path: root/include/linux/nvme-fc-driver.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2016, Avago Technologies
 */

#ifndef _NVME_FC_DRIVER_H
#define _NVME_FC_DRIVER_H 1

#include <linux/scatterlist.h>
#include <linux/blk-mq.h>


/*
 * **********************  FC-NVME LS API ********************
 *
 *  Data structures used by both FC-NVME hosts and FC-NVME
 *  targets to perform FC-NVME LS requests or transmit
 *  responses.
 *
 * ***********************************************************
 */

/**
 * struct nvmefc_ls_req - Request structure passed from the transport
 *            to the LLDD to perform a NVME-FC LS request and obtain
 *            a response.
 *            Used by nvme-fc transport (host) to send LS's such as
 *              Create Association, Create Connection and Disconnect
 *              Association.
 *            Used by the nvmet-fc transport (controller) to send
 *              LS's such as Disconnect Association.
 *
 * Values set by the requestor prior to calling the LLDD ls_req entrypoint:
 * @rqstaddr: pointer to request buffer
 * @rqstdma:  PCI DMA address of request buffer
 * @rqstlen:  Length, in bytes, of request buffer
 * @rspaddr:  pointer to response buffer
 * @rspdma:   PCI DMA address of response buffer
 * @rsplen:   Length, in bytes, of response buffer
 * @timeout:  Maximum amount of time, in seconds, to wait for the LS response.
 *            If timeout exceeded, LLDD to abort LS exchange and complete
 *            LS request with error status.
 * @private:  pointer to memory allocated alongside the ls request structure
 *            that is specifically for the LLDD to use while processing the
 *            request. The length of the buffer corresponds to the
 *            lsrqst_priv_sz value specified in the xxx_template supplied
 *            by the LLDD.
 * @done:     The callback routine the LLDD is to invoke upon completion of
 *            the LS request. req argument is the pointer to the original LS
 *            request structure. Status argument must be 0 upon success, a
 *            negative errno on failure (example: -ENXIO).
 */
struct nvmefc_ls_req {
	void			*rqstaddr;
	dma_addr_t		rqstdma;
	u32			rqstlen;
	void			*rspaddr;
	dma_addr_t		rspdma;
	u32			rsplen;
	u32			timeout;

	void			*private;

	void (*done)(struct nvmefc_ls_req *req, int status);

} __aligned(sizeof(u64));	/* alignment for other things alloc'd with */


/**
 * struct nvmefc_ls_rsp - Structure passed from the transport to the LLDD
 *            to request the transmit the NVME-FC LS response to a
 *            NVME-FC LS request.   The structure originates in the LLDD
 *            and is given to the transport via the xxx_rcv_ls_req()
 *            transport routine. As such, the structure represents the
 *            FC exchange context for the NVME-FC LS request that was
 *            received and which the response is to be sent for.
 *            Used by the LLDD to pass the nvmet-fc transport (controller)
 *              received LS's such as Create Association, Create Connection
 *              and Disconnect Association.
 *            Used by the LLDD to pass the nvme-fc transport (host)
 *              received LS's such as Disconnect Association or Disconnect
 *              Connection.
 *
 * The structure is allocated by the LLDD whenever a LS Request is received
 * from the FC link. The address of the structure is passed to the nvmet-fc
 * or nvme-fc layer via the xxx_rcv_ls_req() transport routines.
 *
 * The address of the structure is to be passed back to the LLDD
 * when the response is to be transmit. The LLDD will use the address to
 * map back to the LLDD exchange structure which maintains information such
 * the remote N_Port that sent the LS as well as any FC exchange context.
 * Upon completion of the LS response transmit, the LLDD will pass the
 * address of the structure back to the transport LS rsp done() routine,
 * allowing the transport release dma resources. Upon completion of
 * the done() routine, no further access to the structure will be made by
 * the transport and the LLDD can de-allocate the structure.
 *
 * Field initialization:
 *   At the time of the xxx_rcv_ls_req() call, there is no content that
 *     is valid in the structure.
 *
 *   When the structure is used for the LLDD->xmt_ls_rsp() call, the
 *     transport layer will fully set the fields in order to specify the
 *     response payload buffer and its length as well as the done routine
 *     to be called upon completion of the transmit.  The transport layer
 *     will also set a private pointer for its own use in the done routine.
 *
 * Values set by the transport layer prior to calling the LLDD xmt_ls_rsp
 * entrypoint:
 * @rspbuf:   pointer to the LS response buffer
 * @rspdma:   PCI DMA address of the LS response buffer
 * @rsplen:   Length, in bytes, of the LS response buffer
 * @done:     The callback routine the LLDD is to invoke upon completion of
 *            transmitting the LS response. req argument is the pointer to
 *            the original ls request.
 * @nvme_fc_private:  pointer to an internal transport-specific structure
 *            used as part of the transport done() processing. The LLDD is
 *            not to access this pointer.
 */
struct nvmefc_ls_rsp {
	void		*rspbuf;
	dma_addr_t	rspdma;
	u16		rsplen;

	void (*done)(struct nvmefc_ls_rsp *rsp);
	void		*nvme_fc_private;	/* LLDD is not to access !! */
};



/*
 * **********************  LLDD FC-NVME Host API ********************
 *
 *  For FC LLDD's that are the NVME Host role.
 *
 * ******************************************************************
 */


/**
 * struct nvme_fc_port_info - port-specific ids and FC connection-specific
 *                            data element used during NVME Host role
 *                            registrations
 *
 * Static fields describing the port being registered:
 * @node_name: FC WWNN for the port
 * @port_name: FC WWPN for the port
 * @port_role: What NVME roles are supported (see FC_PORT_ROLE_xxx)
 * @dev_loss_tmo: maximum delay for reconnects to an association on
 *             this device. Used only on a remoteport.
 *
 * Initialization values for dynamic port fields:
 * @port_id:      FC N_Port_ID currently assigned the port. Upper 8 bits must
 *                be set to 0.
 */
struct nvme_fc_port_info {
	u64			node_name;
	u64			port_name;
	u32			port_role;
	u32			port_id;
	u32			dev_loss_tmo;
};

enum nvmefc_fcp_datadir {
	NVMEFC_FCP_NODATA,	/* payload_length and sg_cnt will be zero */
	NVMEFC_FCP_WRITE,
	NVMEFC_FCP_READ,
};


/**
 * struct nvmefc_fcp_req - Request structure passed from NVME-FC transport
 *                         to LLDD in order to perform a NVME FCP IO operation.
 *
 * Values set by the NVME-FC layer prior to calling the LLDD fcp_io
 * entrypoint.
 * @cmdaddr:   pointer to the FCP CMD IU buffer
 * @rspaddr:   pointer to the FCP RSP IU buffer
 * @cmddma:    PCI DMA address of the FCP CMD IU buffer
 * @rspdma:    PCI DMA address of the FCP RSP IU buffer
 * @cmdlen:    Length, in bytes, of the FCP CMD IU buffer
 * @rsplen:    Length, in bytes, of the FCP RSP IU buffer
 * @payload_length: Length of DATA_IN or DATA_OUT payload data to transfer
 * @sg_table:  scatter/gather structure for payload data
 * @first_sgl: memory for 1st scatter/gather list segment for payload data
 * @sg_cnt:    number of elements in the scatter/gather list
 * @io_dir:    direction of the FCP request (see NVMEFC_FCP_xxx)
 * @done:      The callback routine the LLDD is to invoke upon completion of
 *             the FCP operation. req argument is the pointer to the original
 *             FCP IO operation.
 * @private:   pointer to memory allocated alongside the FCP operation
 *             request structure that is specifically for the LLDD to use
 *             while processing the operation. The length of the buffer
 *             corresponds to the fcprqst_priv_sz value specified in the
 *             nvme_fc_port_template supplied by the LLDD.
 * @sqid:      The nvme SQID the command is being issued on
 *
 * Values set by the LLDD indicating completion status of the FCP operation.
 * Must be set prior to calling the done() callback.
 * @rcv_rsplen: length, in bytes, of the FCP RSP IU received.
 * @transferred_length: amount of payload data, in bytes, that were
 *             transferred. Should equal payload_length on success.
 * @status:    Completion status of the FCP operation. must be 0 upon success,
 *             negative errno value upon failure (ex: -EIO). Note: this is
 *             NOT a reflection of the NVME CQE completion status. Only the
 *             status of the FCP operation at the NVME-FC level.
 */
struct nvmefc_fcp_req {
	void			*cmdaddr;
	void			*rspaddr;
	dma_addr_t		cmddma;
	dma_addr_t		rspdma;
	u16			cmdlen;
	u16			rsplen;

	u32			payload_length;
	struct sg_table		sg_table;
	struct scatterlist	*first_sgl;
	int			sg_cnt;
	enum nvmefc_fcp_datadir	io_dir;

	void (*done)(struct nvmefc_fcp_req *req);

	void			*private;

	__le16			sqid;

	u16			rcv_rsplen;
	u32			transferred_length;
	u32			status;
} __aligned(sizeof(u64));	/* alignment for other things alloc'd with */


/*
 * Direct copy of fc_port_state enum. For later merging
 */
enum nvme_fc_obj_state {
	FC_OBJSTATE_UNKNOWN,
	FC_OBJSTATE_NOTPRESENT,
	FC_OBJSTATE_ONLINE,
	FC_OBJSTATE_OFFLINE,		/* User has taken Port Offline */
	FC_OBJSTATE_BLOCKED,
	FC_OBJSTATE_BYPASSED,
	FC_OBJSTATE_DIAGNOSTICS,
	FC_OBJSTATE_LINKDOWN,
	FC_OBJSTATE_ERROR,
	FC_OBJSTATE_LOOPBACK,
	FC_OBJSTATE_DELETED,
};


/**
 * struct nvme_fc_local_port - structure used between NVME-FC transport and
 *                 a LLDD to reference a local NVME host port.
 *                 Allocated/created by the nvme_fc_register_localport()
 *                 transport interface.
 *
 * Fields with static values for the port. Initialized by the
 * port_info struct supplied to the registration call.
 * @port_num:  NVME-FC transport host port number
 * @port_role: NVME roles are supported on the port (see FC_PORT_ROLE_xxx)
 * @node_name: FC WWNN for the port
 * @port_name: FC WWPN for the port
 * @private:   pointer to memory allocated alongside the local port
 *             structure that is specifically for the LLDD to use.
 *             The length of the buffer corresponds to the local_priv_sz
 *             value specified in the nvme_fc_port_template supplied by
 *             the LLDD.
 * @dev_loss_tmo: maximum delay for reconnects to an association on
 *             this device. To modify, lldd must call
 *             nvme_fc_set_remoteport_devloss().
 *
 * Fields with dynamic values. Val