm_drep(cm_id, NULL, 0))
2366 2367
			shost_printk(KERN_ERR, target->scsi_host,
				     PFX "Sending CM DREP failed\n");
2368
		queue_work(system_long_wq, &target->tl_err_work);
2369 2370 2371
		break;

	case IB_CM_TIMEWAIT_EXIT:
2372 2373
		shost_printk(KERN_ERR, target->scsi_host,
			     PFX "connection closed\n");
2374
		comp = 1;
2375

2376
		ch->status = 0;
2377 2378
		break;

2379 2380 2381 2382 2383
	case IB_CM_MRA_RECEIVED:
	case IB_CM_DREQ_ERROR:
	case IB_CM_DREP_RECEIVED:
		break;

2384
	default:
2385 2386
		shost_printk(KERN_WARNING, target->scsi_host,
			     PFX "Unhandled CM event %d\n", event->event);
2387 2388 2389 2390
		break;
	}

	if (comp)
2391
		complete(&ch->done);
2392 2393 2394 2395

	return 0;
}

2396 2397 2398 2399 2400 2401 2402 2403
/**
 * srp_change_queue_depth - setting device queue depth
 * @sdev: scsi device struct
 * @qdepth: requested queue depth
 *
 * Returns queue depth.
 */
static int
2404
srp_change_queue_depth(struct scsi_device *sdev, int qdepth)
2405
{
2406
	if (!sdev->tagged_supported)
2407
		qdepth = 1;
2408
	return scsi_change_queue_depth(sdev, qdepth);
2409 2410
}

B
Bart Van Assche 已提交
2411 2412
static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag, u64 lun,
			     u8 func)
2413
{
2414
	struct srp_target_port *target = ch->target;
2415
	struct srp_rport *rport = target->rport;
2416
	struct ib_device *dev = target->srp_host->srp_dev->dev;
2417 2418 2419
	struct srp_iu *iu;
	struct srp_tsk_mgmt *tsk_mgmt;

2420
	if (!ch->connected || target->qp_in_error)
2421 2422
		return -1;

2423
	init_completion(&ch->tsk_mgmt_done);
2424

2425
	/*
2426
	 * Lock the rport mutex to avoid that srp_create_ch_ib() is
2427 2428 2429
	 * invoked while a task management function is being sent.
	 */
	mutex_lock(&rport->mutex);
2430 2431 2432
	spin_lock_irq(&ch->lock);
	iu = __srp_get_tx_iu(ch, SRP_IU_TSK_MGMT);
	spin_unlock_irq(&ch->lock);
2433

2434 2435 2436
	if (!iu) {
		mutex_unlock(&rport->mutex);

2437
		return -1;
2438
	}
2439

2440 2441
	ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt,
				   DMA_TO_DEVICE);
2442 2443 2444 2445
	tsk_mgmt = iu->buf;
	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);

	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
B
Bart Van Assche 已提交
2446
	int_to_scsilun(lun, &tsk_mgmt->lun);
2447
	tsk_mgmt->tag		= req_tag | SRP_TAG_TSK_MGMT;
2448
	tsk_mgmt->tsk_mgmt_func = func;
2449
	tsk_mgmt->task_tag	= req_tag;
2450

2451 2452
	ib_dma_sync_single_for_device(dev, iu->dma, sizeof *tsk_mgmt,
				      DMA_TO_DEVICE);
2453 2454
	if (srp_post_send(ch, iu, sizeof(*tsk_mgmt))) {
		srp_put_tx_iu(ch, iu, SRP_IU_TSK_MGMT);
2455 2456
		mutex_unlock(&rport->mutex);

2457 2458
		return -1;
	}
2459
	mutex_unlock(&rport->mutex);
2460

2461
	if (!wait_for_completion_timeout(&ch->tsk_mgmt_done,
2462
					 msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
2463
		return -1;
2464

2465 2466 2467
	return 0;
}

2468 2469
static int srp_abort(struct scsi_cmnd *scmnd)
{
2470
	struct srp_target_port *target = host_to_target(scmnd->device->host);
2471
	struct srp_request *req = (struct srp_request *) scmnd->host_scribble;
B
Bart Van Assche 已提交
2472
	u32 tag;
B
Bart Van Assche 已提交
2473
	u16 ch_idx;
2474
	struct srp_rdma_ch *ch;
2475
	int ret;
2476

2477
	shost_printk(KERN_ERR, target->scsi_host, "SRP abort called\n");
2478

B
Bart Van Assche 已提交
2479
	if (!req)
2480
		return SUCCESS;
B
Bart Van Assche 已提交
2481
	tag = blk_mq_unique_tag(scmnd->request);
B
Bart Van Assche 已提交
2482 2483 2484 2485 2486 2487 2488 2489
	ch_idx = blk_mq_unique_tag_to_hwq(tag);
	if (WARN_ON_ONCE(ch_idx >= target->ch_count))
		return SUCCESS;
	ch = &target->ch[ch_idx];
	if (!srp_claim_req(ch, req, NULL, scmnd))
		return SUCCESS;
	shost_printk(KERN_ERR, target->scsi_host,
		     "Sending SRP abort for tag %#x\n", tag);
B
Bart Van Assche 已提交
2490
	if (srp_send_tsk_mgmt(ch, tag, scmnd->device->lun,
2491
			      SRP_TSK_ABORT_TASK) == 0)
2492
		ret = SUCCESS;
2493
	else if (target->rport->state == SRP_RPORT_LOST)
2494
		ret = FAST_IO_FAIL;
2495 2496
	else
		ret = FAILED;
2497
	srp_free_req(ch, req, scmnd, 0);
B
Bart Van Assche 已提交
2498
	scmnd->result = DID_ABORT << 16;
2499
	scmnd->scsi_done(scmnd);
2500

2501
	return ret;
2502 2503 2504 2505
}

static int srp_reset_device(struct scsi_cmnd *scmnd)
{
2506
	struct srp_target_port *target = host_to_target(scmnd->device->host);
B
Bart Van Assche 已提交
2507
	struct srp_rdma_ch *ch;
2508
	int i;
2509

2510
	shost_printk(KERN_ERR, target->scsi_host, "SRP reset_device called\n");
2511

B
Bart Van Assche 已提交
2512
	ch = &target->ch[0];
2513
	if (srp_send_tsk_mgmt(ch, SRP_TAG_NO_REQ, scmnd->device->lun,
2514
			      SRP_TSK_LUN_RESET))
2515
		return FAILED;
2516
	if (ch->tsk_mgmt_status)
2517 2518
		return FAILED;

B
Bart Van Assche 已提交
2519 2520 2521 2522
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		for (i = 0; i < target->req_ring_size; ++i) {
			struct srp_request *req = &ch->req_ring[i];
2523

B
Bart Van Assche 已提交
2524 2525
			srp_finish_req(ch, req, scmnd->device, DID_RESET << 16);
		}
2526
	}
2527 2528

	return SUCCESS;
2529 2530 2531 2532 2533 2534
}

static int srp_reset_host(struct scsi_cmnd *scmnd)
{
	struct srp_target_port *target = host_to_target(scmnd->device->host);

2535
	shost_printk(KERN_ERR, target->scsi_host, PFX "SRP reset_host called\n");
2536

2537
	return srp_reconnect_rport(target->rport) == 0 ? SUCCESS : FAILED;
2538 2539
}

2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554
static int srp_slave_configure(struct scsi_device *sdev)
{
	struct Scsi_Host *shost = sdev->host;
	struct srp_target_port *target = host_to_target(shost);
	struct request_queue *q = sdev->request_queue;
	unsigned long timeout;

	if (sdev->type == TYPE_DISK) {
		timeout = max_t(unsigned, 30 * HZ, target->rq_tmo_jiffies);
		blk_queue_rq_timeout(q, timeout);
	}

	return 0;
}

2555 2556
static ssize_t show_id_ext(struct device *dev, struct device_attribute *attr,
			   char *buf)
2557
{
2558
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2559

2560
	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->id_ext));
2561 2562
}

2563 2564
static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
			     char *buf)
2565
{
2566
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2567

2568
	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->ioc_guid));
2569 2570
}

2571 2572
static ssize_t show_service_id(struct device *dev,
			       struct device_attribute *attr, char *buf)
2573
{
2574
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2575

2576
	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->service_id));
2577 2578
}

2579 2580
static ssize_t show_pkey(struct device *dev, struct device_attribute *attr,
			 char *buf)
2581
{
2582
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2583

2584
	return sprintf(buf, "0x%04x\n", be16_to_cpu(target->pkey));
2585 2586
}

B
Bart Van Assche 已提交
2587 2588 2589 2590 2591
static ssize_t show_sgid(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct srp_target_port *target = host_to_target(class_to_shost(dev));

2592
	return sprintf(buf, "%pI6\n", target->sgid.raw);
B
Bart Van Assche 已提交
2593 2594
}

2595 2596
static ssize_t show_dgid(struct device *dev, struct device_attribute *attr,
			 char *buf)
2597
{
2598
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
B
Bart Van Assche 已提交
2599
	struct srp_rdma_ch *ch = &target->ch[0];
2600

2601
	return sprintf(buf, "%pI6\n", ch->path.dgid.raw);
2602 2603
}

2604 2605
static ssize_t show_orig_dgid(struct device *dev,
			      struct device_attribute *attr, char *buf)
2606
{
2607
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2608

2609
	return sprintf(buf, "%pI6\n", target->orig_dgid.raw);
2610 2611
}

2612 2613 2614 2615
static ssize_t show_req_lim(struct device *dev,
			    struct device_attribute *attr, char *buf)
{
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
B
Bart Van Assche 已提交
2616 2617
	struct srp_rdma_ch *ch;
	int i, req_lim = INT_MAX;
2618

B
Bart Van Assche 已提交
2619 2620 2621 2622 2623
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		req_lim = min(req_lim, ch->req_lim);
	}
	return sprintf(buf, "%d\n", req_lim);
2624 2625
}

2626 2627
static ssize_t show_zero_req_lim(struct device *dev,
				 struct device_attribute *attr, char *buf)
2628
{
2629
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2630 2631 2632 2633

	return sprintf(buf, "%d\n", target->zero_req_lim);
}

2634 2635
static ssize_t show_local_ib_port(struct device *dev,
				  struct device_attribute *attr, char *buf)
2636
{
2637
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2638 2639 2640 2641

	return sprintf(buf, "%d\n", target->srp_host->port);
}

2642 2643
static ssize_t show_local_ib_device(struct device *dev,
				    struct device_attribute *attr, char *buf)
2644
{
2645
	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2646

2647
	return sprintf(buf, "%s\n", target->srp_host->srp_dev->dev->name);
2648 2649
}

B
Bart Van Assche 已提交
2650 2651 2652 2653 2654 2655 2656 2657
static ssize_t show_ch_count(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct srp_target_port *target = host_to_target(class_to_shost(dev));

	return sprintf(buf, "%d\n", target->ch_count);
}

2658 2659 2660 2661 2662 2663 2664 2665
static ssize_t show_comp_vector(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct srp_target_port *target = host_to_target(class_to_shost(dev));

	return sprintf(buf, "%d\n", target->comp_vector);
}

2666 2667 2668 2669 2670 2671 2672 2673
static ssize_t show_tl_retry_count(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct srp_target_port *target = host_to_target(class_to_shost(dev));

	return sprintf(buf, "%d\n", target->tl_retry_count);
}

2674 2675 2676 2677 2678 2679 2680 2681
static ssize_t show_cmd_sg_entries(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct srp_target_port *target = host_to_target(class_to_shost(dev));

	return sprintf(buf, "%u\n", target->cmd_sg_cnt);
}

2682 2683 2684 2685 2686 2687 2688 2689
static ssize_t show_allow_ext_sg(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	struct srp_target_port *target = host_to_target(class_to_shost(dev));

	return sprintf(buf, "%s\n", target->allow_ext_sg ? "true" : "false");
}

2690 2691 2692 2693
static DEVICE_ATTR(id_ext,	    S_IRUGO, show_id_ext,	   NULL);
static DEVICE_ATTR(ioc_guid,	    S_IRUGO, show_ioc_guid,	   NULL);
static DEVICE_ATTR(service_id,	    S_IRUGO, show_service_id,	   NULL);
static DEVICE_ATTR(pkey,	    S_IRUGO, show_pkey,		   NULL);
B
Bart Van Assche 已提交
2694
static DEVICE_ATTR(sgid,	    S_IRUGO, show_sgid,		   NULL);
2695 2696
static DEVICE_ATTR(dgid,	    S_IRUGO, show_dgid,		   NULL);
static DEVICE_ATTR(orig_dgid,	    S_IRUGO, show_orig_dgid,	   NULL);
2697
static DEVICE_ATTR(req_lim,         S_IRUGO, show_req_lim,         NULL);
2698 2699 2700
static DEVICE_ATTR(zero_req_lim,    S_IRUGO, show_zero_req_lim,	   NULL);
static DEVICE_ATTR(local_ib_port,   S_IRUGO, show_local_ib_port,   NULL);
static DEVICE_ATTR(local_ib_device, S_IRUGO, show_local_ib_device, NULL);
B
Bart Van Assche 已提交
2701
static DEVICE_ATTR(ch_count,        S_IRUGO, show_ch_count,        NULL);
2702
static DEVICE_ATTR(comp_vector,     S_IRUGO, show_comp_vector,     NULL);
2703
static DEVICE_ATTR(tl_retry_count,  S_IRUGO, show_tl_retry_count,  NULL);
2704
static DEVICE_ATTR(cmd_sg_entries,  S_IRUGO, show_cmd_sg_entries,  NULL);
2705
static DEVICE_ATTR(allow_ext_sg,    S_IRUGO, show_allow_ext_sg,    NULL);
2706 2707 2708 2709 2710 2711

static struct device_attribute *srp_host_attrs[] = {
	&dev_attr_id_ext,
	&dev_attr_ioc_guid,
	&dev_attr_service_id,
	&dev_attr_pkey,
B
Bart Van Assche 已提交
2712
	&dev_attr_sgid,
2713 2714
	&dev_attr_dgid,
	&dev_attr_orig_dgid,
2715
	&dev_attr_req_lim,
2716 2717 2718
	&dev_attr_zero_req_lim,
	&dev_attr_local_ib_port,
	&dev_attr_local_ib_device,
B
Bart Van Assche 已提交
2719
	&dev_attr_ch_count,
2720
	&dev_attr_comp_vector,
2721
	&dev_attr_tl_retry_count,
2722
	&dev_attr_cmd_sg_entries,
2723
	&dev_attr_allow_ext_sg,
2724 2725 2726
	NULL
};

2727 2728
static struct scsi_host_template srp_template = {
	.module				= THIS_MODULE,
R
Roland Dreier 已提交
2729 2730
	.name				= "InfiniBand SRP initiator",
	.proc_name			= DRV_NAME,
2731
	.slave_configure		= srp_slave_configure,
2732 2733
	.info				= srp_target_info,
	.queuecommand			= srp_queuecommand,
2734
	.change_queue_depth             = srp_change_queue_depth,
2735 2736 2737
	.eh_abort_handler		= srp_abort,
	.eh_device_reset_handler	= srp_reset_device,
	.eh_host_reset_handler		= srp_reset_host,
B
Bart Van Assche 已提交
2738
	.skip_settle_delay		= true,
2739
	.sg_tablesize			= SRP_DEF_SG_TABLESIZE,
2740
	.can_queue			= SRP_DEFAULT_CMD_SQ_SIZE,
2741
	.this_id			= -1,
2742
	.cmd_per_lun			= SRP_DEFAULT_CMD_SQ_SIZE,
2743
	.use_clustering			= ENABLE_CLUSTERING,
B
Bart Van Assche 已提交
2744 2745
	.shost_attrs			= srp_host_attrs,
	.use_blk_tags			= 1,
2746
	.track_queue_depth		= 1,
2747 2748
};

2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759
static int srp_sdev_count(struct Scsi_Host *host)
{
	struct scsi_device *sdev;
	int c = 0;

	shost_for_each_device(sdev, host)
		c++;

	return c;
}

2760 2761
static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
{
2762 2763 2764
	struct srp_rport_identifiers ids;
	struct srp_rport *rport;

2765
	target->state = SRP_TARGET_SCANNING;
2766
	sprintf(target->target_name, "SRP.T10:%016llX",
2767
		be64_to_cpu(target->id_ext));
2768

2769
	if (scsi_add_host(target->scsi_host, host->srp_dev->dev->dma_device))
2770 2771
		return -ENODEV;

2772 2773
	memcpy(ids.port_id, &target->id_ext, 8);
	memcpy(ids.port_id + 8, &target->ioc_guid, 8);
2774
	ids.roles = SRP_RPORT_ROLE_TARGET;
2775 2776 2777 2778 2779 2780
	rport = srp_rport_add(target->scsi_host, &ids);
	if (IS_ERR(rport)) {
		scsi_remove_host(target->scsi_host);
		return PTR_ERR(rport);
	}

2781
	rport->lld_data = target;
2782
	target->rport = rport;
2783

2784
	spin_lock(&host->target_lock);
2785
	list_add_tail(&target->list, &host->target_list);
2786
	spin_unlock(&host->target_lock);
2787 2788

	scsi_scan_target(&target->scsi_host->shost_gendev,
2789
			 0, target->scsi_id, SCAN_WILD_CARD, 0);
2790

2791 2792
	if (srp_connected_ch(target) < target->ch_count ||
	    target->qp_in_error) {
2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808
		shost_printk(KERN_INFO, target->scsi_host,
			     PFX "SCSI scan failed - removing SCSI host\n");
		srp_queue_remove_work(target);
		goto out;
	}

	pr_debug(PFX "%s: SCSI scan succeeded - detected %d LUNs\n",
		 dev_name(&target->scsi_host->shost_gendev),
		 srp_sdev_count(target->scsi_host));

	spin_lock_irq(&target->lock);
	if (target->state == SRP_TARGET_SCANNING)
		target->state = SRP_TARGET_LIVE;
	spin_unlock_irq(&target->lock);

out:
2809 2810 2811
	return 0;
}

2812
static void srp_release_dev(struct device *dev)
2813 2814
{
	struct srp_host *host =
2815
		container_of(dev, struct srp_host, dev);
2816 2817 2818 2819 2820 2821

	complete(&host->released);
}

static struct class srp_class = {
	.name    = "infiniband_srp",
2822
	.dev_release = srp_release_dev
2823 2824
};

2825 2826
/**
 * srp_conn_unique() - check whether the connection to a target is unique
2827 2828
 * @host:   SRP host.
 * @target: SRP target port.
2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856
 */
static bool srp_conn_unique(struct srp_host *host,
			    struct srp_target_port *target)
{
	struct srp_target_port *t;
	bool ret = false;

	if (target->state == SRP_TARGET_REMOVED)
		goto out;

	ret = true;

	spin_lock(&host->target_lock);
	list_for_each_entry(t, &host->target_list, list) {
		if (t != target &&
		    target->id_ext == t->id_ext &&
		    target->ioc_guid == t->ioc_guid &&
		    target->initiator_ext == t->initiator_ext) {
			ret = false;
			break;
		}
	}
	spin_unlock(&host->target_lock);

out:
	return ret;
}

2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872
/*
 * Target ports are added by writing
 *
 *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
 *     pkey=<P_Key>,service_id=<service ID>
 *
 * to the add_target sysfs attribute.
 */
enum {
	SRP_OPT_ERR		= 0,
	SRP_OPT_ID_EXT		= 1 << 0,
	SRP_OPT_IOC_GUID	= 1 << 1,
	SRP_OPT_DGID		= 1 << 2,
	SRP_OPT_PKEY		= 1 << 3,
	SRP_OPT_SERVICE_ID	= 1 << 4,
	SRP_OPT_MAX_SECT	= 1 << 5,
2873
	SRP_OPT_MAX_CMD_PER_LUN	= 1 << 6,
2874
	SRP_OPT_IO_CLASS	= 1 << 7,
2875
	SRP_OPT_INITIATOR_EXT	= 1 << 8,
2876
	SRP_OPT_CMD_SG_ENTRIES	= 1 << 9,
2877 2878
	SRP_OPT_ALLOW_EXT_SG	= 1 << 10,
	SRP_OPT_SG_TABLESIZE	= 1 << 11,
2879
	SRP_OPT_COMP_VECTOR	= 1 << 12,
2880
	SRP_OPT_TL_RETRY_COUNT	= 1 << 13,
2881
	SRP_OPT_QUEUE_SIZE	= 1 << 14,
2882 2883 2884 2885 2886 2887 2888
	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
				   SRP_OPT_IOC_GUID	|
				   SRP_OPT_DGID		|
				   SRP_OPT_PKEY		|
				   SRP_OPT_SERVICE_ID),
};

2889
static const match_table_t srp_opt_tokens = {
2890 2891 2892 2893 2894 2895 2896
	{ SRP_OPT_ID_EXT,		"id_ext=%s" 		},
	{ SRP_OPT_IOC_GUID,		"ioc_guid=%s" 		},
	{ SRP_OPT_DGID,			"dgid=%s" 		},
	{ SRP_OPT_PKEY,			"pkey=%x" 		},
	{ SRP_OPT_SERVICE_ID,		"service_id=%s"		},
	{ SRP_OPT_MAX_SECT,		"max_sect=%d" 		},
	{ SRP_OPT_MAX_CMD_PER_LUN,	"max_cmd_per_lun=%d" 	},
2897
	{ SRP_OPT_IO_CLASS,		"io_class=%x"		},
2898
	{ SRP_OPT_INITIATOR_EXT,	"initiator_ext=%s"	},
2899
	{ SRP_OPT_CMD_SG_ENTRIES,	"cmd_sg_entries=%u"	},
2900 2901
	{ SRP_OPT_ALLOW_EXT_SG,		"allow_ext_sg=%u"	},
	{ SRP_OPT_SG_TABLESIZE,		"sg_tablesize=%u"	},
2902
	{ SRP_OPT_COMP_VECTOR,		"comp_vector=%u"	},
2903
	{ SRP_OPT_TL_RETRY_COUNT,	"tl_retry_count=%u"	},
2904
	{ SRP_OPT_QUEUE_SIZE,		"queue_size=%d"		},
2905
	{ SRP_OPT_ERR,			NULL 			}
2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923
};

static int srp_parse_options(const char *buf, struct srp_target_port *target)
{
	char *options, *sep_opt;
	char *p;
	char dgid[3];
	substring_t args[MAX_OPT_ARGS];
	int opt_mask = 0;
	int token;
	int ret = -EINVAL;
	int i;

	options = kstrdup(buf, GFP_KERNEL);
	if (!options)
		return -ENOMEM;

	sep_opt = options;
2924
	while ((p = strsep(&sep_opt, ",\n")) != NULL) {
2925 2926 2927 2928 2929 2930 2931 2932 2933
		if (!*p)
			continue;

		token = match_token(p, srp_opt_tokens, args);
		opt_mask |= token;

		switch (token) {
		case SRP_OPT_ID_EXT:
			p = match_strdup(args);
2934 2935 2936 2937
			if (!p) {
				ret = -ENOMEM;
				goto out;
			}
2938 2939 2940 2941 2942 2943
			target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
			kfree(p);
			break;

		case SRP_OPT_IOC_GUID:
			p = match_strdup(args);
2944 2945 2946 2947
			if (!p) {
				ret = -ENOMEM;
				goto out;
			}
2948 2949 2950 2951 2952 2953
			target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
			kfree(p);
			break;

		case SRP_OPT_DGID:
			p = match_strdup(args);
2954 2955 2956 2957
			if (!p) {
				ret = -ENOMEM;
				goto out;
			}
2958
			if (strlen(p) != 32) {
2959
				pr_warn("bad dest GID parameter '%s'\n", p);
2960
				kfree(p);
2961 2962 2963 2964
				goto out;
			}

			for (i = 0; i < 16; ++i) {
2965 2966 2967 2968 2969 2970 2971
				strlcpy(dgid, p + i * 2, sizeof(dgid));
				if (sscanf(dgid, "%hhx",
					   &target->orig_dgid.raw[i]) < 1) {
					ret = -EINVAL;
					kfree(p);
					goto out;
				}
2972
			}
2973
			kfree(p);
2974 2975 2976 2977
			break;

		case SRP_OPT_PKEY:
			if (match_hex(args, &token)) {
2978
				pr_warn("bad P_Key parameter '%s'\n", p);
2979 2980
				goto out;
			}
2981
			target->pkey = cpu_to_be16(token);
2982 2983 2984 2985
			break;

		case SRP_OPT_SERVICE_ID:
			p = match_strdup(args);
2986 2987 2988 2989
			if (!p) {
				ret = -ENOMEM;
				goto out;
			}
2990 2991 2992 2993 2994 2995
			target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
			kfree(p);
			break;

		case SRP_OPT_MAX_SECT:
			if (match_int(args, &token)) {
2996
				pr_warn("bad max sect parameter '%s'\n", p);
2997 2998 2999 3000 3001
				goto out;
			}
			target->scsi_host->max_sectors = token;
			break;

3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013
		case SRP_OPT_QUEUE_SIZE:
			if (match_int(args, &token) || token < 1) {
				pr_warn("bad queue_size parameter '%s'\n", p);
				goto out;
			}
			target->scsi_host->can_queue = token;
			target->queue_size = token + SRP_RSP_SQ_SIZE +
					     SRP_TSK_MGMT_SQ_SIZE;
			if (!(opt_mask & SRP_OPT_MAX_CMD_PER_LUN))
				target->scsi_host->cmd_per_lun = token;
			break;

3014
		case SRP_OPT_MAX_CMD_PER_LUN:
3015
			if (match_int(args, &token) || token < 1) {
3016 3017
				pr_warn("bad max cmd_per_lun parameter '%s'\n",
					p);
3018 3019
				goto out;
			}
3020
			target->scsi_host->cmd_per_lun = token;
3021 3022
			break;

3023 3024
		case SRP_OPT_IO_CLASS:
			if (match_hex(args, &token)) {
3025
				pr_warn("bad IO class parameter '%s'\n", p);
3026 3027 3028 3029
				goto out;
			}
			if (token != SRP_REV10_IB_IO_CLASS &&
			    token != SRP_REV16A_IB_IO_CLASS) {
3030 3031 3032
				pr_warn("unknown IO class parameter value %x specified (use %x or %x).\n",
					token, SRP_REV10_IB_IO_CLASS,
					SRP_REV16A_IB_IO_CLASS);
3033 3034 3035 3036 3037
				goto out;
			}
			target->io_class = token;
			break;

3038 3039
		case SRP_OPT_INITIATOR_EXT:
			p = match_strdup(args);
3040 3041 3042 3043
			if (!p) {
				ret = -ENOMEM;
				goto out;
			}
3044 3045 3046 3047
			target->initiator_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
			kfree(p);
			break;

3048 3049
		case SRP_OPT_CMD_SG_ENTRIES:
			if (match_int(args, &token) || token < 1 || token > 255) {
3050 3051
				pr_warn("bad max cmd_sg_entries parameter '%s'\n",
					p);
3052 3053 3054 3055 3056
				goto out;
			}
			target->cmd_sg_cnt = token;
			break;

3057 3058
		case SRP_OPT_ALLOW_EXT_SG:
			if (match_int(args, &token)) {
3059
				pr_warn("bad allow_ext_sg parameter '%s'\n", p);
3060 3061 3062 3063 3064 3065 3066 3067
				goto out;
			}
			target->allow_ext_sg = !!token;
			break;

		case SRP_OPT_SG_TABLESIZE:
			if (match_int(args, &token) || token < 1 ||
					token > SCSI_MAX_SG_CHAIN_SEGMENTS) {
3068 3069
				pr_warn("bad max sg_tablesize parameter '%s'\n",
					p);
3070 3071 3072 3073 3074
				goto out;
			}
			target->sg_tablesize = token;
			break;

3075 3076 3077 3078 3079 3080 3081 3082
		case SRP_OPT_COMP_VECTOR:
			if (match_int(args, &token) || token < 0) {
				pr_warn("bad comp_vector parameter '%s'\n", p);
				goto out;
			}
			target->comp_vector = token;
			break;

3083 3084 3085 3086 3087 3088 3089 3090 3091
		case SRP_OPT_TL_RETRY_COUNT:
			if (match_int(args, &token) || token < 2 || token > 7) {
				pr_warn("bad tl_retry_count parameter '%s' (must be a number between 2 and 7)\n",
					p);
				goto out;
			}
			target->tl_retry_count = token;
			break;

3092
		default:
3093 3094
			pr_warn("unknown parameter or missing value '%s' in target creation request\n",
				p);
3095 3096 3097 3098 3099 3100 3101 3102 3103 3104
			goto out;
		}
	}

	if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
		ret = 0;
	else
		for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
			if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
			    !(srp_opt_tokens[i].token & opt_mask))
3105 3106
				pr_warn("target creation request is missing parameter '%s'\n",
					srp_opt_tokens[i].pattern);
3107

3108 3109 3110 3111 3112 3113
	if (target->scsi_host->cmd_per_lun > target->scsi_host->can_queue
	    && (opt_mask & SRP_OPT_MAX_CMD_PER_LUN))
		pr_warn("cmd_per_lun = %d > queue_size = %d\n",
			target->scsi_host->cmd_per_lun,
			target->scsi_host->can_queue);

3114 3115 3116 3117 3118
out:
	kfree(options);
	return ret;
}

3119 3120
static ssize_t srp_create_target(struct device *dev,
				 struct device_attribute *attr,
3121 3122 3123
				 const char *buf, size_t count)
{
	struct srp_host *host =
3124
		container_of(dev, struct srp_host, dev);
3125 3126
	struct Scsi_Host *target_host;
	struct srp_target_port *target;
3127
	struct srp_rdma_ch *ch;
3128 3129
	struct srp_device *srp_dev = host->srp_dev;
	struct ib_device *ibdev = srp_dev->dev;
B
Bart Van Assche 已提交
3130 3131
	int ret, node_idx, node, cpu, i;
	bool multich = false;
3132 3133 3134 3135 3136 3137

	target_host = scsi_host_alloc(&srp_template,
				      sizeof (struct srp_target_port));
	if (!target_host)
		return -ENOMEM;

3138
	target_host->transportt  = ib_srp_transport_template;
3139 3140
	target_host->max_channel = 0;
	target_host->max_id      = 1;
B
Bart Van Assche 已提交
3141
	target_host->max_lun     = -1LL;
A
Arne Redlich 已提交
3142
	target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
R
Roland Dreier 已提交
3143

3144 3145
	target = host_to_target(target_host);

3146 3147 3148 3149 3150 3151
	target->io_class	= SRP_REV16A_IB_IO_CLASS;
	target->scsi_host	= target_host;
	target->srp_host	= host;
	target->lkey		= host->srp_dev->mr->lkey;
	target->rkey		= host->srp_dev->mr->rkey;
	target->cmd_sg_cnt	= cmd_sg_entries;
3152 3153
	target->sg_tablesize	= indirect_sg_entries ? : cmd_sg_entries;
	target->allow_ext_sg	= allow_ext_sg;
3154
	target->tl_retry_count	= 7;
3155
	target->queue_size	= SRP_DEFAULT_QUEUE_SIZE;
3156

3157 3158 3159 3160 3161 3162
	/*
	 * Avoid that the SCSI host can be removed by srp_remove_target()
	 * before this function returns.
	 */
	scsi_host_get(target->scsi_host);

3163 3164
	mutex_lock(&host->add_target_mutex);

3165 3166
	ret = srp_parse_options(buf, target);
	if (ret)
3167
		goto out;
3168

B
Bart Van Assche 已提交
3169 3170
	ret = scsi_init_shared_tag_map(target_host, target_host->can_queue);
	if (ret)
3171
		goto out;
B
Bart Van Assche 已提交
3172

3173 3174
	target->req_ring_size = target->queue_size - SRP_TSK_MGMT_SQ_SIZE;

3175 3176 3177 3178 3179 3180 3181
	if (!srp_conn_unique(target->srp_host, target)) {
		shost_printk(KERN_INFO, target->scsi_host,
			     PFX "Already connected to target port with id_ext=%016llx;ioc_guid=%016llx;initiator_ext=%016llx\n",
			     be64_to_cpu(target->id_ext),
			     be64_to_cpu(target->ioc_guid),
			     be64_to_cpu(target->initiator_ext));
		ret = -EEXIST;
3182
		goto out;
3183 3184
	}

3185
	if (!srp_dev->has_fmr && !srp_dev->has_fr && !target->allow_ext_sg &&
3186
	    target->cmd_sg_cnt < target->sg_tablesize) {
3187
		pr_warn("No MR pool and no external indirect descriptors, limiting sg_tablesize to cmd_sg_cnt\n");
3188 3189 3190 3191 3192 3193
		target->sg_tablesize = target->cmd_sg_cnt;
	}

	target_host->sg_tablesize = target->sg_tablesize;
	target->indirect_size = target->sg_tablesize *
				sizeof (struct srp_direct_buf);
3194 3195 3196 3197
	target->max_iu_len = sizeof (struct srp_cmd) +
			     sizeof (struct srp_indirect_buf) +
			     target->cmd_sg_cnt * sizeof (struct srp_direct_buf);

3198
	INIT_WORK(&target->tl_err_work, srp_tl_err_work);
3199
	INIT_WORK(&target->remove_work, srp_remove_work);
3200
	spin_lock_init(&target->lock);
3201
	ret = ib_query_gid(ibdev, host->port, 0, &target->sgid);
3202
	if (ret)
3203
		goto out;
3204

B
Bart Van Assche 已提交
3205 3206 3207 3208 3209 3210 3211 3212 3213
	ret = -ENOMEM;
	target->ch_count = max_t(unsigned, num_online_nodes(),
				 min(ch_count ? :
				     min(4 * num_online_nodes(),
					 ibdev->num_comp_vectors),
				     num_online_cpus()));
	target->ch = kcalloc(target->ch_count, sizeof(*target->ch),
			     GFP_KERNEL);
	if (!target->ch)
3214
		goto out;
3215

B
Bart Van Assche 已提交
3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243
	node_idx = 0;
	for_each_online_node(node) {
		const int ch_start = (node_idx * target->ch_count /
				      num_online_nodes());
		const int ch_end = ((node_idx + 1) * target->ch_count /
				    num_online_nodes());
		const int cv_start = (node_idx * ibdev->num_comp_vectors /
				      num_online_nodes() + target->comp_vector)
				     % ibdev->num_comp_vectors;
		const int cv_end = ((node_idx + 1) * ibdev->num_comp_vectors /
				    num_online_nodes() + target->comp_vector)
				   % ibdev->num_comp_vectors;
		int cpu_idx = 0;

		for_each_online_cpu(cpu) {
			if (cpu_to_node(cpu) != node)
				continue;
			if (ch_start + cpu_idx >= ch_end)
				continue;
			ch = &target->ch[ch_start + cpu_idx];
			ch->target = target;
			ch->comp_vector = cv_start == cv_end ? cv_start :
				cv_start + cpu_idx % (cv_end - cv_start);
			spin_lock_init(&ch->lock);
			INIT_LIST_HEAD(&ch->free_tx);
			ret = srp_new_cm_id(ch);
			if (ret)
				goto err_disconnect;
3244

B
Bart Van Assche 已提交
3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272
			ret = srp_create_ch_ib(ch);
			if (ret)
				goto err_disconnect;

			ret = srp_alloc_req_data(ch);
			if (ret)
				goto err_disconnect;

			ret = srp_connect_ch(ch, multich);
			if (ret) {
				shost_printk(KERN_ERR, target->scsi_host,
					     PFX "Connection %d/%d failed\n",
					     ch_start + cpu_idx,
					     target->ch_count);
				if (node_idx == 0 && cpu_idx == 0) {
					goto err_disconnect;
				} else {
					srp_free_ch_ib(target, ch);
					srp_free_req_data(target, ch);
					target->ch_count = ch - target->ch;
					break;
				}
			}

			multich = true;
			cpu_idx++;
		}
		node_idx++;
3273 3274
	}

B
Bart Van Assche 已提交
3275 3276
	target->scsi_host->nr_hw_queues = target->ch_count;

3277 3278 3279 3280
	ret = srp_add_target(host, target);
	if (ret)
		goto err_disconnect;

3281 3282 3283 3284 3285
	if (target->state != SRP_TARGET_REMOVED) {
		shost_printk(KERN_DEBUG, target->scsi_host, PFX
			     "new target: id_ext %016llx ioc_guid %016llx pkey %04x service_id %016llx sgid %pI6 dgid %pI6\n",
			     be64_to_cpu(target->id_ext),
			     be64_to_cpu(target->ioc_guid),
3286
			     be16_to_cpu(target->pkey),
3287
			     be64_to_cpu(target->service_id),
3288
			     target->sgid.raw, target->orig_dgid.raw);
3289
	}
B
Bart Van Assche 已提交
3290

3291 3292 3293 3294
	ret = count;

out:
	mutex_unlock(&host->add_target_mutex);
3295 3296 3297

	scsi_host_put(target->scsi_host);

3298
	return ret;
3299 3300 3301 3302

err_disconnect:
	srp_disconnect_target(target);

B
Bart Van Assche 已提交
3303 3304 3305 3306 3307
	for (i = 0; i < target->ch_count; i++) {
		ch = &target->ch[i];
		srp_free_ch_ib(target, ch);
		srp_free_req_data(target, ch);
	}
3308

B
Bart Van Assche 已提交
3309
	kfree(target->ch);
3310
	goto out;
3311 3312
}

3313
static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
3314

3315 3316
static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
			  char *buf)
3317
{
3318
	struct srp_host *host = container_of(dev, struct srp_host, dev);
3319

3320
	return sprintf(buf, "%s\n", host->srp_dev->dev->name);
3321 3322
}

3323
static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
3324

3325 3326
static ssize_t show_port(struct device *dev, struct device_attribute *attr,
			 char *buf)
3327
{
3328
	struct srp_host *host = container_of(dev, struct srp_host, dev);
3329 3330 3331 3332

	return sprintf(buf, "%d\n", host->port);
}

3333
static DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
3334

3335
static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
3336 3337 3338 3339 3340 3341 3342 3343
{
	struct srp_host *host;

	host = kzalloc(sizeof *host, GFP_KERNEL);
	if (!host)
		return NULL;

	INIT_LIST_HEAD(&host->target_list);
3344
	spin_lock_init(&host->target_lock);
3345
	init_completion(&host->released);
3346
	mutex_init(&host->add_target_mutex);
3347
	host->srp_dev = device;
3348 3349
	host->port = port;

3350 3351
	host->dev.class = &srp_class;
	host->dev.parent = device->dev->dma_device;
3352
	dev_set_name(&host->dev, "srp-%s-%d", device->dev->name, port);
3353

3354
	if (device_register(&host->dev))
3355
		goto free_host;
3356
	if (device_create_file(&host->dev, &dev_attr_add_target))
3357
		goto err_class;
3358
	if (device_create_file(&host->dev, &dev_attr_ibdev))
3359
		goto err_class;
3360
	if (device_create_file(&host->dev, &dev_attr_port))
3361 3362 3363 3364 3365
		goto err_class;

	return host;

err_class:
3366
	device_unregister(&host->dev);
3367

3368
free_host:
3369 3370 3371 3372 3373 3374 3375
	kfree(host);

	return NULL;
}

static void srp_add_one(struct ib_device *device)
{
3376 3377
	struct srp_device *srp_dev;
	struct ib_device_attr *dev_attr;
3378
	struct srp_host *host;
3379
	int mr_page_shift, p;
3380
	u64 max_pages_per_mr;
3381

3382 3383
	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
	if (!dev_attr)
3384
		return;
3385

3386
	if (ib_query_device(device, dev_attr)) {
3387
		pr_warn("Query device failed for %s\n", device->name);
3388 3389 3390 3391 3392 3393 3394
		goto free_attr;
	}

	srp_dev = kmalloc(sizeof *srp_dev, GFP_KERNEL);
	if (!srp_dev)
		goto free_attr;

3395 3396
	srp_dev->has_fmr = (device->alloc_fmr && device->dealloc_fmr &&
			    device->map_phys_fmr && device->unmap_fmr);
3397 3398 3399 3400 3401 3402 3403
	srp_dev->has_fr = (dev_attr->device_cap_flags &
			   IB_DEVICE_MEM_MGT_EXTENSIONS);
	if (!srp_dev->has_fmr && !srp_dev->has_fr)
		dev_warn(&device->dev, "neither FMR nor FR is supported\n");

	srp_dev->use_fast_reg = (srp_dev->has_fr &&
				 (!srp_dev->has_fmr || prefer_fr));
3404

3405 3406
	/*
	 * Use the smallest page size supported by the HCA, down to a
3407 3408
	 * minimum of 4096 bytes. We're unlikely to build large sglists
	 * out of smaller entries.
3409
	 */
3410 3411 3412 3413 3414 3415 3416
	mr_page_shift		= max(12, ffs(dev_attr->page_size_cap) - 1);
	srp_dev->mr_page_size	= 1 << mr_page_shift;
	srp_dev->mr_page_mask	= ~((u64) srp_dev->mr_page_size - 1);
	max_pages_per_mr	= dev_attr->max_mr_size;
	do_div(max_pages_per_mr, srp_dev->mr_page_size);
	srp_dev->max_pages_per_mr = min_t(u64, SRP_MAX_PAGES_PER_MR,
					  max_pages_per_mr);
3417 3418 3419 3420 3421
	if (srp_dev->use_fast_reg) {
		srp_dev->max_pages_per_mr =
			min_t(u32, srp_dev->max_pages_per_mr,
			      dev_attr->max_fast_reg_page_list_len);
	}
3422 3423
	srp_dev->mr_max_size	= srp_dev->mr_page_size *
				   srp_dev->max_pages_per_mr;
3424
	pr_debug("%s: mr_page_shift = %d, dev_attr->max_mr_size = %#llx, dev_attr->max_fast_reg_page_list_len = %u, max_pages_per_mr = %d, mr_max_size = %#x\n",
3425
		 device->name, mr_page_shift, dev_attr->max_mr_size,
3426
		 dev_attr->max_fast_reg_page_list_len,
3427
		 srp_dev->max_pages_per_mr, srp_dev->mr_max_size);
3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442

	INIT_LIST_HEAD(&srp_dev->dev_list);

	srp_dev->dev = device;
	srp_dev->pd  = ib_alloc_pd(device);
	if (IS_ERR(srp_dev->pd))
		goto free_dev;

	srp_dev->mr = ib_get_dma_mr(srp_dev->pd,
				    IB_ACCESS_LOCAL_WRITE |
				    IB_ACCESS_REMOTE_READ |
				    IB_ACCESS_REMOTE_WRITE);
	if (IS_ERR(srp_dev->mr))
		goto err_pd;

3443
	for (p = rdma_start_port(device); p <= rdma_end_port(device); ++p) {
3444
		host = srp_add_port(srp_dev, p);
3445
		if (host)
3446
			list_add_tail(&host->list, &srp_dev->dev_list);
3447 3448
	}

3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460
	ib_set_client_data(device, &srp_client, srp_dev);

	goto free_attr;

err_pd:
	ib_dealloc_pd(srp_dev->pd);

free_dev:
	kfree(srp_dev);

free_attr:
	kfree(dev_attr);
3461 3462
}

3463
static void srp_remove_one(struct ib_device *device, void *client_data)
3464
{
3465
	struct srp_device *srp_dev;
3466
	struct srp_host *host, *tmp_host;
3467
	struct srp_target_port *target;
3468

3469
	srp_dev = client_data;
3470 3471
	if (!srp_dev)
		return;
3472

3473
	list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
3474
		device_unregister(&host->dev);
3475 3476 3477 3478 3479 3480 3481
		/*
		 * Wait for the sysfs entry to go away, so that no new
		 * target ports can be created.
		 */
		wait_for_completion(&host->released);

		/*
3482
		 * Remove all target ports.
3483
		 */
3484
		spin_lock(&host->target_lock);
3485 3486
		list_for_each_entry(target, &host->target_list, list)
			srp_queue_remove_work(target);
3487
		spin_unlock(&host->target_lock);
3488 3489

		/*
3490
		 * Wait for tl_err and target port removal tasks.
3491
		 */
3492
		flush_workqueue(system_long_wq);
3493
		flush_workqueue(srp_remove_wq);
3494 3495 3496 3497

		kfree(host);
	}

3498 3499 3500 3501
	ib_dereg_mr(srp_dev->mr);
	ib_dealloc_pd(srp_dev->pd);

	kfree(srp_dev);
3502 3503
}

3504
static struct srp_function_template ib_srp_transport_functions = {
3505 3506
	.has_rport_state	 = true,
	.reset_timer_if_blocked	 = true,
3507
	.reconnect_delay	 = &srp_reconnect_delay,
3508 3509 3510
	.fast_io_fail_tmo	 = &srp_fast_io_fail_tmo,
	.dev_loss_tmo		 = &srp_dev_loss_tmo,
	.reconnect		 = srp_rport_reconnect,
3511
	.rport_delete		 = srp_rport_delete,
3512
	.terminate_rport_io	 = srp_terminate_io,
3513 3514
};

3515 3516 3517 3518
static int __init srp_init_module(void)
{
	int ret;

3519
	BUILD_BUG_ON(FIELD_SIZEOF(struct ib_wc, wr_id) < sizeof(void *));
3520

3521
	if (srp_sg_tablesize) {
3522
		pr_warn("srp_sg_tablesize is deprecated, please use cmd_sg_entries\n");
3523 3524 3525 3526 3527 3528 3529 3530
		if (!cmd_sg_entries)
			cmd_sg_entries = srp_sg_tablesize;
	}

	if (!cmd_sg_entries)
		cmd_sg_entries = SRP_DEF_SG_TABLESIZE;

	if (cmd_sg_entries > 255) {
3531
		pr_warn("Clamping cmd_sg_entries to 255\n");
3532
		cmd_sg_entries = 255;
3533 3534
	}

3535 3536 3537
	if (!indirect_sg_entries)
		indirect_sg_entries = cmd_sg_entries;
	else if (indirect_sg_entries < cmd_sg_entries) {
3538 3539
		pr_warn("Bumping up indirect_sg_entries to match cmd_sg_entries (%u)\n",
			cmd_sg_entries);
3540 3541 3542
		indirect_sg_entries = cmd_sg_entries;
	}

3543
	srp_remove_wq = create_workqueue("srp_remove");
3544 3545
	if (!srp_remove_wq) {
		ret = -ENOMEM;
3546 3547 3548 3549
		goto out;
	}

	ret = -ENOMEM;
3550 3551 3552
	ib_srp_transport_template =
		srp_attach_transport(&ib_srp_transport_functions);
	if (!ib_srp_transport_template)
3553
		goto destroy_wq;
3554

3555 3556
	ret = class_register(&srp_class);
	if (ret) {
3557
		pr_err("couldn't register class infiniband_srp\n");
3558
		goto release_tr;
3559 3560
	}

3561 3562
	ib_sa_register_client(&srp_sa_client);

3563 3564
	ret = ib_register_client(&srp_client);
	if (ret) {
3565
		pr_err("couldn't register IB client\n");
3566
		goto unreg_sa;
3567 3568
	}

3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581
out:
	return ret;

unreg_sa:
	ib_sa_unregister_client(&srp_sa_client);
	class_unregister(&srp_class);

release_tr:
	srp_release_transport(ib_srp_transport_template);

destroy_wq:
	destroy_workqueue(srp_remove_wq);
	goto out;
3582 3583 3584 3585 3586
}

static void __exit srp_cleanup_module(void)
{
	ib_unregister_client(&srp_client);
3587
	ib_sa_unregister_client(&srp_sa_client);
3588
	class_unregister(&srp_class);
3589
	srp_release_transport(ib_srp_transport_template);
3590
	destroy_workqueue(srp_remove_wq);
3591 3592 3593 3594
}

module_init(srp_init_module);
module_exit(srp_cleanup_module);