iser_initiator.c

linux内核源码

/*
 * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     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.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * $Id: iser_initiator.c 6964 2006-05-07 11:11:43Z ogerlitz $
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/kfifo.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>

#include "iscsi_iser.h"

/* Constant PDU lengths calculations */
#define ISER_TOTAL_HEADERS_LEN  (sizeof (struct iser_hdr) + \
				 sizeof (struct iscsi_hdr))

/* iser_dto_add_regd_buff - increments the reference count for *
 * the registered buffer & adds it to the DTO object           */
static void iser_dto_add_regd_buff(struct iser_dto *dto,
				   struct iser_regd_buf *regd_buf,
				   unsigned long use_offset,
				   unsigned long use_size)
{
	int add_idx;

	atomic_inc(&regd_buf->ref_count);

	add_idx = dto->regd_vector_len;
	dto->regd[add_idx] = regd_buf;
	dto->used_sz[add_idx] = use_size;
	dto->offset[add_idx] = use_offset;

	dto->regd_vector_len++;
}

/* Register user buffer memory and initialize passive rdma
 *  dto descriptor. Total data size is stored in
 *  iser_ctask->data[ISER_DIR_IN].data_len
 */
static int iser_prepare_read_cmd(struct iscsi_cmd_task *ctask,
				 unsigned int edtl)

{
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_regd_buf *regd_buf;
	int err;
	struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
	struct iser_data_buf *buf_in = &iser_ctask->data[ISER_DIR_IN];

	err = iser_dma_map_task_data(iser_ctask,
				     buf_in,
				     ISER_DIR_IN,
				     DMA_FROM_DEVICE);
	if (err)
		return err;

	if (edtl > iser_ctask->data[ISER_DIR_IN].data_len) {
		iser_err("Total data length: %ld, less than EDTL: "
			 "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
			 iser_ctask->data[ISER_DIR_IN].data_len, edtl,
			 ctask->itt, iser_ctask->iser_conn);
		return -EINVAL;
	}

	err = iser_reg_rdma_mem(iser_ctask,ISER_DIR_IN);
	if (err) {
		iser_err("Failed to set up Data-IN RDMA\n");
		return err;
	}
	regd_buf = &iser_ctask->rdma_regd[ISER_DIR_IN];

	hdr->flags    |= ISER_RSV;
	hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
	hdr->read_va   = cpu_to_be64(regd_buf->reg.va);

	iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
		 ctask->itt, regd_buf->reg.rkey,
		 (unsigned long long)regd_buf->reg.va);

	return 0;
}

/* Register user buffer memory and initialize passive rdma
 *  dto descriptor. Total data size is stored in
 *  ctask->data[ISER_DIR_OUT].data_len
 */
static int
iser_prepare_write_cmd(struct iscsi_cmd_task *ctask,
		       unsigned int imm_sz,
		       unsigned int unsol_sz,
		       unsigned int edtl)
{
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_regd_buf *regd_buf;
	int err;
	struct iser_dto *send_dto = &iser_ctask->desc.dto;
	struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
	struct iser_data_buf *buf_out = &iser_ctask->data[ISER_DIR_OUT];

	err = iser_dma_map_task_data(iser_ctask,
				     buf_out,
				     ISER_DIR_OUT,
				     DMA_TO_DEVICE);
	if (err)
		return err;

	if (edtl > iser_ctask->data[ISER_DIR_OUT].data_len) {
		iser_err("Total data length: %ld, less than EDTL: %d, "
			 "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
			 iser_ctask->data[ISER_DIR_OUT].data_len,
			 edtl, ctask->itt, ctask->conn);
		return -EINVAL;
	}

	err = iser_reg_rdma_mem(iser_ctask,ISER_DIR_OUT);
	if (err != 0) {
		iser_err("Failed to register write cmd RDMA mem\n");
		return err;
	}

	regd_buf = &iser_ctask->rdma_regd[ISER_DIR_OUT];

	if (unsol_sz < edtl) {
		hdr->flags     |= ISER_WSV;
		hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
		hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);

		iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
			 "VA:%#llX + unsol:%d\n",
			 ctask->itt, regd_buf->reg.rkey,
			 (unsigned long long)regd_buf->reg.va, unsol_sz);
	}

	if (imm_sz > 0) {
		iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
			 ctask->itt, imm_sz);
		iser_dto_add_regd_buff(send_dto,
				       regd_buf,
				       0,
				       imm_sz);
	}

	return 0;
}

/**
 * iser_post_receive_control - allocates, initializes and posts receive DTO.
 */
static int iser_post_receive_control(struct iscsi_conn *conn)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iser_desc     *rx_desc;
	struct iser_regd_buf *regd_hdr;
	struct iser_regd_buf *regd_data;
	struct iser_dto      *recv_dto = NULL;
	struct iser_device  *device = iser_conn->ib_conn->device;
	int rx_data_size, err = 0;

	rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
	if (rx_desc == NULL) {
		iser_err("Failed to alloc desc for post recv\n");
		return -ENOMEM;
	}
	rx_desc->type = ISCSI_RX;

	/* for the login sequence we must support rx of upto 8K; login is done
	 * after conn create/bind (connect) and conn stop/bind (reconnect),
	 * what's common for both schemes is that the connection is not started
	 */
	if (conn->c_stage != ISCSI_CONN_STARTED)
		rx_data_size = ISCSI_DEF_MAX_RECV_SEG_LEN;
	else /* FIXME till user space sets conn->max_recv_dlength correctly */
		rx_data_size = 128;

	rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
	if (rx_desc->data == NULL) {
		iser_err("Failed to alloc data buf for post recv\n");
		err = -ENOMEM;
		goto post_rx_kmalloc_failure;
	}

	recv_dto = &rx_desc->dto;
	recv_dto->ib_conn = iser_conn->ib_conn;
	recv_dto->regd_vector_len = 0;

	regd_hdr = &rx_desc->hdr_regd_buf;
	memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
	regd_hdr->device  = device;
	regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
	regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;

	iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);

	iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);

	regd_data = &rx_desc->data_regd_buf;
	memset(regd_data, 0, sizeof(struct iser_regd_buf));
	regd_data->device  = device;
	regd_data->virt_addr  = rx_desc->data;
	regd_data->data_size  = rx_data_size;

	iser_reg_single(device, regd_data, DMA_FROM_DEVICE);

	iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);

	err = iser_post_recv(rx_desc);
	if (!err)
		return 0;

	/* iser_post_recv failed */
	iser_dto_buffs_release(recv_dto);
	kfree(rx_desc->data);
post_rx_kmalloc_failure:
	kmem_cache_free(ig.desc_cache, rx_desc);
	return err;
}

/* creates a new tx descriptor and adds header regd buffer */
static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
				  struct iser_desc       *tx_desc)
{
	struct iser_regd_buf *regd_hdr = &tx_desc->hdr_regd_buf;
	struct iser_dto      *send_dto = &tx_desc->dto;

	memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
	regd_hdr->device  = iser_conn->ib_conn->device;
	regd_hdr->virt_addr  = tx_desc; /* == &tx_desc->iser_header */
	regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;

	send_dto->ib_conn         = iser_conn->ib_conn;
	send_dto->notify_enable   = 1;
	send_dto->regd_vector_len = 0;

	memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
	tx_desc->iser_header.flags = ISER_VER;

	iser_dto_add_regd_buff(send_dto, regd_hdr, 0, 0);
}

/**
 *  iser_conn_set_full_featured_mode - (iSER API)
 */
int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;

	int i;
	/* no need to keep it in a var, we are after login so if this should
	 * be negotiated, by now the result should be available here */
	int initial_post_recv_bufs_num = ISER_MAX_RX_MISC_PDUS;

	iser_dbg("Initially post: %d\n", initial_post_recv_bufs_num);

	/* Check that there is no posted recv or send buffers left - */
	/* they must be consumed during the login phase */
	BUG_ON(atomic_read(&iser_conn->ib_conn->post_recv_buf_count) != 0);
	BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);

	/* Initial post receive buffers */
	for (i = 0; i < initial_post_recv_bufs_num; i++) {
		if (iser_post_receive_control(conn) != 0) {
			iser_err("Failed to post recv bufs at:%d conn:0x%p\n",
				 i, conn);
			return -ENOMEM;
		}
	}
	iser_dbg("Posted %d post recv bufs, conn:0x%p\n", i, conn);
	return 0;
}

static int
iser_check_xmit(struct iscsi_conn *conn, void *task)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;

	if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
	    ISER_QP_MAX_REQ_DTOS) {
		iser_dbg("%ld can't xmit task %p\n",jiffies,task);
		return -ENOBUFS;
	}
	return 0;
}


/**
 * iser_send_command - send command PDU
 */
int iser_send_command(struct iscsi_conn     *conn,
		      struct iscsi_cmd_task *ctask)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_dto *send_dto = NULL;
	unsigned long edtl;
	int err = 0;
	struct iser_data_buf *data_buf;

	struct iscsi_cmd *hdr =  ctask->hdr;
	struct scsi_cmnd *sc  =  ctask->sc;

	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;

	edtl = ntohl(hdr->data_length);

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

	if (hdr->flags & ISCSI_FLAG_CMD_READ)
		data_buf = &iser_ctask->data[ISER_DIR_IN];
	else