blob: 86f6583485ef3f99c678a5ce1087f45e7e2ba1f1 [file] [log] [blame]
/*
* iSER transport for the Open iSCSI Initiator & iSER transport internals
*
* Copyright (C) 2004 Dmitry Yusupov
* Copyright (C) 2004 Alex Aizman
* Copyright (C) 2005 Mike Christie
* based on code maintained by open-iscsi@googlegroups.com
*
* Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
* Copyright (c) 2005, 2006 Cisco Systems. All rights reserved.
* Copyright (c) 2013-2014 Mellanox Technologies. 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.
*/
#ifndef __ISCSI_ISER_H__
#define __ISCSI_ISER_H__
#include <linux/types.h>
#include <linux/net.h>
#include <linux/printk.h>
#include <scsi/libiscsi.h>
#include <scsi/scsi_transport_iscsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/mutex.h>
#include <linux/mempool.h>
#include <linux/uio.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_fmr_pool.h>
#include <rdma/rdma_cm.h>
#define DRV_NAME "iser"
#define PFX DRV_NAME ": "
#define DRV_VER "1.6"
#define iser_dbg(fmt, arg...) \
do { \
if (unlikely(iser_debug_level > 2)) \
printk(KERN_DEBUG PFX "%s: " fmt,\
__func__ , ## arg); \
} while (0)
#define iser_warn(fmt, arg...) \
do { \
if (unlikely(iser_debug_level > 0)) \
pr_warn(PFX "%s: " fmt, \
__func__ , ## arg); \
} while (0)
#define iser_info(fmt, arg...) \
do { \
if (unlikely(iser_debug_level > 1)) \
pr_info(PFX "%s: " fmt, \
__func__ , ## arg); \
} while (0)
#define iser_err(fmt, arg...) \
pr_err(PFX "%s: " fmt, __func__ , ## arg)
#define SHIFT_4K 12
#define SIZE_4K (1ULL << SHIFT_4K)
#define MASK_4K (~(SIZE_4K-1))
/* Default support is 512KB I/O size */
#define ISER_DEF_MAX_SECTORS 1024
#define ISCSI_ISER_DEF_SG_TABLESIZE ((ISER_DEF_MAX_SECTORS * 512) >> SHIFT_4K)
/* Maximum support is 8MB I/O size */
#define ISCSI_ISER_MAX_SG_TABLESIZE ((16384 * 512) >> SHIFT_4K)
#define ISER_DEF_XMIT_CMDS_DEFAULT 512
#if ISCSI_DEF_XMIT_CMDS_MAX > ISER_DEF_XMIT_CMDS_DEFAULT
#define ISER_DEF_XMIT_CMDS_MAX ISCSI_DEF_XMIT_CMDS_MAX
#else
#define ISER_DEF_XMIT_CMDS_MAX ISER_DEF_XMIT_CMDS_DEFAULT
#endif
#define ISER_DEF_CMD_PER_LUN ISER_DEF_XMIT_CMDS_MAX
/* QP settings */
/* Maximal bounds on received asynchronous PDUs */
#define ISER_MAX_RX_MISC_PDUS 4 /* NOOP_IN(2) , ASYNC_EVENT(2) */
#define ISER_MAX_TX_MISC_PDUS 6 /* NOOP_OUT(2), TEXT(1), *
* SCSI_TMFUNC(2), LOGOUT(1) */
#define ISER_QP_MAX_RECV_DTOS (ISER_DEF_XMIT_CMDS_MAX)
#define ISER_MIN_POSTED_RX (ISER_DEF_XMIT_CMDS_MAX >> 2)
/* the max TX (send) WR supported by the iSER QP is defined by *
* max_send_wr = T * (1 + D) + C ; D is how many inflight dataouts we expect *
* to have at max for SCSI command. The tx posting & completion handling code *
* supports -EAGAIN scheme where tx is suspended till the QP has room for more *
* send WR. D=8 comes from 64K/8K */
#define ISER_INFLIGHT_DATAOUTS 8
#define ISER_QP_MAX_REQ_DTOS (ISER_DEF_XMIT_CMDS_MAX * \
(1 + ISER_INFLIGHT_DATAOUTS) + \
ISER_MAX_TX_MISC_PDUS + \
ISER_MAX_RX_MISC_PDUS)
/* Max registration work requests per command */
#define ISER_MAX_REG_WR_PER_CMD 5
/* For Signature we don't support DATAOUTs so no need to make room for them */
#define ISER_QP_SIG_MAX_REQ_DTOS (ISER_DEF_XMIT_CMDS_MAX * \
(1 + ISER_MAX_REG_WR_PER_CMD) + \
ISER_MAX_TX_MISC_PDUS + \
ISER_MAX_RX_MISC_PDUS)
#define ISER_GET_MAX_XMIT_CMDS(send_wr) ((send_wr \
- ISER_MAX_TX_MISC_PDUS \
- ISER_MAX_RX_MISC_PDUS) / \
(1 + ISER_INFLIGHT_DATAOUTS))
#define ISER_WC_BATCH_COUNT 16
#define ISER_SIGNAL_CMD_COUNT 32
#define ISER_VER 0x10
#define ISER_WSV 0x08
#define ISER_RSV 0x04
#define ISER_FASTREG_LI_WRID 0xffffffffffffffffULL
#define ISER_BEACON_WRID 0xfffffffffffffffeULL
/**
* struct iser_hdr - iSER header
*
* @flags: flags support (zbva, remote_inv)
* @rsvd: reserved
* @write_stag: write rkey
* @write_va: write virtual address
* @reaf_stag: read rkey
* @read_va: read virtual address
*/
struct iser_hdr {
u8 flags;
u8 rsvd[3];
__be32 write_stag;
__be64 write_va;
__be32 read_stag;
__be64 read_va;
} __attribute__((packed));
#define ISER_ZBVA_NOT_SUPPORTED 0x80
#define ISER_SEND_W_INV_NOT_SUPPORTED 0x40
struct iser_cm_hdr {
u8 flags;
u8 rsvd[3];
} __packed;
/* Constant PDU lengths calculations */
#define ISER_HEADERS_LEN (sizeof(struct iser_hdr) + sizeof(struct iscsi_hdr))
#define ISER_RECV_DATA_SEG_LEN 128
#define ISER_RX_PAYLOAD_SIZE (ISER_HEADERS_LEN + ISER_RECV_DATA_SEG_LEN)
#define ISER_RX_LOGIN_SIZE (ISER_HEADERS_LEN + ISCSI_DEF_MAX_RECV_SEG_LEN)
/* Length of an object name string */
#define ISER_OBJECT_NAME_SIZE 64
enum iser_conn_state {
ISER_CONN_INIT, /* descriptor allocd, no conn */
ISER_CONN_PENDING, /* in the process of being established */
ISER_CONN_UP, /* up and running */
ISER_CONN_TERMINATING, /* in the process of being terminated */
ISER_CONN_DOWN, /* shut down */
ISER_CONN_STATES_NUM
};
enum iser_task_status {
ISER_TASK_STATUS_INIT = 0,
ISER_TASK_STATUS_STARTED,
ISER_TASK_STATUS_COMPLETED
};
enum iser_data_dir {
ISER_DIR_IN = 0, /* to initiator */
ISER_DIR_OUT, /* from initiator */
ISER_DIRS_NUM
};
/**
* struct iser_data_buf - iSER data buffer
*
* @sg: pointer to the sg list
* @size: num entries of this sg
* @data_len: total beffer byte len
* @dma_nents: returned by dma_map_sg
* @orig_sg: pointer to the original sg list (in case
* we used a copy)
* @orig_size: num entris of orig sg list
*/
struct iser_data_buf {
struct scatterlist *sg;
unsigned int size;
unsigned long data_len;
unsigned int dma_nents;
struct scatterlist *orig_sg;
unsigned int orig_size;
};
/* fwd declarations */
struct iser_device;
struct iscsi_iser_task;
struct iscsi_endpoint;
struct iser_reg_resources;
/**
* struct iser_mem_reg - iSER memory registration info
*
* @sge: memory region sg element
* @rkey: memory region remote key
* @mem_h: pointer to registration context (FMR/Fastreg)
*/
struct iser_mem_reg {
struct ib_sge sge;
u32 rkey;
void *mem_h;
};
enum iser_desc_type {
ISCSI_TX_CONTROL ,
ISCSI_TX_SCSI_COMMAND,
ISCSI_TX_DATAOUT
};
/* Maximum number of work requests per task:
* Data memory region local invalidate + fast registration
* Protection memory region local invalidate + fast registration
* Signature memory region local invalidate + fast registration
* PDU send
*/
#define ISER_MAX_WRS 7
/**
* struct iser_tx_desc - iSER TX descriptor (for send wr_id)
*
* @iser_header: iser header
* @iscsi_header: iscsi header
* @type: command/control/dataout
* @dam_addr: header buffer dma_address
* @tx_sg: sg[0] points to iser/iscsi headers
* sg[1] optionally points to either of immediate data
* unsolicited data-out or control
* @num_sge: number sges used on this TX task
* @mapped: Is the task header mapped
* @wr_idx: Current WR index
* @wrs: Array of WRs per task
* @data_reg: Data buffer registration details
* @prot_reg: Protection buffer registration details
* @sig_attrs: Signature attributes
*/
struct iser_tx_desc {
struct iser_hdr iser_header;
struct iscsi_hdr iscsi_header;
enum iser_desc_type type;
u64 dma_addr;
struct ib_sge tx_sg[2];
int num_sge;
bool mapped;
u8 wr_idx;
struct ib_send_wr wrs[ISER_MAX_WRS];
struct iser_mem_reg data_reg;
struct iser_mem_reg prot_reg;
struct ib_sig_attrs sig_attrs;
};
#define ISER_RX_PAD_SIZE (256 - (ISER_RX_PAYLOAD_SIZE + \
sizeof(u64) + sizeof(struct ib_sge)))
/**
* struct iser_rx_desc - iSER RX descriptor (for recv wr_id)
*
* @iser_header: iser header
* @iscsi_header: iscsi header
* @data: received data segment
* @dma_addr: receive buffer dma address
* @rx_sg: ib_sge of receive buffer
* @pad: for sense data TODO: Modify to maximum sense length supported
*/
struct iser_rx_desc {
struct iser_hdr iser_header;
struct iscsi_hdr iscsi_header;
char data[ISER_RECV_DATA_SEG_LEN];
u64 dma_addr;
struct ib_sge rx_sg;
char pad[ISER_RX_PAD_SIZE];
} __attribute__((packed));
struct iser_conn;
struct ib_conn;
struct iscsi_iser_task;
/**
* struct iser_comp - iSER completion context
*
* @device: pointer to device handle
* @cq: completion queue
* @wcs: work completion array
* @tasklet: Tasklet handle
* @active_qps: Number of active QPs attached
* to completion context
*/
struct iser_comp {
struct iser_device *device;
struct ib_cq *cq;
struct ib_wc wcs[ISER_WC_BATCH_COUNT];
struct tasklet_struct tasklet;
int active_qps;
};
/**
* struct iser_device - Memory registration operations
* per-device registration schemes
*
* @alloc_reg_res: Allocate registration resources
* @free_reg_res: Free registration resources
* @fast_reg_mem: Register memory buffers
* @unreg_mem: Un-register memory buffers
* @reg_desc_get: Get a registration descriptor for pool
* @reg_desc_put: Get a registration descriptor to pool
*/
struct iser_reg_ops {
int (*alloc_reg_res)(struct ib_conn *ib_conn,
unsigned cmds_max,
unsigned int size);
void (*free_reg_res)(struct ib_conn *ib_conn);
int (*reg_mem)(struct iscsi_iser_task *iser_task,
struct iser_data_buf *mem,
struct iser_reg_resources *rsc,
struct iser_mem_reg *reg);
void (*unreg_mem)(struct iscsi_iser_task *iser_task,
enum iser_data_dir cmd_dir);
struct iser_fr_desc * (*reg_desc_get)(struct ib_conn *ib_conn);
void (*reg_desc_put)(struct ib_conn *ib_conn,
struct iser_fr_desc *desc);
};
/**
* struct iser_device - iSER device handle
*
* @ib_device: RDMA device
* @pd: Protection Domain for this device
* @dev_attr: Device attributes container
* @mr: Global DMA memory region
* @event_handler: IB events handle routine
* @ig_list: entry in devices list
* @refcount: Reference counter, dominated by open iser connections
* @comps_used: Number of completion contexts used, Min between online
* cpus and device max completion vectors
* @comps: Dinamically allocated array of completion handlers
* @reg_ops: Registration ops
*/
struct iser_device {
struct ib_device *ib_device;
struct ib_pd *pd;
struct ib_device_attr dev_attr;
struct ib_mr *mr;
struct ib_event_handler event_handler;
struct list_head ig_list;
int refcount;
int comps_used;
struct iser_comp *comps;
struct iser_reg_ops *reg_ops;
};
#define ISER_CHECK_GUARD 0xc0
#define ISER_CHECK_REFTAG 0x0f
#define ISER_CHECK_APPTAG 0x30
/**
* struct iser_reg_resources - Fast registration recources
*
* @mr: memory region
* @fmr_pool: pool of fmrs
* @frpl: fast reg page list used by frwrs
* @page_vec: fast reg page list used by fmr pool
* @mr_valid: is mr valid indicator
*/
struct iser_reg_resources {
union {
struct ib_mr *mr;
struct ib_fmr_pool *fmr_pool;
};
union {
struct ib_fast_reg_page_list *frpl;
struct iser_page_vec *page_vec;
};
u8 mr_valid:1;
};
/**
* struct iser_pi_context - Protection information context
*
* @rsc: protection buffer registration resources
* @sig_mr: signature enable memory region
* @sig_mr_valid: is sig_mr valid indicator
* @sig_protected: is region protected indicator
*/
struct iser_pi_context {
struct iser_reg_resources rsc;
struct ib_mr *sig_mr;
u8 sig_mr_valid:1;
u8 sig_protected:1;
};
/**
* struct iser_fr_desc - Fast registration descriptor
*
* @list: entry in connection fastreg pool
* @rsc: data buffer registration resources
* @pi_ctx: protection information context
*/
struct iser_fr_desc {
struct list_head list;
struct iser_reg_resources rsc;
struct iser_pi_context *pi_ctx;
};
/**
* struct iser_fr_pool: connection fast registration pool
*
* @list: list of fastreg descriptors
* @lock: protects fmr/fastreg pool
* @size: size of the pool
*/
struct iser_fr_pool {
struct list_head list;
spinlock_t lock;
int size;
};
/**
* struct ib_conn - Infiniband related objects
*
* @cma_id: rdma_cm connection maneger handle
* @qp: Connection Queue-pair
* @post_recv_buf_count: post receive counter
* @sig_count: send work request signal count
* @rx_wr: receive work request for batch posts
* @device: reference to iser device
* @comp: iser completion context
* @pi_support: Indicate device T10-PI support
* @beacon: beacon send wr to signal all flush errors were drained
* @flush_comp: completes when all connection completions consumed
* @fr_pool: connection fast registration poool
*/
struct ib_conn {
struct rdma_cm_id *cma_id;
struct ib_qp *qp;
int post_recv_buf_count;
u8 sig_count;
struct ib_recv_wr rx_wr[ISER_MIN_POSTED_RX];
struct iser_device *device;
struct iser_comp *comp;
bool pi_support;
struct ib_send_wr beacon;
struct completion flush_comp;
struct iser_fr_pool fr_pool;
};
/**
* struct iser_conn - iSER connection context
*
* @ib_conn: connection RDMA resources
* @iscsi_conn: link to matching iscsi connection
* @ep: transport handle
* @state: connection logical state
* @qp_max_recv_dtos: maximum number of data outs, corresponds
* to max number of post recvs
* @qp_max_recv_dtos_mask: (qp_max_recv_dtos - 1)
* @min_posted_rx: (qp_max_recv_dtos >> 2)
* @max_cmds: maximum cmds allowed for this connection
* @name: connection peer portal
* @release_work: deffered work for release job
* @state_mutex: protects iser onnection state
* @stop_completion: conn_stop completion
* @ib_completion: RDMA cleanup completion
* @up_completion: connection establishment completed
* (state is ISER_CONN_UP)
* @conn_list: entry in ig conn list
* @login_buf: login data buffer (stores login parameters)
* @login_req_buf: login request buffer
* @login_req_dma: login request buffer dma address
* @login_resp_buf: login response buffer
* @login_resp_dma: login response buffer dma address
* @rx_desc_head: head of rx_descs cyclic buffer
* @rx_descs: rx buffers array (cyclic buffer)
* @num_rx_descs: number of rx descriptors
* @scsi_sg_tablesize: scsi host sg_tablesize
* @scsi_max_sectors: scsi host max sectors
*/
struct iser_conn {
struct ib_conn ib_conn;
struct iscsi_conn *iscsi_conn;
struct iscsi_endpoint *ep;
enum iser_conn_state state;
unsigned qp_max_recv_dtos;
unsigned qp_max_recv_dtos_mask;
unsigned min_posted_rx;
u16 max_cmds;
char name[ISER_OBJECT_NAME_SIZE];
struct work_struct release_work;
struct mutex state_mutex;
struct completion stop_completion;
struct completion ib_completion;
struct completion up_completion;
struct list_head conn_list;
char *login_buf;
char *login_req_buf, *login_resp_buf;
u64 login_req_dma, login_resp_dma;
unsigned int rx_desc_head;
struct iser_rx_desc *rx_descs;
u32 num_rx_descs;
unsigned short scsi_sg_tablesize;
unsigned int scsi_max_sectors;
};
/**
* struct iscsi_iser_task - iser task context
*
* @desc: TX descriptor
* @iser_conn: link to iser connection
* @status: current task status
* @sc: link to scsi command
* @command_sent: indicate if command was sent
* @dir: iser data direction
* @rdma_reg: task rdma registration desc
* @data: iser data buffer desc
* @prot: iser protection buffer desc
*/
struct iscsi_iser_task {
struct iser_tx_desc desc;
struct iser_conn *iser_conn;
enum iser_task_status status;
struct scsi_cmnd *sc;
int command_sent;
int dir[ISER_DIRS_NUM];
struct iser_mem_reg rdma_reg[ISER_DIRS_NUM];
struct iser_data_buf data[ISER_DIRS_NUM];
struct iser_data_buf prot[ISER_DIRS_NUM];
};
struct iser_page_vec {
u64 *pages;
int length;
int offset;
int data_size;
};
/**
* struct iser_global: iSER global context
*
* @device_list_mutex: protects device_list
* @device_list: iser devices global list
* @connlist_mutex: protects connlist
* @connlist: iser connections global list
* @desc_cache: kmem cache for tx dataout
*/
struct iser_global {
struct mutex device_list_mutex;
struct list_head device_list;
struct mutex connlist_mutex;
struct list_head connlist;
struct kmem_cache *desc_cache;
};
extern struct iser_global ig;
extern int iser_debug_level;
extern bool iser_pi_enable;
extern int iser_pi_guard;
extern unsigned int iser_max_sectors;
int iser_assign_reg_ops(struct iser_device *device);
int iser_send_control(struct iscsi_conn *conn,
struct iscsi_task *task);
int iser_send_command(struct iscsi_conn *conn,
struct iscsi_task *task);
int iser_send_data_out(struct iscsi_conn *conn,
struct iscsi_task *task,
struct iscsi_data *hdr);
void iscsi_iser_recv(struct iscsi_conn *conn,
struct iscsi_hdr *hdr,
char *rx_data,
int rx_data_len);
void iser_conn_init(struct iser_conn *iser_conn);
void iser_conn_release(struct iser_conn *iser_conn);
int iser_conn_terminate(struct iser_conn *iser_conn);
void iser_release_work(struct work_struct *work);
void iser_rcv_completion(struct iser_rx_desc *desc,
unsigned long dto_xfer_len,
struct ib_conn *ib_conn);
void iser_snd_completion(struct iser_tx_desc *desc,
struct ib_conn *ib_conn);
void iser_task_rdma_init(struct iscsi_iser_task *task);
void iser_task_rdma_finalize(struct iscsi_iser_task *task);
void iser_free_rx_descriptors(struct iser_conn *iser_conn);
void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,
struct iser_data_buf *mem,
enum iser_data_dir cmd_dir);
int iser_reg_rdma_mem(struct iscsi_iser_task *task,
enum iser_data_dir dir);
void iser_unreg_rdma_mem(struct iscsi_iser_task *task,
enum iser_data_dir dir);
int iser_connect(struct iser_conn *iser_conn,
struct sockaddr *src_addr,
struct sockaddr *dst_addr,
int non_blocking);
void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
enum iser_data_dir cmd_dir);
void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
enum iser_data_dir cmd_dir);
int iser_post_recvl(struct iser_conn *iser_conn);
int iser_post_recvm(struct iser_conn *iser_conn, int count);
int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
bool signal);
int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
struct iser_data_buf *data,
enum iser_data_dir iser_dir,
enum dma_data_direction dma_dir);
void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
struct iser_data_buf *data,
enum dma_data_direction dir);
int iser_initialize_task_headers(struct iscsi_task *task,
struct iser_tx_desc *tx_desc);
int iser_alloc_rx_descriptors(struct iser_conn *iser_conn,
struct iscsi_session *session);
int iser_alloc_fmr_pool(struct ib_conn *ib_conn,
unsigned cmds_max,
unsigned int size);
void iser_free_fmr_pool(struct ib_conn *ib_conn);
int iser_alloc_fastreg_pool(struct ib_conn *ib_conn,
unsigned cmds_max,
unsigned int size);
void iser_free_fastreg_pool(struct ib_conn *ib_conn);
u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
enum iser_data_dir cmd_dir, sector_t *sector);
struct iser_fr_desc *
iser_reg_desc_get_fr(struct ib_conn *ib_conn);
void
iser_reg_desc_put_fr(struct ib_conn *ib_conn,
struct iser_fr_desc *desc);
struct iser_fr_desc *
iser_reg_desc_get_fmr(struct ib_conn *ib_conn);
void
iser_reg_desc_put_fmr(struct ib_conn *ib_conn,
struct iser_fr_desc *desc);
static inline struct ib_send_wr *
iser_tx_next_wr(struct iser_tx_desc *tx_desc)
{
struct ib_send_wr *cur_wr = &tx_desc->wrs[tx_desc->wr_idx];
struct ib_send_wr *last_wr;
if (tx_desc->wr_idx) {
last_wr = &tx_desc->wrs[tx_desc->wr_idx - 1];
last_wr->next = cur_wr;
}
tx_desc->wr_idx++;
return cur_wr;
}
#endif