- 根目录:
- drivers
- infiniband
- ulp
- iser
- iser_verbs.c
/*
* Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
* Copyright (c) 2005, 2006 Cisco Systems. 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include "iscsi_iser.h"
#define ISCSI_ISER_MAX_CONN 8
#define ISER_MAX_RX_CQ_LEN (ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
#define ISER_MAX_TX_CQ_LEN (ISER_QP_MAX_REQ_DTOS * ISCSI_ISER_MAX_CONN)
static void iser_cq_tasklet_fn(unsigned long data);
static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
static void iser_cq_event_callback(struct ib_event *cause, void *context)
{
iser_err("got cq event %d \n", cause->event);
}
static void iser_qp_event_callback(struct ib_event *cause, void *context)
{
iser_err("got qp event %d\n",cause->event);
}
static void iser_event_handler(struct ib_event_handler *handler,
struct ib_event *event)
{
iser_err("async event %d on device %s port %d\n", event->event,
event->device->name, event->element.port_num);
}
/**
* iser_create_device_ib_res - creates Protection Domain (PD), Completion
* Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
* the adapator.
*
* returns 0 on success, -1 on failure
*/
static int iser_create_device_ib_res(struct iser_device *device)
{
device->pd = ib_alloc_pd(device->ib_device);
if (IS_ERR(device->pd))
goto pd_err;
device->rx_cq = ib_create_cq(device->ib_device,
iser_cq_callback,
iser_cq_event_callback,
(void *)device,
ISER_MAX_RX_CQ_LEN, 0);
if (IS_ERR(device->rx_cq))
goto rx_cq_err;
device->tx_cq = ib_create_cq(device->ib_device,
NULL, iser_cq_event_callback,
(void *)device,
ISER_MAX_TX_CQ_LEN, 0);
if (IS_ERR(device->tx_cq))
goto tx_cq_err;
if (ib_req_notify_cq(device->rx_cq, IB_CQ_NEXT_COMP))
goto cq_arm_err;
tasklet_init(&device->cq_tasklet,
iser_cq_tasklet_fn,
(unsigned long)device);
device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_WRITE |
IB_ACCESS_REMOTE_READ);
if (IS_ERR(device->mr))
goto dma_mr_err;
INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
iser_event_handler);
if (ib_register_event_handler(&device->event_handler))
goto handler_err;
return 0;
handler_err:
ib_dereg_mr(device->mr);
dma_mr_err:
tasklet_kill(&device->cq_tasklet);
cq_arm_err:
ib_destroy_cq(device->tx_cq);
tx_cq_err:
ib_destroy_cq(device->rx_cq);
rx_cq_err:
ib_dealloc_pd(device->pd);
pd_err:
iser_err("failed to allocate an IB resource\n");
return -1;
}
/**
* iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
* CQ and PD created with the device associated with the adapator.
*/
static void iser_free_device_ib_res(struct iser_device *device)
{
BUG_ON(device->mr == NULL);
tasklet_kill(&device->cq_tasklet);
(void)ib_unregister_event_handler(&device->event_handler);
(void)ib_dereg_mr(device->mr);
(void)ib_destroy_cq(device->tx_cq);
(void)ib_destroy_cq(device->rx_cq);
(void)ib_dealloc_pd(device->pd);
device->mr = NULL;
device->tx_cq = NULL;
device->rx_cq = NULL;
device->pd = NULL;
}
/**
* iser_create_ib_conn_res - Creates FMR pool and Queue-Pair (QP)
*
* returns 0 on success, -1 on failure
*/
static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
{
struct iser_device *device;
struct ib_qp_init_attr init_attr;
int req_err, resp_err, ret = -ENOMEM;
struct ib_fmr_pool_param params;
BUG_ON(ib_conn->device == NULL);
device = ib_conn->device;
ib_conn->login_buf = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
ISER_RX_LOGIN_SIZE, GFP_KERNEL);
if (!ib_conn->login_buf)
goto out_err;
ib_conn->login_req_buf = ib_conn->login_buf;
ib_conn->login_resp_buf = ib_conn->login_buf + ISCSI_DEF_MAX_RECV_SEG_LEN;
ib_conn->login_req_dma = ib_dma_map_single(ib_conn->device->ib_device,
(void *)ib_conn->login_req_buf,
ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
ib_conn->login_resp_dma = ib_dma_map_single(ib_conn->device->ib_device,
(void *)ib_conn->login_resp_buf,
ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
req_err = ib_dma_mapping_error(device->ib_device, ib_conn->login_req_dma);
resp_err = ib_dma_mapping_error(device->ib_device, ib_conn->login_resp_dma);
if (req_err || resp_err) {
if (req_err)
ib_conn->login_req_dma = 0;
if (resp_err)
ib_conn->login_resp_dma = 0;
goto out_err;
}
ib_conn->page_vec = kmalloc(sizeof(struct iser_page_vec) +
(sizeof(u64) * (ISCSI_ISER_SG_TABLESIZE +1)),
GFP_KERNEL);
if (!ib_conn->page_vec)
goto out_err;
ib_conn->page_vec->pages = (u64 *) (ib_conn->page_vec + 1);
params.page_shift = SHIFT_4K;
/* when the first/last SG element are not start/end *
* page aligned, the map whould be of N+1 pages */
params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
/* make the pool size twice the max number of SCSI commands *
* the ML is expected to queue, watermark for unmap at 50% */
params.pool_size = ISCSI_DEF_XMIT_CMDS_MAX * 2;
params.dirty_watermark = ISCSI_DEF_XMIT_CMDS_MAX;
params.cache = 0;
params.flush_function = NULL;
params.access = (IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_WRITE |
IB_ACCESS_REMOTE_READ);
ib_conn->fmr_pool = ib_create_fmr_pool(device->pd, ¶ms);
if (IS_ERR(ib_conn->fmr_pool)) {
ret = PTR_ERR(ib_conn->fmr_pool);
ib_conn->fmr_pool = NULL;
goto out_err;
}
memset(&init_attr, 0, sizeof init_attr);
init_attr.event_handler = iser_qp_event_callback;
init_attr.qp_context = (void *)ib_conn;
init_attr.send_cq = device->tx_cq;
init_attr.recv_cq = device->rx_cq;
init_attr.cap.max_send_wr = ISER_QP_MAX_REQ_DTOS;
init_attr.cap.max_recv_wr = ISER_QP_MAX_RECV_DTOS;
init_attr.cap.max_send_sge = 2;
init_attr.cap.max_recv_sge = 1;
init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
init_attr.qp_type = IB_QPT_RC;
ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
if (ret)
goto out_err;
ib_conn->qp = ib_conn->cma_id->qp;
iser_err("setting conn %p cma_id %p: fmr_pool %p qp %p\n",
ib_conn, ib_conn->cma_id,
ib_conn->fmr_pool, ib_conn->cma_id->qp);
return ret;
out_err:
iser_err("unable to alloc mem or create resource, err %d\n", ret);
return ret;
}
/**
* releases the FMR pool, QP and CMA ID objects, returns 0 on success,
* -1 on failure
*/
static int iser_free_ib_conn_res(struct iser_conn *ib_conn, int can_destroy_id)
{
BUG_ON(ib_conn == NULL);
iser_err("freeing conn %p cma_id %p fmr pool %p qp %p\n",
ib_conn, ib_conn->cma_id,
ib_conn->fmr_pool, ib_conn->qp);
/* qp is created only once both addr & route are resolved */
if (ib_conn->fmr_pool != NULL)
ib_destroy_fmr_pool(ib_conn->fmr_pool);
if (ib_conn->qp != NULL)
rdma_destroy_qp(ib_conn->cma_id);
/* if cma handler context, the caller acts s.t the cma destroy the id */
if (ib_conn->cma_id != NULL && can_destroy_id)
rdma_destroy_id(ib_conn->cma_id);
ib_conn->fmr_pool = NULL;
ib_conn->qp = NULL;
ib_conn->cma_id = NULL;
kfree(ib_conn->page_vec);
if (ib_conn->login_buf) {
if (ib_conn->login_req_dma)
ib_dma_unmap_single(ib_conn->device->ib_device,
ib_conn->login_req_dma,
ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
if (ib_conn->login_resp_dma)
ib_dma_unmap_single(ib_conn->device->ib_device,
ib_conn->login_resp_dma,
ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
kfree(ib_conn->login_buf);
}
return 0;
}
/**
* based on the resolved device node GUID see if there already allocated
* device for this device. If there's no such, create one.
*/
static
struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
{
struct iser_device *device;
mutex_lock(&ig.device_list_mutex);
list_for_each_entry(device, &ig.device_list, ig_list)
/* find if there's a match using the node GUID */
if (device->ib_device->node_guid == cma_id->device->node_guid)
goto inc_refcnt;
device = kzalloc(sizeof *device, GFP_KERNEL);
if (device == NULL)
goto out;
/* assign this device to the device */
device->ib_device = cma_id->device;
/* init the device and link it into ig device list */
if (iser_create_device_ib_res(device)) {
kfree(device);
device = NULL;
goto out;
}
list_add(&device->ig_list, &ig.device_list);
inc_refcnt:
device->refcount++;
out:
mutex_unlock(&ig.device_list_mutex);
return device;
}
/* if there's no demand for this device, release it */
static void iser_device_try_release(struct iser_device *device)
{
mutex_lock(&ig.device_list_mutex);
device->refcount--;
iser_err("device %p refcount %d\n",device,device->refcount);
if (!device->refcount) {
iser_free_device_ib_res(device);
list_del(&device->ig_list);
kfree(device);
}
mutex_unlock(&ig.device_list_mutex);
}
static int iser_conn_state_comp_exch(struct iser_conn *ib_conn,
enum iser_ib_conn_state comp,
enum iser_ib_conn_state exch)
{
int ret;
spin_lock_bh(&ib_conn->lock);
if ((ret = (ib_conn->state == comp)))
ib_conn->state = exch;
spin_unlock_bh(&ib_conn->lock);
return ret;
}
/**
* Frees all conn objects and deallocs conn descriptor
*/
static void iser_conn_release(struct iser_conn *ib_conn, int can_destroy_id)
{
struct iser_device *device = ib_conn->device;
BUG_ON(ib_conn->state != ISER_CONN_DOWN);
mutex_lock(&ig.connlist_mutex);
list_del(&ib_conn->conn_list);
mutex_unlock(&ig.connlist_mutex);
iser_free_rx_descriptors(ib_conn);
iser_free_ib_conn_res(ib_conn, can_destroy_id);
ib_conn->device = NULL;
/* on EVENT_ADDR_ERROR there's no device yet for this conn */
if (device != NULL)
iser_device_try_release(device);
iscsi_destroy_endpoint(ib_conn->ep);
}
void iser_conn_get(struct iser_conn *ib_conn)
{
atomic_inc(&ib_conn->refcount);
}
int iser_conn_put(struct iser_conn *ib_conn, int can_destroy_id)
{
if (atomic_dec_and_test(&ib_conn->refcount)) {
iser_conn_release(ib_conn, can_destroy_id);
return 1;
}
return 0;
}
/**
* triggers start of the disconnect procedures and wait for them to be done
*/
void iser_conn_terminate(struct iser_conn *ib_conn)
{
int err = 0;
/* change the ib conn state only if the conn is UP, however always call
* rdma_disconnect since this is the only way to cause the CMA to change
* the QP state to ERROR
*/
iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP, ISER_CONN_TERMINATING);
err = rdma_disconnect(ib_conn->cma_id);
if (err)
iser_err("Failed to disconnect, conn: 0x%p err %d\n",
ib_conn,err);
wait_event_interruptible(ib_conn->wait,
ib_conn->state == ISER_CONN_DOWN);
iser_conn_put(ib_conn, 1); /* deref ib conn deallocate */
}
static int iser_connect_error(struct rdma_cm_id *cma_id)
{
struct iser_conn *ib_conn;
ib_conn = (struct iser_conn *)cma_id->context;
ib_conn->state = ISER_CONN_DOWN;
wake_up_interruptible(&ib_conn->wait);
return iser_conn_put(ib_conn, 0); /* deref ib conn's cma id */
}
static int iser_addr_handler(struct rdma_cm_id *cma_id)
{
struct iser_device *device;
struct iser_conn *ib_conn;
int ret;
device = iser_device_find_by_ib_device(cma_id);
if (!device) {
iser_err("device lookup/creation failed\n");
return iser_connect_error(cma_id);
}
ib_conn = (struct iser_conn *)cma_id->context;
ib_conn->device = device;
ret = rdma_resolve_route(cma_id, 1000);
if (ret) {
iser_err("resolve route failed: %d\n", ret);
return iser_connect_error(cma_id);
}
return 0;
}
static int iser_route_handler(struct rdma_cm_id *cma_id)
{
struct rdma_conn_param conn_param;
int ret;
ret = iser_create_ib_conn_res((struct iser_conn *)cma_id->context);
if (ret)
goto failure;
memset(&conn_param, 0, sizeof conn_param);
conn_param.responder_resources = 4;
conn_param.initiator_depth = 1;
conn_param.retry_count = 7;
conn_param.rnr_retry_count = 6;
ret = rdma_connect(cma_id, &conn_param);
if (ret) {
iser_err("failure connecting: %d\n", ret);
goto failure;
}
return 0;
failure:
return iser_connect_error(cma_id);
}
static void iser_connected_handler(struct rdma_cm_id *cma_id)
{
struct iser_conn *ib_conn;
ib_conn = (struct iser_conn *)cma_id->context;
ib_conn->state = ISER_CONN_UP;
wake_up_interruptible(&ib_conn->wait);
}
static int iser_disconnected_handler(struct rdma_cm_id *cma_id)
{
struct iser_conn *ib_conn;
int ret;
ib_conn = (struct iser_conn *)cma_id->context;
/* getting here when the state is UP means that the conn is being *
* terminated asynchronously from the iSCSI layer's perspective. */
if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
ISER_CONN_TERMINATING))
iscsi_conn_failure(ib_conn->iser_conn->iscsi_conn,
ISCSI_ERR_CONN_FAILED);
/* Complete the termination process if no posts are pending */
if (ib_conn->post_recv_buf_count == 0 &&
(atomic_read(&ib_conn->post_send_buf_count) == 0)) {
ib_conn->state = ISER_CONN_DOWN;
wake_up_interruptible(&ib_conn->wait);
}
ret = iser_conn_put(ib_conn, 0); /* deref ib conn's cma id */
return ret;
}
static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
{
int ret = 0;
iser_err("event %d status %d conn %p id %p\n",
event->event, event->status, cma_id->context, cma_id);
switch (event->event) {
case RDMA_CM_EVENT_ADDR_RESOLVED:
ret = iser_addr_handler(cma_id);
break;
case RDMA_CM_EVENT_ROUTE_RESOLVED:
ret = iser_route_handler(cma_id);
break;
case RDMA_CM_EVENT_ESTABLISHED:
iser_connected_handler(cma_id);
break;
case RDMA_CM_EVENT_ADDR_ERROR:
case RDMA_CM_EVENT_ROUTE_ERROR:
case RDMA_CM_EVENT_CONNECT_ERROR:
case RDMA_CM_EVENT_UNREACHABLE:
case RDMA_CM_EVENT_REJECTED:
ret = iser_connect_error(cma_id);
break;
case RDMA_CM_EVENT_DISCONNECTED:
case RDMA_CM_EVENT_DEVICE_REMOVAL:
case RDMA_CM_EVENT_ADDR_CHANGE:
ret = iser_disconnected_handler(cma_id);
break;
default:
iser_err("Unexpected RDMA CM event (%d)\n", event->event);
break;
}
return ret;
}
void iser_conn_init(struct iser_conn *ib_conn)
{
ib_conn->state = ISER_CONN_INIT;
init_waitqueue_head(&ib_conn->wait);
ib_conn->post_recv_buf_count = 0;
atomic_set(&ib_conn->post_send_buf_count, 0);
atomic_set(&ib_conn->refcount, 1); /* ref ib conn allocation */
INIT_LIST_HEAD(&ib_conn->conn_list);
spin_lock_init(&ib_conn->lock);
}
/**
* starts the process of connecting to the target
* sleeps until the connection is established or rejected
*/
int iser_connect(struct iser_conn *ib_conn,
struct sockaddr_in *src_addr,
struct sockaddr_in *dst_addr,
int non_blocking)
{
struct sockaddr *src, *dst;
int err = 0;
sprintf(ib_conn->name, "%pI4:%d",
&dst_addr->sin_addr.s_addr, dst_addr->sin_port);
/* the device is known only --after-- address resolution */
ib_conn->device = NULL;
iser_err("connecting to: %pI4, port 0x%x\n",
&dst_addr->sin_addr, dst_addr->sin_port);
ib_conn->state = ISER_CONN_PENDING;
iser_conn_get(ib_conn); /* ref ib conn's cma id */
ib_conn->cma_id = rdma_create_id(iser_cma_handler,
(void *)ib_conn,
RDMA_PS_TCP, IB_QPT_RC);
if (IS_ERR(ib_conn->cma_id)) {
err = PTR_ERR(ib_conn->cma_id);
iser_err("rdma_create_id failed: %d\n", err);
goto id_failure;
}
src = (struct sockaddr *)src_addr;
dst = (struct sockaddr *)dst_addr;
err = rdma_resolve_addr(ib_conn->cma_id, src, dst, 1000);
if (err) {
iser_err("rdma_resolve_addr failed: %d\n", err);
goto addr_failure;
}
if (!non_blocking) {
wait_event_interruptible(ib_conn->wait,
(ib_conn->state != ISER_CONN_PENDING));
if (ib_conn->state != ISER_CONN_UP) {
err = -EIO;
goto connect_failure;
}
}
mutex_lock(&ig.connlist_mutex);
list_add(&ib_conn->conn_list, &ig.connlist);
mutex_unlock(&ig.connlist_mutex);
return 0;
id_failure:
ib_conn->cma_id = NULL;
addr_failure:
ib_conn->state = ISER_CONN_DOWN;
connect_failure:
iser_conn_release(ib_conn, 1);
return err;
}
/**
* iser_reg_page_vec - Register physical memory
*
* returns: 0 on success, errno code on failure
*/
int iser_reg_page_vec(struct iser_conn *ib_conn,
struct iser_page_vec *page_vec,
struct iser_mem_reg *mem_reg)
{
struct ib_pool_fmr *mem;
u64 io_addr;
u64 *page_list;
int status;
page_list = page_vec->pages;
io_addr = page_list[0];
mem = ib_fmr_pool_map_phys(ib_conn->fmr_pool,
page_list,
page_vec->length,
io_addr);
if (IS_ERR(mem)) {
status = (int)PTR_ERR(mem);
iser_err("ib_fmr_pool_map_phys failed: %d\n", status);
return status;
}
mem_reg->lkey = mem->fmr->lkey;
mem_reg->rkey = mem->fmr->rkey;
mem_reg->len = page_vec->length * SIZE_4K;
mem_reg->va = io_addr;
mem_reg->is_fmr = 1;
mem_reg->mem_h = (void *)mem;
mem_reg->va += page_vec->offset;
mem_reg->len = page_vec->data_size;
iser_dbg("PHYSICAL Mem.register, [PHYS p_array: 0x%p, sz: %d, "
"entry[0]: (0x%08lx,%ld)] -> "
"[lkey: 0x%08X mem_h: 0x%p va: 0x%08lX sz: %ld]\n",
page_vec, page_vec->length,
(unsigned long)page_vec->pages[0],
(unsigned long)page_vec->data_size,
(unsigned int)mem_reg->lkey, mem_reg->mem_h,
(unsigned long)mem_reg->va, (unsigned long)mem_reg->len);
return 0;
}
/**
* Unregister (previosuly registered) memory.
*/
void iser_unreg_mem(struct iser_mem_reg *reg)
{
int ret;
iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
if (ret)
iser_err("ib_fmr_pool_unmap failed %d\n", ret);
reg->mem_h = NULL;
}
int iser_post_recvl(struct iser_conn *ib_conn)
{
struct ib_recv_wr rx_wr, *rx_wr_failed;
struct ib_sge sge;
int ib_ret;
sge.addr = ib_conn->login_resp_dma;
sge.length = ISER_RX_LOGIN_SIZE;
sge.lkey = ib_conn->device->mr->lkey;
rx_wr.wr_id = (unsigned long)ib_conn->login_resp_buf;
rx_wr.sg_list = &sge;
rx_wr.num_sge = 1;
rx_wr.next = NULL;
ib_conn->post_recv_buf_count++;
ib_ret = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
if (ib_ret) {
iser_err("ib_post_recv failed ret=%d\n", ib_ret);
ib_conn->post_recv_buf_count--;
}
return ib_ret;
}
int iser_post_recvm(struct iser_conn *ib_conn, int count)
{
struct ib_recv_wr *rx_wr, *rx_wr_failed;
int i, ib_ret;
unsigned int my_rx_head = ib_conn->rx_desc_head;
struct iser_rx_desc *rx_desc;
for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
rx_desc = &ib_conn->rx_descs[my_rx_head];
rx_wr->wr_id = (unsigned long)rx_desc;
rx_wr->sg_list = &rx_desc->rx_sg;
rx_wr->num_sge = 1;
rx_wr->next = rx_wr + 1;
my_rx_head = (my_rx_head + 1) & (ISER_QP_MAX_RECV_DTOS - 1);
}
rx_wr--;
rx_wr->next = NULL; /* mark end of work requests list */
ib_conn->post_recv_buf_count += count;
ib_ret = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
if (ib_ret) {
iser_err("ib_post_recv failed ret=%d\n", ib_ret);
ib_conn->post_recv_buf_count -= count;
} else
ib_conn->rx_desc_head = my_rx_head;
return ib_ret;
}
/**
* iser_start_send - Initiate a Send DTO operation
*
* returns 0 on success, -1 on failure
*/
int iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc)
{
int ib_ret;
struct ib_send_wr send_wr, *send_wr_failed;
ib_dma_sync_single_for_device(ib_conn->device->ib_device,
tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
send_wr.next = NULL;
send_wr.wr_id = (unsigned long)tx_desc;
send_wr.sg_list = tx_desc->tx_sg;
send_wr.num_sge = tx_desc->num_sge;
send_wr.opcode = IB_WR_SEND;
send_wr.send_flags = IB_SEND_SIGNALED;
atomic_inc(&ib_conn->post_send_buf_count);
ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
if (ib_ret) {
iser_err("ib_post_send failed, ret:%d\n", ib_ret);
atomic_dec(&ib_conn->post_send_buf_count);
}
return ib_ret;
}
static void iser_handle_comp_error(struct iser_tx_desc *desc,
struct iser_conn *ib_conn)
{
if (desc && desc->type == ISCSI_TX_DATAOUT)
kmem_cache_free(ig.desc_cache, desc);
if (ib_conn->post_recv_buf_count == 0 &&
atomic_read(&ib_conn->post_send_buf_count) == 0) {
/* getting here when the state is UP means that the conn is *
* being terminated asynchronously from the iSCSI layer's *
* perspective. */
if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
ISER_CONN_TERMINATING))
iscsi_conn_failure(ib_conn->iser_conn->iscsi_conn,
ISCSI_ERR_CONN_FAILED);
/* no more non completed posts to the QP, complete the
* termination process w.o worrying on disconnect event */
ib_conn->state = ISER_CONN_DOWN;
wake_up_interruptible(&ib_conn->wait);
}
}
static int iser_drain_tx_cq(struct iser_device *device)
{
struct ib_cq *cq = device->tx_cq;
struct ib_wc wc;
struct iser_tx_desc *tx_desc;
struct iser_conn *ib_conn;
int completed_tx = 0;
while (ib_poll_cq(cq, 1, &wc) == 1) {
tx_desc = (struct iser_tx_desc *) (unsigned long) wc.wr_id;
ib_conn = wc.qp->qp_context;
if (wc.status == IB_WC_SUCCESS) {
if (wc.opcode == IB_WC_SEND)
iser_snd_completion(tx_desc, ib_conn);
else
iser_err("expected opcode %d got %d\n",
IB_WC_SEND, wc.opcode);
} else {
iser_err("tx id %llx status %d vend_err %x\n",
wc.wr_id, wc.status, wc.vendor_err);
atomic_dec(&ib_conn->post_send_buf_count);
iser_handle_comp_error(tx_desc, ib_conn);
}
completed_tx++;
}
return completed_tx;
}
static void iser_cq_tasklet_fn(unsigned long data)
{
struct iser_device *device = (struct iser_device *)data;
struct ib_cq *cq = device->rx_cq;
struct ib_wc wc;
struct iser_rx_desc *desc;
unsigned long xfer_len;
struct iser_conn *ib_conn;
int completed_tx, completed_rx;
completed_tx = completed_rx = 0;
while (ib_poll_cq(cq, 1, &wc) == 1) {
desc = (struct iser_rx_desc *) (unsigned long) wc.wr_id;
BUG_ON(desc == NULL);
ib_conn = wc.qp->qp_context;
if (wc.status == IB_WC_SUCCESS) {
if (wc.opcode == IB_WC_RECV) {
xfer_len = (unsigned long)wc.byte_len;
iser_rcv_completion(desc, xfer_len, ib_conn);
} else
iser_err("expected opcode %d got %d\n",
IB_WC_RECV, wc.opcode);
} else {
if (wc.status != IB_WC_WR_FLUSH_ERR)
iser_err("rx id %llx status %d vend_err %x\n",
wc.wr_id, wc.status, wc.vendor_err);
ib_conn->post_recv_buf_count--;
iser_handle_comp_error(NULL, ib_conn);
}
completed_rx++;
if (!(completed_rx & 63))
completed_tx += iser_drain_tx_cq(device);
}
/* #warning "it is assumed here that arming CQ only once its empty" *
* " would not cause interrupts to be missed" */
ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
completed_tx += iser_drain_tx_cq(device);
iser_dbg("got %d rx %d tx completions\n", completed_rx, completed_tx);
}
static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
{
struct iser_device *device = (struct iser_device *)cq_context;
tasklet_schedule(&device->cq_tasklet);
}