Using HPS Memory with Send Calls

To send data using HPS, the user passes one or more of the pointers received from an HPS allocation call to one of the send-type calls along with the MSG_MAPIO flag:

          int ret, sock;
          unsigned long ptrs[15];
          struct msghdr hdr;
          struct iovec iovec[2];

          ret = send(sock, ptrs[0], 4096, MSG_MAPIO);

          hdr.msg_name = NULL;
          hdr.msg_namelen = 0;
          hdr.msg_iov = iovec;
          hdr.msg_iovlen = 2;
          iovec[0].iov_base = ptrs[0];
          iovec[0].iov_len = 4096;
          iovec[1].iov_base = ptrs[1];
          iovec[1].iov_len = 96;
          hdr.msg_control = NULL;
          hdr.msg_controllen = 0;
          hdr.msg_flags = 0;
          ret = sendmsg(sock, &hdr, MSG_MAPIO);

Notes:

• On the send() and sendto() calls, only one pointer and up to 4096 bytes may be sent per call.

• The pointers passed to the any of the send-type calls must be exactly as returned from the allocation call; they may not be altered in any way.