[releases.git] / rdma.c

// SPDX-License-Identifier: GPL-2.0
/*
 * NVMe over Fabrics RDMA host code.
 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <rdma/mr_pool.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/atomic.h>
#include <linux/blk-mq.h>
#include <linux/blk-mq-rdma.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/scatterlist.h>
#include <linux/nvme.h>
#include <asm/unaligned.h>

#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
#include <linux/nvme-rdma.h>

#include "nvme.h"
#include "fabrics.h"


#define NVME_RDMA_CONNECT_TIMEOUT_MS    3000            /* 3 second */

#define NVME_RDMA_MAX_SEGMENTS          256

#define NVME_RDMA_MAX_INLINE_SEGMENTS   4

#define NVME_RDMA_DATA_SGL_SIZE \
        (sizeof(struct scatterlist) * NVME_INLINE_SG_CNT)
#define NVME_RDMA_METADATA_SGL_SIZE \
        (sizeof(struct scatterlist) * NVME_INLINE_METADATA_SG_CNT)

struct nvme_rdma_device {
        struct ib_device        *dev;
        struct ib_pd            *pd;
        struct kref             ref;
        struct list_head        entry;
        unsigned int            num_inline_segments;
};

struct nvme_rdma_qe {
        struct ib_cqe           cqe;
        void                    *data;
        u64                     dma;
};

struct nvme_rdma_sgl {
        int                     nents;
        struct sg_table         sg_table;
};

struct nvme_rdma_queue;
struct nvme_rdma_request {
        struct nvme_request     req;
        struct ib_mr            *mr;
        struct nvme_rdma_qe     sqe;
        union nvme_result       result;
        __le16                  status;
        refcount_t              ref;
        struct ib_sge           sge[1 + NVME_RDMA_MAX_INLINE_SEGMENTS];
        u32                     num_sge;
        struct ib_reg_wr        reg_wr;
        struct ib_cqe           reg_cqe;
        struct nvme_rdma_queue  *queue;
        struct nvme_rdma_sgl    data_sgl;
        struct nvme_rdma_sgl    *metadata_sgl;
        bool                    use_sig_mr;
};

enum nvme_rdma_queue_flags {
        NVME_RDMA_Q_ALLOCATED           = 0,
        NVME_RDMA_Q_LIVE                = 1,
        NVME_RDMA_Q_TR_READY            = 2,
};

struct nvme_rdma_queue {
        struct nvme_rdma_qe     *rsp_ring;
        int                     queue_size;
        size_t                  cmnd_capsule_len;
        struct nvme_rdma_ctrl   *ctrl;
        struct nvme_rdma_device *device;
        struct ib_cq            *ib_cq;
        struct ib_qp            *qp;

        unsigned long           flags;
        struct rdma_cm_id       *cm_id;
        int                     cm_error;
        struct completion       cm_done;
        bool                    pi_support;
        int                     cq_size;
        struct mutex            queue_lock;
};

struct nvme_rdma_ctrl {
        /* read only in the hot path */
        struct nvme_rdma_queue  *queues;

        /* other member variables */
        struct blk_mq_tag_set   tag_set;
        struct work_struct      err_work;

        struct nvme_rdma_qe     async_event_sqe;

        struct delayed_work     reconnect_work;

        struct list_head        list;

        struct blk_mq_tag_set   admin_tag_set;
        struct nvme_rdma_device *device;

        u32                     max_fr_pages;

        struct sockaddr_storage addr;
        struct sockaddr_storage src_addr;

        struct nvme_ctrl        ctrl;
        bool                    use_inline_data;
        u32                     io_queues[HCTX_MAX_TYPES];
};

static inline struct nvme_rdma_ctrl *to_rdma_ctrl(struct nvme_ctrl *ctrl)
{
        return container_of(ctrl, struct nvme_rdma_ctrl, ctrl);
}

static LIST_HEAD(device_list);
static DEFINE_MUTEX(device_list_mutex);

static LIST_HEAD(nvme_rdma_ctrl_list);
static DEFINE_MUTEX(nvme_rdma_ctrl_mutex);

/*
 * Disabling this option makes small I/O goes faster, but is fundamentally
 * unsafe.  With it turned off we will have to register a global rkey that
 * allows read and write access to all physical memory.
 */
static bool register_always = true;
module_param(register_always, bool, 0444);
MODULE_PARM_DESC(register_always,
         "Use memory registration even for contiguous memory regions");

static int nvme_rdma_cm_handler(struct rdma_cm_id *cm_id,
                struct rdma_cm_event *event);
static void nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc);
static void nvme_rdma_complete_rq(struct request *rq);

static const struct blk_mq_ops nvme_rdma_mq_ops;
static const struct blk_mq_ops nvme_rdma_admin_mq_ops;

static inline int nvme_rdma_queue_idx(struct nvme_rdma_queue *queue)
{
        return queue - queue->ctrl->queues;
}

static bool nvme_rdma_poll_queue(struct nvme_rdma_queue *queue)
{
        return nvme_rdma_queue_idx(queue) >
                queue->ctrl->io_queues[HCTX_TYPE_DEFAULT] +
                queue->ctrl->io_queues[HCTX_TYPE_READ];
}

static inline size_t nvme_rdma_inline_data_size(struct nvme_rdma_queue *queue)
{
        return queue->cmnd_capsule_len - sizeof(struct nvme_command);
}

static void nvme_rdma_free_qe(struct ib_device *ibdev, struct nvme_rdma_qe *qe,
                size_t capsule_size, enum dma_data_direction dir)
{
        ib_dma_unmap_single(ibdev, qe->dma, capsule_size, dir);
        kfree(qe->data);
}

static int nvme_rdma_alloc_qe(struct ib_device *ibdev, struct nvme_rdma_qe *qe,
                size_t capsule_size, enum dma_data_direction dir)
{
        qe->data = kzalloc(capsule_size, GFP_KERNEL);
        if (!qe->data)
                return -ENOMEM;

        qe->dma = ib_dma_map_single(ibdev, qe->data, capsule_size, dir);
        if (ib_dma_mapping_error(ibdev, qe->dma)) {
                kfree(qe->data);
                qe->data = NULL;
                return -ENOMEM;
        }

        return 0;
}

static void nvme_rdma_free_ring(struct ib_device *ibdev,
                struct nvme_rdma_qe *ring, size_t ib_queue_size,
                size_t capsule_size, enum dma_data_direction dir)
{
        int i;

        for (i = 0; i < ib_queue_size; i++)
                nvme_rdma_free_qe(ibdev, &ring[i], capsule_size, dir);
        kfree(ring);
}

static struct nvme_rdma_qe *nvme_rdma_alloc_ring(struct ib_device *ibdev,
                size_t ib_queue_size, size_t capsule_size,
                enum dma_data_direction dir)
{
        struct nvme_rdma_qe *ring;
        int i;

        ring = kcalloc(ib_queue_size, sizeof(struct nvme_rdma_qe), GFP_KERNEL);
        if (!ring)
                return NULL;

        /*
         * Bind the CQEs (post recv buffers) DMA mapping to the RDMA queue
         * lifetime. It's safe, since any chage in the underlying RDMA device
         * will issue error recovery and queue re-creation.
         */
        for (i = 0; i < ib_queue_size; i++) {
                if (nvme_rdma_alloc_qe(ibdev, &ring[i], capsule_size, dir))
                        goto out_free_ring;
        }

        return ring;

out_free_ring:
        nvme_rdma_free_ring(ibdev, ring, i, capsule_size, dir);
        return NULL;
}

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

}

static int nvme_rdma_wait_for_cm(struct nvme_rdma_queue *queue)
{
        int ret;

        ret = wait_for_completion_interruptible_timeout(&queue->cm_done,
                        msecs_to_jiffies(NVME_RDMA_CONNECT_TIMEOUT_MS) + 1);
        if (ret < 0)
                return ret;
        if (ret == 0)
                return -ETIMEDOUT;
        WARN_ON_ONCE(queue->cm_error > 0);
        return queue->cm_error;
}

static int nvme_rdma_create_qp(struct nvme_rdma_queue *queue, const int factor)
{
        struct nvme_rdma_device *dev = queue->device;
        struct ib_qp_init_attr init_attr;
        int ret;

        memset(&init_attr, 0, sizeof(init_attr));
        init_attr.event_handler = nvme_rdma_qp_event;
        /* +1 for drain */
        init_attr.cap.max_send_wr = factor * queue->queue_size + 1;
        /* +1 for drain */
        init_attr.cap.max_recv_wr = queue->queue_size + 1;
        init_attr.cap.max_recv_sge = 1;
        init_attr.cap.max_send_sge = 1 + dev->num_inline_segments;
        init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
        init_attr.qp_type = IB_QPT_RC;
        init_attr.send_cq = queue->ib_cq;
        init_attr.recv_cq = queue->ib_cq;
        if (queue->pi_support)
                init_attr.create_flags |= IB_QP_CREATE_INTEGRITY_EN;
        init_attr.qp_context = queue;

        ret = rdma_create_qp(queue->cm_id, dev->pd, &init_attr);

        queue->qp = queue->cm_id->qp;
        return ret;
}

static void nvme_rdma_exit_request(struct blk_mq_tag_set *set,
                struct request *rq, unsigned int hctx_idx)
{
        struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);

        kfree(req->sqe.data);
}

static int nvme_rdma_init_request(struct blk_mq_tag_set *set,
                struct request *rq, unsigned int hctx_idx,
                unsigned int numa_node)
{
        struct nvme_rdma_ctrl *ctrl = set->driver_data;
        struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
        int queue_idx = (set == &ctrl->tag_set) ? hctx_idx + 1 : 0;
        struct nvme_rdma_queue *queue = &ctrl->queues[queue_idx];

        nvme_req(rq)->ctrl = &ctrl->ctrl;
        req->sqe.data = kzalloc(sizeof(struct nvme_command), GFP_KERNEL);
        if (!req->sqe.data)
                return -ENOMEM;

        /* metadata nvme_rdma_sgl struct is located after command's data SGL */
        if (queue->pi_support)
                req->metadata_sgl = (void *)nvme_req(rq) +
                        sizeof(struct nvme_rdma_request) +
                        NVME_RDMA_DATA_SGL_SIZE;

        req->queue = queue;

        return 0;
}

static int nvme_rdma_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
                unsigned int hctx_idx)
{
        struct nvme_rdma_ctrl *ctrl = data;
        struct nvme_rdma_queue *queue = &ctrl->queues[hctx_idx + 1];

        BUG_ON(hctx_idx >= ctrl->ctrl.queue_count);

        hctx->driver_data = queue;
        return 0;
}

static int nvme_rdma_init_admin_hctx(struct blk_mq_hw_ctx *hctx, void *data,
                unsigned int hctx_idx)
{
        struct nvme_rdma_ctrl *ctrl = data;
        struct nvme_rdma_queue *queue = &ctrl->queues[0];

        BUG_ON(hctx_idx != 0);

        hctx->driver_data = queue;
        return 0;
}

static void nvme_rdma_free_dev(struct kref *ref)
{
        struct nvme_rdma_device *ndev =
                container_of(ref, struct nvme_rdma_device, ref);

        mutex_lock(&device_list_mutex);
        list_del(&ndev->entry);
        mutex_unlock(&device_list_mutex);

        ib_dealloc_pd(ndev->pd);
        kfree(ndev);
}

static void nvme_rdma_dev_put(struct nvme_rdma_device *dev)
{
        kref_put(&dev->ref, nvme_rdma_free_dev);
}

static int nvme_rdma_dev_get(struct nvme_rdma_device *dev)
{
        return kref_get_unless_zero(&dev->ref);
}

static struct nvme_rdma_device *
nvme_rdma_find_get_device(struct rdma_cm_id *cm_id)
{
        struct nvme_rdma_device *ndev;

        mutex_lock(&device_list_mutex);
        list_for_each_entry(ndev, &device_list, entry) {
                if (ndev->dev->node_guid == cm_id->device->node_guid &&
                    nvme_rdma_dev_get(ndev))
                        goto out_unlock;
        }

        ndev = kzalloc(sizeof(*ndev), GFP_KERNEL);
        if (!ndev)
                goto out_err;

        ndev->dev = cm_id->device;
        kref_init(&ndev->ref);

        ndev->pd = ib_alloc_pd(ndev->dev,
                register_always ? 0 : IB_PD_UNSAFE_GLOBAL_RKEY);
        if (IS_ERR(ndev->pd))
                goto out_free_dev;

        if (!(ndev->dev->attrs.device_cap_flags &
              IB_DEVICE_MEM_MGT_EXTENSIONS)) {
                dev_err(&ndev->dev->dev,
                        "Memory registrations not supported.\n");
                goto out_free_pd;
        }

        ndev->num_inline_segments = min(NVME_RDMA_MAX_INLINE_SEGMENTS,
                                        ndev->dev->attrs.max_send_sge - 1);
        list_add(&ndev->entry, &device_list);
out_unlock:
        mutex_unlock(&device_list_mutex);
        return ndev;

out_free_pd:
        ib_dealloc_pd(ndev->pd);
out_free_dev:
        kfree(ndev);
out_err:
        mutex_unlock(&device_list_mutex);
        return NULL;
}

static void nvme_rdma_free_cq(struct nvme_rdma_queue *queue)
{
        if (nvme_rdma_poll_queue(queue))
                ib_free_cq(queue->ib_cq);
        else
                ib_cq_pool_put(queue->ib_cq, queue->cq_size);
}

static void nvme_rdma_destroy_queue_ib(struct nvme_rdma_queue *queue)
{
        struct nvme_rdma_device *dev;
        struct ib_device *ibdev;

        if (!test_and_clear_bit(NVME_RDMA_Q_TR_READY, &queue->flags))
                return;

        dev = queue->device;
        ibdev = dev->dev;

        if (queue->pi_support)
                ib_mr_pool_destroy(queue->qp, &queue->qp->sig_mrs);
        ib_mr_pool_destroy(queue->qp, &queue->qp->rdma_mrs);

        /*
         * The cm_id object might have been destroyed during RDMA connection
         * establishment error flow to avoid getting other cma events, thus
         * the destruction of the QP shouldn't use rdma_cm API.
         */
        ib_destroy_qp(queue->qp);
        nvme_rdma_free_cq(queue);

        nvme_rdma_free_ring(ibdev, queue->rsp_ring, queue->queue_size,
                        sizeof(struct nvme_completion), DMA_FROM_DEVICE);

        nvme_rdma_dev_put(dev);
}

static int nvme_rdma_get_max_fr_pages(struct ib_device *ibdev, bool pi_support)
{
        u32 max_page_list_len;

        if (pi_support)
                max_page_list_len = ibdev->attrs.max_pi_fast_reg_page_list_len;
        else
                max_page_list_len = ibdev->attrs.max_fast_reg_page_list_len;

        return min_t(u32, NVME_RDMA_MAX_SEGMENTS, max_page_list_len - 1);
}

static int nvme_rdma_create_cq(struct ib_device *ibdev,
                struct nvme_rdma_queue *queue)
{
        int ret, comp_vector, idx = nvme_rdma_queue_idx(queue);
        enum ib_poll_context poll_ctx;

        /*
         * Spread I/O queues completion vectors according their queue index.
         * Admin queues can always go on completion vector 0.
         */
        comp_vector = (idx == 0 ? idx : idx - 1) % ibdev->num_comp_vectors;

        /* Polling queues need direct cq polling context */
        if (nvme_rdma_poll_queue(queue)) {
                poll_ctx = IB_POLL_DIRECT;
                queue->ib_cq = ib_alloc_cq(ibdev, queue, queue->cq_size,
                                           comp_vector, poll_ctx);
        } else {
                poll_ctx = IB_POLL_SOFTIRQ;
                queue->ib_cq = ib_cq_pool_get(ibdev, queue->cq_size,
                                              comp_vector, poll_ctx);
        }

        if (IS_ERR(queue->ib_cq)) {
                ret = PTR_ERR(queue->ib_cq);
                return ret;
        }

        return 0;
}

static int nvme_rdma_create_queue_ib(struct nvme_rdma_queue *queue)
{
        struct ib_device *ibdev;
        const int send_wr_factor = 3;                   /* MR, SEND, INV */
        const int cq_factor = send_wr_factor + 1;       /* + RECV */
        int ret, pages_per_mr;

        queue->device = nvme_rdma_find_get_device(queue->cm_id);
        if (!queue->device) {
                dev_err(queue->cm_id->device->dev.parent,
                        "no client data found!\n");
                return -ECONNREFUSED;
        }
        ibdev = queue->device->dev;

        /* +1 for ib_stop_cq */
        queue->cq_size = cq_factor * queue->queue_size + 1;

        ret = nvme_rdma_create_cq(ibdev, queue);
        if (ret)
                goto out_put_dev;

        ret = nvme_rdma_create_qp(queue, send_wr_factor);
        if (ret)
                goto out_destroy_ib_cq;

        queue->rsp_ring = nvme_rdma_alloc_ring(ibdev, queue->queue_size,
                        sizeof(struct nvme_completion), DMA_FROM_DEVICE);
        if (!queue->rsp_ring) {
                ret = -ENOMEM;
                goto out_destroy_qp;
        }

        /*
         * Currently we don't use SG_GAPS MR's so if the first entry is
         * misaligned we'll end up using two entries for a single data page,
         * so one additional entry is required.
         */
        pages_per_mr = nvme_rdma_get_max_fr_pages(ibdev, queue->pi_support) + 1;
        ret = ib_mr_pool_init(queue->qp, &queue->qp->rdma_mrs,
                              queue->queue_size,
                              IB_MR_TYPE_MEM_REG,
                              pages_per_mr, 0);
        if (ret) {
                dev_err(queue->ctrl->ctrl.device,
                        "failed to initialize MR pool sized %d for QID %d\n",
                        queue->queue_size, nvme_rdma_queue_idx(queue));
                goto out_destroy_ring;
        }

        if (queue->pi_support) {
                ret = ib_mr_pool_init(queue->qp, &queue->qp->sig_mrs,
                                      queue->queue_size, IB_MR_TYPE_INTEGRITY,
                                      pages_per_mr, pages_per_mr);
                if (ret) {
                        dev_err(queue->ctrl->ctrl.device,
                                "failed to initialize PI MR pool sized %d for QID %d\n",
                                queue->queue_size, nvme_rdma_queue_idx(queue));
                        goto out_destroy_mr_pool;
                }
        }

        set_bit(NVME_RDMA_Q_TR_READY, &queue->flags);

        return 0;

out_destroy_mr_pool:
        ib_mr_pool_destroy(queue->qp, &queue->qp->rdma_mrs);
out_destroy_ring:
        nvme_rdma_free_ring(ibdev, queue->rsp_ring, queue->queue_size,
                            sizeof(struct nvme_completion), DMA_FROM_DEVICE);
out_destroy_qp:
        rdma_destroy_qp(queue->cm_id);
out_destroy_ib_cq:
        nvme_rdma_free_cq(queue);
out_put_dev:
        nvme_rdma_dev_put(queue->device);
        return ret;
}

static int nvme_rdma_alloc_queue(struct nvme_rdma_ctrl *ctrl,
                int idx, size_t queue_size)
{
        struct nvme_rdma_queue *queue;
        struct sockaddr *src_addr = NULL;
        int ret;

        queue = &ctrl->queues[idx];
        mutex_init(&queue->queue_lock);
        queue->ctrl = ctrl;
        if (idx && ctrl->ctrl.max_integrity_segments)
                queue->pi_support = true;
        else
                queue->pi_support = false;
        init_completion(&queue->cm_done);

        if (idx > 0)
                queue->cmnd_capsule_len = ctrl->ctrl.ioccsz * 16;
        else
                queue->cmnd_capsule_len = sizeof(struct nvme_command);

        queue->queue_size = queue_size;

        queue->cm_id = rdma_create_id(&init_net, nvme_rdma_cm_handler, queue,
                        RDMA_PS_TCP, IB_QPT_RC);
        if (IS_ERR(queue->cm_id)) {
                dev_info(ctrl->ctrl.device,
                        "failed to create CM ID: %ld\n", PTR_ERR(queue->cm_id));
                ret = PTR_ERR(queue->cm_id);
                goto out_destroy_mutex;
        }

        if (ctrl->ctrl.opts->mask & NVMF_OPT_HOST_TRADDR)
                src_addr = (struct sockaddr *)&ctrl->src_addr;

        queue->cm_error = -ETIMEDOUT;
        ret = rdma_resolve_addr(queue->cm_id, src_addr,
                        (struct sockaddr *)&ctrl->addr,
                        NVME_RDMA_CONNECT_TIMEOUT_MS);
        if (ret) {
                dev_info(ctrl->ctrl.device,
                        "rdma_resolve_addr failed (%d).\n", ret);
                goto out_destroy_cm_id;
        }

        ret = nvme_rdma_wait_for_cm(queue);
        if (ret) {
                dev_info(ctrl->ctrl.device,
                        "rdma connection establishment failed (%d)\n", ret);
                goto out_destroy_cm_id;
        }

        set_bit(NVME_RDMA_Q_ALLOCATED, &queue->flags);

        return 0;

out_destroy_cm_id:
        rdma_destroy_id(queue->cm_id);
        nvme_rdma_destroy_queue_ib(queue);
out_destroy_mutex:
        mutex_destroy(&queue->queue_lock);
        return ret;
}

static void __nvme_rdma_stop_queue(struct nvme_rdma_queue *queue)
{
        rdma_disconnect(queue->cm_id);
        ib_drain_qp(queue->qp);
}

static void nvme_rdma_stop_queue(struct nvme_rdma_queue *queue)
{
        if (!test_bit(NVME_RDMA_Q_ALLOCATED, &queue->flags))
                return;

        mutex_lock(&queue->queue_lock);
        if (test_and_clear_bit(NVME_RDMA_Q_LIVE, &queue->flags))
                __nvme_rdma_stop_queue(queue);
        mutex_unlock(&queue->queue_lock);
}

static void nvme_rdma_free_queue(struct nvme_rdma_queue *queue)
{
        if (!test_and_clear_bit(NVME_RDMA_Q_ALLOCATED, &queue->flags))
                return;

        rdma_destroy_id(queue->cm_id);
        nvme_rdma_destroy_queue_ib(queue);
        mutex_destroy(&queue->queue_lock);
}

static void nvme_rdma_free_io_queues(struct nvme_rdma_ctrl *ctrl)
{
        int i;

        for (i = 1; i < ctrl->ctrl.queue_count; i++)
                nvme_rdma_free_queue(&ctrl->queues[i]);
}

static void nvme_rdma_stop_io_queues(struct nvme_rdma_ctrl *ctrl)
{
        int i;

        for (i = 1; i < ctrl->ctrl.queue_count; i++)
                nvme_rdma_stop_queue(&ctrl->queues[i]);
}

static int nvme_rdma_start_queue(struct nvme_rdma_ctrl *ctrl, int idx)
{
        struct nvme_rdma_queue *queue = &ctrl->queues[idx];
        bool poll = nvme_rdma_poll_queue(queue);
        int ret;

        if (idx)
                ret = nvmf_connect_io_queue(&ctrl->ctrl, idx, poll);
        else
                ret = nvmf_connect_admin_queue(&ctrl->ctrl);

        if (!ret) {
                set_bit(NVME_RDMA_Q_LIVE, &queue->flags);
        } else {
                if (test_bit(NVME_RDMA_Q_ALLOCATED, &queue->flags))
                        __nvme_rdma_stop_queue(queue);
                dev_info(ctrl->ctrl.device,
                        "failed to connect queue: %d ret=%d\n", idx, ret);
        }
        return ret;
}

static int nvme_rdma_start_io_queues(struct nvme_rdma_ctrl *ctrl)
{
        int i, ret = 0;

        for (i = 1; i < ctrl->ctrl.queue_count; i++) {
                ret = nvme_rdma_start_queue(ctrl, i);
                if (ret)
                        goto out_stop_queues;
        }

        return 0;

out_stop_queues:
        for (i--; i >= 1; i--)
                nvme_rdma_stop_queue(&ctrl->queues[i]);
        return ret;
}

static int nvme_rdma_alloc_io_queues(struct nvme_rdma_ctrl *ctrl)
{
        struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;
        struct ib_device *ibdev = ctrl->device->dev;
        unsigned int nr_io_queues, nr_default_queues;
        unsigned int nr_read_queues, nr_poll_queues;
        int i, ret;

        nr_read_queues = min_t(unsigned int, ibdev->num_comp_vectors,
                                min(opts->nr_io_queues, num_online_cpus()));
        nr_default_queues =  min_t(unsigned int, ibdev->num_comp_vectors,
                                min(opts->nr_write_queues, num_online_cpus()));
        nr_poll_queues = min(opts->nr_poll_queues, num_online_cpus());
        nr_io_queues = nr_read_queues + nr_default_queues + nr_poll_queues;

        ret = nvme_set_queue_count(&ctrl->ctrl, &nr_io_queues);
        if (ret)
                return ret;

        if (nr_io_queues == 0) {
                dev_err(ctrl->ctrl.device,
                        "unable to set any I/O queues\n");
                return -ENOMEM;
        }

        ctrl->ctrl.queue_count = nr_io_queues + 1;
        dev_info(ctrl->ctrl.device,
                "creating %d I/O queues.\n", nr_io_queues);

        if (opts->nr_write_queues && nr_read_queues < nr_io_queues) {
                /*
                 * separate read/write queues
                 * hand out dedicated default queues only after we have
                 * sufficient read queues.
                 */
                ctrl->io_queues[HCTX_TYPE_READ] = nr_read_queues;
                nr_io_queues -= ctrl->io_queues[HCTX_TYPE_READ];
                ctrl->io_queues[HCTX_TYPE_DEFAULT] =
                        min(nr_default_queues, nr_io_queues);
                nr_io_queues -= ctrl->io_queues[HCTX_TYPE_DEFAULT];
        } else {
                /*
                 * shared read/write queues
                 * either no write queues were requested, or we don't have
                 * sufficient queue count to have dedicated default queues.
                 */
                ctrl->io_queues[HCTX_TYPE_DEFAULT] =
                        min(nr_read_queues, nr_io_queues);
                nr_io_queues -= ctrl->io_queues[HCTX_TYPE_DEFAULT];
        }

        if (opts->nr_poll_queues && nr_io_queues) {
                /* map dedicated poll queues only if we have queues left */
                ctrl->io_queues[HCTX_TYPE_POLL] =
                        min(nr_poll_queues, nr_io_queues);
        }

        for (i = 1; i < ctrl->ctrl.queue_count; i++) {
                ret = nvme_rdma_alloc_queue(ctrl, i,
                                ctrl->ctrl.sqsize + 1);
                if (ret)
                        goto out_free_queues;
        }

        return 0;

out_free_queues:
        for (i--; i >= 1; i--)
                nvme_rdma_free_queue(&ctrl->queues[i]);

        return ret;
}

static struct blk_mq_tag_set *nvme_rdma_alloc_tagset(struct nvme_ctrl *nctrl,
                bool admin)
{
        struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);
        struct blk_mq_tag_set *set;
        int ret;

        if (admin) {
                set = &ctrl->admin_tag_set;
                memset(set, 0, sizeof(*set));
                set->ops = &nvme_rdma_admin_mq_ops;
                set->queue_depth = NVME_AQ_MQ_TAG_DEPTH;
                set->reserved_tags = 2; /* connect + keep-alive */
                set->numa_node = nctrl->numa_node;
                set->cmd_size = sizeof(struct nvme_rdma_request) +
                                NVME_RDMA_DATA_SGL_SIZE;
                set->driver_data = ctrl;
                set->nr_hw_queues = 1;
                set->timeout = ADMIN_TIMEOUT;
                set->flags = BLK_MQ_F_NO_SCHED;
        } else {
                set = &ctrl->tag_set;
                memset(set, 0, sizeof(*set));
                set->ops = &nvme_rdma_mq_ops;
                set->queue_depth = nctrl->sqsize + 1;
                set->reserved_tags = 1; /* fabric connect */
                set->numa_node = nctrl->numa_node;
                set->flags = BLK_MQ_F_SHOULD_MERGE;
                set->cmd_size = sizeof(struct nvme_rdma_request) +
                                NVME_RDMA_DATA_SGL_SIZE;
                if (nctrl->max_integrity_segments)
                        set->cmd_size += sizeof(struct nvme_rdma_sgl) +
                                         NVME_RDMA_METADATA_SGL_SIZE;
                set->driver_data = ctrl;
                set->nr_hw_queues = nctrl->queue_count - 1;
                set->timeout = NVME_IO_TIMEOUT;
                set->nr_maps = nctrl->opts->nr_poll_queues ? HCTX_MAX_TYPES : 2;
        }

        ret = blk_mq_alloc_tag_set(set);
        if (ret)
                return ERR_PTR(ret);

        return set;
}

static void nvme_rdma_destroy_admin_queue(struct nvme_rdma_ctrl *ctrl,
                bool remove)
{
        if (remove) {
                blk_cleanup_queue(ctrl->ctrl.admin_q);
                blk_cleanup_queue(ctrl->ctrl.fabrics_q);
                blk_mq_free_tag_set(ctrl->ctrl.admin_tagset);
        }
        if (ctrl->async_event_sqe.data) {
                cancel_work_sync(&ctrl->ctrl.async_event_work);
                nvme_rdma_free_qe(ctrl->device->dev, &ctrl->async_event_sqe,
                                sizeof(struct nvme_command), DMA_TO_DEVICE);
                ctrl->async_event_sqe.data = NULL;
        }
        nvme_rdma_free_queue(&ctrl->queues[0]);
}

static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl,
                bool new)
{
        bool pi_capable = false;
        int error;

        error = nvme_rdma_alloc_queue(ctrl, 0, NVME_AQ_DEPTH);
        if (error)
                return error;

        ctrl->device = ctrl->queues[0].device;
        ctrl->ctrl.numa_node = ibdev_to_node(ctrl->device->dev);

        /* T10-PI support */
        if (ctrl->device->dev->attrs.device_cap_flags &
            IB_DEVICE_INTEGRITY_HANDOVER)
                pi_capable = true;

        ctrl->max_fr_pages = nvme_rdma_get_max_fr_pages(ctrl->device->dev,
                                                        pi_capable);

        /*
         * Bind the async event SQE DMA mapping to the admin queue lifetime.
         * It's safe, since any chage in the underlying RDMA device will issue
         * error recovery and queue re-creation.
         */
        error = nvme_rdma_alloc_qe(ctrl->device->dev, &ctrl->async_event_sqe,
                        sizeof(struct nvme_command), DMA_TO_DEVICE);
        if (error)
                goto out_free_queue;

        if (new) {
                ctrl->ctrl.admin_tagset = nvme_rdma_alloc_tagset(&ctrl->ctrl, true);
                if (IS_ERR(ctrl->ctrl.admin_tagset)) {
                        error = PTR_ERR(ctrl->ctrl.admin_tagset);
                        goto out_free_async_qe;
                }

                ctrl->ctrl.fabrics_q = blk_mq_init_queue(&ctrl->admin_tag_set);
                if (IS_ERR(ctrl->ctrl.fabrics_q)) {
                        error = PTR_ERR(ctrl->ctrl.fabrics_q);
                        goto out_free_tagset;
                }

                ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
                if (IS_ERR(ctrl->ctrl.admin_q)) {
                        error = PTR_ERR(ctrl->ctrl.admin_q);
                        goto out_cleanup_fabrics_q;
                }
        }

        error = nvme_rdma_start_queue(ctrl, 0);
        if (error)
                goto out_cleanup_queue;

        error = nvme_enable_ctrl(&ctrl->ctrl);
        if (error)
                goto out_stop_queue;

        ctrl->ctrl.max_segments = ctrl->max_fr_pages;
        ctrl->ctrl.max_hw_sectors = ctrl->max_fr_pages << (ilog2(SZ_4K) - 9);
        if (pi_capable)
                ctrl->ctrl.max_integrity_segments = ctrl->max_fr_pages;
        else
                ctrl->ctrl.max_integrity_segments = 0;

        blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);

        error = nvme_init_identify(&ctrl->ctrl);
        if (error)
                goto out_quiesce_queue;

        return 0;

out_quiesce_queue:
        blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
        blk_sync_queue(ctrl->ctrl.admin_q);
out_stop_queue:
        nvme_rdma_stop_queue(&ctrl->queues[0]);
        nvme_cancel_admin_tagset(&ctrl->ctrl);
out_cleanup_queue:
        if (new)
                blk_cleanup_queue(ctrl->ctrl.admin_q);
out_cleanup_fabrics_q:
        if (new)
                blk_cleanup_queue(ctrl->ctrl.fabrics_q);
out_free_tagset:
        if (new)
                blk_mq_free_tag_set(ctrl->ctrl.admin_tagset);
out_free_async_qe:
        if (ctrl->async_event_sqe.data) {
                nvme_rdma_free_qe(ctrl->device->dev, &ctrl->async_event_sqe,
                        sizeof(struct nvme_command), DMA_TO_DEVICE);
                ctrl->async_event_sqe.data = NULL;
        }
out_free_queue:
        nvme_rdma_free_queue(&ctrl->queues[0]);
        return error;
}

static void nvme_rdma_destroy_io_queues(struct nvme_rdma_ctrl *ctrl,
                bool remove)
{
        if (remove) {
                blk_cleanup_queue(ctrl->ctrl.connect_q);
                blk_mq_free_tag_set(ctrl->ctrl.tagset);
        }
        nvme_rdma_free_io_queues(ctrl);
}

static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
{
        int ret;

        ret = nvme_rdma_alloc_io_queues(ctrl);
        if (ret)
                return ret;

        if (new) {
                ctrl->ctrl.tagset = nvme_rdma_alloc_tagset(&ctrl->ctrl, false);
                if (IS_ERR(ctrl->ctrl.tagset)) {
                        ret = PTR_ERR(ctrl->ctrl.tagset);
                        goto out_free_io_queues;
                }

                ctrl->ctrl.connect_q = blk_mq_init_queue(&ctrl->tag_set);
                if (IS_ERR(ctrl->ctrl.connect_q)) {
                        ret = PTR_ERR(ctrl->ctrl.connect_q);
                        goto out_free_tag_set;
                }
        }

        ret = nvme_rdma_start_io_queues(ctrl);
        if (ret)
                goto out_cleanup_connect_q;

        if (!new) {
                nvme_start_freeze(&ctrl->ctrl);
                nvme_start_queues(&ctrl->ctrl);
                if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) {
                        /*
                         * If we timed out waiting for freeze we are likely to
                         * be stuck.  Fail the controller initialization just
                         * to be safe.
                         */
                        ret = -ENODEV;
                        nvme_unfreeze(&ctrl->ctrl);
                        goto out_wait_freeze_timed_out;
                }
                blk_mq_update_nr_hw_queues(ctrl->ctrl.tagset,
                        ctrl->ctrl.queue_count - 1);
                nvme_unfreeze(&ctrl->ctrl);
        }

        return 0;

out_wait_freeze_timed_out:
        nvme_stop_queues(&ctrl->ctrl);
        nvme_sync_io_queues(&ctrl->ctrl);
        nvme_rdma_stop_io_queues(ctrl);
out_cleanup_connect_q:
        nvme_cancel_tagset(&ctrl->ctrl);
        if (new)
                blk_cleanup_queue(ctrl->ctrl.connect_q);
out_free_tag_set:
        if (new)
                blk_mq_free_tag_set(ctrl->ctrl.tagset);
out_free_io_queues:
        nvme_rdma_free_io_queues(ctrl);
        return ret;
}

static void nvme_rdma_teardown_admin_queue(struct nvme_rdma_ctrl *ctrl,
                bool remove)
{
        blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
        blk_sync_queue(ctrl->ctrl.admin_q);
        nvme_rdma_stop_queue(&ctrl->queues[0]);
        if (ctrl->ctrl.admin_tagset) {
                blk_mq_tagset_busy_iter(ctrl->ctrl.admin_tagset,
                        nvme_cancel_request, &ctrl->ctrl);
                blk_mq_tagset_wait_completed_request(ctrl->ctrl.admin_tagset);
        }
        if (remove)
                blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
        nvme_rdma_destroy_admin_queue(ctrl, remove);
}

static void nvme_rdma_teardown_io_queues(struct nvme_rdma_ctrl *ctrl,
                bool remove)
{
        if (ctrl->ctrl.queue_count > 1) {
                nvme_stop_queues(&ctrl->ctrl);
                nvme_sync_io_queues(&ctrl->ctrl);
                nvme_rdma_stop_io_queues(ctrl);
                if (ctrl->ctrl.tagset) {
                        blk_mq_tagset_busy_iter(ctrl->ctrl.tagset,
                                nvme_cancel_request, &ctrl->ctrl);
                        blk_mq_tagset_wait_completed_request(ctrl->ctrl.tagset);
                }
                if (remove)
                        nvme_start_queues(&ctrl->ctrl);
                nvme_rdma_destroy_io_queues(ctrl, remove);
        }
}

static void nvme_rdma_stop_ctrl(struct nvme_ctrl *nctrl)
{
        struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);

        cancel_work_sync(&ctrl->err_work);
        cancel_delayed_work_sync(&ctrl->reconnect_work);
}

static void nvme_rdma_free_ctrl(struct nvme_ctrl *nctrl)
{
        struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);

        if (list_empty(&ctrl->list))
                goto free_ctrl;

        mutex_lock(&nvme_rdma_ctrl_mutex);
        list_del(&ctrl->list);
        mutex_unlock(&nvme_rdma_ctrl_mutex);

        nvmf_free_options(nctrl->opts);
free_ctrl:
        kfree(ctrl->queues);
        kfree(ctrl);
}

static void nvme_rdma_reconnect_or_remove(struct nvme_rdma_ctrl *ctrl)
{
        /* If we are resetting/deleting then do nothing */
        if (ctrl->ctrl.state != NVME_CTRL_CONNECTING) {
                WARN_ON_ONCE(ctrl->ctrl.state == NVME_CTRL_NEW ||
                        ctrl->ctrl.state == NVME_CTRL_LIVE);
                return;
        }

        if (nvmf_should_reconnect(&ctrl->ctrl)) {
                dev_info(ctrl->ctrl.device, "Reconnecting in %d seconds...\n",
                        ctrl->ctrl.opts->reconnect_delay);
                queue_delayed_work(nvme_wq, &ctrl->reconnect_work,
                                ctrl->ctrl.opts->reconnect_delay * HZ);
        } else {
                nvme_delete_ctrl(&ctrl->ctrl);
        }
}

static int nvme_rdma_setup_ctrl(struct nvme_rdma_ctrl *ctrl, bool new)
{
        int ret = -EINVAL;
        bool changed;

        ret = nvme_rdma_configure_admin_queue(ctrl, new);
        if (ret)
                return ret;

        if (ctrl->ctrl.icdoff) {
                ret = -EOPNOTSUPP;
                dev_err(ctrl->ctrl.device, "icdoff is not supported!\n");
                goto destroy_admin;
        }

        if (!(ctrl->ctrl.sgls & (1 << 2))) {
                ret = -EOPNOTSUPP;
                dev_err(ctrl->ctrl.device,
                        "Mandatory keyed sgls are not supported!\n");
                goto destroy_admin;
        }

        if (ctrl->ctrl.opts->queue_size > ctrl->ctrl.sqsize + 1) {
                dev_warn(ctrl->ctrl.device,
                        "queue_size %zu > ctrl sqsize %u, clamping down\n",
                        ctrl->ctrl.opts->queue_size, ctrl->ctrl.sqsize + 1);
        }

        if (ctrl->ctrl.sqsize + 1 > ctrl->ctrl.maxcmd) {
                dev_warn(ctrl->ctrl.device,
                        "sqsize %u > ctrl maxcmd %u, clamping down\n",
                        ctrl->ctrl.sqsize + 1, ctrl->ctrl.maxcmd);
                ctrl->ctrl.sqsize = ctrl->ctrl.maxcmd - 1;
        }

        if (ctrl->ctrl.sgls & (1 << 20))
                ctrl->use_inline_data = true;

        if (ctrl->ctrl.queue_count > 1) {
                ret = nvme_rdma_configure_io_queues(ctrl, new);
                if (ret)
                        goto destroy_admin;
        }

        changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE);
        if (!changed) {
                /*
                 * state change failure is ok if we started ctrl delete,
                 * unless we're during creation of a new controller to
                 * avoid races with teardown flow.
                 */
                WARN_ON_ONCE(ctrl->ctrl.state != NVME_CTRL_DELETING &&
                             ctrl->ctrl.state != NVME_CTRL_DELETING_NOIO);
                WARN_ON_ONCE(new);
                ret = -EINVAL;
                goto destroy_io;
        }

        nvme_start_ctrl(&ctrl->ctrl);
        return 0;

destroy_io:
        if (ctrl->ctrl.queue_count > 1) {
                nvme_stop_queues(&ctrl->ctrl);
                nvme_sync_io_queues(&ctrl->ctrl);
                nvme_rdma_stop_io_queues(ctrl);
                nvme_cancel_tagset(&ctrl->ctrl);
                nvme_rdma_destroy_io_queues(ctrl, new);
        }
destroy_admin:
        blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
        blk_sync_queue(ctrl->ctrl.admin_q);
        nvme_rdma_stop_queue(&ctrl->queues[0]);
        nvme_cancel_admin_tagset(&ctrl->ctrl);
        nvme_rdma_destroy_admin_queue(ctrl, new);
        return ret;
}

static void nvme_rdma_reconnect_ctrl_work(struct work_struct *work)
{
        struct nvme_rdma_ctrl *ctrl = container_of(to_delayed_work(work),
                        struct nvme_rdma_ctrl, reconnect_work);

        ++ctrl->ctrl.nr_reconnects;

        if (nvme_rdma_setup_ctrl(ctrl, false))
                goto requeue;

        dev_info(ctrl->ctrl.device, "Successfully reconnected (%d attempts)\n",
                        ctrl->ctrl.nr_reconnects);

        ctrl->ctrl.nr_reconnects = 0;

        return;

requeue:
        dev_info(ctrl->ctrl.device, "Failed reconnect attempt %d\n",
                        ctrl->ctrl.nr_reconnects);
        nvme_rdma_reconnect_or_remove(ctrl);
}

static void nvme_rdma_error_recovery_work(struct work_struct *work)
{
        struct nvme_rdma_ctrl *ctrl = container_of(work,
                        struct nvme_rdma_ctrl, err_work);

        nvme_stop_keep_alive(&ctrl->ctrl);
        flush_work(&ctrl->ctrl.async_event_work);
        nvme_rdma_teardown_io_queues(ctrl, false);
        nvme_start_queues(&ctrl->ctrl);
        nvme_rdma_teardown_admin_queue(ctrl, false);
        blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);

        if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
                /* state change failure is ok if we started ctrl delete */
                WARN_ON_ONCE(ctrl->ctrl.state != NVME_CTRL_DELETING &&
                             ctrl->ctrl.state != NVME_CTRL_DELETING_NOIO);
                return;
        }

        nvme_rdma_reconnect_or_remove(ctrl);
}

static void nvme_rdma_error_recovery(struct nvme_rdma_ctrl *ctrl)
{
        if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING))
                return;

        dev_warn(ctrl->ctrl.device, "starting error recovery\n");
        queue_work(nvme_reset_wq, &ctrl->err_work);
}

static void nvme_rdma_end_request(struct nvme_rdma_request *req)
{
        struct request *rq = blk_mq_rq_from_pdu(req);

        if (!refcount_dec_and_test(&req->ref))
                return;
        if (!nvme_try_complete_req(rq, req->status, req->result))
                nvme_rdma_complete_rq(rq);
}

static void nvme_rdma_wr_error(struct ib_cq *cq, struct ib_wc *wc,
                const char *op)
{
        struct nvme_rdma_queue *queue = wc->qp->qp_context;
        struct nvme_rdma_ctrl *ctrl = queue->ctrl;

        if (ctrl->ctrl.state == NVME_CTRL_LIVE)
                dev_info(ctrl->ctrl.device,
                             "%s for CQE 0x%p failed with status %s (%d)\n",
                             op, wc->wr_cqe,
                             ib_wc_status_msg(wc->status), wc->status);
        nvme_rdma_error_recovery(ctrl);
}

static void nvme_rdma_memreg_done(struct ib_cq *cq, struct ib_wc *wc)
{
        if (unlikely(wc->status != IB_WC_SUCCESS))
                nvme_rdma_wr_error(cq, wc, "MEMREG");
}

static void nvme_rdma_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
{
        struct nvme_rdma_request *req =
                container_of(wc->wr_cqe, struct nvme_rdma_request, reg_cqe);

        if (unlikely(wc->status != IB_WC_SUCCESS))
                nvme_rdma_wr_error(cq, wc, "LOCAL_INV");
        else
                nvme_rdma_end_request(req);
}

static int nvme_rdma_inv_rkey(struct nvme_rdma_queue *queue,
                struct nvme_rdma_request *req)
{
        struct ib_send_wr wr = {
                .opcode             = IB_WR_LOCAL_INV,
                .next               = NULL,
                .num_sge            = 0,
                .send_flags         = IB_SEND_SIGNALED,
                .ex.invalidate_rkey = req->mr->rkey,
        };

        req->reg_cqe.done = nvme_rdma_inv_rkey_done;
        wr.wr_cqe = &req->reg_cqe;

        return ib_post_send(queue->qp, &wr, NULL);
}

static void nvme_rdma_unmap_data(struct nvme_rdma_queue *queue,
                struct request *rq)
{
        struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
        struct nvme_rdma_device *dev = queue->device;
        struct ib_device *ibdev = dev->dev;
        struct list_head *pool = &queue->qp->rdma_mrs;

        if (!blk_rq_nr_phys_segments(rq))
                return;

        if (blk_integrity_rq(rq)) {
                ib_dma_unmap_sg(ibdev, req->metadata_sgl->sg_table.sgl,
                                req->metadata_sgl->nents, rq_dma_dir(rq));
                sg_free_table_chained(&req->metadata_sgl->sg_table,
                                      NVME_INLINE_METADATA_SG_CNT);
        }

        if (req->use_sig_mr)
                pool = &queue->qp->sig_mrs;

        if (req->mr) {
                ib_mr_pool_put(queue->qp, pool, req->mr);
                req->mr = NULL;
        }

        ib_dma_unmap_sg(ibdev, req->data_sgl.sg_table.sgl, req->data_sgl.nents,
                        rq_dma_dir(rq));
        sg_free_table_chained(&req->data_sgl.sg_table, NVME_INLINE_SG_CNT);
}

static int nvme_rdma_set_sg_null(struct nvme_command *c)
{
        struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;

        sg->addr = 0;
        put_unaligned_le24(0, sg->length);
        put_unaligned_le32(0, sg->key);
        sg->type = NVME_KEY_SGL_FMT_DATA_DESC << 4;
        return 0;
}

static int nvme_rdma_map_sg_inline(struct nvme_rdma_queue *queue,
                struct nvme_rdma_request *req, struct nvme_command *c,
                int count)
{
        struct nvme_sgl_desc *sg = &c->common.dptr.sgl;
        struct ib_sge *sge = &req->sge[1];
        struct scatterlist *sgl;
        u32 len = 0;
        int i;

        for_each_sg(req->data_sgl.sg_table.sgl, sgl, count, i) {
                sge->addr = sg_dma_address(sgl);
                sge->length = sg_dma_len(sgl);
                sge->lkey = queue->device->pd->local_dma_lkey;
                len += sge->length;
                sge++;
        }

        sg->addr = cpu_to_le64(queue->ctrl->ctrl.icdoff);
        sg->length = cpu_to_le32(len);
        sg->type = (NVME_SGL_FMT_DATA_DESC << 4) | NVME_SGL_FMT_OFFSET;

        req->num_sge += count;
        return 0;
}

static int nvme_rdma_map_sg_single(struct nvme_rdma_queue *queue,
                struct nvme_rdma_request *req, struct nvme_command *c)
{
        struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;

        sg->addr = cpu_to_le64(sg_dma_address(req->data_sgl.sg_table.sgl));
        put_unaligned_le24(sg_dma_len(req->data_sgl.sg_table.sgl), sg->length);
        put_unaligned_le32(queue->device->pd->unsafe_global_rkey, sg->key);
        sg->type = NVME_KEY_SGL_FMT_DATA_DESC << 4;
        return 0;
}

static int nvme_rdma_map_sg_fr(struct nvme_rdma_queue *queue,
                struct nvme_rdma_request *req, struct nvme_command *c,
                int count)
{
        struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;
        int nr;

        req->mr = ib_mr_pool_get(queue->qp, &queue->qp->rdma_mrs);
        if (WARN_ON_ONCE(!req->mr))
                return -EAGAIN;

        /*
         * Align the MR to a 4K page size to match the ctrl page size and
         * the block virtual boundary.
         */
        nr = ib_map_mr_sg(req->mr, req->data_sgl.sg_table.sgl, count, NULL,
                          SZ_4K);
        if (unlikely(nr < count)) {
                ib_mr_pool_put(queue->qp, &queue->qp->rdma_mrs, req->mr);
                req->mr = NULL;
                if (nr < 0)
                        return nr;
                return -EINVAL;
        }

        ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));

        req->reg_cqe.done = nvme_rdma_memreg_done;
        memset(&req->reg_wr, 0, sizeof(req->reg_wr));
        req->reg_wr.wr.opcode = IB_WR_REG_MR;
        req->reg_wr.wr.wr_cqe = &req->reg_cqe;
        req->reg_wr.wr.num_sge = 0;
        req->reg_wr.mr = req->mr;
        req->reg_wr.key = req->mr->rkey;
        req->reg_wr.access = IB_ACCESS_LOCAL_WRITE |
                             IB_ACCESS_REMOTE_READ |
                             IB_ACCESS_REMOTE_WRITE;

        sg->addr = cpu_to_le64(req->mr->iova);
        put_unaligned_le24(req->mr->length, sg->length);
        put_unaligned_le32(req->mr->rkey, sg->key);
        sg->type = (NVME_KEY_SGL_FMT_DATA_DESC << 4) |
                        NVME_SGL_FMT_INVALIDATE;

        return 0;
}

static void nvme_rdma_set_sig_domain(struct blk_integrity *bi,
                struct nvme_command *cmd, struct ib_sig_domain *domain,
                u16 control, u8 pi_type)
{
        domain->sig_type = IB_SIG_TYPE_T10_DIF;
        domain->sig.dif.bg_type = IB_T10DIF_CRC;
        domain->sig.dif.pi_interval = 1 << bi->interval_exp;
        domain->sig.dif.ref_tag = le32_to_cpu(cmd->rw.reftag);
        if (control & NVME_RW_PRINFO_PRCHK_REF)
                domain->sig.dif.ref_remap = true;

        domain->sig.dif.app_tag = le16_to_cpu(cmd->rw.apptag);
        domain->sig.dif.apptag_check_mask = le16_to_cpu(cmd->rw.appmask);
        domain->sig.dif.app_escape = true;
        if (pi_type == NVME_NS_DPS_PI_TYPE3)
                domain->sig.dif.ref_escape = true;
}

static void nvme_rdma_set_sig_attrs(struct blk_integrity *bi,
                struct nvme_command *cmd, struct ib_sig_attrs *sig_attrs,
                u8 pi_type)
{
        u16 control = le16_to_cpu(cmd->rw.control);

        memset(sig_attrs, 0, sizeof(*sig_attrs));
        if (control & NVME_RW_PRINFO_PRACT) {
                /* for WRITE_INSERT/READ_STRIP no memory domain */
                sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
                nvme_rdma_set_sig_domain(bi, cmd, &sig_attrs->wire, control,
                                         pi_type);
                /* Clear the PRACT bit since HCA will generate/verify the PI */
                control &= ~NVME_RW_PRINFO_PRACT;
                cmd->rw.control = cpu_to_le16(control);
        } else {
                /* for WRITE_PASS/READ_PASS both wire/memory domains exist */
                nvme_rdma_set_sig_domain(bi, cmd, &sig_attrs->wire, control,
                                         pi_type);
                nvme_rdma_set_sig_domain(bi, cmd, &sig_attrs->mem, control,
                                         pi_type);
        }
}

static void nvme_rdma_set_prot_checks(struct nvme_command *cmd, u8 *mask)
{
        *mask = 0;
        if (le16_to_cpu(cmd->rw.control) & NVME_RW_PRINFO_PRCHK_REF)
                *mask |= IB_SIG_CHECK_REFTAG;
        if (le16_to_cpu(cmd->rw.control) & NVME_RW_PRINFO_PRCHK_GUARD)
                *mask |= IB_SIG_CHECK_GUARD;
}

static void nvme_rdma_sig_done(struct ib_cq *cq, struct ib_wc *wc)
{
        if (unlikely(wc->status != IB_WC_SUCCESS))
                nvme_rdma_wr_error(cq, wc, "SIG");
}

static int nvme_rdma_map_sg_pi(struct nvme_rdma_queue *queue,
                struct nvme_rdma_request *req, struct nvme_command *c,
                int count, int pi_count)
{
        struct nvme_rdma_sgl *sgl = &req->data_sgl;
        struct ib_reg_wr *wr = &req->reg_wr;
        struct request *rq = blk_mq_rq_from_pdu(req);
        struct nvme_ns *ns = rq->q->queuedata;
        struct bio *bio = rq->bio;
        struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;
        int nr;

        req->mr = ib_mr_pool_get(queue->qp, &queue->qp->sig_mrs);
        if (WARN_ON_ONCE(!req->mr))
                return -EAGAIN;

        nr = ib_map_mr_sg_pi(req->mr, sgl->sg_table.sgl, count, NULL,
                             req->metadata_sgl->sg_table.sgl, pi_count, NULL,
                             SZ_4K);
        if (unlikely(nr))
                goto mr_put;

        nvme_rdma_set_sig_attrs(blk_get_integrity(bio->bi_disk), c,
                                req->mr->sig_attrs, ns->pi_type);
        nvme_rdma_set_prot_checks(c, &req->mr->sig_attrs->check_mask);

        ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));

        req->reg_cqe.done = nvme_rdma_sig_done;
        memset(wr, 0, sizeof(*wr));
        wr->wr.opcode = IB_WR_REG_MR_INTEGRITY;
        wr->wr.wr_cqe = &req->reg_cqe;
        wr->wr.num_sge = 0;
        wr->wr.send_flags = 0;
        wr->mr = req->mr;
        wr->key = req->mr->rkey;
        wr->access = IB_ACCESS_LOCAL_WRITE |
                     IB_ACCESS_REMOTE_READ |
                     IB_ACCESS_REMOTE_WRITE;

        sg->addr = cpu_to_le64(req->mr->iova);
        put_unaligned_le24(req->mr->length, sg->length);
        put_unaligned_le32(req->mr->rkey, sg->key);
        sg->type = NVME_KEY_SGL_FMT_DATA_DESC << 4;

        return 0;

mr_put:
        ib_mr_pool_put(queue->qp, &queue->qp->sig_mrs, req->mr);
        req->mr = NULL;
        if (nr < 0)
                return nr;
        return -EINVAL;
}

static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
                struct request *rq, struct nvme_command *c)
{
        struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
        struct nvme_rdma_device *dev = queue->device;
        struct ib_device *ibdev = dev->dev;
        int pi_count = 0;
        int count, ret;

        req->num_sge = 1;
        refcount_set(&req->ref, 2); /* send and recv completions */

        c->common.flags |= NVME_CMD_SGL_METABUF;

        if (!blk_rq_nr_phys_segments(rq))
                return nvme_rdma_set_sg_null(c);

        req->data_sgl.sg_table.sgl = (struct scatterlist *)(req + 1);
        ret = sg_alloc_table_chained(&req->data_sgl.sg_table,
                        blk_rq_nr_phys_segments(rq), req->data_sgl.sg_table.sgl,
                        NVME_INLINE_SG_CNT);
        if (ret)
                return -ENOMEM;

        req->data_sgl.nents = blk_rq_map_sg(rq->q, rq,
                                            req->data_sgl.sg_table.sgl);

        count = ib_dma_map_sg(ibdev, req->data_sgl.sg_table.sgl,
                              req->data_sgl.nents, rq_dma_dir(rq));
        if (unlikely(count <= 0)) {
                ret = -EIO;
                goto out_free_table;
        }

        if (blk_integrity_rq(rq)) {
                req->metadata_sgl->sg_table.sgl =
                        (struct scatterlist *)(req->metadata_sgl + 1);
                ret = sg_alloc_table_chained(&req->metadata_sgl->sg_table,
                                blk_rq_count_integrity_sg(rq->q, rq->bio),
                                req->metadata_sgl->sg_table.sgl,
                                NVME_INLINE_METADATA_SG_CNT);
                if (unlikely(ret)) {
                        ret = -ENOMEM;
                        goto out_unmap_sg;
                }

                req->metadata_sgl->nents = blk_rq_map_integrity_sg(rq->q,
                                rq->bio, req->metadata_sgl->sg_table.sgl);
                pi_count = ib_dma_map_sg(ibdev,
                                         req->metadata_sgl->sg_table.sgl,
                                         req->metadata_sgl->nents,
                                         rq_dma_dir(rq));
                if (unlikely(pi_count <= 0)) {
                        ret = -EIO;
                        goto out_free_pi_table;
                }
        }

        if (req->use_sig_mr) {
                ret = nvme_rdma_map_sg_pi(queue, req, c, count, pi_count);
                goto out;
        }

        if (count <= dev->num_inline_segments) {
                if (rq_data_dir(rq) == WRITE && nvme_rdma_queue_idx(queue) &&
                    queue->ctrl->use_inline_data &&
                    blk_rq_payload_bytes(rq) <=
                                nvme_rdma_inline_data_size(queue)) {
                        ret = nvme_rdma_map_sg_inline(queue, req, c, count);
                        goto out;
                }

                if (count == 1 && dev->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY) {
                        ret = nvme_rdma_map_sg_single(queue, req, c);
                        goto out;
                }
        }

        ret = nvme_rdma_map_sg_fr(queue, req, c, count);
out:
        if (unlikely(ret))
                goto out_unmap_pi_sg;

        return 0;

out_unmap_pi_sg:
        if (blk_integrity_rq(rq))
                ib_dma_unmap_sg(ibdev, req->metadata_sgl->sg_table.sgl,
                                req->metadata_sgl->nents, rq_dma_dir(rq));
out_free_pi_table:
        if (blk_integrity_rq(rq))
                sg_free_table_chained(&req->metadata_sgl->sg_table,
                                      NVME_INLINE_METADATA_SG_CNT);
out_unmap_sg:
        ib_dma_unmap_sg(ibdev, req->data_sgl.sg_table.sgl, req->data_sgl.nents,
                        rq_dma_dir(rq));
out_free_table:
        sg_free_table_chained(&req->data_sgl.sg_table, NVME_INLINE_SG_CNT);
        return ret;
}

static void nvme_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
{
        struct nvme_rdma_qe *qe =
                container_of(wc->wr_cqe, struct nvme_rdma_qe, cqe);
        struct nvme_rdma_request *req =
                container_of(qe, struct nvme_rdma_request, sqe);

        if (unlikely(wc->status != IB_WC_SUCCESS))
                nvme_rdma_wr_error(cq, wc, "SEND");
        else
                nvme_rdma_end_request(req);
}

static int nvme_rdma_post_send(struct nvme_rdma_queue *queue,
                struct nvme_rdma_qe *qe, struct ib_sge *sge, u32 num_sge,
                struct ib_send_wr *first)
{
        struct ib_send_wr wr;
        int ret;

        sge->addr   = qe->dma;
        sge->length = sizeof(struct nvme_command);
        sge->lkey   = queue->device->pd->local_dma_lkey;

        wr.next       = NULL;
        wr.wr_cqe     = &qe->cqe;
        wr.sg_list    = sge;
        wr.num_sge    = num_sge;
        wr.opcode     = IB_WR_SEND;
        wr.send_flags = IB_SEND_SIGNALED;

        if (first)
                first->next = &wr;
        else
                first = &wr;

        ret = ib_post_send(queue->qp, first, NULL);
        if (unlikely(ret)) {
                dev_err(queue->ctrl->ctrl.device,
                             "%s failed with error code %d\n", __func__, ret);
        }
        return ret;
}

static int nvme_rdma_post_recv(struct nvme_rdma_queue *queue,
                struct nvme_rdma_qe *qe)
{
        struct ib_recv_wr wr;
        struct ib_sge list;
        int ret;

        list.addr   = qe->dma;
        list.length = sizeof(struct nvme_completion);
        list.lkey   = queue->device->pd->local_dma_lkey;

        qe->cqe.done = nvme_rdma_recv_done;

        wr.next     = NULL;
        wr.wr_cqe   = &qe->cqe;
        wr.sg_list  = &list;
        wr.num_sge  = 1;

        ret = ib_post_recv(queue->qp, &wr, NULL);
        if (unlikely(ret)) {
                dev_err(queue->ctrl->ctrl.device,
                        "%s failed with error code %d\n", __func__, ret);
        }
        return ret;
}

static struct blk_mq_tags *nvme_rdma_tagset(struct nvme_rdma_queue *queue)
{
        u32 queue_idx = nvme_rdma_queue_idx(queue);

        if (queue_idx == 0)
                return queue->ctrl->admin_tag_set.tags[queue_idx];
        return queue->ctrl->tag_set.tags[queue_idx - 1];
}

static void nvme_rdma_async_done(struct ib_cq *cq, struct ib_wc *wc)
{
        if (unlikely(wc->status != IB_WC_SUCCESS))
                nvme_rdma_wr_error(cq, wc, "ASYNC");
}

static void nvme_rdma_submit_async_event(struct nvme_ctrl *arg)
{
        struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(arg);
        struct nvme_rdma_queue *queue = &ctrl->queues[0];
        struct ib_device *dev = queue->device->dev;
        struct nvme_rdma_qe *sqe = &ctrl->async_event_sqe;
        struct nvme_command *cmd = sqe->data;
        struct ib_sge sge;
        int ret;

        ib_dma_sync_single_for_cpu(dev, sqe->dma, sizeof(*cmd), DMA_TO_DEVICE);

        memset(cmd, 0, sizeof(*cmd));
        cmd->common.opcode = nvme_admin_async_event;
        cmd->common.command_id = NVME_AQ_BLK_MQ_DEPTH;
        cmd->common.flags |= NVME_CMD_SGL_METABUF;
        nvme_rdma_set_sg_null(cmd);

        sqe->cqe.done = nvme_rdma_async_done;

        ib_dma_sync_single_for_device(dev, sqe->dma, sizeof(*cmd),
                        DMA_TO_DEVICE);

        ret = nvme_rdma_post_send(queue, sqe, &sge, 1, NULL);
        WARN_ON_ONCE(ret);
}

static void nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
                struct nvme_completion *cqe, struct ib_wc *wc)
{
        struct request *rq;
        struct nvme_rdma_request *req;

        rq = nvme_find_rq(nvme_rdma_tagset(queue), cqe->command_id);
        if (!rq) {
                dev_err(queue->ctrl->ctrl.device,
                        "got bad command_id %#x on QP %#x\n",
                        cqe->command_id, queue->qp->qp_num);
                nvme_rdma_error_recovery(queue->ctrl);
                return;
        }
        req = blk_mq_rq_to_pdu(rq);

        req->status = cqe->status;
        req->result = cqe->result;

        if (wc->wc_flags & IB_WC_WITH_INVALIDATE) {
                if (unlikely(!req->mr ||
                             wc->ex.invalidate_rkey != req->mr->rkey)) {
                        dev_err(queue->ctrl->ctrl.device,
                                "Bogus remote invalidation for rkey %#x\n",
                                req->mr ? req->mr->rkey : 0);
                        nvme_rdma_error_recovery(queue->ctrl);
                }
        } else if (req->mr) {
                int ret;

                ret = nvme_rdma_inv_rkey(queue, req);
                if (unlikely(ret < 0)) {
                        dev_err(queue->ctrl->ctrl.device,
                                "Queueing INV WR for rkey %#x failed (%d)\n",
                                req->mr->rkey, ret);
                        nvme_rdma_error_recovery(queue->ctrl);
                }
                /* the local invalidation completion will end the request */
                return;
        }

        nvme_rdma_end_request(req);
}

static void nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
{
        struct nvme_rdma_qe *qe =
                container_of(wc->wr_cqe, struct nvme_rdma_qe, cqe);
        struct nvme_rdma_queue *queue = wc->qp->qp_context;
        struct ib_device *ibdev = queue->device->dev;
        struct nvme_completion *cqe = qe->data;
        const size_t len = sizeof(struct nvme_completion);

        if (unlikely(wc->status != IB_WC_SUCCESS)) {
                nvme_rdma_wr_error(cq, wc, "RECV");
                return;
        }

        /* sanity checking for received data length */
        if (unlikely(wc->byte_len < len)) {
                dev_err(queue->ctrl->ctrl.device,
                        "Unexpected nvme completion length(%d)\n", wc->byte_len);
                nvme_rdma_error_recovery(queue->ctrl);
                return;
        }

        ib_dma_sync_single_for_cpu(ibdev, qe->dma, len, DMA_FROM_DEVICE);
        /*
         * AEN requests are special as they don't time out and can
         * survive any kind of queue freeze and often don't respond to
         * aborts.  We don't even bother to allocate a struct request
         * for them but rather special case them here.
         */
        if (unlikely(nvme_is_aen_req(nvme_rdma_queue_idx(queue),
                                     cqe->command_id)))
                nvme_complete_async_event(&queue->ctrl->ctrl, cqe->status,
                                &cqe->result);
        else
                nvme_rdma_process_nvme_rsp(queue, cqe, wc);
        ib_dma_sync_single_for_device(ibdev, qe->dma, len, DMA_FROM_DEVICE);

        nvme_rdma_post_recv(queue, qe);
}

static int nvme_rdma_conn_established(struct nvme_rdma_queue *queue)
{
        int ret, i;

        for (i = 0; i < queue->queue_size; i++) {
                ret = nvme_rdma_post_recv(queue, &queue->rsp_ring[i]);
                if (ret)
                        return ret;
        }

        return 0;
}

static int nvme_rdma_conn_rejected(struct nvme_rdma_queue *queue,
                struct rdma_cm_event *ev)
{
        struct rdma_cm_id *cm_id = queue->cm_id;
        int status = ev->status;
        const char *rej_msg;
        const struct nvme_rdma_cm_rej *rej_data;
        u8 rej_data_len;

        rej_msg = rdma_reject_msg(cm_id, status);
        rej_data = rdma_consumer_reject_data(cm_id, ev, &rej_data_len);

        if (rej_data && rej_data_len >= sizeof(u16)) {
                u16 sts = le16_to_cpu(rej_data->sts);

                dev_err(queue->ctrl->ctrl.device,
                      "Connect rejected: status %d (%s) nvme status %d (%s).\n",
                      status, rej_msg, sts, nvme_rdma_cm_msg(sts));
        } else {
                dev_err(queue->ctrl->ctrl.device,
                        "Connect rejected: status %d (%s).\n", status, rej_msg);
        }

        return -ECONNRESET;
}

static int nvme_rdma_addr_resolved(struct nvme_rdma_queue *queue)
{
        struct nvme_ctrl *ctrl = &queue->ctrl->ctrl;
        int ret;

        ret = nvme_rdma_create_queue_ib(queue);
        if (ret)
                return ret;

        if (ctrl->opts->tos >= 0)
                rdma_set_service_type(queue->cm_id, ctrl->opts->tos);
        ret = rdma_resolve_route(queue->cm_id, NVME_RDMA_CONNECT_TIMEOUT_MS);
        if (ret) {
                dev_err(ctrl->device, "rdma_resolve_route failed (%d).\n",
                        queue->cm_error);
                goto out_destroy_queue;
        }

        return 0;

out_destroy_queue:
        nvme_rdma_destroy_queue_ib(queue);
        return ret;
}

static int nvme_rdma_route_resolved(struct nvme_rdma_queue *queue)
{
        struct nvme_rdma_ctrl *ctrl = queue->ctrl;
        struct rdma_conn_param param = { };
        struct nvme_rdma_cm_req priv = { };
        int ret;

        param.qp_num = queue->qp->qp_num;
        param.flow_control = 1;

        param.responder_resources = queue->device->dev->attrs.max_qp_rd_atom;
        /* maximum retry count */
        param.retry_count = 7;
        param.rnr_retry_count = 7;
        param.private_data = &priv;
        param.private_data_len = sizeof(priv);

        priv.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
        priv.qid = cpu_to_le16(nvme_rdma_queue_idx(queue));
        /*
         * set the admin queue depth to the minimum size
         * specified by the Fabrics standard.
         */
        if (priv.qid == 0) {
                priv.hrqsize = cpu_to_le16(NVME_AQ_DEPTH);
                priv.hsqsize = cpu_to_le16(NVME_AQ_DEPTH - 1);
        } else {
                /*
                 * current interpretation of the fabrics spec
                 * is at minimum you make hrqsize sqsize+1, or a
                 * 1's based representation of sqsize.
                 */
                priv.hrqsize = cpu_to_le16(queue->queue_size);
                priv.hsqsize = cpu_to_le16(queue->ctrl->ctrl.sqsize);
        }

        ret = rdma_connect_locked(queue->cm_id, &param);
        if (ret) {
                dev_err(ctrl->ctrl.device,
                        "rdma_connect_locked failed (%d).\n", ret);
                return ret;
        }

        return 0;
}

static int nvme_rdma_cm_handler(struct rdma_cm_id *cm_id,
                struct rdma_cm_event *ev)
{
        struct nvme_rdma_queue *queue = cm_id->context;
        int cm_error = 0;

        dev_dbg(queue->ctrl->ctrl.device, "%s (%d): status %d id %p\n",
                rdma_event_msg(ev->event), ev->event,
                ev->status, cm_id);

        switch (ev->event) {
        case RDMA_CM_EVENT_ADDR_RESOLVED:
                cm_error = nvme_rdma_addr_resolved(queue);
                break;
        case RDMA_CM_EVENT_ROUTE_RESOLVED:
                cm_error = nvme_rdma_route_resolved(queue);
                break;
        case RDMA_CM_EVENT_ESTABLISHED:
                queue->cm_error = nvme_rdma_conn_established(queue);
                /* complete cm_done regardless of success/failure */
                complete(&queue->cm_done);
                return 0;
        case RDMA_CM_EVENT_REJECTED:
                cm_error = nvme_rdma_conn_rejected(queue, ev);
                break;
        case RDMA_CM_EVENT_ROUTE_ERROR:
        case RDMA_CM_EVENT_CONNECT_ERROR:
        case RDMA_CM_EVENT_UNREACHABLE:
        case RDMA_CM_EVENT_ADDR_ERROR:
                dev_dbg(queue->ctrl->ctrl.device,
                        "CM error event %d\n", ev->event);
                cm_error = -ECONNRESET;
                break;
        case RDMA_CM_EVENT_DISCONNECTED:
        case RDMA_CM_EVENT_ADDR_CHANGE:
        case RDMA_CM_EVENT_TIMEWAIT_EXIT:
                dev_dbg(queue->ctrl->ctrl.device,
                        "disconnect received - connection closed\n");
                nvme_rdma_error_recovery(queue->ctrl);
                break;
        case RDMA_CM_EVENT_DEVICE_REMOVAL:
                /* device removal is handled via the ib_client API */
                break;
        default:
                dev_err(queue->ctrl->ctrl.device,
                        "Unexpected RDMA CM event (%d)\n", ev->event);
                nvme_rdma_error_recovery(queue->ctrl);
                break;
        }

        if (cm_error) {
                queue->cm_error = cm_error;
                complete(&queue->cm_done);
        }

        return 0;
}

static void nvme_rdma_complete_timed_out(struct request *rq)
{
        struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
        struct nvme_rdma_queue *queue = req->queue;

        nvme_rdma_stop_queue(queue);
        if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
                nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
                blk_mq_complete_request(rq);
        }
}

static enum blk_eh_timer_return
nvme_rdma_timeout(struct request *rq, bool reserved)
{
        struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
        struct nvme_rdma_queue *queue = req->queue;
        struct nvme_rdma_ctrl *ctrl = queue->ctrl;

        dev_warn(ctrl->ctrl.device, "I/O %d QID %d timeout\n",
                 rq->tag, nvme_rdma_queue_idx(queue));

        if (ctrl->ctrl.state != NVME_CTRL_LIVE) {
                /*
                 * If we are resetting, connecting or deleting we should
                 * complete immediately because we may block controller
                 * teardown or setup sequence
                 * - ctrl disable/shutdown fabrics requests
                 * - connect requests
                 * - initialization admin requests
                 * - I/O requests that entered after unquiescing and
                 *   the controller stopped responding
                 *
                 * All other requests should be cancelled by the error
                 * recovery work, so it's fine that we fail it here.
                 */
                nvme_rdma_complete_timed_out(rq);
                return BLK_EH_DONE;
        }

        /*
         * LIVE state should trigger the normal error recovery which will
         * handle completing this request.
         */
        nvme_rdma_error_recovery(ctrl);
        return BLK_EH_RESET_TIMER;
}

static blk_status_t nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
                const struct blk_mq_queue_data *bd)
{
        struct nvme_ns *ns = hctx->queue->queuedata;
        struct nvme_rdma_queue *queue = hctx->driver_data;
        struct request *rq = bd->rq;
        struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
        struct nvme_rdma_qe *sqe = &req->sqe;
        struct nvme_command *c = sqe->data;
        struct ib_device *dev;
        bool queue_ready = test_bit(NVME_RDMA_Q_LIVE, &queue->flags);
        blk_status_t ret;
        int err;

        WARN_ON_ONCE(rq->tag < 0);

        if (!nvmf_check_ready(&queue->ctrl->ctrl, rq, queue_ready))
                return nvmf_fail_nonready_command(&queue->ctrl->ctrl, rq);

        dev = queue->device->dev;

        req->sqe.dma = ib_dma_map_single(dev, req->sqe.data,
                                         sizeof(struct nvme_command),
                                         DMA_TO_DEVICE);
        err = ib_dma_mapping_error(dev, req->sqe.dma);
        if (unlikely(err))
                return BLK_STS_RESOURCE;

        ib_dma_sync_single_for_cpu(dev, sqe->dma,
                        sizeof(struct nvme_command), DMA_TO_DEVICE);

        ret = nvme_setup_cmd(ns, rq, c);
        if (ret)
                goto unmap_qe;

        blk_mq_start_request(rq);

        if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
            queue->pi_support &&
            (c->common.opcode == nvme_cmd_write ||
             c->common.opcode == nvme_cmd_read) &&
            nvme_ns_has_pi(ns))
                req->use_sig_mr = true;
        else
                req->use_sig_mr = false;

        err = nvme_rdma_map_data(queue, rq, c);
        if (unlikely(err < 0)) {
                dev_err(queue->ctrl->ctrl.device,
                             "Failed to map data (%d)\n", err);
                goto err;
        }

        sqe->cqe.done = nvme_rdma_send_done;

        ib_dma_sync_single_for_device(dev, sqe->dma,
                        sizeof(struct nvme_command), DMA_TO_DEVICE);

        err = nvme_rdma_post_send(queue, sqe, req->sge, req->num_sge,
                        req->mr ? &req->reg_wr.wr : NULL);
        if (unlikely(err))
                goto err_unmap;

        return BLK_STS_OK;

err_unmap:
        nvme_rdma_unmap_data(queue, rq);
err:
        if (err == -ENOMEM || err == -EAGAIN)
                ret = BLK_STS_RESOURCE;
        else
                ret = BLK_STS_IOERR;
        nvme_cleanup_cmd(rq);
unmap_qe:
        ib_dma_unmap_single(dev, req->sqe.dma, sizeof(struct nvme_command),
                            DMA_TO_DEVICE);
        return ret;
}

static int nvme_rdma_poll(struct blk_mq_hw_ctx *hctx)
{
        struct nvme_rdma_queue *queue = hctx->driver_data;

        return ib_process_cq_direct(queue->ib_cq, -1);
}

static void nvme_rdma_check_pi_status(struct nvme_rdma_request *req)
{
        struct request *rq = blk_mq_rq_from_pdu(req);
        struct ib_mr_status mr_status;
        int ret;

        ret = ib_check_mr_status(req->mr, IB_MR_CHECK_SIG_STATUS, &mr_status);
        if (ret) {
                pr_err("ib_check_mr_status failed, ret %d\n", ret);
                nvme_req(rq)->status = NVME_SC_INVALID_PI;
                return;
        }

        if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
                switch (mr_status.sig_err.err_type) {
                case IB_SIG_BAD_GUARD:
                        nvme_req(rq)->status = NVME_SC_GUARD_CHECK;
                        break;
                case IB_SIG_BAD_REFTAG:
                        nvme_req(rq)->status = NVME_SC_REFTAG_CHECK;
                        break;
                case IB_SIG_BAD_APPTAG:
                        nvme_req(rq)->status = NVME_SC_APPTAG_CHECK;
                        break;
                }
                pr_err("PI error found type %d expected 0x%x vs actual 0x%x\n",
                       mr_status.sig_err.err_type, mr_status.sig_err.expected,
                       mr_status.sig_err.actual);
        }
}

static void nvme_rdma_complete_rq(struct request *rq)
{
        struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
        struct nvme_rdma_queue *queue = req->queue;
        struct ib_device *ibdev = queue->device->dev;

        if (req->use_sig_mr)
                nvme_rdma_check_pi_status(req);

        nvme_rdma_unmap_data(queue, rq);
        ib_dma_unmap_single(ibdev, req->sqe.dma, sizeof(struct nvme_command),
                            DMA_TO_DEVICE);
        nvme_complete_rq(rq);
}

static int nvme_rdma_map_queues(struct blk_mq_tag_set *set)
{
        struct nvme_rdma_ctrl *ctrl = set->driver_data;
        struct nvmf_ctrl_options *opts = ctrl->ctrl.opts;

        if (opts->nr_write_queues && ctrl->io_queues[HCTX_TYPE_READ]) {
                /* separate read/write queues */
                set->map[HCTX_TYPE_DEFAULT].nr_queues =
                        ctrl->io_queues[HCTX_TYPE_DEFAULT];
                set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
                set->map[HCTX_TYPE_READ].nr_queues =
                        ctrl->io_queues[HCTX_TYPE_READ];
                set->map[HCTX_TYPE_READ].queue_offset =
                        ctrl->io_queues[HCTX_TYPE_DEFAULT];
        } else {
                /* shared read/write queues */
                set->map[HCTX_TYPE_DEFAULT].nr_queues =
                        ctrl->io_queues[HCTX_TYPE_DEFAULT];
                set->map[HCTX_TYPE_DEFAULT].queue_offset = 0;
                set->map[HCTX_TYPE_READ].nr_queues =
                        ctrl->io_queues[HCTX_TYPE_DEFAULT];
                set->map[HCTX_TYPE_READ].queue_offset = 0;
        }
        blk_mq_rdma_map_queues(&set->map[HCTX_TYPE_DEFAULT],
                        ctrl->device->dev, 0);
        blk_mq_rdma_map_queues(&set->map[HCTX_TYPE_READ],
                        ctrl->device->dev, 0);

        if (opts->nr_poll_queues && ctrl->io_queues[HCTX_TYPE_POLL]) {
                /* map dedicated poll queues only if we have queues left */
                set->map[HCTX_TYPE_POLL].nr_queues =
                                ctrl->io_queues[HCTX_TYPE_POLL];
                set->map[HCTX_TYPE_POLL].queue_offset =
                        ctrl->io_queues[HCTX_TYPE_DEFAULT] +
                        ctrl->io_queues[HCTX_TYPE_READ];
                blk_mq_map_queues(&set->map[HCTX_TYPE_POLL]);
        }

        dev_info(ctrl->ctrl.device,
                "mapped %d/%d/%d default/read/poll queues.\n",
                ctrl->io_queues[HCTX_TYPE_DEFAULT],
                ctrl->io_queues[HCTX_TYPE_READ],
                ctrl->io_queues[HCTX_TYPE_POLL]);

        return 0;
}

static const struct blk_mq_ops nvme_rdma_mq_ops = {
        .queue_rq       = nvme_rdma_queue_rq,
        .complete       = nvme_rdma_complete_rq,
        .init_request   = nvme_rdma_init_request,
        .exit_request   = nvme_rdma_exit_request,
        .init_hctx      = nvme_rdma_init_hctx,
        .timeout        = nvme_rdma_timeout,
        .map_queues     = nvme_rdma_map_queues,
        .poll           = nvme_rdma_poll,
};

static const struct blk_mq_ops nvme_rdma_admin_mq_ops = {
        .queue_rq       = nvme_rdma_queue_rq,
        .complete       = nvme_rdma_complete_rq,
        .init_request   = nvme_rdma_init_request,
        .exit_request   = nvme_rdma_exit_request,
        .init_hctx      = nvme_rdma_init_admin_hctx,
        .timeout        = nvme_rdma_timeout,
};

static void nvme_rdma_shutdown_ctrl(struct nvme_rdma_ctrl *ctrl, bool shutdown)
{
        nvme_rdma_teardown_io_queues(ctrl, shutdown);
        blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
        if (shutdown)
                nvme_shutdown_ctrl(&ctrl->ctrl);
        else
                nvme_disable_ctrl(&ctrl->ctrl);
        nvme_rdma_teardown_admin_queue(ctrl, shutdown);
}

static void nvme_rdma_delete_ctrl(struct nvme_ctrl *ctrl)
{
        nvme_rdma_shutdown_ctrl(to_rdma_ctrl(ctrl), true);
}

static void nvme_rdma_reset_ctrl_work(struct work_struct *work)
{
        struct nvme_rdma_ctrl *ctrl =
                container_of(work, struct nvme_rdma_ctrl, ctrl.reset_work);

        nvme_stop_ctrl(&ctrl->ctrl);
        nvme_rdma_shutdown_ctrl(ctrl, false);

        if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
                /* state change failure should never happen */
                WARN_ON_ONCE(1);
                return;
        }

        if (nvme_rdma_setup_ctrl(ctrl, false))
                goto out_fail;

        return;

out_fail:
        ++ctrl->ctrl.nr_reconnects;
        nvme_rdma_reconnect_or_remove(ctrl);
}

static const struct nvme_ctrl_ops nvme_rdma_ctrl_ops = {
        .name                   = "rdma",
        .module                 = THIS_MODULE,
        .flags                  = NVME_F_FABRICS | NVME_F_METADATA_SUPPORTED,
        .reg_read32             = nvmf_reg_read32,
        .reg_read64             = nvmf_reg_read64,
        .reg_write32            = nvmf_reg_write32,
        .free_ctrl              = nvme_rdma_free_ctrl,
        .submit_async_event     = nvme_rdma_submit_async_event,
        .delete_ctrl            = nvme_rdma_delete_ctrl,
        .get_address            = nvmf_get_address,
        .stop_ctrl              = nvme_rdma_stop_ctrl,
};

/*
 * Fails a connection request if it matches an existing controller
 * (association) with the same tuple:
 * <Host NQN, Host ID, local address, remote address, remote port, SUBSYS NQN>
 *
 * if local address is not specified in the request, it will match an
 * existing controller with all the other parameters the same and no
 * local port address specified as well.
 *
 * The ports don't need to be compared as they are intrinsically
 * already matched by the port pointers supplied.
 */
static bool
nvme_rdma_existing_controller(struct nvmf_ctrl_options *opts)
{
        struct nvme_rdma_ctrl *ctrl;
        bool found = false;

        mutex_lock(&nvme_rdma_ctrl_mutex);
        list_for_each_entry(ctrl, &nvme_rdma_ctrl_list, list) {
                found = nvmf_ip_options_match(&ctrl->ctrl, opts);
                if (found)
                        break;
        }
        mutex_unlock(&nvme_rdma_ctrl_mutex);

        return found;
}

static struct nvme_ctrl *nvme_rdma_create_ctrl(struct device *dev,
                struct nvmf_ctrl_options *opts)
{
        struct nvme_rdma_ctrl *ctrl;
        int ret;
        bool changed;

        ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
        if (!ctrl)
                return ERR_PTR(-ENOMEM);
        ctrl->ctrl.opts = opts;
        INIT_LIST_HEAD(&ctrl->list);

        if (!(opts->mask & NVMF_OPT_TRSVCID)) {
                opts->trsvcid =
                        kstrdup(__stringify(NVME_RDMA_IP_PORT), GFP_KERNEL);
                if (!opts->trsvcid) {
                        ret = -ENOMEM;
                        goto out_free_ctrl;
                }
                opts->mask |= NVMF_OPT_TRSVCID;
        }

        ret = inet_pton_with_scope(&init_net, AF_UNSPEC,
                        opts->traddr, opts->trsvcid, &ctrl->addr);
        if (ret) {
                pr_err("malformed address passed: %s:%s\n",
                        opts->traddr, opts->trsvcid);
                goto out_free_ctrl;
        }

        if (opts->mask & NVMF_OPT_HOST_TRADDR) {
                ret = inet_pton_with_scope(&init_net, AF_UNSPEC,
                        opts->host_traddr, NULL, &ctrl->src_addr);
                if (ret) {
                        pr_err("malformed src address passed: %s\n",
                               opts->host_traddr);
                        goto out_free_ctrl;
                }
        }

        if (!opts->duplicate_connect && nvme_rdma_existing_controller(opts)) {
                ret = -EALREADY;
                goto out_free_ctrl;
        }

        INIT_DELAYED_WORK(&ctrl->reconnect_work,
                        nvme_rdma_reconnect_ctrl_work);
        INIT_WORK(&ctrl->err_work, nvme_rdma_error_recovery_work);
        INIT_WORK(&ctrl->ctrl.reset_work, nvme_rdma_reset_ctrl_work);

        ctrl->ctrl.queue_count = opts->nr_io_queues + opts->nr_write_queues +
                                opts->nr_poll_queues + 1;
        ctrl->ctrl.sqsize = opts->queue_size - 1;
        ctrl->ctrl.kato = opts->kato;

        ret = -ENOMEM;
        ctrl->queues = kcalloc(ctrl->ctrl.queue_count, sizeof(*ctrl->queues),
                                GFP_KERNEL);
        if (!ctrl->queues)
                goto out_free_ctrl;

        ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_rdma_ctrl_ops,
                                0 /* no quirks, we're perfect! */);
        if (ret)
                goto out_kfree_queues;

        changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING);
        WARN_ON_ONCE(!changed);

        ret = nvme_rdma_setup_ctrl(ctrl, true);
        if (ret)
                goto out_uninit_ctrl;

        dev_info(ctrl->ctrl.device, "new ctrl: NQN \"%s\", addr %pISpcs\n",
                ctrl->ctrl.opts->subsysnqn, &ctrl->addr);

        mutex_lock(&nvme_rdma_ctrl_mutex);
        list_add_tail(&ctrl->list, &nvme_rdma_ctrl_list);
        mutex_unlock(&nvme_rdma_ctrl_mutex);

        return &ctrl->ctrl;

out_uninit_ctrl:
        nvme_uninit_ctrl(&ctrl->ctrl);
        nvme_put_ctrl(&ctrl->ctrl);
        if (ret > 0)
                ret = -EIO;
        return ERR_PTR(ret);
out_kfree_queues:
        kfree(ctrl->queues);
out_free_ctrl:
        kfree(ctrl);
        return ERR_PTR(ret);
}

static struct nvmf_transport_ops nvme_rdma_transport = {
        .name           = "rdma",
        .module         = THIS_MODULE,
        .required_opts  = NVMF_OPT_TRADDR,
        .allowed_opts   = NVMF_OPT_TRSVCID | NVMF_OPT_RECONNECT_DELAY |
                          NVMF_OPT_HOST_TRADDR | NVMF_OPT_CTRL_LOSS_TMO |
                          NVMF_OPT_NR_WRITE_QUEUES | NVMF_OPT_NR_POLL_QUEUES |
                          NVMF_OPT_TOS,
        .create_ctrl    = nvme_rdma_create_ctrl,
};

static void nvme_rdma_remove_one(struct ib_device *ib_device, void *client_data)
{
        struct nvme_rdma_ctrl *ctrl;
        struct nvme_rdma_device *ndev;
        bool found = false;

        mutex_lock(&device_list_mutex);
        list_for_each_entry(ndev, &device_list, entry) {
                if (ndev->dev == ib_device) {
                        found = true;
                        break;
                }
        }
        mutex_unlock(&device_list_mutex);

        if (!found)
                return;

        /* Delete all controllers using this device */
        mutex_lock(&nvme_rdma_ctrl_mutex);
        list_for_each_entry(ctrl, &nvme_rdma_ctrl_list, list) {
                if (ctrl->device->dev != ib_device)
                        continue;
                nvme_delete_ctrl(&ctrl->ctrl);
        }
        mutex_unlock(&nvme_rdma_ctrl_mutex);

        flush_workqueue(nvme_delete_wq);
}

static struct ib_client nvme_rdma_ib_client = {
        .name   = "nvme_rdma",
        .remove = nvme_rdma_remove_one
};

static int __init nvme_rdma_init_module(void)
{
        int ret;

        ret = ib_register_client(&nvme_rdma_ib_client);
        if (ret)
                return ret;

        ret = nvmf_register_transport(&nvme_rdma_transport);
        if (ret)
                goto err_unreg_client;

        return 0;

err_unreg_client:
        ib_unregister_client(&nvme_rdma_ib_client);
        return ret;
}

static void __exit nvme_rdma_cleanup_module(void)
{
        struct nvme_rdma_ctrl *ctrl;

        nvmf_unregister_transport(&nvme_rdma_transport);
        ib_unregister_client(&nvme_rdma_ib_client);

        mutex_lock(&nvme_rdma_ctrl_mutex);
        list_for_each_entry(ctrl, &nvme_rdma_ctrl_list, list)
                nvme_delete_ctrl(&ctrl->ctrl);
        mutex_unlock(&nvme_rdma_ctrl_mutex);
        flush_workqueue(nvme_delete_wq);
}

module_init(nvme_rdma_init_module);
module_exit(nvme_rdma_cleanup_module);

MODULE_LICENSE("GPL v2");