Commit 4b8178ec authored by Dean Balandin's avatar Dean Balandin Committed by David S. Miller
Browse files

nvme-tcp-offload: Add device scan implementation 



As part of create_ctrl(), it scans the registered devices and calls
the claim_dev op on each of them, to find the first devices that matches
the connection params. Once the correct devices is found (claim_dev
returns true), we raise the refcnt of that device and return that device
as the device to be used for ctrl currently being created.

Acked-by: default avatarIgor Russkikh <irusskikh@marvell.com>
Signed-off-by: default avatarDean Balandin <dbalandin@marvell.com>
Signed-off-by: default avatarPrabhakar Kushwaha <pkushwaha@marvell.com>
Signed-off-by: default avatarOmkar Kulkarni <okulkarni@marvell.com>
Signed-off-by: default avatarMichal Kalderon <mkalderon@marvell.com>
Signed-off-by: default avatarAriel Elior <aelior@marvell.com>
Signed-off-by: default avatarShai Malin <smalin@marvell.com>
Reviewed-by: default avatarHimanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent af527935

drivers/nvme/host/tcp-offload.c

+77 −0
Original line number Diff line number Diff line
@@ -13,6 +13,11 @@ 
static LIST_HEAD(nvme_tcp_ofld_devices);

static DEFINE_MUTEX(nvme_tcp_ofld_devices_mutex);



static inline struct nvme_tcp_ofld_ctrl *to_tcp_ofld_ctrl(struct nvme_ctrl *nctrl)

{

	return container_of(nctrl, struct nvme_tcp_ofld_ctrl, nctrl);

}



/**

 * nvme_tcp_ofld_register_dev() - NVMeTCP Offload Library registration

 * function.
@@ -96,6 +101,77 @@ void nvme_tcp_ofld_req_done(struct nvme_tcp_ofld_req *req, 
	/* Placeholder - complete request with/without error */

}



static struct nvme_tcp_ofld_dev *

nvme_tcp_ofld_lookup_dev(struct nvme_tcp_ofld_ctrl *ctrl)

{

	struct nvme_tcp_ofld_dev *dev;



	mutex_lock(&nvme_tcp_ofld_devices_mutex);

	list_for_each_entry(dev, &nvme_tcp_ofld_devices, entry) {

		if (dev->ops->claim_dev(dev, ctrl))

			goto out;

	}



	dev = NULL;

out:

	mutex_unlock(&nvme_tcp_ofld_devices_mutex);



	return dev;

}



static struct nvme_ctrl *

nvme_tcp_ofld_create_ctrl(struct device *ndev, struct nvmf_ctrl_options *opts)

{

	struct nvme_tcp_ofld_ctrl *ctrl;

	struct nvme_tcp_ofld_dev *dev;

	struct nvme_ctrl *nctrl;

	int rc = 0;



	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);

	if (!ctrl)

		return ERR_PTR(-ENOMEM);



	nctrl = &ctrl->nctrl;



	/* Init nvme_tcp_ofld_ctrl and nvme_ctrl params based on received opts */



	/* Find device that can reach the dest addr */

	dev = nvme_tcp_ofld_lookup_dev(ctrl);

	if (!dev) {

		pr_info("no device found for addr %s:%s.\n",

			opts->traddr, opts->trsvcid);

		rc = -EINVAL;

		goto out_free_ctrl;

	}



	/* Increase driver refcnt */

	if (!try_module_get(dev->ops->module)) {

		pr_err("try_module_get failed\n");

		dev = NULL;

		goto out_free_ctrl;

	}



	ctrl->dev = dev;



	if (ctrl->dev->ops->max_hw_sectors)

		nctrl->max_hw_sectors = ctrl->dev->ops->max_hw_sectors;

	if (ctrl->dev->ops->max_segments)

		nctrl->max_segments = ctrl->dev->ops->max_segments;



	/* Init queues */



	/* Call nvme_init_ctrl */



	/* Setup ctrl */



	return nctrl;



out_free_ctrl:

	kfree(ctrl);



	return ERR_PTR(rc);

}



static struct nvmf_transport_ops nvme_tcp_ofld_transport = {

	.name		= "tcp_offload",

	.module		= THIS_MODULE,
@@ -105,6 +181,7 @@ static struct nvmf_transport_ops nvme_tcp_ofld_transport = { 
			  NVMF_OPT_RECONNECT_DELAY | NVMF_OPT_HDR_DIGEST |

			  NVMF_OPT_DATA_DIGEST | NVMF_OPT_NR_POLL_QUEUES |

			  NVMF_OPT_TOS,

	.create_ctrl	= nvme_tcp_ofld_create_ctrl,

};



static int __init nvme_tcp_ofld_init_module(void)