iser_initiator.c

linux内核源码

		data_buf = &iser_ctask->data[ISER_DIR_OUT];

	if (scsi_sg_count(sc)) { /* using a scatter list */
		data_buf->buf  = scsi_sglist(sc);
		data_buf->size = scsi_sg_count(sc);
	}

	data_buf->data_len = scsi_bufflen(sc);

	if (hdr->flags & ISCSI_FLAG_CMD_READ) {
		err = iser_prepare_read_cmd(ctask, edtl);
		if (err)
			goto send_command_error;
	}
	if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
		err = iser_prepare_write_cmd(ctask,
					     ctask->imm_count,
				             ctask->imm_count +
					     ctask->unsol_count,
					     edtl);
		if (err)
			goto send_command_error;
	}

	iser_reg_single(iser_conn->ib_conn->device,
			send_dto->regd[0], DMA_TO_DEVICE);

	if (iser_post_receive_control(conn) != 0) {
		iser_err("post_recv failed!\n");
		err = -ENOMEM;
		goto send_command_error;
	}

	iser_ctask->status = ISER_TASK_STATUS_STARTED;

	err = iser_post_send(&iser_ctask->desc);
	if (!err)
		return 0;

send_command_error:
	iser_dto_buffs_release(send_dto);
	iser_err("conn %p failed ctask->itt %d err %d\n",conn, ctask->itt, err);
	return err;
}

/**
 * iser_send_data_out - send data out PDU
 */
int iser_send_data_out(struct iscsi_conn     *conn,
		       struct iscsi_cmd_task *ctask,
		       struct iscsi_data *hdr)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_desc *tx_desc = NULL;
	struct iser_dto *send_dto = NULL;
	unsigned long buf_offset;
	unsigned long data_seg_len;
	unsigned int itt;
	int err = 0;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}

	if (iser_check_xmit(conn, ctask))
		return -ENOBUFS;

	itt = ntohl(hdr->itt);
	data_seg_len = ntoh24(hdr->dlength);
	buf_offset   = ntohl(hdr->offset);

	iser_dbg("%s itt %d dseg_len %d offset %d\n",
		 __func__,(int)itt,(int)data_seg_len,(int)buf_offset);

	tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
	if (tx_desc == NULL) {
		iser_err("Failed to alloc desc for post dataout\n");
		return -ENOMEM;
	}

	tx_desc->type = ISCSI_TX_DATAOUT;
	memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));

	/* build the tx desc regd header and add it to the tx desc dto */
	send_dto = &tx_desc->dto;
	send_dto->ctask = iser_ctask;
	iser_create_send_desc(iser_conn, tx_desc);

	iser_reg_single(iser_conn->ib_conn->device,
			send_dto->regd[0], DMA_TO_DEVICE);

	/* all data was registered for RDMA, we can use the lkey */
	iser_dto_add_regd_buff(send_dto,
			       &iser_ctask->rdma_regd[ISER_DIR_OUT],
			       buf_offset,
			       data_seg_len);

	if (buf_offset + data_seg_len > iser_ctask->data[ISER_DIR_OUT].data_len) {
		iser_err("Offset:%ld & DSL:%ld in Data-Out "
			 "inconsistent with total len:%ld, itt:%d\n",
			 buf_offset, data_seg_len,
			 iser_ctask->data[ISER_DIR_OUT].data_len, itt);
		err = -EINVAL;
		goto send_data_out_error;
	}
	iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
		 itt, buf_offset, data_seg_len);


	err = iser_post_send(tx_desc);
	if (!err)
		return 0;

send_data_out_error:
	iser_dto_buffs_release(send_dto);
	kmem_cache_free(ig.desc_cache, tx_desc);
	iser_err("conn %p failed err %d\n",conn, err);
	return err;
}

int iser_send_control(struct iscsi_conn *conn,
		      struct iscsi_mgmt_task *mtask)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iser_desc *mdesc = mtask->dd_data;
	struct iser_dto *send_dto = NULL;
	unsigned long data_seg_len;
	int err = 0;
	struct iser_regd_buf *regd_buf;
	struct iser_device *device;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}

	if (iser_check_xmit(conn,mtask))
		return -ENOBUFS;

	/* build the tx desc regd header and add it to the tx desc dto */
	mdesc->type = ISCSI_TX_CONTROL;
	send_dto = &mdesc->dto;
	send_dto->ctask = NULL;
	iser_create_send_desc(iser_conn, mdesc);

	device = iser_conn->ib_conn->device;

	iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);

	data_seg_len = ntoh24(mtask->hdr->dlength);

	if (data_seg_len > 0) {
		regd_buf = &mdesc->data_regd_buf;
		memset(regd_buf, 0, sizeof(struct iser_regd_buf));
		regd_buf->device = device;
		regd_buf->virt_addr = mtask->data;
		regd_buf->data_size = mtask->data_count;
		iser_reg_single(device, regd_buf,
				DMA_TO_DEVICE);
		iser_dto_add_regd_buff(send_dto, regd_buf,
				       0,
				       data_seg_len);
	}

	if (iser_post_receive_control(conn) != 0) {
		iser_err("post_rcv_buff failed!\n");
		err = -ENOMEM;
		goto send_control_error;
	}

	err = iser_post_send(mdesc);
	if (!err)
		return 0;

send_control_error:
	iser_dto_buffs_release(send_dto);
	iser_err("conn %p failed err %d\n",conn, err);
	return err;
}

/**
 * iser_rcv_dto_completion - recv DTO completion
 */
void iser_rcv_completion(struct iser_desc *rx_desc,
			 unsigned long dto_xfer_len)
{
	struct iser_dto        *dto = &rx_desc->dto;
	struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
	struct iscsi_session *session = conn->iscsi_conn->session;
	struct iscsi_cmd_task *ctask;
	struct iscsi_iser_cmd_task *iser_ctask;
	struct iscsi_hdr *hdr;
	char   *rx_data = NULL;
	int     rx_data_len = 0;
	unsigned int itt;
	unsigned char opcode;

	hdr = &rx_desc->iscsi_header;

	iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);

	if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
		rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
		rx_data     = dto->regd[1]->virt_addr;
		rx_data    += dto->offset[1];
	}

	opcode = hdr->opcode & ISCSI_OPCODE_MASK;

	if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
	        itt = get_itt(hdr->itt); /* mask out cid and age bits */
		if (!(itt < session->cmds_max))
			iser_err("itt can't be matched to task!!!"
				 "conn %p opcode %d cmds_max %d itt %d\n",
				 conn->iscsi_conn,opcode,session->cmds_max,itt);
		/* use the mapping given with the cmds array indexed by itt */
		ctask = (struct iscsi_cmd_task *)session->cmds[itt];
		iser_ctask = ctask->dd_data;
		iser_dbg("itt %d ctask %p\n",itt,ctask);
		iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
		iser_ctask_rdma_finalize(iser_ctask);
	}

	iser_dto_buffs_release(dto);

	iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);

	kfree(rx_desc->data);
	kmem_cache_free(ig.desc_cache, rx_desc);

	/* decrementing conn->post_recv_buf_count only --after-- freeing the   *
	 * task eliminates the need to worry on tasks which are completed in   *
	 * parallel to the execution of iser_conn_term. So the code that waits *
	 * for the posted rx bufs refcount to become zero handles everything   */
	atomic_dec(&conn->ib_conn->post_recv_buf_count);
}

void iser_snd_completion(struct iser_desc *tx_desc)
{
	struct iser_dto        *dto = &tx_desc->dto;
	struct iser_conn       *ib_conn = dto->ib_conn;
	struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
	struct iscsi_conn      *conn = iser_conn->iscsi_conn;
	struct iscsi_mgmt_task *mtask;
	int resume_tx = 0;

	iser_dbg("Initiator, Data sent dto=0x%p\n", dto);

	iser_dto_buffs_release(dto);

	if (tx_desc->type == ISCSI_TX_DATAOUT)
		kmem_cache_free(ig.desc_cache, tx_desc);

	if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
	    ISER_QP_MAX_REQ_DTOS)
		resume_tx = 1;

	atomic_dec(&ib_conn->post_send_buf_count);

	if (resume_tx) {
		iser_dbg("%ld resuming tx\n",jiffies);
		scsi_queue_work(conn->session->host, &conn->xmitwork);
	}

	if (tx_desc->type == ISCSI_TX_CONTROL) {
		/* this arithmetic is legal by libiscsi dd_data allocation */
		mtask = (void *) ((long)(void *)tx_desc -
				  sizeof(struct iscsi_mgmt_task));
		if (mtask->hdr->itt == RESERVED_ITT) {
			struct iscsi_session *session = conn->session;

			spin_lock(&conn->session->lock);
			list_del(&mtask->running);
			__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
				    sizeof(void*));
			spin_unlock(&session->lock);
		}
	}
}

void iser_ctask_rdma_init(struct iscsi_iser_cmd_task *iser_ctask)

{
	iser_ctask->status = ISER_TASK_STATUS_INIT;

	iser_ctask->dir[ISER_DIR_IN] = 0;
	iser_ctask->dir[ISER_DIR_OUT] = 0;

	iser_ctask->data[ISER_DIR_IN].data_len  = 0;
	iser_ctask->data[ISER_DIR_OUT].data_len = 0;

	memset(&iser_ctask->rdma_regd[ISER_DIR_IN], 0,
	       sizeof(struct iser_regd_buf));
	memset(&iser_ctask->rdma_regd[ISER_DIR_OUT], 0,
	       sizeof(struct iser_regd_buf));
}

void iser_ctask_rdma_finalize(struct iscsi_iser_cmd_task *iser_ctask)
{
	int deferred;
	int is_rdma_aligned = 1;
	struct iser_regd_buf *regd;

	/* if we were reading, copy back to unaligned sglist,
	 * anyway dma_unmap and free the copy
	 */
	if (iser_ctask->data_copy[ISER_DIR_IN].copy_buf != NULL) {
		is_rdma_aligned = 0;
		iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_IN);
	}
	if (iser_ctask->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
		is_rdma_aligned = 0;
		iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_OUT);
	}

	if (iser_ctask->dir[ISER_DIR_IN]) {
		regd = &iser_ctask->rdma_regd[ISER_DIR_IN];
		deferred = iser_regd_buff_release(regd);
		if (deferred) {
			iser_err("%d references remain for BUF-IN rdma reg\n",
				 atomic_read(&regd->ref_count));
		}
	}

	if (iser_ctask->dir[ISER_DIR_OUT]) {
		regd = &iser_ctask->rdma_regd[ISER_DIR_OUT];
		deferred = iser_regd_buff_release(regd);
		if (deferred) {
			iser_err("%d references remain for BUF-OUT rdma reg\n",
				 atomic_read(&regd->ref_count));
		}
	}

       /* if the data was unaligned, it was already unmapped and then copied */
       if (is_rdma_aligned)
		iser_dma_unmap_task_data(iser_ctask);
}

void iser_dto_buffs_release(struct iser_dto *dto)
{
	int i;

	for (i = 0; i < dto->regd_vector_len; i++)
		iser_regd_buff_release(dto->regd[i]);
}