| .\" -*- nroff -*- |
| .\" |
| .TH IBV_POST_SEND 3 2006-10-31 libibverbs "Libibverbs Programmer's Manual" |
| .SH "NAME" |
| ibv_post_send \- post a list of work requests (WRs) to a send queue |
| .SH "SYNOPSIS" |
| .nf |
| .B #include <infiniband/verbs.h> |
| .sp |
| .BI "int ibv_post_send(struct ibv_qp " "*qp" ", struct ibv_send_wr " "*wr" , |
| .BI " struct ibv_send_wr " "**bad_wr" ); |
| .fi |
| .SH "DESCRIPTION" |
| .B ibv_post_send() |
| posts the linked list of work requests (WRs) starting with |
| .I wr |
| to the send queue of the queue pair |
| .I qp\fR. |
| It stops processing WRs from this list at the first failure (that can |
| be detected immediately while requests are being posted), and returns |
| this failing WR through |
| .I bad_wr\fR. |
| .PP |
| The argument |
| .I wr |
| is an ibv_send_wr struct, as defined in <infiniband/verbs.h>. |
| .PP |
| .nf |
| struct ibv_send_wr { |
| .in +8 |
| uint64_t wr_id; /* User defined WR ID */ |
| struct ibv_send_wr *next; /* Pointer to next WR in list, NULL if last WR */ |
| struct ibv_sge *sg_list; /* Pointer to the s/g array */ |
| int num_sge; /* Size of the s/g array */ |
| enum ibv_wr_opcode opcode; /* Operation type */ |
| int send_flags; /* Flags of the WR properties */ |
| uint32_t imm_data; /* Immediate data (in network byte order) */ |
| union { |
| .in +8 |
| struct { |
| .in +8 |
| uint64_t remote_addr; /* Start address of remote memory buffer */ |
| uint32_t rkey; /* Key of the remote Memory Region */ |
| .in -8 |
| } rdma; |
| struct { |
| .in +8 |
| uint64_t remote_addr; /* Start address of remote memory buffer */ |
| uint64_t compare_add; /* Compare operand */ |
| uint64_t swap; /* Swap operand */ |
| uint32_t rkey; /* Key of the remote Memory Region */ |
| .in -8 |
| } atomic; |
| struct { |
| .in +8 |
| struct ibv_ah *ah; /* Address handle (AH) for the remote node address */ |
| uint32_t remote_qpn; /* QP number of the destination QP */ |
| uint32_t remote_qkey; /* Q_Key number of the destination QP */ |
| .in -8 |
| } ud; |
| .in -8 |
| } wr; |
| .in -8 |
| }; |
| .sp |
| .nf |
| struct ibv_sge { |
| .in +8 |
| uint64_t addr; /* Start address of the local memory buffer */ |
| uint32_t length; /* Length of the buffer */ |
| uint32_t lkey; /* Key of the local Memory Region */ |
| .in -8 |
| }; |
| .fi |
| .PP |
| Each QP Transport Service Type supports a specific set of opcodes, as shown in the following table: |
| .PP |
| .nf |
| OPCODE | IBV_QPT_UD | IBV_QPT_UC | IBV_QPT_RC |
| \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\-\-+\-\-\-\-\-\-\-\-\-\-\- |
| IBV_WR_SEND | X | X | X |
| IBV_WR_SEND_WITH_IMM | X | X | X |
| IBV_WR_RDMA_WRITE | | X | X |
| IBV_WR_RDMA_WRITE_WITH_IMM | | X | X |
| IBV_WR_RDMA_READ | | | X |
| IBV_WR_ATOMIC_CMP_AND_SWP | | | X |
| IBV_WR_ATOMIC_FETCH_AND_ADD | | | X |
| .fi |
| .PP |
| The attribute send_flags describes the properties of the \s-1WR\s0. It is either 0 or the bitwise \s-1OR\s0 of one or more of the following flags: |
| .PP |
| .TP |
| .B IBV_SEND_FENCE \fR Set the fence indicator. Valid only for QPs with Transport Service Type \fBIBV_QPT_RC |
| .TP |
| .B IBV_SEND_SIGNALED \fR Set the completion notification indicator. Relevant only if QP was created with sq_sig_all=0 |
| .TP |
| .B IBV_SEND_SOLICITED \fR Set the solicited event indicator. Valid only for Send and RDMA Write with immediate |
| .TP |
| .B IBV_SEND_INLINE \fR Send data in given gather list as inline data |
| in a send WQE. Valid only for Send and RDMA Write. The L_Key will not be checked. |
| .TP |
| .B IBV_SEND_IP_CSUM \fR Offload the IPv4 and TCP/UDP checksum calculation. |
| Valid only when \fBdevice_cap_flags\fR in device_attr indicates current QP is |
| supported by checksum offload. |
| .SH "RETURN VALUE" |
| .B ibv_post_send() |
| returns 0 on success, or the value of errno on failure (which indicates the failure reason). |
| .SH "NOTES" |
| The user should not alter or destroy AHs associated with WRs until |
| request is fully executed and a work completion has been retrieved |
| from the corresponding completion queue (CQ) to avoid unexpected |
| behavior. |
| .PP |
| The buffers used by a WR can only be safely reused after WR the |
| request is fully executed and a work completion has been retrieved |
| from the corresponding completion queue (CQ). However, if the |
| IBV_SEND_INLINE flag was set, the buffer can be reused immediately |
| after the call returns. |
| .SH "SEE ALSO" |
| .BR ibv_create_qp (3), |
| .BR ibv_create_ah (3), |
| .BR ibv_post_recv (3), |
| .BR ibv_post_srq_recv (3), |
| .BR ibv_poll_cq (3) |
| .SH "AUTHORS" |
| .TP |
| Dotan Barak <dotanba@gmail.com> |