include/rdma/rdmavt_qp.h

#ifndef DEF_RDMAVT_INCQP_H
#define DEF_RDMAVT_INCQP_H

/*
 * Copyright(c) 2015 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

/*
 * Send work request queue entry.
 * The size of the sg_list is determined when the QP is created and stored
 * in qp->s_max_sge.
 */
struct rvt_swqe {
	union {
		struct ib_send_wr wr;   /* don't use wr.sg_list */
		struct ib_ud_wr ud_wr;
		struct ib_reg_wr reg_wr;
		struct ib_rdma_wr rdma_wr;
		struct ib_atomic_wr atomic_wr;
	};
	u32 psn;                /* first packet sequence number */
	u32 lpsn;               /* last packet sequence number */
	u32 ssn;                /* send sequence number */
	u32 length;             /* total length of data in sg_list */
	struct rvt_sge sg_list[0];
};

/*
 * Receive work request queue entry.
 * The size of the sg_list is determined when the QP (or SRQ) is created
 * and stored in qp->r_rq.max_sge (or srq->rq.max_sge).
 */
struct rvt_rwqe {
	u64 wr_id;
	u8 num_sge;
	struct ib_sge sg_list[0];
};

/*
 * This structure is used to contain the head pointer, tail pointer,
 * and receive work queue entries as a single memory allocation so
 * it can be mmap'ed into user space.
 * Note that the wq array elements are variable size so you can't
 * just index into the array to get the N'th element;
 * use get_rwqe_ptr() instead.
 */
struct rvt_rwq {
	u32 head;               /* new work requests posted to the head */
	u32 tail;               /* receives pull requests from here. */
	struct rvt_rwqe wq[0];
};

struct rvt_rq {
	struct rvt_rwq *wq;
	u32 size;               /* size of RWQE array */
	u8 max_sge;
	/* protect changes in this struct */
	spinlock_t lock ____cacheline_aligned_in_smp;
};

/*
 * This structure is used by rvt_mmap() to validate an offset
 * when an mmap() request is made.  The vm_area_struct then uses
 * this as its vm_private_data.
 */
struct rvt_mmap_info {
	struct list_head pending_mmaps;
	struct ib_ucontext *context;
	void *obj;
	__u64 offset;
	struct kref ref;
	unsigned size;
};

#define RVT_MAX_RDMA_ATOMIC	16

/*
 * This structure holds the information that the send tasklet needs
 * to send a RDMA read response or atomic operation.
 */
struct rvt_ack_entry {
	u8 opcode;
	u8 sent;
	u32 psn;
	u32 lpsn;
	union {
		struct rvt_sge rdma_sge;
		u64 atomic_data;
	};
};

/*
 * Variables prefixed with s_ are for the requester (sender).
 * Variables prefixed with r_ are for the responder (receiver).
 * Variables prefixed with ack_ are for responder replies.
 *
 * Common variables are protected by both r_rq.lock and s_lock in that order
 * which only happens in modify_qp() or changing the QP 'state'.
 */
struct rvt_qp {
	struct ib_qp ibqp;
	void *priv; /* Driver private data */
	/* read mostly fields above and below */
	struct ib_ah_attr remote_ah_attr;
	struct ib_ah_attr alt_ah_attr;
	struct rvt_qp __rcu *next;           /* link list for QPN hash table */
	struct rvt_swqe *s_wq;  /* send work queue */
	struct rvt_mmap_info *ip;

	unsigned long timeout_jiffies;  /* computed from timeout */

	enum ib_mtu path_mtu;
	int srate_mbps;		/* s_srate (below) converted to Mbit/s */
	u32 remote_qpn;
	u32 pmtu;		/* decoded from path_mtu */
	u32 qkey;               /* QKEY for this QP (for UD or RD) */
	u32 s_size;             /* send work queue size */
	u32 s_rnr_timeout;      /* number of milliseconds for RNR timeout */
	u32 s_ahgpsn;           /* set to the psn in the copy of the header */

	u8 state;               /* QP state */
	u8 allowed_ops;		/* high order bits of allowed opcodes */
	u8 qp_access_flags;
	u8 alt_timeout;         /* Alternate path timeout for this QP */
	u8 timeout;             /* Timeout for this QP */
	u8 s_srate;
	u8 s_mig_state;
	u8 port_num;
	u8 s_pkey_index;        /* PKEY index to use */
	u8 s_alt_pkey_index;    /* Alternate path PKEY index to use */
	u8 r_max_rd_atomic;     /* max number of RDMA read/atomic to receive */
	u8 s_max_rd_atomic;     /* max number of RDMA read/atomic to send */
	u8 s_retry_cnt;         /* number of times to retry */
	u8 s_rnr_retry_cnt;
	u8 r_min_rnr_timer;     /* retry timeout value for RNR NAKs */
	u8 s_max_sge;           /* size of s_wq->sg_list */
	u8 s_draining;

	/* start of read/write fields */
	atomic_t refcount ____cacheline_aligned_in_smp;
	wait_queue_head_t wait;

	struct rvt_ack_entry s_ack_queue[RVT_MAX_RDMA_ATOMIC + 1]
		____cacheline_aligned_in_smp;
	struct rvt_sge_state s_rdma_read_sge;

	spinlock_t r_lock ____cacheline_aligned_in_smp;      /* used for APM */
	unsigned long r_aflags;
	u64 r_wr_id;            /* ID for current receive WQE */
	u32 r_ack_psn;          /* PSN for next ACK or atomic ACK */
	u32 r_len;              /* total length of r_sge */
	u32 r_rcv_len;          /* receive data len processed */
	u32 r_psn;              /* expected rcv packet sequence number */
	u32 r_msn;              /* message sequence number */

	u8 r_state;             /* opcode of last packet received */
	u8 r_flags;
	u8 r_head_ack_queue;    /* index into s_ack_queue[] */

	struct list_head rspwait;       /* link for waiting to respond */

	struct rvt_sge_state r_sge;     /* current receive data */
	struct rvt_rq r_rq;             /* receive work queue */

	spinlock_t s_lock ____cacheline_aligned_in_smp;
	struct rvt_sge_state *s_cur_sge;
	u32 s_flags;
	struct rvt_swqe *s_wqe;
	struct rvt_sge_state s_sge;     /* current send request data */
	struct rvt_mregion *s_rdma_mr;
	struct sdma_engine *s_sde; /* current sde */
	u32 s_cur_size;         /* size of send packet in bytes */
	u32 s_len;              /* total length of s_sge */
	u32 s_rdma_read_len;    /* total length of s_rdma_read_sge */
	u32 s_next_psn;         /* PSN for next request */
	u32 s_last_psn;         /* last response PSN processed */
	u32 s_sending_psn;      /* lowest PSN that is being sent */
	u32 s_sending_hpsn;     /* highest PSN that is being sent */
	u32 s_psn;              /* current packet sequence number */
	u32 s_ack_rdma_psn;     /* PSN for sending RDMA read responses */
	u32 s_ack_psn;          /* PSN for acking sends and RDMA writes */
	u32 s_head;             /* new entries added here */
	u32 s_tail;             /* next entry to process */
	u32 s_cur;              /* current work queue entry */
	u32 s_acked;            /* last un-ACK'ed entry */
	u32 s_last;             /* last completed entry */
	u32 s_ssn;              /* SSN of tail entry */
	u32 s_lsn;              /* limit sequence number (credit) */
	u16 s_hdrwords;         /* size of s_hdr in 32 bit words */
	u16 s_rdma_ack_cnt;
	s8 s_ahgidx;
	u8 s_state;             /* opcode of last packet sent */
	u8 s_ack_state;         /* opcode of packet to ACK */
	u8 s_nak_state;         /* non-zero if NAK is pending */
	u8 r_nak_state;         /* non-zero if NAK is pending */
	u8 s_retry;             /* requester retry counter */
	u8 s_rnr_retry;         /* requester RNR retry counter */
	u8 s_num_rd_atomic;     /* number of RDMA read/atomic pending */
	u8 s_tail_ack_queue;    /* index into s_ack_queue[] */

	struct rvt_sge_state s_ack_rdma_sge;
	struct timer_list s_timer;

	/*
	 * This sge list MUST be last. Do not add anything below here.
	 */
	struct rvt_sge r_sg_list[0] /* verified SGEs */
		____cacheline_aligned_in_smp;
};

struct rvt_srq {
	struct ib_srq ibsrq;
	struct rvt_rq rq;
	struct rvt_mmap_info *ip;
	/* send signal when number of RWQEs < limit */
	u32 limit;
};

#define RVT_QPN_MAX                 BIT(24)
#define RVT_QPNMAP_ENTRIES          (RVT_QPN_MAX / PAGE_SIZE / BITS_PER_BYTE)
#define RVT_BITS_PER_PAGE           (PAGE_SIZE * BITS_PER_BYTE)
#define RVT_BITS_PER_PAGE_MASK      (RVT_BITS_PER_PAGE - 1)

/*
 * QPN-map pages start out as NULL, they get allocated upon
 * first use and are never deallocated. This way,
 * large bitmaps are not allocated unless large numbers of QPs are used.
 */
struct rvt_qpn_map {
	void *page;
};

struct rvt_qpn_table {
	spinlock_t lock; /* protect changes to the qp table */
	unsigned flags;         /* flags for QP0/1 allocated for each port */
	u32 last;               /* last QP number allocated */
	u32 nmaps;              /* size of the map table */
	u16 limit;
	u8  incr;
	/* bit map of free QP numbers other than 0/1 */
	struct rvt_qpn_map map[RVT_QPNMAP_ENTRIES];
};

struct rvt_qp_ibdev {
	u32 qp_table_size;
	u32 qp_table_bits;
	struct rvt_qp __rcu **qp_table;
	spinlock_t qpt_lock; /* qptable lock */
	struct rvt_qpn_table qpn_table;
};

#endif          /* DEF_RDMAVT_INCQP_H */