/* SPDX-License-Identifier: GPL-2.0 */

  #ifndef _RDS_IB_H
  #define _RDS_IB_H
  
  #include <rdma/ib_verbs.h>
  #include <rdma/rdma_cm.h>

  #include <linux/interrupt.h>

  #include <linux/pci.h>
  #include <linux/slab.h>

  #include "rds.h"
  #include "rdma_transport.h"

  #define RDS_IB_MAX_SGE			8
  #define RDS_IB_RECV_SGE 		2
  
  #define RDS_IB_DEFAULT_RECV_WR		1024
  #define RDS_IB_DEFAULT_SEND_WR		256

  #define RDS_IB_DEFAULT_FR_WR		512

  #define RDS_IB_DEFAULT_RETRY_COUNT	1

  #define RDS_IB_SUPPORTED_PROTOCOLS	0x00000003	/* minor versions supported */

  #define RDS_IB_RECYCLE_BATCH_COUNT	32

  #define RDS_IB_WC_MAX			32

  extern struct rw_semaphore rds_ib_devices_lock;

  extern struct list_head rds_ib_devices;
  
  /*
   * IB posts RDS_FRAG_SIZE fragments of pages to the receive queues to
   * try and minimize the amount of memory tied up both the device and
   * socket receive queues.
   */

  struct rds_page_frag {
  	struct list_head	f_item;

  	struct list_head	f_cache_entry;

  	struct scatterlist	f_sg;

  };
  
  struct rds_ib_incoming {
  	struct list_head	ii_frags;

  	struct list_head	ii_cache_entry;

  	struct rds_incoming	ii_inc;
  };

  struct rds_ib_cache_head {
  	struct list_head *first;
  	unsigned long count;
  };
  
  struct rds_ib_refill_cache {

  	struct rds_ib_cache_head __percpu *percpu;

  	struct list_head	 *xfer;
  	struct list_head	 *ready;
  };

  /* This is the common structure for the IB private data exchange in setting up
   * an RDS connection.  The exchange is different for IPv4 and IPv6 connections.
   * The reason is that the address size is different and the addresses
   * exchanged are in the beginning of the structure.  Hence it is not possible
   * for interoperability if same structure is used.
   */
  struct rds_ib_conn_priv_cmn {
  	u8			ricpc_protocol_major;
  	u8			ricpc_protocol_minor;
  	__be16			ricpc_protocol_minor_mask;	/* bitmask */

  	u8			ricpc_dp_toss;
  	u8			ripc_reserved1;
  	__be16			ripc_reserved2;

  	__be64			ricpc_ack_seq;
  	__be32			ricpc_credit;	/* non-zero enables flow ctl */
  };

  struct rds_ib_connect_private {
  	/* Add new fields at the end, and don't permute existing fields. */

  	__be32				dp_saddr;
  	__be32				dp_daddr;
  	struct rds_ib_conn_priv_cmn	dp_cmn;
  };
  
  struct rds6_ib_connect_private {
  	/* Add new fields at the end, and don't permute existing fields. */
  	struct in6_addr			dp_saddr;
  	struct in6_addr			dp_daddr;
  	struct rds_ib_conn_priv_cmn	dp_cmn;
  };
  
  #define dp_protocol_major	dp_cmn.ricpc_protocol_major
  #define dp_protocol_minor	dp_cmn.ricpc_protocol_minor
  #define dp_protocol_minor_mask	dp_cmn.ricpc_protocol_minor_mask
  #define dp_ack_seq		dp_cmn.ricpc_ack_seq
  #define dp_credit		dp_cmn.ricpc_credit
  
  union rds_ib_conn_priv {
  	struct rds_ib_connect_private	ricp_v4;
  	struct rds6_ib_connect_private	ricp_v6;

  };
  
  struct rds_ib_send_work {

  	void			*s_op;

  	union {
  		struct ib_send_wr	s_wr;
  		struct ib_rdma_wr	s_rdma_wr;
  		struct ib_atomic_wr	s_atomic_wr;
  	};

  	struct ib_sge		s_sge[RDS_IB_MAX_SGE];
  	unsigned long		s_queued;
  };
  
  struct rds_ib_recv_work {
  	struct rds_ib_incoming 	*r_ibinc;
  	struct rds_page_frag	*r_frag;
  	struct ib_recv_wr	r_wr;
  	struct ib_sge		r_sge[2];
  };
  
  struct rds_ib_work_ring {
  	u32		w_nr;
  	u32		w_alloc_ptr;
  	u32		w_alloc_ctr;
  	u32		w_free_ptr;
  	atomic_t	w_free_ctr;
  };

  /* Rings are posted with all the allocations they'll need to queue the
   * incoming message to the receiving socket so this can't fail.
   * All fragments start with a header, so we can make sure we're not receiving
   * garbage, and we can tell a small 8 byte fragment from an ACK frame.
   */
  struct rds_ib_ack_state {
  	u64		ack_next;
  	u64		ack_recv;
  	unsigned int	ack_required:1;
  	unsigned int	ack_next_valid:1;
  	unsigned int	ack_recv_valid:1;
  };

  struct rds_ib_device;
  
  struct rds_ib_connection {
  
  	struct list_head	ib_node;
  	struct rds_ib_device	*rds_ibdev;
  	struct rds_connection	*conn;
  
  	/* alphabet soup, IBTA style */
  	struct rdma_cm_id	*i_cm_id;
  	struct ib_pd		*i_pd;

  	struct ib_cq		*i_send_cq;
  	struct ib_cq		*i_recv_cq;

  	struct ib_wc		i_send_wc[RDS_IB_WC_MAX];

  	struct ib_wc		i_recv_wc[RDS_IB_WC_MAX];

  	/* To control the number of wrs from fastreg */
  	atomic_t		i_fastreg_wrs;

  	atomic_t		i_fastreg_inuse_count;

  	/* interrupt handling */

  	struct tasklet_struct	i_send_tasklet;

  	struct tasklet_struct	i_recv_tasklet;

  
  	/* tx */
  	struct rds_ib_work_ring	i_send_ring;

  	struct rm_data_op	*i_data_op;

  	struct rds_header	**i_send_hdrs;
  	dma_addr_t		*i_send_hdrs_dma;

  	struct rds_ib_send_work *i_sends;

  	atomic_t		i_signaled_sends;

  
  	/* rx */
  	struct mutex		i_recv_mutex;
  	struct rds_ib_work_ring	i_recv_ring;
  	struct rds_ib_incoming	*i_ibinc;
  	u32			i_recv_data_rem;

  	struct rds_header	**i_recv_hdrs;
  	dma_addr_t		*i_recv_hdrs_dma;

  	struct rds_ib_recv_work *i_recvs;

  	u64			i_ack_recv;	/* last ACK received */

  	struct rds_ib_refill_cache i_cache_incs;
  	struct rds_ib_refill_cache i_cache_frags;

  	atomic_t		i_cache_allocs;

  
  	/* sending acks */
  	unsigned long		i_ack_flags;

  #ifdef KERNEL_HAS_ATOMIC64
  	atomic64_t		i_ack_next;	/* next ACK to send */
  #else
  	spinlock_t		i_ack_lock;	/* protect i_ack_next */

  	u64			i_ack_next;	/* next ACK to send */

  #endif

  	struct rds_header	*i_ack;
  	struct ib_send_wr	i_ack_wr;
  	struct ib_sge		i_ack_sge;

  	dma_addr_t		i_ack_dma;

  	unsigned long		i_ack_queued;
  
  	/* Flow control related information
  	 *
  	 * Our algorithm uses a pair variables that we need to access
  	 * atomically - one for the send credits, and one posted
  	 * recv credits we need to transfer to remote.
  	 * Rather than protect them using a slow spinlock, we put both into
  	 * a single atomic_t and update it using cmpxchg
  	 */
  	atomic_t		i_credits;
  
  	/* Protocol version specific information */
  	unsigned int		i_flowctl:1;	/* enable/disable flow ctl */
  
  	/* Batched completions */
  	unsigned int		i_unsignaled_wrs;

  
  	/* Endpoint role in connection */
  	bool			i_active_side;

  	atomic_t		i_cq_quiesce;

  
  	/* Send/Recv vectors */
  	int			i_scq_vector;
  	int			i_rcq_vector;

  	u8			i_sl;

  };
  
  /* This assumes that atomic_t is at least 32 bits */
  #define IB_GET_SEND_CREDITS(v)	((v) & 0xffff)
  #define IB_GET_POST_CREDITS(v)	((v) >> 16)
  #define IB_SET_SEND_CREDITS(v)	((v) & 0xffff)
  #define IB_SET_POST_CREDITS(v)	((v) << 16)
  
  struct rds_ib_ipaddr {
  	struct list_head	list;
  	__be32			ipaddr;

  	struct rcu_head		rcu;

  };

  enum {
  	RDS_IB_MR_8K_POOL,
  	RDS_IB_MR_1M_POOL,
  };

  struct rds_ib_device {
  	struct list_head	list;
  	struct list_head	ipaddr_list;
  	struct list_head	conn_list;
  	struct ib_device	*dev;
  	struct ib_pd		*pd;

  	struct dma_pool		*rid_hdrs_pool; /* RDS headers DMA pool */

  	u8			odp_capable:1;

  	unsigned int		max_mrs;

  	struct rds_ib_mr_pool	*mr_1m_pool;
  	struct rds_ib_mr_pool   *mr_8k_pool;

  	unsigned int		max_8k_mrs;
  	unsigned int		max_1m_mrs;

  	int			max_sge;
  	unsigned int		max_wrs;

  	unsigned int		max_initiator_depth;
  	unsigned int		max_responder_resources;

  	spinlock_t		spinlock;	/* protect the above */

  	refcount_t		refcount;

  	struct work_struct	free_work;

  	int			*vector_load;

  };

  static inline int ibdev_to_node(struct ib_device *ibdev)
  {
  	struct device *parent;
  
  	parent = ibdev->dev.parent;
  	return parent ? dev_to_node(parent) : NUMA_NO_NODE;
  }

  #define rdsibdev_to_node(rdsibdev) ibdev_to_node(rdsibdev->dev)

  /* bits for i_ack_flags */
  #define IB_ACK_IN_FLIGHT	0
  #define IB_ACK_REQUESTED	1
  
  /* Magic WR_ID for ACKs */
  #define RDS_IB_ACK_WR_ID	(~(u64) 0)
  
  struct rds_ib_statistics {
  	uint64_t	s_ib_connect_raced;
  	uint64_t	s_ib_listen_closed_stale;

  	uint64_t	s_ib_evt_handler_call;
  	uint64_t	s_ib_tasklet_call;

  	uint64_t	s_ib_tx_cq_event;
  	uint64_t	s_ib_tx_ring_full;
  	uint64_t	s_ib_tx_throttle;
  	uint64_t	s_ib_tx_sg_mapping_failure;
  	uint64_t	s_ib_tx_stalled;
  	uint64_t	s_ib_tx_credit_updates;

  	uint64_t	s_ib_rx_cq_event;
  	uint64_t	s_ib_rx_ring_empty;
  	uint64_t	s_ib_rx_refill_from_cq;
  	uint64_t	s_ib_rx_refill_from_thread;
  	uint64_t	s_ib_rx_alloc_limit;

  	uint64_t	s_ib_rx_total_frags;
  	uint64_t	s_ib_rx_total_incs;

  	uint64_t	s_ib_rx_credit_updates;
  	uint64_t	s_ib_ack_sent;
  	uint64_t	s_ib_ack_send_failure;
  	uint64_t	s_ib_ack_send_delayed;
  	uint64_t	s_ib_ack_send_piggybacked;
  	uint64_t	s_ib_ack_received;

  	uint64_t	s_ib_rdma_mr_8k_alloc;
  	uint64_t	s_ib_rdma_mr_8k_free;
  	uint64_t	s_ib_rdma_mr_8k_used;
  	uint64_t	s_ib_rdma_mr_8k_pool_flush;
  	uint64_t	s_ib_rdma_mr_8k_pool_wait;
  	uint64_t	s_ib_rdma_mr_8k_pool_depleted;
  	uint64_t	s_ib_rdma_mr_1m_alloc;
  	uint64_t	s_ib_rdma_mr_1m_free;
  	uint64_t	s_ib_rdma_mr_1m_used;
  	uint64_t	s_ib_rdma_mr_1m_pool_flush;
  	uint64_t	s_ib_rdma_mr_1m_pool_wait;
  	uint64_t	s_ib_rdma_mr_1m_pool_depleted;

  	uint64_t	s_ib_rdma_mr_8k_reused;
  	uint64_t	s_ib_rdma_mr_1m_reused;

  	uint64_t	s_ib_atomic_cswp;
  	uint64_t	s_ib_atomic_fadd;

  	uint64_t	s_ib_recv_added_to_cache;
  	uint64_t	s_ib_recv_removed_from_cache;

  };
  
  extern struct workqueue_struct *rds_ib_wq;
  
  /*
   * Fake ib_dma_sync_sg_for_{cpu,device} as long as ib_verbs.h
   * doesn't define it.
   */
  static inline void rds_ib_dma_sync_sg_for_cpu(struct ib_device *dev,

  					      struct scatterlist *sglist,
  					      unsigned int sg_dma_len,
  					      int direction)

  {

  	struct scatterlist *sg;

  	unsigned int i;

  	for_each_sg(sglist, sg, sg_dma_len, i) {

  		ib_dma_sync_single_for_cpu(dev, sg_dma_address(sg),
  					   sg_dma_len(sg), direction);

  	}
  }
  #define ib_dma_sync_sg_for_cpu	rds_ib_dma_sync_sg_for_cpu
  
  static inline void rds_ib_dma_sync_sg_for_device(struct ib_device *dev,

  						 struct scatterlist *sglist,
  						 unsigned int sg_dma_len,
  						 int direction)

  {

  	struct scatterlist *sg;

  	unsigned int i;

  	for_each_sg(sglist, sg, sg_dma_len, i) {

  		ib_dma_sync_single_for_device(dev, sg_dma_address(sg),
  					      sg_dma_len(sg), direction);

  	}
  }
  #define ib_dma_sync_sg_for_device	rds_ib_dma_sync_sg_for_device
  
  
  /* ib.c */
  extern struct rds_transport rds_ib_transport;

  struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device);
  void rds_ib_dev_put(struct rds_ib_device *rds_ibdev);

  extern struct ib_client rds_ib_client;

  extern unsigned int rds_ib_retry_count;

  
  extern spinlock_t ib_nodev_conns_lock;
  extern struct list_head ib_nodev_conns;
  
  /* ib_cm.c */
  int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp);
  void rds_ib_conn_free(void *arg);

  int rds_ib_conn_path_connect(struct rds_conn_path *cp);

  void rds_ib_conn_path_shutdown(struct rds_conn_path *cp);

  void rds_ib_state_change(struct sock *sk);

  int rds_ib_listen_init(void);

  void rds_ib_listen_stop(void);

  __printf(2, 3)

  void __rds_ib_conn_error(struct rds_connection *conn, const char *, ...);
  int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,

  			     struct rdma_cm_event *event, bool isv6);
  int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id, bool isv6);

  void rds_ib_cm_connect_complete(struct rds_connection *conn,
  				struct rdma_cm_event *event);

  struct rds_header **rds_dma_hdrs_alloc(struct ib_device *ibdev,
  				       struct dma_pool *pool,
  				       dma_addr_t **dma_addrs, u32 num_hdrs);
  void rds_dma_hdrs_free(struct dma_pool *pool, struct rds_header **hdrs,
  		       dma_addr_t *dma_addrs, u32 num_hdrs);

  
  #define rds_ib_conn_error(conn, fmt...) \
  	__rds_ib_conn_error(conn, KERN_WARNING "RDS/IB: " fmt)
  
  /* ib_rdma.c */

  int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev,
  			 struct in6_addr *ipaddr);

  void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);
  void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn);

  void rds_ib_destroy_nodev_conns(void);

  void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc);

  
  /* ib_recv.c */

  int rds_ib_recv_init(void);

  void rds_ib_recv_exit(void);

  int rds_ib_recv_path(struct rds_conn_path *conn);

  int rds_ib_recv_alloc_caches(struct rds_ib_connection *ic, gfp_t gfp);

  void rds_ib_recv_free_caches(struct rds_ib_connection *ic);

  void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp);

  void rds_ib_inc_free(struct rds_incoming *inc);

  int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);

  void rds_ib_recv_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc,
  			     struct rds_ib_ack_state *state);

  void rds_ib_recv_tasklet_fn(unsigned long data);

  void rds_ib_recv_init_ring(struct rds_ib_connection *ic);
  void rds_ib_recv_clear_ring(struct rds_ib_connection *ic);
  void rds_ib_recv_init_ack(struct rds_ib_connection *ic);
  void rds_ib_attempt_ack(struct rds_ib_connection *ic);
  void rds_ib_ack_send_complete(struct rds_ib_connection *ic);
  u64 rds_ib_piggyb_ack(struct rds_ib_connection *ic);

  void rds_ib_set_ack(struct rds_ib_connection *ic, u64 seq, int ack_required);

  
  /* ib_ring.c */
  void rds_ib_ring_init(struct rds_ib_work_ring *ring, u32 nr);
  void rds_ib_ring_resize(struct rds_ib_work_ring *ring, u32 nr);
  u32 rds_ib_ring_alloc(struct rds_ib_work_ring *ring, u32 val, u32 *pos);
  void rds_ib_ring_free(struct rds_ib_work_ring *ring, u32 val);
  void rds_ib_ring_unalloc(struct rds_ib_work_ring *ring, u32 val);
  int rds_ib_ring_empty(struct rds_ib_work_ring *ring);
  int rds_ib_ring_low(struct rds_ib_work_ring *ring);
  u32 rds_ib_ring_oldest(struct rds_ib_work_ring *ring);
  u32 rds_ib_ring_completed(struct rds_ib_work_ring *ring, u32 wr_id, u32 oldest);
  extern wait_queue_head_t rds_ib_ring_empty_wait;
  
  /* ib_send.c */

  void rds_ib_xmit_path_complete(struct rds_conn_path *cp);

  int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
  		unsigned int hdr_off, unsigned int sg, unsigned int off);

  void rds_ib_send_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc);

  void rds_ib_send_init_ring(struct rds_ib_connection *ic);
  void rds_ib_send_clear_ring(struct rds_ib_connection *ic);

  int rds_ib_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op);

  void rds_ib_send_add_credits(struct rds_connection *conn, unsigned int credits);
  void rds_ib_advertise_credits(struct rds_connection *conn, unsigned int posted);
  int rds_ib_send_grab_credits(struct rds_ib_connection *ic, u32 wanted,

  			     u32 *adv_credits, int need_posted, int max_posted);

  int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op);

  
  /* ib_stats.c */

  DECLARE_PER_CPU_SHARED_ALIGNED(struct rds_ib_statistics, rds_ib_stats);

  #define rds_ib_stats_inc(member) rds_stats_inc_which(rds_ib_stats, member)

  #define rds_ib_stats_add(member, count) \
  		rds_stats_add_which(rds_ib_stats, member, count)

  unsigned int rds_ib_stats_info_copy(struct rds_info_iterator *iter,
  				    unsigned int avail);
  
  /* ib_sysctl.c */

  int rds_ib_sysctl_init(void);

  void rds_ib_sysctl_exit(void);
  extern unsigned long rds_ib_sysctl_max_send_wr;
  extern unsigned long rds_ib_sysctl_max_recv_wr;
  extern unsigned long rds_ib_sysctl_max_unsig_wrs;
  extern unsigned long rds_ib_sysctl_max_unsig_bytes;
  extern unsigned long rds_ib_sysctl_max_recv_allocation;
  extern unsigned int rds_ib_sysctl_flow_control;

  #endif